diff options
Diffstat (limited to 'net/sctp/input.c')
| -rw-r--r-- | net/sctp/input.c | 755 |
1 files changed, 490 insertions, 265 deletions
diff --git a/net/sctp/input.c b/net/sctp/input.c index 28f32243397..f2e2cbd2d75 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. @@ -6,33 +6,29 @@ * 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. * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License - * along with GNU CC; see the file COPYING. If not, write to - * the Free Software Foundation, 59 Temple Place - Suite 330, - * Boston, MA 02111-1307, USA. + * along with GNU CC; see the file COPYING. If not, see + * <http://www.gnu.org/licenses/>. * * Please send any bug reports or fixes you make to the * email address(es): - * lksctp developers <lksctp-developers@lists.sourceforge.net> - * - * Or submit a bug report through the following website: - * http://www.sf.net/projects/lksctp + * lksctp developers <linux-sctp@vger.kernel.org> * * Written or modified by: * La Monte H.P. Yarroll <piggy@acm.org> @@ -43,9 +39,6 @@ * Daisy Chang <daisyc@us.ibm.com> * Sridhar Samudrala <sri@us.ibm.com> * Ardelle Fan <ardelle.fan@intel.com> - * - * Any bugs reported given to us we will try to fix... any fixes shared will - * be incorporated into the next SCTP release. */ #include <linux/types.h> @@ -53,6 +46,7 @@ #include <linux/socket.h> #include <linux/ip.h> #include <linux/time.h> /* For struct timeval */ +#include <linux/slab.h> #include <net/ip.h> #include <net/icmp.h> #include <net/snmp.h> @@ -60,65 +54,46 @@ #include <net/xfrm.h> #include <net/sctp/sctp.h> #include <net/sctp/sm.h> +#include <net/sctp/checksum.h> +#include <net/net_namespace.h> /* Forward declarations for internal helpers. */ static int sctp_rcv_ootb(struct sk_buff *); -static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, - const union sctp_addr *laddr, +static struct sctp_association *__sctp_rcv_lookup(struct net *net, + struct sk_buff *skb, const union sctp_addr *paddr, + const union sctp_addr *laddr, struct sctp_transport **transportp); -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr); +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, + const union sctp_addr *laddr); static struct sctp_association *__sctp_lookup_association( + struct net *net, const union sctp_addr *local, const union sctp_addr *peer, struct sctp_transport **pt); +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) +static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb) { - struct sctphdr *sh; - __u32 cmp, val; - struct sk_buff *list = skb_shinfo(skb)->frag_list; - - sh = (struct sctphdr *) skb->h.raw; - cmp = ntohl(sh->checksum); - - val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb)); - - for (; list; list = list->next) - val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list), - val); - - val = sctp_end_cksum(val); + struct sctphdr *sh = sctp_hdr(skb); + __le32 cmp = sh->checksum; + __le32 val = sctp_compute_cksum(skb, 0); if (val != cmp) { /* CRC failure, dump it. */ - SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS); + SCTP_INC_STATS_BH(net, SCTP_MIB_CHECKSUMERRORS); return -1; } return 0; } -/* The free routine for skbuffs that sctp receives */ -static void sctp_rfree(struct sk_buff *skb) -{ - atomic_sub(sizeof(struct sctp_chunk),&skb->sk->sk_rmem_alloc); - sock_rfree(skb); -} - -/* The ownership wrapper routine to do receive buffer accounting */ -static void sctp_rcv_set_owner_r(struct sk_buff *skb, struct sock *sk) -{ - skb_set_owner_r(skb,sk); - skb->destructor = sctp_rfree; - atomic_add(sizeof(struct sctp_chunk),&sk->sk_rmem_alloc); -} - struct sctp_input_cb { union { struct inet_skb_parm h4; -#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) +#if IS_ENABLED(CONFIG_IPV6) struct inet6_skb_parm h6; #endif } header; @@ -142,20 +117,24 @@ int sctp_rcv(struct sk_buff *skb) union sctp_addr dest; int family; struct sctp_af *af; - int ret = 0; + struct net *net = dev_net(skb->dev); - if (skb->pkt_type!=PACKET_HOST) + if (skb->pkt_type != PACKET_HOST) goto discard_it; - SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS); + SCTP_INC_STATS_BH(net, SCTP_MIB_INSCTPPACKS); + + if (skb_linearize(skb)) + goto discard_it; - sh = (struct sctphdr *) skb->h.raw; + sh = sctp_hdr(skb); /* Pull up the IP and SCTP headers. */ - __skb_pull(skb, skb->h.raw - skb->data); + __skb_pull(skb, skb_transport_offset(skb)); if (skb->len < sizeof(struct sctphdr)) goto discard_it; - if (sctp_rcv_checksum(skb) < 0) + if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) && + sctp_rcv_checksum(net, skb) < 0) goto discard_it; skb_pull(skb, sizeof(struct sctphdr)); @@ -164,7 +143,7 @@ int sctp_rcv(struct sk_buff *skb) if (skb->len < sizeof(struct sctp_chunkhdr)) goto discard_it; - family = ipver2af(skb->nh.iph->version); + family = ipver2af(ip_hdr(skb)->version); af = sctp_get_af_specific(family); if (unlikely(!af)) goto discard_it; @@ -184,13 +163,14 @@ int sctp_rcv(struct sk_buff *skb) * IP broadcast addresses cannot be used in an SCTP transport * address." */ - if (!af->addr_valid(&src, NULL) || !af->addr_valid(&dest, NULL)) + if (!af->addr_valid(&src, NULL, skb) || + !af->addr_valid(&dest, NULL, skb)) goto discard_it; - asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport); + asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport); if (!asoc) - ep = __sctp_rcv_lookup_endpoint(&dest); + ep = __sctp_rcv_lookup_endpoint(net, &dest); /* Retrieve the common input handling substructure. */ rcvr = asoc ? &asoc->base : &ep->base; @@ -200,9 +180,7 @@ int sctp_rcv(struct sk_buff *skb) * If a frame arrives on an interface and the receiving socket is * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB */ - if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) - { - sock_put(sk); + if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) { if (asoc) { sctp_association_put(asoc); asoc = NULL; @@ -210,16 +188,12 @@ int sctp_rcv(struct sk_buff *skb) sctp_endpoint_put(ep); ep = NULL; } - sk = sctp_get_ctl_sock(); + sk = net->sctp.ctl_sock; ep = sctp_sk(sk)->ep; sctp_endpoint_hold(ep); - sock_hold(sk); rcvr = &ep->base; } - if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) - goto discard_release; - /* * RFC 2960, 8.4 - Handle "Out of the blue" Packets. * An SCTP packet is called an "out of the blue" (OOTB) @@ -230,34 +204,24 @@ int sctp_rcv(struct sk_buff *skb) */ if (!asoc) { if (sctp_rcv_ootb(skb)) { - SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES); + SCTP_INC_STATS_BH(net, SCTP_MIB_OUTOFBLUES); goto discard_release; } } - /* SCTP seems to always need a timestamp right now (FIXME) */ - if (skb->tstamp.off_sec == 0) { - __net_timestamp(skb); - sock_enable_timestamp(sk); - } - if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) goto discard_release; + nf_reset(skb); - ret = sk_filter(sk, skb, 1); - if (ret) - goto discard_release; + if (sk_filter(sk, skb)) + goto discard_release; /* Create an SCTP packet structure. */ chunk = sctp_chunkify(skb, asoc, sk); - if (!chunk) { - ret = -ENOMEM; + if (!chunk) goto discard_release; - } SCTP_INPUT_CB(skb)->chunk = chunk; - sctp_rcv_set_owner_r(skb,sk); - /* Remember what endpoint is to handle this packet. */ chunk->rcvr = rcvr; @@ -274,31 +238,51 @@ int sctp_rcv(struct sk_buff *skb) * bottom halves on this lock, but a user may be in the lock too, * so check if it is busy. */ - sctp_bh_lock_sock(sk); + 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. + */ + bh_unlock_sock(sk); + sk = rcvr->sk; + bh_lock_sock(sk); + } - if (sock_owned_by_user(sk)) - sk_add_backlog(sk, skb); - else - sctp_backlog_rcv(sk, skb); + if (sock_owned_by_user(sk)) { + if (sctp_add_backlog(sk, skb)) { + bh_unlock_sock(sk); + sctp_chunk_free(chunk); + skb = NULL; /* sctp_chunk_free already freed the skb */ + goto discard_release; + } + SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_BACKLOG); + } else { + SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_SOFTIRQ); + sctp_inq_push(&chunk->rcvr->inqueue, chunk); + } - /* Release the sock and any reference counts we took in the - * lookup calls. - */ - sctp_bh_unlock_sock(sk); + bh_unlock_sock(sk); + + /* Release the asoc/ep ref we took in the lookup calls. */ if (asoc) sctp_association_put(asoc); else sctp_endpoint_put(ep); - sock_put(sk); - return ret; + + return 0; discard_it: + SCTP_INC_STATS_BH(net, SCTP_MIB_IN_PKT_DISCARDS); kfree_skb(skb); - return ret; + return 0; discard_release: - /* Release any structures we may be holding. */ - sock_put(sk); + /* Release the asoc/ep ref we took in the lookup calls. */ if (asoc) sctp_association_put(asoc); else @@ -307,36 +291,136 @@ discard_release: goto discard_it; } -/* Handle second half of inbound skb processing. If the sock was busy, - * we may have need to delay processing until later when the sock is - * released (on the backlog). If not busy, we call this routine - * directly from the bottom half. +/* Process the backlog queue of the socket. Every skb on + * the backlog holds a ref on an association or endpoint. + * We hold this ref throughout the state machine to make + * sure that the structure we need is still around. */ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) { struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; struct sctp_inq *inqueue = &chunk->rcvr->inqueue; + struct sctp_ep_common *rcvr = NULL; + int backloged = 0; + + rcvr = chunk->rcvr; + + /* If the rcvr is dead then the association or endpoint + * has been deleted and we can safely drop the chunk + * and refs that we are holding. + */ + if (rcvr->dead) { + sctp_chunk_free(chunk); + goto done; + } + + if (unlikely(rcvr->sk != sk)) { + /* In this case, the association moved from one socket to + * another. We are currently sitting on the backlog of the + * old socket, so we need to move. + * However, since we are here in the process context we + * need to take make sure that the user doesn't own + * the new socket when we process the packet. + * If the new socket is user-owned, queue the chunk to the + * backlog of the new socket without dropping any refs. + * Otherwise, we can safely push the chunk on the inqueue. + */ + + sk = rcvr->sk; + bh_lock_sock(sk); + + if (sock_owned_by_user(sk)) { + if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) + sctp_chunk_free(chunk); + else + backloged = 1; + } else + sctp_inq_push(inqueue, chunk); + + bh_unlock_sock(sk); + + /* If the chunk was backloged again, don't drop refs */ + if (backloged) + return 0; + } else { + sctp_inq_push(inqueue, chunk); + } + +done: + /* Release the refs we took in sctp_add_backlog */ + if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) + sctp_association_put(sctp_assoc(rcvr)); + else if (SCTP_EP_TYPE_SOCKET == rcvr->type) + sctp_endpoint_put(sctp_ep(rcvr)); + else + BUG(); + + return 0; +} + +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; + + ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf); + 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; - sctp_inq_push(inqueue, chunk); - return 0; } /* Handle icmp frag needed error. */ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, struct sctp_transport *t, __u32 pmtu) { - if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) { - printk(KERN_WARNING "%s: Reported pmtu %d too low, " - "using default minimum of %d\n", __FUNCTION__, pmtu, - SCTP_DEFAULT_MINSEGMENT); - pmtu = SCTP_DEFAULT_MINSEGMENT; + if (!t || (t->pathmtu <= pmtu)) + return; + + if (sock_owned_by_user(sk)) { + asoc->pmtu_pending = 1; + t->pmtu_pending = 1; + return; } - if (!sock_owned_by_user(sk) && t && (t->pmtu != pmtu)) { - t->pmtu = pmtu; - sctp_assoc_sync_pmtu(asoc); - sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); + if (t->param_flags & SPP_PMTUD_ENABLE) { + /* Update transports view of the MTU */ + sctp_transport_update_pmtu(sk, t, pmtu); + + /* Update association pmtu. */ + sctp_assoc_sync_pmtu(sk, asoc); } + + /* Retransmit with the new pmtu setting. + * Normally, if PMTU discovery is disabled, an ICMP Fragmentation + * Needed will never be sent, but if a message was sent before + * PMTU discovery was disabled that was larger than the PMTU, it + * would not be fragmented, so it must be re-transmitted fragmented. + */ + sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); +} + +void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t, + struct sk_buff *skb) +{ + struct dst_entry *dst; + + if (!t) + return; + dst = sctp_transport_dst_check(t); + if (dst) + dst->ops->redirect(dst, sk, skb); } /* @@ -351,20 +435,35 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, * */ void sctp_icmp_proto_unreachable(struct sock *sk, - struct sctp_association *asoc, - struct sctp_transport *t) + struct sctp_association *asoc, + struct sctp_transport *t) { - SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__); + 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 { + struct net *net = sock_net(sk); + + pr_debug("%s: unrecognized next header type " + "encountered!\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 (del_timer(&t->proto_unreach_timer)) + sctp_association_put(asoc); + sctp_do_sm(net, 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. */ -struct sock *sctp_err_lookup(int family, struct sk_buff *skb, +struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb, struct sctphdr *sctphdr, struct sctp_association **app, struct sctp_transport **tpp) @@ -373,8 +472,11 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb, union sctp_addr daddr; struct sctp_af *af; struct sock *sk = NULL; - struct sctp_association *asoc = 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; @@ -390,43 +492,58 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb, /* Look for an association that matches the incoming ICMP error * packet. */ - asoc = __sctp_lookup_association(&saddr, &daddr, &transport); + asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport); if (!asoc) return NULL; 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 = (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; } - sctp_bh_lock_sock(sk); + bh_lock_sock(sk); /* If too many ICMPs get dropped on busy * servers this needs to be solved differently. */ if (sock_owned_by_user(sk)) - NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); + NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); *app = asoc; *tpp = transport; return sk; out: - sock_put(sk); - if (asoc) - sctp_association_put(asoc); + sctp_association_put(asoc); return NULL; } /* Common cleanup code for icmp/icmpv6 error handler. */ void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) { - sctp_bh_unlock_sock(sk); - sock_put(sk); - if (asoc) - sctp_association_put(asoc); + bh_unlock_sock(sk); + sctp_association_put(asoc); } /* @@ -446,33 +563,34 @@ void sctp_err_finish(struct sock *sk, struct sctp_association *asoc) */ void sctp_v4_err(struct sk_buff *skb, __u32 info) { - struct iphdr *iph = (struct iphdr *)skb->data; - struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2)); - int type = skb->h.icmph->type; - int code = skb->h.icmph->code; + const struct iphdr *iph = (const struct iphdr *)skb->data; + const int ihlen = iph->ihl * 4; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; struct sock *sk; - struct sctp_association *asoc; + struct sctp_association *asoc = NULL; struct sctp_transport *transport; struct inet_sock *inet; - char *saveip, *savesctp; + __u16 saveip, savesctp; int err; + struct net *net = dev_net(skb->dev); - if (skb->len < ((iph->ihl << 2) + 8)) { - ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + if (skb->len < ihlen + 8) { + ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; } /* Fix up skb to look at the embedded net header. */ - saveip = skb->nh.raw; - savesctp = skb->h.raw; - skb->nh.iph = iph; - skb->h.raw = (char *)sh; - sk = sctp_err_lookup(AF_INET, skb, sh, &asoc, &transport); - /* Put back, the original pointers. */ - skb->nh.raw = saveip; - skb->h.raw = savesctp; + saveip = skb->network_header; + savesctp = skb->transport_header; + skb_reset_network_header(skb); + skb_set_transport_header(skb, ihlen); + sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport); + /* Put back, the original values. */ + skb->network_header = saveip; + skb->transport_header = savesctp; if (!sk) { - ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); + ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; } /* Warning: The sock lock is held. Remember to call @@ -491,8 +609,7 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info) if (ICMP_FRAG_NEEDED == code) { sctp_icmp_frag_needed(sk, asoc, transport, info); goto out_unlock; - } - else { + } else { if (ICMP_PROT_UNREACH == code) { sctp_icmp_proto_unreachable(sk, asoc, transport); @@ -510,6 +627,9 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info) err = EHOSTUNREACH; break; + case ICMP_REDIRECT: + sctp_icmp_redirect(sk, transport, skb); + /* Fall through to out_unlock. */ default: goto out_unlock; } @@ -538,17 +658,22 @@ 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; - sctp_errhdr_t *err; ch = (sctp_chunkhdr_t *) skb->data; - ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length)); /* Scan through all the chunks in the packet. */ - while (ch_end > (__u8 *)ch && ch_end < skb->tail) { + 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; /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the * receiver MUST silently discard the OOTB packet and take no @@ -564,23 +689,16 @@ int sctp_rcv_ootb(struct sk_buff *skb) if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) 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. + /* 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_COOKIE_ACK == ch->type) + if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) goto discard; - if (SCTP_CID_ERROR == ch->type) { - sctp_walk_errors(err, ch) { - if (SCTP_ERROR_STALE_COOKIE == err->cause) - goto discard; - } - } - ch = (sctp_chunkhdr_t *) ch_end; - ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length)); - } + } while (ch_end < skb_tail_pointer(skb)); return 0; @@ -591,88 +709,76 @@ discard: /* Insert endpoint into the hash table. */ static void __sctp_hash_endpoint(struct sctp_endpoint *ep) { - struct sctp_ep_common **epp; + struct net *net = sock_net(ep->base.sk); struct sctp_ep_common *epb; struct sctp_hashbucket *head; epb = &ep->base; - epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); + epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); 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; - sctp_write_unlock(&head->lock); + write_lock(&head->lock); + hlist_add_head(&epb->node, &head->chain); + write_unlock(&head->lock); } /* Add an endpoint to the hash. Local BH-safe. */ void sctp_hash_endpoint(struct sctp_endpoint *ep) { - sctp_local_bh_disable(); + local_bh_disable(); __sctp_hash_endpoint(ep); - sctp_local_bh_enable(); + local_bh_enable(); } /* Remove endpoint from the hash table. */ static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) { + struct net *net = sock_net(ep->base.sk); struct sctp_hashbucket *head; struct sctp_ep_common *epb; epb = &ep->base; - epb->hashent = sctp_ep_hashfn(epb->bind_addr.port); + epb->hashent = sctp_ep_hashfn(net, 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; - } - - sctp_write_unlock(&head->lock); + write_lock(&head->lock); + hlist_del_init(&epb->node); + write_unlock(&head->lock); } /* Remove endpoint from the hash. Local BH-safe. */ void sctp_unhash_endpoint(struct sctp_endpoint *ep) { - sctp_local_bh_disable(); + local_bh_disable(); __sctp_unhash_endpoint(ep); - sctp_local_bh_enable(); + local_bh_enable(); } /* Look up an endpoint. */ -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr) +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, + const union sctp_addr *laddr) { struct sctp_hashbucket *head; struct sctp_ep_common *epb; struct sctp_endpoint *ep; int hash; - hash = sctp_ep_hashfn(laddr->v4.sin_port); + hash = sctp_ep_hashfn(net, 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, &head->chain) { ep = sctp_ep(epb); - if (sctp_endpoint_is_match(ep, laddr)) + if (sctp_endpoint_is_match(ep, net, laddr)) goto hit; } - ep = sctp_sk((sctp_get_ctl_sock()))->ep; - epb = &ep->base; + ep = sctp_sk(net->sctp.ctl_sock)->ep; hit: sctp_endpoint_hold(ep); - sock_hold(epb->sk); read_unlock(&head->lock); return ep; } @@ -680,70 +786,67 @@ hit: /* Insert association into the hash table. */ static void __sctp_hash_established(struct sctp_association *asoc) { - struct sctp_ep_common **epp; + struct net *net = sock_net(asoc->base.sk); struct sctp_ep_common *epb; struct sctp_hashbucket *head; epb = &asoc->base; /* Calculate which chain this entry will belong to. */ - epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port); + epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, + asoc->peer.port); 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; - sctp_write_unlock(&head->lock); + write_lock(&head->lock); + hlist_add_head(&epb->node, &head->chain); + write_unlock(&head->lock); } /* Add an association to the hash. Local BH-safe. */ void sctp_hash_established(struct sctp_association *asoc) { - sctp_local_bh_disable(); + if (asoc->temp) + return; + + local_bh_disable(); __sctp_hash_established(asoc); - sctp_local_bh_enable(); + local_bh_enable(); } /* Remove association from the hash table. */ static void __sctp_unhash_established(struct sctp_association *asoc) { + struct net *net = sock_net(asoc->base.sk); struct sctp_hashbucket *head; struct sctp_ep_common *epb; epb = &asoc->base; - epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, + epb->hashent = sctp_assoc_hashfn(net, epb->bind_addr.port, asoc->peer.port); 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; - } - - sctp_write_unlock(&head->lock); + write_lock(&head->lock); + hlist_del_init(&epb->node); + write_unlock(&head->lock); } /* Remove association from the hash table. Local BH-safe. */ void sctp_unhash_established(struct sctp_association *asoc) { - sctp_local_bh_disable(); + if (asoc->temp) + return; + + local_bh_disable(); __sctp_unhash_established(asoc); - sctp_local_bh_enable(); + local_bh_enable(); } /* Look up an association. */ static struct sctp_association *__sctp_lookup_association( + struct net *net, const union sctp_addr *local, const union sctp_addr *peer, struct sctp_transport **pt) @@ -757,12 +860,13 @@ static struct sctp_association *__sctp_lookup_association( /* Optimize here for direct hit, only listening connections can * have wildcards anyways. */ - hash = sctp_assoc_hashfn(local->v4.sin_port, peer->v4.sin_port); + hash = sctp_assoc_hashfn(net, 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, &head->chain) { asoc = sctp_assoc(epb); - transport = sctp_assoc_is_match(asoc, local, peer); + transport = sctp_assoc_is_match(asoc, net, local, peer); if (transport) goto hit; } @@ -774,35 +878,35 @@ static struct sctp_association *__sctp_lookup_association( hit: *pt = transport; sctp_association_hold(asoc); - sock_hold(epb->sk); read_unlock(&head->lock); return asoc; } /* Look up an association. BH-safe. */ -SCTP_STATIC -struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr, +static +struct sctp_association *sctp_lookup_association(struct net *net, + const union sctp_addr *laddr, const union sctp_addr *paddr, - struct sctp_transport **transportp) + struct sctp_transport **transportp) { struct sctp_association *asoc; - sctp_local_bh_disable(); - asoc = __sctp_lookup_association(laddr, paddr, transportp); - sctp_local_bh_enable(); + local_bh_disable(); + asoc = __sctp_lookup_association(net, laddr, paddr, transportp); + local_bh_enable(); return asoc; } /* Is there an association matching the given local and peer addresses? */ -int sctp_has_association(const union sctp_addr *laddr, +int sctp_has_association(struct net *net, + const union sctp_addr *laddr, const union sctp_addr *paddr) { struct sctp_association *asoc; struct sctp_transport *transport; - if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) { - sock_put(asoc->base.sk); + if ((asoc = sctp_lookup_association(net, laddr, paddr, &transport))) { sctp_association_put(asoc); return 1; } @@ -828,38 +932,19 @@ int sctp_has_association(const union sctp_addr *laddr, * in certain circumstances. * */ -static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, +static struct sctp_association *__sctp_rcv_init_lookup(struct net *net, + struct sk_buff *skb, const union sctp_addr *laddr, struct sctp_transport **transportp) { struct sctp_association *asoc; union sctp_addr addr; union sctp_addr *paddr = &addr; - struct sctphdr *sh = (struct sctphdr *) skb->h.raw; - sctp_chunkhdr_t *ch; + struct sctphdr *sh = sctp_hdr(skb); union sctp_params params; sctp_init_chunk_t *init; struct sctp_transport *transport; struct sctp_af *af; - 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. @@ -886,9 +971,9 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb, if (!af) continue; - af->from_addr_param(paddr, params.addr, ntohs(sh->source), 0); + af->from_addr_param(paddr, params.addr, sh->source, 0); - asoc = __sctp_lookup_association(laddr, paddr, &transport); + asoc = __sctp_lookup_association(net, laddr, paddr, &transport); if (asoc) return asoc; } @@ -896,22 +981,162 @@ 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( + struct net *net, + 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->p.type)); + if (unlikely(!af)) + return NULL; + + af->from_addr_param(&paddr, param, peer_port, 0); + + return __sctp_lookup_association(net, 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 association. +*/ +static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, + 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 || net->sctp.addip_noauth) + asoc = __sctp_rcv_asconf_lookup( + net, 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 net *net, + 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. */ + if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK) + return __sctp_rcv_init_lookup(net, skb, laddr, transportp); + + return __sctp_rcv_walk_lookup(net, skb, laddr, transportp); +} + /* Lookup an association for an inbound skb. */ -static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb, +static struct sctp_association *__sctp_rcv_lookup(struct net *net, + struct sk_buff *skb, const union sctp_addr *paddr, const union sctp_addr *laddr, struct sctp_transport **transportp) { struct sctp_association *asoc; - asoc = __sctp_lookup_association(laddr, paddr, transportp); + asoc = __sctp_lookup_association(net, laddr, paddr, transportp); /* Further lookup for INIT/INIT-ACK packets. * SCTP Implementors Guide, 2.18 Handling of address * parameters within the INIT or INIT-ACK. */ if (!asoc) - asoc = __sctp_rcv_init_lookup(skb, laddr, transportp); + asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp); return asoc; } |