|  | /* | 
|  | * INET		An implementation of the TCP/IP protocol suite for the LINUX | 
|  | *		operating system.  INET is implemented using the  BSD Socket | 
|  | *		interface as the means of communication with the user level. | 
|  | * | 
|  | *		Support for INET connection oriented protocols. | 
|  | * | 
|  | * Authors:	See the TCP sources | 
|  | * | 
|  | *		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/jhash.h> | 
|  |  | 
|  | #include <net/inet_connection_sock.h> | 
|  | #include <net/inet_hashtables.h> | 
|  | #include <net/inet_timewait_sock.h> | 
|  | #include <net/ip.h> | 
|  | #include <net/route.h> | 
|  | #include <net/tcp_states.h> | 
|  | #include <net/xfrm.h> | 
|  |  | 
|  | #ifdef INET_CSK_DEBUG | 
|  | const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n"; | 
|  | EXPORT_SYMBOL(inet_csk_timer_bug_msg); | 
|  | #endif | 
|  |  | 
|  | /* | 
|  | * This struct holds the first and last local port number. | 
|  | */ | 
|  | struct local_ports sysctl_local_ports __read_mostly = { | 
|  | .lock = SEQLOCK_UNLOCKED, | 
|  | .range = { 32768, 61000 }, | 
|  | }; | 
|  |  | 
|  | void inet_get_local_port_range(int *low, int *high) | 
|  | { | 
|  | unsigned seq; | 
|  | do { | 
|  | seq = read_seqbegin(&sysctl_local_ports.lock); | 
|  |  | 
|  | *low = sysctl_local_ports.range[0]; | 
|  | *high = sysctl_local_ports.range[1]; | 
|  | } while (read_seqretry(&sysctl_local_ports.lock, seq)); | 
|  | } | 
|  | EXPORT_SYMBOL(inet_get_local_port_range); | 
|  |  | 
|  | int inet_csk_bind_conflict(const struct sock *sk, | 
|  | const struct inet_bind_bucket *tb) | 
|  | { | 
|  | const __be32 sk_rcv_saddr = inet_rcv_saddr(sk); | 
|  | struct sock *sk2; | 
|  | struct hlist_node *node; | 
|  | int reuse = sk->sk_reuse; | 
|  |  | 
|  | /* | 
|  | * Unlike other sk lookup places we do not check | 
|  | * for sk_net here, since _all_ the socks listed | 
|  | * in tb->owners list belong to the same net - the | 
|  | * one this bucket belongs to. | 
|  | */ | 
|  |  | 
|  | sk_for_each_bound(sk2, node, &tb->owners) { | 
|  | if (sk != sk2 && | 
|  | !inet_v6_ipv6only(sk2) && | 
|  | (!sk->sk_bound_dev_if || | 
|  | !sk2->sk_bound_dev_if || | 
|  | sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { | 
|  | if (!reuse || !sk2->sk_reuse || | 
|  | sk2->sk_state == TCP_LISTEN) { | 
|  | const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2); | 
|  | if (!sk2_rcv_saddr || !sk_rcv_saddr || | 
|  | sk2_rcv_saddr == sk_rcv_saddr) | 
|  | break; | 
|  | } | 
|  | } | 
|  | } | 
|  | return node != NULL; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_bind_conflict); | 
|  |  | 
|  | /* Obtain a reference to a local port for the given sock, | 
|  | * if snum is zero it means select any available local port. | 
|  | */ | 
|  | int inet_csk_get_port(struct sock *sk, unsigned short snum) | 
|  | { | 
|  | struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; | 
|  | struct inet_bind_hashbucket *head; | 
|  | struct hlist_node *node; | 
|  | struct inet_bind_bucket *tb; | 
|  | int ret, attempts = 5; | 
|  | struct net *net = sock_net(sk); | 
|  | int smallest_size = -1, smallest_rover; | 
|  |  | 
|  | local_bh_disable(); | 
|  | if (!snum) { | 
|  | int remaining, rover, low, high; | 
|  |  | 
|  | again: | 
|  | inet_get_local_port_range(&low, &high); | 
|  | remaining = (high - low) + 1; | 
|  | smallest_rover = rover = net_random() % remaining + low; | 
|  |  | 
|  | smallest_size = -1; | 
|  | do { | 
|  | head = &hashinfo->bhash[inet_bhashfn(net, rover, | 
|  | hashinfo->bhash_size)]; | 
|  | spin_lock(&head->lock); | 
|  | inet_bind_bucket_for_each(tb, node, &head->chain) | 
|  | if (net_eq(ib_net(tb), net) && tb->port == rover) { | 
|  | if (tb->fastreuse > 0 && | 
|  | sk->sk_reuse && | 
|  | sk->sk_state != TCP_LISTEN && | 
|  | (tb->num_owners < smallest_size || smallest_size == -1)) { | 
|  | smallest_size = tb->num_owners; | 
|  | smallest_rover = rover; | 
|  | if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) { | 
|  | spin_unlock(&head->lock); | 
|  | snum = smallest_rover; | 
|  | goto have_snum; | 
|  | } | 
|  | } | 
|  | goto next; | 
|  | } | 
|  | break; | 
|  | next: | 
|  | spin_unlock(&head->lock); | 
|  | if (++rover > high) | 
|  | rover = low; | 
|  | } while (--remaining > 0); | 
|  |  | 
|  | /* Exhausted local port range during search?  It is not | 
|  | * possible for us to be holding one of the bind hash | 
|  | * locks if this test triggers, because if 'remaining' | 
|  | * drops to zero, we broke out of the do/while loop at | 
|  | * the top level, not from the 'break;' statement. | 
|  | */ | 
|  | ret = 1; | 
|  | if (remaining <= 0) { | 
|  | if (smallest_size != -1) { | 
|  | snum = smallest_rover; | 
|  | goto have_snum; | 
|  | } | 
|  | goto fail; | 
|  | } | 
|  | /* OK, here is the one we will use.  HEAD is | 
|  | * non-NULL and we hold it's mutex. | 
|  | */ | 
|  | snum = rover; | 
|  | } else { | 
|  | have_snum: | 
|  | head = &hashinfo->bhash[inet_bhashfn(net, snum, | 
|  | hashinfo->bhash_size)]; | 
|  | spin_lock(&head->lock); | 
|  | inet_bind_bucket_for_each(tb, node, &head->chain) | 
|  | if (net_eq(ib_net(tb), net) && tb->port == snum) | 
|  | goto tb_found; | 
|  | } | 
|  | tb = NULL; | 
|  | goto tb_not_found; | 
|  | tb_found: | 
|  | if (!hlist_empty(&tb->owners)) { | 
|  | if (tb->fastreuse > 0 && | 
|  | sk->sk_reuse && sk->sk_state != TCP_LISTEN && | 
|  | smallest_size == -1) { | 
|  | goto success; | 
|  | } else { | 
|  | ret = 1; | 
|  | if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) { | 
|  | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && | 
|  | smallest_size != -1 && --attempts >= 0) { | 
|  | spin_unlock(&head->lock); | 
|  | goto again; | 
|  | } | 
|  | goto fail_unlock; | 
|  | } | 
|  | } | 
|  | } | 
|  | tb_not_found: | 
|  | ret = 1; | 
|  | if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, | 
|  | net, head, snum)) == NULL) | 
|  | goto fail_unlock; | 
|  | if (hlist_empty(&tb->owners)) { | 
|  | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN) | 
|  | tb->fastreuse = 1; | 
|  | else | 
|  | tb->fastreuse = 0; | 
|  | } else if (tb->fastreuse && | 
|  | (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) | 
|  | tb->fastreuse = 0; | 
|  | success: | 
|  | if (!inet_csk(sk)->icsk_bind_hash) | 
|  | inet_bind_hash(sk, tb, snum); | 
|  | WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); | 
|  | ret = 0; | 
|  |  | 
|  | fail_unlock: | 
|  | spin_unlock(&head->lock); | 
|  | fail: | 
|  | local_bh_enable(); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_get_port); | 
|  |  | 
|  | /* | 
|  | * Wait for an incoming connection, avoid race conditions. This must be called | 
|  | * with the socket locked. | 
|  | */ | 
|  | static int inet_csk_wait_for_connect(struct sock *sk, long timeo) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | DEFINE_WAIT(wait); | 
|  | int err; | 
|  |  | 
|  | /* | 
|  | * True wake-one mechanism for incoming connections: only | 
|  | * one process gets woken up, not the 'whole herd'. | 
|  | * Since we do not 'race & poll' for established sockets | 
|  | * anymore, the common case will execute the loop only once. | 
|  | * | 
|  | * Subtle issue: "add_wait_queue_exclusive()" will be added | 
|  | * after any current non-exclusive waiters, and we know that | 
|  | * it will always _stay_ after any new non-exclusive waiters | 
|  | * because all non-exclusive waiters are added at the | 
|  | * beginning of the wait-queue. As such, it's ok to "drop" | 
|  | * our exclusiveness temporarily when we get woken up without | 
|  | * having to remove and re-insert us on the wait queue. | 
|  | */ | 
|  | for (;;) { | 
|  | prepare_to_wait_exclusive(sk_sleep(sk), &wait, | 
|  | TASK_INTERRUPTIBLE); | 
|  | release_sock(sk); | 
|  | if (reqsk_queue_empty(&icsk->icsk_accept_queue)) | 
|  | timeo = schedule_timeout(timeo); | 
|  | lock_sock(sk); | 
|  | err = 0; | 
|  | if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) | 
|  | break; | 
|  | err = -EINVAL; | 
|  | if (sk->sk_state != TCP_LISTEN) | 
|  | break; | 
|  | err = sock_intr_errno(timeo); | 
|  | if (signal_pending(current)) | 
|  | break; | 
|  | err = -EAGAIN; | 
|  | if (!timeo) | 
|  | break; | 
|  | } | 
|  | finish_wait(sk_sleep(sk), &wait); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * This will accept the next outstanding connection. | 
|  | */ | 
|  | struct sock *inet_csk_accept(struct sock *sk, int flags, int *err) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | struct sock *newsk; | 
|  | int error; | 
|  |  | 
|  | lock_sock(sk); | 
|  |  | 
|  | /* We need to make sure that this socket is listening, | 
|  | * and that it has something pending. | 
|  | */ | 
|  | error = -EINVAL; | 
|  | if (sk->sk_state != TCP_LISTEN) | 
|  | goto out_err; | 
|  |  | 
|  | /* Find already established connection */ | 
|  | if (reqsk_queue_empty(&icsk->icsk_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_err; | 
|  |  | 
|  | error = inet_csk_wait_for_connect(sk, timeo); | 
|  | if (error) | 
|  | goto out_err; | 
|  | } | 
|  |  | 
|  | newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk); | 
|  | WARN_ON(newsk->sk_state == TCP_SYN_RECV); | 
|  | out: | 
|  | release_sock(sk); | 
|  | return newsk; | 
|  | out_err: | 
|  | newsk = NULL; | 
|  | *err = error; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_accept); | 
|  |  | 
|  | /* | 
|  | * Using different timers for retransmit, delayed acks and probes | 
|  | * We may wish use just one timer maintaining a list of expire jiffies | 
|  | * to optimize. | 
|  | */ | 
|  | void inet_csk_init_xmit_timers(struct sock *sk, | 
|  | void (*retransmit_handler)(unsigned long), | 
|  | void (*delack_handler)(unsigned long), | 
|  | void (*keepalive_handler)(unsigned long)) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  |  | 
|  | setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler, | 
|  | (unsigned long)sk); | 
|  | setup_timer(&icsk->icsk_delack_timer, delack_handler, | 
|  | (unsigned long)sk); | 
|  | setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk); | 
|  | icsk->icsk_pending = icsk->icsk_ack.pending = 0; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_init_xmit_timers); | 
|  |  | 
|  | void inet_csk_clear_xmit_timers(struct sock *sk) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  |  | 
|  | icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0; | 
|  |  | 
|  | sk_stop_timer(sk, &icsk->icsk_retransmit_timer); | 
|  | sk_stop_timer(sk, &icsk->icsk_delack_timer); | 
|  | sk_stop_timer(sk, &sk->sk_timer); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_clear_xmit_timers); | 
|  |  | 
|  | void inet_csk_delete_keepalive_timer(struct sock *sk) | 
|  | { | 
|  | sk_stop_timer(sk, &sk->sk_timer); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); | 
|  |  | 
|  | void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) | 
|  | { | 
|  | sk_reset_timer(sk, &sk->sk_timer, jiffies + len); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); | 
|  |  | 
|  | struct dst_entry *inet_csk_route_req(struct sock *sk, | 
|  | const struct request_sock *req) | 
|  | { | 
|  | struct rtable *rt; | 
|  | const struct inet_request_sock *ireq = inet_rsk(req); | 
|  | struct ip_options *opt = inet_rsk(req)->opt; | 
|  | struct flowi fl = { .oif = sk->sk_bound_dev_if, | 
|  | .mark = sk->sk_mark, | 
|  | .nl_u = { .ip4_u = | 
|  | { .daddr = ((opt && opt->srr) ? | 
|  | opt->faddr : | 
|  | ireq->rmt_addr), | 
|  | .saddr = ireq->loc_addr, | 
|  | .tos = RT_CONN_FLAGS(sk) } }, | 
|  | .proto = sk->sk_protocol, | 
|  | .flags = inet_sk_flowi_flags(sk), | 
|  | .uli_u = { .ports = | 
|  | { .sport = inet_sk(sk)->inet_sport, | 
|  | .dport = ireq->rmt_port } } }; | 
|  | struct net *net = sock_net(sk); | 
|  |  | 
|  | security_req_classify_flow(req, &fl); | 
|  | if (ip_route_output_flow(net, &rt, &fl, sk, 0)) | 
|  | goto no_route; | 
|  | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) | 
|  | goto route_err; | 
|  | return &rt->u.dst; | 
|  |  | 
|  | route_err: | 
|  | ip_rt_put(rt); | 
|  | no_route: | 
|  | IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_route_req); | 
|  |  | 
|  | static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport, | 
|  | const u32 rnd, const u32 synq_hsize) | 
|  | { | 
|  | return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1); | 
|  | } | 
|  |  | 
|  | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | 
|  | #define AF_INET_FAMILY(fam) ((fam) == AF_INET) | 
|  | #else | 
|  | #define AF_INET_FAMILY(fam) 1 | 
|  | #endif | 
|  |  | 
|  | struct request_sock *inet_csk_search_req(const struct sock *sk, | 
|  | struct request_sock ***prevp, | 
|  | const __be16 rport, const __be32 raddr, | 
|  | const __be32 laddr) | 
|  | { | 
|  | const struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | 
|  | struct request_sock *req, **prev; | 
|  |  | 
|  | for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd, | 
|  | lopt->nr_table_entries)]; | 
|  | (req = *prev) != NULL; | 
|  | prev = &req->dl_next) { | 
|  | const struct inet_request_sock *ireq = inet_rsk(req); | 
|  |  | 
|  | if (ireq->rmt_port == rport && | 
|  | ireq->rmt_addr == raddr && | 
|  | ireq->loc_addr == laddr && | 
|  | AF_INET_FAMILY(req->rsk_ops->family)) { | 
|  | WARN_ON(req->sk); | 
|  | *prevp = prev; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | return req; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_search_req); | 
|  |  | 
|  | void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, | 
|  | unsigned long timeout) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | 
|  | const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, | 
|  | lopt->hash_rnd, lopt->nr_table_entries); | 
|  |  | 
|  | reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); | 
|  | inet_csk_reqsk_queue_added(sk, timeout); | 
|  | } | 
|  |  | 
|  | /* Only thing we need from tcp.h */ | 
|  | extern int sysctl_tcp_synack_retries; | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); | 
|  |  | 
|  | /* Decide when to expire the request and when to resend SYN-ACK */ | 
|  | static inline void syn_ack_recalc(struct request_sock *req, const int thresh, | 
|  | const int max_retries, | 
|  | const u8 rskq_defer_accept, | 
|  | int *expire, int *resend) | 
|  | { | 
|  | if (!rskq_defer_accept) { | 
|  | *expire = req->retrans >= thresh; | 
|  | *resend = 1; | 
|  | return; | 
|  | } | 
|  | *expire = req->retrans >= thresh && | 
|  | (!inet_rsk(req)->acked || req->retrans >= max_retries); | 
|  | /* | 
|  | * Do not resend while waiting for data after ACK, | 
|  | * start to resend on end of deferring period to give | 
|  | * last chance for data or ACK to create established socket. | 
|  | */ | 
|  | *resend = !inet_rsk(req)->acked || | 
|  | req->retrans >= rskq_defer_accept - 1; | 
|  | } | 
|  |  | 
|  | void inet_csk_reqsk_queue_prune(struct sock *parent, | 
|  | const unsigned long interval, | 
|  | const unsigned long timeout, | 
|  | const unsigned long max_rto) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(parent); | 
|  | struct request_sock_queue *queue = &icsk->icsk_accept_queue; | 
|  | struct listen_sock *lopt = queue->listen_opt; | 
|  | int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; | 
|  | int thresh = max_retries; | 
|  | unsigned long now = jiffies; | 
|  | struct request_sock **reqp, *req; | 
|  | int i, budget; | 
|  |  | 
|  | if (lopt == NULL || lopt->qlen == 0) | 
|  | return; | 
|  |  | 
|  | /* Normally all the openreqs are young and become mature | 
|  | * (i.e. converted to established socket) for first timeout. | 
|  | * If synack was not acknowledged for 3 seconds, it means | 
|  | * one of the following things: synack was lost, ack was lost, | 
|  | * rtt is high or nobody planned to ack (i.e. synflood). | 
|  | * When server is a bit loaded, queue is populated with old | 
|  | * open requests, reducing effective size of queue. | 
|  | * When server is well loaded, queue size reduces to zero | 
|  | * after several minutes of work. It is not synflood, | 
|  | * it is normal operation. The solution is pruning | 
|  | * too old entries overriding normal timeout, when | 
|  | * situation becomes dangerous. | 
|  | * | 
|  | * Essentially, we reserve half of room for young | 
|  | * embrions; and abort old ones without pity, if old | 
|  | * ones are about to clog our table. | 
|  | */ | 
|  | if (lopt->qlen>>(lopt->max_qlen_log-1)) { | 
|  | int young = (lopt->qlen_young<<1); | 
|  |  | 
|  | while (thresh > 2) { | 
|  | if (lopt->qlen < young) | 
|  | break; | 
|  | thresh--; | 
|  | young <<= 1; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (queue->rskq_defer_accept) | 
|  | max_retries = queue->rskq_defer_accept; | 
|  |  | 
|  | budget = 2 * (lopt->nr_table_entries / (timeout / interval)); | 
|  | i = lopt->clock_hand; | 
|  |  | 
|  | do { | 
|  | reqp=&lopt->syn_table[i]; | 
|  | while ((req = *reqp) != NULL) { | 
|  | if (time_after_eq(now, req->expires)) { | 
|  | int expire = 0, resend = 0; | 
|  |  | 
|  | syn_ack_recalc(req, thresh, max_retries, | 
|  | queue->rskq_defer_accept, | 
|  | &expire, &resend); | 
|  | if (req->rsk_ops->syn_ack_timeout) | 
|  | req->rsk_ops->syn_ack_timeout(parent, req); | 
|  | if (!expire && | 
|  | (!resend || | 
|  | !req->rsk_ops->rtx_syn_ack(parent, req, NULL) || | 
|  | inet_rsk(req)->acked)) { | 
|  | unsigned long timeo; | 
|  |  | 
|  | if (req->retrans++ == 0) | 
|  | lopt->qlen_young--; | 
|  | timeo = min((timeout << req->retrans), max_rto); | 
|  | req->expires = now + timeo; | 
|  | reqp = &req->dl_next; | 
|  | continue; | 
|  | } | 
|  |  | 
|  | /* Drop this request */ | 
|  | inet_csk_reqsk_queue_unlink(parent, req, reqp); | 
|  | reqsk_queue_removed(queue, req); | 
|  | reqsk_free(req); | 
|  | continue; | 
|  | } | 
|  | reqp = &req->dl_next; | 
|  | } | 
|  |  | 
|  | i = (i + 1) & (lopt->nr_table_entries - 1); | 
|  |  | 
|  | } while (--budget > 0); | 
|  |  | 
|  | lopt->clock_hand = i; | 
|  |  | 
|  | if (lopt->qlen) | 
|  | inet_csk_reset_keepalive_timer(parent, interval); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune); | 
|  |  | 
|  | struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req, | 
|  | const gfp_t priority) | 
|  | { | 
|  | struct sock *newsk = sk_clone(sk, priority); | 
|  |  | 
|  | if (newsk != NULL) { | 
|  | struct inet_connection_sock *newicsk = inet_csk(newsk); | 
|  |  | 
|  | newsk->sk_state = TCP_SYN_RECV; | 
|  | newicsk->icsk_bind_hash = NULL; | 
|  |  | 
|  | inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port; | 
|  | inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port); | 
|  | inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port; | 
|  | newsk->sk_write_space = sk_stream_write_space; | 
|  |  | 
|  | newicsk->icsk_retransmits = 0; | 
|  | newicsk->icsk_backoff	  = 0; | 
|  | newicsk->icsk_probes_out  = 0; | 
|  |  | 
|  | /* Deinitialize accept_queue to trap illegal accesses. */ | 
|  | memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); | 
|  |  | 
|  | security_inet_csk_clone(newsk, req); | 
|  | } | 
|  | return newsk; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_clone); | 
|  |  | 
|  | /* | 
|  | * At this point, there should be no process reference to this | 
|  | * socket, and thus no user references at all.  Therefore we | 
|  | * can assume the socket waitqueue is inactive and nobody will | 
|  | * try to jump onto it. | 
|  | */ | 
|  | void inet_csk_destroy_sock(struct sock *sk) | 
|  | { | 
|  | WARN_ON(sk->sk_state != TCP_CLOSE); | 
|  | WARN_ON(!sock_flag(sk, SOCK_DEAD)); | 
|  |  | 
|  | /* It cannot be in hash table! */ | 
|  | WARN_ON(!sk_unhashed(sk)); | 
|  |  | 
|  | /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ | 
|  | WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); | 
|  |  | 
|  | sk->sk_prot->destroy(sk); | 
|  |  | 
|  | sk_stream_kill_queues(sk); | 
|  |  | 
|  | xfrm_sk_free_policy(sk); | 
|  |  | 
|  | sk_refcnt_debug_release(sk); | 
|  |  | 
|  | percpu_counter_dec(sk->sk_prot->orphan_count); | 
|  | sock_put(sk); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(inet_csk_destroy_sock); | 
|  |  | 
|  | int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) | 
|  | { | 
|  | struct inet_sock *inet = inet_sk(sk); | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); | 
|  |  | 
|  | if (rc != 0) | 
|  | return rc; | 
|  |  | 
|  | sk->sk_max_ack_backlog = 0; | 
|  | sk->sk_ack_backlog = 0; | 
|  | inet_csk_delack_init(sk); | 
|  |  | 
|  | /* 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 | 
|  | * after validation is complete. | 
|  | */ | 
|  | sk->sk_state = TCP_LISTEN; | 
|  | if (!sk->sk_prot->get_port(sk, inet->inet_num)) { | 
|  | inet->inet_sport = htons(inet->inet_num); | 
|  |  | 
|  | sk_dst_reset(sk); | 
|  | sk->sk_prot->hash(sk); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | sk->sk_state = TCP_CLOSE; | 
|  | __reqsk_queue_destroy(&icsk->icsk_accept_queue); | 
|  | return -EADDRINUSE; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_listen_start); | 
|  |  | 
|  | /* | 
|  | *	This routine closes sockets which have been at least partially | 
|  | *	opened, but not yet accepted. | 
|  | */ | 
|  | void inet_csk_listen_stop(struct sock *sk) | 
|  | { | 
|  | struct inet_connection_sock *icsk = inet_csk(sk); | 
|  | struct request_sock *acc_req; | 
|  | struct request_sock *req; | 
|  |  | 
|  | inet_csk_delete_keepalive_timer(sk); | 
|  |  | 
|  | /* make all the listen_opt local to us */ | 
|  | acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue); | 
|  |  | 
|  | /* Following specs, it would be better either to send FIN | 
|  | * (and enter FIN-WAIT-1, it is normal close) | 
|  | * or to send active reset (abort). | 
|  | * Certainly, it is pretty dangerous while synflood, but it is | 
|  | * bad justification for our negligence 8) | 
|  | * To be honest, we are not able to make either | 
|  | * of the variants now.			--ANK | 
|  | */ | 
|  | reqsk_queue_destroy(&icsk->icsk_accept_queue); | 
|  |  | 
|  | while ((req = acc_req) != NULL) { | 
|  | struct sock *child = req->sk; | 
|  |  | 
|  | acc_req = req->dl_next; | 
|  |  | 
|  | local_bh_disable(); | 
|  | bh_lock_sock(child); | 
|  | WARN_ON(sock_owned_by_user(child)); | 
|  | sock_hold(child); | 
|  |  | 
|  | sk->sk_prot->disconnect(child, O_NONBLOCK); | 
|  |  | 
|  | sock_orphan(child); | 
|  |  | 
|  | percpu_counter_inc(sk->sk_prot->orphan_count); | 
|  |  | 
|  | inet_csk_destroy_sock(child); | 
|  |  | 
|  | bh_unlock_sock(child); | 
|  | local_bh_enable(); | 
|  | sock_put(child); | 
|  |  | 
|  | sk_acceptq_removed(sk); | 
|  | __reqsk_free(req); | 
|  | } | 
|  | WARN_ON(sk->sk_ack_backlog); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_listen_stop); | 
|  |  | 
|  | void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) | 
|  | { | 
|  | struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; | 
|  | const struct inet_sock *inet = inet_sk(sk); | 
|  |  | 
|  | sin->sin_family		= AF_INET; | 
|  | sin->sin_addr.s_addr	= inet->inet_daddr; | 
|  | sin->sin_port		= inet->inet_dport; | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); | 
|  |  | 
|  | #ifdef CONFIG_COMPAT | 
|  | int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, | 
|  | char __user *optval, int __user *optlen) | 
|  | { | 
|  | const struct inet_connection_sock *icsk = inet_csk(sk); | 
|  |  | 
|  | if (icsk->icsk_af_ops->compat_getsockopt != NULL) | 
|  | return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname, | 
|  | optval, optlen); | 
|  | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | 
|  | optval, optlen); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt); | 
|  |  | 
|  | int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, | 
|  | char __user *optval, unsigned int optlen) | 
|  | { | 
|  | const struct inet_connection_sock *icsk = inet_csk(sk); | 
|  |  | 
|  | if (icsk->icsk_af_ops->compat_setsockopt != NULL) | 
|  | return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname, | 
|  | optval, optlen); | 
|  | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | 
|  | optval, optlen); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt); | 
|  | #endif |