DNS_STATUS DnsQuery_A(const char * service,
unsigned short requestType,
unsigned long options,
void *,
DNS_RECORD * results,
void *)
{
if (results == 0)
return -1;
*results = 0;
struct __res_state statbuf;
res_ninit(&statbuf);
union {
HEADER hdr;
unsigned char buf[PACKETSZ];
} reply;
int replyLen = res_nsearch(&statbuf, service, C_IN, requestType, (unsigned char *)&reply, sizeof(reply));
if (replyLen < 1)
return -1;
unsigned char * replyStart = reply.buf;
unsigned char * replyEnd = reply.buf + replyLen;
unsigned char * cp = reply.buf + sizeof(HEADER);
// ignore questions in response
uint16_t i;
for (i = 0; i < ntohs(reply.hdr.qdcount); i++) {
char qName[MAXDNAME];
if (!GetDN(replyStart, replyEnd, cp, qName))
return -1;
cp += QFIXEDSZ;
}
if (!ProcessDNSRecords(
replyStart,
replyEnd,
cp,
ntohs(reply.hdr.ancount),
ntohs(reply.hdr.nscount),
ntohs(reply.hdr.arcount),
results)) {
DnsRecordListFree(*results, 0);
res_nclose(&statbuf);
return -1;
}
res_nclose(&statbuf);
return 0;
}
bool HHVM_FUNCTION(checkdnsrr, const String& host,
const String& type /* = null_string */) {
int ntype;
if (!validate_dns_arguments(host, type, ntype)) {
return false;
}
unsigned char ans[MAXPACKET];
struct __res_state *res;
res = ResolverInit::s_res.get()->getResolver();
if (res == NULL) {
return false;
}
int i = res_nsearch(res, host.data(), C_IN, ntype, ans, sizeof(ans));
res_nclose(res);
php_dns_free_res(res);
return (i >= 0);
}
bool HHVM_FUNCTION(checkdnsrr, const String& host,
const String& type /* = null_string */) {
IOStatusHelper io("dns_check_record", host.data());
const char *stype;
if (type.empty()) {
stype = "MX";
} else {
stype = type.data();
}
if (host.empty()) {
throw_invalid_argument("host: [empty]");
}
int ntype;
if (!strcasecmp("A", stype)) ntype = DNS_T_A;
else if (!strcasecmp("NS", stype)) ntype = DNS_T_NS;
else if (!strcasecmp("MX", stype)) ntype = DNS_T_MX;
else if (!strcasecmp("PTR", stype)) ntype = DNS_T_PTR;
else if (!strcasecmp("ANY", stype)) ntype = DNS_T_ANY;
else if (!strcasecmp("SOA", stype)) ntype = DNS_T_SOA;
else if (!strcasecmp("TXT", stype)) ntype = DNS_T_TXT;
else if (!strcasecmp("CNAME", stype)) ntype = DNS_T_CNAME;
else if (!strcasecmp("AAAA", stype)) ntype = DNS_T_AAAA;
else if (!strcasecmp("SRV", stype)) ntype = DNS_T_SRV;
else if (!strcasecmp("NAPTR", stype)) ntype = DNS_T_NAPTR;
else if (!strcasecmp("A6", stype)) ntype = DNS_T_A6;
else {
throw_invalid_argument("type: %s", stype);
return false;
}
unsigned char ans[MAXPACKET];
struct __res_state *res;
res = ResolverInit::s_res.get()->getResolver();
if (res == NULL) {
return false;
}
int i = res_nsearch(res, host.data(), C_IN, ntype, ans, sizeof(ans));
res_nclose(res);
php_dns_free_res(res);
return (i >= 0);
}
bool HHVM_FUNCTION(getmxrr, const String& hostname,
VRefParam mxhostsRef,
VRefParam weightsRef /* = null */) {
IOStatusHelper io("dns_get_mx", hostname.data());
int count, qdc;
unsigned short type, weight;
unsigned char ans[MAXPACKET];
char buf[MAXHOSTNAMELEN];
unsigned char *cp, *end;
Array mxhosts;
Array weights;
SCOPE_EXIT {
mxhostsRef = mxhosts;
weightsRef = weights;
};
/* Go! */
struct __res_state *res;
res = ResolverInit::s_res.get()->getResolver();
if (res == NULL) {
return false;
}
int i = res_nsearch(res, hostname.data(), C_IN, DNS_T_MX,
(unsigned char*)&ans, sizeof(ans));
if (i < 0) {
res_nclose(res);
php_dns_free_res(res);
return false;
}
if (i > (int)sizeof(ans)) {
i = sizeof(ans);
}
HEADER *hp = (HEADER *)&ans;
cp = (unsigned char *)&ans + HFIXEDSZ;
end = (unsigned char *)&ans +i;
for (qdc = ntohs((unsigned short)hp->qdcount); qdc--; cp += i + QFIXEDSZ) {
if ((i = dn_skipname(cp, end)) < 0 ) {
res_nclose(res);
php_dns_free_res(res);
return false;
}
}
count = ntohs((unsigned short)hp->ancount);
while (--count >= 0 && cp < end) {
if ((i = dn_skipname(cp, end)) < 0 ) {
res_nclose(res);
php_dns_free_res(res);
return false;
}
cp += i;
GETSHORT(type, cp);
cp += INT16SZ + INT32SZ;
GETSHORT(i, cp);
if (type != DNS_T_MX) {
cp += i;
continue;
}
GETSHORT(weight, cp);
if ((i = dn_expand(ans, end, cp, buf, sizeof(buf)-1)) < 0) {
res_nclose(res);
php_dns_free_res(res);
return false;
}
cp += i;
mxhosts.append(String(buf, CopyString));
weights.append(weight);
}
res_nclose(res);
php_dns_free_res(res);
return true;
}
Variant HHVM_FUNCTION(dns_get_record, const String& hostname, int type /*= -1*/,
VRefParam authnsRef /* = null */,
VRefParam addtlRef /* = null */) {
IOStatusHelper io("dns_get_record", hostname.data(), type);
if (type < 0) type = PHP_DNS_ALL;
if (type & ~PHP_DNS_ALL && type != PHP_DNS_ANY) {
raise_warning("Type '%d' not supported", type);
return false;
}
unsigned char *cp = NULL, *end = NULL;
int qd, an, ns = 0, ar = 0;
querybuf answer;
/* - We emulate an or'ed type mask by querying type by type.
* (Steps 0 - NUMTYPES-1 )
* If additional info is wanted we check again with DNS_T_ANY
* (step NUMTYPES / NUMTYPES+1 )
* store_results is used to skip storing the results retrieved in step
* NUMTYPES+1 when results were already fetched.
* - In case of PHP_DNS_ANY we use the directly fetch DNS_T_ANY.
* (step NUMTYPES+1 )
*/
Array ret;
bool first_query = true;
bool store_results = true;
for (int t = (type == PHP_DNS_ANY ? (PHP_DNS_NUM_TYPES + 1) : 0);
t < PHP_DNS_NUM_TYPES + 2 || first_query; t++) {
first_query = false;
int type_to_fetch;
switch (t) {
case 0:
type_to_fetch = type & PHP_DNS_A ? DNS_T_A : 0;
break;
case 1:
type_to_fetch = type & PHP_DNS_NS ? DNS_T_NS : 0;
break;
case 2:
type_to_fetch = type & PHP_DNS_CNAME ? DNS_T_CNAME : 0;
break;
case 3:
type_to_fetch = type & PHP_DNS_SOA ? DNS_T_SOA : 0;
break;
case 4:
type_to_fetch = type & PHP_DNS_PTR ? DNS_T_PTR : 0;
break;
case 5:
type_to_fetch = type & PHP_DNS_HINFO ? DNS_T_HINFO : 0;
break;
case 6:
type_to_fetch = type & PHP_DNS_MX ? DNS_T_MX : 0;
break;
case 7:
type_to_fetch = type & PHP_DNS_TXT ? DNS_T_TXT : 0;
break;
case 8:
type_to_fetch = type & PHP_DNS_AAAA ? DNS_T_AAAA : 0;
break;
case 9:
type_to_fetch = type & PHP_DNS_SRV ? DNS_T_SRV : 0;
break;
case 10:
type_to_fetch = type & PHP_DNS_NAPTR ? DNS_T_NAPTR : 0;
break;
case 11:
type_to_fetch = type & PHP_DNS_A6 ? DNS_T_A6 : 0;
break;
case PHP_DNS_NUM_TYPES:
store_results = false;
continue;
default:
case (PHP_DNS_NUM_TYPES + 1):
type_to_fetch = DNS_T_ANY;
break;
}
if (!type_to_fetch) continue;
struct __res_state *res;
res = ResolverInit::s_res.get()->getResolver();
if (res == NULL) {
return false;
}
int n = res_nsearch(res, hostname.data(), C_IN, type_to_fetch,
answer.qb2, sizeof answer);
if (n < 0) {
res_nclose(res);
php_dns_free_res(res);
continue;
}
HEADER *hp;
cp = answer.qb2 + HFIXEDSZ;
end = answer.qb2 + n;
hp = (HEADER *)&answer;
qd = ntohs(hp->qdcount);
an = ntohs(hp->ancount);
ns = ntohs(hp->nscount);
ar = ntohs(hp->arcount);
/* Skip QD entries, they're only used by dn_expand later on */
while (qd-- > 0) {
n = dn_skipname(cp, end);
if (n < 0) {
raise_warning("Unable to parse DNS data received");
res_nclose(res);
php_dns_free_res(res);
return false;
}
cp += n + QFIXEDSZ;
}
/* YAY! Our real answers! */
while (an-- && cp && cp < end) {
Array retval;
cp = php_parserr(cp, end, &answer, type_to_fetch, store_results, retval);
if (!retval.empty() && store_results) {
ret.append(retval);
}
}
res_nclose(res);
php_dns_free_res(res);
}
Array authns;
Array addtl;
/* List of Authoritative Name Servers */
while (ns-- > 0 && cp && cp < end) {
Array retval;
cp = php_parserr(cp, end, &answer, DNS_T_ANY, true, retval);
if (!retval.empty()) {
authns.append(retval);
}
}
/* Additional records associated with authoritative name servers */
while (ar-- > 0 && cp && cp < end) {
Array retval;
cp = php_parserr(cp, end, &answer, DNS_T_ANY, true, retval);
if (!retval.empty()) {
addtl.append(retval);
}
}
authnsRef = authns;
addtlRef = addtl;
return ret;
}
/*
* Simplified version of srv_query() for domain auto-discovery.
*/
int
srv_getdom(res_state state, const char *svc_name, char **rrname)
{
union {
HEADER hdr;
uchar_t buf[NS_MAXMSG];
} msg;
int len, qdcount, ancount;
uchar_t *ptr, *eom;
char namebuf[NS_MAXDNAME];
/* query necessary resource records */
*rrname = NULL;
if (DBG(DNS, 1)) {
logger(LOG_DEBUG, "Looking for SRV RRs '%s.*'", svc_name);
}
len = res_nsearch(state, svc_name, C_IN, T_SRV,
msg.buf, sizeof (msg.buf));
if (len < 0) {
if (DBG(DNS, 0)) {
logger(LOG_DEBUG,
"DNS search for '%s' failed (%s)",
svc_name, hstrerror(state->res_h_errno));
}
return (-1);
}
if (len > sizeof (msg.buf)) {
logger(LOG_WARNING,
"DNS query %ib message doesn't fit into %ib buffer",
len, sizeof (msg.buf));
len = sizeof (msg.buf);
}
/* parse the reply header */
ptr = msg.buf + sizeof (msg.hdr);
eom = msg.buf + len;
qdcount = ntohs(msg.hdr.qdcount);
ancount = ntohs(msg.hdr.ancount);
/* skip the question section */
len = ns_skiprr(ptr, eom, ns_s_qd, qdcount);
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
return (-1);
}
ptr += len;
/* parse the answer section */
if (ancount < 1) {
logger(LOG_ERR, "DNS query - no answers");
return (-1);
}
len = dn_expand(msg.buf, eom, ptr, namebuf, sizeof (namebuf));
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
return (-1);
}
*rrname = strdup(namebuf);
if (*rrname == NULL) {
logger(LOG_ERR, "Out of memory");
return (-1);
}
return (0);
}
/*
* Query or search the SRV RRs for a given name.
*
* If dname == NULL then search (as in res_nsearch(3RESOLV), honoring any
* search list/option), else query (as in res_nquery(3RESOLV)).
*
* The output TTL will be the one of the SRV RR with the lowest TTL.
*/
ad_disc_cds_t *
srv_query(res_state state, const char *svc_name, const char *dname,
ad_disc_ds_t *prefer)
{
ad_disc_cds_t *cds_res = NULL;
uchar_t *msg = NULL;
int len, scnt, maxcnt;
msg = malloc(NS_MAXMSG);
if (msg == NULL) {
logger(LOG_ERR, "Out of memory");
return (NULL);
}
/* query necessary resource records */
/* Search, querydomain or query */
if (dname == NULL) {
dname = "*";
if (DBG(DNS, 1)) {
logger(LOG_DEBUG, "Looking for SRV RRs '%s.*'",
svc_name);
}
len = res_nsearch(state, svc_name, C_IN, T_SRV,
msg, NS_MAXMSG);
if (len < 0) {
if (DBG(DNS, 0)) {
logger(LOG_DEBUG,
"DNS search for '%s' failed (%s)",
svc_name, hstrerror(state->res_h_errno));
}
goto errout;
}
} else { /* dname != NULL */
if (DBG(DNS, 1)) {
logger(LOG_DEBUG, "Looking for SRV RRs '%s.%s' ",
svc_name, dname);
}
len = res_nquerydomain(state, svc_name, dname, C_IN, T_SRV,
msg, NS_MAXMSG);
if (len < 0) {
if (DBG(DNS, 0)) {
logger(LOG_DEBUG, "DNS: %s.%s: %s",
svc_name, dname,
hstrerror(state->res_h_errno));
}
goto errout;
}
}
if (len > NS_MAXMSG) {
logger(LOG_WARNING,
"DNS query %ib message doesn't fit into %ib buffer",
len, NS_MAXMSG);
len = NS_MAXMSG;
}
/* parse the reply header */
cds_res = srv_parse(msg, len, &scnt, &maxcnt);
if (cds_res == NULL)
goto errout;
if (prefer != NULL)
add_preferred(cds_res, prefer, &scnt, maxcnt);
get_addresses(cds_res, scnt);
/* sort list of candidates */
if (scnt > 1)
qsort(cds_res, scnt, sizeof (*cds_res),
(int (*)(const void *, const void *))srvcmp);
free(msg);
return (cds_res);
errout:
free(msg);
return (NULL);
}
/*
* krb5int_dns_init()
*
* Initialize an opaque handle. Do name lookup and initial parsing of
* reply, skipping question section. Prepare to iterate over answer
* section. Returns -1 on error, 0 on success.
*/
int
krb5int_dns_init(struct krb5int_dns_state **dsp,
char *host, int nclass, int ntype)
{
#if USE_RES_NINIT
struct __res_state statbuf;
#endif
struct krb5int_dns_state *ds;
int len, ret;
size_t nextincr, maxincr;
unsigned char *p;
*dsp = ds = malloc(sizeof(*ds));
if (ds == NULL)
return -1;
ret = -1;
ds->nclass = nclass;
ds->ntype = ntype;
ds->ansp = NULL;
ds->anslen = 0;
ds->ansmax = 0;
nextincr = 2048;
maxincr = INT_MAX;
#if HAVE_NS_INITPARSE
ds->cur_ans = 0;
#endif
#if USE_RES_NINIT
memset(&statbuf, 0, sizeof(statbuf));
ret = res_ninit(&statbuf);
#else
ret = res_init();
#endif
if (ret < 0)
return -1;
do {
p = (ds->ansp == NULL)
? malloc(nextincr) : realloc(ds->ansp, nextincr);
if (p == NULL) {
ret = -1;
goto errout;
}
ds->ansp = p;
ds->ansmax = nextincr;
#if USE_RES_NINIT
len = res_nsearch(&statbuf, host, ds->nclass, ds->ntype,
ds->ansp, ds->ansmax);
#else
len = res_search(host, ds->nclass, ds->ntype,
ds->ansp, ds->ansmax);
#endif
if ((size_t) len > maxincr) {
ret = -1;
goto errout;
}
while (nextincr < (size_t) len)
nextincr *= 2;
if (len < 0 || nextincr > maxincr) {
ret = -1;
goto errout;
}
} while (len > ds->ansmax);
ds->anslen = len;
#if HAVE_NS_INITPARSE
ret = ns_initparse(ds->ansp, ds->anslen, &ds->msg);
#else
ret = initparse(ds);
#endif
if (ret < 0)
goto errout;
ret = 0;
errout:
#if USE_RES_NINIT
res_ndestroy(&statbuf);
#endif
if (ret < 0) {
if (ds->ansp != NULL) {
free(ds->ansp);
ds->ansp = NULL;
}
}
return ret;
}
