diff options
Diffstat (limited to 'sys/netgraph/ng_bridge.c')
| -rw-r--r-- | sys/netgraph/ng_bridge.c | 1014 |
1 files changed, 1014 insertions, 0 deletions
diff --git a/sys/netgraph/ng_bridge.c b/sys/netgraph/ng_bridge.c new file mode 100644 index 0000000..81ffa68 --- /dev/null +++ b/sys/netgraph/ng_bridge.c @@ -0,0 +1,1014 @@ + +/* + * 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 <archie@freebsd.org> + * + * $FreeBSD$ + */ + +/* + * 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 <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/errno.h> +#include <sys/syslog.h> +#include <sys/socket.h> +#include <sys/ctype.h> + +#include <net/if.h> +#include <net/ethernet.h> + +#include <netinet/in.h> +#include <netinet/ip_fw.h> + +#include <netgraph/ng_message.h> +#include <netgraph/netgraph.h> +#include <netgraph/ng_parse.h> +#include <netgraph/ng_bridge.h> +#include <netgraph/ng_ether.h> + +/* 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; +} + |
