2 * Copyright (c) 2007-2012 Nicira Networks.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/uaccess.h>
24 #include <linux/completion.h>
25 #include <linux/etherdevice.h>
26 #include <linux/if_bridge.h>
27 #include <linux/netdevice.h>
28 #include <linux/rtnetlink.h>
29 #include <net/genetlink.h>
31 #include "openvswitch/brcompat-netlink.h"
34 static struct genl_family brc_genl_family;
35 static struct genl_multicast_group brc_mc_group;
37 /* Time to wait for ovs-vswitchd to respond to a datapath action, in
39 #define BRC_TIMEOUT (HZ * 5)
41 /* Mutex to serialize ovs-brcompatd callbacks. (Some callbacks naturally hold
42 * br_ioctl_mutex, others hold rtnl_lock, but we can't take the former
43 * ourselves and we don't want to hold the latter over a potentially long
45 static DEFINE_MUTEX(brc_serial);
47 /* Userspace communication. */
48 static DEFINE_SPINLOCK(brc_lock); /* Ensure atomic access to these vars. */
49 static DECLARE_COMPLETION(brc_done); /* Userspace signaled operation done? */
50 static struct sk_buff *brc_reply; /* Reply from userspace. */
51 static u32 brc_seq; /* Sequence number for current op. */
53 static struct sk_buff *brc_send_command(struct sk_buff *,
54 struct nlattr **attrs);
55 static int brc_send_simple_command(struct sk_buff *);
57 static struct sk_buff *brc_make_request(int op, const char *bridge,
60 struct sk_buff *skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
64 genlmsg_put(skb, 0, 0, &brc_genl_family, 0, op);
66 NLA_PUT_STRING(skb, BRC_GENL_A_DP_NAME, bridge);
68 NLA_PUT_STRING(skb, BRC_GENL_A_PORT_NAME, port);
77 static int brc_send_simple_command(struct sk_buff *request)
79 struct nlattr *attrs[BRC_GENL_A_MAX + 1];
80 struct sk_buff *reply;
83 reply = brc_send_command(request, attrs);
85 return PTR_ERR(reply);
87 error = nla_get_u32(attrs[BRC_GENL_A_ERR_CODE]);
92 static int brc_add_del_bridge(char __user *uname, int add)
94 struct sk_buff *request;
97 if (!capable(CAP_NET_ADMIN))
100 if (copy_from_user(name, uname, IFNAMSIZ))
103 name[IFNAMSIZ - 1] = 0;
104 request = brc_make_request(add ? BRC_GENL_C_DP_ADD : BRC_GENL_C_DP_DEL,
109 return brc_send_simple_command(request);
112 static int brc_get_indices(int op, const char *br_name,
113 int __user *uindices, int n)
115 struct nlattr *attrs[BRC_GENL_A_MAX + 1];
116 struct sk_buff *request, *reply;
126 request = brc_make_request(op, br_name, NULL);
130 reply = brc_send_command(request, attrs);
131 ret = PTR_ERR(reply);
135 ret = -nla_get_u32(attrs[BRC_GENL_A_ERR_CODE]);
140 if (!attrs[BRC_GENL_A_IFINDEXES])
143 len = nla_len(attrs[BRC_GENL_A_IFINDEXES]);
144 indices = nla_data(attrs[BRC_GENL_A_IFINDEXES]);
145 if (len % sizeof(int))
148 n = min_t(int, n, len / sizeof(int));
149 ret = copy_to_user(uindices, indices, n * sizeof(int)) ? -EFAULT : n;
157 /* Called with br_ioctl_mutex. */
158 static int brc_get_bridges(int __user *uindices, int n)
160 return brc_get_indices(BRC_GENL_C_GET_BRIDGES, NULL, uindices, n);
163 /* Legacy deviceless bridge ioctl's. Called with br_ioctl_mutex. */
164 static int old_deviceless(void __user *uarg)
166 unsigned long args[3];
168 if (copy_from_user(args, uarg, sizeof(args)))
172 case BRCTL_GET_BRIDGES:
173 return brc_get_bridges((int __user *)args[1], args[2]);
175 case BRCTL_ADD_BRIDGE:
176 return brc_add_del_bridge((void __user *)args[1], 1);
177 case BRCTL_DEL_BRIDGE:
178 return brc_add_del_bridge((void __user *)args[1], 0);
184 /* Called with the br_ioctl_mutex. */
186 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
187 brc_ioctl_deviceless_stub(unsigned int cmd, void __user *uarg)
189 brc_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uarg)
195 return old_deviceless(uarg);
198 return brc_add_del_bridge(uarg, 1);
200 return brc_add_del_bridge(uarg, 0);
206 static int brc_add_del_port(struct net_device *dev, int port_ifindex, int add)
208 struct sk_buff *request;
209 struct net_device *port;
212 if (!capable(CAP_NET_ADMIN))
215 port = __dev_get_by_index(&init_net, port_ifindex);
219 /* Save name of dev and port because there's a race between the
220 * rtnl_unlock() and the brc_send_simple_command(). */
221 request = brc_make_request(add ? BRC_GENL_C_PORT_ADD : BRC_GENL_C_PORT_DEL,
222 dev->name, port->name);
227 err = brc_send_simple_command(request);
233 static int brc_get_bridge_info(struct net_device *dev,
234 struct __bridge_info __user *ub)
236 struct __bridge_info b;
238 memset(&b, 0, sizeof(struct __bridge_info));
240 /* First two bytes are the priority, which we should skip. This comes
241 * from struct bridge_id in br_private.h, which is unavailable to us.
243 memcpy((u8 *)&b.bridge_id + 2, dev->dev_addr, ETH_ALEN);
246 if (copy_to_user(ub, &b, sizeof(struct __bridge_info)))
252 static int brc_get_port_list(struct net_device *dev, int __user *uindices,
258 retval = brc_get_indices(BRC_GENL_C_GET_PORTS, dev->name,
266 * Format up to a page worth of forwarding table entries
267 * userbuf -- where to copy result
268 * maxnum -- maximum number of entries desired
269 * (limited to a page for sanity)
270 * offset -- number of records to skip
272 static int brc_get_fdb_entries(struct net_device *dev, void __user *userbuf,
273 unsigned long maxnum, unsigned long offset)
275 struct nlattr *attrs[BRC_GENL_A_MAX + 1];
276 struct sk_buff *request, *reply;
280 /* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
281 if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
282 maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
284 request = brc_make_request(BRC_GENL_C_FDB_QUERY, dev->name, NULL);
287 NLA_PUT_U64(request, BRC_GENL_A_FDB_COUNT, maxnum);
288 NLA_PUT_U64(request, BRC_GENL_A_FDB_SKIP, offset);
291 reply = brc_send_command(request, attrs);
292 retval = PTR_ERR(reply);
296 retval = -nla_get_u32(attrs[BRC_GENL_A_ERR_CODE]);
301 if (!attrs[BRC_GENL_A_FDB_DATA])
303 len = nla_len(attrs[BRC_GENL_A_FDB_DATA]);
304 if (len % sizeof(struct __fdb_entry) ||
305 len / sizeof(struct __fdb_entry) > maxnum)
308 retval = len / sizeof(struct __fdb_entry);
309 if (copy_to_user(userbuf, nla_data(attrs[BRC_GENL_A_FDB_DATA]), len))
323 /* Legacy ioctl's through SIOCDEVPRIVATE. Called with rtnl_lock. */
324 static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
326 unsigned long args[4];
328 if (copy_from_user(args, rq->ifr_data, sizeof(args)))
333 return brc_add_del_port(dev, args[1], 1);
335 return brc_add_del_port(dev, args[1], 0);
337 case BRCTL_GET_BRIDGE_INFO:
338 return brc_get_bridge_info(dev, (struct __bridge_info __user *)args[1]);
340 case BRCTL_GET_PORT_LIST:
341 return brc_get_port_list(dev, (int __user *)args[1], args[2]);
343 case BRCTL_GET_FDB_ENTRIES:
344 return brc_get_fdb_entries(dev, (void __user *)args[1],
351 /* Called with the rtnl_lock. */
352 static int brc_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
358 err = old_dev_ioctl(dev, rq, cmd);
362 return brc_add_del_port(dev, rq->ifr_ifindex, 1);
364 return brc_add_del_port(dev, rq->ifr_ifindex, 0);
375 static struct genl_family brc_genl_family = {
376 .id = GENL_ID_GENERATE,
378 .name = BRC_GENL_FAMILY_NAME,
380 .maxattr = BRC_GENL_A_MAX,
383 static int brc_genl_query(struct sk_buff *skb, struct genl_info *info)
386 struct sk_buff *ans_skb;
389 ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
393 data = genlmsg_put_reply(ans_skb, info, &brc_genl_family,
394 0, BRC_GENL_C_QUERY_MC);
399 NLA_PUT_U32(ans_skb, BRC_GENL_A_MC_GROUP, brc_mc_group.id);
401 genlmsg_end(ans_skb, data);
402 return genlmsg_reply(ans_skb, info);
410 /* Attribute policy: what each attribute may contain. */
411 static struct nla_policy brc_genl_policy[BRC_GENL_A_MAX + 1] = {
412 [BRC_GENL_A_ERR_CODE] = { .type = NLA_U32 },
413 [BRC_GENL_A_FDB_DATA] = { .type = NLA_UNSPEC },
416 static int brc_genl_dp_result(struct sk_buff *skb, struct genl_info *info)
418 unsigned long int flags;
421 if (!info->attrs[BRC_GENL_A_ERR_CODE])
424 skb = skb_clone(skb, GFP_KERNEL);
428 spin_lock_irqsave(&brc_lock, flags);
429 if (brc_seq == info->snd_seq) {
432 kfree_skb(brc_reply);
441 spin_unlock_irqrestore(&brc_lock, flags);
446 static struct genl_ops brc_genl_ops[] = {
447 { .cmd = BRC_GENL_C_QUERY_MC,
448 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privelege. */
450 .doit = brc_genl_query,
452 { .cmd = BRC_GENL_C_DP_RESULT,
453 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privelege. */
454 .policy = brc_genl_policy,
455 .doit = brc_genl_dp_result,
459 static struct sk_buff *brc_send_command(struct sk_buff *request,
460 struct nlattr **attrs)
462 unsigned long int flags;
463 struct sk_buff *reply;
466 mutex_lock(&brc_serial);
468 /* Increment sequence number first, so that we ignore any replies
469 * to stale requests. */
470 spin_lock_irqsave(&brc_lock, flags);
471 nlmsg_hdr(request)->nlmsg_seq = ++brc_seq;
472 INIT_COMPLETION(brc_done);
473 spin_unlock_irqrestore(&brc_lock, flags);
475 nlmsg_end(request, nlmsg_hdr(request));
478 error = genlmsg_multicast(request, 0, brc_mc_group.id, GFP_KERNEL);
482 /* Wait for reply. */
484 if (!wait_for_completion_timeout(&brc_done, BRC_TIMEOUT)) {
485 pr_warn("timed out waiting for userspace\n");
490 spin_lock_irqsave(&brc_lock, flags);
493 spin_unlock_irqrestore(&brc_lock, flags);
495 mutex_unlock(&brc_serial);
497 /* Re-parse message. Can't fail, since it parsed correctly once
499 error = nlmsg_parse(nlmsg_hdr(reply), GENL_HDRLEN,
500 attrs, BRC_GENL_A_MAX, brc_genl_policy);
506 mutex_unlock(&brc_serial);
507 return ERR_PTR(error);
510 static int __init brc_init(void)
514 pr_info("Open vSwitch Bridge Compatibility, built "__DATE__" "__TIME__"\n");
516 /* Set the bridge ioctl handler */
517 brioctl_set(brc_ioctl_deviceless_stub);
519 /* Set the openvswitch_mod device ioctl handler */
520 ovs_dp_ioctl_hook = brc_dev_ioctl;
522 /* Randomize the initial sequence number. This is not a security
523 * feature; it only helps avoid crossed wires between userspace and
524 * the kernel when the module is unloaded and reloaded. */
525 brc_seq = net_random();
527 /* Register generic netlink family to communicate changes to
529 err = genl_register_family_with_ops(&brc_genl_family,
530 brc_genl_ops, ARRAY_SIZE(brc_genl_ops));
534 strcpy(brc_mc_group.name, "brcompat");
535 err = genl_register_mc_group(&brc_genl_family, &brc_mc_group);
542 genl_unregister_family(&brc_genl_family);
544 pr_emerg("failed to install!\n");
548 static void brc_cleanup(void)
550 /* Unregister ioctl hooks */
551 ovs_dp_ioctl_hook = NULL;
554 genl_unregister_family(&brc_genl_family);
557 module_init(brc_init);
558 module_exit(brc_cleanup);
560 MODULE_DESCRIPTION("Open vSwitch bridge compatibility");
561 MODULE_AUTHOR("Nicira Networks");
562 MODULE_LICENSE("GPL");
564 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
566 * In kernels 2.6.36 and later, Open vSwitch can safely coexist with
567 * the Linux bridge module, but it does not make sense to load both bridge and
568 * brcompat_mod, so this prevents it.
570 BRIDGE_MUTUAL_EXCLUSION;