cregit-Linux how code gets into the kernel

Release 4.8 net/sctp/sm_statefuns.c

Directory: net/sctp
/* SCTP kernel 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 is part of the SCTP Linux Kernel Implementation.
 *
 * These are the state functions for the state machine.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    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>
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/slab.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(struct net *net,
				  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(struct net *net,
					     const struct sctp_association *asoc,
					     const struct sctp_chunk *chunk);
static void sctp_send_stale_cookie_err(struct net *net,
				       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(struct net *net,
						 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(struct net *net,
					     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_tabort_8_4_8(struct net *net,
					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);

static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
					   sctp_cmd_seq_t *commands,
					   __be16 error, int sk_err,
					   const struct sctp_association *asoc,
					   struct sctp_transport *transport);

static sctp_disposition_t sctp_sf_abort_violation(
				     struct net *net,
				     const struct sctp_endpoint *ep,
				     const struct sctp_association *asoc,
				     void *arg,
				     sctp_cmd_seq_t *commands,
				     const __u8 *payload,
				     const size_t paylen);

static sctp_disposition_t sctp_sf_violation_chunklen(
				     struct net *net,
				     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_violation_paramlen(
				     struct net *net,
				     const struct sctp_endpoint *ep,
				     const struct sctp_association *asoc,
				     const sctp_subtype_t type,
				     void *arg, void *ext,
				     sctp_cmd_seq_t *commands);

static sctp_disposition_t sctp_sf_violation_ctsn(
				     struct net *net,
				     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_violation_chunk(
				     struct net *net,
				     const struct sctp_endpoint *ep,
				     const struct sctp_association *asoc,
				     const sctp_subtype_t type,
				     void *arg,
				     sctp_cmd_seq_t *commands);

static sctp_ierror_t sctp_sf_authenticate(struct net *net,
				    const struct sctp_endpoint *ep,
				    const struct sctp_association *asoc,
				    const sctp_subtype_t type,
				    struct sctp_chunk *chunk);

static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const sctp_subtype_t type,
					void *arg,
					sctp_cmd_seq_t *commands);

/* 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); /* Previously already marked? */ if (unlikely(chunk->pdiscard)) return 0; if (unlikely(chunk_length < required_length)) return 0; return 1; }

Contributors

PersonTokensPropCommitsCommitProp
sridhar samudralasridhar samudrala4276.36%150.00%
daniel borkmanndaniel borkmann1323.64%150.00%
Total55100.00%2100.00%

/********************************************************** * 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), sctpimpguide 2.41. * 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 and * the T bit is not set * 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(struct net *net, 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_either(chunk, asoc)) return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); /* 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_sf_violation_chunk(net, ep, asoc, type, arg, commands); /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) return sctp_sf_violation_chunklen(net, 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, NULL, GFP_ATOMIC); if (ev) 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(net, SCTP_MIB_SHUTDOWNS); SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); return SCTP_DISPOSITION_DELETE_TCB; }

Contributors

PersonTokensPropCommitsCommitProp
jon grimmjon grimm15367.11%538.46%
vladislav yasevichvladislav yasevich4519.74%215.38%
eric w. biedermaneric w. biederman156.58%215.38%
sridhar samudralasridhar samudrala104.39%215.38%
david s. millerdavid s. miller31.32%17.69%
hideaki yoshifujihideaki yoshifuji20.88%17.69%
Total228100.00%13100.00%

/* * 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(struct net *net, 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; 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(net, 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(net->sctp.ctl_sock)->ep) { SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); return sctp_sf_tabort_8_4_8(net, 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(net, 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(net, ep, asoc, type, arg, commands); /* If the INIT is coming toward a closing socket, we'll send back * and ABORT. Essentially, this catches the race of INIT being * backloged to the socket at the same time as the user isses close(). * Since the socket and all its associations are going away, we * can treat this OOTB */ if (sctp_sstate(ep->base.sk, CLOSING)) return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); /* Verify the INIT chunk before processing it. */ err_chunk = NULL; if (!sctp_verify_init(net, ep, 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(net, 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(net, SCTP_MIB_OUTCTRLCHUNKS); return SCTP_DISPOSITION_CONSUME; } else { return SCTP_DISPOSITION_NOMEM; } } else { return sctp_sf_tabort_8_4_8(net, 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; if (sctp_assoc_set_bind_addr_from_ep(new_asoc, sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) goto nomem_init; /* The call, sctp_process_init(), can fail on memory allocation. */ if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), (sctp_init_chunk_t *)chunk->chunk_hdr, GFP_ATOMIC)) goto nomem_init; /* 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); repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); if (!repl) goto nomem_init; /* 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_NEW_ASOC, SCTP_ASOC(new_asoc)); 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_init: sctp_association_free(new_asoc); nomem: if (err_chunk) sctp_chunk_free(err_chunk); return SCTP_DISPOSITION_NOMEM; }

Contributors

PersonTokensPropCommitsCommitProp
daisy changdaisy chang22235.63%27.69%
jon grimmjon grimm20733.23%830.77%
sridhar samudralasridhar samudrala7812.52%415.38%
vladislav yasevichvladislav yasevich7111.40%311.54%
eric w. biedermaneric w. biederman304.82%415.38%
wei yongjunwei yongjun71.12%13.85%
david s. millerdavid s. miller30.48%13.85%
hideaki yoshifujihideaki yoshifuji30.48%27.69%
vlad yasevichvlad yasevich20.32%13.85%
Total623100.00%26100.00%

/* * 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(struct net *net, 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; struct sctp_chunk *err_chunk; struct sctp_packet *packet; if (!sctp_vtag_verify(chunk, asoc)) return sctp_sf_pdiscard(net, 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_sf_violation_chunk(net, 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(net, ep, asoc, type, arg, commands); /* Grab the INIT header. */ chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; /* Verify the INIT chunk before processing it. */ err_chunk = NULL; if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, &err_chunk)) { sctp_error_t error = SCTP_ERROR_NO_RESOURCE; /* This chunk contains fatal error. It is to be discarded. * Send an ABORT, with causes. If there are no causes, * then there wasn't enough memory. Just terminate * the association. */ if (err_chunk) { packet = sctp_abort_pkt_new(net, 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(net, SCTP_MIB_OUTCTRLCHUNKS); error = SCTP_ERROR_INV_PARAM; } } /* SCTP-AUTH, Section 6.3: * It should be noted that if the receiver wants to tear * down an association in an authenticated way only, the * handling of malformed packets should not result in * tearing down the association. * * This means that if we only want to abort associations * in an authenticated way (i.e AUTH+ABORT), then we * can't destroy this association just because the packet * was malformed. */ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc, chunk->transport); } /* 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)); /* Reset init error count upon receipt of INIT-ACK. */ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); /* 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)); /* SCTP-AUTH: genereate the assocition shared keys so that * we can potentially signe the COOKIE-ECHO. */ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL()); /* 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; }

Contributors

PersonTokensPropCommitsCommitProp
daisy changdaisy chang14231.84%14.17%
jon grimmjon grimm13430.04%520.83%
vladislav yasevichvladislav yasevich6715.02%520.83%
sridhar samudralasridhar samudrala6013.45%416.67%
eric w. biedermaneric w. biederman235.16%312.50%
frank filzfrank filz112.47%14.17%
david s. millerdavid s. miller40.90%14.17%
vlad yasevichvlad yasevich20.45%14.17%
steven colesteven cole10.22%14.17%
lucas de marchilucas de marchi10.22%14.17%
hideaki yoshifujihideaki yoshifuji10.22%14.17%
Total446100.00%24100.00%

/* * 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(struct net *net, 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, *ai_ev = NULL; int error = 0; struct sctp_chunk *err_chk_p; struct sock *sk; /* If the packet is an OOTB packet which is temporarily on the * control endpoint, respond with an ABORT. */ if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); return sctp_sf_tabort_8_4_8(net, 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(net, ep, asoc, type, arg, commands); /* 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. */ sk = ep->base.sk; if (!sctp_sstate(sk, LISTENING) || (sctp_style(sk, TCP) && sk_acceptq_is_full(sk))) return sctp_sf_tabort_8_4_8(net, 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; if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t))) goto nomem; /* 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(net, ep, asoc, chunk, commands, err_chk_p); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); case -SCTP_IERROR_BAD_SIG: default: return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } } /* Delay state machine commands until later. * * 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->subh.cookie_hdr->c.peer_addr, peer_init, GFP_ATOMIC)) goto nomem_init; /* SCTP-AUTH: Now that we've populate required fields in * sctp_process_init, set up the assocaition shared keys as * necessary so that we can potentially authenticate the ACK */ error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC); if (error) goto nomem_init; /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo * is supposed to be authenticated and we have to do delayed * authentication. We've just recreated the association using * the information in the cookie and now it's much easier to * do the authentication. */ if (chunk->auth_chunk) { struct sctp_chunk auth; sctp_ierror_t ret; /* Make sure that we and the peer are AUTH capable */ if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) { sctp_association_free(new_asoc); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } /* set-up our fake chunk so that we can process it */ auth.skb = chunk->auth_chunk; auth.asoc = chunk->asoc; auth.sctp_hdr = chunk->sctp_hdr; auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk, sizeof(sctp_chunkhdr_t)); skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t)); auth.transport = chunk->transport; ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth); if (ret != SCTP_IERROR_NO_ERROR) { sctp_association_free(new_asoc); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } } repl = sctp_make_cookie_ack(new_asoc, chunk); if (!repl) goto nomem_init; /* 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, NULL, GFP_ATOMIC); if (!ev) goto nomem_ev; /* Sockets API Draft Section 5.3.1.6 * When a peer sends a Adaptation Layer Indication parameter , SCTP * delivers this notification to inform the application that of the * peers requested adaptation layer. */ if (new_asoc->peer.adaptation_ind) { ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc, GFP_ATOMIC); if (!ai_ev) goto nomem_aiev; } /* Add all the state machine commands now since we've created * everything. This way we don't introduce memory corruptions * during side-effect processing and correclty count established * associations. */ 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(net, SCTP_MIB_CURRESTAB); SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS); sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); /* This will send the COOKIE ACK */ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); /* Queue the ASSOC_CHANGE event */ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); /* Send up the Adaptation Layer Indication event */ if (ai_ev) sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ai_ev)); return SCTP_DISPOSITION_CONSUME; nomem_aiev: sctp_ulpevent_free(ev); nomem_ev: sctp_chunk_free(repl); nomem_init: sctp_association_free(new_asoc); nomem: return SCTP_DISPOSITION_NOMEM; }

Contributors

PersonTokensPropCommitsCommitProp
vladislav yasevichvladislav yasevich30538.27%621.43%
jon grimmjon grimm28635.88%828.57%
sridhar samudralasridhar samudrala10613.30%414.29%
daniel borkmanndaniel borkmann405.02%13.57%
eric w. biedermaneric w. biederman324.02%310.71%
al viroal viro91.13%13.57%
wei yongjunwei yongjun70.88%13.57%
david s. millerdavid s. miller50.63%13.57%
neil hormanneil horman40.50%13.57%
ivan skytte jorgensenivan skytte jorgensen20.25%13.57%
hideaki yoshifujihideaki yoshifuji10.13%13.57%
Total797100.00%28100.00%

/* * Respond to a normal COOKIE ACK chunk. * We are the side that is asking 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(struct net *net, 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(net, 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(net, 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_INIT_COUNTER_RESET, SCTP_NULL()); /* 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(net, SCTP_MIB_CURRESTAB); SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS); sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); if