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: stable/9/sys/netgraph/ng_socket.c 273912 2014-10-31 18:18:04Z hselasky $
   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 /***************************************************************
  169         Control sockets
  170 ***************************************************************/
  171 
  172 static int
  173 ngc_attach(struct socket *so, int proto, struct thread *td)
  174 {
  175         struct ngpcb *const pcbp = sotongpcb(so);
  176         int error;
  177 
  178         error = priv_check(td, PRIV_NETGRAPH_CONTROL);
  179         if (error)
  180                 return (error);
  181         if (pcbp != NULL)
  182                 return (EISCONN);
  183         return (ng_attach_cntl(so));
  184 }
  185 
  186 static void
  187 ngc_detach(struct socket *so)
  188 {
  189         struct ngpcb *const pcbp = sotongpcb(so);
  190 
  191         KASSERT(pcbp != NULL, ("ngc_detach: pcbp == NULL"));
  192         ng_detach_common(pcbp, NG_CONTROL);
  193 }
  194 
  195 static int
  196 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
  197          struct mbuf *control, struct thread *td)
  198 {
  199         struct ngpcb *const pcbp = sotongpcb(so);
  200         struct ngsock *const priv = NG_NODE_PRIVATE(pcbp->sockdata->node);
  201         struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
  202         struct ng_mesg *msg;
  203         struct mbuf *m0;
  204         item_p item;
  205         char *path = NULL;
  206         int len, error = 0;
  207         struct ng_apply_info apply;
  208 
  209         if (control) {
  210                 error = EINVAL;
  211                 goto release;
  212         }
  213 
  214         /* Require destination as there may be >= 1 hooks on this node. */
  215         if (addr == NULL) {
  216                 error = EDESTADDRREQ;
  217                 goto release;
  218         }
  219 
  220         /*
  221          * Allocate an expendable buffer for the path, chop off
  222          * the sockaddr header, and make sure it's NUL terminated.
  223          */
  224         len = sap->sg_len - 2;
  225         path = malloc(len + 1, M_NETGRAPH_PATH, M_WAITOK);
  226         bcopy(sap->sg_data, path, len);
  227         path[len] = '\0';
  228 
  229         /*
  230          * Move the actual message out of mbufs into a linear buffer.
  231          * Start by adding up the size of the data. (could use mh_len?)
  232          */
  233         for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
  234                 len += m0->m_len;
  235 
  236         /*
  237          * Move the data into a linear buffer as well.
  238          * Messages are not delivered in mbufs.
  239          */
  240         msg = malloc(len + 1, M_NETGRAPH_MSG, M_WAITOK);
  241         m_copydata(m, 0, len, (char *)msg);
  242 
  243         if (msg->header.version != NG_VERSION) {
  244                 free(msg, M_NETGRAPH_MSG);
  245                 error = EINVAL;
  246                 goto release;
  247         }
  248 
  249         /*
  250          * Hack alert!
  251          * We look into the message and if it mkpeers a node of unknown type, we
  252          * try to load it. We need to do this now, in syscall thread, because if
  253          * message gets queued and applied later we will get panic.
  254          */
  255         if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
  256             msg->header.cmd == NGM_MKPEER) {
  257                 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
  258 
  259                 if (ng_findtype(mkp->type) == NULL) {
  260                         char filename[NG_TYPESIZ + 3];
  261                         int fileid;
  262 
  263                         /* Not found, try to load it as a loadable module. */
  264                         snprintf(filename, sizeof(filename), "ng_%s",
  265                             mkp->type);
  266                         error = kern_kldload(curthread, filename, &fileid);
  267                         if (error != 0) {
  268                                 free(msg, M_NETGRAPH_MSG);
  269                                 goto release;
  270                         }
  271 
  272                         /* See if type has been loaded successfully. */
  273                         if (ng_findtype(mkp->type) == NULL) {
  274                                 free(msg, M_NETGRAPH_MSG);
  275                                 (void)kern_kldunload(curthread, fileid,
  276                                     LINKER_UNLOAD_NORMAL);
  277                                 error =  ENXIO;
  278                                 goto release;
  279                         }
  280                 }
  281         }
  282 
  283         item = ng_package_msg(msg, M_WAITOK);
  284         if ((error = ng_address_path((pcbp->sockdata->node), item, path, 0))
  285             != 0) {
  286 #ifdef TRACE_MESSAGES
  287                 printf("ng_address_path: errx=%d\n", error);
  288 #endif
  289                 goto release;
  290         }
  291 
  292 #ifdef TRACE_MESSAGES
  293         printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
  294                 item->el_dest->nd_ID,
  295                 msg->header.typecookie,
  296                 msg->header.cmd,
  297                 msg->header.cmdstr,
  298                 msg->header.flags,
  299                 msg->header.token,
  300                 item->el_dest->nd_type->name);
  301 #endif
  302         SAVE_LINE(item);
  303         /*
  304          * We do not want to return from syscall until the item
  305          * is processed by destination node. We register callback
  306          * on the item, which will update priv->error when item
  307          * was applied.
  308          * If ng_snd_item() has queued item, we sleep until
  309          * callback wakes us up.
  310          */
  311         bzero(&apply, sizeof(apply));
  312         apply.apply = ng_socket_item_applied;
  313         apply.context = priv;
  314         item->apply = &apply;
  315         priv->error = -1;
  316 
  317         error = ng_snd_item(item, 0);
  318 
  319         mtx_lock(&priv->mtx);
  320         if (priv->error == -1)
  321                 msleep(priv, &priv->mtx, 0, "ngsock", 0);
  322         mtx_unlock(&priv->mtx);
  323         KASSERT(priv->error != -1,
  324             ("ng_socket: priv->error wasn't updated"));
  325         error = priv->error;
  326 
  327 release:
  328         if (path != NULL)
  329                 free(path, M_NETGRAPH_PATH);
  330         if (control != NULL)
  331                 m_freem(control);
  332         if (m != NULL)
  333                 m_freem(m);
  334         return (error);
  335 }
  336 
  337 static int
  338 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  339 {
  340         struct ngpcb *const pcbp = sotongpcb(so);
  341 
  342         if (pcbp == 0)
  343                 return (EINVAL);
  344         return (ng_bind(nam, pcbp));
  345 }
  346 
  347 static int
  348 ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  349 {
  350         /*
  351          * At this time refuse to do this.. it used to
  352          * do something but it was undocumented and not used.
  353          */
  354         printf("program tried to connect control socket to remote node\n");
  355         return (EINVAL);
  356 }
  357 
  358 /***************************************************************
  359         Data sockets
  360 ***************************************************************/
  361 
  362 static int
  363 ngd_attach(struct socket *so, int proto, struct thread *td)
  364 {
  365         struct ngpcb *const pcbp = sotongpcb(so);
  366 
  367         if (pcbp != NULL)
  368                 return (EISCONN);
  369         return (ng_attach_data(so));
  370 }
  371 
  372 static void
  373 ngd_detach(struct socket *so)
  374 {
  375         struct ngpcb *const pcbp = sotongpcb(so);
  376 
  377         KASSERT(pcbp != NULL, ("ngd_detach: pcbp == NULL"));
  378         ng_detach_common(pcbp, NG_DATA);
  379 }
  380 
  381 static int
  382 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
  383          struct mbuf *control, struct thread *td)
  384 {
  385         struct ngpcb *const pcbp = sotongpcb(so);
  386         struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
  387         int     len, error;
  388         hook_p  hook = NULL;
  389         char    hookname[NG_HOOKSIZ];
  390 
  391         if ((pcbp == NULL) || (control != NULL)) {
  392                 error = EINVAL;
  393                 goto release;
  394         }
  395         if (pcbp->sockdata == NULL) {
  396                 error = ENOTCONN;
  397                 goto release;
  398         }
  399 
  400         if (sap == NULL)
  401                 len = 0;                /* Make compiler happy. */
  402         else
  403                 len = sap->sg_len - 2;
  404 
  405         /*
  406          * If the user used any of these ways to not specify an address
  407          * then handle specially.
  408          */
  409         if ((sap == NULL) || (len <= 0) || (*sap->sg_data == '\0')) {
  410                 if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
  411                         error = EDESTADDRREQ;
  412                         goto release;
  413                 }
  414                 /*
  415                  * If exactly one hook exists, just use it.
  416                  * Special case to allow write(2) to work on an ng_socket.
  417                  */
  418                 hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
  419         } else {
  420                 if (len >= NG_HOOKSIZ) {
  421                         error = EINVAL;
  422                         goto release;
  423                 }
  424 
  425                 /*
  426                  * chop off the sockaddr header, and make sure it's NUL
  427                  * terminated
  428                  */
  429                 bcopy(sap->sg_data, hookname, len);
  430                 hookname[len] = '\0';
  431 
  432                 /* Find the correct hook from 'hookname' */
  433                 hook = ng_findhook(pcbp->sockdata->node, hookname);
  434                 if (hook == NULL) {
  435                         error = EHOSTUNREACH;
  436                         goto release;
  437                 }
  438         }
  439 
  440         /* Send data. */
  441         NG_SEND_DATA_FLAGS(error, hook, m, NG_WAITOK);
  442 
  443 release:
  444         if (control != NULL)
  445                 m_freem(control);
  446         if (m != NULL)
  447                 m_freem(m);
  448         return (error);
  449 }
  450 
  451 static int
  452 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  453 {
  454         struct ngpcb *const pcbp = sotongpcb(so);
  455 
  456         if (pcbp == 0)
  457                 return (EINVAL);
  458         return (ng_connect_data(nam, pcbp));
  459 }
  460 
  461 /*
  462  * Used for both data and control sockets
  463  */
  464 static int
  465 ng_getsockaddr(struct socket *so, struct sockaddr **addr)
  466 {
  467         struct ngpcb *pcbp;
  468         struct sockaddr_ng *sg;
  469         int sg_len;
  470         int error = 0;
  471 
  472         pcbp = sotongpcb(so);
  473         if ((pcbp == NULL) || (pcbp->sockdata == NULL))
  474                 /* XXXGL: can this still happen? */
  475                 return (EINVAL);
  476 
  477         sg_len = sizeof(struct sockaddr_ng) + NG_NODESIZ -
  478             sizeof(sg->sg_data);
  479         sg = malloc(sg_len, M_SONAME, M_WAITOK | M_ZERO);
  480 
  481         mtx_lock(&pcbp->sockdata->mtx);
  482         if (pcbp->sockdata->node != NULL) {
  483                 node_p node = pcbp->sockdata->node;
  484 
  485                 if (NG_NODE_HAS_NAME(node))
  486                         bcopy(NG_NODE_NAME(node), sg->sg_data,
  487                             strlen(NG_NODE_NAME(node)));
  488                 mtx_unlock(&pcbp->sockdata->mtx);
  489 
  490                 sg->sg_len = sg_len;
  491                 sg->sg_family = AF_NETGRAPH;
  492                 *addr = (struct sockaddr *)sg;
  493         } else {
  494                 mtx_unlock(&pcbp->sockdata->mtx);
  495                 free(sg, M_SONAME);
  496                 error = EINVAL;
  497         }
  498 
  499         return (error);
  500 }
  501 
  502 /*
  503  * Attach a socket to it's protocol specific partner.
  504  * For a control socket, actually create a netgraph node and attach
  505  * to it as well.
  506  */
  507 
  508 static int
  509 ng_attach_cntl(struct socket *so)
  510 {
  511         struct ngsock *priv;
  512         struct ngpcb *pcbp;
  513         node_p node;
  514         int error;
  515 
  516         /* Setup protocol control block */
  517         if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
  518                 return (error);
  519         pcbp = sotongpcb(so);
  520 
  521         /* Make the generic node components */
  522         if ((error = ng_make_node_common(&typestruct, &node)) != 0) {
  523                 ng_detach_common(pcbp, NG_CONTROL);
  524                 return (error);
  525         }
  526 
  527         /*
  528          * Allocate node private info and hash. We start
  529          * with 16 hash entries, however we may grow later
  530          * in ngs_newhook(). We can't predict how much hooks
  531          * does this node plan to have.
  532          */
  533         priv = malloc(sizeof(*priv), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
  534         priv->hash = hashinit(16, M_NETGRAPH_SOCK, &priv->hmask);
  535 
  536         /* Initialize mutex. */
  537         mtx_init(&priv->mtx, "ng_socket", NULL, MTX_DEF);
  538 
  539         /* Link the pcb the private data. */
  540         priv->ctlsock = pcbp;
  541         pcbp->sockdata = priv;
  542         priv->refs++;
  543         priv->node = node;
  544 
  545         /* Store a hint for netstat(1). */
  546         priv->node_id = priv->node->nd_ID;
  547 
  548         /* Link the node and the private data. */
  549         NG_NODE_SET_PRIVATE(priv->node, priv);
  550         NG_NODE_REF(priv->node);
  551         priv->refs++;
  552 
  553         return (0);
  554 }
  555 
  556 static int
  557 ng_attach_data(struct socket *so)
  558 {
  559         return (ng_attach_common(so, NG_DATA));
  560 }
  561 
  562 /*
  563  * Set up a socket protocol control block.
  564  * This code is shared between control and data sockets.
  565  */
  566 static int
  567 ng_attach_common(struct socket *so, int type)
  568 {
  569         struct ngpcb *pcbp;
  570         int error;
  571 
  572         /* Standard socket setup stuff. */
  573         error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
  574         if (error)
  575                 return (error);
  576 
  577         /* Allocate the pcb. */
  578         pcbp = malloc(sizeof(struct ngpcb), M_PCB, M_WAITOK | M_ZERO);
  579         pcbp->type = type;
  580 
  581         /* Link the pcb and the socket. */
  582         so->so_pcb = (caddr_t)pcbp;
  583         pcbp->ng_socket = so;
  584 
  585         /* Add the socket to linked list */
  586         mtx_lock(&ngsocketlist_mtx);
  587         LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
  588         mtx_unlock(&ngsocketlist_mtx);
  589         return (0);
  590 }
  591 
  592 /*
  593  * Disassociate the socket from it's protocol specific
  594  * partner. If it's attached to a node's private data structure,
  595  * then unlink from that too. If we were the last socket attached to it,
  596  * then shut down the entire node. Shared code for control and data sockets.
  597  */
  598 static void
  599 ng_detach_common(struct ngpcb *pcbp, int which)
  600 {
  601         struct ngsock *priv = pcbp->sockdata;
  602 
  603         if (priv != NULL) {
  604                 mtx_lock(&priv->mtx);
  605 
  606                 switch (which) {
  607                 case NG_CONTROL:
  608                         priv->ctlsock = NULL;
  609                         break;
  610                 case NG_DATA:
  611                         priv->datasock = NULL;
  612                         break;
  613                 default:
  614                         panic("%s", __func__);
  615                 }
  616                 pcbp->sockdata = NULL;
  617 
  618                 ng_socket_free_priv(priv);
  619         }
  620 
  621         pcbp->ng_socket->so_pcb = NULL;
  622         mtx_lock(&ngsocketlist_mtx);
  623         LIST_REMOVE(pcbp, socks);
  624         mtx_unlock(&ngsocketlist_mtx);
  625         free(pcbp, M_PCB);
  626 }
  627 
  628 /*
  629  * Remove a reference from node private data.
  630  */
  631 static void
  632 ng_socket_free_priv(struct ngsock *priv)
  633 {
  634         mtx_assert(&priv->mtx, MA_OWNED);
  635 
  636         priv->refs--;
  637 
  638         if (priv->refs == 0) {
  639                 mtx_destroy(&priv->mtx);
  640                 hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
  641                 free(priv, M_NETGRAPH_SOCK);
  642                 return;
  643         }
  644 
  645         if ((priv->refs == 1) && (priv->node != NULL)) {
  646                 node_p node = priv->node;
  647 
  648                 priv->node = NULL;
  649                 mtx_unlock(&priv->mtx);
  650                 NG_NODE_UNREF(node);
  651                 ng_rmnode_self(node);
  652         } else
  653                 mtx_unlock(&priv->mtx);
  654 }
  655 
  656 /*
  657  * Connect the data socket to a named control socket node.
  658  */
  659 static int
  660 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
  661 {
  662         struct sockaddr_ng *sap;
  663         node_p farnode;
  664         struct ngsock *priv;
  665         int error;
  666         item_p item;
  667 
  668         /* If we are already connected, don't do it again. */
  669         if (pcbp->sockdata != NULL)
  670                 return (EISCONN);
  671 
  672         /*
  673          * Find the target (victim) and check it doesn't already have
  674          * a data socket. Also check it is a 'socket' type node.
  675          * Use ng_package_data() and ng_address_path() to do this.
  676          */
  677 
  678         sap = (struct sockaddr_ng *) nam;
  679         /* The item will hold the node reference. */
  680         item = ng_package_data(NULL, NG_WAITOK);
  681 
  682         if ((error = ng_address_path(NULL, item,  sap->sg_data, 0)))
  683                 return (error); /* item is freed on failure */
  684 
  685         /*
  686          * Extract node from item and free item. Remember we now have
  687          * a reference on the node. The item holds it for us.
  688          * when we free the item we release the reference.
  689          */
  690         farnode = item->el_dest; /* shortcut */
  691         if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
  692                 NG_FREE_ITEM(item); /* drop the reference to the node */
  693                 return (EINVAL);
  694         }
  695         priv = NG_NODE_PRIVATE(farnode);
  696         if (priv->datasock != NULL) {
  697                 NG_FREE_ITEM(item);     /* drop the reference to the node */
  698                 return (EADDRINUSE);
  699         }
  700 
  701         /*
  702          * Link the PCB and the private data struct. and note the extra
  703          * reference. Drop the extra reference on the node.
  704          */
  705         mtx_lock(&priv->mtx);
  706         priv->datasock = pcbp;
  707         pcbp->sockdata = priv;
  708         priv->refs++;
  709         mtx_unlock(&priv->mtx);
  710         NG_FREE_ITEM(item);     /* drop the reference to the node */
  711         return (0);
  712 }
  713 
  714 /*
  715  * Binding a socket means giving the corresponding node a name
  716  */
  717 static int
  718 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
  719 {
  720         struct ngsock *const priv = pcbp->sockdata;
  721         struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
  722 
  723         if (priv == NULL) {
  724                 TRAP_ERROR;
  725                 return (EINVAL);
  726         }
  727         if ((sap->sg_len < 4) || (sap->sg_len > (NG_NODESIZ + 2)) ||
  728             (sap->sg_data[0] == '\0') ||
  729             (sap->sg_data[sap->sg_len - 3] != '\0')) {
  730                 TRAP_ERROR;
  731                 return (EINVAL);
  732         }
  733         return (ng_name_node(priv->node, sap->sg_data));
  734 }
  735 
  736 /***************************************************************
  737         Netgraph node
  738 ***************************************************************/
  739 
  740 /*
  741  * You can only create new nodes from the socket end of things.
  742  */
  743 static int
  744 ngs_constructor(node_p nodep)
  745 {
  746         return (EINVAL);
  747 }
  748 
  749 static void
  750 ngs_rehash(node_p node)
  751 {
  752         struct ngsock *priv = NG_NODE_PRIVATE(node);
  753         struct ngshash *new;
  754         struct hookpriv *hp;
  755         hook_p hook;
  756         uint32_t h;
  757         u_long hmask;
  758 
  759         new = hashinit_flags((priv->hmask + 1) * 2, M_NETGRAPH_SOCK, &hmask,
  760             HASH_NOWAIT);
  761         if (new == NULL)
  762                 return;
  763 
  764         LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
  765                 hp = NG_HOOK_PRIVATE(hook);
  766 #ifdef INVARIANTS
  767                 LIST_REMOVE(hp, next);
  768 #endif
  769                 h = hash32_str(NG_HOOK_NAME(hook), HASHINIT) & hmask;
  770                 LIST_INSERT_HEAD(&new[h], hp, next);
  771         }
  772 
  773         hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
  774         priv->hash = new;
  775         priv->hmask = hmask;
  776 }
  777 
  778 /*
  779  * We allow any hook to be connected to the node.
  780  * There is no per-hook private information though.
  781  */
  782 static int
  783 ngs_newhook(node_p node, hook_p hook, const char *name)
  784 {
  785         struct ngsock *const priv = NG_NODE_PRIVATE(node);
  786         struct hookpriv *hp;
  787         uint32_t h;
  788 
  789         hp = malloc(sizeof(*hp), M_NETGRAPH_SOCK, M_NOWAIT);
  790         if (hp == NULL)
  791                 return (ENOMEM);
  792         if (node->nd_numhooks * 2 > priv->hmask)
  793                 ngs_rehash(node);
  794         hp->hook = hook;
  795         h = hash32_str(name, HASHINIT) & priv->hmask;
  796         LIST_INSERT_HEAD(&priv->hash[h], hp, next);
  797         NG_HOOK_SET_PRIVATE(hook, hp);
  798 
  799         return (0);
  800 }
  801 
  802 /*
  803  * If only one hook, allow read(2) and write(2) to work.
  804  */
  805 static int
  806 ngs_connect(hook_p hook)
  807 {
  808         node_p node = NG_HOOK_NODE(hook);
  809         struct ngsock *priv = NG_NODE_PRIVATE(node);
  810 
  811         if ((priv->datasock) && (priv->datasock->ng_socket)) {
  812                 if (NG_NODE_NUMHOOKS(node) == 1)
  813                         priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
  814                 else
  815                         priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
  816         }
  817         return (0);
  818 }
  819 
  820 /* Look up hook by name */
  821 static hook_p
  822 ngs_findhook(node_p node, const char *name)
  823 {
  824         struct ngsock *priv = NG_NODE_PRIVATE(node);
  825         struct hookpriv *hp;
  826         uint32_t h;
  827 
  828         /*
  829          * Microoptimisation for an ng_socket with
  830          * a single hook, which is a common case.
  831          */
  832         if (node->nd_numhooks == 1) {
  833                 hook_p hook;
  834 
  835                 hook = LIST_FIRST(&node->nd_hooks);
  836 
  837                 if (strcmp(NG_HOOK_NAME(hook), name) == 0)
  838                         return (hook);
  839                 else
  840                         return (NULL);
  841         }
  842 
  843         h = hash32_str(name, HASHINIT) & priv->hmask;
  844 
  845         LIST_FOREACH(hp, &priv->hash[h], next)
  846                 if (strcmp(NG_HOOK_NAME(hp->hook), name) == 0)
  847                         return (hp->hook);
  848 
  849         return (NULL);
  850 }
  851 
  852 /*
  853  * Incoming messages get passed up to the control socket.
  854  * Unless they are for us specifically (socket_type)
  855  */
  856 static int
  857 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
  858 {
  859         struct ngsock *const priv = NG_NODE_PRIVATE(node);
  860         struct ngpcb *pcbp;
  861         struct socket *so;
  862         struct sockaddr_ng addr;
  863         struct ng_mesg *msg;
  864         struct mbuf *m;
  865         ng_ID_t retaddr = NGI_RETADDR(item);
  866         int addrlen;
  867         int error = 0;
  868 
  869         NGI_GET_MSG(item, msg);
  870         NG_FREE_ITEM(item);
  871 
  872         /*
  873          * Grab priv->mtx here to prevent destroying of control socket
  874          * after checking that priv->ctlsock is not NULL.
  875          */
  876         mtx_lock(&priv->mtx);
  877         pcbp = priv->ctlsock;
  878 
  879         /*
  880          * Only allow mesgs to be passed if we have the control socket.
  881          * Data sockets can only support the generic messages.
  882          */
  883         if (pcbp == NULL) {
  884                 mtx_unlock(&priv->mtx);
  885                 TRAP_ERROR;
  886                 NG_FREE_MSG(msg);
  887                 return (EINVAL);
  888         }
  889         so = pcbp->ng_socket;
  890         SOCKBUF_LOCK(&so->so_rcv);
  891 
  892         /* As long as the race is handled, priv->mtx may be unlocked now. */
  893         mtx_unlock(&priv->mtx);
  894 
  895 #ifdef TRACE_MESSAGES
  896         printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
  897                 retaddr,
  898                 msg->header.typecookie,
  899                 msg->header.cmd,
  900                 msg->header.cmdstr,
  901                 msg->header.flags,
  902                 msg->header.token);
  903 #endif
  904 
  905         if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
  906                 switch (msg->header.cmd) {
  907                 case NGM_SOCK_CMD_NOLINGER:
  908                         priv->flags |= NGS_FLAG_NOLINGER;
  909                         break;
  910                 case NGM_SOCK_CMD_LINGER:
  911                         priv->flags &= ~NGS_FLAG_NOLINGER;
  912                         break;
  913                 default:
  914                         error = EINVAL;         /* unknown command */
  915                 }
  916                 SOCKBUF_UNLOCK(&so->so_rcv);
  917 
  918                 /* Free the message and return. */
  919                 NG_FREE_MSG(msg);
  920                 return (error);
  921         }
  922 
  923         /* Get the return address into a sockaddr. */
  924         bzero(&addr, sizeof(addr));
  925         addr.sg_len = sizeof(addr);
  926         addr.sg_family = AF_NETGRAPH;
  927         addrlen = snprintf((char *)&addr.sg_data, sizeof(addr.sg_data),
  928             "[%x]:", retaddr);
  929         if (addrlen < 0 || addrlen > sizeof(addr.sg_data)) {
  930                 SOCKBUF_UNLOCK(&so->so_rcv);
  931                 printf("%s: snprintf([%x]) failed - %d\n", __func__, retaddr,
  932                     addrlen);
  933                 NG_FREE_MSG(msg);
  934                 return (EINVAL);
  935         }
  936 
  937         /* Copy the message itself into an mbuf chain. */
  938         m = m_devget((caddr_t)msg, sizeof(struct ng_mesg) + msg->header.arglen,
  939             0, NULL, NULL);
  940 
  941         /*
  942          * Here we free the message. We need to do that
  943          * regardless of whether we got mbufs.
  944          */
  945         NG_FREE_MSG(msg);
  946 
  947         if (m == NULL) {
  948                 SOCKBUF_UNLOCK(&so->so_rcv);
  949                 TRAP_ERROR;
  950                 return (ENOBUFS);
  951         }
  952 
  953         /* Send it up to the socket. */
  954         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&addr, m,
  955             NULL) == 0) {
  956                 SOCKBUF_UNLOCK(&so->so_rcv);
  957                 TRAP_ERROR;
  958                 m_freem(m);
  959                 return (ENOBUFS);
  960         }
  961         sorwakeup_locked(so);
  962         
  963         return (error);
  964 }
  965 
  966 /*
  967  * Receive data on a hook
  968  */
  969 static int
  970 ngs_rcvdata(hook_p hook, item_p item)
  971 {
  972         struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  973         struct ngpcb *const pcbp = priv->datasock;
  974         struct socket *so;
  975         struct sockaddr_ng *addr;
  976         char *addrbuf[NG_HOOKSIZ + 4];
  977         int addrlen;
  978         struct mbuf *m;
  979 
  980         NGI_GET_M(item, m);
  981         NG_FREE_ITEM(item);
  982 
  983         /* If there is no data socket, black-hole it. */
  984         if (pcbp == NULL) {
  985                 NG_FREE_M(m);
  986                 return (0);
  987         }
  988         so = pcbp->ng_socket;
  989 
  990         /* Get the return address into a sockaddr. */
  991         addrlen = strlen(NG_HOOK_NAME(hook));   /* <= NG_HOOKSIZ - 1 */
  992         addr = (struct sockaddr_ng *) addrbuf;
  993         addr->sg_len = addrlen + 3;
  994         addr->sg_family = AF_NETGRAPH;
  995         bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
  996         addr->sg_data[addrlen] = '\0';
  997 
  998         /* Try to tell the socket which hook it came in on. */
  999         if (sbappendaddr(&so->so_rcv, (struct sockaddr *)addr, m, NULL) == 0) {
 1000                 m_freem(m);
 1001                 TRAP_ERROR;
 1002                 return (ENOBUFS);
 1003         }
 1004         sorwakeup(so);
 1005         return (0);
 1006 }
 1007 
 1008 /*
 1009  * Hook disconnection
 1010  *
 1011  * For this type, removal of the last link destroys the node
 1012  * if the NOLINGER flag is set.
 1013  */
 1014 static int
 1015 ngs_disconnect(hook_p hook)
 1016 {
 1017         node_p node = NG_HOOK_NODE(hook);
 1018         struct ngsock *const priv = NG_NODE_PRIVATE(node);
 1019         struct hookpriv *hp = NG_HOOK_PRIVATE(hook);
 1020 
 1021         LIST_REMOVE(hp, next);
 1022         free(hp, M_NETGRAPH_SOCK);
 1023 
 1024         if ((priv->datasock) && (priv->datasock->ng_socket)) {
 1025                 if (NG_NODE_NUMHOOKS(node) == 1)
 1026                         priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
 1027                 else
 1028                         priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
 1029         }
 1030 
 1031         if ((priv->flags & NGS_FLAG_NOLINGER) &&
 1032             (NG_NODE_NUMHOOKS(node) == 0) && (NG_NODE_IS_VALID(node)))
 1033                 ng_rmnode_self(node);
 1034 
 1035         return (0);
 1036 }
 1037 
 1038 /*
 1039  * Do local shutdown processing.
 1040  * In this case, that involves making sure the socket
 1041  * knows we should be shutting down.
 1042  */
 1043 static int
 1044 ngs_shutdown(node_p node)
 1045 {
 1046         struct ngsock *const priv = NG_NODE_PRIVATE(node);
 1047         struct ngpcb *dpcbp, *pcbp;
 1048 
 1049         mtx_lock(&priv->mtx);
 1050         dpcbp = priv->datasock;
 1051         pcbp = priv->ctlsock;
 1052 
 1053         if (dpcbp != NULL)
 1054                 soisdisconnected(dpcbp->ng_socket);
 1055 
 1056         if (pcbp != NULL)
 1057                 soisdisconnected(pcbp->ng_socket);
 1058 
 1059         priv->node = NULL;
 1060         NG_NODE_SET_PRIVATE(node, NULL);
 1061         ng_socket_free_priv(priv);
 1062 
 1063         NG_NODE_UNREF(node);
 1064         return (0);
 1065 }
 1066 
 1067 static void
 1068 ng_socket_item_applied(void *context, int error)
 1069 {
 1070         struct ngsock *const priv = (struct ngsock *)context;
 1071 
 1072         mtx_lock(&priv->mtx);
 1073         priv->error = error;
 1074         wakeup(priv);
 1075         mtx_unlock(&priv->mtx);
 1076 
 1077 }
 1078 
 1079 static  int
 1080 dummy_disconnect(struct socket *so)
 1081 {
 1082         return (0);
 1083 }
 1084 /*
 1085  * Control and data socket type descriptors
 1086  *
 1087  * XXXRW: Perhaps _close should do something?
 1088  */
 1089 
 1090 static struct pr_usrreqs ngc_usrreqs = {
 1091         .pru_abort =            NULL,
 1092         .pru_attach =           ngc_attach,
 1093         .pru_bind =             ngc_bind,
 1094         .pru_connect =          ngc_connect,
 1095         .pru_detach =           ngc_detach,
 1096         .pru_disconnect =       dummy_disconnect,
 1097         .pru_peeraddr =         NULL,
 1098         .pru_send =             ngc_send,
 1099         .pru_shutdown =         NULL,
 1100         .pru_sockaddr =         ng_getsockaddr,
 1101         .pru_close =            NULL,
 1102 };
 1103 
 1104 static struct pr_usrreqs ngd_usrreqs = {
 1105         .pru_abort =            NULL,
 1106         .pru_attach =           ngd_attach,
 1107         .pru_bind =             NULL,
 1108         .pru_connect =          ngd_connect,
 1109         .pru_detach =           ngd_detach,
 1110         .pru_disconnect =       dummy_disconnect,
 1111         .pru_peeraddr =         NULL,
 1112         .pru_send =             ngd_send,
 1113         .pru_shutdown =         NULL,
 1114         .pru_sockaddr =         ng_getsockaddr,
 1115         .pru_close =            NULL,
 1116 };
 1117 
 1118 /*
 1119  * Definitions of protocols supported in the NETGRAPH domain.
 1120  */
 1121 
 1122 extern struct domain ngdomain;          /* stop compiler warnings */
 1123 
 1124 static struct protosw ngsw[] = {
 1125 {
 1126         .pr_type =              SOCK_DGRAM,
 1127         .pr_domain =            &ngdomain,
 1128         .pr_protocol =          NG_CONTROL,
 1129         .pr_flags =             PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
 1130         .pr_usrreqs =           &ngc_usrreqs
 1131 },
 1132 {
 1133         .pr_type =              SOCK_DGRAM,
 1134         .pr_domain =            &ngdomain,
 1135         .pr_protocol =          NG_DATA,
 1136         .pr_flags =             PR_ATOMIC | PR_ADDR,
 1137         .pr_usrreqs =           &ngd_usrreqs
 1138 }
 1139 };
 1140 
 1141 struct domain ngdomain = {
 1142         .dom_family =           AF_NETGRAPH,
 1143         .dom_name =             "netgraph",
 1144         .dom_protosw =          ngsw,
 1145         .dom_protoswNPROTOSW =  &ngsw[sizeof(ngsw) / sizeof(ngsw[0])]
 1146 };
 1147 
 1148 /*
 1149  * Handle loading and unloading for this node type.
 1150  * This is to handle auxiliary linkages (e.g protocol domain addition).
 1151  */
 1152 static int
 1153 ngs_mod_event(module_t mod, int event, void *data)
 1154 {
 1155         int error = 0;
 1156 
 1157         switch (event) {
 1158         case MOD_LOAD:
 1159                 mtx_init(&ngsocketlist_mtx, "ng_socketlist", NULL, MTX_DEF);
 1160                 break;
 1161         case MOD_UNLOAD:
 1162                 /* Ensure there are no open netgraph sockets. */
 1163                 if (!LIST_EMPTY(&ngsocklist)) {
 1164                         error = EBUSY;
 1165                         break;
 1166                 }
 1167 #ifdef NOTYET
 1168                 /* Unregister protocol domain XXX can't do this yet.. */
 1169 #endif
 1170                 error = EBUSY;
 1171                 break;
 1172         default:
 1173                 error = EOPNOTSUPP;
 1174                 break;
 1175         }
 1176         return (error);
 1177 }
 1178 
 1179 VNET_DOMAIN_SET(ng);
 1180 
 1181 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, AF_NETGRAPH, "");
 1182 static SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
 1183 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_DATA, "");
 1184 static SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
 1185 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_CONTROL, "");
 1186 

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