patch-2.3.47 linux/net/bridge/br_fdb.c

• Lines: 319
• Date: Sun Feb 20 10:41:18 2000
• Orig file: v2.3.46/linux/net/bridge/br_fdb.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.46/linux/net/bridge/br_fdb.c linux/net/bridge/br_fdb.c
@@ -0,0 +1,318 @@
+/*
+ *	Forwarding database
+ *	Linux ethernet bridge
+ *
+ *	Authors:
+ *	Lennert Buytenhek		<buytenh@gnu.org>
+ *
+ *	$Id: br_fdb.c,v 1.1 2000/02/18 16:47:12 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 <linux/kernel.h>
+#include <linux/if_bridge.h>
+#include <asm/atomic.h>
+#include <asm/spinlock.h>
+#include <asm/uaccess.h>
+#include "br_private.h"
+
+static __inline__ unsigned long __timeout(struct net_bridge *br)
+{
+	unsigned long timeout;
+
+	timeout = jiffies - br->ageing_time;
+	if (br->topology_change)
+		timeout = jiffies - br->forward_delay;
+
+	return timeout;
+}
+
+static __inline__ int has_expired(struct net_bridge *br,
+				  struct net_bridge_fdb_entry *fdb)
+{
+	if (!fdb->is_static &&
+	    time_before_eq(fdb->ageing_timer, __timeout(br)))
+		return 1;
+
+	return 0;
+}
+
+static __inline__ void copy_fdb(struct __fdb_entry *ent, struct net_bridge_fdb_entry *f)
+{
+	memcpy(ent->mac_addr, f->addr.addr, ETH_ALEN);
+	ent->port_no = f->dst?f->dst->port_no:0;
+	ent->is_local = f->is_local;
+	ent->ageing_timer_value = 0;
+	if (!f->is_static)
+		ent->ageing_timer_value = jiffies - f->ageing_timer;
+}
+
+static __inline__ int br_mac_hash(unsigned char *mac)
+{
+	unsigned long x;
+
+	x = mac[0];
+	x = (x << 2) ^ mac[1];
+	x = (x << 2) ^ mac[2];
+	x = (x << 2) ^ mac[3];
+	x = (x << 2) ^ mac[4];
+	x = (x << 2) ^ mac[5];
+
+	x ^= x >> 8;
+
+	return x & (BR_HASH_SIZE - 1);
+}
+
+static __inline__ void __hash_link(struct net_bridge *br,
+				   struct net_bridge_fdb_entry *ent,
+				   int hash)
+{
+	ent->next_hash = br->hash[hash];
+	if (ent->next_hash != NULL)
+		ent->next_hash->pprev_hash = &ent->next_hash;
+	br->hash[hash] = ent;
+	ent->pprev_hash = &br->hash[hash];
+}
+
+static __inline__ void __hash_unlink(struct net_bridge_fdb_entry *ent)
+{
+	*(ent->pprev_hash) = ent->next_hash;
+	if (ent->next_hash != NULL)
+		ent->next_hash->pprev_hash = ent->pprev_hash;
+	ent->next_hash = NULL;
+	ent->pprev_hash = NULL;
+}
+
+
+
+void br_fdb_changeaddr(struct net_bridge_port *p, unsigned char *newaddr)
+{
+	struct net_bridge *br;
+	int i;
+
+	br = p->br;
+	write_lock_bh(&br->hash_lock);
+	for (i=0;i<BR_HASH_SIZE;i++) {
+		struct net_bridge_fdb_entry *f;
+
+		f = br->hash[i];
+		while (f != NULL) {
+			if (f->dst == p && f->is_local) {
+				__hash_unlink(f);
+				memcpy(f->addr.addr, newaddr, ETH_ALEN);
+				__hash_link(br, f, br_mac_hash(newaddr));
+				write_unlock_bh(&br->hash_lock);
+				return;
+			}
+			f = f->next_hash;
+		}
+	}
+	write_unlock_bh(&br->hash_lock);
+}
+
+void br_fdb_cleanup(struct net_bridge *br)
+{
+	int i;
+	unsigned long timeout;
+
+	timeout = __timeout(br);
+
+	write_lock_bh(&br->hash_lock);
+	for (i=0;i<BR_HASH_SIZE;i++) {
+		struct net_bridge_fdb_entry *f;
+
+		f = br->hash[i];
+		while (f != NULL) {
+			struct net_bridge_fdb_entry *g;
+
+			g = f->next_hash;
+			if (!f->is_static &&
+			    time_before_eq(f->ageing_timer, timeout)) {
+				__hash_unlink(f);
+				br_fdb_put(f);
+			}
+			f = g;
+		}
+	}
+	write_unlock_bh(&br->hash_lock);
+}
+
+void br_fdb_delete_by_port(struct net_bridge *br, struct net_bridge_port *p)
+{
+	int i;
+
+	write_lock_bh(&br->hash_lock);
+	for (i=0;i<BR_HASH_SIZE;i++) {
+		struct net_bridge_fdb_entry *f;
+
+		f = br->hash[i];
+		while (f != NULL) {
+			struct net_bridge_fdb_entry *g;
+
+			g = f->next_hash;
+			if (f->dst == p) {
+				__hash_unlink(f);
+				br_fdb_put(f);
+			}
+			f = g;
+		}
+	}
+	write_unlock_bh(&br->hash_lock);
+}
+
+struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, unsigned char *addr)
+{
+	struct net_bridge_fdb_entry *fdb;
+
+	read_lock_bh(&br->hash_lock);
+	fdb = br->hash[br_mac_hash(addr)];
+	while (fdb != NULL) {
+		if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
+			if (!has_expired(br, fdb)) {
+				atomic_inc(&fdb->use_count);
+				read_unlock_bh(&br->hash_lock);
+				return fdb;
+			}
+
+			read_unlock_bh(&br->hash_lock);
+			return NULL;
+		}
+
+		fdb = fdb->next_hash;
+	}
+
+	read_unlock_bh(&br->hash_lock);
+	return NULL;
+}
+
+void br_fdb_put(struct net_bridge_fdb_entry *ent)
+{
+	if (atomic_dec_and_test(&ent->use_count))
+		kfree(ent);
+}
+
+int br_fdb_get_entries(struct net_bridge *br,
+		       unsigned char *_buf,
+		       int maxnum,
+		       int offset)
+{
+	int i;
+	int num;
+	struct __fdb_entry *walk;
+
+	num = 0;
+	walk = (struct __fdb_entry *)_buf;
+
+	read_lock_bh(&br->hash_lock);
+	for (i=0;i<BR_HASH_SIZE;i++) {
+		struct net_bridge_fdb_entry *f;
+
+		f = br->hash[i];
+		while (f != NULL && num < maxnum) {
+			struct __fdb_entry ent;
+			int err;
+			struct net_bridge_fdb_entry *g;
+
+			if (has_expired(br, f)) {
+				f = f->next_hash;
+				continue;
+			}
+
+			if (offset) {
+				offset--;
+				f = f->next_hash;
+				continue;
+			}
+
+			copy_fdb(&ent, f);
+
+			atomic_inc(&f->use_count);
+			read_unlock_bh(&br->hash_lock);
+			err = copy_to_user(walk, &ent, sizeof(struct __fdb_entry));
+			read_lock_bh(&br->hash_lock);
+
+			g = f->next_hash;
+			br_fdb_put(f);
+
+			if (err)
+				goto out_fault;
+
+			if (f->next_hash == NULL &&
+			    f->pprev_hash == NULL)
+				goto out_disappeared;
+
+			num++;
+			walk++;
+
+			f = g;
+		}
+	}
+
+ out:
+	read_unlock_bh(&br->hash_lock);
+	return num;
+
+ out_disappeared:
+	num = -EAGAIN;
+	goto out;
+
+ out_fault:
+	num = -EFAULT;
+	goto out;
+}
+
+static __inline__ void __fdb_possibly_replace(struct net_bridge_fdb_entry *fdb,
+					      struct net_bridge_port *source,
+					      int is_local)
+{
+	if (!fdb->is_static || is_local) {
+		fdb->dst = source;
+		fdb->is_local = is_local;
+		fdb->is_static = is_local;
+		fdb->ageing_timer = jiffies;
+	}
+}
+
+void br_fdb_insert(struct net_bridge *br,
+		   struct net_bridge_port *source,
+		   unsigned char *addr,
+		   int is_local)
+{
+	struct net_bridge_fdb_entry *fdb;
+	int hash;
+
+	hash = br_mac_hash(addr);
+
+	write_lock_bh(&br->hash_lock);
+	fdb = br->hash[hash];
+	while (fdb != NULL) {
+		if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
+			__fdb_possibly_replace(fdb, source, is_local);
+			write_unlock_bh(&br->hash_lock);
+			return;
+		}
+
+		fdb = fdb->next_hash;
+	}
+
+	fdb = kmalloc(sizeof(*fdb), GFP_ATOMIC);
+	if (fdb == NULL) {
+		write_unlock_bh(&br->hash_lock);
+		return;
+	}
+
+	memcpy(fdb->addr.addr, addr, ETH_ALEN);
+	atomic_set(&fdb->use_count, 1);
+	fdb->dst = source;
+	fdb->is_local = is_local;
+	fdb->is_static = is_local;
+	fdb->ageing_timer = jiffies;
+
+	__hash_link(br, fdb, hash);
+
+	write_unlock_bh(&br->hash_lock);
+}