/*
* Fill the hostent from the given DNS packet.
*/
static int
hostent_from_packet(struct hostent *h, int action, char *pkt, size_t pktlen)
{
struct packed p;
struct header hdr;
struct query q;
struct rr rr;
int r;
packed_init(&p, pkt, pktlen);
unpack_header(&p, &hdr);
for(; hdr.qdcount; hdr.qdcount--)
unpack_query(&p, &q);
for(; hdr.ancount; hdr.ancount--) {
unpack_rr(&p, &rr);
if (rr.rr_class != C_IN)
continue;
switch (rr.rr_type) {
case T_CNAME:
if (action == ASR_GETHOSTBYNAME)
r = hostent_add_alias(h, rr.rr_dname, 1);
else
r = hostent_set_cname(h, rr.rr_dname, 1);
break;
case T_PTR:
if (action != ASR_GETHOSTBYADDR)
continue;
r = hostent_set_cname(h, rr.rr.ptr.ptrname, 1);
/* XXX See if we need MULTI_PTRS_ARE_ALIASES */
break;
case T_A:
if (h->h_addrtype != AF_INET)
break;
r = hostent_set_cname(h, rr.rr_dname, 1);
r = hostent_add_addr(h, &rr.rr.in_a.addr, 4);
break;
case T_AAAA:
if (h->h_addrtype != AF_INET6)
break;
r = hostent_set_cname(h, rr.rr_dname, 1);
r = hostent_add_addr(h, &rr.rr.in_aaaa.addr6, 16);
break;
}
}
return (0);
}
static void
dns_dispatch_mx_preference(struct asr_result *ar, void *arg)
{
struct dns_session *s = arg;
struct unpack pack;
struct dns_header h;
struct dns_query q;
struct dns_rr rr;
char buf[512];
int error;
if (ar->ar_h_errno) {
if (ar->ar_rcode == NXDOMAIN)
error = DNS_ENONAME;
else if (ar->ar_h_errno == NO_RECOVERY
|| ar->ar_h_errno == NO_DATA)
error = DNS_EINVAL;
else
error = DNS_RETRY;
}
else {
error = DNS_ENOTFOUND;
unpack_init(&pack, ar->ar_data, ar->ar_datalen);
if (unpack_header(&pack, &h) != -1 &&
unpack_query(&pack, &q) != -1) {
for (; h.ancount; h.ancount--) {
if (unpack_rr(&pack, &rr) == -1)
break;
if (rr.rr_type != T_MX)
continue;
print_dname(rr.rr.mx.exchange, buf, sizeof(buf));
buf[strlen(buf) - 1] = '\0';
if (!strcasecmp(s->name, buf)) {
error = DNS_OK;
break;
}
}
}
}
free(ar->ar_data);
m_create(s->p, IMSG_MTA_DNS_MX_PREFERENCE, 0, 0, -1);
m_add_id(s->p, s->reqid);
m_add_int(s->p, error);
if (error == DNS_OK)
m_add_int(s->p, rr.rr.mx.preference);
m_close(s->p);
free(s);
}
static void
dns_dispatch_mx(struct asr_result *ar, void *arg)
{
struct dns_session *s = arg;
struct unpack pack;
struct dns_header h;
struct dns_query q;
struct dns_rr rr;
char buf[512];
size_t found;
if (ar->ar_h_errno && ar->ar_h_errno != NO_DATA) {
m_create(s->p, IMSG_MTA_DNS_HOST_END, 0, 0, -1);
m_add_id(s->p, s->reqid);
if (ar->ar_rcode == NXDOMAIN)
m_add_int(s->p, DNS_ENONAME);
else if (ar->ar_h_errno == NO_RECOVERY)
m_add_int(s->p, DNS_EINVAL);
else
m_add_int(s->p, DNS_RETRY);
m_close(s->p);
free(s);
free(ar->ar_data);
return;
}
found = 0;
unpack_init(&pack, ar->ar_data, ar->ar_datalen);
if (unpack_header(&pack, &h) == -1 || unpack_query(&pack, &q) == -1)
return;
for (; h.ancount; h.ancount--) {
if (unpack_rr(&pack, &rr) == -1)
break;
if (rr.rr_type != T_MX)
continue;
print_dname(rr.rr.mx.exchange, buf, sizeof(buf));
buf[strlen(buf) - 1] = '\0';
dns_lookup_host(s, buf, rr.rr.mx.preference);
found++;
}
free(ar->ar_data);
/* fallback to host if no MX is found. */
if (found == 0)
dns_lookup_host(s, s->name, 0);
}
/*
* Fill the hostent from the given DNS packet.
*/
static struct hostent *
hostent_from_packet(int reqtype, int family, char *pkt, size_t pktlen)
{
struct hostent *h;
struct packed p;
struct header hdr;
struct query q;
struct rr rr;
if ((h = hostent_alloc(family)) == NULL)
return (NULL);
packed_init(&p, pkt, pktlen);
unpack_header(&p, &hdr);
for(; hdr.qdcount; hdr.qdcount--)
unpack_query(&p, &q);
for(; hdr.ancount; hdr.ancount--) {
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 (hostent_set_cname(h, rr.rr_dname, 1) == -1)
goto fail;
}
break;
case T_PTR:
if (reqtype != ASR_GETHOSTBYADDR)
break;
if (hostent_set_cname(h, rr.rr.ptr.ptrname, 1) == -1)
goto fail;
/* XXX See if we need MULTI_PTRS_ARE_ALIASES */
break;
case T_A:
if (reqtype != ASR_GETHOSTBYNAME)
break;
if (family != AF_INET)
break;
if (hostent_set_cname(h, rr.rr_dname, 1) == -1)
goto fail;
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)
goto fail;
if (hostent_add_addr(h, &rr.rr.in_aaaa.addr6, 16) == -1)
goto fail;
break;
}
}
return (h);
fail:
free(h);
return (NULL);
}
