6 * Copyright (c) 2000 Whistle Communications, Inc.
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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
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35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
38 * Author: Archie Cobbs <archie@freebsd.org>
40 * $FreeBSD: src/sys/netgraph/ng_bridge.c,v 1.31 2005/02/09 15:14:44 ru Exp $
41 * $DragonFly: src/sys/netgraph7/ng_bridge.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
45 * ng_bridge(4) netgraph node type
47 * The node performs standard intelligent Ethernet bridging over
48 * each of its connected hooks, or links. A simple loop detection
49 * algorithm is included which disables a link for priv->conf.loopTimeout
50 * seconds when a host is seen to have jumped from one link to
51 * another within priv->conf.minStableAge seconds.
53 * We keep a hashtable that maps Ethernet addresses to host info,
54 * which is contained in struct ng_bridge_host's. These structures
55 * tell us on which link the host may be found. A host's entry will
56 * expire after priv->conf.maxStaleness seconds.
58 * This node is optimzed for stable networks, where machines jump
59 * from one port to the other only rarely.
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/kernel.h>
65 #include <sys/malloc.h>
67 #include <sys/errno.h>
68 #include <sys/syslog.h>
69 #include <sys/socket.h>
70 #include <sys/ctype.h>
73 #include <net/ethernet.h>
75 #include <netinet/in.h>
76 #include <net/ipfw/ip_fw.h>
78 #include <netgraph7/ng_message.h>
79 #include <netgraph7/netgraph.h>
80 #include <netgraph7/ng_parse.h>
81 #include "ng_bridge.h"
83 #ifdef NG_SEPARATE_MALLOC
84 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node ");
86 #define M_NETGRAPH_BRIDGE M_NETGRAPH
89 /* Per-link private data */
90 struct ng_bridge_link {
91 hook_p hook; /* netgraph hook */
92 u_int16_t loopCount; /* loop ignore timer */
93 struct ng_bridge_link_stats stats; /* link stats */
96 /* Per-node private data */
97 struct ng_bridge_private {
98 struct ng_bridge_bucket *tab; /* hash table bucket array */
99 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
100 struct ng_bridge_config conf; /* node configuration */
101 node_p node; /* netgraph node */
102 u_int numHosts; /* num entries in table */
103 u_int numBuckets; /* num buckets in table */
104 u_int hashMask; /* numBuckets - 1 */
105 int numLinks; /* num connected links */
106 struct callout timer; /* one second periodic timer */
108 typedef struct ng_bridge_private *priv_p;
110 /* Information about a host, stored in a hash table entry */
111 struct ng_bridge_hent {
112 struct ng_bridge_host host; /* actual host info */
113 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
116 /* Hash table bucket declaration */
117 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
119 /* Netgraph node methods */
120 static ng_constructor_t ng_bridge_constructor;
121 static ng_rcvmsg_t ng_bridge_rcvmsg;
122 static ng_shutdown_t ng_bridge_shutdown;
123 static ng_newhook_t ng_bridge_newhook;
124 static ng_rcvdata_t ng_bridge_rcvdata;
125 static ng_disconnect_t ng_bridge_disconnect;
127 /* Other internal functions */
128 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
129 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
130 static void ng_bridge_rehash(priv_p priv);
131 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
132 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
133 static const char *ng_bridge_nodename(node_p node);
135 /* Ethernet broadcast */
136 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
137 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
139 /* Store each hook's link number in the private field */
140 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
142 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
143 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
144 == ((const u_int32_t *)(b))[0] \
145 && ((const u_int16_t *)(a))[2] \
146 == ((const u_int16_t *)(b))[2])
148 /* Minimum and maximum number of hash buckets. Must be a power of two. */
149 #define MIN_BUCKETS (1 << 5) /* 32 */
150 #define MAX_BUCKETS (1 << 14) /* 16384 */
152 /* Configuration default values */
153 #define DEFAULT_LOOP_TIMEOUT 60
154 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
155 #define DEFAULT_MIN_STABLE_AGE 1
157 /******************************************************************
159 ******************************************************************/
162 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
165 ng_bridge_getTableLength(const struct ng_parse_type *type,
166 const u_char *start, const u_char *buf)
168 const struct ng_bridge_host_ary *const hary
169 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
171 return hary->numHosts;
174 /* Parse type for struct ng_bridge_host_ary */
175 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
176 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
177 static const struct ng_parse_type ng_bridge_host_type = {
178 &ng_parse_struct_type,
179 &ng_bridge_host_type_fields
181 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
182 &ng_bridge_host_type,
183 ng_bridge_getTableLength
185 static const struct ng_parse_type ng_bridge_hary_type = {
186 &ng_parse_array_type,
187 &ng_bridge_hary_type_info
189 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
190 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
191 static const struct ng_parse_type ng_bridge_host_ary_type = {
192 &ng_parse_struct_type,
193 &ng_bridge_host_ary_type_fields
196 /* Parse type for struct ng_bridge_config */
197 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
198 &ng_parse_uint8_type,
201 static const struct ng_parse_type ng_bridge_ipfwary_type = {
202 &ng_parse_fixedarray_type,
203 &ng_bridge_ipfwary_type_info
205 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
206 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
207 static const struct ng_parse_type ng_bridge_config_type = {
208 &ng_parse_struct_type,
209 &ng_bridge_config_type_fields
212 /* Parse type for struct ng_bridge_link_stat */
213 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
214 = NG_BRIDGE_STATS_TYPE_INFO;
215 static const struct ng_parse_type ng_bridge_stats_type = {
216 &ng_parse_struct_type,
217 &ng_bridge_stats_type_fields
220 /* List of commands and how to convert arguments to/from ASCII */
221 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
224 NGM_BRIDGE_SET_CONFIG,
226 &ng_bridge_config_type,
231 NGM_BRIDGE_GET_CONFIG,
234 &ng_bridge_config_type
245 NGM_BRIDGE_GET_STATS,
247 &ng_parse_uint32_type,
248 &ng_bridge_stats_type
252 NGM_BRIDGE_CLR_STATS,
254 &ng_parse_uint32_type,
259 NGM_BRIDGE_GETCLR_STATS,
261 &ng_parse_uint32_type,
262 &ng_bridge_stats_type
266 NGM_BRIDGE_GET_TABLE,
269 &ng_bridge_host_ary_type
274 /* Node type descriptor */
275 static struct ng_type ng_bridge_typestruct = {
276 .version = NG_ABI_VERSION,
277 .name = NG_BRIDGE_NODE_TYPE,
278 .constructor = ng_bridge_constructor,
279 .rcvmsg = ng_bridge_rcvmsg,
280 .shutdown = ng_bridge_shutdown,
281 .newhook = ng_bridge_newhook,
282 .rcvdata = ng_bridge_rcvdata,
283 .disconnect = ng_bridge_disconnect,
284 .cmdlist = ng_bridge_cmdlist,
286 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
288 /******************************************************************
289 NETGRAPH NODE METHODS
290 ******************************************************************/
296 ng_bridge_constructor(node_p node)
300 /* Allocate and initialize private info */
301 priv = kmalloc(sizeof(*priv), M_NETGRAPH_BRIDGE,
302 M_WAITOK | M_NULLOK | M_ZERO);
305 ng_callout_init(&priv->timer);
307 /* Allocate and initialize hash table, etc. */
308 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab),
309 M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK | M_ZERO);
310 if (priv->tab == NULL) {
311 kfree(priv, M_NETGRAPH_BRIDGE);
314 priv->numBuckets = MIN_BUCKETS;
315 priv->hashMask = MIN_BUCKETS - 1;
316 priv->conf.debugLevel = 1;
317 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
318 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
319 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
322 * This node has all kinds of stuff that could be screwed by SMP.
323 * Until it gets it's own internal protection, we go through in
324 * single file. This could hurt a machine bridging beteen two
325 * GB ethernets so it should be fixed.
326 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
329 NG_NODE_FORCE_WRITER(node);
330 NG_NODE_SET_PRIVATE(node, priv);
333 /* Start timer; timer is always running while node is alive */
334 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
341 * Method for attaching a new hook
344 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
346 const priv_p priv = NG_NODE_PRIVATE(node);
348 /* Check for a link hook */
349 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
350 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
355 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
356 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
358 linkNum = strtoul(cp, &eptr, 10);
359 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
361 if (priv->links[linkNum] != NULL)
363 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]),
365 M_WAITOK | M_NULLOK | M_ZERO);
366 if (priv->links[linkNum] == NULL)
368 priv->links[linkNum]->hook = hook;
369 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
374 /* Unknown hook name */
379 * Receive a control message
382 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
384 const priv_p priv = NG_NODE_PRIVATE(node);
385 struct ng_mesg *resp = NULL;
389 NGI_GET_MSG(item, msg);
390 switch (msg->header.typecookie) {
391 case NGM_BRIDGE_COOKIE:
392 switch (msg->header.cmd) {
393 case NGM_BRIDGE_GET_CONFIG:
395 struct ng_bridge_config *conf;
397 NG_MKRESPONSE(resp, msg,
398 sizeof(struct ng_bridge_config), M_WAITOK | M_NULLOK);
403 conf = (struct ng_bridge_config *)resp->data;
404 *conf = priv->conf; /* no sanity checking needed */
407 case NGM_BRIDGE_SET_CONFIG:
409 struct ng_bridge_config *conf;
412 if (msg->header.arglen
413 != sizeof(struct ng_bridge_config)) {
417 conf = (struct ng_bridge_config *)msg->data;
419 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
420 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
423 case NGM_BRIDGE_RESET:
427 /* Flush all entries in the hash table */
428 ng_bridge_remove_hosts(priv, -1);
430 /* Reset all loop detection counters and stats */
431 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
432 if (priv->links[i] == NULL)
434 priv->links[i]->loopCount = 0;
435 bzero(&priv->links[i]->stats,
436 sizeof(priv->links[i]->stats));
440 case NGM_BRIDGE_GET_STATS:
441 case NGM_BRIDGE_CLR_STATS:
442 case NGM_BRIDGE_GETCLR_STATS:
444 struct ng_bridge_link *link;
447 /* Get link number */
448 if (msg->header.arglen != sizeof(u_int32_t)) {
452 linkNum = *((u_int32_t *)msg->data);
453 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
457 if ((link = priv->links[linkNum]) == NULL) {
462 /* Get/clear stats */
463 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
464 NG_MKRESPONSE(resp, msg,
465 sizeof(link->stats), M_WAITOK | M_NULLOK);
471 resp->data, sizeof(link->stats));
473 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
474 bzero(&link->stats, sizeof(link->stats));
477 case NGM_BRIDGE_GET_TABLE:
479 struct ng_bridge_host_ary *ary;
480 struct ng_bridge_hent *hent;
483 NG_MKRESPONSE(resp, msg, sizeof(*ary)
484 + (priv->numHosts * sizeof(*ary->hosts)), M_WAITOK | M_NULLOK);
489 ary = (struct ng_bridge_host_ary *)resp->data;
490 ary->numHosts = priv->numHosts;
491 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
492 SLIST_FOREACH(hent, &priv->tab[bucket], next)
493 ary->hosts[i++] = hent->host;
508 NG_RESPOND_MSG(error, node, item, resp);
514 * Receive data on a hook
517 ng_bridge_rcvdata(hook_p hook, item_p item)
519 const node_p node = NG_HOOK_NODE(hook);
520 const priv_p priv = NG_NODE_PRIVATE(node);
521 struct ng_bridge_host *host;
522 struct ng_bridge_link *link;
523 struct ether_header *eh;
524 int error = 0, linkNum, linksSeen;
527 struct ng_bridge_link *firstLink;
530 /* Get link number */
531 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
532 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
533 ("%s: linkNum=%u", __func__, linkNum));
534 link = priv->links[linkNum];
535 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
537 /* Sanity check packet and pull up header */
538 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
539 link->stats.recvRunts++;
544 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
545 link->stats.memoryFailures++;
549 eh = mtod(m, struct ether_header *);
550 if ((eh->ether_shost[0] & 1) != 0) {
551 link->stats.recvInvalid++;
557 /* Is link disabled due to a loopback condition? */
558 if (link->loopCount != 0) {
559 link->stats.loopDrops++;
562 return (ELOOP); /* XXX is this an appropriate error? */
566 link->stats.recvPackets++;
567 link->stats.recvOctets += m->m_pkthdr.len;
568 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
569 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
570 link->stats.recvBroadcasts++;
573 link->stats.recvMulticasts++;
576 /* Look up packet's source Ethernet address in hashtable */
577 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
579 /* Update time since last heard from this host */
582 /* Did host jump to a different link? */
583 if (host->linkNum != linkNum) {
586 * If the host's old link was recently established
587 * on the old link and it's already jumped to a new
588 * link, declare a loopback condition.
590 if (host->age < priv->conf.minStableAge) {
592 /* Log the problem */
593 if (priv->conf.debugLevel >= 2) {
594 struct ifnet *ifp = m->m_pkthdr.rcvif;
598 snprintf(suffix, sizeof(suffix),
599 " (%s)", ifp->if_xname);
602 log(LOG_WARNING, "ng_bridge: %s:"
603 " loopback detected on %s%s\n",
604 ng_bridge_nodename(node),
605 NG_HOOK_NAME(hook), suffix);
608 /* Mark link as linka non grata */
609 link->loopCount = priv->conf.loopTimeout;
610 link->stats.loopDetects++;
612 /* Forget all hosts on this link */
613 ng_bridge_remove_hosts(priv, linkNum);
616 link->stats.loopDrops++;
619 return (ELOOP); /* XXX appropriate? */
622 /* Move host over to new link */
623 host->linkNum = linkNum;
627 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
628 link->stats.memoryFailures++;
635 /* Run packet through ipfw processing, if enabled */
637 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) {
638 /* XXX not implemented yet */
643 * If unicast and destination host known, deliver to host's link,
644 * unless it is the same link as the packet came in on.
648 /* Determine packet destination link */
649 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
650 struct ng_bridge_link *const destLink
651 = priv->links[host->linkNum];
653 /* If destination same as incoming link, do nothing */
654 KASSERT(destLink != NULL,
655 ("%s: link%d null", __func__, host->linkNum));
656 if (destLink == link) {
662 /* Deliver packet out the destination link */
663 destLink->stats.xmitPackets++;
664 destLink->stats.xmitOctets += m->m_pkthdr.len;
665 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
669 /* Destination host is not known */
670 link->stats.recvUnknown++;
673 /* Distribute unknown, multicast, broadcast pkts to all other links */
675 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
676 struct ng_bridge_link *destLink;
677 struct mbuf *m2 = NULL;
680 * If we have checked all the links then now
681 * send the original on its reserved link
683 if (linksSeen == priv->numLinks) {
684 /* If we never saw a good link, leave. */
685 if (firstLink == NULL) {
690 destLink = firstLink;
692 destLink = priv->links[linkNum];
693 if (destLink != NULL)
695 /* Skip incoming link and disconnected links */
696 if (destLink == NULL || destLink == link) {
699 if (firstLink == NULL) {
701 * This is the first usable link we have found.
702 * Reserve it for the originals.
703 * If we never find another we save a copy.
705 firstLink = destLink;
710 * It's usable link but not the reserved (first) one.
711 * Copy mbuf info for sending.
713 m2 = m_dup(m, MB_DONTWAIT); /* XXX m_copypacket() */
715 link->stats.memoryFailures++;
723 destLink->stats.xmitPackets++;
724 destLink->stats.xmitOctets += m->m_pkthdr.len;
726 case 0: /* unicast */
728 case 1: /* multicast */
729 destLink->stats.xmitMulticasts++;
731 case 2: /* broadcast */
732 destLink->stats.xmitBroadcasts++;
737 if (destLink == firstLink) {
739 * If we've sent all the others, send the original
740 * on the first link we found.
742 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
743 break; /* always done last - not really needed. */
745 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
755 ng_bridge_shutdown(node_p node)
757 const priv_p priv = NG_NODE_PRIVATE(node);
760 * Shut down everything including the timer. Even if the
761 * callout has already been dequeued and is about to be
762 * run, ng_bridge_timeout() won't be fired as the node
763 * is already marked NGF_INVALID, so we're safe to free
766 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
767 ("%s: numLinks=%d numHosts=%d",
768 __func__, priv->numLinks, priv->numHosts));
769 ng_uncallout(&priv->timer, node);
770 NG_NODE_SET_PRIVATE(node, NULL);
772 kfree(priv->tab, M_NETGRAPH_BRIDGE);
773 kfree(priv, M_NETGRAPH_BRIDGE);
778 * Hook disconnection.
781 ng_bridge_disconnect(hook_p hook)
783 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
786 /* Get link number */
787 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
788 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
789 ("%s: linkNum=%u", __func__, linkNum));
791 /* Remove all hosts associated with this link */
792 ng_bridge_remove_hosts(priv, linkNum);
794 /* Free associated link information */
795 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
796 kfree(priv->links[linkNum], M_NETGRAPH_BRIDGE);
797 priv->links[linkNum] = NULL;
800 /* If no more hooks, go away */
801 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
802 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
803 ng_rmnode_self(NG_HOOK_NODE(hook));
808 /******************************************************************
810 ******************************************************************/
815 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
816 ^ ((const u_int16_t *)(addr))[1] \
817 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
820 * Find a host entry in the table.
822 static struct ng_bridge_host *
823 ng_bridge_get(priv_p priv, const u_char *addr)
825 const int bucket = HASH(addr, priv->hashMask);
826 struct ng_bridge_hent *hent;
828 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
829 if (ETHER_EQUAL(hent->host.addr, addr))
830 return (&hent->host);
836 * Add a new host entry to the table. This assumes the host doesn't
837 * already exist in the table. Returns 1 on success, 0 if there
838 * was a memory allocation failure.
841 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
843 const int bucket = HASH(addr, priv->hashMask);
844 struct ng_bridge_hent *hent;
847 /* Assert that entry does not already exist in hashtable */
848 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
849 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
850 ("%s: entry %6D exists in table", __func__, addr, ":"));
854 /* Allocate and initialize new hashtable entry */
855 hent = kmalloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK);
858 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
859 hent->host.linkNum = linkNum;
860 hent->host.staleness = 0;
863 /* Add new element to hash bucket */
864 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
867 /* Resize table if necessary */
868 ng_bridge_rehash(priv);
873 * Resize the hash table. We try to maintain the number of buckets
874 * such that the load factor is in the range 0.25 to 1.0.
876 * If we can't get the new memory then we silently fail. This is OK
877 * because things will still work and we'll try again soon anyway.
880 ng_bridge_rehash(priv_p priv)
882 struct ng_bridge_bucket *newTab;
883 int oldBucket, newBucket;
887 /* Is table too full or too empty? */
888 if (priv->numHosts > priv->numBuckets
889 && (priv->numBuckets << 1) <= MAX_BUCKETS)
890 newNumBuckets = priv->numBuckets << 1;
891 else if (priv->numHosts < (priv->numBuckets >> 2)
892 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
893 newNumBuckets = priv->numBuckets >> 2;
896 newMask = newNumBuckets - 1;
898 /* Allocate and initialize new table */
899 newTab = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE,
904 /* Move all entries from old table to new table */
905 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
906 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
908 while (!SLIST_EMPTY(oldList)) {
909 struct ng_bridge_hent *const hent
910 = SLIST_FIRST(oldList);
912 SLIST_REMOVE_HEAD(oldList, next);
913 newBucket = HASH(hent->host.addr, newMask);
914 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
918 /* Replace old table with new one */
919 if (priv->conf.debugLevel >= 3) {
920 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
921 ng_bridge_nodename(priv->node),
922 priv->numBuckets, newNumBuckets);
924 kfree(priv->tab, M_NETGRAPH_BRIDGE);
925 priv->numBuckets = newNumBuckets;
926 priv->hashMask = newMask;
931 /******************************************************************
933 ******************************************************************/
936 * Remove all hosts associated with a specific link from the hashtable.
937 * If linkNum == -1, then remove all hosts in the table.
940 ng_bridge_remove_hosts(priv_p priv, int linkNum)
944 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
945 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
947 while (*hptr != NULL) {
948 struct ng_bridge_hent *const hent = *hptr;
950 if (linkNum == -1 || hent->host.linkNum == linkNum) {
951 *hptr = SLIST_NEXT(hent, next);
952 kfree(hent, M_NETGRAPH_BRIDGE);
955 hptr = &SLIST_NEXT(hent, next);
961 * Handle our once-per-second timeout event. We do two things:
962 * we decrement link->loopCount for those links being muted due to
963 * a detected loopback condition, and we remove any hosts from
964 * the hashtable whom we haven't heard from in a long while.
967 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
969 const priv_p priv = NG_NODE_PRIVATE(node);
974 /* Update host time counters and remove stale entries */
975 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
976 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
978 while (*hptr != NULL) {
979 struct ng_bridge_hent *const hent = *hptr;
981 /* Make sure host's link really exists */
982 KASSERT(priv->links[hent->host.linkNum] != NULL,
983 ("%s: host %6D on nonexistent link %d\n",
984 __func__, hent->host.addr, ":",
985 hent->host.linkNum));
987 /* Remove hosts we haven't heard from in a while */
988 if (++hent->host.staleness >= priv->conf.maxStaleness) {
989 *hptr = SLIST_NEXT(hent, next);
990 kfree(hent, M_NETGRAPH_BRIDGE);
993 if (hent->host.age < 0xffff)
995 hptr = &SLIST_NEXT(hent, next);
1000 KASSERT(priv->numHosts == counter,
1001 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1003 /* Decrease table size if necessary */
1004 ng_bridge_rehash(priv);
1006 /* Decrease loop counter on muted looped back links */
1007 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
1008 struct ng_bridge_link *const link = priv->links[linkNum];
1011 if (link->loopCount != 0) {
1013 if (link->loopCount == 0
1014 && priv->conf.debugLevel >= 2) {
1015 log(LOG_INFO, "ng_bridge: %s:"
1016 " restoring looped back link%d\n",
1017 ng_bridge_nodename(node), linkNum);
1023 KASSERT(priv->numLinks == counter,
1024 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1026 /* Register a new timeout, keeping the existing node reference */
1027 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1031 * Return node's "name", even if it doesn't have one.
1034 ng_bridge_nodename(node_p node)
1036 static char name[NG_NODESIZ];
1038 if (NG_NODE_NAME(node) != NULL)
1039 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1041 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));