static int
addrinfo_from_pkt(struct asr_query *as, char *pkt, size_t pktlen)
{
struct asr_unpack p;
struct asr_dns_header h;
struct asr_dns_query q;
struct asr_dns_rr rr;
int i;
union {
struct sockaddr sa;
struct sockaddr_in sain;
struct sockaddr_in6 sain6;
} u;
char buf[MAXDNAME], *c;
_asr_unpack_init(&p, pkt, pktlen);
_asr_unpack_header(&p, &h);
for (; h.qdcount; h.qdcount--)
_asr_unpack_query(&p, &q);
for (i = 0; i < h.ancount; i++) {
_asr_unpack_rr(&p, &rr);
if (rr.rr_type != q.q_type ||
rr.rr_class != q.q_class)
continue;
memset(&u, 0, sizeof u);
if (rr.rr_type == T_A) {
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
u.sain.sin_len = sizeof u.sain;
#endif
u.sain.sin_family = AF_INET;
u.sain.sin_addr = rr.rr.in_a.addr;
u.sain.sin_port = 0;
} else if (rr.rr_type == T_AAAA) {
#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_LEN
u.sain6.sin6_len = sizeof u.sain6;
#endif
u.sain6.sin6_family = AF_INET6;
u.sain6.sin6_addr = rr.rr.in_aaaa.addr6;
u.sain6.sin6_port = 0;
} else
continue;
if (as->as.ai.hints.ai_flags & AI_CANONNAME) {
_asr_strdname(rr.rr_dname, buf, sizeof buf);
buf[strlen(buf) - 1] = '\0';
c = res_hnok(buf) ? buf : NULL;
} else if (as->as.ai.hints.ai_flags & AI_FQDN)
c = as->as.ai.fqdn;
else
c = NULL;
if (addrinfo_add(as, &u.sa, c))
return (-1); /* errno set */
}
return (0);
}
/*
* Fill the hostent from the given DNS packet.
*/
static struct hostent_ext *
hostent_from_packet(int reqtype, int family, char *pkt, size_t pktlen)
{
struct hostent_ext *h;
struct asr_unpack p;
struct asr_dns_header hdr;
struct asr_dns_query q;
struct asr_dns_rr rr;
char dname[MAXDNAME];
if ((h = hostent_alloc(family)) == NULL)
return (NULL);
_asr_unpack_init(&p, pkt, pktlen);
_asr_unpack_header(&p, &hdr);
for (; hdr.qdcount; hdr.qdcount--)
_asr_unpack_query(&p, &q);
strlcpy(dname, q.q_dname, sizeof(dname));
for (; hdr.ancount; hdr.ancount--) {
_asr_unpack_rr(&p, &rr);
if (rr.rr_class != C_IN)
continue;
switch (rr.rr_type) {
case T_CNAME:
if (reqtype == ASR_GETHOSTBYNAME) {
if (hostent_add_alias(h, rr.rr_dname, 1) == -1)
goto fail;
} else {
if (strcasecmp(rr.rr_dname, dname) == 0)
strlcpy(dname, rr.rr.cname.cname,
sizeof(dname));
}
break;
case T_PTR:
if (reqtype != ASR_GETHOSTBYADDR)
break;
if (strcasecmp(rr.rr_dname, dname) != 0)
continue;
if (hostent_set_cname(h, rr.rr.ptr.ptrname, 1) == -1)
hostent_add_alias(h, rr.rr.ptr.ptrname, 1);
break;
case T_A:
if (reqtype != ASR_GETHOSTBYNAME)
break;
if (family != AF_INET)
break;
if (hostent_set_cname(h, rr.rr_dname, 1) == -1)
;
if (hostent_add_addr(h, &rr.rr.in_a.addr, 4) == -1)
goto fail;
break;
case T_AAAA:
if (reqtype != ASR_GETHOSTBYNAME)
break;
if (family != AF_INET6)
break;
if (hostent_set_cname(h, rr.rr_dname, 1) == -1)
;
if (hostent_add_addr(h, &rr.rr.in_aaaa.addr6, 16) == -1)
goto fail;
break;
}
}
return (h);
fail:
free(h);
return (NULL);
}