diff options
Diffstat (limited to 'net/sctp/sm_make_chunk.c')
| -rw-r--r-- | net/sctp/sm_make_chunk.c | 3445 |
1 files changed, 3445 insertions, 0 deletions
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c new file mode 100644 index 00000000..a85eeeb5 --- /dev/null +++ b/net/sctp/sm_make_chunk.c @@ -0,0 +1,3445 @@ +/* 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. + * + * This SCTP implementation is free software; + * you can redistribute it and/or modify it under the terms of + * the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This SCTP implementation is distributed in the hope that it + * will be useful, but WITHOUT ANY WARRANTY; without even the implied + * ************************ + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU CC; see the file COPYING. If not, write to + * the Free Software Foundation, 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <lksctp-developers@lists.sourceforge.net> + * + * Or submit a bug report through the following website: + * http://www.sf.net/projects/lksctp + * + * Written or modified by: + * La Monte H.P. Yarroll <piggy@acm.org> + * Karl Knutson <karl@athena.chicago.il.us> + * 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> + * + * Any bugs reported given to us we will try to fix... any fixes shared will + * be incorporated into the next SCTP release. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/net.h> +#include <linux/inet.h> +#include <linux/scatterlist.h> +#include <linux/crypto.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> + +SCTP_STATIC +struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, + __u8 type, __u8 flags, int paylen); +static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + const struct sctp_chunk *init_chunk, + int *cookie_len, + const __u8 *raw_addrs, int addrs_len); +static int sctp_process_param(struct sctp_association *asoc, + union sctp_params param, + const union sctp_addr *peer_addr, + gfp_t gfp); +static void *sctp_addto_param(struct sctp_chunk *chunk, int len, + const void *data); + +/* What was the inbound interface for this chunk? */ +int sctp_chunk_iif(const struct sctp_chunk *chunk) +{ + struct sctp_af *af; + int iif = 0; + + af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); + if (af) + iif = af->skb_iif(chunk->skb); + + return iif; +} + +/* RFC 2960 3.3.2 Initiation (INIT) (1) + * + * Note 2: The ECN capable field is reserved for future use of + * Explicit Congestion Notification. + */ +static const struct sctp_paramhdr ecap_param = { + SCTP_PARAM_ECN_CAPABLE, + 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. + */ +void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, + size_t paylen) +{ + sctp_errhdr_t err; + __u16 len; + + /* Cause code constants are now defined in network order. */ + err.cause = cause_code; + len = sizeof(sctp_errhdr_t) + paylen; + err.length = htons(len); + chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); +} + +/* A helper to initialize an op error inside a + * provided chunk, as most cause codes will be embedded inside an + * abort chunk. Differs from sctp_init_cause in that it won't oops + * if there isn't enough space in the op error chunk + */ +int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, + size_t paylen) +{ + sctp_errhdr_t err; + __u16 len; + + /* Cause code constants are now defined in network order. */ + err.cause = cause_code; + len = sizeof(sctp_errhdr_t) + paylen; + err.length = htons(len); + + if (skb_tailroom(chunk->skb) < len) + return -ENOSPC; + chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, + sizeof(sctp_errhdr_t), + &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) +{ + sctp_inithdr_t init; + union sctp_params addrs; + size_t chunksize; + struct sctp_chunk *retval = NULL; + int num_types, addrs_len = 0; + struct sctp_sock *sp; + sctp_supported_addrs_param_t sat; + __be16 types[2]; + sctp_adaptation_ind_param_t aiparam; + sctp_supported_ext_param_t ext_param; + int num_ext = 0; + __u8 extensions[3]; + sctp_paramhdr_t *auth_chunks = NULL, + *auth_hmacs = NULL; + + /* RFC 2960 3.3.2 Initiation (INIT) (1) + * + * Note 1: The INIT chunks can contain multiple addresses that + * can be IPv4 and/or IPv6 in any combination. + */ + retval = NULL; + + /* Convert the provided bind address list to raw format. */ + addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); + + init.init_tag = htonl(asoc->c.my_vtag); + init.a_rwnd = htonl(asoc->rwnd); + init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); + init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); + init.initial_tsn = htonl(asoc->c.initial_tsn); + + /* How many address types are needed? */ + sp = sctp_sk(asoc->base.sk); + num_types = sp->pf->supported_addrs(sp, types); + + chunksize = sizeof(init) + addrs_len; + chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); + chunksize += sizeof(ecap_param); + + if (sctp_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 (sctp_addip_enable) { + extensions[num_ext] = SCTP_CID_ASCONF; + extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; + num_ext += 2; + } + + if (sp->adaptation_ind) + chunksize += sizeof(aiparam); + + chunksize += vparam_len; + + /* Account for AUTH related parameters */ + if (sctp_auth_enable) { + /* Add random parameter length*/ + chunksize += sizeof(asoc->c.auth_random); + + /* Add HMACS parameter length if any were defined */ + auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; + if (auth_hmacs->length) + chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); + else + auth_hmacs = NULL; + + /* Add CHUNKS parameter length */ + auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; + if (auth_chunks->length) + chunksize += WORD_ROUND(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 += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + + 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_chunk(asoc, SCTP_CID_INIT, 0, chunksize); + if (!retval) + goto nodata; + + retval->subh.init_hdr = + sctp_addto_chunk(retval, sizeof(init), &init); + retval->param_hdr.v = + sctp_addto_chunk(retval, addrs_len, addrs.v); + + /* RFC 2960 3.3.2 Initiation (INIT) (1) + * + * Note 4: This parameter, when present, specifies all the + * address types the sending endpoint can support. The absence + * of this parameter indicates that the sending endpoint can + * support any address type. + */ + sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; + sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); + sctp_addto_chunk(retval, sizeof(sat), &sat); + sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); + + sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); + + /* 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(sctp_supported_ext_param_t) + num_ext); + sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), + &ext_param); + sctp_addto_param(retval, num_ext, extensions); + } + + if (sctp_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 (sctp_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) +{ + sctp_inithdr_t initack; + struct sctp_chunk *retval; + union sctp_params addrs; + struct sctp_sock *sp; + int addrs_len; + sctp_cookie_param_t *cookie; + int cookie_len; + size_t chunksize; + sctp_adaptation_ind_param_t aiparam; + sctp_supported_ext_param_t ext_param; + int num_ext = 0; + __u8 extensions[3]; + sctp_paramhdr_t *auth_chunks = NULL, + *auth_hmacs = NULL, + *auth_random = NULL; + + retval = NULL; + + /* Note: there may be no addresses to embed. */ + addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); + + initack.init_tag = htonl(asoc->c.my_vtag); + initack.a_rwnd = htonl(asoc->rwnd); + initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); + initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); + initack.initial_tsn = htonl(asoc->c.initial_tsn); + + /* FIXME: We really ought to build the cookie right + * into the packet instead of allocating more fresh memory. + */ + cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, + addrs.v, addrs_len); + if (!cookie) + goto nomem_cookie; + + /* Calculate the total size of allocation, include the reserved + * space for reporting unknown parameters if it is specified. + */ + 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 (sp->adaptation_ind) + chunksize += sizeof(aiparam); + + if (asoc->peer.auth_capable) { + auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; + chunksize += ntohs(auth_random->length); + + auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; + if (auth_hmacs->length) + chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); + else + auth_hmacs = NULL; + + auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; + if (auth_chunks->length) + chunksize += WORD_ROUND(ntohs(auth_chunks->length)); + else + auth_chunks = NULL; + + extensions[num_ext] = SCTP_CID_AUTH; + num_ext += 1; + } + + if (num_ext) + chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + + num_ext); + + /* Now allocate and fill out the chunk. */ + retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); + 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.] + */ + retval->transport = chunk->transport; + + retval->subh.init_hdr = + sctp_addto_chunk(retval, sizeof(initack), &initack); + retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); + sctp_addto_chunk(retval, cookie_len, cookie); + if (asoc->peer.ecn_capable) + sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); + if (num_ext) { + ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; + ext_param.param_hdr.length = + htons(sizeof(sctp_supported_ext_param_t) + num_ext); + sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), + &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; + void *cookie; + int cookie_len; + + cookie = asoc->peer.cookie; + cookie_len = asoc->peer.cookie_len; + + /* Build a cookie echo chunk. */ + retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); + if (!retval) + goto nodata; + retval->subh.cookie_hdr = + sctp_addto_chunk(retval, cookie_len, cookie); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [COOKIE ECHO back to where the INIT ACK came from.] + */ + if (chunk) + retval->transport = chunk->transport; + +nodata: + return retval; +} + +/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): + * + * This chunk is used only during the initialization of an + * association. It is used to acknowledge the receipt of a COOKIE + * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent + * within the association, but MAY be bundled with one or more DATA + * chunks or SACK chunk in the same SCTP packet. + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 11 |Chunk Flags | Length = 4 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Chunk Flags: 8 bits + * + * Set to zero on transmit and ignored on receipt. + */ +struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, + const struct sctp_chunk *chunk) +{ + struct sctp_chunk *retval; + + retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [COOKIE ACK back to where the COOKIE ECHO came from.] + */ + if (retval && chunk) + retval->transport = chunk->transport; + + return retval; +} + +/* + * Appendix A: Explicit Congestion Notification: + * CWR: + * + * RFC 2481 details a specific bit for a sender to send in the header of + * its next outbound TCP segment to indicate to its peer that it has + * reduced its congestion window. This is termed the CWR bit. For + * SCTP the same indication is made by including the CWR chunk. + * This chunk contains one data element, i.e. the TSN number that + * was sent in the ECNE chunk. This element represents the lowest + * TSN number in the datagram that was originally marked with the + * CE bit. + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Lowest TSN Number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Note: The CWR is considered a Control chunk. + */ +struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, + const __u32 lowest_tsn, + const struct sctp_chunk *chunk) +{ + struct sctp_chunk *retval; + sctp_cwrhdr_t cwr; + + cwr.lowest_tsn = htonl(lowest_tsn); + retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, + sizeof(sctp_cwrhdr_t)); + + if (!retval) + goto nodata; + + retval->subh.ecn_cwr_hdr = + sctp_addto_chunk(retval, sizeof(cwr), &cwr); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [Report a reduced congestion window back to where the ECNE + * came from.] + */ + if (chunk) + retval->transport = chunk->transport; + +nodata: + return retval; +} + +/* Make an ECNE chunk. This is a congestion experienced report. */ +struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, + const __u32 lowest_tsn) +{ + struct sctp_chunk *retval; + sctp_ecnehdr_t ecne; + + ecne.lowest_tsn = htonl(lowest_tsn); + retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, + sizeof(sctp_ecnehdr_t)); + if (!retval) + goto nodata; + retval->subh.ecne_hdr = + sctp_addto_chunk(retval, sizeof(ecne), &ecne); + +nodata: + return retval; +} + +/* Make a DATA chunk for the given association from the provided + * parameters. However, do not populate the data payload. + */ +struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, + const struct sctp_sndrcvinfo *sinfo, + int data_len, __u8 flags, __u16 ssn) +{ + struct sctp_chunk *retval; + struct sctp_datahdr dp; + int chunk_len; + + /* We assign the TSN as LATE as possible, not here when + * creating the chunk. + */ + dp.tsn = 0; + dp.stream = htons(sinfo->sinfo_stream); + dp.ppid = sinfo->sinfo_ppid; + + /* Set the flags for an unordered send. */ + if (sinfo->sinfo_flags & SCTP_UNORDERED) { + flags |= SCTP_DATA_UNORDERED; + dp.ssn = 0; + } else + dp.ssn = htons(ssn); + + chunk_len = sizeof(dp) + data_len; + retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); + if (!retval) + goto nodata; + + retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); + memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); + +nodata: + return retval; +} + +/* Create a selective ackowledgement (SACK) for the given + * association. This reports on which TSN's we've seen to date, + * including duplicates and gaps. + */ +struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) +{ + struct sctp_chunk *retval; + struct sctp_sackhdr sack; + int len; + __u32 ctsn; + __u16 num_gabs, num_dup_tsns; + struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; + struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; + + memset(gabs, 0, sizeof(gabs)); + ctsn = sctp_tsnmap_get_ctsn(map); + SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); + + /* How much room is needed in the chunk? */ + num_gabs = sctp_tsnmap_num_gabs(map, 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_chunk(asoc, SCTP_CID_SACK, 0, len); + if (!retval) + goto nodata; + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, etc.) to the same destination transport + * address from which it received the DATA or control chunk to + * which it is replying. This rule should also be followed if + * the endpoint is bundling DATA chunks together with the + * reply chunk. + * + * However, when acknowledging multiple DATA chunks received + * in packets from different source addresses in a single + * SACK, the SACK chunk may be transmitted to one of the + * destination transport addresses from which the DATA or + * control chunks being acknowledged were received. + * + * [BUG: We do not implement the following paragraph. + * Perhaps we should remember the last transport we used for a + * SACK and avoid that (if possible) if we have seen any + * duplicates. --piggy] + * + * When a receiver of a duplicate DATA chunk sends a SACK to a + * multi- homed endpoint it MAY be beneficial to vary the + * destination address and not use the source address of the + * DATA chunk. The reason being that receiving a duplicate + * from a multi-homed endpoint might indicate that the return + * path (as specified in the source address of the DATA chunk) + * for the SACK is broken. + * + * [Send to the address from which we last received a DATA chunk.] + */ + retval->transport = asoc->peer.last_data_from; + + retval->subh.sack_hdr = + sctp_addto_chunk(retval, sizeof(sack), &sack); + + /* Add the gap ack block information. */ + if (num_gabs) + sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, + gabs); + + /* Add the duplicate TSN information. */ + if (num_dup_tsns) + sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, + sctp_tsnmap_get_dups(map)); + +nodata: + return retval; +} + +/* Make a SHUTDOWN chunk. */ +struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, + const struct sctp_chunk *chunk) +{ + struct sctp_chunk *retval; + sctp_shutdownhdr_t shut; + __u32 ctsn; + + ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); + shut.cum_tsn_ack = htonl(ctsn); + + retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, + sizeof(sctp_shutdownhdr_t)); + if (!retval) + goto nodata; + + retval->subh.shutdown_hdr = + sctp_addto_chunk(retval, sizeof(shut), &shut); + + if (chunk) + retval->transport = chunk->transport; +nodata: + return retval; +} + +struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, + const struct sctp_chunk *chunk) +{ + struct sctp_chunk *retval; + + retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [ACK back to where the SHUTDOWN came from.] + */ + if (retval && chunk) + retval->transport = chunk->transport; + + return retval; +} + +struct sctp_chunk *sctp_make_shutdown_complete( + const struct sctp_association *asoc, + const struct sctp_chunk *chunk) +{ + struct sctp_chunk *retval; + __u8 flags = 0; + + /* Set the T-bit if we have no association (vtag will be + * reflected) + */ + flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; + + retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK + * came from.] + */ + if (retval && chunk) + retval->transport = chunk->transport; + + return retval; +} + +/* Create an ABORT. Note that we set the T bit if we have no + * association, except when responding to an INIT (sctpimpguide 2.41). + */ +struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, + const struct sctp_chunk *chunk, + const size_t hint) +{ + struct sctp_chunk *retval; + __u8 flags = 0; + + /* Set the T-bit if we have no association and 'chunk' is not + * an INIT (vtag will be reflected). + */ + if (!asoc) { + if (chunk && chunk->chunk_hdr && + chunk->chunk_hdr->type == SCTP_CID_INIT) + flags = 0; + else + flags = SCTP_CHUNK_FLAG_T; + } + + retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [ABORT back to where the offender came from.] + */ + if (retval && chunk) + retval->transport = chunk->transport; + + return retval; +} + +/* Helper to create ABORT with a NO_USER_DATA error. */ +struct sctp_chunk *sctp_make_abort_no_data( + const struct sctp_association *asoc, + const struct sctp_chunk *chunk, __u32 tsn) +{ + struct sctp_chunk *retval; + __be32 payload; + + retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + + sizeof(tsn)); + + if (!retval) + goto no_mem; + + /* Put the tsn back into network byte order. */ + payload = htonl(tsn); + sctp_init_cause(retval, SCTP_ERROR_NO_DATA, 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, + const struct msghdr *msg, + size_t paylen) +{ + struct sctp_chunk *retval; + void *payload = NULL; + int err; + + retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); + if (!retval) + goto err_chunk; + + if (paylen) { + /* Put the msg_iov together into payload. */ + payload = kmalloc(paylen, GFP_KERNEL); + if (!payload) + goto err_payload; + + err = memcpy_fromiovec(payload, msg->msg_iov, paylen); + if (err < 0) + goto err_copy; + } + + sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, 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) +{ + void *target; + int chunklen = ntohs(chunk->chunk_hdr->length); + + 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(sctp_errhdr_t) + paylen + + sizeof(sctp_paramhdr_t)); + if (!retval) + goto end; + + sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + + sizeof(sctp_paramhdr_t)); + + phdr.type = htons(chunk->chunk_hdr->type); + phdr.length = chunk->chunk_hdr->length; + sctp_addto_chunk(retval, paylen, payload); + sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &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) +{ + struct sctp_chunk *retval; + static const char error[] = "The following parameter had invalid length:"; + size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + + sizeof(sctp_paramhdr_t); + + retval = sctp_make_abort(asoc, chunk, payload_len); + if (!retval) + goto nodata; + + sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, + sizeof(error) + sizeof(sctp_paramhdr_t)); + sctp_addto_chunk(retval, sizeof(error), error); + sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); + +nodata: + return retval; +} + +/* Make a HEARTBEAT chunk. */ +struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, + const struct sctp_transport *transport) +{ + struct sctp_chunk *retval; + sctp_sender_hb_info_t hbinfo; + + retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); + + if (!retval) + goto nodata; + + hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; + hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); + hbinfo.daddr = transport->ipaddr; + hbinfo.sent_at = jiffies; + hbinfo.hb_nonce = transport->hb_nonce; + + /* 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); + +nodata: + return retval; +} + +struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, + const struct sctp_chunk *chunk, + const void *payload, const size_t paylen) +{ + struct sctp_chunk *retval; + + retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); + if (!retval) + goto nodata; + + retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it * received the DATA or control chunk + * to which it is replying. + * + * [HBACK back to where the HEARTBEAT came from.] + */ + if (chunk) + retval->transport = chunk->transport; + +nodata: + return retval; +} + +/* Create an Operation Error chunk with the specified space reserved. + * This routine can be used for containing multiple causes in the chunk. + */ +static struct sctp_chunk *sctp_make_op_error_space( + const struct sctp_association *asoc, + const struct sctp_chunk *chunk, + size_t size) +{ + struct sctp_chunk *retval; + + retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, + sizeof(sctp_errhdr_t) + size); + if (!retval) + goto nodata; + + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, etc.) to the same destination transport + * address from which it received the DATA or control chunk + * to which it is replying. + * + */ + if (chunk) + retval->transport = chunk->transport; + +nodata: + return retval; +} + +/* Create an Operation Error chunk of a fixed size, + * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) + * This is a helper function to allocate an error chunk for + * for those invalid parameter codes in which we may not want + * to report all the errors, if the incomming chunk is large + */ +static inline struct sctp_chunk *sctp_make_op_error_fixed( + const struct sctp_association *asoc, + const struct sctp_chunk *chunk) +{ + size_t size = asoc ? asoc->pathmtu : 0; + + if (!size) + size = SCTP_DEFAULT_MAXSEGMENT; + + 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) +{ + struct sctp_chunk *retval; + struct sctp_hmac *hmac_desc; + struct sctp_authhdr auth_hdr; + __u8 *hmac; + + /* 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_chunk(asoc, SCTP_CID_AUTH, 0, + hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); + if (!retval) + return NULL; + + auth_hdr.hmac_id = htons(hmac_desc->hmac_id); + auth_hdr.shkey_id = htons(asoc->active_key_id); + + retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), + &auth_hdr); + + hmac = skb_put(retval->skb, hmac_desc->hmac_len); + memset(hmac, 0, 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[]. + */ +struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, + const struct sctp_association *asoc, + struct sock *sk) +{ + struct sctp_chunk *retval; + + retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); + + if (!retval) + goto nodata; + + if (!sk) { + SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); + } + + INIT_LIST_HEAD(&retval->list); + retval->skb = skb; + retval->asoc = (struct sctp_association *)asoc; + retval->has_tsn = 0; + retval->has_ssn = 0; + retval->rtt_in_progress = 0; + retval->sent_at = 0; + retval->singleton = 1; + retval->end_of_packet = 0; + retval->ecn_ce_done = 0; + retval->pdiscard = 0; + + /* sctpimpguide-05.txt Section 2.8.2 + * M1) Each time a new DATA chunk is transmitted + * set the 'TSN.Missing.Report' count for that TSN to 0. The + * 'TSN.Missing.Report' count will be used to determine missing chunks + * and when to fast retransmit. + */ + retval->tsn_missing_report = 0; + retval->tsn_gap_acked = 0; + retval->fast_retransmit = SCTP_CAN_FRTX; + + /* If this is a fragmented message, track all fragments + * of the message (for SEND_FAILED). + */ + retval->msg = NULL; + + /* Polish the bead hole. */ + INIT_LIST_HEAD(&retval->transmitted_list); + INIT_LIST_HEAD(&retval->frag_list); + SCTP_DBG_OBJCNT_INC(chunk); + atomic_set(&retval->refcnt, 1); + +nodata: + return retval; +} + +/* Set chunk->source and dest based on the IP header in chunk->skb. */ +void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, + union sctp_addr *dest) +{ + memcpy(&chunk->source, src, sizeof(union sctp_addr)); + 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. + */ +SCTP_STATIC +struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, + __u8 type, __u8 flags, int paylen) +{ + struct sctp_chunk *retval; + sctp_chunkhdr_t *chunk_hdr; + struct sk_buff *skb; + struct sock *sk; + + /* No need to allocate LL here, as this is only a chunk. */ + skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), + GFP_ATOMIC); + if (!skb) + goto nodata; + + /* Make room for the chunk header. */ + chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); + chunk_hdr->type = type; + chunk_hdr->flags = flags; + chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); + + sk = asoc ? asoc->base.sk : NULL; + retval = sctp_chunkify(skb, asoc, sk); + if (!retval) { + kfree_skb(skb); + goto nodata; + } + + retval->chunk_hdr = chunk_hdr; + retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); + + /* Determine if the chunk needs to be authenticated */ + if (sctp_auth_send_cid(type, asoc)) + retval->auth = 1; + + /* Set the skb to the belonging sock for accounting. */ + skb->sk = sk; + + return retval; +nodata: + return NULL; +} + + +/* Release the memory occupied by a chunk. */ +static void sctp_chunk_destroy(struct sctp_chunk *chunk) +{ + BUG_ON(!list_empty(&chunk->list)); + list_del_init(&chunk->transmitted_list); + + /* Free the chunk skb data and the SCTP_chunk stub itself. */ + dev_kfree_skb(chunk->skb); + + SCTP_DBG_OBJCNT_DEC(chunk); + kmem_cache_free(sctp_chunk_cachep, chunk); +} + +/* Possibly, free the chunk. */ +void sctp_chunk_free(struct sctp_chunk *chunk) +{ + /* Release our reference on the message tracker. */ + if (chunk->msg) + sctp_datamsg_put(chunk->msg); + + sctp_chunk_put(chunk); +} + +/* Grab a reference to the chunk. */ +void sctp_chunk_hold(struct sctp_chunk *ch) +{ + atomic_inc(&ch->refcnt); +} + +/* Release a reference to the chunk. */ +void sctp_chunk_put(struct sctp_chunk *ch) +{ + if (atomic_dec_and_test(&ch->refcnt)) + sctp_chunk_destroy(ch); +} + +/* Append bytes to the end of a chunk. Will panic if chunk is not big + * enough. + */ +void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) +{ + void *target; + void *padding; + int chunklen = ntohs(chunk->chunk_hdr->length); + int padlen = WORD_ROUND(chunklen) - chunklen; + + padding = skb_put(chunk->skb, padlen); + target = skb_put(chunk->skb, len); + + memset(padding, 0, padlen); + memcpy(target, data, len); + + /* Adjust the chunk length field. */ + chunk->chunk_hdr->length = htons(chunklen + padlen + len); + chunk->chunk_end = skb_tail_pointer(chunk->skb); + + return target; +} + +/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient + * space in the chunk + */ +void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, + int len, const void *data) +{ + if (skb_tailroom(chunk->skb) >= len) + return sctp_addto_chunk(chunk, len, data); + else + return NULL; +} + +/* Append bytes from user space to the end of a chunk. Will panic if + * chunk is not big enough. + * Returns a kernel err value. + */ +int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, + struct iovec *data) +{ + __u8 *target; + int err = 0; + + /* Make room in chunk for data. */ + target = skb_put(chunk->skb, len); + + /* Copy data (whole iovec) into chunk */ + if ((err = memcpy_fromiovecend(target, data, off, len))) + goto out; + + /* Adjust the chunk length field. */ + chunk->chunk_hdr->length = + htons(ntohs(chunk->chunk_hdr->length) + len); + chunk->chunk_end = skb_tail_pointer(chunk->skb); + +out: + return err; +} + +/* Helper function to assign a TSN if needed. This assumes that both + * the data_hdr and association have already been assigned. + */ +void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) +{ + struct sctp_datamsg *msg; + struct sctp_chunk *lchunk; + struct sctp_stream *stream; + __u16 ssn; + __u16 sid; + + if (chunk->has_ssn) + return; + + /* All fragments will be on the same stream */ + sid = ntohs(chunk->subh.data_hdr->stream); + stream = &chunk->asoc->ssnmap->out; + + /* 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, sid); + else + ssn = sctp_ssn_peek(stream, 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; + struct sk_buff *skb; + sctp_scope_t scope; + struct sctp_af *af; + + /* Create the bare association. */ + scope = sctp_scope(sctp_source(chunk)); + asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); + if (!asoc) + goto nodata; + asoc->temp = 1; + skb = chunk->skb; + /* Create an entry for the source address of the packet. */ + af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); + if (unlikely(!af)) + goto fail; + af->from_skb(&asoc->c.peer_addr, skb, 1); +nodata: + return asoc; + +fail: + sctp_association_free(asoc); + return NULL; +} + +/* Build a cookie representing asoc. + * This INCLUDES the param header needed to put the cookie in the INIT ACK. + */ +static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + const struct sctp_chunk *init_chunk, + int *cookie_len, + const __u8 *raw_addrs, int addrs_len) +{ + sctp_cookie_param_t *retval; + struct sctp_signed_cookie *cookie; + struct scatterlist sg; + int headersize, bodysize; + unsigned int keylen; + char *key; + + /* Header size is static data prior to the actual cookie, including + * any padding. + */ + headersize = sizeof(sctp_paramhdr_t) + + (sizeof(struct sctp_signed_cookie) - + sizeof(struct sctp_cookie)); + bodysize = sizeof(struct sctp_cookie) + + ntohs(init_chunk->chunk_hdr->length) + addrs_len; + + /* Pad out the cookie to a multiple to make the signature + * functions simpler to write. + */ + if (bodysize % SCTP_COOKIE_MULTIPLE) + bodysize += SCTP_COOKIE_MULTIPLE + - (bodysize % SCTP_COOKIE_MULTIPLE); + *cookie_len = headersize + bodysize; + + /* 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. */ + do_gettimeofday(&cookie->c.expiration); + TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); + + /* Copy the peer's init packet. */ + memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, + ntohs(init_chunk->chunk_hdr->length)); + + /* Copy the raw local address list of the association. */ + memcpy((__u8 *)&cookie->c.peer_init[0] + + ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); + + if (sctp_sk(ep->base.sk)->hmac) { + struct hash_desc desc; + + /* Sign the message. */ + sg_init_one(&sg, &cookie->c, bodysize); + keylen = SCTP_SECRET_SIZE; + key = (char *)ep->secret_key[ep->current_key]; + desc.tfm = sctp_sk(ep->base.sk)->hmac; + desc.flags = 0; + + if (crypto_hash_setkey(desc.tfm, key, keylen) || + crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) + goto free_cookie; + } + + return retval; + +free_cookie: + kfree(retval); +nodata: + *cookie_len = 0; + return NULL; +} + +/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ +struct sctp_association *sctp_unpack_cookie( + const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + struct sctp_chunk *chunk, gfp_t gfp, + int *error, struct sctp_chunk **errp) +{ + struct sctp_association *retval = NULL; + struct sctp_signed_cookie *cookie; + struct sctp_cookie *bear_cookie; + int headersize, bodysize, fixed_size; + __u8 *digest = ep->digest; + struct scatterlist sg; + unsigned int keylen, len; + char *key; + sctp_scope_t scope; + struct sk_buff *skb = chunk->skb; + struct timeval tv; + struct hash_desc desc; + + /* Header size is static data prior to the actual cookie, including + * any padding. + */ + headersize = sizeof(sctp_chunkhdr_t) + + (sizeof(struct sctp_signed_cookie) - + sizeof(struct sctp_cookie)); + bodysize = ntohs(chunk->chunk_hdr->length) - headersize; + fixed_size = headersize + sizeof(struct sctp_cookie); + + /* Verify that the chunk looks like it even has a cookie. + * There must be enough room for our cookie and our peer's + * INIT chunk. + */ + len = ntohs(chunk->chunk_hdr->length); + if (len < fixed_size + sizeof(struct sctp_chunkhdr)) + goto malformed; + + /* Verify that the cookie has been padded out. */ + if (bodysize % SCTP_COOKIE_MULTIPLE) + goto malformed; + + /* Process the cookie. */ + cookie = chunk->subh.cookie_hdr; + bear_cookie = &cookie->c; + + if (!sctp_sk(ep->base.sk)->hmac) + goto no_hmac; + + /* Check the signature. */ + keylen = SCTP_SECRET_SIZE; + sg_init_one(&sg, bear_cookie, bodysize); + key = (char *)ep->secret_key[ep->current_key]; + desc.tfm = sctp_sk(ep->base.sk)->hmac; + desc.flags = 0; + + memset(digest, 0x00, SCTP_SIGNATURE_SIZE); + if (crypto_hash_setkey(desc.tfm, key, keylen) || + crypto_hash_digest(&desc, &sg, bodysize, digest)) { + *error = -SCTP_IERROR_NOMEM; + goto fail; + } + + if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { + /* Try the previous key. */ + key = (char *)ep->secret_key[ep->last_key]; + memset(digest, 0x00, SCTP_SIGNATURE_SIZE); + if (crypto_hash_setkey(desc.tfm, key, keylen) || + crypto_hash_digest(&desc, &sg, bodysize, digest)) { + *error = -SCTP_IERROR_NOMEM; + goto fail; + } + + if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { + /* Yikes! Still bad signature! */ + *error = -SCTP_IERROR_BAD_SIG; + goto fail; + } + } + +no_hmac: + /* IG Section 2.35.2: + * 3) Compare the port numbers and the verification tag contained + * within the COOKIE ECHO chunk to the actual port numbers and the + * verification tag within the SCTP common header of the received + * packet. If these values do not match the packet MUST be silently + * discarded, + */ + if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { + *error = -SCTP_IERROR_BAD_TAG; + goto fail; + } + + if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || + ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { + *error = -SCTP_IERROR_BAD_PORTS; + goto fail; + } + + /* Check to see if the cookie is stale. If there is already + * an association, there is no need to check cookie's expiration + * for init collision case of lost COOKIE ACK. + * If skb has been timestamped, then use the stamp, otherwise + * use current time. This introduces a small possibility that + * that a cookie may be considered expired, but his would only slow + * down the new association establishment instead of every packet. + */ + if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) + skb_get_timestamp(skb, &tv); + else + do_gettimeofday(&tv); + + if (!asoc && tv_lt(bear_cookie->expiration, tv)) { + /* + * Section 3.3.10.3 Stale Cookie Error (3) + * + * Cause of error + * --------------- + * Stale Cookie Error: Indicates the receipt of a valid State + * Cookie that has expired. + */ + len = ntohs(chunk->chunk_hdr->length); + *errp = sctp_make_op_error_space(asoc, chunk, len); + if (*errp) { + suseconds_t usecs = (tv.tv_sec - + bear_cookie->expiration.tv_sec) * 1000000L + + tv.tv_usec - bear_cookie->expiration.tv_usec; + __be32 n = htonl(usecs); + + sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, + sizeof(n)); + sctp_addto_chunk(*errp, sizeof(n), &n); + *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, + 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->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, + sctp_param_t paramtype, + struct sctp_chunk *chunk, + struct sctp_chunk **errp) +{ + struct __sctp_missing report; + __u16 len; + + len = WORD_ROUND(sizeof(report)); + + /* Make an ERROR chunk, preparing enough room for + * returning multiple unknown parameters. + */ + if (!*errp) + *errp = sctp_make_op_error_space(asoc, chunk, len); + + if (*errp) { + report.num_missing = htonl(1); + report.type = paramtype; + sctp_init_cause(*errp, SCTP_ERROR_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_space(asoc, chunk, len); + + if (*errp) { + sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); + sctp_addto_chunk(*errp, len, param.v); + } + + /* Stop processing this chunk. */ + return 0; +} + +static int sctp_verify_ext_param(union sctp_params param) +{ + __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); + int have_auth = 0; + int have_asconf = 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 (sctp_addip_noauth) + return 1; + + if (sctp_addip_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(sctp_paramhdr_t); + int i; + + for (i = 0; i < num_ext; i++) { + switch (param.ext->chunks[i]) { + case SCTP_CID_FWD_TSN: + if (sctp_prsctp_enable && + !asoc->peer.prsctp_capable) + asoc->peer.prsctp_capable = 1; + break; + case SCTP_CID_AUTH: + /* if the peer reports AUTH, assume that he + * supports AUTH. + */ + if (sctp_auth_enable) + asoc->peer.auth_capable = 1; + break; + case SCTP_CID_ASCONF: + case SCTP_CID_ASCONF_ACK: + if (sctp_addip_enable) + asoc->peer.asconf_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 sctp_ierror_t 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; + /* Fall through */ + case SCTP_PARAM_ACTION_SKIP_ERR: + /* Make an ERROR chunk, preparing enough room for + * returning multiple unknown parameters. + */ + if (NULL == *errp) + *errp = sctp_make_op_error_fixed(asoc, chunk); + + if (*errp) { + if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, + WORD_ROUND(ntohs(param.p->length)))) + sctp_addto_chunk_fixed(*errp, + WORD_ROUND(ntohs(param.p->length)), + param.v); + } else { + /* If there is no memory for generating the ERROR + * report as specified, an ABORT will be triggered + * to the peer and the association won't be + * established. + */ + retval = SCTP_IERROR_NOMEM; + } + 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 sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc, + union sctp_params param, + sctp_cid_t cid, + struct sctp_chunk *chunk, + struct sctp_chunk **err_chunk) +{ + 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(param)) + return SCTP_IERROR_ABORT; + break; + + case SCTP_PARAM_SET_PRIMARY: + if (sctp_addip_enable) + break; + goto fallthrough; + + case SCTP_PARAM_HOST_NAME_ADDRESS: + /* Tell the peer, we won't support this param. */ + sctp_process_hn_param(asoc, param, chunk, err_chunk); + retval = SCTP_IERROR_ABORT; + break; + + case SCTP_PARAM_FWD_TSN_SUPPORT: + if (sctp_prsctp_enable) + break; + goto fallthrough; + + case SCTP_PARAM_RANDOM: + if (!sctp_auth_enable) + goto fallthrough; + + /* 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(sctp_paramhdr_t)) { + sctp_process_inv_paramlength(asoc, param.p, + chunk, err_chunk); + retval = SCTP_IERROR_ABORT; + } + break; + + case SCTP_PARAM_CHUNKS: + if (!sctp_auth_enable) + goto fallthrough; + + /* 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 (!sctp_auth_enable) + goto fallthrough; + + hmacs = (struct sctp_hmac_algo_param *)param.p; + n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 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; +fallthrough: + default: + SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", + 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(const struct sctp_association *asoc, + sctp_cid_t cid, + sctp_init_chunk_t *peer_init, + struct sctp_chunk *chunk, + struct sctp_chunk **errp) +{ + union sctp_params param; + int has_cookie = 0; + int result; + + /* Verify stream values are non-zero. */ + if ((0 == peer_init->init_hdr.num_outbound_streams) || + (0 == peer_init->init_hdr.num_inbound_streams) || + (0 == peer_init->init_hdr.init_tag) || + (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { + + return sctp_process_inv_mandatory(asoc, chunk, errp); + } + + /* Check for missing mandatory parameters. */ + sctp_walk_params(param, peer_init, init_hdr.params) { + + if (SCTP_PARAM_STATE_COOKIE == param.p->type) + has_cookie = 1; + + } /* for (loop through all parameters) */ + + /* There is a possibility that a parameter length was bad and + * in that case we would have stoped walking the parameters. + * The current param.p would point at the bad one. + * Current consensus on the mailing list is to generate a PROTOCOL + * VIOLATION error. We build the ERROR chunk here and let the normal + * error handling code build and send the packet. + */ + if (param.v != (void*)chunk->chunk_end) + 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, init_hdr.params) { + + result = sctp_verify_param(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, + sctp_init_chunk_t *peer_init, gfp_t gfp) +{ + union sctp_params param; + struct sctp_transport *transport; + struct list_head *pos, *temp; + struct sctp_af *af; + union sctp_addr addr; + char *cookie; + 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 a better choice than any of the embedded addresses. + */ + 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, init_hdr.params) { + 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)); + af->from_addr_param(&addr, param.addr, + chunk->sctp_hdr->source, 0); + 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 (!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); + + /* Apply the upper bounds for output streams based on peer's + * number of inbound streams. + */ + if (asoc->c.sinit_num_ostreams > + ntohs(peer_init->init_hdr.num_inbound_streams)) { + asoc->c.sinit_num_ostreams = + ntohs(peer_init->init_hdr.num_inbound_streams); + } + + if (asoc->c.sinit_max_instreams > + ntohs(peer_init->init_hdr.num_outbound_streams)) { + asoc->c.sinit_max_instreams = + ntohs(peer_init->init_hdr.num_outbound_streams); + } + + /* Copy Initiation tag from INIT to VT_peer in cookie. */ + asoc->c.peer_vtag = asoc->peer.i.init_tag; + + /* Peer Rwnd : Current calculated value of the peer's rwnd. */ + asoc->peer.rwnd = asoc->peer.i.a_rwnd; + + /* Copy cookie in case we need to resend COOKIE-ECHO. */ + cookie = asoc->peer.cookie; + if (cookie) { + asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); + if (!asoc->peer.cookie) + goto clean_up; + } + + /* 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. + */ + + /* Allocate storage for the negotiated streams if it is not a temporary + * association. + */ + if (!asoc->temp) { + int error; + + asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, + asoc->c.sinit_num_ostreams, gfp); + if (!asoc->ssnmap) + goto clean_up; + + error = sctp_assoc_set_id(asoc, gfp); + if (error) + 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) +{ + union sctp_addr addr; + int i; + __u16 sat; + int retval = 1; + sctp_scope_t scope; + time_t stale; + struct sctp_af *af; + union sctp_addr_param *addr_param; + struct sctp_transport *t; + + /* 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)); + af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); + scope = sctp_scope(peer_addr); + if (sctp_in_scope(&addr, scope)) + if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) + return 0; + break; + + case SCTP_PARAM_COOKIE_PRESERVATIVE: + if (!sctp_cookie_preserve_enable) + break; + + stale = ntohl(param.life->lifespan_increment); + + /* Suggested Cookie Life span increment's unit is msec, + * (1/1000sec). + */ + asoc->cookie_life.tv_sec += stale / 1000; + asoc->cookie_life.tv_usec += (stale % 1000) * 1000; + break; + + case SCTP_PARAM_HOST_NAME_ADDRESS: + SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); + break; + + case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: + /* Turn off the default values first so we'll know which + * ones are really set by the peer. + */ + asoc->peer.ipv4_address = 0; + asoc->peer.ipv6_address = 0; + + /* 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(sctp_paramhdr_t); + if (sat) + sat /= sizeof(__u16); + + for (i = 0; i < sat; ++i) { + switch (param.sat->types[i]) { + case SCTP_PARAM_IPV4_ADDRESS: + asoc->peer.ipv4_address = 1; + break; + + case SCTP_PARAM_IPV6_ADDRESS: + if (PF_INET6 == asoc->base.sk->sk_family) + asoc->peer.ipv6_address = 1; + break; + + case SCTP_PARAM_HOST_NAME_ADDRESS: + asoc->peer.hostname_address = 1; + break; + + default: /* Just ignore anything else. */ + break; + } + } + break; + + case SCTP_PARAM_STATE_COOKIE: + asoc->peer.cookie_len = + ntohs(param.p->length) - sizeof(sctp_paramhdr_t); + asoc->peer.cookie = param.cookie->body; + break; + + case SCTP_PARAM_HEARTBEAT_INFO: + /* Would be odd to receive, but it causes no problems. */ + break; + + case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: + /* Rejected during verify stage. */ + break; + + case SCTP_PARAM_ECN_CAPABLE: + asoc->peer.ecn_capable = 1; + break; + + case SCTP_PARAM_ADAPTATION_LAYER_IND: + asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); + break; + + case SCTP_PARAM_SET_PRIMARY: + if (!sctp_addip_enable) + goto fall_through; + + addr_param = param.v + sizeof(sctp_addip_param_t); + + af = sctp_get_af_specific(param_type2af(param.p->type)); + af->from_addr_param(&addr, addr_param, + htons(asoc->peer.port), 0); + + /* if the address is invalid, we can't process it. + * XXX: see spec for what to do. + */ + 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 (sctp_prsctp_enable) { + asoc->peer.prsctp_capable = 1; + break; + } + /* Fall Through */ + goto fall_through; + + case SCTP_PARAM_RANDOM: + if (!sctp_auth_enable) + goto fall_through; + + /* Save peer's random parameter */ + 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 (!sctp_auth_enable) + goto fall_through; + + /* Save peer's HMAC list */ + 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 (!sctp_auth_enable) + goto fall_through; + + 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. + */ + SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", + ntohs(param.p->type), asoc); + break; + } + + return retval; +} + +/* Select a new verification tag. */ +__u32 sctp_generate_tag(const struct sctp_endpoint *ep) +{ + /* I believe that this random number generator complies with RFC1750. + * A tag of 0 is reserved for special cases (e.g. INIT). + */ + __u32 x; + + do { + get_random_bytes(&x, sizeof(__u32)); + } while (x == 0); + + return x; +} + +/* Select an initial TSN to send during startup. */ +__u32 sctp_generate_tsn(const struct sctp_endpoint *ep) +{ + __u32 retval; + + get_random_bytes(&retval, sizeof(__u32)); + return retval; +} + +/* + * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 0xC1 | Chunk Flags | Chunk Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Serial Number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Address Parameter | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF Parameter #1 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * \ \ + * / .... / + * \ \ + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF Parameter #N | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Address Parameter and other parameter will not be wrapped in this function + */ +static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, + union sctp_addr *addr, + int vparam_len) +{ + sctp_addiphdr_t asconf; + struct sctp_chunk *retval; + int length = sizeof(asconf) + vparam_len; + union sctp_addr_param addrparam; + int addrlen; + struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); + + addrlen = af->to_addr_param(addr, &addrparam); + if (!addrlen) + return NULL; + length += addrlen; + + /* Create the chunk. */ + retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); + if (!retval) + return NULL; + + asconf.serial = htonl(asoc->addip_serial++); + + retval->subh.addip_hdr = + sctp_addto_chunk(retval, sizeof(asconf), &asconf); + retval->param_hdr.v = + sctp_addto_chunk(retval, addrlen, &addrparam); + + return retval; +} + +/* ADDIP + * 3.2.1 Add IP Address + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 0xC001 | Length = Variable | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF-Request Correlation ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Address Parameter | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * 3.2.2 Delete IP Address + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 0xC002 | Length = Variable | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF-Request Correlation ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Address Parameter | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ +struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, + union sctp_addr *laddr, + struct sockaddr *addrs, + int addrcnt, + __be16 flags) +{ + sctp_addip_param_t param; + struct sctp_chunk *retval; + union sctp_addr_param addr_param; + union sctp_addr *addr; + void *addr_buf; + struct sctp_af *af; + int paramlen = sizeof(param); + int addr_param_len = 0; + int totallen = 0; + int i; + int del_pickup = 0; + + /* 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; + SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", 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 = 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 = 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) +{ + sctp_addip_param_t param; + struct sctp_chunk *retval; + int len = sizeof(param); + union sctp_addr_param addrparam; + int addrlen; + struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); + + addrlen = af->to_addr_param(addr, &addrparam); + if (!addrlen) + return NULL; + len += addrlen; + + /* Create the chunk and make asconf header. */ + retval = sctp_make_asconf(asoc, addr, len); + if (!retval) + return NULL; + + param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; + param.param_hdr.length = htons(len); + param.crr_id = 0; + + sctp_addto_chunk(retval, sizeof(param), ¶m); + sctp_addto_chunk(retval, addrlen, &addrparam); + + return retval; +} + +/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 0x80 | Chunk Flags | Chunk Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Serial Number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF Parameter Response#1 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * \ \ + * / .... / + * \ \ + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ASCONF Parameter Response#N | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Create an ASCONF_ACK chunk with enough space for the parameter responses. + */ +static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, + __u32 serial, int vparam_len) +{ + sctp_addiphdr_t asconf; + struct sctp_chunk *retval; + int length = sizeof(asconf) + vparam_len; + + /* Create the chunk. */ + retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); + if (!retval) + return NULL; + + asconf.serial = htonl(serial); + + retval->subh.addip_hdr = + sctp_addto_chunk(retval, sizeof(asconf), &asconf); + + return retval; +} + +/* Add response parameters to an ASCONF_ACK chunk. */ +static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, + __be16 err_code, sctp_addip_param_t *asconf_param) +{ + sctp_addip_param_t ack_param; + sctp_errhdr_t err_param; + int asconf_param_len = 0; + int err_param_len = 0; + __be16 response_type; + + if (SCTP_ERROR_NO_ERROR == err_code) { + response_type = SCTP_PARAM_SUCCESS_REPORT; + } else { + response_type = SCTP_PARAM_ERR_CAUSE; + err_param_len = sizeof(err_param); + if (asconf_param) + asconf_param_len = + ntohs(asconf_param->param_hdr.length); + } + + /* Add Success Indication or Error Cause Indication parameter. */ + ack_param.param_hdr.type = response_type; + ack_param.param_hdr.length = htons(sizeof(ack_param) + + err_param_len + + asconf_param_len); + ack_param.crr_id = crr_id; + sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); + + if (SCTP_ERROR_NO_ERROR == err_code) + return; + + /* Add Error Cause parameter. */ + err_param.cause = err_code; + err_param.length = htons(err_param_len + asconf_param_len); + sctp_addto_chunk(chunk, err_param_len, &err_param); + + /* Add the failed TLV copied from ASCONF chunk. */ + if (asconf_param) + sctp_addto_chunk(chunk, asconf_param_len, asconf_param); +} + +/* Process a asconf parameter. */ +static __be16 sctp_process_asconf_param(struct sctp_association *asoc, + struct sctp_chunk *asconf, + sctp_addip_param_t *asconf_param) +{ + struct sctp_transport *peer; + struct sctp_af *af; + union sctp_addr addr; + union sctp_addr_param *addr_param; + + addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); + + 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; + + af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); + + /* 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)); + + /* 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. */ + if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) + sctp_transport_hold(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); + } else + sctp_assoc_del_peer(asoc, &addr); + 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.v4, sctp_source(asconf), sizeof(addr)); + + 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. */ +int sctp_verify_asconf(const struct sctp_association *asoc, + struct sctp_paramhdr *param_hdr, void *chunk_end, + struct sctp_paramhdr **errp) { + sctp_addip_param_t *asconf_param; + union sctp_params param; + int length, plen; + + param.v = (sctp_paramhdr_t *) param_hdr; + while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { + length = ntohs(param.p->length); + *errp = param.p; + + if (param.v > chunk_end - length || + length < sizeof(sctp_paramhdr_t)) + return 0; + + switch (param.p->type) { + case SCTP_PARAM_ADD_IP: + case SCTP_PARAM_DEL_IP: + case SCTP_PARAM_SET_PRIMARY: + asconf_param = (sctp_addip_param_t *)param.v; + plen = ntohs(asconf_param->param_hdr.length); + if (plen < sizeof(sctp_addip_param_t) + + sizeof(sctp_paramhdr_t)) + return 0; + break; + case SCTP_PARAM_SUCCESS_REPORT: + case SCTP_PARAM_ADAPTATION_LAYER_IND: + if (length != sizeof(sctp_addip_param_t)) + return 0; + + break; + default: + break; + } + + param.v += WORD_ROUND(length); + } + + if (param.v != chunk_end) + return 0; + + return 1; +} + +/* Process an incoming ASCONF chunk with the next expected serial no. and + * return an ASCONF_ACK chunk to be sent in response. + */ +struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, + struct sctp_chunk *asconf) +{ + sctp_addiphdr_t *hdr; + union sctp_addr_param *addr_param; + sctp_addip_param_t *asconf_param; + struct sctp_chunk *asconf_ack; + + __be16 err_code; + int length = 0; + int chunk_len; + __u32 serial; + int all_param_pass = 1; + + chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); + hdr = (sctp_addiphdr_t *)asconf->skb->data; + serial = ntohl(hdr->serial); + + /* Skip the addiphdr and store a pointer to address parameter. */ + length = sizeof(sctp_addiphdr_t); + addr_param = (union sctp_addr_param *)(asconf->skb->data + length); + chunk_len -= length; + + /* Skip the address parameter and store a pointer to the first + * asconf parameter. + */ + length = ntohs(addr_param->p.length); + asconf_param = (void *)addr_param + length; + chunk_len -= length; + + /* create an ASCONF_ACK chunk. + * Based on the definitions of parameters, we know that the size of + * ASCONF_ACK parameters are less than or equal to the 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. */ + while (chunk_len > 0) { + err_code = sctp_process_asconf_param(asoc, asconf, + asconf_param); + /* ADDIP 4.1 A7) + * If an error response is received for a TLV parameter, + * all TLVs with no response before the failed TLV are + * considered successful if not reported. All TLVs after + * the failed response are considered unsuccessful unless + * a specific success indication is present for the parameter. + */ + if (SCTP_ERROR_NO_ERROR != err_code) + all_param_pass = 0; + + if (!all_param_pass) + sctp_add_asconf_response(asconf_ack, + asconf_param->crr_id, err_code, + asconf_param); + + /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add + * an IP address sends an 'Out of Resource' in its response, it + * MUST also fail any subsequent add or delete requests bundled + * in the ASCONF. + */ + if (SCTP_ERROR_RSRC_LOW == err_code) + goto done; + + /* Move to the next ASCONF param. */ + length = ntohs(asconf_param->param_hdr.length); + asconf_param = (void *)asconf_param + length; + chunk_len -= length; + } + +done: + asoc->peer.addip_serial++; + + /* If we are sending a new ASCONF_ACK hold a reference to it in assoc + * after freeing the reference to old asconf ack if any. + */ + if (asconf_ack) { + 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, + sctp_addip_param_t *asconf_param) +{ + struct sctp_af *af; + union sctp_addr addr; + struct sctp_bind_addr *bp = &asoc->base.bind_addr; + union sctp_addr_param *addr_param; + struct sctp_transport *transport; + struct sctp_sockaddr_entry *saddr; + + addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); + + /* We have checked the packet before, so we do not check again. */ + af = sctp_get_af_specific(param_type2af(addr_param->p.type)); + af->from_addr_param(&addr, addr_param, htons(bp->port), 0); + + 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) { + dst_release(transport->dst); + transport->dst = NULL; + } + 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) { + dst_release(transport->dst); + transport->dst = NULL; + } + 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, + sctp_addip_param_t *asconf_param, + int no_err) +{ + sctp_addip_param_t *asconf_ack_param; + sctp_errhdr_t *err_param; + int length; + int asconf_ack_len; + __be16 err_code; + + 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(sctp_chunkhdr_t); + + /* Skip the addiphdr from the asconf_ack chunk and store a pointer to + * the first asconf_ack parameter. + */ + length = sizeof(sctp_addiphdr_t); + asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + + length); + asconf_ack_len -= length; + + while (asconf_ack_len > 0) { + if (asconf_ack_param->crr_id == asconf_param->crr_id) { + switch(asconf_ack_param->param_hdr.type) { + case SCTP_PARAM_SUCCESS_REPORT: + return SCTP_ERROR_NO_ERROR; + case SCTP_PARAM_ERR_CAUSE: + length = sizeof(sctp_addip_param_t); + err_param = (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; + union sctp_addr_param *addr_param; + sctp_addip_param_t *asconf_param; + int length = 0; + int asconf_len = asconf->skb->len; + int all_param_pass = 0; + int no_err = 1; + int retval = 0; + __be16 err_code = SCTP_ERROR_NO_ERROR; + + /* Skip the chunkhdr and addiphdr from the last asconf sent and store + * a pointer to address parameter. + */ + length = sizeof(sctp_addip_chunk_t); + addr_param = (union sctp_addr_param *)(asconf->skb->data + length); + asconf_len -= length; + + /* Skip the address parameter in the last asconf sent and store a + * pointer to the first asconf 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(sctp_addiphdr_t)) + all_param_pass = 1; + + /* Process the TLVs contained in the last sent ASCONF chunk. */ + while (asconf_len > 0) { + if (all_param_pass) + err_code = SCTP_ERROR_NO_ERROR; + else { + err_code = sctp_get_asconf_response(asconf_ack, + asconf_param, + no_err); + if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) + no_err = 0; + } + + switch (err_code) { + case SCTP_ERROR_NO_ERROR: + 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_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); + + 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; +} |