__u32 total_retrans; /* Total retransmits for entire connection */
- /* The syn_wait_lock is necessary only to avoid proc interface having
- * to grab the main lock sock while browsing the listening hash
- * (otherwise it's deadlock prone).
- * This lock is acquired in read mode only from listening_get_next()
- * and it's acquired in write mode _only_ from code that is actively
- * changing the syn_wait_queue. All readers that are holding
- * the master sock lock don't need to grab this lock in read mode
- * too as the syn_wait_queue writes are always protected from
- * the main sock lock.
- */
- rwlock_t syn_wait_lock;
- struct tcp_listen_opt *listen_opt;
-
- /* FIFO of established children */
- struct request_sock *accept_queue;
- struct request_sock *accept_queue_tail;
+ struct request_sock_queue accept_queue; /* FIFO of established children */
unsigned int keepalive_time; /* time before keep alive takes place */
unsigned int keepalive_intvl; /* time interval between keep alive probes */
#define _REQUEST_SOCK_H
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/types.h>
+
#include <net/sock.h>
struct request_sock;
__reqsk_free(req);
}
+extern int sysctl_max_syn_backlog;
+
+/** struct tcp_listen_opt - listen state
+ *
+ * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
+ */
+struct tcp_listen_opt {
+ u8 max_qlen_log;
+ /* 3 bytes hole, try to use */
+ int qlen;
+ int qlen_young;
+ int clock_hand;
+ u32 hash_rnd;
+ struct request_sock *syn_table[0];
+};
+
+/** struct request_sock_queue - queue of request_socks
+ *
+ * @rskq_accept_head - FIFO head of established children
+ * @rskq_accept_tail - FIFO tail of established children
+ * @syn_wait_lock - serializer
+ *
+ * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
+ * lock sock while browsing the listening hash (otherwise it's deadlock prone).
+ *
+ * This lock is acquired in read mode only from listening_get_next() seq_file
+ * op and it's acquired in write mode _only_ from code that is actively
+ * changing rskq_accept_head. All readers that are holding the master sock lock
+ * don't need to grab this lock in read mode too as rskq_accept_head. writes
+ * are always protected from the main sock lock.
+ */
+struct request_sock_queue {
+ struct request_sock *rskq_accept_head;
+ struct request_sock *rskq_accept_tail;
+ rwlock_t syn_wait_lock;
+ struct tcp_listen_opt *listen_opt;
+};
+
+extern int reqsk_queue_alloc(struct request_sock_queue *queue,
+ const int nr_table_entries);
+
+static inline struct tcp_listen_opt *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue)
+{
+ struct tcp_listen_opt *lopt;
+
+ write_lock_bh(&queue->syn_wait_lock);
+ lopt = queue->listen_opt;
+ queue->listen_opt = NULL;
+ write_unlock_bh(&queue->syn_wait_lock);
+
+ return lopt;
+}
+
+static inline void reqsk_queue_destroy(struct request_sock_queue *queue)
+{
+ kfree(reqsk_queue_yank_listen_sk(queue));
+}
+
+static inline struct request_sock *
+ reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
+{
+ struct request_sock *req = queue->rskq_accept_head;
+
+ queue->rskq_accept_head = queue->rskq_accept_head = NULL;
+ return req;
+}
+
+static inline int reqsk_queue_empty(struct request_sock_queue *queue)
+{
+ return queue->rskq_accept_head == NULL;
+}
+
+static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
+ struct request_sock *req,
+ struct request_sock **prev_req)
+{
+ write_lock(&queue->syn_wait_lock);
+ *prev_req = req->dl_next;
+ write_unlock(&queue->syn_wait_lock);
+}
+
+static inline void reqsk_queue_add(struct request_sock_queue *queue,
+ struct request_sock *req,
+ struct sock *parent,
+ struct sock *child)
+{
+ req->sk = child;
+ sk_acceptq_added(parent);
+
+ if (queue->rskq_accept_head == NULL)
+ queue->rskq_accept_head = req;
+ else
+ queue->rskq_accept_tail->dl_next = req;
+
+ queue->rskq_accept_tail = req;
+ req->dl_next = NULL;
+}
+
+static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
+{
+ struct request_sock *req = queue->rskq_accept_head;
+
+ BUG_TRAP(req != NULL);
+
+ queue->rskq_accept_head = req->dl_next;
+ if (queue->rskq_accept_head == NULL)
+ queue->rskq_accept_tail = NULL;
+
+ return req;
+}
+
+static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
+ struct sock *parent)
+{
+ struct request_sock *req = reqsk_queue_remove(queue);
+ struct sock *child = req->sk;
+
+ BUG_TRAP(child != NULL);
+
+ sk_acceptq_removed(parent);
+ __reqsk_free(req);
+ return child;
+}
+
+static inline int reqsk_queue_removed(struct request_sock_queue *queue,
+ struct request_sock *req)
+{
+ struct tcp_listen_opt *lopt = queue->listen_opt;
+
+ if (req->retrans == 0)
+ --lopt->qlen_young;
+
+ return --lopt->qlen;
+}
+
+static inline int reqsk_queue_added(struct request_sock_queue *queue)
+{
+ struct tcp_listen_opt *lopt = queue->listen_opt;
+ const int prev_qlen = lopt->qlen;
+
+ lopt->qlen_young++;
+ lopt->qlen++;
+ return prev_qlen;
+}
+
+static inline int reqsk_queue_len(struct request_sock_queue *queue)
+{
+ return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
+}
+
+static inline int reqsk_queue_len_young(struct request_sock_queue *queue)
+{
+ return queue->listen_opt->qlen_young;
+}
+
+static inline int reqsk_queue_is_full(struct request_sock_queue *queue)
+{
+ return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
+}
+
+static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
+ u32 hash, struct request_sock *req,
+ unsigned timeout)
+{
+ struct tcp_listen_opt *lopt = queue->listen_opt;
+
+ req->expires = jiffies + timeout;
+ req->retrans = 0;
+ req->sk = NULL;
+ req->dl_next = lopt->syn_table[hash];
+
+ write_lock(&queue->syn_wait_lock);
+ lopt->syn_table[hash] = req;
+ write_unlock(&queue->syn_wait_lock);
+}
+
#endif /* _REQUEST_SOCK_H */
static inline void tcp_acceptq_queue(struct sock *sk, struct request_sock *req,
struct sock *child)
{
- struct tcp_sock *tp = tcp_sk(sk);
-
- req->sk = child;
- sk_acceptq_added(sk);
-
- if (!tp->accept_queue_tail) {
- tp->accept_queue = req;
- } else {
- tp->accept_queue_tail->dl_next = req;
- }
- tp->accept_queue_tail = req;
- req->dl_next = NULL;
+ reqsk_queue_add(&tcp_sk(sk)->accept_queue, req, sk, child);
}
-struct tcp_listen_opt
-{
- u8 max_qlen_log; /* log_2 of maximal queued SYNs */
- int qlen;
- int qlen_young;
- int clock_hand;
- u32 hash_rnd;
- struct request_sock *syn_table[TCP_SYNQ_HSIZE];
-};
-
static inline void
tcp_synq_removed(struct sock *sk, struct request_sock *req)
{
- struct tcp_listen_opt *lopt = tcp_sk(sk)->listen_opt;
-
- if (--lopt->qlen == 0)
+ if (reqsk_queue_removed(&tcp_sk(sk)->accept_queue, req) == 0)
tcp_delete_keepalive_timer(sk);
- if (req->retrans == 0)
- lopt->qlen_young--;
}
static inline void tcp_synq_added(struct sock *sk)
{
- struct tcp_listen_opt *lopt = tcp_sk(sk)->listen_opt;
-
- if (lopt->qlen++ == 0)
+ if (reqsk_queue_added(&tcp_sk(sk)->accept_queue) == 0)
tcp_reset_keepalive_timer(sk, TCP_TIMEOUT_INIT);
- lopt->qlen_young++;
}
static inline int tcp_synq_len(struct sock *sk)
{
- return tcp_sk(sk)->listen_opt->qlen;
+ return reqsk_queue_len(&tcp_sk(sk)->accept_queue);
}
static inline int tcp_synq_young(struct sock *sk)
{
- return tcp_sk(sk)->listen_opt->qlen_young;
+ return reqsk_queue_len_young(&tcp_sk(sk)->accept_queue);
}
static inline int tcp_synq_is_full(struct sock *sk)
{
- return tcp_synq_len(sk) >> tcp_sk(sk)->listen_opt->max_qlen_log;
+ return reqsk_queue_is_full(&tcp_sk(sk)->accept_queue);
}
static inline void tcp_synq_unlink(struct tcp_sock *tp, struct request_sock *req,
- struct request_sock **prev)
+ struct request_sock **prev)
{
- write_lock(&tp->syn_wait_lock);
- *prev = req->dl_next;
- write_unlock(&tp->syn_wait_lock);
+ reqsk_queue_unlink(&tp->accept_queue, req, prev);
}
static inline void tcp_synq_drop(struct sock *sk, struct request_sock *req,
# Makefile for the Linux networking core.
#
-obj-y := sock.o skbuff.o iovec.o datagram.o stream.o scm.o gen_stats.o gen_estimator.o
+obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \
+ gen_stats.o gen_estimator.o
obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
--- /dev/null
+/*
+ * NET Generic infrastructure for Network protocols.
+ *
+ * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * From code originally in include/net/tcp.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <net/request_sock.h>
+
+int reqsk_queue_alloc(struct request_sock_queue *queue,
+ const int nr_table_entries)
+{
+ const int lopt_size = sizeof(struct tcp_listen_opt) +
+ nr_table_entries * sizeof(struct request_sock *);
+ struct tcp_listen_opt *lopt = kmalloc(lopt_size, GFP_KERNEL);
+
+ if (lopt == NULL)
+ return -ENOMEM;
+
+ memset(lopt, 0, lopt_size);
+
+ for (lopt->max_qlen_log = 6;
+ (1 << lopt->max_qlen_log) < sysctl_max_syn_backlog;
+ lopt->max_qlen_log++);
+
+ get_random_bytes(&lopt->hash_rnd, sizeof(lopt->hash_rnd));
+ rwlock_init(&queue->syn_wait_lock);
+ queue->rskq_accept_head = queue->rskq_accept_head = NULL;
+
+ write_lock_bh(&queue->syn_wait_lock);
+ queue->listen_opt = lopt;
+ write_unlock_bh(&queue->syn_wait_lock);
+
+ return 0;
+}
+
+EXPORT_SYMBOL(reqsk_queue_alloc);
static __inline__ unsigned int tcp_listen_poll(struct sock *sk,
poll_table *wait)
{
- return tcp_sk(sk)->accept_queue ? (POLLIN | POLLRDNORM) : 0;
+ return !reqsk_queue_empty(&tcp_sk(sk)->accept_queue) ? (POLLIN | POLLRDNORM) : 0;
}
/*
{
struct inet_sock *inet = inet_sk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt;
+ int rc = reqsk_queue_alloc(&tp->accept_queue, TCP_SYNQ_HSIZE);
+
+ if (rc != 0)
+ return rc;
sk->sk_max_ack_backlog = 0;
sk->sk_ack_backlog = 0;
- tp->accept_queue = tp->accept_queue_tail = NULL;
- rwlock_init(&tp->syn_wait_lock);
tcp_delack_init(tp);
- lopt = kmalloc(sizeof(struct tcp_listen_opt), GFP_KERNEL);
- if (!lopt)
- return -ENOMEM;
-
- memset(lopt, 0, sizeof(struct tcp_listen_opt));
- for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++)
- if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog)
- break;
- get_random_bytes(&lopt->hash_rnd, 4);
-
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = lopt;
- write_unlock_bh(&tp->syn_wait_lock);
-
/* There is race window here: we announce ourselves listening,
* but this transition is still not validated by get_port().
* It is OK, because this socket enters to hash table only
}
sk->sk_state = TCP_CLOSE;
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = NULL;
- write_unlock_bh(&tp->syn_wait_lock);
- kfree(lopt);
+ reqsk_queue_destroy(&tp->accept_queue);
return -EADDRINUSE;
}
static void tcp_listen_stop (struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt = tp->listen_opt;
- struct request_sock *acc_req = tp->accept_queue;
+ struct tcp_listen_opt *lopt;
+ struct request_sock *acc_req;
struct request_sock *req;
int i;
tcp_delete_keepalive_timer(sk);
/* make all the listen_opt local to us */
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = NULL;
- write_unlock_bh(&tp->syn_wait_lock);
- tp->accept_queue = tp->accept_queue_tail = NULL;
+ lopt = reqsk_queue_yank_listen_sk(&tp->accept_queue);
+ acc_req = reqsk_queue_yank_acceptq(&tp->accept_queue);
if (lopt->qlen) {
for (i = 0; i < TCP_SYNQ_HSIZE; i++) {
prepare_to_wait_exclusive(sk->sk_sleep, &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
- if (!tp->accept_queue)
+ if (reqsk_queue_empty(&tp->accept_queue))
timeo = schedule_timeout(timeo);
lock_sock(sk);
err = 0;
- if (tp->accept_queue)
+ if (!reqsk_queue_empty(&tp->accept_queue))
break;
err = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
struct sock *tcp_accept(struct sock *sk, int flags, int *err)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct request_sock *req;
struct sock *newsk;
int error;
*/
error = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
- goto out;
+ goto out_err;
/* Find already established connection */
- if (!tp->accept_queue) {
+ if (reqsk_queue_empty(&tp->accept_queue)) {
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
/* If this is a non blocking socket don't sleep */
error = -EAGAIN;
if (!timeo)
- goto out;
+ goto out_err;
error = wait_for_connect(sk, timeo);
if (error)
- goto out;
+ goto out_err;
}
- req = tp->accept_queue;
- if ((tp->accept_queue = req->dl_next) == NULL)
- tp->accept_queue_tail = NULL;
-
- newsk = req->sk;
- sk_acceptq_removed(sk);
- __reqsk_free(req);
+ newsk = reqsk_queue_get_child(&tp->accept_queue, sk);
BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
- release_sock(sk);
- return newsk;
-
out:
release_sock(sk);
+ return newsk;
+out_err:
+ newsk = NULL;
*err = error;
- return NULL;
+ goto out;
}
/*
entry.family = sk->sk_family;
- read_lock_bh(&tp->syn_wait_lock);
+ read_lock_bh(&tp->accept_queue.syn_wait_lock);
- lopt = tp->listen_opt;
+ lopt = tp->accept_queue.listen_opt;
if (!lopt || !lopt->qlen)
goto out;
}
out:
- read_unlock_bh(&tp->syn_wait_lock);
+ read_unlock_bh(&tp->accept_queue.syn_wait_lock);
return err;
}
__u16 rport,
__u32 raddr, __u32 laddr)
{
- struct tcp_listen_opt *lopt = tp->listen_opt;
+ struct tcp_listen_opt *lopt = tp->accept_queue.listen_opt;
struct request_sock *req, **prev;
for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport, lopt->hash_rnd)];
static void tcp_v4_synq_add(struct sock *sk, struct request_sock *req)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt = tp->listen_opt;
+ struct tcp_listen_opt *lopt = tp->accept_queue.listen_opt;
u32 h = tcp_v4_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, lopt->hash_rnd);
- req->expires = jiffies + TCP_TIMEOUT_INIT;
- req->retrans = 0;
- req->sk = NULL;
- req->dl_next = lopt->syn_table[h];
-
- write_lock(&tp->syn_wait_lock);
- lopt->syn_table[h] = req;
- write_unlock(&tp->syn_wait_lock);
-
+ reqsk_queue_hash_req(&tp->accept_queue, h, req, TCP_TIMEOUT_INIT);
tcp_synq_added(sk);
}
if (++st->sbucket >= TCP_SYNQ_HSIZE)
break;
get_req:
- req = tp->listen_opt->syn_table[st->sbucket];
+ req = tp->accept_queue.listen_opt->syn_table[st->sbucket];
}
sk = sk_next(st->syn_wait_sk);
st->state = TCP_SEQ_STATE_LISTENING;
- read_unlock_bh(&tp->syn_wait_lock);
+ read_unlock_bh(&tp->accept_queue.syn_wait_lock);
} else {
tp = tcp_sk(sk);
- read_lock_bh(&tp->syn_wait_lock);
- if (tp->listen_opt && tp->listen_opt->qlen)
+ read_lock_bh(&tp->accept_queue.syn_wait_lock);
+ if (reqsk_queue_len(&tp->accept_queue))
goto start_req;
- read_unlock_bh(&tp->syn_wait_lock);
+ read_unlock_bh(&tp->accept_queue.syn_wait_lock);
sk = sk_next(sk);
}
get_sk:
goto out;
}
tp = tcp_sk(sk);
- read_lock_bh(&tp->syn_wait_lock);
- if (tp->listen_opt && tp->listen_opt->qlen) {
+ read_lock_bh(&tp->accept_queue.syn_wait_lock);
+ if (reqsk_queue_len(&tp->accept_queue)) {
start_req:
st->uid = sock_i_uid(sk);
st->syn_wait_sk = sk;
st->sbucket = 0;
goto get_req;
}
- read_unlock_bh(&tp->syn_wait_lock);
+ read_unlock_bh(&tp->accept_queue.syn_wait_lock);
}
if (++st->bucket < TCP_LHTABLE_SIZE) {
sk = sk_head(&tcp_listening_hash[st->bucket]);
case TCP_SEQ_STATE_OPENREQ:
if (v) {
struct tcp_sock *tp = tcp_sk(st->syn_wait_sk);
- read_unlock_bh(&tp->syn_wait_lock);
+ read_unlock_bh(&tp->accept_queue.syn_wait_lock);
}
case TCP_SEQ_STATE_LISTENING:
if (v != SEQ_START_TOKEN)
newtp->probes_out = 0;
newtp->rx_opt.num_sacks = 0;
newtp->urg_data = 0;
- newtp->listen_opt = NULL;
- newtp->accept_queue = newtp->accept_queue_tail = NULL;
- /* Deinitialize syn_wait_lock to trap illegal accesses. */
- memset(&newtp->syn_wait_lock, 0, sizeof(newtp->syn_wait_lock));
+ /* Deinitialize accept_queue to trap illegal accesses. */
+ memset(&newtp->accept_queue, 0, sizeof(newtp->accept_queue));
/* Back to base struct sock members. */
newsk->sk_err = 0;
static void tcp_synack_timer(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt = tp->listen_opt;
+ struct tcp_listen_opt *lopt = tp->accept_queue.listen_opt;
int max_retries = tp->syn_retries ? : sysctl_tcp_synack_retries;
int thresh = max_retries;
unsigned long now = jiffies;
}
/* Drop this request */
- write_lock(&tp->syn_wait_lock);
- *reqp = req->dl_next;
- write_unlock(&tp->syn_wait_lock);
- lopt->qlen--;
- if (req->retrans == 0)
- lopt->qlen_young--;
+ tcp_synq_unlink(tp, req, reqp);
+ reqsk_queue_removed(&tp->accept_queue, req);
reqsk_free(req);
continue;
}
struct in6_addr *laddr,
int iif)
{
- struct tcp_listen_opt *lopt = tp->listen_opt;
+ struct tcp_listen_opt *lopt = tp->accept_queue.listen_opt;
struct request_sock *req, **prev;
for (prev = &lopt->syn_table[tcp_v6_synq_hash(raddr, rport, lopt->hash_rnd)];
static void tcp_v6_synq_add(struct sock *sk, struct request_sock *req)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt = tp->listen_opt;
+ struct tcp_listen_opt *lopt = tp->accept_queue.listen_opt;
u32 h = tcp_v6_synq_hash(&tcp6_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, lopt->hash_rnd);
- req->sk = NULL;
- req->expires = jiffies + TCP_TIMEOUT_INIT;
- req->retrans = 0;
- req->dl_next = lopt->syn_table[h];
-
- write_lock(&tp->syn_wait_lock);
- lopt->syn_table[h] = req;
- write_unlock(&tp->syn_wait_lock);
-
+ reqsk_queue_hash_req(&tp->accept_queue, h, req, TCP_TIMEOUT_INIT);
tcp_synq_added(sk);
}
projects / linux-2.6 / commitdiff