The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_base.c

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    1 /*-
    2  * Copyright (c) 1996-1999 Whistle Communications, Inc.
    3  * All rights reserved.
    4  *
    5  * Subject to the following obligations and disclaimer of warranty, use and
    6  * redistribution of this software, in source or object code forms, with or
    7  * without modifications are expressly permitted by Whistle Communications;
    8  * provided, however, that:
    9  * 1. Any and all reproductions of the source or object code must include the
   10  *    copyright notice above and the following disclaimer of warranties; and
   11  * 2. No rights are granted, in any manner or form, to use Whistle
   12  *    Communications, Inc. trademarks, including the mark "WHISTLE
   13  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   14  *    such appears in the above copyright notice or in the software.
   15  *
   16  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   17  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   18  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   19  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   21  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   22  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   23  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   24  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   25  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   26  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   27  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   28  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   31  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   32  * OF SUCH DAMAGE.
   33  *
   34  * Authors: Julian Elischer <julian@freebsd.org>
   35  *          Archie Cobbs <archie@freebsd.org>
   36  *
   37  * $FreeBSD$
   38  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
   39  */
   40 
   41 /*
   42  * This file implements the base netgraph code.
   43  */
   44 
   45 #include <sys/param.h>
   46 #include <sys/systm.h>
   47 #include <sys/ctype.h>
   48 #include <sys/hash.h>
   49 #include <sys/kdb.h>
   50 #include <sys/kernel.h>
   51 #include <sys/kthread.h>
   52 #include <sys/ktr.h>
   53 #include <sys/limits.h>
   54 #include <sys/lock.h>
   55 #include <sys/malloc.h>
   56 #include <sys/mbuf.h>
   57 #include <sys/proc.h>
   58 #include <sys/epoch.h>
   59 #include <sys/queue.h>
   60 #include <sys/refcount.h>
   61 #include <sys/rwlock.h>
   62 #include <sys/smp.h>
   63 #include <sys/sysctl.h>
   64 #include <sys/syslog.h>
   65 #include <sys/unistd.h>
   66 #include <machine/cpu.h>
   67 #include <vm/uma.h>
   68 
   69 #include <net/netisr.h>
   70 #include <net/vnet.h>
   71 
   72 #include <netgraph/ng_message.h>
   73 #include <netgraph/netgraph.h>
   74 #include <netgraph/ng_parse.h>
   75 
   76 MODULE_VERSION(netgraph, NG_ABI_VERSION);
   77 
   78 /* Mutex to protect topology events. */
   79 static struct rwlock    ng_topo_lock;
   80 #define TOPOLOGY_RLOCK()        rw_rlock(&ng_topo_lock)
   81 #define TOPOLOGY_RUNLOCK()      rw_runlock(&ng_topo_lock)
   82 #define TOPOLOGY_WLOCK()        rw_wlock(&ng_topo_lock)
   83 #define TOPOLOGY_WUNLOCK()      rw_wunlock(&ng_topo_lock)
   84 #define TOPOLOGY_NOTOWNED()     rw_assert(&ng_topo_lock, RA_UNLOCKED)
   85 
   86 #ifdef  NETGRAPH_DEBUG
   87 static struct mtx       ng_nodelist_mtx; /* protects global node/hook lists */
   88 static struct mtx       ngq_mtx;        /* protects the queue item list */
   89 
   90 static SLIST_HEAD(, ng_node) ng_allnodes;
   91 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
   92 static SLIST_HEAD(, ng_hook) ng_allhooks;
   93 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
   94 
   95 static void ng_dumpitems(void);
   96 static void ng_dumpnodes(void);
   97 static void ng_dumphooks(void);
   98 
   99 #endif  /* NETGRAPH_DEBUG */
  100 /*
  101  * DEAD versions of the structures.
  102  * In order to avoid races, it is sometimes necessary to point
  103  * at SOMETHING even though theoretically, the current entity is
  104  * INVALID. Use these to avoid these races.
  105  */
  106 struct ng_type ng_deadtype = {
  107         NG_ABI_VERSION,
  108         "dead",
  109         NULL,   /* modevent */
  110         NULL,   /* constructor */
  111         NULL,   /* rcvmsg */
  112         NULL,   /* shutdown */
  113         NULL,   /* newhook */
  114         NULL,   /* findhook */
  115         NULL,   /* connect */
  116         NULL,   /* rcvdata */
  117         NULL,   /* disconnect */
  118         NULL,   /* cmdlist */
  119 };
  120 
  121 struct ng_node ng_deadnode = {
  122         "dead",
  123         &ng_deadtype,   
  124         NGF_INVALID,
  125         0,      /* numhooks */
  126         NULL,   /* private */
  127         0,      /* ID */
  128         LIST_HEAD_INITIALIZER(ng_deadnode.nd_hooks),
  129         {},     /* all_nodes list entry */
  130         {},     /* id hashtable list entry */
  131         {       0,
  132                 0,
  133                 {}, /* should never use! (should hang) */
  134                 {}, /* workqueue entry */
  135                 STAILQ_HEAD_INITIALIZER(ng_deadnode.nd_input_queue.queue),
  136         },
  137         1,      /* refs */
  138         NULL,   /* vnet */
  139 #ifdef  NETGRAPH_DEBUG
  140         ND_MAGIC,
  141         __FILE__,
  142         __LINE__,
  143         {NULL}
  144 #endif  /* NETGRAPH_DEBUG */
  145 };
  146 
  147 struct ng_hook ng_deadhook = {
  148         "dead",
  149         NULL,           /* private */
  150         HK_INVALID | HK_DEAD,
  151         0,              /* undefined data link type */
  152         &ng_deadhook,   /* Peer is self */
  153         &ng_deadnode,   /* attached to deadnode */
  154         {},             /* hooks list */
  155         NULL,           /* override rcvmsg() */
  156         NULL,           /* override rcvdata() */
  157         1,              /* refs always >= 1 */
  158 #ifdef  NETGRAPH_DEBUG
  159         HK_MAGIC,
  160         __FILE__,
  161         __LINE__,
  162         {NULL}
  163 #endif  /* NETGRAPH_DEBUG */
  164 };
  165 
  166 /*
  167  * END DEAD STRUCTURES
  168  */
  169 /* List nodes with unallocated work */
  170 static STAILQ_HEAD(, ng_node) ng_worklist = STAILQ_HEAD_INITIALIZER(ng_worklist);
  171 static struct mtx       ng_worklist_mtx;   /* MUST LOCK NODE FIRST */
  172 
  173 /* List of installed types */
  174 static LIST_HEAD(, ng_type) ng_typelist;
  175 static struct rwlock    ng_typelist_lock;
  176 #define TYPELIST_RLOCK()        rw_rlock(&ng_typelist_lock)
  177 #define TYPELIST_RUNLOCK()      rw_runlock(&ng_typelist_lock)
  178 #define TYPELIST_WLOCK()        rw_wlock(&ng_typelist_lock)
  179 #define TYPELIST_WUNLOCK()      rw_wunlock(&ng_typelist_lock)
  180 
  181 /* Hash related definitions. */
  182 LIST_HEAD(nodehash, ng_node);
  183 VNET_DEFINE_STATIC(struct nodehash *, ng_ID_hash);
  184 VNET_DEFINE_STATIC(u_long, ng_ID_hmask);
  185 VNET_DEFINE_STATIC(u_long, ng_nodes);
  186 VNET_DEFINE_STATIC(struct nodehash *, ng_name_hash);
  187 VNET_DEFINE_STATIC(u_long, ng_name_hmask);
  188 VNET_DEFINE_STATIC(u_long, ng_named_nodes);
  189 #define V_ng_ID_hash            VNET(ng_ID_hash)
  190 #define V_ng_ID_hmask           VNET(ng_ID_hmask)
  191 #define V_ng_nodes              VNET(ng_nodes)
  192 #define V_ng_name_hash          VNET(ng_name_hash)
  193 #define V_ng_name_hmask         VNET(ng_name_hmask)
  194 #define V_ng_named_nodes        VNET(ng_named_nodes)
  195 
  196 static struct rwlock    ng_idhash_lock;
  197 #define IDHASH_RLOCK()          rw_rlock(&ng_idhash_lock)
  198 #define IDHASH_RUNLOCK()        rw_runlock(&ng_idhash_lock)
  199 #define IDHASH_WLOCK()          rw_wlock(&ng_idhash_lock)
  200 #define IDHASH_WUNLOCK()        rw_wunlock(&ng_idhash_lock)
  201 
  202 /* Method to find a node.. used twice so do it here */
  203 #define NG_IDHASH_FN(ID) ((ID) % (V_ng_ID_hmask + 1))
  204 #define NG_IDHASH_FIND(ID, node)                                        \
  205         do {                                                            \
  206                 rw_assert(&ng_idhash_lock, RA_LOCKED);                  \
  207                 LIST_FOREACH(node, &V_ng_ID_hash[NG_IDHASH_FN(ID)],     \
  208                                                 nd_idnodes) {           \
  209                         if (NG_NODE_IS_VALID(node)                      \
  210                         && (NG_NODE_ID(node) == ID)) {                  \
  211                                 break;                                  \
  212                         }                                               \
  213                 }                                                       \
  214         } while (0)
  215 
  216 static struct rwlock    ng_namehash_lock;
  217 #define NAMEHASH_RLOCK()        rw_rlock(&ng_namehash_lock)
  218 #define NAMEHASH_RUNLOCK()      rw_runlock(&ng_namehash_lock)
  219 #define NAMEHASH_WLOCK()        rw_wlock(&ng_namehash_lock)
  220 #define NAMEHASH_WUNLOCK()      rw_wunlock(&ng_namehash_lock)
  221 
  222 /* Internal functions */
  223 static int      ng_add_hook(node_p node, const char *name, hook_p * hookp);
  224 static int      ng_generic_msg(node_p here, item_p item, hook_p lasthook);
  225 static ng_ID_t  ng_decodeidname(const char *name);
  226 static int      ngb_mod_event(module_t mod, int event, void *data);
  227 static void     ng_worklist_add(node_p node);
  228 static void     ngthread(void *);
  229 static int      ng_apply_item(node_p node, item_p item, int rw);
  230 static void     ng_flush_input_queue(node_p node);
  231 static node_p   ng_ID2noderef(ng_ID_t ID);
  232 static int      ng_con_nodes(item_p item, node_p node, const char *name,
  233                     node_p node2, const char *name2);
  234 static int      ng_con_part2(node_p node, item_p item, hook_p hook);
  235 static int      ng_con_part3(node_p node, item_p item, hook_p hook);
  236 static int      ng_mkpeer(node_p node, const char *name, const char *name2,
  237                     char *type);
  238 static void     ng_name_rehash(void);
  239 static void     ng_ID_rehash(void);
  240 
  241 /* Imported, these used to be externally visible, some may go back. */
  242 void    ng_destroy_hook(hook_p hook);
  243 int     ng_path2noderef(node_p here, const char *path,
  244         node_p *dest, hook_p *lasthook);
  245 int     ng_make_node(const char *type, node_p *nodepp);
  246 int     ng_path_parse(char *addr, char **node, char **path, char **hook);
  247 void    ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
  248 void    ng_unname(node_p node);
  249 
  250 /* Our own netgraph malloc type */
  251 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
  252 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
  253 static MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook",
  254     "netgraph hook structures");
  255 static MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node",
  256     "netgraph node structures");
  257 static MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item",
  258     "netgraph item structures");
  259 
  260 /* Should not be visible outside this file */
  261 
  262 #define _NG_ALLOC_HOOK(hook) \
  263         hook = malloc(sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
  264 #define _NG_ALLOC_NODE(node) \
  265         node = malloc(sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
  266 
  267 #define NG_QUEUE_LOCK_INIT(n)                   \
  268         mtx_init(&(n)->q_mtx, "ng_node", NULL, MTX_DEF)
  269 #define NG_QUEUE_LOCK(n)                        \
  270         mtx_lock(&(n)->q_mtx)
  271 #define NG_QUEUE_UNLOCK(n)                      \
  272         mtx_unlock(&(n)->q_mtx)
  273 #define NG_WORKLIST_LOCK_INIT()                 \
  274         mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_DEF)
  275 #define NG_WORKLIST_LOCK()                      \
  276         mtx_lock(&ng_worklist_mtx)
  277 #define NG_WORKLIST_UNLOCK()                    \
  278         mtx_unlock(&ng_worklist_mtx)
  279 #define NG_WORKLIST_SLEEP()                     \
  280         mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
  281 #define NG_WORKLIST_WAKEUP()                    \
  282         wakeup_one(&ng_worklist)
  283 
  284 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
  285 /*
  286  * In debug mode:
  287  * In an attempt to help track reference count screwups
  288  * we do not free objects back to the malloc system, but keep them
  289  * in a local cache where we can examine them and keep information safely
  290  * after they have been freed.
  291  * We use this scheme for nodes and hooks, and to some extent for items.
  292  */
  293 static __inline hook_p
  294 ng_alloc_hook(void)
  295 {
  296         hook_p hook;
  297         SLIST_ENTRY(ng_hook) temp;
  298         mtx_lock(&ng_nodelist_mtx);
  299         hook = LIST_FIRST(&ng_freehooks);
  300         if (hook) {
  301                 LIST_REMOVE(hook, hk_hooks);
  302                 bcopy(&hook->hk_all, &temp, sizeof(temp));
  303                 bzero(hook, sizeof(struct ng_hook));
  304                 bcopy(&temp, &hook->hk_all, sizeof(temp));
  305                 mtx_unlock(&ng_nodelist_mtx);
  306                 hook->hk_magic = HK_MAGIC;
  307         } else {
  308                 mtx_unlock(&ng_nodelist_mtx);
  309                 _NG_ALLOC_HOOK(hook);
  310                 if (hook) {
  311                         hook->hk_magic = HK_MAGIC;
  312                         mtx_lock(&ng_nodelist_mtx);
  313                         SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
  314                         mtx_unlock(&ng_nodelist_mtx);
  315                 }
  316         }
  317         return (hook);
  318 }
  319 
  320 static __inline node_p
  321 ng_alloc_node(void)
  322 {
  323         node_p node;
  324         SLIST_ENTRY(ng_node) temp;
  325         mtx_lock(&ng_nodelist_mtx);
  326         node = LIST_FIRST(&ng_freenodes);
  327         if (node) {
  328                 LIST_REMOVE(node, nd_nodes);
  329                 bcopy(&node->nd_all, &temp, sizeof(temp));
  330                 bzero(node, sizeof(struct ng_node));
  331                 bcopy(&temp, &node->nd_all, sizeof(temp));
  332                 mtx_unlock(&ng_nodelist_mtx);
  333                 node->nd_magic = ND_MAGIC;
  334         } else {
  335                 mtx_unlock(&ng_nodelist_mtx);
  336                 _NG_ALLOC_NODE(node);
  337                 if (node) {
  338                         node->nd_magic = ND_MAGIC;
  339                         mtx_lock(&ng_nodelist_mtx);
  340                         SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
  341                         mtx_unlock(&ng_nodelist_mtx);
  342                 }
  343         }
  344         return (node);
  345 }
  346 
  347 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
  348 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
  349 
  350 #define NG_FREE_HOOK(hook)                                              \
  351         do {                                                            \
  352                 mtx_lock(&ng_nodelist_mtx);                             \
  353                 LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);        \
  354                 hook->hk_magic = 0;                                     \
  355                 mtx_unlock(&ng_nodelist_mtx);                           \
  356         } while (0)
  357 
  358 #define NG_FREE_NODE(node)                                              \
  359         do {                                                            \
  360                 mtx_lock(&ng_nodelist_mtx);                             \
  361                 LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);        \
  362                 node->nd_magic = 0;                                     \
  363                 mtx_unlock(&ng_nodelist_mtx);                           \
  364         } while (0)
  365 
  366 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
  367 
  368 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
  369 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
  370 
  371 #define NG_FREE_HOOK(hook) do { free((hook), M_NETGRAPH_HOOK); } while (0)
  372 #define NG_FREE_NODE(node) do { free((node), M_NETGRAPH_NODE); } while (0)
  373 
  374 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
  375 
  376 /* Set this to kdb_enter("X") to catch all errors as they occur */
  377 #ifndef TRAP_ERROR
  378 #define TRAP_ERROR()
  379 #endif
  380 
  381 VNET_DEFINE_STATIC(ng_ID_t, nextID) = 1;
  382 #define V_nextID                        VNET(nextID)
  383 
  384 #ifdef INVARIANTS
  385 #define CHECK_DATA_MBUF(m)      do {                                    \
  386                 struct mbuf *n;                                         \
  387                 int total;                                              \
  388                                                                         \
  389                 M_ASSERTPKTHDR(m);                                      \
  390                 for (total = 0, n = (m); n != NULL; n = n->m_next) {    \
  391                         total += n->m_len;                              \
  392                         if (n->m_nextpkt != NULL)                       \
  393                                 panic("%s: m_nextpkt", __func__);       \
  394                 }                                                       \
  395                                                                         \
  396                 if ((m)->m_pkthdr.len != total) {                       \
  397                         panic("%s: %d != %d",                           \
  398                             __func__, (m)->m_pkthdr.len, total);        \
  399                 }                                                       \
  400         } while (0)
  401 #else
  402 #define CHECK_DATA_MBUF(m)
  403 #endif
  404 
  405 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  406 
  407 /************************************************************************
  408         Parse type definitions for generic messages
  409 ************************************************************************/
  410 
  411 /* Handy structure parse type defining macro */
  412 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)                          \
  413 static const struct ng_parse_struct_field                               \
  414         ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;  \
  415 static const struct ng_parse_type ng_generic_ ## lo ## _type = {        \
  416         &ng_parse_struct_type,                                          \
  417         &ng_ ## lo ## _type_fields                                      \
  418 }
  419 
  420 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
  421 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
  422 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
  423 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
  424 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
  425 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
  426 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
  427 
  428 /* Get length of an array when the length is stored as a 32 bit
  429    value immediately preceding the array -- as with struct namelist
  430    and struct typelist. */
  431 static int
  432 ng_generic_list_getLength(const struct ng_parse_type *type,
  433         const u_char *start, const u_char *buf)
  434 {
  435         return *((const u_int32_t *)(buf - 4));
  436 }
  437 
  438 /* Get length of the array of struct linkinfo inside a struct hooklist */
  439 static int
  440 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
  441         const u_char *start, const u_char *buf)
  442 {
  443         const struct hooklist *hl = (const struct hooklist *)start;
  444 
  445         return hl->nodeinfo.hooks;
  446 }
  447 
  448 /* Array type for a variable length array of struct namelist */
  449 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
  450         &ng_generic_nodeinfo_type,
  451         &ng_generic_list_getLength
  452 };
  453 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
  454         &ng_parse_array_type,
  455         &ng_nodeinfoarray_type_info
  456 };
  457 
  458 /* Array type for a variable length array of struct typelist */
  459 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
  460         &ng_generic_typeinfo_type,
  461         &ng_generic_list_getLength
  462 };
  463 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
  464         &ng_parse_array_type,
  465         &ng_typeinfoarray_type_info
  466 };
  467 
  468 /* Array type for array of struct linkinfo in struct hooklist */
  469 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
  470         &ng_generic_linkinfo_type,
  471         &ng_generic_linkinfo_getLength
  472 };
  473 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
  474         &ng_parse_array_type,
  475         &ng_generic_linkinfo_array_type_info
  476 };
  477 
  478 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_typeinfoarray_type));
  479 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
  480         (&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
  481 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
  482         (&ng_generic_nodeinfoarray_type));
  483 
  484 /* List of commands and how to convert arguments to/from ASCII */
  485 static const struct ng_cmdlist ng_generic_cmds[] = {
  486         {
  487           NGM_GENERIC_COOKIE,
  488           NGM_SHUTDOWN,
  489           "shutdown",
  490           NULL,
  491           NULL
  492         },
  493         {
  494           NGM_GENERIC_COOKIE,
  495           NGM_MKPEER,
  496           "mkpeer",
  497           &ng_generic_mkpeer_type,
  498           NULL
  499         },
  500         {
  501           NGM_GENERIC_COOKIE,
  502           NGM_CONNECT,
  503           "connect",
  504           &ng_generic_connect_type,
  505           NULL
  506         },
  507         {
  508           NGM_GENERIC_COOKIE,
  509           NGM_NAME,
  510           "name",
  511           &ng_generic_name_type,
  512           NULL
  513         },
  514         {
  515           NGM_GENERIC_COOKIE,
  516           NGM_RMHOOK,
  517           "rmhook",
  518           &ng_generic_rmhook_type,
  519           NULL
  520         },
  521         {
  522           NGM_GENERIC_COOKIE,
  523           NGM_NODEINFO,
  524           "nodeinfo",
  525           NULL,
  526           &ng_generic_nodeinfo_type
  527         },
  528         {
  529           NGM_GENERIC_COOKIE,
  530           NGM_LISTHOOKS,
  531           "listhooks",
  532           NULL,
  533           &ng_generic_hooklist_type
  534         },
  535         {
  536           NGM_GENERIC_COOKIE,
  537           NGM_LISTNAMES,
  538           "listnames",
  539           NULL,
  540           &ng_generic_listnodes_type    /* same as NGM_LISTNODES */
  541         },
  542         {
  543           NGM_GENERIC_COOKIE,
  544           NGM_LISTNODES,
  545           "listnodes",
  546           NULL,
  547           &ng_generic_listnodes_type
  548         },
  549         {
  550           NGM_GENERIC_COOKIE,
  551           NGM_LISTTYPES,
  552           "listtypes",
  553           NULL,
  554           &ng_generic_typelist_type
  555         },
  556         {
  557           NGM_GENERIC_COOKIE,
  558           NGM_TEXT_CONFIG,
  559           "textconfig",
  560           NULL,
  561           &ng_parse_string_type
  562         },
  563         {
  564           NGM_GENERIC_COOKIE,
  565           NGM_TEXT_STATUS,
  566           "textstatus",
  567           NULL,
  568           &ng_parse_string_type
  569         },
  570         {
  571           NGM_GENERIC_COOKIE,
  572           NGM_ASCII2BINARY,
  573           "ascii2binary",
  574           &ng_parse_ng_mesg_type,
  575           &ng_parse_ng_mesg_type
  576         },
  577         {
  578           NGM_GENERIC_COOKIE,
  579           NGM_BINARY2ASCII,
  580           "binary2ascii",
  581           &ng_parse_ng_mesg_type,
  582           &ng_parse_ng_mesg_type
  583         },
  584         { 0 }
  585 };
  586 
  587 /************************************************************************
  588                         Node routines
  589 ************************************************************************/
  590 
  591 /*
  592  * Instantiate a node of the requested type
  593  */
  594 int
  595 ng_make_node(const char *typename, node_p *nodepp)
  596 {
  597         struct ng_type *type;
  598         int     error;
  599 
  600         /* Check that the type makes sense */
  601         if (typename == NULL) {
  602                 TRAP_ERROR();
  603                 return (EINVAL);
  604         }
  605 
  606         /* Locate the node type. If we fail we return. Do not try to load
  607          * module.
  608          */
  609         if ((type = ng_findtype(typename)) == NULL)
  610                 return (ENXIO);
  611 
  612         /*
  613          * If we have a constructor, then make the node and
  614          * call the constructor to do type specific initialisation.
  615          */
  616         if (type->constructor != NULL) {
  617                 if ((error = ng_make_node_common(type, nodepp)) == 0) {
  618                         if ((error = ((*type->constructor)(*nodepp))) != 0) {
  619                                 NG_NODE_UNREF(*nodepp);
  620                         }
  621                 }
  622         } else {
  623                 /*
  624                  * Node has no constructor. We cannot ask for one
  625                  * to be made. It must be brought into existence by
  626                  * some external agency. The external agency should
  627                  * call ng_make_node_common() directly to get the
  628                  * netgraph part initialised.
  629                  */
  630                 TRAP_ERROR();
  631                 error = EINVAL;
  632         }
  633         return (error);
  634 }
  635 
  636 /*
  637  * Generic node creation. Called by node initialisation for externally
  638  * instantiated nodes (e.g. hardware, sockets, etc ).
  639  * The returned node has a reference count of 1.
  640  */
  641 int
  642 ng_make_node_common(struct ng_type *type, node_p *nodepp)
  643 {
  644         node_p node;
  645 
  646         /* Require the node type to have been already installed */
  647         if (ng_findtype(type->name) == NULL) {
  648                 TRAP_ERROR();
  649                 return (EINVAL);
  650         }
  651 
  652         /* Make a node and try attach it to the type */
  653         NG_ALLOC_NODE(node);
  654         if (node == NULL) {
  655                 TRAP_ERROR();
  656                 return (ENOMEM);
  657         }
  658         node->nd_type = type;
  659 #ifdef VIMAGE
  660         node->nd_vnet = curvnet;
  661 #endif
  662         NG_NODE_REF(node);                              /* note reference */
  663         type->refs++;
  664 
  665         NG_QUEUE_LOCK_INIT(&node->nd_input_queue);
  666         STAILQ_INIT(&node->nd_input_queue.queue);
  667         node->nd_input_queue.q_flags = 0;
  668 
  669         /* Initialize hook list for new node */
  670         LIST_INIT(&node->nd_hooks);
  671 
  672         /* Get an ID and put us in the hash chain. */
  673         IDHASH_WLOCK();
  674         for (;;) { /* wrap protection, even if silly */
  675                 node_p node2 = NULL;
  676                 node->nd_ID = V_nextID++; /* 137/sec for 1 year before wrap */
  677 
  678                 /* Is there a problem with the new number? */
  679                 NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
  680                 if ((node->nd_ID != 0) && (node2 == NULL)) {
  681                         break;
  682                 }
  683         }
  684         V_ng_nodes++;
  685         if (V_ng_nodes * 2 > V_ng_ID_hmask)
  686                 ng_ID_rehash();
  687         LIST_INSERT_HEAD(&V_ng_ID_hash[NG_IDHASH_FN(node->nd_ID)], node,
  688             nd_idnodes);
  689         IDHASH_WUNLOCK();
  690 
  691         /* Done */
  692         *nodepp = node;
  693         return (0);
  694 }
  695 
  696 /*
  697  * Forceably start the shutdown process on a node. Either call
  698  * its shutdown method, or do the default shutdown if there is
  699  * no type-specific method.
  700  *
  701  * We can only be called from a shutdown message, so we know we have
  702  * a writer lock, and therefore exclusive access. It also means
  703  * that we should not be on the work queue, but we check anyhow.
  704  *
  705  * Persistent node types must have a type-specific method which
  706  * allocates a new node in which case, this one is irretrievably going away,
  707  * or cleans up anything it needs, and just makes the node valid again,
  708  * in which case we allow the node to survive.
  709  *
  710  * XXX We need to think of how to tell a persistent node that we
  711  * REALLY need to go away because the hardware has gone or we
  712  * are rebooting.... etc.
  713  */
  714 void
  715 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
  716 {
  717         hook_p hook;
  718 
  719         /* Check if it's already shutting down */
  720         if ((node->nd_flags & NGF_CLOSING) != 0)
  721                 return;
  722 
  723         if (node == &ng_deadnode) {
  724                 printf ("shutdown called on deadnode\n");
  725                 return;
  726         }
  727 
  728         /* Add an extra reference so it doesn't go away during this */
  729         NG_NODE_REF(node);
  730 
  731         /*
  732          * Mark it invalid so any newcomers know not to try use it
  733          * Also add our own mark so we can't recurse
  734          * note that NGF_INVALID does not do this as it's also set during
  735          * creation
  736          */
  737         node->nd_flags |= NGF_INVALID|NGF_CLOSING;
  738 
  739         /* If node has its pre-shutdown method, then call it first*/
  740         if (node->nd_type && node->nd_type->close)
  741                 (*node->nd_type->close)(node);
  742 
  743         /* Notify all remaining connected nodes to disconnect */
  744         while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
  745                 ng_destroy_hook(hook);
  746 
  747         /*
  748          * Drain the input queue forceably.
  749          * it has no hooks so what's it going to do, bleed on someone?
  750          * Theoretically we came here from a queue entry that was added
  751          * Just before the queue was closed, so it should be empty anyway.
  752          * Also removes us from worklist if needed.
  753          */
  754         ng_flush_input_queue(node);
  755 
  756         /* Ask the type if it has anything to do in this case */
  757         if (node->nd_type && node->nd_type->shutdown) {
  758                 (*node->nd_type->shutdown)(node);
  759                 if (NG_NODE_IS_VALID(node)) {
  760                         /*
  761                          * Well, blow me down if the node code hasn't declared
  762                          * that it doesn't want to die.
  763                          * Presumably it is a persistent node.
  764                          * If we REALLY want it to go away,
  765                          *  e.g. hardware going away,
  766                          * Our caller should set NGF_REALLY_DIE in nd_flags.
  767                          */
  768                         node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
  769                         NG_NODE_UNREF(node); /* Assume they still have theirs */
  770                         return;
  771                 }
  772         } else {                                /* do the default thing */
  773                 NG_NODE_UNREF(node);
  774         }
  775 
  776         ng_unname(node); /* basically a NOP these days */
  777 
  778         /*
  779          * Remove extra reference, possibly the last
  780          * Possible other holders of references may include
  781          * timeout callouts, but theoretically the node's supposed to
  782          * have cancelled them. Possibly hardware dependencies may
  783          * force a driver to 'linger' with a reference.
  784          */
  785         NG_NODE_UNREF(node);
  786 }
  787 
  788 /*
  789  * Remove a reference to the node, possibly the last.
  790  * deadnode always acts as it were the last.
  791  */
  792 void
  793 ng_unref_node(node_p node)
  794 {
  795 
  796         if (node == &ng_deadnode)
  797                 return;
  798 
  799         CURVNET_SET(node->nd_vnet);
  800 
  801         if (refcount_release(&node->nd_refs)) { /* we were the last */
  802 
  803                 node->nd_type->refs--; /* XXX maybe should get types lock? */
  804                 NAMEHASH_WLOCK();
  805                 if (NG_NODE_HAS_NAME(node)) {
  806                         V_ng_named_nodes--;
  807                         LIST_REMOVE(node, nd_nodes);
  808                 }
  809                 NAMEHASH_WUNLOCK();
  810 
  811                 IDHASH_WLOCK();
  812                 V_ng_nodes--;
  813                 LIST_REMOVE(node, nd_idnodes);
  814                 IDHASH_WUNLOCK();
  815 
  816                 mtx_destroy(&node->nd_input_queue.q_mtx);
  817                 NG_FREE_NODE(node);
  818         }
  819         CURVNET_RESTORE();
  820 }
  821 
  822 /************************************************************************
  823                         Node ID handling
  824 ************************************************************************/
  825 static node_p
  826 ng_ID2noderef(ng_ID_t ID)
  827 {
  828         node_p node;
  829 
  830         IDHASH_RLOCK();
  831         NG_IDHASH_FIND(ID, node);
  832         if (node)
  833                 NG_NODE_REF(node);
  834         IDHASH_RUNLOCK();
  835         return(node);
  836 }
  837 
  838 ng_ID_t
  839 ng_node2ID(node_cp node)
  840 {
  841         return (node ? NG_NODE_ID(node) : 0);
  842 }
  843 
  844 /************************************************************************
  845                         Node name handling
  846 ************************************************************************/
  847 
  848 /*
  849  * Assign a node a name.
  850  */
  851 int
  852 ng_name_node(node_p node, const char *name)
  853 {
  854         uint32_t hash;
  855         node_p node2;
  856         int i;
  857 
  858         /* Rename without change is a noop */
  859         if (strcmp(NG_NODE_NAME(node), name) == 0)
  860                 return (0);
  861 
  862         /* Check the name is valid */
  863         for (i = 0; i < NG_NODESIZ; i++) {
  864                 if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
  865                         break;
  866         }
  867         if (i == 0 || name[i] != '\0') {
  868                 TRAP_ERROR();
  869                 return (EINVAL);
  870         }
  871         if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
  872                 TRAP_ERROR();
  873                 return (EINVAL);
  874         }
  875 
  876         NAMEHASH_WLOCK();
  877         if (V_ng_named_nodes * 2 > V_ng_name_hmask)
  878                 ng_name_rehash();
  879 
  880         hash = hash32_str(name, HASHINIT) & V_ng_name_hmask;
  881         /* Check the name isn't already being used. */
  882         LIST_FOREACH(node2, &V_ng_name_hash[hash], nd_nodes)
  883                 if (NG_NODE_IS_VALID(node2) &&
  884                     (strcmp(NG_NODE_NAME(node2), name) == 0)) {
  885                         NAMEHASH_WUNLOCK();
  886                         return (EADDRINUSE);
  887                 }
  888 
  889         if (NG_NODE_HAS_NAME(node))
  890                 LIST_REMOVE(node, nd_nodes);
  891         else
  892                 V_ng_named_nodes++;
  893         /* Copy it. */
  894         strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
  895         /* Update name hash. */
  896         LIST_INSERT_HEAD(&V_ng_name_hash[hash], node, nd_nodes);
  897         NAMEHASH_WUNLOCK();
  898 
  899         return (0);
  900 }
  901 
  902 /*
  903  * Find a node by absolute name. The name should NOT end with ':'
  904  * The name "." means "this node" and "[xxx]" means "the node
  905  * with ID (ie, at address) xxx".
  906  *
  907  * Returns the node if found, else NULL.
  908  * Eventually should add something faster than a sequential search.
  909  * Note it acquires a reference on the node so you can be sure it's still
  910  * there.
  911  */
  912 node_p
  913 ng_name2noderef(node_p here, const char *name)
  914 {
  915         node_p node;
  916         ng_ID_t temp;
  917         int     hash;
  918 
  919         /* "." means "this node" */
  920         if (strcmp(name, ".") == 0) {
  921                 NG_NODE_REF(here);
  922                 return(here);
  923         }
  924 
  925         /* Check for name-by-ID */
  926         if ((temp = ng_decodeidname(name)) != 0) {
  927                 return (ng_ID2noderef(temp));
  928         }
  929 
  930         /* Find node by name. */
  931         hash = hash32_str(name, HASHINIT) & V_ng_name_hmask;
  932         NAMEHASH_RLOCK();
  933         LIST_FOREACH(node, &V_ng_name_hash[hash], nd_nodes)
  934                 if (NG_NODE_IS_VALID(node) &&
  935                     (strcmp(NG_NODE_NAME(node), name) == 0)) {
  936                         NG_NODE_REF(node);
  937                         break;
  938                 }
  939         NAMEHASH_RUNLOCK();
  940 
  941         return (node);
  942 }
  943 
  944 /*
  945  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
  946  * string is not valid, otherwise returns the value.
  947  */
  948 static ng_ID_t
  949 ng_decodeidname(const char *name)
  950 {
  951         const int len = strlen(name);
  952         char *eptr;
  953         u_long val;
  954 
  955         /* Check for proper length, brackets, no leading junk */
  956         if ((len < 3) || (name[0] != '[') || (name[len - 1] != ']') ||
  957             (!isxdigit(name[1])))
  958                 return ((ng_ID_t)0);
  959 
  960         /* Decode number */
  961         val = strtoul(name + 1, &eptr, 16);
  962         if ((eptr - name != len - 1) || (val == ULONG_MAX) || (val == 0))
  963                 return ((ng_ID_t)0);
  964 
  965         return ((ng_ID_t)val);
  966 }
  967 
  968 /*
  969  * Remove a name from a node. This should only be called
  970  * when shutting down and removing the node.
  971  */
  972 void
  973 ng_unname(node_p node)
  974 {
  975 }
  976 
  977 /*
  978  * Allocate a bigger name hash.
  979  */
  980 static void
  981 ng_name_rehash(void)
  982 {
  983         struct nodehash *new;
  984         uint32_t hash;
  985         u_long hmask;
  986         node_p node, node2;
  987         int i;
  988 
  989         new = hashinit_flags((V_ng_name_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask,
  990             HASH_NOWAIT);
  991         if (new == NULL)
  992                 return;
  993 
  994         for (i = 0; i <= V_ng_name_hmask; i++)
  995                 LIST_FOREACH_SAFE(node, &V_ng_name_hash[i], nd_nodes, node2) {
  996 #ifdef INVARIANTS
  997                         LIST_REMOVE(node, nd_nodes);
  998 #endif
  999                         hash = hash32_str(NG_NODE_NAME(node), HASHINIT) & hmask;
 1000                         LIST_INSERT_HEAD(&new[hash], node, nd_nodes);
 1001                 }
 1002 
 1003         hashdestroy(V_ng_name_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
 1004         V_ng_name_hash = new;
 1005         V_ng_name_hmask = hmask;
 1006 }
 1007 
 1008 /*
 1009  * Allocate a bigger ID hash.
 1010  */
 1011 static void
 1012 ng_ID_rehash(void)
 1013 {
 1014         struct nodehash *new;
 1015         uint32_t hash;
 1016         u_long hmask;
 1017         node_p node, node2;
 1018         int i;
 1019 
 1020         new = hashinit_flags((V_ng_ID_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask,
 1021             HASH_NOWAIT);
 1022         if (new == NULL)
 1023                 return;
 1024 
 1025         for (i = 0; i <= V_ng_ID_hmask; i++)
 1026                 LIST_FOREACH_SAFE(node, &V_ng_ID_hash[i], nd_idnodes, node2) {
 1027 #ifdef INVARIANTS
 1028                         LIST_REMOVE(node, nd_idnodes);
 1029 #endif
 1030                         hash = (node->nd_ID % (hmask + 1));
 1031                         LIST_INSERT_HEAD(&new[hash], node, nd_idnodes);
 1032                 }
 1033 
 1034         hashdestroy(V_ng_ID_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
 1035         V_ng_ID_hash = new;
 1036         V_ng_ID_hmask = hmask;
 1037 }
 1038 
 1039 /************************************************************************
 1040                         Hook routines
 1041  Names are not optional. Hooks are always connected, except for a
 1042  brief moment within these routines. On invalidation or during creation
 1043  they are connected to the 'dead' hook.
 1044 ************************************************************************/
 1045 
 1046 /*
 1047  * Remove a hook reference
 1048  */
 1049 void
 1050 ng_unref_hook(hook_p hook)
 1051 {
 1052 
 1053         if (hook == &ng_deadhook)
 1054                 return;
 1055 
 1056         if (refcount_release(&hook->hk_refs)) { /* we were the last */
 1057                 if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
 1058                         _NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
 1059                 NG_FREE_HOOK(hook);
 1060         }
 1061 }
 1062 
 1063 /*
 1064  * Add an unconnected hook to a node. Only used internally.
 1065  * Assumes node is locked. (XXX not yet true )
 1066  */
 1067 static int
 1068 ng_add_hook(node_p node, const char *name, hook_p *hookp)
 1069 {
 1070         hook_p hook;
 1071         int error = 0;
 1072 
 1073         /* Check that the given name is good */
 1074         if (name == NULL) {
 1075                 TRAP_ERROR();
 1076                 return (EINVAL);
 1077         }
 1078         if (ng_findhook(node, name) != NULL) {
 1079                 TRAP_ERROR();
 1080                 return (EEXIST);
 1081         }
 1082 
 1083         /* Allocate the hook and link it up */
 1084         NG_ALLOC_HOOK(hook);
 1085         if (hook == NULL) {
 1086                 TRAP_ERROR();
 1087                 return (ENOMEM);
 1088         }
 1089         hook->hk_refs = 1;              /* add a reference for us to return */
 1090         hook->hk_flags = HK_INVALID;
 1091         hook->hk_peer = &ng_deadhook;   /* start off this way */
 1092         hook->hk_node = node;
 1093         NG_NODE_REF(node);              /* each hook counts as a reference */
 1094 
 1095         /* Set hook name */
 1096         strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
 1097 
 1098         /*
 1099          * Check if the node type code has something to say about it
 1100          * If it fails, the unref of the hook will also unref the node.
 1101          */
 1102         if (node->nd_type->newhook != NULL) {
 1103                 if ((error = (*node->nd_type->newhook)(node, hook, name))) {
 1104                         NG_HOOK_UNREF(hook);    /* this frees the hook */
 1105                         return (error);
 1106                 }
 1107         }
 1108         /*
 1109          * The 'type' agrees so far, so go ahead and link it in.
 1110          * We'll ask again later when we actually connect the hooks.
 1111          */
 1112         LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
 1113         node->nd_numhooks++;
 1114         NG_HOOK_REF(hook);      /* one for the node */
 1115 
 1116         if (hookp)
 1117                 *hookp = hook;
 1118         return (0);
 1119 }
 1120 
 1121 /*
 1122  * Find a hook
 1123  *
 1124  * Node types may supply their own optimized routines for finding
 1125  * hooks.  If none is supplied, we just do a linear search.
 1126  * XXX Possibly we should add a reference to the hook?
 1127  */
 1128 hook_p
 1129 ng_findhook(node_p node, const char *name)
 1130 {
 1131         hook_p hook;
 1132 
 1133         if (node->nd_type->findhook != NULL)
 1134                 return (*node->nd_type->findhook)(node, name);
 1135         LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
 1136                 if (NG_HOOK_IS_VALID(hook) &&
 1137                     (strcmp(NG_HOOK_NAME(hook), name) == 0))
 1138                         return (hook);
 1139         }
 1140         return (NULL);
 1141 }
 1142 
 1143 /*
 1144  * Destroy a hook
 1145  *
 1146  * As hooks are always attached, this really destroys two hooks.
 1147  * The one given, and the one attached to it. Disconnect the hooks
 1148  * from each other first. We reconnect the peer hook to the 'dead'
 1149  * hook so that it can still exist after we depart. We then
 1150  * send the peer its own destroy message. This ensures that we only
 1151  * interact with the peer's structures when it is locked processing that
 1152  * message. We hold a reference to the peer hook so we are guaranteed that
 1153  * the peer hook and node are still going to exist until
 1154  * we are finished there as the hook holds a ref on the node.
 1155  * We run this same code again on the peer hook, but that time it is already
 1156  * attached to the 'dead' hook.
 1157  *
 1158  * This routine is called at all stages of hook creation
 1159  * on error detection and must be able to handle any such stage.
 1160  */
 1161 void
 1162 ng_destroy_hook(hook_p hook)
 1163 {
 1164         hook_p peer;
 1165         node_p node;
 1166 
 1167         if (hook == &ng_deadhook) {     /* better safe than sorry */
 1168                 printf("ng_destroy_hook called on deadhook\n");
 1169                 return;
 1170         }
 1171 
 1172         /*
 1173          * Protect divorce process with mutex, to avoid races on
 1174          * simultaneous disconnect.
 1175          */
 1176         TOPOLOGY_WLOCK();
 1177 
 1178         hook->hk_flags |= HK_INVALID;
 1179 
 1180         peer = NG_HOOK_PEER(hook);
 1181         node = NG_HOOK_NODE(hook);
 1182 
 1183         if (peer && (peer != &ng_deadhook)) {
 1184                 /*
 1185                  * Set the peer to point to ng_deadhook
 1186                  * from this moment on we are effectively independent it.
 1187                  * send it an rmhook message of its own.
 1188                  */
 1189                 peer->hk_peer = &ng_deadhook;   /* They no longer know us */
 1190                 hook->hk_peer = &ng_deadhook;   /* Nor us, them */
 1191                 if (NG_HOOK_NODE(peer) == &ng_deadnode) {
 1192                         /*
 1193                          * If it's already divorced from a node,
 1194                          * just free it.
 1195                          */
 1196                         TOPOLOGY_WUNLOCK();
 1197                 } else {
 1198                         TOPOLOGY_WUNLOCK();
 1199                         ng_rmhook_self(peer);   /* Send it a surprise */
 1200                 }
 1201                 NG_HOOK_UNREF(peer);            /* account for peer link */
 1202                 NG_HOOK_UNREF(hook);            /* account for peer link */
 1203         } else
 1204                 TOPOLOGY_WUNLOCK();
 1205 
 1206         TOPOLOGY_NOTOWNED();
 1207 
 1208         /*
 1209          * Remove the hook from the node's list to avoid possible recursion
 1210          * in case the disconnection results in node shutdown.
 1211          */
 1212         if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
 1213                 return;
 1214         }
 1215         LIST_REMOVE(hook, hk_hooks);
 1216         node->nd_numhooks--;
 1217         if (node->nd_type->disconnect) {
 1218                 /*
 1219                  * The type handler may elect to destroy the node so don't
 1220                  * trust its existence after this point. (except
 1221                  * that we still hold a reference on it. (which we
 1222                  * inherrited from the hook we are destroying)
 1223                  */
 1224                 (*node->nd_type->disconnect) (hook);
 1225         }
 1226 
 1227         /*
 1228          * Note that because we will point to ng_deadnode, the original node
 1229          * is not decremented automatically so we do that manually.
 1230          */
 1231         _NG_HOOK_NODE(hook) = &ng_deadnode;
 1232         NG_NODE_UNREF(node);    /* We no longer point to it so adjust count */
 1233         NG_HOOK_UNREF(hook);    /* Account for linkage (in list) to node */
 1234 }
 1235 
 1236 /*
 1237  * Take two hooks on a node and merge the connection so that the given node
 1238  * is effectively bypassed.
 1239  */
 1240 int
 1241 ng_bypass(hook_p hook1, hook_p hook2)
 1242 {
 1243         if (hook1->hk_node != hook2->hk_node) {
 1244                 TRAP_ERROR();
 1245                 return (EINVAL);
 1246         }
 1247         TOPOLOGY_WLOCK();
 1248         if (NG_HOOK_NOT_VALID(hook1) || NG_HOOK_NOT_VALID(hook2)) {
 1249                 TOPOLOGY_WUNLOCK();
 1250                 return (EINVAL);
 1251         }
 1252         hook1->hk_peer->hk_peer = hook2->hk_peer;
 1253         hook2->hk_peer->hk_peer = hook1->hk_peer;
 1254 
 1255         hook1->hk_peer = &ng_deadhook;
 1256         hook2->hk_peer = &ng_deadhook;
 1257         TOPOLOGY_WUNLOCK();
 1258 
 1259         NG_HOOK_UNREF(hook1);
 1260         NG_HOOK_UNREF(hook2);
 1261 
 1262         /* XXX If we ever cache methods on hooks update them as well */
 1263         ng_destroy_hook(hook1);
 1264         ng_destroy_hook(hook2);
 1265         return (0);
 1266 }
 1267 
 1268 /*
 1269  * Install a new netgraph type
 1270  */
 1271 int
 1272 ng_newtype(struct ng_type *tp)
 1273 {
 1274         const size_t namelen = strlen(tp->name);
 1275 
 1276         /* Check version and type name fields */
 1277         if ((tp->version != NG_ABI_VERSION) || (namelen == 0) ||
 1278             (namelen >= NG_TYPESIZ)) {
 1279                 TRAP_ERROR();
 1280                 if (tp->version != NG_ABI_VERSION) {
 1281                         printf("Netgraph: Node type rejected. ABI mismatch. "
 1282                             "Suggest recompile\n");
 1283                 }
 1284                 return (EINVAL);
 1285         }
 1286 
 1287         /* Check for name collision */
 1288         if (ng_findtype(tp->name) != NULL) {
 1289                 TRAP_ERROR();
 1290                 return (EEXIST);
 1291         }
 1292 
 1293         /* Link in new type */
 1294         TYPELIST_WLOCK();
 1295         LIST_INSERT_HEAD(&ng_typelist, tp, types);
 1296         tp->refs = 1;   /* first ref is linked list */
 1297         TYPELIST_WUNLOCK();
 1298         return (0);
 1299 }
 1300 
 1301 /*
 1302  * unlink a netgraph type
 1303  * If no examples exist
 1304  */
 1305 int
 1306 ng_rmtype(struct ng_type *tp)
 1307 {
 1308         /* Check for name collision */
 1309         if (tp->refs != 1) {
 1310                 TRAP_ERROR();
 1311                 return (EBUSY);
 1312         }
 1313 
 1314         /* Unlink type */
 1315         TYPELIST_WLOCK();
 1316         LIST_REMOVE(tp, types);
 1317         TYPELIST_WUNLOCK();
 1318         return (0);
 1319 }
 1320 
 1321 /*
 1322  * Look for a type of the name given
 1323  */
 1324 struct ng_type *
 1325 ng_findtype(const char *typename)
 1326 {
 1327         struct ng_type *type;
 1328 
 1329         TYPELIST_RLOCK();
 1330         LIST_FOREACH(type, &ng_typelist, types) {
 1331                 if (strcmp(type->name, typename) == 0)
 1332                         break;
 1333         }
 1334         TYPELIST_RUNLOCK();
 1335         return (type);
 1336 }
 1337 
 1338 /************************************************************************
 1339                         Composite routines
 1340 ************************************************************************/
 1341 /*
 1342  * Connect two nodes using the specified hooks, using queued functions.
 1343  */
 1344 static int
 1345 ng_con_part3(node_p node, item_p item, hook_p hook)
 1346 {
 1347         int     error = 0;
 1348 
 1349         /*
 1350          * When we run, we know that the node 'node' is locked for us.
 1351          * Our caller has a reference on the hook.
 1352          * Our caller has a reference on the node.
 1353          * (In this case our caller is ng_apply_item() ).
 1354          * The peer hook has a reference on the hook.
 1355          * We are all set up except for the final call to the node, and
 1356          * the clearing of the INVALID flag.
 1357          */
 1358         if (NG_HOOK_NODE(hook) == &ng_deadnode) {
 1359                 /*
 1360                  * The node must have been freed again since we last visited
 1361                  * here. ng_destry_hook() has this effect but nothing else does.
 1362                  * We should just release our references and
 1363                  * free anything we can think of.
 1364                  * Since we know it's been destroyed, and it's our caller
 1365                  * that holds the references, just return.
 1366                  */
 1367                 ERROUT(ENOENT);
 1368         }
 1369         if (hook->hk_node->nd_type->connect) {
 1370                 if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
 1371                         ng_destroy_hook(hook);  /* also zaps peer */
 1372                         printf("failed in ng_con_part3()\n");
 1373                         ERROUT(error);
 1374                 }
 1375         }
 1376         /*
 1377          *  XXX this is wrong for SMP. Possibly we need
 1378          * to separate out 'create' and 'invalid' flags.
 1379          * should only set flags on hooks we have locked under our node.
 1380          */
 1381         hook->hk_flags &= ~HK_INVALID;
 1382 done:
 1383         NG_FREE_ITEM(item);
 1384         return (error);
 1385 }
 1386 
 1387 static int
 1388 ng_con_part2(node_p node, item_p item, hook_p hook)
 1389 {
 1390         hook_p  peer;
 1391         int     error = 0;
 1392 
 1393         /*
 1394          * When we run, we know that the node 'node' is locked for us.
 1395          * Our caller has a reference on the hook.
 1396          * Our caller has a reference on the node.
 1397          * (In this case our caller is ng_apply_item() ).
 1398          * The peer hook has a reference on the hook.
 1399          * our node pointer points to the 'dead' node.
 1400          * First check the hook name is unique.
 1401          * Should not happen because we checked before queueing this.
 1402          */
 1403         if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
 1404                 TRAP_ERROR();
 1405                 ng_destroy_hook(hook); /* should destroy peer too */
 1406                 printf("failed in ng_con_part2()\n");
 1407                 ERROUT(EEXIST);
 1408         }
 1409         /*
 1410          * Check if the node type code has something to say about it
 1411          * If it fails, the unref of the hook will also unref the attached node,
 1412          * however since that node is 'ng_deadnode' this will do nothing.
 1413          * The peer hook will also be destroyed.
 1414          */
 1415         if (node->nd_type->newhook != NULL) {
 1416                 if ((error = (*node->nd_type->newhook)(node, hook,
 1417                     hook->hk_name))) {
 1418                         ng_destroy_hook(hook); /* should destroy peer too */
 1419                         printf("failed in ng_con_part2()\n");
 1420                         ERROUT(error);
 1421                 }
 1422         }
 1423 
 1424         /*
 1425          * The 'type' agrees so far, so go ahead and link it in.
 1426          * We'll ask again later when we actually connect the hooks.
 1427          */
 1428         hook->hk_node = node;           /* just overwrite ng_deadnode */
 1429         NG_NODE_REF(node);              /* each hook counts as a reference */
 1430         LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
 1431         node->nd_numhooks++;
 1432         NG_HOOK_REF(hook);      /* one for the node */
 1433 
 1434         /*
 1435          * We now have a symmetrical situation, where both hooks have been
 1436          * linked to their nodes, the newhook methods have been called
 1437          * And the references are all correct. The hooks are still marked
 1438          * as invalid, as we have not called the 'connect' methods
 1439          * yet.
 1440          * We can call the local one immediately as we have the
 1441          * node locked, but we need to queue the remote one.
 1442          */
 1443         if (hook->hk_node->nd_type->connect) {
 1444                 if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
 1445                         ng_destroy_hook(hook);  /* also zaps peer */
 1446                         printf("failed in ng_con_part2(A)\n");
 1447                         ERROUT(error);
 1448                 }
 1449         }
 1450 
 1451         /*
 1452          * Acquire topo mutex to avoid race with ng_destroy_hook().
 1453          */
 1454         TOPOLOGY_RLOCK();
 1455         peer = hook->hk_peer;
 1456         if (peer == &ng_deadhook) {
 1457                 TOPOLOGY_RUNLOCK();
 1458                 printf("failed in ng_con_part2(B)\n");
 1459                 ng_destroy_hook(hook);
 1460                 ERROUT(ENOENT);
 1461         }
 1462         TOPOLOGY_RUNLOCK();
 1463 
 1464         if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
 1465             NULL, 0, NG_REUSE_ITEM))) {
 1466                 printf("failed in ng_con_part2(C)\n");
 1467                 ng_destroy_hook(hook);  /* also zaps peer */
 1468                 return (error);         /* item was consumed. */
 1469         }
 1470         hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
 1471         return (0);                     /* item was consumed. */
 1472 done:
 1473         NG_FREE_ITEM(item);
 1474         return (error);
 1475 }
 1476 
 1477 /*
 1478  * Connect this node with another node. We assume that this node is
 1479  * currently locked, as we are only called from an NGM_CONNECT message.
 1480  */
 1481 static int
 1482 ng_con_nodes(item_p item, node_p node, const char *name,
 1483     node_p node2, const char *name2)
 1484 {
 1485         int     error;
 1486         hook_p  hook;
 1487         hook_p  hook2;
 1488 
 1489         if (ng_findhook(node2, name2) != NULL) {
 1490                 return(EEXIST);
 1491         }
 1492         if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
 1493                 return (error);
 1494         /* Allocate the other hook and link it up */
 1495         NG_ALLOC_HOOK(hook2);
 1496         if (hook2 == NULL) {
 1497                 TRAP_ERROR();
 1498                 ng_destroy_hook(hook);  /* XXX check ref counts so far */
 1499                 NG_HOOK_UNREF(hook);    /* including our ref */
 1500                 return (ENOMEM);
 1501         }
 1502         hook2->hk_refs = 1;             /* start with a reference for us. */
 1503         hook2->hk_flags = HK_INVALID;
 1504         hook2->hk_peer = hook;          /* Link the two together */
 1505         hook->hk_peer = hook2;  
 1506         NG_HOOK_REF(hook);              /* Add a ref for the peer to each*/
 1507         NG_HOOK_REF(hook2);
 1508         hook2->hk_node = &ng_deadnode;
 1509         strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
 1510 
 1511         /*
 1512          * Queue the function above.
 1513          * Procesing continues in that function in the lock context of
 1514          * the other node.
 1515          */
 1516         if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
 1517             NG_NOFLAGS))) {
 1518                 printf("failed in ng_con_nodes(): %d\n", error);
 1519                 ng_destroy_hook(hook);  /* also zaps peer */
 1520         }
 1521 
 1522         NG_HOOK_UNREF(hook);            /* Let each hook go if it wants to */
 1523         NG_HOOK_UNREF(hook2);
 1524         return (error);
 1525 }
 1526 
 1527 /*
 1528  * Make a peer and connect.
 1529  * We assume that the local node is locked.
 1530  * The new node probably doesn't need a lock until
 1531  * it has a hook, because it cannot really have any work until then,
 1532  * but we should think about it a bit more.
 1533  *
 1534  * The problem may come if the other node also fires up
 1535  * some hardware or a timer or some other source of activation,
 1536  * also it may already get a command msg via it's ID.
 1537  *
 1538  * We could use the same method as ng_con_nodes() but we'd have
 1539  * to add ability to remove the node when failing. (Not hard, just
 1540  * make arg1 point to the node to remove).
 1541  * Unless of course we just ignore failure to connect and leave
 1542  * an unconnected node?
 1543  */
 1544 static int
 1545 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
 1546 {
 1547         node_p  node2;
 1548         hook_p  hook1, hook2;
 1549         int     error;
 1550 
 1551         if ((error = ng_make_node(type, &node2))) {
 1552                 return (error);
 1553         }
 1554 
 1555         if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
 1556                 ng_rmnode(node2, NULL, NULL, 0);
 1557                 return (error);
 1558         }
 1559 
 1560         if ((error = ng_add_hook(node2, name2, &hook2))) {
 1561                 ng_rmnode(node2, NULL, NULL, 0);
 1562                 ng_destroy_hook(hook1);
 1563                 NG_HOOK_UNREF(hook1);
 1564                 return (error);
 1565         }
 1566 
 1567         /*
 1568          * Actually link the two hooks together.
 1569          */
 1570         hook1->hk_peer = hook2;
 1571         hook2->hk_peer = hook1;
 1572 
 1573         /* Each hook is referenced by the other */
 1574         NG_HOOK_REF(hook1);
 1575         NG_HOOK_REF(hook2);
 1576 
 1577         /* Give each node the opportunity to veto the pending connection */
 1578         if (hook1->hk_node->nd_type->connect) {
 1579                 error = (*hook1->hk_node->nd_type->connect) (hook1);
 1580         }
 1581 
 1582         if ((error == 0) && hook2->hk_node->nd_type->connect) {
 1583                 error = (*hook2->hk_node->nd_type->connect) (hook2);
 1584         }
 1585 
 1586         /*
 1587          * drop the references we were holding on the two hooks.
 1588          */
 1589         if (error) {
 1590                 ng_destroy_hook(hook2); /* also zaps hook1 */
 1591                 ng_rmnode(node2, NULL, NULL, 0);
 1592         } else {
 1593                 /* As a last act, allow the hooks to be used */
 1594                 hook1->hk_flags &= ~HK_INVALID;
 1595                 hook2->hk_flags &= ~HK_INVALID;
 1596         }
 1597         NG_HOOK_UNREF(hook1);
 1598         NG_HOOK_UNREF(hook2);
 1599         return (error);
 1600 }
 1601 
 1602 /************************************************************************
 1603                 Utility routines to send self messages
 1604 ************************************************************************/
 1605 
 1606 /* Shut this node down as soon as everyone is clear of it */
 1607 /* Should add arg "immediately" to jump the queue */
 1608 int
 1609 ng_rmnode_self(node_p node)
 1610 {
 1611         int             error;
 1612 
 1613         if (node == &ng_deadnode)
 1614                 return (0);
 1615         node->nd_flags |= NGF_INVALID;
 1616         if (node->nd_flags & NGF_CLOSING)
 1617                 return (0);
 1618 
 1619         error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
 1620         return (error);
 1621 }
 1622 
 1623 static void
 1624 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
 1625 {
 1626         ng_destroy_hook(hook);
 1627         return ;
 1628 }
 1629 
 1630 int
 1631 ng_rmhook_self(hook_p hook)
 1632 {
 1633         int             error;
 1634         node_p node = NG_HOOK_NODE(hook);
 1635 
 1636         if (node == &ng_deadnode)
 1637                 return (0);
 1638 
 1639         error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
 1640         return (error);
 1641 }
 1642 
 1643 /***********************************************************************
 1644  * Parse and verify a string of the form:  <NODE:><PATH>
 1645  *
 1646  * Such a string can refer to a specific node or a specific hook
 1647  * on a specific node, depending on how you look at it. In the
 1648  * latter case, the PATH component must not end in a dot.
 1649  *
 1650  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
 1651  * of hook names separated by dots. This breaks out the original
 1652  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
 1653  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
 1654  * the final hook component of <PATH>, if any, otherwise NULL.
 1655  *
 1656  * This returns -1 if the path is malformed. The char ** are optional.
 1657  ***********************************************************************/
 1658 int
 1659 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
 1660 {
 1661         char    *node, *path, *hook;
 1662         int     k;
 1663 
 1664         /*
 1665          * Extract absolute NODE, if any
 1666          */
 1667         for (path = addr; *path && *path != ':'; path++);
 1668         if (*path) {
 1669                 node = addr;    /* Here's the NODE */
 1670                 *path++ = '\0'; /* Here's the PATH */
 1671 
 1672                 /* Node name must not be empty */
 1673                 if (!*node)
 1674                         return -1;
 1675 
 1676                 /* A name of "." is OK; otherwise '.' not allowed */
 1677                 if (strcmp(node, ".") != 0) {
 1678                         for (k = 0; node[k]; k++)
 1679                                 if (node[k] == '.')
 1680                                         return -1;
 1681                 }
 1682         } else {
 1683                 node = NULL;    /* No absolute NODE */
 1684                 path = addr;    /* Here's the PATH */
 1685         }
 1686 
 1687         /* Snoop for illegal characters in PATH */
 1688         for (k = 0; path[k]; k++)
 1689                 if (path[k] == ':')
 1690                         return -1;
 1691 
 1692         /* Check for no repeated dots in PATH */
 1693         for (k = 0; path[k]; k++)
 1694                 if (path[k] == '.' && path[k + 1] == '.')
 1695                         return -1;
 1696 
 1697         /* Remove extra (degenerate) dots from beginning or end of PATH */
 1698         if (path[0] == '.')
 1699                 path++;
 1700         if (*path && path[strlen(path) - 1] == '.')
 1701                 path[strlen(path) - 1] = 0;
 1702 
 1703         /* If PATH has a dot, then we're not talking about a hook */
 1704         if (*path) {
 1705                 for (hook = path, k = 0; path[k]; k++)
 1706                         if (path[k] == '.') {
 1707                                 hook = NULL;
 1708                                 break;
 1709                         }
 1710         } else
 1711                 path = hook = NULL;
 1712 
 1713         /* Done */
 1714         if (nodep)
 1715                 *nodep = node;
 1716         if (pathp)
 1717                 *pathp = path;
 1718         if (hookp)
 1719                 *hookp = hook;
 1720         return (0);
 1721 }
 1722 
 1723 /*
 1724  * Given a path, which may be absolute or relative, and a starting node,
 1725  * return the destination node.
 1726  */
 1727 int
 1728 ng_path2noderef(node_p here, const char *address, node_p *destp,
 1729     hook_p *lasthook)
 1730 {
 1731         char    fullpath[NG_PATHSIZ];
 1732         char   *nodename, *path;
 1733         node_p  node, oldnode;
 1734 
 1735         /* Initialize */
 1736         if (destp == NULL) {
 1737                 TRAP_ERROR();
 1738                 return EINVAL;
 1739         }
 1740         *destp = NULL;
 1741 
 1742         /* Make a writable copy of address for ng_path_parse() */
 1743         strncpy(fullpath, address, sizeof(fullpath) - 1);
 1744         fullpath[sizeof(fullpath) - 1] = '\0';
 1745 
 1746         /* Parse out node and sequence of hooks */
 1747         if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
 1748                 TRAP_ERROR();
 1749                 return EINVAL;
 1750         }
 1751 
 1752         /*
 1753          * For an absolute address, jump to the starting node.
 1754          * Note that this holds a reference on the node for us.
 1755          * Don't forget to drop the reference if we don't need it.
 1756          */
 1757         if (nodename) {
 1758                 node = ng_name2noderef(here, nodename);
 1759                 if (node == NULL) {
 1760                         TRAP_ERROR();
 1761                         return (ENOENT);
 1762                 }
 1763         } else {
 1764                 if (here == NULL) {
 1765                         TRAP_ERROR();
 1766                         return (EINVAL);
 1767                 }
 1768                 node = here;
 1769                 NG_NODE_REF(node);
 1770         }
 1771 
 1772         if (path == NULL) {
 1773                 if (lasthook != NULL)
 1774                         *lasthook = NULL;
 1775                 *destp = node;
 1776                 return (0);
 1777         }
 1778 
 1779         /*
 1780          * Now follow the sequence of hooks
 1781          *
 1782          * XXXGL: The path may demolish as we go the sequence, but if
 1783          * we hold the topology mutex at critical places, then, I hope,
 1784          * we would always have valid pointers in hand, although the
 1785          * path behind us may no longer exist.
 1786          */
 1787         for (;;) {
 1788                 hook_p hook;
 1789                 char *segment;
 1790 
 1791                 /*
 1792                  * Break out the next path segment. Replace the dot we just
 1793                  * found with a NUL; "path" points to the next segment (or the
 1794                  * NUL at the end).
 1795                  */
 1796                 for (segment = path; *path != '\0'; path++) {
 1797                         if (*path == '.') {
 1798                                 *path++ = '\0';
 1799                                 break;
 1800                         }
 1801                 }
 1802 
 1803                 /* We have a segment, so look for a hook by that name */
 1804                 hook = ng_findhook(node, segment);
 1805 
 1806                 TOPOLOGY_WLOCK();
 1807                 /* Can't get there from here... */
 1808                 if (hook == NULL || NG_HOOK_PEER(hook) == NULL ||
 1809                     NG_HOOK_NOT_VALID(hook) ||
 1810                     NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
 1811                         TRAP_ERROR();
 1812                         NG_NODE_UNREF(node);
 1813                         TOPOLOGY_WUNLOCK();
 1814                         return (ENOENT);
 1815                 }
 1816 
 1817                 /*
 1818                  * Hop on over to the next node
 1819                  * XXX
 1820                  * Big race conditions here as hooks and nodes go away
 1821                  * *** Idea.. store an ng_ID_t in each hook and use that
 1822                  * instead of the direct hook in this crawl?
 1823                  */
 1824                 oldnode = node;
 1825                 if ((node = NG_PEER_NODE(hook)))
 1826                         NG_NODE_REF(node);      /* XXX RACE */
 1827                 NG_NODE_UNREF(oldnode); /* XXX another race */
 1828                 if (NG_NODE_NOT_VALID(node)) {
 1829                         NG_NODE_UNREF(node);    /* XXX more races */
 1830                         TOPOLOGY_WUNLOCK();
 1831                         TRAP_ERROR();
 1832                         return (ENXIO);
 1833                 }
 1834 
 1835                 if (*path == '\0') {
 1836                         if (lasthook != NULL) {
 1837                                 if (hook != NULL) {
 1838                                         *lasthook = NG_HOOK_PEER(hook);
 1839                                         NG_HOOK_REF(*lasthook);
 1840                                 } else
 1841                                         *lasthook = NULL;
 1842                         }
 1843                         TOPOLOGY_WUNLOCK();
 1844                         *destp = node;
 1845                         return (0);
 1846                 }
 1847                 TOPOLOGY_WUNLOCK();
 1848         }
 1849 }
 1850 
 1851 /***************************************************************\
 1852 * Input queue handling.
 1853 * All activities are submitted to the node via the input queue
 1854 * which implements a multiple-reader/single-writer gate.
 1855 * Items which cannot be handled immediately are queued.
 1856 *
 1857 * read-write queue locking inline functions                     *
 1858 \***************************************************************/
 1859 
 1860 static __inline void    ng_queue_rw(node_p node, item_p  item, int rw);
 1861 static __inline item_p  ng_dequeue(node_p node, int *rw);
 1862 static __inline item_p  ng_acquire_read(node_p node, item_p  item);
 1863 static __inline item_p  ng_acquire_write(node_p node, item_p  item);
 1864 static __inline void    ng_leave_read(node_p node);
 1865 static __inline void    ng_leave_write(node_p node);
 1866 
 1867 /*
 1868  * Definition of the bits fields in the ng_queue flag word.
 1869  * Defined here rather than in netgraph.h because no-one should fiddle
 1870  * with them.
 1871  *
 1872  * The ordering here may be important! don't shuffle these.
 1873  */
 1874 /*-
 1875  Safety Barrier--------+ (adjustable to suit taste) (not used yet)
 1876                        |
 1877                        V
 1878 +-------+-------+-------+-------+-------+-------+-------+-------+
 1879   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
 1880   | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
 1881   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
 1882 +-------+-------+-------+-------+-------+-------+-------+-------+
 1883   \___________________________ ____________________________/ | |
 1884                             V                                | |
 1885                   [active reader count]                      | |
 1886                                                              | |
 1887             Operation Pending -------------------------------+ |
 1888                                                                |
 1889           Active Writer ---------------------------------------+
 1890 
 1891 Node queue has such semantics:
 1892 - All flags modifications are atomic.
 1893 - Reader count can be incremented only if there is no writer or pending flags.
 1894   As soon as this can't be done with single operation, it is implemented with
 1895   spin loop and atomic_cmpset().
 1896 - Writer flag can be set only if there is no any bits set.
 1897   It is implemented with atomic_cmpset().
 1898 - Pending flag can be set any time, but to avoid collision on queue processing
 1899   all queue fields are protected by the mutex.
 1900 - Queue processing thread reads queue holding the mutex, but releases it while
 1901   processing. When queue is empty pending flag is removed.
 1902 */
 1903 
 1904 #define WRITER_ACTIVE   0x00000001
 1905 #define OP_PENDING      0x00000002
 1906 #define READER_INCREMENT 0x00000004
 1907 #define READER_MASK     0xfffffffc      /* Not valid if WRITER_ACTIVE is set */
 1908 #define SAFETY_BARRIER  0x00100000      /* 128K items queued should be enough */
 1909 
 1910 /* Defines of more elaborate states on the queue */
 1911 /* Mask of bits a new read cares about */
 1912 #define NGQ_RMASK       (WRITER_ACTIVE|OP_PENDING)
 1913 
 1914 /* Mask of bits a new write cares about */
 1915 #define NGQ_WMASK       (NGQ_RMASK|READER_MASK)
 1916 
 1917 /* Test to decide if there is something on the queue. */
 1918 #define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
 1919 
 1920 /* How to decide what the next queued item is. */
 1921 #define HEAD_IS_READER(QP)  NGI_QUEUED_READER(STAILQ_FIRST(&(QP)->queue))
 1922 #define HEAD_IS_WRITER(QP)  NGI_QUEUED_WRITER(STAILQ_FIRST(&(QP)->queue)) /* notused */
 1923 
 1924 /* Read the status to decide if the next item on the queue can now run. */
 1925 #define QUEUED_READER_CAN_PROCEED(QP)                   \
 1926                 (((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
 1927 #define QUEUED_WRITER_CAN_PROCEED(QP)                   \
 1928                 (((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
 1929 
 1930 /* Is there a chance of getting ANY work off the queue? */
 1931 #define NEXT_QUEUED_ITEM_CAN_PROCEED(QP)                                \
 1932         ((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) :         \
 1933                                 QUEUED_WRITER_CAN_PROCEED(QP))
 1934 
 1935 #define NGQRW_R 0
 1936 #define NGQRW_W 1
 1937 
 1938 #define NGQ2_WORKQ      0x00000001
 1939 
 1940 /*
 1941  * Taking into account the current state of the queue and node, possibly take
 1942  * the next entry off the queue and return it. Return NULL if there was
 1943  * nothing we could return, either because there really was nothing there, or
 1944  * because the node was in a state where it cannot yet process the next item
 1945  * on the queue.
 1946  */
 1947 static __inline item_p
 1948 ng_dequeue(node_p node, int *rw)
 1949 {
 1950         item_p item;
 1951         struct ng_queue *ngq = &node->nd_input_queue;
 1952 
 1953         /* This MUST be called with the mutex held. */
 1954         mtx_assert(&ngq->q_mtx, MA_OWNED);
 1955 
 1956         /* If there is nothing queued, then just return. */
 1957         if (!QUEUE_ACTIVE(ngq)) {
 1958                 CTR4(KTR_NET, "%20s: node [%x] (%p) queue empty; "
 1959                     "queue flags 0x%lx", __func__,
 1960                     node->nd_ID, node, ngq->q_flags);
 1961                 return (NULL);
 1962         }
 1963 
 1964         /*
 1965          * From here, we can assume there is a head item.
 1966          * We need to find out what it is and if it can be dequeued, given
 1967          * the current state of the node.
 1968          */
 1969         if (HEAD_IS_READER(ngq)) {
 1970                 while (1) {
 1971                         long t = ngq->q_flags;
 1972                         if (t & WRITER_ACTIVE) {
 1973                                 /* There is writer, reader can't proceed. */
 1974                                 CTR4(KTR_NET, "%20s: node [%x] (%p) queued "
 1975                                     "reader can't proceed; queue flags 0x%lx",
 1976                                     __func__, node->nd_ID, node, t);
 1977                                 return (NULL);
 1978                         }
 1979                         if (atomic_cmpset_acq_int(&ngq->q_flags, t,
 1980                             t + READER_INCREMENT))
 1981                                 break;
 1982                         cpu_spinwait();
 1983                 }
 1984                 /* We have got reader lock for the node. */
 1985                 *rw = NGQRW_R;
 1986         } else if (atomic_cmpset_acq_int(&ngq->q_flags, OP_PENDING,
 1987             OP_PENDING + WRITER_ACTIVE)) {
 1988                 /* We have got writer lock for the node. */
 1989                 *rw = NGQRW_W;
 1990         } else {
 1991                 /* There is somebody other, writer can't proceed. */
 1992                 CTR4(KTR_NET, "%20s: node [%x] (%p) queued writer can't "
 1993                     "proceed; queue flags 0x%lx", __func__, node->nd_ID, node,
 1994                     ngq->q_flags);
 1995                 return (NULL);
 1996         }
 1997 
 1998         /*
 1999          * Now we dequeue the request (whatever it may be) and correct the
 2000          * pending flags and the next and last pointers.
 2001          */
 2002         item = STAILQ_FIRST(&ngq->queue);
 2003         STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
 2004         if (STAILQ_EMPTY(&ngq->queue))
 2005                 atomic_clear_int(&ngq->q_flags, OP_PENDING);
 2006         CTR6(KTR_NET, "%20s: node [%x] (%p) returning item %p as %s; queue "
 2007             "flags 0x%lx", __func__, node->nd_ID, node, item, *rw ? "WRITER" :
 2008             "READER", ngq->q_flags);
 2009         return (item);
 2010 }
 2011 
 2012 /*
 2013  * Queue a packet to be picked up later by someone else.
 2014  * If the queue could be run now, add node to the queue handler's worklist.
 2015  */
 2016 static __inline void
 2017 ng_queue_rw(node_p node, item_p  item, int rw)
 2018 {
 2019         struct ng_queue *ngq = &node->nd_input_queue;
 2020         if (rw == NGQRW_W)
 2021                 NGI_SET_WRITER(item);
 2022         else
 2023                 NGI_SET_READER(item);
 2024         item->depth = 1;
 2025 
 2026         NG_QUEUE_LOCK(ngq);
 2027         /* Set OP_PENDING flag and enqueue the item. */
 2028         atomic_set_int(&ngq->q_flags, OP_PENDING);
 2029         STAILQ_INSERT_TAIL(&ngq->queue, item, el_next);
 2030 
 2031         CTR5(KTR_NET, "%20s: node [%x] (%p) queued item %p as %s", __func__,
 2032             node->nd_ID, node, item, rw ? "WRITER" : "READER" );
 2033 
 2034         /*
 2035          * We can take the worklist lock with the node locked
 2036          * BUT NOT THE REVERSE!
 2037          */
 2038         if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 2039                 ng_worklist_add(node);
 2040         NG_QUEUE_UNLOCK(ngq);
 2041 }
 2042 
 2043 /* Acquire reader lock on node. If node is busy, queue the packet. */
 2044 static __inline item_p
 2045 ng_acquire_read(node_p node, item_p item)
 2046 {
 2047         KASSERT(node != &ng_deadnode,
 2048             ("%s: working on deadnode", __func__));
 2049 
 2050         /* Reader needs node without writer and pending items. */
 2051         for (;;) {
 2052                 long t = node->nd_input_queue.q_flags;
 2053                 if (t & NGQ_RMASK)
 2054                         break; /* Node is not ready for reader. */
 2055                 if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags, t,
 2056                     t + READER_INCREMENT)) {
 2057                         /* Successfully grabbed node */
 2058                         CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
 2059                             __func__, node->nd_ID, node, item);
 2060                         return (item);
 2061                 }
 2062                 cpu_spinwait();
 2063         }
 2064 
 2065         /* Queue the request for later. */
 2066         ng_queue_rw(node, item, NGQRW_R);
 2067 
 2068         return (NULL);
 2069 }
 2070 
 2071 /* Acquire writer lock on node. If node is busy, queue the packet. */
 2072 static __inline item_p
 2073 ng_acquire_write(node_p node, item_p item)
 2074 {
 2075         KASSERT(node != &ng_deadnode,
 2076             ("%s: working on deadnode", __func__));
 2077 
 2078         /* Writer needs completely idle node. */
 2079         if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags, 0,
 2080             WRITER_ACTIVE)) {
 2081                 /* Successfully grabbed node */
 2082                 CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
 2083                     __func__, node->nd_ID, node, item);
 2084                 return (item);
 2085         }
 2086 
 2087         /* Queue the request for later. */
 2088         ng_queue_rw(node, item, NGQRW_W);
 2089 
 2090         return (NULL);
 2091 }
 2092 
 2093 #if 0
 2094 static __inline item_p
 2095 ng_upgrade_write(node_p node, item_p item)
 2096 {
 2097         struct ng_queue *ngq = &node->nd_input_queue;
 2098         KASSERT(node != &ng_deadnode,
 2099             ("%s: working on deadnode", __func__));
 2100 
 2101         NGI_SET_WRITER(item);
 2102 
 2103         NG_QUEUE_LOCK(ngq);
 2104 
 2105         /*
 2106          * There will never be no readers as we are there ourselves.
 2107          * Set the WRITER_ACTIVE flags ASAP to block out fast track readers.
 2108          * The caller we are running from will call ng_leave_read()
 2109          * soon, so we must account for that. We must leave again with the
 2110          * READER lock. If we find other readers, then
 2111          * queue the request for later. However "later" may be rignt now
 2112          * if there are no readers. We don't really care if there are queued
 2113          * items as we will bypass them anyhow.
 2114          */
 2115         atomic_add_int(&ngq->q_flags, WRITER_ACTIVE - READER_INCREMENT);
 2116         if ((ngq->q_flags & (NGQ_WMASK & ~OP_PENDING)) == WRITER_ACTIVE) {
 2117                 NG_QUEUE_UNLOCK(ngq);
 2118                 
 2119                 /* It's just us, act on the item. */
 2120                 /* will NOT drop writer lock when done */
 2121                 ng_apply_item(node, item, 0);
 2122 
 2123                 /*
 2124                  * Having acted on the item, atomically
 2125                  * downgrade back to READER and finish up.
 2126                  */
 2127                 atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
 2128 
 2129                 /* Our caller will call ng_leave_read() */
 2130                 return;
 2131         }
 2132         /*
 2133          * It's not just us active, so queue us AT THE HEAD.
 2134          * "Why?" I hear you ask.
 2135          * Put us at the head of the queue as we've already been
 2136          * through it once. If there is nothing else waiting,
 2137          * set the correct flags.
 2138          */
 2139         if (STAILQ_EMPTY(&ngq->queue)) {
 2140                 /* We've gone from, 0 to 1 item in the queue */
 2141                 atomic_set_int(&ngq->q_flags, OP_PENDING);
 2142 
 2143                 CTR3(KTR_NET, "%20s: node [%x] (%p) set OP_PENDING", __func__,
 2144                     node->nd_ID, node);
 2145         };
 2146         STAILQ_INSERT_HEAD(&ngq->queue, item, el_next);
 2147         CTR4(KTR_NET, "%20s: node [%x] (%p) requeued item %p as WRITER",
 2148             __func__, node->nd_ID, node, item );
 2149 
 2150         /* Reverse what we did above. That downgrades us back to reader */
 2151         atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
 2152         if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 2153                 ng_worklist_add(node);
 2154         NG_QUEUE_UNLOCK(ngq);
 2155 
 2156         return;
 2157 }
 2158 #endif
 2159 
 2160 /* Release reader lock. */
 2161 static __inline void
 2162 ng_leave_read(node_p node)
 2163 {
 2164         atomic_subtract_rel_int(&node->nd_input_queue.q_flags, READER_INCREMENT);
 2165 }
 2166 
 2167 /* Release writer lock. */
 2168 static __inline void
 2169 ng_leave_write(node_p node)
 2170 {
 2171         atomic_clear_rel_int(&node->nd_input_queue.q_flags, WRITER_ACTIVE);
 2172 }
 2173 
 2174 /* Purge node queue. Called on node shutdown. */
 2175 static void
 2176 ng_flush_input_queue(node_p node)
 2177 {
 2178         struct ng_queue *ngq = &node->nd_input_queue;
 2179         item_p item;
 2180 
 2181         NG_QUEUE_LOCK(ngq);
 2182         while ((item = STAILQ_FIRST(&ngq->queue)) != NULL) {
 2183                 STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
 2184                 if (STAILQ_EMPTY(&ngq->queue))
 2185                         atomic_clear_int(&ngq->q_flags, OP_PENDING);
 2186                 NG_QUEUE_UNLOCK(ngq);
 2187 
 2188                 /* If the item is supplying a callback, call it with an error */
 2189                 if (item->apply != NULL) {
 2190                         if (item->depth == 1)
 2191                                 item->apply->error = ENOENT;
 2192                         if (refcount_release(&item->apply->refs)) {
 2193                                 (*item->apply->apply)(item->apply->context,
 2194                                     item->apply->error);
 2195                         }
 2196                 }
 2197                 NG_FREE_ITEM(item);
 2198                 NG_QUEUE_LOCK(ngq);
 2199         }
 2200         NG_QUEUE_UNLOCK(ngq);
 2201 }
 2202 
 2203 /***********************************************************************
 2204 * Externally visible method for sending or queueing messages or data.
 2205 ***********************************************************************/
 2206 
 2207 /*
 2208  * The module code should have filled out the item correctly by this stage:
 2209  * Common:
 2210  *    reference to destination node.
 2211  *    Reference to destination rcv hook if relevant.
 2212  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
 2213  * Data:
 2214  *    pointer to mbuf
 2215  * Control_Message:
 2216  *    pointer to msg.
 2217  *    ID of original sender node. (return address)
 2218  * Function:
 2219  *    Function pointer
 2220  *    void * argument
 2221  *    integer argument
 2222  *
 2223  * The nodes have several routines and macros to help with this task:
 2224  */
 2225 
 2226 int
 2227 ng_snd_item(item_p item, int flags)
 2228 {
 2229         hook_p hook;
 2230         node_p node;
 2231         int queue, rw;
 2232         struct ng_queue *ngq;
 2233         int error = 0;
 2234 
 2235         /* We are sending item, so it must be present! */
 2236         KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
 2237 
 2238 #ifdef  NETGRAPH_DEBUG
 2239         _ngi_check(item, __FILE__, __LINE__);
 2240 #endif
 2241 
 2242         /* Item was sent once more, postpone apply() call. */
 2243         if (item->apply)
 2244                 refcount_acquire(&item->apply->refs);
 2245 
 2246         node = NGI_NODE(item);
 2247         /* Node is never optional. */
 2248         KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
 2249 
 2250         hook = NGI_HOOK(item);
 2251         /* Valid hook and mbuf are mandatory for data. */
 2252         if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
 2253                 KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
 2254                 if (NGI_M(item) == NULL)
 2255                         ERROUT(EINVAL);
 2256                 CHECK_DATA_MBUF(NGI_M(item));
 2257         }
 2258 
 2259         /*
 2260          * If the item or the node specifies single threading, force
 2261          * writer semantics. Similarly, the node may say one hook always
 2262          * produces writers. These are overrides.
 2263          */
 2264         if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
 2265             (node->nd_flags & NGF_FORCE_WRITER) ||
 2266             (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
 2267                 rw = NGQRW_W;
 2268         } else {
 2269                 rw = NGQRW_R;
 2270         }
 2271 
 2272         /*
 2273          * If sender or receiver requests queued delivery, or call graph
 2274          * loops back from outbound to inbound path, or stack usage
 2275          * level is dangerous - enqueue message.
 2276          */
 2277         if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
 2278                 queue = 1;
 2279         } else if (hook && (hook->hk_flags & HK_TO_INBOUND) &&
 2280             curthread->td_ng_outbound) {
 2281                 queue = 1;
 2282         } else {
 2283                 queue = 0;
 2284 
 2285                 /*
 2286                  * Most of netgraph nodes have small stack consumption and
 2287                  * for them 25% of free stack space is more than enough.
 2288                  * Nodes/hooks with higher stack usage should be marked as
 2289                  * HI_STACK. For them 50% of stack will be guaranteed then.
 2290                  * XXX: Values 25% and 50% are completely empirical.
 2291                  */
 2292                 size_t  st, su, sl;
 2293                 GET_STACK_USAGE(st, su);
 2294                 sl = st - su;
 2295                 if ((sl * 4 < st) || ((sl * 2 < st) &&
 2296                     ((node->nd_flags & NGF_HI_STACK) || (hook &&
 2297                     (hook->hk_flags & HK_HI_STACK)))))
 2298                         queue = 1;
 2299         }
 2300 
 2301         if (queue) {
 2302                 /* Put it on the queue for that node*/
 2303                 ng_queue_rw(node, item, rw);
 2304                 return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
 2305         }
 2306 
 2307         /*
 2308          * We already decided how we will be queueud or treated.
 2309          * Try get the appropriate operating permission.
 2310          */
 2311         if (rw == NGQRW_R)
 2312                 item = ng_acquire_read(node, item);
 2313         else
 2314                 item = ng_acquire_write(node, item);
 2315 
 2316         /* Item was queued while trying to get permission. */
 2317         if (item == NULL)
 2318                 return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
 2319 
 2320         NGI_GET_NODE(item, node); /* zaps stored node */
 2321 
 2322         item->depth++;
 2323         error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
 2324 
 2325         /* If something is waiting on queue and ready, schedule it. */
 2326         ngq = &node->nd_input_queue;
 2327         if (QUEUE_ACTIVE(ngq)) {
 2328                 NG_QUEUE_LOCK(ngq);
 2329                 if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 2330                         ng_worklist_add(node);
 2331                 NG_QUEUE_UNLOCK(ngq);
 2332         }
 2333 
 2334         /*
 2335          * Node may go away as soon as we remove the reference.
 2336          * Whatever we do, DO NOT access the node again!
 2337          */
 2338         NG_NODE_UNREF(node);
 2339 
 2340         return (error);
 2341 
 2342 done:
 2343         /* If was not sent, apply callback here. */
 2344         if (item->apply != NULL) {
 2345                 if (item->depth == 0 && error != 0)
 2346                         item->apply->error = error;
 2347                 if (refcount_release(&item->apply->refs)) {
 2348                         (*item->apply->apply)(item->apply->context,
 2349                             item->apply->error);
 2350                 }
 2351         }
 2352 
 2353         NG_FREE_ITEM(item);
 2354         return (error);
 2355 }
 2356 
 2357 /*
 2358  * We have an item that was possibly queued somewhere.
 2359  * It should contain all the information needed
 2360  * to run it on the appropriate node/hook.
 2361  * If there is apply pointer and we own the last reference, call apply().
 2362  */
 2363 static int
 2364 ng_apply_item(node_p node, item_p item, int rw)
 2365 {
 2366         hook_p  hook;
 2367         ng_rcvdata_t *rcvdata;
 2368         ng_rcvmsg_t *rcvmsg;
 2369         struct ng_apply_info *apply;
 2370         int     error = 0, depth;
 2371 
 2372         /* Node and item are never optional. */
 2373         KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
 2374         KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
 2375 
 2376         NGI_GET_HOOK(item, hook); /* clears stored hook */
 2377 #ifdef  NETGRAPH_DEBUG
 2378         _ngi_check(item, __FILE__, __LINE__);
 2379 #endif
 2380 
 2381         apply = item->apply;
 2382         depth = item->depth;
 2383 
 2384         switch (item->el_flags & NGQF_TYPE) {
 2385         case NGQF_DATA:
 2386                 /*
 2387                  * Check things are still ok as when we were queued.
 2388                  */
 2389                 KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
 2390                 if (NG_HOOK_NOT_VALID(hook) ||
 2391                     NG_NODE_NOT_VALID(node)) {
 2392                         error = EIO;
 2393                         NG_FREE_ITEM(item);
 2394                         break;
 2395                 }
 2396                 /*
 2397                  * If no receive method, just silently drop it.
 2398                  * Give preference to the hook over-ride method.
 2399                  */
 2400                 if ((!(rcvdata = hook->hk_rcvdata)) &&
 2401                     (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
 2402                         error = 0;
 2403                         NG_FREE_ITEM(item);
 2404                         break;
 2405                 }
 2406                 error = (*rcvdata)(hook, item);
 2407                 break;
 2408         case NGQF_MESG:
 2409                 if (hook && NG_HOOK_NOT_VALID(hook)) {
 2410                         /*
 2411                          * The hook has been zapped then we can't use it.
 2412                          * Immediately drop its reference.
 2413                          * The message may not need it.
 2414                          */
 2415                         NG_HOOK_UNREF(hook);
 2416                         hook = NULL;
 2417                 }
 2418                 /*
 2419                  * Similarly, if the node is a zombie there is
 2420                  * nothing we can do with it, drop everything.
 2421                  */
 2422                 if (NG_NODE_NOT_VALID(node)) {
 2423                         TRAP_ERROR();
 2424                         error = EINVAL;
 2425                         NG_FREE_ITEM(item);
 2426                         break;
 2427                 }
 2428                 /*
 2429                  * Call the appropriate message handler for the object.
 2430                  * It is up to the message handler to free the message.
 2431                  * If it's a generic message, handle it generically,
 2432                  * otherwise call the type's message handler (if it exists).
 2433                  * XXX (race). Remember that a queued message may
 2434                  * reference a node or hook that has just been
 2435                  * invalidated. It will exist as the queue code
 2436                  * is holding a reference, but..
 2437                  */
 2438                 if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
 2439                     ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
 2440                         error = ng_generic_msg(node, item, hook);
 2441                         break;
 2442                 }
 2443                 if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
 2444                     (!(rcvmsg = node->nd_type->rcvmsg))) {
 2445                         TRAP_ERROR();
 2446                         error = 0;
 2447                         NG_FREE_ITEM(item);
 2448                         break;
 2449                 }
 2450                 error = (*rcvmsg)(node, item, hook);
 2451                 break;
 2452         case NGQF_FN:
 2453         case NGQF_FN2:
 2454                 /*
 2455                  * In the case of the shutdown message we allow it to hit
 2456                  * even if the node is invalid.
 2457                  */
 2458                 if (NG_NODE_NOT_VALID(node) &&
 2459                     NGI_FN(item) != &ng_rmnode) {
 2460                         TRAP_ERROR();
 2461                         error = EINVAL;
 2462                         NG_FREE_ITEM(item);
 2463                         break;
 2464                 }
 2465                 /* Same is about some internal functions and invalid hook. */
 2466                 if (hook && NG_HOOK_NOT_VALID(hook) &&
 2467                     NGI_FN2(item) != &ng_con_part2 &&
 2468                     NGI_FN2(item) != &ng_con_part3 &&
 2469                     NGI_FN(item) != &ng_rmhook_part2) {
 2470                         TRAP_ERROR();
 2471                         error = EINVAL;
 2472                         NG_FREE_ITEM(item);
 2473                         break;
 2474                 }
 2475                 
 2476                 if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
 2477                         (*NGI_FN(item))(node, hook, NGI_ARG1(item),
 2478                             NGI_ARG2(item));
 2479                         NG_FREE_ITEM(item);
 2480                 } else  /* it is NGQF_FN2 */
 2481                         error = (*NGI_FN2(item))(node, item, hook);
 2482                 break;
 2483         }
 2484         /*
 2485          * We held references on some of the resources
 2486          * that we took from the item. Now that we have
 2487          * finished doing everything, drop those references.
 2488          */
 2489         if (hook)
 2490                 NG_HOOK_UNREF(hook);
 2491 
 2492         if (rw == NGQRW_R)
 2493                 ng_leave_read(node);
 2494         else
 2495                 ng_leave_write(node);
 2496 
 2497         /* Apply callback. */
 2498         if (apply != NULL) {
 2499                 if (depth == 1 && error != 0)
 2500                         apply->error = error;
 2501                 if (refcount_release(&apply->refs))
 2502                         (*apply->apply)(apply->context, apply->error);
 2503         }
 2504 
 2505         return (error);
 2506 }
 2507 
 2508 /***********************************************************************
 2509  * Implement the 'generic' control messages
 2510  ***********************************************************************/
 2511 static int
 2512 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
 2513 {
 2514         int error = 0;
 2515         struct ng_mesg *msg;
 2516         struct ng_mesg *resp = NULL;
 2517 
 2518         NGI_GET_MSG(item, msg);
 2519         if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
 2520                 TRAP_ERROR();
 2521                 error = EINVAL;
 2522                 goto out;
 2523         }
 2524         switch (msg->header.cmd) {
 2525         case NGM_SHUTDOWN:
 2526                 ng_rmnode(here, NULL, NULL, 0);
 2527                 break;
 2528         case NGM_MKPEER:
 2529             {
 2530                 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
 2531 
 2532                 if (msg->header.arglen != sizeof(*mkp)) {
 2533                         TRAP_ERROR();
 2534                         error = EINVAL;
 2535                         break;
 2536                 }
 2537                 mkp->type[sizeof(mkp->type) - 1] = '\0';
 2538                 mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
 2539                 mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
 2540                 error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
 2541                 break;
 2542             }
 2543         case NGM_CONNECT:
 2544             {
 2545                 struct ngm_connect *const con =
 2546                         (struct ngm_connect *) msg->data;
 2547                 node_p node2;
 2548 
 2549                 if (msg->header.arglen != sizeof(*con)) {
 2550                         TRAP_ERROR();
 2551                         error = EINVAL;
 2552                         break;
 2553                 }
 2554                 con->path[sizeof(con->path) - 1] = '\0';
 2555                 con->ourhook[sizeof(con->ourhook) - 1] = '\0';
 2556                 con->peerhook[sizeof(con->peerhook) - 1] = '\0';
 2557                 /* Don't forget we get a reference.. */
 2558                 error = ng_path2noderef(here, con->path, &node2, NULL);
 2559                 if (error)
 2560                         break;
 2561                 error = ng_con_nodes(item, here, con->ourhook,
 2562                     node2, con->peerhook);
 2563                 NG_NODE_UNREF(node2);
 2564                 break;
 2565             }
 2566         case NGM_NAME:
 2567             {
 2568                 struct ngm_name *const nam = (struct ngm_name *) msg->data;
 2569 
 2570                 if (msg->header.arglen != sizeof(*nam)) {
 2571                         TRAP_ERROR();
 2572                         error = EINVAL;
 2573                         break;
 2574                 }
 2575                 nam->name[sizeof(nam->name) - 1] = '\0';
 2576                 error = ng_name_node(here, nam->name);
 2577                 break;
 2578             }
 2579         case NGM_RMHOOK:
 2580             {
 2581                 struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
 2582                 hook_p hook;
 2583 
 2584                 if (msg->header.arglen != sizeof(*rmh)) {
 2585                         TRAP_ERROR();
 2586                         error = EINVAL;
 2587                         break;
 2588                 }
 2589                 rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
 2590                 if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
 2591                         ng_destroy_hook(hook);
 2592                 break;
 2593             }
 2594         case NGM_NODEINFO:
 2595             {
 2596                 struct nodeinfo *ni;
 2597 
 2598                 NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
 2599                 if (resp == NULL) {
 2600                         error = ENOMEM;
 2601                         break;
 2602                 }
 2603 
 2604                 /* Fill in node info */
 2605                 ni = (struct nodeinfo *) resp->data;
 2606                 if (NG_NODE_HAS_NAME(here))
 2607                         strcpy(ni->name, NG_NODE_NAME(here));
 2608                 strcpy(ni->type, here->nd_type->name);
 2609                 ni->id = ng_node2ID(here);
 2610                 ni->hooks = here->nd_numhooks;
 2611                 break;
 2612             }
 2613         case NGM_LISTHOOKS:
 2614             {
 2615                 const int nhooks = here->nd_numhooks;
 2616                 struct hooklist *hl;
 2617                 struct nodeinfo *ni;
 2618                 hook_p hook;
 2619 
 2620                 /* Get response struct */
 2621                 NG_MKRESPONSE(resp, msg, sizeof(*hl) +
 2622                     (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
 2623                 if (resp == NULL) {
 2624                         error = ENOMEM;
 2625                         break;
 2626                 }
 2627                 hl = (struct hooklist *) resp->data;
 2628                 ni = &hl->nodeinfo;
 2629 
 2630                 /* Fill in node info */
 2631                 if (NG_NODE_HAS_NAME(here))
 2632                         strcpy(ni->name, NG_NODE_NAME(here));
 2633                 strcpy(ni->type, here->nd_type->name);
 2634                 ni->id = ng_node2ID(here);
 2635 
 2636                 /* Cycle through the linked list of hooks */
 2637                 ni->hooks = 0;
 2638                 LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
 2639                         struct linkinfo *const link = &hl->link[ni->hooks];
 2640 
 2641                         if (ni->hooks >= nhooks) {
 2642                                 log(LOG_ERR, "%s: number of %s changed\n",
 2643                                     __func__, "hooks");
 2644                                 break;
 2645                         }
 2646                         if (NG_HOOK_NOT_VALID(hook))
 2647                                 continue;
 2648                         strcpy(link->ourhook, NG_HOOK_NAME(hook));
 2649                         strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
 2650                         if (NG_PEER_NODE_NAME(hook)[0] != '\0')
 2651                                 strcpy(link->nodeinfo.name,
 2652                                     NG_PEER_NODE_NAME(hook));
 2653                         strcpy(link->nodeinfo.type,
 2654                            NG_PEER_NODE(hook)->nd_type->name);
 2655                         link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
 2656                         link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
 2657                         ni->hooks++;
 2658                 }
 2659                 break;
 2660             }
 2661 
 2662         case NGM_LISTNODES:
 2663             {
 2664                 struct namelist *nl;
 2665                 node_p node;
 2666                 int i;
 2667 
 2668                 IDHASH_RLOCK();
 2669                 /* Get response struct. */
 2670                 NG_MKRESPONSE(resp, msg, sizeof(*nl) +
 2671                     (V_ng_nodes * sizeof(struct nodeinfo)), M_NOWAIT);
 2672                 if (resp == NULL) {
 2673                         IDHASH_RUNLOCK();
 2674                         error = ENOMEM;
 2675                         break;
 2676                 }
 2677                 nl = (struct namelist *) resp->data;
 2678 
 2679                 /* Cycle through the lists of nodes. */
 2680                 nl->numnames = 0;
 2681                 for (i = 0; i <= V_ng_ID_hmask; i++) {
 2682                         LIST_FOREACH(node, &V_ng_ID_hash[i], nd_idnodes) {
 2683                                 struct nodeinfo *const np =
 2684                                     &nl->nodeinfo[nl->numnames];
 2685 
 2686                                 if (NG_NODE_NOT_VALID(node))
 2687                                         continue;
 2688                                 if (NG_NODE_HAS_NAME(node))
 2689                                         strcpy(np->name, NG_NODE_NAME(node));
 2690                                 strcpy(np->type, node->nd_type->name);
 2691                                 np->id = ng_node2ID(node);
 2692                                 np->hooks = node->nd_numhooks;
 2693                                 KASSERT(nl->numnames < V_ng_nodes,
 2694                                     ("%s: no space", __func__));
 2695                                 nl->numnames++;
 2696                         }
 2697                 }
 2698                 IDHASH_RUNLOCK();
 2699                 break;
 2700             }
 2701         case NGM_LISTNAMES:
 2702             {
 2703                 struct namelist *nl;
 2704                 node_p node;
 2705                 int i;
 2706 
 2707                 NAMEHASH_RLOCK();
 2708                 /* Get response struct. */
 2709                 NG_MKRESPONSE(resp, msg, sizeof(*nl) +
 2710                     (V_ng_named_nodes * sizeof(struct nodeinfo)), M_NOWAIT);
 2711                 if (resp == NULL) {
 2712                         NAMEHASH_RUNLOCK();
 2713                         error = ENOMEM;
 2714                         break;
 2715                 }
 2716                 nl = (struct namelist *) resp->data;
 2717 
 2718                 /* Cycle through the lists of nodes. */
 2719                 nl->numnames = 0;
 2720                 for (i = 0; i <= V_ng_name_hmask; i++) {
 2721                         LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
 2722                                 struct nodeinfo *const np =
 2723                                     &nl->nodeinfo[nl->numnames];
 2724 
 2725                                 if (NG_NODE_NOT_VALID(node))
 2726                                         continue;
 2727                                 strcpy(np->name, NG_NODE_NAME(node));
 2728                                 strcpy(np->type, node->nd_type->name);
 2729                                 np->id = ng_node2ID(node);
 2730                                 np->hooks = node->nd_numhooks;
 2731                                 KASSERT(nl->numnames < V_ng_named_nodes,
 2732                                     ("%s: no space", __func__));
 2733                                 nl->numnames++;
 2734                         }
 2735                 }
 2736                 NAMEHASH_RUNLOCK();
 2737                 break;
 2738             }
 2739 
 2740         case NGM_LISTTYPES:
 2741             {
 2742                 struct typelist *tl;
 2743                 struct ng_type *type;
 2744                 int num = 0;
 2745 
 2746                 TYPELIST_RLOCK();
 2747                 /* Count number of types */
 2748                 LIST_FOREACH(type, &ng_typelist, types)
 2749                         num++;
 2750 
 2751                 /* Get response struct */
 2752                 NG_MKRESPONSE(resp, msg, sizeof(*tl) +
 2753                     (num * sizeof(struct typeinfo)), M_NOWAIT);
 2754                 if (resp == NULL) {
 2755                         TYPELIST_RUNLOCK();
 2756                         error = ENOMEM;
 2757                         break;
 2758                 }
 2759                 tl = (struct typelist *) resp->data;
 2760 
 2761                 /* Cycle through the linked list of types */
 2762                 tl->numtypes = 0;
 2763                 LIST_FOREACH(type, &ng_typelist, types) {
 2764                         struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
 2765 
 2766                         strcpy(tp->type_name, type->name);
 2767                         tp->numnodes = type->refs - 1; /* don't count list */
 2768                         KASSERT(tl->numtypes < num, ("%s: no space", __func__));
 2769                         tl->numtypes++;
 2770                 }
 2771                 TYPELIST_RUNLOCK();
 2772                 break;
 2773             }
 2774 
 2775         case NGM_BINARY2ASCII:
 2776             {
 2777                 int bufSize = 1024;
 2778                 const struct ng_parse_type *argstype;
 2779                 const struct ng_cmdlist *c;
 2780                 struct ng_mesg *binary, *ascii;
 2781 
 2782                 /* Data area must contain a valid netgraph message */
 2783                 binary = (struct ng_mesg *)msg->data;
 2784                 if (msg->header.arglen < sizeof(struct ng_mesg) ||
 2785                     (msg->header.arglen - sizeof(struct ng_mesg) <
 2786                     binary->header.arglen)) {
 2787                         TRAP_ERROR();
 2788                         error = EINVAL;
 2789                         break;
 2790                 }
 2791 retry_b2a:
 2792                 /* Get a response message with lots of room */
 2793                 NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
 2794                 if (resp == NULL) {
 2795                         error = ENOMEM;
 2796                         break;
 2797                 }
 2798                 ascii = (struct ng_mesg *)resp->data;
 2799 
 2800                 /* Copy binary message header to response message payload */
 2801                 bcopy(binary, ascii, sizeof(*binary));
 2802 
 2803                 /* Find command by matching typecookie and command number */
 2804                 for (c = here->nd_type->cmdlist; c != NULL && c->name != NULL;
 2805                     c++) {
 2806                         if (binary->header.typecookie == c->cookie &&
 2807                             binary->header.cmd == c->cmd)
 2808                                 break;
 2809                 }
 2810                 if (c == NULL || c->name == NULL) {
 2811                         for (c = ng_generic_cmds; c->name != NULL; c++) {
 2812                                 if (binary->header.typecookie == c->cookie &&
 2813                                     binary->header.cmd == c->cmd)
 2814                                         break;
 2815                         }
 2816                         if (c->name == NULL) {
 2817                                 NG_FREE_MSG(resp);
 2818                                 error = ENOSYS;
 2819                                 break;
 2820                         }
 2821                 }
 2822 
 2823                 /* Convert command name to ASCII */
 2824                 snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
 2825                     "%s", c->name);
 2826 
 2827                 /* Convert command arguments to ASCII */
 2828                 argstype = (binary->header.flags & NGF_RESP) ?
 2829                     c->respType : c->mesgType;
 2830                 if (argstype == NULL) {
 2831                         *ascii->data = '\0';
 2832                 } else {
 2833                         error = ng_unparse(argstype, (u_char *)binary->data,
 2834                             ascii->data, bufSize);
 2835                         if (error == ERANGE) {
 2836                                 NG_FREE_MSG(resp);
 2837                                 bufSize *= 2;
 2838                                 goto retry_b2a;
 2839                         } else if (error) {
 2840                                 NG_FREE_MSG(resp);
 2841                                 break;
 2842                         }
 2843                 }
 2844 
 2845                 /* Return the result as struct ng_mesg plus ASCII string */
 2846                 bufSize = strlen(ascii->data) + 1;
 2847                 ascii->header.arglen = bufSize;
 2848                 resp->header.arglen = sizeof(*ascii) + bufSize;
 2849                 break;
 2850             }
 2851 
 2852         case NGM_ASCII2BINARY:
 2853             {
 2854                 int bufSize = 20 * 1024;        /* XXX hard coded constant */
 2855                 const struct ng_cmdlist *c;
 2856                 const struct ng_parse_type *argstype;
 2857                 struct ng_mesg *ascii, *binary;
 2858                 int off = 0;
 2859 
 2860                 /* Data area must contain at least a struct ng_mesg + '\0' */
 2861                 ascii = (struct ng_mesg *)msg->data;
 2862                 if ((msg->header.arglen < sizeof(*ascii) + 1) ||
 2863                     (ascii->header.arglen < 1) ||
 2864                     (msg->header.arglen < sizeof(*ascii) +
 2865                     ascii->header.arglen)) {
 2866                         TRAP_ERROR();
 2867                         error = EINVAL;
 2868                         break;
 2869                 }
 2870                 ascii->data[ascii->header.arglen - 1] = '\0';
 2871 
 2872                 /* Get a response message with lots of room */
 2873                 NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
 2874                 if (resp == NULL) {
 2875                         error = ENOMEM;
 2876                         break;
 2877                 }
 2878                 binary = (struct ng_mesg *)resp->data;
 2879 
 2880                 /* Copy ASCII message header to response message payload */
 2881                 bcopy(ascii, binary, sizeof(*ascii));
 2882 
 2883                 /* Find command by matching ASCII command string */
 2884                 for (c = here->nd_type->cmdlist;
 2885                     c != NULL && c->name != NULL; c++) {
 2886                         if (strcmp(ascii->header.cmdstr, c->name) == 0)
 2887                                 break;
 2888                 }
 2889                 if (c == NULL || c->name == NULL) {
 2890                         for (c = ng_generic_cmds; c->name != NULL; c++) {
 2891                                 if (strcmp(ascii->header.cmdstr, c->name) == 0)
 2892                                         break;
 2893                         }
 2894                         if (c->name == NULL) {
 2895                                 NG_FREE_MSG(resp);
 2896                                 error = ENOSYS;
 2897                                 break;
 2898                         }
 2899                 }
 2900 
 2901                 /* Convert command name to binary */
 2902                 binary->header.cmd = c->cmd;
 2903                 binary->header.typecookie = c->cookie;
 2904 
 2905                 /* Convert command arguments to binary */
 2906                 argstype = (binary->header.flags & NGF_RESP) ?
 2907                     c->respType : c->mesgType;
 2908                 if (argstype == NULL) {
 2909                         bufSize = 0;
 2910                 } else {
 2911                         if ((error = ng_parse(argstype, ascii->data, &off,
 2912                             (u_char *)binary->data, &bufSize)) != 0) {
 2913                                 NG_FREE_MSG(resp);
 2914                                 break;
 2915                         }
 2916                 }
 2917 
 2918                 /* Return the result */
 2919                 binary->header.arglen = bufSize;
 2920                 resp->header.arglen = sizeof(*binary) + bufSize;
 2921                 break;
 2922             }
 2923 
 2924         case NGM_TEXT_CONFIG:
 2925         case NGM_TEXT_STATUS:
 2926                 /*
 2927                  * This one is tricky as it passes the command down to the
 2928                  * actual node, even though it is a generic type command.
 2929                  * This means we must assume that the item/msg is already freed
 2930                  * when control passes back to us.
 2931                  */
 2932                 if (here->nd_type->rcvmsg != NULL) {
 2933                         NGI_MSG(item) = msg; /* put it back as we found it */
 2934                         return((*here->nd_type->rcvmsg)(here, item, lasthook));
 2935                 }
 2936                 /* Fall through if rcvmsg not supported */
 2937         default:
 2938                 TRAP_ERROR();
 2939                 error = EINVAL;
 2940         }
 2941         /*
 2942          * Sometimes a generic message may be statically allocated
 2943          * to avoid problems with allocating when in tight memory situations.
 2944          * Don't free it if it is so.
 2945          * I break them apart here, because erros may cause a free if the item
 2946          * in which case we'd be doing it twice.
 2947          * they are kept together above, to simplify freeing.
 2948          */
 2949 out:
 2950         NG_RESPOND_MSG(error, here, item, resp);
 2951         NG_FREE_MSG(msg);
 2952         return (error);
 2953 }
 2954 
 2955 /************************************************************************
 2956                         Queue element get/free routines
 2957 ************************************************************************/
 2958 
 2959 uma_zone_t                      ng_qzone;
 2960 uma_zone_t                      ng_qdzone;
 2961 static int                      numthreads = 0; /* number of queue threads */
 2962 static int                      maxalloc = 4096;/* limit the damage of a leak */
 2963 static int                      maxdata = 4096; /* limit the damage of a DoS */
 2964 
 2965 SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
 2966     0, "Number of queue processing threads");
 2967 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
 2968     0, "Maximum number of non-data queue items to allocate");
 2969 SYSCTL_INT(_net_graph, OID_AUTO, maxdata, CTLFLAG_RDTUN, &maxdata,
 2970     0, "Maximum number of data queue items to allocate");
 2971 
 2972 #ifdef  NETGRAPH_DEBUG
 2973 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
 2974 static int allocated;   /* number of items malloc'd */
 2975 #endif
 2976 
 2977 /*
 2978  * Get a queue entry.
 2979  * This is usually called when a packet first enters netgraph.
 2980  * By definition, this is usually from an interrupt, or from a user.
 2981  * Users are not so important, but try be quick for the times that it's
 2982  * an interrupt.
 2983  */
 2984 static __inline item_p
 2985 ng_alloc_item(int type, int flags)
 2986 {
 2987         item_p item;
 2988 
 2989         KASSERT(((type & ~NGQF_TYPE) == 0),
 2990             ("%s: incorrect item type: %d", __func__, type));
 2991 
 2992         item = uma_zalloc((type == NGQF_DATA) ? ng_qdzone : ng_qzone,
 2993             ((flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT) | M_ZERO);
 2994 
 2995         if (item) {
 2996                 item->el_flags = type;
 2997 #ifdef  NETGRAPH_DEBUG
 2998                 mtx_lock(&ngq_mtx);
 2999                 TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
 3000                 allocated++;
 3001                 mtx_unlock(&ngq_mtx);
 3002 #endif
 3003         }
 3004 
 3005         return (item);
 3006 }
 3007 
 3008 /*
 3009  * Release a queue entry
 3010  */
 3011 void
 3012 ng_free_item(item_p item)
 3013 {
 3014         /*
 3015          * The item may hold resources on its own. We need to free
 3016          * these before we can free the item. What they are depends upon
 3017          * what kind of item it is. it is important that nodes zero
 3018          * out pointers to resources that they remove from the item
 3019          * or we release them again here.
 3020          */
 3021         switch (item->el_flags & NGQF_TYPE) {
 3022         case NGQF_DATA:
 3023                 /* If we have an mbuf still attached.. */
 3024                 NG_FREE_M(_NGI_M(item));
 3025                 break;
 3026         case NGQF_MESG:
 3027                 _NGI_RETADDR(item) = 0;
 3028                 NG_FREE_MSG(_NGI_MSG(item));
 3029                 break;
 3030         case NGQF_FN:
 3031         case NGQF_FN2:
 3032                 /* nothing to free really, */
 3033                 _NGI_FN(item) = NULL;
 3034                 _NGI_ARG1(item) = NULL;
 3035                 _NGI_ARG2(item) = 0;
 3036                 break;
 3037         }
 3038         /* If we still have a node or hook referenced... */
 3039         _NGI_CLR_NODE(item);
 3040         _NGI_CLR_HOOK(item);
 3041 
 3042 #ifdef  NETGRAPH_DEBUG
 3043         mtx_lock(&ngq_mtx);
 3044         TAILQ_REMOVE(&ng_itemlist, item, all);
 3045         allocated--;
 3046         mtx_unlock(&ngq_mtx);
 3047 #endif
 3048         uma_zfree(((item->el_flags & NGQF_TYPE) == NGQF_DATA) ?
 3049             ng_qdzone : ng_qzone, item);
 3050 }
 3051 
 3052 /*
 3053  * Change type of the queue entry.
 3054  * Possibly reallocates it from another UMA zone.
 3055  */
 3056 static __inline item_p
 3057 ng_realloc_item(item_p pitem, int type, int flags)
 3058 {
 3059         item_p item;
 3060         int from, to;
 3061 
 3062         KASSERT((pitem != NULL), ("%s: can't reallocate NULL", __func__));
 3063         KASSERT(((type & ~NGQF_TYPE) == 0),
 3064             ("%s: incorrect item type: %d", __func__, type));
 3065 
 3066         from = ((pitem->el_flags & NGQF_TYPE) == NGQF_DATA);
 3067         to = (type == NGQF_DATA);
 3068         if (from != to) {
 3069                 /* If reallocation is required do it and copy item. */
 3070                 if ((item = ng_alloc_item(type, flags)) == NULL) {
 3071                         ng_free_item(pitem);
 3072                         return (NULL);
 3073                 }
 3074                 *item = *pitem;
 3075                 ng_free_item(pitem);
 3076         } else
 3077                 item = pitem;
 3078         item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
 3079 
 3080         return (item);
 3081 }
 3082 
 3083 /************************************************************************
 3084                         Module routines
 3085 ************************************************************************/
 3086 
 3087 /*
 3088  * Handle the loading/unloading of a netgraph node type module
 3089  */
 3090 int
 3091 ng_mod_event(module_t mod, int event, void *data)
 3092 {
 3093         struct ng_type *const type = data;
 3094         int error = 0;
 3095 
 3096         switch (event) {
 3097         case MOD_LOAD:
 3098 
 3099                 /* Register new netgraph node type */
 3100                 if ((error = ng_newtype(type)) != 0)
 3101                         break;
 3102 
 3103                 /* Call type specific code */
 3104                 if (type->mod_event != NULL)
 3105                         if ((error = (*type->mod_event)(mod, event, data))) {
 3106                                 TYPELIST_WLOCK();
 3107                                 type->refs--;   /* undo it */
 3108                                 LIST_REMOVE(type, types);
 3109                                 TYPELIST_WUNLOCK();
 3110                         }
 3111                 break;
 3112 
 3113         case MOD_UNLOAD:
 3114                 if (type->refs > 1) {           /* make sure no nodes exist! */
 3115                         error = EBUSY;
 3116                 } else {
 3117                         if (type->refs == 0) /* failed load, nothing to undo */
 3118                                 break;
 3119                         if (type->mod_event != NULL) {  /* check with type */
 3120                                 error = (*type->mod_event)(mod, event, data);
 3121                                 if (error != 0) /* type refuses.. */
 3122                                         break;
 3123                         }
 3124                         TYPELIST_WLOCK();
 3125                         LIST_REMOVE(type, types);
 3126                         TYPELIST_WUNLOCK();
 3127                 }
 3128                 break;
 3129 
 3130         default:
 3131                 if (type->mod_event != NULL)
 3132                         error = (*type->mod_event)(mod, event, data);
 3133                 else
 3134                         error = EOPNOTSUPP;             /* XXX ? */
 3135                 break;
 3136         }
 3137         return (error);
 3138 }
 3139 
 3140 static void
 3141 vnet_netgraph_init(const void *unused __unused)
 3142 {
 3143 
 3144         /* We start with small hashes, but they can grow. */
 3145         V_ng_ID_hash = hashinit(16, M_NETGRAPH_NODE, &V_ng_ID_hmask);
 3146         V_ng_name_hash = hashinit(16, M_NETGRAPH_NODE, &V_ng_name_hmask);
 3147 }
 3148 VNET_SYSINIT(vnet_netgraph_init, SI_SUB_NETGRAPH, SI_ORDER_FIRST,
 3149     vnet_netgraph_init, NULL);
 3150 
 3151 #ifdef VIMAGE
 3152 static void
 3153 vnet_netgraph_uninit(const void *unused __unused)
 3154 {
 3155         node_p node = NULL, last_killed = NULL;
 3156         int i;
 3157 
 3158         do {
 3159                 /* Find a node to kill */
 3160                 IDHASH_RLOCK();
 3161                 for (i = 0; i <= V_ng_ID_hmask; i++) {
 3162                         LIST_FOREACH(node, &V_ng_ID_hash[i], nd_idnodes) {
 3163                                 if (node != &ng_deadnode) {
 3164                                         NG_NODE_REF(node);
 3165                                         break;
 3166                                 }
 3167                         }
 3168                         if (node != NULL)
 3169                                 break;
 3170                 }
 3171                 IDHASH_RUNLOCK();
 3172 
 3173                 /* Attempt to kill it only if it is a regular node */
 3174                 if (node != NULL) {
 3175                         if (node == last_killed) {
 3176                                 if (node->nd_flags & NGF_REALLY_DIE)
 3177                                         panic("ng node %s won't die",
 3178                                             node->nd_name);
 3179                                 /* The node persisted itself.  Try again. */
 3180                                 node->nd_flags |= NGF_REALLY_DIE;
 3181                         }
 3182                         ng_rmnode(node, NULL, NULL, 0);
 3183                         NG_NODE_UNREF(node);
 3184                         last_killed = node;
 3185                 }
 3186         } while (node != NULL);
 3187 
 3188         hashdestroy(V_ng_name_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
 3189         hashdestroy(V_ng_ID_hash, M_NETGRAPH_NODE, V_ng_ID_hmask);
 3190 }
 3191 VNET_SYSUNINIT(vnet_netgraph_uninit, SI_SUB_NETGRAPH, SI_ORDER_FIRST,
 3192     vnet_netgraph_uninit, NULL);
 3193 #endif /* VIMAGE */
 3194 
 3195 /*
 3196  * Handle loading and unloading for this code.
 3197  * The only thing we need to link into is the NETISR strucure.
 3198  */
 3199 static int
 3200 ngb_mod_event(module_t mod, int event, void *data)
 3201 {
 3202         struct proc *p;
 3203         struct thread *td;
 3204         int i, error = 0;
 3205 
 3206         switch (event) {
 3207         case MOD_LOAD:
 3208                 /* Initialize everything. */
 3209                 NG_WORKLIST_LOCK_INIT();
 3210                 rw_init(&ng_typelist_lock, "netgraph types");
 3211                 rw_init(&ng_idhash_lock, "netgraph idhash");
 3212                 rw_init(&ng_namehash_lock, "netgraph namehash");
 3213                 rw_init(&ng_topo_lock, "netgraph topology mutex");
 3214 #ifdef  NETGRAPH_DEBUG
 3215                 mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
 3216                     MTX_DEF);
 3217                 mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
 3218                     MTX_DEF);
 3219 #endif
 3220                 ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
 3221                     NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
 3222                 uma_zone_set_max(ng_qzone, maxalloc);
 3223                 ng_qdzone = uma_zcreate("NetGraph data items",
 3224                     sizeof(struct ng_item), NULL, NULL, NULL, NULL,
 3225                     UMA_ALIGN_CACHE, 0);
 3226                 uma_zone_set_max(ng_qdzone, maxdata);
 3227                 /* Autoconfigure number of threads. */
 3228                 if (numthreads <= 0)
 3229                         numthreads = mp_ncpus;
 3230                 /* Create threads. */
 3231                 p = NULL; /* start with no process */
 3232                 for (i = 0; i < numthreads; i++) {
 3233                         if (kproc_kthread_add(ngthread, NULL, &p, &td,
 3234                             RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
 3235                                 numthreads = i;
 3236                                 break;
 3237                         }
 3238                 }
 3239                 break;
 3240         case MOD_UNLOAD:
 3241                 /* You can't unload it because an interface may be using it. */
 3242                 error = EBUSY;
 3243                 break;
 3244         default:
 3245                 error = EOPNOTSUPP;
 3246                 break;
 3247         }
 3248         return (error);
 3249 }
 3250 
 3251 static moduledata_t netgraph_mod = {
 3252         "netgraph",
 3253         ngb_mod_event,
 3254         (NULL)
 3255 };
 3256 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_FIRST);
 3257 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 3258     "netgraph Family");
 3259 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_ABI_VERSION,"");
 3260 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_VERSION, "");
 3261 
 3262 #ifdef  NETGRAPH_DEBUG
 3263 void
 3264 dumphook (hook_p hook, char *file, int line)
 3265 {
 3266         printf("hook: name %s, %d refs, Last touched:\n",
 3267                 _NG_HOOK_NAME(hook), hook->hk_refs);
 3268         printf("        Last active @ %s, line %d\n",
 3269                 hook->lastfile, hook->lastline);
 3270         if (line) {
 3271                 printf(" problem discovered at file %s, line %d\n", file, line);
 3272 #ifdef KDB
 3273                 kdb_backtrace();
 3274 #endif
 3275         }
 3276 }
 3277 
 3278 void
 3279 dumpnode(node_p node, char *file, int line)
 3280 {
 3281         printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
 3282                 _NG_NODE_ID(node), node->nd_type->name,
 3283                 node->nd_numhooks, node->nd_flags,
 3284                 node->nd_refs, node->nd_name);
 3285         printf("        Last active @ %s, line %d\n",
 3286                 node->lastfile, node->lastline);
 3287         if (line) {
 3288                 printf(" problem discovered at file %s, line %d\n", file, line);
 3289 #ifdef KDB
 3290                 kdb_backtrace();
 3291 #endif
 3292         }
 3293 }
 3294 
 3295 void
 3296 dumpitem(item_p item, char *file, int line)
 3297 {
 3298         printf(" ACTIVE item, last used at %s, line %d",
 3299                 item->lastfile, item->lastline);
 3300         switch(item->el_flags & NGQF_TYPE) {
 3301         case NGQF_DATA:
 3302                 printf(" - [data]\n");
 3303                 break;
 3304         case NGQF_MESG:
 3305                 printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
 3306                 break;
 3307         case NGQF_FN:
 3308                 printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
 3309                         _NGI_FN(item),
 3310                         _NGI_NODE(item),
 3311                         _NGI_HOOK(item),
 3312                         item->body.fn.fn_arg1,
 3313                         item->body.fn.fn_arg2,
 3314                         item->body.fn.fn_arg2);
 3315                 break;
 3316         case NGQF_FN2:
 3317                 printf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
 3318                         _NGI_FN2(item),
 3319                         _NGI_NODE(item),
 3320                         _NGI_HOOK(item),
 3321                         item->body.fn.fn_arg1,
 3322                         item->body.fn.fn_arg2,
 3323                         item->body.fn.fn_arg2);
 3324                 break;
 3325         }
 3326         if (line) {
 3327                 printf(" problem discovered at file %s, line %d\n", file, line);
 3328                 if (_NGI_NODE(item)) {
 3329                         printf("node %p ([%x])\n",
 3330                                 _NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
 3331                 }
 3332         }
 3333 }
 3334 
 3335 static void
 3336 ng_dumpitems(void)
 3337 {
 3338         item_p item;
 3339         int i = 1;
 3340         TAILQ_FOREACH(item, &ng_itemlist, all) {
 3341                 printf("[%d] ", i++);
 3342                 dumpitem(item, NULL, 0);
 3343         }
 3344 }
 3345 
 3346 static void
 3347 ng_dumpnodes(void)
 3348 {
 3349         node_p node;
 3350         int i = 1;
 3351         mtx_lock(&ng_nodelist_mtx);
 3352         SLIST_FOREACH(node, &ng_allnodes, nd_all) {
 3353                 printf("[%d] ", i++);
 3354                 dumpnode(node, NULL, 0);
 3355         }
 3356         mtx_unlock(&ng_nodelist_mtx);
 3357 }
 3358 
 3359 static void
 3360 ng_dumphooks(void)
 3361 {
 3362         hook_p hook;
 3363         int i = 1;
 3364         mtx_lock(&ng_nodelist_mtx);
 3365         SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
 3366                 printf("[%d] ", i++);
 3367                 dumphook(hook, NULL, 0);
 3368         }
 3369         mtx_unlock(&ng_nodelist_mtx);
 3370 }
 3371 
 3372 static int
 3373 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
 3374 {
 3375         int error;
 3376         int val;
 3377 
 3378         val = allocated;
 3379         error = sysctl_handle_int(oidp, &val, 0, req);
 3380         if (error != 0 || req->newptr == NULL)
 3381                 return (error);
 3382         if (val == 42) {
 3383                 ng_dumpitems();
 3384                 ng_dumpnodes();
 3385                 ng_dumphooks();
 3386         }
 3387         return (0);
 3388 }
 3389 
 3390 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items,
 3391     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int),
 3392     sysctl_debug_ng_dump_items, "I",
 3393     "Number of allocated items");
 3394 #endif  /* NETGRAPH_DEBUG */
 3395 
 3396 /***********************************************************************
 3397 * Worklist routines
 3398 **********************************************************************/
 3399 /*
 3400  * Pick a node off the list of nodes with work,
 3401  * try get an item to process off it. Remove the node from the list.
 3402  */
 3403 static void
 3404 ngthread(void *arg)
 3405 {
 3406         for (;;) {
 3407                 struct epoch_tracker et;
 3408                 node_p  node;
 3409 
 3410                 /* Get node from the worklist. */
 3411                 NG_WORKLIST_LOCK();
 3412                 while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
 3413                         NG_WORKLIST_SLEEP();
 3414                 STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
 3415                 NG_WORKLIST_UNLOCK();
 3416                 CURVNET_SET(node->nd_vnet);
 3417                 CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
 3418                     __func__, node->nd_ID, node);
 3419                 /*
 3420                  * We have the node. We also take over the reference
 3421                  * that the list had on it.
 3422                  * Now process as much as you can, until it won't
 3423                  * let you have another item off the queue.
 3424                  * All this time, keep the reference
 3425                  * that lets us be sure that the node still exists.
 3426                  * Let the reference go at the last minute.
 3427                  */
 3428                 NET_EPOCH_ENTER(et);
 3429                 for (;;) {
 3430                         item_p item;
 3431                         int rw;
 3432 
 3433                         NG_QUEUE_LOCK(&node->nd_input_queue);
 3434                         item = ng_dequeue(node, &rw);
 3435                         if (item == NULL) {
 3436                                 node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
 3437                                 NG_QUEUE_UNLOCK(&node->nd_input_queue);
 3438                                 break; /* go look for another node */
 3439                         } else {
 3440                                 NG_QUEUE_UNLOCK(&node->nd_input_queue);
 3441                                 NGI_GET_NODE(item, node); /* zaps stored node */
 3442 
 3443                                 if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {
 3444                                         /*
 3445                                          * NGQF_MESG items should never be processed in
 3446                                          * NET_EPOCH context. So, temporary exit from EPOCH.
 3447                                          */
 3448                                         NET_EPOCH_EXIT(et);
 3449                                         ng_apply_item(node, item, rw);
 3450                                         NET_EPOCH_ENTER(et);
 3451                                 } else {
 3452                                         ng_apply_item(node, item, rw);
 3453                                 }
 3454 
 3455                                 NG_NODE_UNREF(node);
 3456                         }
 3457                 }
 3458                 NET_EPOCH_EXIT(et);
 3459                 NG_NODE_UNREF(node);
 3460                 CURVNET_RESTORE();
 3461         }
 3462 }
 3463 
 3464 /*
 3465  * XXX
 3466  * It's possible that a debugging NG_NODE_REF may need
 3467  * to be outside the mutex zone
 3468  */
 3469 static void
 3470 ng_worklist_add(node_p node)
 3471 {
 3472 
 3473         mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
 3474 
 3475         if ((node->nd_input_queue.q_flags2 & NGQ2_WORKQ) == 0) {
 3476                 /*
 3477                  * If we are not already on the work queue,
 3478                  * then put us on.
 3479                  */
 3480                 node->nd_input_queue.q_flags2 |= NGQ2_WORKQ;
 3481                 NG_NODE_REF(node); /* XXX safe in mutex? */
 3482                 NG_WORKLIST_LOCK();
 3483                 STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
 3484                 NG_WORKLIST_UNLOCK();
 3485                 CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
 3486                     node->nd_ID, node);
 3487                 NG_WORKLIST_WAKEUP();
 3488         } else {
 3489                 CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
 3490                     __func__, node->nd_ID, node);
 3491         }
 3492 }
 3493 
 3494 /***********************************************************************
 3495 * Externally useable functions to set up a queue item ready for sending
 3496 ***********************************************************************/
 3497 
 3498 #ifdef  NETGRAPH_DEBUG
 3499 #define ITEM_DEBUG_CHECKS                                               \
 3500         do {                                                            \
 3501                 if (NGI_NODE(item) ) {                                  \
 3502                         printf("item already has node");                \
 3503                         kdb_enter(KDB_WHY_NETGRAPH, "has node");        \
 3504                         NGI_CLR_NODE(item);                             \
 3505                 }                                                       \
 3506                 if (NGI_HOOK(item) ) {                                  \
 3507                         printf("item already has hook");                \
 3508                         kdb_enter(KDB_WHY_NETGRAPH, "has hook");        \
 3509                         NGI_CLR_HOOK(item);                             \
 3510                 }                                                       \
 3511         } while (0)
 3512 #else
 3513 #define ITEM_DEBUG_CHECKS
 3514 #endif
 3515 
 3516 /*
 3517  * Put mbuf into the item.
 3518  * Hook and node references will be removed when the item is dequeued.
 3519  * (or equivalent)
 3520  * (XXX) Unsafe because no reference held by peer on remote node.
 3521  * remote node might go away in this timescale.
 3522  * We know the hooks can't go away because that would require getting
 3523  * a writer item on both nodes and we must have at least a  reader
 3524  * here to be able to do this.
 3525  * Note that the hook loaded is the REMOTE hook.
 3526  *
 3527  * This is possibly in the critical path for new data.
 3528  */
 3529 item_p
 3530 ng_package_data(struct mbuf *m, int flags)
 3531 {
 3532         item_p item;
 3533 
 3534         if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
 3535                 NG_FREE_M(m);
 3536                 return (NULL);
 3537         }
 3538         ITEM_DEBUG_CHECKS;
 3539         item->el_flags |= NGQF_READER;
 3540         NGI_M(item) = m;
 3541         return (item);
 3542 }
 3543 
 3544 /*
 3545  * Allocate a queue item and put items into it..
 3546  * Evaluate the address as this will be needed to queue it and
 3547  * to work out what some of the fields should be.
 3548  * Hook and node references will be removed when the item is dequeued.
 3549  * (or equivalent)
 3550  */
 3551 item_p
 3552 ng_package_msg(struct ng_mesg *msg, int flags)
 3553 {
 3554         item_p item;
 3555 
 3556         if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
 3557                 NG_FREE_MSG(msg);
 3558                 return (NULL);
 3559         }
 3560         ITEM_DEBUG_CHECKS;
 3561         /* Messages items count as writers unless explicitly exempted. */
 3562         if (msg->header.cmd & NGM_READONLY)
 3563                 item->el_flags |= NGQF_READER;
 3564         else
 3565                 item->el_flags |= NGQF_WRITER;
 3566         /*
 3567          * Set the current lasthook into the queue item
 3568          */
 3569         NGI_MSG(item) = msg;
 3570         NGI_RETADDR(item) = 0;
 3571         return (item);
 3572 }
 3573 
 3574 #define SET_RETADDR(item, here, retaddr)                                \
 3575         do {    /* Data or fn items don't have retaddrs */              \
 3576                 if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {        \
 3577                         if (retaddr) {                                  \
 3578                                 NGI_RETADDR(item) = retaddr;            \
 3579                         } else {                                        \
 3580                                 /*                                      \
 3581                                  * The old return address should be ok. \
 3582                                  * If there isn't one, use the address  \
 3583                                  * here.                                \
 3584                                  */                                     \
 3585                                 if (NGI_RETADDR(item) == 0) {           \
 3586                                         NGI_RETADDR(item)               \
 3587                                                 = ng_node2ID(here);     \
 3588                                 }                                       \
 3589                         }                                               \
 3590                 }                                                       \
 3591         } while (0)
 3592 
 3593 int
 3594 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
 3595 {
 3596         hook_p peer;
 3597         node_p peernode;
 3598         ITEM_DEBUG_CHECKS;
 3599         /*
 3600          * Quick sanity check..
 3601          * Since a hook holds a reference on its node, once we know
 3602          * that the peer is still connected (even if invalid,) we know
 3603          * that the peer node is present, though maybe invalid.
 3604          */
 3605         TOPOLOGY_RLOCK();
 3606         if ((hook == NULL) || NG_HOOK_NOT_VALID(hook) ||
 3607             NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
 3608             NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
 3609                 NG_FREE_ITEM(item);
 3610                 TRAP_ERROR();
 3611                 TOPOLOGY_RUNLOCK();
 3612                 return (ENETDOWN);
 3613         }
 3614 
 3615         /*
 3616          * Transfer our interest to the other (peer) end.
 3617          */
 3618         NG_HOOK_REF(peer);
 3619         NG_NODE_REF(peernode);
 3620         NGI_SET_HOOK(item, peer);
 3621         NGI_SET_NODE(item, peernode);
 3622         SET_RETADDR(item, here, retaddr);
 3623 
 3624         TOPOLOGY_RUNLOCK();
 3625 
 3626         return (0);
 3627 }
 3628 
 3629 int
 3630 ng_address_path(node_p here, item_p item, const char *address, ng_ID_t retaddr)
 3631 {
 3632         node_p  dest = NULL;
 3633         hook_p  hook = NULL;
 3634         int     error;
 3635 
 3636         ITEM_DEBUG_CHECKS;
 3637         /*
 3638          * Note that ng_path2noderef increments the reference count
 3639          * on the node for us if it finds one. So we don't have to.
 3640          */
 3641         error = ng_path2noderef(here, address, &dest, &hook);
 3642         if (error) {
 3643                 NG_FREE_ITEM(item);
 3644                 return (error);
 3645         }
 3646         NGI_SET_NODE(item, dest);
 3647         if (hook)
 3648                 NGI_SET_HOOK(item, hook);
 3649 
 3650         SET_RETADDR(item, here, retaddr);
 3651         return (0);
 3652 }
 3653 
 3654 int
 3655 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
 3656 {
 3657         node_p dest;
 3658 
 3659         ITEM_DEBUG_CHECKS;
 3660         /*
 3661          * Find the target node.
 3662          */
 3663         dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
 3664         if (dest == NULL) {
 3665                 NG_FREE_ITEM(item);
 3666                 TRAP_ERROR();
 3667                 return(EINVAL);
 3668         }
 3669         /* Fill out the contents */
 3670         NGI_SET_NODE(item, dest);
 3671         NGI_CLR_HOOK(item);
 3672         SET_RETADDR(item, here, retaddr);
 3673         return (0);
 3674 }
 3675 
 3676 /*
 3677  * special case to send a message to self (e.g. destroy node)
 3678  * Possibly indicate an arrival hook too.
 3679  * Useful for removing that hook :-)
 3680  */
 3681 item_p
 3682 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
 3683 {
 3684         item_p item;
 3685 
 3686         /*
 3687          * Find the target node.
 3688          * If there is a HOOK argument, then use that in preference
 3689          * to the address.
 3690          */
 3691         if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
 3692                 NG_FREE_MSG(msg);
 3693                 return (NULL);
 3694         }
 3695 
 3696         /* Fill out the contents */
 3697         item->el_flags |= NGQF_WRITER;
 3698         NG_NODE_REF(here);
 3699         NGI_SET_NODE(item, here);
 3700         if (hook) {
 3701                 NG_HOOK_REF(hook);
 3702                 NGI_SET_HOOK(item, hook);
 3703         }
 3704         NGI_MSG(item) = msg;
 3705         NGI_RETADDR(item) = ng_node2ID(here);
 3706         return (item);
 3707 }
 3708 
 3709 /*
 3710  * Send ng_item_fn function call to the specified node.
 3711  */
 3712 
 3713 int
 3714 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
 3715 {
 3716 
 3717         return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
 3718 }
 3719 
 3720 int
 3721 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
 3722         int flags)
 3723 {
 3724         item_p item;
 3725 
 3726         if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
 3727                 return (ENOMEM);
 3728         }
 3729         item->el_flags |= NGQF_WRITER;
 3730         NG_NODE_REF(node); /* and one for the item */
 3731         NGI_SET_NODE(item, node);
 3732         if (hook) {
 3733                 NG_HOOK_REF(hook);
 3734                 NGI_SET_HOOK(item, hook);
 3735         }
 3736         NGI_FN(item) = fn;
 3737         NGI_ARG1(item) = arg1;
 3738         NGI_ARG2(item) = arg2;
 3739         return(ng_snd_item(item, flags));
 3740 }
 3741 
 3742 /*
 3743  * Send ng_item_fn2 function call to the specified node.
 3744  *
 3745  * If an optional pitem parameter is supplied, its apply
 3746  * callback will be copied to the new item. If also NG_REUSE_ITEM
 3747  * flag is set, no new item will be allocated, but pitem will
 3748  * be used.
 3749  */
 3750 int
 3751 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
 3752         int arg2, int flags)
 3753 {
 3754         item_p item;
 3755 
 3756         KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
 3757             ("%s: NG_REUSE_ITEM but no pitem", __func__));
 3758 
 3759         /*
 3760          * Allocate a new item if no supplied or
 3761          * if we can't use supplied one.
 3762          */
 3763         if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
 3764                 if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
 3765                         return (ENOMEM);
 3766                 if (pitem != NULL)
 3767                         item->apply = pitem->apply;
 3768         } else {
 3769                 if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
 3770                         return (ENOMEM);
 3771         }
 3772 
 3773         item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
 3774         NG_NODE_REF(node); /* and one for the item */
 3775         NGI_SET_NODE(item, node);
 3776         if (hook) {
 3777                 NG_HOOK_REF(hook);
 3778                 NGI_SET_HOOK(item, hook);
 3779         }
 3780         NGI_FN2(item) = fn;
 3781         NGI_ARG1(item) = arg1;
 3782         NGI_ARG2(item) = arg2;
 3783         return(ng_snd_item(item, flags));
 3784 }
 3785 
 3786 /*
 3787  * Official timeout routines for Netgraph nodes.
 3788  */
 3789 static void
 3790 ng_callout_trampoline(void *arg)
 3791 {
 3792         struct epoch_tracker et;
 3793         item_p item = arg;
 3794 
 3795         NET_EPOCH_ENTER(et);
 3796         CURVNET_SET(NGI_NODE(item)->nd_vnet);
 3797         ng_snd_item(item, 0);
 3798         CURVNET_RESTORE();
 3799         NET_EPOCH_EXIT(et);
 3800 }
 3801 
 3802 int
 3803 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
 3804     ng_item_fn *fn, void * arg1, int arg2)
 3805 {
 3806         item_p item, oitem;
 3807 
 3808         if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
 3809                 return (ENOMEM);
 3810 
 3811         item->el_flags |= NGQF_WRITER;
 3812         NG_NODE_REF(node);              /* and one for the item */
 3813         NGI_SET_NODE(item, node);
 3814         if (hook) {
 3815                 NG_HOOK_REF(hook);
 3816                 NGI_SET_HOOK(item, hook);
 3817         }
 3818         NGI_FN(item) = fn;
 3819         NGI_ARG1(item) = arg1;
 3820         NGI_ARG2(item) = arg2;
 3821         oitem = c->c_arg;
 3822         if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
 3823             oitem != NULL)
 3824                 NG_FREE_ITEM(oitem);
 3825         return (0);
 3826 }
 3827 
 3828 /*
 3829  * Free references and item if callout_stop/callout_drain returned 1,
 3830  * meaning that callout was successfully stopped and now references
 3831  * belong to us.
 3832  */
 3833 static void
 3834 ng_uncallout_internal(struct callout *c, node_p node)
 3835 {
 3836         item_p item;
 3837 
 3838         item = c->c_arg;
 3839         if ((c->c_func == &ng_callout_trampoline) &&
 3840             (item != NULL) && (NGI_NODE(item) == node)) {
 3841                 /*
 3842                  * We successfully removed it from the queue before it ran
 3843                  * So now we need to unreference everything that was
 3844                  * given extra references. (NG_FREE_ITEM does this).
 3845                  */
 3846                 NG_FREE_ITEM(item);
 3847         }
 3848         c->c_arg = NULL;
 3849 }
 3850 
 3851 
 3852 /* A special modified version of callout_stop() */
 3853 int
 3854 ng_uncallout(struct callout *c, node_p node)
 3855 {
 3856         int rval;
 3857 
 3858         rval = callout_stop(c);
 3859         if (rval > 0)
 3860                 /*
 3861                  * XXXGL: in case if callout is already running and next
 3862                  * invocation is scheduled at the same time, callout_stop()
 3863                  * returns 0. See d153eeee97d. In this case netgraph(4) would
 3864                  * leak resources. However, no nodes are known to induce such
 3865                  * behavior.
 3866                  */
 3867                 ng_uncallout_internal(c, node);
 3868 
 3869         return (rval);
 3870 }
 3871 
 3872 /* A special modified version of callout_drain() */
 3873 int
 3874 ng_uncallout_drain(struct callout *c, node_p node)
 3875 {
 3876         int rval;
 3877 
 3878         rval = callout_drain(c);
 3879         if (rval > 0)
 3880                 ng_uncallout_internal(c, node);
 3881 
 3882         return (rval);
 3883 }
 3884 
 3885 /*
 3886  * Set the address, if none given, give the node here.
 3887  */
 3888 void
 3889 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
 3890 {
 3891         if (retaddr) {
 3892                 NGI_RETADDR(item) = retaddr;
 3893         } else {
 3894                 /*
 3895                  * The old return address should be ok.
 3896                  * If there isn't one, use the address here.
 3897                  */
 3898                 NGI_RETADDR(item) = ng_node2ID(here);
 3899         }
 3900 }

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