/**
* __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
*
* @sk: socket struct in question
* @snum: port number to look up
* @udptable: hash list table, must be of UDP_HTABLE_SIZE
* @port_rover: pointer to record of last unallocated port
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
int __udp_lib_get_port(struct sock *sk, unsigned short snum,
struct hlist_head udptable[], int *port_rover,
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2 ) )
{
struct hlist_node *node;
struct hlist_head *head;
struct sock *sk2;
int error = 1;
write_lock_bh(&udp_hash_lock);
if (snum == 0) {
int best_size_so_far, best, result, i;
if (*port_rover > sysctl_local_port_range[1] ||
*port_rover < sysctl_local_port_range[0])
*port_rover = sysctl_local_port_range[0];
best_size_so_far = 32767;
best = result = *port_rover;
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
int size;
head = &udptable[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(head)) {
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, head) {
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_lib_lport_inuse(result, udptable))
break;
}
if (i >= (1 << 16) / UDP_HTABLE_SIZE)
goto fail;
gotit:
*port_rover = snum = result;
} else {
/**
* udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
*
* @sk: socket struct in question
* @snum: port number to look up
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
int udp_lib_get_port(struct sock *sk, unsigned short snum,
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2 ) )
{
struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
struct hlist_node *node;
struct hlist_head *head;
struct sock *sk2;
int error = 1;
struct net *net = sock_net(sk);
write_lock_bh(&udp_hash_lock);
if (!snum) {
int i, low, high, remaining;
unsigned rover, best, best_size_so_far;
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));
}
/* All ports in use! */
goto fail;
gotit:
snum = rover;
} else {
/**
* __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
*
* @sk: socket struct in question
* @snum: port number to look up
* @udptable: hash list table, must be of UDP_HTABLE_SIZE
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
int __udp_lib_get_port(struct sock *sk, unsigned short snum,
struct hlist_head udptable[],
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2 ) )
{
struct hlist_node *node;
struct hlist_head *head;
struct sock *sk2;
int error = 1;
write_lock_bh(&udp_hash_lock);
if (!snum) {
int i;
int low = sysctl_local_port_range[0];
int high = sysctl_local_port_range[1];
unsigned rover, best, best_size_so_far;
best_size_so_far = UINT_MAX;
best = rover = net_random() % (high - low) + low;
/* 1st pass: look for empty (or shortest) hash chain */
for (i = 0; i < UDP_HTABLE_SIZE; i++) {
int size = 0;
head = &udptable[rover & (UDP_HTABLE_SIZE - 1)];
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(rover, udptable))
goto gotit;
rover += UDP_HTABLE_SIZE;
if (rover > high)
rover = low + ((rover - low)
& (UDP_HTABLE_SIZE - 1));
}
/* All ports in use! */
goto fail;
gotit:
snum = rover;
} else {
