patch-2.4.23 linux-2.4.23/net/sctp/sm_make_chunk.c
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- Lines: 2200
- Date:
2003-11-28 10:26:21.000000000 -0800
- Orig file:
linux-2.4.22/net/sctp/sm_make_chunk.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.22/net/sctp/sm_make_chunk.c linux-2.4.23/net/sctp/sm_make_chunk.c
@@ -0,0 +1,2199 @@
+/* SCTP kernel reference Implementation
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2002 Intel Corp.
+ * Copyright (c) 2001-2002 International Business Machines Corp.
+ *
+ * This file is part of the SCTP kernel reference Implementation
+ *
+ * This file includes part of the implementation of the add-IP extension,
+ * based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
+ * for the SCTP kernel reference Implementation.
+ *
+ * These functions work with the state functions in sctp_sm_statefuns.c
+ * to implement the state operations. These functions implement the
+ * steps which require modifying existing data structures.
+ *
+ * The SCTP reference implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * The SCTP reference implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING. If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ * lksctp developers <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>
+ *
+ * Any bugs reported given to us we will try to fix... any fixes shared will
+ * be incorporated into the next SCTP release.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <asm/scatterlist.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>
+
+/* What was the inbound interface for this chunk? */
+int sctp_chunk_iif(const struct sctp_chunk *chunk)
+{
+ struct sctp_af *af;
+ int iif = 0;
+
+ af = sctp_get_af_specific(ipver2af(chunk->skb->nh.iph->version));
+ if (af)
+ iif = af->skb_iif(chunk->skb);
+
+ return iif;
+}
+
+/* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 2: The ECN capable field is reserved for future use of
+ * Explicit Congestion Notification.
+ */
+static const sctp_ecn_capable_param_t ecap_param = {
+ {
+ SCTP_PARAM_ECN_CAPABLE,
+ __constant_htons(sizeof(sctp_ecn_capable_param_t)),
+ }
+};
+
+/* A helper to initialize to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk.
+ */
+void sctp_init_cause(sctp_chunk_t *chunk, __u16 cause_code,
+ const void *payload, size_t paylen)
+{
+ sctp_errhdr_t err;
+ int padlen;
+ __u16 len;
+
+ /* Cause code constants are now defined in network order. */
+ err.cause = cause_code;
+ len = sizeof(sctp_errhdr_t) + paylen;
+ padlen = len % 4;
+ err.length = htons(len);
+ len += padlen;
+ sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
+ chunk->subh.err_hdr = sctp_addto_chunk(chunk, paylen, payload);
+}
+
+/* 3.3.2 Initiation (INIT) (1)
+ *
+ * This chunk is used to initiate a SCTP association between two
+ * endpoints. The format of the INIT chunk is shown below:
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 1 | Chunk Flags | Chunk Length |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Initiate Tag |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Advertised Receiver Window Credit (a_rwnd) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Number of Outbound Streams | Number of Inbound Streams |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Initial TSN |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * \ \
+ * / Optional/Variable-Length Parameters /
+ * \ \
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *
+ * The INIT chunk contains the following parameters. Unless otherwise
+ * noted, each parameter MUST only be included once in the INIT chunk.
+ *
+ * Fixed Parameters Status
+ * ----------------------------------------------
+ * Initiate Tag Mandatory
+ * Advertised Receiver Window Credit Mandatory
+ * Number of Outbound Streams Mandatory
+ * Number of Inbound Streams Mandatory
+ * Initial TSN Mandatory
+ *
+ * Variable Parameters Status Type Value
+ * -------------------------------------------------------------
+ * IPv4 Address (Note 1) Optional 5
+ * IPv6 Address (Note 1) Optional 6
+ * Cookie Preservative Optional 9
+ * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
+ * Host Name Address (Note 3) Optional 11
+ * Supported Address Types (Note 4) Optional 12
+ */
+sctp_chunk_t *sctp_make_init(const struct sctp_association *asoc,
+ const sctp_bind_addr_t *bp,
+ int gfp, int vparam_len)
+{
+ sctp_inithdr_t init;
+ union sctp_params addrs;
+ size_t chunksize;
+ sctp_chunk_t *retval = NULL;
+ int num_types, addrs_len = 0;
+ struct sctp_opt *sp;
+ sctp_supported_addrs_param_t sat;
+ __u16 types[2];
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 1: The INIT chunks can contain multiple addresses that
+ * can be IPv4 and/or IPv6 in any combination.
+ */
+ retval = NULL;
+
+ /* Convert the provided bind address list to raw format. */
+ addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
+
+ init.init_tag = htonl(asoc->c.my_vtag);
+ init.a_rwnd = htonl(asoc->rwnd);
+ init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
+ init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
+ init.initial_tsn = htonl(asoc->c.initial_tsn);
+
+ /* How many address types are needed? */
+ sp = sctp_sk(asoc->base.sk);
+ num_types = sp->pf->supported_addrs(sp, types);
+
+ chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
+ chunksize += sizeof(ecap_param);
+ chunksize += vparam_len;
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 3: An INIT chunk MUST NOT contain more than one Host
+ * Name address parameter. Moreover, the sender of the INIT
+ * MUST NOT combine any other address types with the Host Name
+ * address in the INIT. The receiver of INIT MUST ignore any
+ * other address types if the Host Name address parameter is
+ * present in the received INIT chunk.
+ *
+ * PLEASE DO NOT FIXME [This version does not support Host Name.]
+ */
+
+ retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
+ if (!retval)
+ goto nodata;
+
+ retval->subh.init_hdr =
+ sctp_addto_chunk(retval, sizeof(init), &init);
+ retval->param_hdr.v =
+ sctp_addto_chunk(retval, addrs_len, addrs.v);
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 4: This parameter, when present, specifies all the
+ * address types the sending endpoint can support. The absence
+ * of this parameter indicates that the sending endpoint can
+ * support any address type.
+ */
+ sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
+ sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
+ sctp_addto_chunk(retval, sizeof(sat), &sat);
+ sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
+
+ sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
+nodata:
+ if (addrs.v)
+ kfree(addrs.v);
+ return retval;
+}
+
+sctp_chunk_t *sctp_make_init_ack(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ int gfp, int unkparam_len)
+{
+ sctp_inithdr_t initack;
+ sctp_chunk_t *retval;
+ union sctp_params addrs;
+ int addrs_len;
+ sctp_cookie_param_t *cookie;
+ int cookie_len;
+ size_t chunksize;
+
+ retval = NULL;
+
+ /* Note: there may be no addresses to embed. */
+ addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
+
+ initack.init_tag = htonl(asoc->c.my_vtag);
+ initack.a_rwnd = htonl(asoc->rwnd);
+ initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
+ initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
+ initack.initial_tsn = htonl(asoc->c.initial_tsn);
+
+ /* FIXME: We really ought to build the cookie right
+ * into the packet instead of allocating more fresh memory.
+ */
+ cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
+ addrs.v, addrs_len);
+ if (!cookie)
+ goto nomem_cookie;
+
+ /* Calculate the total size of allocation, include the reserved
+ * space for reporting unknown parameters if it is specified.
+ */
+ chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
+
+ /* Tell peer that we'll do ECN only if peer advertised such cap. */
+ if (asoc->peer.ecn_capable)
+ chunksize += sizeof(ecap_param);
+
+ /* Now allocate and fill out the chunk. */
+ retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
+ if (!retval)
+ goto nomem_chunk;
+
+ /* Per the advice in RFC 2960 6.4, send this reply to
+ * the source of the INIT packet.
+ */
+ retval->transport = chunk->transport;
+ retval->subh.init_hdr =
+ sctp_addto_chunk(retval, sizeof(initack), &initack);
+ retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
+ sctp_addto_chunk(retval, cookie_len, cookie);
+ if (asoc->peer.ecn_capable)
+ sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
+
+ /* We need to remove the const qualifier at this point. */
+ retval->asoc = (struct sctp_association *) asoc;
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [INIT ACK back to where the INIT came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+nomem_chunk:
+ kfree(cookie);
+nomem_cookie:
+ if (addrs.v)
+ 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.
+ */
+sctp_chunk_t *sctp_make_cookie_echo(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *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.
+ */
+sctp_chunk_t *sctp_make_cookie_ack(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *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.
+ */
+sctp_chunk_t *sctp_make_cwr(const struct sctp_association *asoc,
+ const __u32 lowest_tsn,
+ const sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *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. */
+sctp_chunk_t *sctp_make_ecne(const struct sctp_association *asoc,
+ const __u32 lowest_tsn)
+{
+ sctp_chunk_t *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.
+ */
+sctp_chunk_t *sctp_make_datafrag_empty(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ int data_len, __u8 flags, __u16 ssn)
+{
+ sctp_chunk_t *retval;
+ sctp_datahdr_t dp;
+ int chunk_len;
+
+ /* We assign the TSN as LATE as possible, not here when
+ * creating the chunk.
+ */
+ dp.tsn= 1000000; /* This marker is a debugging aid. */
+ dp.stream = htons(sinfo->sinfo_stream);
+ dp.ppid = htonl(sinfo->sinfo_ppid);
+ dp.ssn = htons(ssn);
+
+ /* Set the flags for an unordered send. */
+ if (sinfo->sinfo_flags & MSG_UNORDERED)
+ flags |= SCTP_DATA_UNORDERED;
+
+ 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;
+}
+
+/* Make a DATA chunk for the given association. Populate the data
+ * payload.
+ */
+sctp_chunk_t *sctp_make_datafrag(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ int data_len, const __u8 *data,
+ __u8 flags, __u16 ssn)
+{
+ sctp_chunk_t *retval;
+
+ retval = sctp_make_datafrag_empty(asoc, sinfo, data_len, flags, ssn);
+ if (retval)
+ sctp_addto_chunk(retval, data_len, data);
+
+ return retval;
+}
+
+/* Make a DATA chunk for the given association to ride on stream id
+ * 'stream', with a payload id of 'payload', and a body of 'data'.
+ */
+sctp_chunk_t *sctp_make_data(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ int data_len, const __u8 *data)
+{
+ sctp_chunk_t *retval = NULL;
+
+ retval = sctp_make_data_empty(asoc, sinfo, data_len);
+ if (retval)
+ sctp_addto_chunk(retval, data_len, data);
+ return retval;
+}
+
+/* Make a DATA chunk for the given association to ride on stream id
+ * 'stream', with a payload id of 'payload', and a body big enough to
+ * hold 'data_len' octets of data. We use this version when we need
+ * to build the message AFTER allocating memory.
+ */
+sctp_chunk_t *sctp_make_data_empty(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ int data_len)
+{
+ __u8 flags = SCTP_DATA_NOT_FRAG;
+
+ return sctp_make_datafrag_empty(asoc, sinfo, data_len, flags, 0);
+}
+
+/* Create a selective ackowledgement (SACK) for the given
+ * association. This reports on which TSN's we've seen to date,
+ * including duplicates and gaps.
+ */
+sctp_chunk_t *sctp_make_sack(const struct sctp_association *asoc)
+{
+ sctp_chunk_t *retval;
+ sctp_sackhdr_t sack;
+ sctp_gap_ack_block_t gab;
+ int length;
+ __u32 ctsn;
+ struct sctp_tsnmap_iter iter;
+ __u16 num_gabs, num_dup_tsns;
+ struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
+
+ ctsn = sctp_tsnmap_get_ctsn(map);
+ SCTP_DEBUG_PRINTK("sackCTSNAck sent is 0x%x.\n", ctsn);
+
+ /* Count the number of Gap Ack Blocks. */
+ num_gabs = 0;
+
+ if (sctp_tsnmap_has_gap(map)) {
+ sctp_tsnmap_iter_init(map, &iter);
+ while (sctp_tsnmap_next_gap_ack(map, &iter,
+ &gab.start, &gab.end))
+ num_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);
+
+ length = sizeof(sack)
+ + sizeof(sctp_gap_ack_block_t) * num_gabs
+ + sizeof(__u32) * num_dup_tsns;
+
+ /* Create the chunk. */
+ retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, length);
+ 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);
+
+ /* Put the Gap Ack Blocks into the chunk. */
+ if (num_gabs) {
+ sctp_tsnmap_iter_init(map, &iter);
+ while(sctp_tsnmap_next_gap_ack(map, &iter,
+ &gab.start, &gab.end)) {
+ gab.start = htons(gab.start);
+ gab.end = htons(gab.end);
+ sctp_addto_chunk(retval, sizeof(sctp_gap_ack_block_t),
+ &gab);
+ }
+ }
+
+ /* Register the duplicates. */
+ sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
+ sctp_tsnmap_get_dups(map));
+
+nodata:
+ return retval;
+}
+
+/* Make a SHUTDOWN chunk. */
+sctp_chunk_t *sctp_make_shutdown(const struct sctp_association *asoc)
+{
+ sctp_chunk_t *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);
+nodata:
+ return retval;
+}
+
+sctp_chunk_t *sctp_make_shutdown_ack(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *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;
+}
+
+sctp_chunk_t *sctp_make_shutdown_complete(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *retval;
+ __u8 flags = 0;
+
+ /* Maybe set the T-bit if we have no association. */
+ 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.
+ */
+sctp_chunk_t *sctp_make_abort(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ const size_t hint)
+{
+ sctp_chunk_t *retval;
+ __u8 flags = 0;
+
+ /* Maybe set the T-bit if we have no association. */
+ flags |= asoc ? 0 : 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. */
+sctp_chunk_t *sctp_make_abort_no_data(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk, __u32 tsn)
+{
+ sctp_chunk_t *retval;
+ __u32 payload;
+
+ retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
+ + sizeof(tsn));
+
+ if (!retval)
+ goto no_mem;
+
+ /* Put the tsn back into network byte order. */
+ payload = htonl(tsn);
+ sctp_init_cause(retval, SCTP_ERROR_NO_DATA, (const void *)&payload,
+ sizeof(payload));
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [ABORT back to where the offender came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+no_mem:
+ return retval;
+}
+
+/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
+sctp_chunk_t *sctp_make_abort_user(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ const struct msghdr *msg)
+{
+ sctp_chunk_t *retval;
+ void *payload = NULL, *payoff;
+ size_t paylen;
+ struct iovec *iov = msg->msg_iov;
+ int iovlen = msg->msg_iovlen;
+
+ paylen = get_user_iov_size(iov, iovlen);
+ retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen);
+ if (!retval)
+ goto err_chunk;
+
+ if (paylen) {
+ /* Put the msg_iov together into payload. */
+ payload = kmalloc(paylen, GFP_ATOMIC);
+ if (!payload)
+ goto err_payload;
+ payoff = payload;
+
+ for (; iovlen > 0; --iovlen) {
+ if (copy_from_user(payoff, iov->iov_base,iov->iov_len))
+ goto err_copy;
+ payoff += iov->iov_len;
+ iov++;
+ }
+ }
+
+ sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, payload, paylen);
+
+ if (paylen)
+ kfree(payload);
+
+ return retval;
+
+err_copy:
+ kfree(payload);
+err_payload:
+ sctp_free_chunk(retval);
+ retval = NULL;
+err_chunk:
+ return retval;
+}
+
+/* Make a HEARTBEAT chunk. */
+sctp_chunk_t *sctp_make_heartbeat(const struct sctp_association *asoc,
+ const struct sctp_transport *transport,
+ const void *payload, const size_t paylen)
+{
+ sctp_chunk_t *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT,
+ 0, paylen);
+
+ if (!retval)
+ goto nodata;
+
+ /* Cast away the 'const', as this is just telling the chunk
+ * what transport it belongs to.
+ */
+ retval->transport = (struct sctp_transport *) transport;
+ retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
+
+nodata:
+ return retval;
+}
+
+sctp_chunk_t *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ const void *payload, const size_t paylen)
+{
+ sctp_chunk_t *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.
+ */
+sctp_chunk_t *sctp_make_op_error_space(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ size_t size)
+{
+ sctp_chunk_t *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. */
+sctp_chunk_t *sctp_make_op_error(const struct sctp_association *asoc,
+ const sctp_chunk_t *chunk,
+ __u16 cause_code, const void *payload,
+ size_t paylen)
+{
+ sctp_chunk_t *retval = sctp_make_op_error_space(asoc, chunk, paylen);
+
+ if (!retval)
+ goto nodata;
+
+ sctp_init_cause(retval, cause_code, payload, paylen);
+
+nodata:
+ return retval;
+}
+
+/********************************************************************
+ * 2nd Level Abstractions
+ ********************************************************************/
+
+/* Turn an skb into a chunk.
+ * FIXME: Eventually move the structure directly inside the skb->cb[].
+ */
+sctp_chunk_t *sctp_chunkify(struct sk_buff *skb,
+ const struct sctp_association *asoc,
+ struct sock *sk)
+{
+ sctp_chunk_t *retval = t_new(sctp_chunk_t, GFP_ATOMIC);
+
+ if (!retval)
+ goto nodata;
+ memset(retval, 0, sizeof(sctp_chunk_t));
+
+ if (!sk) {
+ SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
+ }
+
+ retval->skb = skb;
+ retval->asoc = (struct sctp_association *)asoc;
+ retval->num_times_sent = 0;
+ retval->has_tsn = 0;
+ retval->has_ssn = 0;
+ retval->rtt_in_progress = 0;
+ retval->sent_at = jiffies;
+ retval->singleton = 1;
+ retval->end_of_packet = 0;
+ retval->ecn_ce_done = 0;
+ retval->pdiscard = 0;
+
+ /* sctpimpguide-05.txt Section 2.8.2
+ * M1) Each time a new DATA chunk is transmitted
+ * set the 'TSN.Missing.Report' count for that TSN to 0. The
+ * 'TSN.Missing.Report' count will be used to determine missing chunks
+ * and when to fast retransmit.
+ */
+ retval->tsn_missing_report = 0;
+ retval->tsn_gap_acked = 0;
+ retval->fast_retransmit = 0;
+
+ /* Polish the bead hole. */
+ INIT_LIST_HEAD(&retval->transmitted_list);
+ INIT_LIST_HEAD(&retval->frag_list);
+ SCTP_DBG_OBJCNT_INC(chunk);
+
+nodata:
+ return retval;
+}
+
+/* Set chunk->source and dest based on the IP header in chunk->skb. */
+void sctp_init_addrs(sctp_chunk_t *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 sctp_chunk_t *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_chunk_t *sctp_make_chunk(const struct sctp_association *asoc,
+ __u8 type, __u8 flags, int paylen)
+{
+ sctp_chunk_t *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(sctp_chunkhdr_t);
+
+ /* Set the skb to the belonging sock for accounting. */
+ skb->sk = sk;
+
+ return retval;
+
+nodata:
+ return NULL;
+}
+
+/* Release the memory occupied by a chunk. */
+void sctp_free_chunk(sctp_chunk_t *chunk)
+{
+ /* Make sure that we are not on any list. */
+ skb_unlink((struct sk_buff *) chunk);
+ list_del(&chunk->transmitted_list);
+
+ /* Free the chunk skb data and the SCTP_chunk stub itself. */
+ dev_kfree_skb(chunk->skb);
+
+ kfree(chunk);
+ SCTP_DBG_OBJCNT_DEC(chunk);
+}
+
+
+/* Append bytes to the end of a chunk. Will panic if chunk is not big
+ * enough.
+ */
+void *sctp_addto_chunk(sctp_chunk_t *chunk, int len, const void *data)
+{
+ void *target;
+ void *padding;
+ int chunklen = ntohs(chunk->chunk_hdr->length);
+ int padlen = chunklen % 4;
+
+ padding = skb_put(chunk->skb, padlen);
+ target = skb_put(chunk->skb, len);
+
+ memset(padding, 0, padlen);
+ memcpy(target, data, len);
+
+ /* Adjust the chunk length field. */
+ chunk->chunk_hdr->length = htons(chunklen + padlen + len);
+ chunk->chunk_end = chunk->skb->tail;
+
+ return target;
+}
+
+/* Append bytes from user space to the end of a chunk. Will panic if
+ * chunk is not big enough.
+ * Returns a kernel err value.
+ */
+static int sctp_user_addto_chunk(sctp_chunk_t *chunk, int off, int len,
+ struct iovec *data)
+{
+ __u8 *target;
+ int err = 0;
+
+ /* Make room in chunk for data. */
+ target = skb_put(chunk->skb, len);
+
+ /* Copy data (whole iovec) into chunk */
+ if ((err = memcpy_fromiovecend(target, data, off, len)))
+ goto out;
+
+ /* Adjust the chunk length field. */
+ chunk->chunk_hdr->length =
+ htons(ntohs(chunk->chunk_hdr->length) + len);
+ chunk->chunk_end = chunk->skb->tail;
+
+out:
+ return err;
+}
+
+/* A data chunk can have a maximum payload of (2^16 - 20). Break
+ * down any such message into smaller chunks. Opportunistically, fragment
+ * the chunks down to the current MTU constraints. We may get refragmented
+ * later if the PMTU changes, but it is _much better_ to fragment immediately
+ * with a reasonable guess than always doing our fragmentation on the
+ * soft-interrupt.
+ */
+
+
+int sctp_datachunks_from_user(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ struct msghdr *msg, int msg_len,
+ struct sk_buff_head *chunks)
+{
+ int max, whole, i, offset, over, err;
+ int len, first_len;
+ sctp_chunk_t *chunk;
+ __u8 frag;
+
+ /* What is a reasonable fragmentation point right now? */
+ max = asoc->pmtu;
+ if (max < SCTP_MIN_PMTU)
+ max = SCTP_MIN_PMTU;
+ max -= SCTP_IP_OVERHEAD;
+
+ /* Make sure not beyond maximum chunk size. */
+ if (max > SCTP_MAX_CHUNK_LEN)
+ max = SCTP_MAX_CHUNK_LEN;
+
+ /* Subtract out the overhead of a data chunk header. */
+ max -= sizeof(struct sctp_data_chunk);
+
+ whole = 0;
+ first_len = max;
+
+ /* Encourage Cookie-ECHO bundling. */
+ if (asoc->state < SCTP_STATE_COOKIE_ECHOED) {
+ whole = msg_len / (max - SCTP_ARBITRARY_COOKIE_ECHO_LEN);
+
+ /* Account for the DATA to be bundled with the COOKIE-ECHO. */
+ if (whole) {
+ first_len = max - SCTP_ARBITRARY_COOKIE_ECHO_LEN;
+ msg_len -= first_len;
+ whole = 1;
+ }
+ }
+
+ /* How many full sized? How many bytes leftover? */
+ whole += msg_len / max;
+ over = msg_len % max;
+ offset = 0;
+
+ if (whole && over)
+ SCTP_INC_STATS_USER(SctpFragUsrMsgs);
+
+ /* Create chunks for all the full sized DATA chunks. */
+ for (i=0, len=first_len; i < whole; i++) {
+ frag = SCTP_DATA_MIDDLE_FRAG;
+
+ if (0 == i)
+ frag |= SCTP_DATA_FIRST_FRAG;
+
+ if ((i == (whole - 1)) && !over)
+ frag |= SCTP_DATA_LAST_FRAG;
+
+ chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
+
+ if (!chunk)
+ goto nomem;
+ err = sctp_user_addto_chunk(chunk, offset, len, msg->msg_iov);
+ if (err < 0)
+ goto errout;
+
+ offset += len;
+
+ /* Put the chunk->skb back into the form expected by send. */
+ __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
+ - (__u8 *)chunk->skb->data);
+
+ __skb_queue_tail(chunks, (struct sk_buff *)chunk);
+
+ /* The first chunk, the first chunk was likely short
+ * to allow bundling, so reset to full size.
+ */
+ if (0 == i)
+ len = max;
+ }
+
+ /* .. now the leftover bytes. */
+ if (over) {
+ if (!whole)
+ frag = SCTP_DATA_NOT_FRAG;
+ else
+ frag = SCTP_DATA_LAST_FRAG;
+
+ chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
+
+ if (!chunk)
+ goto nomem;
+
+ err = sctp_user_addto_chunk(chunk, offset, over, msg->msg_iov);
+
+ /* Put the chunk->skb back into the form expected by send. */
+ __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
+ - (__u8 *)chunk->skb->data);
+ if (err < 0)
+ goto errout;
+
+ __skb_queue_tail(chunks, (struct sk_buff *)chunk);
+ }
+ err = 0;
+ goto out;
+
+nomem:
+ err = -ENOMEM;
+errout:
+ while ((chunk = (sctp_chunk_t *)__skb_dequeue(chunks)))
+ sctp_free_chunk(chunk);
+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(sctp_chunk_t *chunk)
+{
+ __u16 ssn;
+ __u16 sid;
+
+ if (chunk->has_ssn)
+ return;
+
+ /* This is the last possible instant to assign a SSN. */
+ if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
+ ssn = 0;
+ } else {
+ sid = htons(chunk->subh.data_hdr->stream);
+ if (chunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
+ ssn = sctp_ssn_next(&chunk->asoc->ssnmap->out, sid);
+ else
+ ssn = sctp_ssn_peek(&chunk->asoc->ssnmap->out, sid);
+ ssn = htons(ssn);
+ }
+
+ chunk->subh.data_hdr->ssn = ssn;
+ chunk->has_ssn = 1;
+}
+
+/* Helper function to assign a TSN if needed. This assumes that both
+ * the data_hdr and association have already been assigned.
+ */
+void sctp_chunk_assign_tsn(sctp_chunk_t *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, int gfp)
+{
+ struct sctp_association *asoc;
+ struct sk_buff *skb;
+ sctp_scope_t scope;
+
+ /* 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. */
+ /* FIXME: Use the af specific helpers. */
+ switch (skb->nh.iph->version) {
+ case 4:
+ asoc->c.peer_addr.v4.sin_family = AF_INET;
+ asoc->c.peer_addr.v4.sin_port = ntohs(chunk->sctp_hdr->source);
+ asoc->c.peer_addr.v4.sin_addr.s_addr = skb->nh.iph->saddr;
+ break;
+
+ case 6:
+ asoc->c.peer_addr.v6.sin6_family = AF_INET6;
+ asoc->c.peer_addr.v6.sin6_port
+ = ntohs(chunk->sctp_hdr->source);
+ asoc->c.peer_addr.v6.sin6_flowinfo = 0; /* BUG BUG BUG */
+ asoc->c.peer_addr.v6.sin6_addr = skb->nh.ipv6h->saddr;
+ asoc->c.peer_addr.v6.sin6_scope_id =
+ ((struct inet6_skb_parm *)skb->cb)->iif;
+ break;
+
+ default:
+ /* Yikes! I never heard of this kind of address. */
+ goto fail;
+ };
+
+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.
+ */
+sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_chunk_t *init_chunk,
+ int *cookie_len,
+ const __u8 *raw_addrs, int addrs_len)
+{
+ sctp_cookie_param_t *retval;
+ sctp_signed_cookie_t *cookie;
+ struct scatterlist sg;
+ int headersize, bodysize;
+ unsigned int keylen;
+ char *key;
+
+ headersize = sizeof(sctp_paramhdr_t) + SCTP_SECRET_SIZE;
+ bodysize = sizeof(sctp_cookie_t)
+ + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
+
+ /* Pad out the cookie to a multiple to make the signature
+ * functions simpler to write.
+ */
+ if (bodysize % SCTP_COOKIE_MULTIPLE)
+ bodysize += SCTP_COOKIE_MULTIPLE
+ - (bodysize % SCTP_COOKIE_MULTIPLE);
+ *cookie_len = headersize + bodysize;
+
+ retval = (sctp_cookie_param_t *)kmalloc(*cookie_len, GFP_ATOMIC);
+
+ if (!retval) {
+ *cookie_len = 0;
+ goto nodata;
+ }
+
+ /* Clear this memory since we are sending this data structure
+ * out on the network.
+ */
+ memset(retval, 0x00, *cookie_len);
+ cookie = (sctp_signed_cookie_t *) 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;
+
+ /* Set an expiration time for the cookie. */
+ do_gettimeofday(&cookie->c.expiration);
+ tv_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) {
+ /* Sign the message. */
+ sg.page = virt_to_page(&cookie->c);
+ sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE;
+ sg.length = bodysize;
+ keylen = SCTP_SECRET_SIZE;
+ key = (char *)ep->secret_key[ep->current_key];
+
+ sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen,
+ &sg, 1, cookie->signature);
+ } else
+ sctp_hash_digest(ep->secret_key[ep->current_key],
+ SCTP_SECRET_SIZE, (__u8 *) &cookie->c,
+ bodysize, cookie->signature);
+
+nodata:
+ return retval;
+}
+
+/* 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,
+ sctp_chunk_t *chunk, int gfp,
+ int *error, sctp_chunk_t **errp)
+{
+ struct sctp_association *retval = NULL;
+ sctp_signed_cookie_t *cookie;
+ sctp_cookie_t *bear_cookie;
+ int headersize, bodysize, fixed_size;
+ __u8 digest[SCTP_SIGNATURE_SIZE];
+ int secret;
+ struct scatterlist sg;
+ unsigned int keylen;
+ char *key;
+ sctp_scope_t scope;
+ struct sk_buff *skb = chunk->skb;
+
+ headersize = sizeof(sctp_chunkhdr_t) + SCTP_SECRET_SIZE;
+ bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
+ fixed_size = headersize + sizeof(sctp_cookie_t);
+
+ /* 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.
+ */
+ if (ntohs(chunk->chunk_hdr->length) <
+ (fixed_size + sizeof(sctp_chunkhdr_t)))
+ 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) {
+ secret = ep->current_key;
+ sctp_hash_digest(ep->secret_key[secret], SCTP_SECRET_SIZE,
+ (__u8 *) bear_cookie, bodysize, digest);
+
+ if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
+ /* Try the previous key. */
+ secret = ep->last_key;
+ sctp_hash_digest(ep->secret_key[secret],
+ SCTP_SECRET_SIZE, (__u8 *) bear_cookie,
+ bodysize, digest);
+
+ if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
+ /* Yikes! Still bad signature! */
+ *error = -SCTP_IERROR_BAD_SIG;
+ goto fail;
+ }
+
+ }
+
+ goto no_hmac;
+ }
+
+ /* Check the signature. */
+ keylen = SCTP_SECRET_SIZE;
+ sg.page = virt_to_page(bear_cookie);
+ sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE;
+ sg.length = bodysize;
+ key = (char *)ep->secret_key[ep->current_key];
+
+ memset(digest, 0x00, sizeof(digest));
+ sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen, &sg,
+ 1, digest);
+
+ if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
+ /* Try the previous key. */
+ key = (char *)ep->secret_key[ep->last_key];
+ memset(digest, 0x00, sizeof(digest));
+ sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen,
+ &sg, 1, digest);
+
+ if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
+ /* Yikes! Still bad signature! */
+ *error = -SCTP_IERROR_BAD_SIG;
+ goto fail;
+ }
+ }
+
+no_hmac:
+ /* 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 (!asoc && tv_lt(bear_cookie->expiration, skb->stamp)) {
+ __u16 len;
+ /*
+ * Section 3.3.10.3 Stale Cookie Error (3)
+ *
+ * Cause of error
+ * ---------------
+ * Stale Cookie Error: Indicates the receipt of a valid State
+ * Cookie that has expired.
+ */
+ len = ntohs(chunk->chunk_hdr->length);
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+ if (*errp) {
+ suseconds_t usecs = (skb->stamp.tv_sec -
+ bear_cookie->expiration.tv_sec) * 1000000L +
+ skb->stamp.tv_usec -
+ bear_cookie->expiration.tv_usec;
+
+ usecs = htonl(usecs);
+ sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
+ &usecs, sizeof(usecs));
+ *error = -SCTP_IERROR_STALE_COOKIE;
+ } else
+ *error = -SCTP_IERROR_NOMEM;
+
+ goto fail;
+ }
+
+ /* Make a new base association. */
+ scope = sctp_scope(sctp_source(chunk));
+ retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
+ if (!retval) {
+ *error = -SCTP_IERROR_NOMEM;
+ goto fail;
+ }
+
+ /* Set up our peer's port number. */
+ retval->peer.port = ntohs(chunk->sctp_hdr->source);
+
+ /* Populate the association from the cookie. */
+ retval->c = *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,
+ GFP_ATOMIC);
+ }
+
+ retval->next_tsn = retval->c.initial_tsn;
+ retval->ctsn_ack_point = retval->next_tsn - 1;
+
+ /* The INIT stuff will be done by the side effects. */
+ return retval;
+
+fail:
+ if (retval)
+ sctp_association_free(retval);
+
+ return NULL;
+
+malformed:
+ /* Yikes! The packet is either corrupt or deliberately
+ * malformed.
+ */
+ *error = -SCTP_IERROR_MALFORMED;
+ goto fail;
+}
+
+/********************************************************************
+ * 3rd Level Abstractions
+ ********************************************************************/
+
+struct __sctp_missing {
+ __u32 num_missing;
+ __u16 type;
+} __attribute__((packed));;
+
+/*
+ * Report a missing mandatory parameter.
+ */
+static int sctp_process_missing_param(const struct sctp_association *asoc,
+ sctp_param_t paramtype,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **errp)
+{
+ struct __sctp_missing report;
+ __u16 len;
+
+ len = WORD_ROUND(sizeof(report));
+
+ /* Make an ERROR chunk, preparing enough room for
+ * returning multiple unknown parameters.
+ */
+ if (!*errp)
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+
+ if (*errp) {
+ report.num_missing = htonl(1);
+ report.type = paramtype;
+ sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM,
+ &report, sizeof(report));
+ }
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+/* Report an Invalid Mandatory Parameter. */
+static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **errp)
+{
+ /* Invalid Mandatory Parameter Error has no payload. */
+
+ if (!*errp)
+ *errp = sctp_make_op_error_space(asoc, chunk, 0);
+
+ if (*errp)
+ sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, NULL, 0);
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+/* 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,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **errp)
+{
+ __u16 len = ntohs(param.p->length);
+
+ /* Make an ERROR chunk. */
+ if (!*errp)
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+
+ if (*errp)
+ sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED,
+ param.v, len);
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+/* RFC 3.2.1 & the Implementers Guide 2.2.
+ *
+ * The Parameter Types are encoded such that the
+ * highest-order two bits specify the action that must be
+ * taken if the processing endpoint does not recognize the
+ * Parameter Type.
+ *
+ * 00 - Stop processing this SCTP chunk and discard it,
+ * do not process any further chunks within it.
+ *
+ * 01 - Stop processing this SCTP chunk and discard it,
+ * do not process any further chunks within it, and report
+ * the unrecognized parameter in an 'Unrecognized
+ * Parameter Type' (in either an ERROR or in the INIT ACK).
+ *
+ * 10 - Skip this parameter and continue processing.
+ *
+ * 11 - Skip this parameter and continue processing but
+ * report the unrecognized parameter in an
+ * 'Unrecognized Parameter Type' (in either an ERROR or in
+ * the INIT ACK).
+ *
+ * Return value:
+ * 0 - discard the chunk
+ * 1 - continue with the chunk
+ */
+static int sctp_process_unk_param(const struct sctp_association *asoc,
+ union sctp_params param,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **errp)
+{
+ int retval = 1;
+
+ switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
+ case SCTP_PARAM_ACTION_DISCARD:
+ retval = 0;
+ break;
+ case SCTP_PARAM_ACTION_DISCARD_ERR:
+ retval = 0;
+ /* Make an ERROR chunk, preparing enough room for
+ * returning multiple unknown parameters.
+ */
+ if (NULL == *errp)
+ *errp = sctp_make_op_error_space(asoc, chunk,
+ ntohs(chunk->chunk_hdr->length));
+
+ if (*errp)
+ sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+ param.v,
+ WORD_ROUND(ntohs(param.p->length)));
+
+ break;
+ case SCTP_PARAM_ACTION_SKIP:
+ break;
+ case SCTP_PARAM_ACTION_SKIP_ERR:
+ /* Make an ERROR chunk, preparing enough room for
+ * returning multiple unknown parameters.
+ */
+ if (NULL == *errp)
+ *errp = sctp_make_op_error_space(asoc, chunk,
+ ntohs(chunk->chunk_hdr->length));
+
+ if (*errp) {
+ sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+ param.v,
+ WORD_ROUND(ntohs(param.p->length)));
+ } else {
+ /* If there is no memory for generating the ERROR
+ * report as specified, an ABORT will be triggered
+ * to the peer and the association won't be
+ * established.
+ */
+ retval = 0;
+ }
+
+ break;
+ default:
+ break;
+ }
+
+ return retval;
+}
+
+/* Find unrecognized parameters in the chunk.
+ * Return values:
+ * 0 - discard the chunk
+ * 1 - continue with the chunk
+ */
+static int sctp_verify_param(const struct sctp_association *asoc,
+ union sctp_params param,
+ sctp_cid_t cid,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **err_chunk)
+{
+ int retval = 1;
+
+ /* FIXME - This routine is not looking at each parameter per the
+ * chunk type, i.e., unrecognized parameters should be further
+ * identified based on the chunk id.
+ */
+
+ switch (param.p->type) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ case SCTP_PARAM_IPV6_ADDRESS:
+ case SCTP_PARAM_COOKIE_PRESERVATIVE:
+ case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
+ case SCTP_PARAM_STATE_COOKIE:
+ case SCTP_PARAM_HEARTBEAT_INFO:
+ case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
+ case SCTP_PARAM_ECN_CAPABLE:
+ break;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ /* Tell the peer, we won't support this param. */
+ return sctp_process_hn_param(asoc, param, chunk, err_chunk);
+ default:
+ SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
+ ntohs(param.p->type), cid);
+ return sctp_process_unk_param(asoc, param, chunk, err_chunk);
+
+ break;
+ }
+ return retval;
+}
+
+/* Verify the INIT packet before we process it. */
+int sctp_verify_init(const struct sctp_association *asoc,
+ sctp_cid_t cid,
+ sctp_init_chunk_t *peer_init,
+ sctp_chunk_t *chunk,
+ sctp_chunk_t **errp)
+{
+ union sctp_params param;
+ int has_cookie = 0;
+
+ /* Verify stream values are non-zero. */
+ if ((0 == peer_init->init_hdr.num_outbound_streams) ||
+ (0 == peer_init->init_hdr.num_inbound_streams)) {
+
+ sctp_process_inv_mandatory(asoc, chunk, errp);
+ return 0;
+ }
+
+ /* Check for missing mandatory parameters. */
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+
+ if (SCTP_PARAM_STATE_COOKIE == param.p->type)
+ has_cookie = 1;
+
+ } /* for (loop through all parameters) */
+
+ /* The only missing mandatory param possible today is
+ * the state cookie for an INIT-ACK chunk.
+ */
+ if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) {
+ sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
+ chunk, errp);
+ return 0;
+ }
+
+ /* Find unrecognized parameters. */
+
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+
+ if (!sctp_verify_param(asoc, param, cid, chunk, errp))
+ return 0;
+
+ } /* for (loop through all parameters) */
+
+ return 1;
+}
+
+/* Unpack the parameters in an INIT packet into an association.
+ * Returns 0 on failure, else success.
+ * FIXME: This is an association method.
+ */
+int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
+ const union sctp_addr *peer_addr,
+ sctp_init_chunk_t *peer_init, int gfp)
+{
+ union sctp_params param;
+ struct sctp_transport *transport;
+ struct list_head *pos, *temp;
+ char *cookie;
+
+ /* We must include the address that the INIT packet came from.
+ * This is the only address that matters for an INIT packet.
+ * When processing a COOKIE ECHO, we retrieve the from address
+ * of the INIT from the cookie.
+ */
+
+ /* This implementation defaults to making the first transport
+ * added as the primary transport. The source address seems to
+ * be a a better choice than any of the embedded addresses.
+ */
+ if (peer_addr)
+ if(!sctp_assoc_add_peer(asoc, peer_addr, gfp))
+ goto nomem;
+
+ /* Process the initialization parameters. */
+
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+
+ if (!sctp_process_param(asoc, param, peer_addr, gfp))
+ goto clean_up;
+ }
+
+ /* The fixed INIT headers are always in network byte
+ * order.
+ */
+ asoc->peer.i.init_tag =
+ ntohl(peer_init->init_hdr.init_tag);
+ asoc->peer.i.a_rwnd =
+ ntohl(peer_init->init_hdr.a_rwnd);
+ asoc->peer.i.num_outbound_streams =
+ ntohs(peer_init->init_hdr.num_outbound_streams);
+ asoc->peer.i.num_inbound_streams =
+ ntohs(peer_init->init_hdr.num_inbound_streams);
+ asoc->peer.i.initial_tsn =
+ ntohl(peer_init->init_hdr.initial_tsn);
+
+ /* Apply the upper bounds for output streams based on peer's
+ * number of inbound streams.
+ */
+ if (asoc->c.sinit_num_ostreams >
+ ntohs(peer_init->init_hdr.num_inbound_streams)) {
+ asoc->c.sinit_num_ostreams =
+ ntohs(peer_init->init_hdr.num_inbound_streams);
+ }
+
+ if (asoc->c.sinit_max_instreams >
+ ntohs(peer_init->init_hdr.num_outbound_streams)) {
+ asoc->c.sinit_max_instreams =
+ ntohs(peer_init->init_hdr.num_outbound_streams);
+ }
+
+ /* Copy Initiation tag from INIT to VT_peer in cookie. */
+ asoc->c.peer_vtag = asoc->peer.i.init_tag;
+
+ /* Peer Rwnd : Current calculated value of the peer's rwnd. */
+ asoc->peer.rwnd = asoc->peer.i.a_rwnd;
+
+ /* Copy cookie in case we need to resend COOKIE-ECHO. */
+ cookie = asoc->peer.cookie;
+ if (cookie) {
+ asoc->peer.cookie = kmalloc(asoc->peer.cookie_len, gfp);
+ if (!asoc->peer.cookie)
+ goto clean_up;
+ memcpy(asoc->peer.cookie, cookie, asoc->peer.cookie_len);
+ }
+
+ /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
+ * high (for example, implementations MAY use the size of the receiver
+ * advertised window).
+ */
+ list_for_each(pos, &asoc->peer.transport_addr_list) {
+ transport = list_entry(pos, struct sctp_transport, transports);
+ transport->ssthresh = asoc->peer.i.a_rwnd;
+ }
+
+ /* Set up the TSN tracking pieces. */
+ sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
+ asoc->peer.i.initial_tsn);
+
+ /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
+ *
+ * The stream sequence number in all the streams shall start
+ * from 0 when the association is established. Also, when the
+ * stream sequence number reaches the value 65535 the next
+ * stream sequence number shall be set to 0.
+ */
+
+ /* Allocate storage for the negotiated streams. */
+ asoc->ssnmap = sctp_ssnmap_new(asoc->peer.i.num_outbound_streams,
+ asoc->c.sinit_num_ostreams, gfp);
+ if (!asoc->ssnmap)
+ goto nomem_ssnmap;
+
+ /* 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;
+
+nomem_ssnmap:
+clean_up:
+ /* Release the transport structures. */
+ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
+ transport = list_entry(pos, struct sctp_transport, transports);
+ list_del(pos);
+ sctp_transport_free(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.
+ */
+int sctp_process_param(struct sctp_association *asoc, union sctp_params param,
+ const union sctp_addr *peer_addr, int gfp)
+{
+ union sctp_addr addr;
+ int i;
+ __u16 sat;
+ int retval = 1;
+ sctp_scope_t scope;
+ time_t stale;
+
+ /* 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->family)
+ break;
+ /* Fall through. */
+ case SCTP_PARAM_IPV4_ADDRESS:
+ sctp_param2sockaddr(&addr, param.addr, asoc->peer.port, 0);
+ scope = sctp_scope(peer_addr);
+ if (sctp_in_scope(&addr, scope))
+ if (!sctp_assoc_add_peer(asoc, &addr, gfp))
+ return 0;
+ break;
+
+ case SCTP_PARAM_COOKIE_PRESERVATIVE:
+ if (!sctp_proto.cookie_preserve_enable)
+ break;
+
+ stale = ntohl(param.life->lifespan_increment);
+
+ /* Suggested Cookie Life span increment's unit is msec,
+ * (1/1000sec).
+ */
+ asoc->cookie_life.tv_sec += stale / 1000;
+ asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
+ break;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
+ break;
+
+ case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
+ /* Turn off the default values first so we'll know which
+ * ones are really set by the peer.
+ */
+ asoc->peer.ipv4_address = 0;
+ asoc->peer.ipv6_address = 0;
+
+ /* Cycle through address types; avoid divide by 0. */
+ sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ if (sat)
+ sat /= sizeof(__u16);
+
+ for (i = 0; i < sat; ++i) {
+ switch (param.sat->types[i]) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ asoc->peer.ipv4_address = 1;
+ break;
+
+ case SCTP_PARAM_IPV6_ADDRESS:
+ asoc->peer.ipv6_address = 1;
+ break;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ asoc->peer.hostname_address = 1;
+ break;
+
+ default: /* Just ignore anything else. */
+ break;
+ };
+ }
+ break;
+
+ case SCTP_PARAM_STATE_COOKIE:
+ asoc->peer.cookie_len =
+ ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ asoc->peer.cookie = param.cookie->body;
+ break;
+
+ case SCTP_PARAM_HEARTBEAT_INFO:
+ /* Would be odd to receive, but it causes no problems. */
+ break;
+
+ case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
+ /* Rejected during verify stage. */
+ break;
+
+ case SCTP_PARAM_ECN_CAPABLE:
+ asoc->peer.ecn_capable = 1;
+ break;
+
+ 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;
+}
+
+/********************************************************************
+ * 4th Level Abstractions
+ ********************************************************************/
+
+/* Convert from an SCTP IP parameter to a union sctp_addr. */
+void sctp_param2sockaddr(union sctp_addr *addr, sctp_addr_param_t *param,
+ __u16 port, int iif)
+{
+ switch(param->v4.param_hdr.type) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ addr->v4.sin_family = AF_INET;
+ addr->v4.sin_port = port;
+ addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
+ break;
+
+ case SCTP_PARAM_IPV6_ADDRESS:
+ addr->v6.sin6_family = AF_INET6;
+ addr->v6.sin6_port = port;
+ addr->v6.sin6_flowinfo = 0; /* BUG */
+ addr->v6.sin6_addr = param->v6.addr;
+ addr->v6.sin6_scope_id = iif;
+ break;
+
+ default:
+ SCTP_DEBUG_PRINTK("Illegal address type %d\n",
+ ntohs(param->v4.param_hdr.type));
+ break;
+ };
+}
+
+/* Convert an IP address in an SCTP param into a sockaddr_in. */
+/* Returns true if a valid conversion was possible. */
+int sctp_addr2sockaddr(union sctp_params p, union sctp_addr *sa)
+{
+ switch (p.p->type) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ sa->v4.sin_addr = *((struct in_addr *)&p.v4->addr);
+ sa->v4.sin_family = AF_INET;
+ break;
+
+ case SCTP_PARAM_IPV6_ADDRESS:
+ *((struct in6_addr *)&sa->v4.sin_addr)
+ = p.v6->addr;
+ sa->v4.sin_family = AF_INET6;
+ break;
+
+ default:
+ return 0;
+ };
+
+ return 1;
+}
+
+/* Convert a sockaddr_in to an IP address in an SCTP param.
+ * Returns len if a valid conversion was possible.
+ */
+int sockaddr2sctp_addr(const union sctp_addr *sa, sctp_addr_param_t *p)
+{
+ int len = 0;
+
+ switch (sa->v4.sin_family) {
+ case AF_INET:
+ p->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
+ p->v4.param_hdr.length = ntohs(sizeof(sctp_ipv4addr_param_t));
+ len = sizeof(sctp_ipv4addr_param_t);
+ p->v4.addr.s_addr = sa->v4.sin_addr.s_addr;
+ break;
+
+ case AF_INET6:
+ p->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
+ p->v6.param_hdr.length = ntohs(sizeof(sctp_ipv6addr_param_t));
+ len = sizeof(sctp_ipv6addr_param_t);
+ p->v6.addr = *(&sa->v6.sin6_addr);
+ break;
+
+ default:
+ printk(KERN_WARNING "sockaddr2sctp_addr: Illegal family %d.\n",
+ sa->v4.sin_family);
+ return 0;
+ };
+
+ return len;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)