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authorRobert Love <rlove@google.com>2008-05-12 17:08:29 -0400
committerDima Zavin <dima@android.com>2011-02-02 11:18:43 -0800
commit0a0977f0edd13a3be7b56b812144e066be01bae9 (patch)
tree5f00d680a2e585ac5af07647706e94c716fd5ea3 /net/ipv4/tcp_ipv4.c
parent7bc22b2fd1472da6ec0b1eeddf8d1ed35777170c (diff)
net: socket ioctl to reset connections matching local address
Introduce a new socket ioctl, SIOCKILLADDR, that nukes all sockets bound to the same local address. This is useful in situations with dynamic IPs, to kill stuck connections. Signed-off-by: Brian Swetland <swetland@google.com> net: fix tcp_v4_nuke_addr Signed-off-by: Dima Zavin <dima@android.com> net: ipv4: Fix a spinlock recursion bug in tcp_v4_nuke. We can't hold the lock while calling to tcp_done(), so we drop it before calling. We then have to start at the top of the chain again. Signed-off-by: Dima Zavin <dima@android.com> net: ipv4: Fix race in tcp_v4_nuke_addr(). To fix a recursive deadlock in 2.6.29, we stopped holding the hash table lock across tcp_done() calls. This fixed the deadlock, but introduced a race where the socket could die or change state. Fix: Before unlocking the hash table, we grab a reference to the socket. We can then unlock the hash table without risk of the socket going away. We then lock the socket, which is safe because it is pinned. We can then call tcp_done() without recursive deadlock and without race. Upon return, we unlock the socket and then unpin it, killing it. Change-Id: Idcdae072b48238b01bdbc8823b60310f1976e045 Signed-off-by: Robert Love <rlove@google.com> Acked-by: Dima Zavin <dima@android.com> ipv4: disable bottom halves around call to tcp_done(). Signed-off-by: Robert Love <rlove@google.com> Signed-off-by: Colin Cross <ccross@android.com> ipv4: Move sk_error_report inside bh_lock_sock in tcp_v4_nuke_addr When sk_error_report is called, it wakes up the user-space thread, which then calls tcp_close. When the tcp_close is interrupted by the tcp_v4_nuke_addr ioctl thread running tcp_done, it leaks 392 bytes and triggers a WARN_ON. This patch moves the call to sk_error_report inside the bh_lock_sock, which matches the locking used in tcp_v4_err. Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 02f583b3744..e15498eaff8 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1941,6 +1941,49 @@ 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. */