diff options
| -rw-r--r-- | networking/traceroute.c | 206 |
1 files changed, 135 insertions, 71 deletions
diff --git a/networking/traceroute.c b/networking/traceroute.c index 7dde105..ddde922 100644 --- a/networking/traceroute.c +++ b/networking/traceroute.c @@ -414,9 +414,32 @@ struct globals { waittime = 5; \ } while (0) -#define outicmp ((struct icmp *)(outip + 1)) -#define outudp ((struct udphdr *)(outip + 1)) - +#define outudp ((struct udphdr *)(outip + 1)) +#define outudp6 ((struct udphdr *)(((struct ip6_hdr*)outip) + 1)) +#define outicmp ((struct icmp *)(outip + 1)) +#define outicmp6 ((struct icmp *)(((struct ip6_hdr*)outip) + 1)) +/* NB: for icmp echo, IPv4 and IPv6 fields are the same size and offset: + * struct icmp: + * uint8_t icmp_type; + * uint8_t icmp_code; + * uint16_t icmp_cksum; + * uint16_t icmp_id; + * uint16_t icmp_seq; + * struct icmp6_hdr: + * uint8_t icmp6_type; + * uint8_t icmp6_code; + * uint16_t icmp6_cksum; + * uint16_t icmp6_id; + * uint16_t icmp6_seq; + * therefore both outicmp and outicmp6 are pointers to *IPv4* icmp struct. + * SIZEOF_ICMP_HDR == 8 is the same for both, as well. + * However, values of these pointers are not the same (since IPv6 IP header is larger), + * and icmp_type constants are not the same: + * #define ICMP_ECHO 8 + * #define ICMP_ECHOREPLY 0 + * #define ICMP6_ECHO_REQUEST 128 + * #define ICMP6_ECHO_REPLY 129 + */ static int wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms) @@ -446,14 +469,16 @@ send_probe(int seq, int ttl) { int len, res; void *out; + struct icmp *icp; /* Payload */ #if ENABLE_TRACEROUTE6 if (dest_lsa->u.sa.sa_family == AF_INET6) { - struct outdata6_t *pkt = (struct outdata6_t *) outdata; + struct outdata6_t *pkt = (void *) outdata; pkt->ident6 = htonl(ident); pkt->seq6 = htonl(seq); /*gettimeofday(&pkt->tv, &tz);*/ + icp = outicmp6; } else #endif { @@ -461,19 +486,23 @@ send_probe(int seq, int ttl) outdata->ttl = ttl; // UNUSED: was storing gettimeofday's result there, but never ever checked it /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/ - - if (option_mask32 & OPT_USE_ICMP) { - outicmp->icmp_seq = htons(seq); - - /* Always calculate checksum for icmp packets */ - outicmp->icmp_cksum = 0; - outicmp->icmp_cksum = inet_cksum( - outicmp, - ((char*)outip + packlen) - (char*)outicmp - ); - if (outicmp->icmp_cksum == 0) - outicmp->icmp_cksum = 0xffff; - } + icp = outicmp; + } + out = outdata; + if (option_mask32 & OPT_USE_ICMP) { + out = icp; + /*icp->icmp_type = ICMP[6]_ECHO; - already set */ + /*icp->icmp_code = 0; - already set */ + /*icp->icmp_id = ident; - already set */ + icp->icmp_seq = htons(seq); + /* Always calculate checksum for icmp packets */ + icp->icmp_cksum = 0; + icp->icmp_cksum = inet_cksum( + icp, + ((char*)outip + packlen) - (char*)icp + ); + if (icp->icmp_cksum == 0) + icp->icmp_cksum = 0xffff; } //BUG! verbose is (x & OPT_VERBOSE), not a counter! @@ -502,7 +531,6 @@ send_probe(int seq, int ttl) } #endif - out = outdata; #if ENABLE_TRACEROUTE6 if (dest_lsa->u.sa.sa_family == AF_INET6) { res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl); @@ -516,8 +544,6 @@ send_probe(int seq, int ttl) if (res != 0) bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl); #endif - if (option_mask32 & OPT_USE_ICMP) - out = outicmp; } if (!(option_mask32 & OPT_USE_ICMP)) { @@ -579,7 +605,12 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq) int hlen; const struct ip *ip; + /* NB: reads from (AF_INET, SOCK_RAW, IPPROTO_ICMP) socket + * return the entire IP packet (IOW: they do not strip IP header). + * This differs from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) sockets!? + */ ip = (struct ip *) recv_pkt; + hlen = ip->ip_hl << 2; if (read_len < hlen + ICMP_MINLEN) { #if ENABLE_FEATURE_TRACEROUTE_VERBOSE @@ -598,9 +629,20 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq) if (code == ICMP_UNREACH_NEEDFRAG) pmtu = ntohs(icp->icmp_nextmtu); + if ((option_mask32 & OPT_USE_ICMP) + && type == ICMP_ECHOREPLY + && icp->icmp_id == htons(ident) + && icp->icmp_seq == htons(seq) + ) { + /* In UDP mode, when we reach the machine, we (usually) + * would get "port unreachable" - in ICMP we got "echo reply". + * Simulate "port unreachable" for caller: + */ + return ICMP_UNREACH_PORT+1; + } + if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || type == ICMP_UNREACH - || type == ICMP_ECHOREPLY ) { const struct ip *hip; const struct udphdr *up; @@ -610,14 +652,6 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq) if (option_mask32 & OPT_USE_ICMP) { struct icmp *hicmp; - /* XXX */ - if (type == ICMP_ECHOREPLY - && icp->icmp_id == htons(ident) - && icp->icmp_seq == htons(seq) - ) { - return ICMP_UNREACH_PORT+1; - } - hicmp = (struct icmp *)((unsigned char *)hip + hlen); if (hlen + SIZEOF_ICMP_HDR <= read_len && hip->ip_p == IPPROTO_ICMP @@ -648,6 +682,7 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq) printf("\n%d bytes from %s to " "%s: icmp type %d (%s) code %d\n", read_len, inet_ntoa(from->sin_addr), +//BUG: inet_ntoa() returns static buf! x2 is NONO! inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code); for (i = 4; i < read_len; i += sizeof(*lp)) @@ -673,11 +708,27 @@ packet_ok(int read_len, len_and_sockaddr *from_lsa, if (from_lsa->u.sa.sa_family == AF_INET) return packet4_ok(read_len, &from_lsa->u.sin, seq); + /* NB: reads from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) socket + * return only ICMP packet (IOW: they strip IPv6 header). + * This differs from (AF_INET, SOCK_RAW, IPPROTO_ICMP) sockets!? + */ icp = (struct icmp6_hdr *) recv_pkt; type = icp->icmp6_type; code = icp->icmp6_code; + if ((option_mask32 & OPT_USE_ICMP) + && type == ICMP6_ECHO_REPLY + && icp->icmp6_id == htons(ident) + && icp->icmp6_seq == htons(seq) + ) { + /* In UDP mode, when we reach the machine, we (usually) + * would get "port unreachable" - in ICMP we got "echo reply". + * Simulate "port unreachable" for caller: + */ + return (ICMP6_DST_UNREACH_NOPORT << 8) + 1; + } + if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) || type == ICMP6_DST_UNREACH ) { @@ -787,8 +838,13 @@ print(int read_len, const struct sockaddr *from, const struct sockaddr *to) if (verbose) { char *ina = xmalloc_sockaddr2dotted_noport(to); #if ENABLE_TRACEROUTE6 + /* NB: reads from (AF_INET, SOCK_RAW, IPPROTO_ICMP) socket + * return the entire IP packet (IOW: they do not strip IP header). + * Reads from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) do strip IPv6 + * header and return only ICMP6 packet. Weird. + */ if (to->sa_family == AF_INET6) { - read_len -= sizeof(struct ip6_hdr); + /* read_len -= sizeof(struct ip6_hdr); - WRONG! */ } else #endif { @@ -844,6 +900,9 @@ common_traceroute_main(int op, char **argv) struct sockaddr *lastaddr; struct sockaddr *to; + /* Ensure the socket fds won't be 0, 1 or 2 */ + bb_sanitize_stdio(); + INIT_G(); op |= getopt32(argv, "^" @@ -885,12 +944,14 @@ common_traceroute_main(int op, char **argv) /* Process destination and optional packet size */ minpacket = sizeof(struct ip) - + SIZEOF_ICMP_HDR + + sizeof(struct udphdr) + sizeof(struct outdata_t); - if (!(op & OPT_USE_ICMP)) + if (op & OPT_USE_ICMP) { minpacket = sizeof(struct ip) - + sizeof(struct udphdr) + + SIZEOF_ICMP_HDR + sizeof(struct outdata_t); + port = 0; /* on ICMP6 sockets, sendto(ipv6.nonzero_port) throws EINVAL */ + } #if ENABLE_TRACEROUTE6 af = AF_UNSPEC; if (op & OPT_IPV4) @@ -899,10 +960,15 @@ common_traceroute_main(int op, char **argv) af = AF_INET6; dest_lsa = xhost_and_af2sockaddr(argv[0], port, af); af = dest_lsa->u.sa.sa_family; - if (af == AF_INET6) + if (af == AF_INET6) { minpacket = sizeof(struct ip6_hdr) - + sizeof(struct udphdr) - + sizeof(struct outdata6_t); + + sizeof(struct udphdr) + + sizeof(struct outdata6_t); + if (op & OPT_USE_ICMP) + minpacket = sizeof(struct ip6_hdr) + + SIZEOF_ICMP_HDR + + sizeof(struct outdata6_t); + } #else dest_lsa = xhost2sockaddr(argv[0], port); #endif @@ -910,13 +976,10 @@ common_traceroute_main(int op, char **argv) if (argv[1]) packlen = xatoul_range(argv[1], minpacket, 32 * 1024); - /* Ensure the socket fds won't be 0, 1 or 2 */ - bb_sanitize_stdio(); - #if ENABLE_TRACEROUTE6 if (af == AF_INET6) { xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock); - setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); + setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); //why? } else #endif { @@ -934,7 +997,10 @@ common_traceroute_main(int op, char **argv) if (af == AF_INET6) { if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0) bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM"); - xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock); + if (op & OPT_USE_ICMP) + xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), sndsock); + else + xmove_fd(xsocket(AF_INET6, SOCK_DGRAM, 0), sndsock); } else #endif { @@ -943,6 +1009,7 @@ common_traceroute_main(int op, char **argv) else xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock); } +//TODO xmove_fd to here! #ifdef SO_SNDBUF if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) { @@ -970,21 +1037,25 @@ common_traceroute_main(int op, char **argv) ident = getpid(); if (!ENABLE_TRACEROUTE6 || af == AF_INET) { + outdata = (void*)(outudp + 1); if (op & OPT_USE_ICMP) { ident |= 0x8000; outicmp->icmp_type = ICMP_ECHO; + /*outicmp->icmp_code = 0; - set by xzalloc */ outicmp->icmp_id = htons(ident); - outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR); - } else { - outdata = (struct outdata_t *)(outudp + 1); + outdata = (void*)((char *)outicmp + SIZEOF_ICMP_HDR); } } #if ENABLE_TRACEROUTE6 if (af == AF_INET6) { - outdata = (void*)((char*)outip - + sizeof(struct ip6_hdr) - + sizeof(struct udphdr) - ); + outdata = (void*)(outudp6 + 1); + if (op & OPT_USE_ICMP) { + ident |= 0x8000; + outicmp6->icmp_type = ICMP6_ECHO_REQUEST; + /*outicmp->icmp_code = 0; - set by xzalloc */ + outicmp6->icmp_id = htons(ident); + outdata = (void*)((char *)outicmp6 + SIZEOF_ICMP_HDR); + } } #endif @@ -1013,26 +1084,16 @@ common_traceroute_main(int op, char **argv) //TODO: why we don't do it for IPv4? len_and_sockaddr *source_lsa; - int probe_fd = xsocket(af, SOCK_DGRAM, 0); - if (op & OPT_DEVICE) - setsockopt_bindtodevice(probe_fd, device); - set_nport(&dest_lsa->u.sa, htons(1025)); - /* dummy connect. makes kernel pick source IP (and port) */ - xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len); set_nport(&dest_lsa->u.sa, htons(port)); - - /* read IP and port */ - source_lsa = get_sock_lsa(probe_fd); + /* Connect makes kernel pick source IP and port */ + xconnect(sndsock, &dest_lsa->u.sa, dest_lsa->len); + /* Read IP and port */ + source_lsa = get_sock_lsa(sndsock); if (source_lsa == NULL) bb_simple_error_msg_and_die("can't get probe addr"); - - close(probe_fd); - - /* bind our sockets to this IP (but not port) */ + /* bind our recv socket to this IP (but not port) */ set_nport(&source_lsa->u.sa, 0); - xbind(sndsock, &source_lsa->u.sa, source_lsa->len); xbind(rcvsock, &source_lsa->u.sa, source_lsa->len); - free(source_lsa); } #endif @@ -1067,10 +1128,9 @@ common_traceroute_main(int op, char **argv) unsigned t1; unsigned t2; int left_ms; - struct ip *ip; fflush_all(); - if (probe != 0 && pausemsecs > 0) + if (probe != 0) msleep(pausemsecs); send_probe(++seq, ttl); @@ -1099,15 +1159,18 @@ common_traceroute_main(int op, char **argv) } print_delta_ms(t1, t2); - ip = (struct ip *)recv_pkt; - if (from_lsa->u.sa.sa_family == AF_INET) - if (op & OPT_TTL_FLAG) + if (from_lsa->u.sa.sa_family == AF_INET) { + if (op & OPT_TTL_FLAG) { + struct ip *ip = (struct ip *)recv_pkt; printf(" (%d)", ip->ip_ttl); + } + } - /* time exceeded in transit */ + /* Got a "time exceeded in transit" icmp message? */ if (icmp_code == -1) break; + icmp_code--; switch (icmp_code) { #if ENABLE_TRACEROUTE6 @@ -1115,12 +1178,13 @@ common_traceroute_main(int op, char **argv) got_there = 1; break; #endif - case ICMP_UNREACH_PORT: + case ICMP_UNREACH_PORT: { + struct ip *ip = (struct ip *)recv_pkt; if (ip->ip_ttl <= 1) printf(" !"); got_there = 1; break; - + } case ICMP_UNREACH_NET: #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET) case ICMP6_DST_UNREACH_NOROUTE << 8: |