Thanks, useful(at least for me). On Apr 5, 2011, at 5:57 PM, Stuart Henderson wrote:
> On 2011/04/05 16:51, Stuart Henderson wrote: >> if -t is used, display a notice when the TOS changes en-route. >> ok? > > oh, it's better with a (contrived) example: > > $ traceroute -nt 7 naiad > traceroute to naiad.spacehopper.org (195.95.187.35), 64 hops max, 40 byte packets > 1 85.158.44.145 0.441 ms (TOS=33!) 0.328 ms 0.396 ms > 2 193.178.223.245 14.637 ms 15.213 ms 15.466 ms > 3 194.39.143.145 16.600 ms 15.468 ms 16.206 ms > 4 194.39.143.205 16.483 ms 16.210 ms 15.843 ms > 5 193.203.5.182 17.475 ms 16.708 ms 16.986 ms > 6 195.95.187.248 17.211 ms (TOS=4!) 16.460 ms 16.468 ms > 7 195.95.187.35 27.99 ms 16.207 ms 17.467 ms > > > >> Index: traceroute.8 >> =================================================================== >> RCS file: /cvs/src/usr.sbin/traceroute/traceroute.8,v >> retrieving revision 1.44 >> diff -u -p -r1.44 traceroute.8 >> --- traceroute.8 8 Jul 2010 20:23:03 -0000 1.44 >> +++ traceroute.8 5 Apr 2011 15:50:38 -0000 >> @@ -177,6 +177,8 @@ in probe packets to the following value >> The value must be a decimal integer in the range 0 to 255. >> This option can be used to >> see if different types-of-service result in different paths. >> +If this option is used, changes to the type-of-service in the >> +returned packets are displayed. >> (If you are not running a >> .Bx 4.3 tahoe >> or later system, this may be academic since the normal network >> @@ -384,6 +386,8 @@ ever occur and the associated gateway is >> (destination network or host unreachable for TOS), >> .Sy !<code> >> (other ICMP unreachable code). >> +.Sy TOS=xxx >> +(TOS bit in returned packet differs from last hop). >> If almost all the probes result in some kind of unreachable, >> .Nm >> will give up and exit. >> Index: traceroute.c >> =================================================================== >> RCS file: /cvs/src/usr.sbin/traceroute/traceroute.c,v >> retrieving revision 1.74 >> diff -u -p -r1.74 traceroute.c >> --- traceroute.c 22 Mar 2011 10:16:23 -0000 1.74 >> +++ traceroute.c 5 Apr 2011 15:50:38 -0000 >> @@ -293,11 +293,13 @@ main(int argc, char *argv[]) >> int mib[4] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_DEFTTL }; >> int ttl_flag = 0, incflag = 1, protoset = 0, sump = 0; >> int ch, i, lsrr = 0, on = 1, probe, seq = 0, tos = 0; >> + int last_tos, tos_returned; >> size_t size = sizeof(max_ttl); >> struct sockaddr_in from, to; >> struct hostent *hp; >> u_int32_t tmprnd; >> - struct ip *ip; >> + struct ip *ip, *inner_ip; >> + struct icmp *icp; >> u_int8_t ttl; >> char *ep; >> const char *errstr; >> @@ -427,7 +429,7 @@ main(int argc, char *argv[]) >> l = strtol(optarg, &ep, 10); >> if (errno || !*optarg || *ep || l < 0 || l > 255) >> errx(1, "tos must be 0 to 255."); >> - tos = (int)l; >> + last_tos = tos = (int)l; >> break; >> case 'v': >> verbose++; >> @@ -636,9 +638,21 @@ main(int argc, char *argv[]) >> ++got_there; >> break; >> } >> + >> + icp = (struct icmp *) (((u_char >> *)ip)+(ip->ip_hl<<2)); >> + inner_ip = (struct ip *) (((u_char *)icp)+8); >> + >> + tos_returned = inner_ip->ip_tos; >> + >> + if (tos_returned != last_tos) >> + printf (" (TOS=%d!)", tos_returned); >> + >> + last_tos = tos_returned; >> + >> /* time exceeded in transit */ >> if (i == -1) >> break; >> + >> code = i - 1; >> switch (code) { >> case ICMP_UNREACH_PORT: