848 lines
24 KiB
C
848 lines
24 KiB
C
#ifndef lint
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static char *rcsid =
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"@(#)$Header: traceroute.c,v 1.27 95/10/18 00:17:06 leres Exp $ (LBL)";
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#endif
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/*
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* traceroute host - trace the route ip packets follow going to "host".
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*
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* Attempt to trace the route an ip packet would follow to some
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* internet host. We find out intermediate hops by launching probe
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* packets with a small ttl (time to live) then listening for an
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* icmp "time exceeded" reply from a gateway. We start our probes
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* with a ttl of one and increase by one until we get an icmp "port
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* unreachable" (which means we got to "host") or hit a max (which
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* defaults to 30 hops & can be changed with the -m flag). Three
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* probes (change with -q flag) are sent at each ttl setting and a
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* line is printed showing the ttl, address of the gateway and
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* round trip time of each probe. If the probe answers come from
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* different gateways, the address of each responding system will
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* be printed. If there is no response within a 5 sec. timeout
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* interval (changed with the -w flag), a "*" is printed for that
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* probe.
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*
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* Probe packets are UDP format. We don't want the destination
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* host to process them so the destination port is set to an
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* unlikely value (if some clod on the destination is using that
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* value, it can be changed with the -p flag).
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*
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* A sample use might be:
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*
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* [yak 71]% traceroute nis.nsf.net.
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* traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
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* 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
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* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
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* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
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* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
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* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
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* 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
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* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
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* 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
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* 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
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* 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
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* 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
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*
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* Note that lines 2 & 3 are the same. This is due to a buggy
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* kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
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* packets with a zero ttl.
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*
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* A more interesting example is:
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*
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* [yak 72]% traceroute allspice.lcs.mit.edu.
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* traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
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* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
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* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
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* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
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* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
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* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
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* 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
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* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
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* 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
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* 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
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* 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
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* 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
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* 12 * * *
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* 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
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* 14 * * *
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* 15 * * *
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* 16 * * *
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* 17 * * *
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* 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
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*
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* (I start to see why I'm having so much trouble with mail to
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* MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
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* either don't send ICMP "time exceeded" messages or send them
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* with a ttl too small to reach us. 14 - 17 are running the
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* MIT C Gateway code that doesn't send "time exceeded"s. God
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* only knows what's going on with 12.
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*
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* The silent gateway 12 in the above may be the result of a bug in
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* the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
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* sends an unreachable message using whatever ttl remains in the
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* original datagram. Since, for gateways, the remaining ttl is
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* zero, the icmp "time exceeded" is guaranteed to not make it back
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* to us. The behavior of this bug is slightly more interesting
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* when it appears on the destination system:
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*
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* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
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* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
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* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
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* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
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* 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
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* 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
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* 7 * * *
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* 8 * * *
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* 9 * * *
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* 10 * * *
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* 11 * * *
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* 12 * * *
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* 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
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*
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* Notice that there are 12 "gateways" (13 is the final
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* destination) and exactly the last half of them are "missing".
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* What's really happening is that rip (a Sun-3 running Sun OS3.5)
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* is using the ttl from our arriving datagram as the ttl in its
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* icmp reply. So, the reply will time out on the return path
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* (with no notice sent to anyone since icmp's aren't sent for
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* icmp's) until we probe with a ttl that's at least twice the path
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* length. I.e., rip is really only 7 hops away. A reply that
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* returns with a ttl of 1 is a clue this problem exists.
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* Traceroute prints a "!" after the time if the ttl is <= 1.
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* Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
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* non-standard (HPUX) software, expect to see this problem
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* frequently and/or take care picking the target host of your
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* probes.
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*
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* Other possible annotations after the time are !H, !N, !P (got a host,
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* network or protocol unreachable, respectively), !S or !F (source
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* route failed or fragmentation needed -- neither of these should
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* ever occur and the associated gateway is busted if you see one). If
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* almost all the probes result in some kind of unreachable, traceroute
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* will give up and exit.
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*
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* Notes
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* -----
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* This program must be run by root or be setuid. (I suggest that
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* you *don't* make it setuid -- casual use could result in a lot
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* of unnecessary traffic on our poor, congested nets.)
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*
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* This program requires a kernel mod that does not appear in any
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* system available from Berkeley: A raw ip socket using proto
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* IPPROTO_RAW must interpret the data sent as an ip datagram (as
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* opposed to data to be wrapped in a ip datagram). See the README
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* file that came with the source to this program for a description
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* of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
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* vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
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* MODIFIED TO RUN THIS PROGRAM.
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*
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* The udp port usage may appear bizarre (well, ok, it is bizarre).
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* The problem is that an icmp message only contains 8 bytes of
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* data from the original datagram. 8 bytes is the size of a udp
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* header so, if we want to associate replies with the original
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* datagram, the necessary information must be encoded into the
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* udp header (the ip id could be used but there's no way to
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* interlock with the kernel's assignment of ip id's and, anyway,
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* it would have taken a lot more kernel hacking to allow this
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* code to set the ip id). So, to allow two or more users to
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* use traceroute simultaneously, we use this task's pid as the
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* source port (the high bit is set to move the port number out
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* of the "likely" range). To keep track of which probe is being
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* replied to (so times and/or hop counts don't get confused by a
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* reply that was delayed in transit), we increment the destination
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* port number before each probe.
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*
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* Don't use this as a coding example. I was trying to find a
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* routing problem and this code sort-of popped out after 48 hours
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* without sleep. I was amazed it ever compiled, much less ran.
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*
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* I stole the idea for this program from Steve Deering. Since
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* the first release, I've learned that had I attended the right
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* IETF working group meetings, I also could have stolen it from Guy
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* Almes or Matt Mathis. I don't know (or care) who came up with
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* the idea first. I envy the originators' perspicacity and I'm
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* glad they didn't keep the idea a secret.
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*
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* Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
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* enhancements to the original distribution.
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*
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* I've hacked up a round-trip-route version of this that works by
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* sending a loose-source-routed udp datagram through the destination
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* back to yourself. Unfortunately, SO many gateways botch source
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* routing, the thing is almost worthless. Maybe one day...
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*
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* -- Van Jacobson (van@ee.lbl.gov)
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* Tue Dec 20 03:50:13 PST 1988
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*/
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#include <sys/param.h>
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#include <sys/file.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <netinet/in_systm.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/udp.h>
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#include <arpa/inet.h>
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#include <ctype.h>
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#include <unistd.h>
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#include <errno.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "gnuc.h"
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#ifdef HAVE_OS_PROTO_H
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#include "os-proto.h"
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#endif
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#define MAXPACKET 65535 /* max ip packet size */
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#ifndef MAXHOSTNAMELEN
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#define MAXHOSTNAMELEN 64
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#endif
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#if !defined(HAVE_BZERO) && !defined(bzero)
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#define bzero(s, n) memset(s, 0, n)
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#define bcopy(s, d, n) memcpy(d, s, n)
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#endif
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#if !defined(HAVE_SETLINEBUF) && !defined(setlinebuf)
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#define setlinebuf(f) setvbuf(f, NULL, _IOLBF, 0)
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#endif
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#define Fprintf (void)fprintf
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#define Sprintf (void)sprintf
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#define Printf (void)printf
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/*
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* format of a (udp) probe packet.
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*/
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struct opacket {
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struct ip ip;
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struct udphdr udp;
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u_char seq; /* sequence number of this packet */
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u_char ttl; /* ttl packet left with */
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struct timeval tv; /* time packet left */
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};
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u_char packet[512]; /* last inbound (icmp) packet */
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struct opacket *outpacket; /* last output (udp) packet */
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int s; /* receive (icmp) socket file descriptor */
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int sndsock; /* send (udp) socket file descriptor */
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struct sockaddr whereto; /* Who to try to reach */
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int datalen; /* How much data */
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char *source = 0;
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char *hostname;
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char hnamebuf[MAXHOSTNAMELEN];
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int nprobes = 3;
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int max_ttl = 30;
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u_short ident;
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u_short port = 32768+666; /* start udp dest port # for probe packets */
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int options; /* socket options */
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int verbose;
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int waittime = 5; /* time to wait for response (in seconds) */
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int nflag; /* print addresses numerically */
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char usage[] =
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"Usage: traceroute [-dnrv] [-w wait] [-m max_ttl] [-p port#] [-q nqueries] [-t tos] [-s src_addr] [-g gateway] host [data size]\n";
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/* Forwards */
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double deltaT(struct timeval *, struct timeval *);
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int main(int, char **);
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int wait_for_reply(int, struct sockaddr_in *, struct timeval *);
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void send_probe(int, int, struct timeval *);
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char *pr_type(u_char);
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int packet_ok(u_char *, int, struct sockaddr_in *, int);
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void print(u_char *, int, struct sockaddr_in *);
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void tvsub(struct timeval *, struct timeval *);
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char *inetname(struct in_addr);
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double
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deltaT(struct timeval *t1p, struct timeval *t2p)
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{
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register double dt;
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dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
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(double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
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return (dt);
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}
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int
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main(int argc, char **argv)
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{
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struct sockaddr_in from;
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char **av = argv;
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struct sockaddr_in *to = (struct sockaddr_in *) &whereto;
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int on = 1;
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struct protoent *pe;
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int ttl, probe, i;
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int seq = 0;
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int tos = 0;
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struct hostent *hp;
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int lsrr = 0;
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u_long gw;
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u_char optlist[MAX_IPOPTLEN], *oix;
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oix = optlist;
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bzero(optlist, sizeof(optlist));
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argc--, av++;
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while (argc && *av[0] == '-') {
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while (*++av[0])
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switch (*av[0]) {
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case 'd':
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options |= SO_DEBUG;
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break;
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case 'g':
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argc--, av++;
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if ((lsrr+1) >= ((MAX_IPOPTLEN-IPOPT_MINOFF)/sizeof(u_long))) {
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Fprintf(stderr,"No more than %d gateways\n",
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(u_int)((MAX_IPOPTLEN-IPOPT_MINOFF)/sizeof(u_long))-1);
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exit(1);
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}
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if (lsrr == 0) {
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*oix++ = IPOPT_LSRR;
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oix++; /* Fill in total length later */
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*oix++ = IPOPT_MINOFF; /* Pointer to LSRR addresses */
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}
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lsrr++;
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if (isdigit(*av[0])) {
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gw = inet_addr(*av);
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if (gw) {
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bcopy(&gw, oix, sizeof(u_long));
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} else {
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Fprintf(stderr, "Unknown host %s\n",av[0]);
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exit(1);
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}
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} else {
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hp = gethostbyname(av[0]);
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if (hp) {
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bcopy(hp->h_addr, oix, sizeof(u_long));
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} else {
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Fprintf(stderr, "Unknown host %s\n",av[0]);
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exit(1);
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}
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}
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oix += sizeof(u_long);
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goto nextarg;
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case 'm':
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argc--, av++;
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max_ttl = atoi(av[0]);
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if (max_ttl <= 1) {
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Fprintf(stderr, "max ttl must be >1\n");
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exit(1);
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}
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goto nextarg;
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case 'n':
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nflag++;
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break;
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case 'p':
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argc--, av++;
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port = atoi(av[0]);
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if (port < 1) {
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Fprintf(stderr, "port must be >0\n");
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exit(1);
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}
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goto nextarg;
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|
case 'q':
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argc--, av++;
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nprobes = atoi(av[0]);
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if (nprobes < 1) {
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Fprintf(stderr, "nprobes must be >0\n");
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exit(1);
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}
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goto nextarg;
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case 'r':
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options |= SO_DONTROUTE;
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break;
|
|
case 's':
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/*
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* set the ip source address of the outbound
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* probe (e.g., on a multi-homed host).
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*/
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argc--, av++;
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source = av[0];
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goto nextarg;
|
|
case 't':
|
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argc--, av++;
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tos = atoi(av[0]);
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if (tos < 0 || tos > 255) {
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Fprintf(stderr, "tos must be 0 to 255\n");
|
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exit(1);
|
|
}
|
|
goto nextarg;
|
|
case 'v':
|
|
verbose++;
|
|
break;
|
|
case 'w':
|
|
argc--, av++;
|
|
waittime = atoi(av[0]);
|
|
if (waittime <= 1) {
|
|
Fprintf(stderr, "wait must be >1 sec\n");
|
|
exit(1);
|
|
}
|
|
goto nextarg;
|
|
default:
|
|
Printf(usage);
|
|
exit(1);
|
|
}
|
|
nextarg:
|
|
argc--, av++;
|
|
}
|
|
if (argc != 1) {
|
|
Printf(usage);
|
|
exit(1);
|
|
}
|
|
setlinebuf (stdout);
|
|
|
|
bzero((char *)&whereto, sizeof(struct sockaddr));
|
|
to->sin_family = AF_INET;
|
|
to->sin_addr.s_addr = inet_addr(av[0]);
|
|
if (to->sin_addr.s_addr != -1) {
|
|
(void) strcpy(hnamebuf, av[0]);
|
|
hostname = hnamebuf;
|
|
} else {
|
|
hp = gethostbyname(av[0]);
|
|
if (hp) {
|
|
to->sin_family = hp->h_addrtype;
|
|
bcopy(hp->h_addr, (caddr_t)&to->sin_addr, hp->h_length);
|
|
hostname = strdup(hp->h_name);
|
|
} else {
|
|
Printf("%s: unknown host %s\n", argv[0], av[0]);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
if (argc >= 2)
|
|
datalen = atoi(av[1]);
|
|
if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) {
|
|
Fprintf(stderr, "traceroute: packet size must be 0 <= s < %d\n",
|
|
(u_int)(MAXPACKET - sizeof(struct opacket)));
|
|
exit(1);
|
|
}
|
|
datalen += sizeof(struct opacket);
|
|
outpacket = (struct opacket *)malloc((unsigned)datalen);
|
|
if (! outpacket) {
|
|
perror("traceroute: malloc");
|
|
exit(1);
|
|
}
|
|
bzero((char *)outpacket, datalen);
|
|
outpacket->ip.ip_dst = to->sin_addr;
|
|
outpacket->ip.ip_tos = tos;
|
|
outpacket->ip.ip_v = IPVERSION;
|
|
outpacket->ip.ip_hl = sizeof(struct ip) >> 2;
|
|
|
|
ident = (getpid() & 0xffff) | 0x8000;
|
|
|
|
if ((pe = getprotobyname("icmp")) == NULL) {
|
|
Fprintf(stderr, "icmp: unknown protocol\n");
|
|
exit(10);
|
|
}
|
|
if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) {
|
|
perror("traceroute: icmp socket");
|
|
exit(5);
|
|
}
|
|
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("traceroute: raw socket");
|
|
exit(5);
|
|
}
|
|
|
|
if (lsrr > 0) {
|
|
lsrr++;
|
|
optlist[IPOPT_OLEN]=IPOPT_MINOFF-1+(lsrr*sizeof(u_long));
|
|
bcopy((caddr_t)&to->sin_addr, oix, sizeof(u_long));
|
|
oix += sizeof(u_long);
|
|
while ((oix - optlist)&3) oix++; /* Pad to an even boundry */
|
|
|
|
if ((pe = getprotobyname("ip")) == NULL) {
|
|
perror("traceroute: unknown protocol ip\n");
|
|
exit(10);
|
|
}
|
|
#ifdef IP_OPTIONS
|
|
if ((setsockopt(sndsock, pe->p_proto, IP_OPTIONS, optlist, oix-optlist)) < 0) {
|
|
perror("traceroute: lsrr options");
|
|
exit(5);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#ifdef SO_SNDBUF
|
|
if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
|
|
sizeof(datalen)) < 0) {
|
|
perror("traceroute: SO_SNDBUF");
|
|
exit(6);
|
|
}
|
|
#endif SO_SNDBUF
|
|
#ifdef IP_HDRINCL
|
|
if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
|
|
sizeof(on)) < 0) {
|
|
perror("traceroute: IP_HDRINCL");
|
|
exit(6);
|
|
}
|
|
#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) {
|
|
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) {
|
|
Printf("traceroute: unknown host %s\n", source);
|
|
exit(1);
|
|
}
|
|
outpacket->ip.ip_src = from.sin_addr;
|
|
#ifndef IP_HDRINCL
|
|
if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) {
|
|
perror ("traceroute: bind:");
|
|
exit (1);
|
|
}
|
|
#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;
|
|
struct timeval t1, t2;
|
|
struct timezone tz;
|
|
struct ip *ip;
|
|
|
|
(void) gettimeofday(&t1, &tz);
|
|
send_probe(++seq, ttl, &t1);
|
|
while ((cc = wait_for_reply(s, &from, &t1)) != 0) {
|
|
(void) gettimeofday(&t2, &tz);
|
|
if ((i = packet_ok(packet, cc, &from, seq))) {
|
|
if (from.sin_addr.s_addr != lastaddr) {
|
|
print(packet, cc, &from);
|
|
lastaddr = from.sin_addr.s_addr;
|
|
}
|
|
Printf(" %.3f 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;
|
|
}
|
|
}
|
|
if (cc == 0)
|
|
Printf(" *");
|
|
(void) fflush(stdout);
|
|
}
|
|
putchar('\n');
|
|
if (got_there || unreachable >= nprobes-1)
|
|
exit(0);
|
|
}
|
|
exit(0);
|
|
}
|
|
|
|
int
|
|
wait_for_reply(int sock, struct sockaddr_in *from, struct timeval *sent)
|
|
{
|
|
fd_set fds;
|
|
struct timeval now, wait;
|
|
int cc = 0;
|
|
int fromlen = sizeof (*from);
|
|
|
|
FD_ZERO(&fds);
|
|
FD_SET(sock, &fds);
|
|
gettimeofday(&now, NULL);
|
|
wait.tv_sec = (sent->tv_sec + waittime) - now.tv_sec;
|
|
wait.tv_usec = sent->tv_usec - now.tv_usec;
|
|
if (wait.tv_usec < 0) {
|
|
wait.tv_usec += 1000000;
|
|
wait.tv_sec--;
|
|
}
|
|
if (wait.tv_sec < 0)
|
|
wait.tv_sec = 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);
|
|
}
|
|
|
|
|
|
void
|
|
send_probe(int seq, int ttl, struct timeval *tp)
|
|
{
|
|
struct opacket *op = outpacket;
|
|
struct ip *ip = &op->ip;
|
|
struct udphdr *up = &op->udp;
|
|
int i;
|
|
|
|
ip->ip_off = 0;
|
|
ip->ip_p = IPPROTO_UDP;
|
|
ip->ip_len = datalen;
|
|
ip->ip_ttl = ttl;
|
|
|
|
up->uh_sport = htons(ident);
|
|
up->uh_dport = htons(port+seq);
|
|
up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip)));
|
|
up->uh_sum = 0;
|
|
|
|
op->seq = seq;
|
|
op->ttl = ttl;
|
|
op->tv = *tp;
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Convert an ICMP "type" field to a printable string.
|
|
*/
|
|
char *
|
|
pr_type(u_char t)
|
|
{
|
|
static char *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]);
|
|
}
|
|
|
|
|
|
int
|
|
packet_ok(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->uh_sport == htons(ident) &&
|
|
up->uh_dport == 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);
|
|
}
|
|
|
|
|
|
void
|
|
print(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));
|
|
}
|
|
|
|
|
|
#ifdef notyet
|
|
/*
|
|
* Checksum routine for Internet Protocol family headers (C Version)
|
|
*/
|
|
in_cksum(u_short *addr, int len)
|
|
{
|
|
register int nleft = len;
|
|
register u_short *w = addr;
|
|
register u_short answer;
|
|
register int sum = 0;
|
|
|
|
/*
|
|
* Our algorithm is simple, using a 32 bit accumulator (sum),
|
|
* we add sequential 16 bit words to it, and at the end, fold
|
|
* back all the carry bits from the top 16 bits into the lower
|
|
* 16 bits.
|
|
*/
|
|
while (nleft > 1) {
|
|
sum += *w++;
|
|
nleft -= 2;
|
|
}
|
|
|
|
/* mop up an odd byte, if necessary */
|
|
if (nleft == 1)
|
|
sum += *(u_char *)w;
|
|
|
|
/*
|
|
* add back carry outs from top 16 bits to low 16 bits
|
|
*/
|
|
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
|
|
sum += (sum >> 16); /* add carry */
|
|
answer = ~sum; /* truncate to 16 bits */
|
|
return (answer);
|
|
}
|
|
#endif notyet
|
|
|
|
/*
|
|
* Subtract 2 timeval structs: out = out - in.
|
|
* Out is assumed to be >= in.
|
|
*/
|
|
void
|
|
tvsub(register struct timeval *out, register struct timeval *in)
|
|
{
|
|
if ((out->tv_usec -= in->tv_usec) < 0) {
|
|
out->tv_sec--;
|
|
out->tv_usec += 1000000;
|
|
}
|
|
out->tv_sec -= in->tv_sec;
|
|
}
|
|
|
|
|
|
/*
|
|
* Construct an Internet address representation.
|
|
* If the nflag has been supplied, give
|
|
* numeric value, otherwise try for symbolic name.
|
|
*/
|
|
char *
|
|
inetname(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 = strchr(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 = strchr(hp->h_name, '.')) &&
|
|
!strcmp(cp + 1, domain))
|
|
*cp = 0;
|
|
cp = hp->h_name;
|
|
}
|
|
}
|
|
if (cp)
|
|
(void) strcpy(line, cp);
|
|
else {
|
|
in.s_addr = ntohl(in.s_addr);
|
|
#define C(x) ((x) & 0xff)
|
|
Sprintf(line, "%lu.%lu.%lu.%lu", C(in.s_addr >> 24),
|
|
C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr));
|
|
}
|
|
return (line);
|
|
}
|