Forwarding table paranoia:
* Solve some potential problems if a device changes address and one or
more device has the same address.
* Warn if new device added to a bridge matches a entry that has shown
up on the network.
* Also don't put static entries in the timer list, they don't time
out so shouldn't be there.
diff -Nru a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
--- a/net/bridge/br_fdb.c 2004-05-21 15:39:18 -07:00
+++ b/net/bridge/br_fdb.c 2004-05-21 15:39:18 -07:00
@@ -23,6 +23,8 @@
#include "br_private.h"
static kmem_cache_t *br_fdb_cache;
+static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
+ const unsigned char *addr, int is_local);
void __init br_fdb_init(void)
{
@@ -72,37 +74,49 @@
static __inline__ void fdb_delete(struct net_bridge_fdb_entry *f)
{
hlist_del(&f->hlist);
- list_del(&f->age_list);
+ if (!f->is_static)
+ list_del(&f->age_list);
+
br_fdb_put(f);
}
void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
{
- struct net_bridge *br;
+ struct net_bridge *br = p->br;
int i;
- int newhash = br_mac_hash(newaddr);
-
- br = p->br;
+
write_lock_bh(&br->hash_lock);
- for (i=0;i<BR_HASH_SIZE;i++) {
+
+ /* Search all chains since old address/hash is unknown */
+ for (i = 0; i < BR_HASH_SIZE; i++) {
struct hlist_node *h;
-
hlist_for_each(h, &br->hash[i]) {
- struct net_bridge_fdb_entry *f
- = hlist_entry(h, struct net_bridge_fdb_entry,
hlist);
+ struct net_bridge_fdb_entry *f;
+ f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
if (f->dst == p && f->is_local) {
- memcpy(f->addr.addr, newaddr, ETH_ALEN);
- if (newhash != i) {
- hlist_del(&f->hlist);
- hlist_add_head(&f->hlist,
- &br->hash[newhash]);
+ /* maybe another port has same hw addr? */
+ struct net_bridge_port *op;
+ list_for_each_entry(op, &br->port_list, list) {
+ if (op != p &&
+ !memcmp(op->dev->dev_addr,
+ f->addr.addr, ETH_ALEN)) {
+ f->dst = op;
+ goto insert;
+ }
}
- goto out;
+
+ /* delete old one */
+ fdb_delete(f);
+ goto insert;
}
}
}
- out:
+ insert:
+ /* insert new address, may fail if invalid address or dup. */
+ fdb_insert(br, p, newaddr, 1);
+
+
write_unlock_bh(&br->hash_lock);
}
@@ -121,11 +135,10 @@
unsigned long expires = f->ageing_timer + delay;
if (time_before_eq(expires, jiffies)) {
- if (!f->is_static) {
- pr_debug("expire age %lu jiffies %lu\n",
- f->ageing_timer, jiffies);
- fdb_delete(f);
- }
+ WARN_ON(f->is_static);
+ pr_debug("expire age %lu jiffies %lu\n",
+ f->ageing_timer, jiffies);
+ fdb_delete(f);
} else {
mod_timer(&br->gc_timer, expires);
break;
@@ -139,7 +152,7 @@
int i;
write_lock_bh(&br->hash_lock);
- for (i=0;i<BR_HASH_SIZE;i++) {
+ for (i = 0; i < BR_HASH_SIZE; i++) {
struct hlist_node *h, *g;
hlist_for_each_safe(h, g, &br->hash[i]) {
@@ -247,50 +260,52 @@
return num;
}
-int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
+static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
const unsigned char *addr, int is_local)
{
struct hlist_node *h;
struct net_bridge_fdb_entry *fdb;
int hash = br_mac_hash(addr);
- int ret = 0;
if (!is_valid_ether_addr(addr))
return -EADDRNOTAVAIL;
- write_lock_bh(&br->hash_lock);
- hlist_for_each(h, &br->hash[hash]) {
- fdb = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
+ hlist_for_each_entry(fdb, h, &br->hash[hash], hlist) {
if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
/* attempt to update an entry for a local interface */
- if (unlikely(fdb->is_local)) {
+ if (fdb->is_local) {
/* it is okay to have multiple ports with same
* address, just don't allow to be spoofed.
*/
- if (!is_local) {
- if (net_ratelimit())
- printk(KERN_WARNING "%s:
received packet with "
- " own address as source
address\n",
- source->dev->name);
- ret = -EEXIST;
- }
- goto out;
+ if (is_local)
+ return 0;
+
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s: received
packet with "
+ " own address as source
address\n",
+ source->dev->name);
+ return -EEXIST;
}
- if (likely(!fdb->is_static || is_local)) {
- /* move to end of age list */
- list_del(&fdb->age_list);
+ if (is_local) {
+ printk(KERN_WARNING "%s adding interface with
same address "
+ "as a received packet\n",
+ source->dev->name);
goto update;
}
- goto out;
+
+ if (fdb->is_static)
+ return 0;
+
+ /* move to end of age list */
+ list_del(&fdb->age_list);
+ goto update;
}
}
fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
- if (unlikely(fdb == NULL)) {
- ret = -ENOMEM;
- goto out;
- }
+ if (!fdb)
+ return ENOMEM;
memcpy(fdb->addr.addr, addr, ETH_ALEN);
atomic_set(&fdb->use_count, 1);
@@ -306,9 +321,19 @@
fdb->is_local = is_local;
fdb->is_static = is_local;
fdb->ageing_timer = jiffies;
- list_add_tail(&fdb->age_list, &br->age_list);
- out:
- write_unlock_bh(&br->hash_lock);
+ if (!is_local)
+ list_add_tail(&fdb->age_list, &br->age_list);
+
+ return 0;
+}
+
+int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
+ const unsigned char *addr, int is_local)
+{
+ int ret;
+ write_lock_bh(&br->hash_lock);
+ ret = fdb_insert(br, source, addr, is_local);
+ write_unlock_bh(&br->hash_lock);
return ret;
}
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