That was the problem. I wasn't aware order of declaration mattered, but apparently it does when dealing with scripts. The declaration of my FromDump elements was after the declaration of my Script element in the configuration. I moved the FromDump elements above my Script declaration and filepos now reports "24". Thanks!
Robert Ross DSCI Inc. Office: 732.542.3113 x173 Home: 609.702.8114 Cell: 609.509.5139 Fax: 253.550.6198 -----Original Message----- From: Beyers Cronje [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 20, 2007 11:07 AM To: Robert Ross Cc: Eddie Kohler; [EMAIL PROTECTED] Subject: Re: [Click] FromDump restart Hi Robert, Running your config below and pcap file I get: click conf/fromdump.click First Offset: 24 1194550918.323930: 66 | 00180125 a9fb0017 3f525f52 08004500 0034829e 40003006 1194550918.384094: 54 | 00180125 a9fb0017 3f525f52 08004500 0028829f 40003006 1194550918.444360: 66 | 00180125 a9fb0017 3f525f52 08004500 003482a4 40003006 ...... I'm running git version from a few weeks back. I wonder if it is possible that your script element is getting initialized before your FromDump element? Beyers On Nov 20, 2007 4:25 PM, Robert Ross <[EMAIL PROTECTED]> wrote: > I tried this and, as I said before, the position returned is "0": > > fd::FromDump(/tmp/foo.trace, > TIMING true, FORCE_IP false, ACTIVE false, END_CALL > restarter.step) > -> Print(TIMESTAMP true) -> Discard; > > restarter::Script(init first_offset $(fd.filepos), > print "First Offset: " $first_offset , > write fd.active true, > pause, > write fd.filepos $first_offset, > write fd.reset_timing, > loop) > > > This prints: > > First Offset: 0 > > > > Robert Ross > DSCI Inc. > Office: 732.542.3113 x173 > Home: 609.702.8114 > Cell: 609.509.5139 > Fax: 253.550.6198 > > -----Original Message----- > From: Eddie Kohler [mailto:[EMAIL PROTECTED] > Sent: Monday, November 19, 2007 1:38 PM > To: Robert Ross > Cc: click@amsterdam.lcs.mit.edu > Subject: Re: [Click] FromDump restart > > I think you did not try this, because it should have worked, but who > knows? I checked in an update so that TIMING and FORCE_IP are > compatible, and added a "FromDump::reset_timing" handler so that you > can reset timing information when looping back into the file. > > fd::FromDump(/tmp/foo.trace, > TIMING true, FORCE_IP false, ACTIVE false, END_CALL > restarter.step) > -> Print(TIMESTAMP true) -> Discard; > > restarter::Script(init first_offset $(fd.filepos), > write fd.active true, > pause, > write fd.filepos $first_offset, > write fd.reset_timing, > loop) > > > Eddie > > > Robert Ross wrote: > > > > I thought I had tried this already. When I tried it, fd.filepose > > returned "0" as the starting position. The only difference I see is > > that I did not use "FORCE_IP true" because need to use the "TIMING" > > keyword. The two are apparently mutually exclusive. > > > > Robert Ross > > DSCI Inc. > > Office: 732.542.3113 x173 > > Home: 609.702.8114 > > Cell: 609.509.5139 > > Fax: 253.550.6198 > > > > -----Original Message----- > > From: Eddie Kohler [mailto:[EMAIL PROTECTED] > > Sent: Saturday, November 17, 2007 10:03 PM > > To: Robert Ross > > Cc: click@amsterdam.lcs.mit.edu > > Subject: Re: [Click] FromDump restart > > > > Hi Robert, > > > > The problem with filepos is that filepos=0 is the pcap file header. > > You need to set it to the first byte of actual packet data, which > > might be > > 24 or 28 depending on pcap version. > > > > This script works for me. It relies on the fact that FromDump skips > > the header at initialization time, but does not actually read any > > packets until ACTIVE is true. > > > > > > fd::FromDump(~/src/ipsumdump/test/one-byte-payload.trace, > > FORCE_IP true, ACTIVE false, END_CALL restarter.step) > > -> IPPrint -> Discard; > > > > restarter::Script(init first_offset $(fd.filepos), > > write fd.active true, > > pause, > > write fd.filepos $first_offset, > > loop) > > > > > > Eddie > > > > > > Robert Ross wrote: > >> I'm trying to use a Script element along with a FromDump to loop a > > small PCAP file several times with a delay between replays. The > > script basically works except for one critical element: I cannot > > seem > > > to reset the FromDump "filepos" handler to the beginning of the file. > > > As indicated in the documentation, the issue appears to be > > determining > > > the correct byte offset for the beginning of the first packet in the > file. > > I've tried the following with no luck: > >> > >> 1. Setting filepos=0. If only it were that simple... > >> 2. Wait until the first packet has come out and "poke" the script > > using a Counter element. Then use the script to calculate various > > starting positions using a combination of read handlers from > > FromDump and Counter. > >> > >> Some of the questions I have are: > >> > >> 1. Both packet_filepos and filepos provide byte offsets, but the > > documentation does not adequately describe what these offsets > represent. > > Is packet_filepos the end point of the last packet read? The start > > point of the last packet read? The start point of the next packet > > to be read? Something else? What is the difference between filepos > > and packet_filepos? > >> 2. Is there another simpler way to loop a PCAP file that I'm > missing? > >> 3. Assuming I knew the correct offset, is it even possible to > >> reset > > the filepos and re-play the PCAP file again? > >> > >> As a general suggestion, added LOOP and LOOP_INTERVAL keywords to > >> the > > various dump elements could be extremely useful. In the absence of > > those, at the very least a "restart" or "start_pos" handler would be > > equally useful. I'm currently wondering why the "filepos" handler > > is even writeable... > >> > >> Thanks, > >> Robert A. Ross > >> DSCI Inc. > >> 609-509-5139 > >> _______________________________________________ > >> click mailing list > >> click@amsterdam.lcs.mit.edu > >> https://amsterdam.lcs.mit.edu/mailman/listinfo/click > > _______________________________________________ > click mailing list > click@amsterdam.lcs.mit.edu > https://amsterdam.lcs.mit.edu/mailman/listinfo/click > _______________________________________________ click mailing list click@amsterdam.lcs.mit.edu https://amsterdam.lcs.mit.edu/mailman/listinfo/click
