From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- net/bridge/br_fdb.c | 368 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 368 insertions(+) create mode 100644 net/bridge/br_fdb.c (limited to 'net/bridge/br_fdb.c') diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c new file mode 100644 index 000000000000..e6c2200b7ca3 --- /dev/null +++ b/net/bridge/br_fdb.c @@ -0,0 +1,368 @@ +/* + * Forwarding database + * Linux ethernet bridge + * + * Authors: + * Lennert Buytenhek + * + * $Id: br_fdb.c,v 1.6 2002/01/17 00:57:07 davem Exp $ + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#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); + +void __init br_fdb_init(void) +{ + br_fdb_cache = kmem_cache_create("bridge_fdb_cache", + sizeof(struct net_bridge_fdb_entry), + 0, + SLAB_HWCACHE_ALIGN, NULL, NULL); +} + +void __exit br_fdb_fini(void) +{ + kmem_cache_destroy(br_fdb_cache); +} + + +/* if topology_changing then use forward_delay (default 15 sec) + * otherwise keep longer (default 5 minutes) + */ +static __inline__ unsigned long hold_time(const struct net_bridge *br) +{ + return br->topology_change ? br->forward_delay : br->ageing_time; +} + +static __inline__ int has_expired(const struct net_bridge *br, + const struct net_bridge_fdb_entry *fdb) +{ + return !fdb->is_static + && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies); +} + +static __inline__ int br_mac_hash(const unsigned char *mac) +{ + return jhash(mac, ETH_ALEN, 0) & (BR_HASH_SIZE - 1); +} + +static __inline__ void fdb_delete(struct net_bridge_fdb_entry *f) +{ + hlist_del_rcu(&f->hlist); + br_fdb_put(f); +} + +void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr) +{ + struct net_bridge *br = p->br; + int i; + + spin_lock_bh(&br->hash_lock); + + /* 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; + + f = hlist_entry(h, struct net_bridge_fdb_entry, hlist); + if (f->dst == p && f->is_local) { + /* 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; + } + } + + /* delete old one */ + fdb_delete(f); + goto insert; + } + } + } + insert: + /* insert new address, may fail if invalid address or dup. */ + fdb_insert(br, p, newaddr); + + spin_unlock_bh(&br->hash_lock); +} + +void br_fdb_cleanup(unsigned long _data) +{ + struct net_bridge *br = (struct net_bridge *)_data; + unsigned long delay = hold_time(br); + int i; + + spin_lock_bh(&br->hash_lock); + for (i = 0; i < BR_HASH_SIZE; i++) { + struct net_bridge_fdb_entry *f; + struct hlist_node *h, *n; + + hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) { + if (!f->is_static && + time_before_eq(f->ageing_timer + delay, jiffies)) + fdb_delete(f); + } + } + spin_unlock_bh(&br->hash_lock); + + mod_timer(&br->gc_timer, jiffies + HZ/10); +} + +void br_fdb_delete_by_port(struct net_bridge *br, struct net_bridge_port *p) +{ + int i; + + spin_lock_bh(&br->hash_lock); + for (i = 0; i < BR_HASH_SIZE; i++) { + struct hlist_node *h, *g; + + hlist_for_each_safe(h, g, &br->hash[i]) { + struct net_bridge_fdb_entry *f + = hlist_entry(h, struct net_bridge_fdb_entry, hlist); + if (f->dst != p) + continue; + + /* + * if multiple ports all have the same device address + * then when one port is deleted, assign + * the local entry to other port + */ + if (f->is_local) { + 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 skip_delete; + } + } + } + + fdb_delete(f); + skip_delete: ; + } + } + spin_unlock_bh(&br->hash_lock); +} + +/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */ +struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, + const unsigned char *addr) +{ + struct hlist_node *h; + struct net_bridge_fdb_entry *fdb; + + hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) { + if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) { + if (unlikely(has_expired(br, fdb))) + break; + return fdb; + } + } + + return NULL; +} + +/* Interface used by ATM hook that keeps a ref count */ +struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, + unsigned char *addr) +{ + struct net_bridge_fdb_entry *fdb; + + rcu_read_lock(); + fdb = __br_fdb_get(br, addr); + if (fdb) + atomic_inc(&fdb->use_count); + rcu_read_unlock(); + return fdb; +} + +static void fdb_rcu_free(struct rcu_head *head) +{ + struct net_bridge_fdb_entry *ent + = container_of(head, struct net_bridge_fdb_entry, rcu); + kmem_cache_free(br_fdb_cache, ent); +} + +/* Set entry up for deletion with RCU */ +void br_fdb_put(struct net_bridge_fdb_entry *ent) +{ + if (atomic_dec_and_test(&ent->use_count)) + call_rcu(&ent->rcu, fdb_rcu_free); +} + +/* + * Fill buffer with forwarding table records in + * the API format. + */ +int br_fdb_fillbuf(struct net_bridge *br, void *buf, + unsigned long maxnum, unsigned long skip) +{ + struct __fdb_entry *fe = buf; + int i, num = 0; + struct hlist_node *h; + struct net_bridge_fdb_entry *f; + + memset(buf, 0, maxnum*sizeof(struct __fdb_entry)); + + rcu_read_lock(); + for (i = 0; i < BR_HASH_SIZE; i++) { + hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) { + if (num >= maxnum) + goto out; + + if (has_expired(br, f)) + continue; + + if (skip) { + --skip; + continue; + } + + /* convert from internal format to API */ + memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN); + fe->port_no = f->dst->port_no; + fe->is_local = f->is_local; + if (!f->is_static) + fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer); + ++fe; + ++num; + } + } + + out: + rcu_read_unlock(); + + return num; +} + +static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head, + const unsigned char *addr) +{ + struct hlist_node *h; + struct net_bridge_fdb_entry *fdb; + + hlist_for_each_entry_rcu(fdb, h, head, hlist) { + if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) + return fdb; + } + return NULL; +} + +static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, + struct net_bridge_port *source, + const unsigned char *addr, + int is_local) +{ + struct net_bridge_fdb_entry *fdb; + + fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); + if (fdb) { + memcpy(fdb->addr.addr, addr, ETH_ALEN); + atomic_set(&fdb->use_count, 1); + hlist_add_head_rcu(&fdb->hlist, head); + + fdb->dst = source; + fdb->is_local = is_local; + fdb->is_static = is_local; + fdb->ageing_timer = jiffies; + } + return fdb; +} + +static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr) +{ + struct hlist_head *head = &br->hash[br_mac_hash(addr)]; + struct net_bridge_fdb_entry *fdb; + + if (!is_valid_ether_addr(addr)) + return -EINVAL; + + fdb = fdb_find(head, addr); + if (fdb) { + /* it is okay to have multiple ports with same + * address, just use the first one. + */ + if (fdb->is_local) + return 0; + + printk(KERN_WARNING "%s adding interface with same address " + "as a received packet\n", + source->dev->name); + fdb_delete(fdb); + } + + if (!fdb_create(head, source, addr, 1)) + return -ENOMEM; + + return 0; +} + +int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr) +{ + int ret; + + spin_lock_bh(&br->hash_lock); + ret = fdb_insert(br, source, addr); + spin_unlock_bh(&br->hash_lock); + return ret; +} + +void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr) +{ + struct hlist_head *head = &br->hash[br_mac_hash(addr)]; + struct net_bridge_fdb_entry *fdb; + + /* some users want to always flood. */ + if (hold_time(br) == 0) + return; + + rcu_read_lock(); + fdb = fdb_find(head, addr); + if (likely(fdb)) { + /* attempt to update an entry for a local interface */ + if (unlikely(fdb->is_local)) { + if (net_ratelimit()) + printk(KERN_WARNING "%s: received packet with " + " own address as source address\n", + source->dev->name); + } else { + /* fastpath: update of existing entry */ + fdb->dst = source; + fdb->ageing_timer = jiffies; + } + } else { + spin_lock_bh(&br->hash_lock); + if (!fdb_find(head, addr)) + fdb_create(head, source, addr, 0); + /* else we lose race and someone else inserts + * it first, don't bother updating + */ + spin_unlock_bh(&br->hash_lock); + } + rcu_read_unlock(); +} -- cgit v1.2.3