11da177e4SLinus Torvalds /* SCTP kernel reference Implementation 21da177e4SLinus Torvalds * Copyright (c) 1999-2000 Cisco, Inc. 31da177e4SLinus Torvalds * Copyright (c) 1999-2001 Motorola, Inc. 41da177e4SLinus Torvalds * Copyright (c) 2001-2003 International Business Machines, Corp. 51da177e4SLinus Torvalds * Copyright (c) 2001 Intel Corp. 61da177e4SLinus Torvalds * Copyright (c) 2001 Nokia, Inc. 71da177e4SLinus Torvalds * Copyright (c) 2001 La Monte H.P. Yarroll 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * This file is part of the SCTP kernel reference Implementation 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * These functions handle all input from the IP layer into SCTP. 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds * The SCTP reference implementation is free software; 141da177e4SLinus Torvalds * you can redistribute it and/or modify it under the terms of 151da177e4SLinus Torvalds * the GNU General Public License as published by 161da177e4SLinus Torvalds * the Free Software Foundation; either version 2, or (at your option) 171da177e4SLinus Torvalds * any later version. 181da177e4SLinus Torvalds * 191da177e4SLinus Torvalds * The SCTP reference implementation is distributed in the hope that it 201da177e4SLinus Torvalds * will be useful, but WITHOUT ANY WARRANTY; without even the implied 211da177e4SLinus Torvalds * ************************ 221da177e4SLinus Torvalds * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 231da177e4SLinus Torvalds * See the GNU General Public License for more details. 241da177e4SLinus Torvalds * 251da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License 261da177e4SLinus Torvalds * along with GNU CC; see the file COPYING. If not, write to 271da177e4SLinus Torvalds * the Free Software Foundation, 59 Temple Place - Suite 330, 281da177e4SLinus Torvalds * Boston, MA 02111-1307, USA. 291da177e4SLinus Torvalds * 301da177e4SLinus Torvalds * Please send any bug reports or fixes you make to the 311da177e4SLinus Torvalds * email address(es): 321da177e4SLinus Torvalds * lksctp developers <lksctp-developers@lists.sourceforge.net> 331da177e4SLinus Torvalds * 341da177e4SLinus Torvalds * Or submit a bug report through the following website: 351da177e4SLinus Torvalds * http://www.sf.net/projects/lksctp 361da177e4SLinus Torvalds * 371da177e4SLinus Torvalds * Written or modified by: 381da177e4SLinus Torvalds * La Monte H.P. Yarroll <piggy@acm.org> 391da177e4SLinus Torvalds * Karl Knutson <karl@athena.chicago.il.us> 401da177e4SLinus Torvalds * Xingang Guo <xingang.guo@intel.com> 411da177e4SLinus Torvalds * Jon Grimm <jgrimm@us.ibm.com> 421da177e4SLinus Torvalds * Hui Huang <hui.huang@nokia.com> 431da177e4SLinus Torvalds * Daisy Chang <daisyc@us.ibm.com> 441da177e4SLinus Torvalds * Sridhar Samudrala <sri@us.ibm.com> 451da177e4SLinus Torvalds * Ardelle Fan <ardelle.fan@intel.com> 461da177e4SLinus Torvalds * 471da177e4SLinus Torvalds * Any bugs reported given to us we will try to fix... any fixes shared will 481da177e4SLinus Torvalds * be incorporated into the next SCTP release. 491da177e4SLinus Torvalds */ 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds #include <linux/types.h> 521da177e4SLinus Torvalds #include <linux/list.h> /* For struct list_head */ 531da177e4SLinus Torvalds #include <linux/socket.h> 541da177e4SLinus Torvalds #include <linux/ip.h> 551da177e4SLinus Torvalds #include <linux/time.h> /* For struct timeval */ 561da177e4SLinus Torvalds #include <net/ip.h> 571da177e4SLinus Torvalds #include <net/icmp.h> 581da177e4SLinus Torvalds #include <net/snmp.h> 591da177e4SLinus Torvalds #include <net/sock.h> 601da177e4SLinus Torvalds #include <net/xfrm.h> 611da177e4SLinus Torvalds #include <net/sctp/sctp.h> 621da177e4SLinus Torvalds #include <net/sctp/sm.h> 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds /* Forward declarations for internal helpers. */ 651da177e4SLinus Torvalds static int sctp_rcv_ootb(struct sk_buff *); 661da177e4SLinus Torvalds static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, 671da177e4SLinus Torvalds const union sctp_addr *laddr, 681da177e4SLinus Torvalds const union sctp_addr *paddr, 691da177e4SLinus Torvalds struct sctp_transport **transportp); 701da177e4SLinus Torvalds static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr); 711da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 721da177e4SLinus Torvalds const union sctp_addr *local, 731da177e4SLinus Torvalds const union sctp_addr *peer, 741da177e4SLinus Torvalds struct sctp_transport **pt); 751da177e4SLinus Torvalds 7661c9fed4SVladislav Yasevich static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb); 7761c9fed4SVladislav Yasevich 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds /* Calculate the SCTP checksum of an SCTP packet. */ 801da177e4SLinus Torvalds static inline int sctp_rcv_checksum(struct sk_buff *skb) 811da177e4SLinus Torvalds { 821da177e4SLinus Torvalds struct sctphdr *sh; 831da177e4SLinus Torvalds __u32 cmp, val; 841da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 851da177e4SLinus Torvalds 861da177e4SLinus Torvalds sh = (struct sctphdr *) skb->h.raw; 871da177e4SLinus Torvalds cmp = ntohl(sh->checksum); 881da177e4SLinus Torvalds 891da177e4SLinus Torvalds val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds for (; list; list = list->next) 921da177e4SLinus Torvalds val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), 931da177e4SLinus Torvalds val); 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds val = sctp_end_cksum(val); 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds if (val != cmp) { 981da177e4SLinus Torvalds /* CRC failure, dump it. */ 991da177e4SLinus Torvalds SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS); 1001da177e4SLinus Torvalds return -1; 1011da177e4SLinus Torvalds } 1021da177e4SLinus Torvalds return 0; 1031da177e4SLinus Torvalds } 1041da177e4SLinus Torvalds 10579af02c2SDavid S. Miller struct sctp_input_cb { 10679af02c2SDavid S. Miller union { 10779af02c2SDavid S. Miller struct inet_skb_parm h4; 10879af02c2SDavid S. Miller #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) 10979af02c2SDavid S. Miller struct inet6_skb_parm h6; 11079af02c2SDavid S. Miller #endif 11179af02c2SDavid S. Miller } header; 11279af02c2SDavid S. Miller struct sctp_chunk *chunk; 11379af02c2SDavid S. Miller }; 11479af02c2SDavid S. Miller #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) 11579af02c2SDavid S. Miller 1161da177e4SLinus Torvalds /* 1171da177e4SLinus Torvalds * This is the routine which IP calls when receiving an SCTP packet. 1181da177e4SLinus Torvalds */ 1191da177e4SLinus Torvalds int sctp_rcv(struct sk_buff *skb) 1201da177e4SLinus Torvalds { 1211da177e4SLinus Torvalds struct sock *sk; 1221da177e4SLinus Torvalds struct sctp_association *asoc; 1231da177e4SLinus Torvalds struct sctp_endpoint *ep = NULL; 1241da177e4SLinus Torvalds struct sctp_ep_common *rcvr; 1251da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 1261da177e4SLinus Torvalds struct sctp_chunk *chunk; 1271da177e4SLinus Torvalds struct sctphdr *sh; 1281da177e4SLinus Torvalds union sctp_addr src; 1291da177e4SLinus Torvalds union sctp_addr dest; 130*e2fccedbSAl Viro union sctp_addr tmp, tmp2; 1311da177e4SLinus Torvalds int family; 1321da177e4SLinus Torvalds struct sctp_af *af; 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds if (skb->pkt_type!=PACKET_HOST) 1351da177e4SLinus Torvalds goto discard_it; 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS); 1381da177e4SLinus Torvalds 13928cd7752SHerbert Xu if (skb_linearize(skb)) 14028cd7752SHerbert Xu goto discard_it; 14128cd7752SHerbert Xu 1421da177e4SLinus Torvalds sh = (struct sctphdr *) skb->h.raw; 1431da177e4SLinus Torvalds 1441da177e4SLinus Torvalds /* Pull up the IP and SCTP headers. */ 1451da177e4SLinus Torvalds __skb_pull(skb, skb->h.raw - skb->data); 1461da177e4SLinus Torvalds if (skb->len < sizeof(struct sctphdr)) 1471da177e4SLinus Torvalds goto discard_it; 148503b55fdSSridhar Samudrala if ((skb->ip_summed != CHECKSUM_UNNECESSARY) && 149503b55fdSSridhar Samudrala (sctp_rcv_checksum(skb) < 0)) 1501da177e4SLinus Torvalds goto discard_it; 1511da177e4SLinus Torvalds 1521da177e4SLinus Torvalds skb_pull(skb, sizeof(struct sctphdr)); 1531da177e4SLinus Torvalds 1541da177e4SLinus Torvalds /* Make sure we at least have chunk headers worth of data left. */ 1551da177e4SLinus Torvalds if (skb->len < sizeof(struct sctp_chunkhdr)) 1561da177e4SLinus Torvalds goto discard_it; 1571da177e4SLinus Torvalds 1581da177e4SLinus Torvalds family = ipver2af(skb->nh.iph->version); 1591da177e4SLinus Torvalds af = sctp_get_af_specific(family); 1601da177e4SLinus Torvalds if (unlikely(!af)) 1611da177e4SLinus Torvalds goto discard_it; 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 1641da177e4SLinus Torvalds af->from_skb(&src, skb, 1); 1651da177e4SLinus Torvalds af->from_skb(&dest, skb, 0); 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds /* If the packet is to or from a non-unicast address, 1681da177e4SLinus Torvalds * silently discard the packet. 1691da177e4SLinus Torvalds * 1701da177e4SLinus Torvalds * This is not clearly defined in the RFC except in section 1711da177e4SLinus Torvalds * 8.4 - OOTB handling. However, based on the book "Stream Control 1721da177e4SLinus Torvalds * Transmission Protocol" 2.1, "It is important to note that the 1731da177e4SLinus Torvalds * IP address of an SCTP transport address must be a routable 1741da177e4SLinus Torvalds * unicast address. In other words, IP multicast addresses and 1751da177e4SLinus Torvalds * IP broadcast addresses cannot be used in an SCTP transport 1761da177e4SLinus Torvalds * address." 1771da177e4SLinus Torvalds */ 1785636bef7SVlad Yasevich if (!af->addr_valid(&src, NULL, skb) || 1795636bef7SVlad Yasevich !af->addr_valid(&dest, NULL, skb)) 1801da177e4SLinus Torvalds goto discard_it; 1811da177e4SLinus Torvalds 1821c7d1fc1SAl Viro flip_to_n(&tmp, &dest); 183*e2fccedbSAl Viro flip_to_n(&tmp2, &src); 184*e2fccedbSAl Viro 185*e2fccedbSAl Viro asoc = __sctp_rcv_lookup(skb, &tmp2, &tmp, &transport); 1861c7d1fc1SAl Viro 1870fd9a65aSNeil Horman if (!asoc) 1881c7d1fc1SAl Viro ep = __sctp_rcv_lookup_endpoint(&tmp); 1890fd9a65aSNeil Horman 1900fd9a65aSNeil Horman /* Retrieve the common input handling substructure. */ 1910fd9a65aSNeil Horman rcvr = asoc ? &asoc->base : &ep->base; 1920fd9a65aSNeil Horman sk = rcvr->sk; 1930fd9a65aSNeil Horman 1940fd9a65aSNeil Horman /* 1950fd9a65aSNeil Horman * If a frame arrives on an interface and the receiving socket is 1960fd9a65aSNeil Horman * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB 1970fd9a65aSNeil Horman */ 1980fd9a65aSNeil Horman if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) 1990fd9a65aSNeil Horman { 2000fd9a65aSNeil Horman if (asoc) { 2010fd9a65aSNeil Horman sctp_association_put(asoc); 2020fd9a65aSNeil Horman asoc = NULL; 2030fd9a65aSNeil Horman } else { 2040fd9a65aSNeil Horman sctp_endpoint_put(ep); 2050fd9a65aSNeil Horman ep = NULL; 2060fd9a65aSNeil Horman } 2070fd9a65aSNeil Horman sk = sctp_get_ctl_sock(); 2080fd9a65aSNeil Horman ep = sctp_sk(sk)->ep; 2090fd9a65aSNeil Horman sctp_endpoint_hold(ep); 2100fd9a65aSNeil Horman rcvr = &ep->base; 2110fd9a65aSNeil Horman } 2120fd9a65aSNeil Horman 2131da177e4SLinus Torvalds /* 2141da177e4SLinus Torvalds * RFC 2960, 8.4 - Handle "Out of the blue" Packets. 2151da177e4SLinus Torvalds * An SCTP packet is called an "out of the blue" (OOTB) 2161da177e4SLinus Torvalds * packet if it is correctly formed, i.e., passed the 2171da177e4SLinus Torvalds * receiver's checksum check, but the receiver is not 2181da177e4SLinus Torvalds * able to identify the association to which this 2191da177e4SLinus Torvalds * packet belongs. 2201da177e4SLinus Torvalds */ 2211da177e4SLinus Torvalds if (!asoc) { 2221da177e4SLinus Torvalds if (sctp_rcv_ootb(skb)) { 2231da177e4SLinus Torvalds SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES); 2241da177e4SLinus Torvalds goto discard_release; 2251da177e4SLinus Torvalds } 2261da177e4SLinus Torvalds } 2271da177e4SLinus Torvalds 2281da177e4SLinus Torvalds if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) 2291da177e4SLinus Torvalds goto discard_release; 230b59c2701SPatrick McHardy nf_reset(skb); 2311da177e4SLinus Torvalds 232fda9ef5dSDmitry Mishin if (sk_filter(sk, skb)) 2331da177e4SLinus Torvalds goto discard_release; 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds /* Create an SCTP packet structure. */ 2361da177e4SLinus Torvalds chunk = sctp_chunkify(skb, asoc, sk); 2372babf9daSHerbert Xu if (!chunk) 2381da177e4SLinus Torvalds goto discard_release; 23979af02c2SDavid S. Miller SCTP_INPUT_CB(skb)->chunk = chunk; 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvalds /* Remember what endpoint is to handle this packet. */ 2421da177e4SLinus Torvalds chunk->rcvr = rcvr; 2431da177e4SLinus Torvalds 2441da177e4SLinus Torvalds /* Remember the SCTP header. */ 2451da177e4SLinus Torvalds chunk->sctp_hdr = sh; 2461da177e4SLinus Torvalds 2471da177e4SLinus Torvalds /* Set the source and destination addresses of the incoming chunk. */ 2481da177e4SLinus Torvalds sctp_init_addrs(chunk, &src, &dest); 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds /* Remember where we came from. */ 2511da177e4SLinus Torvalds chunk->transport = transport; 2521da177e4SLinus Torvalds 2531da177e4SLinus Torvalds /* Acquire access to the sock lock. Note: We are safe from other 2541da177e4SLinus Torvalds * bottom halves on this lock, but a user may be in the lock too, 2551da177e4SLinus Torvalds * so check if it is busy. 2561da177e4SLinus Torvalds */ 2571da177e4SLinus Torvalds sctp_bh_lock_sock(sk); 2581da177e4SLinus Torvalds 259ac0b0462SSridhar Samudrala if (sock_owned_by_user(sk)) { 260ac0b0462SSridhar Samudrala SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG); 26161c9fed4SVladislav Yasevich sctp_add_backlog(sk, skb); 262ac0b0462SSridhar Samudrala } else { 263ac0b0462SSridhar Samudrala SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ); 26461c9fed4SVladislav Yasevich sctp_inq_push(&chunk->rcvr->inqueue, chunk); 265ac0b0462SSridhar Samudrala } 2661da177e4SLinus Torvalds 2671da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 26861c9fed4SVladislav Yasevich 26961c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 27061c9fed4SVladislav Yasevich if (asoc) 27161c9fed4SVladislav Yasevich sctp_association_put(asoc); 27261c9fed4SVladislav Yasevich else 27361c9fed4SVladislav Yasevich sctp_endpoint_put(ep); 2747a48f923SSridhar Samudrala 2752babf9daSHerbert Xu return 0; 2761da177e4SLinus Torvalds 2771da177e4SLinus Torvalds discard_it: 278ac0b0462SSridhar Samudrala SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS); 2791da177e4SLinus Torvalds kfree_skb(skb); 2802babf9daSHerbert Xu return 0; 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds discard_release: 28361c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 2840fd9a65aSNeil Horman if (asoc) 2851da177e4SLinus Torvalds sctp_association_put(asoc); 2860fd9a65aSNeil Horman else 2871da177e4SLinus Torvalds sctp_endpoint_put(ep); 2881da177e4SLinus Torvalds 2891da177e4SLinus Torvalds goto discard_it; 2901da177e4SLinus Torvalds } 2911da177e4SLinus Torvalds 29261c9fed4SVladislav Yasevich /* Process the backlog queue of the socket. Every skb on 29361c9fed4SVladislav Yasevich * the backlog holds a ref on an association or endpoint. 29461c9fed4SVladislav Yasevich * We hold this ref throughout the state machine to make 29561c9fed4SVladislav Yasevich * sure that the structure we need is still around. 2961da177e4SLinus Torvalds */ 2971da177e4SLinus Torvalds int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) 2981da177e4SLinus Torvalds { 29979af02c2SDavid S. Miller struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 30061c9fed4SVladislav Yasevich struct sctp_inq *inqueue = &chunk->rcvr->inqueue; 3017a48f923SSridhar Samudrala struct sctp_ep_common *rcvr = NULL; 30261c9fed4SVladislav Yasevich int backloged = 0; 3031da177e4SLinus Torvalds 3047a48f923SSridhar Samudrala rcvr = chunk->rcvr; 305c4d2444eSSridhar Samudrala 30661c9fed4SVladislav Yasevich /* If the rcvr is dead then the association or endpoint 30761c9fed4SVladislav Yasevich * has been deleted and we can safely drop the chunk 30861c9fed4SVladislav Yasevich * and refs that we are holding. 30961c9fed4SVladislav Yasevich */ 3107a48f923SSridhar Samudrala if (rcvr->dead) { 3117a48f923SSridhar Samudrala sctp_chunk_free(chunk); 31261c9fed4SVladislav Yasevich goto done; 31361c9fed4SVladislav Yasevich } 31461c9fed4SVladislav Yasevich 31561c9fed4SVladislav Yasevich if (unlikely(rcvr->sk != sk)) { 31661c9fed4SVladislav Yasevich /* In this case, the association moved from one socket to 31761c9fed4SVladislav Yasevich * another. We are currently sitting on the backlog of the 31861c9fed4SVladislav Yasevich * old socket, so we need to move. 31961c9fed4SVladislav Yasevich * However, since we are here in the process context we 32061c9fed4SVladislav Yasevich * need to take make sure that the user doesn't own 32161c9fed4SVladislav Yasevich * the new socket when we process the packet. 32261c9fed4SVladislav Yasevich * If the new socket is user-owned, queue the chunk to the 32361c9fed4SVladislav Yasevich * backlog of the new socket without dropping any refs. 32461c9fed4SVladislav Yasevich * Otherwise, we can safely push the chunk on the inqueue. 32561c9fed4SVladislav Yasevich */ 32661c9fed4SVladislav Yasevich 32761c9fed4SVladislav Yasevich sk = rcvr->sk; 32861c9fed4SVladislav Yasevich sctp_bh_lock_sock(sk); 32961c9fed4SVladislav Yasevich 33061c9fed4SVladislav Yasevich if (sock_owned_by_user(sk)) { 33161c9fed4SVladislav Yasevich sk_add_backlog(sk, skb); 33261c9fed4SVladislav Yasevich backloged = 1; 33361c9fed4SVladislav Yasevich } else 33461c9fed4SVladislav Yasevich sctp_inq_push(inqueue, chunk); 33561c9fed4SVladislav Yasevich 33661c9fed4SVladislav Yasevich sctp_bh_unlock_sock(sk); 33761c9fed4SVladislav Yasevich 33861c9fed4SVladislav Yasevich /* If the chunk was backloged again, don't drop refs */ 33961c9fed4SVladislav Yasevich if (backloged) 34061c9fed4SVladislav Yasevich return 0; 3417a48f923SSridhar Samudrala } else { 3421da177e4SLinus Torvalds sctp_inq_push(inqueue, chunk); 3437a48f923SSridhar Samudrala } 3447a48f923SSridhar Samudrala 34561c9fed4SVladislav Yasevich done: 34661c9fed4SVladislav Yasevich /* Release the refs we took in sctp_add_backlog */ 3477a48f923SSridhar Samudrala if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 3487a48f923SSridhar Samudrala sctp_association_put(sctp_assoc(rcvr)); 34961c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 3507a48f923SSridhar Samudrala sctp_endpoint_put(sctp_ep(rcvr)); 35161c9fed4SVladislav Yasevich else 35261c9fed4SVladislav Yasevich BUG(); 3537a48f923SSridhar Samudrala 3541da177e4SLinus Torvalds return 0; 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds 35761c9fed4SVladislav Yasevich static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb) 358c4d2444eSSridhar Samudrala { 35961c9fed4SVladislav Yasevich struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 36061c9fed4SVladislav Yasevich struct sctp_ep_common *rcvr = chunk->rcvr; 361c4d2444eSSridhar Samudrala 36261c9fed4SVladislav Yasevich /* Hold the assoc/ep while hanging on the backlog queue. 36361c9fed4SVladislav Yasevich * This way, we know structures we need will not disappear from us 36461c9fed4SVladislav Yasevich */ 36561c9fed4SVladislav Yasevich if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 36661c9fed4SVladislav Yasevich sctp_association_hold(sctp_assoc(rcvr)); 36761c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 36861c9fed4SVladislav Yasevich sctp_endpoint_hold(sctp_ep(rcvr)); 369c4d2444eSSridhar Samudrala else 37061c9fed4SVladislav Yasevich BUG(); 37161c9fed4SVladislav Yasevich 37261c9fed4SVladislav Yasevich sk_add_backlog(sk, skb); 373c4d2444eSSridhar Samudrala } 374c4d2444eSSridhar Samudrala 3751da177e4SLinus Torvalds /* Handle icmp frag needed error. */ 3761da177e4SLinus Torvalds void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, 3771da177e4SLinus Torvalds struct sctp_transport *t, __u32 pmtu) 3781da177e4SLinus Torvalds { 37952ccb8e9SFrank Filz if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu)) 38052ccb8e9SFrank Filz return; 38152ccb8e9SFrank Filz 38252ccb8e9SFrank Filz if (t->param_flags & SPP_PMTUD_ENABLE) { 3831da177e4SLinus Torvalds if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) { 3841da177e4SLinus Torvalds printk(KERN_WARNING "%s: Reported pmtu %d too low, " 38552ccb8e9SFrank Filz "using default minimum of %d\n", 38652ccb8e9SFrank Filz __FUNCTION__, pmtu, 3871da177e4SLinus Torvalds SCTP_DEFAULT_MINSEGMENT); 38852ccb8e9SFrank Filz /* Use default minimum segment size and disable 38952ccb8e9SFrank Filz * pmtu discovery on this transport. 39052ccb8e9SFrank Filz */ 39152ccb8e9SFrank Filz t->pathmtu = SCTP_DEFAULT_MINSEGMENT; 392b56bab46SVlad Yasevich t->param_flags = (t->param_flags & ~SPP_PMTUD) | 39352ccb8e9SFrank Filz SPP_PMTUD_DISABLE; 39452ccb8e9SFrank Filz } else { 39552ccb8e9SFrank Filz t->pathmtu = pmtu; 3961da177e4SLinus Torvalds } 3971da177e4SLinus Torvalds 39852ccb8e9SFrank Filz /* Update association pmtu. */ 3991da177e4SLinus Torvalds sctp_assoc_sync_pmtu(asoc); 4001da177e4SLinus Torvalds } 40152ccb8e9SFrank Filz 40252ccb8e9SFrank Filz /* Retransmit with the new pmtu setting. 40352ccb8e9SFrank Filz * Normally, if PMTU discovery is disabled, an ICMP Fragmentation 40452ccb8e9SFrank Filz * Needed will never be sent, but if a message was sent before 40552ccb8e9SFrank Filz * PMTU discovery was disabled that was larger than the PMTU, it 40652ccb8e9SFrank Filz * would not be fragmented, so it must be re-transmitted fragmented. 40752ccb8e9SFrank Filz */ 40852ccb8e9SFrank Filz sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); 4091da177e4SLinus Torvalds } 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds /* 4121da177e4SLinus Torvalds * SCTP Implementer's Guide, 2.37 ICMP handling procedures 4131da177e4SLinus Torvalds * 4141da177e4SLinus Torvalds * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" 4151da177e4SLinus Torvalds * or a "Protocol Unreachable" treat this message as an abort 4161da177e4SLinus Torvalds * with the T bit set. 4171da177e4SLinus Torvalds * 4181da177e4SLinus Torvalds * This function sends an event to the state machine, which will abort the 4191da177e4SLinus Torvalds * association. 4201da177e4SLinus Torvalds * 4211da177e4SLinus Torvalds */ 4221da177e4SLinus Torvalds void sctp_icmp_proto_unreachable(struct sock *sk, 4231da177e4SLinus Torvalds struct sctp_association *asoc, 4241da177e4SLinus Torvalds struct sctp_transport *t) 4251da177e4SLinus Torvalds { 4261da177e4SLinus Torvalds SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__); 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds sctp_do_sm(SCTP_EVENT_T_OTHER, 4291da177e4SLinus Torvalds SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), 4303f7a87d2SFrank Filz asoc->state, asoc->ep, asoc, t, 4311da177e4SLinus Torvalds GFP_ATOMIC); 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds 4351da177e4SLinus Torvalds /* Common lookup code for icmp/icmpv6 error handler. */ 4361da177e4SLinus Torvalds struct sock *sctp_err_lookup(int family, struct sk_buff *skb, 4371da177e4SLinus Torvalds struct sctphdr *sctphdr, 4381da177e4SLinus Torvalds struct sctp_association **app, 4391da177e4SLinus Torvalds struct sctp_transport **tpp) 4401da177e4SLinus Torvalds { 4411da177e4SLinus Torvalds union sctp_addr saddr; 4421da177e4SLinus Torvalds union sctp_addr daddr; 4431da177e4SLinus Torvalds struct sctp_af *af; 4441da177e4SLinus Torvalds struct sock *sk = NULL; 4458de8c873SSridhar Samudrala struct sctp_association *asoc; 4461da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 447*e2fccedbSAl Viro union sctp_addr tmp, tmp2; 4481da177e4SLinus Torvalds 449d1ad1ff2SSridhar Samudrala *app = NULL; *tpp = NULL; 4501da177e4SLinus Torvalds 4511da177e4SLinus Torvalds af = sctp_get_af_specific(family); 4521da177e4SLinus Torvalds if (unlikely(!af)) { 4531da177e4SLinus Torvalds return NULL; 4541da177e4SLinus Torvalds } 4551da177e4SLinus Torvalds 4561da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 4571da177e4SLinus Torvalds af->from_skb(&saddr, skb, 1); 4581da177e4SLinus Torvalds af->from_skb(&daddr, skb, 0); 459*e2fccedbSAl Viro flip_to_n(&tmp, &saddr); 460*e2fccedbSAl Viro flip_to_n(&tmp2, &daddr); 4611da177e4SLinus Torvalds 4621da177e4SLinus Torvalds /* Look for an association that matches the incoming ICMP error 4631da177e4SLinus Torvalds * packet. 4641da177e4SLinus Torvalds */ 465*e2fccedbSAl Viro asoc = __sctp_lookup_association(&tmp, &tmp2, &transport); 466d1ad1ff2SSridhar Samudrala if (!asoc) 4671da177e4SLinus Torvalds return NULL; 4681da177e4SLinus Torvalds 4691da177e4SLinus Torvalds sk = asoc->base.sk; 4701da177e4SLinus Torvalds 4711da177e4SLinus Torvalds if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) { 4721da177e4SLinus Torvalds ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); 4731da177e4SLinus Torvalds goto out; 4741da177e4SLinus Torvalds } 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds sctp_bh_lock_sock(sk); 4771da177e4SLinus Torvalds 4781da177e4SLinus Torvalds /* If too many ICMPs get dropped on busy 4791da177e4SLinus Torvalds * servers this needs to be solved differently. 4801da177e4SLinus Torvalds */ 4811da177e4SLinus Torvalds if (sock_owned_by_user(sk)) 4821da177e4SLinus Torvalds NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); 4831da177e4SLinus Torvalds 4841da177e4SLinus Torvalds *app = asoc; 4851da177e4SLinus Torvalds *tpp = transport; 4861da177e4SLinus Torvalds return sk; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds out: 4891da177e4SLinus Torvalds if (asoc) 4901da177e4SLinus Torvalds sctp_association_put(asoc); 4911da177e4SLinus Torvalds return NULL; 4921da177e4SLinus Torvalds } 4931da177e4SLinus Torvalds 4941da177e4SLinus Torvalds /* Common cleanup code for icmp/icmpv6 error handler. */ 495d1ad1ff2SSridhar Samudrala void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) 4961da177e4SLinus Torvalds { 4971da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 4981da177e4SLinus Torvalds if (asoc) 4991da177e4SLinus Torvalds sctp_association_put(asoc); 5001da177e4SLinus Torvalds } 5011da177e4SLinus Torvalds 5021da177e4SLinus Torvalds /* 5031da177e4SLinus Torvalds * This routine is called by the ICMP module when it gets some 5041da177e4SLinus Torvalds * sort of error condition. If err < 0 then the socket should 5051da177e4SLinus Torvalds * be closed and the error returned to the user. If err > 0 5061da177e4SLinus Torvalds * it's just the icmp type << 8 | icmp code. After adjustment 5071da177e4SLinus Torvalds * header points to the first 8 bytes of the sctp header. We need 5081da177e4SLinus Torvalds * to find the appropriate port. 5091da177e4SLinus Torvalds * 5101da177e4SLinus Torvalds * The locking strategy used here is very "optimistic". When 5111da177e4SLinus Torvalds * someone else accesses the socket the ICMP is just dropped 5121da177e4SLinus Torvalds * and for some paths there is no check at all. 5131da177e4SLinus Torvalds * A more general error queue to queue errors for later handling 5141da177e4SLinus Torvalds * is probably better. 5151da177e4SLinus Torvalds * 5161da177e4SLinus Torvalds */ 5171da177e4SLinus Torvalds void sctp_v4_err(struct sk_buff *skb, __u32 info) 5181da177e4SLinus Torvalds { 5191da177e4SLinus Torvalds struct iphdr *iph = (struct iphdr *)skb->data; 5201da177e4SLinus Torvalds struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2)); 5211da177e4SLinus Torvalds int type = skb->h.icmph->type; 5221da177e4SLinus Torvalds int code = skb->h.icmph->code; 5231da177e4SLinus Torvalds struct sock *sk; 5248de8c873SSridhar Samudrala struct sctp_association *asoc = NULL; 5251da177e4SLinus Torvalds struct sctp_transport *transport; 5261da177e4SLinus Torvalds struct inet_sock *inet; 5271da177e4SLinus Torvalds char *saveip, *savesctp; 5281da177e4SLinus Torvalds int err; 5291da177e4SLinus Torvalds 5301da177e4SLinus Torvalds if (skb->len < ((iph->ihl << 2) + 8)) { 5311da177e4SLinus Torvalds ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); 5321da177e4SLinus Torvalds return; 5331da177e4SLinus Torvalds } 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds /* Fix up skb to look at the embedded net header. */ 5361da177e4SLinus Torvalds saveip = skb->nh.raw; 5371da177e4SLinus Torvalds savesctp = skb->h.raw; 5381da177e4SLinus Torvalds skb->nh.iph = iph; 5391da177e4SLinus Torvalds skb->h.raw = (char *)sh; 540d1ad1ff2SSridhar Samudrala sk = sctp_err_lookup(AF_INET, skb, sh, &asoc, &transport); 5411da177e4SLinus Torvalds /* Put back, the original pointers. */ 5421da177e4SLinus Torvalds skb->nh.raw = saveip; 5431da177e4SLinus Torvalds skb->h.raw = savesctp; 5441da177e4SLinus Torvalds if (!sk) { 5451da177e4SLinus Torvalds ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); 5461da177e4SLinus Torvalds return; 5471da177e4SLinus Torvalds } 5481da177e4SLinus Torvalds /* Warning: The sock lock is held. Remember to call 5491da177e4SLinus Torvalds * sctp_err_finish! 5501da177e4SLinus Torvalds */ 5511da177e4SLinus Torvalds 5521da177e4SLinus Torvalds switch (type) { 5531da177e4SLinus Torvalds case ICMP_PARAMETERPROB: 5541da177e4SLinus Torvalds err = EPROTO; 5551da177e4SLinus Torvalds break; 5561da177e4SLinus Torvalds case ICMP_DEST_UNREACH: 5571da177e4SLinus Torvalds if (code > NR_ICMP_UNREACH) 5581da177e4SLinus Torvalds goto out_unlock; 5591da177e4SLinus Torvalds 5601da177e4SLinus Torvalds /* PMTU discovery (RFC1191) */ 5611da177e4SLinus Torvalds if (ICMP_FRAG_NEEDED == code) { 5621da177e4SLinus Torvalds sctp_icmp_frag_needed(sk, asoc, transport, info); 5631da177e4SLinus Torvalds goto out_unlock; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds else { 5661da177e4SLinus Torvalds if (ICMP_PROT_UNREACH == code) { 567d1ad1ff2SSridhar Samudrala sctp_icmp_proto_unreachable(sk, asoc, 5681da177e4SLinus Torvalds transport); 5691da177e4SLinus Torvalds goto out_unlock; 5701da177e4SLinus Torvalds } 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds err = icmp_err_convert[code].errno; 5731da177e4SLinus Torvalds break; 5741da177e4SLinus Torvalds case ICMP_TIME_EXCEEDED: 5751da177e4SLinus Torvalds /* Ignore any time exceeded errors due to fragment reassembly 5761da177e4SLinus Torvalds * timeouts. 5771da177e4SLinus Torvalds */ 5781da177e4SLinus Torvalds if (ICMP_EXC_FRAGTIME == code) 5791da177e4SLinus Torvalds goto out_unlock; 5801da177e4SLinus Torvalds 5811da177e4SLinus Torvalds err = EHOSTUNREACH; 5821da177e4SLinus Torvalds break; 5831da177e4SLinus Torvalds default: 5841da177e4SLinus Torvalds goto out_unlock; 5851da177e4SLinus Torvalds } 5861da177e4SLinus Torvalds 5871da177e4SLinus Torvalds inet = inet_sk(sk); 5881da177e4SLinus Torvalds if (!sock_owned_by_user(sk) && inet->recverr) { 5891da177e4SLinus Torvalds sk->sk_err = err; 5901da177e4SLinus Torvalds sk->sk_error_report(sk); 5911da177e4SLinus Torvalds } else { /* Only an error on timeout */ 5921da177e4SLinus Torvalds sk->sk_err_soft = err; 5931da177e4SLinus Torvalds } 5941da177e4SLinus Torvalds 5951da177e4SLinus Torvalds out_unlock: 596d1ad1ff2SSridhar Samudrala sctp_err_finish(sk, asoc); 5971da177e4SLinus Torvalds } 5981da177e4SLinus Torvalds 5991da177e4SLinus Torvalds /* 6001da177e4SLinus Torvalds * RFC 2960, 8.4 - Handle "Out of the blue" Packets. 6011da177e4SLinus Torvalds * 6021da177e4SLinus Torvalds * This function scans all the chunks in the OOTB packet to determine if 6031da177e4SLinus Torvalds * the packet should be discarded right away. If a response might be needed 6041da177e4SLinus Torvalds * for this packet, or, if further processing is possible, the packet will 6051da177e4SLinus Torvalds * be queued to a proper inqueue for the next phase of handling. 6061da177e4SLinus Torvalds * 6071da177e4SLinus Torvalds * Output: 6081da177e4SLinus Torvalds * Return 0 - If further processing is needed. 6091da177e4SLinus Torvalds * Return 1 - If the packet can be discarded right away. 6101da177e4SLinus Torvalds */ 6111da177e4SLinus Torvalds int sctp_rcv_ootb(struct sk_buff *skb) 6121da177e4SLinus Torvalds { 6131da177e4SLinus Torvalds sctp_chunkhdr_t *ch; 6141da177e4SLinus Torvalds __u8 *ch_end; 6151da177e4SLinus Torvalds sctp_errhdr_t *err; 6161da177e4SLinus Torvalds 6171da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) skb->data; 6181da177e4SLinus Torvalds 6191da177e4SLinus Torvalds /* Scan through all the chunks in the packet. */ 620a7d1f1b6STsutomu Fujii do { 621a7d1f1b6STsutomu Fujii /* Break out if chunk length is less then minimal. */ 622a7d1f1b6STsutomu Fujii if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) 623a7d1f1b6STsutomu Fujii break; 624a7d1f1b6STsutomu Fujii 625a7d1f1b6STsutomu Fujii ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); 626a7d1f1b6STsutomu Fujii if (ch_end > skb->tail) 627a7d1f1b6STsutomu Fujii break; 6281da177e4SLinus Torvalds 6291da177e4SLinus Torvalds /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the 6301da177e4SLinus Torvalds * receiver MUST silently discard the OOTB packet and take no 6311da177e4SLinus Torvalds * further action. 6321da177e4SLinus Torvalds */ 6331da177e4SLinus Torvalds if (SCTP_CID_ABORT == ch->type) 6341da177e4SLinus Torvalds goto discard; 6351da177e4SLinus Torvalds 6361da177e4SLinus Torvalds /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE 6371da177e4SLinus Torvalds * chunk, the receiver should silently discard the packet 6381da177e4SLinus Torvalds * and take no further action. 6391da177e4SLinus Torvalds */ 6401da177e4SLinus Torvalds if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) 6411da177e4SLinus Torvalds goto discard; 6421da177e4SLinus Torvalds 6431da177e4SLinus Torvalds /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR 6441da177e4SLinus Torvalds * or a COOKIE ACK the SCTP Packet should be silently 6451da177e4SLinus Torvalds * discarded. 6461da177e4SLinus Torvalds */ 6471da177e4SLinus Torvalds if (SCTP_CID_COOKIE_ACK == ch->type) 6481da177e4SLinus Torvalds goto discard; 6491da177e4SLinus Torvalds 6501da177e4SLinus Torvalds if (SCTP_CID_ERROR == ch->type) { 6511da177e4SLinus Torvalds sctp_walk_errors(err, ch) { 6521da177e4SLinus Torvalds if (SCTP_ERROR_STALE_COOKIE == err->cause) 6531da177e4SLinus Torvalds goto discard; 6541da177e4SLinus Torvalds } 6551da177e4SLinus Torvalds } 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) ch_end; 658a7d1f1b6STsutomu Fujii } while (ch_end < skb->tail); 6591da177e4SLinus Torvalds 6601da177e4SLinus Torvalds return 0; 6611da177e4SLinus Torvalds 6621da177e4SLinus Torvalds discard: 6631da177e4SLinus Torvalds return 1; 6641da177e4SLinus Torvalds } 6651da177e4SLinus Torvalds 6661da177e4SLinus Torvalds /* Insert endpoint into the hash table. */ 6671da177e4SLinus Torvalds static void __sctp_hash_endpoint(struct sctp_endpoint *ep) 6681da177e4SLinus Torvalds { 6691da177e4SLinus Torvalds struct sctp_ep_common **epp; 6701da177e4SLinus Torvalds struct sctp_ep_common *epb; 6711da177e4SLinus Torvalds struct sctp_hashbucket *head; 6721da177e4SLinus Torvalds 6731da177e4SLinus Torvalds epb = &ep->base; 6741da177e4SLinus Torvalds 6751da177e4SLinus Torvalds epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); 6761da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 6771da177e4SLinus Torvalds 6781da177e4SLinus Torvalds sctp_write_lock(&head->lock); 6791da177e4SLinus Torvalds epp = &head->chain; 6801da177e4SLinus Torvalds epb->next = *epp; 6811da177e4SLinus Torvalds if (epb->next) 6821da177e4SLinus Torvalds (*epp)->pprev = &epb->next; 6831da177e4SLinus Torvalds *epp = epb; 6841da177e4SLinus Torvalds epb->pprev = epp; 6851da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 6861da177e4SLinus Torvalds } 6871da177e4SLinus Torvalds 6881da177e4SLinus Torvalds /* Add an endpoint to the hash. Local BH-safe. */ 6891da177e4SLinus Torvalds void sctp_hash_endpoint(struct sctp_endpoint *ep) 6901da177e4SLinus Torvalds { 6911da177e4SLinus Torvalds sctp_local_bh_disable(); 6921da177e4SLinus Torvalds __sctp_hash_endpoint(ep); 6931da177e4SLinus Torvalds sctp_local_bh_enable(); 6941da177e4SLinus Torvalds } 6951da177e4SLinus Torvalds 6961da177e4SLinus Torvalds /* Remove endpoint from the hash table. */ 6971da177e4SLinus Torvalds static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) 6981da177e4SLinus Torvalds { 6991da177e4SLinus Torvalds struct sctp_hashbucket *head; 7001da177e4SLinus Torvalds struct sctp_ep_common *epb; 7011da177e4SLinus Torvalds 7021da177e4SLinus Torvalds epb = &ep->base; 7031da177e4SLinus Torvalds 7041da177e4SLinus Torvalds epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); 7051da177e4SLinus Torvalds 7061da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds sctp_write_lock(&head->lock); 7091da177e4SLinus Torvalds 7101da177e4SLinus Torvalds if (epb->pprev) { 7111da177e4SLinus Torvalds if (epb->next) 7121da177e4SLinus Torvalds epb->next->pprev = epb->pprev; 7131da177e4SLinus Torvalds *epb->pprev = epb->next; 7141da177e4SLinus Torvalds epb->pprev = NULL; 7151da177e4SLinus Torvalds } 7161da177e4SLinus Torvalds 7171da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7181da177e4SLinus Torvalds } 7191da177e4SLinus Torvalds 7201da177e4SLinus Torvalds /* Remove endpoint from the hash. Local BH-safe. */ 7211da177e4SLinus Torvalds void sctp_unhash_endpoint(struct sctp_endpoint *ep) 7221da177e4SLinus Torvalds { 7231da177e4SLinus Torvalds sctp_local_bh_disable(); 7241da177e4SLinus Torvalds __sctp_unhash_endpoint(ep); 7251da177e4SLinus Torvalds sctp_local_bh_enable(); 7261da177e4SLinus Torvalds } 7271da177e4SLinus Torvalds 7281da177e4SLinus Torvalds /* Look up an endpoint. */ 7291da177e4SLinus Torvalds static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr) 7301da177e4SLinus Torvalds { 7311da177e4SLinus Torvalds struct sctp_hashbucket *head; 7321da177e4SLinus Torvalds struct sctp_ep_common *epb; 7331da177e4SLinus Torvalds struct sctp_endpoint *ep; 7341da177e4SLinus Torvalds int hash; 7351da177e4SLinus Torvalds 7361c7d1fc1SAl Viro hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port)); 7371da177e4SLinus Torvalds head = &sctp_ep_hashtable[hash]; 7381da177e4SLinus Torvalds read_lock(&head->lock); 7391da177e4SLinus Torvalds for (epb = head->chain; epb; epb = epb->next) { 7401da177e4SLinus Torvalds ep = sctp_ep(epb); 7411da177e4SLinus Torvalds if (sctp_endpoint_is_match(ep, laddr)) 7421da177e4SLinus Torvalds goto hit; 7431da177e4SLinus Torvalds } 7441da177e4SLinus Torvalds 7451da177e4SLinus Torvalds ep = sctp_sk((sctp_get_ctl_sock()))->ep; 7461da177e4SLinus Torvalds epb = &ep->base; 7471da177e4SLinus Torvalds 7481da177e4SLinus Torvalds hit: 7491da177e4SLinus Torvalds sctp_endpoint_hold(ep); 7501da177e4SLinus Torvalds read_unlock(&head->lock); 7511da177e4SLinus Torvalds return ep; 7521da177e4SLinus Torvalds } 7531da177e4SLinus Torvalds 7541da177e4SLinus Torvalds /* Insert association into the hash table. */ 7551da177e4SLinus Torvalds static void __sctp_hash_established(struct sctp_association *asoc) 7561da177e4SLinus Torvalds { 7571da177e4SLinus Torvalds struct sctp_ep_common **epp; 7581da177e4SLinus Torvalds struct sctp_ep_common *epb; 7591da177e4SLinus Torvalds struct sctp_hashbucket *head; 7601da177e4SLinus Torvalds 7611da177e4SLinus Torvalds epb = &asoc->base; 7621da177e4SLinus Torvalds 7631da177e4SLinus Torvalds /* Calculate which chain this entry will belong to. */ 7641da177e4SLinus Torvalds epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port); 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 7671da177e4SLinus Torvalds 7681da177e4SLinus Torvalds sctp_write_lock(&head->lock); 7691da177e4SLinus Torvalds epp = &head->chain; 7701da177e4SLinus Torvalds epb->next = *epp; 7711da177e4SLinus Torvalds if (epb->next) 7721da177e4SLinus Torvalds (*epp)->pprev = &epb->next; 7731da177e4SLinus Torvalds *epp = epb; 7741da177e4SLinus Torvalds epb->pprev = epp; 7751da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7761da177e4SLinus Torvalds } 7771da177e4SLinus Torvalds 7781da177e4SLinus Torvalds /* Add an association to the hash. Local BH-safe. */ 7791da177e4SLinus Torvalds void sctp_hash_established(struct sctp_association *asoc) 7801da177e4SLinus Torvalds { 781de76e695SVlad Yasevich if (asoc->temp) 782de76e695SVlad Yasevich return; 783de76e695SVlad Yasevich 7841da177e4SLinus Torvalds sctp_local_bh_disable(); 7851da177e4SLinus Torvalds __sctp_hash_established(asoc); 7861da177e4SLinus Torvalds sctp_local_bh_enable(); 7871da177e4SLinus Torvalds } 7881da177e4SLinus Torvalds 7891da177e4SLinus Torvalds /* Remove association from the hash table. */ 7901da177e4SLinus Torvalds static void __sctp_unhash_established(struct sctp_association *asoc) 7911da177e4SLinus Torvalds { 7921da177e4SLinus Torvalds struct sctp_hashbucket *head; 7931da177e4SLinus Torvalds struct sctp_ep_common *epb; 7941da177e4SLinus Torvalds 7951da177e4SLinus Torvalds epb = &asoc->base; 7961da177e4SLinus Torvalds 7971da177e4SLinus Torvalds epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, 7981da177e4SLinus Torvalds asoc->peer.port); 7991da177e4SLinus Torvalds 8001da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 8011da177e4SLinus Torvalds 8021da177e4SLinus Torvalds sctp_write_lock(&head->lock); 8031da177e4SLinus Torvalds 8041da177e4SLinus Torvalds if (epb->pprev) { 8051da177e4SLinus Torvalds if (epb->next) 8061da177e4SLinus Torvalds epb->next->pprev = epb->pprev; 8071da177e4SLinus Torvalds *epb->pprev = epb->next; 8081da177e4SLinus Torvalds epb->pprev = NULL; 8091da177e4SLinus Torvalds } 8101da177e4SLinus Torvalds 8111da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 8121da177e4SLinus Torvalds } 8131da177e4SLinus Torvalds 8141da177e4SLinus Torvalds /* Remove association from the hash table. Local BH-safe. */ 8151da177e4SLinus Torvalds void sctp_unhash_established(struct sctp_association *asoc) 8161da177e4SLinus Torvalds { 817de76e695SVlad Yasevich if (asoc->temp) 818de76e695SVlad Yasevich return; 819de76e695SVlad Yasevich 8201da177e4SLinus Torvalds sctp_local_bh_disable(); 8211da177e4SLinus Torvalds __sctp_unhash_established(asoc); 8221da177e4SLinus Torvalds sctp_local_bh_enable(); 8231da177e4SLinus Torvalds } 8241da177e4SLinus Torvalds 8251da177e4SLinus Torvalds /* Look up an association. */ 8261da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 8271da177e4SLinus Torvalds const union sctp_addr *local, 8281da177e4SLinus Torvalds const union sctp_addr *peer, 8291da177e4SLinus Torvalds struct sctp_transport **pt) 8301da177e4SLinus Torvalds { 8311da177e4SLinus Torvalds struct sctp_hashbucket *head; 8321da177e4SLinus Torvalds struct sctp_ep_common *epb; 8331da177e4SLinus Torvalds struct sctp_association *asoc; 8341da177e4SLinus Torvalds struct sctp_transport *transport; 8351da177e4SLinus Torvalds int hash; 8361da177e4SLinus Torvalds 8371da177e4SLinus Torvalds /* Optimize here for direct hit, only listening connections can 8381da177e4SLinus Torvalds * have wildcards anyways. 8391da177e4SLinus Torvalds */ 840*e2fccedbSAl Viro hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port)); 8411da177e4SLinus Torvalds head = &sctp_assoc_hashtable[hash]; 8421da177e4SLinus Torvalds read_lock(&head->lock); 8431da177e4SLinus Torvalds for (epb = head->chain; epb; epb = epb->next) { 8441da177e4SLinus Torvalds asoc = sctp_assoc(epb); 8451da177e4SLinus Torvalds transport = sctp_assoc_is_match(asoc, local, peer); 8461da177e4SLinus Torvalds if (transport) 8471da177e4SLinus Torvalds goto hit; 8481da177e4SLinus Torvalds } 8491da177e4SLinus Torvalds 8501da177e4SLinus Torvalds read_unlock(&head->lock); 8511da177e4SLinus Torvalds 8521da177e4SLinus Torvalds return NULL; 8531da177e4SLinus Torvalds 8541da177e4SLinus Torvalds hit: 8551da177e4SLinus Torvalds *pt = transport; 8561da177e4SLinus Torvalds sctp_association_hold(asoc); 8571da177e4SLinus Torvalds read_unlock(&head->lock); 8581da177e4SLinus Torvalds return asoc; 8591da177e4SLinus Torvalds } 8601da177e4SLinus Torvalds 8611da177e4SLinus Torvalds /* Look up an association. BH-safe. */ 8621da177e4SLinus Torvalds SCTP_STATIC 8631da177e4SLinus Torvalds struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr, 8641da177e4SLinus Torvalds const union sctp_addr *paddr, 8651da177e4SLinus Torvalds struct sctp_transport **transportp) 8661da177e4SLinus Torvalds { 8671da177e4SLinus Torvalds struct sctp_association *asoc; 8681da177e4SLinus Torvalds 8691da177e4SLinus Torvalds sctp_local_bh_disable(); 8701da177e4SLinus Torvalds asoc = __sctp_lookup_association(laddr, paddr, transportp); 8711da177e4SLinus Torvalds sctp_local_bh_enable(); 8721da177e4SLinus Torvalds 8731da177e4SLinus Torvalds return asoc; 8741da177e4SLinus Torvalds } 8751da177e4SLinus Torvalds 8761da177e4SLinus Torvalds /* Is there an association matching the given local and peer addresses? */ 8771da177e4SLinus Torvalds int sctp_has_association(const union sctp_addr *laddr, 8781da177e4SLinus Torvalds const union sctp_addr *paddr) 8791da177e4SLinus Torvalds { 8801da177e4SLinus Torvalds struct sctp_association *asoc; 8811da177e4SLinus Torvalds struct sctp_transport *transport; 882*e2fccedbSAl Viro union sctp_addr tmp, tmp2; 883*e2fccedbSAl Viro flip_to_n(&tmp, laddr); 884*e2fccedbSAl Viro flip_to_n(&tmp2, paddr); 8851da177e4SLinus Torvalds 886*e2fccedbSAl Viro if ((asoc = sctp_lookup_association(&tmp, &tmp2, &transport))) { 8871da177e4SLinus Torvalds sctp_association_put(asoc); 8881da177e4SLinus Torvalds return 1; 8891da177e4SLinus Torvalds } 8901da177e4SLinus Torvalds 8911da177e4SLinus Torvalds return 0; 8921da177e4SLinus Torvalds } 8931da177e4SLinus Torvalds 8941da177e4SLinus Torvalds /* 8951da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 8961da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 8971da177e4SLinus Torvalds * 8981da177e4SLinus Torvalds * D) When searching for a matching TCB upon reception of an INIT 8991da177e4SLinus Torvalds * or INIT-ACK chunk the receiver SHOULD use not only the 9001da177e4SLinus Torvalds * source address of the packet (containing the INIT or 9011da177e4SLinus Torvalds * INIT-ACK) but the receiver SHOULD also use all valid 9021da177e4SLinus Torvalds * address parameters contained within the chunk. 9031da177e4SLinus Torvalds * 9041da177e4SLinus Torvalds * 2.18.3 Solution description 9051da177e4SLinus Torvalds * 9061da177e4SLinus Torvalds * This new text clearly specifies to an implementor the need 9071da177e4SLinus Torvalds * to look within the INIT or INIT-ACK. Any implementation that 9081da177e4SLinus Torvalds * does not do this, may not be able to establish associations 9091da177e4SLinus Torvalds * in certain circumstances. 9101da177e4SLinus Torvalds * 9111da177e4SLinus Torvalds */ 9121da177e4SLinus Torvalds static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, 9131da177e4SLinus Torvalds const union sctp_addr *laddr, struct sctp_transport **transportp) 9141da177e4SLinus Torvalds { 9151da177e4SLinus Torvalds struct sctp_association *asoc; 9161da177e4SLinus Torvalds union sctp_addr addr; 9171da177e4SLinus Torvalds union sctp_addr *paddr = &addr; 9181da177e4SLinus Torvalds struct sctphdr *sh = (struct sctphdr *) skb->h.raw; 9191da177e4SLinus Torvalds sctp_chunkhdr_t *ch; 9201da177e4SLinus Torvalds union sctp_params params; 9211da177e4SLinus Torvalds sctp_init_chunk_t *init; 9221da177e4SLinus Torvalds struct sctp_transport *transport; 9231da177e4SLinus Torvalds struct sctp_af *af; 924*e2fccedbSAl Viro union sctp_addr tmp2; 9251da177e4SLinus Torvalds 9261da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) skb->data; 9271da177e4SLinus Torvalds 9281da177e4SLinus Torvalds /* If this is INIT/INIT-ACK look inside the chunk too. */ 9291da177e4SLinus Torvalds switch (ch->type) { 9301da177e4SLinus Torvalds case SCTP_CID_INIT: 9311da177e4SLinus Torvalds case SCTP_CID_INIT_ACK: 9321da177e4SLinus Torvalds break; 9331da177e4SLinus Torvalds default: 9341da177e4SLinus Torvalds return NULL; 9351da177e4SLinus Torvalds } 9361da177e4SLinus Torvalds 9371da177e4SLinus Torvalds /* The code below will attempt to walk the chunk and extract 9381da177e4SLinus Torvalds * parameter information. Before we do that, we need to verify 9391da177e4SLinus Torvalds * that the chunk length doesn't cause overflow. Otherwise, we'll 9401da177e4SLinus Torvalds * walk off the end. 9411da177e4SLinus Torvalds */ 9421da177e4SLinus Torvalds if (WORD_ROUND(ntohs(ch->length)) > skb->len) 9431da177e4SLinus Torvalds return NULL; 9441da177e4SLinus Torvalds 9451da177e4SLinus Torvalds /* 9461da177e4SLinus Torvalds * This code will NOT touch anything inside the chunk--it is 9471da177e4SLinus Torvalds * strictly READ-ONLY. 9481da177e4SLinus Torvalds * 9491da177e4SLinus Torvalds * RFC 2960 3 SCTP packet Format 9501da177e4SLinus Torvalds * 9511da177e4SLinus Torvalds * Multiple chunks can be bundled into one SCTP packet up to 9521da177e4SLinus Torvalds * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN 9531da177e4SLinus Torvalds * COMPLETE chunks. These chunks MUST NOT be bundled with any 9541da177e4SLinus Torvalds * other chunk in a packet. See Section 6.10 for more details 9551da177e4SLinus Torvalds * on chunk bundling. 9561da177e4SLinus Torvalds */ 9571da177e4SLinus Torvalds 9581da177e4SLinus Torvalds /* Find the start of the TLVs and the end of the chunk. This is 9591da177e4SLinus Torvalds * the region we search for address parameters. 9601da177e4SLinus Torvalds */ 9611da177e4SLinus Torvalds init = (sctp_init_chunk_t *)skb->data; 9621da177e4SLinus Torvalds 9631da177e4SLinus Torvalds /* Walk the parameters looking for embedded addresses. */ 9641da177e4SLinus Torvalds sctp_walk_params(params, init, init_hdr.params) { 9651da177e4SLinus Torvalds 9661da177e4SLinus Torvalds /* Note: Ignoring hostname addresses. */ 9671da177e4SLinus Torvalds af = sctp_get_af_specific(param_type2af(params.p->type)); 9681da177e4SLinus Torvalds if (!af) 9691da177e4SLinus Torvalds continue; 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds af->from_addr_param(paddr, params.addr, ntohs(sh->source), 0); 972*e2fccedbSAl Viro flip_to_n(&tmp2, paddr); 9731da177e4SLinus Torvalds 974*e2fccedbSAl Viro asoc = __sctp_lookup_association(laddr, &tmp2, &transport); 9751da177e4SLinus Torvalds if (asoc) 9761da177e4SLinus Torvalds return asoc; 9771da177e4SLinus Torvalds } 9781da177e4SLinus Torvalds 9791da177e4SLinus Torvalds return NULL; 9801da177e4SLinus Torvalds } 9811da177e4SLinus Torvalds 9821da177e4SLinus Torvalds /* Lookup an association for an inbound skb. */ 9831da177e4SLinus Torvalds static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, 9841da177e4SLinus Torvalds const union sctp_addr *paddr, 9851da177e4SLinus Torvalds const union sctp_addr *laddr, 9861da177e4SLinus Torvalds struct sctp_transport **transportp) 9871da177e4SLinus Torvalds { 9881da177e4SLinus Torvalds struct sctp_association *asoc; 9891da177e4SLinus Torvalds 9901da177e4SLinus Torvalds asoc = __sctp_lookup_association(laddr, paddr, transportp); 9911da177e4SLinus Torvalds 9921da177e4SLinus Torvalds /* Further lookup for INIT/INIT-ACK packets. 9931da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 9941da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 9951da177e4SLinus Torvalds */ 9961da177e4SLinus Torvalds if (!asoc) 9971da177e4SLinus Torvalds asoc = __sctp_rcv_init_lookup(skb, laddr, transportp); 9981da177e4SLinus Torvalds 9991da177e4SLinus Torvalds return asoc; 10001da177e4SLinus Torvalds } 1001