diff options
| -rw-r--r-- | net/ipv4/udp.c | 56 |
1 files changed, 12 insertions, 44 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 85f8e8e10b1..67d8430b4a2 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -155,55 +155,23 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum, write_lock_bh(&udp_hash_lock); if (!snum) { - int i, low, high, remaining; - unsigned rover, best, best_size_so_far; + int low, high, remaining; + unsigned rand; + unsigned short first; inet_get_local_port_range(&low, &high); remaining = (high - low) + 1; - best_size_so_far = UINT_MAX; - best = rover = net_random() % remaining + low; - - /* 1st pass: look for empty (or shortest) hash chain */ - for (i = 0; i < UDP_HTABLE_SIZE; i++) { - int size = 0; - - head = &udptable[udp_hashfn(net, rover)]; - if (hlist_empty(head)) - goto gotit; - - sk_for_each(sk2, node, head) { - if (++size >= best_size_so_far) - goto next; - } - best_size_so_far = size; - best = rover; - next: - /* fold back if end of range */ - if (++rover > high) - rover = low + ((rover - low) - & (UDP_HTABLE_SIZE - 1)); - - - } - - /* 2nd pass: find hole in shortest hash chain */ - rover = best; - for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) { - if (! __udp_lib_lport_inuse(net, rover, udptable)) - goto gotit; - rover += UDP_HTABLE_SIZE; - if (rover > high) - rover = low + ((rover - low) - & (UDP_HTABLE_SIZE - 1)); + rand = net_random(); + snum = first = rand % remaining + low; + rand |= 1; + while (__udp_lib_lport_inuse(net, snum, udptable)) { + do { + snum = snum + rand; + } while (snum < low || snum > high); + if (snum == first) + goto fail; } - - - /* All ports in use! */ - goto fail; - -gotit: - snum = rover; } else { head = &udptable[udp_hashfn(net, snum)]; |