diff options
author | Eric Andersen <andersen@codepoet.org> | 2001-07-10 20:29:00 +0400 |
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committer | Eric Andersen <andersen@codepoet.org> | 2001-07-10 20:29:00 +0400 |
commit | 5c58d283bbd71db2a43379fc2b804f6c138cf35e (patch) | |
tree | 6dd8028a88bf560831a117cba5f59709237055e9 /networking/traceroute.c | |
parent | 91b84603d3c3f3911bee87c8ad02c06cb8fc95ae (diff) |
A traceroute applet from vodz. This could probably be slimmed down,
but will do for now...
Diffstat (limited to 'networking/traceroute.c')
-rw-r--r-- | networking/traceroute.c | 593 |
1 files changed, 593 insertions, 0 deletions
diff --git a/networking/traceroute.c b/networking/traceroute.c new file mode 100644 index 000000000..a02be8a9e --- /dev/null +++ b/networking/traceroute.c @@ -0,0 +1,593 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Van Jacobson. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * traceroute host - trace the route ip packets follow going to "host". + * Notes + * ----- + * This program must be run by root or be setuid. (I suggest that + * you *don't* make it setuid -- casual use could result in a lot + * of unnecessary traffic on our poor, congested nets.) + * + * I stole the idea for this program from Steve Deering. Since + * the first release, I've learned that had I attended the right + * IETF working group meetings, I also could have stolen it from Guy + * Almes or Matt Mathis. I don't know (or care) who came up with + * the idea first. I envy the originators' perspicacity and I'm + * glad they didn't keep the idea a secret. + * + * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or + * enhancements to the original distribution. + * + * I've hacked up a round-trip-route version of this that works by + * sending a loose-source-routed udp datagram through the destination + * back to yourself. Unfortunately, SO many gateways botch source + * routing, the thing is almost worthless. Maybe one day... + * + * -- Van Jacobson (van@helios.ee.lbl.gov) + * Tue Dec 20 03:50:13 PST 1988 + */ + +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/time.h> +#include <netdb.h> +#include <endian.h> +#include <arpa/inet.h> +#include <netinet/udp.h> +#include <netinet/ip.h> +#include <netinet/ip_icmp.h> + + +#define MAXPACKET 65535 /* max ip packet size */ +#ifndef MAXHOSTNAMELEN +#define MAXHOSTNAMELEN 64 +#endif + +/* + * format of a (udp) probe packet. + */ +struct opacket { + struct ip ip; + struct udphdr udp; + u_char seq; /* sequence number of this packet */ + u_char ttl; /* ttl packet left with */ + struct timeval tv; /* time packet left */ +}; + +/* + * Definitions for internet protocol version 4. + * Per RFC 791, September 1981. + */ +#define IPVERSION 4 + + +#include "busybox.h" + +static int wait_for_reply (int, struct sockaddr_in *, int); +static void send_probe (int, int); +static double deltaT (struct timeval *, struct timeval *); +static int packet_ok (u_char *, int, struct sockaddr_in *, int); +static void print (u_char *, int, struct sockaddr_in *); +static char *inetname (struct in_addr); + +static u_char packet[512]; /* last inbound (icmp) packet */ +static struct opacket *outpacket; /* last output (udp) packet */ + +static int s; /* receive (icmp) socket file descriptor */ +static int sndsock; /* send (udp) socket file descriptor */ + +static struct sockaddr whereto; /* Who to try to reach */ +static int datalen; /* How much data */ + +static char *hostname; + +static int max_ttl = 30; +static u_short ident; +static u_short port = 32768+666; /* start udp dest port # for probe packets */ + +static int verbose; +static int waittime = 5; /* time to wait for response (in seconds) */ +static int nflag; /* print addresses numerically */ + +int +#ifndef BB_TRACEROUTE +main(argc, argv) +#else +traceroute_main(argc, argv) +#endif + int argc; + char *argv[]; +{ + extern char *optarg; + extern int optind; + struct hostent *hp; + struct protoent *pe; + struct sockaddr_in from, *to; + int ch, i, on, probe, seq, tos, ttl; + + int options = 0; /* socket options */ + char *source = 0; + int nprobes = 3; + + on = 1; + seq = tos = 0; + to = (struct sockaddr_in *)&whereto; + while ((ch = getopt(argc, argv, "dm:np:q:rs:t:w:v")) != EOF) + switch(ch) { + case 'd': + options |= SO_DEBUG; + break; + case 'm': + max_ttl = atoi(optarg); + if (max_ttl <= 1) + error_msg_and_die("max ttl must be >1."); + break; + case 'n': + nflag++; + break; + case 'p': + port = atoi(optarg); + if (port < 1) + error_msg_and_die("port must be >0."); + break; + case 'q': + nprobes = atoi(optarg); + if (nprobes < 1) + error_msg_and_die("nprobes must be >0."); + break; + case 'r': + options |= SO_DONTROUTE; + break; + case 's': + /* + * set the ip source address of the outbound + * probe (e.g., on a multi-homed host). + */ + source = optarg; + break; + case 't': + tos = atoi(optarg); + if (tos < 0 || tos > 255) + error_msg_and_die("tos must be 0 to 255."); + break; + case 'v': + verbose++; + break; + case 'w': + waittime = atoi(optarg); + if (waittime <= 1) + error_msg_and_die("wait must be >1 sec."); + break; + default: + show_usage(); + } + argc -= optind; + argv += optind; + + if (argc < 1) + show_usage(); + + setlinebuf (stdout); + + (void) bzero((char *)&whereto, sizeof(struct sockaddr)); + to->sin_family = AF_INET; + to->sin_addr.s_addr = inet_addr(*argv); + if (to->sin_addr.s_addr != -1) + hostname = *argv; + else { + hp = gethostbyname(*argv); + if (hp) { + to->sin_family = hp->h_addrtype; + bcopy(hp->h_addr, (caddr_t)&to->sin_addr, hp->h_length); + hostname = (char *)hp->h_name; + } else { + error_msg_and_die("unknown host %s", *argv); + } + } + if (*++argv) + datalen = atoi(*argv); + if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) + error_msg_and_die("packet size must be 0 <= s < %d.", + MAXPACKET - sizeof(struct opacket)); + datalen += sizeof(struct opacket); + outpacket = (struct opacket *)xmalloc((unsigned)datalen); + (void) bzero((char *)outpacket, datalen); + outpacket->ip.ip_dst = to->sin_addr; + outpacket->ip.ip_tos = tos; + outpacket->ip.ip_v = IPVERSION; + outpacket->ip.ip_id = 0; + + ident = (getpid() & 0xffff) | 0x8000; + + if ((pe = getprotobyname("icmp")) == NULL) + error_msg_and_die("icmp: unknown protocol"); + if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) + perror_msg_and_die("icmp socket"); + if (options & SO_DEBUG) + (void) setsockopt(s, SOL_SOCKET, SO_DEBUG, + (char *)&on, sizeof(on)); + if (options & SO_DONTROUTE) + (void) setsockopt(s, SOL_SOCKET, SO_DONTROUTE, + (char *)&on, sizeof(on)); + + if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) + perror_msg_and_die("raw socket"); +#ifdef SO_SNDBUF + if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen, + sizeof(datalen)) < 0) + perror_msg_and_die("SO_SNDBUF"); +#endif SO_SNDBUF +#ifdef IP_HDRINCL + if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on, + sizeof(on)) < 0) + perror_msg_and_die("IP_HDRINCL"); +#endif IP_HDRINCL + if (options & SO_DEBUG) + (void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, + (char *)&on, sizeof(on)); + if (options & SO_DONTROUTE) + (void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, + (char *)&on, sizeof(on)); + + if (source) { + (void) bzero((char *)&from, sizeof(struct sockaddr)); + from.sin_family = AF_INET; + from.sin_addr.s_addr = inet_addr(source); + if (from.sin_addr.s_addr == -1) + error_msg_and_die("unknown host %s", source); + outpacket->ip.ip_src = from.sin_addr; +#ifndef IP_HDRINCL + if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) + perror_msg_and_die("bind"); +#endif IP_HDRINCL + } + + fprintf(stderr, "traceroute to %s (%s)", hostname, + inet_ntoa(to->sin_addr)); + if (source) + fprintf(stderr, " from %s", source); + fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen); + (void) fflush(stderr); + + for (ttl = 1; ttl <= max_ttl; ++ttl) { + u_long lastaddr = 0; + int got_there = 0; + int unreachable = 0; + + printf("%2d ", ttl); + for (probe = 0; probe < nprobes; ++probe) { + int cc, reset_timer; + struct timeval t1, t2; + struct timezone tz; + struct ip *ip; + + (void) gettimeofday(&t1, &tz); + send_probe(++seq, ttl); + reset_timer = 1; + while ((cc = wait_for_reply(s, &from, reset_timer)) != 0) { + (void) gettimeofday(&t2, &tz); + if ((i = packet_ok(packet, cc, &from, seq))) { + reset_timer = 1; + if (from.sin_addr.s_addr != lastaddr) { + print(packet, cc, &from); + lastaddr = from.sin_addr.s_addr; + } + printf(" %g ms", deltaT(&t1, &t2)); + switch(i - 1) { + case ICMP_UNREACH_PORT: +#ifndef ARCHAIC + ip = (struct ip *)packet; + if (ip->ip_ttl <= 1) + printf(" !"); +#endif ARCHAIC + ++got_there; + break; + case ICMP_UNREACH_NET: + ++unreachable; + printf(" !N"); + break; + case ICMP_UNREACH_HOST: + ++unreachable; + printf(" !H"); + break; + case ICMP_UNREACH_PROTOCOL: + ++got_there; + printf(" !P"); + break; + case ICMP_UNREACH_NEEDFRAG: + ++unreachable; + printf(" !F"); + break; + case ICMP_UNREACH_SRCFAIL: + ++unreachable; + printf(" !S"); + break; + } + break; + } else + reset_timer = 0; + } + if (cc == 0) + printf(" *"); + (void) fflush(stdout); + } + putchar('\n'); + if (got_there || unreachable >= nprobes-1) + exit(0); + } + + return 0; +} + +static int +wait_for_reply(sock, from, reset_timer) + int sock; + struct sockaddr_in *from; + int reset_timer; +{ + fd_set fds; + static struct timeval wait; + int cc = 0; + int fromlen = sizeof (*from); + + FD_ZERO(&fds); + FD_SET(sock, &fds); + if (reset_timer) { + /* + * traceroute could hang if someone else has a ping + * running and our ICMP reply gets dropped but we don't + * realize it because we keep waking up to handle those + * other ICMP packets that keep coming in. To fix this, + * "reset_timer" will only be true if the last packet that + * came in was for us or if this is the first time we're + * waiting for a reply since sending out a probe. Note + * that this takes advantage of the select() feature on + * Linux where the remaining timeout is written to the + * struct timeval area. + */ + wait.tv_sec = waittime; + wait.tv_usec = 0; + } + + if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) + cc=recvfrom(s, (char *)packet, sizeof(packet), 0, + (struct sockaddr *)from, &fromlen); + + return(cc); +} + + +static void +send_probe(seq, ttl) + int seq, ttl; +{ + struct opacket *op = outpacket; + struct ip *ip = &op->ip; + struct udphdr *up = &op->udp; + int i; + struct timezone tz; + + ip->ip_off = 0; + ip->ip_hl = sizeof(*ip) >> 2; + ip->ip_p = IPPROTO_UDP; + ip->ip_len = datalen; + ip->ip_ttl = ttl; + ip->ip_v = IPVERSION; + ip->ip_id = htons(ident+seq); + + up->source = htons(ident); + up->dest = htons(port+seq); + up->len = htons((u_short)(datalen - sizeof(struct ip))); + up->check = 0; + + op->seq = seq; + op->ttl = ttl; + (void) gettimeofday(&op->tv, &tz); + + i = sendto(sndsock, (char *)outpacket, datalen, 0, &whereto, + sizeof(struct sockaddr)); + if (i < 0 || i != datalen) { + if (i<0) + perror("sendto"); + printf("traceroute: wrote %s %d chars, ret=%d\n", hostname, + datalen, i); + (void) fflush(stdout); + } +} + + +static double +deltaT(t1p, t2p) + struct timeval *t1p, *t2p; +{ + register double dt; + + dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 + + (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0; + return (dt); +} + + +/* + * Convert an ICMP "type" field to a printable string. + */ +static const char * +pr_type(t) + u_char t; +{ + static const char * const ttab[] = { + "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", + "Source Quench", "Redirect", "ICMP 6", "ICMP 7", + "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", + "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", + "Info Reply" + }; + + if(t > 16) + return("OUT-OF-RANGE"); + + return(ttab[t]); +} + + +static int +packet_ok(buf, cc, from, seq) + u_char *buf; + int cc; + struct sockaddr_in *from; + int seq; +{ + register struct icmp *icp; + u_char type, code; + int hlen; +#ifndef ARCHAIC + struct ip *ip; + + ip = (struct ip *) buf; + hlen = ip->ip_hl << 2; + if (cc < hlen + ICMP_MINLEN) { + if (verbose) + printf("packet too short (%d bytes) from %s\n", cc, + inet_ntoa(from->sin_addr)); + return (0); + } + cc -= hlen; + icp = (struct icmp *)(buf + hlen); +#else + icp = (struct icmp *)buf; +#endif ARCHAIC + type = icp->icmp_type; code = icp->icmp_code; + if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || + type == ICMP_UNREACH) { + struct ip *hip; + struct udphdr *up; + + hip = &icp->icmp_ip; + hlen = hip->ip_hl << 2; + up = (struct udphdr *)((u_char *)hip + hlen); + if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP && + up->source == htons(ident) && + up->dest == htons(port+seq)) + return (type == ICMP_TIMXCEED? -1 : code+1); + } +#ifndef ARCHAIC + if (verbose) { + int i; + u_long *lp = (u_long *)&icp->icmp_ip; + + printf("\n%d bytes from %s to %s", cc, + inet_ntoa(from->sin_addr), inet_ntoa(ip->ip_dst)); + printf(": icmp type %d (%s) code %d\n", type, pr_type(type), + icp->icmp_code); + for (i = 4; i < cc ; i += sizeof(long)) + printf("%2d: x%8.8lx\n", i, *lp++); + } +#endif ARCHAIC + return(0); +} + + +static void +print(buf, cc, from) + u_char *buf; + int cc; + struct sockaddr_in *from; +{ + struct ip *ip; + int hlen; + + ip = (struct ip *) buf; + hlen = ip->ip_hl << 2; + cc -= hlen; + + if (nflag) + printf(" %s", inet_ntoa(from->sin_addr)); + else + printf(" %s (%s)", inetname(from->sin_addr), + inet_ntoa(from->sin_addr)); + + if (verbose) + printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); +} + + +/* + * Construct an Internet address representation. + * If the nflag has been supplied, give + * numeric value, otherwise try for symbolic name. + */ +static char * +inetname(in) + struct in_addr in; +{ + register char *cp; + static char line[50]; + struct hostent *hp; + static char domain[MAXHOSTNAMELEN + 1]; + static int first = 1; + + if (first && !nflag) { + first = 0; + if (gethostname(domain, MAXHOSTNAMELEN) == 0 && + (cp = index(domain, '.'))) + (void) strcpy(domain, cp + 1); + else + domain[0] = 0; + } + cp = 0; + if (!nflag && in.s_addr != INADDR_ANY) { + hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET); + if (hp) { + if ((cp = index(hp->h_name, '.')) && + !strcmp(cp + 1, domain)) + *cp = 0; + cp = (char *)hp->h_name; + } + } + if (cp) + (void) strcpy(line, cp); + else { + in.s_addr = ntohl(in.s_addr); +#define C(x) ((x) & 0xff) + sprintf(line, "%u.%u.%u.%u", C(in.s_addr >> 24), + C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr)); + } + return (line); +} |