160c778b2SVlad Yasevich /* SCTP kernel 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 * 960c778b2SVlad Yasevich * This file is part of the SCTP kernel implementation 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * These functions handle all input from the IP layer into SCTP. 121da177e4SLinus Torvalds * 1360c778b2SVlad Yasevich * This SCTP 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 * 1960c778b2SVlad Yasevich * This SCTP 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 */ 565a0e3ad6STejun Heo #include <linux/slab.h> 571da177e4SLinus Torvalds #include <net/ip.h> 581da177e4SLinus Torvalds #include <net/icmp.h> 591da177e4SLinus Torvalds #include <net/snmp.h> 601da177e4SLinus Torvalds #include <net/sock.h> 611da177e4SLinus Torvalds #include <net/xfrm.h> 621da177e4SLinus Torvalds #include <net/sctp/sctp.h> 631da177e4SLinus Torvalds #include <net/sctp/sm.h> 649ad0977fSVlad Yasevich #include <net/sctp/checksum.h> 65dcfc23caSPavel Emelyanov #include <net/net_namespace.h> 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds /* Forward declarations for internal helpers. */ 681da177e4SLinus Torvalds static int sctp_rcv_ootb(struct sk_buff *); 694110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup(struct net *net, 704110cc25SEric W. Biederman struct sk_buff *skb, 711da177e4SLinus Torvalds const union sctp_addr *paddr, 72*57565993SNicolas Dichtel const union sctp_addr *laddr, 731da177e4SLinus Torvalds struct sctp_transport **transportp); 744cdadcbcSEric W. Biederman static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, 754cdadcbcSEric W. Biederman const union sctp_addr *laddr); 761da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 774110cc25SEric W. Biederman struct net *net, 781da177e4SLinus Torvalds const union sctp_addr *local, 791da177e4SLinus Torvalds const union sctp_addr *peer, 801da177e4SLinus Torvalds struct sctp_transport **pt); 811da177e4SLinus Torvalds 8250b1a782SZhu Yi static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb); 8361c9fed4SVladislav Yasevich 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds /* Calculate the SCTP checksum of an SCTP packet. */ 86b01a2407SEric W. Biederman static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb) 871da177e4SLinus Torvalds { 882c0fd387SArnaldo Carvalho de Melo struct sctphdr *sh = sctp_hdr(skb); 894458f04cSVlad Yasevich __le32 cmp = sh->checksum; 901b003be3SDavid S. Miller struct sk_buff *list; 914458f04cSVlad Yasevich __le32 val; 924458f04cSVlad Yasevich __u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); 931da177e4SLinus Torvalds 941b003be3SDavid S. Miller skb_walk_frags(skb, list) 954458f04cSVlad Yasevich tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), 964458f04cSVlad Yasevich tmp); 971da177e4SLinus Torvalds 984458f04cSVlad Yasevich val = sctp_end_cksum(tmp); 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds if (val != cmp) { 1011da177e4SLinus Torvalds /* CRC failure, dump it. */ 102b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_CHECKSUMERRORS); 1031da177e4SLinus Torvalds return -1; 1041da177e4SLinus Torvalds } 1051da177e4SLinus Torvalds return 0; 1061da177e4SLinus Torvalds } 1071da177e4SLinus Torvalds 10879af02c2SDavid S. Miller struct sctp_input_cb { 10979af02c2SDavid S. Miller union { 11079af02c2SDavid S. Miller struct inet_skb_parm h4; 111dfd56b8bSEric Dumazet #if IS_ENABLED(CONFIG_IPV6) 11279af02c2SDavid S. Miller struct inet6_skb_parm h6; 11379af02c2SDavid S. Miller #endif 11479af02c2SDavid S. Miller } header; 11579af02c2SDavid S. Miller struct sctp_chunk *chunk; 11679af02c2SDavid S. Miller }; 11779af02c2SDavid S. Miller #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) 11879af02c2SDavid S. Miller 1191da177e4SLinus Torvalds /* 1201da177e4SLinus Torvalds * This is the routine which IP calls when receiving an SCTP packet. 1211da177e4SLinus Torvalds */ 1221da177e4SLinus Torvalds int sctp_rcv(struct sk_buff *skb) 1231da177e4SLinus Torvalds { 1241da177e4SLinus Torvalds struct sock *sk; 1251da177e4SLinus Torvalds struct sctp_association *asoc; 1261da177e4SLinus Torvalds struct sctp_endpoint *ep = NULL; 1271da177e4SLinus Torvalds struct sctp_ep_common *rcvr; 1281da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 1291da177e4SLinus Torvalds struct sctp_chunk *chunk; 1301da177e4SLinus Torvalds struct sctphdr *sh; 1311da177e4SLinus Torvalds union sctp_addr src; 1321da177e4SLinus Torvalds union sctp_addr dest; 1331da177e4SLinus Torvalds int family; 1341da177e4SLinus Torvalds struct sctp_af *af; 1354cdadcbcSEric W. Biederman struct net *net = dev_net(skb->dev); 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds if (skb->pkt_type!=PACKET_HOST) 1381da177e4SLinus Torvalds goto discard_it; 1391da177e4SLinus Torvalds 140b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_INSCTPPACKS); 1411da177e4SLinus Torvalds 14228cd7752SHerbert Xu if (skb_linearize(skb)) 14328cd7752SHerbert Xu goto discard_it; 14428cd7752SHerbert Xu 1452c0fd387SArnaldo Carvalho de Melo sh = sctp_hdr(skb); 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds /* Pull up the IP and SCTP headers. */ 148ea2ae17dSArnaldo Carvalho de Melo __skb_pull(skb, skb_transport_offset(skb)); 1491da177e4SLinus Torvalds if (skb->len < sizeof(struct sctphdr)) 1501da177e4SLinus Torvalds goto discard_it; 15106e86806SLucas Nussbaum if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) && 152b01a2407SEric W. Biederman sctp_rcv_checksum(net, skb) < 0) 1531da177e4SLinus Torvalds goto discard_it; 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds skb_pull(skb, sizeof(struct sctphdr)); 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds /* Make sure we at least have chunk headers worth of data left. */ 1581da177e4SLinus Torvalds if (skb->len < sizeof(struct sctp_chunkhdr)) 1591da177e4SLinus Torvalds goto discard_it; 1601da177e4SLinus Torvalds 161eddc9ec5SArnaldo Carvalho de Melo family = ipver2af(ip_hdr(skb)->version); 1621da177e4SLinus Torvalds af = sctp_get_af_specific(family); 1631da177e4SLinus Torvalds if (unlikely(!af)) 1641da177e4SLinus Torvalds goto discard_it; 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 1671da177e4SLinus Torvalds af->from_skb(&src, skb, 1); 1681da177e4SLinus Torvalds af->from_skb(&dest, skb, 0); 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds /* If the packet is to or from a non-unicast address, 1711da177e4SLinus Torvalds * silently discard the packet. 1721da177e4SLinus Torvalds * 1731da177e4SLinus Torvalds * This is not clearly defined in the RFC except in section 1741da177e4SLinus Torvalds * 8.4 - OOTB handling. However, based on the book "Stream Control 1751da177e4SLinus Torvalds * Transmission Protocol" 2.1, "It is important to note that the 1761da177e4SLinus Torvalds * IP address of an SCTP transport address must be a routable 1771da177e4SLinus Torvalds * unicast address. In other words, IP multicast addresses and 1781da177e4SLinus Torvalds * IP broadcast addresses cannot be used in an SCTP transport 1791da177e4SLinus Torvalds * address." 1801da177e4SLinus Torvalds */ 1815636bef7SVlad Yasevich if (!af->addr_valid(&src, NULL, skb) || 1825636bef7SVlad Yasevich !af->addr_valid(&dest, NULL, skb)) 1831da177e4SLinus Torvalds goto discard_it; 1841da177e4SLinus Torvalds 1854110cc25SEric W. Biederman asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport); 1861c7d1fc1SAl Viro 1870fd9a65aSNeil Horman if (!asoc) 1884cdadcbcSEric W. Biederman ep = __sctp_rcv_lookup_endpoint(net, &dest); 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 } 2072ce95503SEric W. Biederman sk = net->sctp.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)) { 223b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, 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. */ 248d55c41b1SAl Viro 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 259ae53b5bdSVlad Yasevich if (sk != rcvr->sk) { 260ae53b5bdSVlad Yasevich /* Our cached sk is different from the rcvr->sk. This is 261ae53b5bdSVlad Yasevich * because migrate()/accept() may have moved the association 262ae53b5bdSVlad Yasevich * to a new socket and released all the sockets. So now we 263ae53b5bdSVlad Yasevich * are holding a lock on the old socket while the user may 264ae53b5bdSVlad Yasevich * be doing something with the new socket. Switch our veiw 265ae53b5bdSVlad Yasevich * of the current sk. 266ae53b5bdSVlad Yasevich */ 267ae53b5bdSVlad Yasevich sctp_bh_unlock_sock(sk); 268ae53b5bdSVlad Yasevich sk = rcvr->sk; 269ae53b5bdSVlad Yasevich sctp_bh_lock_sock(sk); 270ae53b5bdSVlad Yasevich } 271ae53b5bdSVlad Yasevich 272ac0b0462SSridhar Samudrala if (sock_owned_by_user(sk)) { 27350b1a782SZhu Yi if (sctp_add_backlog(sk, skb)) { 27450b1a782SZhu Yi sctp_bh_unlock_sock(sk); 27550b1a782SZhu Yi sctp_chunk_free(chunk); 27650b1a782SZhu Yi skb = NULL; /* sctp_chunk_free already freed the skb */ 27750b1a782SZhu Yi goto discard_release; 27850b1a782SZhu Yi } 279b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_BACKLOG); 280ac0b0462SSridhar Samudrala } else { 281b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_SOFTIRQ); 28261c9fed4SVladislav Yasevich sctp_inq_push(&chunk->rcvr->inqueue, chunk); 283ac0b0462SSridhar Samudrala } 2841da177e4SLinus Torvalds 2851da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 28661c9fed4SVladislav Yasevich 28761c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 28861c9fed4SVladislav Yasevich if (asoc) 28961c9fed4SVladislav Yasevich sctp_association_put(asoc); 29061c9fed4SVladislav Yasevich else 29161c9fed4SVladislav Yasevich sctp_endpoint_put(ep); 2927a48f923SSridhar Samudrala 2932babf9daSHerbert Xu return 0; 2941da177e4SLinus Torvalds 2951da177e4SLinus Torvalds discard_it: 296b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_DISCARDS); 2971da177e4SLinus Torvalds kfree_skb(skb); 2982babf9daSHerbert Xu return 0; 2991da177e4SLinus Torvalds 3001da177e4SLinus Torvalds discard_release: 30161c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 3020fd9a65aSNeil Horman if (asoc) 3031da177e4SLinus Torvalds sctp_association_put(asoc); 3040fd9a65aSNeil Horman else 3051da177e4SLinus Torvalds sctp_endpoint_put(ep); 3061da177e4SLinus Torvalds 3071da177e4SLinus Torvalds goto discard_it; 3081da177e4SLinus Torvalds } 3091da177e4SLinus Torvalds 31061c9fed4SVladislav Yasevich /* Process the backlog queue of the socket. Every skb on 31161c9fed4SVladislav Yasevich * the backlog holds a ref on an association or endpoint. 31261c9fed4SVladislav Yasevich * We hold this ref throughout the state machine to make 31361c9fed4SVladislav Yasevich * sure that the structure we need is still around. 3141da177e4SLinus Torvalds */ 3151da177e4SLinus Torvalds int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) 3161da177e4SLinus Torvalds { 31779af02c2SDavid S. Miller struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 31861c9fed4SVladislav Yasevich struct sctp_inq *inqueue = &chunk->rcvr->inqueue; 3197a48f923SSridhar Samudrala struct sctp_ep_common *rcvr = NULL; 32061c9fed4SVladislav Yasevich int backloged = 0; 3211da177e4SLinus Torvalds 3227a48f923SSridhar Samudrala rcvr = chunk->rcvr; 323c4d2444eSSridhar Samudrala 32461c9fed4SVladislav Yasevich /* If the rcvr is dead then the association or endpoint 32561c9fed4SVladislav Yasevich * has been deleted and we can safely drop the chunk 32661c9fed4SVladislav Yasevich * and refs that we are holding. 32761c9fed4SVladislav Yasevich */ 3287a48f923SSridhar Samudrala if (rcvr->dead) { 3297a48f923SSridhar Samudrala sctp_chunk_free(chunk); 33061c9fed4SVladislav Yasevich goto done; 33161c9fed4SVladislav Yasevich } 33261c9fed4SVladislav Yasevich 33361c9fed4SVladislav Yasevich if (unlikely(rcvr->sk != sk)) { 33461c9fed4SVladislav Yasevich /* In this case, the association moved from one socket to 33561c9fed4SVladislav Yasevich * another. We are currently sitting on the backlog of the 33661c9fed4SVladislav Yasevich * old socket, so we need to move. 33761c9fed4SVladislav Yasevich * However, since we are here in the process context we 33861c9fed4SVladislav Yasevich * need to take make sure that the user doesn't own 33961c9fed4SVladislav Yasevich * the new socket when we process the packet. 34061c9fed4SVladislav Yasevich * If the new socket is user-owned, queue the chunk to the 34161c9fed4SVladislav Yasevich * backlog of the new socket without dropping any refs. 34261c9fed4SVladislav Yasevich * Otherwise, we can safely push the chunk on the inqueue. 34361c9fed4SVladislav Yasevich */ 34461c9fed4SVladislav Yasevich 34561c9fed4SVladislav Yasevich sk = rcvr->sk; 34661c9fed4SVladislav Yasevich sctp_bh_lock_sock(sk); 34761c9fed4SVladislav Yasevich 34861c9fed4SVladislav Yasevich if (sock_owned_by_user(sk)) { 349f545a38fSEric Dumazet if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) 35050b1a782SZhu Yi sctp_chunk_free(chunk); 35150b1a782SZhu Yi else 35261c9fed4SVladislav Yasevich backloged = 1; 35361c9fed4SVladislav Yasevich } else 35461c9fed4SVladislav Yasevich sctp_inq_push(inqueue, chunk); 35561c9fed4SVladislav Yasevich 35661c9fed4SVladislav Yasevich sctp_bh_unlock_sock(sk); 35761c9fed4SVladislav Yasevich 35861c9fed4SVladislav Yasevich /* If the chunk was backloged again, don't drop refs */ 35961c9fed4SVladislav Yasevich if (backloged) 36061c9fed4SVladislav Yasevich return 0; 3617a48f923SSridhar Samudrala } else { 3621da177e4SLinus Torvalds sctp_inq_push(inqueue, chunk); 3637a48f923SSridhar Samudrala } 3647a48f923SSridhar Samudrala 36561c9fed4SVladislav Yasevich done: 36661c9fed4SVladislav Yasevich /* Release the refs we took in sctp_add_backlog */ 3677a48f923SSridhar Samudrala if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 3687a48f923SSridhar Samudrala sctp_association_put(sctp_assoc(rcvr)); 36961c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 3707a48f923SSridhar Samudrala sctp_endpoint_put(sctp_ep(rcvr)); 37161c9fed4SVladislav Yasevich else 37261c9fed4SVladislav Yasevich BUG(); 3737a48f923SSridhar Samudrala 3741da177e4SLinus Torvalds return 0; 3751da177e4SLinus Torvalds } 3761da177e4SLinus Torvalds 37750b1a782SZhu Yi static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb) 378c4d2444eSSridhar Samudrala { 37961c9fed4SVladislav Yasevich struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 38061c9fed4SVladislav Yasevich struct sctp_ep_common *rcvr = chunk->rcvr; 38150b1a782SZhu Yi int ret; 382c4d2444eSSridhar Samudrala 383f545a38fSEric Dumazet ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf); 38450b1a782SZhu Yi if (!ret) { 38561c9fed4SVladislav Yasevich /* Hold the assoc/ep while hanging on the backlog queue. 38650b1a782SZhu Yi * This way, we know structures we need will not disappear 38750b1a782SZhu Yi * from us 38861c9fed4SVladislav Yasevich */ 38961c9fed4SVladislav Yasevich if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 39061c9fed4SVladislav Yasevich sctp_association_hold(sctp_assoc(rcvr)); 39161c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 39261c9fed4SVladislav Yasevich sctp_endpoint_hold(sctp_ep(rcvr)); 393c4d2444eSSridhar Samudrala else 39461c9fed4SVladislav Yasevich BUG(); 39550b1a782SZhu Yi } 39650b1a782SZhu Yi return ret; 39761c9fed4SVladislav Yasevich 398c4d2444eSSridhar Samudrala } 399c4d2444eSSridhar Samudrala 4001da177e4SLinus Torvalds /* Handle icmp frag needed error. */ 4011da177e4SLinus Torvalds void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, 4021da177e4SLinus Torvalds struct sctp_transport *t, __u32 pmtu) 4031da177e4SLinus Torvalds { 40491bd6b1eSWei Yongjun if (!t || (t->pathmtu <= pmtu)) 40552ccb8e9SFrank Filz return; 40652ccb8e9SFrank Filz 4078a479491SVlad Yasevich if (sock_owned_by_user(sk)) { 4088a479491SVlad Yasevich asoc->pmtu_pending = 1; 4098a479491SVlad Yasevich t->pmtu_pending = 1; 4108a479491SVlad Yasevich return; 4118a479491SVlad Yasevich } 4128a479491SVlad Yasevich 41352ccb8e9SFrank Filz if (t->param_flags & SPP_PMTUD_ENABLE) { 414c910b47eSVlad Yasevich /* Update transports view of the MTU */ 41502f3d4ceSDavid S. Miller sctp_transport_update_pmtu(sk, t, pmtu); 4161da177e4SLinus Torvalds 41752ccb8e9SFrank Filz /* Update association pmtu. */ 41802f3d4ceSDavid S. Miller sctp_assoc_sync_pmtu(sk, asoc); 4191da177e4SLinus Torvalds } 42052ccb8e9SFrank Filz 42152ccb8e9SFrank Filz /* Retransmit with the new pmtu setting. 42252ccb8e9SFrank Filz * Normally, if PMTU discovery is disabled, an ICMP Fragmentation 42352ccb8e9SFrank Filz * Needed will never be sent, but if a message was sent before 42452ccb8e9SFrank Filz * PMTU discovery was disabled that was larger than the PMTU, it 42552ccb8e9SFrank Filz * would not be fragmented, so it must be re-transmitted fragmented. 42652ccb8e9SFrank Filz */ 42752ccb8e9SFrank Filz sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); 4281da177e4SLinus Torvalds } 4291da177e4SLinus Torvalds 430ec18d9a2SDavid S. Miller void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t, 43155be7a9cSDavid S. Miller struct sk_buff *skb) 43255be7a9cSDavid S. Miller { 43355be7a9cSDavid S. Miller struct dst_entry *dst; 43455be7a9cSDavid S. Miller 43555be7a9cSDavid S. Miller if (!t) 43655be7a9cSDavid S. Miller return; 43755be7a9cSDavid S. Miller dst = sctp_transport_dst_check(t); 4381ed5c48fSDavid S. Miller if (dst) 4396700c270SDavid S. Miller dst->ops->redirect(dst, sk, skb); 44055be7a9cSDavid S. Miller } 44155be7a9cSDavid S. Miller 4421da177e4SLinus Torvalds /* 4431da177e4SLinus Torvalds * SCTP Implementer's Guide, 2.37 ICMP handling procedures 4441da177e4SLinus Torvalds * 4451da177e4SLinus Torvalds * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" 4461da177e4SLinus Torvalds * or a "Protocol Unreachable" treat this message as an abort 4471da177e4SLinus Torvalds * with the T bit set. 4481da177e4SLinus Torvalds * 4491da177e4SLinus Torvalds * This function sends an event to the state machine, which will abort the 4501da177e4SLinus Torvalds * association. 4511da177e4SLinus Torvalds * 4521da177e4SLinus Torvalds */ 4531da177e4SLinus Torvalds void sctp_icmp_proto_unreachable(struct sock *sk, 4541da177e4SLinus Torvalds struct sctp_association *asoc, 4551da177e4SLinus Torvalds struct sctp_transport *t) 4561da177e4SLinus Torvalds { 4570dc47877SHarvey Harrison SCTP_DEBUG_PRINTK("%s\n", __func__); 4581da177e4SLinus Torvalds 45950b5d6adSVlad Yasevich if (sock_owned_by_user(sk)) { 46050b5d6adSVlad Yasevich if (timer_pending(&t->proto_unreach_timer)) 46150b5d6adSVlad Yasevich return; 46250b5d6adSVlad Yasevich else { 46350b5d6adSVlad Yasevich if (!mod_timer(&t->proto_unreach_timer, 46450b5d6adSVlad Yasevich jiffies + (HZ/20))) 46550b5d6adSVlad Yasevich sctp_association_hold(asoc); 46650b5d6adSVlad Yasevich } 46750b5d6adSVlad Yasevich 46850b5d6adSVlad Yasevich } else { 46955e26eb9SEric W. Biederman struct net *net = sock_net(sk); 47055e26eb9SEric W. Biederman 47150b5d6adSVlad Yasevich if (timer_pending(&t->proto_unreach_timer) && 47250b5d6adSVlad Yasevich del_timer(&t->proto_unreach_timer)) 47350b5d6adSVlad Yasevich sctp_association_put(asoc); 47450b5d6adSVlad Yasevich 47555e26eb9SEric W. Biederman sctp_do_sm(net, SCTP_EVENT_T_OTHER, 4761da177e4SLinus Torvalds SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), 4773f7a87d2SFrank Filz asoc->state, asoc->ep, asoc, t, 4781da177e4SLinus Torvalds GFP_ATOMIC); 47950b5d6adSVlad Yasevich } 4801da177e4SLinus Torvalds } 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds /* Common lookup code for icmp/icmpv6 error handler. */ 4834110cc25SEric W. Biederman struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb, 4841da177e4SLinus Torvalds struct sctphdr *sctphdr, 4851da177e4SLinus Torvalds struct sctp_association **app, 4861da177e4SLinus Torvalds struct sctp_transport **tpp) 4871da177e4SLinus Torvalds { 4881da177e4SLinus Torvalds union sctp_addr saddr; 4891da177e4SLinus Torvalds union sctp_addr daddr; 4901da177e4SLinus Torvalds struct sctp_af *af; 4911da177e4SLinus Torvalds struct sock *sk = NULL; 4928de8c873SSridhar Samudrala struct sctp_association *asoc; 4931da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 4947115e632SWei Yongjun struct sctp_init_chunk *chunkhdr; 4957115e632SWei Yongjun __u32 vtag = ntohl(sctphdr->vtag); 4967115e632SWei Yongjun int len = skb->len - ((void *)sctphdr - (void *)skb->data); 4971da177e4SLinus Torvalds 498d1ad1ff2SSridhar Samudrala *app = NULL; *tpp = NULL; 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds af = sctp_get_af_specific(family); 5011da177e4SLinus Torvalds if (unlikely(!af)) { 5021da177e4SLinus Torvalds return NULL; 5031da177e4SLinus Torvalds } 5041da177e4SLinus Torvalds 5051da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 5061da177e4SLinus Torvalds af->from_skb(&saddr, skb, 1); 5071da177e4SLinus Torvalds af->from_skb(&daddr, skb, 0); 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds /* Look for an association that matches the incoming ICMP error 5101da177e4SLinus Torvalds * packet. 5111da177e4SLinus Torvalds */ 5124110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport); 513d1ad1ff2SSridhar Samudrala if (!asoc) 5141da177e4SLinus Torvalds return NULL; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds sk = asoc->base.sk; 5171da177e4SLinus Torvalds 5187115e632SWei Yongjun /* RFC 4960, Appendix C. ICMP Handling 5197115e632SWei Yongjun * 5207115e632SWei Yongjun * ICMP6) An implementation MUST validate that the Verification Tag 5217115e632SWei Yongjun * contained in the ICMP message matches the Verification Tag of 5227115e632SWei Yongjun * the peer. If the Verification Tag is not 0 and does NOT 5237115e632SWei Yongjun * match, discard the ICMP message. If it is 0 and the ICMP 5247115e632SWei Yongjun * message contains enough bytes to verify that the chunk type is 5257115e632SWei Yongjun * an INIT chunk and that the Initiate Tag matches the tag of the 5267115e632SWei Yongjun * peer, continue with ICMP7. If the ICMP message is too short 5277115e632SWei Yongjun * or the chunk type or the Initiate Tag does not match, silently 5287115e632SWei Yongjun * discard the packet. 5297115e632SWei Yongjun */ 5307115e632SWei Yongjun if (vtag == 0) { 531ea110733SJoe Perches chunkhdr = (void *)sctphdr + sizeof(struct sctphdr); 5327115e632SWei Yongjun if (len < sizeof(struct sctphdr) + sizeof(sctp_chunkhdr_t) 5337115e632SWei Yongjun + sizeof(__be32) || 5347115e632SWei Yongjun chunkhdr->chunk_hdr.type != SCTP_CID_INIT || 5357115e632SWei Yongjun ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) { 5367115e632SWei Yongjun goto out; 5377115e632SWei Yongjun } 5387115e632SWei Yongjun } else if (vtag != asoc->c.peer_vtag) { 5391da177e4SLinus Torvalds goto out; 5401da177e4SLinus Torvalds } 5411da177e4SLinus Torvalds 5421da177e4SLinus Torvalds sctp_bh_lock_sock(sk); 5431da177e4SLinus Torvalds 5441da177e4SLinus Torvalds /* If too many ICMPs get dropped on busy 5451da177e4SLinus Torvalds * servers this needs to be solved differently. 5461da177e4SLinus Torvalds */ 5471da177e4SLinus Torvalds if (sock_owned_by_user(sk)) 548b01a2407SEric W. Biederman NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); 5491da177e4SLinus Torvalds 5501da177e4SLinus Torvalds *app = asoc; 5511da177e4SLinus Torvalds *tpp = transport; 5521da177e4SLinus Torvalds return sk; 5531da177e4SLinus Torvalds 5541da177e4SLinus Torvalds out: 5551da177e4SLinus Torvalds if (asoc) 5561da177e4SLinus Torvalds sctp_association_put(asoc); 5571da177e4SLinus Torvalds return NULL; 5581da177e4SLinus Torvalds } 5591da177e4SLinus Torvalds 5601da177e4SLinus Torvalds /* Common cleanup code for icmp/icmpv6 error handler. */ 561d1ad1ff2SSridhar Samudrala void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) 5621da177e4SLinus Torvalds { 5631da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 5641da177e4SLinus Torvalds if (asoc) 5651da177e4SLinus Torvalds sctp_association_put(asoc); 5661da177e4SLinus Torvalds } 5671da177e4SLinus Torvalds 5681da177e4SLinus Torvalds /* 5691da177e4SLinus Torvalds * This routine is called by the ICMP module when it gets some 5701da177e4SLinus Torvalds * sort of error condition. If err < 0 then the socket should 5711da177e4SLinus Torvalds * be closed and the error returned to the user. If err > 0 5721da177e4SLinus Torvalds * it's just the icmp type << 8 | icmp code. After adjustment 5731da177e4SLinus Torvalds * header points to the first 8 bytes of the sctp header. We need 5741da177e4SLinus Torvalds * to find the appropriate port. 5751da177e4SLinus Torvalds * 5761da177e4SLinus Torvalds * The locking strategy used here is very "optimistic". When 5771da177e4SLinus Torvalds * someone else accesses the socket the ICMP is just dropped 5781da177e4SLinus Torvalds * and for some paths there is no check at all. 5791da177e4SLinus Torvalds * A more general error queue to queue errors for later handling 5801da177e4SLinus Torvalds * is probably better. 5811da177e4SLinus Torvalds * 5821da177e4SLinus Torvalds */ 5831da177e4SLinus Torvalds void sctp_v4_err(struct sk_buff *skb, __u32 info) 5841da177e4SLinus Torvalds { 585b71d1d42SEric Dumazet const struct iphdr *iph = (const struct iphdr *)skb->data; 586a27ef749SArnaldo Carvalho de Melo const int ihlen = iph->ihl * 4; 58788c7664fSArnaldo Carvalho de Melo const int type = icmp_hdr(skb)->type; 58888c7664fSArnaldo Carvalho de Melo const int code = icmp_hdr(skb)->code; 5891da177e4SLinus Torvalds struct sock *sk; 5908de8c873SSridhar Samudrala struct sctp_association *asoc = NULL; 5911da177e4SLinus Torvalds struct sctp_transport *transport; 5921da177e4SLinus Torvalds struct inet_sock *inet; 5932e07fa9cSArnaldo Carvalho de Melo sk_buff_data_t saveip, savesctp; 5941da177e4SLinus Torvalds int err; 5954110cc25SEric W. Biederman struct net *net = dev_net(skb->dev); 5961da177e4SLinus Torvalds 597a27ef749SArnaldo Carvalho de Melo if (skb->len < ihlen + 8) { 598b01a2407SEric W. Biederman ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 5991da177e4SLinus Torvalds return; 6001da177e4SLinus Torvalds } 6011da177e4SLinus Torvalds 6021da177e4SLinus Torvalds /* Fix up skb to look at the embedded net header. */ 603b0e380b1SArnaldo Carvalho de Melo saveip = skb->network_header; 604b0e380b1SArnaldo Carvalho de Melo savesctp = skb->transport_header; 60531c7711bSArnaldo Carvalho de Melo skb_reset_network_header(skb); 606a27ef749SArnaldo Carvalho de Melo skb_set_transport_header(skb, ihlen); 6074110cc25SEric W. Biederman sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport); 6082e07fa9cSArnaldo Carvalho de Melo /* Put back, the original values. */ 609b0e380b1SArnaldo Carvalho de Melo skb->network_header = saveip; 610b0e380b1SArnaldo Carvalho de Melo skb->transport_header = savesctp; 6111da177e4SLinus Torvalds if (!sk) { 612b01a2407SEric W. Biederman ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 6131da177e4SLinus Torvalds return; 6141da177e4SLinus Torvalds } 6151da177e4SLinus Torvalds /* Warning: The sock lock is held. Remember to call 6161da177e4SLinus Torvalds * sctp_err_finish! 6171da177e4SLinus Torvalds */ 6181da177e4SLinus Torvalds 6191da177e4SLinus Torvalds switch (type) { 6201da177e4SLinus Torvalds case ICMP_PARAMETERPROB: 6211da177e4SLinus Torvalds err = EPROTO; 6221da177e4SLinus Torvalds break; 6231da177e4SLinus Torvalds case ICMP_DEST_UNREACH: 6241da177e4SLinus Torvalds if (code > NR_ICMP_UNREACH) 6251da177e4SLinus Torvalds goto out_unlock; 6261da177e4SLinus Torvalds 6271da177e4SLinus Torvalds /* PMTU discovery (RFC1191) */ 6281da177e4SLinus Torvalds if (ICMP_FRAG_NEEDED == code) { 6291da177e4SLinus Torvalds sctp_icmp_frag_needed(sk, asoc, transport, info); 6301da177e4SLinus Torvalds goto out_unlock; 6311da177e4SLinus Torvalds } 6321da177e4SLinus Torvalds else { 6331da177e4SLinus Torvalds if (ICMP_PROT_UNREACH == code) { 634d1ad1ff2SSridhar Samudrala sctp_icmp_proto_unreachable(sk, asoc, 6351da177e4SLinus Torvalds transport); 6361da177e4SLinus Torvalds goto out_unlock; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds } 6391da177e4SLinus Torvalds err = icmp_err_convert[code].errno; 6401da177e4SLinus Torvalds break; 6411da177e4SLinus Torvalds case ICMP_TIME_EXCEEDED: 6421da177e4SLinus Torvalds /* Ignore any time exceeded errors due to fragment reassembly 6431da177e4SLinus Torvalds * timeouts. 6441da177e4SLinus Torvalds */ 6451da177e4SLinus Torvalds if (ICMP_EXC_FRAGTIME == code) 6461da177e4SLinus Torvalds goto out_unlock; 6471da177e4SLinus Torvalds 6481da177e4SLinus Torvalds err = EHOSTUNREACH; 6491da177e4SLinus Torvalds break; 65055be7a9cSDavid S. Miller case ICMP_REDIRECT: 65155be7a9cSDavid S. Miller sctp_icmp_redirect(sk, transport, skb); 65255be7a9cSDavid S. Miller err = 0; 65355be7a9cSDavid S. Miller break; 6541da177e4SLinus Torvalds default: 6551da177e4SLinus Torvalds goto out_unlock; 6561da177e4SLinus Torvalds } 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds inet = inet_sk(sk); 6591da177e4SLinus Torvalds if (!sock_owned_by_user(sk) && inet->recverr) { 6601da177e4SLinus Torvalds sk->sk_err = err; 6611da177e4SLinus Torvalds sk->sk_error_report(sk); 6621da177e4SLinus Torvalds } else { /* Only an error on timeout */ 6631da177e4SLinus Torvalds sk->sk_err_soft = err; 6641da177e4SLinus Torvalds } 6651da177e4SLinus Torvalds 6661da177e4SLinus Torvalds out_unlock: 667d1ad1ff2SSridhar Samudrala sctp_err_finish(sk, asoc); 6681da177e4SLinus Torvalds } 6691da177e4SLinus Torvalds 6701da177e4SLinus Torvalds /* 6711da177e4SLinus Torvalds * RFC 2960, 8.4 - Handle "Out of the blue" Packets. 6721da177e4SLinus Torvalds * 6731da177e4SLinus Torvalds * This function scans all the chunks in the OOTB packet to determine if 6741da177e4SLinus Torvalds * the packet should be discarded right away. If a response might be needed 6751da177e4SLinus Torvalds * for this packet, or, if further processing is possible, the packet will 6761da177e4SLinus Torvalds * be queued to a proper inqueue for the next phase of handling. 6771da177e4SLinus Torvalds * 6781da177e4SLinus Torvalds * Output: 6791da177e4SLinus Torvalds * Return 0 - If further processing is needed. 6801da177e4SLinus Torvalds * Return 1 - If the packet can be discarded right away. 6811da177e4SLinus Torvalds */ 68204675210Ssebastian@breakpoint.cc static int sctp_rcv_ootb(struct sk_buff *skb) 6831da177e4SLinus Torvalds { 6841da177e4SLinus Torvalds sctp_chunkhdr_t *ch; 6851da177e4SLinus Torvalds __u8 *ch_end; 6861da177e4SLinus Torvalds 6871da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) skb->data; 6881da177e4SLinus Torvalds 6891da177e4SLinus Torvalds /* Scan through all the chunks in the packet. */ 690a7d1f1b6STsutomu Fujii do { 691a7d1f1b6STsutomu Fujii /* Break out if chunk length is less then minimal. */ 692a7d1f1b6STsutomu Fujii if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) 693a7d1f1b6STsutomu Fujii break; 694a7d1f1b6STsutomu Fujii 695a7d1f1b6STsutomu Fujii ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); 69627a884dcSArnaldo Carvalho de Melo if (ch_end > skb_tail_pointer(skb)) 697a7d1f1b6STsutomu Fujii break; 6981da177e4SLinus Torvalds 6991da177e4SLinus Torvalds /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the 7001da177e4SLinus Torvalds * receiver MUST silently discard the OOTB packet and take no 7011da177e4SLinus Torvalds * further action. 7021da177e4SLinus Torvalds */ 7031da177e4SLinus Torvalds if (SCTP_CID_ABORT == ch->type) 7041da177e4SLinus Torvalds goto discard; 7051da177e4SLinus Torvalds 7061da177e4SLinus Torvalds /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE 7071da177e4SLinus Torvalds * chunk, the receiver should silently discard the packet 7081da177e4SLinus Torvalds * and take no further action. 7091da177e4SLinus Torvalds */ 7101da177e4SLinus Torvalds if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) 7111da177e4SLinus Torvalds goto discard; 7121da177e4SLinus Torvalds 7133c77f961SVlad Yasevich /* RFC 4460, 2.11.2 7143c77f961SVlad Yasevich * This will discard packets with INIT chunk bundled as 7153c77f961SVlad Yasevich * subsequent chunks in the packet. When INIT is first, 7163c77f961SVlad Yasevich * the normal INIT processing will discard the chunk. 7173c77f961SVlad Yasevich */ 7183c77f961SVlad Yasevich if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) 7193c77f961SVlad Yasevich goto discard; 7203c77f961SVlad Yasevich 7211da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) ch_end; 72227a884dcSArnaldo Carvalho de Melo } while (ch_end < skb_tail_pointer(skb)); 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds return 0; 7251da177e4SLinus Torvalds 7261da177e4SLinus Torvalds discard: 7271da177e4SLinus Torvalds return 1; 7281da177e4SLinus Torvalds } 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds /* Insert endpoint into the hash table. */ 7311da177e4SLinus Torvalds static void __sctp_hash_endpoint(struct sctp_endpoint *ep) 7321da177e4SLinus Torvalds { 7334cdadcbcSEric W. Biederman struct net *net = sock_net(ep->base.sk); 7341da177e4SLinus Torvalds struct sctp_ep_common *epb; 7351da177e4SLinus Torvalds struct sctp_hashbucket *head; 7361da177e4SLinus Torvalds 7371da177e4SLinus Torvalds epb = &ep->base; 7381da177e4SLinus Torvalds 7394cdadcbcSEric W. Biederman epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); 7401da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 7411da177e4SLinus Torvalds 7421da177e4SLinus Torvalds sctp_write_lock(&head->lock); 743d970dbf8SVlad Yasevich hlist_add_head(&epb->node, &head->chain); 7441da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7451da177e4SLinus Torvalds } 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds /* Add an endpoint to the hash. Local BH-safe. */ 7481da177e4SLinus Torvalds void sctp_hash_endpoint(struct sctp_endpoint *ep) 7491da177e4SLinus Torvalds { 7501da177e4SLinus Torvalds sctp_local_bh_disable(); 7511da177e4SLinus Torvalds __sctp_hash_endpoint(ep); 7521da177e4SLinus Torvalds sctp_local_bh_enable(); 7531da177e4SLinus Torvalds } 7541da177e4SLinus Torvalds 7551da177e4SLinus Torvalds /* Remove endpoint from the hash table. */ 7561da177e4SLinus Torvalds static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) 7571da177e4SLinus Torvalds { 7584cdadcbcSEric W. Biederman struct net *net = sock_net(ep->base.sk); 7591da177e4SLinus Torvalds struct sctp_hashbucket *head; 7601da177e4SLinus Torvalds struct sctp_ep_common *epb; 7611da177e4SLinus Torvalds 7621da177e4SLinus Torvalds epb = &ep->base; 7631da177e4SLinus Torvalds 7644cdadcbcSEric W. Biederman epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 7671da177e4SLinus Torvalds 7681da177e4SLinus Torvalds sctp_write_lock(&head->lock); 7692eebc1e1SNeil Horman hlist_del_init(&epb->node); 7701da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7711da177e4SLinus Torvalds } 7721da177e4SLinus Torvalds 7731da177e4SLinus Torvalds /* Remove endpoint from the hash. Local BH-safe. */ 7741da177e4SLinus Torvalds void sctp_unhash_endpoint(struct sctp_endpoint *ep) 7751da177e4SLinus Torvalds { 7761da177e4SLinus Torvalds sctp_local_bh_disable(); 7771da177e4SLinus Torvalds __sctp_unhash_endpoint(ep); 7781da177e4SLinus Torvalds sctp_local_bh_enable(); 7791da177e4SLinus Torvalds } 7801da177e4SLinus Torvalds 7811da177e4SLinus Torvalds /* Look up an endpoint. */ 7824cdadcbcSEric W. Biederman static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, 7834cdadcbcSEric W. Biederman const union sctp_addr *laddr) 7841da177e4SLinus Torvalds { 7851da177e4SLinus Torvalds struct sctp_hashbucket *head; 7861da177e4SLinus Torvalds struct sctp_ep_common *epb; 7871da177e4SLinus Torvalds struct sctp_endpoint *ep; 788d970dbf8SVlad Yasevich struct hlist_node *node; 7891da177e4SLinus Torvalds int hash; 7901da177e4SLinus Torvalds 7914cdadcbcSEric W. Biederman hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port)); 7921da177e4SLinus Torvalds head = &sctp_ep_hashtable[hash]; 7931da177e4SLinus Torvalds read_lock(&head->lock); 794d970dbf8SVlad Yasevich sctp_for_each_hentry(epb, node, &head->chain) { 7951da177e4SLinus Torvalds ep = sctp_ep(epb); 7964cdadcbcSEric W. Biederman if (sctp_endpoint_is_match(ep, net, laddr)) 7971da177e4SLinus Torvalds goto hit; 7981da177e4SLinus Torvalds } 7991da177e4SLinus Torvalds 8002ce95503SEric W. Biederman ep = sctp_sk(net->sctp.ctl_sock)->ep; 8011da177e4SLinus Torvalds 8021da177e4SLinus Torvalds hit: 8031da177e4SLinus Torvalds sctp_endpoint_hold(ep); 8041da177e4SLinus Torvalds read_unlock(&head->lock); 8051da177e4SLinus Torvalds return ep; 8061da177e4SLinus Torvalds } 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds /* Insert association into the hash table. */ 8091da177e4SLinus Torvalds static void __sctp_hash_established(struct sctp_association *asoc) 8101da177e4SLinus Torvalds { 8114110cc25SEric W. Biederman struct net *net = sock_net(asoc->base.sk); 8121da177e4SLinus Torvalds struct sctp_ep_common *epb; 8131da177e4SLinus Torvalds struct sctp_hashbucket *head; 8141da177e4SLinus Torvalds 8151da177e4SLinus Torvalds epb = &asoc->base; 8161da177e4SLinus Torvalds 8171da177e4SLinus Torvalds /* Calculate which chain this entry will belong to. */ 8184110cc25SEric W. Biederman epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, 8194110cc25SEric W. Biederman asoc->peer.port); 8201da177e4SLinus Torvalds 8211da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 8221da177e4SLinus Torvalds 8231da177e4SLinus Torvalds sctp_write_lock(&head->lock); 824d970dbf8SVlad Yasevich hlist_add_head(&epb->node, &head->chain); 8251da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 8261da177e4SLinus Torvalds } 8271da177e4SLinus Torvalds 8281da177e4SLinus Torvalds /* Add an association to the hash. Local BH-safe. */ 8291da177e4SLinus Torvalds void sctp_hash_established(struct sctp_association *asoc) 8301da177e4SLinus Torvalds { 831de76e695SVlad Yasevich if (asoc->temp) 832de76e695SVlad Yasevich return; 833de76e695SVlad Yasevich 8341da177e4SLinus Torvalds sctp_local_bh_disable(); 8351da177e4SLinus Torvalds __sctp_hash_established(asoc); 8361da177e4SLinus Torvalds sctp_local_bh_enable(); 8371da177e4SLinus Torvalds } 8381da177e4SLinus Torvalds 8391da177e4SLinus Torvalds /* Remove association from the hash table. */ 8401da177e4SLinus Torvalds static void __sctp_unhash_established(struct sctp_association *asoc) 8411da177e4SLinus Torvalds { 8424110cc25SEric W. Biederman struct net *net = sock_net(asoc->base.sk); 8431da177e4SLinus Torvalds struct sctp_hashbucket *head; 8441da177e4SLinus Torvalds struct sctp_ep_common *epb; 8451da177e4SLinus Torvalds 8461da177e4SLinus Torvalds epb = &asoc->base; 8471da177e4SLinus Torvalds 8484110cc25SEric W. Biederman epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, 8491da177e4SLinus Torvalds asoc->peer.port); 8501da177e4SLinus Torvalds 8511da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 8521da177e4SLinus Torvalds 8531da177e4SLinus Torvalds sctp_write_lock(&head->lock); 8542eebc1e1SNeil Horman hlist_del_init(&epb->node); 8551da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 8561da177e4SLinus Torvalds } 8571da177e4SLinus Torvalds 8581da177e4SLinus Torvalds /* Remove association from the hash table. Local BH-safe. */ 8591da177e4SLinus Torvalds void sctp_unhash_established(struct sctp_association *asoc) 8601da177e4SLinus Torvalds { 861de76e695SVlad Yasevich if (asoc->temp) 862de76e695SVlad Yasevich return; 863de76e695SVlad Yasevich 8641da177e4SLinus Torvalds sctp_local_bh_disable(); 8651da177e4SLinus Torvalds __sctp_unhash_established(asoc); 8661da177e4SLinus Torvalds sctp_local_bh_enable(); 8671da177e4SLinus Torvalds } 8681da177e4SLinus Torvalds 8691da177e4SLinus Torvalds /* Look up an association. */ 8701da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 8714110cc25SEric W. Biederman struct net *net, 8721da177e4SLinus Torvalds const union sctp_addr *local, 8731da177e4SLinus Torvalds const union sctp_addr *peer, 8741da177e4SLinus Torvalds struct sctp_transport **pt) 8751da177e4SLinus Torvalds { 8761da177e4SLinus Torvalds struct sctp_hashbucket *head; 8771da177e4SLinus Torvalds struct sctp_ep_common *epb; 8781da177e4SLinus Torvalds struct sctp_association *asoc; 8791da177e4SLinus Torvalds struct sctp_transport *transport; 880d970dbf8SVlad Yasevich struct hlist_node *node; 8811da177e4SLinus Torvalds int hash; 8821da177e4SLinus Torvalds 8831da177e4SLinus Torvalds /* Optimize here for direct hit, only listening connections can 8841da177e4SLinus Torvalds * have wildcards anyways. 8851da177e4SLinus Torvalds */ 8864110cc25SEric W. Biederman hash = sctp_assoc_hashfn(net, ntohs(local->v4.sin_port), 8874110cc25SEric W. Biederman ntohs(peer->v4.sin_port)); 8881da177e4SLinus Torvalds head = &sctp_assoc_hashtable[hash]; 8891da177e4SLinus Torvalds read_lock(&head->lock); 890d970dbf8SVlad Yasevich sctp_for_each_hentry(epb, node, &head->chain) { 8911da177e4SLinus Torvalds asoc = sctp_assoc(epb); 8924110cc25SEric W. Biederman transport = sctp_assoc_is_match(asoc, net, local, peer); 8931da177e4SLinus Torvalds if (transport) 8941da177e4SLinus Torvalds goto hit; 8951da177e4SLinus Torvalds } 8961da177e4SLinus Torvalds 8971da177e4SLinus Torvalds read_unlock(&head->lock); 8981da177e4SLinus Torvalds 8991da177e4SLinus Torvalds return NULL; 9001da177e4SLinus Torvalds 9011da177e4SLinus Torvalds hit: 9021da177e4SLinus Torvalds *pt = transport; 9031da177e4SLinus Torvalds sctp_association_hold(asoc); 9041da177e4SLinus Torvalds read_unlock(&head->lock); 9051da177e4SLinus Torvalds return asoc; 9061da177e4SLinus Torvalds } 9071da177e4SLinus Torvalds 9081da177e4SLinus Torvalds /* Look up an association. BH-safe. */ 9091da177e4SLinus Torvalds SCTP_STATIC 9104110cc25SEric W. Biederman struct sctp_association *sctp_lookup_association(struct net *net, 9114110cc25SEric W. Biederman const union sctp_addr *laddr, 9121da177e4SLinus Torvalds const union sctp_addr *paddr, 9131da177e4SLinus Torvalds struct sctp_transport **transportp) 9141da177e4SLinus Torvalds { 9151da177e4SLinus Torvalds struct sctp_association *asoc; 9161da177e4SLinus Torvalds 9171da177e4SLinus Torvalds sctp_local_bh_disable(); 9184110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, transportp); 9191da177e4SLinus Torvalds sctp_local_bh_enable(); 9201da177e4SLinus Torvalds 9211da177e4SLinus Torvalds return asoc; 9221da177e4SLinus Torvalds } 9231da177e4SLinus Torvalds 9241da177e4SLinus Torvalds /* Is there an association matching the given local and peer addresses? */ 9254110cc25SEric W. Biederman int sctp_has_association(struct net *net, 9264110cc25SEric W. Biederman const union sctp_addr *laddr, 9271da177e4SLinus Torvalds const union sctp_addr *paddr) 9281da177e4SLinus Torvalds { 9291da177e4SLinus Torvalds struct sctp_association *asoc; 9301da177e4SLinus Torvalds struct sctp_transport *transport; 9311da177e4SLinus Torvalds 9324110cc25SEric W. Biederman if ((asoc = sctp_lookup_association(net, laddr, paddr, &transport))) { 9331da177e4SLinus Torvalds sctp_association_put(asoc); 9341da177e4SLinus Torvalds return 1; 9351da177e4SLinus Torvalds } 9361da177e4SLinus Torvalds 9371da177e4SLinus Torvalds return 0; 9381da177e4SLinus Torvalds } 9391da177e4SLinus Torvalds 9401da177e4SLinus Torvalds /* 9411da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 9421da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 9431da177e4SLinus Torvalds * 9441da177e4SLinus Torvalds * D) When searching for a matching TCB upon reception of an INIT 9451da177e4SLinus Torvalds * or INIT-ACK chunk the receiver SHOULD use not only the 9461da177e4SLinus Torvalds * source address of the packet (containing the INIT or 9471da177e4SLinus Torvalds * INIT-ACK) but the receiver SHOULD also use all valid 9481da177e4SLinus Torvalds * address parameters contained within the chunk. 9491da177e4SLinus Torvalds * 9501da177e4SLinus Torvalds * 2.18.3 Solution description 9511da177e4SLinus Torvalds * 9521da177e4SLinus Torvalds * This new text clearly specifies to an implementor the need 9531da177e4SLinus Torvalds * to look within the INIT or INIT-ACK. Any implementation that 9541da177e4SLinus Torvalds * does not do this, may not be able to establish associations 9551da177e4SLinus Torvalds * in certain circumstances. 9561da177e4SLinus Torvalds * 9571da177e4SLinus Torvalds */ 9584110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_init_lookup(struct net *net, 9594110cc25SEric W. Biederman struct sk_buff *skb, 9601da177e4SLinus Torvalds const union sctp_addr *laddr, struct sctp_transport **transportp) 9611da177e4SLinus Torvalds { 9621da177e4SLinus Torvalds struct sctp_association *asoc; 9631da177e4SLinus Torvalds union sctp_addr addr; 9641da177e4SLinus Torvalds union sctp_addr *paddr = &addr; 9652c0fd387SArnaldo Carvalho de Melo struct sctphdr *sh = sctp_hdr(skb); 9661da177e4SLinus Torvalds union sctp_params params; 9671da177e4SLinus Torvalds sctp_init_chunk_t *init; 9681da177e4SLinus Torvalds struct sctp_transport *transport; 9691da177e4SLinus Torvalds struct sctp_af *af; 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds /* 9721da177e4SLinus Torvalds * This code will NOT touch anything inside the chunk--it is 9731da177e4SLinus Torvalds * strictly READ-ONLY. 9741da177e4SLinus Torvalds * 9751da177e4SLinus Torvalds * RFC 2960 3 SCTP packet Format 9761da177e4SLinus Torvalds * 9771da177e4SLinus Torvalds * Multiple chunks can be bundled into one SCTP packet up to 9781da177e4SLinus Torvalds * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN 9791da177e4SLinus Torvalds * COMPLETE chunks. These chunks MUST NOT be bundled with any 9801da177e4SLinus Torvalds * other chunk in a packet. See Section 6.10 for more details 9811da177e4SLinus Torvalds * on chunk bundling. 9821da177e4SLinus Torvalds */ 9831da177e4SLinus Torvalds 9841da177e4SLinus Torvalds /* Find the start of the TLVs and the end of the chunk. This is 9851da177e4SLinus Torvalds * the region we search for address parameters. 9861da177e4SLinus Torvalds */ 9871da177e4SLinus Torvalds init = (sctp_init_chunk_t *)skb->data; 9881da177e4SLinus Torvalds 9891da177e4SLinus Torvalds /* Walk the parameters looking for embedded addresses. */ 9901da177e4SLinus Torvalds sctp_walk_params(params, init, init_hdr.params) { 9911da177e4SLinus Torvalds 9921da177e4SLinus Torvalds /* Note: Ignoring hostname addresses. */ 9931da177e4SLinus Torvalds af = sctp_get_af_specific(param_type2af(params.p->type)); 9941da177e4SLinus Torvalds if (!af) 9951da177e4SLinus Torvalds continue; 9961da177e4SLinus Torvalds 997dd86d136SAl Viro af->from_addr_param(paddr, params.addr, sh->source, 0); 9981da177e4SLinus Torvalds 9994110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, &transport); 10001da177e4SLinus Torvalds if (asoc) 10011da177e4SLinus Torvalds return asoc; 10021da177e4SLinus Torvalds } 10031da177e4SLinus Torvalds 10041da177e4SLinus Torvalds return NULL; 10051da177e4SLinus Torvalds } 10061da177e4SLinus Torvalds 1007df218577SVlad Yasevich /* ADD-IP, Section 5.2 1008df218577SVlad Yasevich * When an endpoint receives an ASCONF Chunk from the remote peer 1009df218577SVlad Yasevich * special procedures may be needed to identify the association the 1010df218577SVlad Yasevich * ASCONF Chunk is associated with. To properly find the association 1011df218577SVlad Yasevich * the following procedures SHOULD be followed: 1012df218577SVlad Yasevich * 1013df218577SVlad Yasevich * D2) If the association is not found, use the address found in the 1014df218577SVlad Yasevich * Address Parameter TLV combined with the port number found in the 1015df218577SVlad Yasevich * SCTP common header. If found proceed to rule D4. 1016df218577SVlad Yasevich * 1017df218577SVlad Yasevich * D2-ext) If more than one ASCONF Chunks are packed together, use the 1018df218577SVlad Yasevich * address found in the ASCONF Address Parameter TLV of each of the 1019df218577SVlad Yasevich * subsequent ASCONF Chunks. If found, proceed to rule D4. 1020df218577SVlad Yasevich */ 1021df218577SVlad Yasevich static struct sctp_association *__sctp_rcv_asconf_lookup( 10224110cc25SEric W. Biederman struct net *net, 1023df218577SVlad Yasevich sctp_chunkhdr_t *ch, 1024df218577SVlad Yasevich const union sctp_addr *laddr, 1025bc92dd19SAl Viro __be16 peer_port, 1026df218577SVlad Yasevich struct sctp_transport **transportp) 1027df218577SVlad Yasevich { 1028df218577SVlad Yasevich sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch; 1029df218577SVlad Yasevich struct sctp_af *af; 1030df218577SVlad Yasevich union sctp_addr_param *param; 1031df218577SVlad Yasevich union sctp_addr paddr; 1032df218577SVlad Yasevich 1033df218577SVlad Yasevich /* Skip over the ADDIP header and find the Address parameter */ 1034df218577SVlad Yasevich param = (union sctp_addr_param *)(asconf + 1); 1035df218577SVlad Yasevich 10366a435732SShan Wei af = sctp_get_af_specific(param_type2af(param->p.type)); 1037df218577SVlad Yasevich if (unlikely(!af)) 1038df218577SVlad Yasevich return NULL; 1039df218577SVlad Yasevich 1040df218577SVlad Yasevich af->from_addr_param(&paddr, param, peer_port, 0); 1041df218577SVlad Yasevich 10424110cc25SEric W. Biederman return __sctp_lookup_association(net, laddr, &paddr, transportp); 1043df218577SVlad Yasevich } 1044df218577SVlad Yasevich 1045df218577SVlad Yasevich 1046bbd0d598SVlad Yasevich /* SCTP-AUTH, Section 6.3: 1047bbd0d598SVlad Yasevich * If the receiver does not find a STCB for a packet containing an AUTH 1048bbd0d598SVlad Yasevich * chunk as the first chunk and not a COOKIE-ECHO chunk as the second 1049bbd0d598SVlad Yasevich * chunk, it MUST use the chunks after the AUTH chunk to look up an existing 1050bbd0d598SVlad Yasevich * association. 1051bbd0d598SVlad Yasevich * 1052bbd0d598SVlad Yasevich * This means that any chunks that can help us identify the association need 105325985edcSLucas De Marchi * to be looked at to find this association. 1054bbd0d598SVlad Yasevich */ 10554110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, 10564110cc25SEric W. Biederman struct sk_buff *skb, 1057bbd0d598SVlad Yasevich const union sctp_addr *laddr, 1058bbd0d598SVlad Yasevich struct sctp_transport **transportp) 1059bbd0d598SVlad Yasevich { 1060df218577SVlad Yasevich struct sctp_association *asoc = NULL; 1061df218577SVlad Yasevich sctp_chunkhdr_t *ch; 1062df218577SVlad Yasevich int have_auth = 0; 1063df218577SVlad Yasevich unsigned int chunk_num = 1; 1064df218577SVlad Yasevich __u8 *ch_end; 1065df218577SVlad Yasevich 1066df218577SVlad Yasevich /* Walk through the chunks looking for AUTH or ASCONF chunks 1067df218577SVlad Yasevich * to help us find the association. 1068bbd0d598SVlad Yasevich */ 1069df218577SVlad Yasevich ch = (sctp_chunkhdr_t *) skb->data; 1070df218577SVlad Yasevich do { 1071df218577SVlad Yasevich /* Break out if chunk length is less then minimal. */ 1072df218577SVlad Yasevich if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) 1073df218577SVlad Yasevich break; 1074df218577SVlad Yasevich 1075df218577SVlad Yasevich ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); 1076df218577SVlad Yasevich if (ch_end > skb_tail_pointer(skb)) 1077df218577SVlad Yasevich break; 1078df218577SVlad Yasevich 1079df218577SVlad Yasevich switch(ch->type) { 1080df218577SVlad Yasevich case SCTP_CID_AUTH: 1081df218577SVlad Yasevich have_auth = chunk_num; 1082df218577SVlad Yasevich break; 1083df218577SVlad Yasevich 1084df218577SVlad Yasevich case SCTP_CID_COOKIE_ECHO: 1085df218577SVlad Yasevich /* If a packet arrives containing an AUTH chunk as 1086df218577SVlad Yasevich * a first chunk, a COOKIE-ECHO chunk as the second 1087df218577SVlad Yasevich * chunk, and possibly more chunks after them, and 1088df218577SVlad Yasevich * the receiver does not have an STCB for that 1089df218577SVlad Yasevich * packet, then authentication is based on 1090df218577SVlad Yasevich * the contents of the COOKIE- ECHO chunk. 1091df218577SVlad Yasevich */ 1092df218577SVlad Yasevich if (have_auth == 1 && chunk_num == 2) 1093bbd0d598SVlad Yasevich return NULL; 1094df218577SVlad Yasevich break; 1095df218577SVlad Yasevich 1096df218577SVlad Yasevich case SCTP_CID_ASCONF: 1097e1fc3b14SEric W. Biederman if (have_auth || net->sctp.addip_noauth) 10984110cc25SEric W. Biederman asoc = __sctp_rcv_asconf_lookup( 10994110cc25SEric W. Biederman net, ch, laddr, 1100df218577SVlad Yasevich sctp_hdr(skb)->source, 1101df218577SVlad Yasevich transportp); 1102df218577SVlad Yasevich default: 1103df218577SVlad Yasevich break; 1104df218577SVlad Yasevich } 1105df218577SVlad Yasevich 1106df218577SVlad Yasevich if (asoc) 1107df218577SVlad Yasevich break; 1108df218577SVlad Yasevich 1109df218577SVlad Yasevich ch = (sctp_chunkhdr_t *) ch_end; 1110df218577SVlad Yasevich chunk_num++; 1111df218577SVlad Yasevich } while (ch_end < skb_tail_pointer(skb)); 1112df218577SVlad Yasevich 1113df218577SVlad Yasevich return asoc; 1114bbd0d598SVlad Yasevich } 1115bbd0d598SVlad Yasevich 1116bbd0d598SVlad Yasevich /* 1117bbd0d598SVlad Yasevich * There are circumstances when we need to look inside the SCTP packet 1118bbd0d598SVlad Yasevich * for information to help us find the association. Examples 1119bbd0d598SVlad Yasevich * include looking inside of INIT/INIT-ACK chunks or after the AUTH 1120bbd0d598SVlad Yasevich * chunks. 1121bbd0d598SVlad Yasevich */ 11224110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net, 11234110cc25SEric W. Biederman struct sk_buff *skb, 1124bbd0d598SVlad Yasevich const union sctp_addr *laddr, 1125bbd0d598SVlad Yasevich struct sctp_transport **transportp) 1126bbd0d598SVlad Yasevich { 1127bbd0d598SVlad Yasevich sctp_chunkhdr_t *ch; 1128bbd0d598SVlad Yasevich 1129bbd0d598SVlad Yasevich ch = (sctp_chunkhdr_t *) skb->data; 1130bbd0d598SVlad Yasevich 1131df218577SVlad Yasevich /* The code below will attempt to walk the chunk and extract 1132df218577SVlad Yasevich * parameter information. Before we do that, we need to verify 1133df218577SVlad Yasevich * that the chunk length doesn't cause overflow. Otherwise, we'll 1134df218577SVlad Yasevich * walk off the end. 1135df218577SVlad Yasevich */ 1136df218577SVlad Yasevich if (WORD_ROUND(ntohs(ch->length)) > skb->len) 1137df218577SVlad Yasevich return NULL; 1138df218577SVlad Yasevich 1139bbd0d598SVlad Yasevich /* If this is INIT/INIT-ACK look inside the chunk too. */ 1140bbd0d598SVlad Yasevich switch (ch->type) { 1141bbd0d598SVlad Yasevich case SCTP_CID_INIT: 1142bbd0d598SVlad Yasevich case SCTP_CID_INIT_ACK: 11434110cc25SEric W. Biederman return __sctp_rcv_init_lookup(net, skb, laddr, transportp); 1144bbd0d598SVlad Yasevich break; 1145bbd0d598SVlad Yasevich 1146df218577SVlad Yasevich default: 11474110cc25SEric W. Biederman return __sctp_rcv_walk_lookup(net, skb, laddr, transportp); 1148bbd0d598SVlad Yasevich break; 1149bbd0d598SVlad Yasevich } 1150bbd0d598SVlad Yasevich 1151df218577SVlad Yasevich 1152bbd0d598SVlad Yasevich return NULL; 1153bbd0d598SVlad Yasevich } 1154bbd0d598SVlad Yasevich 11551da177e4SLinus Torvalds /* Lookup an association for an inbound skb. */ 11564110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup(struct net *net, 11574110cc25SEric W. Biederman struct sk_buff *skb, 11581da177e4SLinus Torvalds const union sctp_addr *paddr, 11591da177e4SLinus Torvalds const union sctp_addr *laddr, 11601da177e4SLinus Torvalds struct sctp_transport **transportp) 11611da177e4SLinus Torvalds { 11621da177e4SLinus Torvalds struct sctp_association *asoc; 11631da177e4SLinus Torvalds 11644110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, transportp); 11651da177e4SLinus Torvalds 11661da177e4SLinus Torvalds /* Further lookup for INIT/INIT-ACK packets. 11671da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 11681da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 11691da177e4SLinus Torvalds */ 11701da177e4SLinus Torvalds if (!asoc) 11714110cc25SEric W. Biederman asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp); 11721da177e4SLinus Torvalds 11731da177e4SLinus Torvalds return asoc; 11741da177e4SLinus Torvalds } 1175