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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Vxlan multicast group handling4 *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 on15 * multicast address is brought up16 */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, &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#endif46 }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, &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#endif80 }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(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 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 &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 */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#endif135 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 has140 * 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#endif150 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#endif163 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 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(&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 }199out: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 216static 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 236int 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 255int 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}273