-/* SCTP kernel reference Implementation
+/* 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 Nokia, Inc.
* Copyright (c) 2001 La Monte H.P. Yarroll
*
- * This file is part of the SCTP kernel reference Implementation
+ * This file is part of the SCTP kernel implementation
*
* These functions handle all input from the IP layer into SCTP.
*
- * The SCTP reference implementation is free software;
+ * 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.
*
- * The SCTP reference implementation is distributed in the hope that it
+ * 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.
#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 *);
struct sctp_association *asoc,
struct sctp_transport *t)
{
- SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__);
+ SCTP_DEBUG_PRINTK("%s\n", __func__);
sctp_do_sm(SCTP_EVENT_T_OTHER,
SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
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;
sk = asoc->base.sk;
- if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ /* 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 = (struct sctp_init_chunk *)((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;
}
* servers this needs to be solved differently.
*/
if (sock_owned_by_user(sk))
- NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
+ NET_INC_STATS_BH(&init_net, LINUX_MIB_LOCKDROPPEDICMPS);
*app = asoc;
*tpp = transport;
int err;
if (skb->len < ihlen + 8) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS);
return;
}
skb->network_header = saveip;
skb->transport_header = savesctp;
if (!sk) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS);
return;
}
/* Warning: The sock lock is held. Remember to call
}
ep = sctp_sk((sctp_get_ctl_sock()))->ep;
- epb = &ep->base;
hit:
sctp_endpoint_hold(ep);
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;
-
/*
* This code will NOT touch anything inside the chunk--it is
* strictly READ-ONLY.
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->v4.param_hdr.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
*
* This means that any chunks that can help us identify the association need
* to be looked at to find this assocation.
-*
-* TODO: The only chunk currently defined that can do that is ASCONF, but we
-* don't support that functionality yet.
*/
-static struct sctp_association *__sctp_rcv_auth_lookup(struct sk_buff *skb,
- const union sctp_addr *paddr,
+static struct sctp_association *__sctp_rcv_walk_lookup(struct sk_buff *skb,
const union sctp_addr *laddr,
struct sctp_transport **transportp)
{
- /* XXX - walk through the chunks looking for something that can
- * help us find the association. INIT, and INIT-ACK are not permitted.
- * That leaves ASCONF, but we don't support that yet.
+ 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.
*/
- return NULL;
+ 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;
}
/*
* chunks.
*/
static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
- const union sctp_addr *paddr,
const union sctp_addr *laddr,
struct sctp_transport **transportp)
{
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:
return __sctp_rcv_init_lookup(skb, laddr, transportp);
break;
- case SCTP_CID_AUTH:
- return __sctp_rcv_auth_lookup(skb, paddr, laddr, transportp);
+ default:
+ return __sctp_rcv_walk_lookup(skb, laddr, transportp);
break;
}
+
return NULL;
}
* parameters within the INIT or INIT-ACK.
*/
if (!asoc)
- asoc = __sctp_rcv_lookup_harder(skb, paddr, laddr, transportp);
+ asoc = __sctp_rcv_lookup_harder(skb, laddr, transportp);
return asoc;
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff