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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sctp/sm_statefuns.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/sctp/sm_statefuns.c')
-rw-r--r--net/sctp/sm_statefuns.c5238
1 files changed, 5238 insertions, 0 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
new file mode 100644
index 00000000000..278c56a2d07
--- /dev/null
+++ b/net/sctp/sm_statefuns.c
@@ -0,0 +1,5238 @@
+/* SCTP kernel reference Implementation
+ * (C) Copyright IBM Corp. 2001, 2004
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2002 Intel Corp.
+ * Copyright (c) 2002 Nokia Corp.
+ *
+ * This file is part of the SCTP kernel reference Implementation
+ *
+ * This is part of the SCTP Linux Kernel Reference Implementation.
+ *
+ * These are the state functions for the state machine.
+ *
+ * The SCTP reference 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
+ * 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>
+ * Mathew Kotowsky <kotowsky@sctp.org>
+ * Sridhar Samudrala <samudrala@us.ibm.com>
+ * Jon Grimm <jgrimm@us.ibm.com>
+ * Hui Huang <hui.huang@nokia.com>
+ * Dajiang Zhang <dajiang.zhang@nokia.com>
+ * Daisy Chang <daisyc@us.ibm.com>
+ * Ardelle Fan <ardelle.fan@intel.com>
+ * Ryan Layer <rmlayer@us.ibm.com>
+ * Kevin Gao <kevin.gao@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/kernel.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <net/sock.h>
+#include <net/inet_ecn.h>
+#include <linux/skbuff.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+#include <net/sctp/structs.h>
+
+static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ const void *payload,
+ size_t paylen);
+static int sctp_eat_data(const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands);
+static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk);
+static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_chunk *err_chunk);
+static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
+
+
+/* Small helper function that checks if the chunk length
+ * is of the appropriate length. The 'required_length' argument
+ * is set to be the size of a specific chunk we are testing.
+ * Return Values: 1 = Valid length
+ * 0 = Invalid length
+ *
+ */
+static inline int
+sctp_chunk_length_valid(struct sctp_chunk *chunk,
+ __u16 required_length)
+{
+ __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
+
+ if (unlikely(chunk_length < required_length))
+ return 0;
+
+ return 1;
+}
+
+/**********************************************************
+ * These are the state functions for handling chunk events.
+ **********************************************************/
+
+/*
+ * Process the final SHUTDOWN COMPLETE.
+ *
+ * Section: 4 (C) (diagram), 9.2
+ * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
+ * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
+ * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
+ * should stop the T2-shutdown timer and remove all knowledge of the
+ * association (and thus the association enters the CLOSED state).
+ *
+ * Verification Tag: 8.5.1(C)
+ * C) Rules for packet carrying SHUTDOWN COMPLETE:
+ * ...
+ * - The receiver of a SHUTDOWN COMPLETE shall accept the packet if the
+ * Verification Tag field of the packet matches its own tag OR it is
+ * set to its peer's tag and the T bit is set in the Chunk Flags.
+ * Otherwise, the receiver MUST silently discard the packet and take
+ * no further action. An endpoint MUST ignore the SHUTDOWN COMPLETE if
+ * it is not in the SHUTDOWN-ACK-SENT state.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_ulpevent *ev;
+
+ /* RFC 2960 6.10 Bundling
+ *
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ */
+ if (!chunk->singleton)
+ return SCTP_DISPOSITION_VIOLATION;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* RFC 2960 10.2 SCTP-to-ULP
+ *
+ * H) SHUTDOWN COMPLETE notification
+ *
+ * When SCTP completes the shutdown procedures (section 9.2) this
+ * notification is passed to the upper layer.
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
+ 0, 0, 0, GFP_ATOMIC);
+ if (!ev)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
+ * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
+ * not the chunk should be discarded. If the endpoint is in
+ * the SHUTDOWN-ACK-SENT state the endpoint should stop the
+ * T2-shutdown timer and remove all knowledge of the
+ * association (and thus the association enters the CLOSED
+ * state).
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+
+ SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
+ SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal INIT chunk.
+ * We are the side that is being asked for an association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, B
+ * B) "Z" shall respond immediately with an INIT ACK chunk. The
+ * destination IP address of the INIT ACK MUST be set to the source
+ * IP address of the INIT to which this INIT ACK is responding. In
+ * the response, besides filling in other parameters, "Z" must set the
+ * Verification Tag field to Tag_A, and also provide its own
+ * Verification Tag (Tag_Z) in the Initiate Tag field.
+ *
+ * Verification Tag: Must be 0.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *repl;
+ struct sctp_association *new_asoc;
+ struct sctp_chunk *err_chunk;
+ struct sctp_packet *packet;
+ sctp_unrecognized_param_t *unk_param;
+ struct sock *sk;
+ int len;
+
+ /* 6.10 Bundling
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ *
+ * IG Section 2.11.2
+ * Furthermore, we require that the receiver of an INIT chunk MUST
+ * enforce these rules by silently discarding an arriving packet
+ * with an INIT chunk that is bundled with other chunks.
+ */
+ if (!chunk->singleton)
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* If the packet is an OOTB packet which is temporarily on the
+ * control endpoint, respond with an ABORT.
+ */
+ if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
+
+ sk = ep->base.sk;
+ /* If the endpoint is not listening or if the number of associations
+ * on the TCP-style socket exceed the max backlog, respond with an
+ * ABORT.
+ */
+ if (!sctp_sstate(sk, LISTENING) ||
+ (sctp_style(sk, TCP) &&
+ sk_acceptq_is_full(sk)))
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
+
+ /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
+ * Tag.
+ */
+ if (chunk->sctp_hdr->vtag != 0)
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
+
+ /* Make sure that the INIT chunk has a valid length.
+ * Normally, this would cause an ABORT with a Protocol Violation
+ * error, but since we don't have an association, we'll
+ * just discard the packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* Verify the INIT chunk before processing it. */
+ err_chunk = NULL;
+ if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
+ (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
+ &err_chunk)) {
+ /* This chunk contains fatal error. It is to be discarded.
+ * Send an ABORT, with causes if there is any.
+ */
+ if (err_chunk) {
+ packet = sctp_abort_pkt_new(ep, asoc, arg,
+ (__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t),
+ ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t));
+
+ sctp_chunk_free(err_chunk);
+
+ if (packet) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ return SCTP_DISPOSITION_CONSUME;
+ } else {
+ return SCTP_DISPOSITION_NOMEM;
+ }
+ } else {
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
+ commands);
+ }
+ }
+
+ /* Grab the INIT header. */
+ chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
+
+ /* Tag the variable length parameters. */
+ chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
+
+ new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
+ if (!new_asoc)
+ goto nomem;
+
+ /* The call, sctp_process_init(), can fail on memory allocation. */
+ if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
+ sctp_source(chunk),
+ (sctp_init_chunk_t *)chunk->chunk_hdr,
+ GFP_ATOMIC))
+ goto nomem_init;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
+
+ /* B) "Z" shall respond immediately with an INIT ACK chunk. */
+
+ /* If there are errors need to be reported for unknown parameters,
+ * make sure to reserve enough room in the INIT ACK for them.
+ */
+ len = 0;
+ if (err_chunk)
+ len = ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t);
+
+ if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
+ goto nomem_ack;
+
+ repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
+ if (!repl)
+ goto nomem_ack;
+
+ /* If there are errors need to be reported for unknown parameters,
+ * include them in the outgoing INIT ACK as "Unrecognized parameter"
+ * parameter.
+ */
+ if (err_chunk) {
+ /* Get the "Unrecognized parameter" parameter(s) out of the
+ * ERROR chunk generated by sctp_verify_init(). Since the
+ * error cause code for "unknown parameter" and the
+ * "Unrecognized parameter" type is the same, we can
+ * construct the parameters in INIT ACK by copying the
+ * ERROR causes over.
+ */
+ unk_param = (sctp_unrecognized_param_t *)
+ ((__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t));
+ /* Replace the cause code with the "Unrecognized parameter"
+ * parameter type.
+ */
+ sctp_addto_chunk(repl, len, unk_param);
+ sctp_chunk_free(err_chunk);
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /*
+ * Note: After sending out INIT ACK with the State Cookie parameter,
+ * "Z" MUST NOT allocate any resources, nor keep any states for the
+ * new association. Otherwise, "Z" will be vulnerable to resource
+ * attacks.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+
+nomem_ack:
+ if (err_chunk)
+ sctp_chunk_free(err_chunk);
+nomem_init:
+ sctp_association_free(new_asoc);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal INIT ACK chunk.
+ * We are the side that is initiating the association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, C
+ * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
+ * timer and leave COOKIE-WAIT state. "A" shall then send the State
+ * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
+ * the T1-cookie timer, and enter the COOKIE-ECHOED state.
+ *
+ * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
+ * DATA chunks, but it MUST be the first chunk in the packet and
+ * until the COOKIE ACK is returned the sender MUST NOT send any
+ * other packets to the peer.
+ *
+ * Verification Tag: 3.3.3
+ * If the value of the Initiate Tag in a received INIT ACK chunk is
+ * found to be 0, the receiver MUST treat it as an error and close the
+ * association by transmitting an ABORT.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_init_chunk_t *initchunk;
+ __u32 init_tag;
+ struct sctp_chunk *err_chunk;
+ struct sctp_packet *packet;
+ sctp_disposition_t ret;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* Make sure that the INIT-ACK chunk has a valid length */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+ /* 6.10 Bundling
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ */
+ if (!chunk->singleton)
+ return SCTP_DISPOSITION_VIOLATION;
+
+ /* Grab the INIT header. */
+ chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
+
+ init_tag = ntohl(chunk->subh.init_hdr->init_tag);
+
+ /* Verification Tag: 3.3.3
+ * If the value of the Initiate Tag in a received INIT ACK
+ * chunk is found to be 0, the receiver MUST treat it as an
+ * error and close the association by transmitting an ABORT.
+ */
+ if (!init_tag) {
+ struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
+ if (!reply)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ /* Verify the INIT chunk before processing it. */
+ err_chunk = NULL;
+ if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
+ (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
+ &err_chunk)) {
+
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+
+ /* This chunk contains fatal error. It is to be discarded.
+ * Send an ABORT, with causes if there is any.
+ */
+ if (err_chunk) {
+ packet = sctp_abort_pkt_new(ep, asoc, arg,
+ (__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t),
+ ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t));
+
+ sctp_chunk_free(err_chunk);
+
+ if (packet) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
+ SCTP_NULL());
+ return SCTP_DISPOSITION_CONSUME;
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
+ SCTP_NULL());
+ return SCTP_DISPOSITION_NOMEM;
+ }
+ } else {
+ ret = sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
+ commands);
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
+ SCTP_NULL());
+ return ret;
+ }
+ }
+
+ /* Tag the variable length parameters. Note that we never
+ * convert the parameters in an INIT chunk.
+ */
+ chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
+
+ initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
+ SCTP_PEER_INIT(initchunk));
+
+ /* 5.1 C) "A" shall stop the T1-init timer and leave
+ * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
+ * timer, and enter the COOKIE-ECHOED state.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
+
+ /* 5.1 C) "A" shall then send the State Cookie received in the
+ * INIT ACK chunk in a COOKIE ECHO chunk, ...
+ */
+ /* If there is any errors to report, send the ERROR chunk generated
+ * for unknown parameters as well.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
+ SCTP_CHUNK(err_chunk));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal COOKIE ECHO chunk.
+ * We are the side that is being asked for an association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, D
+ * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
+ * with a COOKIE ACK chunk after building a TCB and moving to
+ * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
+ * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
+ * chunk MUST be the first chunk in the packet.
+ *
+ * IMPLEMENTATION NOTE: An implementation may choose to send the
+ * Communication Up notification to the SCTP user upon reception
+ * of a valid COOKIE ECHO chunk.
+ *
+ * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
+ * D) Rules for packet carrying a COOKIE ECHO
+ *
+ * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
+ * Initial Tag received in the INIT ACK.
+ *
+ * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_association *new_asoc;
+ sctp_init_chunk_t *peer_init;
+ struct sctp_chunk *repl;
+ struct sctp_ulpevent *ev;
+ int error = 0;
+ struct sctp_chunk *err_chk_p;
+
+ /* If the packet is an OOTB packet which is temporarily on the
+ * control endpoint, respond with an ABORT.
+ */
+ if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
+ return sctp_sf_ootb(ep, asoc, type, arg, commands);
+
+ /* Make sure that the COOKIE_ECHO chunk has a valid length.
+ * In this case, we check that we have enough for at least a
+ * chunk header. More detailed verification is done
+ * in sctp_unpack_cookie().
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* "Decode" the chunk. We have no optional parameters so we
+ * are in good shape.
+ */
+ chunk->subh.cookie_hdr =
+ (struct sctp_signed_cookie *)chunk->skb->data;
+ skb_pull(chunk->skb,
+ ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t));
+
+ /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
+ * "Z" will reply with a COOKIE ACK chunk after building a TCB
+ * and moving to the ESTABLISHED state.
+ */
+ new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
+ &err_chk_p);
+
+ /* FIXME:
+ * If the re-build failed, what is the proper error path
+ * from here?
+ *
+ * [We should abort the association. --piggy]
+ */
+ if (!new_asoc) {
+ /* FIXME: Several errors are possible. A bad cookie should
+ * be silently discarded, but think about logging it too.
+ */
+ switch (error) {
+ case -SCTP_IERROR_NOMEM:
+ goto nomem;
+
+ case -SCTP_IERROR_STALE_COOKIE:
+ sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
+ err_chk_p);
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ case -SCTP_IERROR_BAD_SIG:
+ default:
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ };
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
+ SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
+
+ if (new_asoc->autoclose)
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
+
+ /* Re-build the bind address for the association is done in
+ * the sctp_unpack_cookie() already.
+ */
+ /* This is a brand-new association, so these are not yet side
+ * effects--it is safe to run them here.
+ */
+ peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
+
+ if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
+ &chunk->subh.cookie_hdr->c.peer_addr,
+ peer_init, GFP_ATOMIC))
+ goto nomem_init;
+
+ repl = sctp_make_cookie_ack(new_asoc, chunk);
+ if (!repl)
+ goto nomem_repl;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * D) IMPLEMENTATION NOTE: An implementation may choose to
+ * send the Communication Up notification to the SCTP user
+ * upon reception of a valid COOKIE ECHO chunk.
+ */
+ ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
+ new_asoc->c.sinit_num_ostreams,
+ new_asoc->c.sinit_max_instreams,
+ GFP_ATOMIC);
+ if (!ev)
+ goto nomem_ev;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaption Layer Indication parameter , SCTP
+ * delivers this notification to inform the application that of the
+ * peers requested adaption layer.
+ */
+ if (new_asoc->peer.adaption_ind) {
+ ev = sctp_ulpevent_make_adaption_indication(new_asoc,
+ GFP_ATOMIC);
+ if (!ev)
+ goto nomem_ev;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem_ev:
+ sctp_chunk_free(repl);
+nomem_repl:
+nomem_init:
+ sctp_association_free(new_asoc);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal COOKIE ACK chunk.
+ * We are the side that is being asked for an association.
+ *
+ * RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
+ * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
+ * timer. It may also notify its ULP about the successful
+ * establishment of the association with a Communication Up
+ * notification (see Section 10).
+ *
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_ulpevent *ev;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* Verify that the chunk length for the COOKIE-ACK is OK.
+ * If we don't do this, any bundled chunks may be junked.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
+ /* Reset init error count upon receipt of COOKIE-ACK,
+ * to avoid problems with the managemement of this
+ * counter in stale cookie situations when a transition back
+ * from the COOKIE-ECHOED state to the COOKIE-WAIT
+ * state is performed.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_COUNTER_RESET,
+ SCTP_COUNTER(SCTP_COUNTER_INIT_ERROR));
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * E) Upon reception of the COOKIE ACK, endpoint "A" will move
+ * from the COOKIE-ECHOED state to the ESTABLISHED state,
+ * stopping the T1-cookie timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
+ SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
+ if (asoc->autoclose)
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
+
+ /* It may also notify its ULP about the successful
+ * establishment of the association with a Communication Up
+ * notification (see Section 10).
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
+ 0, asoc->c.sinit_num_ostreams,
+ asoc->c.sinit_max_instreams,
+ GFP_ATOMIC);
+
+ if (!ev)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaption Layer Indication parameter , SCTP
+ * delivers this notification to inform the application that of the
+ * peers requested adaption layer.
+ */
+ if (asoc->peer.adaption_ind) {
+ ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
+ if (!ev)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Generate and sendout a heartbeat packet. */
+static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_transport *transport = (struct sctp_transport *) arg;
+ struct sctp_chunk *reply;
+ sctp_sender_hb_info_t hbinfo;
+ size_t paylen = 0;
+
+ hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
+ hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
+ hbinfo.daddr = transport->ipaddr;
+ hbinfo.sent_at = jiffies;
+
+ /* Send a heartbeat to our peer. */
+ paylen = sizeof(sctp_sender_hb_info_t);
+ reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
+ if (!reply)
+ return SCTP_DISPOSITION_NOMEM;
+
+ /* Set rto_pending indicating that an RTT measurement
+ * is started with this heartbeat chunk.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
+ SCTP_TRANSPORT(transport));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* Generate a HEARTBEAT packet on the given transport. */
+sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_transport *transport = (struct sctp_transport *) arg;
+
+ if (asoc->overall_error_count > asoc->max_retrans) {
+ /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_U32(SCTP_ERROR_NO_ERROR));
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ /* Section 3.3.5.
+ * The Sender-specific Heartbeat Info field should normally include
+ * information about the sender's current time when this HEARTBEAT
+ * chunk is sent and the destination transport address to which this
+ * HEARTBEAT is sent (see Section 8.3).
+ */
+
+ if (transport->hb_allowed) {
+ if (SCTP_DISPOSITION_NOMEM ==
+ sctp_sf_heartbeat(ep, asoc, type, arg,
+ commands))
+ return SCTP_DISPOSITION_NOMEM;
+ /* Set transport error counter and association error counter
+ * when sending heartbeat.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
+ SCTP_TRANSPORT(transport));
+ }
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
+ SCTP_TRANSPORT(transport));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Process an heartbeat request.
+ *
+ * Section: 8.3 Path Heartbeat
+ * The receiver of the HEARTBEAT should immediately respond with a
+ * HEARTBEAT ACK that contains the Heartbeat Information field copied
+ * from the received HEARTBEAT chunk.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ * When receiving an SCTP packet, the endpoint MUST ensure that the
+ * value in the Verification Tag field of the received SCTP packet
+ * matches its own Tag. If the received Verification Tag value does not
+ * match the receiver's own tag value, the receiver shall silently
+ * discard the packet and shall not process it any further except for
+ * those cases listed in Section 8.5.1 below.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *reply;
+ size_t paylen = 0;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* Make sure that the HEARTBEAT chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
+ /* 8.3 The receiver of the HEARTBEAT should immediately
+ * respond with a HEARTBEAT ACK that contains the Heartbeat
+ * Information field copied from the received HEARTBEAT chunk.
+ */
+ chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
+ paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
+ skb_pull(chunk->skb, paylen);
+
+ reply = sctp_make_heartbeat_ack(asoc, chunk,
+ chunk->subh.hb_hdr, paylen);
+ if (!reply)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Process the returning HEARTBEAT ACK.
+ *
+ * Section: 8.3 Path Heartbeat
+ * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
+ * should clear the error counter of the destination transport
+ * address to which the HEARTBEAT was sent, and mark the destination
+ * transport address as active if it is not so marked. The endpoint may
+ * optionally report to the upper layer when an inactive destination
+ * address is marked as active due to the reception of the latest
+ * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
+ * clear the association overall error count as well (as defined
+ * in section 8.1).
+ *
+ * The receiver of the HEARTBEAT ACK should also perform an RTT
+ * measurement for that destination transport address using the time
+ * value carried in the HEARTBEAT ACK chunk.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ union sctp_addr from_addr;
+ struct sctp_transport *link;
+ sctp_sender_hb_info_t *hbinfo;
+ unsigned long max_interval;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
+ hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
+ from_addr = hbinfo->daddr;
+ link = sctp_assoc_lookup_paddr(asoc, &from_addr);
+
+ /* This should never happen, but lets log it if so. */
+ if (!link) {
+ printk(KERN_WARNING
+ "%s: Could not find address %d.%d.%d.%d\n",
+ __FUNCTION__, NIPQUAD(from_addr.v4.sin_addr));
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ max_interval = link->hb_interval + link->rto;
+
+ /* Check if the timestamp looks valid. */
+ if (time_after(hbinfo->sent_at, jiffies) ||
+ time_after(jiffies, hbinfo->sent_at + max_interval)) {
+ SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
+ "received for transport: %p\n",
+ __FUNCTION__, link);
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
+ * the HEARTBEAT should clear the error counter of the
+ * destination transport address to which