| /* |
| * tracepath6.c |
| * |
| * 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. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <netinet/icmp6.h> |
| |
| #include <linux/types.h> |
| #include <linux/errqueue.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <netdb.h> |
| #include <resolv.h> |
| #include <sys/time.h> |
| #include <sys/uio.h> |
| #include <arpa/inet.h> |
| |
| #ifdef USE_IDN |
| #include <idna.h> |
| #include <locale.h> |
| #endif |
| |
| #ifndef SOL_IPV6 |
| #define SOL_IPV6 IPPROTO_IPV6 |
| #endif |
| |
| #ifndef IP_PMTUDISC_DO |
| #define IP_PMTUDISC_DO 3 |
| #endif |
| #ifndef IPV6_PMTUDISC_DO |
| #define IPV6_PMTUDISC_DO 3 |
| #endif |
| |
| #define MAX_HOPS_LIMIT 255 |
| #define MAX_HOPS_DEFAULT 30 |
| |
| struct hhistory |
| { |
| int hops; |
| struct timeval sendtime; |
| }; |
| |
| struct hhistory his[64]; |
| int hisptr; |
| |
| sa_family_t family = AF_INET6; |
| struct sockaddr_storage target; |
| socklen_t targetlen; |
| __u16 base_port; |
| int max_hops = MAX_HOPS_DEFAULT; |
| |
| int overhead; |
| int mtu; |
| void *pktbuf; |
| int hops_to = -1; |
| int hops_from = -1; |
| int no_resolve = 0; |
| int show_both = 0; |
| int mapped; |
| |
| #define HOST_COLUMN_SIZE 52 |
| |
| struct probehdr |
| { |
| __u32 ttl; |
| struct timeval tv; |
| }; |
| |
| void data_wait(int fd) |
| { |
| fd_set fds; |
| struct timeval tv; |
| FD_ZERO(&fds); |
| FD_SET(fd, &fds); |
| tv.tv_sec = 1; |
| tv.tv_usec = 0; |
| select(fd+1, &fds, NULL, NULL, &tv); |
| } |
| |
| void print_host(const char *a, const char *b, int both) |
| { |
| int plen; |
| plen = printf("%s", a); |
| if (both) |
| plen += printf(" (%s)", b); |
| if (plen >= HOST_COLUMN_SIZE) |
| plen = HOST_COLUMN_SIZE - 1; |
| printf("%*s", HOST_COLUMN_SIZE - plen, ""); |
| } |
| |
| int recverr(int fd, int ttl) |
| { |
| int res; |
| struct probehdr rcvbuf; |
| char cbuf[512]; |
| struct iovec iov; |
| struct msghdr msg; |
| struct cmsghdr *cmsg; |
| struct sock_extended_err *e; |
| struct sockaddr_storage addr; |
| struct timeval tv; |
| struct timeval *rettv; |
| int slot = 0; |
| int rethops; |
| int sndhops; |
| int progress = -1; |
| int broken_router; |
| |
| restart: |
| memset(&rcvbuf, -1, sizeof(rcvbuf)); |
| iov.iov_base = &rcvbuf; |
| iov.iov_len = sizeof(rcvbuf); |
| msg.msg_name = (caddr_t)&addr; |
| msg.msg_namelen = sizeof(addr); |
| msg.msg_iov = &iov; |
| msg.msg_iovlen = 1; |
| msg.msg_flags = 0; |
| msg.msg_control = cbuf; |
| msg.msg_controllen = sizeof(cbuf); |
| |
| gettimeofday(&tv, NULL); |
| res = recvmsg(fd, &msg, MSG_ERRQUEUE); |
| if (res < 0) { |
| if (errno == EAGAIN) |
| return progress; |
| goto restart; |
| } |
| |
| progress = mtu; |
| |
| rethops = -1; |
| sndhops = -1; |
| e = NULL; |
| rettv = NULL; |
| |
| slot = -base_port; |
| switch (family) { |
| case AF_INET6: |
| slot += ntohs(((struct sockaddr_in6 *)&addr)->sin6_port); |
| break; |
| case AF_INET: |
| slot += ntohs(((struct sockaddr_in *)&addr)->sin_port); |
| break; |
| } |
| |
| if (slot >= 0 && slot < 63 && his[slot].hops) { |
| sndhops = his[slot].hops; |
| rettv = &his[slot].sendtime; |
| his[slot].hops = 0; |
| } |
| broken_router = 0; |
| if (res == sizeof(rcvbuf)) { |
| if (rcvbuf.ttl == 0 || rcvbuf.tv.tv_sec == 0) |
| broken_router = 1; |
| else { |
| sndhops = rcvbuf.ttl; |
| rettv = &rcvbuf.tv; |
| } |
| } |
| |
| for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
| switch (cmsg->cmsg_level) { |
| case SOL_IPV6: |
| switch(cmsg->cmsg_type) { |
| case IPV6_RECVERR: |
| e = (struct sock_extended_err *)CMSG_DATA(cmsg); |
| break; |
| case IPV6_HOPLIMIT: |
| #ifdef IPV6_2292HOPLIMIT |
| case IPV6_2292HOPLIMIT: |
| #endif |
| memcpy(&rethops, CMSG_DATA(cmsg), sizeof(rethops)); |
| break; |
| default: |
| printf("cmsg6:%d\n ", cmsg->cmsg_type); |
| } |
| break; |
| case SOL_IP: |
| switch(cmsg->cmsg_type) { |
| case IP_RECVERR: |
| e = (struct sock_extended_err *)CMSG_DATA(cmsg); |
| break; |
| case IP_TTL: |
| rethops = *(__u8*)CMSG_DATA(cmsg); |
| break; |
| default: |
| printf("cmsg4:%d\n ", cmsg->cmsg_type); |
| } |
| } |
| } |
| if (e == NULL) { |
| printf("no info\n"); |
| return 0; |
| } |
| if (e->ee_origin == SO_EE_ORIGIN_LOCAL) |
| printf("%2d?: %-32s ", ttl, "[LOCALHOST]"); |
| else if (e->ee_origin == SO_EE_ORIGIN_ICMP6 || |
| e->ee_origin == SO_EE_ORIGIN_ICMP) { |
| char abuf[NI_MAXHOST], hbuf[NI_MAXHOST]; |
| struct sockaddr *sa = (struct sockaddr *)(e + 1); |
| socklen_t salen; |
| |
| if (sndhops>0) |
| printf("%2d: ", sndhops); |
| else |
| printf("%2d?: ", ttl); |
| |
| switch (sa->sa_family) { |
| case AF_INET6: |
| salen = sizeof(struct sockaddr_in6); |
| break; |
| case AF_INET: |
| salen = sizeof(struct sockaddr_in); |
| break; |
| default: |
| salen = 0; |
| } |
| |
| if (no_resolve || show_both) { |
| if (getnameinfo(sa, salen, |
| abuf, sizeof(abuf), NULL, 0, |
| NI_NUMERICHOST)) |
| strcpy(abuf, "???"); |
| } else |
| abuf[0] = 0; |
| |
| if (!no_resolve || show_both) { |
| fflush(stdout); |
| if (getnameinfo(sa, salen, |
| hbuf, sizeof(hbuf), NULL, 0, |
| 0 |
| #ifdef USE_IDN |
| | NI_IDN |
| #endif |
| )) |
| strcpy(hbuf, "???"); |
| } else |
| hbuf[0] = 0; |
| |
| if (no_resolve) |
| print_host(abuf, hbuf, show_both); |
| else |
| print_host(hbuf, abuf, show_both); |
| } |
| |
| if (rettv) { |
| int diff = (tv.tv_sec-rettv->tv_sec)*1000000+(tv.tv_usec-rettv->tv_usec); |
| printf("%3d.%03dms ", diff/1000, diff%1000); |
| if (broken_router) |
| printf("(This broken router returned corrupted payload) "); |
| } |
| |
| switch (e->ee_errno) { |
| case ETIMEDOUT: |
| printf("\n"); |
| break; |
| case EMSGSIZE: |
| printf("pmtu %d\n", e->ee_info); |
| mtu = e->ee_info; |
| progress = mtu; |
| break; |
| case ECONNREFUSED: |
| printf("reached\n"); |
| hops_to = sndhops<0 ? ttl : sndhops; |
| hops_from = rethops; |
| return 0; |
| case EPROTO: |
| printf("!P\n"); |
| return 0; |
| case EHOSTUNREACH: |
| if ((e->ee_origin == SO_EE_ORIGIN_ICMP && |
| e->ee_type == 11 && |
| e->ee_code == 0) || |
| (e->ee_origin == SO_EE_ORIGIN_ICMP6 && |
| e->ee_type == 3 && |
| e->ee_code == 0)) { |
| if (rethops>=0) { |
| if (rethops<=64) |
| rethops = 65-rethops; |
| else if (rethops<=128) |
| rethops = 129-rethops; |
| else |
| rethops = 256-rethops; |
| if (sndhops>=0 && rethops != sndhops) |
| printf("asymm %2d ", rethops); |
| else if (sndhops<0 && rethops != ttl) |
| printf("asymm %2d ", rethops); |
| } |
| printf("\n"); |
| break; |
| } |
| printf("!H\n"); |
| return 0; |
| case ENETUNREACH: |
| printf("!N\n"); |
| return 0; |
| case EACCES: |
| printf("!A\n"); |
| return 0; |
| default: |
| printf("\n"); |
| errno = e->ee_errno; |
| perror("NET ERROR"); |
| return 0; |
| } |
| goto restart; |
| } |
| |
| int probe_ttl(int fd, int ttl) |
| { |
| int i; |
| struct probehdr *hdr = pktbuf; |
| |
| memset(pktbuf, 0, mtu); |
| restart: |
| |
| for (i=0; i<10; i++) { |
| int res; |
| |
| hdr->ttl = ttl; |
| switch (family) { |
| case AF_INET6: |
| ((struct sockaddr_in6 *)&target)->sin6_port = htons(base_port + hisptr); |
| break; |
| case AF_INET: |
| ((struct sockaddr_in *)&target)->sin_port = htons(base_port + hisptr); |
| break; |
| } |
| gettimeofday(&hdr->tv, NULL); |
| his[hisptr].hops = ttl; |
| his[hisptr].sendtime = hdr->tv; |
| if (sendto(fd, pktbuf, mtu-overhead, 0, (struct sockaddr *)&target, targetlen) > 0) |
| break; |
| res = recverr(fd, ttl); |
| his[hisptr].hops = 0; |
| if (res==0) |
| return 0; |
| if (res > 0) |
| goto restart; |
| } |
| hisptr = (hisptr + 1) & 63; |
| |
| if (i<10) { |
| data_wait(fd); |
| if (recv(fd, pktbuf, mtu, MSG_DONTWAIT) > 0) { |
| printf("%2d?: reply received 8)\n", ttl); |
| return 0; |
| } |
| return recverr(fd, ttl); |
| } |
| |
| printf("%2d: send failed\n", ttl); |
| return 0; |
| } |
| |
| static void usage(void) __attribute((noreturn)); |
| |
| static void usage(void) |
| { |
| fprintf(stderr, "Usage: tracepath6 [-n] [-b] [-l <len>] [-p port] <destination>\n"); |
| exit(-1); |
| } |
| |
| |
| int main(int argc, char **argv) |
| { |
| int fd; |
| int on; |
| int ttl; |
| char *p; |
| struct addrinfo hints, *ai, *ai0; |
| int ch; |
| int gai; |
| char pbuf[NI_MAXSERV]; |
| |
| #ifdef USE_IDN |
| setlocale(LC_ALL, ""); |
| #endif |
| |
| while ((ch = getopt(argc, argv, "nbh?l:m:p:")) != EOF) { |
| switch(ch) { |
| case 'n': |
| no_resolve = 1; |
| break; |
| case 'b': |
| show_both = 1; |
| break; |
| case 'l': |
| mtu = atoi(optarg); |
| break; |
| case 'm': |
| max_hops = atoi(optarg); |
| if (max_hops < 0 || max_hops > MAX_HOPS_LIMIT) { |
| fprintf(stderr, |
| "Error: max hops must be 0 .. %d (inclusive).\n", |
| MAX_HOPS_LIMIT); |
| } |
| break; |
| case 'p': |
| base_port = atoi(optarg); |
| break; |
| default: |
| usage(); |
| } |
| } |
| |
| argc -= optind; |
| argv += optind; |
| |
| if (argc != 1) |
| usage(); |
| |
| /* Backward compatiblity */ |
| if (!base_port) { |
| p = strchr(argv[0], '/'); |
| if (p) { |
| *p = 0; |
| base_port = (unsigned)atoi(p+1); |
| } else { |
| base_port = 44444; |
| } |
| } |
| sprintf(pbuf, "%u", base_port); |
| |
| memset(&hints, 0, sizeof(hints)); |
| hints.ai_family = family; |
| hints.ai_socktype = SOCK_DGRAM; |
| hints.ai_protocol = IPPROTO_UDP; |
| #ifdef USE_IDN |
| hints.ai_flags = AI_IDN; |
| #endif |
| gai = getaddrinfo(argv[0], pbuf, &hints, &ai0); |
| if (gai) { |
| fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(gai)); |
| exit(1); |
| } |
| |
| fd = -1; |
| for (ai = ai0; ai; ai = ai->ai_next) { |
| /* sanity check */ |
| if (family && ai->ai_family != family) |
| continue; |
| if (ai->ai_family != AF_INET6 && |
| ai->ai_family != AF_INET) |
| continue; |
| family = ai->ai_family; |
| fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
| if (fd < 0) |
| continue; |
| memcpy(&target, ai->ai_addr, sizeof(target)); |
| targetlen = ai->ai_addrlen; |
| break; |
| } |
| if (fd < 0) { |
| perror("socket/connect"); |
| exit(1); |
| } |
| freeaddrinfo(ai0); |
| |
| switch (family) { |
| case AF_INET6: |
| overhead = 48; |
| if (!mtu) |
| mtu = 128000; |
| if (mtu <= overhead) |
| goto pktlen_error; |
| |
| on = IPV6_PMTUDISC_DO; |
| if (setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)) && |
| (on = IPV6_PMTUDISC_DO, |
| setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)))) { |
| perror("IPV6_MTU_DISCOVER"); |
| exit(1); |
| } |
| on = 1; |
| if (setsockopt(fd, SOL_IPV6, IPV6_RECVERR, &on, sizeof(on))) { |
| perror("IPV6_RECVERR"); |
| exit(1); |
| } |
| if ( |
| #ifdef IPV6_RECVHOPLIMIT |
| setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) && |
| setsockopt(fd, SOL_IPV6, IPV6_2292HOPLIMIT, &on, sizeof(on)) |
| #else |
| setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) |
| #endif |
| ) { |
| perror("IPV6_HOPLIMIT"); |
| exit(1); |
| } |
| if (!IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *)&target)->sin6_addr))) |
| break; |
| mapped = 1; |
| /*FALLTHROUGH*/ |
| case AF_INET: |
| overhead = 28; |
| if (!mtu) |
| mtu = 65535; |
| if (mtu <= overhead) |
| goto pktlen_error; |
| |
| on = IP_PMTUDISC_DO; |
| if (setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on))) { |
| perror("IP_MTU_DISCOVER"); |
| exit(1); |
| } |
| on = 1; |
| if (setsockopt(fd, SOL_IP, IP_RECVERR, &on, sizeof(on))) { |
| perror("IP_RECVERR"); |
| exit(1); |
| } |
| if (setsockopt(fd, SOL_IP, IP_RECVTTL, &on, sizeof(on))) { |
| perror("IP_RECVTTL"); |
| exit(1); |
| } |
| } |
| |
| pktbuf = malloc(mtu); |
| if (!pktbuf) { |
| perror("malloc"); |
| exit(1); |
| } |
| |
| for (ttl = 1; ttl <= max_hops; ttl++) { |
| int res; |
| int i; |
| |
| on = ttl; |
| switch (family) { |
| case AF_INET6: |
| if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &on, sizeof(on))) { |
| perror("IPV6_UNICAST_HOPS"); |
| exit(1); |
| } |
| if (!mapped) |
| break; |
| /*FALLTHROUGH*/ |
| case AF_INET: |
| if (setsockopt(fd, SOL_IP, IP_TTL, &on, sizeof(on))) { |
| perror("IP_TTL"); |
| exit(1); |
| } |
| } |
| |
| restart: |
| for (i=0; i<3; i++) { |
| int old_mtu; |
| |
| old_mtu = mtu; |
| res = probe_ttl(fd, ttl); |
| if (mtu != old_mtu) |
| goto restart; |
| if (res == 0) |
| goto done; |
| if (res > 0) |
| break; |
| } |
| |
| if (res < 0) |
| printf("%2d: no reply\n", ttl); |
| } |
| printf(" Too many hops: pmtu %d\n", mtu); |
| |
| done: |
| printf(" Resume: pmtu %d ", mtu); |
| if (hops_to>=0) |
| printf("hops %d ", hops_to); |
| if (hops_from>=0) |
| printf("back %d ", hops_from); |
| printf("\n"); |
| exit(0); |
| |
| pktlen_error: |
| fprintf(stderr, "Error: pktlen must be > %d and <= %d\n", |
| overhead, INT_MAX); |
| exit(1); |
| } |