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recv_v6.lc
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#include "trace.h"## 1 ##src/traceroute/recv_v6.c##
/*## 2 ##src/traceroute/recv_v6.c##
* Return: -3 on timeout## 3 ##src/traceroute/recv_v6.c##
* -2 on ICMP time exceeded in transit (caller keeps going)## 4 ##src/traceroute/recv_v6.c##
* -1 on ICMP port unreachable (caller is done)## 5 ##src/traceroute/recv_v6.c##
* >= 0 return value is some other ICMP unreachable code## 6 ##src/traceroute/recv_v6.c##
*/## 7 ##src/traceroute/recv_v6.c##
int## 8 ##src/traceroute/recv_v6.c##
recv_v6(int seq, struct timeval *tv)## 9 ##src/traceroute/recv_v6.c##
{## 10 ##src/traceroute/recv_v6.c##
#ifdef IPV6## 11 ##src/traceroute/recv_v6.c##
int hlen1, hlen2, icmp6len;## 12 ##src/traceroute/recv_v6.c##
ssize_t n;## 13 ##src/traceroute/recv_v6.c##
socklen_t len;## 14 ##src/traceroute/recv_v6.c##
struct ip6_hdr *ip6, *hip6;## 15 ##src/traceroute/recv_v6.c##
struct icmp6_hdr *icmp6;## 16 ##src/traceroute/recv_v6.c##
struct udphdr *udp;## 17 ##src/traceroute/recv_v6.c##
alarm(3);## 18 ##src/traceroute/recv_v6.c##
for (;;) {## 19 ##src/traceroute/recv_v6.c##
len = pr->salen;## 20 ##src/traceroute/recv_v6.c##
n = recvfrom(recvfd, recvbuf, sizeof(recvbuf), 0, pr->sarecv, &len);## 21 ##src/traceroute/recv_v6.c##
if (n < 0) {## 22 ##src/traceroute/recv_v6.c##
if (errno == EINTR)## 23 ##src/traceroute/recv_v6.c##
return (-3); /* alarm expired */## 24 ##src/traceroute/recv_v6.c##
else## 25 ##src/traceroute/recv_v6.c##
err_sys("recvfrom error");## 26 ##src/traceroute/recv_v6.c##
}## 27 ##src/traceroute/recv_v6.c##
Gettimeofday(tv, NULL); /* get time of packet arrival */## 28 ##src/traceroute/recv_v6.c##
ip6 = (struct ip6_hdr *) recvbuf; /* start of IPv6 header */## 29 ##src/traceroute/recv_v6.c##
hlen1 = sizeof(struct ip6_hdr);## 30 ##src/traceroute/recv_v6.c##
icmp6 = (struct icmp6_hdr *) (recvbuf + hlen1); /* ICMP hdr */## 31 ##src/traceroute/recv_v6.c##
if ((icmp6len = n - hlen1) < 8)## 32 ##src/traceroute/recv_v6.c##
err_quit("icmp6len (%d) < 8", icmp6len);## 33 ##src/traceroute/recv_v6.c##
if (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED &&## 34 ##src/traceroute/recv_v6.c##
icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) {## 35 ##src/traceroute/recv_v6.c##
if (icmp6len < 8 + 40 + 8)## 36 ##src/traceroute/recv_v6.c##
err_quit("icmp6len (%d) < 8 + 40 + 8", icmp6len);## 37 ##src/traceroute/recv_v6.c##
hip6 = (struct ip6_hdr *) (recvbuf + hlen1 + 8);## 38 ##src/traceroute/recv_v6.c##
hlen2 = sizeof(struct ip6_hdr);## 39 ##src/traceroute/recv_v6.c##
udp = (struct udphdr *) (recvbuf + hlen1 + 8 + hlen2);## 40 ##src/traceroute/recv_v6.c##
if (hip6->ip6_nxt == IPPROTO_UDP &&## 41 ##src/traceroute/recv_v6.c##
udp->uh_sport == htons(sport) &&## 42 ##src/traceroute/recv_v6.c##
udp->uh_dport == htons(dport + seq))## 43 ##src/traceroute/recv_v6.c##
return (-2); /* we hit an intermediate router */## 44 ##src/traceroute/recv_v6.c##
} else if (icmp6->icmp6_type == ICMP6_DST_UNREACH) {## 45 ##src/traceroute/recv_v6.c##
if (icmp6len < 8 + 40 + 8)## 46 ##src/traceroute/recv_v6.c##
err_quit("icmp6len (%d) < 8 + 40 + 8", icmp6len);## 47 ##src/traceroute/recv_v6.c##
hip6 = (struct ip6_hdr *) (recvbuf + hlen1 + 8);## 48 ##src/traceroute/recv_v6.c##
hlen2 = 40;## 49 ##src/traceroute/recv_v6.c##
udp = (struct udphdr *) (recvbuf + hlen1 + 8 + hlen2);## 50 ##src/traceroute/recv_v6.c##
if (hip6->ip6_nxt == IPPROTO_UDP &&## 51 ##src/traceroute/recv_v6.c##
udp->uh_sport == htons(sport) &&## 52 ##src/traceroute/recv_v6.c##
udp->uh_dport == htons(dport + seq)) {## 53 ##src/traceroute/recv_v6.c##
if (icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)## 54 ##src/traceroute/recv_v6.c##
return (-1); /* have reached destination */## 55 ##src/traceroute/recv_v6.c##
else## 56 ##src/traceroute/recv_v6.c##
return (icmp6->icmp6_code); /* 0, 1, 2, ... */## 57 ##src/traceroute/recv_v6.c##
}## 58 ##src/traceroute/recv_v6.c##
} else if (verbose) {## 59 ##src/traceroute/recv_v6.c##
printf(" (from %s: type = %d, code = %d)\n",## 60 ##src/traceroute/recv_v6.c##
Sock_ntop_host(pr->sarecv, pr->salen),## 61 ##src/traceroute/recv_v6.c##
icmp6->icmp6_type, icmp6->icmp6_code);## 62 ##src/traceroute/recv_v6.c##
}## 63 ##src/traceroute/recv_v6.c##
/* Some other ICMP error, recvfrom() again */## 64 ##src/traceroute/recv_v6.c##
}## 65 ##src/traceroute/recv_v6.c##
#endif## 66 ##src/traceroute/recv_v6.c##
}## 67 ##src/traceroute/recv_v6.c##