multicast: Extend ip address command to enable multicast group join/leave on
Joining multicast group on ethernet level via "ip maddr" command would
not work if we have an Ethernet switch that does igmp snooping since
the switch would not replicate multicast packets on ports that did not
have IGMP reports for the multicast addresses.
Linux vxlan interfaces created via "ip link add vxlan" have the group option
that enables then to do the required join.
By extending ip address command with option "autojoin" we can get similar
functionality for openvswitch vxlan interfaces as well as other tunneling
mechanisms that need to receive multicast traffic. The kernel code is
structured similar to how the vxlan driver does a group join / leave.
example:
ip address add 224.1.1.10/24 dev eth5 autojoin
ip address del 224.1.1.10/24 dev eth5
Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index dbe2254..1b26c6c 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -49,6 +49,7 @@
struct sock *fibnl;
struct sock * __percpu *icmp_sk;
+ struct sock *mc_autojoin_sk;
struct inet_peer_base *peers;
struct tcpm_hash_bucket *tcp_metrics_hash;
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 69ae41f..ca0db12 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -67,6 +67,7 @@
struct sock *ndisc_sk;
struct sock *tcp_sk;
struct sock *igmp_sk;
+ struct sock *mc_autojoin_sk;
#ifdef CONFIG_IPV6_MROUTE
#ifndef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
struct mr6_table *mrt6;
diff --git a/include/uapi/linux/if_addr.h b/include/uapi/linux/if_addr.h
index dea10a8..40fdfea 100644
--- a/include/uapi/linux/if_addr.h
+++ b/include/uapi/linux/if_addr.h
@@ -50,6 +50,7 @@
#define IFA_F_PERMANENT 0x80
#define IFA_F_MANAGETEMPADDR 0x100
#define IFA_F_NOPREFIXROUTE 0x200
+#define IFA_F_MCAUTOJOIN 0x400
struct ifa_cacheinfo {
__u32 ifa_prefered;
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 3a8985c..5105759 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -548,6 +548,26 @@
return NULL;
}
+static int ip_mc_config(struct sock *sk, bool join, const struct in_ifaddr *ifa)
+{
+ struct ip_mreqn mreq = {
+ .imr_multiaddr.s_addr = ifa->ifa_address,
+ .imr_ifindex = ifa->ifa_dev->dev->ifindex,
+ };
+ int ret;
+
+ ASSERT_RTNL();
+
+ lock_sock(sk);
+ if (join)
+ ret = __ip_mc_join_group(sk, &mreq);
+ else
+ ret = __ip_mc_leave_group(sk, &mreq);
+ release_sock(sk);
+
+ return ret;
+}
+
static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
@@ -584,6 +604,8 @@
!inet_ifa_match(nla_get_be32(tb[IFA_ADDRESS]), ifa)))
continue;
+ if (ipv4_is_multicast(ifa->ifa_address))
+ ip_mc_config(net->ipv4.mc_autojoin_sk, false, ifa);
__inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).portid);
return 0;
}
@@ -838,6 +860,15 @@
* userspace already relies on not having to provide this.
*/
set_ifa_lifetime(ifa, valid_lft, prefered_lft);
+ if (ifa->ifa_flags & IFA_F_MCAUTOJOIN) {
+ int ret = ip_mc_config(net->ipv4.mc_autojoin_sk,
+ true, ifa);
+
+ if (ret < 0) {
+ inet_free_ifa(ifa);
+ return ret;
+ }
+ }
return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).portid);
} else {
inet_free_ifa(ifa);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 4b1172d..5cb1ef4 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -97,6 +97,7 @@
#include <net/route.h>
#include <net/sock.h>
#include <net/checksum.h>
+#include <net/inet_common.h>
#include <linux/netfilter_ipv4.h>
#ifdef CONFIG_IP_MROUTE
#include <linux/mroute.h>
@@ -2740,6 +2741,7 @@
static int __net_init igmp_net_init(struct net *net)
{
struct proc_dir_entry *pde;
+ int err;
pde = proc_create("igmp", S_IRUGO, net->proc_net, &igmp_mc_seq_fops);
if (!pde)
@@ -2748,8 +2750,18 @@
&igmp_mcf_seq_fops);
if (!pde)
goto out_mcfilter;
+ err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
+ SOCK_DGRAM, 0, net);
+ if (err < 0) {
+ pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
+ err);
+ goto out_sock;
+ }
+
return 0;
+out_sock:
+ remove_proc_entry("mcfilter", net->proc_net);
out_mcfilter:
remove_proc_entry("igmp", net->proc_net);
out_igmp:
@@ -2760,6 +2772,7 @@
{
remove_proc_entry("mcfilter", net->proc_net);
remove_proc_entry("igmp", net->proc_net);
+ inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
}
static struct pernet_operations igmp_net_ops = {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 98e4a63..783bccfc 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2464,6 +2464,23 @@
return err;
}
+static int ipv6_mc_config(struct sock *sk, bool join,
+ const struct in6_addr *addr, int ifindex)
+{
+ int ret;
+
+ ASSERT_RTNL();
+
+ lock_sock(sk);
+ if (join)
+ ret = __ipv6_sock_mc_join(sk, ifindex, addr);
+ else
+ ret = __ipv6_sock_mc_drop(sk, ifindex, addr);
+ release_sock(sk);
+
+ return ret;
+}
+
/*
* Manual configuration of address on an interface
*/
@@ -2476,10 +2493,10 @@
struct inet6_ifaddr *ifp;
struct inet6_dev *idev;
struct net_device *dev;
+ unsigned long timeout;
+ clock_t expires;
int scope;
u32 flags;
- clock_t expires;
- unsigned long timeout;
ASSERT_RTNL();
@@ -2501,6 +2518,14 @@
if (IS_ERR(idev))
return PTR_ERR(idev);
+ if (ifa_flags & IFA_F_MCAUTOJOIN) {
+ int ret = ipv6_mc_config(net->ipv6.mc_autojoin_sk,
+ true, pfx, ifindex);
+
+ if (ret < 0)
+ return ret;
+ }
+
scope = ipv6_addr_scope(pfx);
timeout = addrconf_timeout_fixup(valid_lft, HZ);
@@ -2542,6 +2567,9 @@
in6_ifa_put(ifp);
addrconf_verify_rtnl();
return 0;
+ } else if (ifa_flags & IFA_F_MCAUTOJOIN) {
+ ipv6_mc_config(net->ipv6.mc_autojoin_sk,
+ false, pfx, ifindex);
}
return PTR_ERR(ifp);
@@ -2578,6 +2606,10 @@
jiffies);
ipv6_del_addr(ifp);
addrconf_verify_rtnl();
+ if (ipv6_addr_is_multicast(pfx)) {
+ ipv6_mc_config(net->ipv6.mc_autojoin_sk,
+ false, pfx, dev->ifindex);
+ }
return 0;
}
}
@@ -3945,7 +3977,7 @@
/* We ignore other flags so far. */
ifa_flags &= IFA_F_NODAD | IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
- IFA_F_NOPREFIXROUTE;
+ IFA_F_NOPREFIXROUTE | IFA_F_MCAUTOJOIN;
ifa = ipv6_get_ifaddr(net, pfx, dev, 1);
if (ifa == NULL) {
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index e4955d0..1dd1fed 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -2929,20 +2929,32 @@
inet6_sk(net->ipv6.igmp_sk)->hop_limit = 1;
+ err = inet_ctl_sock_create(&net->ipv6.mc_autojoin_sk, PF_INET6,
+ SOCK_RAW, IPPROTO_ICMPV6, net);
+ if (err < 0) {
+ pr_err("Failed to initialize the IGMP6 autojoin socket (err %d)\n",
+ err);
+ goto out_sock_create;
+ }
+
err = igmp6_proc_init(net);
if (err)
- goto out_sock_create;
-out:
- return err;
+ goto out_sock_create_autojoin;
+ return 0;
+
+out_sock_create_autojoin:
+ inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
out_sock_create:
inet_ctl_sock_destroy(net->ipv6.igmp_sk);
- goto out;
+out:
+ return err;
}
static void __net_exit igmp6_net_exit(struct net *net)
{
inet_ctl_sock_destroy(net->ipv6.igmp_sk);
+ inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
igmp6_proc_exit(net);
}
