drivers/net/vxlan/vxlan_multicast.c

   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  */
  17 int 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, &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
  51 int 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, &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
  85 static bool vxlan_group_used_match(union vxlan_addr *ip, int ifindex,
  86                                    union vxlan_addr *rip, int rifindex)
  87 {
  88         if (!vxlan_addr_multicast(rip))
  89                 return false;
  90
  91         if (!vxlan_addr_equal(rip, ip))
  92                 return false;
  93
  94         if (rifindex != ifindex)
  95                 return false;
  96
  97         return true;
  98 }
  99
 100 static 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                                    &vxlan->default_dst.remote_ip,
 108                                    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(&v->remote_ip))
 113                         continue;
 114
 115                 if (vxlan_group_used_match(ip, ifindex,
 116                                            &v->remote_ip,
 117                                            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 */
 125 bool 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(&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(&sock6->refcnt) == 1)
 148                 return false;
 149 #endif
 150
 151         list_for_each_entry(vxlan, &vn->vxlan_list, next) {
 152                 if (!netif_running(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                                                     &vxlan->default_dst.remote_ip,
 169                                                     vxlan->default_dst.remote_ifindex))
 170                                 continue;
 171                 }
 172
 173                 return true;
 174         }
 175
 176         return false;
 177 }
 178
 179 static 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(&v->remote_ip))
 187                         continue;
 188                 /* skip if address is same as default address */
 189                 if (vxlan_addr_equal(&v->remote_ip,
 190                                      &vxlan->default_dst.remote_ip))
 191                         continue;
 192                 ret = vxlan_igmp_join(vxlan, &v->remote_ip, 0);
 193                 if (ret == -EADDRINUSE)
 194                         ret = 0;
 195                 if (ret)
 196                         goto out;
 197                 vgood = v;
 198         }
 199 out:
 200         if (ret) {
 201                 list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
 202                         if (!vxlan_addr_multicast(&v->remote_ip))
 203                                 continue;
 204                         if (vxlan_addr_equal(&v->remote_ip,
 205                                              &vxlan->default_dst.remote_ip))
 206                                 continue;
 207                         vxlan_igmp_leave(vxlan, &v->remote_ip, 0);
 208                         if (v == vgood)
 209                                 break;
 210                 }
 211         }
 212
 213         return ret;
 214 }
 215
 216 static int vxlan_multicast_leave_vnigrp(struct vxlan_dev *vxlan)
 217 {
 218         struct vxlan_net *vn = net_generic(vxlan->net, 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(&v->remote_ip) &&
 225                     !vxlan_group_used(vn, vxlan, v->vni, &v->remote_ip,
 226                                       0)) {
 227                         ret = vxlan_igmp_leave(vxlan, &v->remote_ip, 0);
 228                         if (ret)
 229                                 last_err = ret;
 230                 }
 231         }
 232
 233         return last_err;
 234 }
 235
 236 int vxlan_multicast_join(struct vxlan_dev *vxlan)
 237 {
 238         int ret = 0;
 239
 240         if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
 241                 ret = vxlan_igmp_join(vxlan, &vxlan->default_dst.remote_ip,
 242                                       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
 255 int vxlan_multicast_leave(struct vxlan_dev *vxlan)
 256 {
 257         struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 258         int ret = 0;
 259
 260         if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
 261             !vxlan_group_used(vn, vxlan, 0, NULL, 0)) {
 262                 ret = vxlan_igmp_leave(vxlan, &vxlan->default_dst.remote_ip,
 263                                        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 }