diff options
Diffstat (limited to 'net/ipv4/inet_connection_sock.c')
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 978 |
1 files changed, 978 insertions, 0 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c new file mode 100644 index 000000000..8976ca423 --- /dev/null +++ b/net/ipv4/inet_connection_sock.c @@ -0,0 +1,978 @@ +/* + * 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> +#include <net/tcp.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 + +void inet_get_local_port_range(struct net *net, int *low, int *high) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&net->ipv4.ip_local_ports.lock); + + *low = net->ipv4.ip_local_ports.range[0]; + *high = net->ipv4.ip_local_ports.range[1]; + } while (read_seqretry(&net->ipv4.ip_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, bool relax) +{ + struct sock *sk2; + int reuse = sk->sk_reuse; + int reuseport = sk->sk_reuseport; + kuid_t uid = sock_i_uid((struct sock *)sk); + + /* + * 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, &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) && + (!reuseport || !sk2->sk_reuseport || + (sk2->sk_state != TCP_TIME_WAIT && + !uid_eq(uid, sock_i_uid(sk2))))) { + + if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr || + sk2->sk_rcv_saddr == sk->sk_rcv_saddr) + break; + } + if (!relax && reuse && sk2->sk_reuse && + sk2->sk_state != TCP_LISTEN) { + + if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr || + sk2->sk_rcv_saddr == sk->sk_rcv_saddr) + break; + } + } + } + return sk2 != 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 inet_bind_bucket *tb; + int ret, attempts = 5; + struct net *net = sock_net(sk); + int smallest_size = -1, smallest_rover; + kuid_t uid = sock_i_uid(sk); + + local_bh_disable(); + if (!snum) { + int remaining, rover, low, high; + +again: + inet_get_local_port_range(net, &low, &high); + remaining = (high - low) + 1; + smallest_rover = rover = prandom_u32() % remaining + low; + + smallest_size = -1; + do { + if (inet_is_local_reserved_port(net, rover)) + goto next_nolock; + head = &hashinfo->bhash[inet_bhashfn(net, rover, + hashinfo->bhash_size)]; + spin_lock(&head->lock); + inet_bind_bucket_for_each(tb, &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->fastreuseport > 0 && + sk->sk_reuseport && + uid_eq(tb->fastuid, uid))) && + (tb->num_owners < smallest_size || smallest_size == -1)) { + smallest_size = tb->num_owners; + smallest_rover = rover; + if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 && + !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { + snum = smallest_rover; + goto tb_found; + } + } + if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { + snum = rover; + goto tb_found; + } + goto next; + } + break; + next: + spin_unlock(&head->lock); + next_nolock: + 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, &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 (sk->sk_reuse == SK_FORCE_REUSE) + goto success; + + if (((tb->fastreuse > 0 && + sk->sk_reuse && sk->sk_state != TCP_LISTEN) || + (tb->fastreuseport > 0 && + sk->sk_reuseport && uid_eq(tb->fastuid, uid))) && + smallest_size == -1) { + goto success; + } else { + ret = 1; + if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) { + if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) || + (tb->fastreuseport > 0 && + sk->sk_reuseport && uid_eq(tb->fastuid, uid))) && + 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; + if (sk->sk_reuseport) { + tb->fastreuseport = 1; + tb->fastuid = uid; + } else + tb->fastreuseport = 0; + } else { + if (tb->fastreuse && + (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) + tb->fastreuse = 0; + if (tb->fastreuseport && + (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))) + tb->fastreuseport = 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); + sched_annotate_sleep(); + 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 request_sock_queue *queue = &icsk->icsk_accept_queue; + struct request_sock *req; + 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(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; + } + req = reqsk_queue_remove(queue); + newsk = req->sk; + + sk_acceptq_removed(sk); + if (sk->sk_protocol == IPPROTO_TCP && + tcp_rsk(req)->tfo_listener && + queue->fastopenq) { + spin_lock_bh(&queue->fastopenq->lock); + if (tcp_rsk(req)->tfo_listener) { + /* We are still waiting for the final ACK from 3WHS + * so can't free req now. Instead, we set req->sk to + * NULL to signify that the child socket is taken + * so reqsk_fastopen_remove() will free the req + * when 3WHS finishes (or is aborted). + */ + req->sk = NULL; + req = NULL; + } + spin_unlock_bh(&queue->fastopenq->lock); + } +out: + release_sock(sk); + if (req) + reqsk_put(req); + return newsk; +out_err: + newsk = NULL; + req = 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, + struct flowi4 *fl4, + const struct request_sock *req) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + struct net *net = read_pnet(&ireq->ireq_net); + struct ip_options_rcu *opt = ireq->opt; + struct rtable *rt; + + flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + sk->sk_protocol, inet_sk_flowi_flags(sk), + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, + ireq->ir_loc_addr, ireq->ir_rmt_port, + htons(ireq->ir_num)); + security_req_classify_flow(req, flowi4_to_flowi(fl4)); + rt = ip_route_output_flow(net, fl4, sk); + if (IS_ERR(rt)) + goto no_route; + if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) + goto route_err; + return &rt->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); + +struct dst_entry *inet_csk_route_child_sock(struct sock *sk, + struct sock *newsk, + const struct request_sock *req) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + struct net *net = read_pnet(&ireq->ireq_net); + struct inet_sock *newinet = inet_sk(newsk); + struct ip_options_rcu *opt; + struct flowi4 *fl4; + struct rtable *rt; + + fl4 = &newinet->cork.fl.u.ip4; + + rcu_read_lock(); + opt = rcu_dereference(newinet->inet_opt); + flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + sk->sk_protocol, inet_sk_flowi_flags(sk), + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, + ireq->ir_loc_addr, ireq->ir_rmt_port, + htons(ireq->ir_num)); + security_req_classify_flow(req, flowi4_to_flowi(fl4)); + rt = ip_route_output_flow(net, fl4, sk); + if (IS_ERR(rt)) + goto no_route; + if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) + goto route_err; + rcu_read_unlock(); + return &rt->dst; + +route_err: + ip_rt_put(rt); +no_route: + rcu_read_unlock(); + IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); + return NULL; +} +EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); + +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 IS_ENABLED(CONFIG_IPV6) +#define AF_INET_FAMILY(fam) ((fam) == AF_INET) +#else +#define AF_INET_FAMILY(fam) true +#endif + +/* Note: this is temporary : + * req sock will no longer be in listener hash table +*/ +struct request_sock *inet_csk_search_req(struct sock *sk, + const __be16 rport, + const __be32 raddr, + const __be32 laddr) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; + struct request_sock *req; + u32 hash = inet_synq_hash(raddr, rport, lopt->hash_rnd, + lopt->nr_table_entries); + + spin_lock(&icsk->icsk_accept_queue.syn_wait_lock); + for (req = lopt->syn_table[hash]; req != NULL; req = req->dl_next) { + const struct inet_request_sock *ireq = inet_rsk(req); + + if (ireq->ir_rmt_port == rport && + ireq->ir_rmt_addr == raddr && + ireq->ir_loc_addr == laddr && + AF_INET_FAMILY(req->rsk_ops->family)) { + atomic_inc(&req->rsk_refcnt); + WARN_ON(req->sk); + break; + } + } + spin_unlock(&icsk->icsk_accept_queue.syn_wait_lock); + + 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)->ir_rmt_addr, + inet_rsk(req)->ir_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); +} +EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); + +/* Only thing we need from tcp.h */ +extern int sysctl_tcp_synack_retries; + + +/* 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->num_timeout >= thresh; + *resend = 1; + return; + } + *expire = req->num_timeout >= thresh && + (!inet_rsk(req)->acked || req->num_timeout >= 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->num_timeout >= rskq_defer_accept - 1; +} + +int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req) +{ + int err = req->rsk_ops->rtx_syn_ack(parent, req); + + if (!err) + req->num_retrans++; + return err; +} +EXPORT_SYMBOL(inet_rtx_syn_ack); + +/* return true if req was found in the syn_table[] */ +static bool reqsk_queue_unlink(struct request_sock_queue *queue, + struct request_sock *req) +{ + struct listen_sock *lopt = queue->listen_opt; + struct request_sock **prev; + bool found = false; + + spin_lock(&queue->syn_wait_lock); + + for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL; + prev = &(*prev)->dl_next) { + if (*prev == req) { + *prev = req->dl_next; + found = true; + break; + } + } + + spin_unlock(&queue->syn_wait_lock); + if (del_timer(&req->rsk_timer)) + reqsk_put(req); + return found; +} + +void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) +{ + if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) { + reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); + reqsk_put(req); + } +} +EXPORT_SYMBOL(inet_csk_reqsk_queue_drop); + +static void reqsk_timer_handler(unsigned long data) +{ + struct request_sock *req = (struct request_sock *)data; + struct sock *sk_listener = req->rsk_listener; + struct inet_connection_sock *icsk = inet_csk(sk_listener); + struct request_sock_queue *queue = &icsk->icsk_accept_queue; + struct listen_sock *lopt = queue->listen_opt; + int qlen, expire = 0, resend = 0; + int max_retries, thresh; + u8 defer_accept; + + if (sk_listener->sk_state != TCP_LISTEN || !lopt) { + reqsk_put(req); + return; + } + + max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; + thresh = max_retries; + /* Normally all the openreqs are young and become mature + * (i.e. converted to established socket) for first timeout. + * If synack was not acknowledged for 1 second, 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. + */ + qlen = listen_sock_qlen(lopt); + if (qlen >> (lopt->max_qlen_log - 1)) { + int young = listen_sock_young(lopt) << 1; + + while (thresh > 2) { + if (qlen < young) + break; + thresh--; + young <<= 1; + } + } + defer_accept = READ_ONCE(queue->rskq_defer_accept); + if (defer_accept) + max_retries = defer_accept; + syn_ack_recalc(req, thresh, max_retries, defer_accept, + &expire, &resend); + req->rsk_ops->syn_ack_timeout(req); + if (!expire && + (!resend || + !inet_rtx_syn_ack(sk_listener, req) || + inet_rsk(req)->acked)) { + unsigned long timeo; + + if (req->num_timeout++ == 0) + atomic_inc(&lopt->young_dec); + timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); + mod_timer_pinned(&req->rsk_timer, jiffies + timeo); + return; + } + inet_csk_reqsk_queue_drop(sk_listener, req); + reqsk_put(req); +} + +void reqsk_queue_hash_req(struct request_sock_queue *queue, + u32 hash, struct request_sock *req, + unsigned long timeout) +{ + struct listen_sock *lopt = queue->listen_opt; + + req->num_retrans = 0; + req->num_timeout = 0; + req->sk = NULL; + + /* before letting lookups find us, make sure all req fields + * are committed to memory and refcnt initialized. + */ + smp_wmb(); + atomic_set(&req->rsk_refcnt, 2); + setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req); + req->rsk_hash = hash; + + spin_lock(&queue->syn_wait_lock); + req->dl_next = lopt->syn_table[hash]; + lopt->syn_table[hash] = req; + spin_unlock(&queue->syn_wait_lock); + + mod_timer_pinned(&req->rsk_timer, jiffies + timeout); +} +EXPORT_SYMBOL(reqsk_queue_hash_req); + +/** + * inet_csk_clone_lock - clone an inet socket, and lock its clone + * @sk: the socket to clone + * @req: request_sock + * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) + * + * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) + */ +struct sock *inet_csk_clone_lock(const struct sock *sk, + const struct request_sock *req, + const gfp_t priority) +{ + struct sock *newsk = sk_clone_lock(sk, priority); + + if (newsk) { + 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)->ir_rmt_port; + inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num; + inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num); + newsk->sk_write_space = sk_stream_write_space; + + newsk->sk_mark = inet_rsk(req)->ir_mark; + atomic64_set(&newsk->sk_cookie, + atomic64_read(&inet_rsk(req)->ir_cookie)); + + 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_lock); + +/* + * 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); + +/* This function allows to force a closure of a socket after the call to + * tcp/dccp_create_openreq_child(). + */ +void inet_csk_prepare_forced_close(struct sock *sk) + __releases(&sk->sk_lock.slock) +{ + /* sk_clone_lock locked the socket and set refcnt to 2 */ + bh_unlock_sock(sk); + sock_put(sk); + + /* The below has to be done to allow calling inet_csk_destroy_sock */ + sock_set_flag(sk, SOCK_DEAD); + percpu_counter_inc(sk->sk_prot->orphan_count); + inet_sk(sk)->inet_num = 0; +} +EXPORT_SYMBOL(inet_csk_prepare_forced_close); + +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_queue *queue = &icsk->icsk_accept_queue; + struct request_sock *acc_req; + struct request_sock *req; + + /* make all the listen_opt local to us */ + acc_req = reqsk_queue_yank_acceptq(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(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); + + if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) { + BUG_ON(tcp_sk(child)->fastopen_rsk != req); + BUG_ON(sk != req->rsk_listener); + + /* Paranoid, to prevent race condition if + * an inbound pkt destined for child is + * blocked by sock lock in tcp_v4_rcv(). + * Also to satisfy an assertion in + * tcp_v4_destroy_sock(). + */ + tcp_sk(child)->fastopen_rsk = NULL; + } + inet_csk_destroy_sock(child); + + bh_unlock_sock(child); + local_bh_enable(); + sock_put(child); + + sk_acceptq_removed(sk); + reqsk_put(req); + } + if (queue->fastopenq) { + /* Free all the reqs queued in rskq_rst_head. */ + spin_lock_bh(&queue->fastopenq->lock); + acc_req = queue->fastopenq->rskq_rst_head; + queue->fastopenq->rskq_rst_head = NULL; + spin_unlock_bh(&queue->fastopenq->lock); + while ((req = acc_req) != NULL) { + acc_req = req->dl_next; + reqsk_put(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) + 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) + 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 + +static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + struct flowi4 *fl4; + struct rtable *rt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + fl4 = &fl->u.ip4; + rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, + inet->inet_saddr, inet->inet_dport, + inet->inet_sport, sk->sk_protocol, + RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); + if (IS_ERR(rt)) + rt = NULL; + if (rt) + sk_setup_caps(sk, &rt->dst); + rcu_read_unlock(); + + return &rt->dst; +} + +struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu) +{ + struct dst_entry *dst = __sk_dst_check(sk, 0); + struct inet_sock *inet = inet_sk(sk); + + if (!dst) { + dst = inet_csk_rebuild_route(sk, &inet->cork.fl); + if (!dst) + goto out; + } + dst->ops->update_pmtu(dst, sk, NULL, mtu); + + dst = __sk_dst_check(sk, 0); + if (!dst) + dst = inet_csk_rebuild_route(sk, &inet->cork.fl); +out: + return dst; +} +EXPORT_SYMBOL_GPL(inet_csk_update_pmtu); |