diff options
| author | Stephen Hemminger <shemminger@osdl.org> | 2005-11-03 16:33:23 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@mandriva.com> | 2005-11-05 21:23:15 -0200 |
| commit | 6df716340da3a6fdd33d73d7ed4c6f7590ca1c42 (patch) | |
| tree | 1b3ba3d1a0a08b9b4eaa624a66414b87a70b6fe9 /net/ipv4 | |
| parent | 6151b31c9616d71f714fc7ef8e2306f67f3b94c3 (diff) | |
| download | op-kernel-dev-6df716340da3a6fdd33d73d7ed4c6f7590ca1c42.zip op-kernel-dev-6df716340da3a6fdd33d73d7ed4c6f7590ca1c42.tar.gz | |
[TCP/DCCP]: Randomize port selection
This patch randomizes the port selected on bind() for connections
to help with possible security attacks. It should also be faster
in most cases because there is no need for a global lock.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 14 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 2 |
3 files changed, 3 insertions, 14 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 94468a7..3fe021f 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -78,17 +78,9 @@ int inet_csk_get_port(struct inet_hashinfo *hashinfo, int low = sysctl_local_port_range[0]; int high = sysctl_local_port_range[1]; int remaining = (high - low) + 1; - int rover; + int rover = net_random() % (high - low) + low; - spin_lock(&hashinfo->portalloc_lock); - if (hashinfo->port_rover < low) - rover = low; - else - rover = hashinfo->port_rover; do { - rover++; - if (rover > high) - rover = low; head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)]; spin_lock(&head->lock); inet_bind_bucket_for_each(tb, node, &head->chain) @@ -97,9 +89,9 @@ int inet_csk_get_port(struct inet_hashinfo *hashinfo, break; next: spin_unlock(&head->lock); + if (++rover > high) + rover = low; } while (--remaining > 0); - hashinfo->port_rover = rover; - spin_unlock(&hashinfo->portalloc_lock); /* Exhausted local port range during search? It is not * possible for us to be holding one of the bind hash diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f3f0013..72b7c22 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2112,7 +2112,6 @@ void __init tcp_init(void) sysctl_tcp_max_orphans >>= (3 - order); sysctl_max_syn_backlog = 128; } - tcp_hashinfo.port_rover = sysctl_local_port_range[0] - 1; sysctl_tcp_mem[0] = 768 << order; sysctl_tcp_mem[1] = 1024 << order; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index c85819d..49d67cd 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -93,8 +93,6 @@ struct inet_hashinfo __cacheline_aligned tcp_hashinfo = { .lhash_lock = RW_LOCK_UNLOCKED, .lhash_users = ATOMIC_INIT(0), .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait), - .portalloc_lock = SPIN_LOCK_UNLOCKED, - .port_rover = 1024 - 1, }; static int tcp_v4_get_port(struct sock *sk, unsigned short snum) |
