/* * ng_bridge.c * * Copyright (c) 2000 Whistle Communications, Inc. * All rights reserved. * * Subject to the following obligations and disclaimer of warranty, use and * redistribution of this software, in source or object code forms, with or * without modifications are expressly permitted by Whistle Communications; * provided, however, that: * 1. Any and all reproductions of the source or object code must include the * copyright notice above and the following disclaimer of warranties; and * 2. No rights are granted, in any manner or form, to use Whistle * Communications, Inc. trademarks, including the mark "WHISTLE * COMMUNICATIONS" on advertising, endorsements, or otherwise except as * such appears in the above copyright notice or in the software. * * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * Author: Archie Cobbs * * $FreeBSD$ */ /* * ng_bridge(4) netgraph node type * * The node performs standard intelligent Ethernet bridging over * each of its connected hooks, or links. A simple loop detection * algorithm is included which disables a link for priv->conf.loopTimeout * seconds when a host is seen to have jumped from one link to * another within priv->conf.minStableAge seconds. * * We keep a hashtable that maps Ethernet addresses to host info, * which is contained in struct ng_bridge_host's. These structures * tell us on which link the host may be found. A host's entry will * expire after priv->conf.maxStaleness seconds. * * This node is optimzed for stable networks, where machines jump * from one port to the other only rarely. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Per-link private data */ struct ng_bridge_link { hook_p hook; /* netgraph hook */ u_int16_t loopCount; /* loop ignore timer */ struct ng_bridge_link_stats stats; /* link stats */ }; /* Per-node private data */ struct ng_bridge_private { struct ng_bridge_bucket *tab; /* hash table bucket array */ struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; struct ng_bridge_config conf; /* node configuration */ node_p node; /* netgraph node */ u_int numHosts; /* num entries in table */ u_int numBuckets; /* num buckets in table */ u_int hashMask; /* numBuckets - 1 */ int numLinks; /* num connected links */ struct callout timer; /* one second periodic timer */ }; typedef struct ng_bridge_private *priv_p; /* Information about a host, stored in a hash table entry */ struct ng_bridge_hent { struct ng_bridge_host host; /* actual host info */ SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ }; /* Hash table bucket declaration */ SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); /* Netgraph node methods */ static ng_constructor_t ng_bridge_constructor; static ng_rcvmsg_t ng_bridge_rcvmsg; static ng_shutdown_t ng_bridge_rmnode; static ng_newhook_t ng_bridge_newhook; static ng_rcvdata_t ng_bridge_rcvdata; static ng_disconnect_t ng_bridge_disconnect; /* Other internal functions */ static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); static void ng_bridge_rehash(priv_p priv); static void ng_bridge_remove_hosts(priv_p priv, int linkNum); static void ng_bridge_timeout(void *arg); static const char *ng_bridge_nodename(node_p node); /* Ethernet broadcast */ static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; /* Store each hook's link number in the private field */ #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ == ((const u_int32_t *)(b))[0] \ && ((const u_int16_t *)(a))[2] \ == ((const u_int16_t *)(b))[2]) /* Minimum and maximum number of hash buckets. Must be a power of two. */ #define MIN_BUCKETS (1 << 5) /* 32 */ #define MAX_BUCKETS (1 << 14) /* 16384 */ /* Configuration default values */ #define DEFAULT_LOOP_TIMEOUT 60 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ #define DEFAULT_MIN_STABLE_AGE 1 /****************************************************************** NETGRAPH PARSE TYPES ******************************************************************/ /* * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE */ static int ng_bridge_getTableLength(const struct ng_parse_type *type, const u_char *start, const u_char *buf) { const struct ng_bridge_host_ary *const hary = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); return hary->numHosts; } /* Parse type for struct ng_bridge_host_ary */ static const struct ng_parse_struct_info ng_bridge_host_type_info = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type); static const struct ng_parse_type ng_bridge_host_type = { &ng_parse_struct_type, &ng_bridge_host_type_info }; static const struct ng_parse_array_info ng_bridge_hary_type_info = { &ng_bridge_host_type, ng_bridge_getTableLength }; static const struct ng_parse_type ng_bridge_hary_type = { &ng_parse_array_type, &ng_bridge_hary_type_info }; static const struct ng_parse_struct_info ng_bridge_host_ary_type_info = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); static const struct ng_parse_type ng_bridge_host_ary_type = { &ng_parse_struct_type, &ng_bridge_host_ary_type_info }; /* Parse type for struct ng_bridge_config */ static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { &ng_parse_uint8_type, NG_BRIDGE_MAX_LINKS }; static const struct ng_parse_type ng_bridge_ipfwary_type = { &ng_parse_fixedarray_type, &ng_bridge_ipfwary_type_info }; static const struct ng_parse_struct_info ng_bridge_config_type_info = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); static const struct ng_parse_type ng_bridge_config_type = { &ng_parse_struct_type, &ng_bridge_config_type_info }; /* Parse type for struct ng_bridge_link_stat */ static const struct ng_parse_struct_info ng_bridge_stats_type_info = NG_BRIDGE_STATS_TYPE_INFO; static const struct ng_parse_type ng_bridge_stats_type = { &ng_parse_struct_type, &ng_bridge_stats_type_info }; /* List of commands and how to convert arguments to/from ASCII */ static const struct ng_cmdlist ng_bridge_cmdlist[] = { { NGM_BRIDGE_COOKIE, NGM_BRIDGE_SET_CONFIG, "setconfig", &ng_bridge_config_type, NULL }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_GET_CONFIG, "getconfig", NULL, &ng_bridge_config_type }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_RESET, "reset", NULL, NULL }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_GET_STATS, "getstats", &ng_parse_uint32_type, &ng_bridge_stats_type }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_CLR_STATS, "clrstats", &ng_parse_uint32_type, NULL }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_GETCLR_STATS, "getclrstats", &ng_parse_uint32_type, &ng_bridge_stats_type }, { NGM_BRIDGE_COOKIE, NGM_BRIDGE_GET_TABLE, "gettable", NULL, &ng_bridge_host_ary_type }, { 0 } }; /* Node type descriptor */ static struct ng_type ng_bridge_typestruct = { NG_VERSION, NG_BRIDGE_NODE_TYPE, NULL, ng_bridge_constructor, ng_bridge_rcvmsg, ng_bridge_rmnode, ng_bridge_newhook, NULL, NULL, ng_bridge_rcvdata, ng_bridge_rcvdata, ng_bridge_disconnect, ng_bridge_cmdlist, }; NETGRAPH_INIT(ether, &ng_bridge_typestruct); /* Depend on ng_ether so we can use the Ethernet parse type */ MODULE_DEPEND(ng_bridge, ng_ether, 1, 1, 1); /****************************************************************** NETGRAPH NODE METHODS ******************************************************************/ /* * Node constructor */ static int ng_bridge_constructor(node_p *nodep) { priv_p priv; int error; /* Allocate and initialize private info */ MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT); if (priv == NULL) return (ENOMEM); bzero(priv, sizeof(*priv)); callout_init(&priv->timer); /* Allocate and initialize hash table, etc. */ MALLOC(priv->tab, struct ng_bridge_bucket *, MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT); if (priv->tab == NULL) { FREE(priv, M_NETGRAPH); return (ENOMEM); } bzero(priv->tab, MIN_BUCKETS * sizeof(*priv->tab)); /* init SLIST's */ priv->numBuckets = MIN_BUCKETS; priv->hashMask = MIN_BUCKETS - 1; priv->conf.debugLevel = 1; priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; /* Call superclass constructor */ if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { FREE(priv, M_NETGRAPH); return (error); } (*nodep)->private = priv; priv->node = *nodep; /* Start timer by faking a timeout event */ (*nodep)->refs++; ng_bridge_timeout(*nodep); return (0); } /* * Method for attaching a new hook */ static int ng_bridge_newhook(node_p node, hook_p hook, const char *name) { const priv_p priv = node->private; /* Check for a link hook */ if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { const char *cp; char *eptr; u_long linkNum; cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) return (EINVAL); linkNum = strtoul(cp, &eptr, 10); if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) return (EINVAL); if (priv->links[linkNum] != NULL) return (EISCONN); MALLOC(priv->links[linkNum], struct ng_bridge_link *, sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT); if (priv->links[linkNum] == NULL) return (ENOMEM); bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); priv->links[linkNum]->hook = hook; LINK_NUM(hook) = linkNum; priv->numLinks++; return (0); } /* Unknown hook name */ return (EINVAL); } /* * Receive a control message */ static int ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr, hook_p lasthook) { const priv_p priv = node->private; struct ng_mesg *resp = NULL; int error = 0; switch (msg->header.typecookie) { case NGM_BRIDGE_COOKIE: switch (msg->header.cmd) { case NGM_BRIDGE_GET_CONFIG: { struct ng_bridge_config *conf; NG_MKRESPONSE(resp, msg, sizeof(struct ng_bridge_config), M_NOWAIT); if (resp == NULL) { error = ENOMEM; break; } conf = (struct ng_bridge_config *)resp->data; *conf = priv->conf; /* no sanity checking needed */ break; } case NGM_BRIDGE_SET_CONFIG: { struct ng_bridge_config *conf; int i; if (msg->header.arglen != sizeof(struct ng_bridge_config)) { error = EINVAL; break; } conf = (struct ng_bridge_config *)msg->data; priv->conf = *conf; for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; break; } case NGM_BRIDGE_RESET: { int i; /* Flush all entries in the hash table */ ng_bridge_remove_hosts(priv, -1); /* Reset all loop detection counters and stats */ for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { if (priv->links[i] == NULL) continue; priv->links[i]->loopCount = 0; bzero(&priv->links[i]->stats, sizeof(priv->links[i]->stats)); } break; } case NGM_BRIDGE_GET_STATS: case NGM_BRIDGE_CLR_STATS: case NGM_BRIDGE_GETCLR_STATS: { struct ng_bridge_link *link; int linkNum; /* Get link number */ if (msg->header.arglen != sizeof(u_int32_t)) { error = EINVAL; break; } linkNum = *((u_int32_t *)msg->data); if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { error = EINVAL; break; } if ((link = priv->links[linkNum]) == NULL) { error = ENOTCONN; break; } /* Get/clear stats */ if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { NG_MKRESPONSE(resp, msg, sizeof(link->stats), M_NOWAIT); if (resp == NULL) { error = ENOMEM; break; } bcopy(&link->stats, resp->data, sizeof(link->stats)); } if (msg->header.cmd != NGM_BRIDGE_GET_STATS) bzero(&link->stats, sizeof(link->stats)); break; } case NGM_BRIDGE_GET_TABLE: { struct ng_bridge_host_ary *ary; struct ng_bridge_hent *hent; int i = 0, bucket; NG_MKRESPONSE(resp, msg, sizeof(*ary) + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); if (resp == NULL) { error = ENOMEM; break; } ary = (struct ng_bridge_host_ary *)resp->data; ary->numHosts = priv->numHosts; for (bucket = 0; bucket < priv->numBuckets; bucket++) { SLIST_FOREACH(hent, &priv->tab[bucket], next) ary->hosts[i++] = hent->host; } break; } default: error = EINVAL; break; } break; default: error = EINVAL; break; } /* Done */ if (rptr) *rptr = resp; else if (resp != NULL) FREE(resp, M_NETGRAPH); FREE(msg, M_NETGRAPH); return (error); } /* * Receive data on a hook */ static int ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, struct mbuf **ret_m, meta_p *ret_meta) { const node_p node = hook->node; const priv_p priv = node->private; struct ng_bridge_host *host; struct ng_bridge_link *link; struct ether_header *eh; int error = 0, linkNum; int i, manycast; /* Get link number */ linkNum = LINK_NUM(hook); KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, ("%s: linkNum=%u", __FUNCTION__, linkNum)); link = priv->links[linkNum]; KASSERT(link != NULL, ("%s: link%d null", __FUNCTION__, linkNum)); /* Sanity check packet and pull up header */ if (m->m_pkthdr.len < ETHER_HDR_LEN) { link->stats.recvRunts++; NG_FREE_DATA(m, meta); return (EINVAL); } if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { link->stats.memoryFailures++; NG_FREE_META(meta); return (ENOBUFS); } eh = mtod(m, struct ether_header *); if ((eh->ether_shost[0] & 1) != 0) { link->stats.recvInvalid++; NG_FREE_DATA(m, meta); return (EINVAL); } /* Is link disabled due to a loopback condition? */ if (link->loopCount != 0) { link->stats.loopDrops++; NG_FREE_DATA(m, meta); return (ELOOP); /* XXX is this an appropriate error? */ } /* Update stats */ link->stats.recvPackets++; link->stats.recvOctets += m->m_pkthdr.len; if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { link->stats.recvBroadcasts++; manycast = 2; } else link->stats.recvMulticasts++; } /* Look up packet's source Ethernet address in hashtable */ if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { /* Update time since last heard from this host */ host->staleness = 0; /* Did host jump to a different link? */ if (host->linkNum != linkNum) { /* * If the host's old link was recently established * on the old link and it's already jumped to a new * link, declare a loopback condition. */ if (host->age < priv->conf.minStableAge) { /* Log the problem */ if (priv->conf.debugLevel >= 2) { struct ifnet *ifp = m->m_pkthdr.rcvif; char suffix[32]; if (ifp != NULL) snprintf(suffix, sizeof(suffix), " (%s%d)", ifp->if_name, ifp->if_unit); else *suffix = '\0'; log(LOG_WARNING, "ng_bridge: %s:" " loopback detected on %s%s\n", ng_bridge_nodename(node), hook->name, suffix); } /* Mark link as linka non grata */ link->loopCount = priv->conf.loopTimeout; link->stats.loopDetects++; /* Forget all hosts on this link */ ng_bridge_remove_hosts(priv, linkNum); /* Drop packet */ link->stats.loopDrops++; NG_FREE_DATA(m, meta); return (ELOOP); /* XXX appropriate? */ } /* Move host over to new link */ host->linkNum = linkNum; host->age = 0; } } else { if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { link->stats.memoryFailures++; NG_FREE_DATA(m, meta); return (ENOMEM); } } /* Run packet through ipfw processing, if enabled */ if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { /* XXX not implemented yet */ } /* * If unicast and destination host known, deliver to host's link, * unless it is the same link as the packet came in on. */ if (!manycast) { /* Determine packet destination link */ if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { struct ng_bridge_link *const destLink = priv->links[host->linkNum]; /* If destination same as incoming link, do nothing */ KASSERT(destLink != NULL, ("%s: link%d null", __FUNCTION__, host->linkNum)); if (destLink == link) { NG_FREE_DATA(m, meta); return (0); } /* Deliver packet out the destination link */ destLink->stats.xmitPackets++; destLink->stats.xmitOctets += m->m_pkthdr.len; NG_SEND_DATA(error, destLink->hook, m, meta); return (error); } /* Destination host is not known */ link->stats.recvUnknown++; } /* Distribute unknown, multicast, broadcast pkts to all other links */ for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { struct ng_bridge_link *const destLink = priv->links[linkNum]; meta_p meta2 = NULL; struct mbuf *m2; /* Skip incoming link and disconnected links */ if (destLink == NULL || destLink == link) continue; /* Copy mbuf and meta info */ if (++i == priv->numLinks - 1) { /* last link */ m2 = m; meta2 = meta; } else { m2 = m_copypacket(m, M_NOWAIT); /* XXX m_dup()? */ if (m2 == NULL) { link->stats.memoryFailures++; NG_FREE_DATA(m, meta); return (ENOBUFS); } if (meta != NULL && (meta2 = ng_copy_meta(meta)) == NULL) { link->stats.memoryFailures++; m_freem(m2); NG_FREE_DATA(m, meta); return (ENOMEM); } } /* Update stats */ destLink->stats.xmitPackets++; destLink->stats.xmitOctets += m->m_pkthdr.len; switch (manycast) { case 0: /* unicast */ break; case 1: /* multicast */ destLink->stats.xmitMulticasts++; break; case 2: /* broadcast */ destLink->stats.xmitBroadcasts++; break; } /* Send packet */ NG_SEND_DATA(error, destLink->hook, m2, meta2); } return (error); } /* * Shutdown node */ static int ng_bridge_rmnode(node_p node) { const priv_p priv = node->private; ng_unname(node); ng_cutlinks(node); /* frees all link and host info */ KASSERT(priv->numLinks == 0 && priv->numHosts == 0, ("%s: numLinks=%d numHosts=%d", __FUNCTION__, priv->numLinks, priv->numHosts)); FREE(priv->tab, M_NETGRAPH); FREE(priv, M_NETGRAPH); node->private = NULL; ng_unref(node); return (0); } /* * Hook disconnection. */ static int ng_bridge_disconnect(hook_p hook) { const priv_p priv = hook->node->private; int linkNum; /* Get link number */ linkNum = LINK_NUM(hook); KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, ("%s: linkNum=%u", __FUNCTION__, linkNum)); /* Remove all hosts associated with this link */ ng_bridge_remove_hosts(priv, linkNum); /* Free associated link information */ KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __FUNCTION__)); FREE(priv->links[linkNum], M_NETGRAPH); priv->links[linkNum] = NULL; priv->numLinks--; /* If no more hooks, go away */ if (hook->node->numhooks == 0) ng_rmnode(hook->node); return (0); } /****************************************************************** HASH TABLE FUNCTIONS ******************************************************************/ /* * Hash algorithm * * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. */ #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ ^ ((const u_int16_t *)(addr))[1] \ ^ ((const u_int16_t *)(addr))[2]) & (mask) ) /* * Find a host entry in the table. */ static struct ng_bridge_host * ng_bridge_get(priv_p priv, const u_char *addr) { const int bucket = HASH(addr, priv->hashMask); struct ng_bridge_hent *hent; SLIST_FOREACH(hent, &priv->tab[bucket], next) { if (ETHER_EQUAL(hent->host.addr, addr)) return (&hent->host); } return (NULL); } /* * Add a new host entry to the table. This assumes the host doesn't * already exist in the table. Returns 1 on success, 0 if there * was a memory allocation failure. */ static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) { const int bucket = HASH(addr, priv->hashMask); struct ng_bridge_hent *hent; #ifdef INVARIANTS /* Assert that entry does not already exist in hashtable */ SLIST_FOREACH(hent, &priv->tab[bucket], next) { KASSERT(!ETHER_EQUAL(hent->host.addr, addr), ("%s: entry %6D exists in table", __FUNCTION__, addr, ":")); } #endif /* Allocate and initialize new hashtable entry */ MALLOC(hent, struct ng_bridge_hent *, sizeof(*hent), M_NETGRAPH, M_NOWAIT); if (hent == NULL) return (0); bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); hent->host.linkNum = linkNum; hent->host.staleness = 0; hent->host.age = 0; /* Add new element to hash bucket */ SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); priv->numHosts++; /* Resize table if necessary */ ng_bridge_rehash(priv); return (1); } /* * Resize the hash table. We try to maintain the number of buckets * such that the load factor is in the range 0.25 to 1.0. * * If we can't get the new memory then we silently fail. This is OK * because things will still work and we'll try again soon anyway. */ static void ng_bridge_rehash(priv_p priv) { struct ng_bridge_bucket *newTab; int oldBucket, newBucket; int newNumBuckets; u_int newMask; /* Is table too full or too empty? */ if (priv->numHosts > priv->numBuckets && (priv->numBuckets << 1) <= MAX_BUCKETS) newNumBuckets = priv->numBuckets << 1; else if (priv->numHosts < (priv->numBuckets >> 2) && (priv->numBuckets >> 2) >= MIN_BUCKETS) newNumBuckets = priv->numBuckets >> 2; else return; newMask = newNumBuckets - 1; /* Allocate and initialize new table */ MALLOC(newTab, struct ng_bridge_bucket *, newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT); if (newTab == NULL) return; bzero(newTab, newNumBuckets * sizeof(*newTab)); /* Move all entries from old table to new table */ for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; while (!SLIST_EMPTY(oldList)) { struct ng_bridge_hent *const hent = SLIST_FIRST(oldList); SLIST_REMOVE_HEAD(oldList, next); newBucket = HASH(hent->host.addr, newMask); SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); } } /* Replace old table with new one */ if (priv->conf.debugLevel >= 3) { log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", ng_bridge_nodename(priv->node), priv->numBuckets, newNumBuckets); } FREE(priv->tab, M_NETGRAPH); priv->numBuckets = newNumBuckets; priv->hashMask = newMask; priv->tab = newTab; return; } /****************************************************************** MISC FUNCTIONS ******************************************************************/ /* * Remove all hosts associated with a specific link from the hashtable. * If linkNum == -1, then remove all hosts in the table. */ static void ng_bridge_remove_hosts(priv_p priv, int linkNum) { int bucket; for (bucket = 0; bucket < priv->numBuckets; bucket++) { struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); while (*hptr != NULL) { struct ng_bridge_hent *const hent = *hptr; if (linkNum == -1 || hent->host.linkNum == linkNum) { *hptr = SLIST_NEXT(hent, next); FREE(hent, M_NETGRAPH); priv->numHosts--; } else hptr = &SLIST_NEXT(hent, next); } } } /* * Handle our once-per-second timeout event. We do two things: * we decrement link->loopCount for those links being muted due to * a detected loopback condition, and we remove any hosts from * the hashtable whom we haven't heard from in a long while. */ static void ng_bridge_timeout(void *arg) { const node_p node = arg; const priv_p priv = node->private; int s, bucket; int counter = 0; int linkNum; /* Avoid race condition with ng_bridge_shutdown() */ s = splnet(); if ((node->flags & NG_INVALID) != 0 || priv == NULL) { ng_unref(node); splx(s); return; } /* Register a new timeout, keeping the existing node reference */ callout_reset(&priv->timer, hz, ng_bridge_timeout, node); /* Update host time counters and remove stale entries */ for (bucket = 0; bucket < priv->numBuckets; bucket++) { struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); while (*hptr != NULL) { struct ng_bridge_hent *const hent = *hptr; /* Make sure host's link really exists */ KASSERT(priv->links[hent->host.linkNum] != NULL, ("%s: host %6D on nonexistent link %d\n", __FUNCTION__, hent->host.addr, ":", hent->host.linkNum)); /* Remove hosts we haven't heard from in a while */ if (++hent->host.staleness >= priv->conf.maxStaleness) { *hptr = SLIST_NEXT(hent, next); FREE(hent, M_NETGRAPH); priv->numHosts--; } else { if (hent->host.age < 0xffff) hent->host.age++; hptr = &SLIST_NEXT(hent, next); counter++; } } } KASSERT(priv->numHosts == counter, ("%s: hosts: %d != %d", __FUNCTION__, priv->numHosts, counter)); /* Decrease table size if necessary */ ng_bridge_rehash(priv); /* Decrease loop counter on muted looped back links */ for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { struct ng_bridge_link *const link = priv->links[linkNum]; if (link != NULL) { if (link->loopCount != 0) { link->loopCount--; if (link->loopCount == 0 && priv->conf.debugLevel >= 2) { log(LOG_INFO, "ng_bridge: %s:" " restoring looped back link%d\n", ng_bridge_nodename(node), linkNum); } } counter++; } } KASSERT(priv->numLinks == counter, ("%s: links: %d != %d", __FUNCTION__, priv->numLinks, counter)); /* Done */ splx(s); } /* * Return node's "name", even if it doesn't have one. */ static const char * ng_bridge_nodename(node_p node) { static char name[NG_NODELEN+1]; if (node->name != NULL) snprintf(name, sizeof(name), "%s", node->name); else snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); return name; }