You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
22 years ago
|
#include "stralloc.h"
|
||
|
|
#include "byte.h"
|
||
|
|
#include "uint16.h"
|
||
|
|
#include "dns.h"
|
||
|
|
|
||
|
|
static char *q = 0;
|
||
|
|
|
||
|
|
int dns_mx_packet(stralloc *out,const char *buf,unsigned int len)
|
||
|
|
{
|
||
|
|
unsigned int pos;
|
||
|
|
char header[12];
|
||
|
|
char pref[2];
|
||
|
|
uint16 numanswers;
|
||
|
|
uint16 datalen;
|
||
|
|
|
||
|
|
if (!stralloc_copys(out,"")) return -1;
|
||
|
|
|
||
|
|
pos = dns_packet_copy(buf,len,0,header,12); if (!pos) return -1;
|
||
|
|
uint16_unpack_big(header + 6,&numanswers);
|
||
|
|
pos = dns_packet_skipname(buf,len,pos); if (!pos) return -1;
|
||
|
|
pos += 4;
|
||
|
|
|
||
|
|
while (numanswers--) {
|
||
|
|
pos = dns_packet_skipname(buf,len,pos); if (!pos) return -1;
|
||
|
|
pos = dns_packet_copy(buf,len,pos,header,10); if (!pos) return -1;
|
||
|
|
uint16_unpack_big(header + 8,&datalen);
|
||
|
|
if (byte_equal(header,2,DNS_T_MX))
|
||
|
|
if (byte_equal(header + 2,2,DNS_C_IN)) {
|
||
|
|
if (!dns_packet_copy(buf,len,pos,pref,2)) return -1;
|
||
|
|
if (!dns_packet_getname(buf,len,pos + 2,&q)) return -1;
|
||
|
|
if (!stralloc_catb(out,pref,2)) return -1;
|
||
|
|
if (!dns_domain_todot_cat(out,q)) return -1;
|
||
|
|
if (!stralloc_0(out)) return -1;
|
||
|
|
}
|
||
|
|
pos += datalen;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int dns_mx(stralloc *out,const stralloc *fqdn)
|
||
|
|
{
|
||
|
|
if (!dns_domain_fromdot(&q,fqdn->s,fqdn->len)) return -1;
|
||
|
|
if (dns_resolve(q,DNS_T_MX) == -1) return -1;
|
||
|
|
if (dns_mx_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen) == -1) return -1;
|
||
|
|
dns_transmit_free(&dns_resolve_tx);
|
||
|
|
dns_domain_free(&q);
|
||
|
|
return 0;
|
||
|
|
}
|