Re: tcpdump 3.4 bug?

From: acpizer (acpizerat_private)
Date: Thu Jun 17 1999 - 04:19:06 PDT

  • Next message: Raymond Dijkxhoorn: "[RHSA-1999:013-02] New XFree86 packages (updated) (fwd)"

    The given source for killing tcpdump will only work on local networks
    since routers drop the bad packet it creates, a more constuctive patch for
    tcpdump is listed below.
    
    -- snip --
    diff -r -p print-ip.orig.c print-ip.c
    *** print-ip.orig.c     Thu Jun 17 11:24:17 1999
    --- print-ip.c  Thu Jun 17 14:07:50 1999
    *************** ip_print(register const u_char *bp, regi
    *** 374,379 ****
    --- 374,384 ----
                    (void)printf("truncated-ip %d", length);
                    return;
            }
    +
    +         if (ip->ip_hl == 0) {
    +                 (void)printf("bad ip packet - header length = 0\n");
    +                 return;
    +         }
            hlen = ip->ip_hl * 4;
    
            len = ntohs(ip->ip_len);
    -- snip --
    
     Cheers.
    
    -------------------------------------------------------------------------------
    "Probably you've only really grown up, when you can bear not being understood."
    
                                  Marian Gold /Alphaville
    



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