diff options
| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-10-10 17:30:18 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-10-10 17:30:18 -0700 |
| commit | 06393009000779b00a558fd2f280882cc7dc2008 (patch) | |
| tree | 0cd2e1f4cedd58c3c8056018bb6148dddd21d6ab /net/sctp/socket.c | |
| parent | 3c0cfc135829b98f7a4894938652f9ef78e24237 (diff) | |
| download | linux-06393009000779b00a558fd2f280882cc7dc2008.tar.bz2 | |
[SCTP]: port randomization
Add port randomization rather than a simple fixed rover
for use with SCTP. This makes it act similar to TCP, UDP, DCCP
when allocating ports.
No longer need port_alloc_lock as well (suggestion by Brian Haley).
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/socket.c')
| -rw-r--r-- | net/sctp/socket.c | 21 |
1 files changed, 5 insertions, 16 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index f3e1a9c811ad..7cd58ef84eda 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5314,22 +5314,13 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) sctp_local_bh_disable(); if (snum == 0) { - /* Search for an available port. - * - * 'sctp_port_rover' was the last port assigned, so - * we start to search from 'sctp_port_rover + - * 1'. What we do is first check if port 'rover' is - * already in the hash table; if not, we use that; if - * it is, we try next. - */ - int low = sysctl_local_port_range[0]; - int high = sysctl_local_port_range[1]; - int remaining = (high - low) + 1; - int rover; + /* Search for an available port. */ + unsigned int low = sysctl_local_port_range[0]; + unsigned int high = sysctl_local_port_range[1]; + unsigned int remaining = (high - low) + 1; + unsigned int rover = net_random() % remaining + low; int index; - sctp_spin_lock(&sctp_port_alloc_lock); - rover = sctp_port_rover; do { rover++; if ((rover < low) || (rover > high)) @@ -5344,8 +5335,6 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) next: sctp_spin_unlock(&head->lock); } while (--remaining > 0); - sctp_port_rover = rover; - sctp_spin_unlock(&sctp_port_alloc_lock); /* Exhausted local port range during search? */ ret = 1; |