* 2 of the License, or (at your option) any later version.
*/
-#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/wait.h>
+#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
+#include <net/ip.h>
/*
* Allocate and initialize a new local port bind bucket.
* The bindhash mutex for snum's hash chain must be held here.
*/
-struct inet_bind_bucket *inet_bind_bucket_create(kmem_cache_t *cachep,
+struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
struct inet_bind_hashbucket *head,
const unsigned short snum)
{
- struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, SLAB_ATOMIC);
+ struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
if (tb != NULL) {
tb->port = snum;
return tb;
}
-EXPORT_SYMBOL(inet_bind_bucket_create);
-
/*
* Caller must hold hashbucket lock for this tb with local BH disabled
*/
-void inet_bind_bucket_destroy(kmem_cache_t *cachep, struct inet_bind_bucket *tb)
+void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
{
if (hlist_empty(&tb->owners)) {
__hlist_del(&tb->node);
kmem_cache_free(cachep, tb);
}
}
+
+void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
+ const unsigned short snum)
+{
+ inet_sk(sk)->num = snum;
+ sk_add_bind_node(sk, &tb->owners);
+ inet_csk(sk)->icsk_bind_hash = tb;
+}
+
+/*
+ * Get rid of any references to a local port held by the given sock.
+ */
+static void __inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk)
+{
+ const int bhash = inet_bhashfn(inet_sk(sk)->num, hashinfo->bhash_size);
+ struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
+ struct inet_bind_bucket *tb;
+
+ spin_lock(&head->lock);
+ tb = inet_csk(sk)->icsk_bind_hash;
+ __sk_del_bind_node(sk);
+ inet_csk(sk)->icsk_bind_hash = NULL;
+ inet_sk(sk)->num = 0;
+ inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+ spin_unlock(&head->lock);
+}
+
+void inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk)
+{
+ local_bh_disable();
+ __inet_put_port(hashinfo, sk);
+ local_bh_enable();
+}
+
+EXPORT_SYMBOL(inet_put_port);
+
+/*
+ * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines (wake up each
+ * exclusive lock release). It should be ifdefed really.
+ */
+void inet_listen_wlock(struct inet_hashinfo *hashinfo)
+{
+ write_lock(&hashinfo->lhash_lock);
+
+ if (atomic_read(&hashinfo->lhash_users)) {
+ DEFINE_WAIT(wait);
+
+ for (;;) {
+ prepare_to_wait_exclusive(&hashinfo->lhash_wait,
+ &wait, TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&hashinfo->lhash_users))
+ break;
+ write_unlock_bh(&hashinfo->lhash_lock);
+ schedule();
+ write_lock_bh(&hashinfo->lhash_lock);
+ }
+
+ finish_wait(&hashinfo->lhash_wait, &wait);
+ }
+}
+
+EXPORT_SYMBOL(inet_listen_wlock);
+
+/*
+ * Don't inline this cruft. Here are some nice properties to exploit here. The
+ * BSD API does not allow a listening sock to specify the remote port nor the
+ * remote address for the connection. So always assume those are both
+ * wildcarded during the search since they can never be otherwise.
+ */
+static struct sock *inet_lookup_listener_slow(const struct hlist_head *head,
+ const __be32 daddr,
+ const unsigned short hnum,
+ const int dif)
+{
+ struct sock *result = NULL, *sk;
+ const struct hlist_node *node;
+ int hiscore = -1;
+
+ sk_for_each(sk, node, head) {
+ const struct inet_sock *inet = inet_sk(sk);
+
+ if (inet->num == hnum && !ipv6_only_sock(sk)) {
+ const __be32 rcv_saddr = inet->rcv_saddr;
+ int score = sk->sk_family == PF_INET ? 1 : 0;
+
+ if (rcv_saddr) {
+ if (rcv_saddr != daddr)
+ continue;
+ score += 2;
+ }
+ if (sk->sk_bound_dev_if) {
+ if (sk->sk_bound_dev_if != dif)
+ continue;
+ score += 2;
+ }
+ if (score == 5)
+ return sk;
+ if (score > hiscore) {
+ hiscore = score;
+ result = sk;
+ }
+ }
+ }
+ return result;
+}
+
+/* Optimize the common listener case. */
+struct sock *__inet_lookup_listener(struct inet_hashinfo *hashinfo,
+ const __be32 daddr, const unsigned short hnum,
+ const int dif)
+{
+ struct sock *sk = NULL;
+ const struct hlist_head *head;
+
+ read_lock(&hashinfo->lhash_lock);
+ head = &hashinfo->listening_hash[inet_lhashfn(hnum)];
+ if (!hlist_empty(head)) {
+ const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
+
+ if (inet->num == hnum && !sk->sk_node.next &&
+ (!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
+ (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
+ !sk->sk_bound_dev_if)
+ goto sherry_cache;
+ sk = inet_lookup_listener_slow(head, daddr, hnum, dif);
+ }
+ if (sk) {
+sherry_cache:
+ sock_hold(sk);
+ }
+ read_unlock(&hashinfo->lhash_lock);
+ return sk;
+}
+EXPORT_SYMBOL_GPL(__inet_lookup_listener);
+
+/* called with local bh disabled */
+static int __inet_check_established(struct inet_timewait_death_row *death_row,
+ struct sock *sk, __u16 lport,
+ struct inet_timewait_sock **twp)
+{
+ struct inet_hashinfo *hinfo = death_row->hashinfo;
+ struct inet_sock *inet = inet_sk(sk);
+ __be32 daddr = inet->rcv_saddr;
+ __be32 saddr = inet->daddr;
+ int dif = sk->sk_bound_dev_if;
+ INET_ADDR_COOKIE(acookie, saddr, daddr)
+ const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
+ unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
+ struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
+ rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
+ struct sock *sk2;
+ const struct hlist_node *node;
+ struct inet_timewait_sock *tw;
+
+ prefetch(head->chain.first);
+ write_lock(lock);
+
+ /* Check TIME-WAIT sockets first. */
+ sk_for_each(sk2, node, &head->twchain) {
+ tw = inet_twsk(sk2);
+
+ if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) {
+ if (twsk_unique(sk, sk2, twp))
+ goto unique;
+ else
+ goto not_unique;
+ }
+ }
+ tw = NULL;
+
+ /* And established part... */
+ sk_for_each(sk2, node, &head->chain) {
+ if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
+ goto not_unique;
+ }
+
+unique:
+ /* Must record num and sport now. Otherwise we will see
+ * in hash table socket with a funny identity. */
+ inet->num = lport;
+ inet->sport = htons(lport);
+ sk->sk_hash = hash;
+ BUG_TRAP(sk_unhashed(sk));
+ __sk_add_node(sk, &head->chain);
+ sock_prot_inc_use(sk->sk_prot);
+ write_unlock(lock);
+
+ if (twp) {
+ *twp = tw;
+ NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
+ } else if (tw) {
+ /* Silly. Should hash-dance instead... */
+ inet_twsk_deschedule(tw, death_row);
+ NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
+
+ inet_twsk_put(tw);
+ }
+
+ return 0;
+
+not_unique:
+ write_unlock(lock);
+ return -EADDRNOTAVAIL;
+}
+
+static inline u32 inet_sk_port_offset(const struct sock *sk)
+{
+ const struct inet_sock *inet = inet_sk(sk);
+ return secure_ipv4_port_ephemeral(inet->rcv_saddr, inet->daddr,
+ inet->dport);
+}
+
+/*
+ * Bind a port for a connect operation and hash it.
+ */
+int inet_hash_connect(struct inet_timewait_death_row *death_row,
+ struct sock *sk)
+{
+ struct inet_hashinfo *hinfo = death_row->hashinfo;
+ const unsigned short snum = inet_sk(sk)->num;
+ struct inet_bind_hashbucket *head;
+ struct inet_bind_bucket *tb;
+ int ret;
+
+ if (!snum) {
+ int i, remaining, low, high, port;
+ static u32 hint;
+ u32 offset = hint + inet_sk_port_offset(sk);
+ struct hlist_node *node;
+ struct inet_timewait_sock *tw = NULL;
+
+ inet_get_local_port_range(&low, &high);
+ remaining = (high - low) + 1;
+
+ local_bh_disable();
+ for (i = 1; i <= remaining; i++) {
+ port = low + (i + offset) % remaining;
+ head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
+ spin_lock(&head->lock);
+
+ /* Does not bother with rcv_saddr checks,
+ * because the established check is already
+ * unique enough.
+ */
+ inet_bind_bucket_for_each(tb, node, &head->chain) {
+ if (tb->port == port) {
+ BUG_TRAP(!hlist_empty(&tb->owners));
+ if (tb->fastreuse >= 0)
+ goto next_port;
+ if (!__inet_check_established(death_row,
+ sk, port,
+ &tw))
+ goto ok;
+ goto next_port;
+ }
+ }
+
+ tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, head, port);
+ if (!tb) {
+ spin_unlock(&head->lock);
+ break;
+ }
+ tb->fastreuse = -1;
+ goto ok;
+
+ next_port:
+ spin_unlock(&head->lock);
+ }
+ local_bh_enable();
+
+ return -EADDRNOTAVAIL;
+
+ok:
+ hint += i;
+
+ /* Head lock still held and bh's disabled */
+ inet_bind_hash(sk, tb, port);
+ if (sk_unhashed(sk)) {
+ inet_sk(sk)->sport = htons(port);
+ __inet_hash(hinfo, sk, 0);
+ }
+ spin_unlock(&head->lock);
+
+ if (tw) {
+ inet_twsk_deschedule(tw, death_row);
+ inet_twsk_put(tw);
+ }
+
+ ret = 0;
+ goto out;
+ }
+
+ head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
+ tb = inet_csk(sk)->icsk_bind_hash;
+ spin_lock_bh(&head->lock);
+ if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
+ __inet_hash(hinfo, sk, 0);
+ spin_unlock_bh(&head->lock);
+ return 0;
+ } else {
+ spin_unlock(&head->lock);
+ /* No definite answer... Walk to established hash table */
+ ret = __inet_check_established(death_row, sk, snum, NULL);
+out:
+ local_bh_enable();
+ return ret;
+ }
+}
+
+EXPORT_SYMBOL_GPL(inet_hash_connect);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff