void tcp_v4_err(struct sk_buff *skb, u32 info) { struct iphdr *iph = (struct iphdr *)skb->data; struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); struct tcp_sock *tp; struct inet_sock *inet; int type = skb->h.icmph->type; int code = skb->h.icmph->code; struct sock *sk; __u32 seq; int err; if (skb->len < (iph->ihl << 2) + 8) { ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); return; } sk = inet_lookup(&tcp_hashinfo, iph->daddr, th->dest, iph->saddr, th->source, inet_iif(skb)); if (!sk) { ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); return; } if (sk->sk_state == TCP_TIME_WAIT) { inet_twsk_put((struct inet_timewait_sock *)sk); return; } 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); if (sk->sk_state == TCP_CLOSE) goto out; tp = tcp_sk(sk); seq = ntohl(th->seq); if (sk->sk_state != TCP_LISTEN && !between(seq, tp->snd_una, tp->snd_nxt)) { NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS); goto out; } switch (type) { case ICMP_SOURCE_QUENCH: /* Just silently ignore these. */ goto out; case ICMP_PARAMETERPROB: err = EPROTO; break; case ICMP_DEST_UNREACH: if (code > NR_ICMP_UNREACH) goto out; if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ if (!sock_owned_by_user(sk)) do_pmtu_discovery(sk, iph, info); goto out; } err = icmp_err_convert[code].errno; break; case ICMP_TIME_EXCEEDED: err = EHOSTUNREACH; break; default: goto out; } switch (sk->sk_state) { struct request_sock *req, **prev; case TCP_LISTEN: if (sock_owned_by_user(sk)) goto out; req = inet_csk_search_req(sk, &prev, th->dest, iph->daddr, iph->saddr); if (!req) goto out; /* ICMPs are not backlogged, hence we cannot get an established socket here. */ BUG_TRAP(!req->sk); if (seq != tcp_rsk(req)->snt_isn) { NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS); goto out; } /* * Still in SYN_RECV, just remove it silently. * There is no good way to pass the error to the newly * created socket, and POSIX does not want network * errors returned from accept(). */ inet_csk_reqsk_queue_drop(sk, req, prev); goto out; case TCP_SYN_SENT: case TCP_SYN_RECV: /* Cannot happen. It can f.e. if SYNs crossed. */ if (!sock_owned_by_user(sk)) { TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); sk->sk_err = err; sk->sk_error_report(sk); tcp_done(sk); } else { sk->sk_err_soft = err; } goto out; } /* If we've already connected we will keep trying * until we time out, or the user gives up. * * rfc1122 4.2.3.9 allows to consider as hard errors * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, * but it is obsoleted by pmtu discovery). * * Note, that in modern internet, where routing is unreliable * and in each dark corner broken firewalls sit, sending random * errors ordered by their masters even this two messages finally lose * their original sense (even Linux sends invalid PORT_UNREACHs) * * Now we are in compliance with RFCs. * --ANK (980905) */ inet = inet_sk(sk); if (!sock_owned_by_user(sk) && inet->recverr) { sk->sk_err = err; sk->sk_error_report(sk); } else { /* Only an error on timeout */ sk->sk_err_soft = err; } out: bh_unlock_sock(sk); sock_put(sk); }
static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req, struct request_values *rvp) { TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); return tcp_v6_send_synack(sk, req, rvp); }
static 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; const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); struct ipv6_pinfo *np; struct sock *sk; int err; struct tcp_sock *tp; __u32 seq; sk = inet6_lookup(&tcp_hashinfo, &hdr->daddr, th->dest, &hdr->saddr, th->source, skb->dev->ifindex); if (sk == NULL) { ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); return; } if (sk->sk_state == TCP_TIME_WAIT) { inet_twsk_put((struct inet_timewait_sock *)sk); return; } bh_lock_sock(sk); if (sock_owned_by_user(sk)) NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); if (sk->sk_state == TCP_CLOSE) goto out; tp = tcp_sk(sk); seq = ntohl(th->seq); if (sk->sk_state != TCP_LISTEN && !between(seq, tp->snd_una, tp->snd_nxt)) { NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS); goto out; } np = inet6_sk(sk); if (type == ICMPV6_PKT_TOOBIG) { struct dst_entry *dst = NULL; if (sock_owned_by_user(sk)) goto out; if ((1 << sk->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 inet_sock *inet = inet_sk(sk); struct flowi fl; /* BUGGG_FUTURE: Again, it is not clear how to handle rthdr case. Ignore this complexity for now. */ memset(&fl, 0, sizeof(fl)); fl.proto = IPPROTO_TCP; ipv6_addr_copy(&fl.fl6_dst, &np->daddr); ipv6_addr_copy(&fl.fl6_src, &np->saddr); fl.oif = sk->sk_bound_dev_if; fl.fl_ip_dport = inet->dport; fl.fl_ip_sport = inet->sport; if ((err = ip6_dst_lookup(sk, &dst, &fl))) { sk->sk_err_soft = -err; goto out; } if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) { sk->sk_err_soft = -err; goto out; } } else dst_hold(dst); if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { tcp_sync_mss(sk, dst_mtu(dst)); 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 request_sock */ switch (sk->sk_state) { struct request_sock *req, **prev; case TCP_LISTEN: if (sock_owned_by_user(sk)) goto out; req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr, &hdr->saddr, inet6_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 != tcp_rsk(req)->snt_isn) { NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS); goto out; } inet_csk_reqsk_queue_drop(sk, req, prev); goto out; case TCP_SYN_SENT: case TCP_SYN_RECV: /* Cannot happen. It can, it SYNs are crossed. --ANK */ if (!sock_owned_by_user(sk)) { TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); sk->sk_err = err; sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ tcp_done(sk); } else sk->sk_err_soft = err; goto out; } if (!sock_owned_by_user(sk) && np->recverr) { sk->sk_err = err; sk->sk_error_report(sk); } else sk->sk_err_soft = err; out: bh_unlock_sock(sk); sock_put(sk); }