tcp_ipv6.c
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上传日期:2013-04-10
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文件大小:51k
- /*
- * TCP over IPv6
- * Linux INET6 implementation
- *
- * Authors:
- * Pedro Roque <roque@di.fc.ul.pt>
- *
- * $Id: tcp_ipv6.c,v 1.142.2.1 2001/12/21 05:06:08 davem Exp $
- *
- * Based on:
- * linux/net/ipv4/tcp.c
- * linux/net/ipv4/tcp_input.c
- * linux/net/ipv4/tcp_output.c
- *
- * Fixes:
- * Hideaki YOSHIFUJI : sin6_scope_id support
- *
- * This program 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 of the License, or (at your option) any later version.
- */
- #define __NO_VERSION__
- #include <linux/module.h>
- #include <linux/config.h>
- #include <linux/errno.h>
- #include <linux/types.h>
- #include <linux/socket.h>
- #include <linux/sockios.h>
- #include <linux/net.h>
- #include <linux/sched.h>
- #include <linux/in.h>
- #include <linux/in6.h>
- #include <linux/netdevice.h>
- #include <linux/init.h>
- #include <linux/ipsec.h>
- #include <linux/ipv6.h>
- #include <linux/icmpv6.h>
- #include <linux/random.h>
- #include <net/tcp.h>
- #include <net/ndisc.h>
- #include <net/ipv6.h>
- #include <net/transp_v6.h>
- #include <net/addrconf.h>
- #include <net/ip6_route.h>
- #include <net/inet_ecn.h>
- #include <asm/uaccess.h>
- static void tcp_v6_send_reset(struct sk_buff *skb);
- static void tcp_v6_or_send_ack(struct sk_buff *skb, struct open_request *req);
- static void tcp_v6_send_check(struct sock *sk, struct tcphdr *th, int len,
- struct sk_buff *skb);
- static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
- static int tcp_v6_xmit(struct sk_buff *skb);
- static struct tcp_func ipv6_mapped;
- static struct tcp_func ipv6_specific;
- /* I have no idea if this is a good hash for v6 or not. -DaveM */
- static __inline__ int tcp_v6_hashfn(struct in6_addr *laddr, u16 lport,
- struct in6_addr *faddr, u16 fport)
- {
- int hashent = (lport ^ fport);
- hashent ^= (laddr->s6_addr32[3] ^ faddr->s6_addr32[3]);
- hashent ^= hashent>>16;
- hashent ^= hashent>>8;
- return (hashent & (tcp_ehash_size - 1));
- }
- static __inline__ int tcp_v6_sk_hashfn(struct sock *sk)
- {
- struct in6_addr *laddr = &sk->net_pinfo.af_inet6.rcv_saddr;
- struct in6_addr *faddr = &sk->net_pinfo.af_inet6.daddr;
- __u16 lport = sk->num;
- __u16 fport = sk->dport;
- return tcp_v6_hashfn(laddr, lport, faddr, fport);
- }
- /* Grrr, addr_type already calculated by caller, but I don't want
- * to add some silly "cookie" argument to this method just for that.
- * But it doesn't matter, the recalculation is in the rarest path
- * this function ever takes.
- */
- static int tcp_v6_get_port(struct sock *sk, unsigned short snum)
- {
- struct tcp_bind_hashbucket *head;
- struct tcp_bind_bucket *tb;
- int ret;
- local_bh_disable();
- if (snum == 0) {
- int low = sysctl_local_port_range[0];
- int high = sysctl_local_port_range[1];
- int remaining = (high - low) + 1;
- int rover;
- spin_lock(&tcp_portalloc_lock);
- rover = tcp_port_rover;
- do { rover++;
- if ((rover < low) || (rover > high))
- rover = low;
- head = &tcp_bhash[tcp_bhashfn(rover)];
- spin_lock(&head->lock);
- for (tb = head->chain; tb; tb = tb->next)
- if (tb->port == rover)
- goto next;
- break;
- next:
- spin_unlock(&head->lock);
- } while (--remaining > 0);
- tcp_port_rover = rover;
- spin_unlock(&tcp_portalloc_lock);
- /* Exhausted local port range during search? */
- ret = 1;
- if (remaining <= 0)
- goto fail;
- /* OK, here is the one we will use. */
- snum = rover;
- tb = NULL;
- } else {
- head = &tcp_bhash[tcp_bhashfn(snum)];
- spin_lock(&head->lock);
- for (tb = head->chain; tb != NULL; tb = tb->next)
- if (tb->port == snum)
- break;
- }
- if (tb != NULL && tb->owners != NULL) {
- if (tb->fastreuse > 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
- goto success;
- } else {
- struct sock *sk2 = tb->owners;
- int sk_reuse = sk->reuse;
- int addr_type = ipv6_addr_type(&sk->net_pinfo.af_inet6.rcv_saddr);
- /* We must walk the whole port owner list in this case. -DaveM */
- for( ; sk2 != NULL; sk2 = sk2->bind_next) {
- if (sk != sk2 &&
- sk->bound_dev_if == sk2->bound_dev_if) {
- if (!sk_reuse ||
- !sk2->reuse ||
- sk2->state == TCP_LISTEN) {
- /* NOTE: IPv6 tw bucket have different format */
- if (!sk2->rcv_saddr ||
- addr_type == IPV6_ADDR_ANY ||
- !ipv6_addr_cmp(&sk->net_pinfo.af_inet6.rcv_saddr,
- sk2->state != TCP_TIME_WAIT ?
- &sk2->net_pinfo.af_inet6.rcv_saddr :
- &((struct tcp_tw_bucket*)sk)->v6_rcv_saddr) ||
- (addr_type==IPV6_ADDR_MAPPED && sk2->family==AF_INET &&
- sk->rcv_saddr==sk2->rcv_saddr))
- break;
- }
- }
- }
- /* If we found a conflict, fail. */
- ret = 1;
- if (sk2 != NULL)
- goto fail_unlock;
- }
- }
- ret = 1;
- if (tb == NULL &&
- (tb = tcp_bucket_create(head, snum)) == NULL)
- goto fail_unlock;
- if (tb->owners == NULL) {
- if (sk->reuse && sk->state != TCP_LISTEN)
- tb->fastreuse = 1;
- else
- tb->fastreuse = 0;
- } else if (tb->fastreuse &&
- ((sk->reuse == 0) || (sk->state == TCP_LISTEN)))
- tb->fastreuse = 0;
- success:
- sk->num = snum;
- if (sk->prev == NULL) {
- if ((sk->bind_next = tb->owners) != NULL)
- tb->owners->bind_pprev = &sk->bind_next;
- tb->owners = sk;
- sk->bind_pprev = &tb->owners;
- sk->prev = (struct sock *) tb;
- } else {
- BUG_TRAP(sk->prev == (struct sock *) tb);
- }
- ret = 0;
- fail_unlock:
- spin_unlock(&head->lock);
- fail:
- local_bh_enable();
- return ret;
- }
- static __inline__ void __tcp_v6_hash(struct sock *sk)
- {
- struct sock **skp;
- rwlock_t *lock;
- BUG_TRAP(sk->pprev==NULL);
- if(sk->state == TCP_LISTEN) {
- skp = &tcp_listening_hash[tcp_sk_listen_hashfn(sk)];
- lock = &tcp_lhash_lock;
- tcp_listen_wlock();
- } else {
- skp = &tcp_ehash[(sk->hashent = tcp_v6_sk_hashfn(sk))].chain;
- lock = &tcp_ehash[sk->hashent].lock;
- write_lock(lock);
- }
- if((sk->next = *skp) != NULL)
- (*skp)->pprev = &sk->next;
- *skp = sk;
- sk->pprev = skp;
- sock_prot_inc_use(sk->prot);
- write_unlock(lock);
- }
- static void tcp_v6_hash(struct sock *sk)
- {
- if(sk->state != TCP_CLOSE) {
- if (sk->tp_pinfo.af_tcp.af_specific == &ipv6_mapped) {
- tcp_prot.hash(sk);
- return;
- }
- local_bh_disable();
- __tcp_v6_hash(sk);
- local_bh_enable();
- }
- }
- static struct sock *tcp_v6_lookup_listener(struct in6_addr *daddr, unsigned short hnum, int dif)
- {
- struct sock *sk;
- struct sock *result = NULL;
- int score, hiscore;
- hiscore=0;
- read_lock(&tcp_lhash_lock);
- sk = tcp_listening_hash[tcp_lhashfn(hnum)];
- for(; sk; sk = sk->next) {
- if((sk->num == hnum) && (sk->family == PF_INET6)) {
- struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
-
- score = 1;
- if(!ipv6_addr_any(&np->rcv_saddr)) {
- if(ipv6_addr_cmp(&np->rcv_saddr, daddr))
- continue;
- score++;
- }
- if (sk->bound_dev_if) {
- if (sk->bound_dev_if != dif)
- continue;
- score++;
- }
- if (score == 3) {
- result = sk;
- break;
- }
- if (score > hiscore) {
- hiscore = score;
- result = sk;
- }
- }
- }
- if (result)
- sock_hold(result);
- read_unlock(&tcp_lhash_lock);
- return result;
- }
- /* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
- * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
- *
- * The sockhash lock must be held as a reader here.
- */
- static inline struct sock *__tcp_v6_lookup_established(struct in6_addr *saddr, u16 sport,
- struct in6_addr *daddr, u16 hnum,
- int dif)
- {
- struct tcp_ehash_bucket *head;
- struct sock *sk;
- __u32 ports = TCP_COMBINED_PORTS(sport, hnum);
- int hash;
- /* Optimize here for direct hit, only listening connections can
- * have wildcards anyways.
- */
- hash = tcp_v6_hashfn(daddr, hnum, saddr, sport);
- head = &tcp_ehash[hash];
- read_lock(&head->lock);
- for(sk = head->chain; sk; sk = sk->next) {
- /* For IPV6 do the cheaper port and family tests first. */
- if(TCP_IPV6_MATCH(sk, saddr, daddr, ports, dif))
- goto hit; /* You sunk my battleship! */
- }
- /* Must check for a TIME_WAIT'er before going to listener hash. */
- for(sk = (head + tcp_ehash_size)->chain; sk; sk = sk->next) {
- if(*((__u32 *)&(sk->dport)) == ports &&
- sk->family == PF_INET6) {
- struct tcp_tw_bucket *tw = (struct tcp_tw_bucket *)sk;
- if(!ipv6_addr_cmp(&tw->v6_daddr, saddr) &&
- !ipv6_addr_cmp(&tw->v6_rcv_saddr, daddr) &&
- (!sk->bound_dev_if || sk->bound_dev_if == dif))
- goto hit;
- }
- }
- read_unlock(&head->lock);
- return NULL;
- hit:
- sock_hold(sk);
- read_unlock(&head->lock);
- return sk;
- }
- static inline struct sock *__tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
- struct in6_addr *daddr, u16 hnum,
- int dif)
- {
- struct sock *sk;
- sk = __tcp_v6_lookup_established(saddr, sport, daddr, hnum, dif);
- if (sk)
- return sk;
- return tcp_v6_lookup_listener(daddr, hnum, dif);
- }
- __inline__ struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
- struct in6_addr *daddr, u16 dport,
- int dif)
- {
- struct sock *sk;
- local_bh_disable();
- sk = __tcp_v6_lookup(saddr, sport, daddr, ntohs(dport), dif);
- local_bh_enable();
- return sk;
- }
- /*
- * Open request hash tables.
- */
- static __inline__ unsigned tcp_v6_synq_hash(struct in6_addr *raddr, u16 rport)
- {
- unsigned h = raddr->s6_addr32[3] ^ rport;
- h ^= h>>16;
- h ^= h>>8;
- return h&(TCP_SYNQ_HSIZE-1);
- }
- static struct open_request *tcp_v6_search_req(struct tcp_opt *tp,
- struct open_request ***prevp,
- __u16 rport,
- struct in6_addr *raddr,
- struct in6_addr *laddr,
- int iif)
- {
- struct tcp_listen_opt *lopt = tp->listen_opt;
- struct open_request *req, **prev;
- for (prev = &lopt->syn_table[tcp_v6_synq_hash(raddr, rport)];
- (req = *prev) != NULL;
- prev = &req->dl_next) {
- if (req->rmt_port == rport &&
- req->class->family == AF_INET6 &&
- !ipv6_addr_cmp(&req->af.v6_req.rmt_addr, raddr) &&
- !ipv6_addr_cmp(&req->af.v6_req.loc_addr, laddr) &&
- (!req->af.v6_req.iif || req->af.v6_req.iif == iif)) {
- BUG_TRAP(req->sk == NULL);
- *prevp = prev;
- return req;
- }
- }
- return NULL;
- }
- static __inline__ u16 tcp_v6_check(struct tcphdr *th, int len,
- struct in6_addr *saddr,
- struct in6_addr *daddr,
- unsigned long base)
- {
- return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
- }
- static __u32 tcp_v6_init_sequence(struct sock *sk, struct sk_buff *skb)
- {
- if (skb->protocol == htons(ETH_P_IPV6)) {
- return secure_tcpv6_sequence_number(skb->nh.ipv6h->daddr.s6_addr32,
- skb->nh.ipv6h->saddr.s6_addr32,
- skb->h.th->dest,
- skb->h.th->source);
- } else {
- return secure_tcp_sequence_number(skb->nh.iph->daddr,
- skb->nh.iph->saddr,
- skb->h.th->dest,
- skb->h.th->source);
- }
- }
- static int tcp_v6_check_established(struct sock *sk)
- {
- struct in6_addr *daddr = &sk->net_pinfo.af_inet6.rcv_saddr;
- struct in6_addr *saddr = &sk->net_pinfo.af_inet6.daddr;
- int dif = sk->bound_dev_if;
- u32 ports = TCP_COMBINED_PORTS(sk->dport, sk->num);
- int hash = tcp_v6_hashfn(daddr, sk->num, saddr, sk->dport);
- struct tcp_ehash_bucket *head = &tcp_ehash[hash];
- struct sock *sk2, **skp;
- struct tcp_tw_bucket *tw;
- write_lock_bh(&head->lock);
- for(skp = &(head + tcp_ehash_size)->chain; (sk2=*skp)!=NULL; skp = &sk2->next) {
- tw = (struct tcp_tw_bucket*)sk2;
- if(*((__u32 *)&(sk2->dport)) == ports &&
- sk2->family == PF_INET6 &&
- !ipv6_addr_cmp(&tw->v6_daddr, saddr) &&
- !ipv6_addr_cmp(&tw->v6_rcv_saddr, daddr) &&
- sk2->bound_dev_if == sk->bound_dev_if) {
- struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
- if (tw->ts_recent_stamp) {
- /* See comment in tcp_ipv4.c */
- if ((tp->write_seq = tw->snd_nxt+65535+2) == 0)
- tp->write_seq = 1;
- tp->ts_recent = tw->ts_recent;
- tp->ts_recent_stamp = tw->ts_recent_stamp;
- sock_hold(sk2);
- skp = &head->chain;
- goto unique;
- } else
- goto not_unique;
- }
- }
- tw = NULL;
- for(skp = &head->chain; (sk2=*skp)!=NULL; skp = &sk2->next) {
- if(TCP_IPV6_MATCH(sk, saddr, daddr, ports, dif))
- goto not_unique;
- }
- unique:
- BUG_TRAP(sk->pprev==NULL);
- if ((sk->next = *skp) != NULL)
- (*skp)->pprev = &sk->next;
- *skp = sk;
- sk->pprev = skp;
- sk->hashent = hash;
- sock_prot_inc_use(sk->prot);
- write_unlock_bh(&head->lock);
- if (tw) {
- /* Silly. Should hash-dance instead... */
- local_bh_disable();
- tcp_tw_deschedule(tw);
- tcp_timewait_kill(tw);
- NET_INC_STATS_BH(TimeWaitRecycled);
- local_bh_enable();
- tcp_tw_put(tw);
- }
- return 0;
- not_unique:
- write_unlock_bh(&head->lock);
- return -EADDRNOTAVAIL;
- }
- static int tcp_v6_hash_connect(struct sock *sk)
- {
- struct tcp_bind_hashbucket *head;
- struct tcp_bind_bucket *tb;
- /* XXX */
- if (sk->num == 0) {
- int err = tcp_v6_get_port(sk, sk->num);
- if (err)
- return err;
- sk->sport = htons(sk->num);
- }
- head = &tcp_bhash[tcp_bhashfn(sk->num)];
- tb = head->chain;
- spin_lock_bh(&head->lock);
- if (tb->owners == sk && sk->bind_next == NULL) {
- __tcp_v6_hash(sk);
- spin_unlock_bh(&head->lock);
- return 0;
- } else {
- spin_unlock_bh(&head->lock);
- return tcp_v6_check_established(sk);
- }
- }
- static __inline__ int tcp_v6_iif(struct sk_buff *skb)
- {
- struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
- return opt->iif;
- }
- static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
- int addr_len)
- {
- struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
- struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
- struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
- struct in6_addr *saddr = NULL;
- struct in6_addr saddr_buf;
- struct flowi fl;
- struct dst_entry *dst;
- int addr_type;
- int err;
- if (addr_len < SIN6_LEN_RFC2133)
- return -EINVAL;
- if (usin->sin6_family != AF_INET6)
- return(-EAFNOSUPPORT);
- fl.fl6_flowlabel = 0;
- if (np->sndflow) {
- fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
- IP6_ECN_flow_init(fl.fl6_flowlabel);
- if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
- struct ip6_flowlabel *flowlabel;
- flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
- if (flowlabel == NULL)
- return -EINVAL;
- ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
- fl6_sock_release(flowlabel);
- }
- }
- /*
- * connect() to INADDR_ANY means loopback (BSD'ism).
- */
-
- if(ipv6_addr_any(&usin->sin6_addr))
- usin->sin6_addr.s6_addr[15] = 0x1;
- addr_type = ipv6_addr_type(&usin->sin6_addr);
- if(addr_type & IPV6_ADDR_MULTICAST)
- return -ENETUNREACH;
- if (addr_type&IPV6_ADDR_LINKLOCAL) {
- if (addr_len >= sizeof(struct sockaddr_in6) &&
- usin->sin6_scope_id) {
- /* If interface is set while binding, indices
- * must coincide.
- */
- if (sk->bound_dev_if &&
- sk->bound_dev_if != usin->sin6_scope_id)
- return -EINVAL;
- sk->bound_dev_if = usin->sin6_scope_id;
- }
- /* Connect to link-local address requires an interface */
- if (sk->bound_dev_if == 0)
- return -EINVAL;
- }
- if (tp->ts_recent_stamp && ipv6_addr_cmp(&np->daddr, &usin->sin6_addr)) {
- tp->ts_recent = 0;
- tp->ts_recent_stamp = 0;
- tp->write_seq = 0;
- }
- ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
- np->flow_label = fl.fl6_flowlabel;
- /*
- * TCP over IPv4
- */
- if (addr_type == IPV6_ADDR_MAPPED) {
- u32 exthdrlen = tp->ext_header_len;
- struct sockaddr_in sin;
- SOCK_DEBUG(sk, "connect: ipv4 mappedn");
- sin.sin_family = AF_INET;
- sin.sin_port = usin->sin6_port;
- sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
- sk->tp_pinfo.af_tcp.af_specific = &ipv6_mapped;
- sk->backlog_rcv = tcp_v4_do_rcv;
- err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
- if (err) {
- tp->ext_header_len = exthdrlen;
- sk->tp_pinfo.af_tcp.af_specific = &ipv6_specific;
- sk->backlog_rcv = tcp_v6_do_rcv;
- goto failure;
- } else {
- ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
- sk->saddr);
- ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
- sk->rcv_saddr);
- }
- return err;
- }
- if (!ipv6_addr_any(&np->rcv_saddr))
- saddr = &np->rcv_saddr;
- fl.proto = IPPROTO_TCP;
- fl.fl6_dst = &np->daddr;
- fl.fl6_src = saddr;
- fl.oif = sk->bound_dev_if;
- fl.uli_u.ports.dport = usin->sin6_port;
- fl.uli_u.ports.sport = sk->sport;
- if (np->opt && np->opt->srcrt) {
- struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
- fl.nl_u.ip6_u.daddr = rt0->addr;
- }
- dst = ip6_route_output(sk, &fl);
- if ((err = dst->error) != 0) {
- dst_release(dst);
- goto failure;
- }
- ip6_dst_store(sk, dst, NULL);
- sk->route_caps = dst->dev->features&~NETIF_F_IP_CSUM;
- if (saddr == NULL) {
- err = ipv6_get_saddr(dst, &np->daddr, &saddr_buf);
- if (err)
- goto failure;
- saddr = &saddr_buf;
- }
- /* set the source address */
- ipv6_addr_copy(&np->rcv_saddr, saddr);
- ipv6_addr_copy(&np->saddr, saddr);
- sk->rcv_saddr= LOOPBACK4_IPV6;
- tp->ext_header_len = 0;
- if (np->opt)
- tp->ext_header_len = np->opt->opt_flen+np->opt->opt_nflen;
- tp->mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
- sk->dport = usin->sin6_port;
- tcp_set_state(sk, TCP_SYN_SENT);
- err = tcp_v6_hash_connect(sk);
- if (err)
- goto late_failure;
- if (!tp->write_seq)
- tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
- np->daddr.s6_addr32,
- sk->sport, sk->dport);
- err = tcp_connect(sk);
- if (err)
- goto late_failure;
- return 0;
- late_failure:
- tcp_set_state(sk, TCP_CLOSE);
- failure:
- __sk_dst_reset(sk);
- sk->dport = 0;
- sk->route_caps = 0;
- return err;
- }
- void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
- int type, int code, int offset, __u32 info)
- {
- struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
- struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
- struct ipv6_pinfo *np;
- struct sock *sk;
- int err;
- struct tcp_opt *tp;
- __u32 seq;
- sk = tcp_v6_lookup(&hdr->daddr, th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
- if (sk == NULL) {
- ICMP6_INC_STATS_BH(Icmp6InErrors);
- return;
- }
- if (sk->state == TCP_TIME_WAIT) {
- tcp_tw_put((struct tcp_tw_bucket*)sk);
- return;
- }
- bh_lock_sock(sk);
- if (sk->lock.users)
- NET_INC_STATS_BH(LockDroppedIcmps);
- if (sk->state == TCP_CLOSE)
- goto out;
- tp = &sk->tp_pinfo.af_tcp;
- seq = ntohl(th->seq);
- if (sk->state != TCP_LISTEN && !between(seq, tp->snd_una, tp->snd_nxt)) {
- NET_INC_STATS_BH(OutOfWindowIcmps);
- goto out;
- }
- np = &sk->net_pinfo.af_inet6;
- if (type == ICMPV6_PKT_TOOBIG) {
- struct dst_entry *dst = NULL;
- if (sk->lock.users)
- goto out;
- if ((1<<sk->state)&(TCPF_LISTEN|TCPF_CLOSE))
- goto out;
- /* icmp should have updated the destination cache entry */
- dst = __sk_dst_check(sk, np->dst_cookie);
- if (dst == NULL) {
- struct flowi fl;
- /* BUGGG_FUTURE: Again, it is not clear how
- to handle rthdr case. Ignore this complexity
- for now.
- */
- fl.proto = IPPROTO_TCP;
- fl.nl_u.ip6_u.daddr = &np->daddr;
- fl.nl_u.ip6_u.saddr = &np->saddr;
- fl.oif = sk->bound_dev_if;
- fl.uli_u.ports.dport = sk->dport;
- fl.uli_u.ports.sport = sk->sport;
- dst = ip6_route_output(sk, &fl);
- } else
- dst_clone(dst);
- if (dst->error) {
- sk->err_soft = -dst->error;
- } else if (tp->pmtu_cookie > dst->pmtu) {
- tcp_sync_mss(sk, dst->pmtu);
- tcp_simple_retransmit(sk);
- } /* else let the usual retransmit timer handle it */
- dst_release(dst);
- goto out;
- }
- icmpv6_err_convert(type, code, &err);
- /* Might be for an open_request */
- switch (sk->state) {
- struct open_request *req, **prev;
- case TCP_LISTEN:
- if (sk->lock.users)
- goto out;
- req = tcp_v6_search_req(tp, &prev, th->dest, &hdr->daddr,
- &hdr->saddr, tcp_v6_iif(skb));
- if (!req)
- goto out;
- /* ICMPs are not backlogged, hence we cannot get
- * an established socket here.
- */
- BUG_TRAP(req->sk == NULL);
- if (seq != req->snt_isn) {
- NET_INC_STATS_BH(OutOfWindowIcmps);
- goto out;
- }
- tcp_synq_drop(sk, req, prev);
- goto out;
- case TCP_SYN_SENT:
- case TCP_SYN_RECV: /* Cannot happen.
- It can, it SYNs are crossed. --ANK */
- if (sk->lock.users == 0) {
- TCP_INC_STATS_BH(TcpAttemptFails);
- sk->err = err;
- sk->error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
- tcp_done(sk);
- } else {
- sk->err_soft = err;
- }
- goto out;
- }
- if (sk->lock.users == 0 && np->recverr) {
- sk->err = err;
- sk->error_report(sk);
- } else {
- sk->err_soft = err;
- }
- out:
- bh_unlock_sock(sk);
- sock_put(sk);
- }
- static int tcp_v6_send_synack(struct sock *sk, struct open_request *req,
- struct dst_entry *dst)
- {
- struct sk_buff * skb;
- struct ipv6_txoptions *opt = NULL;
- struct flowi fl;
- int err = -1;
- fl.proto = IPPROTO_TCP;
- fl.nl_u.ip6_u.daddr = &req->af.v6_req.rmt_addr;
- fl.nl_u.ip6_u.saddr = &req->af.v6_req.loc_addr;
- fl.fl6_flowlabel = 0;
- fl.oif = req->af.v6_req.iif;
- fl.uli_u.ports.dport = req->rmt_port;
- fl.uli_u.ports.sport = sk->sport;
- if (dst == NULL) {
- opt = sk->net_pinfo.af_inet6.opt;
- if (opt == NULL &&
- sk->net_pinfo.af_inet6.rxopt.bits.srcrt == 2 &&
- req->af.v6_req.pktopts) {
- struct sk_buff *pktopts = req->af.v6_req.pktopts;
- struct inet6_skb_parm *rxopt = (struct inet6_skb_parm *)pktopts->cb;
- if (rxopt->srcrt)
- opt = ipv6_invert_rthdr(sk, (struct ipv6_rt_hdr*)(pktopts->nh.raw + rxopt->srcrt));
- }
- if (opt && opt->srcrt) {
- struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
- fl.nl_u.ip6_u.daddr = rt0->addr;
- }
- dst = ip6_route_output(sk, &fl);
- if (dst->error)
- goto done;
- }
- skb = tcp_make_synack(sk, dst, req);
- if (skb) {
- struct tcphdr *th = skb->h.th;
- th->check = tcp_v6_check(th, skb->len,
- &req->af.v6_req.loc_addr, &req->af.v6_req.rmt_addr,
- csum_partial((char *)th, skb->len, skb->csum));
- fl.nl_u.ip6_u.daddr = &req->af.v6_req.rmt_addr;
- err = ip6_xmit(sk, skb, &fl, opt);
- if (err == NET_XMIT_CN)
- err = 0;
- }
- done:
- dst_release(dst);
- if (opt && opt != sk->net_pinfo.af_inet6.opt)
- sock_kfree_s(sk, opt, opt->tot_len);
- return err;
- }
- static void tcp_v6_or_free(struct open_request *req)
- {
- if (req->af.v6_req.pktopts)
- kfree_skb(req->af.v6_req.pktopts);
- }
- static struct or_calltable or_ipv6 = {
- AF_INET6,
- tcp_v6_send_synack,
- tcp_v6_or_send_ack,
- tcp_v6_or_free,
- tcp_v6_send_reset
- };
- static int ipv6_opt_accepted(struct sock *sk, struct sk_buff *skb)
- {
- struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
- if (sk->net_pinfo.af_inet6.rxopt.all) {
- if ((opt->hop && sk->net_pinfo.af_inet6.rxopt.bits.hopopts) ||
- ((IPV6_FLOWINFO_MASK&*(u32*)skb->nh.raw) &&
- sk->net_pinfo.af_inet6.rxopt.bits.rxflow) ||
- (opt->srcrt && sk->net_pinfo.af_inet6.rxopt.bits.srcrt) ||
- ((opt->dst1 || opt->dst0) && sk->net_pinfo.af_inet6.rxopt.bits.dstopts))
- return 1;
- }
- return 0;
- }
- static void tcp_v6_send_check(struct sock *sk, struct tcphdr *th, int len,
- struct sk_buff *skb)
- {
- struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
- if (skb->ip_summed == CHECKSUM_HW) {
- th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP, 0);
- skb->csum = offsetof(struct tcphdr, check);
- } else {
- th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
- csum_partial((char *)th, th->doff<<2,
- skb->csum));
- }
- }
- static void tcp_v6_send_reset(struct sk_buff *skb)
- {
- struct tcphdr *th = skb->h.th, *t1;
- struct sk_buff *buff;
- struct flowi fl;
- if (th->rst)
- return;
- if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr))
- return;
- /*
- * We need to grab some memory, and put together an RST,
- * and then put it into the queue to be sent.
- */
- buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr), GFP_ATOMIC);
- if (buff == NULL)
- return;
- skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr));
- t1 = (struct tcphdr *) skb_push(buff,sizeof(struct tcphdr));
- /* Swap the send and the receive. */
- memset(t1, 0, sizeof(*t1));
- t1->dest = th->source;
- t1->source = th->dest;
- t1->doff = sizeof(*t1)/4;
- t1->rst = 1;
-
- if(th->ack) {
- t1->seq = th->ack_seq;
- } else {
- t1->ack = 1;
- t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
- + skb->len - (th->doff<<2));
- }
- buff->csum = csum_partial((char *)t1, sizeof(*t1), 0);
- fl.nl_u.ip6_u.daddr = &skb->nh.ipv6h->saddr;
- fl.nl_u.ip6_u.saddr = &skb->nh.ipv6h->daddr;
- fl.fl6_flowlabel = 0;
- t1->check = csum_ipv6_magic(fl.nl_u.ip6_u.saddr,
- fl.nl_u.ip6_u.daddr,
- sizeof(*t1), IPPROTO_TCP,
- buff->csum);
- fl.proto = IPPROTO_TCP;
- fl.oif = tcp_v6_iif(skb);
- fl.uli_u.ports.dport = t1->dest;
- fl.uli_u.ports.sport = t1->source;
- /* sk = NULL, but it is safe for now. RST socket required. */
- buff->dst = ip6_route_output(NULL, &fl);
- if (buff->dst->error == 0) {
- ip6_xmit(NULL, buff, &fl, NULL);
- TCP_INC_STATS_BH(TcpOutSegs);
- TCP_INC_STATS_BH(TcpOutRsts);
- return;
- }
- kfree_skb(buff);
- }
- static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
- {
- struct tcphdr *th = skb->h.th, *t1;
- struct sk_buff *buff;
- struct flowi fl;
- int tot_len = sizeof(struct tcphdr);
- buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr), GFP_ATOMIC);
- if (buff == NULL)
- return;
- skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr));
- if (ts)
- tot_len += 3*4;
- t1 = (struct tcphdr *) skb_push(buff,tot_len);
- /* Swap the send and the receive. */
- memset(t1, 0, sizeof(*t1));
- t1->dest = th->source;
- t1->source = th->dest;
- t1->doff = tot_len/4;
- t1->seq = htonl(seq);
- t1->ack_seq = htonl(ack);
- t1->ack = 1;
- t1->window = htons(win);
-
- if (ts) {
- u32 *ptr = (u32*)(t1 + 1);
- *ptr++ = htonl((TCPOPT_NOP << 24) |
- (TCPOPT_NOP << 16) |
- (TCPOPT_TIMESTAMP << 8) |
- TCPOLEN_TIMESTAMP);
- *ptr++ = htonl(tcp_time_stamp);
- *ptr = htonl(ts);
- }
- buff->csum = csum_partial((char *)t1, tot_len, 0);
- fl.nl_u.ip6_u.daddr = &skb->nh.ipv6h->saddr;
- fl.nl_u.ip6_u.saddr = &skb->nh.ipv6h->daddr;
- fl.fl6_flowlabel = 0;
- t1->check = csum_ipv6_magic(fl.nl_u.ip6_u.saddr,
- fl.nl_u.ip6_u.daddr,
- tot_len, IPPROTO_TCP,
- buff->csum);
- fl.proto = IPPROTO_TCP;
- fl.oif = tcp_v6_iif(skb);
- fl.uli_u.ports.dport = t1->dest;
- fl.uli_u.ports.sport = t1->source;
- buff->dst = ip6_route_output(NULL, &fl);
- if (buff->dst->error == 0) {
- ip6_xmit(NULL, buff, &fl, NULL);
- TCP_INC_STATS_BH(TcpOutSegs);
- return;
- }
- kfree_skb(buff);
- }
- static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
- {
- struct tcp_tw_bucket *tw = (struct tcp_tw_bucket *)sk;
- tcp_v6_send_ack(skb, tw->snd_nxt, tw->rcv_nxt,
- tw->rcv_wnd>>tw->rcv_wscale, tw->ts_recent);
- tcp_tw_put(tw);
- }
- static void tcp_v6_or_send_ack(struct sk_buff *skb, struct open_request *req)
- {
- tcp_v6_send_ack(skb, req->snt_isn+1, req->rcv_isn+1, req->rcv_wnd, req->ts_recent);
- }
- static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
- {
- struct open_request *req, **prev;
- struct tcphdr *th = skb->h.th;
- struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
- struct sock *nsk;
- /* Find possible connection requests. */
- req = tcp_v6_search_req(tp, &prev, th->source, &skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr, tcp_v6_iif(skb));
- if (req)
- return tcp_check_req(sk, skb, req, prev);
- nsk = __tcp_v6_lookup_established(&skb->nh.ipv6h->saddr,
- th->source,
- &skb->nh.ipv6h->daddr,
- ntohs(th->dest),
- tcp_v6_iif(skb));
- if (nsk) {
- if (nsk->state != TCP_TIME_WAIT) {
- bh_lock_sock(nsk);
- return nsk;
- }
- tcp_tw_put((struct tcp_tw_bucket*)nsk);
- return NULL;
- }
- #if 0 /*def CONFIG_SYN_COOKIES*/
- if (!th->rst && !th->syn && th->ack)
- sk = cookie_v6_check(sk, skb, &(IPCB(skb)->opt));
- #endif
- return sk;
- }
- static void tcp_v6_synq_add(struct sock *sk, struct open_request *req)
- {
- struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
- struct tcp_listen_opt *lopt = tp->listen_opt;
- unsigned h = tcp_v6_synq_hash(&req->af.v6_req.rmt_addr, req->rmt_port);
- req->sk = NULL;
- req->expires = jiffies + TCP_TIMEOUT_INIT;
- req->retrans = 0;
- req->dl_next = lopt->syn_table[h];
- write_lock(&tp->syn_wait_lock);
- lopt->syn_table[h] = req;
- write_unlock(&tp->syn_wait_lock);
- tcp_synq_added(sk);
- }
- /* FIXME: this is substantially similar to the ipv4 code.
- * Can some kind of merge be done? -- erics
- */
- static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
- {
- struct tcp_opt tp;
- struct open_request *req = NULL;
- __u32 isn = TCP_SKB_CB(skb)->when;
- if (skb->protocol == htons(ETH_P_IP))
- return tcp_v4_conn_request(sk, skb);
- /* FIXME: do the same check for anycast */
- if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr))
- goto drop;
- /*
- * There are no SYN attacks on IPv6, yet...
- */
- if (tcp_synq_is_full(sk) && !isn) {
- if (net_ratelimit())
- printk(KERN_INFO "TCPv6: dropping request, synflood is possiblen");
- goto drop;
- }
- if (tcp_acceptq_is_full(sk) && tcp_synq_young(sk) > 1)
- goto drop;
- req = tcp_openreq_alloc();
- if (req == NULL)
- goto drop;
- tcp_clear_options(&tp);
- tp.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
- tp.user_mss = sk->tp_pinfo.af_tcp.user_mss;
- tcp_parse_options(skb, &tp, 0);
- tp.tstamp_ok = tp.saw_tstamp;
- tcp_openreq_init(req, &tp, skb);
- req->class = &or_ipv6;
- ipv6_addr_copy(&req->af.v6_req.rmt_addr, &skb->nh.ipv6h->saddr);
- ipv6_addr_copy(&req->af.v6_req.loc_addr, &skb->nh.ipv6h->daddr);
- TCP_ECN_create_request(req, skb->h.th);
- req->af.v6_req.pktopts = NULL;
- if (ipv6_opt_accepted(sk, skb) ||
- sk->net_pinfo.af_inet6.rxopt.bits.rxinfo ||
- sk->net_pinfo.af_inet6.rxopt.bits.rxhlim) {
- atomic_inc(&skb->users);
- req->af.v6_req.pktopts = skb;
- }
- req->af.v6_req.iif = sk->bound_dev_if;
- /* So that link locals have meaning */
- if (!sk->bound_dev_if && ipv6_addr_type(&req->af.v6_req.rmt_addr)&IPV6_ADDR_LINKLOCAL)
- req->af.v6_req.iif = tcp_v6_iif(skb);
- if (isn == 0)
- isn = tcp_v6_init_sequence(sk,skb);
- req->snt_isn = isn;
- if (tcp_v6_send_synack(sk, req, NULL))
- goto drop;
- tcp_v6_synq_add(sk, req);
- return 0;
- drop:
- if (req)
- tcp_openreq_free(req);
- TCP_INC_STATS_BH(TcpAttemptFails);
- return 0; /* don't send reset */
- }
- static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
- struct open_request *req,
- struct dst_entry *dst)
- {
- struct ipv6_pinfo *np;
- struct flowi fl;
- struct tcp_opt *newtp;
- struct sock *newsk;
- struct ipv6_txoptions *opt;
- if (skb->protocol == htons(ETH_P_IP)) {
- /*
- * v6 mapped
- */
- newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
- if (newsk == NULL)
- return NULL;
- np = &newsk->net_pinfo.af_inet6;
- ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000FFFF),
- newsk->daddr);
- ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
- newsk->saddr);
- ipv6_addr_copy(&np->rcv_saddr, &np->saddr);
- newsk->tp_pinfo.af_tcp.af_specific = &ipv6_mapped;
- newsk->backlog_rcv = tcp_v4_do_rcv;
- newsk->net_pinfo.af_inet6.pktoptions = NULL;
- newsk->net_pinfo.af_inet6.opt = NULL;
- newsk->net_pinfo.af_inet6.mcast_oif = tcp_v6_iif(skb);
- newsk->net_pinfo.af_inet6.mcast_hops = skb->nh.ipv6h->hop_limit;
- /* Charge newly allocated IPv6 socket. Though it is mapped,
- * it is IPv6 yet.
- */
- #ifdef INET_REFCNT_DEBUG
- atomic_inc(&inet6_sock_nr);
- #endif
- MOD_INC_USE_COUNT;
- /* It is tricky place. Until this moment IPv4 tcp
- worked with IPv6 af_tcp.af_specific.
- Sync it now.
- */
- tcp_sync_mss(newsk, newsk->tp_pinfo.af_tcp.pmtu_cookie);
- return newsk;
- }
- opt = sk->net_pinfo.af_inet6.opt;
- if (tcp_acceptq_is_full(sk))
- goto out_overflow;
- if (sk->net_pinfo.af_inet6.rxopt.bits.srcrt == 2 &&
- opt == NULL && req->af.v6_req.pktopts) {
- struct inet6_skb_parm *rxopt = (struct inet6_skb_parm *)req->af.v6_req.pktopts->cb;
- if (rxopt->srcrt)
- opt = ipv6_invert_rthdr(sk, (struct ipv6_rt_hdr*)(req->af.v6_req.pktopts->nh.raw+rxopt->srcrt));
- }
- if (dst == NULL) {
- fl.proto = IPPROTO_TCP;
- fl.nl_u.ip6_u.daddr = &req->af.v6_req.rmt_addr;
- if (opt && opt->srcrt) {
- struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
- fl.nl_u.ip6_u.daddr = rt0->addr;
- }
- fl.nl_u.ip6_u.saddr = &req->af.v6_req.loc_addr;
- fl.fl6_flowlabel = 0;
- fl.oif = sk->bound_dev_if;
- fl.uli_u.ports.dport = req->rmt_port;
- fl.uli_u.ports.sport = sk->sport;
- dst = ip6_route_output(sk, &fl);
- }
- if (dst->error)
- goto out;
- newsk = tcp_create_openreq_child(sk, req, skb);
- if (newsk == NULL)
- goto out;
- /* Charge newly allocated IPv6 socket */
- #ifdef INET_REFCNT_DEBUG
- atomic_inc(&inet6_sock_nr);
- #endif
- MOD_INC_USE_COUNT;
- ip6_dst_store(newsk, dst, NULL);
- sk->route_caps = dst->dev->features&~NETIF_F_IP_CSUM;
- newtp = &(newsk->tp_pinfo.af_tcp);
- np = &newsk->net_pinfo.af_inet6;
- ipv6_addr_copy(&np->daddr, &req->af.v6_req.rmt_addr);
- ipv6_addr_copy(&np->saddr, &req->af.v6_req.loc_addr);
- ipv6_addr_copy(&np->rcv_saddr, &req->af.v6_req.loc_addr);
- newsk->bound_dev_if = req->af.v6_req.iif;
- /* Now IPv6 options...
- First: no IPv4 options.
- */
- newsk->protinfo.af_inet.opt = NULL;
- /* Clone RX bits */
- np->rxopt.all = sk->net_pinfo.af_inet6.rxopt.all;
- /* Clone pktoptions received with SYN */
- np->pktoptions = NULL;
- if (req->af.v6_req.pktopts) {
- np->pktoptions = skb_clone(req->af.v6_req.pktopts, GFP_ATOMIC);
- kfree_skb(req->af.v6_req.pktopts);
- req->af.v6_req.pktopts = NULL;
- if (np->pktoptions)
- skb_set_owner_r(np->pktoptions, newsk);
- }
- np->opt = NULL;
- np->mcast_oif = tcp_v6_iif(skb);
- np->mcast_hops = skb->nh.ipv6h->hop_limit;
- /* Clone native IPv6 options from listening socket (if any)
- Yes, keeping reference count would be much more clever,
- but we make one more one thing there: reattach optmem
- to newsk.
- */
- if (opt) {
- np->opt = ipv6_dup_options(newsk, opt);
- if (opt != sk->net_pinfo.af_inet6.opt)
- sock_kfree_s(sk, opt, opt->tot_len);
- }
- newtp->ext_header_len = 0;
- if (np->opt)
- newtp->ext_header_len = np->opt->opt_nflen + np->opt->opt_flen;
- tcp_sync_mss(newsk, dst->pmtu);
- newtp->advmss = dst->advmss;
- tcp_initialize_rcv_mss(newsk);
- newsk->daddr = LOOPBACK4_IPV6;
- newsk->saddr = LOOPBACK4_IPV6;
- newsk->rcv_saddr= LOOPBACK4_IPV6;
- __tcp_v6_hash(newsk);
- tcp_inherit_port(sk, newsk);
- return newsk;
- out_overflow:
- NET_INC_STATS_BH(ListenOverflows);
- out:
- NET_INC_STATS_BH(ListenDrops);
- if (opt && opt != sk->net_pinfo.af_inet6.opt)
- sock_kfree_s(sk, opt, opt->tot_len);
- dst_release(dst);
- return NULL;
- }
- static int tcp_v6_checksum_init(struct sk_buff *skb)
- {
- if (skb->ip_summed == CHECKSUM_HW) {
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (!tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,skb->csum))
- return 0;
- NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "hw tcp v6 csum failedn"));
- }
- if (skb->len <= 76) {
- if (tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,skb_checksum(skb, 0, skb->len, 0)))
- return -1;
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- } else {
- skb->csum = ~tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,0);
- }
- return 0;
- }
- /* The socket must have it's spinlock held when we get
- * here.
- *
- * We have a potential double-lock case here, so even when
- * doing backlog processing we use the BH locking scheme.
- * This is because we cannot sleep with the original spinlock
- * held.
- */
- static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
- {
- #ifdef CONFIG_FILTER
- struct sk_filter *filter;
- #endif
- struct sk_buff *opt_skb = NULL;
- /* Imagine: socket is IPv6. IPv4 packet arrives,
- goes to IPv4 receive handler and backlogged.
- From backlog it always goes here. Kerboom...
- Fortunately, tcp_rcv_established and rcv_established
- handle them correctly, but it is not case with
- tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
- */
- if (skb->protocol == htons(ETH_P_IP))
- return tcp_v4_do_rcv(sk, skb);
- #ifdef CONFIG_FILTER
- filter = sk->filter;
- if (filter && sk_filter(skb, filter))
- goto discard;
- #endif /* CONFIG_FILTER */
- /*
- * socket locking is here for SMP purposes as backlog rcv
- * is currently called with bh processing disabled.
- */
- IP6_INC_STATS_BH(Ip6InDelivers);
- /* Do Stevens' IPV6_PKTOPTIONS.
- Yes, guys, it is the only place in our code, where we
- may make it not affecting IPv4.
- The rest of code is protocol independent,
- and I do not like idea to uglify IPv4.
- Actually, all the idea behind IPV6_PKTOPTIONS
- looks not very well thought. For now we latch
- options, received in the last packet, enqueued
- by tcp. Feel free to propose better solution.
- --ANK (980728)
- */
- if (sk->net_pinfo.af_inet6.rxopt.all)
- opt_skb = skb_clone(skb, GFP_ATOMIC);
- if (sk->state == TCP_ESTABLISHED) { /* Fast path */
- TCP_CHECK_TIMER(sk);
- if (tcp_rcv_established(sk, skb, skb->h.th, skb->len))
- goto reset;
- TCP_CHECK_TIMER(sk);
- if (opt_skb)
- goto ipv6_pktoptions;
- return 0;
- }
- if (skb->len < (skb->h.th->doff<<2) || tcp_checksum_complete(skb))
- goto csum_err;
- if (sk->state == TCP_LISTEN) {
- struct sock *nsk = tcp_v6_hnd_req(sk, skb);
- if (!nsk)
- goto discard;
- /*
- * Queue it on the new socket if the new socket is active,
- * otherwise we just shortcircuit this and continue with
- * the new socket..
- */
- if(nsk != sk) {
- if (tcp_child_process(sk, nsk, skb))
- goto reset;
- if (opt_skb)
- __kfree_skb(opt_skb);
- return 0;
- }
- }
- TCP_CHECK_TIMER(sk);
- if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len))
- goto reset;
- TCP_CHECK_TIMER(sk);
- if (opt_skb)
- goto ipv6_pktoptions;
- return 0;
- reset:
- tcp_v6_send_reset(skb);
- discard:
- if (opt_skb)
- __kfree_skb(opt_skb);
- kfree_skb(skb);
- return 0;
- csum_err:
- TCP_INC_STATS_BH(TcpInErrs);
- goto discard;
- ipv6_pktoptions:
- /* Do you ask, what is it?
- 1. skb was enqueued by tcp.
- 2. skb is added to tail of read queue, rather than out of order.
- 3. socket is not in passive state.
- 4. Finally, it really contains options, which user wants to receive.
- */
- if (TCP_SKB_CB(opt_skb)->end_seq == sk->tp_pinfo.af_tcp.rcv_nxt &&
- !((1<<sk->state)&(TCPF_CLOSE|TCPF_LISTEN))) {
- if (sk->net_pinfo.af_inet6.rxopt.bits.rxinfo)
- sk->net_pinfo.af_inet6.mcast_oif = tcp_v6_iif(opt_skb);
- if (sk->net_pinfo.af_inet6.rxopt.bits.rxhlim)
- sk->net_pinfo.af_inet6.mcast_hops = opt_skb->nh.ipv6h->hop_limit;
- if (ipv6_opt_accepted(sk, opt_skb)) {
- skb_set_owner_r(opt_skb, sk);
- opt_skb = xchg(&sk->net_pinfo.af_inet6.pktoptions, opt_skb);
- } else {
- __kfree_skb(opt_skb);
- opt_skb = xchg(&sk->net_pinfo.af_inet6.pktoptions, NULL);
- }
- }
- if (opt_skb)
- kfree_skb(opt_skb);
- return 0;
- }
- int tcp_v6_rcv(struct sk_buff *skb)
- {
- struct tcphdr *th;
- struct sock *sk;
- int ret;
- if (skb->pkt_type != PACKET_HOST)
- goto discard_it;
- /*
- * Count it even if it's bad.
- */
- TCP_INC_STATS_BH(TcpInSegs);
- if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
- goto discard_it;
- th = skb->h.th;
- if (th->doff < sizeof(struct tcphdr)/4)
- goto bad_packet;
- if (!pskb_may_pull(skb, th->doff*4))
- goto discard_it;
- if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
- tcp_v6_checksum_init(skb) < 0))
- goto bad_packet;
- th = skb->h.th;
- TCP_SKB_CB(skb)->seq = ntohl(th->seq);
- TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
- skb->len - th->doff*4);
- TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
- TCP_SKB_CB(skb)->when = 0;
- TCP_SKB_CB(skb)->flags = ip6_get_dsfield(skb->nh.ipv6h);
- TCP_SKB_CB(skb)->sacked = 0;
- sk = __tcp_v6_lookup(&skb->nh.ipv6h->saddr, th->source,
- &skb->nh.ipv6h->daddr, ntohs(th->dest), tcp_v6_iif(skb));
- if (!sk)
- goto no_tcp_socket;
- process:
- if(!ipsec_sk_policy(sk,skb))
- goto discard_and_relse;
- if(sk->state == TCP_TIME_WAIT)
- goto do_time_wait;
- skb->dev = NULL;
- bh_lock_sock(sk);
- ret = 0;
- if (!sk->lock.users) {
- if (!tcp_prequeue(sk, skb))
- ret = tcp_v6_do_rcv(sk, skb);
- } else
- sk_add_backlog(sk, skb);
- bh_unlock_sock(sk);
- sock_put(sk);
- return ret;
- no_tcp_socket:
- if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
- bad_packet:
- TCP_INC_STATS_BH(TcpInErrs);
- } else {
- tcp_v6_send_reset(skb);
- }
- discard_it:
- /*
- * Discard frame
- */
- kfree_skb(skb);
- return 0;
- discard_and_relse:
- sock_put(sk);
- goto discard_it;
- do_time_wait:
- if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
- TCP_INC_STATS_BH(TcpInErrs);
- sock_put(sk);
- goto discard_it;
- }
- switch(tcp_timewait_state_process((struct tcp_tw_bucket *)sk,
- skb, th, skb->len)) {
- case TCP_TW_SYN:
- {
- struct sock *sk2;
- sk2 = tcp_v6_lookup_listener(&skb->nh.ipv6h->daddr, ntohs(th->dest), tcp_v6_iif(skb));
- if (sk2 != NULL) {
- tcp_tw_deschedule((struct tcp_tw_bucket *)sk);
- tcp_timewait_kill((struct tcp_tw_bucket *)sk);
- tcp_tw_put((struct tcp_tw_bucket *)sk);
- sk = sk2;
- goto process;
- }
- /* Fall through to ACK */
- }
- case TCP_TW_ACK:
- tcp_v6_timewait_ack(sk, skb);
- break;
- case TCP_TW_RST:
- goto no_tcp_socket;
- case TCP_TW_SUCCESS:;
- }
- goto discard_it;
- }
- static int tcp_v6_rebuild_header(struct sock *sk)
- {
- int err;
- struct dst_entry *dst;
- struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
- dst = __sk_dst_check(sk, np->dst_cookie);
- if (dst == NULL) {
- struct flowi fl;
- fl.proto = IPPROTO_TCP;
- fl.nl_u.ip6_u.daddr = &np->daddr;
- fl.nl_u.ip6_u.saddr = &np->saddr;
- fl.fl6_flowlabel = np->flow_label;
- fl.oif = sk->bound_dev_if;
- fl.uli_u.ports.dport = sk->dport;
- fl.uli_u.ports.sport = sk->sport;
- if (np->opt && np->opt->srcrt) {
- struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
- fl.nl_u.ip6_u.daddr = rt0->addr;
- }
- dst = ip6_route_output(sk, &fl);
- if (dst->error) {
- err = dst->error;
- dst_release(dst);
- sk->route_caps = 0;
- return err;
- }
- ip6_dst_store(sk, dst, NULL);
- sk->route_caps = dst->dev->features&~NETIF_F_IP_CSUM;
- }
- return 0;
- }
- static int tcp_v6_xmit(struct sk_buff *skb)
- {
- struct sock *sk = skb->sk;
- struct ipv6_pinfo * np = &sk->net_pinfo.af_inet6;
- struct flowi fl;
- struct dst_entry *dst;
- fl.proto = IPPROTO_TCP;
- fl.fl6_dst = &np->daddr;
- fl.fl6_src = &np->saddr;
- fl.fl6_flowlabel = np->flow_label;
- IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
- fl.oif = sk->bound_dev_if;
- fl.uli_u.ports.sport = sk->sport;
- fl.uli_u.ports.dport = sk->dport;
- if (np->opt && np->opt->srcrt) {
- struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
- fl.nl_u.ip6_u.daddr = rt0->addr;
- }
- dst = __sk_dst_check(sk, np->dst_cookie);
- if (dst == NULL) {
- dst = ip6_route_output(sk, &fl);
- if (dst->error) {
- sk->err_soft = -dst->error;
- dst_release(dst);
- return -sk->err_soft;
- }
- ip6_dst_store(sk, dst, NULL);
- }
- skb->dst = dst_clone(dst);
- /* Restore final destination back after routing done */
- fl.nl_u.ip6_u.daddr = &np->daddr;
- return ip6_xmit(sk, skb, &fl, np->opt);
- }
- static void v6_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
- {
- struct ipv6_pinfo * np = &sk->net_pinfo.af_inet6;
- struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
- sin6->sin6_family = AF_INET6;
- memcpy(&sin6->sin6_addr, &np->daddr, sizeof(struct in6_addr));
- sin6->sin6_port = sk->dport;
- /* We do not store received flowlabel for TCP */
- sin6->sin6_flowinfo = 0;
- sin6->sin6_scope_id = 0;
- if (sk->bound_dev_if && ipv6_addr_type(&sin6->sin6_addr)&IPV6_ADDR_LINKLOCAL)
- sin6->sin6_scope_id = sk->bound_dev_if;
- }
- static int tcp_v6_remember_stamp(struct sock *sk)
- {
- /* Alas, not yet... */
- return 0;
- }
- static struct tcp_func ipv6_specific = {
- tcp_v6_xmit,
- tcp_v6_send_check,
- tcp_v6_rebuild_header,
- tcp_v6_conn_request,
- tcp_v6_syn_recv_sock,
- tcp_v6_remember_stamp,
- sizeof(struct ipv6hdr),
- ipv6_setsockopt,
- ipv6_getsockopt,
- v6_addr2sockaddr,
- sizeof(struct sockaddr_in6)
- };
- /*
- * TCP over IPv4 via INET6 API
- */
- static struct tcp_func ipv6_mapped = {
- ip_queue_xmit,
- tcp_v4_send_check,
- tcp_v4_rebuild_header,
- tcp_v6_conn_request,
- tcp_v6_syn_recv_sock,
- tcp_v4_remember_stamp,
- sizeof(struct iphdr),
- ipv6_setsockopt,
- ipv6_getsockopt,
- v6_addr2sockaddr,
- sizeof(struct sockaddr_in6)
- };
- /* NOTE: A lot of things set to zero explicitly by call to
- * sk_alloc() so need not be done here.
- */
- static int tcp_v6_init_sock(struct sock *sk)
- {
- struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
- skb_queue_head_init(&tp->out_of_order_queue);
- tcp_init_xmit_timers(sk);
- tcp_prequeue_init(tp);
- tp->rto = TCP_TIMEOUT_INIT;
- tp->mdev = TCP_TIMEOUT_INIT;
- /* So many TCP implementations out there (incorrectly) count the
- * initial SYN frame in their delayed-ACK and congestion control
- * algorithms that we must have the following bandaid to talk
- * efficiently to them. -DaveM
- */
- tp->snd_cwnd = 2;
- /* See draft-stevens-tcpca-spec-01 for discussion of the
- * initialization of these values.
- */
- tp->snd_ssthresh = 0x7fffffff;
- tp->snd_cwnd_clamp = ~0;
- tp->mss_cache = 536;
- tp->reordering = sysctl_tcp_reordering;
- sk->state = TCP_CLOSE;
- sk->tp_pinfo.af_tcp.af_specific = &ipv6_specific;
- sk->write_space = tcp_write_space;
- sk->use_write_queue = 1;
- sk->sndbuf = sysctl_tcp_wmem[1];
- sk->rcvbuf = sysctl_tcp_rmem[1];
- atomic_inc(&tcp_sockets_allocated);
- return 0;
- }
- static int tcp_v6_destroy_sock(struct sock *sk)
- {
- struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
- tcp_clear_xmit_timers(sk);
- /* Cleanup up the write buffer. */
- tcp_writequeue_purge(sk);
- /* Cleans up our, hopefully empty, out_of_order_queue. */
- __skb_queue_purge(&tp->out_of_order_queue);
- /* Clean prequeue, it must be empty really */
- __skb_queue_purge(&tp->ucopy.prequeue);
- /* Clean up a referenced TCP bind bucket. */
- if(sk->prev != NULL)
- tcp_put_port(sk);
- /* If sendmsg cached page exists, toss it. */
- if (tp->sndmsg_page != NULL)
- __free_page(tp->sndmsg_page);
- atomic_dec(&tcp_sockets_allocated);
- return inet6_destroy_sock(sk);
- }
- /* Proc filesystem TCPv6 sock list dumping. */
- static void get_openreq6(struct sock *sk, struct open_request *req, char *tmpbuf, int i, int uid)
- {
- struct in6_addr *dest, *src;
- int ttd = req->expires - jiffies;
- if (ttd < 0)
- ttd = 0;
- src = &req->af.v6_req.loc_addr;
- dest = &req->af.v6_req.rmt_addr;
- sprintf(tmpbuf,
- "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
- "%02X %08X:%08X %02X:%08X %08X %5d %8d %d %d %p",
- i,
- src->s6_addr32[0], src->s6_addr32[1],
- src->s6_addr32[2], src->s6_addr32[3],
- ntohs(sk->sport),
- dest->s6_addr32[0], dest->s6_addr32[1],
- dest->s6_addr32[2], dest->s6_addr32[3],
- ntohs(req->rmt_port),
- TCP_SYN_RECV,
- 0,0, /* could print option size, but that is af dependent. */
- 1, /* timers active (only the expire timer) */
- ttd,
- req->retrans,
- uid,
- 0, /* non standard timer */
- 0, /* open_requests have no inode */
- 0, req);
- }
- static void get_tcp6_sock(struct sock *sp, char *tmpbuf, int i)
- {
- struct in6_addr *dest, *src;
- __u16 destp, srcp;
- int timer_active;
- unsigned long timer_expires;
- struct tcp_opt *tp = &sp->tp_pinfo.af_tcp;
- dest = &sp->net_pinfo.af_inet6.daddr;
- src = &sp->net_pinfo.af_inet6.rcv_saddr;
- destp = ntohs(sp->dport);
- srcp = ntohs(sp->sport);
- if (tp->pending == TCP_TIME_RETRANS) {
- timer_active = 1;
- timer_expires = tp->timeout;
- } else if (tp->pending == TCP_TIME_PROBE0) {
- timer_active = 4;
- timer_expires = tp->timeout;
- } else if (timer_pending(&sp->timer)) {
- timer_active = 2;
- timer_expires = sp->timer.expires;
- } else {
- timer_active = 0;
- timer_expires = jiffies;
- }
- sprintf(tmpbuf,
- "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
- "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d",
- i,
- src->s6_addr32[0], src->s6_addr32[1],
- src->s6_addr32[2], src->s6_addr32[3], srcp,
- dest->s6_addr32[0], dest->s6_addr32[1],
- dest->s6_addr32[2], dest->s6_addr32[3], destp,
- sp->state,
- tp->write_seq-tp->snd_una, tp->rcv_nxt-tp->copied_seq,
- timer_active, timer_expires-jiffies,
- tp->retransmits,
- sock_i_uid(sp),
- tp->probes_out,
- sock_i_ino(sp),
- atomic_read(&sp->refcnt), sp,
- tp->rto, tp->ack.ato, (tp->ack.quick<<1)|tp->ack.pingpong,
- tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
- );
- }
- static void get_timewait6_sock(struct tcp_tw_bucket *tw, char *tmpbuf, int i)
- {
- struct in6_addr *dest, *src;
- __u16 destp, srcp;
- int ttd = tw->ttd - jiffies;
- if (ttd < 0)
- ttd = 0;
- dest = &tw->v6_daddr;
- src = &tw->v6_rcv_saddr;
- destp = ntohs(tw->dport);
- srcp = ntohs(tw->sport);
- sprintf(tmpbuf,
- "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
- "%02X %08X:%08X %02X:%08X %08X %5d %8d %d %d %p",
- i,
- src->s6_addr32[0], src->s6_addr32[1],
- src->s6_addr32[2], src->s6_addr32[3], srcp,
- dest->s6_addr32[0], dest->s6_addr32[1],
- dest->s6_addr32[2], dest->s6_addr32[3], destp,
- tw->substate, 0, 0,
- 3, ttd, 0, 0, 0, 0,
- atomic_read(&tw->refcnt), tw);
- }
- #define LINE_LEN 190
- #define LINE_FMT "%-190sn"
- int tcp6_get_info(char *buffer, char **start, off_t offset, int length)
- {
- int len = 0, num = 0, i;
- off_t begin, pos = 0;
- char tmpbuf[LINE_LEN+2];
- if (offset < LINE_LEN+1)
- len += sprintf(buffer, LINE_FMT,
- " sl " /* 6 */
- "local_address " /* 38 */
- "remote_address " /* 38 */
- "st tx_queue rx_queue tr tm->when retrnsmt" /* 41 */
- " uid timeout inode"); /* 21 */
- /*----*/
- /*144 */
- pos = LINE_LEN+1;
- /* First, walk listening socket table. */
- tcp_listen_lock();
- for(i = 0; i < TCP_LHTABLE_SIZE; i++) {
- struct sock *sk = tcp_listening_hash[i];
- struct tcp_listen_opt *lopt;
- int k;
- for (sk = tcp_listening_hash[i]; sk; sk = sk->next, num++) {
- struct open_request *req;
- int uid;
- struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
- if (sk->family != PF_INET6)
- continue;
- pos += LINE_LEN+1;
- if (pos >= offset) {
- get_tcp6_sock(sk, tmpbuf, num);
- len += sprintf(buffer+len, LINE_FMT, tmpbuf);
- if (pos >= offset + length) {
- tcp_listen_unlock();
- goto out_no_bh;
- }
- }
- uid = sock_i_uid(sk);
- read_lock_bh(&tp->syn_wait_lock);
- lopt = tp->listen_opt;
- if (lopt && lopt->qlen != 0) {
- for (k=0; k<TCP_SYNQ_HSIZE; k++) {
- for (req = lopt->syn_table[k]; req; req = req->dl_next, num++) {
- if (req->class->family != PF_INET6)
- continue;
- pos += LINE_LEN+1;
- if (pos <= offset)
- continue;
- get_openreq6(sk, req, tmpbuf, num, uid);
- len += sprintf(buffer+len, LINE_FMT, tmpbuf);
- if (pos >= offset + length) {
- read_unlock_bh(&tp->syn_wait_lock);
- tcp_listen_unlock();
- goto out_no_bh;
- }
- }
- }
- }
- read_unlock_bh(&tp->syn_wait_lock);
- /* Completed requests are in normal socket hash table */
- }
- }
- tcp_listen_unlock();
- local_bh_disable();
- /* Next, walk established hash chain. */
- for (i = 0; i < tcp_ehash_size; i++) {
- struct tcp_ehash_bucket *head = &tcp_ehash[i];
- struct sock *sk;
- struct tcp_tw_bucket *tw;
- read_lock(&head->lock);
- for(sk = head->chain; sk; sk = sk->next, num++) {
- if (sk->family != PF_INET6)
- continue;
- pos += LINE_LEN+1;
- if (pos <= offset)
- continue;
- get_tcp6_sock(sk, tmpbuf, num);
- len += sprintf(buffer+len, LINE_FMT, tmpbuf);
- if (pos >= offset + length) {
- read_unlock(&head->lock);
- goto out;
- }
- }
- for (tw = (struct tcp_tw_bucket *)tcp_ehash[i+tcp_ehash_size].chain;
- tw != NULL;
- tw = (struct tcp_tw_bucket *)tw->next, num++) {
- if (tw->family != PF_INET6)
- continue;
- pos += LINE_LEN+1;
- if (pos <= offset)
- continue;
- get_timewait6_sock(tw, tmpbuf, num);
- len += sprintf(buffer+len, LINE_FMT, tmpbuf);
- if (pos >= offset + length) {
- read_unlock(&head->lock);
- goto out;
- }
- }
- read_unlock(&head->lock);
- }
- out:
- local_bh_enable();
- out_no_bh:
- begin = len - (pos - offset);
- *start = buffer + begin;
- len -= begin;
- if (len > length)
- len = length;
- if (len < 0)
- len = 0;
- return len;
- }
- struct proto tcpv6_prot = {
- name: "TCPv6",
- close: tcp_close,
- connect: tcp_v6_connect,
- disconnect: tcp_disconnect,
- accept: tcp_accept,
- ioctl: tcp_ioctl,
- init: tcp_v6_init_sock,
- destroy: tcp_v6_destroy_sock,
- shutdown: tcp_shutdown,
- setsockopt: tcp_setsockopt,
- getsockopt: tcp_getsockopt,
- sendmsg: tcp_sendmsg,
- recvmsg: tcp_recvmsg,
- backlog_rcv: tcp_v6_do_rcv,
- hash: tcp_v6_hash,
- unhash: tcp_unhash,
- get_port: tcp_v6_get_port,
- };
- static struct inet6_protocol tcpv6_protocol =
- {
- tcp_v6_rcv, /* TCP handler */
- tcp_v6_err, /* TCP error control */
- NULL, /* next */
- IPPROTO_TCP, /* protocol ID */
- 0, /* copy */
- NULL, /* data */
- "TCPv6" /* name */
- };
- extern struct proto_ops inet6_stream_ops;
- static struct inet_protosw tcpv6_protosw = {
- type: SOCK_STREAM,
- protocol: IPPROTO_TCP,
- prot: &tcpv6_prot,
- ops: &inet6_stream_ops,
- capability: -1,
- no_check: 0,
- flags: INET_PROTOSW_PERMANENT,
- };
- void __init tcpv6_init(void)
- {
- /* register inet6 protocol */
- inet6_add_protocol(&tcpv6_protocol);
- inet6_register_protosw(&tcpv6_protosw);
- }