1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Vxlan multicast group handling
4 *
5 */
6#include <linux/kernel.h>
7#include <net/net_namespace.h>
8#include <net/sock.h>
9#include <linux/igmp.h>
10#include <net/vxlan.h>
11
12#include "vxlan_private.h"
13
14/* Update multicast group membership when first VNI on
15 * multicast address is brought up
16 */
17int vxlan_igmp_join(struct vxlan_dev *vxlan, union vxlan_addr *rip,
18 int rifindex)
19{
20 union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
21 int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
22 int ret = -EINVAL;
23 struct sock *sk;
24
25 if (ip->sa.sa_family == AF_INET) {
26 struct vxlan_sock *sock4 = rtnl_dereference(vxlan->vn4_sock);
27 struct ip_mreqn mreq = {
28 .imr_multiaddr.s_addr = ip->sin.sin_addr.s_addr,
29 .imr_ifindex = ifindex,
30 };
31
32 sk = sock4->sock->sk;
33 lock_sock(sk);
34 ret = ip_mc_join_group(sk, imr: &mreq);
35 release_sock(sk);
36#if IS_ENABLED(CONFIG_IPV6)
37 } else {
38 struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
39
40 sk = sock6->sock->sk;
41 lock_sock(sk);
42 ret = ipv6_stub->ipv6_sock_mc_join(sk, ifindex,
43 &ip->sin6.sin6_addr);
44 release_sock(sk);
45#endif
46 }
47
48 return ret;
49}
50
51int vxlan_igmp_leave(struct vxlan_dev *vxlan, union vxlan_addr *rip,
52 int rifindex)
53{
54 union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
55 int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
56 int ret = -EINVAL;
57 struct sock *sk;
58
59 if (ip->sa.sa_family == AF_INET) {
60 struct vxlan_sock *sock4 = rtnl_dereference(vxlan->vn4_sock);
61 struct ip_mreqn mreq = {
62 .imr_multiaddr.s_addr = ip->sin.sin_addr.s_addr,
63 .imr_ifindex = ifindex,
64 };
65
66 sk = sock4->sock->sk;
67 lock_sock(sk);
68 ret = ip_mc_leave_group(sk, imr: &mreq);
69 release_sock(sk);
70#if IS_ENABLED(CONFIG_IPV6)
71 } else {
72 struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
73
74 sk = sock6->sock->sk;
75 lock_sock(sk);
76 ret = ipv6_stub->ipv6_sock_mc_drop(sk, ifindex,
77 &ip->sin6.sin6_addr);
78 release_sock(sk);
79#endif
80 }
81
82 return ret;
83}
84
85static bool vxlan_group_used_match(union vxlan_addr *ip, int ifindex,
86 union vxlan_addr *rip, int rifindex)
87{
88 if (!vxlan_addr_multicast(ipa: rip))
89 return false;
90
91 if (!vxlan_addr_equal(a: rip, b: ip))
92 return false;
93
94 if (rifindex != ifindex)
95 return false;
96
97 return true;
98}
99
100static bool vxlan_group_used_by_vnifilter(struct vxlan_dev *vxlan,
101 union vxlan_addr *ip, int ifindex)
102{
103 struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
104 struct vxlan_vni_node *v, *tmp;
105
106 if (vxlan_group_used_match(ip, ifindex,
107 rip: &vxlan->default_dst.remote_ip,
108 rifindex: vxlan->default_dst.remote_ifindex))
109 return true;
110
111 list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
112 if (!vxlan_addr_multicast(ipa: &v->remote_ip))
113 continue;
114
115 if (vxlan_group_used_match(ip, ifindex,
116 rip: &v->remote_ip,
117 rifindex: vxlan->default_dst.remote_ifindex))
118 return true;
119 }
120
121 return false;
122}
123
124/* See if multicast group is already in use by other ID */
125bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
126 __be32 vni, union vxlan_addr *rip, int rifindex)
127{
128 union vxlan_addr *ip = (rip ? : &dev->default_dst.remote_ip);
129 int ifindex = (rifindex ? : dev->default_dst.remote_ifindex);
130 struct vxlan_dev *vxlan;
131 struct vxlan_sock *sock4;
132#if IS_ENABLED(CONFIG_IPV6)
133 struct vxlan_sock *sock6;
134#endif
135 unsigned short family = dev->default_dst.remote_ip.sa.sa_family;
136
137 sock4 = rtnl_dereference(dev->vn4_sock);
138
139 /* The vxlan_sock is only used by dev, leaving group has
140 * no effect on other vxlan devices.
141 */
142 if (family == AF_INET && sock4 && refcount_read(r: &sock4->refcnt) == 1)
143 return false;
144
145#if IS_ENABLED(CONFIG_IPV6)
146 sock6 = rtnl_dereference(dev->vn6_sock);
147 if (family == AF_INET6 && sock6 && refcount_read(r: &sock6->refcnt) == 1)
148 return false;
149#endif
150
151 list_for_each_entry(vxlan, &vn->vxlan_list, next) {
152 if (!netif_running(dev: vxlan->dev) || vxlan == dev)
153 continue;
154
155 if (family == AF_INET &&
156 rtnl_dereference(vxlan->vn4_sock) != sock4)
157 continue;
158#if IS_ENABLED(CONFIG_IPV6)
159 if (family == AF_INET6 &&
160 rtnl_dereference(vxlan->vn6_sock) != sock6)
161 continue;
162#endif
163 if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
164 if (!vxlan_group_used_by_vnifilter(vxlan, ip, ifindex))
165 continue;
166 } else {
167 if (!vxlan_group_used_match(ip, ifindex,
168 rip: &vxlan->default_dst.remote_ip,
169 rifindex: vxlan->default_dst.remote_ifindex))
170 continue;
171 }
172
173 return true;
174 }
175
176 return false;
177}
178
179static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan)
180{
181 struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
182 struct vxlan_vni_node *v, *tmp, *vgood = NULL;
183 int ret = 0;
184
185 list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
186 if (!vxlan_addr_multicast(ipa: &v->remote_ip))
187 continue;
188 /* skip if address is same as default address */
189 if (vxlan_addr_equal(a: &v->remote_ip,
190 b: &vxlan->default_dst.remote_ip))
191 continue;
192 ret = vxlan_igmp_join(vxlan, rip: &v->remote_ip, rifindex: 0);
193 if (ret == -EADDRINUSE)
194 ret = 0;
195 if (ret)
196 goto out;
197 vgood = v;
198 }
199out:
200 if (ret) {
201 list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
202 if (!vxlan_addr_multicast(ipa: &v->remote_ip))
203 continue;
204 if (vxlan_addr_equal(a: &v->remote_ip,
205 b: &vxlan->default_dst.remote_ip))
206 continue;
207 vxlan_igmp_leave(vxlan, rip: &v->remote_ip, rifindex: 0);
208 if (v == vgood)
209 break;
210 }
211 }
212
213 return ret;
214}
215
216static int vxlan_multicast_leave_vnigrp(struct vxlan_dev *vxlan)
217{
218 struct vxlan_net *vn = net_generic(net: vxlan->net, id: vxlan_net_id);
219 struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
220 struct vxlan_vni_node *v, *tmp;
221 int last_err = 0, ret;
222
223 list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
224 if (vxlan_addr_multicast(ipa: &v->remote_ip) &&
225 !vxlan_group_used(vn, dev: vxlan, vni: v->vni, rip: &v->remote_ip,
226 rifindex: 0)) {
227 ret = vxlan_igmp_leave(vxlan, rip: &v->remote_ip, rifindex: 0);
228 if (ret)
229 last_err = ret;
230 }
231 }
232
233 return last_err;
234}
235
236int vxlan_multicast_join(struct vxlan_dev *vxlan)
237{
238 int ret = 0;
239
240 if (vxlan_addr_multicast(ipa: &vxlan->default_dst.remote_ip)) {
241 ret = vxlan_igmp_join(vxlan, rip: &vxlan->default_dst.remote_ip,
242 rifindex: vxlan->default_dst.remote_ifindex);
243 if (ret == -EADDRINUSE)
244 ret = 0;
245 if (ret)
246 return ret;
247 }
248
249 if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
250 return vxlan_multicast_join_vnigrp(vxlan);
251
252 return 0;
253}
254
255int vxlan_multicast_leave(struct vxlan_dev *vxlan)
256{
257 struct vxlan_net *vn = net_generic(net: vxlan->net, id: vxlan_net_id);
258 int ret = 0;
259
260 if (vxlan_addr_multicast(ipa: &vxlan->default_dst.remote_ip) &&
261 !vxlan_group_used(vn, dev: vxlan, vni: 0, NULL, rifindex: 0)) {
262 ret = vxlan_igmp_leave(vxlan, rip: &vxlan->default_dst.remote_ip,
263 rifindex: vxlan->default_dst.remote_ifindex);
264 if (ret)
265 return ret;
266 }
267
268 if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
269 return vxlan_multicast_leave_vnigrp(vxlan);
270
271 return 0;
272}
273

source code of linux/drivers/net/vxlan/vxlan_multicast.c