The connect() routine returns -EADDRNOTAVAIL without doing a 4
tuple check when the hash buckets were previously allocated by
bind() and all local ports are used.
The bind() routine creates the local port hash buckets in
inet_csk_get_port(). Depending on the socket options it sets
tb->fastreuse and tb->fastreuseport to 0 or 1 in the bucket.
However the __inet_hash_connect() routine initializes the hash
buckets differently and sets these to -1. The end result is
that connect() calling into __inet_hash_connect() will
subsequently ignore the check_established() routine if, here
__inet_hash_connect()
.
.
if (tb->fastreuse >= 0 ||↩
tb->fastreuseport >= 0)↩
goto next_port;
and cycle through all local ports until it returns -EADDRNOTAVAIL.
The 4 tuple check is in check_established() so connect() can fail
unnecessarily.
Prerequisites for this to happen:
1) The local tcp port range must be exhausted.
2) A process must have called bind() followed by connect() for all
local ports.
3) A different process calls connect() only which returns -EADDRNOTAVAIL.
4) The system more than 1 interface configured.
If a system has 2 IP Addresses and all local tcp ports are in use
for connection from IP Address (1). Connecting to the same ports
via IP Address (2) should work based on the 4 tuple rule. But it
fails under this condition.
To fix this make __inet_hash_connect() honour inet_csk_get_port()'s
tb->fastreuse* variables.
Signed-off-by: Jon Maxwell <jmaxwel...@gmail.com>
---
net/ipv4/inet_hashtables.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 9111a4e..b39e89e 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -513,8 +513,8 @@ int __inet_hash_connect(struct inet_timewait_death_row
*death_row,
inet_bind_bucket_for_each(tb, &head->chain) {
if (net_eq(ib_net(tb), net) &&
tb->port == port) {
- if (tb->fastreuse >= 0 ||
- tb->fastreuseport >= 0)
+ if (tb->fastreuse > 0 ||
+ tb->fastreuseport > 0)
goto next_port;
WARN_ON(hlist_empty(&tb->owners));
if (!check_established(death_row, sk,
@@ -530,8 +530,6 @@ int __inet_hash_connect(struct inet_timewait_death_row
*death_row,
spin_unlock(&head->lock);
break;
}
- tb->fastreuse = -1;
- tb->fastreuseport = -1;
goto ok;
next_port:
--
1.8.3.1
--
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