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Quelle sm_make_chunk.cSprache: C |
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// SPDX-License-Identifier: GPL-2.0-or-later /* 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. * * This file is part of the SCTP kernel 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. * * 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> * C. Robin <chris@hundredacre.ac.uk> * Jon Grimm <jgrimm@us.ibm.com> * Xingang Guo <xingang.guo@intel.com> * Dajiang Zhang <dajiang.zhang@nokia.com> * Sridhar Samudrala <sri@us.ibm.com> * Daisy Chang <daisyc@us.ibm.com> * Ardelle Fan <ardelle.fan@intel.com> * Kevin Gao <kevin.gao@intel.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <crypto/hash.h> #include <crypto/utils.h> #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/scatterlist.h> #include <linux/slab.h> #include <net/sock.h> #include <linux/skbuff.h> #include <linux/random.h> /* for get_random_bytes */ #include <net/sctp/sctp.h> #include <net/sctp/sm.h> static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen, gfp_t gfp); static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, __u8 flags, int paylen, gfp_t gfp); static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen, gfp_t gfp); static struct sctp_cookie_param *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); static void *sctp_addto_param(struct sctp_chunk *chunk, int len, const void *data); /* Control chunk destructor */ static void sctp_control_release_owner(struct sk_buff *skb) { struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; if (chunk->shkey) { struct sctp_shared_key *shkey = chunk->shkey; struct sctp_association *asoc = chunk->asoc; /* refcnt == 2 and !list_empty mean after this release, it's * not being used anywhere, and it's time to notify userland * that this shkey can be freed if it's been deactivated. */ if (shkey->deactivated && !list_empty(&shkey->key_list) && refcount_read(&shkey->refcnt) == 2) { struct sctp_ulpevent *ev; ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, SCTP_AUTH_FREE_KEY, GFP_KERNEL); if (ev) asoc->stream.si->enqueue_event(&asoc->ulpq, ev); } sctp_auth_shkey_release(chunk->shkey); } } static void sctp_control_set_owner_w(struct sctp_chunk *chunk) { struct sctp_association *asoc = chunk->asoc; struct sk_buff *skb = chunk->skb; /* TODO: properly account for control chunks. * To do it right we'll need: * 1) endpoint if association isn't known. * 2) proper memory accounting. * * For now don't do anything for now. */ if (chunk->auth) { chunk->shkey = asoc->shkey; sctp_auth_shkey_hold(chunk->shkey); } skb->sk = asoc ? asoc->base.sk : NULL; skb_shinfo(skb)->destructor_arg = chunk; skb->destructor = sctp_control_release_owner; } /* 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, cpu_to_be16(sizeof(struct sctp_paramhdr)), }; static const struct sctp_paramhdr prsctp_param = { SCTP_PARAM_FWD_TSN_SUPPORT, cpu_to_be16(sizeof(struct sctp_paramhdr)), }; /* A helper to initialize an op error inside a provided chunk, as most * cause codes will be embedded inside an abort chunk. */ int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, size_t paylen) { struct sctp_errhdr err; __u16 len; /* Cause code constants are now defined in network order. */ err.cause = cause_code; len = sizeof(err) + paylen; err.length = htons(len); if (skb_tailroom(chunk->skb) < len) return -ENOSPC; chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); return 0; } /* 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) { struct sctp_supported_ext_param ext_param; struct sctp_adaptation_ind_param aiparam; struct sctp_paramhdr *auth_chunks = NULL; struct sctp_paramhdr *auth_hmacs = NULL; struct sctp_supported_addrs_param sat; struct sctp_endpoint *ep = asoc->ep; struct sctp_chunk *retval = NULL; int num_types, addrs_len = 0; struct sctp_inithdr init; union sctp_params addrs; struct sctp_sock *sp; __u8 extensions[5]; size_t chunksize; __be16 types[2]; int num_ext = 0; /* 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. */ /* 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; chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); if (asoc->ep->ecn_enable) chunksize += sizeof(ecap_param); if (asoc->ep->prsctp_enable) chunksize += sizeof(prsctp_param); /* ADDIP: Section 4.2.7: * An implementation supporting this extension [ADDIP] MUST list * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and * INIT-ACK parameters. */ if (asoc->ep->asconf_enable) { extensions[num_ext] = SCTP_CID_ASCONF; extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; num_ext += 2; } if (asoc->ep->reconf_enable) { extensions[num_ext] = SCTP_CID_RECONF; num_ext += 1; } if (sp->adaptation_ind) chunksize += sizeof(aiparam); if (asoc->ep->intl_enable) { extensions[num_ext] = SCTP_CID_I_DATA; num_ext += 1; } chunksize += vparam_len; /* Account for AUTH related parameters */ if (ep->auth_enable) { /* Add random parameter length*/ chunksize += sizeof(asoc->c.auth_random); /* Add HMACS parameter length if any were defined */ auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; if (auth_hmacs->length) chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); else auth_hmacs = NULL; /* Add CHUNKS parameter length */ auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; if (auth_chunks->length) chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); else auth_chunks = NULL; extensions[num_ext] = SCTP_CID_AUTH; num_ext += 1; } /* If we have any extensions to report, account for that */ if (num_ext) chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); /* 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_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 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); if (asoc->ep->ecn_enable) sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); /* Add the supported extensions parameter. Be nice and add this * fist before addiding the parameters for the extensions themselves */ if (num_ext) { ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); sctp_addto_param(retval, num_ext, extensions); } if (asoc->ep->prsctp_enable) sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); if (sp->adaptation_ind) { aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; aiparam.param_hdr.length = htons(sizeof(aiparam)); aiparam.adaptation_ind = htonl(sp->adaptation_ind); sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); } /* Add SCTP-AUTH chunks to the parameter list */ if (ep->auth_enable) { sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), asoc->c.auth_random); if (auth_hmacs) sctp_addto_chunk(retval, ntohs(auth_hmacs->length), auth_hmacs); if (auth_chunks) sctp_addto_chunk(retval, ntohs(auth_chunks->length), auth_chunks); } 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) { struct sctp_supported_ext_param ext_param; struct sctp_adaptation_ind_param aiparam; struct sctp_paramhdr *auth_chunks = NULL; struct sctp_paramhdr *auth_random = NULL; struct sctp_paramhdr *auth_hmacs = NULL; struct sctp_chunk *retval = NULL; struct sctp_cookie_param *cookie; struct sctp_inithdr initack; union sctp_params addrs; struct sctp_sock *sp; __u8 extensions[5]; size_t chunksize; int num_ext = 0; int cookie_len; int addrs_len; /* 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. */ sp = sctp_sk(asoc->base.sk); 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); if (asoc->peer.prsctp_capable) chunksize += sizeof(prsctp_param); if (asoc->peer.asconf_capable) { extensions[num_ext] = SCTP_CID_ASCONF; extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; num_ext += 2; } if (asoc->peer.reconf_capable) { extensions[num_ext] = SCTP_CID_RECONF; num_ext += 1; } if (sp->adaptation_ind) chunksize += sizeof(aiparam); if (asoc->peer.intl_capable) { extensions[num_ext] = SCTP_CID_I_DATA; num_ext += 1; } if (asoc->peer.auth_capable) { auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; chunksize += ntohs(auth_random->length); auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; if (auth_hmacs->length) chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); else auth_hmacs = NULL; auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; if (auth_chunks->length) chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); else auth_chunks = NULL; extensions[num_ext] = SCTP_CID_AUTH; num_ext += 1; } if (num_ext) chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); /* Now allocate and fill out the chunk. */ retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); if (!retval) goto nomem_chunk; /* 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->transport) retval->transport = sctp_assoc_lookup_paddr(asoc, &chunk->transport->ipaddr); 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 (num_ext) { ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); sctp_addto_param(retval, num_ext, extensions); } if (asoc->peer.prsctp_capable) sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); if (sp->adaptation_ind) { aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; aiparam.param_hdr.length = htons(sizeof(aiparam)); aiparam.adaptation_ind = htonl(sp->adaptation_ind); sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); } if (asoc->peer.auth_capable) { sctp_addto_chunk(retval, ntohs(auth_random->length), auth_random); if (auth_hmacs) sctp_addto_chunk(retval, ntohs(auth_hmacs->length), auth_hmacs); if (auth_chunks) sctp_addto_chunk(retval, ntohs(auth_chunks->length), auth_chunks); } /* We need to remove the const qualifier at this point. */ retval->asoc = (struct sctp_association *) asoc; 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; int cookie_len; void *cookie; cookie = asoc->peer.cookie; cookie_len = asoc->peer.cookie_len; /* Build a cookie echo chunk. */ retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len, GFP_ATOMIC); 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_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); /* 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 && chunk->transport) retval->transport = sctp_assoc_lookup_paddr(asoc, &chunk->transport->ipaddr); 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; struct sctp_cwrhdr cwr; cwr.lowest_tsn = htonl(lowest_tsn); retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, sizeof(cwr), GFP_ATOMIC); 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; struct sctp_ecnehdr ecne; ecne.lowest_tsn = htonl(lowest_tsn); retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, sizeof(ecne), GFP_ATOMIC); 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(const struct sctp_association *asoc, const struct sctp_sndrcvinfo *sinfo, int len, __u8 flags, gfp_t gfp) { struct sctp_chunk *retval; struct sctp_datahdr dp; /* We assign the TSN as LATE as possible, not here when * creating the chunk. */ memset(&dp, 0, sizeof(dp)); dp.ppid = sinfo->sinfo_ppid; dp.stream = htons(sinfo->sinfo_stream); /* Set the flags for an unordered send. */ if (sinfo->sinfo_flags & SCTP_UNORDERED) flags |= SCTP_DATA_UNORDERED; retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); if (!retval) return NULL; retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 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(struct sctp_association *asoc) { struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; __u16 num_gabs, num_dup_tsns; struct sctp_transport *trans; struct sctp_chunk *retval; struct sctp_sackhdr sack; __u32 ctsn; int len; memset(gabs, 0, sizeof(gabs)); ctsn = sctp_tsnmap_get_ctsn(map); pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); /* How much room is needed in the chunk? */ num_gabs = sctp_tsnmap_num_gabs(map, gabs); 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_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 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, gabs); /* Add the duplicate TSN information. */ if (num_dup_tsns) { asoc->stats.idupchunks += num_dup_tsns; sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, sctp_tsnmap_get_dups(map)); } /* Once we have a sack generated, check to see what our sack * generation is, if its 0, reset the transports to 0, and reset * the association generation to 1 * * The idea is that zero is never used as a valid generation for the * association so no transport will match after a wrap event like this, * Until the next sack */ if (++asoc->peer.sack_generation == 0) { list_for_each_entry(trans, &asoc->peer.transport_addr_list, transports) trans->sack_generation = 0; asoc->peer.sack_generation = 1; } 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_shutdownhdr shut; struct sctp_chunk *retval; __u32 ctsn; ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); shut.cum_tsn_ack = htonl(ctsn); retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, sizeof(shut), GFP_ATOMIC); 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_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, GFP_ATOMIC); /* 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_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0, GFP_ATOMIC); /* 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_control(asoc, SCTP_CID_ABORT, flags, hint, GFP_ATOMIC); /* 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; __be32 payload; retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 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, sizeof(payload)); sctp_addto_chunk(retval, sizeof(payload), (const void *)&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, struct msghdr *msg, size_t paylen) { struct sctp_chunk *retval; void *payload = NULL; int err; retval = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr) + 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_from_msg(payload, msg, paylen); if (err < 0) goto err_copy; } sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); sctp_addto_chunk(retval, paylen, payload); if (paylen) kfree(payload); return retval; err_copy: kfree(payload); err_payload: sctp_chunk_free(retval); retval = NULL; err_chunk: return retval; } /* Append bytes to the end of a parameter. Will panic if chunk is not big * enough. */ static void *sctp_addto_param(struct sctp_chunk *chunk, int len, const void *data) { int chunklen = ntohs(chunk->chunk_hdr->length); void *target; target = skb_put(chunk->skb, len); if (data) memcpy(target, data, len); else memset(target, 0, len); /* Adjust the chunk length field. */ chunk->chunk_hdr->length = htons(chunklen + len); chunk->chunk_end = skb_tail_pointer(chunk->skb); return target; } /* 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(struct sctp_errhdr) + paylen + sizeof(phdr)); if (!retval) goto end; sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + sizeof(phdr)); phdr.type = htons(chunk->chunk_hdr->type); phdr.length = chunk->chunk_hdr->length; sctp_addto_chunk(retval, paylen, payload); sctp_addto_param(retval, sizeof(phdr), &phdr); end: return retval; } struct sctp_chunk *sctp_make_violation_paramlen( const struct sctp_association *asoc, const struct sctp_chunk *chunk, struct sctp_paramhdr *param) { static const char error[] = "The following parameter had invalid length:"; size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + sizeof(*param); struct sctp_chunk *retval; retval = sctp_make_abort(asoc, chunk, payload_len); if (!retval) goto nodata; sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error) + sizeof(*param)); sctp_addto_chunk(retval, sizeof(error), error); sctp_addto_param(retval, sizeof(*param), param); nodata: return retval; } struct sctp_chunk *sctp_make_violation_max_retrans( const struct sctp_association *asoc, const struct sctp_chunk *chunk) { static const char error[] = "Association exceeded its max_retrans count"; size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); struct sctp_chunk *retval; retval = sctp_make_abort(asoc, chunk, payload_len); if (!retval) goto nodata; sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); sctp_addto_chunk(retval, sizeof(error), error); nodata: return retval; } struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, const struct sctp_chunk *chunk) { struct sctp_new_encap_port_hdr nep; struct sctp_chunk *retval; retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + sizeof(nep)); if (!retval) goto nodata; sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; nep.new_port = chunk->transport->encap_port; sctp_addto_chunk(retval, sizeof(nep), &nep); nodata: return retval; } /* Make a HEARTBEAT chunk. */ struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, const struct sctp_transport *transport, __u32 probe_size) { struct sctp_sender_hb_info hbinfo = {}; struct sctp_chunk *retval; retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo), GFP_ATOMIC); if (!retval) goto nodata; hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; hbinfo.param_hdr.length = htons(sizeof(hbinfo)); hbinfo.daddr = transport->ipaddr; hbinfo.sent_at = jiffies; hbinfo.hb_nonce = transport->hb_nonce; hbinfo.probe_size = probe_size; /* 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, sizeof(hbinfo), &hbinfo); retval->pmtu_probe = !!probe_size; 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_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, GFP_ATOMIC); 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; } /* RFC4820 3. Padding Chunk (PAD) * 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 = 0x84 | Flags=0 | Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | | * \ Padding Data / * / \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) { struct sctp_chunk *retval; retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); if (!retval) return NULL; skb_put_zero(retval->skb, len); retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); retval->chunk_end = skb_tail_pointer(retval->skb); 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_control(asoc, SCTP_CID_ERROR, 0, sizeof(struct sctp_errhdr) + size, GFP_ATOMIC); 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 of a fixed size, specifically, * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. * This is a helper function to allocate an error chunk for those * invalid parameter codes in which we may not want to report all the * errors, if the incoming chunk is large. If it can't fit in a single * packet, we ignore it. */ static inline struct sctp_chunk *sctp_make_op_error_limited( const struct sctp_association *asoc, const struct sctp_chunk *chunk) { size_t size = SCTP_DEFAULT_MAXSEGMENT; struct sctp_sock *sp = NULL; if (asoc) { size = min_t(size_t, size, asoc->pathmtu); sp = sctp_sk(asoc->base.sk); } size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); return sctp_make_op_error_space(asoc, chunk, size); } /* 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, size_t reserve_tail) { struct sctp_chunk *retval; retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); if (!retval) goto nodata; sctp_init_cause(retval, cause_code, paylen + reserve_tail); sctp_addto_chunk(retval, paylen, payload); if (reserve_tail) sctp_addto_param(retval, reserve_tail, NULL); nodata: return retval; } struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, __u16 key_id) { struct sctp_authhdr auth_hdr; struct sctp_hmac *hmac_desc; struct sctp_chunk *retval; /* Get the first hmac that the peer told us to use */ hmac_desc = sctp_auth_asoc_get_hmac(asoc); if (unlikely(!hmac_desc)) return NULL; retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, hmac_desc->hmac_len + sizeof(auth_hdr), GFP_ATOMIC); if (!retval) return NULL; auth_hdr.hmac_id = htons(hmac_desc->hmac_id); auth_hdr.shkey_id = htons(key_id); retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), &auth_hdr); skb_put_zero(retval->skb, hmac_desc->hmac_len); /* Adjust the chunk header to include the empty MAC */ retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); retval->chunk_end = skb_tail_pointer(retval->skb); return retval; } /******************************************************************** * 2nd Level Abstractions ********************************************************************/ /* Turn an skb into a chunk. * FIXME: Eventually move the structure directly inside the skb->cb[]. * * 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. * */ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, const struct sctp_association *asoc, struct sock *sk, gfp_t gfp) { struct sctp_chunk *retval; retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); if (!retval) goto nodata; if (!sk) pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); INIT_LIST_HEAD(&retval->list); retval->skb = skb; retval->asoc = (struct sctp_association *)asoc; retval->singleton = 1; retval->fast_retransmit = SCTP_CAN_FRTX; /* Polish the bead hole. */ INIT_LIST_HEAD(&retval->transmitted_list); INIT_LIST_HEAD(&retval->frag_list); SCTP_DBG_OBJCNT_INC(chunk); refcount_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)); memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); } /* 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; } else { /* Otherwise, extract it from the IP header. */ return &chunk->source; } } /* Create a new chunk, setting the type and flags headers from the * arguments, reserving enough space for a 'paylen' byte payload. */ static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen, gfp_t gfp) { struct sctp_chunkhdr *chunk_hdr; struct sctp_chunk *retval; struct sk_buff *skb; struct sock *sk; int chunklen; chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); if (chunklen > SCTP_MAX_CHUNK_LEN) goto nodata; /* No need to allocate LL here, as this is only a chunk. */ skb = alloc_skb(chunklen, gfp); if (!skb) goto nodata; /* Make room for the chunk header. */ chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); chunk_hdr->type = type; chunk_hdr->flags = flags; chunk_hdr->length = htons(sizeof(*chunk_hdr)); sk = asoc ? asoc->base.sk : NULL; retval = sctp_chunkify(skb, asoc, sk, gfp); if (!retval) { kfree_skb(skb); goto nodata; } retval->chunk_hdr = chunk_hdr; retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); /* Determine if the chunk needs to be authenticated */ if (sctp_auth_send_cid(type, asoc)) retval->auth = 1; return retval; nodata: return NULL; } static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, __u8 flags, int paylen, gfp_t gfp) { return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); } struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, __u8 flags, int paylen, gfp_t gfp) { return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); } static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, __u8 type, __u8 flags, int paylen, gfp_t gfp) { struct sctp_chunk *chunk; chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); if (chunk) sctp_control_set_owner_w(chunk); return chunk; } /* Release the memory occupied by a chunk. */ static void sctp_chunk_destroy(struct sctp_chunk *chunk) { BUG_ON(!list_empty(&chunk->list)); list_del_init(&chunk->transmitted_list); consume_skb(chunk->skb); consume_skb(chunk->auth_chunk); SCTP_DBG_OBJCNT_DEC(chunk); kmem_cache_free(sctp_chunk_cachep, chunk); } /* Possibly, free the chunk. */ void sctp_chunk_free(struct sctp_chunk *chunk) { /* 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) { refcount_inc(&ch->refcnt); } /* Release a reference to the chunk. */ void sctp_chunk_put(struct sctp_chunk *ch) { if (refcount_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) { int chunklen = ntohs(chunk->chunk_hdr->length); int padlen = SCTP_PAD4(chunklen) - chunklen; void *target; skb_put_zero(chunk->skb, padlen); target = skb_put_data(chunk->skb, data, len); /* Adjust the chunk length field. */ chunk->chunk_hdr->length = htons(chunklen + padlen + len); chunk->chunk_end = skb_tail_pointer(chunk->skb); 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 len, struct iov_iter *from) { void *target; /* Make room in chunk for data. */ target = skb_put(chunk->skb, len); /* Copy data (whole iovec) into chunk */ if (!copy_from_iter_full(target, len, from)) return -EFAULT; /* Adjust the chunk length field. */ chunk->chunk_hdr->length = htons(ntohs(chunk->chunk_hdr->length) + len); chunk->chunk_end = skb_tail_pointer(chunk->skb); return 0; } /* 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) { struct sctp_stream *stream; struct sctp_chunk *lchunk; struct sctp_datamsg *msg; __u16 ssn, sid; if (chunk->has_ssn) return; /* All fragments will be on the same stream */ sid = ntohs(chunk->subh.data_hdr->stream); stream = &chunk->asoc->stream; /* Now assign the sequence number to the entire message. * All fragments must have the same stream sequence number. */ msg = chunk->msg; list_for_each_entry(lchunk, &msg->chunks, frag_list) { if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { ssn = 0; } else { if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) ssn = sctp_ssn_next(stream, out, sid); else ssn = sctp_ssn_peek(stream, out, sid); } lchunk->subh.data_hdr->ssn = htons(ssn); lchunk->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; enum sctp_scope scope; struct sk_buff *skb; /* 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. */ SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); nodata: return asoc; } /* Build a cookie representing asoc. * This INCLUDES the param header needed to put the cookie in the INIT ACK. */ static struct sctp_cookie_param *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) { struct sctp_signed_cookie *cookie; struct sctp_cookie_param *retval; int headersize, bodysize; /* Header size is static data prior to the actual cookie, including * any padding. */ headersize = sizeof(struct sctp_paramhdr) + (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; /* Clear this memory since we are sending this data structure * out on the network. */ retval = kzalloc(*cookie_len, GFP_ATOMIC); if (!retval) goto nodata; 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 adaptation indication in the cookie. */ cookie->c.adaptation_ind = asoc->peer.adaptation_ind; /* Set an expiration time for the cookie. */ cookie->c.expiration = ktime_add(asoc->cookie_life, ktime_get_real()); /* Copy the peer's init packet. */ memcpy(cookie + 1, init_chunk->chunk_hdr, ntohs(init_chunk->chunk_hdr->length)); /* Copy the raw local address list of the association. */ memcpy((__u8 *)(cookie + 1) + ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); if (sctp_sk(ep->base.sk)->hmac) { struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; int err; /* Sign the message. */ err = crypto_shash_setkey(tfm, ep->secret_key, sizeof(ep->secret_key)) ?: crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, cookie->signature); if (err) 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; int headersize, bodysize, fixed_size; struct sctp_signed_cookie *cookie; struct sk_buff *skb = chunk->skb; struct sctp_cookie *bear_cookie; __u8 *digest = ep->digest; enum sctp_scope scope; unsigned int len; ktime_t kt; /* Header size is static data prior to the actual cookie, including * any padding. */ headersize = sizeof(struct sctp_chunkhdr) + (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. */ { struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; int err; err = crypto_shash_setkey(tfm, ep->secret_key, sizeof(ep->secret_key)) ?: crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, digest); if (err) { *error = -SCTP_IERROR_NOMEM; goto fail; } } if (crypto_memneq(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { *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 * a cookie may be considered expired, but this would only slow * down the new association establishment instead of every packet. */ if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) kt = skb_get_ktime(skb); else kt = ktime_get_real(); if (!asoc && ktime_before(bear_cookie->expiration, kt)) { suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); __be32 n = htonl(usecs); /* * 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. */ *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_STALE_COOKIE, &n, sizeof(n), 0); if (*errp) *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)) { sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, sizeof(chunk->dest), SCTP_ADDR_SRC, 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->strreset_outseq = retval->c.initial_tsn; retval->adv_peer_ack_point = retval->ctsn_ack_point; retval->peer.prsctp_capable = retval->c.prsctp_capable; retval->peer.adaptation_ind = retval->c.adaptation_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 { __be32 num_missing; __be16 type; } __packed; /* * Report a missing mandatory parameter. */ static int sctp_process_missing_param(const struct sctp_association *asoc, enum sctp_param paramtype, struct sctp_chunk *chunk, struct sctp_chunk **errp) { struct __sctp_missing report; __u16 len; len = SCTP_PAD4(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_MISS_PARAM, sizeof(report)); sctp_addto_chunk(*errp, sizeof(report), &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, 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) { /* This is a fatal error. Any accumulated non-fatal errors are * not reported. */ if (*errp) sctp_chunk_free(*errp); /* Create an error chunk and fill it in with our payload. */ *errp = sctp_make_violation_paramlen(asoc, chunk, 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); /* Processing of the HOST_NAME parameter will generate an * ABORT. If we've accumulated any non-fatal errors, they * would be unrecognized parameters and we should not include * them in the ABORT. */ if (*errp) sctp_chunk_free(*errp); *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, param.v, len, 0); /* Stop processing this chunk. */ return 0; } static int sctp_verify_ext_param(struct net *net, const struct sctp_endpoint *ep, union sctp_params param) { __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); int have_asconf = 0; int have_auth = 0; int i; for (i = 0; i < num_ext; i++) { switch (param.ext->chunks[i]) { case SCTP_CID_AUTH: have_auth = 1; break; case SCTP_CID_ASCONF: case SCTP_CID_ASCONF_ACK: have_asconf = 1; break; } } /* ADD-IP Security: The draft requires us to ABORT or ignore the * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this * only if ADD-IP is turned on and we are not backward-compatible * mode. */ if (net->sctp.addip_noauth) return 1; if (ep->asconf_enable && !have_auth && have_asconf) return 0; return 1; } static void sctp_process_ext_param(struct sctp_association *asoc, union sctp_params param) { __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); int i; for (i = 0; i < num_ext; i++) { switch (param.ext->chunks[i]) { case SCTP_CID_RECONF: if (asoc->ep->reconf_enable) asoc->peer.reconf_capable = 1; break; case SCTP_CID_FWD_TSN: if (asoc->ep->prsctp_enable) asoc->peer.prsctp_capable = 1; break; case SCTP_CID_AUTH: /* if the peer reports AUTH, assume that he * supports AUTH. */ if (asoc->ep->auth_enable) asoc->peer.auth_capable = 1; break; case SCTP_CID_ASCONF: case SCTP_CID_ASCONF_ACK: if (asoc->ep->asconf_enable) asoc->peer.asconf_capable = 1; break; case SCTP_CID_I_DATA: if (asoc->ep->intl_enable) asoc->peer.intl_capable = 1; break; default: break; } } } /* 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 parameter; do not process any further * parameters within this chunk * * 01 - Stop processing this parameter, do not process any further * parameters within this chunk, and report the unrecognized * parameter in an 'Unrecognized Parameter' ERROR chunk. * * 10 - Skip this parameter and continue processing. * * 11 - Skip this parameter and continue processing but * report the unrecognized parameter in an * 'Unrecognized Parameter' ERROR chunk. * * Return value: * SCTP_IERROR_NO_ERROR - continue with the chunk * SCTP_IERROR_ERROR - stop and report an error. * SCTP_IERROR_NOMEME - out of memory. */ static enum sctp_ierror sctp_process_unk_param( const struct sctp_association *asoc, union sctp_params param, struct sctp_chunk *chunk, struct sctp_chunk **errp) { int retval = SCTP_IERROR_NO_ERROR; switch (param.p->type & SCTP_PARAM_ACTION_MASK) { case SCTP_PARAM_ACTION_DISCARD: retval = SCTP_IERROR_ERROR; break; case SCTP_PARAM_ACTION_SKIP: break; case SCTP_PARAM_ACTION_DISCARD_ERR: retval = SCTP_IERROR_ERROR; fallthrough; case SCTP_PARAM_ACTION_SKIP_ERR: /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. */ if (!*errp) { *errp = sctp_make_op_error_limited(asoc, chunk); if (!*errp) { /* 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 = SCTP_IERROR_NOMEM; break; } } if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, ntohs(param.p->length))) sctp_addto_chunk(*errp, ntohs(param.p->length), param.v); break; default: break; } return retval; } /* Verify variable length parameters * Return values: * SCTP_IERROR_ABORT - trigger an ABORT * SCTP_IERROR_NOMEM - out of memory (abort) * SCTP_IERROR_ERROR - stop processing, trigger an ERROR * SCTP_IERROR_NO_ERROR - continue with the chunk */ static enum sctp_ierror sctp_verify_param(struct net *net, const struct sctp_endpoint *ep, const struct sctp_association *asoc, union sctp_params param, enum sctp_cid cid, struct sctp_chunk *chunk, struct sctp_chunk **err_chunk) { struct sctp_hmac_algo_param *hmacs; int retval = SCTP_IERROR_NO_ERROR; __u16 n_elt, id = 0; int i; /* 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_ADAPTATION_LAYER_IND: break; case SCTP_PARAM_SUPPORTED_EXT: if (!sctp_verify_ext_param(net, ep, param)) return SCTP_IERROR_ABORT; break; case SCTP_PARAM_SET_PRIMARY: if (!ep->asconf_enable) goto unhandled; if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + sizeof(struct sctp_paramhdr)) { sctp_process_inv_paramlength(asoc, param.p, chunk, err_chunk); retval = SCTP_IERROR_ABORT; } break; case SCTP_PARAM_HOST_NAME_ADDRESS: /* This param has been Deprecated, send ABORT. */ sctp_process_hn_param(asoc, param, chunk, err_chunk); retval = SCTP_IERROR_ABORT; break; case SCTP_PARAM_FWD_TSN_SUPPORT: if (ep->prsctp_enable) break; goto unhandled; case SCTP_PARAM_RANDOM: if (!ep->auth_enable) goto unhandled; /* SCTP-AUTH: Secion 6.1 * If the random number is not 32 byte long the association * MUST be aborted. The ABORT chunk SHOULD contain the error * cause 'Protocol Violation'. */ if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { sctp_process_inv_paramlength(asoc, param.p, chunk, err_chunk); retval = SCTP_IERROR_ABORT; } break; case SCTP_PARAM_CHUNKS: if (!ep->auth_enable) goto unhandled; /* SCTP-AUTH: Section 3.2 * The CHUNKS parameter MUST be included once in the INIT or * INIT-ACK chunk if the sender wants to receive authenticated * chunks. Its maximum length is 260 bytes. */ if (260 < ntohs(param.p->length)) { sctp_process_inv_paramlength(asoc, param.p, chunk, err_chunk); retval = SCTP_IERROR_ABORT; } break; case SCTP_PARAM_HMAC_ALGO: if (!ep->auth_enable) goto unhandled; hmacs = (struct sctp_hmac_algo_param *)param.p; n_elt = (ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) >> 1; /* SCTP-AUTH: Section 6.1 * The HMAC algorithm based on SHA-1 MUST be supported and * included in the HMAC-ALGO parameter. */ for (i = 0; i < n_elt; i++) { id = ntohs(hmacs->hmac_ids[i]); if (id == SCTP_AUTH_HMAC_ID_SHA1) break; } if (id != SCTP_AUTH_HMAC_ID_SHA1) { sctp_process_inv_paramlength(asoc, param.p, chunk, err_chunk); retval = SCTP_IERROR_ABORT; } break; unhandled: default: pr_debug("%s: unrecognized param:%d for chunk:%d\n", __func__, ntohs(param.p->type), cid); retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); break; } return retval; } /* Verify the INIT packet before we process it. */ int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, const struct sctp_association *asoc, enum sctp_cid cid, struct sctp_init_chunk *peer_init, struct sctp_chunk *chunk, struct sctp_chunk **errp) { union sctp_params param; bool has_cookie = false; int result; /* Check for missing mandatory parameters. Note: Initial TSN is * also mandatory, but is not checked here since the valid range * is 0..2**32-1. RFC4960, section 3.3.3. */ if (peer_init->init_hdr.num_outbound_streams == 0 || peer_init->init_hdr.num_inbound_streams == 0 || peer_init->init_hdr.init_tag == 0 || ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) return sctp_process_inv_mandatory(asoc, chunk, errp); sctp_walk_params(param, peer_init) { if (param.p->type == SCTP_PARAM_STATE_COOKIE) has_cookie = true; } /* 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) return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); /* The only missing mandatory param possible today is * the state cookie for an INIT-ACK chunk. */ if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, chunk, errp); /* Verify all the variable length parameters */ sctp_walk_params(param, peer_init) { result = sctp_verify_param(net, ep, asoc, param, cid, chunk, errp); switch (result) { case SCTP_IERROR_ABORT: case SCTP_IERROR_NOMEM: return 0; case SCTP_IERROR_ERROR: return 1; case SCTP_IERROR_NO_ERROR: default: break; } } /* 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, struct sctp_chunk *chunk, const union sctp_addr *peer_addr, struct sctp_init_chunk *peer_init, gfp_t gfp) { struct sctp_transport *transport; struct list_head *pos, *temp; union sctp_params param; union sctp_addr addr; struct sctp_af *af; int src_match = 0; /* 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 better choice than any of the embedded addresses. */ asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) goto nomem; if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) src_match = 1; /* Process the initialization parameters. */ sctp_walk_params(param, peer_init) { if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { af = sctp_get_af_specific(param_type2af(param.p->type)); if (!af->from_addr_param(&addr, param.addr, chunk->sctp_hdr->source, 0)) continue; if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) src_match = 1; } if (!sctp_process_param(asoc, param, peer_addr, gfp)) goto clean_up; } /* source address of chunk may not match any valid address */ if (!src_match) goto clean_up; /* AUTH: After processing the parameters, make sure that we * have all the required info to potentially do authentications. */ if (asoc->peer.auth_capable && (!asoc->peer.peer_random || !asoc->peer.peer_hmacs)) asoc->peer.auth_capable = 0; /* In a non-backward compatible mode, if the peer claims * support for ADD-IP but not AUTH, the ADD-IP spec states * that we MUST ABORT the association. Section 6. The section * also give us an option to silently ignore the packet, which * is what we'll do here. */ if (!asoc->base.net->sctp.addip_noauth && (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | SCTP_PARAM_DEL_IP | SCTP_PARAM_SET_PRIMARY); asoc->peer.asconf_capable = 0; 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); asoc->strreset_inseq = asoc->peer.i.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; /* 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_entry(transport, &asoc->peer.transport_addr_list, transports) { transport->ssthresh = asoc->peer.i.a_rwnd; } /* Set up the TSN tracking pieces. */ if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, asoc->peer.i.initial_tsn, gfp)) goto clean_up; /* 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. */ if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, asoc->c.sinit_max_instreams, gfp)) goto clean_up; /* Update frag_point when stream_interleave may get changed. */ sctp_assoc_update_frag_point(asoc); if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) goto clean_up; /* 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); if (transport->state != SCTP_ACTIVE) sctp_assoc_rm_peer(asoc, transport); } 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) { struct sctp_endpoint *ep = asoc->ep; union sctp_addr_param *addr_param; struct net *net = asoc->base.net; struct sctp_transport *t; enum sctp_scope scope; union sctp_addr addr; struct sctp_af *af; int retval = 1, i; u32 stale; __u16 sat; /* 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; goto do_addr_param; case SCTP_PARAM_IPV4_ADDRESS: /* v4 addresses are not allowed on v6-only socket */ if (ipv6_only_sock(asoc->base.sk)) break; do_addr_param: af = sctp_get_af_specific(param_type2af(param.p->type)); if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) break; scope = sctp_scope(peer_addr); if (sctp_in_scope(net, &addr, scope)) if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) return 0; break; case SCTP_PARAM_COOKIE_PRESERVATIVE: if (!net->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 = ktime_add_ms(asoc->cookie_life, stale); 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; /* Assume that peer supports the address family * by which it sends a packet. */ if (peer_addr->sa.sa_family == AF_INET6) asoc->peer.ipv6_address = 1; else if (peer_addr->sa.sa_family == AF_INET) asoc->peer.ipv4_address = 1; /* Cycle through address types; avoid divide by 0. */ sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 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: if (PF_INET6 == asoc->base.sk->sk_family) asoc->peer.ipv6_address = 1; break; default: /* Just ignore anything else. */ break; } } break; case SCTP_PARAM_STATE_COOKIE: asoc->peer.cookie_len = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); kfree(asoc->peer.cookie); asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); if (!asoc->peer.cookie) retval = 0; 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: if (asoc->ep->ecn_enable) { asoc->peer.ecn_capable = 1; break; } /* Fall Through */ goto fall_through; case SCTP_PARAM_ADAPTATION_LAYER_IND: asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); break; case SCTP_PARAM_SET_PRIMARY: if (!ep->asconf_enable) goto fall_through; addr_param = param.v + sizeof(struct sctp_addip_param); af = sctp_get_af_specific(param_type2af(addr_param->p.type)); if (!af) break; if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) break; if (!af->addr_valid(&addr, NULL, NULL)) break; t = sctp_assoc_lookup_paddr(asoc, &addr); if (!t) break; sctp_assoc_set_primary(asoc, t); break; case SCTP_PARAM_SUPPORTED_EXT: sctp_process_ext_param(asoc, param); break; case SCTP_PARAM_FWD_TSN_SUPPORT: if (asoc->ep->prsctp_enable) { asoc->peer.prsctp_capable = 1; break; } /* Fall Through */ goto fall_through; case SCTP_PARAM_RANDOM: if (!ep->auth_enable) goto fall_through; /* Save peer's random parameter */ kfree(asoc->peer.peer_random); asoc->peer.peer_random = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_random) { retval = 0; break; } break; case SCTP_PARAM_HMAC_ALGO: if (!ep->auth_enable) goto fall_through; /* Save peer's HMAC list */ kfree(asoc->peer.peer_hmacs); asoc->peer.peer_hmacs = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_hmacs) { retval = 0; break; } /* Set the default HMAC the peer requested*/ sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); break; case SCTP_PARAM_CHUNKS: if (!ep->auth_enable) goto fall_through; kfree(asoc->peer.peer_chunks); asoc->peer.peer_chunks = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_chunks) retval = 0; 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. */ pr_debug("%s: ignoring param:%d for association:%p.\n", __func__, 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) { struct sctp_addiphdr 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_control(asoc, SCTP_CID_ASCONF, 0, length, GFP_ATOMIC); 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) { union sctp_addr_param addr_param; struct sctp_addip_param param; int paramlen = sizeof(param); struct sctp_chunk *retval; int addr_param_len = 0; union sctp_addr *addr; int totallen = 0, i; int del_pickup = 0; struct sctp_af *af; void *addr_buf; /* Get total length of all the address parameters. */ addr_buf = addrs; for (i = 0; i < addrcnt; i++) { 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; if (asoc->asconf_addr_del_pending && !del_pickup) { /* reuse the parameter length from the same scope one */ totallen += paramlen; totallen += addr_param_len; del_pickup = 1; pr_debug("%s: picked same-scope del_pending addr, " "totallen for all addresses is %d\n", __func__, totallen); } } /* 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 = 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 = htonl(i); sctp_addto_chunk(retval, paramlen, ¶m); sctp_addto_chunk(retval, addr_param_len, &addr_param); addr_buf += af->sockaddr_len; } if (flags == SCTP_PARAM_ADD_IP && del_pickup) { addr = asoc->asconf_addr_del_pending; af = sctp_get_af_specific(addr->v4.sin_family); addr_param_len = af->to_addr_param(addr, &addr_param); param.param_hdr.type = SCTP_PARAM_DEL_IP; param.param_hdr.length = htons(paramlen + addr_param_len); param.crr_id = htonl(i); sctp_addto_chunk(retval, paramlen, ¶m); sctp_addto_chunk(retval, addr_param_len, &addr_param); } 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) { struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); union sctp_addr_param addrparam; struct sctp_addip_param param; struct sctp_chunk *retval; int len = sizeof(param); int addrlen; 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) { struct sctp_addiphdr asconf; struct sctp_chunk *retval; int length = sizeof(asconf) + vparam_len; /* Create the chunk. */ retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, GFP_ATOMIC); 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, __be32 crr_id, __be16 err_code, struct sctp_addip_param *asconf_param) { struct sctp_addip_param ack_param; struct sctp_errhdr 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, struct sctp_addip_param *asconf_param) { union sctp_addr_param *addr_param; struct sctp_transport *peer; union sctp_addr addr; struct sctp_af *af; addr_param = (void *)asconf_param + sizeof(*asconf_param); if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) return SCTP_ERROR_UNKNOWN_PARAM; switch (addr_param->p.type) { case SCTP_PARAM_IPV6_ADDRESS: if (!asoc->peer.ipv6_address) return SCTP_ERROR_DNS_FAILED; break; case SCTP_PARAM_IPV4_ADDRESS: if (!asoc->peer.ipv4_address) return SCTP_ERROR_DNS_FAILED; break; default: return SCTP_ERROR_DNS_FAILED; } af = sctp_get_af_specific(param_type2af(addr_param->p.type)); if (unlikely(!af)) return SCTP_ERROR_DNS_FAILED; if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) return SCTP_ERROR_DNS_FAILED; /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast * or multicast address. * (note: wildcard is permitted and requires special handling so * make sure we check for that) */ if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) return SCTP_ERROR_DNS_FAILED; switch (asconf_param->param_hdr.type) { case SCTP_PARAM_ADD_IP: /* Section 4.2.1: * If the address 0.0.0.0 or ::0 is provided, the source * address of the packet MUST be added. */ if (af->is_any(&addr)) memcpy(&addr, &asconf->source, sizeof(addr)); if (security_sctp_bind_connect(asoc->ep->base.sk, SCTP_PARAM_ADD_IP, (struct sockaddr *)&addr, af->sockaddr_len)) return SCTP_ERROR_REQ_REFUSED; /* 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, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); if (!peer) return SCTP_ERROR_RSRC_LOW; /* Start the heartbeat timer. */ sctp_transport_reset_hb_timer(peer); asoc->new_transport = 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'. */ if (asoc->peer.transport_count == 1) 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' */ if (sctp_cmp_addr_exact(&asconf->source, &addr)) return SCTP_ERROR_DEL_SRC_IP; /* Section 4.2.2 * If the address 0.0.0.0 or ::0 is provided, all * addresses of the peer except the source address of the * packet MUST be deleted. */ if (af->is_any(&addr)) { sctp_assoc_set_primary(asoc, asconf->transport); sctp_assoc_del_nonprimary_peers(asoc, asconf->transport); return SCTP_ERROR_NO_ERROR; } /* If the address is not part of the association, the * ASCONF-ACK with Error Cause Indication Parameter * which including cause of Unresolvable Address should * be sent. */ peer = sctp_assoc_lookup_paddr(asoc, &addr); if (!peer) return SCTP_ERROR_DNS_FAILED; sctp_assoc_rm_peer(asoc, peer); break; case SCTP_PARAM_SET_PRIMARY: /* ADDIP Section 4.2.4 * If the address 0.0.0.0 or ::0 is provided, the receiver * MAY mark the source address of the packet as its * primary. */ if (af->is_any(&addr)) memcpy(&addr, sctp_source(asconf), sizeof(addr)); if (security_sctp_bind_connect(asoc->ep->base.sk, SCTP_PARAM_SET_PRIMARY, (struct sockaddr *)&addr, af->sockaddr_len)) return SCTP_ERROR_REQ_REFUSED; peer = sctp_assoc_lookup_paddr(asoc, &addr); if (!peer) return SCTP_ERROR_DNS_FAILED; sctp_assoc_set_primary(asoc, peer); break; } return SCTP_ERROR_NO_ERROR; } /* Verify the ASCONF packet before we process it. */ bool sctp_verify_asconf(const struct sctp_association *asoc, struct sctp_chunk *chunk, bool addr_param_needed, struct sctp_paramhdr **errp) { struct sctp_addip_chunk *addip; bool addr_param_seen = false; union sctp_params param; addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; sctp_walk_params(param, addip) { size_t length = ntohs(param.p->length); *errp = param.p; switch (param.p->type) { case SCTP_PARAM_ERR_CAUSE: break; case SCTP_PARAM_IPV4_ADDRESS: if (length != sizeof(struct sctp_ipv4addr_param)) return false; /* ensure there is only one addr param and it's in the * beginning of addip_hdr params, or we reject it. */ if (param.v != (addip + 1)) return false; addr_param_seen = true; break; case SCTP_PARAM_IPV6_ADDRESS: if (length != sizeof(struct sctp_ipv6addr_param)) return false; if (param.v != (addip + 1)) return false; addr_param_seen = true; break; case SCTP_PARAM_ADD_IP: case SCTP_PARAM_DEL_IP: case SCTP_PARAM_SET_PRIMARY: /* In ASCONF chunks, these need to be first. */ if (addr_param_needed && !addr_param_seen) return false; length = ntohs(param.addip->param_hdr.length); if (length < sizeof(struct sctp_addip_param) + sizeof(**errp)) return false; break; case SCTP_PARAM_SUCCESS_REPORT: case SCTP_PARAM_ADAPTATION_LAYER_IND: if (length != sizeof(struct sctp_addip_param)) return false; break; default: /* This is unknown to us, reject! */ return false; } } /* Remaining sanity checks. */ if (addr_param_needed && !addr_param_seen) return false; if (!addr_param_needed && addr_param_seen) return false; if (param.v != chunk->chunk_end) return false; return true; } /* 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) { union sctp_addr_param *addr_param; struct sctp_addip_chunk *addip; struct sctp_chunk *asconf_ack; bool all_param_pass = true; struct sctp_addiphdr *hdr; int length = 0, chunk_len; union sctp_params param; __be16 err_code; __u32 serial; addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(struct sctp_chunkhdr); hdr = (struct sctp_addiphdr *)asconf->skb->data; serial = ntohl(hdr->serial); /* Skip the addiphdr and store a pointer to address parameter. */ length = sizeof(*hdr); 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 parameter. */ length = ntohs(addr_param->p.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 fourfold of ASCONF * parameters. */ asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); if (!asconf_ack) goto done; /* Process the TLVs contained within the ASCONF chunk. */ sctp_walk_params(param, addip) { /* Skip preceding address parameters. */ if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || param.p->type == SCTP_PARAM_IPV6_ADDRESS) continue; err_code = sctp_process_asconf_param(asoc, asconf, param.addip); /* 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 (err_code != SCTP_ERROR_NO_ERROR) all_param_pass = false; if (!all_param_pass) sctp_add_asconf_response(asconf_ack, param.addip->crr_id, err_code, param.addip); /* 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 (err_code == SCTP_ERROR_RSRC_LOW) goto done; } 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) { sctp_chunk_hold(asconf_ack); list_add_tail(&asconf_ack->transmitted_list, &asoc->asconf_ack_list); } return asconf_ack; } /* Process a asconf parameter that is successfully acked. */ static void sctp_asconf_param_success(struct sctp_association *asoc, struct sctp_addip_param *asconf_param) { struct sctp_bind_addr *bp = &asoc->base.bind_addr; union sctp_addr_param *addr_param; struct sctp_sockaddr_entry *saddr; struct sctp_transport *transport; union sctp_addr addr; struct sctp_af *af; addr_param = (void *)asconf_param + sizeof(*asconf_param); /* We have checked the packet before, so we do not check again. */ af = sctp_get_af_specific(param_type2af(addr_param->p.type)); if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) return; switch (asconf_param->param_hdr.type) { case SCTP_PARAM_ADD_IP: /* This is always done in BH context with a socket lock * held, so the list can not change. */ local_bh_disable(); list_for_each_entry(saddr, &bp->address_list, list) { if (sctp_cmp_addr_exact(&saddr->a, &addr)) saddr->state = SCTP_ADDR_SRC; } local_bh_enable(); list_for_each_entry(transport, &asoc->peer.transport_addr_list, transports) { sctp_transport_dst_release(transport); } break; case SCTP_PARAM_DEL_IP: local_bh_disable(); sctp_del_bind_addr(bp, &addr); if (asoc->asconf_addr_del_pending != NULL && sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { kfree(asoc->asconf_addr_del_pending); asoc->asconf_addr_del_pending = NULL; } local_bh_enable(); list_for_each_entry(transport, &asoc->peer.transport_addr_list, transports) { sctp_transport_dst_release(transport); } break; default: break; } } /* 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, struct sctp_addip_param *asconf_param, int no_err) { struct sctp_addip_param *asconf_ack_param; struct sctp_errhdr *err_param; int asconf_ack_len; __be16 err_code; int length; if (no_err) err_code = SCTP_ERROR_NO_ERROR; else err_code = SCTP_ERROR_REQ_REFUSED; asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - sizeof(struct sctp_chunkhdr); /* Skip the addiphdr from the asconf_ack chunk and store a pointer to * the first asconf_ack parameter. */ length = sizeof(struct sctp_addiphdr); asconf_ack_param = (struct sctp_addip_param *)(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(*asconf_ack_param); err_param = (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 = (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; struct sctp_addip_param *asconf_param; __be16 err_code = SCTP_ERROR_NO_ERROR; union sctp_addr_param *addr_param; int asconf_len = asconf->skb->len; int all_param_pass = 0; int length = 0; int no_err = 1; int retval = 0; /* Skip the chunkhdr and addiphdr from the last asconf sent and store * a pointer to address parameter. */ length = sizeof(struct sctp_addip_chunk); 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 parameter. */ length = ntohs(addr_param->p.length); asconf_param = (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(struct sctp_addiphdr)) 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: sctp_asconf_param_success(asoc, asconf_param); break; case SCTP_ERROR_RSRC_LOW: retval = 1; break; case SCTP_ERROR_UNKNOWN_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 = (void *)asconf_param + length; asconf_len -= length; } if (no_err && asoc->src_out_of_asoc_ok) { asoc->src_out_of_asoc_ok = 0; sctp_transport_immediate_rtx(asoc->peer.primary_path); } /* Free the cached last sent asconf chunk. */ list_del_init(&asconf->transmitted_list); sctp_chunk_free(asconf); asoc->addip_last_asconf = NULL; 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_hdr ftsn_hdr; struct sctp_fwdtsn_skip skip; size_t hint; int i; hint = (nstreams + 1) * sizeof(__u32); retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); if (!retval) return NULL; 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; } struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, __u32 new_cum_tsn, size_t nstreams, struct sctp_ifwdtsn_skip *skiplist) { struct sctp_chunk *retval = NULL; struct sctp_ifwdtsn_hdr ftsn_hdr; size_t hint; hint = (nstreams + 1) * sizeof(__u32); retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, GFP_ATOMIC); if (!retval) return NULL; ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); retval->subh.ifwdtsn_hdr = sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); return retval; } /* RE-CONFIG 3.1 (RE-CONFIG chunk) * 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 = 130 | Chunk Flags | Chunk Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ \ * / Re-configuration Parameter / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ \ * / Re-configuration Parameter (optional) / * \ \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, int length) { struct sctp_reconf_chunk *reconf; struct sctp_chunk *retval; retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, GFP_ATOMIC); if (!retval) return NULL; reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; retval->param_hdr.v = (u8 *)(reconf + 1); return retval; } /* RE-CONFIG 4.1 (STREAM OUT RESET) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Request Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Response Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Sender's Last Assigned TSN | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream Number 1 (optional) | Stream Number 2 (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * / ...... / * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream Number N-1 (optional) | Stream Number N (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * RE-CONFIG 4.2 (STREAM IN RESET) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Request Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream Number 1 (optional) | Stream Number 2 (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * / ...... / * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream Number N-1 (optional) | Stream Number N (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_strreset_req( const struct sctp_association *asoc, __u16 stream_num, __be16 *stream_list, bool out, bool in) { __u16 stream_len = stream_num * sizeof(__u16); struct sctp_strreset_outreq outreq; struct sctp_strreset_inreq inreq; struct sctp_chunk *retval; __u16 outlen, inlen; outlen = (sizeof(outreq) + stream_len) * out; inlen = (sizeof(inreq) + stream_len) * in; retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); if (!retval) return NULL; if (outlen) { outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; outreq.param_hdr.length = htons(outlen); outreq.request_seq = htonl(asoc->strreset_outseq); outreq.response_seq = htonl(asoc->strreset_inseq - 1); outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); sctp_addto_chunk(retval, sizeof(outreq), &outreq); if (stream_len) sctp_addto_chunk(retval, stream_len, stream_list); } if (inlen) { inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; inreq.param_hdr.length = htons(inlen); inreq.request_seq = htonl(asoc->strreset_outseq + out); sctp_addto_chunk(retval, sizeof(inreq), &inreq); if (stream_len) sctp_addto_chunk(retval, stream_len, stream_list); } return retval; } /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 15 | Parameter Length = 8 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Request Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_strreset_tsnreq( const struct sctp_association *asoc) { struct sctp_strreset_tsnreq tsnreq; __u16 length = sizeof(tsnreq); struct sctp_chunk *retval; retval = sctp_make_reconf(asoc, length); if (!retval) return NULL; tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; tsnreq.param_hdr.length = htons(length); tsnreq.request_seq = htonl(asoc->strreset_outseq); sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); return retval; } /* RE-CONFIG 4.5/4.6 (ADD STREAM) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 17 | Parameter Length = 12 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Request Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Number of new streams | Reserved | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_strreset_addstrm( const struct sctp_association *asoc, __u16 out, __u16 in) { struct sctp_strreset_addstrm addstrm; __u16 size = sizeof(addstrm); struct sctp_chunk *retval; retval = sctp_make_reconf(asoc, (!!out + !!in) * size); if (!retval) return NULL; if (out) { addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; addstrm.param_hdr.length = htons(size); addstrm.number_of_streams = htons(out); addstrm.request_seq = htonl(asoc->strreset_outseq); addstrm.reserved = 0; sctp_addto_chunk(retval, size, &addstrm); } if (in) { addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; addstrm.param_hdr.length = htons(size); addstrm.number_of_streams = htons(in); addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); addstrm.reserved = 0; sctp_addto_chunk(retval, size, &addstrm); } return retval; } /* RE-CONFIG 4.4 (RESP) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 16 | Parameter Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Response Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Result | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, __u32 result, __u32 sn) { struct sctp_strreset_resp resp; __u16 length = sizeof(resp); struct sctp_chunk *retval; retval = sctp_make_reconf(asoc, length); if (!retval) return NULL; resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; resp.param_hdr.length = htons(length); resp.response_seq = htonl(sn); resp.result = htonl(result); sctp_addto_chunk(retval, sizeof(resp), &resp); return retval; } /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Parameter Type = 16 | Parameter Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Re-configuration Response Sequence Number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Result | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Sender's Next TSN (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Receiver's Next TSN (optional) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, __u32 result, __u32 sn, __u32 sender_tsn, __u32 receiver_tsn) { struct sctp_strreset_resptsn tsnresp; __u16 length = sizeof(tsnresp); struct sctp_chunk *retval; retval = sctp_make_reconf(asoc, length); if (!retval) return NULL; tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; tsnresp.param_hdr.length = htons(length); tsnresp.response_seq = htonl(sn); tsnresp.result = htonl(result); tsnresp.senders_next_tsn = htonl(sender_tsn); tsnresp.receivers_next_tsn = htonl(receiver_tsn); sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); return retval; } bool sctp_verify_reconf(const struct sctp_association *asoc, struct sctp_chunk *chunk, struct sctp_paramhdr **errp) { struct sctp_reconf_chunk *hdr; union sctp_params param; __be16 last = 0; __u16 cnt = 0; hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; sctp_walk_params(param, hdr) { __u16 length = ntohs(param.p->length); *errp = param.p; if (cnt++ > 2) return false; switch (param.p->type) { case SCTP_PARAM_RESET_OUT_REQUEST: if (length < sizeof(struct sctp_strreset_outreq) || (last && last != SCTP_PARAM_RESET_RESPONSE && last != SCTP_PARAM_RESET_IN_REQUEST)) return false; break; case SCTP_PARAM_RESET_IN_REQUEST: if (length < sizeof(struct sctp_strreset_inreq) || (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) return false; break; case SCTP_PARAM_RESET_RESPONSE: if ((length != sizeof(struct sctp_strreset_resp) && length != sizeof(struct sctp_strreset_resptsn)) || (last && last != SCTP_PARAM_RESET_RESPONSE && last != SCTP_PARAM_RESET_OUT_REQUEST)) return false; break; case SCTP_PARAM_RESET_TSN_REQUEST: if (length != sizeof(struct sctp_strreset_tsnreq) || last) return false; break; case SCTP_PARAM_RESET_ADD_IN_STREAMS: if (length != sizeof(struct sctp_strreset_addstrm) || (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) return false; break; case SCTP_PARAM_RESET_ADD_OUT_STREAMS: if (length != sizeof(struct sctp_strreset_addstrm) || (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) return false; break; default: return false; } last = param.p->type; } return true; }
¤ Dauer der Verarbeitung: 0.55 Sekunden (vorverarbeitet am 2026-04-28) ¤*© Formatika GbR, Deutschland |
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2026-05-26