Vlad Yasevich | 60c778b | 2008-01-11 09:57:09 -0500 | [diff] [blame] | 1 | /* SCTP kernel implementation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * (C) Copyright IBM Corp. 2001, 2004 |
| 3 | * Copyright (c) 1999-2000 Cisco, Inc. |
| 4 | * Copyright (c) 1999-2001 Motorola, Inc. |
| 5 | * |
Vlad Yasevich | 60c778b | 2008-01-11 09:57:09 -0500 | [diff] [blame] | 6 | * This file is part of the SCTP kernel implementation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
| 8 | * These functions handle output processing. |
| 9 | * |
Vlad Yasevich | 60c778b | 2008-01-11 09:57:09 -0500 | [diff] [blame] | 10 | * This SCTP implementation is free software; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * you can redistribute it and/or modify it under the terms of |
| 12 | * the GNU General Public License as published by |
| 13 | * the Free Software Foundation; either version 2, or (at your option) |
| 14 | * any later version. |
| 15 | * |
Vlad Yasevich | 60c778b | 2008-01-11 09:57:09 -0500 | [diff] [blame] | 16 | * This SCTP implementation is distributed in the hope that it |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 18 | * ************************ |
| 19 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 20 | * See the GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with GNU CC; see the file COPYING. If not, write to |
| 24 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
| 25 | * Boston, MA 02111-1307, USA. |
| 26 | * |
| 27 | * Please send any bug reports or fixes you make to the |
| 28 | * email address(es): |
| 29 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| 30 | * |
| 31 | * Or submit a bug report through the following website: |
| 32 | * http://www.sf.net/projects/lksctp |
| 33 | * |
| 34 | * Written or modified by: |
| 35 | * La Monte H.P. Yarroll <piggy@acm.org> |
| 36 | * Karl Knutson <karl@athena.chicago.il.us> |
| 37 | * Jon Grimm <jgrimm@austin.ibm.com> |
| 38 | * Sridhar Samudrala <sri@us.ibm.com> |
| 39 | * |
| 40 | * Any bugs reported given to us we will try to fix... any fixes shared will |
| 41 | * be incorporated into the next SCTP release. |
| 42 | */ |
| 43 | |
| 44 | #include <linux/types.h> |
| 45 | #include <linux/kernel.h> |
| 46 | #include <linux/wait.h> |
| 47 | #include <linux/time.h> |
| 48 | #include <linux/ip.h> |
| 49 | #include <linux/ipv6.h> |
| 50 | #include <linux/init.h> |
| 51 | #include <net/inet_ecn.h> |
Vlad Yasevich | 8d2f9e8 | 2009-03-21 13:41:09 -0700 | [diff] [blame] | 52 | #include <net/ip.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <net/icmp.h> |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 54 | #include <net/net_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #include <linux/socket.h> /* for sa_family_t */ |
| 57 | #include <net/sock.h> |
| 58 | |
| 59 | #include <net/sctp/sctp.h> |
| 60 | #include <net/sctp/sm.h> |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 61 | #include <net/sctp/checksum.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
| 63 | /* Forward declarations for private helpers. */ |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 64 | static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | struct sctp_chunk *chunk); |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 66 | static void sctp_packet_append_data(struct sctp_packet *packet, |
| 67 | struct sctp_chunk *chunk); |
| 68 | static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet, |
| 69 | struct sctp_chunk *chunk, |
| 70 | u16 chunk_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
| 72 | /* Config a packet. |
| 73 | * This appears to be a followup set of initializations. |
| 74 | */ |
| 75 | struct sctp_packet *sctp_packet_config(struct sctp_packet *packet, |
| 76 | __u32 vtag, int ecn_capable) |
| 77 | { |
| 78 | struct sctp_chunk *chunk = NULL; |
| 79 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 80 | SCTP_DEBUG_PRINTK("%s: packet:%p vtag:0x%x\n", __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | packet, vtag); |
| 82 | |
| 83 | packet->vtag = vtag; |
| 84 | packet->has_cookie_echo = 0; |
| 85 | packet->has_sack = 0; |
Vlad Yasevich | a29a5bd | 2007-09-16 19:31:35 -0700 | [diff] [blame] | 86 | packet->has_auth = 0; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 87 | packet->has_data = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | packet->ipfragok = 0; |
Vlad Yasevich | a29a5bd | 2007-09-16 19:31:35 -0700 | [diff] [blame] | 89 | packet->auth = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
| 91 | if (ecn_capable && sctp_packet_empty(packet)) { |
| 92 | chunk = sctp_get_ecne_prepend(packet->transport->asoc); |
| 93 | |
| 94 | /* If there a is a prepend chunk stick it on the list before |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 95 | * any other chunks get appended. |
| 96 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | if (chunk) |
| 98 | sctp_packet_append_chunk(packet, chunk); |
| 99 | } |
| 100 | |
| 101 | return packet; |
| 102 | } |
| 103 | |
| 104 | /* Initialize the packet structure. */ |
| 105 | struct sctp_packet *sctp_packet_init(struct sctp_packet *packet, |
| 106 | struct sctp_transport *transport, |
| 107 | __u16 sport, __u16 dport) |
| 108 | { |
| 109 | struct sctp_association *asoc = transport->asoc; |
| 110 | size_t overhead; |
| 111 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 112 | SCTP_DEBUG_PRINTK("%s: packet:%p transport:%p\n", __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | packet, transport); |
| 114 | |
| 115 | packet->transport = transport; |
| 116 | packet->source_port = sport; |
| 117 | packet->destination_port = dport; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 118 | INIT_LIST_HEAD(&packet->chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | if (asoc) { |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 120 | struct sctp_sock *sp = sctp_sk(asoc->base.sk); |
| 121 | overhead = sp->pf->af->net_header_len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | } else { |
| 123 | overhead = sizeof(struct ipv6hdr); |
| 124 | } |
| 125 | overhead += sizeof(struct sctphdr); |
| 126 | packet->overhead = overhead; |
| 127 | packet->size = overhead; |
| 128 | packet->vtag = 0; |
| 129 | packet->has_cookie_echo = 0; |
| 130 | packet->has_sack = 0; |
Vlad Yasevich | a29a5bd | 2007-09-16 19:31:35 -0700 | [diff] [blame] | 131 | packet->has_auth = 0; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 132 | packet->has_data = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | packet->ipfragok = 0; |
| 134 | packet->malloced = 0; |
Vlad Yasevich | a29a5bd | 2007-09-16 19:31:35 -0700 | [diff] [blame] | 135 | packet->auth = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | return packet; |
| 137 | } |
| 138 | |
| 139 | /* Free a packet. */ |
| 140 | void sctp_packet_free(struct sctp_packet *packet) |
| 141 | { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 142 | struct sctp_chunk *chunk, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 144 | SCTP_DEBUG_PRINTK("%s: packet:%p\n", __func__, packet); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 146 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
| 147 | list_del_init(&chunk->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | sctp_chunk_free(chunk); |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 149 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | |
| 151 | if (packet->malloced) |
| 152 | kfree(packet); |
| 153 | } |
| 154 | |
| 155 | /* This routine tries to append the chunk to the offered packet. If adding |
| 156 | * the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk |
| 157 | * is not present in the packet, it transmits the input packet. |
| 158 | * Data can be bundled with a packet containing a COOKIE_ECHO chunk as long |
| 159 | * as it can fit in the packet, but any more data that does not fit in this |
| 160 | * packet can be sent only after receiving the COOKIE_ACK. |
| 161 | */ |
| 162 | sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet, |
Vlad Yasevich | 2e3216c | 2008-06-19 16:08:18 -0700 | [diff] [blame] | 163 | struct sctp_chunk *chunk, |
| 164 | int one_packet) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | { |
| 166 | sctp_xmit_t retval; |
| 167 | int error = 0; |
| 168 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 169 | SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | packet, chunk); |
| 171 | |
| 172 | switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) { |
| 173 | case SCTP_XMIT_PMTU_FULL: |
| 174 | if (!packet->has_cookie_echo) { |
| 175 | error = sctp_packet_transmit(packet); |
| 176 | if (error < 0) |
| 177 | chunk->skb->sk->sk_err = -error; |
| 178 | |
| 179 | /* If we have an empty packet, then we can NOT ever |
| 180 | * return PMTU_FULL. |
| 181 | */ |
Vlad Yasevich | 2e3216c | 2008-06-19 16:08:18 -0700 | [diff] [blame] | 182 | if (!one_packet) |
| 183 | retval = sctp_packet_append_chunk(packet, |
| 184 | chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
| 186 | break; |
| 187 | |
| 188 | case SCTP_XMIT_RWND_FULL: |
| 189 | case SCTP_XMIT_OK: |
| 190 | case SCTP_XMIT_NAGLE_DELAY: |
| 191 | break; |
Stephen Hemminger | 3ff50b7 | 2007-04-20 17:09:22 -0700 | [diff] [blame] | 192 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | |
| 194 | return retval; |
| 195 | } |
| 196 | |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 197 | /* Try to bundle an auth chunk into the packet. */ |
| 198 | static sctp_xmit_t sctp_packet_bundle_auth(struct sctp_packet *pkt, |
| 199 | struct sctp_chunk *chunk) |
| 200 | { |
| 201 | struct sctp_association *asoc = pkt->transport->asoc; |
| 202 | struct sctp_chunk *auth; |
| 203 | sctp_xmit_t retval = SCTP_XMIT_OK; |
| 204 | |
| 205 | /* if we don't have an association, we can't do authentication */ |
| 206 | if (!asoc) |
| 207 | return retval; |
| 208 | |
| 209 | /* See if this is an auth chunk we are bundling or if |
| 210 | * auth is already bundled. |
| 211 | */ |
| 212 | if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->auth) |
| 213 | return retval; |
| 214 | |
| 215 | /* if the peer did not request this chunk to be authenticated, |
| 216 | * don't do it |
| 217 | */ |
| 218 | if (!chunk->auth) |
| 219 | return retval; |
| 220 | |
| 221 | auth = sctp_make_auth(asoc); |
| 222 | if (!auth) |
| 223 | return retval; |
| 224 | |
| 225 | retval = sctp_packet_append_chunk(pkt, auth); |
| 226 | |
| 227 | return retval; |
| 228 | } |
| 229 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | /* Try to bundle a SACK with the packet. */ |
| 231 | static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt, |
| 232 | struct sctp_chunk *chunk) |
| 233 | { |
| 234 | sctp_xmit_t retval = SCTP_XMIT_OK; |
| 235 | |
| 236 | /* If sending DATA and haven't aleady bundled a SACK, try to |
| 237 | * bundle one in to the packet. |
| 238 | */ |
| 239 | if (sctp_chunk_is_data(chunk) && !pkt->has_sack && |
| 240 | !pkt->has_cookie_echo) { |
| 241 | struct sctp_association *asoc; |
Doug Graham | af87b82 | 2009-07-29 12:05:57 -0400 | [diff] [blame] | 242 | struct timer_list *timer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | asoc = pkt->transport->asoc; |
Doug Graham | af87b82 | 2009-07-29 12:05:57 -0400 | [diff] [blame] | 244 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | |
Doug Graham | af87b82 | 2009-07-29 12:05:57 -0400 | [diff] [blame] | 246 | /* If the SACK timer is running, we have a pending SACK */ |
| 247 | if (timer_pending(timer)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | struct sctp_chunk *sack; |
| 249 | asoc->a_rwnd = asoc->rwnd; |
| 250 | sack = sctp_make_sack(asoc); |
| 251 | if (sack) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | retval = sctp_packet_append_chunk(pkt, sack); |
| 253 | asoc->peer.sack_needed = 0; |
Doug Graham | af87b82 | 2009-07-29 12:05:57 -0400 | [diff] [blame] | 254 | if (del_timer(timer)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | sctp_association_put(asoc); |
| 256 | } |
| 257 | } |
| 258 | } |
| 259 | return retval; |
| 260 | } |
| 261 | |
| 262 | /* Append a chunk to the offered packet reporting back any inability to do |
| 263 | * so. |
| 264 | */ |
| 265 | sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet, |
| 266 | struct sctp_chunk *chunk) |
| 267 | { |
| 268 | sctp_xmit_t retval = SCTP_XMIT_OK; |
| 269 | __u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 271 | SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, packet, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | chunk); |
| 273 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 274 | /* Data chunks are special. Before seeing what else we can |
| 275 | * bundle into this packet, check to see if we are allowed to |
| 276 | * send this DATA. |
| 277 | */ |
| 278 | if (sctp_chunk_is_data(chunk)) { |
| 279 | retval = sctp_packet_can_append_data(packet, chunk); |
| 280 | if (retval != SCTP_XMIT_OK) |
| 281 | goto finish; |
| 282 | } |
| 283 | |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 284 | /* Try to bundle AUTH chunk */ |
| 285 | retval = sctp_packet_bundle_auth(packet, chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | if (retval != SCTP_XMIT_OK) |
| 287 | goto finish; |
| 288 | |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 289 | /* Try to bundle SACK chunk */ |
| 290 | retval = sctp_packet_bundle_sack(packet, chunk); |
| 291 | if (retval != SCTP_XMIT_OK) |
| 292 | goto finish; |
| 293 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 294 | /* Check to see if this chunk will fit into the packet */ |
| 295 | retval = sctp_packet_will_fit(packet, chunk, chunk_len); |
| 296 | if (retval != SCTP_XMIT_OK) |
| 297 | goto finish; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 299 | /* We believe that this chunk is OK to add to the packet */ |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 300 | switch (chunk->chunk_hdr->type) { |
| 301 | case SCTP_CID_DATA: |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 302 | /* Account for the data being in the packet */ |
| 303 | sctp_packet_append_data(packet, chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | /* Disallow SACK bundling after DATA. */ |
| 305 | packet->has_sack = 1; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 306 | /* Disallow AUTH bundling after DATA */ |
| 307 | packet->has_auth = 1; |
| 308 | /* Let it be knows that packet has DATA in it */ |
| 309 | packet->has_data = 1; |
Vlad Yasevich | 759af00 | 2009-01-22 14:53:01 -0800 | [diff] [blame] | 310 | /* timestamp the chunk for rtx purposes */ |
| 311 | chunk->sent_at = jiffies; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 312 | break; |
| 313 | case SCTP_CID_COOKIE_ECHO: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | packet->has_cookie_echo = 1; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 315 | break; |
| 316 | |
| 317 | case SCTP_CID_SACK: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | packet->has_sack = 1; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 319 | break; |
| 320 | |
| 321 | case SCTP_CID_AUTH: |
| 322 | packet->has_auth = 1; |
| 323 | packet->auth = chunk; |
| 324 | break; |
| 325 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | |
| 327 | /* It is OK to send this chunk. */ |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 328 | list_add_tail(&chunk->list, &packet->chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | packet->size += chunk_len; |
| 330 | chunk->transport = packet->transport; |
| 331 | finish: |
| 332 | return retval; |
| 333 | } |
| 334 | |
| 335 | /* All packets are sent to the network through this function from |
| 336 | * sctp_outq_tail(). |
| 337 | * |
| 338 | * The return value is a normal kernel error return value. |
| 339 | */ |
| 340 | int sctp_packet_transmit(struct sctp_packet *packet) |
| 341 | { |
| 342 | struct sctp_transport *tp = packet->transport; |
| 343 | struct sctp_association *asoc = tp->asoc; |
| 344 | struct sctphdr *sh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | struct sk_buff *nskb; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 346 | struct sctp_chunk *chunk, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | struct sock *sk; |
| 348 | int err = 0; |
| 349 | int padding; /* How much padding do we need? */ |
| 350 | __u8 has_data = 0; |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 351 | struct dst_entry *dst = tp->dst; |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 352 | unsigned char *auth = NULL; /* pointer to auth in skb data */ |
| 353 | __u32 cksum_buf_len = sizeof(struct sctphdr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 355 | SCTP_DEBUG_PRINTK("%s: packet:%p\n", __func__, packet); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | |
| 357 | /* Do NOT generate a chunkless packet. */ |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 358 | if (list_empty(&packet->chunk_list)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | return err; |
| 360 | |
| 361 | /* Set up convenience variables... */ |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 362 | chunk = list_entry(packet->chunk_list.next, struct sctp_chunk, list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | sk = chunk->skb->sk; |
| 364 | |
| 365 | /* Allocate the new skb. */ |
Sridhar Samudrala | 594ccc1 | 2005-04-28 12:00:23 -0700 | [diff] [blame] | 366 | nskb = alloc_skb(packet->size + LL_MAX_HEADER, GFP_ATOMIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | if (!nskb) |
| 368 | goto nomem; |
| 369 | |
| 370 | /* Make sure the outbound skb has enough header room reserved. */ |
Sridhar Samudrala | 594ccc1 | 2005-04-28 12:00:23 -0700 | [diff] [blame] | 371 | skb_reserve(nskb, packet->overhead + LL_MAX_HEADER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | |
| 373 | /* Set the owning socket so that we know where to get the |
| 374 | * destination IP address. |
| 375 | */ |
| 376 | skb_set_owner_w(nskb, sk); |
| 377 | |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 378 | /* The 'obsolete' field of dst is set to 2 when a dst is freed. */ |
| 379 | if (!dst || (dst->obsolete > 1)) { |
| 380 | dst_release(dst); |
| 381 | sctp_transport_route(tp, NULL, sctp_sk(sk)); |
| 382 | if (asoc && (asoc->param_flags & SPP_PMTUD_ENABLE)) { |
| 383 | sctp_assoc_sync_pmtu(asoc); |
| 384 | } |
| 385 | } |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 386 | dst = dst_clone(tp->dst); |
| 387 | skb_dst_set(nskb, dst); |
Wei Yongjun | ff0ac74 | 2009-06-28 22:49:37 +0000 | [diff] [blame] | 388 | if (!dst) |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 389 | goto no_route; |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 390 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | /* Build the SCTP header. */ |
| 392 | sh = (struct sctphdr *)skb_push(nskb, sizeof(struct sctphdr)); |
Jesse Brandeburg | 8dc92f7 | 2009-04-27 22:35:52 +0000 | [diff] [blame] | 393 | skb_reset_transport_header(nskb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | sh->source = htons(packet->source_port); |
| 395 | sh->dest = htons(packet->destination_port); |
| 396 | |
| 397 | /* From 6.8 Adler-32 Checksum Calculation: |
| 398 | * After the packet is constructed (containing the SCTP common |
| 399 | * header and one or more control or DATA chunks), the |
| 400 | * transmitter shall: |
| 401 | * |
| 402 | * 1) Fill in the proper Verification Tag in the SCTP common |
| 403 | * header and initialize the checksum field to 0's. |
| 404 | */ |
| 405 | sh->vtag = htonl(packet->vtag); |
| 406 | sh->checksum = 0; |
| 407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | /** |
| 409 | * 6.10 Bundling |
| 410 | * |
| 411 | * An endpoint bundles chunks by simply including multiple |
| 412 | * chunks in one outbound SCTP packet. ... |
| 413 | */ |
| 414 | |
| 415 | /** |
| 416 | * 3.2 Chunk Field Descriptions |
| 417 | * |
| 418 | * The total length of a chunk (including Type, Length and |
| 419 | * Value fields) MUST be a multiple of 4 bytes. If the length |
| 420 | * of the chunk is not a multiple of 4 bytes, the sender MUST |
| 421 | * pad the chunk with all zero bytes and this padding is not |
| 422 | * included in the chunk length field. The sender should |
| 423 | * never pad with more than 3 bytes. |
| 424 | * |
| 425 | * [This whole comment explains WORD_ROUND() below.] |
| 426 | */ |
| 427 | SCTP_DEBUG_PRINTK("***sctp_transmit_packet***\n"); |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 428 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
| 429 | list_del_init(&chunk->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | if (sctp_chunk_is_data(chunk)) { |
| 431 | |
| 432 | if (!chunk->has_tsn) { |
| 433 | sctp_chunk_assign_ssn(chunk); |
| 434 | sctp_chunk_assign_tsn(chunk); |
| 435 | |
| 436 | /* 6.3.1 C4) When data is in flight and when allowed |
| 437 | * by rule C5, a new RTT measurement MUST be made each |
| 438 | * round trip. Furthermore, new RTT measurements |
| 439 | * SHOULD be made no more than once per round-trip |
| 440 | * for a given destination transport address. |
| 441 | */ |
| 442 | |
| 443 | if (!tp->rto_pending) { |
| 444 | chunk->rtt_in_progress = 1; |
| 445 | tp->rto_pending = 1; |
| 446 | } |
| 447 | } else |
| 448 | chunk->resent = 1; |
| 449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | has_data = 1; |
| 451 | } |
| 452 | |
| 453 | padding = WORD_ROUND(chunk->skb->len) - chunk->skb->len; |
| 454 | if (padding) |
| 455 | memset(skb_put(chunk->skb, padding), 0, padding); |
| 456 | |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 457 | /* if this is the auth chunk that we are adding, |
| 458 | * store pointer where it will be added and put |
| 459 | * the auth into the packet. |
| 460 | */ |
| 461 | if (chunk == packet->auth) |
| 462 | auth = skb_tail_pointer(nskb); |
| 463 | |
| 464 | cksum_buf_len += chunk->skb->len; |
| 465 | memcpy(skb_put(nskb, chunk->skb->len), |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 466 | chunk->skb->data, chunk->skb->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
| 468 | SCTP_DEBUG_PRINTK("%s %p[%s] %s 0x%x, %s %d, %s %d, %s %d\n", |
| 469 | "*** Chunk", chunk, |
| 470 | sctp_cname(SCTP_ST_CHUNK( |
| 471 | chunk->chunk_hdr->type)), |
| 472 | chunk->has_tsn ? "TSN" : "No TSN", |
| 473 | chunk->has_tsn ? |
| 474 | ntohl(chunk->subh.data_hdr->tsn) : 0, |
| 475 | "length", ntohs(chunk->chunk_hdr->length), |
| 476 | "chunk->skb->len", chunk->skb->len, |
| 477 | "rtt_in_progress", chunk->rtt_in_progress); |
| 478 | |
| 479 | /* |
| 480 | * If this is a control chunk, this is our last |
| 481 | * reference. Free data chunks after they've been |
| 482 | * acknowledged or have failed. |
| 483 | */ |
| 484 | if (!sctp_chunk_is_data(chunk)) |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 485 | sctp_chunk_free(chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | } |
| 487 | |
Vlad Yasevich | 4cd57c8 | 2007-09-16 19:32:45 -0700 | [diff] [blame] | 488 | /* SCTP-AUTH, Section 6.2 |
| 489 | * The sender MUST calculate the MAC as described in RFC2104 [2] |
| 490 | * using the hash function H as described by the MAC Identifier and |
| 491 | * the shared association key K based on the endpoint pair shared key |
| 492 | * described by the shared key identifier. The 'data' used for the |
| 493 | * computation of the AUTH-chunk is given by the AUTH chunk with its |
| 494 | * HMAC field set to zero (as shown in Figure 6) followed by all |
| 495 | * chunks that are placed after the AUTH chunk in the SCTP packet. |
| 496 | */ |
| 497 | if (auth) |
| 498 | sctp_auth_calculate_hmac(asoc, nskb, |
| 499 | (struct sctp_auth_chunk *)auth, |
| 500 | GFP_ATOMIC); |
| 501 | |
| 502 | /* 2) Calculate the Adler-32 checksum of the whole packet, |
| 503 | * including the SCTP common header and all the |
| 504 | * chunks. |
| 505 | * |
| 506 | * Note: Adler-32 is no longer applicable, as has been replaced |
| 507 | * by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>. |
| 508 | */ |
Jesse Brandeburg | 8dc92f7 | 2009-04-27 22:35:52 +0000 | [diff] [blame] | 509 | if (!sctp_checksum_disable && |
| 510 | !(dst->dev->features & (NETIF_F_NO_CSUM | NETIF_F_SCTP_CSUM))) { |
Vlad Yasevich | 4458f04 | 2009-02-13 08:33:42 +0000 | [diff] [blame] | 511 | __u32 crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len); |
| 512 | |
| 513 | /* 3) Put the resultant value into the checksum field in the |
| 514 | * common header, and leave the rest of the bits unchanged. |
| 515 | */ |
| 516 | sh->checksum = sctp_end_cksum(crc32); |
Jesse Brandeburg | 8dc92f7 | 2009-04-27 22:35:52 +0000 | [diff] [blame] | 517 | } else { |
| 518 | if (dst->dev->features & NETIF_F_SCTP_CSUM) { |
| 519 | /* no need to seed psuedo checksum for SCTP */ |
| 520 | nskb->ip_summed = CHECKSUM_PARTIAL; |
| 521 | nskb->csum_start = (skb_transport_header(nskb) - |
| 522 | nskb->head); |
| 523 | nskb->csum_offset = offsetof(struct sctphdr, checksum); |
| 524 | } else { |
| 525 | nskb->ip_summed = CHECKSUM_UNNECESSARY; |
| 526 | } |
| 527 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | /* IP layer ECN support |
| 530 | * From RFC 2481 |
| 531 | * "The ECN-Capable Transport (ECT) bit would be set by the |
| 532 | * data sender to indicate that the end-points of the |
| 533 | * transport protocol are ECN-capable." |
| 534 | * |
| 535 | * Now setting the ECT bit all the time, as it should not cause |
| 536 | * any problems protocol-wise even if our peer ignores it. |
| 537 | * |
| 538 | * Note: The works for IPv6 layer checks this bit too later |
| 539 | * in transmission. See IP6_ECN_flow_xmit(). |
| 540 | */ |
Vlad Yasevich | b9031d9 | 2008-06-04 12:40:15 -0700 | [diff] [blame] | 541 | (*tp->af_specific->ecn_capable)(nskb->sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | |
| 543 | /* Set up the IP options. */ |
| 544 | /* BUG: not implemented |
| 545 | * For v4 this all lives somewhere in sk->sk_opt... |
| 546 | */ |
| 547 | |
| 548 | /* Dump that on IP! */ |
| 549 | if (asoc && asoc->peer.last_sent_to != tp) { |
| 550 | /* Considering the multiple CPU scenario, this is a |
| 551 | * "correcter" place for last_sent_to. --xguo |
| 552 | */ |
| 553 | asoc->peer.last_sent_to = tp; |
| 554 | } |
| 555 | |
| 556 | if (has_data) { |
| 557 | struct timer_list *timer; |
| 558 | unsigned long timeout; |
| 559 | |
| 560 | tp->last_time_used = jiffies; |
| 561 | |
| 562 | /* Restart the AUTOCLOSE timer when sending data. */ |
| 563 | if (sctp_state(asoc, ESTABLISHED) && asoc->autoclose) { |
| 564 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; |
| 565 | timeout = asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; |
| 566 | |
| 567 | if (!mod_timer(timer, jiffies + timeout)) |
| 568 | sctp_association_hold(asoc); |
| 569 | } |
| 570 | } |
| 571 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb len %d\n", |
| 573 | nskb->len); |
| 574 | |
Herbert Xu | f880374 | 2008-08-03 21:15:08 -0700 | [diff] [blame] | 575 | nskb->local_df = packet->ipfragok; |
| 576 | (*tp->af_specific->sctp_xmit)(nskb, tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
| 578 | out: |
| 579 | packet->size = packet->overhead; |
| 580 | return err; |
| 581 | no_route: |
| 582 | kfree_skb(nskb); |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 583 | IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | |
| 585 | /* FIXME: Returning the 'err' will effect all the associations |
| 586 | * associated with a socket, although only one of the paths of the |
| 587 | * association is unreachable. |
| 588 | * The real failure of a transport or association can be passed on |
| 589 | * to the user via notifications. So setting this error may not be |
| 590 | * required. |
| 591 | */ |
| 592 | /* err = -EHOSTUNREACH; */ |
| 593 | err: |
| 594 | /* Control chunks are unreliable so just drop them. DATA chunks |
| 595 | * will get resent or dropped later. |
| 596 | */ |
| 597 | |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 598 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
| 599 | list_del_init(&chunk->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | if (!sctp_chunk_is_data(chunk)) |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 601 | sctp_chunk_free(chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | } |
| 603 | goto out; |
| 604 | nomem: |
| 605 | err = -ENOMEM; |
| 606 | goto err; |
| 607 | } |
| 608 | |
| 609 | /******************************************************************** |
| 610 | * 2nd Level Abstractions |
| 611 | ********************************************************************/ |
| 612 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 613 | /* This private function check to see if a chunk can be added */ |
| 614 | static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | struct sctp_chunk *chunk) |
| 616 | { |
| 617 | sctp_xmit_t retval = SCTP_XMIT_OK; |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 618 | size_t datasize, rwnd, inflight, flight_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | struct sctp_transport *transport = packet->transport; |
| 620 | __u32 max_burst_bytes; |
| 621 | struct sctp_association *asoc = transport->asoc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | struct sctp_outq *q = &asoc->outqueue; |
| 623 | |
| 624 | /* RFC 2960 6.1 Transmission of DATA Chunks |
| 625 | * |
| 626 | * A) At any given time, the data sender MUST NOT transmit new data to |
| 627 | * any destination transport address if its peer's rwnd indicates |
| 628 | * that the peer has no buffer space (i.e. rwnd is 0, see Section |
| 629 | * 6.2.1). However, regardless of the value of rwnd (including if it |
| 630 | * is 0), the data sender can always have one DATA chunk in flight to |
| 631 | * the receiver if allowed by cwnd (see rule B below). This rule |
| 632 | * allows the sender to probe for a change in rwnd that the sender |
| 633 | * missed due to the SACK having been lost in transit from the data |
| 634 | * receiver to the data sender. |
| 635 | */ |
| 636 | |
| 637 | rwnd = asoc->peer.rwnd; |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 638 | inflight = q->outstanding_bytes; |
| 639 | flight_size = transport->flight_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | |
| 641 | datasize = sctp_data_size(chunk); |
| 642 | |
| 643 | if (datasize > rwnd) { |
| 644 | if (inflight > 0) { |
| 645 | /* We have (at least) one data chunk in flight, |
| 646 | * so we can't fall back to rule 6.1 B). |
| 647 | */ |
| 648 | retval = SCTP_XMIT_RWND_FULL; |
| 649 | goto finish; |
| 650 | } |
| 651 | } |
| 652 | |
| 653 | /* sctpimpguide-05 2.14.2 |
| 654 | * D) When the time comes for the sender to |
| 655 | * transmit new DATA chunks, the protocol parameter Max.Burst MUST |
| 656 | * first be applied to limit how many new DATA chunks may be sent. |
| 657 | * The limit is applied by adjusting cwnd as follows: |
| 658 | * if ((flightsize + Max.Burst * MTU) < cwnd) |
| 659 | * cwnd = flightsize + Max.Burst * MTU |
| 660 | */ |
Frank Filz | 52ccb8e | 2005-12-22 11:36:46 -0800 | [diff] [blame] | 661 | max_burst_bytes = asoc->max_burst * asoc->pathmtu; |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 662 | if ((flight_size + max_burst_bytes) < transport->cwnd) { |
| 663 | transport->cwnd = flight_size + max_burst_bytes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | SCTP_DEBUG_PRINTK("%s: cwnd limited by max_burst: " |
| 665 | "transport: %p, cwnd: %d, " |
| 666 | "ssthresh: %d, flight_size: %d, " |
| 667 | "pba: %d\n", |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 668 | __func__, transport, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | transport->cwnd, |
| 670 | transport->ssthresh, |
| 671 | transport->flight_size, |
| 672 | transport->partial_bytes_acked); |
| 673 | } |
| 674 | |
| 675 | /* RFC 2960 6.1 Transmission of DATA Chunks |
| 676 | * |
| 677 | * B) At any given time, the sender MUST NOT transmit new data |
| 678 | * to a given transport address if it has cwnd or more bytes |
| 679 | * of data outstanding to that transport address. |
| 680 | */ |
| 681 | /* RFC 7.2.4 & the Implementers Guide 2.8. |
| 682 | * |
| 683 | * 3) ... |
| 684 | * When a Fast Retransmit is being performed the sender SHOULD |
| 685 | * ignore the value of cwnd and SHOULD NOT delay retransmission. |
| 686 | */ |
Neil Horman | c226ef9 | 2008-07-25 12:44:09 -0400 | [diff] [blame] | 687 | if (chunk->fast_retransmit != SCTP_NEED_FRTX) |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 688 | if (flight_size >= transport->cwnd) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | retval = SCTP_XMIT_RWND_FULL; |
| 690 | goto finish; |
| 691 | } |
| 692 | |
| 693 | /* Nagle's algorithm to solve small-packet problem: |
| 694 | * Inhibit the sending of new chunks when new outgoing data arrives |
| 695 | * if any previously transmitted data on the connection remains |
| 696 | * unacknowledged. |
| 697 | */ |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 698 | if (!sctp_sk(asoc->base.sk)->nodelay && sctp_packet_empty(packet) && |
| 699 | inflight && sctp_state(asoc, ESTABLISHED)) { |
Vlad Yasevich | b29e790 | 2009-09-04 18:20:59 -0400 | [diff] [blame^] | 700 | unsigned max = transport->pathmtu - packet->overhead; |
| 701 | unsigned len = chunk->skb->len + q->out_qlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | |
| 703 | /* Check whether this chunk and all the rest of pending |
| 704 | * data will fit or delay in hopes of bundling a full |
| 705 | * sized packet. |
| 706 | */ |
Vlad Yasevich | b29e790 | 2009-09-04 18:20:59 -0400 | [diff] [blame^] | 707 | if (len < max) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | retval = SCTP_XMIT_NAGLE_DELAY; |
| 709 | goto finish; |
| 710 | } |
| 711 | } |
| 712 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 713 | finish: |
| 714 | return retval; |
| 715 | } |
| 716 | |
| 717 | /* This private function does management things when adding DATA chunk */ |
| 718 | static void sctp_packet_append_data(struct sctp_packet *packet, |
| 719 | struct sctp_chunk *chunk) |
| 720 | { |
| 721 | struct sctp_transport *transport = packet->transport; |
| 722 | size_t datasize = sctp_data_size(chunk); |
| 723 | struct sctp_association *asoc = transport->asoc; |
| 724 | u32 rwnd = asoc->peer.rwnd; |
| 725 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | /* Keep track of how many bytes are in flight over this transport. */ |
| 727 | transport->flight_size += datasize; |
| 728 | |
| 729 | /* Keep track of how many bytes are in flight to the receiver. */ |
| 730 | asoc->outqueue.outstanding_bytes += datasize; |
| 731 | |
Sridhar Samudrala | cd49788 | 2006-09-29 17:09:05 -0700 | [diff] [blame] | 732 | /* Update our view of the receiver's rwnd. Include sk_buff overhead |
| 733 | * while updating peer.rwnd so that it reduces the chances of a |
| 734 | * receiver running out of receive buffer space even when receive |
| 735 | * window is still open. This can happen when a sender is sending |
| 736 | * sending small messages. |
| 737 | */ |
| 738 | datasize += sizeof(struct sk_buff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | if (datasize < rwnd) |
| 740 | rwnd -= datasize; |
| 741 | else |
| 742 | rwnd = 0; |
| 743 | |
| 744 | asoc->peer.rwnd = rwnd; |
| 745 | /* Has been accepted for transmission. */ |
| 746 | if (!asoc->peer.prsctp_capable) |
| 747 | chunk->msg->can_abandon = 0; |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 748 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | |
Vlad Yasevich | e83963b | 2009-08-07 10:43:07 -0400 | [diff] [blame] | 750 | static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet, |
| 751 | struct sctp_chunk *chunk, |
| 752 | u16 chunk_len) |
| 753 | { |
| 754 | size_t psize; |
| 755 | size_t pmtu; |
| 756 | int too_big; |
| 757 | sctp_xmit_t retval = SCTP_XMIT_OK; |
| 758 | |
| 759 | psize = packet->size; |
| 760 | pmtu = ((packet->transport->asoc) ? |
| 761 | (packet->transport->asoc->pathmtu) : |
| 762 | (packet->transport->pathmtu)); |
| 763 | |
| 764 | too_big = (psize + chunk_len > pmtu); |
| 765 | |
| 766 | /* Decide if we need to fragment or resubmit later. */ |
| 767 | if (too_big) { |
| 768 | /* It's OK to fragmet at IP level if any one of the following |
| 769 | * is true: |
| 770 | * 1. The packet is empty (meaning this chunk is greater |
| 771 | * the MTU) |
| 772 | * 2. The chunk we are adding is a control chunk |
| 773 | * 3. The packet doesn't have any data in it yet and data |
| 774 | * requires authentication. |
| 775 | */ |
| 776 | if (sctp_packet_empty(packet) || !sctp_chunk_is_data(chunk) || |
| 777 | (!packet->has_data && chunk->auth)) { |
| 778 | /* We no longer do re-fragmentation. |
| 779 | * Just fragment at the IP layer, if we |
| 780 | * actually hit this condition |
| 781 | */ |
| 782 | packet->ipfragok = 1; |
| 783 | } else { |
| 784 | retval = SCTP_XMIT_PMTU_FULL; |
| 785 | } |
| 786 | } |
| 787 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | return retval; |
| 789 | } |