Commit 06393009 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller

[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: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3c0cfc13
...@@ -197,8 +197,6 @@ extern struct sctp_globals { ...@@ -197,8 +197,6 @@ extern struct sctp_globals {
/* This is the sctp port control hash. */ /* This is the sctp port control hash. */
int port_hashsize; int port_hashsize;
int port_rover;
spinlock_t port_alloc_lock; /* Protects port_rover. */
struct sctp_bind_hashbucket *port_hashtable; struct sctp_bind_hashbucket *port_hashtable;
/* This is the global local address list. /* This is the global local address list.
......
...@@ -1172,9 +1172,6 @@ SCTP_STATIC __init int sctp_init(void) ...@@ -1172,9 +1172,6 @@ SCTP_STATIC __init int sctp_init(void)
sctp_port_hashtable[i].chain = NULL; sctp_port_hashtable[i].chain = NULL;
} }
spin_lock_init(&sctp_port_alloc_lock);
sctp_port_rover = sysctl_local_port_range[0] - 1;
printk(KERN_INFO "SCTP: Hash tables configured " printk(KERN_INFO "SCTP: Hash tables configured "
"(established %d bind %d)\n", "(established %d bind %d)\n",
sctp_assoc_hashsize, sctp_port_hashsize); sctp_assoc_hashsize, sctp_port_hashsize);
......
...@@ -5314,22 +5314,13 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) ...@@ -5314,22 +5314,13 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
sctp_local_bh_disable(); sctp_local_bh_disable();
if (snum == 0) { if (snum == 0) {
/* Search for an available port. /* Search for an available port. */
* unsigned int low = sysctl_local_port_range[0];
* 'sctp_port_rover' was the last port assigned, so unsigned int high = sysctl_local_port_range[1];
* we start to search from 'sctp_port_rover + unsigned int remaining = (high - low) + 1;
* 1'. What we do is first check if port 'rover' is unsigned int rover = net_random() % remaining + low;
* 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;
int index; int index;
sctp_spin_lock(&sctp_port_alloc_lock);
rover = sctp_port_rover;
do { do {
rover++; rover++;
if ((rover < low) || (rover > high)) if ((rover < low) || (rover > high))
...@@ -5344,8 +5335,6 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) ...@@ -5344,8 +5335,6 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
next: next:
sctp_spin_unlock(&head->lock); sctp_spin_unlock(&head->lock);
} while (--remaining > 0); } while (--remaining > 0);
sctp_port_rover = rover;
sctp_spin_unlock(&sctp_port_alloc_lock);
/* Exhausted local port range during search? */ /* Exhausted local port range during search? */
ret = 1; ret = 1;
......
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