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

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    1 /*
    2  * ng_socket.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  * Author: Julian Elischer <julian@freebsd.org>
   39  *
   40  * $FreeBSD: releng/10.1/sys/netgraph/ng_socket.c 231823 2012-02-16 14:44:52Z glebius $
   41  * $Whistle: ng_socket.c,v 1.28 1999/11/01 09:24:52 julian Exp $
   42  */
   43 
   44 /*
   45  * Netgraph socket nodes
   46  *
   47  * There are two types of netgraph sockets, control and data.
   48  * Control sockets have a netgraph node, but data sockets are
   49  * parasitic on control sockets, and have no node of their own.
   50  */
   51 
   52 #include <sys/param.h>
   53 #include <sys/domain.h>
   54 #include <sys/hash.h>
   55 #include <sys/kernel.h>
   56 #include <sys/linker.h>
   57 #include <sys/lock.h>
   58 #include <sys/malloc.h>
   59 #include <sys/mbuf.h>
   60 #include <sys/mutex.h>
   61 #include <sys/priv.h>
   62 #include <sys/protosw.h>
   63 #include <sys/queue.h>
   64 #include <sys/socket.h>
   65 #include <sys/socketvar.h>
   66 #include <sys/syscallsubr.h>
   67 #include <sys/sysctl.h>
   68 
   69 #include <net/vnet.h>
   70 
   71 #include <netgraph/ng_message.h>
   72 #include <netgraph/netgraph.h>
   73 #include <netgraph/ng_socketvar.h>
   74 #include <netgraph/ng_socket.h>
   75 
   76 #ifdef NG_SEPARATE_MALLOC
   77 static MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info");
   78 static MALLOC_DEFINE(M_NETGRAPH_SOCK, "netgraph_sock", "netgraph socket info");
   79 #else
   80 #define M_NETGRAPH_PATH M_NETGRAPH
   81 #define M_NETGRAPH_SOCK M_NETGRAPH
   82 #endif
   83 
   84 /*
   85  * It's Ascii-art time!
   86  *   +-------------+   +-------------+
   87  *   |socket  (ctl)|   |socket (data)|
   88  *   +-------------+   +-------------+
   89  *          ^                 ^
   90  *          |                 |
   91  *          v                 v
   92  *    +-----------+     +-----------+
   93  *    |pcb   (ctl)|     |pcb  (data)|
   94  *    +-----------+     +-----------+
   95  *          ^                 ^
   96  *          |                 |
   97  *          v                 v
   98  *      +--------------------------+
   99  *      |   Socket type private    |
  100  *      |       data               |
  101  *      +--------------------------+
  102  *                   ^
  103  *                   |
  104  *                   v
  105  *           +----------------+
  106  *           | struct ng_node |
  107  *           +----------------+
  108  */
  109 
  110 /* Netgraph node methods */
  111 static ng_constructor_t ngs_constructor;
  112 static ng_rcvmsg_t      ngs_rcvmsg;
  113 static ng_shutdown_t    ngs_shutdown;
  114 static ng_newhook_t     ngs_newhook;
  115 static ng_connect_t     ngs_connect;
  116 static ng_findhook_t    ngs_findhook;
  117 static ng_rcvdata_t     ngs_rcvdata;
  118 static ng_disconnect_t  ngs_disconnect;
  119 
  120 /* Internal methods */
  121 static int      ng_attach_data(struct socket *so);
  122 static int      ng_attach_cntl(struct socket *so);
  123 static int      ng_attach_common(struct socket *so, int type);
  124 static void     ng_detach_common(struct ngpcb *pcbp, int type);
  125 static void     ng_socket_free_priv(struct ngsock *priv);
  126 static int      ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
  127 static int      ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
  128 
  129 static int      ngs_mod_event(module_t mod, int event, void *data);
  130 static void     ng_socket_item_applied(void *context, int error);
  131 
  132 /* Netgraph type descriptor */
  133 static struct ng_type typestruct = {
  134         .version =      NG_ABI_VERSION,
  135         .name =         NG_SOCKET_NODE_TYPE,
  136         .mod_event =    ngs_mod_event,
  137         .constructor =  ngs_constructor,
  138         .rcvmsg =       ngs_rcvmsg,
  139         .shutdown =     ngs_shutdown,
  140         .newhook =      ngs_newhook,
  141         .connect =      ngs_connect,
  142         .findhook =     ngs_findhook,
  143         .rcvdata =      ngs_rcvdata,
  144         .disconnect =   ngs_disconnect,
  145 };
  146 NETGRAPH_INIT_ORDERED(socket, &typestruct, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
  147 
  148 /* Buffer space */
  149 static u_long ngpdg_sendspace = 20 * 1024;      /* really max datagram size */
  150 SYSCTL_ULONG(_net_graph, OID_AUTO, maxdgram, CTLFLAG_RW,
  151     &ngpdg_sendspace , 0, "Maximum outgoing Netgraph datagram size");
  152 static u_long ngpdg_recvspace = 20 * 1024;
  153 SYSCTL_ULONG(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
  154     &ngpdg_recvspace , 0, "Maximum space for incoming Netgraph datagrams");
  155 
  156 /* List of all sockets (for netstat -f netgraph) */
  157 static LIST_HEAD(, ngpcb) ngsocklist;
  158 
  159 static struct mtx       ngsocketlist_mtx;
  160 
  161 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
  162 
  163 /* If getting unexplained errors returned, set this to "kdb_enter("X"); */
  164 #ifndef TRAP_ERROR
  165 #define TRAP_ERROR
  166 #endif
  167 
  168 struct hookpriv {
  169         LIST_ENTRY(hookpriv)    next;
  170         hook_p                  hook;
  171 };
  172 LIST_HEAD(ngshash, hookpriv);
  173 
  174 /* Per-node private data */
  175 struct ngsock {
  176         struct ng_node  *node;          /* the associated netgraph node */
  177         struct ngpcb    *datasock;      /* optional data socket */
  178         struct ngpcb    *ctlsock;       /* optional control socket */
  179         struct ngshash  *hash;          /* hash for hook names */
  180         u_long          hmask;          /* hash mask */
  181         int     flags;
  182         int     refs;
  183         struct mtx      mtx;            /* mtx to wait on */
  184         int             error;          /* place to store error */
  185 };
  186 
  187 #define NGS_FLAG_NOLINGER       1       /* close with last hook */
  188 
  189 /***************************************************************
  190         Control sockets
  191 ***************************************************************/
  192 
  193 static int
  194 ngc_attach(struct socket *so, int proto, struct thread *td)
  195 {
  196         struct ngpcb *const pcbp = sotongpcb(so);
  197         int error;
  198 
  199         error = priv_check(td, PRIV_NETGRAPH_CONTROL);
  200         if (error)
  201                 return (error);
  202         if (pcbp != NULL)
  203                 return (EISCONN);
  204         return (ng_attach_cntl(so));
  205 }
  206 
  207 static void
  208 ngc_detach(struct socket *so)
  209 {
  210         struct ngpcb *const pcbp = sotongpcb(so);
  211 
  212         KASSERT(pcbp != NULL, ("ngc_detach: pcbp == NULL"));
  213         ng_detach_common(pcbp, NG_CONTROL);
  214 }
  215 
  216 static int
  217 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
  218          struct mbuf *control, struct thread *td)
  219 {
  220         struct ngpcb *const pcbp = sotongpcb(so);
  221         struct ngsock *const priv = NG_NODE_PRIVATE(pcbp->sockdata->node);
  222         struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
  223         struct ng_mesg *msg;
  224         struct mbuf *m0;
  225         item_p item;
  226         char *path = NULL;
  227         int len, error = 0;
  228         struct ng_apply_info apply;
  229 
  230         if (control) {
  231                 error = EINVAL;
  232                 goto release;
  233         }
  234 
  235         /* Require destination as there may be >= 1 hooks on this node. */
  236         if (addr == NULL) {
  237                 error = EDESTADDRREQ;
  238                 goto release;
  239         }
  240 
  241         /*
  242          * Allocate an expendable buffer for the path, chop off
  243          * the sockaddr header, and make sure it's NUL terminated.
  244          */
  245         len = sap->sg_len - 2;
  246         path = malloc(len + 1, M_NETGRAPH_PATH, M_WAITOK);
  247         bcopy(sap->sg_data, path, len);
  248         path[len] = '\0';
  249 
  250         /*
  251          * Move the actual message out of mbufs into a linear buffer.
  252          * Start by adding up the size of the data. (could use mh_len?)
  253          */
  254         for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
  255                 len += m0->m_len;
  256 
  257         /*
  258          * Move the data into a linear buffer as well.
  259          * Messages are not delivered in mbufs.
  260          */
  261         msg = malloc(len + 1, M_NETGRAPH_MSG, M_WAITOK);
  262         m_copydata(m, 0, len, (char *)msg);
  263 
  264         if (msg->header.version != NG_VERSION) {
  265                 free(msg, M_NETGRAPH_MSG);
  266                 error = EINVAL;
  267                 goto release;
  268         }
  269 
  270         /*
  271          * Hack alert!
  272          * We look into the message and if it mkpeers a node of unknown type, we
  273          * try to load it. We need to do this now, in syscall thread, because if
  274          * message gets queued and applied later we will get panic.
  275          */
  276         if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
  277             msg->header.cmd == NGM_MKPEER) {
  278                 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
  279 
  280                 if (ng_findtype(mkp->type) == NULL) {
  281                         char filename[NG_TYPESIZ + 3];
  282                         int fileid;
  283 
  284                         /* Not found, try to load it as a loadable module. */
  285                         snprintf(filename, sizeof(filename), "ng_%s",
  286                             mkp->type);
  287                         error = kern_kldload(curthread, filename, &fileid);
  288                         if (error != 0) {
  289                                 free(msg, M_NETGRAPH_MSG);
  290                                 goto release;
  291                         }
  292 
  293                         /* See if type has been loaded successfully. */
  294                         if (ng_findtype(mkp->type) == NULL) {
  295                                 free(msg, M_NETGRAPH_MSG);
  296                                 (void)kern_kldunload(curthread, fileid,
  297                                     LINKER_UNLOAD_NORMAL);
  298                                 error =  ENXIO;
  299                                 goto release;
  300                         }
  301                 }
  302         }
  303 
  304         item = ng_package_msg(msg, M_WAITOK);
  305         if ((error = ng_address_path((pcbp->sockdata->node), item, path, 0))
  306             != 0) {
  307 #ifdef TRACE_MESSAGES
  308                 printf("ng_address_path: errx=%d\n", error);
  309 #endif
  310                 goto release;
  311         }
  312 
  313 #ifdef TRACE_MESSAGES
  314         printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
  315                 item->el_dest->nd_ID,
  316                 msg->header.typecookie,
  317                 msg->header.cmd,
  318                 msg->header.cmdstr,
  319                 msg->header.flags,
  320                 msg->header.token,
  321                 item->el_dest->nd_type->name);
  322 #endif
  323         SAVE_LINE(item);
  324         /*
  325          * We do not want to return from syscall until the item
  326          * is processed by destination node. We register callback
  327          * on the item, which will update priv->error when item
  328          * was applied.
  329          * If ng_snd_item() has queued item, we sleep until
  330          * callback wakes us up.
  331          */
  332         bzero(&apply, sizeof(apply));
  333         apply.apply = ng_socket_item_applied;
  334         apply.context = priv;
  335         item->apply = &apply;
  336         priv->error = -1;
  337 
  338         error = ng_snd_item(item, 0);
  339 
  340         mtx_lock(&priv->mtx);
  341         if (priv->error == -1)
  342                 msleep(priv, &priv->mtx, 0, "ngsock", 0);
  343         mtx_unlock(&priv->mtx);
  344         KASSERT(priv->error != -1,
  345             ("ng_socket: priv->error wasn't updated"));
  346         error = priv->error;
  347 
  348 release:
  349         if (path != NULL)
  350                 free(path, M_NETGRAPH_PATH);
  351         if (control != NULL)
  352                 m_freem(control);
  353         if (m != NULL)
  354                 m_freem(m);
  355         return (error);
  356 }
  357 
  358 static int
  359 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  360 {
  361         struct ngpcb *const pcbp = sotongpcb(so);
  362 
  363         if (pcbp == 0)
  364                 return (EINVAL);
  365         return (ng_bind(nam, pcbp));
  366 }
  367 
  368 static int
  369 ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  370 {
  371         /*
  372          * At this time refuse to do this.. it used to
  373          * do something but it was undocumented and not used.
  374          */
  375         printf("program tried to connect control socket to remote node\n");
  376         return (EINVAL);
  377 }
  378 
  379 /***************************************************************
  380         Data sockets
  381 ***************************************************************/
  382 
  383 static int
  384 ngd_attach(struct socket *so, int proto, struct thread *td)
  385 {
  386         struct ngpcb *const pcbp = sotongpcb(so);
  387 
  388         if (pcbp != NULL)
  389                 return (EISCONN);
  390         return (ng_attach_data(so));
  391 }
  392 
  393 static void
  394 ngd_detach(struct socket *so)
  395 {
  396         struct ngpcb *const pcbp = sotongpcb(so);
  397 
  398         KASSERT(pcbp != NULL, ("ngd_detach: pcbp == NULL"));
  399         ng_detach_common(pcbp, NG_DATA);
  400 }
  401 
  402 static int
  403 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
  404          struct mbuf *control, struct thread *td)
  405 {
  406         struct ngpcb *const pcbp = sotongpcb(so);
  407         struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
  408         int     len, error;
  409         hook_p  hook = NULL;
  410         char    hookname[NG_HOOKSIZ];
  411 
  412         if ((pcbp == NULL) || (control != NULL)) {
  413                 error = EINVAL;
  414                 goto release;
  415         }
  416         if (pcbp->sockdata == NULL) {
  417                 error = ENOTCONN;
  418                 goto release;
  419         }
  420 
  421         if (sap == NULL)
  422                 len = 0;                /* Make compiler happy. */
  423         else
  424                 len = sap->sg_len - 2;
  425 
  426         /*
  427          * If the user used any of these ways to not specify an address
  428          * then handle specially.
  429          */
  430         if ((sap == NULL) || (len <= 0) || (*sap->sg_data == '\0')) {
  431                 if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
  432                         error = EDESTADDRREQ;
  433                         goto release;
  434                 }
  435                 /*
  436                  * If exactly one hook exists, just use it.
  437                  * Special case to allow write(2) to work on an ng_socket.
  438                  */
  439                 hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
  440         } else {
  441                 if (len >= NG_HOOKSIZ) {
  442                         error = EINVAL;
  443                         goto release;
  444                 }
  445 
  446                 /*
  447                  * chop off the sockaddr header, and make sure it's NUL
  448                  * terminated
  449                  */
  450                 bcopy(sap->sg_data, hookname, len);
  451                 hookname[len] = '\0';
  452 
  453                 /* Find the correct hook from 'hookname' */
  454                 hook = ng_findhook(pcbp->sockdata->node, hookname);
  455                 if (hook == NULL) {
  456                         error = EHOSTUNREACH;
  457                         goto release;
  458                 }
  459         }
  460 
  461         /* Send data. */
  462         NG_SEND_DATA_FLAGS(error, hook, m, NG_WAITOK);
  463 
  464 release:
  465         if (control != NULL)
  466                 m_freem(control);
  467         if (m != NULL)
  468                 m_freem(m);
  469         return (error);
  470 }
  471 
  472 static int
  473 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  474 {
  475         struct ngpcb *const pcbp = sotongpcb(so);
  476 
  477         if (pcbp == 0)
  478                 return (EINVAL);
  479         return (ng_connect_data(nam, pcbp));
  480 }
  481 
  482 /*
  483  * Used for both data and control sockets
  484  */
  485 static int
  486 ng_getsockaddr(struct socket *so, struct sockaddr **addr)
  487 {
  488         struct ngpcb *pcbp;
  489         struct sockaddr_ng *sg;
  490         int sg_len;
  491         int error = 0;
  492 
  493         pcbp = sotongpcb(so);
  494         if ((pcbp == NULL) || (pcbp->sockdata == NULL))
  495                 /* XXXGL: can this still happen? */
  496                 return (EINVAL);
  497 
  498         sg_len = sizeof(struct sockaddr_ng) + NG_NODESIZ -
  499             sizeof(sg->sg_data);
  500         sg = malloc(sg_len, M_SONAME, M_WAITOK | M_ZERO);
  501 
  502         mtx_lock(&pcbp->sockdata->mtx);
  503         if (pcbp->sockdata->node != NULL) {
  504                 node_p node = pcbp->sockdata->node;
  505 
  506                 if (NG_NODE_HAS_NAME(node))
  507                         bcopy(NG_NODE_NAME(node), sg->sg_data,
  508                             strlen(NG_NODE_NAME(node)));
  509                 mtx_unlock(&pcbp->sockdata->mtx);
  510 
  511                 sg->sg_len = sg_len;
  512                 sg->sg_family = AF_NETGRAPH;
  513                 *addr = (struct sockaddr *)sg;
  514         } else {
  515                 mtx_unlock(&pcbp->sockdata->mtx);
  516                 free(sg, M_SONAME);
  517                 error = EINVAL;
  518         }
  519 
  520         return (error);
  521 }
  522 
  523 /*
  524  * Attach a socket to it's protocol specific partner.
  525  * For a control socket, actually create a netgraph node and attach
  526  * to it as well.
  527  */
  528 
  529 static int
  530 ng_attach_cntl(struct socket *so)
  531 {
  532         struct ngsock *priv;
  533         struct ngpcb *pcbp;
  534         node_p node;
  535         int error;
  536 
  537         /* Setup protocol control block */
  538         if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
  539                 return (error);
  540         pcbp = sotongpcb(so);
  541 
  542         /* Make the generic node components */
  543         if ((error = ng_make_node_common(&typestruct, &node)) != 0) {
  544                 ng_detach_common(pcbp, NG_CONTROL);
  545                 return (error);
  546         }
  547 
  548         /*
  549          * Allocate node private info and hash. We start
  550          * with 16 hash entries, however we may grow later
  551          * in ngs_newhook(). We can't predict how much hooks
  552          * does this node plan to have.
  553          */
  554         priv = malloc(sizeof(*priv), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
  555         priv->hash = hashinit(16, M_NETGRAPH_SOCK, &priv->hmask);
  556 
  557         /* Initialize mutex. */
  558         mtx_init(&priv->mtx, "ng_socket", NULL, MTX_DEF);
  559 
  560         /* Link the pcb the private data. */
  561         priv->ctlsock = pcbp;
  562         pcbp->sockdata = priv;
  563         priv->refs++;
  564         priv->node = node;
  565         pcbp->node_id = node->nd_ID;    /* hint for netstat(1) */
  566 
  567         /* Link the node and the private data. */
  568         NG_NODE_SET_PRIVATE(priv->node, priv);
  569         NG_NODE_REF(priv->node);
  570         priv->refs++;
  571 
  572         return (0);
  573 }
  574 
  575 static int
  576 ng_attach_data(struct socket *so)
  577 {
  578         return (ng_attach_common(so, NG_DATA));
  579 }
  580 
  581 /*
  582  * Set up a socket protocol control block.
  583  * This code is shared between control and data sockets.
  584  */
  585 static int
  586 ng_attach_common(struct socket *so, int type)
  587 {
  588         struct ngpcb *pcbp;
  589         int error;
  590 
  591         /* Standard socket setup stuff. */
  592         error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
  593         if (error)
  594                 return (error);
  595 
  596         /* Allocate the pcb. */
  597         pcbp = malloc(sizeof(struct ngpcb), M_PCB, M_WAITOK | M_ZERO);
  598         pcbp->type = type;
  599 
  600         /* Link the pcb and the socket. */
  601         so->so_pcb = (caddr_t)pcbp;
  602         pcbp->ng_socket = so;
  603 
  604         /* Add the socket to linked list */
  605         mtx_lock(&ngsocketlist_mtx);
  606         LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
  607         mtx_unlock(&ngsocketlist_mtx);
  608         return (0);
  609 }
  610 
  611 /*
  612  * Disassociate the socket from it's protocol specific
  613  * partner. If it's attached to a node's private data structure,
  614  * then unlink from that too. If we were the last socket attached to it,
  615  * then shut down the entire node. Shared code for control and data sockets.
  616  */
  617 static void
  618 ng_detach_common(struct ngpcb *pcbp, int which)
  619 {
  620         struct ngsock *priv = pcbp->sockdata;
  621 
  622         if (priv != NULL) {
  623                 mtx_lock(&priv->mtx);
  624 
  625                 switch (which) {
  626                 case NG_CONTROL:
  627                         priv->ctlsock = NULL;
  628                         break;
  629                 case NG_DATA:
  630                         priv->datasock = NULL;
  631                         break;
  632                 default:
  633                         panic("%s", __func__);
  634                 }
  635                 pcbp->sockdata = NULL;
  636                 pcbp->node_id = 0;
  637 
  638                 ng_socket_free_priv(priv);
  639         }
  640 
  641         pcbp->ng_socket->so_pcb = NULL;
  642         mtx_lock(&ngsocketlist_mtx);
  643         LIST_REMOVE(pcbp, socks);
  644         mtx_unlock(&ngsocketlist_mtx);
  645         free(pcbp, M_PCB);
  646 }
  647 
  648 /*
  649  * Remove a reference from node private data.
  650  */
  651 static void
  652 ng_socket_free_priv(struct ngsock *priv)
  653 {
  654         mtx_assert(&priv->mtx, MA_OWNED);
  655 
  656         priv->refs--;
  657 
  658         if (priv->refs == 0) {
  659                 mtx_destroy(&priv->mtx);
  660                 hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
  661                 free(priv, M_NETGRAPH_SOCK);
  662                 return;
  663         }
  664 
  665         if ((priv->refs == 1) && (priv->node != NULL)) {
  666                 node_p node = priv->node;
  667 
  668                 priv->node = NULL;
  669                 mtx_unlock(&priv->mtx);
  670                 NG_NODE_UNREF(node);
  671                 ng_rmnode_self(node);
  672         } else
  673                 mtx_unlock(&priv->mtx);
  674 }
  675 
  676 /*
  677  * Connect the data socket to a named control socket node.
  678  */
  679 static int
  680 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
  681 {
  682         struct sockaddr_ng *sap;
  683         node_p farnode;
  684         struct ngsock *priv;
  685         int error;
  686         item_p item;
  687 
  688         /* If we are already connected, don't do it again. */
  689         if (pcbp->sockdata != NULL)
  690                 return (EISCONN);
  691 
  692         /*
  693          * Find the target (victim) and check it doesn't already have
  694          * a data socket. Also check it is a 'socket' type node.
  695          * Use ng_package_data() and ng_address_path() to do this.
  696          */
  697 
  698         sap = (struct sockaddr_ng *) nam;
  699         /* The item will hold the node reference. */
  700         item = ng_package_data(NULL, NG_WAITOK);
  701 
  702         if ((error = ng_address_path(NULL, item,  sap->sg_data, 0)))
  703                 return (error); /* item is freed on failure */
  704 
  705         /*
  706          * Extract node from item and free item. Remember we now have
  707          * a reference on the node. The item holds it for us.
  708          * when we free the item we release the reference.
  709          */
  710         farnode = item->el_dest; /* shortcut */
  711         if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
  712                 NG_FREE_ITEM(item); /* drop the reference to the node */
  713                 return (EINVAL);
  714         }
  715         priv = NG_NODE_PRIVATE(farnode);
  716         if (priv->datasock != NULL) {
  717                 NG_FREE_ITEM(item);     /* drop the reference to the node */
  718                 return (EADDRINUSE);
  719         }
  720 
  721         /*
  722          * Link the PCB and the private data struct. and note the extra
  723          * reference. Drop the extra reference on the node.
  724          */
  725         mtx_lock(&priv->mtx);
  726         priv->datasock = pcbp;
  727         pcbp->sockdata = priv;
  728         pcbp->node_id = priv->node->nd_ID;      /* hint for netstat(1) */
  729         priv->refs++;
  730         mtx_unlock(&priv->mtx);
  731         NG_FREE_ITEM(item);     /* drop the reference to the node */
  732         return (0);
  733 }
  734 
  735 /*
  736  * Binding a socket means giving the corresponding node a name
  737  */
  738 static int
  739 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
  740 {
  741         struct ngsock *const priv = pcbp->sockdata;
  742         struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
  743 
  744         if (priv == NULL) {
  745                 TRAP_ERROR;
  746                 return (EINVAL);
  747         }
  748         if ((sap->sg_len < 4) || (sap->sg_len > (NG_NODESIZ + 2)) ||
  749             (sap->sg_data[0] == '\0') ||
  750             (sap->sg_data[sap->sg_len - 3] != '\0')) {
  751                 TRAP_ERROR;
  752                 return (EINVAL);
  753         }
  754         return (ng_name_node(priv->node, sap->sg_data));
  755 }
  756 
  757 /***************************************************************
  758         Netgraph node
  759 ***************************************************************/
  760 
  761 /*
  762  * You can only create new nodes from the socket end of things.
  763  */
  764 static int
  765 ngs_constructor(node_p nodep)
  766 {
  767         return (EINVAL);
  768 }
  769 
  770 static void
  771 ngs_rehash(node_p node)
  772 {
  773         struct ngsock *priv = NG_NODE_PRIVATE(node);
  774         struct ngshash *new;
  775         struct hookpriv *hp;
  776         hook_p hook;
  777         uint32_t h;
  778         u_long hmask;
  779 
  780         new = hashinit_flags((priv->hmask + 1) * 2, M_NETGRAPH_SOCK, &hmask,
  781             HASH_NOWAIT);
  782         if (new == NULL)
  783                 return;
  784 
  785         LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
  786                 hp = NG_HOOK_PRIVATE(hook);
  787 #ifdef INVARIANTS
  788                 LIST_REMOVE(hp, next);
  789 #endif
  790                 h = hash32_str(NG_HOOK_NAME(hook), HASHINIT) & hmask;
  791                 LIST_INSERT_HEAD(&new[h], hp, next);
  792         }
  793 
  794         hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
  795         priv->hash = new;
  796         priv->hmask = hmask;
  797 }
  798 
  799 /*
  800  * We allow any hook to be connected to the node.
  801  * There is no per-hook private information though.
  802  */
  803 static int
  804 ngs_newhook(node_p node, hook_p hook, const char *name)
  805 {
  806         struct ngsock *const priv = NG_NODE_PRIVATE(node);
  807         struct hookpriv *hp;
  808         uint32_t h;
  809 
  810         hp = malloc(sizeof(*hp), M_NETGRAPH_SOCK, M_NOWAIT);
  811         if (hp == NULL)
  812                 return (ENOMEM);
  813         if (node->nd_numhooks * 2 > priv->hmask)
  814                 ngs_rehash(node);
  815         hp->hook = hook;
  816         h = hash32_str(name, HASHINIT) & priv->hmask;
  817         LIST_INSERT_HEAD(&priv->hash[h], hp, next);
  818         NG_HOOK_SET_PRIVATE(hook, hp);
  819 
  820         return (0);
  821 }
  822 
  823 /*
  824  * If only one hook, allow read(2) and write(2) to work.
  825  */
  826 static int
  827 ngs_connect(hook_p hook)
  828 {
  829         node_p node = NG_HOOK_NODE(hook);
  830         struct ngsock *priv = NG_NODE_PRIVATE(node);
  831 
  832         if ((priv->datasock) && (priv->datasock->ng_socket)) {
  833                 if (NG_NODE_NUMHOOKS(node) == 1)
  834                         priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
  835                 else
  836                         priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
  837         }
  838         return (0);
  839 }
  840 
  841 /* Look up hook by name */
  842 static hook_p
  843 ngs_findhook(node_p node, const char *name)
  844 {
  845         struct ngsock *priv = NG_NODE_PRIVATE(node);
  846         struct hookpriv *hp;
  847         uint32_t h;
  848 
  849         /*
  850          * Microoptimisation for an ng_socket with
  851          * a single hook, which is a common case.
  852          */
  853         if (node->nd_numhooks == 1) {
  854                 hook_p hook;
  855 
  856                 hook = LIST_FIRST(&node->nd_hooks);
  857 
  858                 if (strcmp(NG_HOOK_NAME(hook), name) == 0)
  859                         return (hook);
  860                 else
  861                         return (NULL);
  862         }
  863 
  864         h = hash32_str(name, HASHINIT) & priv->hmask;
  865 
  866         LIST_FOREACH(hp, &priv->hash[h], next)
  867                 if (strcmp(NG_HOOK_NAME(hp->hook), name) == 0)
  868                         return (hp->hook);
  869 
  870         return (NULL);
  871 }
  872 
  873 /*
  874  * Incoming messages get passed up to the control socket.
  875  * Unless they are for us specifically (socket_type)
  876  */
  877 static int
  878 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
  879 {
  880         struct ngsock *const priv = NG_NODE_PRIVATE(node);
  881         struct ngpcb *pcbp;
  882         struct socket *so;
  883         struct sockaddr_ng addr;
  884         struct ng_mesg *msg;
  885         struct mbuf *m;
  886         ng_ID_t retaddr = NGI_RETADDR(item);
  887         int addrlen;
  888         int error = 0;
  889 
  890         NGI_GET_MSG(item, msg);
  891         NG_FREE_ITEM(item);
  892 
  893         /*
  894          * Grab priv->mtx here to prevent destroying of control socket
  895          * after checking that priv->ctlsock is not NULL.
  896          */
  897         mtx_lock(&priv->mtx);
  898         pcbp = priv->ctlsock;
  899 
  900         /*
  901          * Only allow mesgs to be passed if we have the control socket.
  902          * Data sockets can only support the generic messages.
  903          */
  904         if (pcbp == NULL) {
  905                 mtx_unlock(&priv->mtx);
  906                 TRAP_ERROR;
  907                 NG_FREE_MSG(msg);
  908                 return (EINVAL);
  909         }
  910         so = pcbp->ng_socket;
  911         SOCKBUF_LOCK(&so->so_rcv);
  912 
  913         /* As long as the race is handled, priv->mtx may be unlocked now. */
  914         mtx_unlock(&priv->mtx);
  915 
  916 #ifdef TRACE_MESSAGES
  917         printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
  918                 retaddr,
  919                 msg->header.typecookie,
  920                 msg->header.cmd,
  921                 msg->header.cmdstr,
  922                 msg->header.flags,
  923                 msg->header.token);
  924 #endif
  925 
  926         if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
  927                 switch (msg->header.cmd) {
  928                 case NGM_SOCK_CMD_NOLINGER:
  929                         priv->flags |= NGS_FLAG_NOLINGER;
  930                         break;
  931                 case NGM_SOCK_CMD_LINGER:
  932                         priv->flags &= ~NGS_FLAG_NOLINGER;
  933                         break;
  934                 default:
  935                         error = EINVAL;         /* unknown command */
  936                 }
  937                 SOCKBUF_UNLOCK(&so->so_rcv);
  938 
  939                 /* Free the message and return. */
  940                 NG_FREE_MSG(msg);
  941                 return (error);
  942         }
  943 
  944         /* Get the return address into a sockaddr. */
  945         bzero(&addr, sizeof(addr));
  946         addr.sg_len = sizeof(addr);
  947         addr.sg_family = AF_NETGRAPH;
  948         addrlen = snprintf((char *)&addr.sg_data, sizeof(addr.sg_data),
  949             "[%x]:", retaddr);
  950         if (addrlen < 0 || addrlen > sizeof(addr.sg_data)) {
  951                 SOCKBUF_UNLOCK(&so->so_rcv);
  952                 printf("%s: snprintf([%x]) failed - %d\n", __func__, retaddr,
  953                     addrlen);
  954                 NG_FREE_MSG(msg);
  955                 return (EINVAL);
  956         }
  957 
  958         /* Copy the message itself into an mbuf chain. */
  959         m = m_devget((caddr_t)msg, sizeof(struct ng_mesg) + msg->header.arglen,
  960             0, NULL, NULL);
  961 
  962         /*
  963          * Here we free the message. We need to do that
  964          * regardless of whether we got mbufs.
  965          */
  966         NG_FREE_MSG(msg);
  967 
  968         if (m == NULL) {
  969                 SOCKBUF_UNLOCK(&so->so_rcv);
  970                 TRAP_ERROR;
  971                 return (ENOBUFS);
  972         }
  973 
  974         /* Send it up to the socket. */
  975         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&addr, m,
  976             NULL) == 0) {
  977                 SOCKBUF_UNLOCK(&so->so_rcv);
  978                 TRAP_ERROR;
  979                 m_freem(m);
  980                 return (ENOBUFS);
  981         }
  982         sorwakeup_locked(so);
  983         
  984         return (error);
  985 }
  986 
  987 /*
  988  * Receive data on a hook
  989  */
  990 static int
  991 ngs_rcvdata(hook_p hook, item_p item)
  992 {
  993         struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  994         struct ngpcb *const pcbp = priv->datasock;
  995         struct socket *so;
  996         struct sockaddr_ng *addr;
  997         char *addrbuf[NG_HOOKSIZ + 4];
  998         int addrlen;
  999         struct mbuf *m;
 1000 
 1001         NGI_GET_M(item, m);
 1002         NG_FREE_ITEM(item);
 1003 
 1004         /* If there is no data socket, black-hole it. */
 1005         if (pcbp == NULL) {
 1006                 NG_FREE_M(m);
 1007                 return (0);
 1008         }
 1009         so = pcbp->ng_socket;
 1010 
 1011         /* Get the return address into a sockaddr. */
 1012         addrlen = strlen(NG_HOOK_NAME(hook));   /* <= NG_HOOKSIZ - 1 */
 1013         addr = (struct sockaddr_ng *) addrbuf;
 1014         addr->sg_len = addrlen + 3;
 1015         addr->sg_family = AF_NETGRAPH;
 1016         bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
 1017         addr->sg_data[addrlen] = '\0';
 1018 
 1019         /* Try to tell the socket which hook it came in on. */
 1020         if (sbappendaddr(&so->so_rcv, (struct sockaddr *)addr, m, NULL) == 0) {
 1021                 m_freem(m);
 1022                 TRAP_ERROR;
 1023                 return (ENOBUFS);
 1024         }
 1025         sorwakeup(so);
 1026         return (0);
 1027 }
 1028 
 1029 /*
 1030  * Hook disconnection
 1031  *
 1032  * For this type, removal of the last link destroys the node
 1033  * if the NOLINGER flag is set.
 1034  */
 1035 static int
 1036 ngs_disconnect(hook_p hook)
 1037 {
 1038         node_p node = NG_HOOK_NODE(hook);
 1039         struct ngsock *const priv = NG_NODE_PRIVATE(node);
 1040         struct hookpriv *hp = NG_HOOK_PRIVATE(hook);
 1041 
 1042         LIST_REMOVE(hp, next);
 1043         free(hp, M_NETGRAPH_SOCK);
 1044 
 1045         if ((priv->datasock) && (priv->datasock->ng_socket)) {
 1046                 if (NG_NODE_NUMHOOKS(node) == 1)
 1047                         priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
 1048                 else
 1049                         priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
 1050         }
 1051 
 1052         if ((priv->flags & NGS_FLAG_NOLINGER) &&
 1053             (NG_NODE_NUMHOOKS(node) == 0) && (NG_NODE_IS_VALID(node)))
 1054                 ng_rmnode_self(node);
 1055 
 1056         return (0);
 1057 }
 1058 
 1059 /*
 1060  * Do local shutdown processing.
 1061  * In this case, that involves making sure the socket
 1062  * knows we should be shutting down.
 1063  */
 1064 static int
 1065 ngs_shutdown(node_p node)
 1066 {
 1067         struct ngsock *const priv = NG_NODE_PRIVATE(node);
 1068         struct ngpcb *dpcbp, *pcbp;
 1069 
 1070         mtx_lock(&priv->mtx);
 1071         dpcbp = priv->datasock;
 1072         pcbp = priv->ctlsock;
 1073 
 1074         if (dpcbp != NULL)
 1075                 soisdisconnected(dpcbp->ng_socket);
 1076 
 1077         if (pcbp != NULL)
 1078                 soisdisconnected(pcbp->ng_socket);
 1079 
 1080         priv->node = NULL;
 1081         NG_NODE_SET_PRIVATE(node, NULL);
 1082         ng_socket_free_priv(priv);
 1083 
 1084         NG_NODE_UNREF(node);
 1085         return (0);
 1086 }
 1087 
 1088 static void
 1089 ng_socket_item_applied(void *context, int error)
 1090 {
 1091         struct ngsock *const priv = (struct ngsock *)context;
 1092 
 1093         mtx_lock(&priv->mtx);
 1094         priv->error = error;
 1095         wakeup(priv);
 1096         mtx_unlock(&priv->mtx);
 1097 
 1098 }
 1099 
 1100 static  int
 1101 dummy_disconnect(struct socket *so)
 1102 {
 1103         return (0);
 1104 }
 1105 /*
 1106  * Control and data socket type descriptors
 1107  *
 1108  * XXXRW: Perhaps _close should do something?
 1109  */
 1110 
 1111 static struct pr_usrreqs ngc_usrreqs = {
 1112         .pru_abort =            NULL,
 1113         .pru_attach =           ngc_attach,
 1114         .pru_bind =             ngc_bind,
 1115         .pru_connect =          ngc_connect,
 1116         .pru_detach =           ngc_detach,
 1117         .pru_disconnect =       dummy_disconnect,
 1118         .pru_peeraddr =         NULL,
 1119         .pru_send =             ngc_send,
 1120         .pru_shutdown =         NULL,
 1121         .pru_sockaddr =         ng_getsockaddr,
 1122         .pru_close =            NULL,
 1123 };
 1124 
 1125 static struct pr_usrreqs ngd_usrreqs = {
 1126         .pru_abort =            NULL,
 1127         .pru_attach =           ngd_attach,
 1128         .pru_bind =             NULL,
 1129         .pru_connect =          ngd_connect,
 1130         .pru_detach =           ngd_detach,
 1131         .pru_disconnect =       dummy_disconnect,
 1132         .pru_peeraddr =         NULL,
 1133         .pru_send =             ngd_send,
 1134         .pru_shutdown =         NULL,
 1135         .pru_sockaddr =         ng_getsockaddr,
 1136         .pru_close =            NULL,
 1137 };
 1138 
 1139 /*
 1140  * Definitions of protocols supported in the NETGRAPH domain.
 1141  */
 1142 
 1143 extern struct domain ngdomain;          /* stop compiler warnings */
 1144 
 1145 static struct protosw ngsw[] = {
 1146 {
 1147         .pr_type =              SOCK_DGRAM,
 1148         .pr_domain =            &ngdomain,
 1149         .pr_protocol =          NG_CONTROL,
 1150         .pr_flags =             PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
 1151         .pr_usrreqs =           &ngc_usrreqs
 1152 },
 1153 {
 1154         .pr_type =              SOCK_DGRAM,
 1155         .pr_domain =            &ngdomain,
 1156         .pr_protocol =          NG_DATA,
 1157         .pr_flags =             PR_ATOMIC | PR_ADDR,
 1158         .pr_usrreqs =           &ngd_usrreqs
 1159 }
 1160 };
 1161 
 1162 struct domain ngdomain = {
 1163         .dom_family =           AF_NETGRAPH,
 1164         .dom_name =             "netgraph",
 1165         .dom_protosw =          ngsw,
 1166         .dom_protoswNPROTOSW =  &ngsw[sizeof(ngsw) / sizeof(ngsw[0])]
 1167 };
 1168 
 1169 /*
 1170  * Handle loading and unloading for this node type.
 1171  * This is to handle auxiliary linkages (e.g protocol domain addition).
 1172  */
 1173 static int
 1174 ngs_mod_event(module_t mod, int event, void *data)
 1175 {
 1176         int error = 0;
 1177 
 1178         switch (event) {
 1179         case MOD_LOAD:
 1180                 mtx_init(&ngsocketlist_mtx, "ng_socketlist", NULL, MTX_DEF);
 1181                 break;
 1182         case MOD_UNLOAD:
 1183                 /* Ensure there are no open netgraph sockets. */
 1184                 if (!LIST_EMPTY(&ngsocklist)) {
 1185                         error = EBUSY;
 1186                         break;
 1187                 }
 1188 #ifdef NOTYET
 1189                 /* Unregister protocol domain XXX can't do this yet.. */
 1190 #endif
 1191                 error = EBUSY;
 1192                 break;
 1193         default:
 1194                 error = EOPNOTSUPP;
 1195                 break;
 1196         }
 1197         return (error);
 1198 }
 1199 
 1200 VNET_DOMAIN_SET(ng);
 1201 
 1202 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
 1203 static SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
 1204 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
 1205 static SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
 1206 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
 1207 

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