Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* SCTP kernel reference Implementation |
| 2 | * Copyright (c) 1999-2000 Cisco, Inc. |
| 3 | * Copyright (c) 1999-2001 Motorola, Inc. |
| 4 | * Copyright (c) 2001-2003 International Business Machines, Corp. |
| 5 | * Copyright (c) 2001 Intel Corp. |
| 6 | * Copyright (c) 2001 Nokia, Inc. |
| 7 | * Copyright (c) 2001 La Monte H.P. Yarroll |
| 8 | * |
| 9 | * This file is part of the SCTP kernel reference Implementation |
| 10 | * |
| 11 | * These functions handle all input from the IP layer into SCTP. |
| 12 | * |
| 13 | * The SCTP reference implementation is free software; |
| 14 | * you can redistribute it and/or modify it under the terms of |
| 15 | * the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2, or (at your option) |
| 17 | * any later version. |
| 18 | * |
| 19 | * The SCTP reference implementation is distributed in the hope that it |
| 20 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 21 | * ************************ |
| 22 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 23 | * See the GNU General Public License for more details. |
| 24 | * |
| 25 | * You should have received a copy of the GNU General Public License |
| 26 | * along with GNU CC; see the file COPYING. If not, write to |
| 27 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
| 28 | * Boston, MA 02111-1307, USA. |
| 29 | * |
| 30 | * Please send any bug reports or fixes you make to the |
| 31 | * email address(es): |
| 32 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| 33 | * |
| 34 | * Or submit a bug report through the following website: |
| 35 | * http://www.sf.net/projects/lksctp |
| 36 | * |
| 37 | * Written or modified by: |
| 38 | * La Monte H.P. Yarroll <piggy@acm.org> |
| 39 | * Karl Knutson <karl@athena.chicago.il.us> |
| 40 | * Xingang Guo <xingang.guo@intel.com> |
| 41 | * Jon Grimm <jgrimm@us.ibm.com> |
| 42 | * Hui Huang <hui.huang@nokia.com> |
| 43 | * Daisy Chang <daisyc@us.ibm.com> |
| 44 | * Sridhar Samudrala <sri@us.ibm.com> |
| 45 | * Ardelle Fan <ardelle.fan@intel.com> |
| 46 | * |
| 47 | * Any bugs reported given to us we will try to fix... any fixes shared will |
| 48 | * be incorporated into the next SCTP release. |
| 49 | */ |
| 50 | |
| 51 | #include <linux/types.h> |
| 52 | #include <linux/list.h> /* For struct list_head */ |
| 53 | #include <linux/socket.h> |
| 54 | #include <linux/ip.h> |
| 55 | #include <linux/time.h> /* For struct timeval */ |
| 56 | #include <net/ip.h> |
| 57 | #include <net/icmp.h> |
| 58 | #include <net/snmp.h> |
| 59 | #include <net/sock.h> |
| 60 | #include <net/xfrm.h> |
| 61 | #include <net/sctp/sctp.h> |
| 62 | #include <net/sctp/sm.h> |
| 63 | |
| 64 | /* Forward declarations for internal helpers. */ |
| 65 | static int sctp_rcv_ootb(struct sk_buff *); |
| 66 | static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, |
| 67 | const union sctp_addr *laddr, |
| 68 | const union sctp_addr *paddr, |
| 69 | struct sctp_transport **transportp); |
| 70 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr); |
| 71 | static struct sctp_association *__sctp_lookup_association( |
| 72 | const union sctp_addr *local, |
| 73 | const union sctp_addr *peer, |
| 74 | struct sctp_transport **pt); |
| 75 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 76 | static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb); |
| 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | /* Calculate the SCTP checksum of an SCTP packet. */ |
| 80 | static inline int sctp_rcv_checksum(struct sk_buff *skb) |
| 81 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
Arnaldo Carvalho de Melo | 2c0fd38 | 2007-03-13 13:59:32 -0300 | [diff] [blame] | 83 | struct sctphdr *sh = sctp_hdr(skb); |
| 84 | __u32 cmp = ntohl(sh->checksum); |
| 85 | __u32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | |
| 87 | for (; list; list = list->next) |
| 88 | val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), |
| 89 | val); |
| 90 | |
| 91 | val = sctp_end_cksum(val); |
| 92 | |
| 93 | if (val != cmp) { |
| 94 | /* CRC failure, dump it. */ |
| 95 | SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS); |
| 96 | return -1; |
| 97 | } |
| 98 | return 0; |
| 99 | } |
| 100 | |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 101 | struct sctp_input_cb { |
| 102 | union { |
| 103 | struct inet_skb_parm h4; |
| 104 | #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) |
| 105 | struct inet6_skb_parm h6; |
| 106 | #endif |
| 107 | } header; |
| 108 | struct sctp_chunk *chunk; |
| 109 | }; |
| 110 | #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) |
| 111 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | /* |
| 113 | * This is the routine which IP calls when receiving an SCTP packet. |
| 114 | */ |
| 115 | int sctp_rcv(struct sk_buff *skb) |
| 116 | { |
| 117 | struct sock *sk; |
| 118 | struct sctp_association *asoc; |
| 119 | struct sctp_endpoint *ep = NULL; |
| 120 | struct sctp_ep_common *rcvr; |
| 121 | struct sctp_transport *transport = NULL; |
| 122 | struct sctp_chunk *chunk; |
| 123 | struct sctphdr *sh; |
| 124 | union sctp_addr src; |
| 125 | union sctp_addr dest; |
| 126 | int family; |
| 127 | struct sctp_af *af; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | if (skb->pkt_type!=PACKET_HOST) |
| 130 | goto discard_it; |
| 131 | |
| 132 | SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS); |
| 133 | |
Herbert Xu | 28cd775 | 2006-10-29 23:46:42 -0800 | [diff] [blame] | 134 | if (skb_linearize(skb)) |
| 135 | goto discard_it; |
| 136 | |
Arnaldo Carvalho de Melo | 2c0fd38 | 2007-03-13 13:59:32 -0300 | [diff] [blame] | 137 | sh = sctp_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
| 139 | /* Pull up the IP and SCTP headers. */ |
Arnaldo Carvalho de Melo | ea2ae17 | 2007-04-25 17:55:53 -0700 | [diff] [blame] | 140 | __skb_pull(skb, skb_transport_offset(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | if (skb->len < sizeof(struct sctphdr)) |
| 142 | goto discard_it; |
Sridhar Samudrala | 503b55f | 2006-06-17 22:57:28 -0700 | [diff] [blame] | 143 | if ((skb->ip_summed != CHECKSUM_UNNECESSARY) && |
| 144 | (sctp_rcv_checksum(skb) < 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | goto discard_it; |
| 146 | |
| 147 | skb_pull(skb, sizeof(struct sctphdr)); |
| 148 | |
| 149 | /* Make sure we at least have chunk headers worth of data left. */ |
| 150 | if (skb->len < sizeof(struct sctp_chunkhdr)) |
| 151 | goto discard_it; |
| 152 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 153 | family = ipver2af(ip_hdr(skb)->version); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | af = sctp_get_af_specific(family); |
| 155 | if (unlikely(!af)) |
| 156 | goto discard_it; |
| 157 | |
| 158 | /* Initialize local addresses for lookups. */ |
| 159 | af->from_skb(&src, skb, 1); |
| 160 | af->from_skb(&dest, skb, 0); |
| 161 | |
| 162 | /* If the packet is to or from a non-unicast address, |
| 163 | * silently discard the packet. |
| 164 | * |
| 165 | * This is not clearly defined in the RFC except in section |
| 166 | * 8.4 - OOTB handling. However, based on the book "Stream Control |
| 167 | * Transmission Protocol" 2.1, "It is important to note that the |
| 168 | * IP address of an SCTP transport address must be a routable |
| 169 | * unicast address. In other words, IP multicast addresses and |
| 170 | * IP broadcast addresses cannot be used in an SCTP transport |
| 171 | * address." |
| 172 | */ |
Vlad Yasevich | 5636bef | 2006-06-17 22:55:35 -0700 | [diff] [blame] | 173 | if (!af->addr_valid(&src, NULL, skb) || |
| 174 | !af->addr_valid(&dest, NULL, skb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | goto discard_it; |
| 176 | |
Al Viro | d55c41b | 2006-11-20 17:09:40 -0800 | [diff] [blame] | 177 | asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport); |
Al Viro | 1c7d1fc | 2006-11-20 17:08:09 -0800 | [diff] [blame] | 178 | |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 179 | if (!asoc) |
Al Viro | d55c41b | 2006-11-20 17:09:40 -0800 | [diff] [blame] | 180 | ep = __sctp_rcv_lookup_endpoint(&dest); |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 181 | |
| 182 | /* Retrieve the common input handling substructure. */ |
| 183 | rcvr = asoc ? &asoc->base : &ep->base; |
| 184 | sk = rcvr->sk; |
| 185 | |
| 186 | /* |
| 187 | * If a frame arrives on an interface and the receiving socket is |
| 188 | * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB |
| 189 | */ |
| 190 | if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) |
| 191 | { |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 192 | if (asoc) { |
| 193 | sctp_association_put(asoc); |
| 194 | asoc = NULL; |
| 195 | } else { |
| 196 | sctp_endpoint_put(ep); |
| 197 | ep = NULL; |
| 198 | } |
| 199 | sk = sctp_get_ctl_sock(); |
| 200 | ep = sctp_sk(sk)->ep; |
| 201 | sctp_endpoint_hold(ep); |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 202 | rcvr = &ep->base; |
| 203 | } |
| 204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | /* |
| 206 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. |
| 207 | * An SCTP packet is called an "out of the blue" (OOTB) |
| 208 | * packet if it is correctly formed, i.e., passed the |
| 209 | * receiver's checksum check, but the receiver is not |
| 210 | * able to identify the association to which this |
| 211 | * packet belongs. |
| 212 | */ |
| 213 | if (!asoc) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | if (sctp_rcv_ootb(skb)) { |
| 215 | SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES); |
| 216 | goto discard_release; |
| 217 | } |
| 218 | } |
| 219 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) |
| 221 | goto discard_release; |
Patrick McHardy | b59c270 | 2006-01-06 23:06:10 -0800 | [diff] [blame] | 222 | nf_reset(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
Dmitry Mishin | fda9ef5 | 2006-08-31 15:28:39 -0700 | [diff] [blame] | 224 | if (sk_filter(sk, skb)) |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 225 | goto discard_release; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
| 227 | /* Create an SCTP packet structure. */ |
| 228 | chunk = sctp_chunkify(skb, asoc, sk); |
Herbert Xu | 2babf9d | 2006-03-25 01:25:29 -0800 | [diff] [blame] | 229 | if (!chunk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | goto discard_release; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 231 | SCTP_INPUT_CB(skb)->chunk = chunk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | /* Remember what endpoint is to handle this packet. */ |
| 234 | chunk->rcvr = rcvr; |
| 235 | |
| 236 | /* Remember the SCTP header. */ |
| 237 | chunk->sctp_hdr = sh; |
| 238 | |
| 239 | /* Set the source and destination addresses of the incoming chunk. */ |
Al Viro | d55c41b | 2006-11-20 17:09:40 -0800 | [diff] [blame] | 240 | sctp_init_addrs(chunk, &src, &dest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | |
| 242 | /* Remember where we came from. */ |
| 243 | chunk->transport = transport; |
| 244 | |
| 245 | /* Acquire access to the sock lock. Note: We are safe from other |
| 246 | * bottom halves on this lock, but a user may be in the lock too, |
| 247 | * so check if it is busy. |
| 248 | */ |
| 249 | sctp_bh_lock_sock(sk); |
| 250 | |
Sridhar Samudrala | ac0b046 | 2006-08-22 00:15:33 -0700 | [diff] [blame] | 251 | if (sock_owned_by_user(sk)) { |
| 252 | SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG); |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 253 | sctp_add_backlog(sk, skb); |
Sridhar Samudrala | ac0b046 | 2006-08-22 00:15:33 -0700 | [diff] [blame] | 254 | } else { |
| 255 | SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ); |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 256 | sctp_inq_push(&chunk->rcvr->inqueue, chunk); |
Sridhar Samudrala | ac0b046 | 2006-08-22 00:15:33 -0700 | [diff] [blame] | 257 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | sctp_bh_unlock_sock(sk); |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 260 | |
| 261 | /* Release the asoc/ep ref we took in the lookup calls. */ |
| 262 | if (asoc) |
| 263 | sctp_association_put(asoc); |
| 264 | else |
| 265 | sctp_endpoint_put(ep); |
Sridhar Samudrala | 7a48f92 | 2006-01-17 11:51:28 -0800 | [diff] [blame] | 266 | |
Herbert Xu | 2babf9d | 2006-03-25 01:25:29 -0800 | [diff] [blame] | 267 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | |
| 269 | discard_it: |
Sridhar Samudrala | ac0b046 | 2006-08-22 00:15:33 -0700 | [diff] [blame] | 270 | SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | kfree_skb(skb); |
Herbert Xu | 2babf9d | 2006-03-25 01:25:29 -0800 | [diff] [blame] | 272 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | |
| 274 | discard_release: |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 275 | /* Release the asoc/ep ref we took in the lookup calls. */ |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 276 | if (asoc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | sctp_association_put(asoc); |
Neil Horman | 0fd9a65 | 2005-06-13 15:11:24 -0700 | [diff] [blame] | 278 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | sctp_endpoint_put(ep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | |
| 281 | goto discard_it; |
| 282 | } |
| 283 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 284 | /* Process the backlog queue of the socket. Every skb on |
| 285 | * the backlog holds a ref on an association or endpoint. |
| 286 | * We hold this ref throughout the state machine to make |
| 287 | * sure that the structure we need is still around. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | */ |
| 289 | int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) |
| 290 | { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 291 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 292 | struct sctp_inq *inqueue = &chunk->rcvr->inqueue; |
| 293 | struct sctp_ep_common *rcvr = NULL; |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 294 | int backloged = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 296 | rcvr = chunk->rcvr; |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 297 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 298 | /* If the rcvr is dead then the association or endpoint |
| 299 | * has been deleted and we can safely drop the chunk |
| 300 | * and refs that we are holding. |
| 301 | */ |
| 302 | if (rcvr->dead) { |
| 303 | sctp_chunk_free(chunk); |
| 304 | goto done; |
| 305 | } |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 306 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 307 | if (unlikely(rcvr->sk != sk)) { |
| 308 | /* In this case, the association moved from one socket to |
| 309 | * another. We are currently sitting on the backlog of the |
| 310 | * old socket, so we need to move. |
| 311 | * However, since we are here in the process context we |
| 312 | * need to take make sure that the user doesn't own |
| 313 | * the new socket when we process the packet. |
| 314 | * If the new socket is user-owned, queue the chunk to the |
| 315 | * backlog of the new socket without dropping any refs. |
| 316 | * Otherwise, we can safely push the chunk on the inqueue. |
| 317 | */ |
Sridhar Samudrala | 7a48f92 | 2006-01-17 11:51:28 -0800 | [diff] [blame] | 318 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 319 | sk = rcvr->sk; |
| 320 | sctp_bh_lock_sock(sk); |
| 321 | |
| 322 | if (sock_owned_by_user(sk)) { |
| 323 | sk_add_backlog(sk, skb); |
| 324 | backloged = 1; |
| 325 | } else |
| 326 | sctp_inq_push(inqueue, chunk); |
| 327 | |
| 328 | sctp_bh_unlock_sock(sk); |
| 329 | |
| 330 | /* If the chunk was backloged again, don't drop refs */ |
| 331 | if (backloged) |
| 332 | return 0; |
| 333 | } else { |
| 334 | sctp_inq_push(inqueue, chunk); |
| 335 | } |
| 336 | |
| 337 | done: |
| 338 | /* Release the refs we took in sctp_add_backlog */ |
| 339 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) |
| 340 | sctp_association_put(sctp_assoc(rcvr)); |
| 341 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
| 342 | sctp_endpoint_put(sctp_ep(rcvr)); |
| 343 | else |
| 344 | BUG(); |
| 345 | |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 346 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | } |
| 348 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 349 | static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb) |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 350 | { |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 351 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
| 352 | struct sctp_ep_common *rcvr = chunk->rcvr; |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 353 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 354 | /* Hold the assoc/ep while hanging on the backlog queue. |
| 355 | * This way, we know structures we need will not disappear from us |
| 356 | */ |
| 357 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) |
| 358 | sctp_association_hold(sctp_assoc(rcvr)); |
| 359 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
| 360 | sctp_endpoint_hold(sctp_ep(rcvr)); |
| 361 | else |
| 362 | BUG(); |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 363 | |
Vladislav Yasevich | 61c9fed | 2006-05-19 11:01:18 -0700 | [diff] [blame] | 364 | sk_add_backlog(sk, skb); |
Sridhar Samudrala | c4d2444 | 2006-01-17 11:56:26 -0800 | [diff] [blame] | 365 | } |
| 366 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | /* Handle icmp frag needed error. */ |
| 368 | void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, |
| 369 | struct sctp_transport *t, __u32 pmtu) |
| 370 | { |
Frank Filz | 52ccb8e | 2005-12-22 11:36:46 -0800 | [diff] [blame] | 371 | if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu)) |
| 372 | return; |
| 373 | |
| 374 | if (t->param_flags & SPP_PMTUD_ENABLE) { |
| 375 | if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) { |
| 376 | printk(KERN_WARNING "%s: Reported pmtu %d too low, " |
| 377 | "using default minimum of %d\n", |
| 378 | __FUNCTION__, pmtu, |
| 379 | SCTP_DEFAULT_MINSEGMENT); |
| 380 | /* Use default minimum segment size and disable |
| 381 | * pmtu discovery on this transport. |
| 382 | */ |
| 383 | t->pathmtu = SCTP_DEFAULT_MINSEGMENT; |
Vlad Yasevich | b56bab4 | 2006-09-29 17:09:34 -0700 | [diff] [blame] | 384 | t->param_flags = (t->param_flags & ~SPP_PMTUD) | |
Frank Filz | 52ccb8e | 2005-12-22 11:36:46 -0800 | [diff] [blame] | 385 | SPP_PMTUD_DISABLE; |
| 386 | } else { |
| 387 | t->pathmtu = pmtu; |
| 388 | } |
| 389 | |
| 390 | /* Update association pmtu. */ |
| 391 | sctp_assoc_sync_pmtu(asoc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | } |
| 393 | |
Frank Filz | 52ccb8e | 2005-12-22 11:36:46 -0800 | [diff] [blame] | 394 | /* Retransmit with the new pmtu setting. |
| 395 | * Normally, if PMTU discovery is disabled, an ICMP Fragmentation |
| 396 | * Needed will never be sent, but if a message was sent before |
| 397 | * PMTU discovery was disabled that was larger than the PMTU, it |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 398 | * would not be fragmented, so it must be re-transmitted fragmented. |
Frank Filz | 52ccb8e | 2005-12-22 11:36:46 -0800 | [diff] [blame] | 399 | */ |
| 400 | sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
| 402 | |
| 403 | /* |
| 404 | * SCTP Implementer's Guide, 2.37 ICMP handling procedures |
| 405 | * |
| 406 | * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" |
| 407 | * or a "Protocol Unreachable" treat this message as an abort |
| 408 | * with the T bit set. |
| 409 | * |
| 410 | * This function sends an event to the state machine, which will abort the |
| 411 | * association. |
| 412 | * |
| 413 | */ |
| 414 | void sctp_icmp_proto_unreachable(struct sock *sk, |
YOSHIFUJI Hideaki | d808ad9 | 2007-02-09 23:25:18 +0900 | [diff] [blame] | 415 | struct sctp_association *asoc, |
| 416 | struct sctp_transport *t) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | { |
| 418 | SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__); |
| 419 | |
| 420 | sctp_do_sm(SCTP_EVENT_T_OTHER, |
| 421 | SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), |
Frank Filz | 3f7a87d | 2005-06-20 13:14:57 -0700 | [diff] [blame] | 422 | asoc->state, asoc->ep, asoc, t, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | GFP_ATOMIC); |
| 424 | |
| 425 | } |
| 426 | |
| 427 | /* Common lookup code for icmp/icmpv6 error handler. */ |
| 428 | struct sock *sctp_err_lookup(int family, struct sk_buff *skb, |
| 429 | struct sctphdr *sctphdr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | struct sctp_association **app, |
| 431 | struct sctp_transport **tpp) |
| 432 | { |
| 433 | union sctp_addr saddr; |
| 434 | union sctp_addr daddr; |
| 435 | struct sctp_af *af; |
| 436 | struct sock *sk = NULL; |
Sridhar Samudrala | 8de8c87 | 2006-05-19 10:58:12 -0700 | [diff] [blame] | 437 | struct sctp_association *asoc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | struct sctp_transport *transport = NULL; |
| 439 | |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 440 | *app = NULL; *tpp = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | |
| 442 | af = sctp_get_af_specific(family); |
| 443 | if (unlikely(!af)) { |
| 444 | return NULL; |
| 445 | } |
| 446 | |
| 447 | /* Initialize local addresses for lookups. */ |
| 448 | af->from_skb(&saddr, skb, 1); |
| 449 | af->from_skb(&daddr, skb, 0); |
| 450 | |
| 451 | /* Look for an association that matches the incoming ICMP error |
| 452 | * packet. |
| 453 | */ |
Al Viro | d55c41b | 2006-11-20 17:09:40 -0800 | [diff] [blame] | 454 | asoc = __sctp_lookup_association(&saddr, &daddr, &transport); |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 455 | if (!asoc) |
| 456 | return NULL; |
| 457 | |
| 458 | sk = asoc->base.sk; |
| 459 | |
| 460 | if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) { |
| 461 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); |
| 462 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | sctp_bh_lock_sock(sk); |
| 466 | |
| 467 | /* If too many ICMPs get dropped on busy |
| 468 | * servers this needs to be solved differently. |
| 469 | */ |
| 470 | if (sock_owned_by_user(sk)) |
| 471 | NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); |
| 472 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | *app = asoc; |
| 474 | *tpp = transport; |
| 475 | return sk; |
| 476 | |
| 477 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | if (asoc) |
| 479 | sctp_association_put(asoc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | return NULL; |
| 481 | } |
| 482 | |
| 483 | /* Common cleanup code for icmp/icmpv6 error handler. */ |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 484 | void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | { |
| 486 | sctp_bh_unlock_sock(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | if (asoc) |
| 488 | sctp_association_put(asoc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | } |
| 490 | |
| 491 | /* |
| 492 | * This routine is called by the ICMP module when it gets some |
| 493 | * sort of error condition. If err < 0 then the socket should |
| 494 | * be closed and the error returned to the user. If err > 0 |
| 495 | * it's just the icmp type << 8 | icmp code. After adjustment |
| 496 | * header points to the first 8 bytes of the sctp header. We need |
| 497 | * to find the appropriate port. |
| 498 | * |
| 499 | * The locking strategy used here is very "optimistic". When |
| 500 | * someone else accesses the socket the ICMP is just dropped |
| 501 | * and for some paths there is no check at all. |
| 502 | * A more general error queue to queue errors for later handling |
| 503 | * is probably better. |
| 504 | * |
| 505 | */ |
| 506 | void sctp_v4_err(struct sk_buff *skb, __u32 info) |
| 507 | { |
| 508 | struct iphdr *iph = (struct iphdr *)skb->data; |
| 509 | struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2)); |
Arnaldo Carvalho de Melo | 88c7664 | 2007-03-13 14:43:18 -0300 | [diff] [blame^] | 510 | const int type = icmp_hdr(skb)->type; |
| 511 | const int code = icmp_hdr(skb)->code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | struct sock *sk; |
Sridhar Samudrala | 8de8c87 | 2006-05-19 10:58:12 -0700 | [diff] [blame] | 513 | struct sctp_association *asoc = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | struct sctp_transport *transport; |
| 515 | struct inet_sock *inet; |
| 516 | char *saveip, *savesctp; |
| 517 | int err; |
| 518 | |
| 519 | if (skb->len < ((iph->ihl << 2) + 8)) { |
| 520 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); |
| 521 | return; |
| 522 | } |
| 523 | |
| 524 | /* Fix up skb to look at the embedded net header. */ |
| 525 | saveip = skb->nh.raw; |
| 526 | savesctp = skb->h.raw; |
Arnaldo Carvalho de Melo | 31c7711 | 2007-03-10 19:04:55 -0300 | [diff] [blame] | 527 | skb_reset_network_header(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | skb->h.raw = (char *)sh; |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 529 | sk = sctp_err_lookup(AF_INET, skb, sh, &asoc, &transport); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | /* Put back, the original pointers. */ |
| 531 | skb->nh.raw = saveip; |
| 532 | skb->h.raw = savesctp; |
| 533 | if (!sk) { |
| 534 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); |
| 535 | return; |
| 536 | } |
| 537 | /* Warning: The sock lock is held. Remember to call |
| 538 | * sctp_err_finish! |
| 539 | */ |
| 540 | |
| 541 | switch (type) { |
| 542 | case ICMP_PARAMETERPROB: |
| 543 | err = EPROTO; |
| 544 | break; |
| 545 | case ICMP_DEST_UNREACH: |
| 546 | if (code > NR_ICMP_UNREACH) |
| 547 | goto out_unlock; |
| 548 | |
| 549 | /* PMTU discovery (RFC1191) */ |
| 550 | if (ICMP_FRAG_NEEDED == code) { |
| 551 | sctp_icmp_frag_needed(sk, asoc, transport, info); |
| 552 | goto out_unlock; |
| 553 | } |
| 554 | else { |
| 555 | if (ICMP_PROT_UNREACH == code) { |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 556 | sctp_icmp_proto_unreachable(sk, asoc, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | transport); |
| 558 | goto out_unlock; |
| 559 | } |
| 560 | } |
| 561 | err = icmp_err_convert[code].errno; |
| 562 | break; |
| 563 | case ICMP_TIME_EXCEEDED: |
| 564 | /* Ignore any time exceeded errors due to fragment reassembly |
| 565 | * timeouts. |
| 566 | */ |
| 567 | if (ICMP_EXC_FRAGTIME == code) |
| 568 | goto out_unlock; |
| 569 | |
| 570 | err = EHOSTUNREACH; |
| 571 | break; |
| 572 | default: |
| 573 | goto out_unlock; |
| 574 | } |
| 575 | |
| 576 | inet = inet_sk(sk); |
| 577 | if (!sock_owned_by_user(sk) && inet->recverr) { |
| 578 | sk->sk_err = err; |
| 579 | sk->sk_error_report(sk); |
| 580 | } else { /* Only an error on timeout */ |
| 581 | sk->sk_err_soft = err; |
| 582 | } |
| 583 | |
| 584 | out_unlock: |
Sridhar Samudrala | d1ad1ff | 2005-07-18 13:44:10 -0700 | [diff] [blame] | 585 | sctp_err_finish(sk, asoc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | } |
| 587 | |
| 588 | /* |
| 589 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. |
| 590 | * |
| 591 | * This function scans all the chunks in the OOTB packet to determine if |
| 592 | * the packet should be discarded right away. If a response might be needed |
| 593 | * for this packet, or, if further processing is possible, the packet will |
| 594 | * be queued to a proper inqueue for the next phase of handling. |
| 595 | * |
| 596 | * Output: |
| 597 | * Return 0 - If further processing is needed. |
| 598 | * Return 1 - If the packet can be discarded right away. |
| 599 | */ |
| 600 | int sctp_rcv_ootb(struct sk_buff *skb) |
| 601 | { |
| 602 | sctp_chunkhdr_t *ch; |
| 603 | __u8 *ch_end; |
| 604 | sctp_errhdr_t *err; |
| 605 | |
| 606 | ch = (sctp_chunkhdr_t *) skb->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | |
| 608 | /* Scan through all the chunks in the packet. */ |
Tsutomu Fujii | a7d1f1b | 2006-01-17 11:57:09 -0800 | [diff] [blame] | 609 | do { |
| 610 | /* Break out if chunk length is less then minimal. */ |
| 611 | if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) |
| 612 | break; |
| 613 | |
| 614 | ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); |
| 615 | if (ch_end > skb->tail) |
| 616 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | |
| 618 | /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the |
| 619 | * receiver MUST silently discard the OOTB packet and take no |
| 620 | * further action. |
| 621 | */ |
| 622 | if (SCTP_CID_ABORT == ch->type) |
| 623 | goto discard; |
| 624 | |
| 625 | /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE |
| 626 | * chunk, the receiver should silently discard the packet |
| 627 | * and take no further action. |
| 628 | */ |
| 629 | if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) |
| 630 | goto discard; |
| 631 | |
| 632 | /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR |
| 633 | * or a COOKIE ACK the SCTP Packet should be silently |
| 634 | * discarded. |
| 635 | */ |
| 636 | if (SCTP_CID_COOKIE_ACK == ch->type) |
| 637 | goto discard; |
| 638 | |
| 639 | if (SCTP_CID_ERROR == ch->type) { |
| 640 | sctp_walk_errors(err, ch) { |
| 641 | if (SCTP_ERROR_STALE_COOKIE == err->cause) |
| 642 | goto discard; |
| 643 | } |
| 644 | } |
| 645 | |
| 646 | ch = (sctp_chunkhdr_t *) ch_end; |
Tsutomu Fujii | a7d1f1b | 2006-01-17 11:57:09 -0800 | [diff] [blame] | 647 | } while (ch_end < skb->tail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | |
| 649 | return 0; |
| 650 | |
| 651 | discard: |
| 652 | return 1; |
| 653 | } |
| 654 | |
| 655 | /* Insert endpoint into the hash table. */ |
| 656 | static void __sctp_hash_endpoint(struct sctp_endpoint *ep) |
| 657 | { |
| 658 | struct sctp_ep_common **epp; |
| 659 | struct sctp_ep_common *epb; |
| 660 | struct sctp_hashbucket *head; |
| 661 | |
| 662 | epb = &ep->base; |
| 663 | |
| 664 | epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); |
| 665 | head = &sctp_ep_hashtable[epb->hashent]; |
| 666 | |
| 667 | sctp_write_lock(&head->lock); |
| 668 | epp = &head->chain; |
| 669 | epb->next = *epp; |
| 670 | if (epb->next) |
| 671 | (*epp)->pprev = &epb->next; |
| 672 | *epp = epb; |
| 673 | epb->pprev = epp; |
| 674 | sctp_write_unlock(&head->lock); |
| 675 | } |
| 676 | |
| 677 | /* Add an endpoint to the hash. Local BH-safe. */ |
| 678 | void sctp_hash_endpoint(struct sctp_endpoint *ep) |
| 679 | { |
| 680 | sctp_local_bh_disable(); |
| 681 | __sctp_hash_endpoint(ep); |
| 682 | sctp_local_bh_enable(); |
| 683 | } |
| 684 | |
| 685 | /* Remove endpoint from the hash table. */ |
| 686 | static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) |
| 687 | { |
| 688 | struct sctp_hashbucket *head; |
| 689 | struct sctp_ep_common *epb; |
| 690 | |
| 691 | epb = &ep->base; |
| 692 | |
| 693 | epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); |
| 694 | |
| 695 | head = &sctp_ep_hashtable[epb->hashent]; |
| 696 | |
| 697 | sctp_write_lock(&head->lock); |
| 698 | |
| 699 | if (epb->pprev) { |
| 700 | if (epb->next) |
| 701 | epb->next->pprev = epb->pprev; |
| 702 | *epb->pprev = epb->next; |
| 703 | epb->pprev = NULL; |
| 704 | } |
| 705 | |
| 706 | sctp_write_unlock(&head->lock); |
| 707 | } |
| 708 | |
| 709 | /* Remove endpoint from the hash. Local BH-safe. */ |
| 710 | void sctp_unhash_endpoint(struct sctp_endpoint *ep) |
| 711 | { |
| 712 | sctp_local_bh_disable(); |
| 713 | __sctp_unhash_endpoint(ep); |
| 714 | sctp_local_bh_enable(); |
| 715 | } |
| 716 | |
| 717 | /* Look up an endpoint. */ |
| 718 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr) |
| 719 | { |
| 720 | struct sctp_hashbucket *head; |
| 721 | struct sctp_ep_common *epb; |
| 722 | struct sctp_endpoint *ep; |
| 723 | int hash; |
| 724 | |
Al Viro | 1c7d1fc | 2006-11-20 17:08:09 -0800 | [diff] [blame] | 725 | hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | head = &sctp_ep_hashtable[hash]; |
| 727 | read_lock(&head->lock); |
| 728 | for (epb = head->chain; epb; epb = epb->next) { |
| 729 | ep = sctp_ep(epb); |
| 730 | if (sctp_endpoint_is_match(ep, laddr)) |
| 731 | goto hit; |
| 732 | } |
| 733 | |
| 734 | ep = sctp_sk((sctp_get_ctl_sock()))->ep; |
| 735 | epb = &ep->base; |
| 736 | |
| 737 | hit: |
| 738 | sctp_endpoint_hold(ep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | read_unlock(&head->lock); |
| 740 | return ep; |
| 741 | } |
| 742 | |
| 743 | /* Insert association into the hash table. */ |
| 744 | static void __sctp_hash_established(struct sctp_association *asoc) |
| 745 | { |
| 746 | struct sctp_ep_common **epp; |
| 747 | struct sctp_ep_common *epb; |
| 748 | struct sctp_hashbucket *head; |
| 749 | |
| 750 | epb = &asoc->base; |
| 751 | |
| 752 | /* Calculate which chain this entry will belong to. */ |
| 753 | epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port); |
| 754 | |
| 755 | head = &sctp_assoc_hashtable[epb->hashent]; |
| 756 | |
| 757 | sctp_write_lock(&head->lock); |
| 758 | epp = &head->chain; |
| 759 | epb->next = *epp; |
| 760 | if (epb->next) |
| 761 | (*epp)->pprev = &epb->next; |
| 762 | *epp = epb; |
| 763 | epb->pprev = epp; |
| 764 | sctp_write_unlock(&head->lock); |
| 765 | } |
| 766 | |
| 767 | /* Add an association to the hash. Local BH-safe. */ |
| 768 | void sctp_hash_established(struct sctp_association *asoc) |
| 769 | { |
Vlad Yasevich | de76e69 | 2006-10-30 18:55:11 -0800 | [diff] [blame] | 770 | if (asoc->temp) |
| 771 | return; |
| 772 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | sctp_local_bh_disable(); |
| 774 | __sctp_hash_established(asoc); |
| 775 | sctp_local_bh_enable(); |
| 776 | } |
| 777 | |
| 778 | /* Remove association from the hash table. */ |
| 779 | static void __sctp_unhash_established(struct sctp_association *asoc) |
| 780 | { |
| 781 | struct sctp_hashbucket *head; |
| 782 | struct sctp_ep_common *epb; |
| 783 | |
| 784 | epb = &asoc->base; |
| 785 | |
| 786 | epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, |
| 787 | asoc->peer.port); |
| 788 | |
| 789 | head = &sctp_assoc_hashtable[epb->hashent]; |
| 790 | |
| 791 | sctp_write_lock(&head->lock); |
| 792 | |
| 793 | if (epb->pprev) { |
| 794 | if (epb->next) |
| 795 | epb->next->pprev = epb->pprev; |
| 796 | *epb->pprev = epb->next; |
| 797 | epb->pprev = NULL; |
| 798 | } |
| 799 | |
| 800 | sctp_write_unlock(&head->lock); |
| 801 | } |
| 802 | |
| 803 | /* Remove association from the hash table. Local BH-safe. */ |
| 804 | void sctp_unhash_established(struct sctp_association *asoc) |
| 805 | { |
Vlad Yasevich | de76e69 | 2006-10-30 18:55:11 -0800 | [diff] [blame] | 806 | if (asoc->temp) |
| 807 | return; |
| 808 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | sctp_local_bh_disable(); |
| 810 | __sctp_unhash_established(asoc); |
| 811 | sctp_local_bh_enable(); |
| 812 | } |
| 813 | |
| 814 | /* Look up an association. */ |
| 815 | static struct sctp_association *__sctp_lookup_association( |
| 816 | const union sctp_addr *local, |
| 817 | const union sctp_addr *peer, |
| 818 | struct sctp_transport **pt) |
| 819 | { |
| 820 | struct sctp_hashbucket *head; |
| 821 | struct sctp_ep_common *epb; |
| 822 | struct sctp_association *asoc; |
| 823 | struct sctp_transport *transport; |
| 824 | int hash; |
| 825 | |
| 826 | /* Optimize here for direct hit, only listening connections can |
| 827 | * have wildcards anyways. |
| 828 | */ |
Al Viro | e2fcced | 2006-11-20 17:08:41 -0800 | [diff] [blame] | 829 | hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | head = &sctp_assoc_hashtable[hash]; |
| 831 | read_lock(&head->lock); |
| 832 | for (epb = head->chain; epb; epb = epb->next) { |
| 833 | asoc = sctp_assoc(epb); |
| 834 | transport = sctp_assoc_is_match(asoc, local, peer); |
| 835 | if (transport) |
| 836 | goto hit; |
| 837 | } |
| 838 | |
| 839 | read_unlock(&head->lock); |
| 840 | |
| 841 | return NULL; |
| 842 | |
| 843 | hit: |
| 844 | *pt = transport; |
| 845 | sctp_association_hold(asoc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | read_unlock(&head->lock); |
| 847 | return asoc; |
| 848 | } |
| 849 | |
| 850 | /* Look up an association. BH-safe. */ |
| 851 | SCTP_STATIC |
| 852 | struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr, |
| 853 | const union sctp_addr *paddr, |
| 854 | struct sctp_transport **transportp) |
| 855 | { |
| 856 | struct sctp_association *asoc; |
| 857 | |
| 858 | sctp_local_bh_disable(); |
| 859 | asoc = __sctp_lookup_association(laddr, paddr, transportp); |
| 860 | sctp_local_bh_enable(); |
| 861 | |
| 862 | return asoc; |
| 863 | } |
| 864 | |
| 865 | /* Is there an association matching the given local and peer addresses? */ |
| 866 | int sctp_has_association(const union sctp_addr *laddr, |
| 867 | const union sctp_addr *paddr) |
| 868 | { |
| 869 | struct sctp_association *asoc; |
| 870 | struct sctp_transport *transport; |
| 871 | |
Al Viro | 6c7be55 | 2006-11-20 17:11:50 -0800 | [diff] [blame] | 872 | if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | sctp_association_put(asoc); |
| 874 | return 1; |
| 875 | } |
| 876 | |
| 877 | return 0; |
| 878 | } |
| 879 | |
| 880 | /* |
| 881 | * SCTP Implementors Guide, 2.18 Handling of address |
| 882 | * parameters within the INIT or INIT-ACK. |
| 883 | * |
| 884 | * D) When searching for a matching TCB upon reception of an INIT |
| 885 | * or INIT-ACK chunk the receiver SHOULD use not only the |
| 886 | * source address of the packet (containing the INIT or |
| 887 | * INIT-ACK) but the receiver SHOULD also use all valid |
| 888 | * address parameters contained within the chunk. |
| 889 | * |
| 890 | * 2.18.3 Solution description |
| 891 | * |
| 892 | * This new text clearly specifies to an implementor the need |
| 893 | * to look within the INIT or INIT-ACK. Any implementation that |
| 894 | * does not do this, may not be able to establish associations |
| 895 | * in certain circumstances. |
| 896 | * |
| 897 | */ |
| 898 | static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, |
| 899 | const union sctp_addr *laddr, struct sctp_transport **transportp) |
| 900 | { |
| 901 | struct sctp_association *asoc; |
| 902 | union sctp_addr addr; |
| 903 | union sctp_addr *paddr = &addr; |
Arnaldo Carvalho de Melo | 2c0fd38 | 2007-03-13 13:59:32 -0300 | [diff] [blame] | 904 | struct sctphdr *sh = sctp_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | sctp_chunkhdr_t *ch; |
| 906 | union sctp_params params; |
| 907 | sctp_init_chunk_t *init; |
| 908 | struct sctp_transport *transport; |
| 909 | struct sctp_af *af; |
| 910 | |
| 911 | ch = (sctp_chunkhdr_t *) skb->data; |
| 912 | |
| 913 | /* If this is INIT/INIT-ACK look inside the chunk too. */ |
| 914 | switch (ch->type) { |
| 915 | case SCTP_CID_INIT: |
| 916 | case SCTP_CID_INIT_ACK: |
| 917 | break; |
| 918 | default: |
| 919 | return NULL; |
| 920 | } |
| 921 | |
| 922 | /* The code below will attempt to walk the chunk and extract |
| 923 | * parameter information. Before we do that, we need to verify |
| 924 | * that the chunk length doesn't cause overflow. Otherwise, we'll |
| 925 | * walk off the end. |
| 926 | */ |
| 927 | if (WORD_ROUND(ntohs(ch->length)) > skb->len) |
| 928 | return NULL; |
| 929 | |
| 930 | /* |
| 931 | * This code will NOT touch anything inside the chunk--it is |
| 932 | * strictly READ-ONLY. |
| 933 | * |
| 934 | * RFC 2960 3 SCTP packet Format |
| 935 | * |
| 936 | * Multiple chunks can be bundled into one SCTP packet up to |
| 937 | * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN |
| 938 | * COMPLETE chunks. These chunks MUST NOT be bundled with any |
| 939 | * other chunk in a packet. See Section 6.10 for more details |
| 940 | * on chunk bundling. |
| 941 | */ |
| 942 | |
| 943 | /* Find the start of the TLVs and the end of the chunk. This is |
| 944 | * the region we search for address parameters. |
| 945 | */ |
| 946 | init = (sctp_init_chunk_t *)skb->data; |
| 947 | |
| 948 | /* Walk the parameters looking for embedded addresses. */ |
| 949 | sctp_walk_params(params, init, init_hdr.params) { |
| 950 | |
| 951 | /* Note: Ignoring hostname addresses. */ |
| 952 | af = sctp_get_af_specific(param_type2af(params.p->type)); |
| 953 | if (!af) |
| 954 | continue; |
| 955 | |
Al Viro | dd86d13 | 2006-11-20 17:11:13 -0800 | [diff] [blame] | 956 | af->from_addr_param(paddr, params.addr, sh->source, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | |
Al Viro | dd86d13 | 2006-11-20 17:11:13 -0800 | [diff] [blame] | 958 | asoc = __sctp_lookup_association(laddr, paddr, &transport); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 959 | if (asoc) |
| 960 | return asoc; |
| 961 | } |
| 962 | |
| 963 | return NULL; |
| 964 | } |
| 965 | |
| 966 | /* Lookup an association for an inbound skb. */ |
| 967 | static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, |
| 968 | const union sctp_addr *paddr, |
| 969 | const union sctp_addr *laddr, |
| 970 | struct sctp_transport **transportp) |
| 971 | { |
| 972 | struct sctp_association *asoc; |
| 973 | |
| 974 | asoc = __sctp_lookup_association(laddr, paddr, transportp); |
| 975 | |
| 976 | /* Further lookup for INIT/INIT-ACK packets. |
| 977 | * SCTP Implementors Guide, 2.18 Handling of address |
| 978 | * parameters within the INIT or INIT-ACK. |
| 979 | */ |
| 980 | if (!asoc) |
| 981 | asoc = __sctp_rcv_init_lookup(skb, laddr, transportp); |
| 982 | |
| 983 | return asoc; |
| 984 | } |