#if HAVE_CRT
#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>
#endif //HAVE_CRT
/*
* Copyright (C) 2020, University of the Basque Country (UPV/EHU)
* Contact for licensing options: <licensing-mcpttclient(at)mcopenplatform(dot)com>
*
* The original file was part of Open Source Doubango Framework
* Copyright (C) 2010-2011 Mamadou Diop.
* Copyright (C) 2012 Doubango Telecom <http://doubango.org>
*
* This file is part of Open Source Doubango Framework.
*
* DOUBANGO is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* DOUBANGO is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with DOUBANGO.
*
*/
/**@file tnet_dns.c
* @brief DNS utility functions (RFCS [1034 1035] [3401 3402 3403 3404] [3761]).
*
*/
#include "tnet_dns.h"
#include "tnet_dns_regexp.h"
#include "tnet_dns_message.h"
#include "tnet_dns_opt.h"
#include "tnet_dns_srv.h"
#include "tnet_dns_naptr.h"
#include "tnet_types.h"
#include "tsk_memory.h"
#include "tsk_time.h"
#include "tsk_debug.h"
#include "tsk_string.h"
#include <string.h> /* tsk_strlen, memser, .... */
#include <ctype.h> /* isdigist */
/* DNS cache functions */
int tnet_dns_cache_maintenance(tnet_dns_ctx_t *ctx);
int tnet_dns_cache_entry_add(tnet_dns_ctx_t *ctx, const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype, tnet_dns_response_t* response);
const tnet_dns_cache_entry_t* tnet_dns_cache_entry_get(tnet_dns_ctx_t *ctx, const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype);
/**@defgroup tnet_dns_group DNS utility functions (RFCS [1034 1035] [3401 3402 3403 3404]).
*
* <h1>11 DNS</h1>
* <p>
* The DNS Stack (RFC 1034 and RFC 1035) contains all network functions to send queries (both IPv4 and IPv6) and parse responses. <br>
* The core framework implements RFC 3401, 3402, 3403 and 3404, also known as Dynamic Delegation Discovery System (DDDS).
* </p>
* <p>
* The DNS servers are automatically loaded by the stack when you create a context (@ref tnet_dns_ctx_create()). <br>
* On Windows systems (XP, VISTA, 7 and CE) the servers are retrieved using WIN32 APIs. On Unix-like systems (both desktop and embedded) such as Debian, Ubuntu, Nokia�s N900� the list of DNS servers comes from �/etc/resolv.conf� file. <br>
* On Google Android operating system, this file is missing and the DNS settings are stored in the shared memory. You can access this shared memory by using @a property_get() and @a property_set() function which are part of Bionic. <br>
* In all cases, you can retrieve the DNS servers yourself (e.g. using java/C# Frameworks) and add them to the context using @ref tnet_dns_add_server().
* </p>
* <p>
* DNS resolution is always performed in a synchronous manner and is thread-safe. For all DNS requests the default timeout value is 5 seconds (@ref TNET_DNS_TIMEOUT_DEFAULT).
* The stack also implements the ENUM protocol (RFC 3761).
* </p>
*
* <h2>11.1 Resource Records</h2>
* The table below lists all DNS Resource Records (RR) for which we provide a parser.
*
* <table>
* <tr><td>Code</td> <td>RFC</td> <td>Description</td> <td>Well-defined type</td></tr>
* <tr><td>A</td> <td>RFC 1035</td> <td>IPv4 address</td> <td>tnet_dns_a_t</td></tr>
* <tr><td>AAAA</td> <td>RFC 3596</td> <td>IPv6 address</td> <td>tnet_dns_aaaa_t</td></tr>
* <tr><td>CNAME</td> <td>RFC 1035</td> <td>Canonical name</td> <td>tnet_dns_cname_t</td></tr>
* <tr><td>MX</td> <td>RFC 2035</td> <td>Mail exchange</td> <td>tnet_dns_mx_t</td></tr>
* <tr><td>NAPTR</td> <td>RFC 3403</td> <td>Naming Authority Pointer</td> <td>tnet_dns_naptr_t</td></tr>
* <tr><td>NS</td> <td>RFC 1035</td> <td>Name Server</td> <td>tnet_dns_ns_t</td></tr>
* <tr><td>OPT</td> <td>RFC 2671</td> <td>Option</td> <td>tnet_dns_opt_t</td></tr>
* <tr><td>PTR</td> <td>RFC 1035</td> <td>Pointer record</td> <td>tnet_dns_ptr_t</td></tr>
* <tr><td>SOA</td> <td>RFC1035</td> <td>Start Of Authority record</td> <td>tnet_dns_soa_t</td></tr>
* <tr><td>SRV</td> <td>RFC 2782</td> <td>Service locator</td> <td>tnet_dns_srv_t</td></tr>
* </table>
*
* Here is an example of how to use the DNS stack to perform DNS NAPTR resolution and print the result to the console.
*
* @code
tnet_dns_ctx_t *ctx = tnet_dns_ctx_create();
tnet_dns_response_t *response = tsk_null;
const tsk_list_item_t* item;
const tnet_dns_rr_t* rr;
if((response = tnet_dns_resolve(ctx, "sip2sip.info", qclass_in, qtype_naptr)))
{
if(TNET_DNS_RESPONSE_IS_SUCCESS(response)){
TSK_DEBUG_INFO("We got a success response from the DNS server.");
// loop through the answers
tsk_list_foreach(item, response->Answers){
rr = item->data;
if(rr->qtype == qtype_naptr){
const tnet_dns_naptr_t *naptr = (const tnet_dns_naptr_t*)rr;
TSK_DEBUG_INFO("order=%u pref=%u flags=%s services=%s regexp=%s replacement=%s",
naptr->order,
naptr->preference,
naptr->flags,
naptr->services,
naptr->regexp,
naptr->replacement);
}
}
}
else{
TSK_DEBUG_ERROR("We got an error response from the DNS server. Error code: %u", response->Header.RCODE);
}
}
TSK_OBJECT_SAFE_FREE(response);
TSK_OBJECT_SAFE_FREE(ctx);
* @endcode
* The @a ctx could be used several times and is a well-defined object.<br>
* The console will output:
* <i>INFO: We got a success response from the DNS server.</i><br>
* <i>INFO: order=10 pref=0 flags=S services=SIP+d2u regexp=(null) replacement=_sip._udp.sip2sip.info</i><br>
*
* <h2>11.2 ENUM</h2>
* ENUM (E.164 Number Mapping) protocol has been defined in RFC 3761.
* ENUM protocol is used to transform telephone numbers of the PSTN network (e.g. +33600000) into internet resource addresses (e.g. sip:diopmamadou@example.com) by using DNS lookup (NAPTR). The internet resource address could be an email, ICQ, IAX2, H.323 �
* In our case (3GPP IMS) it is typically used to convert TEL URIs (e.g. tel:+33600000) into SIP URIs (sip:+33600000;user=phone). The telephone number to convert should be a valid E.164 number.
*
* <h3>11.2.1 Usage</h3>
* The code below shows how to gets the SIP address (with the higher order) associated to an E.164 telephone number.
*
* @code
tnet_dns_ctx_t *ctx = tnet_dns_ctx_create();
tnet_dns_response_t* response = tsk_null;
char* uri = tsk_null;
if((uri = tnet_dns_enum_2(ctx, "E2U+SIP", "+1-800-555-5555","e164.org"))){
TSK_DEBUG_INFO("URI=%s", uri);
TSK_FREE(uri);
}
else{
TSK_DEBUG_ERROR("ENUM(%s) failed", "+1-800-555-5555");
}
TSK_OBJECT_SAFE_FREE(response);
TSK_OBJECT_SAFE_FREE(ctx);
* @endcode
*
* Console Output:<br>
* <i>INFO: URI=sip:16416418000-555-5555@sip.tollfreegateway.com</i><br>
*
* E2U+SIP is the name of SIP ENUM service assigned by the IANA. Any assigned service () could be used even if the associated addresse type isn�t a well-knonw internet address.
* To get all internet addresses (email, IAX2, ICQ, H.323 �) associated to the telephone, use @ref tnet_dns_enum() instead of @ref tnet_dns_enum_2().
*/
/**@ingroup tnet_dns_group
* Creates new DNS context.
*/
tnet_dns_ctx_t* tnet_dns_ctx_create()
{
return tsk_object_new(tnet_dns_ctx_def_t);
}
/**@ingroup tnet_dns_group
* Creates new DNS cache entry.
*/
tnet_dns_cache_entry_t* tnet_dns_cache_entry_create(const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype, tnet_dns_response_t* answer)
{
return tsk_object_new(tnet_dns_cache_entry_def_t, qname, qclass, qtype, answer);
}
/**@ingroup tnet_dns_group
* Cleanup the internal DNS cache.
* @param ctx The DNS context containing the cache to cleanup.
* The context contains the user's preference and should be created using @ref tnet_dns_ctx_create().
* @retval Zero if succeeed and non-zero error code otherwise.
*/
int tnet_dns_cache_clear(tnet_dns_ctx_t* ctx)
{
if (ctx){
tsk_safeobj_lock(ctx);
tsk_list_clear_items(ctx->cache);
tsk_safeobj_unlock(ctx);
return 0;
}
return -1;
}
/**@ingroup tnet_dns_group
* Sends DNS request over the network. The request will be sent each 500 milliseconds until @ref TNET_DNS_TIMEOUT_DEFAULT milliseconds is reached.
* @param ctx The DNS context to use. The context contains the user's preference and should be created using @ref tnet_dns_ctx_create().
* @param qname The domain name (e.g. google.com).
* @param qclass The CLASS of the query.
* @param qtype The type of the query.
* @retval The DNS response. The @a answers in the @a response are already filtered.
* MUST be destroyed using @a TSK_OBJECT_SAFE_FREE() macro.
* @sa @ref tnet_dns_query_srv, @ref tnet_dns_query_naptr_srv, @ref tnet_dns_enum.
*
* @code
* tnet_dns_ctx_t *ctx = tnet_dns_ctx_create();
* tnet_dns_response_t *response = tnet_dns_resolve(ctx, "sip2sip.info", qclass_in, qtype_srv);
* TSK_OBJECT_SAFE_FREE(response);
* TSK_OBJECT_SAFE_FREE(ctx);
* @endcode
*/
tnet_dns_response_t *tnet_dns_resolve(tnet_dns_ctx_t* ctx, const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype)
{
#if HAVE_DNS_H
struct sockaddr_storage result;
struct sockaddr *from;
uint32_t fromlen;
char buf[TNET_DNS_DGRAM_SIZE_DEFAULT];
int32_t ret;
tnet_dns_response_t *response = tsk_null;
tnet_socket_t *localsocket4 = tnet_socket_create(TNET_SOCKET_HOST_ANY, TNET_SOCKET_PORT_ANY, tnet_socket_type_udp_ipv4);
tnet_socket_t *localsocket6 = tnet_socket_create(TNET_SOCKET_HOST_ANY, TNET_SOCKET_PORT_ANY, tnet_socket_type_udp_ipv6);
tsk_safeobj_lock(ctx);
// First, try with IPv4
if(TNET_SOCKET_IS_VALID(localsocket4)){
if((ret = tnet_getsockname(localsocket4->fd, &result))){
TNET_PRINT_LAST_ERROR("tnet_getsockname() failed.");
goto ipv6;
}
from = (struct sockaddr *) &result;
fromlen = tnet_get_sockaddr_size(from);
if ((ret = dns_search(ctx->resolv_handle, qname, qclass, qtype, buf, TNET_DNS_DGRAM_SIZE_DEFAULT, from, &fromlen)) > 0) {
response = tnet_dns_message_deserialize((uint8_t *) buf, ret);
goto done;
}
else{
TNET_PRINT_LAST_ERROR("dns_search_v4()");
}
}
ipv6:
// Then, try with IPv6
if(TNET_SOCKET_IS_VALID(localsocket6)){
if((ret = tnet_getsockname(localsocket6->fd, &result))){
TNET_PRINT_LAST_ERROR("tnet_getsockname() failed.");
goto done;
}
from = (struct sockaddr *) &result;
fromlen = tnet_get_sockaddr_size(from);
if((ret = dns_search(ctx->resolv_handle, qname, qclass, qtype, buf, TNET_DNS_DGRAM_SIZE_DEFAULT, from, &fromlen)) > 0){
response = tnet_dns_message_deserialize((uint8_t *) buf, ret);
goto done;
}
else{
TNET_PRINT_LAST_ERROR("dns_search_v6()");
}
}
done:
tsk_safeobj_unlock(ctx);
TSK_OBJECT_SAFE_FREE(localsocket4);
TSK_OBJECT_SAFE_FREE(localsocket6);
return response;
#else
tsk_buffer_t *output = tsk_null;
tnet_dns_query_t* query = tnet_dns_query_create(qname, qclass, qtype);
tnet_dns_response_t *response = tsk_null;
tsk_bool_t from_cache = tsk_false;
/* Check validity */
if (!ctx || !query){
goto bail;
}
/* Is there any DNS Server? */
if (TSK_LIST_IS_EMPTY(ctx->servers)){
TSK_DEBUG_ERROR("Failed to load DNS Servers. You can add new DNS servers by using \"tnet_dns_add_server\".");
goto bail;
}
/* Cache maintenance */
if (!TSK_LIST_IS_EMPTY(ctx->cache)){
/* Only do maintenance if the cache is not empty */
tnet_dns_cache_maintenance(ctx);
}
/* Retrieve data from cache. */
if (ctx->caching){
const tnet_dns_cache_entry_t *entry = tnet_dns_cache_entry_get(ctx, qname, qclass, qtype);
if (entry){
response = tsk_object_ref(((tnet_dns_cache_entry_t*)entry)->response);
from_cache = tsk_true;
goto bail;
}
}
/* Set user preference */
query->Header.RD = ctx->recursion;
/* EDNS0 */
if (ctx->edns0){
tnet_dns_opt_t *rr_opt = tnet_dns_opt_create(TNET_DNS_DGRAM_SIZE_DEFAULT);
if (!query->Additionals){
query->Additionals = tsk_list_create();
}
tsk_list_push_back_data(query->Additionals, (void**)&rr_opt);
query->Header.ARCOUNT++;
}
/* Serialize and send to the server. */
if (!(output = tnet_dns_message_serialize(query))){
TSK_DEBUG_ERROR("Failed to serialize the DNS message.");
goto bail;
}
/* ============================ */
// Send and Recaive data
/* ============================ */
{
int ret = -1;
struct timeval tv;
fd_set set;
tnet_fd_t maxFD;
uint64_t timeout = 0;
tsk_list_item_t *item;
const tnet_address_t *address;
struct sockaddr_storage server;
tnet_socket_t *localsocket4 = tnet_socket_create(TNET_SOCKET_HOST_ANY, TNET_SOCKET_PORT_ANY, tnet_socket_type_udp_ipv4);
tnet_socket_t *localsocket6 = tnet_socket_create(TNET_SOCKET_HOST_ANY, TNET_SOCKET_PORT_ANY, tnet_socket_type_udp_ipv6);
tsk_bool_t useIPv6 = TNET_SOCKET_IS_VALID(localsocket6);
tsk_safeobj_lock(ctx);
/* Check socket validity */
if (!TNET_SOCKET_IS_VALID(localsocket4)){
goto done;
}
/* Always wait 500ms before retransmission */
tv.tv_sec = 0;
tv.tv_usec = (500 * 1000);
do
{
//
// Send data (loop through all intefaces)
//
tsk_list_foreach(item, ctx->servers)
{
address = item->data;
if (!address->ip ||
(address->family != AF_INET && address->family != AF_INET6) ||
(address->family == AF_INET6 && !TNET_SOCKET_IS_VALID(localsocket6))){
continue;
}
if (tnet_sockaddr_init(address->ip, ctx->server_port, (address->family == AF_INET ? tnet_socket_type_udp_ipv4 : tnet_socket_type_udp_ipv6), &server)){
TSK_DEBUG_ERROR("Failed to initialize the DNS server address: \"%s\"", address->ip);
continue;
}
TSK_DEBUG_INFO("Sending DNS query to \"%s\"", address->ip);
if (address->family == AF_INET6){
if ((ret = tnet_sockfd_sendto(localsocket6->fd, (const struct sockaddr*)&server, output->data, output->size))){
// succeed?
break;
}
}
else{
if ((ret = tnet_sockfd_sendto(localsocket4->fd, (const struct sockaddr*)&server, output->data, output->size))){
// succeed?
break;
}
}
}
//
// Received data
//
/* First time? ==> set timeout value */
if (!timeout){
timeout = tsk_time_epoch() + ctx->timeout;
}
/* Set FDs */
FD_ZERO(&set);
FD_SET(localsocket4->fd, &set);
if (useIPv6){
FD_SET(localsocket6->fd, &set);
maxFD = TSK_MAX(localsocket4->fd, localsocket6->fd);
}
else{
maxFD = localsocket4->fd;
}
/* wait for response */
if ((ret = select(maxFD + 1, &set, NULL, NULL, &tv)) < 0){ /* Error */
TNET_PRINT_LAST_ERROR("Select failed.");
goto done;
}
else if (ret == 0){ /* timeout ==> do nothing */
}
else{ /* there is data to read */
unsigned int len = 0;
void* data = 0;
tnet_fd_t active_fd;
/* Find active file descriptor */
if (FD_ISSET(localsocket4->fd, &set)){
active_fd = localsocket4->fd;
}
else if (FD_ISSET(localsocket6->fd, &set)){
active_fd = localsocket4->fd;
}
else{
TSK_DEBUG_ERROR("FD_ISSET ==> Invalid file descriptor.");
continue;
}
/* Check how how many bytes are pending */
if ((ret = tnet_ioctlt(active_fd, FIONREAD, &len)) < 0){
TSK_DEBUG_ERROR("tnet_ioctlt failed with error code:%d", tnet_geterrno());
goto done;
}
/* Receive pending data */
#if HAVE_CRT //Debug memory
data = calloc(len, sizeof(uint8_t));
#else
data = tsk_calloc(len, sizeof(uint8_t));
#endif //HAVE_CRT
if ((ret = tnet_sockfd_recv(active_fd, data, len, 0)) < 0){
TSK_FREE(data);
TSK_DEBUG_ERROR("tnet_sockfd_recv failed with error code:%d", tnet_geterrno());
goto done;
}
/* Parse the incoming response. */
response = tnet_dns_message_deserialize(data, (tsk_size_t)ret);
TSK_FREE(data);
if (response)
{ /* response successfuly parsed */
if (query->Header.ID != response->Header.ID || !TNET_DNS_MESSAGE_IS_RESPONSE(response)){
/* Not same transaction id ==> continue*/
TSK_OBJECT_SAFE_FREE(response);
}
else goto done;
}
}
} while (timeout > tsk_time_epoch());
done:
tsk_safeobj_unlock(ctx);
TSK_OBJECT_SAFE_FREE(localsocket4);
TSK_OBJECT_SAFE_FREE(localsocket6);
goto bail;
}
bail:
TSK_OBJECT_SAFE_FREE(query);
TSK_OBJECT_SAFE_FREE(output);
/* Add the result to the cache. */
if (response){
if (!from_cache && ctx->caching){
tnet_dns_cache_entry_add(ctx, qname, qclass, qtype, response);
}
}
else{
TSK_DEBUG_ERROR("Failed to contact the DNS server.");
}
return response;
#endif
}
/**@ingroup tnet_dns_group
* Gets list of URIs associated to this telephone number by using ENUM protocol (RFC 3761).
* @param ctx The DNS context.
* The context contains the user's preference and should be created using @ref tnet_dns_ctx_create().
* @param e164num A valid E.164 number (e.g. +1-800-555-5555).
* @param domain The domain name (e.g e164.arpa, e164.org, ...). If Null, default value is "e164.arpa" (IANA).
* @retval The DNS response with NAPTR RRs. The @a answers in the @a response are already filtered.
* MUST be destroyed using @a TSK_OBJECT_SAFE_FREE macro.
* @sa @ref tnet_dns_resolve, @ref tnet_dns_enum_2.
*/
tnet_dns_response_t* tnet_dns_enum(tnet_dns_ctx_t* ctx, const char* e164num, const char* domain)
{
char e164domain[255];
tnet_dns_response_t* ret = tsk_null;
int e164size;
int i, j; // must be signed
e164size = (int)tsk_strlen(e164num);
if (!ctx || !e164num || !e164size){
goto bail;
}
if (e164size /* max=15 digits + ".e164.arpa" + '+' */ >= (sizeof(e164domain) - 1)){
TSK_DEBUG_ERROR("%s is an invalid E.164 number.", e164num);
goto bail;
}
memset(e164domain, '\0', sizeof(e164domain));
/* RFC 3761 - 2.4. Valid Databases
1. Remove all characters with the exception of the digits. For
example, the First Well Known Rule produced the Key
"+442079460148". This step would simply remove the leading "+",
producing "442079460148".
2. Put dots (".") between each digit. Example:
4.4.2.0.7.9.4.6.0.1.4.8
3. Reverse the order of the digits. Example:
8.4.1.0.6.4.9.7.0.2.4.4
4. Append the string ".e164.arpa" to the end. Example:
8.4.1.0.6.4.9.7.0.2.4.4.e164.arpa
This domain-name is used to request NAPTR records which may contain
the end result or, if the flags field is blank, produces new keys in
the form of domain-names from the DNS.
*/
for (i = e164size - 1, j = 0; i >= 0; i--){
if (!isdigit(e164num[i])){
continue;
}
e164domain[j++] = e164num[i];
e164domain[j++] = '.';
}
// append domain name
if (domain){
memcpy(&e164domain[j], domain, ((tsk_strlen(domain) + j) >= sizeof(e164domain) - 1) ? (sizeof(e164domain) - j - 1) : tsk_strlen(domain));
}
else{
memcpy(&e164domain[j], "e164.arpa", 9);
}
/* == Performs DNS (NAPTR) lookup == */
ret = tnet_dns_resolve(ctx, e164domain, qclass_in, qtype_naptr);
bail:
return ret;
}
/**@ingroup tnet_dns_group
* Gets the internate address associated to this telephone number by using ENUM protocol (RFC 3761).
* Only terminale rules containing uris(flags="u") will be considered and the regex string will be executed on the original string for
* substitution. <br>
* <b> Parsing complex regexp will probably fail (99.99% chance). Please use @ref tnet_dns_enum if you want to use your own regexp parser. </b>
* @param ctx The DNS context.
* The context contains the user's preference and should be created using @ref tnet_dns_ctx_create().
* @param service The ENUM service (e.g. E2U+SIP).
* @param e164num A valid E.164 number (e.g. +1-800-555-5555).
* @param domain The domain name (e.g e164.arpa, e164.org, ...). If Null, default value is "e164.arpa" (IANA).
* @retval The Internet address (SIP, email, ICQ, fax, ...) associated to this service.
* MUST be freed using @a TSK_FREE macro.
* @sa @ref tnet_dns_resolve, @ref tnet_dns_enum.
*/
char* tnet_dns_enum_2(tnet_dns_ctx_t* ctx, const char* service, const char* e164num, const char* domain)
{
tnet_dns_response_t* response;
const tsk_list_item_t* item;
char* ret = tsk_null;
const tnet_dns_rr_t* rr;
if ((response = tnet_dns_enum(ctx, e164num, domain))){
if (TNET_DNS_RESPONSE_IS_SUCCESS(response)){
tsk_list_foreach(item, response->Answers){
rr = item->data;
if (rr->qtype == qtype_naptr){
const tnet_dns_naptr_t *naptr = (const tnet_dns_naptr_t*)rr;
/* RFC 3403 - 6.2 E164 Example
Both the ENUM [18] and URI Resolution [4] Applications use the 'u'
flag. This flag states that the Rule is terminal and that the output
is a URI which contains the information needed to contact that
telephone service.
*/
if (tsk_striequals(naptr->flags, "u") && tsk_striequals(naptr->services, service)){
/* RFC 3403 - 4.1 Packet Format
The fields (replacement and regexp) are also mutually exclusive. If a record is
returned that has values for both fields then it is considered to
be in error and SHOULD be either ignored or an error returned.
*/
if (naptr->regexp && naptr->replacement){
continue;
}
if ((ret = tnet_dns_regex_parse(e164num, naptr->regexp))){
break;
}
}
}
}
}
else{
TSK_DEBUG_ERROR("We got an error response from the DNS server. Error code: %u", response->Header.RCODE);
}
TSK_OBJECT_SAFE_FREE(response);
}
return ret;
}
/**@ingroup tnet_dns_group
* Performs DNS SRV resolution.
* @param ctx The DNS context.
* The context contains the user's preference and should be created using @ref tnet_dns_ctx_create.
* @param service The name of the service (e.g. SIP+D2U).
* @param hostname The result containing an IP address or FQDN.
* @param port The port associated to the result.
* @retval Zero if succeed and non-zero error code otherwise.
* @sa @ref tnet_dns_resolve.
*
* @code
* tnet_dns_ctx_t *ctx = tnet_dns_ctx_create();
* char* hostname = 0;
* tnet_port_t port = 0;
*
* if(!tnet_dns_query_srv(ctx, "_sip._udp.sip2sip.info", &hostname, &port)){
* TSK_DEBUG_INFO("DNS SRV succeed ==> hostname=%s and port=%u", hostname, port);
* }
*
* TSK_FREE(hostname);
* TSK_OBJECT_SAFE_FREE(ctx);
* @endcode
*/
int tnet_dns_query_srv(tnet_dns_ctx_t *ctx, const char* service, char** hostname, tnet_port_t* port)
{
tnet_dns_response_t *response;
if (!ctx){
return -1;
}
// tnet_dns_resolve is thread-safe
if ((response = tnet_dns_resolve(ctx, service, qclass_in, qtype_srv)))
{
const tsk_list_item_t *item;
const tnet_dns_rr_t* rr;
tsk_list_foreach(item, response->Answers) /* Already Filtered ==> Peek the first One */
{
rr = item->data;
if (rr->qtype == qtype_srv){
const tnet_dns_srv_t *srv = (const tnet_dns_srv_t*)rr;
tsk_strupdate(hostname, srv->target);
*port = srv->port;
break;
}
}
}
TSK_OBJECT_SAFE_FREE(response);
return (hostname && !tsk_strnullORempty(*hostname)) ? 0 : -2;
}
/**@ingroup tnet_dns_group
* Performs DNS NAPTR followed by DNS SRV resolution.
* @param ctx The DNS context.
* The context contains the user's preference and should be created using @ref tnet_dns_ctx_create().
* @param domain The Name of the domain (e.g. google.com).
* @param service The name of the service (e.g. SIP+D2U).
* @param hostname The result containing an IP address or FQDN. Should be Null.
* @param port The port associated to the result.
* @retval Zero if succeed and non-zero error code otherwise.
* @sa @ref tnet_dns_resolve.
*
* @code
* tnet_dns_ctx_t *ctx = tnet_dns_ctx_create();
* char* hostname = tsk_null;
* tnet_port_t port = 0;
*
* if(!tnet_dns_query_naptr_srv(ctx, "sip2sip.info", "SIP+D2U", &hostname, &port)){
* TSK_DEBUG_INFO("DNS NAPTR+SRV succeed ==> hostname=%s and port=%u", hostname, port);
* }
*
* TSK_FREE(hostname);
* TSK_OBJECT_SAFE_FREE(ctx);
* @endcode
*/
int tnet_dns_query_naptr_srv(tnet_dns_ctx_t *ctx, const char* domain, const char* service, char** hostname, tnet_port_t* port)
{
tnet_dns_response_t *response;
if (!ctx || !hostname){
TSK_DEBUG_ERROR("Invalid parameters.");
return -1;
}
/* reset (do not free the user supplied value). trying to free dummy value will cause access violation error ==> zero. */
*hostname = tsk_null;
// tnet_dns_resolve is thread-safe
if ((response = tnet_dns_resolve(ctx, domain, qclass_in, qtype_naptr))){
const tsk_list_item_t *item;
const tnet_dns_rr_t* rr;
char* replacement = tsk_null; /* e.g. _sip._udp.example.com */
char* flags = tsk_null;/* e.g. S, A, AAAA, A6, U, P ... */
tsk_list_foreach(item, response->Answers) /* Already Filtered ==> Peek the first One */
{
rr = item->data;
if (rr->qtype == qtype_naptr){
tnet_dns_naptr_t *naptr = (tnet_dns_naptr_t*)rr;
if (tsk_striequals(service, naptr->services)){
tsk_strupdate(&replacement, naptr->replacement);
tsk_strupdate(&flags, naptr->flags);
break;
}
}
}
if (flags && replacement){
if (tsk_striequals(flags, "S")){
tnet_dns_query_srv(ctx, replacement, hostname, port);
}
else if (tsk_striequals(flags, "A") || tsk_striequals(flags, "AAAA") || tsk_striequals(flags, "A6")){
TSK_DEBUG_WARN("Defaulting port value.");
tsk_strupdate(hostname, replacement);
*port = 5060;
}
else{
TSK_DEBUG_ERROR("DNS NAPTR query returned invalid flags");
}
}
else{
TSK_DEBUG_INFO("DNS NAPTR (%s) query returned zero result", domain);
}
TSK_FREE(flags);
TSK_FREE(replacement);
}
TSK_OBJECT_SAFE_FREE(response);
return (hostname && *hostname && !tsk_strempty(*hostname)) ? 0 : -2;
}
// remove timedout entries
int tnet_dns_cache_maintenance(tnet_dns_ctx_t *ctx)
{
if (ctx)
{
tsk_list_item_t *item;
tsk_safeobj_lock(ctx);
again:
tsk_list_foreach(item, ctx->cache)
{
// FIXME: ttl should be from RR::ttl
tnet_dns_cache_entry_t *entry = (tnet_dns_cache_entry_t*)item->data;
if ((entry->epoch + ctx->cache_ttl) < tsk_time_epoch()){
tsk_list_remove_item_by_data(ctx->cache, entry);
goto again; /* Do not delete data while looping */
}
}
tsk_safeobj_unlock(ctx);
return 0;
}
return -1;
}
// add an entry to the cache
int tnet_dns_cache_entry_add(tnet_dns_ctx_t *ctx, const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype, tnet_dns_response_t* response)
{
int ret = -1;
if (ctx)
{
tnet_dns_cache_entry_t *entry;
tsk_safeobj_lock(ctx);
entry = 0;
/* Retrieve from cache */
entry = (tnet_dns_cache_entry_t*)tnet_dns_cache_entry_get(ctx, qname, qclass, qtype);
if (entry){
/* UPDATE */
TSK_OBJECT_SAFE_FREE(entry->response);
entry->response = tsk_object_ref(response);
entry->epoch = tsk_time_epoch();
ret = 0;
goto done;
}
else{
/* CREATE */
entry = tnet_dns_cache_entry_create(qname, qclass, qtype, response);
if (entry){
tsk_list_push_back_data(ctx->cache, (void**)&entry);
ret = 0;
goto done;
}
else{
ret = -2;
goto done;
}
}
done:
tsk_safeobj_unlock(ctx);
}
return ret;
}
// get an entry from the cache
const tnet_dns_cache_entry_t* tnet_dns_cache_entry_get(tnet_dns_ctx_t *ctx, const char* qname, tnet_dns_qclass_t qclass, tnet_dns_qtype_t qtype)
{
tnet_dns_cache_entry_t *ret = tsk_null;
if (ctx)
{
tsk_list_item_t *item;
tsk_safeobj_lock(ctx);
tsk_list_foreach(item, ctx->cache){
tnet_dns_cache_entry_t *entry = (tnet_dns_cache_entry_t*)item->data;
if (entry->qtype == qtype && entry->qclass == qclass && tsk_strequals(entry->qname, qname)){
ret = entry;
break;
}
}
tsk_safeobj_unlock(ctx);
}
return ret;
}
/**@ingroup tnet_dns_group
* Adds new DNS server to the list of the list of servers to query.
* @param ctx DNS context containing the user parameters. The new DNS server will be added to this context.
* @param host The IP address (or FQDN) of the dns server to add to the server.
* @retval zero if succeed and non-zero error code otherwise.
*/
int tnet_dns_add_server(tnet_dns_ctx_t *ctx, const char* host)
{
tnet_address_t *address;
if (!ctx || !host){
return -1;
}
if (!ctx->servers){
ctx->servers = tsk_list_create();
}
if ((address = tnet_address_create(host))){
address->family = tnet_get_family(host, TNET_DNS_SERVER_PORT_DEFAULT);
address->dnsserver = 1;
tsk_list_push_ascending_data(ctx->servers, (void**)&address);
return 0;
}
return -2;
}
//=================================================================================================
// [[DNS CACHE ENTRY]] object definition
//
static tsk_object_t* tnet_dns_cache_entry_ctor(tsk_object_t * self, va_list * app)
{
tnet_dns_cache_entry_t *entry = self;
if (entry){
entry->qname = tsk_strdup(va_arg(*app, const char*));
entry->qclass = va_arg(*app, tnet_dns_qtype_t);
entry->qtype = va_arg(*app, tnet_dns_qtype_t);
entry->response = tsk_object_ref(va_arg(*app, tnet_dns_response_t*));
entry->epoch = tsk_time_epoch();
}
return self;
}
static tsk_object_t* tnet_dns_cache_entry_dtor(tsk_object_t * self)
{
tnet_dns_cache_entry_t *entry = self;
if (entry){
TSK_OBJECT_SAFE_FREE(entry->response);
}
return self;
}
static const tsk_object_def_t tnet_dns_cache_entry_def_s =
{
sizeof(tnet_dns_cache_entry_t),
tnet_dns_cache_entry_ctor,
tnet_dns_cache_entry_dtor,
tsk_null,
};
const tsk_object_def_t *tnet_dns_cache_entry_def_t = &tnet_dns_cache_entry_def_s;
//=================================================================================================
// [[DNS CONTEXT]] object definition
//
static tsk_object_t* tnet_dns_ctx_ctor(tsk_object_t * self, va_list * app)
{
tnet_dns_ctx_t *ctx = self;
if (ctx){
ctx->timeout = TNET_DNS_TIMEOUT_DEFAULT;
ctx->recursion = tsk_true;
ctx->edns0 = tsk_true;
ctx->caching = tsk_false;
ctx->cache_ttl = TNET_DNS_CACHE_TTL;
ctx->server_port = TNET_DNS_SERVER_PORT_DEFAULT;
/* Gets all dns servers. */
ctx->servers = tnet_get_addresses_all_dnsservers();
/* Creates empty cache. */
ctx->cache = tsk_list_create();
#if HAVE_DNS_H
ctx->resolv_handle = dns_open(NULL);
#endif
tsk_safeobj_init(ctx);
}
return self;
}
static tsk_object_t* tnet_dns_ctx_dtor(tsk_object_t * self)
{
tnet_dns_ctx_t *ctx = self;
if (ctx){
tsk_safeobj_deinit(ctx);
TSK_OBJECT_SAFE_FREE(ctx->servers);
TSK_OBJECT_SAFE_FREE(ctx->cache);
#if HAVE_DNS_H
dns_free(ctx->resolv_handle);
#endif
}
return self;
}
static const tsk_object_def_t tnet_dns_ctx_def_s =
{
sizeof(tnet_dns_ctx_t),
tnet_dns_ctx_ctor,
tnet_dns_ctx_dtor,
tsk_null,
};
const tsk_object_def_t *tnet_dns_ctx_def_t = &tnet_dns_ctx_def_s;