summaryrefslogtreecommitdiff
path: root/net/bridge/br_mdb.c
blob: a8cfbf5f3c6857656ad8f3c3467918117ba28074 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
#include <linux/err.h>
#include <linux/igmp.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <net/ip.h>
#include <net/netlink.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#endif

#include "br_private.h"

static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
			       struct net_device *dev)
{
	struct net_bridge *br = netdev_priv(dev);
	struct net_bridge_port *p;
	struct hlist_node *n;
	struct nlattr *nest;

	if (!br->multicast_router || hlist_empty(&br->router_list))
		return 0;

	nest = nla_nest_start(skb, MDBA_ROUTER);
	if (nest == NULL)
		return -EMSGSIZE;

	hlist_for_each_entry_rcu(p, n, &br->router_list, rlist) {
		if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
			goto fail;
	}

	nla_nest_end(skb, nest);
	return 0;
fail:
	nla_nest_cancel(skb, nest);
	return -EMSGSIZE;
}

static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
			    struct net_device *dev)
{
	struct net_bridge *br = netdev_priv(dev);
	struct net_bridge_mdb_htable *mdb;
	struct nlattr *nest, *nest2;
	int i, err = 0;
	int idx = 0, s_idx = cb->args[1];

	if (br->multicast_disabled)
		return 0;

	mdb = rcu_dereference(br->mdb);
	if (!mdb)
		return 0;

	nest = nla_nest_start(skb, MDBA_MDB);
	if (nest == NULL)
		return -EMSGSIZE;

	for (i = 0; i < mdb->max; i++) {
		struct hlist_node *h;
		struct net_bridge_mdb_entry *mp;
		struct net_bridge_port_group *p, **pp;
		struct net_bridge_port *port;

		hlist_for_each_entry_rcu(mp, h, &mdb->mhash[i], hlist[mdb->ver]) {
			if (idx < s_idx)
				goto skip;

			nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
			if (nest2 == NULL) {
				err = -EMSGSIZE;
				goto out;
			}

			for (pp = &mp->ports;
			     (p = rcu_dereference(*pp)) != NULL;
			      pp = &p->next) {
				port = p->port;
				if (port) {
					struct br_mdb_entry e;
					e.ifindex = port->dev->ifindex;
					e.addr.u.ip4 = p->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
					e.addr.u.ip6 = p->addr.u.ip6;
#endif
					e.addr.proto = p->addr.proto;
					if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
						nla_nest_cancel(skb, nest2);
						err = -EMSGSIZE;
						goto out;
					}
				}
			}
			nla_nest_end(skb, nest2);
		skip:
			idx++;
		}
	}

out:
	cb->args[1] = idx;
	nla_nest_end(skb, nest);
	return err;
}

static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net_device *dev;
	struct net *net = sock_net(skb->sk);
	struct nlmsghdr *nlh = NULL;
	int idx = 0, s_idx;

	s_idx = cb->args[0];

	rcu_read_lock();

	/* In theory this could be wrapped to 0... */
	cb->seq = net->dev_base_seq + br_mdb_rehash_seq;

	for_each_netdev_rcu(net, dev) {
		if (dev->priv_flags & IFF_EBRIDGE) {
			struct br_port_msg *bpm;

			if (idx < s_idx)
				goto skip;

			nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
					cb->nlh->nlmsg_seq, RTM_GETMDB,
					sizeof(*bpm), NLM_F_MULTI);
			if (nlh == NULL)
				break;

			bpm = nlmsg_data(nlh);
			bpm->ifindex = dev->ifindex;
			if (br_mdb_fill_info(skb, cb, dev) < 0)
				goto out;
			if (br_rports_fill_info(skb, cb, dev) < 0)
				goto out;

			cb->args[1] = 0;
			nlmsg_end(skb, nlh);
		skip:
			idx++;
		}
	}

out:
	if (nlh)
		nlmsg_end(skb, nlh);
	rcu_read_unlock();
	cb->args[0] = idx;
	return skb->len;
}

static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
				   struct net_device *dev,
				   struct br_mdb_entry *entry, u32 pid,
				   u32 seq, int type, unsigned int flags)
{
	struct nlmsghdr *nlh;
	struct br_port_msg *bpm;
	struct nlattr *nest, *nest2;

	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
	if (!nlh)
		return -EMSGSIZE;

	bpm = nlmsg_data(nlh);
	bpm->family  = AF_BRIDGE;
	bpm->ifindex = dev->ifindex;
	nest = nla_nest_start(skb, MDBA_MDB);
	if (nest == NULL)
		goto cancel;
	nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
	if (nest2 == NULL)
		goto end;

	if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
		goto end;

	nla_nest_end(skb, nest2);
	nla_nest_end(skb, nest);
	return nlmsg_end(skb, nlh);

end:
	nla_nest_end(skb, nest);
cancel:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static inline size_t rtnl_mdb_nlmsg_size(void)
{
	return NLMSG_ALIGN(sizeof(struct br_port_msg))
		+ nla_total_size(sizeof(struct br_mdb_entry));
}

static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
			    int type)
{
	struct net *net = dev_net(dev);
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
	if (!skb)
		goto errout;

	err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
	if (err < 0) {
		kfree_skb(skb);
		goto errout;
	}

	rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
	return;
errout:
	rtnl_set_sk_err(net, RTNLGRP_MDB, err);
}

void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
		   struct br_ip *group, int type)
{
	struct br_mdb_entry entry;

	entry.ifindex = port->dev->ifindex;
	entry.addr.proto = group->proto;
	entry.addr.u.ip4 = group->u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
	entry.addr.u.ip6 = group->u.ip6;
#endif
	__br_mdb_notify(dev, &entry, type);
}

void br_mdb_init(void)
{
	rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
}