dnsmx.c

   1 #include "buffer.h"
   2 #include "exit.h"
   3 #include "strerr.h"
   4 #include "uint16.h"
   5 #include "byte.h"
   6 #include "str.h"
   7 #include "fmt.h"
   8 #include "dns.h"
   9
  10 #define FATAL "dnsmx: fatal: "
  11
  12 void nomem(void)
  13 {
  14   strerr_die2x(111,FATAL,"out of memory");
  15 }
  16
  17 static char seed[128];
  18
  19 static stralloc fqdn;
  20 static char *q;
  21 static stralloc out;
  22 char strnum[FMT_ULONG];
  23
  24 int main(int argc,char **argv)
  25 {
  26   int i;
  27   int j;
  28   uint16 pref;
  29
  30   dns_random_init(seed);
  31
  32   if (*argv) ++argv;
  33
  34   while (*argv) {
  35     if (!stralloc_copys(&fqdn,*argv)) nomem();
  36     if (dns_mx(&out,&fqdn) == -1)
  37       strerr_die4sys(111,FATAL,"unable to find MX records for ",*argv,": ");
  38
  39     if (!out.len) {
  40       if (!dns_domain_fromdot(&q,*argv,str_len(*argv))) nomem();
  41       if (!stralloc_copys(&out,"0 ")) nomem();
  42       if (!dns_domain_todot_cat(&out,q)) nomem();
  43       if (!stralloc_cats(&out,"\n")) nomem();
  44       buffer_put(buffer_1,out.s,out.len);
  45     }
  46     else {
  47       i = 0;
  48       while (i + 2 < out.len) {
  49         j = byte_chr(out.s + i + 2,out.len - i - 2,0);
  50         uint16_unpack_big(out.s + i,&pref);
  51         buffer_put(buffer_1,strnum,fmt_ulong(strnum,pref));
  52         buffer_puts(buffer_1," ");
  53         buffer_put(buffer_1,out.s + i + 2,j);
  54         buffer_puts(buffer_1,"\n");
  55         i += j + 3;
  56       }
  57     }
  58
  59     ++argv;
  60   }
  61
  62   buffer_flush(buffer_1);
  63   _exit(0);
  64 }