printpacket.c

   1 #include "uint16.h"
   2 #include "uint32.h"
   3 #include "error.h"
   4 #include "byte.h"
   5 #include "dns.h"
   6 #include "printrecord.h"
   7 #include "printpacket.h"
   8
   9 static char *d;
  10
  11 #define X(s) if (!stralloc_cats(out,s)) return 0;
  12 #define NUM(u) if (!stralloc_catulong0(out,u,0)) return 0;
  13
  14 unsigned int printpacket_cat(stralloc *out,char *buf,unsigned int len)
  15 {
  16   uint16 numqueries;
  17   uint16 numanswers;
  18   uint16 numauthority;
  19   uint16 numglue;
  20   unsigned int pos;
  21   char data[12];
  22   uint16 type;
  23
  24   pos = dns_packet_copy(buf,len,0,data,12); if (!pos) return 0;
  25
  26   uint16_unpack_big(data + 4,&numqueries);
  27   uint16_unpack_big(data + 6,&numanswers);
  28   uint16_unpack_big(data + 8,&numauthority);
  29   uint16_unpack_big(data + 10,&numglue);
  30
  31   NUM(len)
  32   X(" bytes, ")
  33   NUM(numqueries)
  34   X("+")
  35   NUM(numanswers)
  36   X("+")
  37   NUM(numauthority)
  38   X("+")
  39   NUM(numglue)
  40   X(" records")
  41
  42   if (data[2] & 128) X(", response")
  43   if (data[2] & 120) X(", weird op")
  44   if (data[2] & 4) X(", authoritative")
  45   if (data[2] & 2) X(", truncated")
  46   if (data[2] & 1) X(", weird rd")
  47   if (data[3] & 128) X(", weird ra")
  48   switch(data[3] & 15) {
  49     case 0: X(", noerror"); break;
  50     case 3: X(", nxdomain"); break;
  51     case 4: X(", notimp"); break;
  52     case 5: X(", refused"); break;
  53     default: X(", weird rcode");
  54   }
  55   if (data[3] & 112) X(", weird z")
  56
  57   X("\n")
  58
  59   while (numqueries) {
  60     --numqueries;
  61     X("query: ")
  62
  63     pos = dns_packet_getname(buf,len,pos,&d); if (!pos) return 0;
  64     pos = dns_packet_copy(buf,len,pos,data,4); if (!pos) return 0;
  65
  66     if (byte_diff(data + 2,2,DNS_C_IN)) {
  67       X("weird class")
  68     }
  69     else {
  70       uint16_unpack_big(data,&type);
  71       NUM(type)
  72       X(" ")
  73       if (!dns_domain_todot_cat(out,d)) return 0;
  74     }
  75     X("\n")
  76   }
  77
  78   for (;;) {
  79     if (numanswers) { --numanswers; X("answer: ") }
  80     else if (numauthority) { --numauthority; X("authority: ") }
  81     else if (numglue) { --numglue; X("additional: ") }
  82     else break;
  83
  84     pos = printrecord_cat(out,buf,len,pos,0,0);
  85     if (!pos) return 0;
  86   }
  87
  88   if (pos != len) { errno = error_proto; return 0; }
  89   return 1;
  90 }