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#include "stralloc.h"
#include "uint16.h"
#include "byte.h"
#include "dns.h"
int dns_ip4_packet(stralloc *out,char *buf,unsigned int len)
{
unsigned int pos;
char header[12];
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_A))
if (byte_equal(header + 2,2,DNS_C_IN))
if (datalen == 4) {
if (!dns_packet_copy(buf,len,pos,header,4)) return -1;
if (!stralloc_catb(out,header,4)) return -1;
}
pos += datalen;
}
dns_sortip(out->s,out->len);
return 0;
}
static char *q = 0;
int dns_ip4(stralloc *out,stralloc *fqdn)
{
unsigned int i;
char code;
char ch;
if (!stralloc_copys(out,"")) return -1;
code = 0;
for (i = 0;i <= fqdn->len;++i) {
if (i < fqdn->len)
ch = fqdn->s[i];
else
ch = '.';
if ((ch == '[') || (ch == ']')) continue;
if (ch == '.') {
if (!stralloc_append(out,&code)) return -1;
code = 0;
continue;
}
if ((ch >= '0') && (ch <= '9')) {
code *= 10;
code += ch - '0';
continue;
}
if (!dns_domain_fromdot(&q,fqdn->s,fqdn->len)) return -1;
if (dns_resolve(q,DNS_T_A) == -1) return -1;
if (dns_ip4_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;
}
out->len &= ~3;
return 0;
}
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