bridge: add rcu_read_lock on transmit
[linux-2.6.git] / net / bridge / br_device.c
1 /*
2  *      Device handling code
3  *      Linux ethernet bridge
4  *
5  *      Authors:
6  *      Lennert Buytenhek               <buytenh@gnu.org>
7  *
8  *      This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/netdevice.h>
16 #include <linux/netpoll.h>
17 #include <linux/etherdevice.h>
18 #include <linux/ethtool.h>
19 #include <linux/list.h>
20 #include <linux/netfilter_bridge.h>
21
22 #include <asm/uaccess.h>
23 #include "br_private.h"
24
25 /* net device transmit always called with BH disabled */
26 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
27 {
28         struct net_bridge *br = netdev_priv(dev);
29         const unsigned char *dest = skb->data;
30         struct net_bridge_fdb_entry *dst;
31         struct net_bridge_mdb_entry *mdst;
32         struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
33
34 #ifdef CONFIG_BRIDGE_NETFILTER
35         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
36                 br_nf_pre_routing_finish_bridge_slow(skb);
37                 return NETDEV_TX_OK;
38         }
39 #endif
40
41         brstats->tx_packets++;
42         brstats->tx_bytes += skb->len;
43
44         BR_INPUT_SKB_CB(skb)->brdev = dev;
45
46         skb_reset_mac_header(skb);
47         skb_pull(skb, ETH_HLEN);
48
49         rcu_read_lock();
50         if (is_multicast_ether_addr(dest)) {
51                 if (br_multicast_rcv(br, NULL, skb))
52                         goto out;
53
54                 mdst = br_mdb_get(br, skb);
55                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
56                         br_multicast_deliver(mdst, skb);
57                 else
58                         br_flood_deliver(br, skb);
59         } else if ((dst = __br_fdb_get(br, dest)) != NULL)
60                 br_deliver(dst->dst, skb);
61         else
62                 br_flood_deliver(br, skb);
63
64 out:
65         rcu_read_unlock();
66         return NETDEV_TX_OK;
67 }
68
69 static int br_dev_open(struct net_device *dev)
70 {
71         struct net_bridge *br = netdev_priv(dev);
72
73         br_features_recompute(br);
74         netif_start_queue(dev);
75         br_stp_enable_bridge(br);
76         br_multicast_open(br);
77
78         return 0;
79 }
80
81 static void br_dev_set_multicast_list(struct net_device *dev)
82 {
83 }
84
85 static int br_dev_stop(struct net_device *dev)
86 {
87         struct net_bridge *br = netdev_priv(dev);
88
89         br_stp_disable_bridge(br);
90         br_multicast_stop(br);
91
92         netif_stop_queue(dev);
93
94         return 0;
95 }
96
97 static struct net_device_stats *br_get_stats(struct net_device *dev)
98 {
99         struct net_bridge *br = netdev_priv(dev);
100         struct net_device_stats *stats = &dev->stats;
101         struct br_cpu_netstats sum = { 0 };
102         unsigned int cpu;
103
104         for_each_possible_cpu(cpu) {
105                 const struct br_cpu_netstats *bstats
106                         = per_cpu_ptr(br->stats, cpu);
107
108                 sum.tx_bytes   += bstats->tx_bytes;
109                 sum.tx_packets += bstats->tx_packets;
110                 sum.rx_bytes   += bstats->rx_bytes;
111                 sum.rx_packets += bstats->rx_packets;
112         }
113
114         stats->tx_bytes   = sum.tx_bytes;
115         stats->tx_packets = sum.tx_packets;
116         stats->rx_bytes   = sum.rx_bytes;
117         stats->rx_packets = sum.rx_packets;
118
119         return stats;
120 }
121
122 static int br_change_mtu(struct net_device *dev, int new_mtu)
123 {
124         struct net_bridge *br = netdev_priv(dev);
125         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
126                 return -EINVAL;
127
128         dev->mtu = new_mtu;
129
130 #ifdef CONFIG_BRIDGE_NETFILTER
131         /* remember the MTU in the rtable for PMTU */
132         br->fake_rtable.u.dst.metrics[RTAX_MTU - 1] = new_mtu;
133 #endif
134
135         return 0;
136 }
137
138 /* Allow setting mac address to any valid ethernet address. */
139 static int br_set_mac_address(struct net_device *dev, void *p)
140 {
141         struct net_bridge *br = netdev_priv(dev);
142         struct sockaddr *addr = p;
143
144         if (!is_valid_ether_addr(addr->sa_data))
145                 return -EINVAL;
146
147         spin_lock_bh(&br->lock);
148         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
149         br_stp_change_bridge_id(br, addr->sa_data);
150         br->flags |= BR_SET_MAC_ADDR;
151         spin_unlock_bh(&br->lock);
152
153         return 0;
154 }
155
156 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
157 {
158         strcpy(info->driver, "bridge");
159         strcpy(info->version, BR_VERSION);
160         strcpy(info->fw_version, "N/A");
161         strcpy(info->bus_info, "N/A");
162 }
163
164 static int br_set_sg(struct net_device *dev, u32 data)
165 {
166         struct net_bridge *br = netdev_priv(dev);
167
168         if (data)
169                 br->feature_mask |= NETIF_F_SG;
170         else
171                 br->feature_mask &= ~NETIF_F_SG;
172
173         br_features_recompute(br);
174         return 0;
175 }
176
177 static int br_set_tso(struct net_device *dev, u32 data)
178 {
179         struct net_bridge *br = netdev_priv(dev);
180
181         if (data)
182                 br->feature_mask |= NETIF_F_TSO;
183         else
184                 br->feature_mask &= ~NETIF_F_TSO;
185
186         br_features_recompute(br);
187         return 0;
188 }
189
190 static int br_set_tx_csum(struct net_device *dev, u32 data)
191 {
192         struct net_bridge *br = netdev_priv(dev);
193
194         if (data)
195                 br->feature_mask |= NETIF_F_NO_CSUM;
196         else
197                 br->feature_mask &= ~NETIF_F_ALL_CSUM;
198
199         br_features_recompute(br);
200         return 0;
201 }
202
203 #ifdef CONFIG_NET_POLL_CONTROLLER
204 static bool br_devices_support_netpoll(struct net_bridge *br)
205 {
206         struct net_bridge_port *p;
207         bool ret = true;
208         int count = 0;
209         unsigned long flags;
210
211         spin_lock_irqsave(&br->lock, flags);
212         list_for_each_entry(p, &br->port_list, list) {
213                 count++;
214                 if ((p->dev->priv_flags & IFF_DISABLE_NETPOLL) ||
215                     !p->dev->netdev_ops->ndo_poll_controller)
216                         ret = false;
217         }
218         spin_unlock_irqrestore(&br->lock, flags);
219         return count != 0 && ret;
220 }
221
222 void br_netpoll_cleanup(struct net_device *dev)
223 {
224         struct net_bridge *br = netdev_priv(dev);
225         struct net_bridge_port *p, *n;
226         const struct net_device_ops *ops;
227
228         br->dev->npinfo = NULL;
229         list_for_each_entry_safe(p, n, &br->port_list, list) {
230                 if (p->dev) {
231                         ops = p->dev->netdev_ops;
232                         if (ops->ndo_netpoll_cleanup)
233                                 ops->ndo_netpoll_cleanup(p->dev);
234                         else
235                                 p->dev->npinfo = NULL;
236                 }
237         }
238 }
239
240 void br_netpoll_disable(struct net_bridge *br,
241                         struct net_device *dev)
242 {
243         if (br_devices_support_netpoll(br))
244                 br->dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
245         if (dev->netdev_ops->ndo_netpoll_cleanup)
246                 dev->netdev_ops->ndo_netpoll_cleanup(dev);
247         else
248                 dev->npinfo = NULL;
249 }
250
251 void br_netpoll_enable(struct net_bridge *br,
252                        struct net_device *dev)
253 {
254         if (br_devices_support_netpoll(br)) {
255                 br->dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
256                 if (br->dev->npinfo)
257                         dev->npinfo = br->dev->npinfo;
258         } else if (!(br->dev->priv_flags & IFF_DISABLE_NETPOLL)) {
259                 br->dev->priv_flags |= IFF_DISABLE_NETPOLL;
260                 br_info(br,"new device %s does not support netpoll (disabling)",
261                         dev->name);
262         }
263 }
264
265 #endif
266
267 static const struct ethtool_ops br_ethtool_ops = {
268         .get_drvinfo    = br_getinfo,
269         .get_link       = ethtool_op_get_link,
270         .get_tx_csum    = ethtool_op_get_tx_csum,
271         .set_tx_csum    = br_set_tx_csum,
272         .get_sg         = ethtool_op_get_sg,
273         .set_sg         = br_set_sg,
274         .get_tso        = ethtool_op_get_tso,
275         .set_tso        = br_set_tso,
276         .get_ufo        = ethtool_op_get_ufo,
277         .set_ufo        = ethtool_op_set_ufo,
278         .get_flags      = ethtool_op_get_flags,
279 };
280
281 static const struct net_device_ops br_netdev_ops = {
282         .ndo_open                = br_dev_open,
283         .ndo_stop                = br_dev_stop,
284         .ndo_start_xmit          = br_dev_xmit,
285         .ndo_get_stats           = br_get_stats,
286         .ndo_set_mac_address     = br_set_mac_address,
287         .ndo_set_multicast_list  = br_dev_set_multicast_list,
288         .ndo_change_mtu          = br_change_mtu,
289         .ndo_do_ioctl            = br_dev_ioctl,
290 #ifdef CONFIG_NET_POLL_CONTROLLER
291         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
292 #endif
293 };
294
295 static void br_dev_free(struct net_device *dev)
296 {
297         struct net_bridge *br = netdev_priv(dev);
298
299         free_percpu(br->stats);
300         free_netdev(dev);
301 }
302
303 void br_dev_setup(struct net_device *dev)
304 {
305         random_ether_addr(dev->dev_addr);
306         ether_setup(dev);
307
308         dev->netdev_ops = &br_netdev_ops;
309         dev->destructor = br_dev_free;
310         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
311         dev->tx_queue_len = 0;
312         dev->priv_flags = IFF_EBRIDGE;
313
314         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
315                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
316                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO;
317 }