X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fsctp%2Finput.c;h=ea2192444ce66413261d20ce8ec236279496d141;hb=b2e75eff5e859d0c294e7405958362b26a423c6e;hp=45d6a644cf06a75b3ff560f8acbbf33fd7a6edf1;hpb=c910b47e1811b3f8b184108c48de3d7af3e2999b;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/sctp/input.c b/net/sctp/input.c index 45d6a64..ea21924 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1,4 +1,4 @@ -/* SCTP kernel reference Implementation +/* SCTP kernel implementation * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * Copyright (c) 2001-2003 International Business Machines, Corp. @@ -6,17 +6,17 @@ * Copyright (c) 2001 Nokia, Inc. * Copyright (c) 2001 La Monte H.P. Yarroll * - * This file is part of the SCTP kernel reference Implementation + * This file is part of the SCTP kernel implementation * * These functions handle all input from the IP layer into SCTP. * - * The SCTP reference implementation is free software; + * This SCTP implementation is free software; * you can redistribute it and/or modify it under the terms of * the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * - * The SCTP reference implementation is distributed in the hope that it + * This SCTP implementation is distributed in the hope that it * will be useful, but WITHOUT ANY WARRANTY; without even the implied * ************************ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. @@ -53,6 +53,7 @@ #include #include #include /* For struct timeval */ +#include #include #include #include @@ -60,6 +61,8 @@ #include #include #include +#include +#include /* Forward declarations for internal helpers. */ static int sctp_rcv_ootb(struct sk_buff *); @@ -73,22 +76,23 @@ static struct sctp_association *__sctp_lookup_association( const union sctp_addr *peer, struct sctp_transport **pt); -static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb); +static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb); /* Calculate the SCTP checksum of an SCTP packet. */ static inline int sctp_rcv_checksum(struct sk_buff *skb) { - struct sk_buff *list = skb_shinfo(skb)->frag_list; struct sctphdr *sh = sctp_hdr(skb); - __u32 cmp = ntohl(sh->checksum); - __u32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); + __le32 cmp = sh->checksum; + struct sk_buff *list; + __le32 val; + __u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); - for (; list; list = list->next) - val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), - val); + skb_walk_frags(skb, list) + tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), + tmp); - val = sctp_end_cksum(val); + val = sctp_end_cksum(tmp); if (val != cmp) { /* CRC failure, dump it. */ @@ -140,7 +144,8 @@ int sctp_rcv(struct sk_buff *skb) __skb_pull(skb, skb_transport_offset(skb)); if (skb->len < sizeof(struct sctphdr)) goto discard_it; - if (!skb_csum_unnecessary(skb) && sctp_rcv_checksum(skb) < 0) + if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) && + sctp_rcv_checksum(skb) < 0) goto discard_it; skb_pull(skb, sizeof(struct sctphdr)); @@ -247,9 +252,27 @@ int sctp_rcv(struct sk_buff *skb) */ sctp_bh_lock_sock(sk); + if (sk != rcvr->sk) { + /* Our cached sk is different from the rcvr->sk. This is + * because migrate()/accept() may have moved the association + * to a new socket and released all the sockets. So now we + * are holding a lock on the old socket while the user may + * be doing something with the new socket. Switch our veiw + * of the current sk. + */ + sctp_bh_unlock_sock(sk); + sk = rcvr->sk; + sctp_bh_lock_sock(sk); + } + if (sock_owned_by_user(sk)) { + if (sctp_add_backlog(sk, skb)) { + sctp_bh_unlock_sock(sk); + sctp_chunk_free(chunk); + skb = NULL; /* sctp_chunk_free already freed the skb */ + goto discard_release; + } SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG); - sctp_add_backlog(sk, skb); } else { SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ); sctp_inq_push(&chunk->rcvr->inqueue, chunk); @@ -319,8 +342,10 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) sctp_bh_lock_sock(sk); if (sock_owned_by_user(sk)) { - sk_add_backlog(sk, skb); - backloged = 1; + if (sk_add_backlog(sk, skb)) + sctp_chunk_free(chunk); + else + backloged = 1; } else sctp_inq_push(inqueue, chunk); @@ -345,31 +370,42 @@ done: return 0; } -static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb) +static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb) { struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; struct sctp_ep_common *rcvr = chunk->rcvr; + int ret; - /* Hold the assoc/ep while hanging on the backlog queue. - * This way, we know structures we need will not disappear from us - */ - if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) - sctp_association_hold(sctp_assoc(rcvr)); - else if (SCTP_EP_TYPE_SOCKET == rcvr->type) - sctp_endpoint_hold(sctp_ep(rcvr)); - else - BUG(); + ret = sk_add_backlog(sk, skb); + if (!ret) { + /* Hold the assoc/ep while hanging on the backlog queue. + * This way, we know structures we need will not disappear + * from us + */ + if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) + sctp_association_hold(sctp_assoc(rcvr)); + else if (SCTP_EP_TYPE_SOCKET == rcvr->type) + sctp_endpoint_hold(sctp_ep(rcvr)); + else + BUG(); + } + return ret; - sk_add_backlog(sk, skb); } /* Handle icmp frag needed error. */ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, struct sctp_transport *t, __u32 pmtu) { - if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu)) + if (!t || (t->pathmtu <= pmtu)) return; + if (sock_owned_by_user(sk)) { + asoc->pmtu_pending = 1; + t->pmtu_pending = 1; + return; + } + if (t->param_flags & SPP_PMTUD_ENABLE) { /* Update transports view of the MTU */ sctp_transport_update_pmtu(t, pmtu); @@ -402,13 +438,27 @@ void sctp_icmp_proto_unreachable(struct sock *sk, struct sctp_association *asoc, struct sctp_transport *t) { - SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__); + SCTP_DEBUG_PRINTK("%s\n", __func__); - sctp_do_sm(SCTP_EVENT_T_OTHER, - SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), - asoc->state, asoc->ep, asoc, t, - GFP_ATOMIC); + if (sock_owned_by_user(sk)) { + if (timer_pending(&t->proto_unreach_timer)) + return; + else { + if (!mod_timer(&t->proto_unreach_timer, + jiffies + (HZ/20))) + sctp_association_hold(asoc); + } + + } else { + if (timer_pending(&t->proto_unreach_timer) && + del_timer(&t->proto_unreach_timer)) + sctp_association_put(asoc); + sctp_do_sm(SCTP_EVENT_T_OTHER, + SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), + asoc->state, asoc->ep, asoc, t, + GFP_ATOMIC); + } } /* Common lookup code for icmp/icmpv6 error handler. */ @@ -423,6 +473,9 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb, struct sock *sk = NULL; struct sctp_association *asoc; struct sctp_transport *transport = NULL; + struct sctp_init_chunk *chunkhdr; + __u32 vtag = ntohl(sctphdr->vtag); + int len = skb->len - ((void *)sctphdr - (void *)skb->data); *app = NULL; *tpp = NULL; @@ -444,8 +497,28 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb, sk = asoc->base.sk; - if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) { - ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + /* RFC 4960, Appendix C. ICMP Handling + * + * ICMP6) An implementation MUST validate that the Verification Tag + * contained in the ICMP message matches the Verification Tag of + * the peer. If the Verification Tag is not 0 and does NOT + * match, discard the ICMP message. If it is 0 and the ICMP + * message contains enough bytes to verify that the chunk type is + * an INIT chunk and that the Initiate Tag matches the tag of the + * peer, continue with ICMP7. If the ICMP message is too short + * or the chunk type or the Initiate Tag does not match, silently + * discard the packet. + */ + if (vtag == 0) { + chunkhdr = (struct sctp_init_chunk *)((void *)sctphdr + + sizeof(struct sctphdr)); + if (len < sizeof(struct sctphdr) + sizeof(sctp_chunkhdr_t) + + sizeof(__be32) || + chunkhdr->chunk_hdr.type != SCTP_CID_INIT || + ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) { + goto out; + } + } else if (vtag != asoc->c.peer_vtag) { goto out; } @@ -455,7 +528,7 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb, * servers this needs to be solved differently. */ if (sock_owned_by_user(sk)) - NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); + NET_INC_STATS_BH(&init_net, LINUX_MIB_LOCKDROPPEDICMPS); *app = asoc; *tpp = transport; @@ -504,7 +577,7 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info) int err; if (skb->len < ihlen + 8) { - ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS); return; } @@ -518,7 +591,7 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info) skb->network_header = saveip; skb->transport_header = savesctp; if (!sk) { - ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS); return; } /* Warning: The sock lock is held. Remember to call @@ -584,7 +657,7 @@ out_unlock: * Return 0 - If further processing is needed. * Return 1 - If the packet can be discarded right away. */ -int sctp_rcv_ootb(struct sk_buff *skb) +static int sctp_rcv_ootb(struct sk_buff *skb) { sctp_chunkhdr_t *ch; __u8 *ch_end; @@ -616,6 +689,14 @@ int sctp_rcv_ootb(struct sk_buff *skb) if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) goto discard; + /* RFC 4460, 2.11.2 + * This will discard packets with INIT chunk bundled as + * subsequent chunks in the packet. When INIT is first, + * the normal INIT processing will discard the chunk. + */ + if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) + goto discard; + /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR * or a COOKIE ACK the SCTP Packet should be silently * discarded. @@ -642,7 +723,6 @@ discard: /* Insert endpoint into the hash table. */ static void __sctp_hash_endpoint(struct sctp_endpoint *ep) { - struct sctp_ep_common **epp; struct sctp_ep_common *epb; struct sctp_hashbucket *head; @@ -652,12 +732,7 @@ static void __sctp_hash_endpoint(struct sctp_endpoint *ep) head = &sctp_ep_hashtable[epb->hashent]; sctp_write_lock(&head->lock); - epp = &head->chain; - epb->next = *epp; - if (epb->next) - (*epp)->pprev = &epb->next; - *epp = epb; - epb->pprev = epp; + hlist_add_head(&epb->node, &head->chain); sctp_write_unlock(&head->lock); } @@ -677,19 +752,15 @@ static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) epb = &ep->base; + if (hlist_unhashed(&epb->node)) + return; + epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); head = &sctp_ep_hashtable[epb->hashent]; sctp_write_lock(&head->lock); - - if (epb->pprev) { - if (epb->next) - epb->next->pprev = epb->pprev; - *epb->pprev = epb->next; - epb->pprev = NULL; - } - + __hlist_del(&epb->node); sctp_write_unlock(&head->lock); } @@ -707,19 +778,19 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *l struct sctp_hashbucket *head; struct sctp_ep_common *epb; struct sctp_endpoint *ep; + struct hlist_node *node; int hash; hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port)); head = &sctp_ep_hashtable[hash]; read_lock(&head->lock); - for (epb = head->chain; epb; epb = epb->next) { + sctp_for_each_hentry(epb, node, &head->chain) { ep = sctp_ep(epb); if (sctp_endpoint_is_match(ep, laddr)) goto hit; } ep = sctp_sk((sctp_get_ctl_sock()))->ep; - epb = &ep->base; hit: sctp_endpoint_hold(ep); @@ -730,7 +801,6 @@ hit: /* Insert association into the hash table. */ static void __sctp_hash_established(struct sctp_association *asoc) { - struct sctp_ep_common **epp; struct sctp_ep_common *epb; struct sctp_hashbucket *head; @@ -742,12 +812,7 @@ static void __sctp_hash_established(struct sctp_association *asoc) head = &sctp_assoc_hashtable[epb->hashent]; sctp_write_lock(&head->lock); - epp = &head->chain; - epb->next = *epp; - if (epb->next) - (*epp)->pprev = &epb->next; - *epp = epb; - epb->pprev = epp; + hlist_add_head(&epb->node, &head->chain); sctp_write_unlock(&head->lock); } @@ -776,14 +841,7 @@ static void __sctp_unhash_established(struct sctp_association *asoc) head = &sctp_assoc_hashtable[epb->hashent]; sctp_write_lock(&head->lock); - - if (epb->pprev) { - if (epb->next) - epb->next->pprev = epb->pprev; - *epb->pprev = epb->next; - epb->pprev = NULL; - } - + __hlist_del(&epb->node); sctp_write_unlock(&head->lock); } @@ -808,6 +866,7 @@ static struct sctp_association *__sctp_lookup_association( struct sctp_ep_common *epb; struct sctp_association *asoc; struct sctp_transport *transport; + struct hlist_node *node; int hash; /* Optimize here for direct hit, only listening connections can @@ -816,7 +875,7 @@ static struct sctp_association *__sctp_lookup_association( hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port)); head = &sctp_assoc_hashtable[hash]; read_lock(&head->lock); - for (epb = head->chain; epb; epb = epb->next) { + sctp_for_each_hentry(epb, node, &head->chain) { asoc = sctp_assoc(epb); transport = sctp_assoc_is_match(asoc, local, peer); if (transport) @@ -897,23 +956,6 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, ch = (sctp_chunkhdr_t *) skb->data; - /* If this is INIT/INIT-ACK look inside the chunk too. */ - switch (ch->type) { - case SCTP_CID_INIT: - case SCTP_CID_INIT_ACK: - break; - default: - return NULL; - } - - /* The code below will attempt to walk the chunk and extract - * parameter information. Before we do that, we need to verify - * that the chunk length doesn't cause overflow. Otherwise, we'll - * walk off the end. - */ - if (WORD_ROUND(ntohs(ch->length)) > skb->len) - return NULL; - /* * This code will NOT touch anything inside the chunk--it is * strictly READ-ONLY. @@ -950,6 +992,150 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, return NULL; } +/* ADD-IP, Section 5.2 + * When an endpoint receives an ASCONF Chunk from the remote peer + * special procedures may be needed to identify the association the + * ASCONF Chunk is associated with. To properly find the association + * the following procedures SHOULD be followed: + * + * D2) If the association is not found, use the address found in the + * Address Parameter TLV combined with the port number found in the + * SCTP common header. If found proceed to rule D4. + * + * D2-ext) If more than one ASCONF Chunks are packed together, use the + * address found in the ASCONF Address Parameter TLV of each of the + * subsequent ASCONF Chunks. If found, proceed to rule D4. + */ +static struct sctp_association *__sctp_rcv_asconf_lookup( + sctp_chunkhdr_t *ch, + const union sctp_addr *laddr, + __be16 peer_port, + struct sctp_transport **transportp) +{ + sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch; + struct sctp_af *af; + union sctp_addr_param *param; + union sctp_addr paddr; + + /* Skip over the ADDIP header and find the Address parameter */ + param = (union sctp_addr_param *)(asconf + 1); + + af = sctp_get_af_specific(param_type2af(param->v4.param_hdr.type)); + if (unlikely(!af)) + return NULL; + + af->from_addr_param(&paddr, param, peer_port, 0); + + return __sctp_lookup_association(laddr, &paddr, transportp); +} + + +/* SCTP-AUTH, Section 6.3: +* If the receiver does not find a STCB for a packet containing an AUTH +* chunk as the first chunk and not a COOKIE-ECHO chunk as the second +* chunk, it MUST use the chunks after the AUTH chunk to look up an existing +* association. +* +* This means that any chunks that can help us identify the association need +* to be looked at to find this assocation. +*/ +static struct sctp_association *__sctp_rcv_walk_lookup(struct sk_buff *skb, + const union sctp_addr *laddr, + struct sctp_transport **transportp) +{ + struct sctp_association *asoc = NULL; + sctp_chunkhdr_t *ch; + int have_auth = 0; + unsigned int chunk_num = 1; + __u8 *ch_end; + + /* Walk through the chunks looking for AUTH or ASCONF chunks + * to help us find the association. + */ + ch = (sctp_chunkhdr_t *) skb->data; + do { + /* Break out if chunk length is less then minimal. */ + if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) + break; + + ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); + if (ch_end > skb_tail_pointer(skb)) + break; + + switch(ch->type) { + case SCTP_CID_AUTH: + have_auth = chunk_num; + break; + + case SCTP_CID_COOKIE_ECHO: + /* If a packet arrives containing an AUTH chunk as + * a first chunk, a COOKIE-ECHO chunk as the second + * chunk, and possibly more chunks after them, and + * the receiver does not have an STCB for that + * packet, then authentication is based on + * the contents of the COOKIE- ECHO chunk. + */ + if (have_auth == 1 && chunk_num == 2) + return NULL; + break; + + case SCTP_CID_ASCONF: + if (have_auth || sctp_addip_noauth) + asoc = __sctp_rcv_asconf_lookup(ch, laddr, + sctp_hdr(skb)->source, + transportp); + default: + break; + } + + if (asoc) + break; + + ch = (sctp_chunkhdr_t *) ch_end; + chunk_num++; + } while (ch_end < skb_tail_pointer(skb)); + + return asoc; +} + +/* + * There are circumstances when we need to look inside the SCTP packet + * for information to help us find the association. Examples + * include looking inside of INIT/INIT-ACK chunks or after the AUTH + * chunks. + */ +static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb, + const union sctp_addr *laddr, + struct sctp_transport **transportp) +{ + sctp_chunkhdr_t *ch; + + ch = (sctp_chunkhdr_t *) skb->data; + + /* The code below will attempt to walk the chunk and extract + * parameter information. Before we do that, we need to verify + * that the chunk length doesn't cause overflow. Otherwise, we'll + * walk off the end. + */ + if (WORD_ROUND(ntohs(ch->length)) > skb->len) + return NULL; + + /* If this is INIT/INIT-ACK look inside the chunk too. */ + switch (ch->type) { + case SCTP_CID_INIT: + case SCTP_CID_INIT_ACK: + return __sctp_rcv_init_lookup(skb, laddr, transportp); + break; + + default: + return __sctp_rcv_walk_lookup(skb, laddr, transportp); + break; + } + + + return NULL; +} + /* Lookup an association for an inbound skb. */ static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, const union sctp_addr *paddr, @@ -965,7 +1151,7 @@ static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, * parameters within the INIT or INIT-ACK. */ if (!asoc) - asoc = __sctp_rcv_init_lookup(skb, laddr, transportp); + asoc = __sctp_rcv_lookup_harder(skb, laddr, transportp); return asoc; }