cregit-Linux how code gets into the kernel

Release 4.11 net/sctp/input.c

Directory: net/sctp
/* SCTP kernel implementation
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2003 International Business Machines, Corp.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel implementation
 *
 * These functions handle all input from the IP layer into SCTP.
 *
 * This SCTP implementation 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, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson <karl@athena.chicago.il.us>
 *    Xingang Guo <xingang.guo@intel.com>
 *    Jon Grimm <jgrimm@us.ibm.com>
 *    Hui Huang <hui.huang@nokia.com>
 *    Daisy Chang <daisyc@us.ibm.com>
 *    Sridhar Samudrala <sri@us.ibm.com>
 *    Ardelle Fan <ardelle.fan@intel.com>
 */

#include <linux/types.h>
#include <linux/list.h> /* For struct list_head */
#include <linux/socket.h>
#include <linux/ip.h>
#include <linux/time.h> /* For struct timeval */
#include <linux/slab.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/snmp.h>
#include <net/sock.h>
#include <net/xfrm.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/checksum.h>
#include <net/net_namespace.h>

/* Forward declarations for internal helpers. */
static int sctp_rcv_ootb(struct sk_buff *);
static struct sctp_association *__sctp_rcv_lookup(struct net *net,
				      struct sk_buff *skb,
				      const union sctp_addr *paddr,
				      const union sctp_addr *laddr,
				      struct sctp_transport **transportp);
static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
						const union sctp_addr *laddr);
static struct sctp_association *__sctp_lookup_association(
					struct net *net,
					const union sctp_addr *local,
					const union sctp_addr *peer,
					struct sctp_transport **pt);

static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb);


/* Calculate the SCTP checksum of an SCTP packet.  */



static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb)
{
	struct sctphdr *sh = sctp_hdr(skb);
	__le32 cmp = sh->checksum;
	__le32 val = sctp_compute_cksum(skb, 0);

	if (val != cmp) {
		/* CRC failure, dump it. */
		__SCTP_INC_STATS(net, SCTP_MIB_CHECKSUMERRORS);
		return -1;
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
David S. Miller3856.72%111.11%


Arnaldo Carvalho de Melo1014.93%111.11%


Eric W. Biedermann710.45%111.11%


Sridhar Samudrala57.46%222.22%


Joe Stringer34.48%111.11%


Vladislav Yasevich22.99%111.11%


Hideaki Yoshifuji / 吉藤英明11.49%111.11%


Eric Dumazet11.49%111.11%


Total67100.00%9100.00%



/*
 * This is the routine which IP calls when receiving an SCTP packet.
 */



int sctp_rcv(struct sk_buff *skb)
{
	struct sock *sk;
	struct sctp_association *asoc;
	struct sctp_endpoint *ep = NULL;
	struct sctp_ep_common *rcvr;
	struct sctp_transport *transport = NULL;
	struct sctp_chunk *chunk;
	union sctp_addr src;
	union sctp_addr dest;
	int family;
	struct sctp_af *af;
	struct net *net = dev_net(skb->dev);

	if (skb->pkt_type != PACKET_HOST)
		goto discard_it;

	__SCTP_INC_STATS(net, SCTP_MIB_INSCTPPACKS);

	/* If packet is too small to contain a single chunk, let's not
         * waste time on it anymore.
         */
	if (skb->len < sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) +
		       skb_transport_offset(skb))
		goto discard_it;

	/* If the packet is fragmented and we need to do crc checking,
         * it's better to just linearize it otherwise crc computing
         * takes longer.
         */
	if ((!(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) &&
	     skb_linearize(skb)) ||
	    !pskb_may_pull(skb, sizeof(struct sctphdr)))
		goto discard_it;

	/* Pull up the IP header. */
	__skb_pull(skb, skb_transport_offset(skb));

	skb->csum_valid = 0; /* Previous value not applicable */
	if (skb_csum_unnecessary(skb))
		__skb_decr_checksum_unnecessary(skb);
	else if (!sctp_checksum_disable &&
		 !(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) &&
		 sctp_rcv_checksum(net, skb) < 0)
		goto discard_it;
	skb->csum_valid = 1;

	__skb_pull(skb, sizeof(struct sctphdr));

	family = ipver2af(ip_hdr(skb)->version);
	af = sctp_get_af_specific(family);
	if (unlikely(!af))
		goto discard_it;
	SCTP_INPUT_CB(skb)->af = af;

	/* Initialize local addresses for lookups. */
	af->from_skb(&src, skb, 1);
	af->from_skb(&dest, skb, 0);

	/* If the packet is to or from a non-unicast address,
         * silently discard the packet.
         *
         * This is not clearly defined in the RFC except in section
         * 8.4 - OOTB handling.  However, based on the book "Stream Control
         * Transmission Protocol" 2.1, "It is important to note that the
         * IP address of an SCTP transport address must be a routable
         * unicast address.  In other words, IP multicast addresses and
         * IP broadcast addresses cannot be used in an SCTP transport
         * address."
         */
	if (!af->addr_valid(&src, NULL, skb) ||
	    !af->addr_valid(&dest, NULL, skb))
		goto discard_it;

	asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);

	if (!asoc)
		ep = __sctp_rcv_lookup_endpoint(net, &dest);

	/* Retrieve the common input handling substructure. */
	rcvr = asoc ? &asoc->base : &ep->base;
	sk = rcvr->sk;

	/*
         * If a frame arrives on an interface and the receiving socket is
         * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
         */
	if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) {
		if (transport) {
			sctp_transport_put(transport);
			asoc = NULL;
			transport = NULL;
		} else {
			sctp_endpoint_put(ep);
			ep = NULL;
		}
		sk = net->sctp.ctl_sock;
		ep = sctp_sk(sk)->ep;
		sctp_endpoint_hold(ep);
		rcvr = &ep->base;
	}

	/*
         * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
         * An SCTP packet is called an "out of the blue" (OOTB)
         * packet if it is correctly formed, i.e., passed the
         * receiver's checksum check, but the receiver is not
         * able to identify the association to which this
         * packet belongs.
         */
	if (!asoc) {
		if (sctp_rcv_ootb(skb)) {
			__SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
			goto discard_release;
		}
	}

	if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
		goto discard_release;
	nf_reset(skb);

	if (sk_filter(sk, skb))
		goto discard_release;

	/* Create an SCTP packet structure. */
	chunk = sctp_chunkify(skb, asoc, sk, GFP_ATOMIC);
	if (!chunk)
		goto discard_release;
	SCTP_INPUT_CB(skb)->chunk = chunk;

	/* Remember what endpoint is to handle this packet. */
	chunk->rcvr = rcvr;

	/* Remember the SCTP header. */
	chunk->sctp_hdr = sctp_hdr(skb);

	/* Set the source and destination addresses of the incoming chunk.  */
	sctp_init_addrs(chunk, &src, &dest);

	/* Remember where we came from.  */
	chunk->transport = transport;

	/* Acquire access to the sock lock. Note: We are safe from other
         * bottom halves on this lock, but a user may be in the lock too,
         * so check if it is busy.
         */
	bh_lock_sock(sk);

	if (sk != rcvr->sk) {
		/* Our cached sk is different from the rcvr->sk.  This is
                 * because migrate()/accept() may have moved the association
                 * to a new socket and released all the sockets.  So now we
                 * are holding a lock on the old socket while the user may
                 * be doing something with the new socket.  Switch our veiw
                 * of the current sk.
                 */
		bh_unlock_sock(sk);
		sk = rcvr->sk;
		bh_lock_sock(sk);
	}

	if (sock_owned_by_user(sk)) {
		if (sctp_add_backlog(sk, skb)) {
			bh_unlock_sock(sk);
			sctp_chunk_free(chunk);
			skb = NULL; /* sctp_chunk_free already freed the skb */
			goto discard_release;
		}
		__SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_BACKLOG);
	} else {
		__SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_SOFTIRQ);
		sctp_inq_push(&chunk->rcvr->inqueue, chunk);
	}

	bh_unlock_sock(sk);

	/* Release the asoc/ep ref we took in the lookup calls. */
	if (transport)
		sctp_transport_put(transport);
	else
		sctp_endpoint_put(ep);

	return 0;

discard_it:
	__SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
	kfree_skb(skb);
	return 0;

discard_release:
	/* Release the asoc/ep ref we took in the lookup calls. */
	if (transport)
		sctp_transport_put(transport);
	else
		sctp_endpoint_put(ep);

	goto discard_it;
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm31842.23%816.33%


Neil Horman9712.88%24.08%


Marcelo Ricardo Leitner8110.76%510.20%


Vladislav Yasevich496.51%36.12%


Eric W. Biedermann334.38%48.16%


Yi Zhu253.32%12.04%


Tom Herbert243.19%12.04%


Sridhar Samudrala222.92%510.20%


Al Viro192.52%36.12%


David S. Miller162.12%48.16%


Hideaki Yoshifuji / 吉藤英明131.73%24.08%


Xin Long131.73%12.04%


James Morris101.33%12.04%


Herbert Xu101.33%36.12%


Arnaldo Carvalho de Melo81.06%36.12%


Wang Weidong50.66%12.04%


Patrick McHardy50.66%12.04%


Eric Dumazet50.66%12.04%


Total753100.00%49100.00%



/* Process the backlog queue of the socket.  Every skb on
 * the backlog holds a ref on an association or endpoint.
 * We hold this ref throughout the state machine to make
 * sure that the structure we need is still around.
 */



int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
	struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
	struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
	struct sctp_transport *t = chunk->transport;
	struct sctp_ep_common *rcvr = NULL;
	int backloged = 0;

	rcvr = chunk->rcvr;

	/* If the rcvr is dead then the association or endpoint
         * has been deleted and we can safely drop the chunk
         * and refs that we are holding.
         */
	if (rcvr->dead) {
		sctp_chunk_free(chunk);
		goto done;
	}

	if (unlikely(rcvr->sk != sk)) {
		/* In this case, the association moved from one socket to
                 * another.  We are currently sitting on the backlog of the
                 * old socket, so we need to move.
                 * However, since we are here in the process context we
                 * need to take make sure that the user doesn't own
                 * the new socket when we process the packet.
                 * If the new socket is user-owned, queue the chunk to the
                 * backlog of the new socket without dropping any refs.
                 * Otherwise, we can safely push the chunk on the inqueue.
                 */

		sk = rcvr->sk;
		local_bh_disable();
		bh_lock_sock(sk);

		if (sock_owned_by_user(sk)) {
			if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
				sctp_chunk_free(chunk);
			else
				backloged = 1;
		} else
			sctp_inq_push(inqueue, chunk);

		bh_unlock_sock(sk);
		local_bh_enable();

		/* If the chunk was backloged again, don't drop refs */
		if (backloged)
			return 0;
	} else {
		sctp_inq_push(inqueue, chunk);
	}

done:
	/* Release the refs we took in sctp_add_backlog */
	if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
		sctp_transport_put(t);
	else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
		sctp_endpoint_put(sctp_ep(rcvr));
	else
		BUG();

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Vladislav Yasevich9041.47%17.69%


Sridhar Samudrala5023.04%17.69%


Jon Grimm3616.59%323.08%


Xin Long115.07%17.69%


David S. Miller94.15%215.38%


Yi Zhu94.15%215.38%


Marcelo Ricardo Leitner62.76%17.69%


Eric Dumazet41.84%17.69%


Wang Weidong20.92%17.69%


Total217100.00%13100.00%






static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
{
	struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
	struct sctp_transport *t = chunk->transport;
	struct sctp_ep_common *rcvr = chunk->rcvr;
	int ret;

	ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf);
	if (!ret) {
		/* Hold the assoc/ep while hanging on the backlog queue.
                 * This way, we know structures we need will not disappear
                 * from us
                 */
		if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
			sctp_transport_hold(t);
		else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
			sctp_endpoint_hold(sctp_ep(rcvr));
		else
			BUG();
	}
	return ret;

}


Contributors
PersonTokensPropCommitsCommitProp
Vladislav Yasevich3633.64%116.67%


Sridhar Samudrala3229.91%116.67%


Yi Zhu2422.43%233.33%


Xin Long1110.28%116.67%


Eric Dumazet43.74%116.67%


Total107100.00%6100.00%



/* Handle icmp frag needed error. */



void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
			   struct sctp_transport *t, __u32 pmtu)
{
	if (!t || (t->pathmtu <= pmtu))
		return;

	if (sock_owned_by_user(sk)) {
		asoc->pmtu_pending = 1;
		t->pmtu_pending = 1;
		return;
	}

	if (t->param_flags & SPP_PMTUD_ENABLE) {
		/* Update transports view of the MTU */
		sctp_transport_update_pmtu(t, pmtu);

		/* Update association pmtu. */
		sctp_assoc_sync_pmtu(asoc);
	}

	/* Retransmit with the new pmtu setting.
         * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
         * Needed will never be sent, but if a message was sent before
         * PMTU discovery was disabled that was larger than the PMTU, it
         * would not be fragmented, so it must be re-transmitted fragmented.
         */
	sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
}


Contributors
PersonTokensPropCommitsCommitProp
Sridhar Samudrala4041.67%222.22%


Vladislav Yasevich2526.04%222.22%


Frank Filz2222.92%111.11%


Jon Grimm77.29%222.22%


Hideaki Yoshifuji / 吉藤英明11.04%111.11%


Wei Yongjun11.04%111.11%


Total96100.00%9100.00%






void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
			struct sk_buff *skb)
{
	struct dst_entry *dst;

	if (!t)
		return;
	dst = sctp_transport_dst_check(t);
	if (dst)
		dst->ops->redirect(dst, sk, skb);
}


Contributors
PersonTokensPropCommitsCommitProp
David S. Miller55100.00%2100.00%


Total55100.00%2100.00%



/*
 * SCTP Implementer's Guide, 2.37 ICMP handling procedures
 *
 * ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
 *        or a "Protocol Unreachable" treat this message as an abort
 *        with the T bit set.
 *
 * This function sends an event to the state machine, which will abort the
 * association.
 *
 */



void sctp_icmp_proto_unreachable(struct sock *sk,
			   struct sctp_association *asoc,
			   struct sctp_transport *t)
{
	if (sock_owned_by_user(sk)) {
		if (timer_pending(&t->proto_unreach_timer))
			return;
		else {
			if (!mod_timer(&t->proto_unreach_timer,
						jiffies + (HZ/20)))
				sctp_association_hold(asoc);
		}
	} else {
		struct net *net = sock_net(sk);

		pr_debug("%s: unrecognized next header type "
			 "encountered!\n", __func__);

		if (del_timer(&t->proto_unreach_timer))
			sctp_association_put(asoc);

		sctp_do_sm(net, SCTP_EVENT_T_OTHER,
			   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
			   asoc->state, asoc->ep, asoc, t,
			   GFP_ATOMIC);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Vladislav Yasevich6550.39%120.00%


Sridhar Samudrala4333.33%120.00%


Eric W. Biedermann129.30%120.00%


Daniel Borkmann86.20%120.00%


Frank Filz10.78%120.00%


Total129100.00%5100.00%



/* Common lookup code for icmp/icmpv6 error handler. */



struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb,
			     struct sctphdr *sctphdr,
			     struct sctp_association **app,
			     struct sctp_transport **tpp)
{
	union sctp_addr saddr;
	union sctp_addr daddr;
	struct sctp_af *af;
	struct sock *sk = NULL;
	struct sctp_association *asoc;
	struct sctp_transport *transport = NULL;
	struct sctp_init_chunk *chunkhdr;
	__u32 vtag = ntohl(sctphdr->vtag);
	int len = skb->len - ((void *)sctphdr - (void *)skb->data);

	*app = NULL; *tpp = NULL;

	af = sctp_get_af_specific(family);
	if (unlikely(!af)) {
		return NULL;
	}

	/* Initialize local addresses for lookups. */
	af->from_skb(&saddr, skb, 1);
	af->from_skb(&daddr, skb, 0);

	/* Look for an association that matches the incoming ICMP error
         * packet.
         */
	asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport);
	if (!asoc)
		return NULL;

	sk = asoc->base.sk;

	/* RFC 4960, Appendix C. ICMP Handling
         *
         * ICMP6) An implementation MUST validate that the Verification Tag
         * contained in the ICMP message matches the Verification Tag of
         * the peer.  If the Verification Tag is not 0 and does NOT
         * match, discard the ICMP message.  If it is 0 and the ICMP
         * message contains enough bytes to verify that the chunk type is
         * an INIT chunk and that the Initiate Tag matches the tag of the
         * peer, continue with ICMP7.  If the ICMP message is too short
         * or the chunk type or the Initiate Tag does not match, silently
         * discard the packet.
         */
	if (vtag == 0) {
		chunkhdr = (void *)sctphdr + sizeof(struct sctphdr);
		if (len < sizeof(struct sctphdr) + sizeof(sctp_chunkhdr_t)
			  + sizeof(__be32) ||
		    chunkhdr->chunk_hdr.type != SCTP_CID_INIT ||
		    ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) {
			goto out;
		}
	} else if (vtag != asoc->c.peer_vtag) {
		goto out;
	}

	bh_lock_sock(sk);

	/* If too many ICMPs get dropped on busy
         * servers this needs to be solved differently.
         */
	if (sock_owned_by_user(sk))
		__NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);

	*app = asoc;
	*tpp = transport;
	return sk;

out:
	sctp_transport_put(transport);
	return NULL;
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm11033.85%425.00%


Wei Yongjun10732.92%16.25%


Sridhar Samudrala9128.00%212.50%


Eric W. Biedermann82.46%212.50%


Al Viro20.62%16.25%


Xin Long20.62%16.25%


Hideaki Yoshifuji / 吉藤英明10.31%16.25%


Wang Weidong10.31%16.25%


Pavel Emelyanov10.31%16.25%


David S. Miller10.31%16.25%


Eric Dumazet10.31%16.25%


Total325100.00%16100.00%



/* Common cleanup code for icmp/icmpv6 error handler. */



void sctp_err_finish(struct sock *sk, struct sctp_transport *t)
{
	bh_unlock_sock(sk);
	sctp_transport_put(t);
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm2080.00%133.33%


Xin Long416.00%133.33%


Wang Weidong14.00%133.33%


Total25100.00%3100.00%



/*
 * This routine is called by the ICMP module when it gets some
 * sort of error condition.  If err < 0 then the socket should
 * be closed and the error returned to the user.  If err > 0
 * it's just the icmp type << 8 | icmp code.  After adjustment
 * header points to the first 8 bytes of the sctp header.  We need
 * to find the appropriate port.
 *
 * The locking strategy used here is very "optimistic". When
 * someone else accesses the socket the ICMP is just dropped
 * and for some paths there is no check at all.
 * A more general error queue to queue errors for later handling
 * is probably better.
 *
 */



void sctp_v4_err(struct sk_buff *skb, __u32 info)
{
	const struct iphdr *iph = (const struct iphdr *)skb->data;
	const int ihlen = iph->ihl * 4;
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	struct sctp_association *asoc = NULL;
	struct sctp_transport *transport;
	struct inet_sock *inet;
	__u16 saveip, savesctp;
	int err;
	struct net *net = dev_net(skb->dev);

	/* Fix up skb to look at the embedded net header. */
	saveip = skb->network_header;
	savesctp = skb->transport_header;
	skb_reset_network_header(skb);
	skb_set_transport_header(skb, ihlen);
	sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport);
	/* Put back, the original values. */
	skb->network_header = saveip;
	skb->transport_header = savesctp;
	if (!sk) {
		__ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
		return;
	}
	/* Warning:  The sock lock is held.  Remember to call
         * sctp_err_finish!
         */

	switch (type) {
	case ICMP_PARAMETERPROB:
		err = EPROTO;
		break;
	case ICMP_DEST_UNREACH:
		if (code > NR_ICMP_UNREACH)
			goto out_unlock;

		/* PMTU discovery (RFC1191) */
		if (ICMP_FRAG_NEEDED == code) {
			sctp_icmp_frag_needed(sk, asoc, transport,
					      SCTP_TRUNC4(info));
			goto out_unlock;
		} else {
			if (ICMP_PROT_UNREACH == code) {
				sctp_icmp_proto_unreachable(sk, asoc,
							    transport);
				goto out_unlock;
			}
		}
		err = icmp_err_convert[code].errno;
		break;
	case ICMP_TIME_EXCEEDED:
		/* Ignore any time exceeded errors due to fragment reassembly
                 * timeouts.
                 */
		if (ICMP_EXC_FRAGTIME == code)
			goto out_unlock;

		err = EHOSTUNREACH;
		break;
	case ICMP_REDIRECT:
		sctp_icmp_redirect(sk, transport, skb);
		/* Fall through to out_unlock. */
	default:
		goto out_unlock;
	}

	inet = inet_sk(sk);
	if (!sock_owned_by_user(sk) && inet->recverr) {
		sk->sk_err = err;
		sk->sk_error_report(sk);
	} else {  /* Only an error on timeout */
		sk->sk_err_soft = err;
	}

out_unlock:
	sctp_err_finish(sk, transport);
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm17349.15%311.54%


Sridhar Samudrala10730.40%415.38%


Arnaldo Carvalho de Melo349.66%726.92%


Eric W. Biedermann154.26%27.69%


David S. Miller123.41%13.85%


Marcelo Ricardo Leitner30.85%27.69%


Eric Dumazet30.85%27.69%


Xin Long10.28%13.85%


Daniel Borkmann10.28%13.85%


Hideaki Yoshifuji / 吉藤英明10.28%13.85%


Simon Horman10.28%13.85%


Pavel Emelyanov10.28%13.85%


Total352100.00%26100.00%



/*
 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
 *
 * This function scans all the chunks in the OOTB packet to determine if
 * the packet should be discarded right away.  If a response might be needed
 * for this packet, or, if further processing is possible, the packet will
 * be queued to a proper inqueue for the next phase of handling.
 *
 * Output:
 * Return 0 - If further processing is needed.
 * Return 1 - If the packet can be discarded right away.
 */



static int sctp_rcv_ootb(struct sk_buff *skb)
{
	sctp_chunkhdr_t *ch, _ch;
	int ch_end, offset = 0;

	/* Scan through all the chunks in the packet.  */
	do {
		/* Make sure we have at least the header there */
		if (offset + sizeof(sctp_chunkhdr_t) > skb->len)
			break;

		ch = skb_header_pointer(skb, offset, sizeof(*ch), &_ch);

		/* Break out if chunk length is less then minimal. */
		if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
			break;

		ch_end = offset + SCTP_PAD4(ntohs(ch->length));
		if (ch_end > skb->len)
			break;

		/* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
                 * receiver MUST silently discard the OOTB packet and take no
                 * further action.
                 */
		if (SCTP_CID_ABORT == ch->type)
			goto discard;

		/* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE
                 * chunk, the receiver should silently discard the packet
                 * and take no further action.
                 */
		if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
			goto discard;

		/* RFC 4460, 2.11.2
                 * This will discard packets with INIT chunk bundled as
                 * subsequent chunks in the packet.  When INIT is first,
                 * the normal INIT processing will discard the chunk.
                 */
		if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
			goto discard;

		offset = ch_end;
	} while (ch_end < skb->len);

	return 0;

discard:
	return 1;
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm6337.72%111.11%


Marcelo Ricardo Leitner4627.54%222.22%


Tsutomu Fujii2514.97%111.11%


Vladislav Yasevich2213.17%111.11%


Sridhar Samudrala74.19%222.22%


David S. Miller31.80%111.11%


Sebastian Andrzej Siewior10.60%111.11%


Total167100.00%9100.00%



/* Insert endpoint into the hash table.  */



static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
{
	struct net *net = sock_net(ep->base.sk);
	struct sctp_ep_common *epb;
	struct sctp_hashbucket *head;

	epb = &ep->base;

	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
	head = &sctp_ep_hashtable[epb->hashent];

	write_lock(&head->lock);
	hlist_add_head(&epb->node, &head->chain);
	write_unlock(&head->lock);
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm6971.88%337.50%


Eric W. Biedermann1616.67%112.50%


Vladislav Yasevich77.29%112.50%


Sridhar Samudrala22.08%225.00%


Wang Weidong22.08%112.50%


Total96100.00%8100.00%



/* Add an endpoint to the hash. Local BH-safe. */



void sctp_hash_endpoint(struct sctp_endpoint *ep)
{
	local_bh_disable();
	__sctp_hash_endpoint(ep);
	local_bh_enable();
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm1990.48%266.67%


Wang Weidong29.52%133.33%


Total21100.00%3100.00%



/* Remove endpoint from the hash table.  */



static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
{
	struct net *net = sock_net(ep->base.sk);
	struct sctp_hashbucket *head;
	struct sctp_ep_common *epb;

	epb = &ep->base;

	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);

	head = &sctp_ep_hashtable[epb->hashent];

	write_lock(&head->lock);
	hlist_del_init(&epb->node);
	write_unlock(&head->lock);
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm6672.53%333.33%


Eric W. Biedermann1617.58%111.11%


Vladislav Yasevich44.40%111.11%


Sridhar Samudrala22.20%222.22%


Wang Weidong22.20%111.11%


Neil Horman11.10%111.11%


Total91100.00%9100.00%



/* Remove endpoint from the hash.  Local BH-safe. */



void sctp_unhash_endpoint(struct sctp_endpoint *ep)
{
	local_bh_disable();
	__sctp_unhash_endpoint(ep);
	local_bh_enable();
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm1990.48%266.67%


Wang Weidong29.52%133.33%


Total21100.00%3100.00%



/* Look up an endpoint. */



static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
						const union sctp_addr *laddr)
{
	struct sctp_hashbucket *head;
	struct sctp_ep_common *epb;
	struct sctp_endpoint *ep;
	int hash;

	hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port));
	head = &sctp_ep_hashtable[hash];
	read_lock(&head->lock);
	sctp_for_each_hentry(epb, &head->chain) {
		ep = sctp_ep(epb);
		if (sctp_endpoint_is_match(ep, net, laddr))
			goto hit;
	}

	ep = sctp_sk(net->sctp.ctl_sock)->ep;

hit:
	sctp_endpoint_hold(ep);
	read_unlock(&head->lock);
	return ep;
}


Contributors
PersonTokensPropCommitsCommitProp
Jon Grimm10480.62%440.00%


Eric W. Biedermann1410.85%220.00%


Vladislav Yasevich64.65%110.00%


Al Viro32.33%110.00%


Sridhar Samudrala21.55%220.00%


Total129100.00%10100.00%



/* rhashtable for transport */

struct sctp_hash_cmp_arg {
	
const union sctp_addr	*paddr;
	
const struct net	*net;
	
u16			lport;
};




static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg,
				const void *ptr)
{
	struct sctp_transport *t = (struct sctp_transport *)ptr;
	const struct sctp_hash_cmp_arg *x = arg->key;
	int err = 1;

	if (!sctp_cmp_addr_exact(&t->ipaddr, x->paddr))
		return err;
	if (!sctp_transport_hold(t))
		return err;

	if (!net_eq(sock_net(t->asoc->base.sk), x->