- struct sock *sk2;
- struct hlist_node *node;
-
- write_lock_bh(&udp_hash_lock);
- if (snum == 0) {
- int best_size_so_far, best, result, i;
-
- if (udp_port_rover > sysctl_local_port_range[1] ||
- udp_port_rover < sysctl_local_port_range[0])
- udp_port_rover = sysctl_local_port_range[0];
- best_size_so_far = 32767;
- best = result = udp_port_rover;
- for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
- int size;
- struct hlist_head *list;
-
- list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
- if (hlist_empty(list)) {
- if (result > sysctl_local_port_range[1])
- result = sysctl_local_port_range[0] +
- ((result - sysctl_local_port_range[0]) &
- (UDP_HTABLE_SIZE - 1));
- goto gotit;
- }
- size = 0;
- sk_for_each(sk2, node, list)
- if (++size >= best_size_so_far)
- goto next;
- best_size_so_far = size;
- best = result;
- next:;
- }
- result = best;
- for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
- if (result > sysctl_local_port_range[1])
- result = sysctl_local_port_range[0]
- + ((result - sysctl_local_port_range[0]) &
- (UDP_HTABLE_SIZE - 1));
- if (!udp_lport_inuse(result))
- break;
- }
- if (i >= (1 << 16) / UDP_HTABLE_SIZE)
- goto fail;
-gotit:
- udp_port_rover = snum = result;
- } else {
- sk_for_each(sk2, node,
- &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
- if (inet_sk(sk2)->num == snum &&
- sk2 != sk &&
- (!sk2->sk_bound_dev_if ||
- !sk->sk_bound_dev_if ||
- sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
- (!sk2->sk_reuse || !sk->sk_reuse) &&
- ipv6_rcv_saddr_equal(sk, sk2))
- goto fail;
- }
- }
-
- inet_sk(sk)->num = snum;
- if (sk_unhashed(sk)) {
- sk_add_node(sk, &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]);
- sock_prot_inc_use(sk->sk_prot);
- }
- write_unlock_bh(&udp_hash_lock);
- return 0;
-
-fail:
- write_unlock_bh(&udp_hash_lock);
- return 1;