int dns_ip4_packet(stralloc *out,const 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 int doit(char *q,char qtype[2],char ip[4])
{
int r;
uint32 dlen;
unsigned int qlen;
qlen = dns_domain_length(q);
if (qlen > 255) return 0; /* impossible */
if (byte_diff(qtype,2,DNS_T_A) && byte_diff(qtype,2,DNS_T_ANY)) goto REFUSE;
key[0] = '%';
byte_copy(key + 1,4,ip);
r = cdb_find(&c,key,5);
if (!r) r = cdb_find(&c,key,4);
if (!r) r = cdb_find(&c,key,3);
if (!r) r = cdb_find(&c,key,2);
if (r == -1) return 0;
key[0] = '+';
byte_zero(key + 1,2);
if (r && (cdb_datalen(&c) == 2))
if (cdb_read(&c,key + 1,2,cdb_datapos(&c)) == -1) return 0;
byte_copy(key + 3,qlen,q);
case_lowerb(key + 3,qlen + 3);
r = cdb_find(&c,key,qlen + 3);
if (!r) {
byte_zero(key + 1,2);
r = cdb_find(&c,key,qlen + 3);
}
if (!r) goto REFUSE;
if (r == -1) return 0;
dlen = cdb_datalen(&c);
if (dlen > 512) dlen = 512;
if (cdb_read(&c,data,dlen,cdb_datapos(&c)) == -1) return 0;
dns_sortip(data,dlen);
if (dlen > 12) dlen = 12;
while (dlen >= 4) {
dlen -= 4;
if (!response_rstart(q,DNS_T_A,"\0\0\0\5")) return 0;
if (!response_addbytes(data + dlen,4)) return 0;
response_rfinish(RESPONSE_ANSWER);
}
return 1;
REFUSE:
response[2] &= ~4;
response[3] &= ~15;
response[3] |= 5;
return 1;
}
