[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/net/sctp/input.c b/ap/os/linux/linux-3.4.x/net/sctp/input.c
new file mode 100644
index 0000000..be772c0
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/net/sctp/input.c
@@ -0,0 +1,1135 @@
+/* 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, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ * lksctp developers <lksctp-developers@lists.sourceforge.net>
+ *
+ * Or submit a bug report through the following website:
+ * http://www.sf.net/projects/lksctp
+ *
+ * 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>
+ *
+ * Any bugs reported given to us we will try to fix... any fixes shared will
+ * be incorporated into the next SCTP release.
+ */
+
+#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 sk_buff *skb,
+ const union sctp_addr *laddr,
+ const union sctp_addr *paddr,
+ struct sctp_transport **transportp);
+static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr);
+static struct sctp_association *__sctp_lookup_association(
+ 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 sk_buff *skb)
+{
+ struct sctphdr *sh = sctp_hdr(skb);
+ __le32 cmp = sh->checksum;
+ struct sk_buff *list;
+ __le32 val;
+ __u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
+
+ skb_walk_frags(skb, list)
+ tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
+ tmp);
+
+ val = sctp_end_cksum(tmp);
+
+ if (val != cmp) {
+ /* CRC failure, dump it. */
+ SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS);
+ return -1;
+ }
+ return 0;
+}
+
+struct sctp_input_cb {
+ union {
+ struct inet_skb_parm h4;
+#if IS_ENABLED(CONFIG_IPV6)
+ struct inet6_skb_parm h6;
+#endif
+ } header;
+ struct sctp_chunk *chunk;
+};
+#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
+
+/*
+ * 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;
+ struct sctphdr *sh;
+ union sctp_addr src;
+ union sctp_addr dest;
+ int family;
+ struct sctp_af *af;
+
+ if (skb->pkt_type!=PACKET_HOST)
+ goto discard_it;
+
+ SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
+
+ if (skb_linearize(skb))
+ goto discard_it;
+
+ sh = sctp_hdr(skb);
+
+ /* Pull up the IP and SCTP headers. */
+ __skb_pull(skb, skb_transport_offset(skb));
+ if (skb->len < sizeof(struct sctphdr))
+ goto discard_it;
+ if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) &&
+ sctp_rcv_checksum(skb) < 0)
+ goto discard_it;
+
+ skb_pull(skb, sizeof(struct sctphdr));
+
+ /* Make sure we at least have chunk headers worth of data left. */
+ if (skb->len < sizeof(struct sctp_chunkhdr))
+ goto discard_it;
+
+ family = ipver2af(ip_hdr(skb)->version);
+ af = sctp_get_af_specific(family);
+ if (unlikely(!af))
+ goto discard_it;
+
+ /* 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(skb, &src, &dest, &transport);
+
+ if (!asoc)
+ ep = __sctp_rcv_lookup_endpoint(&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 (asoc) {
+ sctp_association_put(asoc);
+ asoc = NULL;
+ } else {
+ sctp_endpoint_put(ep);
+ ep = NULL;
+ }
+ sk = sctp_get_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_BH(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);
+ 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 = sh;
+
+ /* 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.
+ */
+ sctp_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.
+ */
+ sctp_bh_unlock_sock(sk);
+ sk = rcvr->sk;
+ sctp_bh_lock_sock(sk);
+ }
+
+ if (sock_owned_by_user(sk)) {
+ if (sctp_add_backlog(sk, skb)) {
+ sctp_bh_unlock_sock(sk);
+ sctp_chunk_free(chunk);
+ skb = NULL; /* sctp_chunk_free already freed the skb */
+ goto discard_release;
+ }
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG);
+ } else {
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ);
+ sctp_inq_push(&chunk->rcvr->inqueue, chunk);
+ }
+
+ sctp_bh_unlock_sock(sk);
+
+ /* Release the asoc/ep ref we took in the lookup calls. */
+ if (asoc)
+ sctp_association_put(asoc);
+ else
+ sctp_endpoint_put(ep);
+
+ return 0;
+
+discard_it:
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS);
+ kfree_skb(skb);
+ return 0;
+
+discard_release:
+ /* Release the asoc/ep ref we took in the lookup calls. */
+ if (asoc)
+ sctp_association_put(asoc);
+ else
+ sctp_endpoint_put(ep);
+
+ goto discard_it;
+}
+
+/* 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_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;
+ sctp_bh_lock_sock(sk);
+
+ if (sock_owned_by_user(sk)) {
+ if (sk_add_backlog(sk, skb))
+ sctp_chunk_free(chunk);
+ else
+ backloged = 1;
+ } else
+ sctp_inq_push(inqueue, chunk);
+
+ sctp_bh_unlock_sock(sk);
+
+ /* 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_association_put(sctp_assoc(rcvr));
+ else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
+ sctp_endpoint_put(sctp_ep(rcvr));
+ else
+ BUG();
+
+ return 0;
+}
+
+static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
+{
+ struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
+ struct sctp_ep_common *rcvr = chunk->rcvr;
+ int ret;
+
+ ret = sk_add_backlog(sk, skb);
+ 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_association_hold(sctp_assoc(rcvr));
+ else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
+ sctp_endpoint_hold(sctp_ep(rcvr));
+ else
+ BUG();
+ }
+ return ret;
+
+}
+
+/* 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);
+}
+
+/*
+ * 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)
+{
+ SCTP_DEBUG_PRINTK("%s\n", __func__);
+
+ 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 {
+ if (timer_pending(&t->proto_unreach_timer) &&
+ del_timer(&t->proto_unreach_timer))
+ sctp_association_put(asoc);
+
+ sctp_do_sm(SCTP_EVENT_T_OTHER,
+ SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
+ asoc->state, asoc->ep, asoc, t,
+ GFP_ATOMIC);
+ }
+}
+
+/* Common lookup code for icmp/icmpv6 error handler. */
+struct sock *sctp_err_lookup(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(&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;
+ }
+
+ sctp_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_BH(&init_net, LINUX_MIB_LOCKDROPPEDICMPS);
+
+ *app = asoc;
+ *tpp = transport;
+ return sk;
+
+out:
+ if (asoc)
+ sctp_association_put(asoc);
+ return NULL;
+}
+
+/* Common cleanup code for icmp/icmpv6 error handler. */
+void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
+{
+ sctp_bh_unlock_sock(sk);
+ if (asoc)
+ sctp_association_put(asoc);
+}
+
+/*
+ * 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;
+ sk_buff_data_t saveip, savesctp;
+ int err;
+
+ if (skb->len < ihlen + 8) {
+ ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS);
+ return;
+ }
+
+ /* 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(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_BH(&init_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, 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.
+ */
+static int sctp_rcv_ootb(struct sk_buff *skb)
+{
+ sctp_chunkhdr_t *ch;
+ __u8 *ch_end;
+
+ ch = (sctp_chunkhdr_t *) skb->data;
+
+ /* Scan through all the chunks in the packet. */
+ do {
+ /* Break out if chunk length is less then minimal. */
+ if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
+ break;
+
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ 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;
+
+ ch = (sctp_chunkhdr_t *) ch_end;
+ } while (ch_end < skb_tail_pointer(skb));
+
+ return 0;
+
+discard:
+ return 1;
+}
+
+/* Insert endpoint into the hash table. */
+static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
+{
+ 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);
+ hlist_add_head(&epb->node, &head->chain);
+ 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);
+ hlist_del_init(&epb->node);
+ 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;
+ struct hlist_node *node;
+ int hash;
+
+ hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port));
+ head = &sctp_ep_hashtable[hash];
+ read_lock(&head->lock);
+ sctp_for_each_hentry(epb, node, &head->chain) {
+ ep = sctp_ep(epb);
+ if (sctp_endpoint_is_match(ep, laddr))
+ goto hit;
+ }
+
+ ep = sctp_sk((sctp_get_ctl_sock()))->ep;
+
+hit:
+ sctp_endpoint_hold(ep);
+ 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 *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);
+ hlist_add_head(&epb->node, &head->chain);
+ sctp_write_unlock(&head->lock);
+}
+
+/* Add an association to the hash. Local BH-safe. */
+void sctp_hash_established(struct sctp_association *asoc)
+{
+ if (asoc->temp)
+ return;
+
+ 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);
+ hlist_del_init(&epb->node);
+ sctp_write_unlock(&head->lock);
+}
+
+/* Remove association from the hash table. Local BH-safe. */
+void sctp_unhash_established(struct sctp_association *asoc)
+{
+ if (asoc->temp)
+ return;
+
+ 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;
+ struct hlist_node *node;
+ int hash;
+
+ /* Optimize here for direct hit, only listening connections can
+ * have wildcards anyways.
+ */
+ hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port));
+ head = &sctp_assoc_hashtable[hash];
+ read_lock(&head->lock);
+ sctp_for_each_hentry(epb, node, &head->chain) {
+ 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);
+ 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))) {
+ 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 = sctp_hdr(skb);
+ union sctp_params params;
+ sctp_init_chunk_t *init;
+ struct sctp_transport *transport;
+ struct sctp_af *af;
+
+ /*
+ * 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, sh->source, 0);
+
+ asoc = __sctp_lookup_association(laddr, paddr, &transport);
+ if (asoc)
+ return asoc;
+ }
+
+ return NULL;
+}
+
+/* ADD-IP, Section 5.2
+ * When an endpoint receives an ASCONF Chunk from the remote peer
+ * special procedures may be needed to identify the association the
+ * ASCONF Chunk is associated with. To properly find the association
+ * the following procedures SHOULD be followed:
+ *
+ * D2) If the association is not found, use the address found in the
+ * Address Parameter TLV combined with the port number found in the
+ * SCTP common header. If found proceed to rule D4.
+ *
+ * D2-ext) If more than one ASCONF Chunks are packed together, use the
+ * address found in the ASCONF Address Parameter TLV of each of the
+ * subsequent ASCONF Chunks. If found, proceed to rule D4.
+ */
+static struct sctp_association *__sctp_rcv_asconf_lookup(
+ sctp_chunkhdr_t *ch,
+ const union sctp_addr *laddr,
+ __be16 peer_port,
+ struct sctp_transport **transportp)
+{
+ sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch;
+ struct sctp_af *af;
+ union sctp_addr_param *param;
+ union sctp_addr paddr;
+
+ /* Skip over the ADDIP header and find the Address parameter */
+ param = (union sctp_addr_param *)(asconf + 1);
+
+ af = sctp_get_af_specific(param_type2af(param->p.type));
+ if (unlikely(!af))
+ return NULL;
+
+ af->from_addr_param(&paddr, param, peer_port, 0);
+
+ return __sctp_lookup_association(laddr, &paddr, transportp);
+}
+
+
+/* SCTP-AUTH, Section 6.3:
+* If the receiver does not find a STCB for a packet containing an AUTH
+* chunk as the first chunk and not a COOKIE-ECHO chunk as the second
+* chunk, it MUST use the chunks after the AUTH chunk to look up an existing
+* association.
+*
+* This means that any chunks that can help us identify the association need
+* to be looked at to find this association.
+*/
+static struct sctp_association *__sctp_rcv_walk_lookup(struct sk_buff *skb,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ struct sctp_association *asoc = NULL;
+ sctp_chunkhdr_t *ch;
+ int have_auth = 0;
+ unsigned int chunk_num = 1;
+ __u8 *ch_end;
+
+ /* Walk through the chunks looking for AUTH or ASCONF chunks
+ * to help us find the association.
+ */
+ ch = (sctp_chunkhdr_t *) skb->data;
+ do {
+ /* Break out if chunk length is less then minimal. */
+ if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
+ break;
+
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ break;
+
+ switch(ch->type) {
+ case SCTP_CID_AUTH:
+ have_auth = chunk_num;
+ break;
+
+ case SCTP_CID_COOKIE_ECHO:
+ /* If a packet arrives containing an AUTH chunk as
+ * a first chunk, a COOKIE-ECHO chunk as the second
+ * chunk, and possibly more chunks after them, and
+ * the receiver does not have an STCB for that
+ * packet, then authentication is based on
+ * the contents of the COOKIE- ECHO chunk.
+ */
+ if (have_auth == 1 && chunk_num == 2)
+ return NULL;
+ break;
+
+ case SCTP_CID_ASCONF:
+ if (have_auth || sctp_addip_noauth)
+ asoc = __sctp_rcv_asconf_lookup(ch, laddr,
+ sctp_hdr(skb)->source,
+ transportp);
+ default:
+ break;
+ }
+
+ if (asoc)
+ break;
+
+ ch = (sctp_chunkhdr_t *) ch_end;
+ chunk_num++;
+ } while (ch_end < skb_tail_pointer(skb));
+
+ return asoc;
+}
+
+/*
+ * There are circumstances when we need to look inside the SCTP packet
+ * for information to help us find the association. Examples
+ * include looking inside of INIT/INIT-ACK chunks or after the AUTH
+ * chunks.
+ */
+static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ sctp_chunkhdr_t *ch;
+
+ ch = (sctp_chunkhdr_t *) skb->data;
+
+ /* 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;
+
+ /* If this is INIT/INIT-ACK look inside the chunk too. */
+ switch (ch->type) {
+ case SCTP_CID_INIT:
+ case SCTP_CID_INIT_ACK:
+ return __sctp_rcv_init_lookup(skb, laddr, transportp);
+ break;
+
+ default:
+ return __sctp_rcv_walk_lookup(skb, laddr, transportp);
+ break;
+ }
+
+
+ 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_lookup_harder(skb, laddr, transportp);
+
+ return asoc;
+}