[Devel] [PATCH 5/9] network namespaces: async socket operations

[Andrey Savochkin]

Non-trivial part of socket namespaces: asynchronous events
should be run in proper context.

Signed-off-by: Andrey Savochkin <saw at swsoft.com>
---
 af_inet.c            |   10 ++++++++++
 inet_timewait_sock.c |    8 ++++++++
 tcp_timer.c          |    9 +++++++++
 3 files changed, 27 insertions(+)

--- ./net/ipv4/af_inet.c.venssock-asyn	Mon Aug 14 17:04:07 2006
+++ ./net/ipv4/af_inet.c	Tue Aug 15 13:45:44 2006
@@ -366,10 +366,17 @@ out_rcu_unlock:
 int inet_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
+	struct net_namespace *ns, *orig_net_ns;
 
 	if (sk) {
 		long timeout;
 
+		/* Need to change context here since protocol ->close
+		 * operation may send packets.
+		 */
+		ns = get_net_ns(sk->sk_net_ns);
+		push_net_ns(ns, orig_net_ns);
+
 		/* Applications forget to leave groups before exiting */
 		ip_mc_drop_socket(sk);
 
@@ -386,6 +393,9 @@ int inet_release(struct socket *sock)
 			timeout = sk->sk_lingertime;
 		sock->sk = NULL;
 		sk->sk_prot->close(sk, timeout);
+
+		pop_net_ns(orig_net_ns);
+		put_net_ns(ns);
 	}
 	return 0;
 }
--- ./net/ipv4/inet_timewait_sock.c.venssock-asyn	Tue Aug 15 13:45:44 2006
+++ ./net/ipv4/inet_timewait_sock.c	Tue Aug 15 13:45:44 2006
@@ -129,6 +129,7 @@ static int inet_twdr_do_twkill_work(stru
 {
 	struct inet_timewait_sock *tw;
 	struct hlist_node *node;
+	struct net_namespace *orig_net_ns;
 	unsigned int killed;
 	int ret;
 
@@ -140,8 +141,10 @@ static int inet_twdr_do_twkill_work(stru
 	 */
 	killed = 0;
 	ret = 0;
+	push_net_ns(current_net_ns, orig_net_ns);
 rescan:
 	inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) {
+		switch_net_ns(tw->tw_net_ns);
 		__inet_twsk_del_dead_node(tw);
 		spin_unlock(&twdr->death_lock);
 		__inet_twsk_kill(tw, twdr->hashinfo);
@@ -164,6 +167,7 @@ rescan:
 
 	twdr->tw_count -= killed;
 	NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed);
+	pop_net_ns(orig_net_ns);
 
 	return ret;
 }
@@ -338,10 +342,12 @@ void inet_twdr_twcal_tick(unsigned long 
 	int n, slot;
 	unsigned long j;
 	unsigned long now = jiffies;
+	struct net_namespace *orig_net_ns;
 	int killed = 0;
 	int adv = 0;
 
 	twdr = (struct inet_timewait_death_row *)data;
+	push_net_ns(current_net_ns, orig_net_ns);
 
 	spin_lock(&twdr->death_lock);
 	if (twdr->twcal_hand < 0)
@@ -357,6 +363,7 @@ void inet_twdr_twcal_tick(unsigned long 
 
 			inet_twsk_for_each_inmate_safe(tw, node, safe,
 						       &twdr->twcal_row[slot]) {
+				switch_net_ns(tw->tw_net_ns);
 				__inet_twsk_del_dead_node(tw);
 				__inet_twsk_kill(tw, twdr->hashinfo);
 				inet_twsk_put(tw);
@@ -384,6 +391,7 @@ out:
 		del_timer(&twdr->tw_timer);
 	NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed);
 	spin_unlock(&twdr->death_lock);
+	pop_net_ns(orig_net_ns);
 }
 
 EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);
--- ./net/ipv4/tcp_timer.c.venssock-asyn	Mon Aug 14 16:43:51 2006
+++ ./net/ipv4/tcp_timer.c	Tue Aug 15 13:45:44 2006
@@ -171,7 +171,9 @@ static void tcp_delack_timer(unsigned lo
 	struct sock *sk = (struct sock*)data;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct net_namespace *orig_net_ns;
 
+	push_net_ns(sk->sk_net_ns, orig_net_ns);
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
 		/* Try again later. */
@@ -225,6 +227,7 @@ out:
 out_unlock:
 	bh_unlock_sock(sk);
 	sock_put(sk);
+	pop_net_ns(orig_net_ns);
 }
 
 static void tcp_probe_timer(struct sock *sk)
@@ -384,8 +387,10 @@ static void tcp_write_timer(unsigned lon
 {
 	struct sock *sk = (struct sock*)data;
 	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct net_namespace *orig_net_ns;
 	int event;
 
+	push_net_ns(sk->sk_net_ns, orig_net_ns);
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
 		/* Try again later */
@@ -419,6 +424,7 @@ out:
 out_unlock:
 	bh_unlock_sock(sk);
 	sock_put(sk);
+	pop_net_ns(orig_net_ns);
 }
 
 /*
@@ -447,9 +453,11 @@ static void tcp_keepalive_timer (unsigne
 {
 	struct sock *sk = (struct sock *) data;
 	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct net_namespace *orig_net_ns;
 	struct tcp_sock *tp = tcp_sk(sk);
 	__u32 elapsed;
 
+	push_net_ns(sk->sk_net_ns, orig_net_ns);
 	/* Only process if socket is not in use. */
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
@@ -521,4 +529,5 @@ death:	
 out:
 	bh_unlock_sock(sk);
 	sock_put(sk);
+	put_net_ns(orig_net_ns);
 }