/* 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. * * This file is part of the SCTP kernel reference Implementation * * These functions work with the state functions in sctp_sm_statefuns.c * to implement the state operations. These functions implement the * steps which require modifying existing data structures. * * 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 * * Or submit a bug report through the following website: * http://www.sf.net/projects/lksctp * * Written or modified by: * La Monte H.P. Yarroll * Karl Knutson * C. Robin * Jon Grimm * Xingang Guo * Dajiang Zhang * Sridhar Samudrala * Daisy Chang * Ardelle Fan * Kevin Gao * * Any bugs reported given to us we will try to fix... any fixes shared will * be incorporated into the next SCTP release. */ #include #include #include #include #include #include #include #include #include #include #include /* for get_random_bytes */ #include #include extern kmem_cache_t *sctp_chunk_cachep; SCTP_STATIC struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen); static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, const struct sctp_association *asoc, const struct sctp_chunk *init_chunk, int *cookie_len, const __u8 *raw_addrs, int addrs_len); static int sctp_process_param(struct sctp_association *asoc, union sctp_params param, const union sctp_addr *peer_addr, gfp_t gfp); /* What was the inbound interface for this chunk? */ int sctp_chunk_iif(const struct sctp_chunk *chunk) { struct sctp_af *af; int iif = 0; af = sctp_get_af_specific(ipver2af(chunk->skb->nh.iph->version)); if (af) iif = af->skb_iif(chunk->skb); return iif; } /* RFC 2960 3.3.2 Initiation (INIT) (1) * * Note 2: The ECN capable field is reserved for future use of * Explicit Congestion Notification. */ static const struct sctp_paramhdr ecap_param = { SCTP_PARAM_ECN_CAPABLE, __constant_htons(sizeof(struct sctp_paramhdr)), }; static const struct sctp_paramhdr prsctp_param = { SCTP_PARAM_FWD_TSN_SUPPORT, __constant_htons(sizeof(struct sctp_paramhdr)), }; /* A helper to initialize to initialize an op error inside a * provided chunk, as most cause codes will be embedded inside an * abort chunk. */ void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, const void *payload, size_t paylen) { sctp_errhdr_t err; int padlen; __u16 len; /* Cause code constants are now defined in network order. */ err.cause = cause_code; len = sizeof(sctp_errhdr_t) + paylen; padlen = len % 4; err.length = htons(len); len += padlen; sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); chunk->subh.err_hdr = sctp_addto_chunk(chunk, paylen, payload); } /* 3.3.2 Initiation (INIT) (1) * * This chunk is used to initiate a SCTP association between two * endpoints. The format of the INIT chunk is shown below: * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 1 | Chunk Flags | Chunk Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Initiate Tag | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Advertised Receiver Window Credit (a_rwnd) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Number of Outbound Streams | Number of Inbound Streams | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Initial TSN | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ \ * / Optional/Variable-Length Parameters / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * * The INIT chunk contains the following parameters. Unless otherwise * noted, each parameter MUST only be included once in the INIT chunk. * * Fixed Parameters Status * ---------------------------------------------- * Initiate Tag Mandatory * Advertised Receiver Window Credit Mandatory * Number of Outbound Streams Mandatory * Number of Inbound Streams Mandatory * Initial TSN Mandatory * * Variable Parameters Status Type Value * ------------------------------------------------------------- * IPv4 Address (Note 1) Optional 5 * IPv6 Address (Note 1) Optional 6 * Cookie Preservative Optional 9 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) * Host Name Address (Note 3) Optional 11 * Supported Address Types (Note 4) Optional 12 */ struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, const struct sctp_bind_addr *bp, gfp_t gfp, int vparam_len) { sctp_inithdr_t init; union sctp_params addrs; size_t chunksize; struct sctp_chunk *retval = NULL; int num_types, addrs_len = 0; struct sctp_sock *sp; sctp_supported_addrs_param_t sat; __u16 types[2]; sctp_adaption_ind_param_t aiparam; /* RFC 2960 3.3.2 Initiation (INIT) (1) * * Note 1: The INIT chunks can contain multiple addresses that * can be IPv4 and/or IPv6 in any combination. */ retval = NULL; /* Convert the provided bind address list to raw format. */ addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); init.init_tag = htonl(asoc->c.my_vtag); init.a_rwnd = htonl(asoc->rwnd); init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); init.initial_tsn = htonl(asoc->c.initial_tsn); /* How many address types are needed? */ sp = sctp_sk(asoc->base.sk); num_types = sp->pf->supported_addrs(sp, types); chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types); chunksize += sizeof(ecap_param); if (sctp_prsctp_enable) chunksize += sizeof(prsctp_param); chunksize += sizeof(aiparam); chunksize += vparam_len; /* RFC 2960 3.3.2 Initiation (INIT) (1) * * Note 3: An INIT chunk MUST NOT contain more than one Host * Name address parameter. Moreover, the sender of the INIT * MUST NOT combine any other address types with the Host Name * address in the INIT. The receiver of INIT MUST ignore any * other address types if the Host Name address parameter is * present in the received INIT chunk. * * PLEASE DO NOT FIXME [This version does not support Host Name.] */ retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); if (!retval) goto nodata; retval->subh.init_hdr = sctp_addto_chunk(retval, sizeof(init), &init); retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); /* RFC 2960 3.3.2 Initiation (INIT) (1) * * Note 4: This parameter, when present, specifies all the * address types the sending endpoint can support. The absence * of this parameter indicates that the sending endpoint can * support any address type. */ sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); sctp_addto_chunk(retval, sizeof(sat), &sat); sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); if (sctp_prsctp_enable) sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); aiparam.param_hdr.type = SCTP_PARAM_ADAPTION_LAYER_IND; aiparam.param_hdr.length = htons(sizeof(aiparam)); aiparam.adaption_ind = htonl(sp->adaption_ind); sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); nodata: kfree(addrs.v); return retval; } struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk, gfp_t gfp, int unkparam_len) { sctp_inithdr_t initack; struct sctp_chunk *retval; union sctp_params addrs; int addrs_len; sctp_cookie_param_t *cookie; int cookie_len; size_t chunksize; sctp_adaption_ind_param_t aiparam; retval = NULL; /* Note: there may be no addresses to embed. */ addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); initack.init_tag = htonl(asoc->c.my_vtag); initack.a_rwnd = htonl(asoc->rwnd); initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); initack.initial_tsn = htonl(asoc->c.initial_tsn); /* FIXME: We really ought to build the cookie right * into the packet instead of allocating more fresh memory. */ cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, addrs.v, addrs_len); if (!cookie) goto nomem_cookie; /* Calculate the total size of allocation, include the reserved * space for reporting unknown parameters if it is specified. */ chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; /* Tell peer that we'll do ECN only if peer advertised such cap. */ if (asoc->peer.ecn_capable) chunksize += sizeof(ecap_param); /* Tell peer that we'll do PR-SCTP only if peer advertised. */ if (asoc->peer.prsctp_capable) chunksize += sizeof(prsctp_param); chunksize += sizeof(aiparam); /* Now allocate and fill out the chunk. */ retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); if (!retval) goto nomem_chunk; /* Per the advice in RFC 2960 6.4, send this reply to * the source of the INIT packet. */ retval->transport = chunk->transport; retval->subh.init_hdr = sctp_addto_chunk(retval, sizeof(initack), &initack); retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); sctp_addto_chunk(retval, cookie_len, cookie); if (asoc->peer.ecn_capable) sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); if (asoc->peer.prsctp_capable) sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); aiparam.param_hdr.type = SCTP_PARAM_ADAPTION_LAYER_IND; aiparam.param_hdr.length = htons(sizeof(aiparam)); aiparam.adaption_ind = htonl(sctp_sk(asoc->base.sk)->adaption_ind); sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); /* We need to remove the const qualifier at this point. */ retval->asoc = (struct sctp_association *) asoc; /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it received the DATA or control chunk * to which it is replying. * * [INIT ACK back to where the INIT came from.] */ if (chunk) retval->transport = chunk->transport; nomem_chunk: kfree(cookie); nomem_cookie: kfree(addrs.v); return retval; } /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): * * This chunk is used only during the initialization of an association. * It is sent by the initiator of an association to its peer to complete * the initialization process. This chunk MUST precede any DATA chunk * sent within the association, but MAY be bundled with one or more DATA * chunks in the same packet. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 10 |Chunk Flags | Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * / Cookie / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Chunk Flags: 8 bit * * Set to zero on transmit and ignored on receipt. * * Length: 16 bits (unsigned integer) * * Set to the size of the chunk in bytes, including the 4 bytes of * the chunk header and the size of the Cookie. * * Cookie: variable size * * This field must contain the exact cookie received in the * State Cookie parameter from the previous INIT ACK. * * An implementation SHOULD make the cookie as small as possible * to insure interoperability. */ struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; void *cookie; int cookie_len; cookie = asoc->peer.cookie; cookie_len = asoc->peer.cookie_len; /* Build a cookie echo chunk. */ retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); if (!retval) goto nodata; retval->subh.cookie_hdr = sctp_addto_chunk(retval, cookie_len, cookie); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [COOKIE ECHO back to where the INIT ACK came from.] */ if (chunk) retval->transport = chunk->transport; nodata: return retval; } /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): * * This chunk is used only during the initialization of an * association. It is used to acknowledge the receipt of a COOKIE * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent * within the association, but MAY be bundled with one or more DATA * chunks or SACK chunk in the same SCTP packet. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 11 |Chunk Flags | Length = 4 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Chunk Flags: 8 bits * * Set to zero on transmit and ignored on receipt. */ struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [COOKIE ACK back to where the COOKIE ECHO came from.] */ if (retval && chunk) retval->transport = chunk->transport; return retval; } /* * Appendix A: Explicit Congestion Notification: * CWR: * * RFC 2481 details a specific bit for a sender to send in the header of * its next outbound TCP segment to indicate to its peer that it has * reduced its congestion window. This is termed the CWR bit. For * SCTP the same indication is made by including the CWR chunk. * This chunk contains one data element, i.e. the TSN number that * was sent in the ECNE chunk. This element represents the lowest * TSN number in the datagram that was originally marked with the * CE bit. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Lowest TSN Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Note: The CWR is considered a Control chunk. */ struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, const __u32 lowest_tsn, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; sctp_cwrhdr_t cwr; cwr.lowest_tsn = htonl(lowest_tsn); retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, sizeof(sctp_cwrhdr_t)); if (!retval) goto nodata; retval->subh.ecn_cwr_hdr = sctp_addto_chunk(retval, sizeof(cwr), &cwr); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [Report a reduced congestion window back to where the ECNE * came from.] */ if (chunk) retval->transport = chunk->transport; nodata: return retval; } /* Make an ECNE chunk. This is a congestion experienced report. */ struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, const __u32 lowest_tsn) { struct sctp_chunk *retval; sctp_ecnehdr_t ecne; ecne.lowest_tsn = htonl(lowest_tsn); retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, sizeof(sctp_ecnehdr_t)); if (!retval) goto nodata; retval->subh.ecne_hdr = sctp_addto_chunk(retval, sizeof(ecne), &ecne); nodata: return retval; } /* Make a DATA chunk for the given association from the provided * parameters. However, do not populate the data payload. */ struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, const struct sctp_sndrcvinfo *sinfo, int data_len, __u8 flags, __u16 ssn) { struct sctp_chunk *retval; struct sctp_datahdr dp; int chunk_len; /* We assign the TSN as LATE as possible, not here when * creating the chunk. */ dp.tsn = 0; dp.stream = htons(sinfo->sinfo_stream); dp.ppid = sinfo->sinfo_ppid; /* Set the flags for an unordered send. */ if (sinfo->sinfo_flags & SCTP_UNORDERED) { flags |= SCTP_DATA_UNORDERED; dp.ssn = 0; } else dp.ssn = htons(ssn); chunk_len = sizeof(dp) + data_len; retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); if (!retval) goto nodata; retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); nodata: return retval; } /* Create a selective ackowledgement (SACK) for the given * association. This reports on which TSN's we've seen to date, * including duplicates and gaps. */ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) { struct sctp_chunk *retval; struct sctp_sackhdr sack; int len; __u32 ctsn; __u16 num_gabs, num_dup_tsns; struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; ctsn = sctp_tsnmap_get_ctsn(map); SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); /* How much room is needed in the chunk? */ num_gabs = sctp_tsnmap_num_gabs(map); num_dup_tsns = sctp_tsnmap_num_dups(map); /* Initialize the SACK header. */ sack.cum_tsn_ack = htonl(ctsn); sack.a_rwnd = htonl(asoc->a_rwnd); sack.num_gap_ack_blocks = htons(num_gabs); sack.num_dup_tsns = htons(num_dup_tsns); len = sizeof(sack) + sizeof(struct sctp_gap_ack_block) * num_gabs + sizeof(__u32) * num_dup_tsns; /* Create the chunk. */ retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); if (!retval) goto nodata; /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, etc.) to the same destination transport * address from which it received the DATA or control chunk to * which it is replying. This rule should also be followed if * the endpoint is bundling DATA chunks together with the * reply chunk. * * However, when acknowledging multiple DATA chunks received * in packets from different source addresses in a single * SACK, the SACK chunk may be transmitted to one of the * destination transport addresses from which the DATA or * control chunks being acknowledged were received. * * [BUG: We do not implement the following paragraph. * Perhaps we should remember the last transport we used for a * SACK and avoid that (if possible) if we have seen any * duplicates. --piggy] * * When a receiver of a duplicate DATA chunk sends a SACK to a * multi- homed endpoint it MAY be beneficial to vary the * destination address and not use the source address of the * DATA chunk. The reason being that receiving a duplicate * from a multi-homed endpoint might indicate that the return * path (as specified in the source address of the DATA chunk) * for the SACK is broken. * * [Send to the address from which we last received a DATA chunk.] */ retval->transport = asoc->peer.last_data_from; retval->subh.sack_hdr = sctp_addto_chunk(retval, sizeof(sack), &sack); /* Add the gap ack block information. */ if (num_gabs) sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, sctp_tsnmap_get_gabs(map)); /* Add the duplicate TSN information. */ if (num_dup_tsns) sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, sctp_tsnmap_get_dups(map)); nodata: return retval; } /* Make a SHUTDOWN chunk. */ struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; sctp_shutdownhdr_t shut; __u32 ctsn; ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); shut.cum_tsn_ack = htonl(ctsn); retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, sizeof(sctp_shutdownhdr_t)); if (!retval) goto nodata; retval->subh.shutdown_hdr = sctp_addto_chunk(retval, sizeof(shut), &shut); if (chunk) retval->transport = chunk->transport; nodata: return retval; } struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [ACK back to where the SHUTDOWN came from.] */ if (retval && chunk) retval->transport = chunk->transport; return retval; } struct sctp_chunk *sctp_make_shutdown_complete( const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_chunk *retval; __u8 flags = 0; /* Set the T-bit if we have no association (vtag will be * reflected) */ flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK * came from.] */ if (retval && chunk) retval->transport = chunk->transport; return retval; } /* Create an ABORT. Note that we set the T bit if we have no * association, except when responding to an INIT (sctpimpguide 2.41). */ struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, const struct sctp_chunk *chunk, const size_t hint) { struct sctp_chunk *retval; __u8 flags = 0; /* Set the T-bit if we have no association and 'chunk' is not * an INIT (vtag will be reflected). */ if (!asoc) { if (chunk && chunk->chunk_hdr && chunk->chunk_hdr->type == SCTP_CID_INIT) flags = 0; else flags = SCTP_CHUNK_FLAG_T; } retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [ABORT back to where the offender came from.] */ if (retval && chunk) retval->transport = chunk->transport; return retval; } /* Helper to create ABORT with a NO_USER_DATA error. */ struct sctp_chunk *sctp_make_abort_no_data( const struct sctp_association *asoc, const struct sctp_chunk *chunk, __u32 tsn) { struct sctp_chunk *retval; __u32 payload; retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + sizeof(tsn)); if (!retval) goto no_mem; /* Put the tsn back into network byte order. */ payload = htonl(tsn); sctp_init_cause(retval, SCTP_ERROR_NO_DATA, (const void *)&payload, sizeof(payload)); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [ABORT back to where the offender came from.] */ if (chunk) retval->transport = chunk->transport; no_mem: return retval; } /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, const struct msghdr *msg, size_t paylen) { struct sctp_chunk *retval; void *payload = NULL; int err; retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); if (!retval) goto err_chunk; if (paylen) { /* Put the msg_iov together into payload. */ payload = kmalloc(paylen, GFP_KERNEL); if (!payload) goto err_payload; err = memcpy_fromiovec(payload, msg->msg_iov, paylen); if (err < 0) goto err_copy; } sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, payload, paylen); if (paylen) kfree(payload); return retval; err_copy: kfree(payload); err_payload: sctp_chunk_free(retval); retval = NULL; err_chunk: return retval; } /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ struct sctp_chunk *sctp_make_abort_violation( const struct sctp_association *asoc, const struct sctp_chunk *chunk, const __u8 *payload, const size_t paylen) { struct sctp_chunk *retval; struct sctp_paramhdr phdr; retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen + sizeof(sctp_chunkhdr_t)); if (!retval) goto end; sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, payload, paylen); phdr.type = htons(chunk->chunk_hdr->type); phdr.length = chunk->chunk_hdr->length; sctp_addto_chunk(retval, sizeof(sctp_paramhdr_t), &phdr); end: return retval; } /* Make a HEARTBEAT chunk. */ struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, const struct sctp_transport *transport, const void *payload, const size_t paylen) { struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, paylen); if (!retval) goto nodata; /* Cast away the 'const', as this is just telling the chunk * what transport it belongs to. */ retval->transport = (struct sctp_transport *) transport; retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); nodata: return retval; } struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk, const void *payload, const size_t paylen) { struct sctp_chunk *retval; retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); if (!retval) goto nodata; retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it * received the DATA or control chunk * to which it is replying. * * [HBACK back to where the HEARTBEAT came from.] */ if (chunk) retval->transport = chunk->transport; nodata: return retval; } /* Create an Operation Error chunk with the specified space reserved. * This routine can be used for containing multiple causes in the chunk. */ static struct sctp_chunk *sctp_make_op_error_space( const struct sctp_association *asoc, const struct sctp_chunk *chunk, size_t size) { struct sctp_chunk *retval; retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, sizeof(sctp_errhdr_t) + size); if (!retval) goto nodata; /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, etc.) to the same destination transport * address from which it received the DATA or control chunk * to which it is replying. * */ if (chunk) retval->transport = chunk->transport; nodata: return retval; } /* Create an Operation Error chunk. */ struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, const struct sctp_chunk *chunk, __be16 cause_code, const void *payload, size_t paylen) { struct sctp_chunk *retval; retval = sctp_make_op_error_space(asoc, chunk, paylen); if (!retval) goto nodata; sctp_init_cause(retval, cause_code, payload, paylen); nodata: return retval; } /******************************************************************** * 2nd Level Abstractions ********************************************************************/ /* Turn an skb into a chunk. * FIXME: Eventually move the structure directly inside the skb->cb[]. */ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, const struct sctp_association *asoc, struct sock *sk) { struct sctp_chunk *retval; retval = kmem_cache_alloc(sctp_chunk_cachep, SLAB_ATOMIC); if (!retval) goto nodata; memset(retval, 0, sizeof(struct sctp_chunk)); if (!sk) { SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); } INIT_LIST_HEAD(&retval->list); retval->skb = skb; retval->asoc = (struct sctp_association *)asoc; retval->resent = 0; retval->has_tsn = 0; retval->has_ssn = 0; retval->rtt_in_progress = 0; retval->sent_at = 0; retval->singleton = 1; retval->end_of_packet = 0; retval->ecn_ce_done = 0; retval->pdiscard = 0; /* sctpimpguide-05.txt Section 2.8.2 * M1) Each time a new DATA chunk is transmitted * set the 'TSN.Missing.Report' count for that TSN to 0. The * 'TSN.Missing.Report' count will be used to determine missing chunks * and when to fast retransmit. */ retval->tsn_missing_report = 0; retval->tsn_gap_acked = 0; retval->fast_retransmit = 0; /* If this is a fragmented message, track all fragments * of the message (for SEND_FAILED). */ retval->msg = NULL; /* Polish the bead hole. */ INIT_LIST_HEAD(&retval->transmitted_list); INIT_LIST_HEAD(&retval->frag_list); SCTP_DBG_OBJCNT_INC(chunk); atomic_set(&retval->refcnt, 1); nodata: return retval; } /* Set chunk->source and dest based on the IP header in chunk->skb. */ void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, union sctp_addr *dest) { memcpy(&chunk->source, src, sizeof(union sctp_addr)); flip_to_h(&chunk->source_h, &chunk->source); flip_to_h(&chunk->dest, dest); } /* Extract the source address from a chunk. */ const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) { /* If we have a known transport, use that. */ if (chunk->transport) { return &chunk->transport->ipaddr_h; } else { /* Otherwise, extract it from the IP header. */ return &chunk->source_h; } } /* Create a new chunk, setting the type and flags headers from the * arguments, reserving enough space for a 'paylen' byte payload. */ SCTP_STATIC struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen) { struct sctp_chunk *retval; sctp_chunkhdr_t *chunk_hdr; struct sk_buff *skb; struct sock *sk; /* No need to allocate LL here, as this is only a chunk. */ skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), GFP_ATOMIC); if (!skb) goto nodata; /* Make room for the chunk header. */ chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); chunk_hdr->type = type; chunk_hdr->flags = flags; chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); sk = asoc ? asoc->base.sk : NULL; retval = sctp_chunkify(skb, asoc, sk); if (!retval) { kfree_skb(skb); goto nodata; } retval->chunk_hdr = chunk_hdr; retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); /* Set the skb to the belonging sock for accounting. */ skb->sk = sk; return retval; nodata: return NULL; } /* Release the memory occupied by a chunk. */ static void sctp_chunk_destroy(struct sctp_chunk *chunk) { /* Free the chunk skb data and the SCTP_chunk stub itself. */ dev_kfree_skb(chunk->skb); SCTP_DBG_OBJCNT_DEC(chunk); kmem_cache_free(sctp_chunk_cachep, chunk); } /* Possibly, free the chunk. */ void sctp_chunk_free(struct sctp_chunk *chunk) { BUG_ON(!list_empty(&chunk->list)); list_del_init(&chunk->transmitted_list); /* Release our reference on the message tracker. */ if (chunk->msg) sctp_datamsg_put(chunk->msg); sctp_chunk_put(chunk); } /* Grab a reference to the chunk. */ void sctp_chunk_hold(struct sctp_chunk *ch) { atomic_inc(&ch->refcnt); } /* Release a reference to the chunk. */ void sctp_chunk_put(struct sctp_chunk *ch) { if (atomic_dec_and_test(&ch->refcnt)) sctp_chunk_destroy(ch); } /* Append bytes to the end of a chunk. Will panic if chunk is not big * enough. */ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) { void *target; void *padding; int chunklen = ntohs(chunk->chunk_hdr->length); int padlen = chunklen % 4; padding = skb_put(chunk->skb, padlen); target = skb_put(chunk->skb, len); memset(padding, 0, padlen); memcpy(target, data, len); /* Adjust the chunk length field. */ chunk->chunk_hdr->length = htons(chunklen + padlen + len); chunk->chunk_end = chunk->skb->tail; return target; } /* Append bytes from user space to the end of a chunk. Will panic if * chunk is not big enough. * Returns a kernel err value. */ int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, struct iovec *data) { __u8 *target; int err = 0; /* Make room in chunk for data. */ target = skb_put(chunk->skb, len); /* Copy data (whole iovec) into chunk */ if ((err = memcpy_fromiovecend(target, data, off, len))) goto out; /* Adjust the chunk length field. */ chunk->chunk_hdr->length = htons(ntohs(chunk->chunk_hdr->length) + len); chunk->chunk_end = chunk->skb->tail; out: return err; } /* Helper function to assign a TSN if needed. This assumes that both * the data_hdr and association have already been assigned. */ void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) { __u16 ssn; __u16 sid; if (chunk->has_ssn) return; /* This is the last possible instant to assign a SSN. */ if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { ssn = 0; } else { sid = ntohs(chunk->subh.data_hdr->stream); if (chunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) ssn = sctp_ssn_next(&chunk->asoc->ssnmap->out, sid); else ssn = sctp_ssn_peek(&chunk->asoc->ssnmap->out, sid); ssn = htons(ssn); } chunk->subh.data_hdr->ssn = ssn; chunk->has_ssn = 1; } /* Helper function to assign a TSN if needed. This assumes that both * the data_hdr and association have already been assigned. */ void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) { if (!chunk->has_tsn) { /* This is the last possible instant to * assign a TSN. */ chunk->subh.data_hdr->tsn = htonl(sctp_association_get_next_tsn(chunk->asoc)); chunk->has_tsn = 1; } } /* Create a CLOSED association to use with an incoming packet. */ struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, struct sctp_chunk *chunk, gfp_t gfp) { struct sctp_association *asoc; struct sk_buff *skb; sctp_scope_t scope; struct sctp_af *af; /* Create the bare association. */ scope = sctp_scope(sctp_source(chunk)); asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); if (!asoc) goto nodata; asoc->temp = 1; skb = chunk->skb; /* Create an entry for the source address of the packet. */ af = sctp_get_af_specific(ipver2af(skb->nh.iph->version)); if (unlikely(!af)) goto fail; af->from_skb(&asoc->c.peer_addr, skb, 1); nodata: return asoc; fail: sctp_association_free(asoc); return NULL; } /* Build a cookie representing asoc. * This INCLUDES the param header needed to put the cookie in the INIT ACK. */ static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, const struct sctp_association *asoc, const struct sctp_chunk *init_chunk, int *cookie_len, const __u8 *raw_addrs, int addrs_len) { sctp_cookie_param_t *retval; struct sctp_signed_cookie *cookie; struct scatterlist sg; int headersize, bodysize; unsigned int keylen; char *key; /* Header size is static data prior to the actual cookie, including * any padding. */ headersize = sizeof(sctp_paramhdr_t) + (sizeof(struct sctp_signed_cookie) - sizeof(struct sctp_cookie)); bodysize = sizeof(struct sctp_cookie) + ntohs(init_chunk->chunk_hdr->length) + addrs_len; /* Pad out the cookie to a multiple to make the signature * functions simpler to write. */ if (bodysize % SCTP_COOKIE_MULTIPLE) bodysize += SCTP_COOKIE_MULTIPLE - (bodysize % SCTP_COOKIE_MULTIPLE); *cookie_len = headersize + bodysize; retval = kmalloc(*cookie_len, GFP_ATOMIC); if (!retval) goto nodata; /* Clear this memory since we are sending this data structure * out on the network. */ memset(retval, 0x00, *cookie_len); cookie = (struct sctp_signed_cookie *) retval->body; /* Set up the parameter header. */ retval->p.type = SCTP_PARAM_STATE_COOKIE; retval->p.length = htons(*cookie_len); /* Copy the cookie part of the association itself. */ cookie->c = asoc->c; /* Save the raw address list length in the cookie. */ cookie->c.raw_addr_list_len = addrs_len; /* Remember PR-SCTP capability. */ cookie->c.prsctp_capable = asoc->peer.prsctp_capable; /* Save adaption indication in the cookie. */ cookie->c.adaption_ind = asoc->peer.adaption_ind; /* Set an expiration time for the cookie. */ do_gettimeofday(&cookie->c.expiration); TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); /* Copy the peer's init packet. */ memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, ntohs(init_chunk->chunk_hdr->length)); /* Copy the raw local address list of the association. */ memcpy((__u8 *)&cookie->c.peer_init[0] + ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); if (sctp_sk(ep->base.sk)->hmac) { struct hash_desc desc; /* Sign the message. */ sg.page = virt_to_page(&cookie->c); sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE; sg.length = bodysize; keylen = SCTP_SECRET_SIZE; key = (char *)ep->secret_key[ep->current_key]; desc.tfm = sctp_sk(ep->base.sk)->hmac; desc.flags = 0; if (crypto_hash_setkey(desc.tfm, key, keylen) || crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) goto free_cookie; } return retval; free_cookie: kfree(retval); nodata: *cookie_len = 0; return NULL; } /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ struct sctp_association *sctp_unpack_cookie( const struct sctp_endpoint *ep, const struct sctp_association *asoc, struct sctp_chunk *chunk, gfp_t gfp, int *error, struct sctp_chunk **errp) { struct sctp_association *retval = NULL; struct sctp_signed_cookie *cookie; struct sctp_cookie *bear_cookie; int headersize, bodysize, fixed_size; __u8 *digest = ep->digest; struct scatterlist sg; unsigned int keylen, len; char *key; sctp_scope_t scope; struct sk_buff *skb = chunk->skb; struct timeval tv; struct hash_desc desc; /* Header size is static data prior to the actual cookie, including * any padding. */ headersize = sizeof(sctp_chunkhdr_t) + (sizeof(struct sctp_signed_cookie) - sizeof(struct sctp_cookie)); bodysize = ntohs(chunk->chunk_hdr->length) - headersize; fixed_size = headersize + sizeof(struct sctp_cookie); /* Verify that the chunk looks like it even has a cookie. * There must be enough room for our cookie and our peer's * INIT chunk. */ len = ntohs(chunk->chunk_hdr->length); if (len < fixed_size + sizeof(struct sctp_chunkhdr)) goto malformed; /* Verify that the cookie has been padded out. */ if (bodysize % SCTP_COOKIE_MULTIPLE) goto malformed; /* Process the cookie. */ cookie = chunk->subh.cookie_hdr; bear_cookie = &cookie->c; if (!sctp_sk(ep->base.sk)->hmac) goto no_hmac; /* Check the signature. */ keylen = SCTP_SECRET_SIZE; sg.page = virt_to_page(bear_cookie); sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE; sg.length = bodysize; key = (char *)ep->secret_key[ep->current_key]; desc.tfm = sctp_sk(ep->base.sk)->hmac; desc.flags = 0; memset(digest, 0x00, SCTP_SIGNATURE_SIZE); if (crypto_hash_setkey(desc.tfm, key, keylen) || crypto_hash_digest(&desc, &sg, bodysize, digest)) { *error = -SCTP_IERROR_NOMEM; goto fail; } if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { /* Try the previous key. */ key = (char *)ep->secret_key[ep->last_key]; memset(digest, 0x00, SCTP_SIGNATURE_SIZE); if (crypto_hash_setkey(desc.tfm, key, keylen) || crypto_hash_digest(&desc, &sg, bodysize, digest)) { *error = -SCTP_IERROR_NOMEM; goto fail; } if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { /* Yikes! Still bad signature! */ *error = -SCTP_IERROR_BAD_SIG; goto fail; } } no_hmac: /* IG Section 2.35.2: * 3) Compare the port numbers and the verification tag contained * within the COOKIE ECHO chunk to the actual port numbers and the * verification tag within the SCTP common header of the received * packet. If these values do not match the packet MUST be silently * discarded, */ if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { *error = -SCTP_IERROR_BAD_TAG; goto fail; } if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { *error = -SCTP_IERROR_BAD_PORTS; goto fail; } /* Check to see if the cookie is stale. If there is already * an association, there is no need to check cookie's expiration * for init collision case of lost COOKIE ACK. * If skb has been timestamped, then use the stamp, otherwise * use current time. This introduces a small possibility that * that a cookie may be considered expired, but his would only slow * down the new association establishment instead of every packet. */ if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) skb_get_timestamp(skb, &tv); else do_gettimeofday(&tv); if (!asoc && tv_lt(bear_cookie->expiration, tv)) { __u16 len; /* * Section 3.3.10.3 Stale Cookie Error (3) * * Cause of error * --------------- * Stale Cookie Error: Indicates the receipt of a valid State * Cookie that has expired. */ len = ntohs(chunk->chunk_hdr->length); *errp = sctp_make_op_error_space(asoc, chunk, len); if (*errp) { suseconds_t usecs = (tv.tv_sec - bear_cookie->expiration.tv_sec) * 1000000L + tv.tv_usec - bear_cookie->expiration.tv_usec; usecs = htonl(usecs); sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, &usecs, sizeof(usecs)); *error = -SCTP_IERROR_STALE_COOKIE; } else *error = -SCTP_IERROR_NOMEM; goto fail; } /* Make a new base association. */ scope = sctp_scope(sctp_source(chunk)); retval = sctp_association_new(ep, ep->base.sk, scope, gfp); if (!retval) { *error = -SCTP_IERROR_NOMEM; goto fail; } /* Set up our peer's port number. */ retval->peer.port = ntohs(chunk->sctp_hdr->source); /* Populate the association from the cookie. */ memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, GFP_ATOMIC) < 0) { *error = -SCTP_IERROR_NOMEM; goto fail; } /* Also, add the destination address. */ if (list_empty(&retval->base.bind_addr.address_list)) { union sctp_addr tmp; flip_to_n(&tmp, &chunk->dest); sctp_add_bind_addr(&retval->base.bind_addr, &tmp, 1, GFP_ATOMIC); } retval->next_tsn = retval->c.initial_tsn; retval->ctsn_ack_point = retval->next_tsn - 1; retval->addip_serial = retval->c.initial_tsn; retval->adv_peer_ack_point = retval->ctsn_ack_point; retval->peer.prsctp_capable = retval->c.prsctp_capable; retval->peer.adaption_ind = retval->c.adaption_ind; /* The INIT stuff will be done by the side effects. */ return retval; fail: if (retval) sctp_association_free(retval); return NULL; malformed: /* Yikes! The packet is either corrupt or deliberately * malformed. */ *error = -SCTP_IERROR_MALFORMED; goto fail; } /******************************************************************** * 3rd Level Abstractions ********************************************************************/ struct __sctp_missing { __u32 num_missing; __u16 type; } __attribute__((packed)); /* * Report a missing mandatory parameter. */ static int sctp_process_missing_param(const struct sctp_association *asoc, sctp_param_t paramtype, struct sctp_chunk *chunk, struct sctp_chunk **errp) { struct __sctp_missing report; __u16 len; len = WORD_ROUND(sizeof(report)); /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. */ if (!*errp) *errp = sctp_make_op_error_space(asoc, chunk, len); if (*errp) { report.num_missing = htonl(1); report.type = paramtype; sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, &report, sizeof(report)); } /* Stop processing this chunk. */ return 0; } /* Report an Invalid Mandatory Parameter. */ static int sctp_process_inv_mandatory(const struct sctp_association *asoc, struct sctp_chunk *chunk, struct sctp_chunk **errp) { /* Invalid Mandatory Parameter Error has no payload. */ if (!*errp) *errp = sctp_make_op_error_space(asoc, chunk, 0); if (*errp) sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, NULL, 0); /* Stop processing this chunk. */ return 0; } static int sctp_process_inv_paramlength(const struct sctp_association *asoc, struct sctp_paramhdr *param, const struct sctp_chunk *chunk, struct sctp_chunk **errp) { char error[] = "The following parameter had invalid length:"; size_t payload_len = WORD_ROUND(sizeof(error)) + sizeof(sctp_paramhdr_t); /* Create an error chunk and fill it in with our payload. */ if (!*errp) *errp = sctp_make_op_error_space(asoc, chunk, payload_len); if (*errp) { sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION, error, sizeof(error)); sctp_addto_chunk(*errp, sizeof(sctp_paramhdr_t), param); } return 0; } /* Do not attempt to handle the HOST_NAME parm. However, do * send back an indicator to the peer. */ static int sctp_process_hn_param(const struct sctp_association *asoc, union sctp_params param, struct sctp_chunk *chunk, struct sctp_chunk **errp) { __u16 len = ntohs(param.p->length); /* Make an ERROR chunk. */ if (!*errp) *errp = sctp_make_op_error_space(asoc, chunk, len); if (*errp) sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, param.v, len); /* Stop processing this chunk. */ return 0; } /* RFC 3.2.1 & the Implementers Guide 2.2. * * The Parameter Types are encoded such that the * highest-order two bits specify the action that must be * taken if the processing endpoint does not recognize the * Parameter Type. * * 00 - Stop processing this SCTP chunk and discard it, * do not process any further chunks within it. * * 01 - Stop processing this SCTP chunk and discard it, * do not process any further chunks within it, and report * the unrecognized parameter in an 'Unrecognized * Parameter Type' (in either an ERROR or in the INIT ACK). * * 10 - Skip this parameter and continue processing. * * 11 - Skip this parameter and continue processing but * report the unrecognized parameter in an * 'Unrecognized Parameter Type' (in either an ERROR or in * the INIT ACK). * * Return value: * 0 - discard the chunk * 1 - continue with the chunk */ static int sctp_process_unk_param(const struct sctp_association *asoc, union sctp_params param, struct sctp_chunk *chunk, struct sctp_chunk **errp) { int retval = 1; switch (param.p->type & SCTP_PARAM_ACTION_MASK) { case SCTP_PARAM_ACTION_DISCARD: retval = 0; break; case SCTP_PARAM_ACTION_DISCARD_ERR: retval = 0; /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. */ if (NULL == *errp) *errp = sctp_make_op_error_space(asoc, chunk, ntohs(chunk->chunk_hdr->length)); if (*errp) sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, param.v, WORD_ROUND(ntohs(param.p->length))); break; case SCTP_PARAM_ACTION_SKIP: break; case SCTP_PARAM_ACTION_SKIP_ERR: /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. */ if (NULL == *errp) *errp = sctp_make_op_error_space(asoc, chunk, ntohs(chunk->chunk_hdr->length)); if (*errp) { sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, param.v, WORD_ROUND(ntohs(param.p->length))); } else { /* If there is no memory for generating the ERROR * report as specified, an ABORT will be triggered * to the peer and the association won't be * established. */ retval = 0; } break; default: break; } return retval; } /* Find unrecognized parameters in the chunk. * Return values: * 0 - discard the chunk * 1 - continue with the chunk */ static int sctp_verify_param(const struct sctp_association *asoc, union sctp_params param, sctp_cid_t cid, struct sctp_chunk *chunk, struct sctp_chunk **err_chunk) { int retval = 1; /* FIXME - This routine is not looking at each parameter per the * chunk type, i.e., unrecognized parameters should be further * identified based on the chunk id. */ switch (param.p->type) { case SCTP_PARAM_IPV4_ADDRESS: case SCTP_PARAM_IPV6_ADDRESS: case SCTP_PARAM_COOKIE_PRESERVATIVE: case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: case SCTP_PARAM_STATE_COOKIE: case SCTP_PARAM_HEARTBEAT_INFO: case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: case SCTP_PARAM_ECN_CAPABLE: case SCTP_PARAM_ADAPTION_LAYER_IND: break; case SCTP_PARAM_HOST_NAME_ADDRESS: /* Tell the peer, we won't support this param. */ return sctp_process_hn_param(asoc, param, chunk, err_chunk); case SCTP_PARAM_FWD_TSN_SUPPORT: if (sctp_prsctp_enable) break; /* Fall Through */ default: SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", ntohs(param.p->type), cid); return sctp_process_unk_param(asoc, param, chunk, err_chunk); break; } return retval; } /* Verify the INIT packet before we process it. */ int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t cid, sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, struct sctp_chunk **errp) { union sctp_params param; int has_cookie = 0; /* Verify stream values are non-zero. */ if ((0 == peer_init->init_hdr.num_outbound_streams) || (0 == peer_init->init_hdr.num_inbound_streams)) { sctp_process_inv_mandatory(asoc, chunk, errp); return 0; } /* Check for missing mandatory parameters. */ sctp_walk_params(param, peer_init, init_hdr.params) { if (SCTP_PARAM_STATE_COOKIE == param.p->type) has_cookie = 1; } /* for (loop through all parameters) */ /* There is a possibility that a parameter length was bad and * in that case we would have stoped walking the parameters. * The current param.p would point at the bad one. * Current consensus on the mailing list is to generate a PROTOCOL * VIOLATION error. We build the ERROR chunk here and let the normal * error handling code build and send the packet. */ if (param.v < (void*)chunk->chunk_end - sizeof(sctp_paramhdr_t)) { sctp_process_inv_paramlength(asoc, param.p, chunk, errp); return 0; } /* The only missing mandatory param possible today is * the state cookie for an INIT-ACK chunk. */ if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) { sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, chunk, errp); return 0; } /* Find unrecognized parameters. */ sctp_walk_params(param, peer_init, init_hdr.params) { if (!sctp_verify_param(asoc, param, cid, chunk, errp)) { if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type) return 0; else return 1; } } /* for (loop through all parameters) */ return 1; } /* Unpack the parameters in an INIT packet into an association. * Returns 0 on failure, else success. * FIXME: This is an association method. */ int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid, const union sctp_addr *peer_addr, sctp_init_chunk_t *peer_init, gfp_t gfp) { union sctp_params param; struct sctp_transport *transport; struct list_head *pos, *temp; char *cookie; union sctp_addr tmp; /* We must include the address that the INIT packet came from. * This is the only address that matters for an INIT packet. * When processing a COOKIE ECHO, we retrieve the from address * of the INIT from the cookie. */ /* This implementation defaults to making the first transport * added as the primary transport. The source address seems to * be a a better choice than any of the embedded addresses. */ if (peer_addr) { flip_to_n(&tmp, peer_addr); if(!sctp_assoc_add_peer(asoc, &tmp, gfp, SCTP_ACTIVE)) goto nomem; } /* Process the initialization parameters. */ sctp_walk_params(param, peer_init, init_hdr.params) { if (!sctp_process_param(asoc, param, peer_addr, gfp)) goto clean_up; } /* Walk list of transports, removing transports in the UNKNOWN state. */ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { transport = list_entry(pos, struct sctp_transport, transports); if (transport->state == SCTP_UNKNOWN) { sctp_assoc_rm_peer(asoc, transport); } } /* The fixed INIT headers are always in network byte * order. */ asoc->peer.i.init_tag = ntohl(peer_init->init_hdr.init_tag); asoc->peer.i.a_rwnd = ntohl(peer_init->init_hdr.a_rwnd); asoc->peer.i.num_outbound_streams = ntohs(peer_init->init_hdr.num_outbound_streams); asoc->peer.i.num_inbound_streams = ntohs(peer_init->init_hdr.num_inbound_streams); asoc->peer.i.initial_tsn = ntohl(peer_init->init_hdr.initial_tsn); /* Apply the upper bounds for output streams based on peer's * number of inbound streams. */ if (asoc->c.sinit_num_ostreams > ntohs(peer_init->init_hdr.num_inbound_streams)) { asoc->c.sinit_num_ostreams = ntohs(peer_init->init_hdr.num_inbound_streams); } if (asoc->c.sinit_max_instreams > ntohs(peer_init->init_hdr.num_outbound_streams)) { asoc->c.sinit_max_instreams = ntohs(peer_init->init_hdr.num_outbound_streams); } /* Copy Initiation tag from INIT to VT_peer in cookie. */ asoc->c.peer_vtag = asoc->peer.i.init_tag; /* Peer Rwnd : Current calculated value of the peer's rwnd. */ asoc->peer.rwnd = asoc->peer.i.a_rwnd; /* Copy cookie in case we need to resend COOKIE-ECHO. */ cookie = asoc->peer.cookie; if (cookie) { asoc->peer.cookie = kmalloc(asoc->peer.cookie_len, gfp); if (!asoc->peer.cookie) goto clean_up; memcpy(asoc->peer.cookie, cookie, asoc->peer.cookie_len); } /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily * high (for example, implementations MAY use the size of the receiver * advertised window). */ list_for_each(pos, &asoc->peer.transport_addr_list) { transport = list_entry(pos, struct sctp_transport, transports); transport->ssthresh = asoc->peer.i.a_rwnd; } /* Set up the TSN tracking pieces. */ sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, asoc->peer.i.initial_tsn); /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number * * The stream sequence number in all the streams shall start * from 0 when the association is established. Also, when the * stream sequence number reaches the value 65535 the next * stream sequence number shall be set to 0. */ /* Allocate storage for the negotiated streams if it is not a temporary * association. */ if (!asoc->temp) { int assoc_id; int error; asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, asoc->c.sinit_num_ostreams, gfp); if (!asoc->ssnmap) goto clean_up; retry: if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp))) goto clean_up; spin_lock_bh(&sctp_assocs_id_lock); error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, 1, &assoc_id); spin_unlock_bh(&sctp_assocs_id_lock); if (error == -EAGAIN) goto retry; else if (error) goto clean_up; asoc->assoc_id = (sctp_assoc_t) assoc_id; } /* ADDIP Section 4.1 ASCONF Chunk Procedures * * When an endpoint has an ASCONF signaled change to be sent to the * remote endpoint it should do the following: * ... * A2) A serial number should be assigned to the Chunk. The serial * number should be a monotonically increasing number. All serial * numbers are defined to be initialized at the start of the * association to the same value as the Initial TSN. */ asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; return 1; clean_up: /* Release the transport structures. */ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { transport = list_entry(pos, struct sctp_transport, transports); list_del_init(pos); sctp_transport_free(transport); } asoc->peer.transport_count = 0; nomem: return 0; } /* Update asoc with the option described in param. * * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT * * asoc is the association to update. * param is the variable length parameter to use for update. * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. * If the current packet is an INIT we want to minimize the amount of * work we do. In particular, we should not build transport * structures for the addresses. */ static int sctp_process_param(struct sctp_association *asoc, union sctp_params param, const union sctp_addr *peer_addr, gfp_t gfp) { union sctp_addr addr; int i; __u16 sat; int retval = 1; sctp_scope_t scope; time_t stale; struct sctp_af *af; union sctp_addr tmp; /* We maintain all INIT parameters in network byte order all the * time. This allows us to not worry about whether the parameters * came from a fresh INIT, and INIT ACK, or were stored in a cookie. */ switch (param.p->type) { case SCTP_PARAM_IPV6_ADDRESS: if (PF_INET6 != asoc->base.sk->sk_family) break; /* Fall through. */ case SCTP_PARAM_IPV4_ADDRESS: af = sctp_get_af_specific(param_type2af(param.p->type)); af->from_addr_param(&addr, param.addr, asoc->peer.port, 0); flip_to_n(&tmp, &addr); scope = sctp_scope(peer_addr); if (sctp_in_scope(&tmp, scope)) if (!sctp_assoc_add_peer(asoc, &tmp, gfp, SCTP_UNCONFIRMED)) return 0; break; case SCTP_PARAM_COOKIE_PRESERVATIVE: if (!sctp_cookie_preserve_enable) break; stale = ntohl(param.life->lifespan_increment); /* Suggested Cookie Life span increment's unit is msec, * (1/1000sec). */ asoc->cookie_life.tv_sec += stale / 1000; asoc->cookie_life.tv_usec += (stale % 1000) * 1000; break; case SCTP_PARAM_HOST_NAME_ADDRESS: SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); break; case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: /* Turn off the default values first so we'll know which * ones are really set by the peer. */ asoc->peer.ipv4_address = 0; asoc->peer.ipv6_address = 0; /* Cycle through address types; avoid divide by 0. */ sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); if (sat) sat /= sizeof(__u16); for (i = 0; i < sat; ++i) { switch (param.sat->types[i]) { case SCTP_PARAM_IPV4_ADDRESS: asoc->peer.ipv4_address = 1; break; case SCTP_PARAM_IPV6_ADDRESS: asoc->peer.ipv6_address = 1; break; case SCTP_PARAM_HOST_NAME_ADDRESS: asoc->peer.hostname_address = 1; break; default: /* Just ignore anything else. */ break; }; } break; case SCTP_PARAM_STATE_COOKIE: asoc->peer.cookie_len = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); asoc->peer.cookie = param.cookie->body; break; case SCTP_PARAM_HEARTBEAT_INFO: /* Would be odd to receive, but it causes no problems. */ break; case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: /* Rejected during verify stage. */ break; case SCTP_PARAM_ECN_CAPABLE: asoc->peer.ecn_capable = 1; break; case SCTP_PARAM_ADAPTION_LAYER_IND: asoc->peer.adaption_ind = param.aind->adaption_ind; break; case SCTP_PARAM_FWD_TSN_SUPPORT: if (sctp_prsctp_enable) { asoc->peer.prsctp_capable = 1; break; } /* Fall Through */ default: /* Any unrecognized parameters should have been caught * and handled by sctp_verify_param() which should be * called prior to this routine. Simply log the error * here. */ SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", ntohs(param.p->type), asoc); break; }; return retval; } /* Select a new verification tag. */ __u32 sctp_generate_tag(const struct sctp_endpoint *ep) { /* I believe that this random number generator complies with RFC1750. * A tag of 0 is reserved for special cases (e.g. INIT). */ __u32 x; do { get_random_bytes(&x, sizeof(__u32)); } while (x == 0); return x; } /* Select an initial TSN to send during startup. */ __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) { __u32 retval; get_random_bytes(&retval, sizeof(__u32)); return retval; } /* * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 0xC1 | Chunk Flags | Chunk Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Serial Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Address Parameter | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF Parameter #1 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ \ * / .... / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF Parameter #N | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Address Parameter and other parameter will not be wrapped in this function */ static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, union sctp_addr *addr, int vparam_len) { sctp_addiphdr_t asconf; struct sctp_chunk *retval; int length = sizeof(asconf) + vparam_len; union sctp_addr_param addrparam; int addrlen; struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); addrlen = af->to_addr_param(addr, &addrparam); if (!addrlen) return NULL; length += addrlen; /* Create the chunk. */ retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); if (!retval) return NULL; asconf.serial = htonl(asoc->addip_serial++); retval->subh.addip_hdr = sctp_addto_chunk(retval, sizeof(asconf), &asconf); retval->param_hdr.v = sctp_addto_chunk(retval, addrlen, &addrparam); return retval; } /* ADDIP * 3.2.1 Add IP Address * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 0xC001 | Length = Variable | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF-Request Correlation ID | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Address Parameter | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * 3.2.2 Delete IP Address * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 0xC002 | Length = Variable | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF-Request Correlation ID | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Address Parameter | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * */ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, union sctp_addr *laddr, struct sockaddr *addrs, int addrcnt, __be16 flags) { sctp_addip_param_t param; struct sctp_chunk *retval; union sctp_addr_param addr_param; union sctp_addr *addr; void *addr_buf; struct sctp_af *af; int paramlen = sizeof(param); int addr_param_len = 0; int totallen = 0; int i; /* Get total length of all the address parameters. */ addr_buf = addrs; for (i = 0; i < addrcnt; i++) { addr = (union sctp_addr *)addr_buf; af = sctp_get_af_specific(addr->v4.sin_family); addr_param_len = af->to_addr_param(addr, &addr_param); totallen += paramlen; totallen += addr_param_len; addr_buf += af->sockaddr_len; } /* Create an asconf chunk with the required length. */ retval = sctp_make_asconf(asoc, laddr, totallen); if (!retval) return NULL; /* Add the address parameters to the asconf chunk. */ addr_buf = addrs; for (i = 0; i < addrcnt; i++) { addr = (union sctp_addr *)addr_buf; af = sctp_get_af_specific(addr->v4.sin_family); addr_param_len = af->to_addr_param(addr, &addr_param); param.param_hdr.type = flags; param.param_hdr.length = htons(paramlen + addr_param_len); param.crr_id = i; sctp_addto_chunk(retval, paramlen, ¶m); sctp_addto_chunk(retval, addr_param_len, &addr_param); addr_buf += af->sockaddr_len; } return retval; } /* ADDIP * 3.2.4 Set Primary IP Address * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type =0xC004 | Length = Variable | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF-Request Correlation ID | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Address Parameter | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Create an ASCONF chunk with Set Primary IP address parameter. */ struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, union sctp_addr *addr) { sctp_addip_param_t param; struct sctp_chunk *retval; int len = sizeof(param); union sctp_addr_param addrparam; int addrlen; struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); addrlen = af->to_addr_param(addr, &addrparam); if (!addrlen) return NULL; len += addrlen; /* Create the chunk and make asconf header. */ retval = sctp_make_asconf(asoc, addr, len); if (!retval) return NULL; param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; param.param_hdr.length = htons(len); param.crr_id = 0; sctp_addto_chunk(retval, sizeof(param), ¶m); sctp_addto_chunk(retval, addrlen, &addrparam); return retval; } /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 0x80 | Chunk Flags | Chunk Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Serial Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF Parameter Response#1 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ \ * / .... / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | ASCONF Parameter Response#N | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Create an ASCONF_ACK chunk with enough space for the parameter responses. */ static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, __u32 serial, int vparam_len) { sctp_addiphdr_t asconf; struct sctp_chunk *retval; int length = sizeof(asconf) + vparam_len; /* Create the chunk. */ retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); if (!retval) return NULL; asconf.serial = htonl(serial); retval->subh.addip_hdr = sctp_addto_chunk(retval, sizeof(asconf), &asconf); return retval; } /* Add response parameters to an ASCONF_ACK chunk. */ static void sctp_add_asconf_response(struct sctp_chunk *chunk, __u32 crr_id, __be16 err_code, sctp_addip_param_t *asconf_param) { sctp_addip_param_t ack_param; sctp_errhdr_t err_param; int asconf_param_len = 0; int err_param_len = 0; __be16 response_type; if (SCTP_ERROR_NO_ERROR == err_code) { response_type = SCTP_PARAM_SUCCESS_REPORT; } else { response_type = SCTP_PARAM_ERR_CAUSE; err_param_len = sizeof(err_param); if (asconf_param) asconf_param_len = ntohs(asconf_param->param_hdr.length); } /* Add Success Indication or Error Cause Indication parameter. */ ack_param.param_hdr.type = response_type; ack_param.param_hdr.length = htons(sizeof(ack_param) + err_param_len + asconf_param_len); ack_param.crr_id = crr_id; sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); if (SCTP_ERROR_NO_ERROR == err_code) return; /* Add Error Cause parameter. */ err_param.cause = err_code; err_param.length = htons(err_param_len + asconf_param_len); sctp_addto_chunk(chunk, err_param_len, &err_param); /* Add the failed TLV copied from ASCONF chunk. */ if (asconf_param) sctp_addto_chunk(chunk, asconf_param_len, asconf_param); } /* Process a asconf parameter. */ static __be16 sctp_process_asconf_param(struct sctp_association *asoc, struct sctp_chunk *asconf, sctp_addip_param_t *asconf_param) { struct sctp_transport *peer; struct sctp_af *af; union sctp_addr addr; struct list_head *pos; union sctp_addr_param *addr_param; union sctp_addr tmp, tmp_addr; addr_param = (union sctp_addr_param *) ((void *)asconf_param + sizeof(sctp_addip_param_t)); af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); if (unlikely(!af)) return SCTP_ERROR_INV_PARAM; af->from_addr_param(&addr, addr_param, asoc->peer.port, 0); flip_to_n(&tmp_addr, &addr); switch (asconf_param->param_hdr.type) { case SCTP_PARAM_ADD_IP: /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address * request and does not have the local resources to add this * new address to the association, it MUST return an Error * Cause TLV set to the new error code 'Operation Refused * Due to Resource Shortage'. */ peer = sctp_assoc_add_peer(asoc, &tmp_addr, GFP_ATOMIC, SCTP_UNCONFIRMED); if (!peer) return SCTP_ERROR_RSRC_LOW; /* Start the heartbeat timer. */ if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) sctp_transport_hold(peer); break; case SCTP_PARAM_DEL_IP: /* ADDIP 4.3 D7) If a request is received to delete the * last remaining IP address of a peer endpoint, the receiver * MUST send an Error Cause TLV with the error cause set to the * new error code 'Request to Delete Last Remaining IP Address'. */ pos = asoc->peer.transport_addr_list.next; if (pos->next == &asoc->peer.transport_addr_list) return SCTP_ERROR_DEL_LAST_IP; /* ADDIP 4.3 D8) If a request is received to delete an IP * address which is also the source address of the IP packet * which contained the ASCONF chunk, the receiver MUST reject * this request. To reject the request the receiver MUST send * an Error Cause TLV set to the new error code 'Request to * Delete Source IP Address' */ flip_to_n(&tmp, sctp_source(asconf)); if (sctp_cmp_addr_exact(&tmp, &tmp_addr)) return SCTP_ERROR_DEL_SRC_IP; sctp_assoc_del_peer(asoc, &tmp_addr); break; case SCTP_PARAM_SET_PRIMARY: peer = sctp_assoc_lookup_paddr(asoc, &tmp_addr); if (!peer) return SCTP_ERROR_INV_PARAM; sctp_assoc_set_primary(asoc, peer); break; default: return SCTP_ERROR_INV_PARAM; break; } return SCTP_ERROR_NO_ERROR; } /* Process an incoming ASCONF chunk with the next expected serial no. and * return an ASCONF_ACK chunk to be sent in response. */ struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, struct sctp_chunk *asconf) { sctp_addiphdr_t *hdr; union sctp_addr_param *addr_param; sctp_addip_param_t *asconf_param; struct sctp_chunk *asconf_ack; __be16 err_code; int length = 0; int chunk_len = asconf->skb->len; __u32 serial; int all_param_pass = 1; hdr = (sctp_addiphdr_t *)asconf->skb->data; serial = ntohl(hdr->serial); /* Skip the addiphdr and store a pointer to address parameter. */ length = sizeof(sctp_addiphdr_t); addr_param = (union sctp_addr_param *)(asconf->skb->data + length); chunk_len -= length; /* Skip the address parameter and store a pointer to the first * asconf paramter. */ length = ntohs(addr_param->v4.param_hdr.length); asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); chunk_len -= length; /* create an ASCONF_ACK chunk. * Based on the definitions of parameters, we know that the size of * ASCONF_ACK parameters are less than or equal to the twice of ASCONF * paramters. */ asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2); if (!asconf_ack) goto done; /* Process the TLVs contained within the ASCONF chunk. */ while (chunk_len > 0) { err_code = sctp_process_asconf_param(asoc, asconf, asconf_param); /* ADDIP 4.1 A7) * If an error response is received for a TLV parameter, * all TLVs with no response before the failed TLV are * considered successful if not reported. All TLVs after * the failed response are considered unsuccessful unless * a specific success indication is present for the parameter. */ if (SCTP_ERROR_NO_ERROR != err_code) all_param_pass = 0; if (!all_param_pass) sctp_add_asconf_response(asconf_ack, asconf_param->crr_id, err_code, asconf_param); /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add * an IP address sends an 'Out of Resource' in its response, it * MUST also fail any subsequent add or delete requests bundled * in the ASCONF. */ if (SCTP_ERROR_RSRC_LOW == err_code) goto done; /* Move to the next ASCONF param. */ length = ntohs(asconf_param->param_hdr.length); asconf_param = (sctp_addip_param_t *)((void *)asconf_param + length); chunk_len -= length; } done: asoc->peer.addip_serial++; /* If we are sending a new ASCONF_ACK hold a reference to it in assoc * after freeing the reference to old asconf ack if any. */ if (asconf_ack) { if (asoc->addip_last_asconf_ack) sctp_chunk_free(asoc->addip_last_asconf_ack); sctp_chunk_hold(asconf_ack); asoc->addip_last_asconf_ack = asconf_ack; } return asconf_ack; } /* Process a asconf parameter that is successfully acked. */ static int sctp_asconf_param_success(struct sctp_association *asoc, sctp_addip_param_t *asconf_param) { struct sctp_af *af; union sctp_addr addr; struct sctp_bind_addr *bp = &asoc->base.bind_addr; union sctp_addr_param *addr_param; struct list_head *pos; struct sctp_transport *transport; struct sctp_sockaddr_entry *saddr; int retval = 0; union sctp_addr tmp; addr_param = (union sctp_addr_param *) ((void *)asconf_param + sizeof(sctp_addip_param_t)); /* We have checked the packet before, so we do not check again. */ af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); af->from_addr_param(&addr, addr_param, bp->port, 0); flip_to_n(&tmp, &addr); switch (asconf_param->param_hdr.type) { case SCTP_PARAM_ADD_IP: sctp_local_bh_disable(); sctp_write_lock(&asoc->base.addr_lock); list_for_each(pos, &bp->address_list) { saddr = list_entry(pos, struct sctp_sockaddr_entry, list); if (sctp_cmp_addr_exact(&saddr->a, &tmp)) saddr->use_as_src = 1; } sctp_write_unlock(&asoc->base.addr_lock); sctp_local_bh_enable(); break; case SCTP_PARAM_DEL_IP: sctp_local_bh_disable(); sctp_write_lock(&asoc->base.addr_lock); retval = sctp_del_bind_addr(bp, &tmp); sctp_write_unlock(&asoc->base.addr_lock); sctp_local_bh_enable(); list_for_each(pos, &asoc->peer.transport_addr_list) { transport = list_entry(pos, struct sctp_transport, transports); dst_release(transport->dst); sctp_transport_route(transport, NULL, sctp_sk(asoc->base.sk)); } break; default: break; } return retval; } /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk * for the given asconf parameter. If there is no response for this parameter, * return the error code based on the third argument 'no_err'. * ADDIP 4.1 * A7) If an error response is received for a TLV parameter, all TLVs with no * response before the failed TLV are considered successful if not reported. * All TLVs after the failed response are considered unsuccessful unless a * specific success indication is present for the parameter. */ static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, sctp_addip_param_t *asconf_param, int no_err) { sctp_addip_param_t *asconf_ack_param; sctp_errhdr_t *err_param; int length; int asconf_ack_len = asconf_ack->skb->len; __be16 err_code; if (no_err) err_code = SCTP_ERROR_NO_ERROR; else err_code = SCTP_ERROR_REQ_REFUSED; /* Skip the addiphdr from the asconf_ack chunk and store a pointer to * the first asconf_ack parameter. */ length = sizeof(sctp_addiphdr_t); asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + length); asconf_ack_len -= length; while (asconf_ack_len > 0) { if (asconf_ack_param->crr_id == asconf_param->crr_id) { switch(asconf_ack_param->param_hdr.type) { case SCTP_PARAM_SUCCESS_REPORT: return SCTP_ERROR_NO_ERROR; case SCTP_PARAM_ERR_CAUSE: length = sizeof(sctp_addip_param_t); err_param = (sctp_errhdr_t *) ((void *)asconf_ack_param + length); asconf_ack_len -= length; if (asconf_ack_len > 0) return err_param->cause; else return SCTP_ERROR_INV_PARAM; break; default: return SCTP_ERROR_INV_PARAM; } } length = ntohs(asconf_ack_param->param_hdr.length); asconf_ack_param = (sctp_addip_param_t *) ((void *)asconf_ack_param + length); asconf_ack_len -= length; } return err_code; } /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ int sctp_process_asconf_ack(struct sctp_association *asoc, struct sctp_chunk *asconf_ack) { struct sctp_chunk *asconf = asoc->addip_last_asconf; union sctp_addr_param *addr_param; sctp_addip_param_t *asconf_param; int length = 0; int asconf_len = asconf->skb->len; int all_param_pass = 0; int no_err = 1; int retval = 0; __be16 err_code = SCTP_ERROR_NO_ERROR; /* Skip the chunkhdr and addiphdr from the last asconf sent and store * a pointer to address parameter. */ length = sizeof(sctp_addip_chunk_t); addr_param = (union sctp_addr_param *)(asconf->skb->data + length); asconf_len -= length; /* Skip the address parameter in the last asconf sent and store a * pointer to the first asconf paramter. */ length = ntohs(addr_param->v4.param_hdr.length); asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); asconf_len -= length; /* ADDIP 4.1 * A8) If there is no response(s) to specific TLV parameter(s), and no * failures are indicated, then all request(s) are considered * successful. */ if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) all_param_pass = 1; /* Process the TLVs contained in the last sent ASCONF chunk. */ while (asconf_len > 0) { if (all_param_pass) err_code = SCTP_ERROR_NO_ERROR; else { err_code = sctp_get_asconf_response(asconf_ack, asconf_param, no_err); if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) no_err = 0; } switch (err_code) { case SCTP_ERROR_NO_ERROR: retval = sctp_asconf_param_success(asoc, asconf_param); break; case SCTP_ERROR_RSRC_LOW: retval = 1; break; case SCTP_ERROR_INV_PARAM: /* Disable sending this type of asconf parameter in * future. */ asoc->peer.addip_disabled_mask |= asconf_param->param_hdr.type; break; case SCTP_ERROR_REQ_REFUSED: case SCTP_ERROR_DEL_LAST_IP: case SCTP_ERROR_DEL_SRC_IP: default: break; } /* Skip the processed asconf parameter and move to the next * one. */ length = ntohs(asconf_param->param_hdr.length); asconf_param = (sctp_addip_param_t *)((void *)asconf_param + length); asconf_len -= length; } /* Free the cached last sent asconf chunk. */ sctp_chunk_free(asconf); asoc->addip_last_asconf = NULL; /* Send the next asconf chunk from the addip chunk queue. */ if (!list_empty(&asoc->addip_chunk_list)) { struct list_head *entry = asoc->addip_chunk_list.next; asconf = list_entry(entry, struct sctp_chunk, list); list_del_init(entry); /* Hold the chunk until an ASCONF_ACK is received. */ sctp_chunk_hold(asconf); if (sctp_primitive_ASCONF(asoc, asconf)) sctp_chunk_free(asconf); else asoc->addip_last_asconf = asconf; } return retval; } /* Make a FWD TSN chunk. */ struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, __u32 new_cum_tsn, size_t nstreams, struct sctp_fwdtsn_skip *skiplist) { struct sctp_chunk *retval = NULL; struct sctp_fwdtsn_chunk *ftsn_chunk; struct sctp_fwdtsn_hdr ftsn_hdr; struct sctp_fwdtsn_skip skip; size_t hint; int i; hint = (nstreams + 1) * sizeof(__u32); retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); if (!retval) return NULL; ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr; ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); retval->subh.fwdtsn_hdr = sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); for (i = 0; i < nstreams; i++) { skip.stream = skiplist[i].stream; skip.ssn = skiplist[i].ssn; sctp_addto_chunk(retval, sizeof(skip), &skip); } return retval; }