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 264b2f13a2SJeff Kirsher * along with GNU CC; see the file COPYING. If not, see 274b2f13a2SJeff Kirsher * <http://www.gnu.org/licenses/>. 281da177e4SLinus Torvalds * 291da177e4SLinus Torvalds * Please send any bug reports or fixes you make to the 301da177e4SLinus Torvalds * email address(es): 3191705c61SDaniel Borkmann * lksctp developers <linux-sctp@vger.kernel.org> 321da177e4SLinus Torvalds * 331da177e4SLinus Torvalds * Written or modified by: 341da177e4SLinus Torvalds * La Monte H.P. Yarroll <piggy@acm.org> 351da177e4SLinus Torvalds * Karl Knutson <karl@athena.chicago.il.us> 361da177e4SLinus Torvalds * Xingang Guo <xingang.guo@intel.com> 371da177e4SLinus Torvalds * Jon Grimm <jgrimm@us.ibm.com> 381da177e4SLinus Torvalds * Hui Huang <hui.huang@nokia.com> 391da177e4SLinus Torvalds * Daisy Chang <daisyc@us.ibm.com> 401da177e4SLinus Torvalds * Sridhar Samudrala <sri@us.ibm.com> 411da177e4SLinus Torvalds * Ardelle Fan <ardelle.fan@intel.com> 421da177e4SLinus Torvalds */ 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds #include <linux/types.h> 451da177e4SLinus Torvalds #include <linux/list.h> /* For struct list_head */ 461da177e4SLinus Torvalds #include <linux/socket.h> 471da177e4SLinus Torvalds #include <linux/ip.h> 481da177e4SLinus Torvalds #include <linux/time.h> /* For struct timeval */ 495a0e3ad6STejun Heo #include <linux/slab.h> 501da177e4SLinus Torvalds #include <net/ip.h> 511da177e4SLinus Torvalds #include <net/icmp.h> 521da177e4SLinus Torvalds #include <net/snmp.h> 531da177e4SLinus Torvalds #include <net/sock.h> 541da177e4SLinus Torvalds #include <net/xfrm.h> 551da177e4SLinus Torvalds #include <net/sctp/sctp.h> 561da177e4SLinus Torvalds #include <net/sctp/sm.h> 579ad0977fSVlad Yasevich #include <net/sctp/checksum.h> 58dcfc23caSPavel Emelyanov #include <net/net_namespace.h> 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds /* Forward declarations for internal helpers. */ 611da177e4SLinus Torvalds static int sctp_rcv_ootb(struct sk_buff *); 624110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup(struct net *net, 634110cc25SEric W. Biederman struct sk_buff *skb, 641da177e4SLinus Torvalds const union sctp_addr *paddr, 6557565993SNicolas Dichtel const union sctp_addr *laddr, 661da177e4SLinus Torvalds struct sctp_transport **transportp); 674cdadcbcSEric W. Biederman static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, 684cdadcbcSEric W. Biederman const union sctp_addr *laddr); 691da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 704110cc25SEric W. Biederman struct net *net, 711da177e4SLinus Torvalds const union sctp_addr *local, 721da177e4SLinus Torvalds const union sctp_addr *peer, 731da177e4SLinus Torvalds struct sctp_transport **pt); 741da177e4SLinus Torvalds 7550b1a782SZhu Yi static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb); 7661c9fed4SVladislav Yasevich 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds /* Calculate the SCTP checksum of an SCTP packet. */ 79b01a2407SEric W. Biederman static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb) 801da177e4SLinus Torvalds { 812c0fd387SArnaldo Carvalho de Melo struct sctphdr *sh = sctp_hdr(skb); 824458f04cSVlad Yasevich __le32 cmp = sh->checksum; 83024ec3deSJoe Stringer __le32 val = sctp_compute_cksum(skb, 0); 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds if (val != cmp) { 861da177e4SLinus Torvalds /* CRC failure, dump it. */ 87b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_CHECKSUMERRORS); 881da177e4SLinus Torvalds return -1; 891da177e4SLinus Torvalds } 901da177e4SLinus Torvalds return 0; 911da177e4SLinus Torvalds } 921da177e4SLinus Torvalds 9379af02c2SDavid S. Miller struct sctp_input_cb { 9479af02c2SDavid S. Miller union { 9579af02c2SDavid S. Miller struct inet_skb_parm h4; 96dfd56b8bSEric Dumazet #if IS_ENABLED(CONFIG_IPV6) 9779af02c2SDavid S. Miller struct inet6_skb_parm h6; 9879af02c2SDavid S. Miller #endif 9979af02c2SDavid S. Miller } header; 10079af02c2SDavid S. Miller struct sctp_chunk *chunk; 10179af02c2SDavid S. Miller }; 10279af02c2SDavid S. Miller #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) 10379af02c2SDavid S. Miller 1041da177e4SLinus Torvalds /* 1051da177e4SLinus Torvalds * This is the routine which IP calls when receiving an SCTP packet. 1061da177e4SLinus Torvalds */ 1071da177e4SLinus Torvalds int sctp_rcv(struct sk_buff *skb) 1081da177e4SLinus Torvalds { 1091da177e4SLinus Torvalds struct sock *sk; 1101da177e4SLinus Torvalds struct sctp_association *asoc; 1111da177e4SLinus Torvalds struct sctp_endpoint *ep = NULL; 1121da177e4SLinus Torvalds struct sctp_ep_common *rcvr; 1131da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 1141da177e4SLinus Torvalds struct sctp_chunk *chunk; 1151da177e4SLinus Torvalds struct sctphdr *sh; 1161da177e4SLinus Torvalds union sctp_addr src; 1171da177e4SLinus Torvalds union sctp_addr dest; 1181da177e4SLinus Torvalds int family; 1191da177e4SLinus Torvalds struct sctp_af *af; 1204cdadcbcSEric W. Biederman struct net *net = dev_net(skb->dev); 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds if (skb->pkt_type!=PACKET_HOST) 1231da177e4SLinus Torvalds goto discard_it; 1241da177e4SLinus Torvalds 125b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_INSCTPPACKS); 1261da177e4SLinus Torvalds 12728cd7752SHerbert Xu if (skb_linearize(skb)) 12828cd7752SHerbert Xu goto discard_it; 12928cd7752SHerbert Xu 1302c0fd387SArnaldo Carvalho de Melo sh = sctp_hdr(skb); 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds /* Pull up the IP and SCTP headers. */ 133ea2ae17dSArnaldo Carvalho de Melo __skb_pull(skb, skb_transport_offset(skb)); 1341da177e4SLinus Torvalds if (skb->len < sizeof(struct sctphdr)) 1351da177e4SLinus Torvalds goto discard_it; 13671acc0ddSDavid S. Miller if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) && 137b01a2407SEric W. Biederman sctp_rcv_checksum(net, skb) < 0) 1381da177e4SLinus Torvalds goto discard_it; 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds skb_pull(skb, sizeof(struct sctphdr)); 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds /* Make sure we at least have chunk headers worth of data left. */ 1431da177e4SLinus Torvalds if (skb->len < sizeof(struct sctp_chunkhdr)) 1441da177e4SLinus Torvalds goto discard_it; 1451da177e4SLinus Torvalds 146eddc9ec5SArnaldo Carvalho de Melo family = ipver2af(ip_hdr(skb)->version); 1471da177e4SLinus Torvalds af = sctp_get_af_specific(family); 1481da177e4SLinus Torvalds if (unlikely(!af)) 1491da177e4SLinus Torvalds goto discard_it; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 1521da177e4SLinus Torvalds af->from_skb(&src, skb, 1); 1531da177e4SLinus Torvalds af->from_skb(&dest, skb, 0); 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds /* If the packet is to or from a non-unicast address, 1561da177e4SLinus Torvalds * silently discard the packet. 1571da177e4SLinus Torvalds * 1581da177e4SLinus Torvalds * This is not clearly defined in the RFC except in section 1591da177e4SLinus Torvalds * 8.4 - OOTB handling. However, based on the book "Stream Control 1601da177e4SLinus Torvalds * Transmission Protocol" 2.1, "It is important to note that the 1611da177e4SLinus Torvalds * IP address of an SCTP transport address must be a routable 1621da177e4SLinus Torvalds * unicast address. In other words, IP multicast addresses and 1631da177e4SLinus Torvalds * IP broadcast addresses cannot be used in an SCTP transport 1641da177e4SLinus Torvalds * address." 1651da177e4SLinus Torvalds */ 1665636bef7SVlad Yasevich if (!af->addr_valid(&src, NULL, skb) || 1675636bef7SVlad Yasevich !af->addr_valid(&dest, NULL, skb)) 1681da177e4SLinus Torvalds goto discard_it; 1691da177e4SLinus Torvalds 1704110cc25SEric W. Biederman asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport); 1711c7d1fc1SAl Viro 1720fd9a65aSNeil Horman if (!asoc) 1734cdadcbcSEric W. Biederman ep = __sctp_rcv_lookup_endpoint(net, &dest); 1740fd9a65aSNeil Horman 1750fd9a65aSNeil Horman /* Retrieve the common input handling substructure. */ 1760fd9a65aSNeil Horman rcvr = asoc ? &asoc->base : &ep->base; 1770fd9a65aSNeil Horman sk = rcvr->sk; 1780fd9a65aSNeil Horman 1790fd9a65aSNeil Horman /* 1800fd9a65aSNeil Horman * If a frame arrives on an interface and the receiving socket is 1810fd9a65aSNeil Horman * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB 1820fd9a65aSNeil Horman */ 1830fd9a65aSNeil Horman if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) 1840fd9a65aSNeil Horman { 1850fd9a65aSNeil Horman if (asoc) { 1860fd9a65aSNeil Horman sctp_association_put(asoc); 1870fd9a65aSNeil Horman asoc = NULL; 1880fd9a65aSNeil Horman } else { 1890fd9a65aSNeil Horman sctp_endpoint_put(ep); 1900fd9a65aSNeil Horman ep = NULL; 1910fd9a65aSNeil Horman } 1922ce95503SEric W. Biederman sk = net->sctp.ctl_sock; 1930fd9a65aSNeil Horman ep = sctp_sk(sk)->ep; 1940fd9a65aSNeil Horman sctp_endpoint_hold(ep); 1950fd9a65aSNeil Horman rcvr = &ep->base; 1960fd9a65aSNeil Horman } 1970fd9a65aSNeil Horman 1981da177e4SLinus Torvalds /* 1991da177e4SLinus Torvalds * RFC 2960, 8.4 - Handle "Out of the blue" Packets. 2001da177e4SLinus Torvalds * An SCTP packet is called an "out of the blue" (OOTB) 2011da177e4SLinus Torvalds * packet if it is correctly formed, i.e., passed the 2021da177e4SLinus Torvalds * receiver's checksum check, but the receiver is not 2031da177e4SLinus Torvalds * able to identify the association to which this 2041da177e4SLinus Torvalds * packet belongs. 2051da177e4SLinus Torvalds */ 2061da177e4SLinus Torvalds if (!asoc) { 2071da177e4SLinus Torvalds if (sctp_rcv_ootb(skb)) { 208b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_OUTOFBLUES); 2091da177e4SLinus Torvalds goto discard_release; 2101da177e4SLinus Torvalds } 2111da177e4SLinus Torvalds } 2121da177e4SLinus Torvalds 2131da177e4SLinus Torvalds if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) 2141da177e4SLinus Torvalds goto discard_release; 215b59c2701SPatrick McHardy nf_reset(skb); 2161da177e4SLinus Torvalds 217fda9ef5dSDmitry Mishin if (sk_filter(sk, skb)) 2181da177e4SLinus Torvalds goto discard_release; 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds /* Create an SCTP packet structure. */ 2211da177e4SLinus Torvalds chunk = sctp_chunkify(skb, asoc, sk); 2222babf9daSHerbert Xu if (!chunk) 2231da177e4SLinus Torvalds goto discard_release; 22479af02c2SDavid S. Miller SCTP_INPUT_CB(skb)->chunk = chunk; 2251da177e4SLinus Torvalds 2261da177e4SLinus Torvalds /* Remember what endpoint is to handle this packet. */ 2271da177e4SLinus Torvalds chunk->rcvr = rcvr; 2281da177e4SLinus Torvalds 2291da177e4SLinus Torvalds /* Remember the SCTP header. */ 2301da177e4SLinus Torvalds chunk->sctp_hdr = sh; 2311da177e4SLinus Torvalds 2321da177e4SLinus Torvalds /* Set the source and destination addresses of the incoming chunk. */ 233d55c41b1SAl Viro sctp_init_addrs(chunk, &src, &dest); 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds /* Remember where we came from. */ 2361da177e4SLinus Torvalds chunk->transport = transport; 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds /* Acquire access to the sock lock. Note: We are safe from other 2391da177e4SLinus Torvalds * bottom halves on this lock, but a user may be in the lock too, 2401da177e4SLinus Torvalds * so check if it is busy. 2411da177e4SLinus Torvalds */ 2421da177e4SLinus Torvalds sctp_bh_lock_sock(sk); 2431da177e4SLinus Torvalds 244ae53b5bdSVlad Yasevich if (sk != rcvr->sk) { 245ae53b5bdSVlad Yasevich /* Our cached sk is different from the rcvr->sk. This is 246ae53b5bdSVlad Yasevich * because migrate()/accept() may have moved the association 247ae53b5bdSVlad Yasevich * to a new socket and released all the sockets. So now we 248ae53b5bdSVlad Yasevich * are holding a lock on the old socket while the user may 249ae53b5bdSVlad Yasevich * be doing something with the new socket. Switch our veiw 250ae53b5bdSVlad Yasevich * of the current sk. 251ae53b5bdSVlad Yasevich */ 252ae53b5bdSVlad Yasevich sctp_bh_unlock_sock(sk); 253ae53b5bdSVlad Yasevich sk = rcvr->sk; 254ae53b5bdSVlad Yasevich sctp_bh_lock_sock(sk); 255ae53b5bdSVlad Yasevich } 256ae53b5bdSVlad Yasevich 257ac0b0462SSridhar Samudrala if (sock_owned_by_user(sk)) { 25850b1a782SZhu Yi if (sctp_add_backlog(sk, skb)) { 25950b1a782SZhu Yi sctp_bh_unlock_sock(sk); 26050b1a782SZhu Yi sctp_chunk_free(chunk); 26150b1a782SZhu Yi skb = NULL; /* sctp_chunk_free already freed the skb */ 26250b1a782SZhu Yi goto discard_release; 26350b1a782SZhu Yi } 264b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_BACKLOG); 265ac0b0462SSridhar Samudrala } else { 266b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_SOFTIRQ); 26761c9fed4SVladislav Yasevich sctp_inq_push(&chunk->rcvr->inqueue, chunk); 268ac0b0462SSridhar Samudrala } 2691da177e4SLinus Torvalds 2701da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 27161c9fed4SVladislav Yasevich 27261c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 27361c9fed4SVladislav Yasevich if (asoc) 27461c9fed4SVladislav Yasevich sctp_association_put(asoc); 27561c9fed4SVladislav Yasevich else 27661c9fed4SVladislav Yasevich sctp_endpoint_put(ep); 2777a48f923SSridhar Samudrala 2782babf9daSHerbert Xu return 0; 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds discard_it: 281b01a2407SEric W. Biederman SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_DISCARDS); 2821da177e4SLinus Torvalds kfree_skb(skb); 2832babf9daSHerbert Xu return 0; 2841da177e4SLinus Torvalds 2851da177e4SLinus Torvalds discard_release: 28661c9fed4SVladislav Yasevich /* Release the asoc/ep ref we took in the lookup calls. */ 2870fd9a65aSNeil Horman if (asoc) 2881da177e4SLinus Torvalds sctp_association_put(asoc); 2890fd9a65aSNeil Horman else 2901da177e4SLinus Torvalds sctp_endpoint_put(ep); 2911da177e4SLinus Torvalds 2921da177e4SLinus Torvalds goto discard_it; 2931da177e4SLinus Torvalds } 2941da177e4SLinus Torvalds 29561c9fed4SVladislav Yasevich /* Process the backlog queue of the socket. Every skb on 29661c9fed4SVladislav Yasevich * the backlog holds a ref on an association or endpoint. 29761c9fed4SVladislav Yasevich * We hold this ref throughout the state machine to make 29861c9fed4SVladislav Yasevich * sure that the structure we need is still around. 2991da177e4SLinus Torvalds */ 3001da177e4SLinus Torvalds int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) 3011da177e4SLinus Torvalds { 30279af02c2SDavid S. Miller struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 30361c9fed4SVladislav Yasevich struct sctp_inq *inqueue = &chunk->rcvr->inqueue; 3047a48f923SSridhar Samudrala struct sctp_ep_common *rcvr = NULL; 30561c9fed4SVladislav Yasevich int backloged = 0; 3061da177e4SLinus Torvalds 3077a48f923SSridhar Samudrala rcvr = chunk->rcvr; 308c4d2444eSSridhar Samudrala 30961c9fed4SVladislav Yasevich /* If the rcvr is dead then the association or endpoint 31061c9fed4SVladislav Yasevich * has been deleted and we can safely drop the chunk 31161c9fed4SVladislav Yasevich * and refs that we are holding. 31261c9fed4SVladislav Yasevich */ 3137a48f923SSridhar Samudrala if (rcvr->dead) { 3147a48f923SSridhar Samudrala sctp_chunk_free(chunk); 31561c9fed4SVladislav Yasevich goto done; 31661c9fed4SVladislav Yasevich } 31761c9fed4SVladislav Yasevich 31861c9fed4SVladislav Yasevich if (unlikely(rcvr->sk != sk)) { 31961c9fed4SVladislav Yasevich /* In this case, the association moved from one socket to 32061c9fed4SVladislav Yasevich * another. We are currently sitting on the backlog of the 32161c9fed4SVladislav Yasevich * old socket, so we need to move. 32261c9fed4SVladislav Yasevich * However, since we are here in the process context we 32361c9fed4SVladislav Yasevich * need to take make sure that the user doesn't own 32461c9fed4SVladislav Yasevich * the new socket when we process the packet. 32561c9fed4SVladislav Yasevich * If the new socket is user-owned, queue the chunk to the 32661c9fed4SVladislav Yasevich * backlog of the new socket without dropping any refs. 32761c9fed4SVladislav Yasevich * Otherwise, we can safely push the chunk on the inqueue. 32861c9fed4SVladislav Yasevich */ 32961c9fed4SVladislav Yasevich 33061c9fed4SVladislav Yasevich sk = rcvr->sk; 33161c9fed4SVladislav Yasevich sctp_bh_lock_sock(sk); 33261c9fed4SVladislav Yasevich 33361c9fed4SVladislav Yasevich if (sock_owned_by_user(sk)) { 334f545a38fSEric Dumazet if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) 33550b1a782SZhu Yi sctp_chunk_free(chunk); 33650b1a782SZhu Yi else 33761c9fed4SVladislav Yasevich backloged = 1; 33861c9fed4SVladislav Yasevich } else 33961c9fed4SVladislav Yasevich sctp_inq_push(inqueue, chunk); 34061c9fed4SVladislav Yasevich 34161c9fed4SVladislav Yasevich sctp_bh_unlock_sock(sk); 34261c9fed4SVladislav Yasevich 34361c9fed4SVladislav Yasevich /* If the chunk was backloged again, don't drop refs */ 34461c9fed4SVladislav Yasevich if (backloged) 34561c9fed4SVladislav Yasevich return 0; 3467a48f923SSridhar Samudrala } else { 3471da177e4SLinus Torvalds sctp_inq_push(inqueue, chunk); 3487a48f923SSridhar Samudrala } 3497a48f923SSridhar Samudrala 35061c9fed4SVladislav Yasevich done: 35161c9fed4SVladislav Yasevich /* Release the refs we took in sctp_add_backlog */ 3527a48f923SSridhar Samudrala if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 3537a48f923SSridhar Samudrala sctp_association_put(sctp_assoc(rcvr)); 35461c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 3557a48f923SSridhar Samudrala sctp_endpoint_put(sctp_ep(rcvr)); 35661c9fed4SVladislav Yasevich else 35761c9fed4SVladislav Yasevich BUG(); 3587a48f923SSridhar Samudrala 3591da177e4SLinus Torvalds return 0; 3601da177e4SLinus Torvalds } 3611da177e4SLinus Torvalds 36250b1a782SZhu Yi static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb) 363c4d2444eSSridhar Samudrala { 36461c9fed4SVladislav Yasevich struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; 36561c9fed4SVladislav Yasevich struct sctp_ep_common *rcvr = chunk->rcvr; 36650b1a782SZhu Yi int ret; 367c4d2444eSSridhar Samudrala 368f545a38fSEric Dumazet ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf); 36950b1a782SZhu Yi if (!ret) { 37061c9fed4SVladislav Yasevich /* Hold the assoc/ep while hanging on the backlog queue. 37150b1a782SZhu Yi * This way, we know structures we need will not disappear 37250b1a782SZhu Yi * from us 37361c9fed4SVladislav Yasevich */ 37461c9fed4SVladislav Yasevich if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) 37561c9fed4SVladislav Yasevich sctp_association_hold(sctp_assoc(rcvr)); 37661c9fed4SVladislav Yasevich else if (SCTP_EP_TYPE_SOCKET == rcvr->type) 37761c9fed4SVladislav Yasevich sctp_endpoint_hold(sctp_ep(rcvr)); 378c4d2444eSSridhar Samudrala else 37961c9fed4SVladislav Yasevich BUG(); 38050b1a782SZhu Yi } 38150b1a782SZhu Yi return ret; 38261c9fed4SVladislav Yasevich 383c4d2444eSSridhar Samudrala } 384c4d2444eSSridhar Samudrala 3851da177e4SLinus Torvalds /* Handle icmp frag needed error. */ 3861da177e4SLinus Torvalds void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, 3871da177e4SLinus Torvalds struct sctp_transport *t, __u32 pmtu) 3881da177e4SLinus Torvalds { 38991bd6b1eSWei Yongjun if (!t || (t->pathmtu <= pmtu)) 39052ccb8e9SFrank Filz return; 39152ccb8e9SFrank Filz 3928a479491SVlad Yasevich if (sock_owned_by_user(sk)) { 3938a479491SVlad Yasevich asoc->pmtu_pending = 1; 3948a479491SVlad Yasevich t->pmtu_pending = 1; 3958a479491SVlad Yasevich return; 3968a479491SVlad Yasevich } 3978a479491SVlad Yasevich 39852ccb8e9SFrank Filz if (t->param_flags & SPP_PMTUD_ENABLE) { 399c910b47eSVlad Yasevich /* Update transports view of the MTU */ 40002f3d4ceSDavid S. Miller sctp_transport_update_pmtu(sk, t, pmtu); 4011da177e4SLinus Torvalds 40252ccb8e9SFrank Filz /* Update association pmtu. */ 40302f3d4ceSDavid S. Miller sctp_assoc_sync_pmtu(sk, asoc); 4041da177e4SLinus Torvalds } 40552ccb8e9SFrank Filz 40652ccb8e9SFrank Filz /* Retransmit with the new pmtu setting. 40752ccb8e9SFrank Filz * Normally, if PMTU discovery is disabled, an ICMP Fragmentation 40852ccb8e9SFrank Filz * Needed will never be sent, but if a message was sent before 40952ccb8e9SFrank Filz * PMTU discovery was disabled that was larger than the PMTU, it 41052ccb8e9SFrank Filz * would not be fragmented, so it must be re-transmitted fragmented. 41152ccb8e9SFrank Filz */ 41252ccb8e9SFrank Filz sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); 4131da177e4SLinus Torvalds } 4141da177e4SLinus Torvalds 415ec18d9a2SDavid S. Miller void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t, 41655be7a9cSDavid S. Miller struct sk_buff *skb) 41755be7a9cSDavid S. Miller { 41855be7a9cSDavid S. Miller struct dst_entry *dst; 41955be7a9cSDavid S. Miller 42055be7a9cSDavid S. Miller if (!t) 42155be7a9cSDavid S. Miller return; 42255be7a9cSDavid S. Miller dst = sctp_transport_dst_check(t); 4231ed5c48fSDavid S. Miller if (dst) 4246700c270SDavid S. Miller dst->ops->redirect(dst, sk, skb); 42555be7a9cSDavid S. Miller } 42655be7a9cSDavid S. Miller 4271da177e4SLinus Torvalds /* 4281da177e4SLinus Torvalds * SCTP Implementer's Guide, 2.37 ICMP handling procedures 4291da177e4SLinus Torvalds * 4301da177e4SLinus Torvalds * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" 4311da177e4SLinus Torvalds * or a "Protocol Unreachable" treat this message as an abort 4321da177e4SLinus Torvalds * with the T bit set. 4331da177e4SLinus Torvalds * 4341da177e4SLinus Torvalds * This function sends an event to the state machine, which will abort the 4351da177e4SLinus Torvalds * association. 4361da177e4SLinus Torvalds * 4371da177e4SLinus Torvalds */ 4381da177e4SLinus Torvalds void sctp_icmp_proto_unreachable(struct sock *sk, 4391da177e4SLinus Torvalds struct sctp_association *asoc, 4401da177e4SLinus Torvalds struct sctp_transport *t) 4411da177e4SLinus Torvalds { 44250b5d6adSVlad Yasevich if (sock_owned_by_user(sk)) { 44350b5d6adSVlad Yasevich if (timer_pending(&t->proto_unreach_timer)) 44450b5d6adSVlad Yasevich return; 44550b5d6adSVlad Yasevich else { 44650b5d6adSVlad Yasevich if (!mod_timer(&t->proto_unreach_timer, 44750b5d6adSVlad Yasevich jiffies + (HZ/20))) 44850b5d6adSVlad Yasevich sctp_association_hold(asoc); 44950b5d6adSVlad Yasevich } 45050b5d6adSVlad Yasevich } else { 45155e26eb9SEric W. Biederman struct net *net = sock_net(sk); 45255e26eb9SEric W. Biederman 453bb33381dSDaniel Borkmann pr_debug("%s: unrecognized next header type " 454bb33381dSDaniel Borkmann "encountered!\n", __func__); 455bb33381dSDaniel Borkmann 45625cc4ae9SYing Xue if (del_timer(&t->proto_unreach_timer)) 45750b5d6adSVlad Yasevich sctp_association_put(asoc); 45850b5d6adSVlad Yasevich 45955e26eb9SEric W. Biederman sctp_do_sm(net, SCTP_EVENT_T_OTHER, 4601da177e4SLinus Torvalds SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), 4613f7a87d2SFrank Filz asoc->state, asoc->ep, asoc, t, 4621da177e4SLinus Torvalds GFP_ATOMIC); 46350b5d6adSVlad Yasevich } 4641da177e4SLinus Torvalds } 4651da177e4SLinus Torvalds 4661da177e4SLinus Torvalds /* Common lookup code for icmp/icmpv6 error handler. */ 4674110cc25SEric W. Biederman struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb, 4681da177e4SLinus Torvalds struct sctphdr *sctphdr, 4691da177e4SLinus Torvalds struct sctp_association **app, 4701da177e4SLinus Torvalds struct sctp_transport **tpp) 4711da177e4SLinus Torvalds { 4721da177e4SLinus Torvalds union sctp_addr saddr; 4731da177e4SLinus Torvalds union sctp_addr daddr; 4741da177e4SLinus Torvalds struct sctp_af *af; 4751da177e4SLinus Torvalds struct sock *sk = NULL; 4768de8c873SSridhar Samudrala struct sctp_association *asoc; 4771da177e4SLinus Torvalds struct sctp_transport *transport = NULL; 4787115e632SWei Yongjun struct sctp_init_chunk *chunkhdr; 4797115e632SWei Yongjun __u32 vtag = ntohl(sctphdr->vtag); 4807115e632SWei Yongjun int len = skb->len - ((void *)sctphdr - (void *)skb->data); 4811da177e4SLinus Torvalds 482d1ad1ff2SSridhar Samudrala *app = NULL; *tpp = NULL; 4831da177e4SLinus Torvalds 4841da177e4SLinus Torvalds af = sctp_get_af_specific(family); 4851da177e4SLinus Torvalds if (unlikely(!af)) { 4861da177e4SLinus Torvalds return NULL; 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds /* Initialize local addresses for lookups. */ 4901da177e4SLinus Torvalds af->from_skb(&saddr, skb, 1); 4911da177e4SLinus Torvalds af->from_skb(&daddr, skb, 0); 4921da177e4SLinus Torvalds 4931da177e4SLinus Torvalds /* Look for an association that matches the incoming ICMP error 4941da177e4SLinus Torvalds * packet. 4951da177e4SLinus Torvalds */ 4964110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport); 497d1ad1ff2SSridhar Samudrala if (!asoc) 4981da177e4SLinus Torvalds return NULL; 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds sk = asoc->base.sk; 5011da177e4SLinus Torvalds 5027115e632SWei Yongjun /* RFC 4960, Appendix C. ICMP Handling 5037115e632SWei Yongjun * 5047115e632SWei Yongjun * ICMP6) An implementation MUST validate that the Verification Tag 5057115e632SWei Yongjun * contained in the ICMP message matches the Verification Tag of 5067115e632SWei Yongjun * the peer. If the Verification Tag is not 0 and does NOT 5077115e632SWei Yongjun * match, discard the ICMP message. If it is 0 and the ICMP 5087115e632SWei Yongjun * message contains enough bytes to verify that the chunk type is 5097115e632SWei Yongjun * an INIT chunk and that the Initiate Tag matches the tag of the 5107115e632SWei Yongjun * peer, continue with ICMP7. If the ICMP message is too short 5117115e632SWei Yongjun * or the chunk type or the Initiate Tag does not match, silently 5127115e632SWei Yongjun * discard the packet. 5137115e632SWei Yongjun */ 5147115e632SWei Yongjun if (vtag == 0) { 515ea110733SJoe Perches chunkhdr = (void *)sctphdr + sizeof(struct sctphdr); 5167115e632SWei Yongjun if (len < sizeof(struct sctphdr) + sizeof(sctp_chunkhdr_t) 5177115e632SWei Yongjun + sizeof(__be32) || 5187115e632SWei Yongjun chunkhdr->chunk_hdr.type != SCTP_CID_INIT || 5197115e632SWei Yongjun ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) { 5207115e632SWei Yongjun goto out; 5217115e632SWei Yongjun } 5227115e632SWei Yongjun } else if (vtag != asoc->c.peer_vtag) { 5231da177e4SLinus Torvalds goto out; 5241da177e4SLinus Torvalds } 5251da177e4SLinus Torvalds 5261da177e4SLinus Torvalds sctp_bh_lock_sock(sk); 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds /* If too many ICMPs get dropped on busy 5291da177e4SLinus Torvalds * servers this needs to be solved differently. 5301da177e4SLinus Torvalds */ 5311da177e4SLinus Torvalds if (sock_owned_by_user(sk)) 532b01a2407SEric W. Biederman NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds *app = asoc; 5351da177e4SLinus Torvalds *tpp = transport; 5361da177e4SLinus Torvalds return sk; 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvalds out: 5391da177e4SLinus Torvalds sctp_association_put(asoc); 5401da177e4SLinus Torvalds return NULL; 5411da177e4SLinus Torvalds } 5421da177e4SLinus Torvalds 5431da177e4SLinus Torvalds /* Common cleanup code for icmp/icmpv6 error handler. */ 544d1ad1ff2SSridhar Samudrala void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) 5451da177e4SLinus Torvalds { 5461da177e4SLinus Torvalds sctp_bh_unlock_sock(sk); 5471da177e4SLinus Torvalds sctp_association_put(asoc); 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds 5501da177e4SLinus Torvalds /* 5511da177e4SLinus Torvalds * This routine is called by the ICMP module when it gets some 5521da177e4SLinus Torvalds * sort of error condition. If err < 0 then the socket should 5531da177e4SLinus Torvalds * be closed and the error returned to the user. If err > 0 5541da177e4SLinus Torvalds * it's just the icmp type << 8 | icmp code. After adjustment 5551da177e4SLinus Torvalds * header points to the first 8 bytes of the sctp header. We need 5561da177e4SLinus Torvalds * to find the appropriate port. 5571da177e4SLinus Torvalds * 5581da177e4SLinus Torvalds * The locking strategy used here is very "optimistic". When 5591da177e4SLinus Torvalds * someone else accesses the socket the ICMP is just dropped 5601da177e4SLinus Torvalds * and for some paths there is no check at all. 5611da177e4SLinus Torvalds * A more general error queue to queue errors for later handling 5621da177e4SLinus Torvalds * is probably better. 5631da177e4SLinus Torvalds * 5641da177e4SLinus Torvalds */ 5651da177e4SLinus Torvalds void sctp_v4_err(struct sk_buff *skb, __u32 info) 5661da177e4SLinus Torvalds { 567b71d1d42SEric Dumazet const struct iphdr *iph = (const struct iphdr *)skb->data; 568a27ef749SArnaldo Carvalho de Melo const int ihlen = iph->ihl * 4; 56988c7664fSArnaldo Carvalho de Melo const int type = icmp_hdr(skb)->type; 57088c7664fSArnaldo Carvalho de Melo const int code = icmp_hdr(skb)->code; 5711da177e4SLinus Torvalds struct sock *sk; 5728de8c873SSridhar Samudrala struct sctp_association *asoc = NULL; 5731da177e4SLinus Torvalds struct sctp_transport *transport; 5741da177e4SLinus Torvalds struct inet_sock *inet; 575aef6de51SSimon Horman __u16 saveip, savesctp; 5761da177e4SLinus Torvalds int err; 5774110cc25SEric W. Biederman struct net *net = dev_net(skb->dev); 5781da177e4SLinus Torvalds 579a27ef749SArnaldo Carvalho de Melo if (skb->len < ihlen + 8) { 580b01a2407SEric W. Biederman ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 5811da177e4SLinus Torvalds return; 5821da177e4SLinus Torvalds } 5831da177e4SLinus Torvalds 5841da177e4SLinus Torvalds /* Fix up skb to look at the embedded net header. */ 585b0e380b1SArnaldo Carvalho de Melo saveip = skb->network_header; 586b0e380b1SArnaldo Carvalho de Melo savesctp = skb->transport_header; 58731c7711bSArnaldo Carvalho de Melo skb_reset_network_header(skb); 588a27ef749SArnaldo Carvalho de Melo skb_set_transport_header(skb, ihlen); 5894110cc25SEric W. Biederman sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport); 5902e07fa9cSArnaldo Carvalho de Melo /* Put back, the original values. */ 591b0e380b1SArnaldo Carvalho de Melo skb->network_header = saveip; 592b0e380b1SArnaldo Carvalho de Melo skb->transport_header = savesctp; 5931da177e4SLinus Torvalds if (!sk) { 594b01a2407SEric W. Biederman ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 5951da177e4SLinus Torvalds return; 5961da177e4SLinus Torvalds } 5971da177e4SLinus Torvalds /* Warning: The sock lock is held. Remember to call 5981da177e4SLinus Torvalds * sctp_err_finish! 5991da177e4SLinus Torvalds */ 6001da177e4SLinus Torvalds 6011da177e4SLinus Torvalds switch (type) { 6021da177e4SLinus Torvalds case ICMP_PARAMETERPROB: 6031da177e4SLinus Torvalds err = EPROTO; 6041da177e4SLinus Torvalds break; 6051da177e4SLinus Torvalds case ICMP_DEST_UNREACH: 6061da177e4SLinus Torvalds if (code > NR_ICMP_UNREACH) 6071da177e4SLinus Torvalds goto out_unlock; 6081da177e4SLinus Torvalds 6091da177e4SLinus Torvalds /* PMTU discovery (RFC1191) */ 6101da177e4SLinus Torvalds if (ICMP_FRAG_NEEDED == code) { 6111da177e4SLinus Torvalds sctp_icmp_frag_needed(sk, asoc, transport, info); 6121da177e4SLinus Torvalds goto out_unlock; 6131da177e4SLinus Torvalds } 6141da177e4SLinus Torvalds else { 6151da177e4SLinus Torvalds if (ICMP_PROT_UNREACH == code) { 616d1ad1ff2SSridhar Samudrala sctp_icmp_proto_unreachable(sk, asoc, 6171da177e4SLinus Torvalds transport); 6181da177e4SLinus Torvalds goto out_unlock; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds } 6211da177e4SLinus Torvalds err = icmp_err_convert[code].errno; 6221da177e4SLinus Torvalds break; 6231da177e4SLinus Torvalds case ICMP_TIME_EXCEEDED: 6241da177e4SLinus Torvalds /* Ignore any time exceeded errors due to fragment reassembly 6251da177e4SLinus Torvalds * timeouts. 6261da177e4SLinus Torvalds */ 6271da177e4SLinus Torvalds if (ICMP_EXC_FRAGTIME == code) 6281da177e4SLinus Torvalds goto out_unlock; 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds err = EHOSTUNREACH; 6311da177e4SLinus Torvalds break; 63255be7a9cSDavid S. Miller case ICMP_REDIRECT: 63355be7a9cSDavid S. Miller sctp_icmp_redirect(sk, transport, skb); 6343f96a532SDaniel Borkmann /* Fall through to out_unlock. */ 6351da177e4SLinus Torvalds default: 6361da177e4SLinus Torvalds goto out_unlock; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds 6391da177e4SLinus Torvalds inet = inet_sk(sk); 6401da177e4SLinus Torvalds if (!sock_owned_by_user(sk) && inet->recverr) { 6411da177e4SLinus Torvalds sk->sk_err = err; 6421da177e4SLinus Torvalds sk->sk_error_report(sk); 6431da177e4SLinus Torvalds } else { /* Only an error on timeout */ 6441da177e4SLinus Torvalds sk->sk_err_soft = err; 6451da177e4SLinus Torvalds } 6461da177e4SLinus Torvalds 6471da177e4SLinus Torvalds out_unlock: 648d1ad1ff2SSridhar Samudrala sctp_err_finish(sk, asoc); 6491da177e4SLinus Torvalds } 6501da177e4SLinus Torvalds 6511da177e4SLinus Torvalds /* 6521da177e4SLinus Torvalds * RFC 2960, 8.4 - Handle "Out of the blue" Packets. 6531da177e4SLinus Torvalds * 6541da177e4SLinus Torvalds * This function scans all the chunks in the OOTB packet to determine if 6551da177e4SLinus Torvalds * the packet should be discarded right away. If a response might be needed 6561da177e4SLinus Torvalds * for this packet, or, if further processing is possible, the packet will 6571da177e4SLinus Torvalds * be queued to a proper inqueue for the next phase of handling. 6581da177e4SLinus Torvalds * 6591da177e4SLinus Torvalds * Output: 6601da177e4SLinus Torvalds * Return 0 - If further processing is needed. 6611da177e4SLinus Torvalds * Return 1 - If the packet can be discarded right away. 6621da177e4SLinus Torvalds */ 66304675210Ssebastian@breakpoint.cc static int sctp_rcv_ootb(struct sk_buff *skb) 6641da177e4SLinus Torvalds { 6651da177e4SLinus Torvalds sctp_chunkhdr_t *ch; 6661da177e4SLinus Torvalds __u8 *ch_end; 6671da177e4SLinus Torvalds 6681da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) skb->data; 6691da177e4SLinus Torvalds 6701da177e4SLinus Torvalds /* Scan through all the chunks in the packet. */ 671a7d1f1b6STsutomu Fujii do { 672a7d1f1b6STsutomu Fujii /* Break out if chunk length is less then minimal. */ 673a7d1f1b6STsutomu Fujii if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) 674a7d1f1b6STsutomu Fujii break; 675a7d1f1b6STsutomu Fujii 676a7d1f1b6STsutomu Fujii ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); 67727a884dcSArnaldo Carvalho de Melo if (ch_end > skb_tail_pointer(skb)) 678a7d1f1b6STsutomu Fujii break; 6791da177e4SLinus Torvalds 6801da177e4SLinus Torvalds /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the 6811da177e4SLinus Torvalds * receiver MUST silently discard the OOTB packet and take no 6821da177e4SLinus Torvalds * further action. 6831da177e4SLinus Torvalds */ 6841da177e4SLinus Torvalds if (SCTP_CID_ABORT == ch->type) 6851da177e4SLinus Torvalds goto discard; 6861da177e4SLinus Torvalds 6871da177e4SLinus Torvalds /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE 6881da177e4SLinus Torvalds * chunk, the receiver should silently discard the packet 6891da177e4SLinus Torvalds * and take no further action. 6901da177e4SLinus Torvalds */ 6911da177e4SLinus Torvalds if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) 6921da177e4SLinus Torvalds goto discard; 6931da177e4SLinus Torvalds 6943c77f961SVlad Yasevich /* RFC 4460, 2.11.2 6953c77f961SVlad Yasevich * This will discard packets with INIT chunk bundled as 6963c77f961SVlad Yasevich * subsequent chunks in the packet. When INIT is first, 6973c77f961SVlad Yasevich * the normal INIT processing will discard the chunk. 6983c77f961SVlad Yasevich */ 6993c77f961SVlad Yasevich if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) 7003c77f961SVlad Yasevich goto discard; 7013c77f961SVlad Yasevich 7021da177e4SLinus Torvalds ch = (sctp_chunkhdr_t *) ch_end; 70327a884dcSArnaldo Carvalho de Melo } while (ch_end < skb_tail_pointer(skb)); 7041da177e4SLinus Torvalds 7051da177e4SLinus Torvalds return 0; 7061da177e4SLinus Torvalds 7071da177e4SLinus Torvalds discard: 7081da177e4SLinus Torvalds return 1; 7091da177e4SLinus Torvalds } 7101da177e4SLinus Torvalds 7111da177e4SLinus Torvalds /* Insert endpoint into the hash table. */ 7121da177e4SLinus Torvalds static void __sctp_hash_endpoint(struct sctp_endpoint *ep) 7131da177e4SLinus Torvalds { 7144cdadcbcSEric W. Biederman struct net *net = sock_net(ep->base.sk); 7151da177e4SLinus Torvalds struct sctp_ep_common *epb; 7161da177e4SLinus Torvalds struct sctp_hashbucket *head; 7171da177e4SLinus Torvalds 7181da177e4SLinus Torvalds epb = &ep->base; 7191da177e4SLinus Torvalds 7204cdadcbcSEric W. Biederman epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); 7211da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 7221da177e4SLinus Torvalds 7231da177e4SLinus Torvalds sctp_write_lock(&head->lock); 724d970dbf8SVlad Yasevich hlist_add_head(&epb->node, &head->chain); 7251da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7261da177e4SLinus Torvalds } 7271da177e4SLinus Torvalds 7281da177e4SLinus Torvalds /* Add an endpoint to the hash. Local BH-safe. */ 7291da177e4SLinus Torvalds void sctp_hash_endpoint(struct sctp_endpoint *ep) 7301da177e4SLinus Torvalds { 7311da177e4SLinus Torvalds sctp_local_bh_disable(); 7321da177e4SLinus Torvalds __sctp_hash_endpoint(ep); 7331da177e4SLinus Torvalds sctp_local_bh_enable(); 7341da177e4SLinus Torvalds } 7351da177e4SLinus Torvalds 7361da177e4SLinus Torvalds /* Remove endpoint from the hash table. */ 7371da177e4SLinus Torvalds static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) 7381da177e4SLinus Torvalds { 7394cdadcbcSEric W. Biederman struct net *net = sock_net(ep->base.sk); 7401da177e4SLinus Torvalds struct sctp_hashbucket *head; 7411da177e4SLinus Torvalds struct sctp_ep_common *epb; 7421da177e4SLinus Torvalds 7431da177e4SLinus Torvalds epb = &ep->base; 7441da177e4SLinus Torvalds 7454cdadcbcSEric W. Biederman epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds head = &sctp_ep_hashtable[epb->hashent]; 7481da177e4SLinus Torvalds 7491da177e4SLinus Torvalds sctp_write_lock(&head->lock); 7502eebc1e1SNeil Horman hlist_del_init(&epb->node); 7511da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 7521da177e4SLinus Torvalds } 7531da177e4SLinus Torvalds 7541da177e4SLinus Torvalds /* Remove endpoint from the hash. Local BH-safe. */ 7551da177e4SLinus Torvalds void sctp_unhash_endpoint(struct sctp_endpoint *ep) 7561da177e4SLinus Torvalds { 7571da177e4SLinus Torvalds sctp_local_bh_disable(); 7581da177e4SLinus Torvalds __sctp_unhash_endpoint(ep); 7591da177e4SLinus Torvalds sctp_local_bh_enable(); 7601da177e4SLinus Torvalds } 7611da177e4SLinus Torvalds 7621da177e4SLinus Torvalds /* Look up an endpoint. */ 7634cdadcbcSEric W. Biederman static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, 7644cdadcbcSEric W. Biederman const union sctp_addr *laddr) 7651da177e4SLinus Torvalds { 7661da177e4SLinus Torvalds struct sctp_hashbucket *head; 7671da177e4SLinus Torvalds struct sctp_ep_common *epb; 7681da177e4SLinus Torvalds struct sctp_endpoint *ep; 7691da177e4SLinus Torvalds int hash; 7701da177e4SLinus Torvalds 7714cdadcbcSEric W. Biederman hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port)); 7721da177e4SLinus Torvalds head = &sctp_ep_hashtable[hash]; 7731da177e4SLinus Torvalds read_lock(&head->lock); 774b67bfe0dSSasha Levin sctp_for_each_hentry(epb, &head->chain) { 7751da177e4SLinus Torvalds ep = sctp_ep(epb); 7764cdadcbcSEric W. Biederman if (sctp_endpoint_is_match(ep, net, laddr)) 7771da177e4SLinus Torvalds goto hit; 7781da177e4SLinus Torvalds } 7791da177e4SLinus Torvalds 7802ce95503SEric W. Biederman ep = sctp_sk(net->sctp.ctl_sock)->ep; 7811da177e4SLinus Torvalds 7821da177e4SLinus Torvalds hit: 7831da177e4SLinus Torvalds sctp_endpoint_hold(ep); 7841da177e4SLinus Torvalds read_unlock(&head->lock); 7851da177e4SLinus Torvalds return ep; 7861da177e4SLinus Torvalds } 7871da177e4SLinus Torvalds 7881da177e4SLinus Torvalds /* Insert association into the hash table. */ 7891da177e4SLinus Torvalds static void __sctp_hash_established(struct sctp_association *asoc) 7901da177e4SLinus Torvalds { 7914110cc25SEric W. Biederman struct net *net = sock_net(asoc->base.sk); 7921da177e4SLinus Torvalds struct sctp_ep_common *epb; 7931da177e4SLinus Torvalds struct sctp_hashbucket *head; 7941da177e4SLinus Torvalds 7951da177e4SLinus Torvalds epb = &asoc->base; 7961da177e4SLinus Torvalds 7971da177e4SLinus Torvalds /* Calculate which chain this entry will belong to. */ 7984110cc25SEric W. Biederman epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, 7994110cc25SEric W. Biederman asoc->peer.port); 8001da177e4SLinus Torvalds 8011da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 8021da177e4SLinus Torvalds 8031da177e4SLinus Torvalds sctp_write_lock(&head->lock); 804d970dbf8SVlad Yasevich hlist_add_head(&epb->node, &head->chain); 8051da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 8061da177e4SLinus Torvalds } 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds /* Add an association to the hash. Local BH-safe. */ 8091da177e4SLinus Torvalds void sctp_hash_established(struct sctp_association *asoc) 8101da177e4SLinus Torvalds { 811de76e695SVlad Yasevich if (asoc->temp) 812de76e695SVlad Yasevich return; 813de76e695SVlad Yasevich 8141da177e4SLinus Torvalds sctp_local_bh_disable(); 8151da177e4SLinus Torvalds __sctp_hash_established(asoc); 8161da177e4SLinus Torvalds sctp_local_bh_enable(); 8171da177e4SLinus Torvalds } 8181da177e4SLinus Torvalds 8191da177e4SLinus Torvalds /* Remove association from the hash table. */ 8201da177e4SLinus Torvalds static void __sctp_unhash_established(struct sctp_association *asoc) 8211da177e4SLinus Torvalds { 8224110cc25SEric W. Biederman struct net *net = sock_net(asoc->base.sk); 8231da177e4SLinus Torvalds struct sctp_hashbucket *head; 8241da177e4SLinus Torvalds struct sctp_ep_common *epb; 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds epb = &asoc->base; 8271da177e4SLinus Torvalds 8284110cc25SEric W. Biederman epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, 8291da177e4SLinus Torvalds asoc->peer.port); 8301da177e4SLinus Torvalds 8311da177e4SLinus Torvalds head = &sctp_assoc_hashtable[epb->hashent]; 8321da177e4SLinus Torvalds 8331da177e4SLinus Torvalds sctp_write_lock(&head->lock); 8342eebc1e1SNeil Horman hlist_del_init(&epb->node); 8351da177e4SLinus Torvalds sctp_write_unlock(&head->lock); 8361da177e4SLinus Torvalds } 8371da177e4SLinus Torvalds 8381da177e4SLinus Torvalds /* Remove association from the hash table. Local BH-safe. */ 8391da177e4SLinus Torvalds void sctp_unhash_established(struct sctp_association *asoc) 8401da177e4SLinus Torvalds { 841de76e695SVlad Yasevich if (asoc->temp) 842de76e695SVlad Yasevich return; 843de76e695SVlad Yasevich 8441da177e4SLinus Torvalds sctp_local_bh_disable(); 8451da177e4SLinus Torvalds __sctp_unhash_established(asoc); 8461da177e4SLinus Torvalds sctp_local_bh_enable(); 8471da177e4SLinus Torvalds } 8481da177e4SLinus Torvalds 8491da177e4SLinus Torvalds /* Look up an association. */ 8501da177e4SLinus Torvalds static struct sctp_association *__sctp_lookup_association( 8514110cc25SEric W. Biederman struct net *net, 8521da177e4SLinus Torvalds const union sctp_addr *local, 8531da177e4SLinus Torvalds const union sctp_addr *peer, 8541da177e4SLinus Torvalds struct sctp_transport **pt) 8551da177e4SLinus Torvalds { 8561da177e4SLinus Torvalds struct sctp_hashbucket *head; 8571da177e4SLinus Torvalds struct sctp_ep_common *epb; 8581da177e4SLinus Torvalds struct sctp_association *asoc; 8591da177e4SLinus Torvalds struct sctp_transport *transport; 8601da177e4SLinus Torvalds int hash; 8611da177e4SLinus Torvalds 8621da177e4SLinus Torvalds /* Optimize here for direct hit, only listening connections can 8631da177e4SLinus Torvalds * have wildcards anyways. 8641da177e4SLinus Torvalds */ 8654110cc25SEric W. Biederman hash = sctp_assoc_hashfn(net, ntohs(local->v4.sin_port), 8664110cc25SEric W. Biederman ntohs(peer->v4.sin_port)); 8671da177e4SLinus Torvalds head = &sctp_assoc_hashtable[hash]; 8681da177e4SLinus Torvalds read_lock(&head->lock); 869b67bfe0dSSasha Levin sctp_for_each_hentry(epb, &head->chain) { 8701da177e4SLinus Torvalds asoc = sctp_assoc(epb); 8714110cc25SEric W. Biederman transport = sctp_assoc_is_match(asoc, net, local, peer); 8721da177e4SLinus Torvalds if (transport) 8731da177e4SLinus Torvalds goto hit; 8741da177e4SLinus Torvalds } 8751da177e4SLinus Torvalds 8761da177e4SLinus Torvalds read_unlock(&head->lock); 8771da177e4SLinus Torvalds 8781da177e4SLinus Torvalds return NULL; 8791da177e4SLinus Torvalds 8801da177e4SLinus Torvalds hit: 8811da177e4SLinus Torvalds *pt = transport; 8821da177e4SLinus Torvalds sctp_association_hold(asoc); 8831da177e4SLinus Torvalds read_unlock(&head->lock); 8841da177e4SLinus Torvalds return asoc; 8851da177e4SLinus Torvalds } 8861da177e4SLinus Torvalds 8871da177e4SLinus Torvalds /* Look up an association. BH-safe. */ 888dda91928SDaniel Borkmann static 8894110cc25SEric W. Biederman struct sctp_association *sctp_lookup_association(struct net *net, 8904110cc25SEric W. Biederman const union sctp_addr *laddr, 8911da177e4SLinus Torvalds const union sctp_addr *paddr, 8921da177e4SLinus Torvalds struct sctp_transport **transportp) 8931da177e4SLinus Torvalds { 8941da177e4SLinus Torvalds struct sctp_association *asoc; 8951da177e4SLinus Torvalds 8961da177e4SLinus Torvalds sctp_local_bh_disable(); 8974110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, transportp); 8981da177e4SLinus Torvalds sctp_local_bh_enable(); 8991da177e4SLinus Torvalds 9001da177e4SLinus Torvalds return asoc; 9011da177e4SLinus Torvalds } 9021da177e4SLinus Torvalds 9031da177e4SLinus Torvalds /* Is there an association matching the given local and peer addresses? */ 9044110cc25SEric W. Biederman int sctp_has_association(struct net *net, 9054110cc25SEric W. Biederman const union sctp_addr *laddr, 9061da177e4SLinus Torvalds const union sctp_addr *paddr) 9071da177e4SLinus Torvalds { 9081da177e4SLinus Torvalds struct sctp_association *asoc; 9091da177e4SLinus Torvalds struct sctp_transport *transport; 9101da177e4SLinus Torvalds 9114110cc25SEric W. Biederman if ((asoc = sctp_lookup_association(net, laddr, paddr, &transport))) { 9121da177e4SLinus Torvalds sctp_association_put(asoc); 9131da177e4SLinus Torvalds return 1; 9141da177e4SLinus Torvalds } 9151da177e4SLinus Torvalds 9161da177e4SLinus Torvalds return 0; 9171da177e4SLinus Torvalds } 9181da177e4SLinus Torvalds 9191da177e4SLinus Torvalds /* 9201da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 9211da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 9221da177e4SLinus Torvalds * 9231da177e4SLinus Torvalds * D) When searching for a matching TCB upon reception of an INIT 9241da177e4SLinus Torvalds * or INIT-ACK chunk the receiver SHOULD use not only the 9251da177e4SLinus Torvalds * source address of the packet (containing the INIT or 9261da177e4SLinus Torvalds * INIT-ACK) but the receiver SHOULD also use all valid 9271da177e4SLinus Torvalds * address parameters contained within the chunk. 9281da177e4SLinus Torvalds * 9291da177e4SLinus Torvalds * 2.18.3 Solution description 9301da177e4SLinus Torvalds * 9311da177e4SLinus Torvalds * This new text clearly specifies to an implementor the need 9321da177e4SLinus Torvalds * to look within the INIT or INIT-ACK. Any implementation that 9331da177e4SLinus Torvalds * does not do this, may not be able to establish associations 9341da177e4SLinus Torvalds * in certain circumstances. 9351da177e4SLinus Torvalds * 9361da177e4SLinus Torvalds */ 9374110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_init_lookup(struct net *net, 9384110cc25SEric W. Biederman struct sk_buff *skb, 9391da177e4SLinus Torvalds const union sctp_addr *laddr, struct sctp_transport **transportp) 9401da177e4SLinus Torvalds { 9411da177e4SLinus Torvalds struct sctp_association *asoc; 9421da177e4SLinus Torvalds union sctp_addr addr; 9431da177e4SLinus Torvalds union sctp_addr *paddr = &addr; 9442c0fd387SArnaldo Carvalho de Melo struct sctphdr *sh = sctp_hdr(skb); 9451da177e4SLinus Torvalds union sctp_params params; 9461da177e4SLinus Torvalds sctp_init_chunk_t *init; 9471da177e4SLinus Torvalds struct sctp_transport *transport; 9481da177e4SLinus Torvalds struct sctp_af *af; 9491da177e4SLinus Torvalds 9501da177e4SLinus Torvalds /* 9511da177e4SLinus Torvalds * This code will NOT touch anything inside the chunk--it is 9521da177e4SLinus Torvalds * strictly READ-ONLY. 9531da177e4SLinus Torvalds * 9541da177e4SLinus Torvalds * RFC 2960 3 SCTP packet Format 9551da177e4SLinus Torvalds * 9561da177e4SLinus Torvalds * Multiple chunks can be bundled into one SCTP packet up to 9571da177e4SLinus Torvalds * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN 9581da177e4SLinus Torvalds * COMPLETE chunks. These chunks MUST NOT be bundled with any 9591da177e4SLinus Torvalds * other chunk in a packet. See Section 6.10 for more details 9601da177e4SLinus Torvalds * on chunk bundling. 9611da177e4SLinus Torvalds */ 9621da177e4SLinus Torvalds 9631da177e4SLinus Torvalds /* Find the start of the TLVs and the end of the chunk. This is 9641da177e4SLinus Torvalds * the region we search for address parameters. 9651da177e4SLinus Torvalds */ 9661da177e4SLinus Torvalds init = (sctp_init_chunk_t *)skb->data; 9671da177e4SLinus Torvalds 9681da177e4SLinus Torvalds /* Walk the parameters looking for embedded addresses. */ 9691da177e4SLinus Torvalds sctp_walk_params(params, init, init_hdr.params) { 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds /* Note: Ignoring hostname addresses. */ 9721da177e4SLinus Torvalds af = sctp_get_af_specific(param_type2af(params.p->type)); 9731da177e4SLinus Torvalds if (!af) 9741da177e4SLinus Torvalds continue; 9751da177e4SLinus Torvalds 976dd86d136SAl Viro af->from_addr_param(paddr, params.addr, sh->source, 0); 9771da177e4SLinus Torvalds 9784110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, &transport); 9791da177e4SLinus Torvalds if (asoc) 9801da177e4SLinus Torvalds return asoc; 9811da177e4SLinus Torvalds } 9821da177e4SLinus Torvalds 9831da177e4SLinus Torvalds return NULL; 9841da177e4SLinus Torvalds } 9851da177e4SLinus Torvalds 986df218577SVlad Yasevich /* ADD-IP, Section 5.2 987df218577SVlad Yasevich * When an endpoint receives an ASCONF Chunk from the remote peer 988df218577SVlad Yasevich * special procedures may be needed to identify the association the 989df218577SVlad Yasevich * ASCONF Chunk is associated with. To properly find the association 990df218577SVlad Yasevich * the following procedures SHOULD be followed: 991df218577SVlad Yasevich * 992df218577SVlad Yasevich * D2) If the association is not found, use the address found in the 993df218577SVlad Yasevich * Address Parameter TLV combined with the port number found in the 994df218577SVlad Yasevich * SCTP common header. If found proceed to rule D4. 995df218577SVlad Yasevich * 996df218577SVlad Yasevich * D2-ext) If more than one ASCONF Chunks are packed together, use the 997df218577SVlad Yasevich * address found in the ASCONF Address Parameter TLV of each of the 998df218577SVlad Yasevich * subsequent ASCONF Chunks. If found, proceed to rule D4. 999df218577SVlad Yasevich */ 1000df218577SVlad Yasevich static struct sctp_association *__sctp_rcv_asconf_lookup( 10014110cc25SEric W. Biederman struct net *net, 1002df218577SVlad Yasevich sctp_chunkhdr_t *ch, 1003df218577SVlad Yasevich const union sctp_addr *laddr, 1004bc92dd19SAl Viro __be16 peer_port, 1005df218577SVlad Yasevich struct sctp_transport **transportp) 1006df218577SVlad Yasevich { 1007df218577SVlad Yasevich sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch; 1008df218577SVlad Yasevich struct sctp_af *af; 1009df218577SVlad Yasevich union sctp_addr_param *param; 1010df218577SVlad Yasevich union sctp_addr paddr; 1011df218577SVlad Yasevich 1012df218577SVlad Yasevich /* Skip over the ADDIP header and find the Address parameter */ 1013df218577SVlad Yasevich param = (union sctp_addr_param *)(asconf + 1); 1014df218577SVlad Yasevich 10156a435732SShan Wei af = sctp_get_af_specific(param_type2af(param->p.type)); 1016df218577SVlad Yasevich if (unlikely(!af)) 1017df218577SVlad Yasevich return NULL; 1018df218577SVlad Yasevich 1019df218577SVlad Yasevich af->from_addr_param(&paddr, param, peer_port, 0); 1020df218577SVlad Yasevich 10214110cc25SEric W. Biederman return __sctp_lookup_association(net, laddr, &paddr, transportp); 1022df218577SVlad Yasevich } 1023df218577SVlad Yasevich 1024df218577SVlad Yasevich 1025bbd0d598SVlad Yasevich /* SCTP-AUTH, Section 6.3: 1026bbd0d598SVlad Yasevich * If the receiver does not find a STCB for a packet containing an AUTH 1027bbd0d598SVlad Yasevich * chunk as the first chunk and not a COOKIE-ECHO chunk as the second 1028bbd0d598SVlad Yasevich * chunk, it MUST use the chunks after the AUTH chunk to look up an existing 1029bbd0d598SVlad Yasevich * association. 1030bbd0d598SVlad Yasevich * 1031bbd0d598SVlad Yasevich * This means that any chunks that can help us identify the association need 103225985edcSLucas De Marchi * to be looked at to find this association. 1033bbd0d598SVlad Yasevich */ 10344110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, 10354110cc25SEric W. Biederman struct sk_buff *skb, 1036bbd0d598SVlad Yasevich const union sctp_addr *laddr, 1037bbd0d598SVlad Yasevich struct sctp_transport **transportp) 1038bbd0d598SVlad Yasevich { 1039df218577SVlad Yasevich struct sctp_association *asoc = NULL; 1040df218577SVlad Yasevich sctp_chunkhdr_t *ch; 1041df218577SVlad Yasevich int have_auth = 0; 1042df218577SVlad Yasevich unsigned int chunk_num = 1; 1043df218577SVlad Yasevich __u8 *ch_end; 1044df218577SVlad Yasevich 1045df218577SVlad Yasevich /* Walk through the chunks looking for AUTH or ASCONF chunks 1046df218577SVlad Yasevich * to help us find the association. 1047bbd0d598SVlad Yasevich */ 1048df218577SVlad Yasevich ch = (sctp_chunkhdr_t *) skb->data; 1049df218577SVlad Yasevich do { 1050df218577SVlad Yasevich /* Break out if chunk length is less then minimal. */ 1051df218577SVlad Yasevich if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) 1052df218577SVlad Yasevich break; 1053df218577SVlad Yasevich 1054df218577SVlad Yasevich ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); 1055df218577SVlad Yasevich if (ch_end > skb_tail_pointer(skb)) 1056df218577SVlad Yasevich break; 1057df218577SVlad Yasevich 1058df218577SVlad Yasevich switch(ch->type) { 1059df218577SVlad Yasevich case SCTP_CID_AUTH: 1060df218577SVlad Yasevich have_auth = chunk_num; 1061df218577SVlad Yasevich break; 1062df218577SVlad Yasevich 1063df218577SVlad Yasevich case SCTP_CID_COOKIE_ECHO: 1064df218577SVlad Yasevich /* If a packet arrives containing an AUTH chunk as 1065df218577SVlad Yasevich * a first chunk, a COOKIE-ECHO chunk as the second 1066df218577SVlad Yasevich * chunk, and possibly more chunks after them, and 1067df218577SVlad Yasevich * the receiver does not have an STCB for that 1068df218577SVlad Yasevich * packet, then authentication is based on 1069df218577SVlad Yasevich * the contents of the COOKIE- ECHO chunk. 1070df218577SVlad Yasevich */ 1071df218577SVlad Yasevich if (have_auth == 1 && chunk_num == 2) 1072bbd0d598SVlad Yasevich return NULL; 1073df218577SVlad Yasevich break; 1074df218577SVlad Yasevich 1075df218577SVlad Yasevich case SCTP_CID_ASCONF: 1076e1fc3b14SEric W. Biederman if (have_auth || net->sctp.addip_noauth) 10774110cc25SEric W. Biederman asoc = __sctp_rcv_asconf_lookup( 10784110cc25SEric W. Biederman net, ch, laddr, 1079df218577SVlad Yasevich sctp_hdr(skb)->source, 1080df218577SVlad Yasevich transportp); 1081df218577SVlad Yasevich default: 1082df218577SVlad Yasevich break; 1083df218577SVlad Yasevich } 1084df218577SVlad Yasevich 1085df218577SVlad Yasevich if (asoc) 1086df218577SVlad Yasevich break; 1087df218577SVlad Yasevich 1088df218577SVlad Yasevich ch = (sctp_chunkhdr_t *) ch_end; 1089df218577SVlad Yasevich chunk_num++; 1090df218577SVlad Yasevich } while (ch_end < skb_tail_pointer(skb)); 1091df218577SVlad Yasevich 1092df218577SVlad Yasevich return asoc; 1093bbd0d598SVlad Yasevich } 1094bbd0d598SVlad Yasevich 1095bbd0d598SVlad Yasevich /* 1096bbd0d598SVlad Yasevich * There are circumstances when we need to look inside the SCTP packet 1097bbd0d598SVlad Yasevich * for information to help us find the association. Examples 1098bbd0d598SVlad Yasevich * include looking inside of INIT/INIT-ACK chunks or after the AUTH 1099bbd0d598SVlad Yasevich * chunks. 1100bbd0d598SVlad Yasevich */ 11014110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net, 11024110cc25SEric W. Biederman struct sk_buff *skb, 1103bbd0d598SVlad Yasevich const union sctp_addr *laddr, 1104bbd0d598SVlad Yasevich struct sctp_transport **transportp) 1105bbd0d598SVlad Yasevich { 1106bbd0d598SVlad Yasevich sctp_chunkhdr_t *ch; 1107bbd0d598SVlad Yasevich 1108bbd0d598SVlad Yasevich ch = (sctp_chunkhdr_t *) skb->data; 1109bbd0d598SVlad Yasevich 1110df218577SVlad Yasevich /* The code below will attempt to walk the chunk and extract 1111df218577SVlad Yasevich * parameter information. Before we do that, we need to verify 1112df218577SVlad Yasevich * that the chunk length doesn't cause overflow. Otherwise, we'll 1113df218577SVlad Yasevich * walk off the end. 1114df218577SVlad Yasevich */ 1115df218577SVlad Yasevich if (WORD_ROUND(ntohs(ch->length)) > skb->len) 1116df218577SVlad Yasevich return NULL; 1117df218577SVlad Yasevich 1118bbd0d598SVlad Yasevich /* If this is INIT/INIT-ACK look inside the chunk too. */ 1119*f482f2fcSwangweidong if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK) 11204110cc25SEric W. Biederman return __sctp_rcv_init_lookup(net, skb, laddr, transportp); 1121bbd0d598SVlad Yasevich 11224110cc25SEric W. Biederman return __sctp_rcv_walk_lookup(net, skb, laddr, transportp); 1123bbd0d598SVlad Yasevich } 1124bbd0d598SVlad Yasevich 11251da177e4SLinus Torvalds /* Lookup an association for an inbound skb. */ 11264110cc25SEric W. Biederman static struct sctp_association *__sctp_rcv_lookup(struct net *net, 11274110cc25SEric W. Biederman struct sk_buff *skb, 11281da177e4SLinus Torvalds const union sctp_addr *paddr, 11291da177e4SLinus Torvalds const union sctp_addr *laddr, 11301da177e4SLinus Torvalds struct sctp_transport **transportp) 11311da177e4SLinus Torvalds { 11321da177e4SLinus Torvalds struct sctp_association *asoc; 11331da177e4SLinus Torvalds 11344110cc25SEric W. Biederman asoc = __sctp_lookup_association(net, laddr, paddr, transportp); 11351da177e4SLinus Torvalds 11361da177e4SLinus Torvalds /* Further lookup for INIT/INIT-ACK packets. 11371da177e4SLinus Torvalds * SCTP Implementors Guide, 2.18 Handling of address 11381da177e4SLinus Torvalds * parameters within the INIT or INIT-ACK. 11391da177e4SLinus Torvalds */ 11401da177e4SLinus Torvalds if (!asoc) 11414110cc25SEric W. Biederman asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp); 11421da177e4SLinus Torvalds 11431da177e4SLinus Torvalds return asoc; 11441da177e4SLinus Torvalds } 1145