net: Support nuking IPv6 sockets as well as IPv4.

On Linux, when an interface goes down all its IPv6
addresses are deleted, so relying on knowing the previous
IPv6 addresses on the interface is brittle. Instead,
support nuking all sockets that are bound to IP addresses
that are not configured and up on the system. This
behaviour is triggered by specifying the unspecified
address (:: or 0.0.0.0). If an IP address is specified, the
behaviour is unchanged, except the ioctl now supports IPv6
as well as IPv4.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 22c912c5dde69545d5bb266206129f0f7bea69ec..0b612e7dba28c39e17fb26cd3fda76186ad640ff 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1403,7 +1403,7 @@ extern struct sk_buff **tcp4_gro_receive(struct sk_buff **head,
 extern int tcp_gro_complete(struct sk_buff *skb);
 extern int tcp4_gro_complete(struct sk_buff *skb);
 
-extern void tcp_v4_nuke_addr(__u32 saddr);
+extern int tcp_nuke_addr(struct net *net, struct sockaddr *addr);
 
 #ifdef CONFIG_PROC_FS
 extern int tcp4_proc_init(void);

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 8b7dfaf3b6ea607f32db6bc1e10e24d479ffeaee..ac582d17bf409e739644488d655b76fb5d176177 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -815,8 +815,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
                }
                break;
        case SIOCKILLADDR:      /* Nuke all connections on this address */
-               ret = 0;
-               tcp_v4_nuke_addr(sin->sin_addr.s_addr);
+               ret = tcp_nuke_addr(net, (struct sockaddr *) sin);
                break;
        }
 done:

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 501921e7506a2c5f987194d46c702fef405078f9..dc56a7615783b7e84c4f08e173c7f5a6a194d3c4 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -272,6 +272,7 @@
 #include <net/tcp.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
+#include <net/ip6_route.h>
 #include <net/netdma.h>
 #include <net/sock.h>
 
@@ -3320,3 +3321,99 @@ void __init tcp_init(void)
        tcp_secret_retiring = &tcp_secret_two;
        tcp_secret_secondary = &tcp_secret_two;
 }
+
+static int tcp_is_local(struct net *net, __be32 addr) {
+       struct rtable *rt;
+       struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
+       if (ip_route_output_key(net, &rt, &fl) || !rt)
+               return 0;
+       return rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK);
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int tcp_is_local6(struct net *net, struct in6_addr *addr) {
+       struct rt6_info *rt6 = rt6_lookup(net, addr, addr, 0, 0);
+       return rt6 && rt6->rt6i_dev && (rt6->rt6i_dev->flags & IFF_LOOPBACK);
+}
+#endif
+
+/*
+ * tcp_nuke_addr - destroy all sockets on the given local address
+ * if local address is the unspecified address (0.0.0.0 or ::), destroy all
+ * sockets with local addresses that are not configured.
+ */
+int tcp_nuke_addr(struct net *net, struct sockaddr *addr)
+{
+       int family = addr->sa_family;
+       unsigned int bucket;
+
+       struct in_addr *in;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       struct in6_addr *in6;
+#endif
+       if (family == AF_INET) {
+               in = &((struct sockaddr_in *)addr)->sin_addr;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       } else if (family == AF_INET6) {
+               in6 = &((struct sockaddr_in6 *)addr)->sin6_addr;
+#endif
+       } else {
+               return -EAFNOSUPPORT;
+       }
+
+       for (bucket = 0; bucket < tcp_hashinfo.ehash_mask; bucket++) {
+               struct hlist_nulls_node *node;
+               struct sock *sk;
+               spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, bucket);
+
+restart:
+               spin_lock_bh(lock);
+               sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[bucket].chain) {
+                       struct inet_sock *inet = inet_sk(sk);
+
+                       if (family == AF_INET) {
+                               __be32 s4 = inet->inet_rcv_saddr;
+                               if (in->s_addr != s4 &&
+                                   !(in->s_addr == INADDR_ANY &&
+                                     !tcp_is_local(net, s4)))
+                                       continue;
+                       }
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+                       if (family == AF_INET6) {
+                               struct in6_addr *s6;
+                               if (!inet->pinet6)
+                                       continue;
+                               s6 = &inet->pinet6->rcv_saddr;
+                               if (!ipv6_addr_equal(in6, s6) &&
+                                   !(ipv6_addr_equal(in6, &in6addr_any) &&
+                                     !tcp_is_local6(net, s6)))
+                               continue;
+                       }
+#endif
+
+                       if (sysctl_ip_dynaddr && sk->sk_state == TCP_SYN_SENT)
+                               continue;
+                       if (sock_flag(sk, SOCK_DEAD))
+                               continue;
+
+                       sock_hold(sk);
+                       spin_unlock_bh(lock);
+
+                       local_bh_disable();
+                       bh_lock_sock(sk);
+                       sk->sk_err = ETIMEDOUT;
+                       sk->sk_error_report(sk);
+
+                       tcp_done(sk);
+                       bh_unlock_sock(sk);
+                       local_bh_enable();
+                       sock_put(sk);
+
+                       goto restart;
+               }
+               spin_unlock_bh(lock);
+       }
+
+       return 0;
+}

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c3306fe20f8f609d6c796c1007892eff5a45eca2..020766292bb01009201ec11e60bb0e214854414c 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1969,49 +1969,6 @@ void tcp_v4_destroy_sock(struct sock *sk)
 }
 EXPORT_SYMBOL(tcp_v4_destroy_sock);
 
-/*
- * tcp_v4_nuke_addr - destroy all sockets on the given local address
- */
-void tcp_v4_nuke_addr(__u32 saddr)
-{
-       unsigned int bucket;
-
-       for (bucket = 0; bucket < tcp_hashinfo.ehash_mask; bucket++) {
-               struct hlist_nulls_node *node;
-               struct sock *sk;
-               spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, bucket);
-
-restart:
-               spin_lock_bh(lock);
-               sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[bucket].chain) {
-                       struct inet_sock *inet = inet_sk(sk);
-
-                       if (inet->inet_rcv_saddr != saddr)
-                               continue;
-                       if (sysctl_ip_dynaddr && sk->sk_state == TCP_SYN_SENT)
-                               continue;
-                       if (sock_flag(sk, SOCK_DEAD))
-                               continue;
-
-                       sock_hold(sk);
-                       spin_unlock_bh(lock);
-
-                       local_bh_disable();
-                       bh_lock_sock(sk);
-                       sk->sk_err = ETIMEDOUT;
-                       sk->sk_error_report(sk);
-
-                       tcp_done(sk);
-                       bh_unlock_sock(sk);
-                       local_bh_enable();
-                       sock_put(sk);
-
-                       goto restart;
-               }
-               spin_unlock_bh(lock);
-       }
-}
-
 #ifdef CONFIG_PROC_FS
 /* Proc filesystem TCP sock list dumping. */
 

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 2f421a4beca750781c5be967de6a41dd3013ca27..fa743e0d32074b8cb6c029946e36e620c335c339 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -489,6 +489,21 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
 
 EXPORT_SYMBOL(inet6_getname);
 
+int inet6_killaddr_ioctl(struct net *net, void __user *arg) {
+       struct in6_ifreq ireq;
+       struct sockaddr_in6 sin6;
+
+       if (!capable(CAP_NET_ADMIN))
+               return -EACCES;
+
+       if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
+               return -EFAULT;
+
+       sin6.sin6_family = AF_INET6;
+       ipv6_addr_copy(&sin6.sin6_addr, &ireq.ifr6_addr);
+       return tcp_nuke_addr(net, (struct sockaddr *) &sin6);
+}
+
 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
        struct sock *sk = sock->sk;
@@ -513,6 +528,8 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                return addrconf_del_ifaddr(net, (void __user *) arg);
        case SIOCSIFDSTADDR:
                return addrconf_set_dstaddr(net, (void __user *) arg);
+       case SIOCKILLADDR:
+               return inet6_killaddr_ioctl(net, (void __user *) arg);
        default:
                if (!sk->sk_prot->ioctl)
                        return -ENOIOCTLCMD;