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freebsd-dev/sys/netgraph/ng_bridge.c
julian 1ab8a4da8a Divorce the kernel binary ABI version number from the message 
format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.

Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)
2000-12-18 20:03:32 +00:00

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/*
* 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_ABI_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_disconnect,
ng_bridge_cmdlist,
};
NETGRAPH_INIT(bridge, &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 | M_ZERO);
if (priv == NULL)
return (ENOMEM);
callout_init(&priv->timer, 0);
/* Allocate and initialize hash table, etc. */
MALLOC(priv->tab, struct ng_bridge_bucket *,
MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT | M_ZERO);
if (priv->tab == NULL) {
FREE(priv, M_NETGRAPH);
return (ENOMEM);
}
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|M_ZERO);
if (priv->links[linkNum] == NULL)
return (ENOMEM);
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, struct ng_mesg **resp)
{
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_dup(m, M_NOWAIT); /* XXX m_copypacket() */
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 | 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);
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;
}
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