cregit-Linux how code gets into the kernel

Release 4.11 net/ipv4/inet_connection_sock.c

Directory: net/ipv4
/*
 * 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>
#include <net/sock_reuseport.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

#if IS_ENABLED(CONFIG_IPV6)
/* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
 *                          only, and any IPv4 addresses if not IPv6 only
 * match_wildcard == false: addresses must be exactly the same, i.e.
 *                          IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
 *                          and 0.0.0.0 equals to 0.0.0.0 only
 */



static int ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
				const struct in6_addr *sk2_rcv_saddr6,
				__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
				bool sk1_ipv6only, bool sk2_ipv6only,
				bool match_wildcard)
{
	int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;

	/* if both are mapped, treat as IPv4 */
	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
		if (!sk2_ipv6only) {
			if (sk1_rcv_saddr == sk2_rcv_saddr)
				return 1;
			if (!sk1_rcv_saddr || !sk2_rcv_saddr)
				return match_wildcard;
		}
		return 0;
	}

	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
		return 1;

	if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
		return 1;

	if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
	    !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
		return 1;

	if (sk2_rcv_saddr6 &&
	    ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
		return 1;

	return 0;
}

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Total166100.00%2100.00%



#endif

/* match_wildcard == true:  0.0.0.0 equals to any IPv4 addresses
 * match_wildcard == false: addresses must be exactly the same, i.e.
 *                          0.0.0.0 only equals to 0.0.0.0
 */



static int ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
				bool sk2_ipv6only, bool match_wildcard)
{
	if (!sk2_ipv6only) {
		if (sk1_rcv_saddr == sk2_rcv_saddr)
			return 1;
		if (!sk1_rcv_saddr || !sk2_rcv_saddr)
			return match_wildcard;
	}
	return 0;
}


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Total48100.00%2100.00%






int inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
			 bool match_wildcard)
{
#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == AF_INET6)
		return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
					    inet6_rcv_saddr(sk2),
					    sk->sk_rcv_saddr,
					    sk2->sk_rcv_saddr,
					    ipv6_only_sock(sk),
					    ipv6_only_sock(sk2),
					    match_wildcard);
#endif
	return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
				    ipv6_only_sock(sk2), match_wildcard);
}

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Total89100.00%3100.00%




EXPORT_SYMBOL(inet_rcv_saddr_equal);




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));
}

Contributors
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Stephen Hemminger5059.52%120.00%


Eric W. Biedermann2125.00%120.00%


Eric Dumazet910.71%240.00%


Américo Wang44.76%120.00%


Total84100.00%5100.00%




EXPORT_SYMBOL(inet_get_local_port_range);




static int inet_csk_bind_conflict(const struct sock *sk,
				  const struct inet_bind_bucket *tb,
				  bool relax, bool reuseport_ok)
{
	struct sock *sk2;
	bool reuse = sk->sk_reuse;
	bool reuseport = !!sk->sk_reuseport && reuseport_ok;
	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 &&
		    (!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 ||
			     rcu_access_pointer(sk->sk_reuseport_cb) ||
			     (sk2->sk_state != TCP_TIME_WAIT &&
			     !uid_eq(uid, sock_i_uid(sk2))))) {
				if (inet_rcv_saddr_equal(sk, sk2, true))
					break;
			}
			if (!relax && reuse && sk2->sk_reuse &&
			    sk2->sk_state != TCP_LISTEN) {
				if (inet_rcv_saddr_equal(sk, sk2, true))
					break;
			}
		}
	}
	return sk2 != NULL;
}


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Arnaldo Carvalho de Melo8843.78%216.67%


Tom Herbert5929.35%216.67%


Alexandru Copot2713.43%18.33%


Josef Bacik136.47%18.33%


Craig Gallek73.48%18.33%


Eric Dumazet31.49%216.67%


David S. Miller21.00%18.33%


Pavel Emelyanov10.50%18.33%


Sasha Levin10.50%18.33%


Total201100.00%12100.00%



/*
 * Find an open port number for the socket.  Returns with the
 * inet_bind_hashbucket lock held.
 */


static struct inet_bind_hashbucket *

inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret)
{
	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
	int port = 0;
	struct inet_bind_hashbucket *head;
	struct net *net = sock_net(sk);
	int i, low, high, attempt_half;
	struct inet_bind_bucket *tb;
	u32 remaining, offset;

	attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
other_half_scan:
	inet_get_local_port_range(net, &low, &high);
	high++; /* [32768, 60999] -> [32768, 61000[ */
	if (high - low < 4)
		attempt_half = 0;
	if (attempt_half) {
		int half = low + (((high - low) >> 2) << 1);

		if (attempt_half == 1)
			high = half;
		else
			low = half;
	}
	remaining = high - low;
	if (likely(remaining > 1))
		remaining &= ~1U;

	offset = prandom_u32() % remaining;
	/* __inet_hash_connect() favors ports having @low parity
         * We do the opposite to not pollute connect() users.
         */
	offset |= 1U;

other_parity_scan:
	port = low + offset;
	for (i = 0; i < remaining; i += 2, port += 2) {
		if (unlikely(port >= high))
			port -= remaining;
		if (inet_is_local_reserved_port(net, port))
			continue;
		head = &hinfo->bhash[inet_bhashfn(net, port,
						  hinfo->bhash_size)];
		spin_lock_bh(&head->lock);
		inet_bind_bucket_for_each(tb, &head->chain)
			if (net_eq(ib_net(tb), net) && tb->port == port) {
				if (!inet_csk_bind_conflict(sk, tb, false, false))
					goto success;
				goto next_port;
			}
		tb = NULL;
		goto success;
next_port:
		spin_unlock_bh(&head->lock);
		cond_resched();
	}

	offset--;
	if (!(offset & 1))
		goto other_parity_scan;

	if (attempt_half == 1) {
		/* OK we now try the upper half of the range */
		attempt_half = 2;
		goto other_half_scan;
	}
	return NULL;
success:
	*port_ret = port;
	*tb_ret = tb;
	return head;
}


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Eric Dumazet20052.22%312.00%


Arnaldo Carvalho de Melo7018.28%312.00%


Josef Bacik4110.70%312.00%


Stephen Hemminger164.18%28.00%


Pavel Emelyanov164.18%312.00%


Flavio Leitner92.35%14.00%


Evgeniy Polyakov92.35%14.00%


Américo Wang82.09%28.00%


Octavian Purdila41.04%14.00%


Hideaki Yoshifuji / 吉藤英明30.78%14.00%


Alexandru Copot20.52%14.00%


Eric W. Biedermann20.52%14.00%


Aruna-Hewapathirane10.26%14.00%


Tom Herbert10.26%14.00%


Anton Arapov10.26%14.00%


Total383100.00%25100.00%






static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
				     struct sock *sk)
{
	kuid_t uid = sock_i_uid(sk);

	if (tb->fastreuseport <= 0)
		return 0;
	if (!sk->sk_reuseport)
		return 0;
	if (rcu_access_pointer(sk->sk_reuseport_cb))
		return 0;
	if (!uid_eq(tb->fastuid, uid))
		return 0;
	/* We only need to check the rcv_saddr if this tb was once marked
         * without fastreuseport and then was reset, as we can only know that
         * the fast_*rcv_saddr doesn't have any conflicts with the socks on the
         * owners list.
         */
	if (tb->fastreuseport == FASTREUSEPORT_ANY)
		return 1;
#if IS_ENABLED(CONFIG_IPV6)
	if (tb->fast_sk_family == AF_INET6)
		return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
					    &sk->sk_v6_rcv_saddr,
					    tb->fast_rcv_saddr,
					    sk->sk_rcv_saddr,
					    tb->fast_ipv6_only,
					    ipv6_only_sock(sk), true);
#endif
	return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
				    ipv6_only_sock(sk), true);
}


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Total153100.00%1100.00%



/* Obtain a reference to a local port for the given sock,
 * if snum is zero it means select any available local port.
 * We try to allocate an odd port (and leave even ports for connect())
 */



int inet_csk_get_port(struct sock *sk, unsigned short snum)
{
	bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
	int ret = 1, port = snum;
	struct inet_bind_hashbucket *head;
	struct net *net = sock_net(sk);
	struct inet_bind_bucket *tb = NULL;
	kuid_t uid = sock_i_uid(sk);

	if (!port) {
		head = inet_csk_find_open_port(sk, &tb, &port);
		if (!head)
			return ret;
		if (!tb)
			goto tb_not_found;
		goto success;
	}
	head = &hinfo->bhash[inet_bhashfn(net, port,
					  hinfo->bhash_size)];
	spin_lock_bh(&head->lock);
	inet_bind_bucket_for_each(tb, &head->chain)
		if (net_eq(ib_net(tb), net) && tb->port == port)
			goto tb_found;
tb_not_found:
	tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
				     net, head, port);
	if (!tb)
		goto fail_unlock;
tb_found:
	if (!hlist_empty(&tb->owners)) {
		if (sk->sk_reuse == SK_FORCE_REUSE)
			goto success;

		if ((tb->fastreuse > 0 && reuse) ||
		    sk_reuseport_match(tb, sk))
			goto success;
		if (inet_csk_bind_conflict(sk, tb, true, true))
			goto fail_unlock;
	}
success:
	if (!hlist_empty(&tb->owners)) {
		tb->fastreuse = reuse;
		if (sk->sk_reuseport) {
			tb->fastreuseport = FASTREUSEPORT_ANY;
			tb->fastuid = uid;
			tb->fast_rcv_saddr = sk->sk_rcv_saddr;
			tb->fast_ipv6_only = ipv6_only_sock(sk);
#if IS_ENABLED(CONFIG_IPV6)
			tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
#endif
		} else {
			tb->fastreuseport = 0;
		}
	} else {
		if (!reuse)
			tb->fastreuse = 0;
		if (sk->sk_reuseport) {
			/* We didn't match or we don't have fastreuseport set on
                         * the tb, but we have sk_reuseport set on this socket
                         * and we know that there are no bind conflicts with
                         * this socket in this tb, so reset our tb's reuseport
                         * settings so that any subsequent sockets that match
                         * our current socket will be put on the fast path.
                         *
                         * If we reset we need to set FASTREUSEPORT_STRICT so we
                         * do extra checking for all subsequent sk_reuseport
                         * socks.
                         */
			if (!sk_reuseport_match(tb, sk)) {
				tb->fastreuseport = FASTREUSEPORT_STRICT;
				tb->fastuid = uid;
				tb->fast_rcv_saddr = sk->sk_rcv_saddr;
				tb->fast_ipv6_only = ipv6_only_sock(sk);
#if IS_ENABLED(CONFIG_IPV6)
				tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
#endif
			}
		} else {
			tb->fastreuseport = 0;
		}
	}
	if (!inet_csk(sk)->icsk_bind_hash)
		inet_bind_hash(sk, tb, port);
	WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
	ret = 0;

fail_unlock:
	spin_unlock_bh(&head->lock);
	return ret;
}

Contributors
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Josef Bacik29661.54%426.67%


Arnaldo Carvalho de Melo10722.25%16.67%


Tom Herbert285.82%213.33%


Eric Dumazet275.61%16.67%


Pavel Emelyanov132.70%320.00%


Evgeniy Polyakov51.04%16.67%


Ilpo Järvinen20.42%16.67%


Alexandru Copot20.42%16.67%


Craig Gallek10.21%16.67%


Total481100.00%15100.00%




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;
}


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Eric Dumazet95.88%266.67%


Total153100.00%3100.00%



/*
 * This will accept the next outstanding connection.
 */



struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
{
	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, sk);
	newsk = req->sk;

	if (sk->sk_protocol == IPPROTO_TCP &&
	    tcp_rsk(req)->tfo_listener) {
		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;
}

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Arnaldo Carvalho de Melo14359.58%111.11%


Jerry Chu7631.67%111.11%


Eric Dumazet187.50%666.67%


David Howells31.25%111.11%


Total240100.00%9100.00%




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;
}

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Pavel Emelyanov2220.00%150.00%


Total110100.00%2100.00%




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);
}

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Total68100.00%1100.00%




EXPORT_SYMBOL(inet_csk_clear_xmit_timers);




void inet_csk_delete_keepalive_timer(struct sock *sk)
{
	sk_stop_timer(sk, &sk->sk_timer);
}

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Total20100.00%1100.00%




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);
}

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Total28100.00%1100.00%




EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);




struct dst_entry *inet_csk_route_req(const 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), sk->sk_uid);
	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(net, IPSTATS_MIB_OUTNOROUTES);
	return NULL;
}

Contributors
PersonTokensPropCommitsCommitProp
Arnaldo Carvalho de Melo8340.89%14.76%


David S. Miller4723.15%419.05%


Eric Dumazet3818.72%628.57%


Ilpo Järvinen167.88%14.76%


Venkat Yekkirala62.96%29.52%


Lorenzo Colitti62.96%29.52%


Pavel Emelyanov41.97%29.52%


Atis Elsts10.49%14.76%


Denis V. Lunev10.49%14.76%


Julian Anastasov10.49%14.76%


Total203100.00%21100.00%




EXPORT_SYMBOL_GPL(inet_csk_route_req);




struct dst_entry *inet_csk_route_child_sock(const 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), sk->sk_uid);
	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(net, IPSTATS_MIB_OUTNOROUTES);
	return NULL;
}

Contributors
PersonTokensPropCommitsCommitProp
David S. Miller19680.00%111.11%


Eric Dumazet2510.20%444.44%


Christoph Paasch187.35%111.11%


Lorenzo Colitti52.04%222.22%


Julian Anastasov10.41%111.11%


Total245100.00%9100.00%




EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);

#if IS_ENABLED(CONFIG_IPV6)

#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
#else

#define AF_INET_FAMILY(fam) true
#endif

/* 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