/*-
* 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/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/ctype.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <net/vnet.h>
#include <netinet/in.h>
#if 0 /* not used yet */
#include <netinet/ip_fw.h>
#endif
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_bridge.h>
#ifdef NG_SEPARATE_MALLOC
static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
"netgraph bridge node");
#else
#define M_NETGRAPH_BRIDGE M_NETGRAPH
#endif
/* 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_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 */
int persistent; /* can exist w/o hooks */
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_shutdown;
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, link_p link);
static void ng_bridge_rehash(priv_p priv);
static void ng_bridge_remove_hosts(priv_p priv, link_p link);
static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
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 };
/* 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_field ng_bridge_host_type_fields[]
= NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
static const struct ng_parse_type ng_bridge_host_type = {
&ng_parse_struct_type,
&ng_bridge_host_type_fields
};
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_field ng_bridge_host_ary_type_fields[]
= 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_fields
};
/* Parse type for struct ng_bridge_config */
static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
= NG_BRIDGE_CONFIG_TYPE_INFO;
static const struct ng_parse_type ng_bridge_config_type = {
&ng_parse_struct_type,
&ng_bridge_config_type_fields
};
/* Parse type for struct ng_bridge_link_stat */
static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
= NG_BRIDGE_STATS_TYPE_INFO;
static const struct ng_parse_type ng_bridge_stats_type = {
&ng_parse_struct_type,
&ng_bridge_stats_type_fields
};
/* 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
},
{
NGM_BRIDGE_COOKIE,
NGM_BRIDGE_SET_PERSISTENT,
"setpersistent",
NULL,
NULL
},
{ 0 }
};
/* Node type descriptor */
static struct ng_type ng_bridge_typestruct = {
.version = NG_ABI_VERSION,
.name = NG_BRIDGE_NODE_TYPE,
.constructor = ng_bridge_constructor,
.rcvmsg = ng_bridge_rcvmsg,
.shutdown = ng_bridge_shutdown,
.newhook = ng_bridge_newhook,
.rcvdata = ng_bridge_rcvdata,
.disconnect = ng_bridge_disconnect,
.cmdlist = ng_bridge_cmdlist,
};
NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
/******************************************************************
NETGRAPH NODE METHODS
******************************************************************/
/*
* Node constructor
*/
static int
ng_bridge_constructor(node_p node)
{
priv_p priv;
/* Allocate and initialize private info */
priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
ng_callout_init(&priv->timer);
/* Allocate and initialize hash table, etc. */
priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
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;
/*
* This node has all kinds of stuff that could be screwed by SMP.
* Until it gets it's own internal protection, we go through in
* single file. This could hurt a machine bridging between two
* GB ethernets so it should be fixed.
* When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
* (and atomic ops )
*/
NG_NODE_FORCE_WRITER(node);
NG_NODE_SET_PRIVATE(node, priv);
priv->node = node;
/* Start timer; timer is always running while node is alive */
ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
/* Done */
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 = NG_NODE_PRIVATE(node);
/* Check for a link hook */
if (strlen(name) > strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) {
char linkName[NG_HOOKSIZ];
u_int32_t linkNum;
link_p link;
/* primitive parsing */
linkNum = strtoul(name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
NULL, 10);
/* validation by comparing against the reconstucted name */
snprintf(linkName, sizeof(linkName),
"%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
linkNum);
if (strcmp(linkName, name) != 0)
return (EINVAL);
if(NG_PEER_NODE(hook) == node)
return (ELOOP);
link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE,
M_WAITOK|M_ZERO);
if (link == NULL)
return (ENOMEM);
link->hook = hook;
NG_HOOK_SET_PRIVATE(hook, link);
priv->numLinks++;
return (0);
}
/* Unknown hook name */
return (EINVAL);
}
/*
* Receive a control message
*/
static int
ng_bridge_reset_link(hook_p hook, void *arg __unused)
{
link_p priv = NG_HOOK_PRIVATE(hook);
priv->loopCount = 0;
bzero(&priv->stats, sizeof(priv->stats));
return (1);
}
static int
ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_mesg *resp = NULL;
int error = 0;
struct ng_mesg *msg;
NGI_GET_MSG(item, msg);
switch (msg->header.typecookie) {
#ifdef NGM_BRIDGE_TABLE_ABI
case NGM_BRIDGE_COOKIE_TBL:
switch (msg->header.cmd) {
case NGM_BRIDGE_GET_CONFIG:
{
struct ng_bridge_config_tbl *conf;
NG_MKRESPONSE(resp, msg, sizeof(*conf),
M_NOWAIT|M_ZERO);
if (resp == NULL) {
error = ENOMEM;
break;
}
conf = (struct ng_bridge_config_tbl *)resp->data;
conf->cfg = priv->conf;
break;
}
case NGM_BRIDGE_SET_CONFIG:
{
struct ng_bridge_config_tbl *conf;
if (msg->header.arglen != sizeof(*conf)) {
error = EINVAL;
break;
}
conf = (struct ng_bridge_config_tbl *)msg->data;
priv->conf = conf->cfg;
break;
}
case NGM_BRIDGE_GET_TABLE:
{
struct ng_bridge_host_tbl_ary *ary;
struct ng_bridge_hent *hent;
int i, 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_tbl_ary *)resp->data;
ary->numHosts = priv->numHosts;
i = 0;
for (bucket = 0; bucket < priv->numBuckets; bucket++) {
SLIST_FOREACH(hent, &priv->tab[bucket], next) {
memcpy(ary->hosts[i].addr,
hent->host.addr,
sizeof(ary->hosts[i].addr));
ary->hosts[i].age = hent->host.age;
ary->hosts[i].staleness =
hent->host.staleness;
ary->hosts[i].linkNum = strtol(
NG_HOOK_NAME(hent->host.link->hook) +
strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
NULL, 10);
i++;
}
}
break;
}
}
/* If already handled break, otherwise use new ABI. */
if (resp != NULL || error != 0)
break;
#endif /* NGM_BRIDGE_TABLE_ABI */
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;
if (msg->header.arglen
!= sizeof(struct ng_bridge_config)) {
error = EINVAL;
break;
}
conf = (struct ng_bridge_config *)msg->data;
priv->conf = *conf;
break;
}
case NGM_BRIDGE_RESET:
{
hook_p rethook;
/* Flush all entries in the hash table */
ng_bridge_remove_hosts(priv, NULL);
/* Reset all loop detection counters and stats */
NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
rethook);
break;
}
case NGM_BRIDGE_GET_STATS:
case NGM_BRIDGE_CLR_STATS:
case NGM_BRIDGE_GETCLR_STATS:
{
hook_p hook;
link_p link;
char linkName[NG_HOOKSIZ];
/* Get link number */
if (msg->header.arglen != sizeof(u_int32_t)) {
error = EINVAL;
break;
}
snprintf(linkName, sizeof(linkName),
"%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
*((u_int32_t *)msg->data));
if ((hook = ng_findhook(node, linkName)) == NULL) {
error = ENOTCONN;
break;
}
link = NG_HOOK_PRIVATE(hook);
/* 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) {
memcpy(ary->hosts[i].addr,
hent->host.addr,
sizeof(ary->hosts[i].addr));
ary->hosts[i].age = hent->host.age;
ary->hosts[i].staleness = hent->host.staleness;
strncpy(ary->hosts[i].hook,
NG_HOOK_NAME(hent->host.link->hook),
sizeof(ary->hosts[i].hook));
i++;
}
}
break;
}
case NGM_BRIDGE_SET_PERSISTENT:
{
priv->persistent = 1;
break;
}
default:
error = EINVAL;
break;
}
break;
default:
error = EINVAL;
break;
}
/* Done */
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
return (error);
}
/*
* Receive data on a hook
*/
struct ng_bridge_send_ctx {
link_p foundFirst, incoming;
struct mbuf * m;
int manycast, error;
};
static int
ng_bridge_send_ctx(hook_p dst, void *arg)
{
struct ng_bridge_send_ctx *ctx = arg;
link_p destLink = NG_HOOK_PRIVATE(dst);
struct mbuf *m2 = NULL;
int error = 0;
/* Skip incoming link */
if (destLink == ctx->incoming) {
return (1);
}
if (ctx->foundFirst == NULL) {
/*
* This is the first usable link we have found.
* Reserve it for the originals.
* If we never find another we save a copy.
*/
ctx->foundFirst = destLink;
return (1);
}
/*
* It's usable link but not the reserved (first) one.
* Copy mbuf info for sending.
*/
m2 = m_dup(ctx->m, M_NOWAIT); /* XXX m_copypacket() */
if (m2 == NULL) {
ctx->incoming->stats.memoryFailures++;
ctx->error = ENOBUFS;
return (0); /* abort loop */
}
/* Update stats */
destLink->stats.xmitPackets++;
destLink->stats.xmitOctets += m2->m_pkthdr.len;
switch (ctx->manycast) {
default: /* unknown unicast */
break;
case 1: /* multicast */
destLink->stats.xmitMulticasts++;
break;
case 2: /* broadcast */
destLink->stats.xmitBroadcasts++;
break;
}
/* Send packet */
NG_SEND_DATA_ONLY(error, destLink->hook, m2);
if(error)
ctx->error = error;
return (1);
}
static int
ng_bridge_rcvdata(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_bridge_host *host;
struct ether_header *eh;
struct ng_bridge_send_ctx ctx = { 0 };
hook_p ret;
NGI_GET_M(item, ctx.m);
ctx.incoming = NG_HOOK_PRIVATE(hook);
/* Sanity check packet and pull up header */
if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
ctx.incoming->stats.recvRunts++;
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (EINVAL);
}
if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
ctx.incoming->stats.memoryFailures++;
NG_FREE_ITEM(item);
return (ENOBUFS);
}
eh = mtod(ctx.m, struct ether_header *);
if ((eh->ether_shost[0] & 1) != 0) {
ctx.incoming->stats.recvInvalid++;
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (EINVAL);
}
/* Is link disabled due to a loopback condition? */
if (ctx.incoming->loopCount != 0) {
ctx.incoming->stats.loopDrops++;
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (ELOOP); /* XXX is this an appropriate error? */
}
/* Update stats */
ctx.incoming->stats.recvPackets++;
ctx.incoming->stats.recvOctets += ctx.m->m_pkthdr.len;
if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
ctx.incoming->stats.recvBroadcasts++;
ctx.manycast = 2;
} else
ctx.incoming->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->link != ctx.incoming) {
/*
* 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 = ctx.m->m_pkthdr.rcvif;
char suffix[32];
if (ifp != NULL)
snprintf(suffix, sizeof(suffix),
" (%s)", ifp->if_xname);
else
*suffix = '\0';
log(LOG_WARNING, "ng_bridge: %s:"
" loopback detected on %s%s\n",
ng_bridge_nodename(node),
NG_HOOK_NAME(hook), suffix);
}
/* Mark link as linka non grata */
ctx.incoming->loopCount = priv->conf.loopTimeout;
ctx.incoming->stats.loopDetects++;
/* Forget all hosts on this link */
ng_bridge_remove_hosts(priv, ctx.incoming);
/* Drop packet */
ctx.incoming->stats.loopDrops++;
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (ELOOP); /* XXX appropriate? */
}
/* Move host over to new link */
host->link = ctx.incoming;
host->age = 0;
}
} else {
if (!ng_bridge_put(priv, eh->ether_shost, ctx.incoming)) {
ctx.incoming->stats.memoryFailures++;
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (ENOMEM);
}
}
/* Run packet through ipfw processing, if enabled */
#if 0
if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
/* XXX not implemented yet */
}
#endif
/*
* If unicast and destination host known, deliver to host's link,
* unless it is the same link as the packet came in on.
*/
if (!ctx.manycast) {
/* Determine packet destination link */
if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
link_p destLink = host->link;
/* If destination same as incoming link, do nothing */
if (destLink == ctx.incoming) {
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (0);
}
/* Deliver packet out the destination link */
destLink->stats.xmitPackets++;
destLink->stats.xmitOctets += ctx.m->m_pkthdr.len;
NG_FWD_NEW_DATA(ctx.error, item, destLink->hook, ctx.m);
return (ctx.error);
}
/* Destination host is not known */
ctx.incoming->stats.recvUnknown++;
}
/* Distribute unknown, multicast, broadcast pkts to all other links */
NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
/* If we never saw a good link, leave. */
if (ctx.foundFirst == NULL || ctx.error != 0) {
NG_FREE_ITEM(item);
NG_FREE_M(ctx.m);
return (ctx.error);
}
/*
* If we've sent all the others, send the original
* on the first link we found.
*/
NG_FWD_NEW_DATA(ctx.error, item, ctx.foundFirst->hook, ctx.m);
return (ctx.error);
}
/*
* Shutdown node
*/
static int
ng_bridge_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
/*
* Shut down everything including the timer. Even if the
* callout has already been dequeued and is about to be
* run, ng_bridge_timeout() won't be fired as the node
* is already marked NGF_INVALID, so we're safe to free
* the node now.
*/
KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
("%s: numLinks=%d numHosts=%d",
__func__, priv->numLinks, priv->numHosts));
ng_uncallout(&priv->timer, node);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
free(priv->tab, M_NETGRAPH_BRIDGE);
free(priv, M_NETGRAPH_BRIDGE);
return (0);
}
/*
* Hook disconnection.
*/
static int
ng_bridge_disconnect(hook_p hook)
{
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
link_p link = NG_HOOK_PRIVATE(hook);
/* Remove all hosts associated with this link */
ng_bridge_remove_hosts(priv, link);
/* Free associated link information */
free(link, M_NETGRAPH_BRIDGE);
priv->numLinks--;
/* If no more hooks, go away */
if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
&& !priv->persistent) {
ng_rmnode_self(NG_HOOK_NODE(hook));
}
return (0);
}
/******************************************************************
HASH TABLE FUNCTIONS
******************************************************************/
/*
* Hash algorithm
*/
#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, link_p link)
{
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", __func__, addr, ":"));
}
#endif
/* Allocate and initialize new hashtable entry */
hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
if (hent == NULL)
return (0);
bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
hent->host.link = link;
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 */
newTab = malloc(newNumBuckets * sizeof(*newTab),
M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
if (newTab == NULL)
return;
/* 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_BRIDGE);
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, link_p link)
{
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 (link == NULL || hent->host.link == link) {
*hptr = SLIST_NEXT(hent, next);
free(hent, M_NETGRAPH_BRIDGE);
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 int
ng_bridge_unmute(hook_p hook, void *arg)
{
link_p link = NG_HOOK_PRIVATE(hook);
node_p node = NG_HOOK_NODE(hook);
priv_p priv = NG_NODE_PRIVATE(node);
int *counter = arg;
if (link->loopCount != 0) {
link->loopCount--;
if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
log(LOG_INFO, "ng_bridge: %s:"
" restoring looped back %s\n",
ng_bridge_nodename(node), NG_HOOK_NAME(hook));
}
}
(*counter)++;
return (1);
}
static void
ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
{
const priv_p priv = NG_NODE_PRIVATE(node);
int bucket;
int counter = 0;
hook_p ret;
/* 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;
/* 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_BRIDGE);
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", __func__, priv->numHosts, counter));
/* Decrease table size if necessary */
ng_bridge_rehash(priv);
/* Decrease loop counter on muted looped back links */
counter = 0;
NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
KASSERT(priv->numLinks == counter,
("%s: links: %d != %d", __func__, priv->numLinks, counter));
/* Register a new timeout, keeping the existing node reference */
ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
}
/*
* Return node's "name", even if it doesn't have one.
*/
static const char *
ng_bridge_nodename(node_p node)
{
static char name[NG_NODESIZ];
if (NG_NODE_HAS_NAME(node))
snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
else
snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
return name;
}