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

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    1 /*
    2  * ng_base.c
    3  */
    4 
    5 /*-
    6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
    7  * All rights reserved.
    8  *
    9  * Subject to the following obligations and disclaimer of warranty, use and
   10  * redistribution of this software, in source or object code forms, with or
   11  * without modifications are expressly permitted by Whistle Communications;
   12  * provided, however, that:
   13  * 1. Any and all reproductions of the source or object code must include the
   14  *    copyright notice above and the following disclaimer of warranties; and
   15  * 2. No rights are granted, in any manner or form, to use Whistle
   16  *    Communications, Inc. trademarks, including the mark "WHISTLE
   17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   18  *    such appears in the above copyright notice or in the software.
   19  *
   20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   36  * OF SUCH DAMAGE.
   37  *
   38  * Authors: Julian Elischer <julian@freebsd.org>
   39  *          Archie Cobbs <archie@freebsd.org>
   40  *
   41  * $FreeBSD: releng/8.0/sys/netgraph/ng_base.c 196019 2009-08-01 19:26:27Z rwatson $
   42  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
   43  */
   44 
   45 /*
   46  * This file implements the base netgraph code.
   47  */
   48 
   49 #include <sys/param.h>
   50 #include <sys/systm.h>
   51 #include <sys/ctype.h>
   52 #include <sys/errno.h>
   53 #include <sys/kdb.h>
   54 #include <sys/kernel.h>
   55 #include <sys/ktr.h>
   56 #include <sys/limits.h>
   57 #include <sys/malloc.h>
   58 #include <sys/mbuf.h>
   59 #include <sys/queue.h>
   60 #include <sys/sysctl.h>
   61 #include <sys/syslog.h>
   62 #include <sys/refcount.h>
   63 #include <sys/proc.h>
   64 #include <sys/unistd.h>
   65 #include <sys/kthread.h>
   66 #include <sys/smp.h>
   67 #include <machine/cpu.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 mtx       ng_topo_mtx;
   80 
   81 #ifdef  NETGRAPH_DEBUG
   82 static struct mtx       ng_nodelist_mtx; /* protects global node/hook lists */
   83 static struct mtx       ngq_mtx;        /* protects the queue item list */
   84 
   85 static SLIST_HEAD(, ng_node) ng_allnodes;
   86 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
   87 static SLIST_HEAD(, ng_hook) ng_allhooks;
   88 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
   89 
   90 static void ng_dumpitems(void);
   91 static void ng_dumpnodes(void);
   92 static void ng_dumphooks(void);
   93 
   94 #endif  /* NETGRAPH_DEBUG */
   95 /*
   96  * DEAD versions of the structures.
   97  * In order to avoid races, it is sometimes neccesary to point
   98  * at SOMETHING even though theoretically, the current entity is
   99  * INVALID. Use these to avoid these races.
  100  */
  101 struct ng_type ng_deadtype = {
  102         NG_ABI_VERSION,
  103         "dead",
  104         NULL,   /* modevent */
  105         NULL,   /* constructor */
  106         NULL,   /* rcvmsg */
  107         NULL,   /* shutdown */
  108         NULL,   /* newhook */
  109         NULL,   /* findhook */
  110         NULL,   /* connect */
  111         NULL,   /* rcvdata */
  112         NULL,   /* disconnect */
  113         NULL,   /* cmdlist */
  114 };
  115 
  116 struct ng_node ng_deadnode = {
  117         "dead",
  118         &ng_deadtype,   
  119         NGF_INVALID,
  120         0,      /* numhooks */
  121         NULL,   /* private */
  122         0,      /* ID */
  123         LIST_HEAD_INITIALIZER(ng_deadnode.hooks),
  124         {},     /* all_nodes list entry */
  125         {},     /* id hashtable list entry */
  126         {       0,
  127                 0,
  128                 {}, /* should never use! (should hang) */
  129                 {}, /* workqueue entry */
  130                 STAILQ_HEAD_INITIALIZER(ng_deadnode.nd_input_queue.queue),
  131         },
  132         1,      /* refs */
  133         NULL,   /* vnet */
  134 #ifdef  NETGRAPH_DEBUG
  135         ND_MAGIC,
  136         __FILE__,
  137         __LINE__,
  138         {NULL}
  139 #endif  /* NETGRAPH_DEBUG */
  140 };
  141 
  142 struct ng_hook ng_deadhook = {
  143         "dead",
  144         NULL,           /* private */
  145         HK_INVALID | HK_DEAD,
  146         0,              /* undefined data link type */
  147         &ng_deadhook,   /* Peer is self */
  148         &ng_deadnode,   /* attached to deadnode */
  149         {},             /* hooks list */
  150         NULL,           /* override rcvmsg() */
  151         NULL,           /* override rcvdata() */
  152         1,              /* refs always >= 1 */
  153 #ifdef  NETGRAPH_DEBUG
  154         HK_MAGIC,
  155         __FILE__,
  156         __LINE__,
  157         {NULL}
  158 #endif  /* NETGRAPH_DEBUG */
  159 };
  160 
  161 /*
  162  * END DEAD STRUCTURES
  163  */
  164 /* List nodes with unallocated work */
  165 static STAILQ_HEAD(, ng_node) ng_worklist = STAILQ_HEAD_INITIALIZER(ng_worklist);
  166 static struct mtx       ng_worklist_mtx;   /* MUST LOCK NODE FIRST */
  167 
  168 /* List of installed types */
  169 static LIST_HEAD(, ng_type) ng_typelist;
  170 static struct mtx       ng_typelist_mtx;
  171 
  172 /* Hash related definitions */
  173 /* XXX Don't need to initialise them because it's a LIST */
  174 static VNET_DEFINE(LIST_HEAD(, ng_node), ng_ID_hash[NG_ID_HASH_SIZE]);
  175 #define V_ng_ID_hash                    VNET(ng_ID_hash)
  176 
  177 static struct mtx       ng_idhash_mtx;
  178 /* Method to find a node.. used twice so do it here */
  179 #define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
  180 #define NG_IDHASH_FIND(ID, node)                                        \
  181         do {                                                            \
  182                 mtx_assert(&ng_idhash_mtx, MA_OWNED);                   \
  183                 LIST_FOREACH(node, &V_ng_ID_hash[NG_IDHASH_FN(ID)],     \
  184                                                 nd_idnodes) {           \
  185                         if (NG_NODE_IS_VALID(node)                      \
  186                         && (NG_NODE_ID(node) == ID)) {                  \
  187                                 break;                                  \
  188                         }                                               \
  189                 }                                                       \
  190         } while (0)
  191 
  192 static VNET_DEFINE(LIST_HEAD(, ng_node), ng_name_hash[NG_NAME_HASH_SIZE]);
  193 #define V_ng_name_hash                  VNET(ng_name_hash)
  194 
  195 static struct mtx       ng_namehash_mtx;
  196 #define NG_NAMEHASH(NAME, HASH)                         \
  197         do {                                            \
  198                 u_char  h = 0;                          \
  199                 const u_char    *c;                     \
  200                 for (c = (const u_char*)(NAME); *c; c++)\
  201                         h += *c;                        \
  202                 (HASH) = h % (NG_NAME_HASH_SIZE);       \
  203         } while (0)
  204 
  205 
  206 /* Internal functions */
  207 static int      ng_add_hook(node_p node, const char *name, hook_p * hookp);
  208 static int      ng_generic_msg(node_p here, item_p item, hook_p lasthook);
  209 static ng_ID_t  ng_decodeidname(const char *name);
  210 static int      ngb_mod_event(module_t mod, int event, void *data);
  211 static void     ng_worklist_add(node_p node);
  212 static void     ngthread(void *);
  213 static int      ng_apply_item(node_p node, item_p item, int rw);
  214 static void     ng_flush_input_queue(node_p node);
  215 static node_p   ng_ID2noderef(ng_ID_t ID);
  216 static int      ng_con_nodes(item_p item, node_p node, const char *name,
  217                     node_p node2, const char *name2);
  218 static int      ng_con_part2(node_p node, item_p item, hook_p hook);
  219 static int      ng_con_part3(node_p node, item_p item, hook_p hook);
  220 static int      ng_mkpeer(node_p node, const char *name,
  221                                                 const char *name2, char *type);
  222 
  223 /* Imported, these used to be externally visible, some may go back. */
  224 void    ng_destroy_hook(hook_p hook);
  225 int     ng_path2noderef(node_p here, const char *path,
  226         node_p *dest, hook_p *lasthook);
  227 int     ng_make_node(const char *type, node_p *nodepp);
  228 int     ng_path_parse(char *addr, char **node, char **path, char **hook);
  229 void    ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
  230 void    ng_unname(node_p node);
  231 
  232 
  233 /* Our own netgraph malloc type */
  234 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
  235 MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
  236 MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
  237 MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item", "netgraph item structures");
  238 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
  239 
  240 /* Should not be visible outside this file */
  241 
  242 #define _NG_ALLOC_HOOK(hook) \
  243         hook = malloc(sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
  244 #define _NG_ALLOC_NODE(node) \
  245         node = malloc(sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
  246 
  247 #define NG_QUEUE_LOCK_INIT(n)                   \
  248         mtx_init(&(n)->q_mtx, "ng_node", NULL, MTX_DEF)
  249 #define NG_QUEUE_LOCK(n)                        \
  250         mtx_lock(&(n)->q_mtx)
  251 #define NG_QUEUE_UNLOCK(n)                      \
  252         mtx_unlock(&(n)->q_mtx)
  253 #define NG_WORKLIST_LOCK_INIT()                 \
  254         mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_DEF)
  255 #define NG_WORKLIST_LOCK()                      \
  256         mtx_lock(&ng_worklist_mtx)
  257 #define NG_WORKLIST_UNLOCK()                    \
  258         mtx_unlock(&ng_worklist_mtx)
  259 #define NG_WORKLIST_SLEEP()                     \
  260         mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
  261 #define NG_WORKLIST_WAKEUP()                    \
  262         wakeup_one(&ng_worklist)
  263 
  264 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
  265 /*
  266  * In debug mode:
  267  * In an attempt to help track reference count screwups
  268  * we do not free objects back to the malloc system, but keep them
  269  * in a local cache where we can examine them and keep information safely
  270  * after they have been freed.
  271  * We use this scheme for nodes and hooks, and to some extent for items.
  272  */
  273 static __inline hook_p
  274 ng_alloc_hook(void)
  275 {
  276         hook_p hook;
  277         SLIST_ENTRY(ng_hook) temp;
  278         mtx_lock(&ng_nodelist_mtx);
  279         hook = LIST_FIRST(&ng_freehooks);
  280         if (hook) {
  281                 LIST_REMOVE(hook, hk_hooks);
  282                 bcopy(&hook->hk_all, &temp, sizeof(temp));
  283                 bzero(hook, sizeof(struct ng_hook));
  284                 bcopy(&temp, &hook->hk_all, sizeof(temp));
  285                 mtx_unlock(&ng_nodelist_mtx);
  286                 hook->hk_magic = HK_MAGIC;
  287         } else {
  288                 mtx_unlock(&ng_nodelist_mtx);
  289                 _NG_ALLOC_HOOK(hook);
  290                 if (hook) {
  291                         hook->hk_magic = HK_MAGIC;
  292                         mtx_lock(&ng_nodelist_mtx);
  293                         SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
  294                         mtx_unlock(&ng_nodelist_mtx);
  295                 }
  296         }
  297         return (hook);
  298 }
  299 
  300 static __inline node_p
  301 ng_alloc_node(void)
  302 {
  303         node_p node;
  304         SLIST_ENTRY(ng_node) temp;
  305         mtx_lock(&ng_nodelist_mtx);
  306         node = LIST_FIRST(&ng_freenodes);
  307         if (node) {
  308                 LIST_REMOVE(node, nd_nodes);
  309                 bcopy(&node->nd_all, &temp, sizeof(temp));
  310                 bzero(node, sizeof(struct ng_node));
  311                 bcopy(&temp, &node->nd_all, sizeof(temp));
  312                 mtx_unlock(&ng_nodelist_mtx);
  313                 node->nd_magic = ND_MAGIC;
  314         } else {
  315                 mtx_unlock(&ng_nodelist_mtx);
  316                 _NG_ALLOC_NODE(node);
  317                 if (node) {
  318                         node->nd_magic = ND_MAGIC;
  319                         mtx_lock(&ng_nodelist_mtx);
  320                         SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
  321                         mtx_unlock(&ng_nodelist_mtx);
  322                 }
  323         }
  324         return (node);
  325 }
  326 
  327 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
  328 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
  329 
  330 
  331 #define NG_FREE_HOOK(hook)                                              \
  332         do {                                                            \
  333                 mtx_lock(&ng_nodelist_mtx);                     \
  334                 LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);        \
  335                 hook->hk_magic = 0;                                     \
  336                 mtx_unlock(&ng_nodelist_mtx);                   \
  337         } while (0)
  338 
  339 #define NG_FREE_NODE(node)                                              \
  340         do {                                                            \
  341                 mtx_lock(&ng_nodelist_mtx);                     \
  342                 LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);        \
  343                 node->nd_magic = 0;                                     \
  344                 mtx_unlock(&ng_nodelist_mtx);                   \
  345         } while (0)
  346 
  347 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
  348 
  349 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
  350 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
  351 
  352 #define NG_FREE_HOOK(hook) do { free((hook), M_NETGRAPH_HOOK); } while (0)
  353 #define NG_FREE_NODE(node) do { free((node), M_NETGRAPH_NODE); } while (0)
  354 
  355 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
  356 
  357 /* Set this to kdb_enter("X") to catch all errors as they occur */
  358 #ifndef TRAP_ERROR
  359 #define TRAP_ERROR()
  360 #endif
  361 
  362 static VNET_DEFINE(ng_ID_t, nextID) = 1;
  363 #define V_nextID                        VNET(nextID)
  364 
  365 #ifdef INVARIANTS
  366 #define CHECK_DATA_MBUF(m)      do {                                    \
  367                 struct mbuf *n;                                         \
  368                 int total;                                              \
  369                                                                         \
  370                 M_ASSERTPKTHDR(m);                                      \
  371                 for (total = 0, n = (m); n != NULL; n = n->m_next) {    \
  372                         total += n->m_len;                              \
  373                         if (n->m_nextpkt != NULL)                       \
  374                                 panic("%s: m_nextpkt", __func__);       \
  375                 }                                                       \
  376                                                                         \
  377                 if ((m)->m_pkthdr.len != total) {                       \
  378                         panic("%s: %d != %d",                           \
  379                             __func__, (m)->m_pkthdr.len, total);        \
  380                 }                                                       \
  381         } while (0)
  382 #else
  383 #define CHECK_DATA_MBUF(m)
  384 #endif
  385 
  386 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  387 
  388 /************************************************************************
  389         Parse type definitions for generic messages
  390 ************************************************************************/
  391 
  392 /* Handy structure parse type defining macro */
  393 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)                          \
  394 static const struct ng_parse_struct_field                               \
  395         ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;  \
  396 static const struct ng_parse_type ng_generic_ ## lo ## _type = {        \
  397         &ng_parse_struct_type,                                          \
  398         &ng_ ## lo ## _type_fields                                      \
  399 }
  400 
  401 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
  402 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
  403 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
  404 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
  405 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
  406 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
  407 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
  408 
  409 /* Get length of an array when the length is stored as a 32 bit
  410    value immediately preceding the array -- as with struct namelist
  411    and struct typelist. */
  412 static int
  413 ng_generic_list_getLength(const struct ng_parse_type *type,
  414         const u_char *start, const u_char *buf)
  415 {
  416         return *((const u_int32_t *)(buf - 4));
  417 }
  418 
  419 /* Get length of the array of struct linkinfo inside a struct hooklist */
  420 static int
  421 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
  422         const u_char *start, const u_char *buf)
  423 {
  424         const struct hooklist *hl = (const struct hooklist *)start;
  425 
  426         return hl->nodeinfo.hooks;
  427 }
  428 
  429 /* Array type for a variable length array of struct namelist */
  430 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
  431         &ng_generic_nodeinfo_type,
  432         &ng_generic_list_getLength
  433 };
  434 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
  435         &ng_parse_array_type,
  436         &ng_nodeinfoarray_type_info
  437 };
  438 
  439 /* Array type for a variable length array of struct typelist */
  440 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
  441         &ng_generic_typeinfo_type,
  442         &ng_generic_list_getLength
  443 };
  444 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
  445         &ng_parse_array_type,
  446         &ng_typeinfoarray_type_info
  447 };
  448 
  449 /* Array type for array of struct linkinfo in struct hooklist */
  450 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
  451         &ng_generic_linkinfo_type,
  452         &ng_generic_linkinfo_getLength
  453 };
  454 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
  455         &ng_parse_array_type,
  456         &ng_generic_linkinfo_array_type_info
  457 };
  458 
  459 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
  460 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
  461         (&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
  462 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
  463         (&ng_generic_nodeinfoarray_type));
  464 
  465 /* List of commands and how to convert arguments to/from ASCII */
  466 static const struct ng_cmdlist ng_generic_cmds[] = {
  467         {
  468           NGM_GENERIC_COOKIE,
  469           NGM_SHUTDOWN,
  470           "shutdown",
  471           NULL,
  472           NULL
  473         },
  474         {
  475           NGM_GENERIC_COOKIE,
  476           NGM_MKPEER,
  477           "mkpeer",
  478           &ng_generic_mkpeer_type,
  479           NULL
  480         },
  481         {
  482           NGM_GENERIC_COOKIE,
  483           NGM_CONNECT,
  484           "connect",
  485           &ng_generic_connect_type,
  486           NULL
  487         },
  488         {
  489           NGM_GENERIC_COOKIE,
  490           NGM_NAME,
  491           "name",
  492           &ng_generic_name_type,
  493           NULL
  494         },
  495         {
  496           NGM_GENERIC_COOKIE,
  497           NGM_RMHOOK,
  498           "rmhook",
  499           &ng_generic_rmhook_type,
  500           NULL
  501         },
  502         {
  503           NGM_GENERIC_COOKIE,
  504           NGM_NODEINFO,
  505           "nodeinfo",
  506           NULL,
  507           &ng_generic_nodeinfo_type
  508         },
  509         {
  510           NGM_GENERIC_COOKIE,
  511           NGM_LISTHOOKS,
  512           "listhooks",
  513           NULL,
  514           &ng_generic_hooklist_type
  515         },
  516         {
  517           NGM_GENERIC_COOKIE,
  518           NGM_LISTNAMES,
  519           "listnames",
  520           NULL,
  521           &ng_generic_listnodes_type    /* same as NGM_LISTNODES */
  522         },
  523         {
  524           NGM_GENERIC_COOKIE,
  525           NGM_LISTNODES,
  526           "listnodes",
  527           NULL,
  528           &ng_generic_listnodes_type
  529         },
  530         {
  531           NGM_GENERIC_COOKIE,
  532           NGM_LISTTYPES,
  533           "listtypes",
  534           NULL,
  535           &ng_generic_typeinfo_type
  536         },
  537         {
  538           NGM_GENERIC_COOKIE,
  539           NGM_TEXT_CONFIG,
  540           "textconfig",
  541           NULL,
  542           &ng_parse_string_type
  543         },
  544         {
  545           NGM_GENERIC_COOKIE,
  546           NGM_TEXT_STATUS,
  547           "textstatus",
  548           NULL,
  549           &ng_parse_string_type
  550         },
  551         {
  552           NGM_GENERIC_COOKIE,
  553           NGM_ASCII2BINARY,
  554           "ascii2binary",
  555           &ng_parse_ng_mesg_type,
  556           &ng_parse_ng_mesg_type
  557         },
  558         {
  559           NGM_GENERIC_COOKIE,
  560           NGM_BINARY2ASCII,
  561           "binary2ascii",
  562           &ng_parse_ng_mesg_type,
  563           &ng_parse_ng_mesg_type
  564         },
  565         { 0 }
  566 };
  567 
  568 /************************************************************************
  569                         Node routines
  570 ************************************************************************/
  571 
  572 /*
  573  * Instantiate a node of the requested type
  574  */
  575 int
  576 ng_make_node(const char *typename, node_p *nodepp)
  577 {
  578         struct ng_type *type;
  579         int     error;
  580 
  581         /* Check that the type makes sense */
  582         if (typename == NULL) {
  583                 TRAP_ERROR();
  584                 return (EINVAL);
  585         }
  586 
  587         /* Locate the node type. If we fail we return. Do not try to load
  588          * module.
  589          */
  590         if ((type = ng_findtype(typename)) == NULL)
  591                 return (ENXIO);
  592 
  593         /*
  594          * If we have a constructor, then make the node and
  595          * call the constructor to do type specific initialisation.
  596          */
  597         if (type->constructor != NULL) {
  598                 if ((error = ng_make_node_common(type, nodepp)) == 0) {
  599                         if ((error = ((*type->constructor)(*nodepp)) != 0)) {
  600                                 NG_NODE_UNREF(*nodepp);
  601                         }
  602                 }
  603         } else {
  604                 /*
  605                  * Node has no constructor. We cannot ask for one
  606                  * to be made. It must be brought into existence by
  607                  * some external agency. The external agency should
  608                  * call ng_make_node_common() directly to get the
  609                  * netgraph part initialised.
  610                  */
  611                 TRAP_ERROR();
  612                 error = EINVAL;
  613         }
  614         return (error);
  615 }
  616 
  617 /*
  618  * Generic node creation. Called by node initialisation for externally
  619  * instantiated nodes (e.g. hardware, sockets, etc ).
  620  * The returned node has a reference count of 1.
  621  */
  622 int
  623 ng_make_node_common(struct ng_type *type, node_p *nodepp)
  624 {
  625         node_p node;
  626 
  627         /* Require the node type to have been already installed */
  628         if (ng_findtype(type->name) == NULL) {
  629                 TRAP_ERROR();
  630                 return (EINVAL);
  631         }
  632 
  633         /* Make a node and try attach it to the type */
  634         NG_ALLOC_NODE(node);
  635         if (node == NULL) {
  636                 TRAP_ERROR();
  637                 return (ENOMEM);
  638         }
  639         node->nd_type = type;
  640 #ifdef VIMAGE
  641         node->nd_vnet = curvnet;
  642 #endif
  643         NG_NODE_REF(node);                              /* note reference */
  644         type->refs++;
  645 
  646         NG_QUEUE_LOCK_INIT(&node->nd_input_queue);
  647         STAILQ_INIT(&node->nd_input_queue.queue);
  648         node->nd_input_queue.q_flags = 0;
  649 
  650         /* Initialize hook list for new node */
  651         LIST_INIT(&node->nd_hooks);
  652 
  653         /* Link us into the name hash. */
  654         mtx_lock(&ng_namehash_mtx);
  655         LIST_INSERT_HEAD(&V_ng_name_hash[0], node, nd_nodes);
  656         mtx_unlock(&ng_namehash_mtx);
  657 
  658         /* get an ID and put us in the hash chain */
  659         mtx_lock(&ng_idhash_mtx);
  660         for (;;) { /* wrap protection, even if silly */
  661                 node_p node2 = NULL;
  662                 node->nd_ID = V_nextID++; /* 137/sec for 1 year before wrap */
  663 
  664                 /* Is there a problem with the new number? */
  665                 NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
  666                 if ((node->nd_ID != 0) && (node2 == NULL)) {
  667                         break;
  668                 }
  669         }
  670         LIST_INSERT_HEAD(&V_ng_ID_hash[NG_IDHASH_FN(node->nd_ID)],
  671                                                         node, nd_idnodes);
  672         mtx_unlock(&ng_idhash_mtx);
  673 
  674         /* Done */
  675         *nodepp = node;
  676         return (0);
  677 }
  678 
  679 /*
  680  * Forceably start the shutdown process on a node. Either call
  681  * its shutdown method, or do the default shutdown if there is
  682  * no type-specific method.
  683  *
  684  * We can only be called from a shutdown message, so we know we have
  685  * a writer lock, and therefore exclusive access. It also means
  686  * that we should not be on the work queue, but we check anyhow.
  687  *
  688  * Persistent node types must have a type-specific method which
  689  * allocates a new node in which case, this one is irretrievably going away,
  690  * or cleans up anything it needs, and just makes the node valid again,
  691  * in which case we allow the node to survive.
  692  *
  693  * XXX We need to think of how to tell a persistent node that we
  694  * REALLY need to go away because the hardware has gone or we
  695  * are rebooting.... etc.
  696  */
  697 void
  698 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
  699 {
  700         hook_p hook;
  701 
  702         /* Check if it's already shutting down */
  703         if ((node->nd_flags & NGF_CLOSING) != 0)
  704                 return;
  705 
  706         if (node == &ng_deadnode) {
  707                 printf ("shutdown called on deadnode\n");
  708                 return;
  709         }
  710 
  711         /* Add an extra reference so it doesn't go away during this */
  712         NG_NODE_REF(node);
  713 
  714         /*
  715          * Mark it invalid so any newcomers know not to try use it
  716          * Also add our own mark so we can't recurse
  717          * note that NGF_INVALID does not do this as it's also set during
  718          * creation
  719          */
  720         node->nd_flags |= NGF_INVALID|NGF_CLOSING;
  721 
  722         /* If node has its pre-shutdown method, then call it first*/
  723         if (node->nd_type && node->nd_type->close)
  724                 (*node->nd_type->close)(node);
  725 
  726         /* Notify all remaining connected nodes to disconnect */
  727         while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
  728                 ng_destroy_hook(hook);
  729 
  730         /*
  731          * Drain the input queue forceably.
  732          * it has no hooks so what's it going to do, bleed on someone?
  733          * Theoretically we came here from a queue entry that was added
  734          * Just before the queue was closed, so it should be empty anyway.
  735          * Also removes us from worklist if needed.
  736          */
  737         ng_flush_input_queue(node);
  738 
  739         /* Ask the type if it has anything to do in this case */
  740         if (node->nd_type && node->nd_type->shutdown) {
  741                 (*node->nd_type->shutdown)(node);
  742                 if (NG_NODE_IS_VALID(node)) {
  743                         /*
  744                          * Well, blow me down if the node code hasn't declared
  745                          * that it doesn't want to die.
  746                          * Presumably it is a persistant node.
  747                          * If we REALLY want it to go away,
  748                          *  e.g. hardware going away,
  749                          * Our caller should set NGF_REALLY_DIE in nd_flags.
  750                          */
  751                         node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
  752                         NG_NODE_UNREF(node); /* Assume they still have theirs */
  753                         return;
  754                 }
  755         } else {                                /* do the default thing */
  756                 NG_NODE_UNREF(node);
  757         }
  758 
  759         ng_unname(node); /* basically a NOP these days */
  760 
  761         /*
  762          * Remove extra reference, possibly the last
  763          * Possible other holders of references may include
  764          * timeout callouts, but theoretically the node's supposed to
  765          * have cancelled them. Possibly hardware dependencies may
  766          * force a driver to 'linger' with a reference.
  767          */
  768         NG_NODE_UNREF(node);
  769 }
  770 
  771 /*
  772  * Remove a reference to the node, possibly the last.
  773  * deadnode always acts as it it were the last.
  774  */
  775 int
  776 ng_unref_node(node_p node)
  777 {
  778         int v;
  779 
  780         if (node == &ng_deadnode) {
  781                 return (0);
  782         }
  783 
  784         v = atomic_fetchadd_int(&node->nd_refs, -1);
  785 
  786         if (v == 1) { /* we were the last */
  787 
  788                 mtx_lock(&ng_namehash_mtx);
  789                 node->nd_type->refs--; /* XXX maybe should get types lock? */
  790                 LIST_REMOVE(node, nd_nodes);
  791                 mtx_unlock(&ng_namehash_mtx);
  792 
  793                 mtx_lock(&ng_idhash_mtx);
  794                 LIST_REMOVE(node, nd_idnodes);
  795                 mtx_unlock(&ng_idhash_mtx);
  796 
  797                 mtx_destroy(&node->nd_input_queue.q_mtx);
  798                 NG_FREE_NODE(node);
  799         }
  800         return (v - 1);
  801 }
  802 
  803 /************************************************************************
  804                         Node ID handling
  805 ************************************************************************/
  806 static node_p
  807 ng_ID2noderef(ng_ID_t ID)
  808 {
  809         node_p node;
  810         mtx_lock(&ng_idhash_mtx);
  811         NG_IDHASH_FIND(ID, node);
  812         if(node)
  813                 NG_NODE_REF(node);
  814         mtx_unlock(&ng_idhash_mtx);
  815         return(node);
  816 }
  817 
  818 ng_ID_t
  819 ng_node2ID(node_p node)
  820 {
  821         return (node ? NG_NODE_ID(node) : 0);
  822 }
  823 
  824 /************************************************************************
  825                         Node name handling
  826 ************************************************************************/
  827 
  828 /*
  829  * Assign a node a name. Once assigned, the name cannot be changed.
  830  */
  831 int
  832 ng_name_node(node_p node, const char *name)
  833 {
  834         int i, hash;
  835         node_p node2;
  836 
  837         /* Check the name is valid */
  838         for (i = 0; i < NG_NODESIZ; i++) {
  839                 if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
  840                         break;
  841         }
  842         if (i == 0 || name[i] != '\0') {
  843                 TRAP_ERROR();
  844                 return (EINVAL);
  845         }
  846         if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
  847                 TRAP_ERROR();
  848                 return (EINVAL);
  849         }
  850 
  851         /* Check the name isn't already being used */
  852         if ((node2 = ng_name2noderef(node, name)) != NULL) {
  853                 NG_NODE_UNREF(node2);
  854                 TRAP_ERROR();
  855                 return (EADDRINUSE);
  856         }
  857 
  858         /* copy it */
  859         strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
  860 
  861         /* Update name hash. */
  862         NG_NAMEHASH(name, hash);
  863         mtx_lock(&ng_namehash_mtx);
  864         LIST_REMOVE(node, nd_nodes);
  865         LIST_INSERT_HEAD(&V_ng_name_hash[hash], node, nd_nodes);
  866         mtx_unlock(&ng_namehash_mtx);
  867 
  868         return (0);
  869 }
  870 
  871 /*
  872  * Find a node by absolute name. The name should NOT end with ':'
  873  * The name "." means "this node" and "[xxx]" means "the node
  874  * with ID (ie, at address) xxx".
  875  *
  876  * Returns the node if found, else NULL.
  877  * Eventually should add something faster than a sequential search.
  878  * Note it acquires a reference on the node so you can be sure it's still
  879  * there.
  880  */
  881 node_p
  882 ng_name2noderef(node_p here, const char *name)
  883 {
  884         node_p node;
  885         ng_ID_t temp;
  886         int     hash;
  887 
  888         /* "." means "this node" */
  889         if (strcmp(name, ".") == 0) {
  890                 NG_NODE_REF(here);
  891                 return(here);
  892         }
  893 
  894         /* Check for name-by-ID */
  895         if ((temp = ng_decodeidname(name)) != 0) {
  896                 return (ng_ID2noderef(temp));
  897         }
  898 
  899         /* Find node by name */
  900         NG_NAMEHASH(name, hash);
  901         mtx_lock(&ng_namehash_mtx);
  902         LIST_FOREACH(node, &V_ng_name_hash[hash], nd_nodes) {
  903                 if (NG_NODE_IS_VALID(node) &&
  904                     (strcmp(NG_NODE_NAME(node), name) == 0)) {
  905                         break;
  906                 }
  907         }
  908         if (node)
  909                 NG_NODE_REF(node);
  910         mtx_unlock(&ng_namehash_mtx);
  911         return (node);
  912 }
  913 
  914 /*
  915  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
  916  * string is not valid, otherwise returns the value.
  917  */
  918 static ng_ID_t
  919 ng_decodeidname(const char *name)
  920 {
  921         const int len = strlen(name);
  922         char *eptr;
  923         u_long val;
  924 
  925         /* Check for proper length, brackets, no leading junk */
  926         if ((len < 3)
  927         || (name[0] != '[')
  928         || (name[len - 1] != ']')
  929         || (!isxdigit(name[1]))) {
  930                 return ((ng_ID_t)0);
  931         }
  932 
  933         /* Decode number */
  934         val = strtoul(name + 1, &eptr, 16);
  935         if ((eptr - name != len - 1)
  936         || (val == ULONG_MAX)
  937         || (val == 0)) {
  938                 return ((ng_ID_t)0);
  939         }
  940         return (ng_ID_t)val;
  941 }
  942 
  943 /*
  944  * Remove a name from a node. This should only be called
  945  * when shutting down and removing the node.
  946  * IF we allow name changing this may be more resurrected.
  947  */
  948 void
  949 ng_unname(node_p node)
  950 {
  951 }
  952 
  953 /************************************************************************
  954                         Hook routines
  955  Names are not optional. Hooks are always connected, except for a
  956  brief moment within these routines. On invalidation or during creation
  957  they are connected to the 'dead' hook.
  958 ************************************************************************/
  959 
  960 /*
  961  * Remove a hook reference
  962  */
  963 void
  964 ng_unref_hook(hook_p hook)
  965 {
  966         int v;
  967 
  968         if (hook == &ng_deadhook) {
  969                 return;
  970         }
  971 
  972         v = atomic_fetchadd_int(&hook->hk_refs, -1);
  973 
  974         if (v == 1) { /* we were the last */
  975                 if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
  976                         _NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
  977                 NG_FREE_HOOK(hook);
  978         }
  979 }
  980 
  981 /*
  982  * Add an unconnected hook to a node. Only used internally.
  983  * Assumes node is locked. (XXX not yet true )
  984  */
  985 static int
  986 ng_add_hook(node_p node, const char *name, hook_p *hookp)
  987 {
  988         hook_p hook;
  989         int error = 0;
  990 
  991         /* Check that the given name is good */
  992         if (name == NULL) {
  993                 TRAP_ERROR();
  994                 return (EINVAL);
  995         }
  996         if (ng_findhook(node, name) != NULL) {
  997                 TRAP_ERROR();
  998                 return (EEXIST);
  999         }
 1000 
 1001         /* Allocate the hook and link it up */
 1002         NG_ALLOC_HOOK(hook);
 1003         if (hook == NULL) {
 1004                 TRAP_ERROR();
 1005                 return (ENOMEM);
 1006         }
 1007         hook->hk_refs = 1;              /* add a reference for us to return */
 1008         hook->hk_flags = HK_INVALID;
 1009         hook->hk_peer = &ng_deadhook;   /* start off this way */
 1010         hook->hk_node = node;
 1011         NG_NODE_REF(node);              /* each hook counts as a reference */
 1012 
 1013         /* Set hook name */
 1014         strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
 1015 
 1016         /*
 1017          * Check if the node type code has something to say about it
 1018          * If it fails, the unref of the hook will also unref the node.
 1019          */
 1020         if (node->nd_type->newhook != NULL) {
 1021                 if ((error = (*node->nd_type->newhook)(node, hook, name))) {
 1022                         NG_HOOK_UNREF(hook);    /* this frees the hook */
 1023                         return (error);
 1024                 }
 1025         }
 1026         /*
 1027          * The 'type' agrees so far, so go ahead and link it in.
 1028          * We'll ask again later when we actually connect the hooks.
 1029          */
 1030         LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
 1031         node->nd_numhooks++;
 1032         NG_HOOK_REF(hook);      /* one for the node */
 1033 
 1034         if (hookp)
 1035                 *hookp = hook;
 1036         return (0);
 1037 }
 1038 
 1039 /*
 1040  * Find a hook
 1041  *
 1042  * Node types may supply their own optimized routines for finding
 1043  * hooks.  If none is supplied, we just do a linear search.
 1044  * XXX Possibly we should add a reference to the hook?
 1045  */
 1046 hook_p
 1047 ng_findhook(node_p node, const char *name)
 1048 {
 1049         hook_p hook;
 1050 
 1051         if (node->nd_type->findhook != NULL)
 1052                 return (*node->nd_type->findhook)(node, name);
 1053         LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
 1054                 if (NG_HOOK_IS_VALID(hook)
 1055                 && (strcmp(NG_HOOK_NAME(hook), name) == 0))
 1056                         return (hook);
 1057         }
 1058         return (NULL);
 1059 }
 1060 
 1061 /*
 1062  * Destroy a hook
 1063  *
 1064  * As hooks are always attached, this really destroys two hooks.
 1065  * The one given, and the one attached to it. Disconnect the hooks
 1066  * from each other first. We reconnect the peer hook to the 'dead'
 1067  * hook so that it can still exist after we depart. We then
 1068  * send the peer its own destroy message. This ensures that we only
 1069  * interact with the peer's structures when it is locked processing that
 1070  * message. We hold a reference to the peer hook so we are guaranteed that
 1071  * the peer hook and node are still going to exist until
 1072  * we are finished there as the hook holds a ref on the node.
 1073  * We run this same code again on the peer hook, but that time it is already
 1074  * attached to the 'dead' hook.
 1075  *
 1076  * This routine is called at all stages of hook creation
 1077  * on error detection and must be able to handle any such stage.
 1078  */
 1079 void
 1080 ng_destroy_hook(hook_p hook)
 1081 {
 1082         hook_p peer;
 1083         node_p node;
 1084 
 1085         if (hook == &ng_deadhook) {     /* better safe than sorry */
 1086                 printf("ng_destroy_hook called on deadhook\n");
 1087                 return;
 1088         }
 1089 
 1090         /*
 1091          * Protect divorce process with mutex, to avoid races on
 1092          * simultaneous disconnect.
 1093          */
 1094         mtx_lock(&ng_topo_mtx);
 1095 
 1096         hook->hk_flags |= HK_INVALID;
 1097 
 1098         peer = NG_HOOK_PEER(hook);
 1099         node = NG_HOOK_NODE(hook);
 1100 
 1101         if (peer && (peer != &ng_deadhook)) {
 1102                 /*
 1103                  * Set the peer to point to ng_deadhook
 1104                  * from this moment on we are effectively independent it.
 1105                  * send it an rmhook message of it's own.
 1106                  */
 1107                 peer->hk_peer = &ng_deadhook;   /* They no longer know us */
 1108                 hook->hk_peer = &ng_deadhook;   /* Nor us, them */
 1109                 if (NG_HOOK_NODE(peer) == &ng_deadnode) {
 1110                         /*
 1111                          * If it's already divorced from a node,
 1112                          * just free it.
 1113                          */
 1114                         mtx_unlock(&ng_topo_mtx);
 1115                 } else {
 1116                         mtx_unlock(&ng_topo_mtx);
 1117                         ng_rmhook_self(peer);   /* Send it a surprise */
 1118                 }
 1119                 NG_HOOK_UNREF(peer);            /* account for peer link */
 1120                 NG_HOOK_UNREF(hook);            /* account for peer link */
 1121         } else
 1122                 mtx_unlock(&ng_topo_mtx);
 1123 
 1124         mtx_assert(&ng_topo_mtx, MA_NOTOWNED);
 1125 
 1126         /*
 1127          * Remove the hook from the node's list to avoid possible recursion
 1128          * in case the disconnection results in node shutdown.
 1129          */
 1130         if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
 1131                 return;
 1132         }
 1133         LIST_REMOVE(hook, hk_hooks);
 1134         node->nd_numhooks--;
 1135         if (node->nd_type->disconnect) {
 1136                 /*
 1137                  * The type handler may elect to destroy the node so don't
 1138                  * trust its existence after this point. (except
 1139                  * that we still hold a reference on it. (which we
 1140                  * inherrited from the hook we are destroying)
 1141                  */
 1142                 (*node->nd_type->disconnect) (hook);
 1143         }
 1144 
 1145         /*
 1146          * Note that because we will point to ng_deadnode, the original node
 1147          * is not decremented automatically so we do that manually.
 1148          */
 1149         _NG_HOOK_NODE(hook) = &ng_deadnode;
 1150         NG_NODE_UNREF(node);    /* We no longer point to it so adjust count */
 1151         NG_HOOK_UNREF(hook);    /* Account for linkage (in list) to node */
 1152 }
 1153 
 1154 /*
 1155  * Take two hooks on a node and merge the connection so that the given node
 1156  * is effectively bypassed.
 1157  */
 1158 int
 1159 ng_bypass(hook_p hook1, hook_p hook2)
 1160 {
 1161         if (hook1->hk_node != hook2->hk_node) {
 1162                 TRAP_ERROR();
 1163                 return (EINVAL);
 1164         }
 1165         hook1->hk_peer->hk_peer = hook2->hk_peer;
 1166         hook2->hk_peer->hk_peer = hook1->hk_peer;
 1167 
 1168         hook1->hk_peer = &ng_deadhook;
 1169         hook2->hk_peer = &ng_deadhook;
 1170 
 1171         NG_HOOK_UNREF(hook1);
 1172         NG_HOOK_UNREF(hook2);
 1173 
 1174         /* XXX If we ever cache methods on hooks update them as well */
 1175         ng_destroy_hook(hook1);
 1176         ng_destroy_hook(hook2);
 1177         return (0);
 1178 }
 1179 
 1180 /*
 1181  * Install a new netgraph type
 1182  */
 1183 int
 1184 ng_newtype(struct ng_type *tp)
 1185 {
 1186         const size_t namelen = strlen(tp->name);
 1187 
 1188         /* Check version and type name fields */
 1189         if ((tp->version != NG_ABI_VERSION)
 1190         || (namelen == 0)
 1191         || (namelen >= NG_TYPESIZ)) {
 1192                 TRAP_ERROR();
 1193                 if (tp->version != NG_ABI_VERSION) {
 1194                         printf("Netgraph: Node type rejected. ABI mismatch. Suggest recompile\n");
 1195                 }
 1196                 return (EINVAL);
 1197         }
 1198 
 1199         /* Check for name collision */
 1200         if (ng_findtype(tp->name) != NULL) {
 1201                 TRAP_ERROR();
 1202                 return (EEXIST);
 1203         }
 1204 
 1205 
 1206         /* Link in new type */
 1207         mtx_lock(&ng_typelist_mtx);
 1208         LIST_INSERT_HEAD(&ng_typelist, tp, types);
 1209         tp->refs = 1;   /* first ref is linked list */
 1210         mtx_unlock(&ng_typelist_mtx);
 1211         return (0);
 1212 }
 1213 
 1214 /*
 1215  * unlink a netgraph type
 1216  * If no examples exist
 1217  */
 1218 int
 1219 ng_rmtype(struct ng_type *tp)
 1220 {
 1221         /* Check for name collision */
 1222         if (tp->refs != 1) {
 1223                 TRAP_ERROR();
 1224                 return (EBUSY);
 1225         }
 1226 
 1227         /* Unlink type */
 1228         mtx_lock(&ng_typelist_mtx);
 1229         LIST_REMOVE(tp, types);
 1230         mtx_unlock(&ng_typelist_mtx);
 1231         return (0);
 1232 }
 1233 
 1234 /*
 1235  * Look for a type of the name given
 1236  */
 1237 struct ng_type *
 1238 ng_findtype(const char *typename)
 1239 {
 1240         struct ng_type *type;
 1241 
 1242         mtx_lock(&ng_typelist_mtx);
 1243         LIST_FOREACH(type, &ng_typelist, types) {
 1244                 if (strcmp(type->name, typename) == 0)
 1245                         break;
 1246         }
 1247         mtx_unlock(&ng_typelist_mtx);
 1248         return (type);
 1249 }
 1250 
 1251 /************************************************************************
 1252                         Composite routines
 1253 ************************************************************************/
 1254 /*
 1255  * Connect two nodes using the specified hooks, using queued functions.
 1256  */
 1257 static int
 1258 ng_con_part3(node_p node, item_p item, hook_p hook)
 1259 {
 1260         int     error = 0;
 1261 
 1262         /*
 1263          * When we run, we know that the node 'node' is locked for us.
 1264          * Our caller has a reference on the hook.
 1265          * Our caller has a reference on the node.
 1266          * (In this case our caller is ng_apply_item() ).
 1267          * The peer hook has a reference on the hook.
 1268          * We are all set up except for the final call to the node, and
 1269          * the clearing of the INVALID flag.
 1270          */
 1271         if (NG_HOOK_NODE(hook) == &ng_deadnode) {
 1272                 /*
 1273                  * The node must have been freed again since we last visited
 1274                  * here. ng_destry_hook() has this effect but nothing else does.
 1275                  * We should just release our references and
 1276                  * free anything we can think of.
 1277                  * Since we know it's been destroyed, and it's our caller
 1278                  * that holds the references, just return.
 1279                  */
 1280                 ERROUT(ENOENT);
 1281         }
 1282         if (hook->hk_node->nd_type->connect) {
 1283                 if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
 1284                         ng_destroy_hook(hook);  /* also zaps peer */
 1285                         printf("failed in ng_con_part3()\n");
 1286                         ERROUT(error);
 1287                 }
 1288         }
 1289         /*
 1290          *  XXX this is wrong for SMP. Possibly we need
 1291          * to separate out 'create' and 'invalid' flags.
 1292          * should only set flags on hooks we have locked under our node.
 1293          */
 1294         hook->hk_flags &= ~HK_INVALID;
 1295 done:
 1296         NG_FREE_ITEM(item);
 1297         return (error);
 1298 }
 1299 
 1300 static int
 1301 ng_con_part2(node_p node, item_p item, hook_p hook)
 1302 {
 1303         hook_p  peer;
 1304         int     error = 0;
 1305 
 1306         /*
 1307          * When we run, we know that the node 'node' is locked for us.
 1308          * Our caller has a reference on the hook.
 1309          * Our caller has a reference on the node.
 1310          * (In this case our caller is ng_apply_item() ).
 1311          * The peer hook has a reference on the hook.
 1312          * our node pointer points to the 'dead' node.
 1313          * First check the hook name is unique.
 1314          * Should not happen because we checked before queueing this.
 1315          */
 1316         if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
 1317                 TRAP_ERROR();
 1318                 ng_destroy_hook(hook); /* should destroy peer too */
 1319                 printf("failed in ng_con_part2()\n");
 1320                 ERROUT(EEXIST);
 1321         }
 1322         /*
 1323          * Check if the node type code has something to say about it
 1324          * If it fails, the unref of the hook will also unref the attached node,
 1325          * however since that node is 'ng_deadnode' this will do nothing.
 1326          * The peer hook will also be destroyed.
 1327          */
 1328         if (node->nd_type->newhook != NULL) {
 1329                 if ((error = (*node->nd_type->newhook)(node, hook,
 1330                     hook->hk_name))) {
 1331                         ng_destroy_hook(hook); /* should destroy peer too */
 1332                         printf("failed in ng_con_part2()\n");
 1333                         ERROUT(error);
 1334                 }
 1335         }
 1336 
 1337         /*
 1338          * The 'type' agrees so far, so go ahead and link it in.
 1339          * We'll ask again later when we actually connect the hooks.
 1340          */
 1341         hook->hk_node = node;           /* just overwrite ng_deadnode */
 1342         NG_NODE_REF(node);              /* each hook counts as a reference */
 1343         LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
 1344         node->nd_numhooks++;
 1345         NG_HOOK_REF(hook);      /* one for the node */
 1346         
 1347         /*
 1348          * We now have a symmetrical situation, where both hooks have been
 1349          * linked to their nodes, the newhook methods have been called
 1350          * And the references are all correct. The hooks are still marked
 1351          * as invalid, as we have not called the 'connect' methods
 1352          * yet.
 1353          * We can call the local one immediately as we have the
 1354          * node locked, but we need to queue the remote one.
 1355          */
 1356         if (hook->hk_node->nd_type->connect) {
 1357                 if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
 1358                         ng_destroy_hook(hook);  /* also zaps peer */
 1359                         printf("failed in ng_con_part2(A)\n");
 1360                         ERROUT(error);
 1361                 }
 1362         }
 1363 
 1364         /*
 1365          * Acquire topo mutex to avoid race with ng_destroy_hook().
 1366          */
 1367         mtx_lock(&ng_topo_mtx);
 1368         peer = hook->hk_peer;
 1369         if (peer == &ng_deadhook) {
 1370                 mtx_unlock(&ng_topo_mtx);
 1371                 printf("failed in ng_con_part2(B)\n");
 1372                 ng_destroy_hook(hook);
 1373                 ERROUT(ENOENT);
 1374         }
 1375         mtx_unlock(&ng_topo_mtx);
 1376 
 1377         if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
 1378             NULL, 0, NG_REUSE_ITEM))) {
 1379                 printf("failed in ng_con_part2(C)\n");
 1380                 ng_destroy_hook(hook);  /* also zaps peer */
 1381                 return (error);         /* item was consumed. */
 1382         }
 1383         hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
 1384         return (0);                     /* item was consumed. */
 1385 done:
 1386         NG_FREE_ITEM(item);
 1387         return (error);
 1388 }
 1389 
 1390 /*
 1391  * Connect this node with another node. We assume that this node is
 1392  * currently locked, as we are only called from an NGM_CONNECT message.
 1393  */
 1394 static int
 1395 ng_con_nodes(item_p item, node_p node, const char *name,
 1396     node_p node2, const char *name2)
 1397 {
 1398         int     error;
 1399         hook_p  hook;
 1400         hook_p  hook2;
 1401 
 1402         if (ng_findhook(node2, name2) != NULL) {
 1403                 return(EEXIST);
 1404         }
 1405         if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
 1406                 return (error);
 1407         /* Allocate the other hook and link it up */
 1408         NG_ALLOC_HOOK(hook2);
 1409         if (hook2 == NULL) {
 1410                 TRAP_ERROR();
 1411                 ng_destroy_hook(hook);  /* XXX check ref counts so far */
 1412                 NG_HOOK_UNREF(hook);    /* including our ref */
 1413                 return (ENOMEM);
 1414         }
 1415         hook2->hk_refs = 1;             /* start with a reference for us. */
 1416         hook2->hk_flags = HK_INVALID;
 1417         hook2->hk_peer = hook;          /* Link the two together */
 1418         hook->hk_peer = hook2;  
 1419         NG_HOOK_REF(hook);              /* Add a ref for the peer to each*/
 1420         NG_HOOK_REF(hook2);
 1421         hook2->hk_node = &ng_deadnode;
 1422         strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
 1423 
 1424         /*
 1425          * Queue the function above.
 1426          * Procesing continues in that function in the lock context of
 1427          * the other node.
 1428          */
 1429         if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
 1430             NG_NOFLAGS))) {
 1431                 printf("failed in ng_con_nodes(): %d\n", error);
 1432                 ng_destroy_hook(hook);  /* also zaps peer */
 1433         }
 1434 
 1435         NG_HOOK_UNREF(hook);            /* Let each hook go if it wants to */
 1436         NG_HOOK_UNREF(hook2);
 1437         return (error);
 1438 }
 1439 
 1440 /*
 1441  * Make a peer and connect.
 1442  * We assume that the local node is locked.
 1443  * The new node probably doesn't need a lock until
 1444  * it has a hook, because it cannot really have any work until then,
 1445  * but we should think about it a bit more.
 1446  *
 1447  * The problem may come if the other node also fires up
 1448  * some hardware or a timer or some other source of activation,
 1449  * also it may already get a command msg via it's ID.
 1450  *
 1451  * We could use the same method as ng_con_nodes() but we'd have
 1452  * to add ability to remove the node when failing. (Not hard, just
 1453  * make arg1 point to the node to remove).
 1454  * Unless of course we just ignore failure to connect and leave
 1455  * an unconnected node?
 1456  */
 1457 static int
 1458 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
 1459 {
 1460         node_p  node2;
 1461         hook_p  hook1, hook2;
 1462         int     error;
 1463 
 1464         if ((error = ng_make_node(type, &node2))) {
 1465                 return (error);
 1466         }
 1467 
 1468         if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
 1469                 ng_rmnode(node2, NULL, NULL, 0);
 1470                 return (error);
 1471         }
 1472 
 1473         if ((error = ng_add_hook(node2, name2, &hook2))) {
 1474                 ng_rmnode(node2, NULL, NULL, 0);
 1475                 ng_destroy_hook(hook1);
 1476                 NG_HOOK_UNREF(hook1);
 1477                 return (error);
 1478         }
 1479 
 1480         /*
 1481          * Actually link the two hooks together.
 1482          */
 1483         hook1->hk_peer = hook2;
 1484         hook2->hk_peer = hook1;
 1485 
 1486         /* Each hook is referenced by the other */
 1487         NG_HOOK_REF(hook1);
 1488         NG_HOOK_REF(hook2);
 1489 
 1490         /* Give each node the opportunity to veto the pending connection */
 1491         if (hook1->hk_node->nd_type->connect) {
 1492                 error = (*hook1->hk_node->nd_type->connect) (hook1);
 1493         }
 1494 
 1495         if ((error == 0) && hook2->hk_node->nd_type->connect) {
 1496                 error = (*hook2->hk_node->nd_type->connect) (hook2);
 1497 
 1498         }
 1499 
 1500         /*
 1501          * drop the references we were holding on the two hooks.
 1502          */
 1503         if (error) {
 1504                 ng_destroy_hook(hook2); /* also zaps hook1 */
 1505                 ng_rmnode(node2, NULL, NULL, 0);
 1506         } else {
 1507                 /* As a last act, allow the hooks to be used */
 1508                 hook1->hk_flags &= ~HK_INVALID;
 1509                 hook2->hk_flags &= ~HK_INVALID;
 1510         }
 1511         NG_HOOK_UNREF(hook1);
 1512         NG_HOOK_UNREF(hook2);
 1513         return (error);
 1514 }
 1515 
 1516 /************************************************************************
 1517                 Utility routines to send self messages
 1518 ************************************************************************/
 1519         
 1520 /* Shut this node down as soon as everyone is clear of it */
 1521 /* Should add arg "immediately" to jump the queue */
 1522 int
 1523 ng_rmnode_self(node_p node)
 1524 {
 1525         int             error;
 1526 
 1527         if (node == &ng_deadnode)
 1528                 return (0);
 1529         node->nd_flags |= NGF_INVALID;
 1530         if (node->nd_flags & NGF_CLOSING)
 1531                 return (0);
 1532 
 1533         error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
 1534         return (error);
 1535 }
 1536 
 1537 static void
 1538 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
 1539 {
 1540         ng_destroy_hook(hook);
 1541         return ;
 1542 }
 1543 
 1544 int
 1545 ng_rmhook_self(hook_p hook)
 1546 {
 1547         int             error;
 1548         node_p node = NG_HOOK_NODE(hook);
 1549 
 1550         if (node == &ng_deadnode)
 1551                 return (0);
 1552 
 1553         error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
 1554         return (error);
 1555 }
 1556 
 1557 /***********************************************************************
 1558  * Parse and verify a string of the form:  <NODE:><PATH>
 1559  *
 1560  * Such a string can refer to a specific node or a specific hook
 1561  * on a specific node, depending on how you look at it. In the
 1562  * latter case, the PATH component must not end in a dot.
 1563  *
 1564  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
 1565  * of hook names separated by dots. This breaks out the original
 1566  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
 1567  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
 1568  * the final hook component of <PATH>, if any, otherwise NULL.
 1569  *
 1570  * This returns -1 if the path is malformed. The char ** are optional.
 1571  ***********************************************************************/
 1572 int
 1573 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
 1574 {
 1575         char    *node, *path, *hook;
 1576         int     k;
 1577 
 1578         /*
 1579          * Extract absolute NODE, if any
 1580          */
 1581         for (path = addr; *path && *path != ':'; path++);
 1582         if (*path) {
 1583                 node = addr;    /* Here's the NODE */
 1584                 *path++ = '\0'; /* Here's the PATH */
 1585 
 1586                 /* Node name must not be empty */
 1587                 if (!*node)
 1588                         return -1;
 1589 
 1590                 /* A name of "." is OK; otherwise '.' not allowed */
 1591                 if (strcmp(node, ".") != 0) {
 1592                         for (k = 0; node[k]; k++)
 1593                                 if (node[k] == '.')
 1594                                         return -1;
 1595                 }
 1596         } else {
 1597                 node = NULL;    /* No absolute NODE */
 1598                 path = addr;    /* Here's the PATH */
 1599         }
 1600 
 1601         /* Snoop for illegal characters in PATH */
 1602         for (k = 0; path[k]; k++)
 1603                 if (path[k] == ':')
 1604                         return -1;
 1605 
 1606         /* Check for no repeated dots in PATH */
 1607         for (k = 0; path[k]; k++)
 1608                 if (path[k] == '.' && path[k + 1] == '.')
 1609                         return -1;
 1610 
 1611         /* Remove extra (degenerate) dots from beginning or end of PATH */
 1612         if (path[0] == '.')
 1613                 path++;
 1614         if (*path && path[strlen(path) - 1] == '.')
 1615                 path[strlen(path) - 1] = 0;
 1616 
 1617         /* If PATH has a dot, then we're not talking about a hook */
 1618         if (*path) {
 1619                 for (hook = path, k = 0; path[k]; k++)
 1620                         if (path[k] == '.') {
 1621                                 hook = NULL;
 1622                                 break;
 1623                         }
 1624         } else
 1625                 path = hook = NULL;
 1626 
 1627         /* Done */
 1628         if (nodep)
 1629                 *nodep = node;
 1630         if (pathp)
 1631                 *pathp = path;
 1632         if (hookp)
 1633                 *hookp = hook;
 1634         return (0);
 1635 }
 1636 
 1637 /*
 1638  * Given a path, which may be absolute or relative, and a starting node,
 1639  * return the destination node.
 1640  */
 1641 int
 1642 ng_path2noderef(node_p here, const char *address,
 1643                                 node_p *destp, hook_p *lasthook)
 1644 {
 1645         char    fullpath[NG_PATHSIZ];
 1646         char   *nodename, *path, pbuf[2];
 1647         node_p  node, oldnode;
 1648         char   *cp;
 1649         hook_p hook = NULL;
 1650 
 1651         /* Initialize */
 1652         if (destp == NULL) {
 1653                 TRAP_ERROR();
 1654                 return EINVAL;
 1655         }
 1656         *destp = NULL;
 1657 
 1658         /* Make a writable copy of address for ng_path_parse() */
 1659         strncpy(fullpath, address, sizeof(fullpath) - 1);
 1660         fullpath[sizeof(fullpath) - 1] = '\0';
 1661 
 1662         /* Parse out node and sequence of hooks */
 1663         if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
 1664                 TRAP_ERROR();
 1665                 return EINVAL;
 1666         }
 1667         if (path == NULL) {
 1668                 pbuf[0] = '.';  /* Needs to be writable */
 1669                 pbuf[1] = '\0';
 1670                 path = pbuf;
 1671         }
 1672 
 1673         /*
 1674          * For an absolute address, jump to the starting node.
 1675          * Note that this holds a reference on the node for us.
 1676          * Don't forget to drop the reference if we don't need it.
 1677          */
 1678         if (nodename) {
 1679                 node = ng_name2noderef(here, nodename);
 1680                 if (node == NULL) {
 1681                         TRAP_ERROR();
 1682                         return (ENOENT);
 1683                 }
 1684         } else {
 1685                 if (here == NULL) {
 1686                         TRAP_ERROR();
 1687                         return (EINVAL);
 1688                 }
 1689                 node = here;
 1690                 NG_NODE_REF(node);
 1691         }
 1692 
 1693         /*
 1694          * Now follow the sequence of hooks
 1695          * XXX
 1696          * We actually cannot guarantee that the sequence
 1697          * is not being demolished as we crawl along it
 1698          * without extra-ordinary locking etc.
 1699          * So this is a bit dodgy to say the least.
 1700          * We can probably hold up some things by holding
 1701          * the nodelist mutex for the time of this
 1702          * crawl if we wanted.. At least that way we wouldn't have to
 1703          * worry about the nodes disappearing, but the hooks would still
 1704          * be a problem.
 1705          */
 1706         for (cp = path; node != NULL && *cp != '\0'; ) {
 1707                 char *segment;
 1708 
 1709                 /*
 1710                  * Break out the next path segment. Replace the dot we just
 1711                  * found with a NUL; "cp" points to the next segment (or the
 1712                  * NUL at the end).
 1713                  */
 1714                 for (segment = cp; *cp != '\0'; cp++) {
 1715                         if (*cp == '.') {
 1716                                 *cp++ = '\0';
 1717                                 break;
 1718                         }
 1719                 }
 1720 
 1721                 /* Empty segment */
 1722                 if (*segment == '\0')
 1723                         continue;
 1724 
 1725                 /* We have a segment, so look for a hook by that name */
 1726                 hook = ng_findhook(node, segment);
 1727 
 1728                 /* Can't get there from here... */
 1729                 if (hook == NULL
 1730                     || NG_HOOK_PEER(hook) == NULL
 1731                     || NG_HOOK_NOT_VALID(hook)
 1732                     || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
 1733                         TRAP_ERROR();
 1734                         NG_NODE_UNREF(node);
 1735 #if 0
 1736                         printf("hooknotvalid %s %s %d %d %d %d ",
 1737                                         path,
 1738                                         segment,
 1739                                         hook == NULL,
 1740                                         NG_HOOK_PEER(hook) == NULL,
 1741                                         NG_HOOK_NOT_VALID(hook),
 1742                                         NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook)));
 1743 #endif
 1744                         return (ENOENT);
 1745                 }
 1746 
 1747                 /*
 1748                  * Hop on over to the next node
 1749                  * XXX
 1750                  * Big race conditions here as hooks and nodes go away
 1751                  * *** Idea.. store an ng_ID_t in each hook and use that
 1752                  * instead of the direct hook in this crawl?
 1753                  */
 1754                 oldnode = node;
 1755                 if ((node = NG_PEER_NODE(hook)))
 1756                         NG_NODE_REF(node);      /* XXX RACE */
 1757                 NG_NODE_UNREF(oldnode); /* XXX another race */
 1758                 if (NG_NODE_NOT_VALID(node)) {
 1759                         NG_NODE_UNREF(node);    /* XXX more races */
 1760                         node = NULL;
 1761                 }
 1762         }
 1763 
 1764         /* If node somehow missing, fail here (probably this is not needed) */
 1765         if (node == NULL) {
 1766                 TRAP_ERROR();
 1767                 return (ENXIO);
 1768         }
 1769 
 1770         /* Done */
 1771         *destp = node;
 1772         if (lasthook != NULL)
 1773                 *lasthook = (hook ? NG_HOOK_PEER(hook) : NULL);
 1774         return (0);
 1775 }
 1776 
 1777 /***************************************************************\
 1778 * Input queue handling.
 1779 * All activities are submitted to the node via the input queue
 1780 * which implements a multiple-reader/single-writer gate.
 1781 * Items which cannot be handled immediately are queued.
 1782 *
 1783 * read-write queue locking inline functions                     *
 1784 \***************************************************************/
 1785 
 1786 static __inline void    ng_queue_rw(node_p node, item_p  item, int rw);
 1787 static __inline item_p  ng_dequeue(node_p node, int *rw);
 1788 static __inline item_p  ng_acquire_read(node_p node, item_p  item);
 1789 static __inline item_p  ng_acquire_write(node_p node, item_p  item);
 1790 static __inline void    ng_leave_read(node_p node);
 1791 static __inline void    ng_leave_write(node_p node);
 1792 
 1793 /*
 1794  * Definition of the bits fields in the ng_queue flag word.
 1795  * Defined here rather than in netgraph.h because no-one should fiddle
 1796  * with them.
 1797  *
 1798  * The ordering here may be important! don't shuffle these.
 1799  */
 1800 /*-
 1801  Safety Barrier--------+ (adjustable to suit taste) (not used yet)
 1802                        |
 1803                        V
 1804 +-------+-------+-------+-------+-------+-------+-------+-------+
 1805   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
 1806   | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
 1807   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
 1808 +-------+-------+-------+-------+-------+-------+-------+-------+
 1809   \___________________________ ____________________________/ | |
 1810                             V                                | |
 1811                   [active reader count]                      | |
 1812                                                              | |
 1813             Operation Pending -------------------------------+ |
 1814                                                                |
 1815           Active Writer ---------------------------------------+
 1816 
 1817 Node queue has such semantics:
 1818 - All flags modifications are atomic.
 1819 - Reader count can be incremented only if there is no writer or pending flags.
 1820   As soon as this can't be done with single operation, it is implemented with
 1821   spin loop and atomic_cmpset().
 1822 - Writer flag can be set only if there is no any bits set.
 1823   It is implemented with atomic_cmpset().
 1824 - Pending flag can be set any time, but to avoid collision on queue processing
 1825   all queue fields are protected by the mutex.
 1826 - Queue processing thread reads queue holding the mutex, but releases it while
 1827   processing. When queue is empty pending flag is removed.
 1828 */
 1829 
 1830 #define WRITER_ACTIVE   0x00000001
 1831 #define OP_PENDING      0x00000002
 1832 #define READER_INCREMENT 0x00000004
 1833 #define READER_MASK     0xfffffffc      /* Not valid if WRITER_ACTIVE is set */
 1834 #define SAFETY_BARRIER  0x00100000      /* 128K items queued should be enough */
 1835 
 1836 /* Defines of more elaborate states on the queue */
 1837 /* Mask of bits a new read cares about */
 1838 #define NGQ_RMASK       (WRITER_ACTIVE|OP_PENDING)
 1839 
 1840 /* Mask of bits a new write cares about */
 1841 #define NGQ_WMASK       (NGQ_RMASK|READER_MASK)
 1842 
 1843 /* Test to decide if there is something on the queue. */
 1844 #define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
 1845 
 1846 /* How to decide what the next queued item is. */
 1847 #define HEAD_IS_READER(QP)  NGI_QUEUED_READER(STAILQ_FIRST(&(QP)->queue))
 1848 #define HEAD_IS_WRITER(QP)  NGI_QUEUED_WRITER(STAILQ_FIRST(&(QP)->queue)) /* notused */
 1849 
 1850 /* Read the status to decide if the next item on the queue can now run. */
 1851 #define QUEUED_READER_CAN_PROCEED(QP)                   \
 1852                 (((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
 1853 #define QUEUED_WRITER_CAN_PROCEED(QP)                   \
 1854                 (((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
 1855 
 1856 /* Is there a chance of getting ANY work off the queue? */
 1857 #define NEXT_QUEUED_ITEM_CAN_PROCEED(QP)                                \
 1858         ((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) :         \
 1859                                 QUEUED_WRITER_CAN_PROCEED(QP))
 1860 
 1861 #define NGQRW_R 0
 1862 #define NGQRW_W 1
 1863 
 1864 #define NGQ2_WORKQ      0x00000001
 1865 
 1866 /*
 1867  * Taking into account the current state of the queue and node, possibly take
 1868  * the next entry off the queue and return it. Return NULL if there was
 1869  * nothing we could return, either because there really was nothing there, or
 1870  * because the node was in a state where it cannot yet process the next item
 1871  * on the queue.
 1872  */
 1873 static __inline item_p
 1874 ng_dequeue(node_p node, int *rw)
 1875 {
 1876         item_p item;
 1877         struct ng_queue *ngq = &node->nd_input_queue;
 1878 
 1879         /* This MUST be called with the mutex held. */
 1880         mtx_assert(&ngq->q_mtx, MA_OWNED);
 1881 
 1882         /* If there is nothing queued, then just return. */
 1883         if (!QUEUE_ACTIVE(ngq)) {
 1884                 CTR4(KTR_NET, "%20s: node [%x] (%p) queue empty; "
 1885                     "queue flags 0x%lx", __func__,
 1886                     node->nd_ID, node, ngq->q_flags);
 1887                 return (NULL);
 1888         }
 1889 
 1890         /*
 1891          * From here, we can assume there is a head item.
 1892          * We need to find out what it is and if it can be dequeued, given
 1893          * the current state of the node.
 1894          */
 1895         if (HEAD_IS_READER(ngq)) {
 1896                 while (1) {
 1897                         long t = ngq->q_flags;
 1898                         if (t & WRITER_ACTIVE) {
 1899                                 /* There is writer, reader can't proceed. */
 1900                                 CTR4(KTR_NET, "%20s: node [%x] (%p) queued reader "
 1901                                     "can't proceed; queue flags 0x%lx", __func__,
 1902                                     node->nd_ID, node, t);
 1903                                 return (NULL);
 1904                         }
 1905                         if (atomic_cmpset_acq_int(&ngq->q_flags, t,
 1906                             t + READER_INCREMENT))
 1907                                 break;
 1908                         cpu_spinwait();
 1909                 }
 1910                 /* We have got reader lock for the node. */
 1911                 *rw = NGQRW_R;
 1912         } else if (atomic_cmpset_acq_int(&ngq->q_flags, OP_PENDING,
 1913             OP_PENDING + WRITER_ACTIVE)) {
 1914                 /* We have got writer lock for the node. */
 1915                 *rw = NGQRW_W;
 1916         } else {
 1917                 /* There is somebody other, writer can't proceed. */
 1918                 CTR4(KTR_NET, "%20s: node [%x] (%p) queued writer "
 1919                     "can't proceed; queue flags 0x%lx", __func__,
 1920                     node->nd_ID, node, ngq->q_flags);
 1921                 return (NULL);
 1922         }
 1923 
 1924         /*
 1925          * Now we dequeue the request (whatever it may be) and correct the
 1926          * pending flags and the next and last pointers.
 1927          */
 1928         item = STAILQ_FIRST(&ngq->queue);
 1929         STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
 1930         if (STAILQ_EMPTY(&ngq->queue))
 1931                 atomic_clear_int(&ngq->q_flags, OP_PENDING);
 1932         CTR6(KTR_NET, "%20s: node [%x] (%p) returning item %p as %s; "
 1933             "queue flags 0x%lx", __func__,
 1934             node->nd_ID, node, item, *rw ? "WRITER" : "READER" ,
 1935             ngq->q_flags);
 1936         return (item);
 1937 }
 1938 
 1939 /*
 1940  * Queue a packet to be picked up later by someone else.
 1941  * If the queue could be run now, add node to the queue handler's worklist.
 1942  */
 1943 static __inline void
 1944 ng_queue_rw(node_p node, item_p  item, int rw)
 1945 {
 1946         struct ng_queue *ngq = &node->nd_input_queue;
 1947         if (rw == NGQRW_W)
 1948                 NGI_SET_WRITER(item);
 1949         else
 1950                 NGI_SET_READER(item);
 1951 
 1952         NG_QUEUE_LOCK(ngq);
 1953         /* Set OP_PENDING flag and enqueue the item. */
 1954         atomic_set_int(&ngq->q_flags, OP_PENDING);
 1955         STAILQ_INSERT_TAIL(&ngq->queue, item, el_next);
 1956 
 1957         CTR5(KTR_NET, "%20s: node [%x] (%p) queued item %p as %s", __func__,
 1958             node->nd_ID, node, item, rw ? "WRITER" : "READER" );
 1959             
 1960         /*
 1961          * We can take the worklist lock with the node locked
 1962          * BUT NOT THE REVERSE!
 1963          */
 1964         if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 1965                 ng_worklist_add(node);
 1966         NG_QUEUE_UNLOCK(ngq);
 1967 }
 1968 
 1969 /* Acquire reader lock on node. If node is busy, queue the packet. */
 1970 static __inline item_p
 1971 ng_acquire_read(node_p node, item_p item)
 1972 {
 1973         KASSERT(node != &ng_deadnode,
 1974             ("%s: working on deadnode", __func__));
 1975 
 1976         /* Reader needs node without writer and pending items. */
 1977         while (1) {
 1978                 long t = node->nd_input_queue.q_flags;
 1979                 if (t & NGQ_RMASK)
 1980                         break; /* Node is not ready for reader. */
 1981                 if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
 1982                     t, t + READER_INCREMENT)) {
 1983                         /* Successfully grabbed node */
 1984                         CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
 1985                             __func__, node->nd_ID, node, item);
 1986                         return (item);
 1987                 }
 1988                 cpu_spinwait();
 1989         };
 1990 
 1991         /* Queue the request for later. */
 1992         ng_queue_rw(node, item, NGQRW_R);
 1993 
 1994         return (NULL);
 1995 }
 1996 
 1997 /* Acquire writer lock on node. If node is busy, queue the packet. */
 1998 static __inline item_p
 1999 ng_acquire_write(node_p node, item_p item)
 2000 {
 2001         KASSERT(node != &ng_deadnode,
 2002             ("%s: working on deadnode", __func__));
 2003 
 2004         /* Writer needs completely idle node. */
 2005         if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
 2006             0, WRITER_ACTIVE)) {
 2007                 /* Successfully grabbed node */
 2008                 CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
 2009                     __func__, node->nd_ID, node, item);
 2010                 return (item);
 2011         }
 2012 
 2013         /* Queue the request for later. */
 2014         ng_queue_rw(node, item, NGQRW_W);
 2015 
 2016         return (NULL);
 2017 }
 2018 
 2019 #if 0
 2020 static __inline item_p
 2021 ng_upgrade_write(node_p node, item_p item)
 2022 {
 2023         struct ng_queue *ngq = &node->nd_input_queue;
 2024         KASSERT(node != &ng_deadnode,
 2025             ("%s: working on deadnode", __func__));
 2026 
 2027         NGI_SET_WRITER(item);
 2028 
 2029         NG_QUEUE_LOCK(ngq);
 2030 
 2031         /*
 2032          * There will never be no readers as we are there ourselves.
 2033          * Set the WRITER_ACTIVE flags ASAP to block out fast track readers.
 2034          * The caller we are running from will call ng_leave_read()
 2035          * soon, so we must account for that. We must leave again with the
 2036          * READER lock. If we find other readers, then
 2037          * queue the request for later. However "later" may be rignt now
 2038          * if there are no readers. We don't really care if there are queued
 2039          * items as we will bypass them anyhow.
 2040          */
 2041         atomic_add_int(&ngq->q_flags, WRITER_ACTIVE - READER_INCREMENT);
 2042         if ((ngq->q_flags & (NGQ_WMASK & ~OP_PENDING)) == WRITER_ACTIVE) {
 2043                 NG_QUEUE_UNLOCK(ngq);
 2044                 
 2045                 /* It's just us, act on the item. */
 2046                 /* will NOT drop writer lock when done */
 2047                 ng_apply_item(node, item, 0);
 2048 
 2049                 /*
 2050                  * Having acted on the item, atomically 
 2051                  * down grade back to READER and finish up
 2052                  */
 2053                 atomic_add_int(&ngq->q_flags,
 2054                     READER_INCREMENT - WRITER_ACTIVE);
 2055 
 2056                 /* Our caller will call ng_leave_read() */
 2057                 return;
 2058         }
 2059         /*
 2060          * It's not just us active, so queue us AT THE HEAD.
 2061          * "Why?" I hear you ask.
 2062          * Put us at the head of the queue as we've already been
 2063          * through it once. If there is nothing else waiting,
 2064          * set the correct flags.
 2065          */
 2066         if (STAILQ_EMPTY(&ngq->queue)) {
 2067                 /* We've gone from, 0 to 1 item in the queue */
 2068                 atomic_set_int(&ngq->q_flags, OP_PENDING);
 2069 
 2070                 CTR3(KTR_NET, "%20s: node [%x] (%p) set OP_PENDING", __func__,
 2071                     node->nd_ID, node);
 2072         };
 2073         STAILQ_INSERT_HEAD(&ngq->queue, item, el_next);
 2074         CTR4(KTR_NET, "%20s: node [%x] (%p) requeued item %p as WRITER",
 2075             __func__, node->nd_ID, node, item );
 2076 
 2077         /* Reverse what we did above. That downgrades us back to reader */
 2078         atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
 2079         if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 2080                 ng_worklist_add(node);
 2081         NG_QUEUE_UNLOCK(ngq);
 2082 
 2083         return;
 2084 }
 2085 #endif
 2086 
 2087 /* Release reader lock. */
 2088 static __inline void
 2089 ng_leave_read(node_p node)
 2090 {
 2091         atomic_subtract_rel_int(&node->nd_input_queue.q_flags, READER_INCREMENT);
 2092 }
 2093 
 2094 /* Release writer lock. */
 2095 static __inline void
 2096 ng_leave_write(node_p node)
 2097 {
 2098         atomic_clear_rel_int(&node->nd_input_queue.q_flags, WRITER_ACTIVE);
 2099 }
 2100 
 2101 /* Purge node queue. Called on node shutdown. */
 2102 static void
 2103 ng_flush_input_queue(node_p node)
 2104 {
 2105         struct ng_queue *ngq = &node->nd_input_queue;
 2106         item_p item;
 2107 
 2108         NG_QUEUE_LOCK(ngq);
 2109         while ((item = STAILQ_FIRST(&ngq->queue)) != NULL) {
 2110                 STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
 2111                 if (STAILQ_EMPTY(&ngq->queue))
 2112                         atomic_clear_int(&ngq->q_flags, OP_PENDING);
 2113                 NG_QUEUE_UNLOCK(ngq);
 2114 
 2115                 /* If the item is supplying a callback, call it with an error */
 2116                 if (item->apply != NULL) {
 2117                         if (item->depth == 1)
 2118                                 item->apply->error = ENOENT;
 2119                         if (refcount_release(&item->apply->refs)) {
 2120                                 (*item->apply->apply)(item->apply->context,
 2121                                     item->apply->error);
 2122                         }
 2123                 }
 2124                 NG_FREE_ITEM(item);
 2125                 NG_QUEUE_LOCK(ngq);
 2126         }
 2127         NG_QUEUE_UNLOCK(ngq);
 2128 }
 2129 
 2130 /***********************************************************************
 2131 * Externally visible method for sending or queueing messages or data.
 2132 ***********************************************************************/
 2133 
 2134 /*
 2135  * The module code should have filled out the item correctly by this stage:
 2136  * Common:
 2137  *    reference to destination node.
 2138  *    Reference to destination rcv hook if relevant.
 2139  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
 2140  * Data:
 2141  *    pointer to mbuf
 2142  * Control_Message:
 2143  *    pointer to msg.
 2144  *    ID of original sender node. (return address)
 2145  * Function:
 2146  *    Function pointer
 2147  *    void * argument
 2148  *    integer argument
 2149  *
 2150  * The nodes have several routines and macros to help with this task:
 2151  */
 2152 
 2153 int
 2154 ng_snd_item(item_p item, int flags)
 2155 {
 2156         hook_p hook;
 2157         node_p node;
 2158         int queue, rw;
 2159         struct ng_queue *ngq;
 2160         int error = 0;
 2161 
 2162         /* We are sending item, so it must be present! */
 2163         KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
 2164 
 2165 #ifdef  NETGRAPH_DEBUG
 2166         _ngi_check(item, __FILE__, __LINE__);
 2167 #endif
 2168 
 2169         /* Item was sent once more, postpone apply() call. */
 2170         if (item->apply)
 2171                 refcount_acquire(&item->apply->refs);
 2172 
 2173         node = NGI_NODE(item);
 2174         /* Node is never optional. */
 2175         KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
 2176 
 2177         hook = NGI_HOOK(item);
 2178         /* Valid hook and mbuf are mandatory for data. */
 2179         if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
 2180                 KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
 2181                 if (NGI_M(item) == NULL)
 2182                         ERROUT(EINVAL);
 2183                 CHECK_DATA_MBUF(NGI_M(item));
 2184         }
 2185 
 2186         /*
 2187          * If the item or the node specifies single threading, force
 2188          * writer semantics. Similarly, the node may say one hook always
 2189          * produces writers. These are overrides.
 2190          */
 2191         if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
 2192             (node->nd_flags & NGF_FORCE_WRITER) ||
 2193             (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
 2194                 rw = NGQRW_W;
 2195         } else {
 2196                 rw = NGQRW_R;
 2197         }
 2198 
 2199         /*
 2200          * If sender or receiver requests queued delivery, or call graph
 2201          * loops back from outbound to inbound path, or stack usage
 2202          * level is dangerous - enqueue message.
 2203          */
 2204         if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
 2205                 queue = 1;
 2206         } else if (hook && (hook->hk_flags & HK_TO_INBOUND) &&
 2207             curthread->td_ng_outbound) {
 2208                 queue = 1;
 2209         } else {
 2210                 queue = 0;
 2211 #ifdef GET_STACK_USAGE
 2212                 /*
 2213                  * Most of netgraph nodes have small stack consumption and
 2214                  * for them 25% of free stack space is more than enough.
 2215                  * Nodes/hooks with higher stack usage should be marked as
 2216                  * HI_STACK. For them 50% of stack will be guaranteed then.
 2217                  * XXX: Values 25% and 50% are completely empirical.
 2218                  */
 2219                 size_t  st, su, sl;
 2220                 GET_STACK_USAGE(st, su);
 2221                 sl = st - su;
 2222                 if ((sl * 4 < st) ||
 2223                     ((sl * 2 < st) && ((node->nd_flags & NGF_HI_STACK) ||
 2224                       (hook && (hook->hk_flags & HK_HI_STACK))))) {
 2225                         queue = 1;
 2226                 }
 2227 #endif
 2228         }
 2229 
 2230         if (queue) {
 2231                 item->depth = 1;
 2232                 /* Put it on the queue for that node*/
 2233                 ng_queue_rw(node, item, rw);
 2234                 return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
 2235         }
 2236 
 2237         /*
 2238          * We already decided how we will be queueud or treated.
 2239          * Try get the appropriate operating permission.
 2240          */
 2241         if (rw == NGQRW_R)
 2242                 item = ng_acquire_read(node, item);
 2243         else
 2244                 item = ng_acquire_write(node, item);
 2245 
 2246         /* Item was queued while trying to get permission. */
 2247         if (item == NULL)
 2248                 return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
 2249 
 2250         NGI_GET_NODE(item, node); /* zaps stored node */
 2251 
 2252         item->depth++;
 2253         error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
 2254 
 2255         /* If something is waiting on queue and ready, schedule it. */
 2256         ngq = &node->nd_input_queue;
 2257         if (QUEUE_ACTIVE(ngq)) {
 2258                 NG_QUEUE_LOCK(ngq);
 2259                 if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
 2260                         ng_worklist_add(node);
 2261                 NG_QUEUE_UNLOCK(ngq);
 2262         }
 2263 
 2264         /*
 2265          * Node may go away as soon as we remove the reference.
 2266          * Whatever we do, DO NOT access the node again!
 2267          */
 2268         NG_NODE_UNREF(node);
 2269 
 2270         return (error);
 2271 
 2272 done:
 2273         /* If was not sent, apply callback here. */
 2274         if (item->apply != NULL) {
 2275                 if (item->depth == 0 && error != 0)
 2276                         item->apply->error = error;
 2277                 if (refcount_release(&item->apply->refs)) {
 2278                         (*item->apply->apply)(item->apply->context,
 2279                             item->apply->error);
 2280                 }
 2281         }
 2282 
 2283         NG_FREE_ITEM(item);
 2284         return (error);
 2285 }
 2286 
 2287 /*
 2288  * We have an item that was possibly queued somewhere.
 2289  * It should contain all the information needed
 2290  * to run it on the appropriate node/hook.
 2291  * If there is apply pointer and we own the last reference, call apply().
 2292  */
 2293 static int
 2294 ng_apply_item(node_p node, item_p item, int rw)
 2295 {
 2296         hook_p  hook;
 2297         ng_rcvdata_t *rcvdata;
 2298         ng_rcvmsg_t *rcvmsg;
 2299         struct ng_apply_info *apply;
 2300         int     error = 0, depth;
 2301 
 2302         /* Node and item are never optional. */
 2303         KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
 2304         KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
 2305 
 2306         NGI_GET_HOOK(item, hook); /* clears stored hook */
 2307 #ifdef  NETGRAPH_DEBUG
 2308         _ngi_check(item, __FILE__, __LINE__);
 2309 #endif
 2310 
 2311         apply = item->apply;
 2312         depth = item->depth;
 2313 
 2314         switch (item->el_flags & NGQF_TYPE) {
 2315         case NGQF_DATA:
 2316                 /*
 2317                  * Check things are still ok as when we were queued.
 2318                  */
 2319                 KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
 2320                 if (NG_HOOK_NOT_VALID(hook) ||
 2321                     NG_NODE_NOT_VALID(node)) {
 2322                         error = EIO;
 2323                         NG_FREE_ITEM(item);
 2324                         break;
 2325                 }
 2326                 /*
 2327                  * If no receive method, just silently drop it.
 2328                  * Give preference to the hook over-ride method
 2329                  */
 2330                 if ((!(rcvdata = hook->hk_rcvdata))
 2331                 && (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
 2332                         error = 0;
 2333                         NG_FREE_ITEM(item);
 2334                         break;
 2335                 }
 2336                 error = (*rcvdata)(hook, item);
 2337                 break;
 2338         case NGQF_MESG:
 2339                 if (hook && NG_HOOK_NOT_VALID(hook)) {
 2340                         /*
 2341                          * The hook has been zapped then we can't use it.
 2342                          * Immediately drop its reference.
 2343                          * The message may not need it.
 2344                          */
 2345                         NG_HOOK_UNREF(hook);
 2346                         hook = NULL;
 2347                 }
 2348                 /*
 2349                  * Similarly, if the node is a zombie there is
 2350                  * nothing we can do with it, drop everything.
 2351                  */
 2352                 if (NG_NODE_NOT_VALID(node)) {
 2353                         TRAP_ERROR();
 2354                         error = EINVAL;
 2355                         NG_FREE_ITEM(item);
 2356                         break;
 2357                 }
 2358                 /*
 2359                  * Call the appropriate message handler for the object.
 2360                  * It is up to the message handler to free the message.
 2361                  * If it's a generic message, handle it generically,
 2362                  * otherwise call the type's message handler (if it exists).
 2363                  * XXX (race). Remember that a queued message may
 2364                  * reference a node or hook that has just been
 2365                  * invalidated. It will exist as the queue code
 2366                  * is holding a reference, but..
 2367                  */
 2368                 if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
 2369                     ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
 2370                         error = ng_generic_msg(node, item, hook);
 2371                         break;
 2372                 }
 2373                 if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
 2374                     (!(rcvmsg = node->nd_type->rcvmsg))) {
 2375                         TRAP_ERROR();
 2376                         error = 0;
 2377                         NG_FREE_ITEM(item);
 2378                         break;
 2379                 }
 2380                 error = (*rcvmsg)(node, item, hook);
 2381                 break;
 2382         case NGQF_FN:
 2383         case NGQF_FN2:
 2384                 /*
 2385                  * In the case of the shutdown message we allow it to hit
 2386                  * even if the node is invalid.
 2387                  */
 2388                 if (NG_NODE_NOT_VALID(node) &&
 2389                     NGI_FN(item) != &ng_rmnode) {
 2390                         TRAP_ERROR();
 2391                         error = EINVAL;
 2392                         NG_FREE_ITEM(item);
 2393                         break;
 2394                 }
 2395                 /* Same is about some internal functions and invalid hook. */
 2396                 if (hook && NG_HOOK_NOT_VALID(hook) &&
 2397                     NGI_FN2(item) != &ng_con_part2 &&
 2398                     NGI_FN2(item) != &ng_con_part3 &&
 2399                     NGI_FN(item) != &ng_rmhook_part2) {
 2400                         TRAP_ERROR();
 2401                         error = EINVAL;
 2402                         NG_FREE_ITEM(item);
 2403                         break;
 2404                 }
 2405                 
 2406                 if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
 2407                         (*NGI_FN(item))(node, hook, NGI_ARG1(item),
 2408                             NGI_ARG2(item));
 2409                         NG_FREE_ITEM(item);
 2410                 } else  /* it is NGQF_FN2 */
 2411                         error = (*NGI_FN2(item))(node, item, hook);
 2412                 break;
 2413         }
 2414         /*
 2415          * We held references on some of the resources
 2416          * that we took from the item. Now that we have
 2417          * finished doing everything, drop those references.
 2418          */
 2419         if (hook)
 2420                 NG_HOOK_UNREF(hook);
 2421 
 2422         if (rw == NGQRW_R)
 2423                 ng_leave_read(node);
 2424         else
 2425                 ng_leave_write(node);
 2426 
 2427         /* Apply callback. */
 2428         if (apply != NULL) {
 2429                 if (depth == 1 && error != 0)
 2430                         apply->error = error;
 2431                 if (refcount_release(&apply->refs))
 2432                         (*apply->apply)(apply->context, apply->error);
 2433         }
 2434 
 2435         return (error);
 2436 }
 2437 
 2438 /***********************************************************************
 2439  * Implement the 'generic' control messages
 2440  ***********************************************************************/
 2441 static int
 2442 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
 2443 {
 2444         int error = 0;
 2445         struct ng_mesg *msg;
 2446         struct ng_mesg *resp = NULL;
 2447 
 2448         NGI_GET_MSG(item, msg);
 2449         if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
 2450                 TRAP_ERROR();
 2451                 error = EINVAL;
 2452                 goto out;
 2453         }
 2454         switch (msg->header.cmd) {
 2455         case NGM_SHUTDOWN:
 2456                 ng_rmnode(here, NULL, NULL, 0);
 2457                 break;
 2458         case NGM_MKPEER:
 2459             {
 2460                 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
 2461 
 2462                 if (msg->header.arglen != sizeof(*mkp)) {
 2463                         TRAP_ERROR();
 2464                         error = EINVAL;
 2465                         break;
 2466                 }
 2467                 mkp->type[sizeof(mkp->type) - 1] = '\0';
 2468                 mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
 2469                 mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
 2470                 error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
 2471                 break;
 2472             }
 2473         case NGM_CONNECT:
 2474             {
 2475                 struct ngm_connect *const con =
 2476                         (struct ngm_connect *) msg->data;
 2477                 node_p node2;
 2478 
 2479                 if (msg->header.arglen != sizeof(*con)) {
 2480                         TRAP_ERROR();
 2481                         error = EINVAL;
 2482                         break;
 2483                 }
 2484                 con->path[sizeof(con->path) - 1] = '\0';
 2485                 con->ourhook[sizeof(con->ourhook) - 1] = '\0';
 2486                 con->peerhook[sizeof(con->peerhook) - 1] = '\0';
 2487                 /* Don't forget we get a reference.. */
 2488                 error = ng_path2noderef(here, con->path, &node2, NULL);
 2489                 if (error)
 2490                         break;
 2491                 error = ng_con_nodes(item, here, con->ourhook,
 2492                     node2, con->peerhook);
 2493                 NG_NODE_UNREF(node2);
 2494                 break;
 2495             }
 2496         case NGM_NAME:
 2497             {
 2498                 struct ngm_name *const nam = (struct ngm_name *) msg->data;
 2499 
 2500                 if (msg->header.arglen != sizeof(*nam)) {
 2501                         TRAP_ERROR();
 2502                         error = EINVAL;
 2503                         break;
 2504                 }
 2505                 nam->name[sizeof(nam->name) - 1] = '\0';
 2506                 error = ng_name_node(here, nam->name);
 2507                 break;
 2508             }
 2509         case NGM_RMHOOK:
 2510             {
 2511                 struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
 2512                 hook_p hook;
 2513 
 2514                 if (msg->header.arglen != sizeof(*rmh)) {
 2515                         TRAP_ERROR();
 2516                         error = EINVAL;
 2517                         break;
 2518                 }
 2519                 rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
 2520                 if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
 2521                         ng_destroy_hook(hook);
 2522                 break;
 2523             }
 2524         case NGM_NODEINFO:
 2525             {
 2526                 struct nodeinfo *ni;
 2527 
 2528                 NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
 2529                 if (resp == NULL) {
 2530                         error = ENOMEM;
 2531                         break;
 2532                 }
 2533 
 2534                 /* Fill in node info */
 2535                 ni = (struct nodeinfo *) resp->data;
 2536                 if (NG_NODE_HAS_NAME(here))
 2537                         strcpy(ni->name, NG_NODE_NAME(here));
 2538                 strcpy(ni->type, here->nd_type->name);
 2539                 ni->id = ng_node2ID(here);
 2540                 ni->hooks = here->nd_numhooks;
 2541                 break;
 2542             }
 2543         case NGM_LISTHOOKS:
 2544             {
 2545                 const int nhooks = here->nd_numhooks;
 2546                 struct hooklist *hl;
 2547                 struct nodeinfo *ni;
 2548                 hook_p hook;
 2549 
 2550                 /* Get response struct */
 2551                 NG_MKRESPONSE(resp, msg, sizeof(*hl)
 2552                     + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
 2553                 if (resp == NULL) {
 2554                         error = ENOMEM;
 2555                         break;
 2556                 }
 2557                 hl = (struct hooklist *) resp->data;
 2558                 ni = &hl->nodeinfo;
 2559 
 2560                 /* Fill in node info */
 2561                 if (NG_NODE_HAS_NAME(here))
 2562                         strcpy(ni->name, NG_NODE_NAME(here));
 2563                 strcpy(ni->type, here->nd_type->name);
 2564                 ni->id = ng_node2ID(here);
 2565 
 2566                 /* Cycle through the linked list of hooks */
 2567                 ni->hooks = 0;
 2568                 LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
 2569                         struct linkinfo *const link = &hl->link[ni->hooks];
 2570 
 2571                         if (ni->hooks >= nhooks) {
 2572                                 log(LOG_ERR, "%s: number of %s changed\n",
 2573                                     __func__, "hooks");
 2574                                 break;
 2575                         }
 2576                         if (NG_HOOK_NOT_VALID(hook))
 2577                                 continue;
 2578                         strcpy(link->ourhook, NG_HOOK_NAME(hook));
 2579                         strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
 2580                         if (NG_PEER_NODE_NAME(hook)[0] != '\0')
 2581                                 strcpy(link->nodeinfo.name,
 2582                                     NG_PEER_NODE_NAME(hook));
 2583                         strcpy(link->nodeinfo.type,
 2584                            NG_PEER_NODE(hook)->nd_type->name);
 2585                         link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
 2586                         link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
 2587                         ni->hooks++;
 2588                 }
 2589                 break;
 2590             }
 2591 
 2592         case NGM_LISTNAMES:
 2593         case NGM_LISTNODES:
 2594             {
 2595                 const int unnamed = (msg->header.cmd == NGM_LISTNODES);
 2596                 struct namelist *nl;
 2597                 node_p node;
 2598                 int num = 0, i;
 2599 
 2600                 mtx_lock(&ng_namehash_mtx);
 2601                 /* Count number of nodes */
 2602                 for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
 2603                         LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
 2604                                 if (NG_NODE_IS_VALID(node) &&
 2605                                     (unnamed || NG_NODE_HAS_NAME(node))) {
 2606                                         num++;
 2607                                 }
 2608                         }
 2609                 }
 2610                 mtx_unlock(&ng_namehash_mtx);
 2611 
 2612                 /* Get response struct */
 2613                 NG_MKRESPONSE(resp, msg, sizeof(*nl)
 2614                     + (num * sizeof(struct nodeinfo)), M_NOWAIT);
 2615                 if (resp == NULL) {
 2616                         error = ENOMEM;
 2617                         break;
 2618                 }
 2619                 nl = (struct namelist *) resp->data;
 2620 
 2621                 /* Cycle through the linked list of nodes */
 2622                 nl->numnames = 0;
 2623                 mtx_lock(&ng_namehash_mtx);
 2624                 for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
 2625                         LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
 2626                                 struct nodeinfo *const np =
 2627                                     &nl->nodeinfo[nl->numnames];
 2628 
 2629                                 if (NG_NODE_NOT_VALID(node))
 2630                                         continue;
 2631                                 if (!unnamed && (! NG_NODE_HAS_NAME(node)))
 2632                                         continue;
 2633                                 if (nl->numnames >= num) {
 2634                                         log(LOG_ERR, "%s: number of nodes changed\n",
 2635                                             __func__);
 2636                                         break;
 2637                                 }
 2638                                 if (NG_NODE_HAS_NAME(node))
 2639                                         strcpy(np->name, NG_NODE_NAME(node));
 2640                                 strcpy(np->type, node->nd_type->name);
 2641                                 np->id = ng_node2ID(node);
 2642                                 np->hooks = node->nd_numhooks;
 2643                                 nl->numnames++;
 2644                         }
 2645                 }
 2646                 mtx_unlock(&ng_namehash_mtx);
 2647                 break;
 2648             }
 2649 
 2650         case NGM_LISTTYPES:
 2651             {
 2652                 struct typelist *tl;
 2653                 struct ng_type *type;
 2654                 int num = 0;
 2655 
 2656                 mtx_lock(&ng_typelist_mtx);
 2657                 /* Count number of types */
 2658                 LIST_FOREACH(type, &ng_typelist, types) {
 2659                         num++;
 2660                 }
 2661                 mtx_unlock(&ng_typelist_mtx);
 2662 
 2663                 /* Get response struct */
 2664                 NG_MKRESPONSE(resp, msg, sizeof(*tl)
 2665                     + (num * sizeof(struct typeinfo)), M_NOWAIT);
 2666                 if (resp == NULL) {
 2667                         error = ENOMEM;
 2668                         break;
 2669                 }
 2670                 tl = (struct typelist *) resp->data;
 2671 
 2672                 /* Cycle through the linked list of types */
 2673                 tl->numtypes = 0;
 2674                 mtx_lock(&ng_typelist_mtx);
 2675                 LIST_FOREACH(type, &ng_typelist, types) {
 2676                         struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
 2677 
 2678                         if (tl->numtypes >= num) {
 2679                                 log(LOG_ERR, "%s: number of %s changed\n",
 2680                                     __func__, "types");
 2681                                 break;
 2682                         }
 2683                         strcpy(tp->type_name, type->name);
 2684                         tp->numnodes = type->refs - 1; /* don't count list */
 2685                         tl->numtypes++;
 2686                 }
 2687                 mtx_unlock(&ng_typelist_mtx);
 2688                 break;
 2689             }
 2690 
 2691         case NGM_BINARY2ASCII:
 2692             {
 2693                 int bufSize = 20 * 1024;        /* XXX hard coded constant */
 2694                 const struct ng_parse_type *argstype;
 2695                 const struct ng_cmdlist *c;
 2696                 struct ng_mesg *binary, *ascii;
 2697 
 2698                 /* Data area must contain a valid netgraph message */
 2699                 binary = (struct ng_mesg *)msg->data;
 2700                 if (msg->header.arglen < sizeof(struct ng_mesg) ||
 2701                     (msg->header.arglen - sizeof(struct ng_mesg) <
 2702                     binary->header.arglen)) {
 2703                         TRAP_ERROR();
 2704                         error = EINVAL;
 2705                         break;
 2706                 }
 2707 
 2708                 /* Get a response message with lots of room */
 2709                 NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
 2710                 if (resp == NULL) {
 2711                         error = ENOMEM;
 2712                         break;
 2713                 }
 2714                 ascii = (struct ng_mesg *)resp->data;
 2715 
 2716                 /* Copy binary message header to response message payload */
 2717                 bcopy(binary, ascii, sizeof(*binary));
 2718 
 2719                 /* Find command by matching typecookie and command number */
 2720                 for (c = here->nd_type->cmdlist;
 2721                     c != NULL && c->name != NULL; c++) {
 2722                         if (binary->header.typecookie == c->cookie
 2723                             && binary->header.cmd == c->cmd)
 2724                                 break;
 2725                 }
 2726                 if (c == NULL || c->name == NULL) {
 2727                         for (c = ng_generic_cmds; c->name != NULL; c++) {
 2728                                 if (binary->header.typecookie == c->cookie
 2729                                     && binary->header.cmd == c->cmd)
 2730                                         break;
 2731                         }
 2732                         if (c->name == NULL) {
 2733                                 NG_FREE_MSG(resp);
 2734                                 error = ENOSYS;
 2735                                 break;
 2736                         }
 2737                 }
 2738 
 2739                 /* Convert command name to ASCII */
 2740                 snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
 2741                     "%s", c->name);
 2742 
 2743                 /* Convert command arguments to ASCII */
 2744                 argstype = (binary->header.flags & NGF_RESP) ?
 2745                     c->respType : c->mesgType;
 2746                 if (argstype == NULL) {
 2747                         *ascii->data = '\0';
 2748                 } else {
 2749                         if ((error = ng_unparse(argstype,
 2750                             (u_char *)binary->data,
 2751                             ascii->data, bufSize)) != 0) {
 2752                                 NG_FREE_MSG(resp);
 2753                                 break;
 2754                         }
 2755                 }
 2756 
 2757                 /* Return the result as struct ng_mesg plus ASCII string */
 2758                 bufSize = strlen(ascii->data) + 1;
 2759                 ascii->header.arglen = bufSize;
 2760                 resp->header.arglen = sizeof(*ascii) + bufSize;
 2761                 break;
 2762             }
 2763 
 2764         case NGM_ASCII2BINARY:
 2765             {
 2766                 int bufSize = 2000;     /* XXX hard coded constant */
 2767                 const struct ng_cmdlist *c;
 2768                 const struct ng_parse_type *argstype;
 2769                 struct ng_mesg *ascii, *binary;
 2770                 int off = 0;
 2771 
 2772                 /* Data area must contain at least a struct ng_mesg + '\0' */
 2773                 ascii = (struct ng_mesg *)msg->data;
 2774                 if ((msg->header.arglen < sizeof(*ascii) + 1) ||
 2775                     (ascii->header.arglen < 1) ||
 2776                     (msg->header.arglen < sizeof(*ascii) +
 2777                     ascii->header.arglen)) {
 2778                         TRAP_ERROR();
 2779                         error = EINVAL;
 2780                         break;
 2781                 }
 2782                 ascii->data[ascii->header.arglen - 1] = '\0';
 2783 
 2784                 /* Get a response message with lots of room */
 2785                 NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
 2786                 if (resp == NULL) {
 2787                         error = ENOMEM;
 2788                         break;
 2789                 }
 2790                 binary = (struct ng_mesg *)resp->data;
 2791 
 2792                 /* Copy ASCII message header to response message payload */
 2793                 bcopy(ascii, binary, sizeof(*ascii));
 2794 
 2795                 /* Find command by matching ASCII command string */
 2796                 for (c = here->nd_type->cmdlist;
 2797                     c != NULL && c->name != NULL; c++) {
 2798                         if (strcmp(ascii->header.cmdstr, c->name) == 0)
 2799                                 break;
 2800                 }
 2801                 if (c == NULL || c->name == NULL) {
 2802                         for (c = ng_generic_cmds; c->name != NULL; c++) {
 2803                                 if (strcmp(ascii->header.cmdstr, c->name) == 0)
 2804                                         break;
 2805                         }
 2806                         if (c->name == NULL) {
 2807                                 NG_FREE_MSG(resp);
 2808                                 error = ENOSYS;
 2809                                 break;
 2810                         }
 2811                 }
 2812 
 2813                 /* Convert command name to binary */
 2814                 binary->header.cmd = c->cmd;
 2815                 binary->header.typecookie = c->cookie;
 2816 
 2817                 /* Convert command arguments to binary */
 2818                 argstype = (binary->header.flags & NGF_RESP) ?
 2819                     c->respType : c->mesgType;
 2820                 if (argstype == NULL) {
 2821                         bufSize = 0;
 2822                 } else {
 2823                         if ((error = ng_parse(argstype, ascii->data,
 2824                             &off, (u_char *)binary->data, &bufSize)) != 0) {
 2825                                 NG_FREE_MSG(resp);
 2826                                 break;
 2827                         }
 2828                 }
 2829 
 2830                 /* Return the result */
 2831                 binary->header.arglen = bufSize;
 2832                 resp->header.arglen = sizeof(*binary) + bufSize;
 2833                 break;
 2834             }
 2835 
 2836         case NGM_TEXT_CONFIG:
 2837         case NGM_TEXT_STATUS:
 2838                 /*
 2839                  * This one is tricky as it passes the command down to the
 2840                  * actual node, even though it is a generic type command.
 2841                  * This means we must assume that the item/msg is already freed
 2842                  * when control passes back to us.
 2843                  */
 2844                 if (here->nd_type->rcvmsg != NULL) {
 2845                         NGI_MSG(item) = msg; /* put it back as we found it */
 2846                         return((*here->nd_type->rcvmsg)(here, item, lasthook));
 2847                 }
 2848                 /* Fall through if rcvmsg not supported */
 2849         default:
 2850                 TRAP_ERROR();
 2851                 error = EINVAL;
 2852         }
 2853         /*
 2854          * Sometimes a generic message may be statically allocated
 2855          * to avoid problems with allocating when in tight memeory situations.
 2856          * Don't free it if it is so.
 2857          * I break them appart here, because erros may cause a free if the item
 2858          * in which case we'd be doing it twice.
 2859          * they are kept together above, to simplify freeing.
 2860          */
 2861 out:
 2862         NG_RESPOND_MSG(error, here, item, resp);
 2863         NG_FREE_MSG(msg);
 2864         return (error);
 2865 }
 2866 
 2867 /************************************************************************
 2868                         Queue element get/free routines
 2869 ************************************************************************/
 2870 
 2871 uma_zone_t                      ng_qzone;
 2872 uma_zone_t                      ng_qdzone;
 2873 static int                      numthreads = 0; /* number of queue threads */
 2874 static int                      maxalloc = 4096;/* limit the damage of a leak */
 2875 static int                      maxdata = 512;  /* limit the damage of a DoS */
 2876 
 2877 TUNABLE_INT("net.graph.threads", &numthreads);
 2878 SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
 2879     0, "Number of queue processing threads");
 2880 TUNABLE_INT("net.graph.maxalloc", &maxalloc);
 2881 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
 2882     0, "Maximum number of non-data queue items to allocate");
 2883 TUNABLE_INT("net.graph.maxdata", &maxdata);
 2884 SYSCTL_INT(_net_graph, OID_AUTO, maxdata, CTLFLAG_RDTUN, &maxdata,
 2885     0, "Maximum number of data queue items to allocate");
 2886 
 2887 #ifdef  NETGRAPH_DEBUG
 2888 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
 2889 static int                      allocated;      /* number of items malloc'd */
 2890 #endif
 2891 
 2892 /*
 2893  * Get a queue entry.
 2894  * This is usually called when a packet first enters netgraph.
 2895  * By definition, this is usually from an interrupt, or from a user.
 2896  * Users are not so important, but try be quick for the times that it's
 2897  * an interrupt.
 2898  */
 2899 static __inline item_p
 2900 ng_alloc_item(int type, int flags)
 2901 {
 2902         item_p item;
 2903 
 2904         KASSERT(((type & ~NGQF_TYPE) == 0),
 2905             ("%s: incorrect item type: %d", __func__, type));
 2906 
 2907         item = uma_zalloc((type == NGQF_DATA)?ng_qdzone:ng_qzone,
 2908             ((flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT) | M_ZERO);
 2909 
 2910         if (item) {
 2911                 item->el_flags = type;
 2912 #ifdef  NETGRAPH_DEBUG
 2913                 mtx_lock(&ngq_mtx);
 2914                 TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
 2915                 allocated++;
 2916                 mtx_unlock(&ngq_mtx);
 2917 #endif
 2918         }
 2919 
 2920         return (item);
 2921 }
 2922 
 2923 /*
 2924  * Release a queue entry
 2925  */
 2926 void
 2927 ng_free_item(item_p item)
 2928 {
 2929         /*
 2930          * The item may hold resources on it's own. We need to free
 2931          * these before we can free the item. What they are depends upon
 2932          * what kind of item it is. it is important that nodes zero
 2933          * out pointers to resources that they remove from the item
 2934          * or we release them again here.
 2935          */
 2936         switch (item->el_flags & NGQF_TYPE) {
 2937         case NGQF_DATA:
 2938                 /* If we have an mbuf still attached.. */
 2939                 NG_FREE_M(_NGI_M(item));
 2940                 break;
 2941         case NGQF_MESG:
 2942                 _NGI_RETADDR(item) = 0;
 2943                 NG_FREE_MSG(_NGI_MSG(item));
 2944                 break;
 2945         case NGQF_FN:
 2946         case NGQF_FN2:
 2947                 /* nothing to free really, */
 2948                 _NGI_FN(item) = NULL;
 2949                 _NGI_ARG1(item) = NULL;
 2950                 _NGI_ARG2(item) = 0;
 2951                 break;
 2952         }
 2953         /* If we still have a node or hook referenced... */
 2954         _NGI_CLR_NODE(item);
 2955         _NGI_CLR_HOOK(item);
 2956 
 2957 #ifdef  NETGRAPH_DEBUG
 2958         mtx_lock(&ngq_mtx);
 2959         TAILQ_REMOVE(&ng_itemlist, item, all);
 2960         allocated--;
 2961         mtx_unlock(&ngq_mtx);
 2962 #endif
 2963         uma_zfree(((item->el_flags & NGQF_TYPE) == NGQF_DATA)?
 2964             ng_qdzone:ng_qzone, item);
 2965 }
 2966 
 2967 /*
 2968  * Change type of the queue entry.
 2969  * Possibly reallocates it from another UMA zone.
 2970  */
 2971 static __inline item_p
 2972 ng_realloc_item(item_p pitem, int type, int flags)
 2973 {
 2974         item_p item;
 2975         int from, to;
 2976 
 2977         KASSERT((pitem != NULL), ("%s: can't reallocate NULL", __func__));
 2978         KASSERT(((type & ~NGQF_TYPE) == 0),
 2979             ("%s: incorrect item type: %d", __func__, type));
 2980 
 2981         from = ((pitem->el_flags & NGQF_TYPE) == NGQF_DATA);
 2982         to = (type == NGQF_DATA);
 2983         if (from != to) {
 2984                 /* If reallocation is required do it and copy item. */
 2985                 if ((item = ng_alloc_item(type, flags)) == NULL) {
 2986                         ng_free_item(pitem);
 2987                         return (NULL);
 2988                 }
 2989                 *item = *pitem;
 2990                 ng_free_item(pitem);
 2991         } else
 2992                 item = pitem;
 2993         item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
 2994 
 2995         return (item);
 2996 }
 2997 
 2998 /************************************************************************
 2999                         Module routines
 3000 ************************************************************************/
 3001 
 3002 /*
 3003  * Handle the loading/unloading of a netgraph node type module
 3004  */
 3005 int
 3006 ng_mod_event(module_t mod, int event, void *data)
 3007 {
 3008         struct ng_type *const type = data;
 3009         int s, error = 0;
 3010 
 3011         switch (event) {
 3012         case MOD_LOAD:
 3013 
 3014                 /* Register new netgraph node type */
 3015                 s = splnet();
 3016                 if ((error = ng_newtype(type)) != 0) {
 3017                         splx(s);
 3018                         break;
 3019                 }
 3020 
 3021                 /* Call type specific code */
 3022                 if (type->mod_event != NULL)
 3023                         if ((error = (*type->mod_event)(mod, event, data))) {
 3024                                 mtx_lock(&ng_typelist_mtx);
 3025                                 type->refs--;   /* undo it */
 3026                                 LIST_REMOVE(type, types);
 3027                                 mtx_unlock(&ng_typelist_mtx);
 3028                         }
 3029                 splx(s);
 3030                 break;
 3031 
 3032         case MOD_UNLOAD:
 3033                 s = splnet();
 3034                 if (type->refs > 1) {           /* make sure no nodes exist! */
 3035                         error = EBUSY;
 3036                 } else {
 3037                         if (type->refs == 0) {
 3038                                 /* failed load, nothing to undo */
 3039                                 splx(s);
 3040                                 break;
 3041                         }
 3042                         if (type->mod_event != NULL) {  /* check with type */
 3043                                 error = (*type->mod_event)(mod, event, data);
 3044                                 if (error != 0) {       /* type refuses.. */
 3045                                         splx(s);
 3046                                         break;
 3047                                 }
 3048                         }
 3049                         mtx_lock(&ng_typelist_mtx);
 3050                         LIST_REMOVE(type, types);
 3051                         mtx_unlock(&ng_typelist_mtx);
 3052                 }
 3053                 splx(s);
 3054                 break;
 3055 
 3056         default:
 3057                 if (type->mod_event != NULL)
 3058                         error = (*type->mod_event)(mod, event, data);
 3059                 else
 3060                         error = EOPNOTSUPP;             /* XXX ? */
 3061                 break;
 3062         }
 3063         return (error);
 3064 }
 3065 
 3066 #ifdef VIMAGE 
 3067 static void
 3068 vnet_netgraph_uninit(const void *unused __unused)
 3069 {
 3070 #if 0
 3071         node_p node, last_killed = NULL;
 3072 
 3073         /* XXXRW: utterly bogus. */
 3074         while ((node = LIST_FIRST(&V_ng_allnodes)) != NULL) {
 3075                 if (node == last_killed) {
 3076                         /* This should never happen */
 3077                         node->nd_flags |= NGF_REALLY_DIE;
 3078                         printf("netgraph node %s needs NGF_REALLY_DIE\n",
 3079                             node->nd_name);
 3080                         ng_rmnode(node, NULL, NULL, 0);
 3081                         /* This must never happen */
 3082                         if (node == LIST_FIRST(&V_ng_allnodes))
 3083                                 panic("netgraph node %s won't die",
 3084                                     node->nd_name);
 3085                 }
 3086                 ng_rmnode(node, NULL, NULL, 0);
 3087                 last_killed = node;
 3088         }
 3089 #endif
 3090 }
 3091 VNET_SYSUNINIT(vnet_netgraph_uninit, SI_SUB_NETGRAPH, SI_ORDER_ANY,
 3092     vnet_netgraph_uninit, NULL);
 3093 #endif /* VIMAGE */
 3094 
 3095 /*
 3096  * Handle loading and unloading for this code.
 3097  * The only thing we need to link into is the NETISR strucure.
 3098  */
 3099 static int
 3100 ngb_mod_event(module_t mod, int event, void *data)
 3101 {
 3102         struct proc *p;
 3103         struct thread *td;
 3104         int i, error = 0;
 3105 
 3106         switch (event) {
 3107         case MOD_LOAD:
 3108                 /* Initialize everything. */
 3109                 NG_WORKLIST_LOCK_INIT();
 3110                 mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL,
 3111                     MTX_DEF);
 3112                 mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", NULL,
 3113                     MTX_DEF);
 3114                 mtx_init(&ng_namehash_mtx, "netgraph namehash mutex", NULL,
 3115                     MTX_DEF);
 3116                 mtx_init(&ng_topo_mtx, "netgraph topology mutex", NULL,
 3117                     MTX_DEF);
 3118 #ifdef  NETGRAPH_DEBUG
 3119                 mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
 3120                     MTX_DEF);
 3121                 mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
 3122                     MTX_DEF);
 3123 #endif
 3124                 ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
 3125                     NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
 3126                 uma_zone_set_max(ng_qzone, maxalloc);
 3127                 ng_qdzone = uma_zcreate("NetGraph data items", sizeof(struct ng_item),
 3128                     NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
 3129                 uma_zone_set_max(ng_qdzone, maxdata);
 3130                 /* Autoconfigure number of threads. */
 3131                 if (numthreads <= 0)
 3132                         numthreads = mp_ncpus;
 3133                 /* Create threads. */
 3134                 p = NULL; /* start with no process */
 3135                 for (i = 0; i < numthreads; i++) {
 3136                         if (kproc_kthread_add(ngthread, NULL, &p, &td,
 3137                             RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
 3138                                 numthreads = i;
 3139                                 break;
 3140                         }
 3141                 }
 3142                 break;
 3143         case MOD_UNLOAD:
 3144                 /* You can't unload it because an interface may be using it. */
 3145                 error = EBUSY;
 3146                 break;
 3147         default:
 3148                 error = EOPNOTSUPP;
 3149                 break;
 3150         }
 3151         return (error);
 3152 }
 3153 
 3154 static moduledata_t netgraph_mod = {
 3155         "netgraph",
 3156         ngb_mod_event,
 3157         (NULL)
 3158 };
 3159 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_MIDDLE);
 3160 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
 3161 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
 3162 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
 3163 
 3164 #ifdef  NETGRAPH_DEBUG
 3165 void
 3166 dumphook (hook_p hook, char *file, int line)
 3167 {
 3168         printf("hook: name %s, %d refs, Last touched:\n",
 3169                 _NG_HOOK_NAME(hook), hook->hk_refs);
 3170         printf("        Last active @ %s, line %d\n",
 3171                 hook->lastfile, hook->lastline);
 3172         if (line) {
 3173                 printf(" problem discovered at file %s, line %d\n", file, line);
 3174         }
 3175 }
 3176 
 3177 void
 3178 dumpnode(node_p node, char *file, int line)
 3179 {
 3180         printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
 3181                 _NG_NODE_ID(node), node->nd_type->name,
 3182                 node->nd_numhooks, node->nd_flags,
 3183                 node->nd_refs, node->nd_name);
 3184         printf("        Last active @ %s, line %d\n",
 3185                 node->lastfile, node->lastline);
 3186         if (line) {
 3187                 printf(" problem discovered at file %s, line %d\n", file, line);
 3188         }
 3189 }
 3190 
 3191 void
 3192 dumpitem(item_p item, char *file, int line)
 3193 {
 3194         printf(" ACTIVE item, last used at %s, line %d",
 3195                 item->lastfile, item->lastline);
 3196         switch(item->el_flags & NGQF_TYPE) {
 3197         case NGQF_DATA:
 3198                 printf(" - [data]\n");
 3199                 break;
 3200         case NGQF_MESG:
 3201                 printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
 3202                 break;
 3203         case NGQF_FN:
 3204                 printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
 3205                         _NGI_FN(item),
 3206                         _NGI_NODE(item),
 3207                         _NGI_HOOK(item),
 3208                         item->body.fn.fn_arg1,
 3209                         item->body.fn.fn_arg2,
 3210                         item->body.fn.fn_arg2);
 3211                 break;
 3212         case NGQF_FN2:
 3213                 printf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
 3214                         _NGI_FN2(item),
 3215                         _NGI_NODE(item),
 3216                         _NGI_HOOK(item),
 3217                         item->body.fn.fn_arg1,
 3218                         item->body.fn.fn_arg2,
 3219                         item->body.fn.fn_arg2);
 3220                 break;
 3221         }
 3222         if (line) {
 3223                 printf(" problem discovered at file %s, line %d\n", file, line);
 3224                 if (_NGI_NODE(item)) {
 3225                         printf("node %p ([%x])\n",
 3226                                 _NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
 3227                 }
 3228         }
 3229 }
 3230 
 3231 static void
 3232 ng_dumpitems(void)
 3233 {
 3234         item_p item;
 3235         int i = 1;
 3236         TAILQ_FOREACH(item, &ng_itemlist, all) {
 3237                 printf("[%d] ", i++);
 3238                 dumpitem(item, NULL, 0);
 3239         }
 3240 }
 3241 
 3242 static void
 3243 ng_dumpnodes(void)
 3244 {
 3245         node_p node;
 3246         int i = 1;
 3247         mtx_lock(&ng_nodelist_mtx);
 3248         SLIST_FOREACH(node, &ng_allnodes, nd_all) {
 3249                 printf("[%d] ", i++);
 3250                 dumpnode(node, NULL, 0);
 3251         }
 3252         mtx_unlock(&ng_nodelist_mtx);
 3253 }
 3254 
 3255 static void
 3256 ng_dumphooks(void)
 3257 {
 3258         hook_p hook;
 3259         int i = 1;
 3260         mtx_lock(&ng_nodelist_mtx);
 3261         SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
 3262                 printf("[%d] ", i++);
 3263                 dumphook(hook, NULL, 0);
 3264         }
 3265         mtx_unlock(&ng_nodelist_mtx);
 3266 }
 3267 
 3268 static int
 3269 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
 3270 {
 3271         int error;
 3272         int val;
 3273         int i;
 3274 
 3275         val = allocated;
 3276         i = 1;
 3277         error = sysctl_handle_int(oidp, &val, 0, req);
 3278         if (error != 0 || req->newptr == NULL)
 3279                 return (error);
 3280         if (val == 42) {
 3281                 ng_dumpitems();
 3282                 ng_dumpnodes();
 3283                 ng_dumphooks();
 3284         }
 3285         return (0);
 3286 }
 3287 
 3288 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
 3289     0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
 3290 #endif  /* NETGRAPH_DEBUG */
 3291 
 3292 
 3293 /***********************************************************************
 3294 * Worklist routines
 3295 **********************************************************************/
 3296 /*
 3297  * Pick a node off the list of nodes with work,
 3298  * try get an item to process off it. Remove the node from the list.
 3299  */
 3300 static void
 3301 ngthread(void *arg)
 3302 {
 3303         for (;;) {
 3304                 node_p  node;
 3305 
 3306                 /* Get node from the worklist. */
 3307                 NG_WORKLIST_LOCK();
 3308                 while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
 3309                         NG_WORKLIST_SLEEP();
 3310                 STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
 3311                 NG_WORKLIST_UNLOCK();
 3312                 CURVNET_SET(node->nd_vnet);
 3313                 CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
 3314                     __func__, node->nd_ID, node);
 3315                 /*
 3316                  * We have the node. We also take over the reference
 3317                  * that the list had on it.
 3318                  * Now process as much as you can, until it won't
 3319                  * let you have another item off the queue.
 3320                  * All this time, keep the reference
 3321                  * that lets us be sure that the node still exists.
 3322                  * Let the reference go at the last minute.
 3323                  */
 3324                 for (;;) {
 3325                         item_p item;
 3326                         int rw;
 3327 
 3328                         NG_QUEUE_LOCK(&node->nd_input_queue);
 3329                         item = ng_dequeue(node, &rw);
 3330                         if (item == NULL) {
 3331                                 node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
 3332                                 NG_QUEUE_UNLOCK(&node->nd_input_queue);
 3333                                 break; /* go look for another node */
 3334                         } else {
 3335                                 NG_QUEUE_UNLOCK(&node->nd_input_queue);
 3336                                 NGI_GET_NODE(item, node); /* zaps stored node */
 3337                                 ng_apply_item(node, item, rw);
 3338                                 NG_NODE_UNREF(node);
 3339                         }
 3340                 }
 3341                 NG_NODE_UNREF(node);
 3342                 CURVNET_RESTORE();
 3343         }
 3344 }
 3345 
 3346 /*
 3347  * XXX
 3348  * It's posible that a debugging NG_NODE_REF may need
 3349  * to be outside the mutex zone
 3350  */
 3351 static void
 3352 ng_worklist_add(node_p node)
 3353 {
 3354 
 3355         mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
 3356 
 3357         if ((node->nd_input_queue.q_flags2 & NGQ2_WORKQ) == 0) {
 3358                 /*
 3359                  * If we are not already on the work queue,
 3360                  * then put us on.
 3361                  */
 3362                 node->nd_input_queue.q_flags2 |= NGQ2_WORKQ;
 3363                 NG_NODE_REF(node); /* XXX fafe in mutex? */
 3364                 NG_WORKLIST_LOCK();
 3365                 STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
 3366                 NG_WORKLIST_UNLOCK();
 3367                 CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
 3368                     node->nd_ID, node);
 3369                 NG_WORKLIST_WAKEUP();
 3370         } else {
 3371                 CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
 3372                     __func__, node->nd_ID, node);
 3373         }
 3374 }
 3375 
 3376 
 3377 /***********************************************************************
 3378 * Externally useable functions to set up a queue item ready for sending
 3379 ***********************************************************************/
 3380 
 3381 #ifdef  NETGRAPH_DEBUG
 3382 #define ITEM_DEBUG_CHECKS                                               \
 3383         do {                                                            \
 3384                 if (NGI_NODE(item) ) {                                  \
 3385                         printf("item already has node");                \
 3386                         kdb_enter(KDB_WHY_NETGRAPH, "has node");        \
 3387                         NGI_CLR_NODE(item);                             \
 3388                 }                                                       \
 3389                 if (NGI_HOOK(item) ) {                                  \
 3390                         printf("item already has hook");                \
 3391                         kdb_enter(KDB_WHY_NETGRAPH, "has hook");        \
 3392                         NGI_CLR_HOOK(item);                             \
 3393                 }                                                       \
 3394         } while (0)
 3395 #else
 3396 #define ITEM_DEBUG_CHECKS
 3397 #endif
 3398 
 3399 /*
 3400  * Put mbuf into the item.
 3401  * Hook and node references will be removed when the item is dequeued.
 3402  * (or equivalent)
 3403  * (XXX) Unsafe because no reference held by peer on remote node.
 3404  * remote node might go away in this timescale.
 3405  * We know the hooks can't go away because that would require getting
 3406  * a writer item on both nodes and we must have at least a  reader
 3407  * here to be able to do this.
 3408  * Note that the hook loaded is the REMOTE hook.
 3409  *
 3410  * This is possibly in the critical path for new data.
 3411  */
 3412 item_p
 3413 ng_package_data(struct mbuf *m, int flags)
 3414 {
 3415         item_p item;
 3416 
 3417         if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
 3418                 NG_FREE_M(m);
 3419                 return (NULL);
 3420         }
 3421         ITEM_DEBUG_CHECKS;
 3422         item->el_flags |= NGQF_READER;
 3423         NGI_M(item) = m;
 3424         return (item);
 3425 }
 3426 
 3427 /*
 3428  * Allocate a queue item and put items into it..
 3429  * Evaluate the address as this will be needed to queue it and
 3430  * to work out what some of the fields should be.
 3431  * Hook and node references will be removed when the item is dequeued.
 3432  * (or equivalent)
 3433  */
 3434 item_p
 3435 ng_package_msg(struct ng_mesg *msg, int flags)
 3436 {
 3437         item_p item;
 3438 
 3439         if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
 3440                 NG_FREE_MSG(msg);
 3441                 return (NULL);
 3442         }
 3443         ITEM_DEBUG_CHECKS;
 3444         /* Messages items count as writers unless explicitly exempted. */
 3445         if (msg->header.cmd & NGM_READONLY)
 3446                 item->el_flags |= NGQF_READER;
 3447         else
 3448                 item->el_flags |= NGQF_WRITER;
 3449         /*
 3450          * Set the current lasthook into the queue item
 3451          */
 3452         NGI_MSG(item) = msg;
 3453         NGI_RETADDR(item) = 0;
 3454         return (item);
 3455 }
 3456 
 3457 
 3458 
 3459 #define SET_RETADDR(item, here, retaddr)                                \
 3460         do {    /* Data or fn items don't have retaddrs */              \
 3461                 if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {        \
 3462                         if (retaddr) {                                  \
 3463                                 NGI_RETADDR(item) = retaddr;            \
 3464                         } else {                                        \
 3465                                 /*                                      \
 3466                                  * The old return address should be ok. \
 3467                                  * If there isn't one, use the address  \
 3468                                  * here.                                \
 3469                                  */                                     \
 3470                                 if (NGI_RETADDR(item) == 0) {           \
 3471                                         NGI_RETADDR(item)               \
 3472                                                 = ng_node2ID(here);     \
 3473                                 }                                       \
 3474                         }                                               \
 3475                 }                                                       \
 3476         } while (0)
 3477 
 3478 int
 3479 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
 3480 {
 3481         hook_p peer;
 3482         node_p peernode;
 3483         ITEM_DEBUG_CHECKS;
 3484         /*
 3485          * Quick sanity check..
 3486          * Since a hook holds a reference on it's node, once we know
 3487          * that the peer is still connected (even if invalid,) we know
 3488          * that the peer node is present, though maybe invalid.
 3489          */
 3490         if ((hook == NULL) ||
 3491             NG_HOOK_NOT_VALID(hook) ||
 3492             NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
 3493             NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
 3494                 NG_FREE_ITEM(item);
 3495                 TRAP_ERROR();
 3496                 return (ENETDOWN);
 3497         }
 3498 
 3499         /*
 3500          * Transfer our interest to the other (peer) end.
 3501          */
 3502         NG_HOOK_REF(peer);
 3503         NG_NODE_REF(peernode);
 3504         NGI_SET_HOOK(item, peer);
 3505         NGI_SET_NODE(item, peernode);
 3506         SET_RETADDR(item, here, retaddr);
 3507         return (0);
 3508 }
 3509 
 3510 int
 3511 ng_address_path(node_p here, item_p item, char *address, ng_ID_t retaddr)
 3512 {
 3513         node_p  dest = NULL;
 3514         hook_p  hook = NULL;
 3515         int     error;
 3516 
 3517         ITEM_DEBUG_CHECKS;
 3518         /*
 3519          * Note that ng_path2noderef increments the reference count
 3520          * on the node for us if it finds one. So we don't have to.
 3521          */
 3522         error = ng_path2noderef(here, address, &dest, &hook);
 3523         if (error) {
 3524                 NG_FREE_ITEM(item);
 3525                 return (error);
 3526         }
 3527         NGI_SET_NODE(item, dest);
 3528         if ( hook) {
 3529                 NG_HOOK_REF(hook);      /* don't let it go while on the queue */
 3530                 NGI_SET_HOOK(item, hook);
 3531         }
 3532         SET_RETADDR(item, here, retaddr);
 3533         return (0);
 3534 }
 3535 
 3536 int
 3537 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
 3538 {
 3539         node_p dest;
 3540 
 3541         ITEM_DEBUG_CHECKS;
 3542         /*
 3543          * Find the target node.
 3544          */
 3545         dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
 3546         if (dest == NULL) {
 3547                 NG_FREE_ITEM(item);
 3548                 TRAP_ERROR();
 3549                 return(EINVAL);
 3550         }
 3551         /* Fill out the contents */
 3552         NGI_SET_NODE(item, dest);
 3553         NGI_CLR_HOOK(item);
 3554         SET_RETADDR(item, here, retaddr);
 3555         return (0);
 3556 }
 3557 
 3558 /*
 3559  * special case to send a message to self (e.g. destroy node)
 3560  * Possibly indicate an arrival hook too.
 3561  * Useful for removing that hook :-)
 3562  */
 3563 item_p
 3564 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
 3565 {
 3566         item_p item;
 3567 
 3568         /*
 3569          * Find the target node.
 3570          * If there is a HOOK argument, then use that in preference
 3571          * to the address.
 3572          */
 3573         if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
 3574                 NG_FREE_MSG(msg);
 3575                 return (NULL);
 3576         }
 3577 
 3578         /* Fill out the contents */
 3579         item->el_flags |= NGQF_WRITER;
 3580         NG_NODE_REF(here);
 3581         NGI_SET_NODE(item, here);
 3582         if (hook) {
 3583                 NG_HOOK_REF(hook);
 3584                 NGI_SET_HOOK(item, hook);
 3585         }
 3586         NGI_MSG(item) = msg;
 3587         NGI_RETADDR(item) = ng_node2ID(here);
 3588         return (item);
 3589 }
 3590 
 3591 /*
 3592  * Send ng_item_fn function call to the specified node.
 3593  */
 3594 
 3595 int
 3596 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
 3597 {
 3598 
 3599         return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
 3600 }
 3601 
 3602 int
 3603 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
 3604         int flags)
 3605 {
 3606         item_p item;
 3607 
 3608         if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
 3609                 return (ENOMEM);
 3610         }
 3611         item->el_flags |= NGQF_WRITER;
 3612         NG_NODE_REF(node); /* and one for the item */
 3613         NGI_SET_NODE(item, node);
 3614         if (hook) {
 3615                 NG_HOOK_REF(hook);
 3616                 NGI_SET_HOOK(item, hook);
 3617         }
 3618         NGI_FN(item) = fn;
 3619         NGI_ARG1(item) = arg1;
 3620         NGI_ARG2(item) = arg2;
 3621         return(ng_snd_item(item, flags));
 3622 }
 3623 
 3624 /*
 3625  * Send ng_item_fn2 function call to the specified node.
 3626  *
 3627  * If an optional pitem parameter is supplied, its apply
 3628  * callback will be copied to the new item. If also NG_REUSE_ITEM
 3629  * flag is set, no new item will be allocated, but pitem will
 3630  * be used.
 3631  */
 3632 int
 3633 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
 3634         int arg2, int flags)
 3635 {
 3636         item_p item;
 3637 
 3638         KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
 3639             ("%s: NG_REUSE_ITEM but no pitem", __func__));
 3640 
 3641         /*
 3642          * Allocate a new item if no supplied or
 3643          * if we can't use supplied one.
 3644          */
 3645         if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
 3646                 if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
 3647                         return (ENOMEM);
 3648                 if (pitem != NULL)
 3649                         item->apply = pitem->apply;
 3650         } else {
 3651                 if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
 3652                         return (ENOMEM);
 3653         }
 3654 
 3655         item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
 3656         NG_NODE_REF(node); /* and one for the item */
 3657         NGI_SET_NODE(item, node);
 3658         if (hook) {
 3659                 NG_HOOK_REF(hook);
 3660                 NGI_SET_HOOK(item, hook);
 3661         }
 3662         NGI_FN2(item) = fn;
 3663         NGI_ARG1(item) = arg1;
 3664         NGI_ARG2(item) = arg2;
 3665         return(ng_snd_item(item, flags));
 3666 }
 3667 
 3668 /*
 3669  * Official timeout routines for Netgraph nodes.
 3670  */
 3671 static void
 3672 ng_callout_trampoline(void *arg)
 3673 {
 3674         item_p item = arg;
 3675 
 3676         CURVNET_SET(NGI_NODE(item)->nd_vnet);
 3677         ng_snd_item(item, 0);
 3678         CURVNET_RESTORE();
 3679 }
 3680 
 3681 
 3682 int
 3683 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
 3684     ng_item_fn *fn, void * arg1, int arg2)
 3685 {
 3686         item_p item, oitem;
 3687 
 3688         if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
 3689                 return (ENOMEM);
 3690 
 3691         item->el_flags |= NGQF_WRITER;
 3692         NG_NODE_REF(node);              /* and one for the item */
 3693         NGI_SET_NODE(item, node);
 3694         if (hook) {
 3695                 NG_HOOK_REF(hook);
 3696                 NGI_SET_HOOK(item, hook);
 3697         }
 3698         NGI_FN(item) = fn;
 3699         NGI_ARG1(item) = arg1;
 3700         NGI_ARG2(item) = arg2;
 3701         oitem = c->c_arg;
 3702         if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
 3703             oitem != NULL)
 3704                 NG_FREE_ITEM(oitem);
 3705         return (0);
 3706 }
 3707 
 3708 /* A special modified version of untimeout() */
 3709 int
 3710 ng_uncallout(struct callout *c, node_p node)
 3711 {
 3712         item_p item;
 3713         int rval;
 3714 
 3715         KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
 3716         KASSERT(node != NULL, ("ng_uncallout: NULL node"));
 3717 
 3718         rval = callout_stop(c);
 3719         item = c->c_arg;
 3720         /* Do an extra check */
 3721         if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
 3722             (NGI_NODE(item) == node)) {
 3723                 /*
 3724                  * We successfully removed it from the queue before it ran
 3725                  * So now we need to unreference everything that was
 3726                  * given extra references. (NG_FREE_ITEM does this).
 3727                  */
 3728                 NG_FREE_ITEM(item);
 3729         }
 3730         c->c_arg = NULL;
 3731 
 3732         return (rval);
 3733 }
 3734 
 3735 /*
 3736  * Set the address, if none given, give the node here.
 3737  */
 3738 void
 3739 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
 3740 {
 3741         if (retaddr) {
 3742                 NGI_RETADDR(item) = retaddr;
 3743         } else {
 3744                 /*
 3745                  * The old return address should be ok.
 3746                  * If there isn't one, use the address here.
 3747                  */
 3748                 NGI_RETADDR(item) = ng_node2ID(here);
 3749         }
 3750 }
 3751 
 3752 #define TESTING
 3753 #ifdef TESTING
 3754 /* just test all the macros */
 3755 void
 3756 ng_macro_test(item_p item);
 3757 void
 3758 ng_macro_test(item_p item)
 3759 {
 3760         node_p node = NULL;
 3761         hook_p hook = NULL;
 3762         struct mbuf *m;
 3763         struct ng_mesg *msg;
 3764         ng_ID_t retaddr;
 3765         int     error;
 3766 
 3767         NGI_GET_M(item, m);
 3768         NGI_GET_MSG(item, msg);
 3769         retaddr = NGI_RETADDR(item);
 3770         NG_SEND_DATA(error, hook, m, NULL);
 3771         NG_SEND_DATA_ONLY(error, hook, m);
 3772         NG_FWD_NEW_DATA(error, item, hook, m);
 3773         NG_FWD_ITEM_HOOK(error, item, hook);
 3774         NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
 3775         NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
 3776         NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
 3777         NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
 3778 }
 3779 #endif /* TESTING */
 3780 

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