![Frank Filz](/assets/img/avatar_default.png)
This patch adds support to set/get heartbeat interval, maximum number of retransmissions, pathmtu, sackdelay time for a particular transport/ association/socket as per the latest SCTP sockets api draft11. Signed-off-by: Frank Filz <ffilz@us.ibm.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
916 lines
24 KiB
C
916 lines
24 KiB
C
/* SCTP kernel reference Implementation
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* Copyright (c) 1999-2000 Cisco, Inc.
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001-2003 International Business Machines, Corp.
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* Copyright (c) 2001 Intel Corp.
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* Copyright (c) 2001 Nokia, Inc.
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* Copyright (c) 2001 La Monte H.P. Yarroll
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*
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* This file is part of the SCTP kernel reference Implementation
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*
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* These functions handle all input from the IP layer into SCTP.
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*
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* The SCTP reference implementation is free software;
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* you can redistribute it and/or modify it under the terms of
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* the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* The SCTP reference implementation is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* ************************
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU CC; see the file COPYING. If not, write to
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* the Free Software Foundation, 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <lksctp-developers@lists.sourceforge.net>
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*
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* Or submit a bug report through the following website:
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* http://www.sf.net/projects/lksctp
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*
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* Written or modified by:
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* La Monte H.P. Yarroll <piggy@acm.org>
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* Karl Knutson <karl@athena.chicago.il.us>
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* Xingang Guo <xingang.guo@intel.com>
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* Jon Grimm <jgrimm@us.ibm.com>
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* Hui Huang <hui.huang@nokia.com>
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* Daisy Chang <daisyc@us.ibm.com>
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* Sridhar Samudrala <sri@us.ibm.com>
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* Ardelle Fan <ardelle.fan@intel.com>
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*
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* Any bugs reported given to us we will try to fix... any fixes shared will
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* be incorporated into the next SCTP release.
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*/
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#include <linux/types.h>
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#include <linux/list.h> /* For struct list_head */
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#include <linux/socket.h>
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#include <linux/ip.h>
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#include <linux/time.h> /* For struct timeval */
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#include <net/ip.h>
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#include <net/icmp.h>
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#include <net/snmp.h>
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#include <net/sock.h>
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#include <net/xfrm.h>
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#include <net/sctp/sctp.h>
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#include <net/sctp/sm.h>
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/* Forward declarations for internal helpers. */
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static int sctp_rcv_ootb(struct sk_buff *);
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static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
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const union sctp_addr *laddr,
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const union sctp_addr *paddr,
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struct sctp_transport **transportp);
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static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr);
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static struct sctp_association *__sctp_lookup_association(
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const union sctp_addr *local,
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const union sctp_addr *peer,
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struct sctp_transport **pt);
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/* Calculate the SCTP checksum of an SCTP packet. */
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static inline int sctp_rcv_checksum(struct sk_buff *skb)
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{
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struct sctphdr *sh;
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__u32 cmp, val;
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struct sk_buff *list = skb_shinfo(skb)->frag_list;
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sh = (struct sctphdr *) skb->h.raw;
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cmp = ntohl(sh->checksum);
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val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
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for (; list; list = list->next)
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val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
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val);
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val = sctp_end_cksum(val);
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if (val != cmp) {
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/* CRC failure, dump it. */
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SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS);
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return -1;
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}
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return 0;
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}
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struct sctp_input_cb {
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union {
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struct inet_skb_parm h4;
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#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
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struct inet6_skb_parm h6;
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#endif
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} header;
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struct sctp_chunk *chunk;
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};
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#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
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/*
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* This is the routine which IP calls when receiving an SCTP packet.
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*/
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int sctp_rcv(struct sk_buff *skb)
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{
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struct sock *sk;
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struct sctp_association *asoc;
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struct sctp_endpoint *ep = NULL;
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struct sctp_ep_common *rcvr;
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struct sctp_transport *transport = NULL;
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struct sctp_chunk *chunk;
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struct sctphdr *sh;
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union sctp_addr src;
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union sctp_addr dest;
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int family;
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struct sctp_af *af;
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int ret = 0;
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if (skb->pkt_type!=PACKET_HOST)
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goto discard_it;
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SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
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sh = (struct sctphdr *) skb->h.raw;
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/* Pull up the IP and SCTP headers. */
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__skb_pull(skb, skb->h.raw - skb->data);
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if (skb->len < sizeof(struct sctphdr))
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goto discard_it;
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if (sctp_rcv_checksum(skb) < 0)
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goto discard_it;
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skb_pull(skb, sizeof(struct sctphdr));
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/* Make sure we at least have chunk headers worth of data left. */
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if (skb->len < sizeof(struct sctp_chunkhdr))
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goto discard_it;
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family = ipver2af(skb->nh.iph->version);
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af = sctp_get_af_specific(family);
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if (unlikely(!af))
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goto discard_it;
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/* Initialize local addresses for lookups. */
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af->from_skb(&src, skb, 1);
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af->from_skb(&dest, skb, 0);
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/* If the packet is to or from a non-unicast address,
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* silently discard the packet.
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*
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* This is not clearly defined in the RFC except in section
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* 8.4 - OOTB handling. However, based on the book "Stream Control
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* Transmission Protocol" 2.1, "It is important to note that the
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* IP address of an SCTP transport address must be a routable
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* unicast address. In other words, IP multicast addresses and
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* IP broadcast addresses cannot be used in an SCTP transport
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* address."
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*/
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if (!af->addr_valid(&src, NULL) || !af->addr_valid(&dest, NULL))
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goto discard_it;
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asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport);
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if (!asoc)
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ep = __sctp_rcv_lookup_endpoint(&dest);
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/* Retrieve the common input handling substructure. */
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rcvr = asoc ? &asoc->base : &ep->base;
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sk = rcvr->sk;
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/*
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* If a frame arrives on an interface and the receiving socket is
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* bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
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*/
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if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb)))
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{
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sock_put(sk);
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if (asoc) {
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sctp_association_put(asoc);
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asoc = NULL;
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} else {
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sctp_endpoint_put(ep);
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ep = NULL;
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}
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sk = sctp_get_ctl_sock();
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ep = sctp_sk(sk)->ep;
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sctp_endpoint_hold(ep);
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sock_hold(sk);
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rcvr = &ep->base;
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}
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/*
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* RFC 2960, 8.4 - Handle "Out of the blue" Packets.
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* An SCTP packet is called an "out of the blue" (OOTB)
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* packet if it is correctly formed, i.e., passed the
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* receiver's checksum check, but the receiver is not
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* able to identify the association to which this
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* packet belongs.
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*/
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if (!asoc) {
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if (sctp_rcv_ootb(skb)) {
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SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES);
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goto discard_release;
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}
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}
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/* SCTP seems to always need a timestamp right now (FIXME) */
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if (skb->tstamp.off_sec == 0) {
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__net_timestamp(skb);
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sock_enable_timestamp(sk);
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}
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if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
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goto discard_release;
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ret = sk_filter(sk, skb, 1);
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if (ret)
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goto discard_release;
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/* Create an SCTP packet structure. */
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chunk = sctp_chunkify(skb, asoc, sk);
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if (!chunk) {
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ret = -ENOMEM;
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goto discard_release;
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}
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SCTP_INPUT_CB(skb)->chunk = chunk;
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/* Remember what endpoint is to handle this packet. */
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chunk->rcvr = rcvr;
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/* Remember the SCTP header. */
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chunk->sctp_hdr = sh;
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/* Set the source and destination addresses of the incoming chunk. */
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sctp_init_addrs(chunk, &src, &dest);
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/* Remember where we came from. */
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chunk->transport = transport;
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/* Acquire access to the sock lock. Note: We are safe from other
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* bottom halves on this lock, but a user may be in the lock too,
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* so check if it is busy.
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*/
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sctp_bh_lock_sock(sk);
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if (sock_owned_by_user(sk))
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sk_add_backlog(sk, skb);
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else
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sctp_backlog_rcv(sk, skb);
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/* Release the sock and any reference counts we took in the
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* lookup calls.
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*/
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sctp_bh_unlock_sock(sk);
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if (asoc)
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sctp_association_put(asoc);
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else
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sctp_endpoint_put(ep);
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sock_put(sk);
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return ret;
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discard_it:
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kfree_skb(skb);
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return ret;
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discard_release:
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/* Release any structures we may be holding. */
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sock_put(sk);
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if (asoc)
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sctp_association_put(asoc);
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else
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sctp_endpoint_put(ep);
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goto discard_it;
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}
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/* Handle second half of inbound skb processing. If the sock was busy,
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* we may have need to delay processing until later when the sock is
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* released (on the backlog). If not busy, we call this routine
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* directly from the bottom half.
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*/
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int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
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{
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struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
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struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
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sctp_inq_push(inqueue, chunk);
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return 0;
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}
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/* Handle icmp frag needed error. */
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void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
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struct sctp_transport *t, __u32 pmtu)
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{
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if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu))
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return;
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if (t->param_flags & SPP_PMTUD_ENABLE) {
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if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
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printk(KERN_WARNING "%s: Reported pmtu %d too low, "
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"using default minimum of %d\n",
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__FUNCTION__, pmtu,
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SCTP_DEFAULT_MINSEGMENT);
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/* Use default minimum segment size and disable
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* pmtu discovery on this transport.
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*/
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t->pathmtu = SCTP_DEFAULT_MINSEGMENT;
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t->param_flags = (t->param_flags & ~SPP_HB) |
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SPP_PMTUD_DISABLE;
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} else {
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t->pathmtu = pmtu;
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}
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/* Update association pmtu. */
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sctp_assoc_sync_pmtu(asoc);
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}
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/* Retransmit with the new pmtu setting.
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* Normally, if PMTU discovery is disabled, an ICMP Fragmentation
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* Needed will never be sent, but if a message was sent before
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* PMTU discovery was disabled that was larger than the PMTU, it
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* would not be fragmented, so it must be re-transmitted fragmented.
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*/
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sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
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}
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/*
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* SCTP Implementer's Guide, 2.37 ICMP handling procedures
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*
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* ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
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* or a "Protocol Unreachable" treat this message as an abort
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* with the T bit set.
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*
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* This function sends an event to the state machine, which will abort the
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* association.
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*
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*/
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void sctp_icmp_proto_unreachable(struct sock *sk,
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struct sctp_association *asoc,
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struct sctp_transport *t)
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{
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SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__);
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sctp_do_sm(SCTP_EVENT_T_OTHER,
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SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
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asoc->state, asoc->ep, asoc, t,
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GFP_ATOMIC);
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}
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/* Common lookup code for icmp/icmpv6 error handler. */
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struct sock *sctp_err_lookup(int family, struct sk_buff *skb,
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struct sctphdr *sctphdr,
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struct sctp_association **app,
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struct sctp_transport **tpp)
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{
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union sctp_addr saddr;
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union sctp_addr daddr;
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struct sctp_af *af;
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struct sock *sk = NULL;
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struct sctp_association *asoc = NULL;
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struct sctp_transport *transport = NULL;
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*app = NULL; *tpp = NULL;
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af = sctp_get_af_specific(family);
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if (unlikely(!af)) {
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return NULL;
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}
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/* Initialize local addresses for lookups. */
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af->from_skb(&saddr, skb, 1);
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af->from_skb(&daddr, skb, 0);
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/* Look for an association that matches the incoming ICMP error
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* packet.
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*/
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asoc = __sctp_lookup_association(&saddr, &daddr, &transport);
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if (!asoc)
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return NULL;
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sk = asoc->base.sk;
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if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) {
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ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
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goto out;
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}
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sctp_bh_lock_sock(sk);
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/* If too many ICMPs get dropped on busy
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* servers this needs to be solved differently.
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*/
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if (sock_owned_by_user(sk))
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NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
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*app = asoc;
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*tpp = transport;
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return sk;
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out:
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sock_put(sk);
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if (asoc)
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sctp_association_put(asoc);
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return NULL;
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}
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/* Common cleanup code for icmp/icmpv6 error handler. */
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void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
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{
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sctp_bh_unlock_sock(sk);
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sock_put(sk);
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if (asoc)
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sctp_association_put(asoc);
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}
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|
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/*
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* This routine is called by the ICMP module when it gets some
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* sort of error condition. If err < 0 then the socket should
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* be closed and the error returned to the user. If err > 0
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* it's just the icmp type << 8 | icmp code. After adjustment
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* header points to the first 8 bytes of the sctp header. We need
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* to find the appropriate port.
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*
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* The locking strategy used here is very "optimistic". When
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* someone else accesses the socket the ICMP is just dropped
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* and for some paths there is no check at all.
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* A more general error queue to queue errors for later handling
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* is probably better.
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*
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*/
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void sctp_v4_err(struct sk_buff *skb, __u32 info)
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{
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struct iphdr *iph = (struct iphdr *)skb->data;
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struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2));
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int type = skb->h.icmph->type;
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int code = skb->h.icmph->code;
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struct sock *sk;
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struct sctp_association *asoc;
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struct sctp_transport *transport;
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struct inet_sock *inet;
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char *saveip, *savesctp;
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int err;
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if (skb->len < ((iph->ihl << 2) + 8)) {
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ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
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return;
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}
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|
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/* Fix up skb to look at the embedded net header. */
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saveip = skb->nh.raw;
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savesctp = skb->h.raw;
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skb->nh.iph = iph;
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skb->h.raw = (char *)sh;
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sk = sctp_err_lookup(AF_INET, skb, sh, &asoc, &transport);
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/* Put back, the original pointers. */
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skb->nh.raw = saveip;
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skb->h.raw = savesctp;
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if (!sk) {
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ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
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return;
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}
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/* Warning: The sock lock is held. Remember to call
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* sctp_err_finish!
|
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*/
|
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|
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switch (type) {
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case ICMP_PARAMETERPROB:
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err = EPROTO;
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break;
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case ICMP_DEST_UNREACH:
|
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if (code > NR_ICMP_UNREACH)
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goto out_unlock;
|
|
|
|
/* PMTU discovery (RFC1191) */
|
|
if (ICMP_FRAG_NEEDED == code) {
|
|
sctp_icmp_frag_needed(sk, asoc, transport, 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;
|
|
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, asoc);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int sctp_rcv_ootb(struct sk_buff *skb)
|
|
{
|
|
sctp_chunkhdr_t *ch;
|
|
__u8 *ch_end;
|
|
sctp_errhdr_t *err;
|
|
|
|
ch = (sctp_chunkhdr_t *) skb->data;
|
|
ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length));
|
|
|
|
/* Scan through all the chunks in the packet. */
|
|
while (ch_end > (__u8 *)ch && ch_end < skb->tail) {
|
|
|
|
/* 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 8.4, 7) If the packet contains a "Stale cookie" ERROR
|
|
* or a COOKIE ACK the SCTP Packet should be silently
|
|
* discarded.
|
|
*/
|
|
if (SCTP_CID_COOKIE_ACK == ch->type)
|
|
goto discard;
|
|
|
|
if (SCTP_CID_ERROR == ch->type) {
|
|
sctp_walk_errors(err, ch) {
|
|
if (SCTP_ERROR_STALE_COOKIE == err->cause)
|
|
goto discard;
|
|
}
|
|
}
|
|
|
|
ch = (sctp_chunkhdr_t *) ch_end;
|
|
ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length));
|
|
}
|
|
|
|
return 0;
|
|
|
|
discard:
|
|
return 1;
|
|
}
|
|
|
|
/* Insert endpoint into the hash table. */
|
|
static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
|
|
{
|
|
struct sctp_ep_common **epp;
|
|
struct sctp_ep_common *epb;
|
|
struct sctp_hashbucket *head;
|
|
|
|
epb = &ep->base;
|
|
|
|
epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
|
|
head = &sctp_ep_hashtable[epb->hashent];
|
|
|
|
sctp_write_lock(&head->lock);
|
|
epp = &head->chain;
|
|
epb->next = *epp;
|
|
if (epb->next)
|
|
(*epp)->pprev = &epb->next;
|
|
*epp = epb;
|
|
epb->pprev = epp;
|
|
sctp_write_unlock(&head->lock);
|
|
}
|
|
|
|
/* Add an endpoint to the hash. Local BH-safe. */
|
|
void sctp_hash_endpoint(struct sctp_endpoint *ep)
|
|
{
|
|
sctp_local_bh_disable();
|
|
__sctp_hash_endpoint(ep);
|
|
sctp_local_bh_enable();
|
|
}
|
|
|
|
/* Remove endpoint from the hash table. */
|
|
static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
|
|
{
|
|
struct sctp_hashbucket *head;
|
|
struct sctp_ep_common *epb;
|
|
|
|
epb = &ep->base;
|
|
|
|
epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
|
|
|
|
head = &sctp_ep_hashtable[epb->hashent];
|
|
|
|
sctp_write_lock(&head->lock);
|
|
|
|
if (epb->pprev) {
|
|
if (epb->next)
|
|
epb->next->pprev = epb->pprev;
|
|
*epb->pprev = epb->next;
|
|
epb->pprev = NULL;
|
|
}
|
|
|
|
sctp_write_unlock(&head->lock);
|
|
}
|
|
|
|
/* Remove endpoint from the hash. Local BH-safe. */
|
|
void sctp_unhash_endpoint(struct sctp_endpoint *ep)
|
|
{
|
|
sctp_local_bh_disable();
|
|
__sctp_unhash_endpoint(ep);
|
|
sctp_local_bh_enable();
|
|
}
|
|
|
|
/* Look up an endpoint. */
|
|
static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr)
|
|
{
|
|
struct sctp_hashbucket *head;
|
|
struct sctp_ep_common *epb;
|
|
struct sctp_endpoint *ep;
|
|
int hash;
|
|
|
|
hash = sctp_ep_hashfn(laddr->v4.sin_port);
|
|
head = &sctp_ep_hashtable[hash];
|
|
read_lock(&head->lock);
|
|
for (epb = head->chain; epb; epb = epb->next) {
|
|
ep = sctp_ep(epb);
|
|
if (sctp_endpoint_is_match(ep, laddr))
|
|
goto hit;
|
|
}
|
|
|
|
ep = sctp_sk((sctp_get_ctl_sock()))->ep;
|
|
epb = &ep->base;
|
|
|
|
hit:
|
|
sctp_endpoint_hold(ep);
|
|
sock_hold(epb->sk);
|
|
read_unlock(&head->lock);
|
|
return ep;
|
|
}
|
|
|
|
/* Insert association into the hash table. */
|
|
static void __sctp_hash_established(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_ep_common **epp;
|
|
struct sctp_ep_common *epb;
|
|
struct sctp_hashbucket *head;
|
|
|
|
epb = &asoc->base;
|
|
|
|
/* Calculate which chain this entry will belong to. */
|
|
epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port);
|
|
|
|
head = &sctp_assoc_hashtable[epb->hashent];
|
|
|
|
sctp_write_lock(&head->lock);
|
|
epp = &head->chain;
|
|
epb->next = *epp;
|
|
if (epb->next)
|
|
(*epp)->pprev = &epb->next;
|
|
*epp = epb;
|
|
epb->pprev = epp;
|
|
sctp_write_unlock(&head->lock);
|
|
}
|
|
|
|
/* Add an association to the hash. Local BH-safe. */
|
|
void sctp_hash_established(struct sctp_association *asoc)
|
|
{
|
|
sctp_local_bh_disable();
|
|
__sctp_hash_established(asoc);
|
|
sctp_local_bh_enable();
|
|
}
|
|
|
|
/* Remove association from the hash table. */
|
|
static void __sctp_unhash_established(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_hashbucket *head;
|
|
struct sctp_ep_common *epb;
|
|
|
|
epb = &asoc->base;
|
|
|
|
epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port,
|
|
asoc->peer.port);
|
|
|
|
head = &sctp_assoc_hashtable[epb->hashent];
|
|
|
|
sctp_write_lock(&head->lock);
|
|
|
|
if (epb->pprev) {
|
|
if (epb->next)
|
|
epb->next->pprev = epb->pprev;
|
|
*epb->pprev = epb->next;
|
|
epb->pprev = NULL;
|
|
}
|
|
|
|
sctp_write_unlock(&head->lock);
|
|
}
|
|
|
|
/* Remove association from the hash table. Local BH-safe. */
|
|
void sctp_unhash_established(struct sctp_association *asoc)
|
|
{
|
|
sctp_local_bh_disable();
|
|
__sctp_unhash_established(asoc);
|
|
sctp_local_bh_enable();
|
|
}
|
|
|
|
/* Look up an association. */
|
|
static struct sctp_association *__sctp_lookup_association(
|
|
const union sctp_addr *local,
|
|
const union sctp_addr *peer,
|
|
struct sctp_transport **pt)
|
|
{
|
|
struct sctp_hashbucket *head;
|
|
struct sctp_ep_common *epb;
|
|
struct sctp_association *asoc;
|
|
struct sctp_transport *transport;
|
|
int hash;
|
|
|
|
/* Optimize here for direct hit, only listening connections can
|
|
* have wildcards anyways.
|
|
*/
|
|
hash = sctp_assoc_hashfn(local->v4.sin_port, peer->v4.sin_port);
|
|
head = &sctp_assoc_hashtable[hash];
|
|
read_lock(&head->lock);
|
|
for (epb = head->chain; epb; epb = epb->next) {
|
|
asoc = sctp_assoc(epb);
|
|
transport = sctp_assoc_is_match(asoc, local, peer);
|
|
if (transport)
|
|
goto hit;
|
|
}
|
|
|
|
read_unlock(&head->lock);
|
|
|
|
return NULL;
|
|
|
|
hit:
|
|
*pt = transport;
|
|
sctp_association_hold(asoc);
|
|
sock_hold(epb->sk);
|
|
read_unlock(&head->lock);
|
|
return asoc;
|
|
}
|
|
|
|
/* Look up an association. BH-safe. */
|
|
SCTP_STATIC
|
|
struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr,
|
|
const union sctp_addr *paddr,
|
|
struct sctp_transport **transportp)
|
|
{
|
|
struct sctp_association *asoc;
|
|
|
|
sctp_local_bh_disable();
|
|
asoc = __sctp_lookup_association(laddr, paddr, transportp);
|
|
sctp_local_bh_enable();
|
|
|
|
return asoc;
|
|
}
|
|
|
|
/* Is there an association matching the given local and peer addresses? */
|
|
int sctp_has_association(const union sctp_addr *laddr,
|
|
const union sctp_addr *paddr)
|
|
{
|
|
struct sctp_association *asoc;
|
|
struct sctp_transport *transport;
|
|
|
|
if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) {
|
|
sock_put(asoc->base.sk);
|
|
sctp_association_put(asoc);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* SCTP Implementors Guide, 2.18 Handling of address
|
|
* parameters within the INIT or INIT-ACK.
|
|
*
|
|
* D) When searching for a matching TCB upon reception of an INIT
|
|
* or INIT-ACK chunk the receiver SHOULD use not only the
|
|
* source address of the packet (containing the INIT or
|
|
* INIT-ACK) but the receiver SHOULD also use all valid
|
|
* address parameters contained within the chunk.
|
|
*
|
|
* 2.18.3 Solution description
|
|
*
|
|
* This new text clearly specifies to an implementor the need
|
|
* to look within the INIT or INIT-ACK. Any implementation that
|
|
* does not do this, may not be able to establish associations
|
|
* in certain circumstances.
|
|
*
|
|
*/
|
|
static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
|
|
const union sctp_addr *laddr, struct sctp_transport **transportp)
|
|
{
|
|
struct sctp_association *asoc;
|
|
union sctp_addr addr;
|
|
union sctp_addr *paddr = &addr;
|
|
struct sctphdr *sh = (struct sctphdr *) skb->h.raw;
|
|
sctp_chunkhdr_t *ch;
|
|
union sctp_params params;
|
|
sctp_init_chunk_t *init;
|
|
struct sctp_transport *transport;
|
|
struct sctp_af *af;
|
|
|
|
ch = (sctp_chunkhdr_t *) skb->data;
|
|
|
|
/* If this is INIT/INIT-ACK look inside the chunk too. */
|
|
switch (ch->type) {
|
|
case SCTP_CID_INIT:
|
|
case SCTP_CID_INIT_ACK:
|
|
break;
|
|
default:
|
|
return NULL;
|
|
}
|
|
|
|
/* The code below will attempt to walk the chunk and extract
|
|
* parameter information. Before we do that, we need to verify
|
|
* that the chunk length doesn't cause overflow. Otherwise, we'll
|
|
* walk off the end.
|
|
*/
|
|
if (WORD_ROUND(ntohs(ch->length)) > skb->len)
|
|
return NULL;
|
|
|
|
/*
|
|
* This code will NOT touch anything inside the chunk--it is
|
|
* strictly READ-ONLY.
|
|
*
|
|
* RFC 2960 3 SCTP packet Format
|
|
*
|
|
* Multiple chunks can be bundled into one SCTP packet up to
|
|
* the MTU size, except for the INIT, INIT ACK, and SHUTDOWN
|
|
* COMPLETE chunks. These chunks MUST NOT be bundled with any
|
|
* other chunk in a packet. See Section 6.10 for more details
|
|
* on chunk bundling.
|
|
*/
|
|
|
|
/* Find the start of the TLVs and the end of the chunk. This is
|
|
* the region we search for address parameters.
|
|
*/
|
|
init = (sctp_init_chunk_t *)skb->data;
|
|
|
|
/* Walk the parameters looking for embedded addresses. */
|
|
sctp_walk_params(params, init, init_hdr.params) {
|
|
|
|
/* Note: Ignoring hostname addresses. */
|
|
af = sctp_get_af_specific(param_type2af(params.p->type));
|
|
if (!af)
|
|
continue;
|
|
|
|
af->from_addr_param(paddr, params.addr, ntohs(sh->source), 0);
|
|
|
|
asoc = __sctp_lookup_association(laddr, paddr, &transport);
|
|
if (asoc)
|
|
return asoc;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Lookup an association for an inbound skb. */
|
|
static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
|
|
const union sctp_addr *paddr,
|
|
const union sctp_addr *laddr,
|
|
struct sctp_transport **transportp)
|
|
{
|
|
struct sctp_association *asoc;
|
|
|
|
asoc = __sctp_lookup_association(laddr, paddr, transportp);
|
|
|
|
/* Further lookup for INIT/INIT-ACK packets.
|
|
* SCTP Implementors Guide, 2.18 Handling of address
|
|
* parameters within the INIT or INIT-ACK.
|
|
*/
|
|
if (!asoc)
|
|
asoc = __sctp_rcv_init_lookup(skb, laddr, transportp);
|
|
|
|
return asoc;
|
|
}
|