The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_bridge.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*
    2  * ng_bridge.c
    3  */
    4 
    5 /*-
    6  * Copyright (c) 2000 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: Archie Cobbs <archie@freebsd.org>
   39  *
   40  * $FreeBSD: releng/9.1/sys/netgraph/ng_bridge.c 220768 2011-04-18 09:12:27Z glebius $
   41  */
   42 
   43 /*
   44  * ng_bridge(4) netgraph node type
   45  *
   46  * The node performs standard intelligent Ethernet bridging over
   47  * each of its connected hooks, or links.  A simple loop detection
   48  * algorithm is included which disables a link for priv->conf.loopTimeout
   49  * seconds when a host is seen to have jumped from one link to
   50  * another within priv->conf.minStableAge seconds.
   51  *
   52  * We keep a hashtable that maps Ethernet addresses to host info,
   53  * which is contained in struct ng_bridge_host's. These structures
   54  * tell us on which link the host may be found. A host's entry will
   55  * expire after priv->conf.maxStaleness seconds.
   56  *
   57  * This node is optimzed for stable networks, where machines jump
   58  * from one port to the other only rarely.
   59  */
   60 
   61 #include <sys/param.h>
   62 #include <sys/systm.h>
   63 #include <sys/kernel.h>
   64 #include <sys/lock.h>
   65 #include <sys/malloc.h>
   66 #include <sys/mbuf.h>
   67 #include <sys/errno.h>
   68 #include <sys/rwlock.h>
   69 #include <sys/syslog.h>
   70 #include <sys/socket.h>
   71 #include <sys/ctype.h>
   72 
   73 #include <net/if.h>
   74 #include <net/ethernet.h>
   75 #include <net/vnet.h>
   76 
   77 #include <netinet/in.h>
   78 #if 0   /* not used yet */
   79 #include <netinet/ip_fw.h>
   80 #endif
   81 #include <netgraph/ng_message.h>
   82 #include <netgraph/netgraph.h>
   83 #include <netgraph/ng_parse.h>
   84 #include <netgraph/ng_bridge.h>
   85 
   86 #ifdef NG_SEPARATE_MALLOC
   87 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node");
   88 #else
   89 #define M_NETGRAPH_BRIDGE M_NETGRAPH
   90 #endif
   91 
   92 /* Per-link private data */
   93 struct ng_bridge_link {
   94         hook_p                          hook;           /* netgraph hook */
   95         u_int16_t                       loopCount;      /* loop ignore timer */
   96         struct ng_bridge_link_stats     stats;          /* link stats */
   97 };
   98 
   99 /* Per-node private data */
  100 struct ng_bridge_private {
  101         struct ng_bridge_bucket *tab;           /* hash table bucket array */
  102         struct ng_bridge_link   *links[NG_BRIDGE_MAX_LINKS];
  103         struct ng_bridge_config conf;           /* node configuration */
  104         node_p                  node;           /* netgraph node */
  105         u_int                   numHosts;       /* num entries in table */
  106         u_int                   numBuckets;     /* num buckets in table */
  107         u_int                   hashMask;       /* numBuckets - 1 */
  108         int                     numLinks;       /* num connected links */
  109         int                     persistent;     /* can exist w/o hooks */
  110         struct callout          timer;          /* one second periodic timer */
  111 };
  112 typedef struct ng_bridge_private *priv_p;
  113 
  114 /* Information about a host, stored in a hash table entry */
  115 struct ng_bridge_hent {
  116         struct ng_bridge_host           host;   /* actual host info */
  117         SLIST_ENTRY(ng_bridge_hent)     next;   /* next entry in bucket */
  118 };
  119 
  120 /* Hash table bucket declaration */
  121 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
  122 
  123 /* Netgraph node methods */
  124 static ng_constructor_t ng_bridge_constructor;
  125 static ng_rcvmsg_t      ng_bridge_rcvmsg;
  126 static ng_shutdown_t    ng_bridge_shutdown;
  127 static ng_newhook_t     ng_bridge_newhook;
  128 static ng_rcvdata_t     ng_bridge_rcvdata;
  129 static ng_disconnect_t  ng_bridge_disconnect;
  130 
  131 /* Other internal functions */
  132 static struct   ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
  133 static int      ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
  134 static void     ng_bridge_rehash(priv_p priv);
  135 static void     ng_bridge_remove_hosts(priv_p priv, int linkNum);
  136 static void     ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
  137 static const    char *ng_bridge_nodename(node_p node);
  138 
  139 /* Ethernet broadcast */
  140 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
  141     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  142 
  143 /* Store each hook's link number in the private field */
  144 #define LINK_NUM(hook)          (*(u_int16_t *)(&(hook)->private))
  145 
  146 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
  147 #define ETHER_EQUAL(a,b)        (((const u_int32_t *)(a))[0] \
  148                                         == ((const u_int32_t *)(b))[0] \
  149                                     && ((const u_int16_t *)(a))[2] \
  150                                         == ((const u_int16_t *)(b))[2])
  151 
  152 /* Minimum and maximum number of hash buckets. Must be a power of two. */
  153 #define MIN_BUCKETS             (1 << 5)        /* 32 */
  154 #define MAX_BUCKETS             (1 << 14)       /* 16384 */
  155 
  156 /* Configuration default values */
  157 #define DEFAULT_LOOP_TIMEOUT    60
  158 #define DEFAULT_MAX_STALENESS   (15 * 60)       /* same as ARP timeout */
  159 #define DEFAULT_MIN_STABLE_AGE  1
  160 
  161 /******************************************************************
  162                     NETGRAPH PARSE TYPES
  163 ******************************************************************/
  164 
  165 /*
  166  * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
  167  */
  168 static int
  169 ng_bridge_getTableLength(const struct ng_parse_type *type,
  170         const u_char *start, const u_char *buf)
  171 {
  172         const struct ng_bridge_host_ary *const hary
  173             = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
  174 
  175         return hary->numHosts;
  176 }
  177 
  178 /* Parse type for struct ng_bridge_host_ary */
  179 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
  180         = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
  181 static const struct ng_parse_type ng_bridge_host_type = {
  182         &ng_parse_struct_type,
  183         &ng_bridge_host_type_fields
  184 };
  185 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
  186         &ng_bridge_host_type,
  187         ng_bridge_getTableLength
  188 };
  189 static const struct ng_parse_type ng_bridge_hary_type = {
  190         &ng_parse_array_type,
  191         &ng_bridge_hary_type_info
  192 };
  193 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
  194         = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
  195 static const struct ng_parse_type ng_bridge_host_ary_type = {
  196         &ng_parse_struct_type,
  197         &ng_bridge_host_ary_type_fields
  198 };
  199 
  200 /* Parse type for struct ng_bridge_config */
  201 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
  202         &ng_parse_uint8_type,
  203         NG_BRIDGE_MAX_LINKS
  204 };
  205 static const struct ng_parse_type ng_bridge_ipfwary_type = {
  206         &ng_parse_fixedarray_type,
  207         &ng_bridge_ipfwary_type_info
  208 };
  209 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
  210         = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
  211 static const struct ng_parse_type ng_bridge_config_type = {
  212         &ng_parse_struct_type,
  213         &ng_bridge_config_type_fields
  214 };
  215 
  216 /* Parse type for struct ng_bridge_link_stat */
  217 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
  218         = NG_BRIDGE_STATS_TYPE_INFO;
  219 static const struct ng_parse_type ng_bridge_stats_type = {
  220         &ng_parse_struct_type,
  221         &ng_bridge_stats_type_fields
  222 };
  223 
  224 /* List of commands and how to convert arguments to/from ASCII */
  225 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
  226         {
  227           NGM_BRIDGE_COOKIE,
  228           NGM_BRIDGE_SET_CONFIG,
  229           "setconfig",
  230           &ng_bridge_config_type,
  231           NULL
  232         },
  233         {
  234           NGM_BRIDGE_COOKIE,
  235           NGM_BRIDGE_GET_CONFIG,
  236           "getconfig",
  237           NULL,
  238           &ng_bridge_config_type
  239         },
  240         {
  241           NGM_BRIDGE_COOKIE,
  242           NGM_BRIDGE_RESET,
  243           "reset",
  244           NULL,
  245           NULL
  246         },
  247         {
  248           NGM_BRIDGE_COOKIE,
  249           NGM_BRIDGE_GET_STATS,
  250           "getstats",
  251           &ng_parse_uint32_type,
  252           &ng_bridge_stats_type
  253         },
  254         {
  255           NGM_BRIDGE_COOKIE,
  256           NGM_BRIDGE_CLR_STATS,
  257           "clrstats",
  258           &ng_parse_uint32_type,
  259           NULL
  260         },
  261         {
  262           NGM_BRIDGE_COOKIE,
  263           NGM_BRIDGE_GETCLR_STATS,
  264           "getclrstats",
  265           &ng_parse_uint32_type,
  266           &ng_bridge_stats_type
  267         },
  268         {
  269           NGM_BRIDGE_COOKIE,
  270           NGM_BRIDGE_GET_TABLE,
  271           "gettable",
  272           NULL,
  273           &ng_bridge_host_ary_type
  274         },
  275         {
  276           NGM_BRIDGE_COOKIE,
  277           NGM_BRIDGE_SET_PERSISTENT,
  278           "setpersistent",
  279           NULL,
  280           NULL
  281         },
  282         { 0 }
  283 };
  284 
  285 /* Node type descriptor */
  286 static struct ng_type ng_bridge_typestruct = {
  287         .version =      NG_ABI_VERSION,
  288         .name =         NG_BRIDGE_NODE_TYPE,
  289         .constructor =  ng_bridge_constructor,
  290         .rcvmsg =       ng_bridge_rcvmsg,
  291         .shutdown =     ng_bridge_shutdown,
  292         .newhook =      ng_bridge_newhook,
  293         .rcvdata =      ng_bridge_rcvdata,
  294         .disconnect =   ng_bridge_disconnect,
  295         .cmdlist =      ng_bridge_cmdlist,
  296 };
  297 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
  298 
  299 /******************************************************************
  300                     NETGRAPH NODE METHODS
  301 ******************************************************************/
  302 
  303 /*
  304  * Node constructor
  305  */
  306 static int
  307 ng_bridge_constructor(node_p node)
  308 {
  309         priv_p priv;
  310 
  311         /* Allocate and initialize private info */
  312         priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
  313         ng_callout_init(&priv->timer);
  314 
  315         /* Allocate and initialize hash table, etc. */
  316         priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
  317             M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
  318         priv->numBuckets = MIN_BUCKETS;
  319         priv->hashMask = MIN_BUCKETS - 1;
  320         priv->conf.debugLevel = 1;
  321         priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
  322         priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
  323         priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
  324 
  325         /*
  326          * This node has all kinds of stuff that could be screwed by SMP.
  327          * Until it gets it's own internal protection, we go through in 
  328          * single file. This could hurt a machine bridging beteen two 
  329          * GB ethernets so it should be fixed. 
  330          * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
  331          * (and atomic ops )
  332          */
  333         NG_NODE_FORCE_WRITER(node);
  334         NG_NODE_SET_PRIVATE(node, priv);
  335         priv->node = node;
  336 
  337         /* Start timer; timer is always running while node is alive */
  338         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
  339 
  340         /* Done */
  341         return (0);
  342 }
  343 
  344 /*
  345  * Method for attaching a new hook
  346  */
  347 static  int
  348 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
  349 {
  350         const priv_p priv = NG_NODE_PRIVATE(node);
  351 
  352         /* Check for a link hook */
  353         if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
  354             strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
  355                 const char *cp;
  356                 char *eptr;
  357                 u_long linkNum;
  358 
  359                 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
  360                 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
  361                         return (EINVAL);
  362                 linkNum = strtoul(cp, &eptr, 10);
  363                 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
  364                         return (EINVAL);
  365                 if (priv->links[linkNum] != NULL)
  366                         return (EISCONN);
  367                 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]),
  368                     M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
  369                 if (priv->links[linkNum] == NULL)
  370                         return (ENOMEM);
  371                 priv->links[linkNum]->hook = hook;
  372                 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
  373                 priv->numLinks++;
  374                 return (0);
  375         }
  376 
  377         /* Unknown hook name */
  378         return (EINVAL);
  379 }
  380 
  381 /*
  382  * Receive a control message
  383  */
  384 static int
  385 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
  386 {
  387         const priv_p priv = NG_NODE_PRIVATE(node);
  388         struct ng_mesg *resp = NULL;
  389         int error = 0;
  390         struct ng_mesg *msg;
  391 
  392         NGI_GET_MSG(item, msg);
  393         switch (msg->header.typecookie) {
  394         case NGM_BRIDGE_COOKIE:
  395                 switch (msg->header.cmd) {
  396                 case NGM_BRIDGE_GET_CONFIG:
  397                     {
  398                         struct ng_bridge_config *conf;
  399 
  400                         NG_MKRESPONSE(resp, msg,
  401                             sizeof(struct ng_bridge_config), M_NOWAIT);
  402                         if (resp == NULL) {
  403                                 error = ENOMEM;
  404                                 break;
  405                         }
  406                         conf = (struct ng_bridge_config *)resp->data;
  407                         *conf = priv->conf;     /* no sanity checking needed */
  408                         break;
  409                     }
  410                 case NGM_BRIDGE_SET_CONFIG:
  411                     {
  412                         struct ng_bridge_config *conf;
  413                         int i;
  414 
  415                         if (msg->header.arglen
  416                             != sizeof(struct ng_bridge_config)) {
  417                                 error = EINVAL;
  418                                 break;
  419                         }
  420                         conf = (struct ng_bridge_config *)msg->data;
  421                         priv->conf = *conf;
  422                         for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
  423                                 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
  424                         break;
  425                     }
  426                 case NGM_BRIDGE_RESET:
  427                     {
  428                         int i;
  429 
  430                         /* Flush all entries in the hash table */
  431                         ng_bridge_remove_hosts(priv, -1);
  432 
  433                         /* Reset all loop detection counters and stats */
  434                         for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
  435                                 if (priv->links[i] == NULL)
  436                                         continue;
  437                                 priv->links[i]->loopCount = 0;
  438                                 bzero(&priv->links[i]->stats,
  439                                     sizeof(priv->links[i]->stats));
  440                         }
  441                         break;
  442                     }
  443                 case NGM_BRIDGE_GET_STATS:
  444                 case NGM_BRIDGE_CLR_STATS:
  445                 case NGM_BRIDGE_GETCLR_STATS:
  446                     {
  447                         struct ng_bridge_link *link;
  448                         int linkNum;
  449 
  450                         /* Get link number */
  451                         if (msg->header.arglen != sizeof(u_int32_t)) {
  452                                 error = EINVAL;
  453                                 break;
  454                         }
  455                         linkNum = *((u_int32_t *)msg->data);
  456                         if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
  457                                 error = EINVAL;
  458                                 break;
  459                         }
  460                         if ((link = priv->links[linkNum]) == NULL) {
  461                                 error = ENOTCONN;
  462                                 break;
  463                         }
  464 
  465                         /* Get/clear stats */
  466                         if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
  467                                 NG_MKRESPONSE(resp, msg,
  468                                     sizeof(link->stats), M_NOWAIT);
  469                                 if (resp == NULL) {
  470                                         error = ENOMEM;
  471                                         break;
  472                                 }
  473                                 bcopy(&link->stats,
  474                                     resp->data, sizeof(link->stats));
  475                         }
  476                         if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
  477                                 bzero(&link->stats, sizeof(link->stats));
  478                         break;
  479                     }
  480                 case NGM_BRIDGE_GET_TABLE:
  481                     {
  482                         struct ng_bridge_host_ary *ary;
  483                         struct ng_bridge_hent *hent;
  484                         int i = 0, bucket;
  485 
  486                         NG_MKRESPONSE(resp, msg, sizeof(*ary)
  487                             + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
  488                         if (resp == NULL) {
  489                                 error = ENOMEM;
  490                                 break;
  491                         }
  492                         ary = (struct ng_bridge_host_ary *)resp->data;
  493                         ary->numHosts = priv->numHosts;
  494                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
  495                                 SLIST_FOREACH(hent, &priv->tab[bucket], next)
  496                                         ary->hosts[i++] = hent->host;
  497                         }
  498                         break;
  499                     }
  500                 case NGM_BRIDGE_SET_PERSISTENT:
  501                     {
  502                         priv->persistent = 1;
  503                         break;
  504                     }
  505                 default:
  506                         error = EINVAL;
  507                         break;
  508                 }
  509                 break;
  510         default:
  511                 error = EINVAL;
  512                 break;
  513         }
  514 
  515         /* Done */
  516         NG_RESPOND_MSG(error, node, item, resp);
  517         NG_FREE_MSG(msg);
  518         return (error);
  519 }
  520 
  521 /*
  522  * Receive data on a hook
  523  */
  524 static int
  525 ng_bridge_rcvdata(hook_p hook, item_p item)
  526 {
  527         const node_p node = NG_HOOK_NODE(hook);
  528         const priv_p priv = NG_NODE_PRIVATE(node);
  529         struct ng_bridge_host *host;
  530         struct ng_bridge_link *link;
  531         struct ether_header *eh;
  532         int error = 0, linkNum, linksSeen;
  533         int manycast;
  534         struct mbuf *m;
  535         struct ng_bridge_link *firstLink;
  536 
  537         NGI_GET_M(item, m);
  538         /* Get link number */
  539         linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
  540         KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
  541             ("%s: linkNum=%u", __func__, linkNum));
  542         link = priv->links[linkNum];
  543         KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
  544 
  545         /* Sanity check packet and pull up header */
  546         if (m->m_pkthdr.len < ETHER_HDR_LEN) {
  547                 link->stats.recvRunts++;
  548                 NG_FREE_ITEM(item);
  549                 NG_FREE_M(m);
  550                 return (EINVAL);
  551         }
  552         if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
  553                 link->stats.memoryFailures++;
  554                 NG_FREE_ITEM(item);
  555                 return (ENOBUFS);
  556         }
  557         eh = mtod(m, struct ether_header *);
  558         if ((eh->ether_shost[0] & 1) != 0) {
  559                 link->stats.recvInvalid++;
  560                 NG_FREE_ITEM(item);
  561                 NG_FREE_M(m);
  562                 return (EINVAL);
  563         }
  564 
  565         /* Is link disabled due to a loopback condition? */
  566         if (link->loopCount != 0) {
  567                 link->stats.loopDrops++;
  568                 NG_FREE_ITEM(item);
  569                 NG_FREE_M(m);
  570                 return (ELOOP);         /* XXX is this an appropriate error? */
  571         }
  572 
  573         /* Update stats */
  574         link->stats.recvPackets++;
  575         link->stats.recvOctets += m->m_pkthdr.len;
  576         if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
  577                 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
  578                         link->stats.recvBroadcasts++;
  579                         manycast = 2;
  580                 } else
  581                         link->stats.recvMulticasts++;
  582         }
  583 
  584         /* Look up packet's source Ethernet address in hashtable */
  585         if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
  586 
  587                 /* Update time since last heard from this host */
  588                 host->staleness = 0;
  589 
  590                 /* Did host jump to a different link? */
  591                 if (host->linkNum != linkNum) {
  592 
  593                         /*
  594                          * If the host's old link was recently established
  595                          * on the old link and it's already jumped to a new
  596                          * link, declare a loopback condition.
  597                          */
  598                         if (host->age < priv->conf.minStableAge) {
  599 
  600                                 /* Log the problem */
  601                                 if (priv->conf.debugLevel >= 2) {
  602                                         struct ifnet *ifp = m->m_pkthdr.rcvif;
  603                                         char suffix[32];
  604 
  605                                         if (ifp != NULL)
  606                                                 snprintf(suffix, sizeof(suffix),
  607                                                     " (%s)", ifp->if_xname);
  608                                         else
  609                                                 *suffix = '\0';
  610                                         log(LOG_WARNING, "ng_bridge: %s:"
  611                                             " loopback detected on %s%s\n",
  612                                             ng_bridge_nodename(node),
  613                                             NG_HOOK_NAME(hook), suffix);
  614                                 }
  615 
  616                                 /* Mark link as linka non grata */
  617                                 link->loopCount = priv->conf.loopTimeout;
  618                                 link->stats.loopDetects++;
  619 
  620                                 /* Forget all hosts on this link */
  621                                 ng_bridge_remove_hosts(priv, linkNum);
  622 
  623                                 /* Drop packet */
  624                                 link->stats.loopDrops++;
  625                                 NG_FREE_ITEM(item);
  626                                 NG_FREE_M(m);
  627                                 return (ELOOP);         /* XXX appropriate? */
  628                         }
  629 
  630                         /* Move host over to new link */
  631                         host->linkNum = linkNum;
  632                         host->age = 0;
  633                 }
  634         } else {
  635                 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
  636                         link->stats.memoryFailures++;
  637                         NG_FREE_ITEM(item);
  638                         NG_FREE_M(m);
  639                         return (ENOMEM);
  640                 }
  641         }
  642 
  643         /* Run packet through ipfw processing, if enabled */
  644 #if 0
  645         if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
  646                 /* XXX not implemented yet */
  647         }
  648 #endif
  649 
  650         /*
  651          * If unicast and destination host known, deliver to host's link,
  652          * unless it is the same link as the packet came in on.
  653          */
  654         if (!manycast) {
  655 
  656                 /* Determine packet destination link */
  657                 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
  658                         struct ng_bridge_link *const destLink
  659                             = priv->links[host->linkNum];
  660 
  661                         /* If destination same as incoming link, do nothing */
  662                         KASSERT(destLink != NULL,
  663                             ("%s: link%d null", __func__, host->linkNum));
  664                         if (destLink == link) {
  665                                 NG_FREE_ITEM(item);
  666                                 NG_FREE_M(m);
  667                                 return (0);
  668                         }
  669 
  670                         /* Deliver packet out the destination link */
  671                         destLink->stats.xmitPackets++;
  672                         destLink->stats.xmitOctets += m->m_pkthdr.len;
  673                         NG_FWD_NEW_DATA(error, item, destLink->hook, m);
  674                         return (error);
  675                 }
  676 
  677                 /* Destination host is not known */
  678                 link->stats.recvUnknown++;
  679         }
  680 
  681         /* Distribute unknown, multicast, broadcast pkts to all other links */
  682         firstLink = NULL;
  683         for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
  684                 struct ng_bridge_link *destLink;
  685                 struct mbuf *m2 = NULL;
  686 
  687                 /*
  688                  * If we have checked all the links then now
  689                  * send the original on its reserved link
  690                  */
  691                 if (linksSeen == priv->numLinks) {
  692                         /* If we never saw a good link, leave. */
  693                         if (firstLink == NULL) {
  694                                 NG_FREE_ITEM(item);
  695                                 NG_FREE_M(m);
  696                                 return (0);
  697                         }       
  698                         destLink = firstLink;
  699                 } else {
  700                         destLink = priv->links[linkNum];
  701                         if (destLink != NULL)
  702                                 linksSeen++;
  703                         /* Skip incoming link and disconnected links */
  704                         if (destLink == NULL || destLink == link) {
  705                                 continue;
  706                         }
  707                         if (firstLink == NULL) {
  708                                 /*
  709                                  * This is the first usable link we have found.
  710                                  * Reserve it for the originals.
  711                                  * If we never find another we save a copy.
  712                                  */
  713                                 firstLink = destLink;
  714                                 continue;
  715                         }
  716 
  717                         /*
  718                          * It's usable link but not the reserved (first) one.
  719                          * Copy mbuf info for sending.
  720                          */
  721                         m2 = m_dup(m, M_DONTWAIT);      /* XXX m_copypacket() */
  722                         if (m2 == NULL) {
  723                                 link->stats.memoryFailures++;
  724                                 NG_FREE_ITEM(item);
  725                                 NG_FREE_M(m);
  726                                 return (ENOBUFS);
  727                         }
  728                 }
  729 
  730                 /* Update stats */
  731                 destLink->stats.xmitPackets++;
  732                 destLink->stats.xmitOctets += m->m_pkthdr.len;
  733                 switch (manycast) {
  734                 case 0:                                 /* unicast */
  735                         break;
  736                 case 1:                                 /* multicast */
  737                         destLink->stats.xmitMulticasts++;
  738                         break;
  739                 case 2:                                 /* broadcast */
  740                         destLink->stats.xmitBroadcasts++;
  741                         break;
  742                 }
  743 
  744                 /* Send packet */
  745                 if (destLink == firstLink) { 
  746                         /*
  747                          * If we've sent all the others, send the original
  748                          * on the first link we found.
  749                          */
  750                         NG_FWD_NEW_DATA(error, item, destLink->hook, m);
  751                         break; /* always done last - not really needed. */
  752                 } else {
  753                         NG_SEND_DATA_ONLY(error, destLink->hook, m2);
  754                 }
  755         }
  756         return (error);
  757 }
  758 
  759 /*
  760  * Shutdown node
  761  */
  762 static int
  763 ng_bridge_shutdown(node_p node)
  764 {
  765         const priv_p priv = NG_NODE_PRIVATE(node);
  766 
  767         /*
  768          * Shut down everything including the timer.  Even if the
  769          * callout has already been dequeued and is about to be
  770          * run, ng_bridge_timeout() won't be fired as the node
  771          * is already marked NGF_INVALID, so we're safe to free
  772          * the node now.
  773          */
  774         KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
  775             ("%s: numLinks=%d numHosts=%d",
  776             __func__, priv->numLinks, priv->numHosts));
  777         ng_uncallout(&priv->timer, node);
  778         NG_NODE_SET_PRIVATE(node, NULL);
  779         NG_NODE_UNREF(node);
  780         free(priv->tab, M_NETGRAPH_BRIDGE);
  781         free(priv, M_NETGRAPH_BRIDGE);
  782         return (0);
  783 }
  784 
  785 /*
  786  * Hook disconnection.
  787  */
  788 static int
  789 ng_bridge_disconnect(hook_p hook)
  790 {
  791         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  792         int linkNum;
  793 
  794         /* Get link number */
  795         linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
  796         KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
  797             ("%s: linkNum=%u", __func__, linkNum));
  798 
  799         /* Remove all hosts associated with this link */
  800         ng_bridge_remove_hosts(priv, linkNum);
  801 
  802         /* Free associated link information */
  803         KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
  804         free(priv->links[linkNum], M_NETGRAPH_BRIDGE);
  805         priv->links[linkNum] = NULL;
  806         priv->numLinks--;
  807 
  808         /* If no more hooks, go away */
  809         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
  810             && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
  811             && !priv->persistent) {
  812                 ng_rmnode_self(NG_HOOK_NODE(hook));
  813         }
  814         return (0);
  815 }
  816 
  817 /******************************************************************
  818                     HASH TABLE FUNCTIONS
  819 ******************************************************************/
  820 
  821 /*
  822  * Hash algorithm
  823  */
  824 #define HASH(addr,mask)         ( (((const u_int16_t *)(addr))[0]       \
  825                                  ^ ((const u_int16_t *)(addr))[1]       \
  826                                  ^ ((const u_int16_t *)(addr))[2]) & (mask) )
  827 
  828 /*
  829  * Find a host entry in the table.
  830  */
  831 static struct ng_bridge_host *
  832 ng_bridge_get(priv_p priv, const u_char *addr)
  833 {
  834         const int bucket = HASH(addr, priv->hashMask);
  835         struct ng_bridge_hent *hent;
  836 
  837         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
  838                 if (ETHER_EQUAL(hent->host.addr, addr))
  839                         return (&hent->host);
  840         }
  841         return (NULL);
  842 }
  843 
  844 /*
  845  * Add a new host entry to the table. This assumes the host doesn't
  846  * already exist in the table. Returns 1 on success, 0 if there
  847  * was a memory allocation failure.
  848  */
  849 static int
  850 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
  851 {
  852         const int bucket = HASH(addr, priv->hashMask);
  853         struct ng_bridge_hent *hent;
  854 
  855 #ifdef INVARIANTS
  856         /* Assert that entry does not already exist in hashtable */
  857         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
  858                 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
  859                     ("%s: entry %6D exists in table", __func__, addr, ":"));
  860         }
  861 #endif
  862 
  863         /* Allocate and initialize new hashtable entry */
  864         hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
  865         if (hent == NULL)
  866                 return (0);
  867         bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
  868         hent->host.linkNum = linkNum;
  869         hent->host.staleness = 0;
  870         hent->host.age = 0;
  871 
  872         /* Add new element to hash bucket */
  873         SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
  874         priv->numHosts++;
  875 
  876         /* Resize table if necessary */
  877         ng_bridge_rehash(priv);
  878         return (1);
  879 }
  880 
  881 /*
  882  * Resize the hash table. We try to maintain the number of buckets
  883  * such that the load factor is in the range 0.25 to 1.0.
  884  *
  885  * If we can't get the new memory then we silently fail. This is OK
  886  * because things will still work and we'll try again soon anyway.
  887  */
  888 static void
  889 ng_bridge_rehash(priv_p priv)
  890 {
  891         struct ng_bridge_bucket *newTab;
  892         int oldBucket, newBucket;
  893         int newNumBuckets;
  894         u_int newMask;
  895 
  896         /* Is table too full or too empty? */
  897         if (priv->numHosts > priv->numBuckets
  898             && (priv->numBuckets << 1) <= MAX_BUCKETS)
  899                 newNumBuckets = priv->numBuckets << 1;
  900         else if (priv->numHosts < (priv->numBuckets >> 2)
  901             && (priv->numBuckets >> 2) >= MIN_BUCKETS)
  902                 newNumBuckets = priv->numBuckets >> 2;
  903         else
  904                 return;
  905         newMask = newNumBuckets - 1;
  906 
  907         /* Allocate and initialize new table */
  908         newTab = malloc(newNumBuckets * sizeof(*newTab),
  909             M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
  910         if (newTab == NULL)
  911                 return;
  912 
  913         /* Move all entries from old table to new table */
  914         for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
  915                 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
  916 
  917                 while (!SLIST_EMPTY(oldList)) {
  918                         struct ng_bridge_hent *const hent
  919                             = SLIST_FIRST(oldList);
  920 
  921                         SLIST_REMOVE_HEAD(oldList, next);
  922                         newBucket = HASH(hent->host.addr, newMask);
  923                         SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
  924                 }
  925         }
  926 
  927         /* Replace old table with new one */
  928         if (priv->conf.debugLevel >= 3) {
  929                 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
  930                     ng_bridge_nodename(priv->node),
  931                     priv->numBuckets, newNumBuckets);
  932         }
  933         free(priv->tab, M_NETGRAPH_BRIDGE);
  934         priv->numBuckets = newNumBuckets;
  935         priv->hashMask = newMask;
  936         priv->tab = newTab;
  937         return;
  938 }
  939 
  940 /******************************************************************
  941                     MISC FUNCTIONS
  942 ******************************************************************/
  943 
  944 /*
  945  * Remove all hosts associated with a specific link from the hashtable.
  946  * If linkNum == -1, then remove all hosts in the table.
  947  */
  948 static void
  949 ng_bridge_remove_hosts(priv_p priv, int linkNum)
  950 {
  951         int bucket;
  952 
  953         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
  954                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
  955 
  956                 while (*hptr != NULL) {
  957                         struct ng_bridge_hent *const hent = *hptr;
  958 
  959                         if (linkNum == -1 || hent->host.linkNum == linkNum) {
  960                                 *hptr = SLIST_NEXT(hent, next);
  961                                 free(hent, M_NETGRAPH_BRIDGE);
  962                                 priv->numHosts--;
  963                         } else
  964                                 hptr = &SLIST_NEXT(hent, next);
  965                 }
  966         }
  967 }
  968 
  969 /*
  970  * Handle our once-per-second timeout event. We do two things:
  971  * we decrement link->loopCount for those links being muted due to
  972  * a detected loopback condition, and we remove any hosts from
  973  * the hashtable whom we haven't heard from in a long while.
  974  */
  975 static void
  976 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
  977 {
  978         const priv_p priv = NG_NODE_PRIVATE(node);
  979         int bucket;
  980         int counter = 0;
  981         int linkNum;
  982 
  983         /* Update host time counters and remove stale entries */
  984         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
  985                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
  986 
  987                 while (*hptr != NULL) {
  988                         struct ng_bridge_hent *const hent = *hptr;
  989 
  990                         /* Make sure host's link really exists */
  991                         KASSERT(priv->links[hent->host.linkNum] != NULL,
  992                             ("%s: host %6D on nonexistent link %d\n",
  993                             __func__, hent->host.addr, ":",
  994                             hent->host.linkNum));
  995 
  996                         /* Remove hosts we haven't heard from in a while */
  997                         if (++hent->host.staleness >= priv->conf.maxStaleness) {
  998                                 *hptr = SLIST_NEXT(hent, next);
  999                                 free(hent, M_NETGRAPH_BRIDGE);
 1000                                 priv->numHosts--;
 1001                         } else {
 1002                                 if (hent->host.age < 0xffff)
 1003                                         hent->host.age++;
 1004                                 hptr = &SLIST_NEXT(hent, next);
 1005                                 counter++;
 1006                         }
 1007                 }
 1008         }
 1009         KASSERT(priv->numHosts == counter,
 1010             ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
 1011 
 1012         /* Decrease table size if necessary */
 1013         ng_bridge_rehash(priv);
 1014 
 1015         /* Decrease loop counter on muted looped back links */
 1016         for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
 1017                 struct ng_bridge_link *const link = priv->links[linkNum];
 1018 
 1019                 if (link != NULL) {
 1020                         if (link->loopCount != 0) {
 1021                                 link->loopCount--;
 1022                                 if (link->loopCount == 0
 1023                                     && priv->conf.debugLevel >= 2) {
 1024                                         log(LOG_INFO, "ng_bridge: %s:"
 1025                                             " restoring looped back link%d\n",
 1026                                             ng_bridge_nodename(node), linkNum);
 1027                                 }
 1028                         }
 1029                         counter++;
 1030                 }
 1031         }
 1032         KASSERT(priv->numLinks == counter,
 1033             ("%s: links: %d != %d", __func__, priv->numLinks, counter));
 1034 
 1035         /* Register a new timeout, keeping the existing node reference */
 1036         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
 1037 }
 1038 
 1039 /*
 1040  * Return node's "name", even if it doesn't have one.
 1041  */
 1042 static const char *
 1043 ng_bridge_nodename(node_p node)
 1044 {
 1045         static char name[NG_NODESIZ];
 1046 
 1047         if (NG_NODE_NAME(node) != NULL)
 1048                 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
 1049         else
 1050                 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
 1051         return name;
 1052 }
 1053 

Cache object: 27ccd35c2bff57e525c1053ea16f9624


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.