mirror of
https://github.com/samba-team/samba.git
synced 2024-12-24 21:34:56 +03:00
376 lines
8.5 KiB
C
376 lines
8.5 KiB
C
/*
|
|
Linux DNS client library implementation
|
|
|
|
Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com>
|
|
Copyright (C) 2006 Gerald Carter <jerry@samba.org>
|
|
|
|
** NOTE! The following LGPL license applies to the libaddns
|
|
** library. This does NOT imply that all of Samba is released
|
|
** under the LGPL
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
This library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "replace.h"
|
|
#include "dns.h"
|
|
#include <sys/time.h>
|
|
#include <unistd.h>
|
|
#include "system/select.h"
|
|
|
|
static int destroy_dns_connection(struct dns_connection *conn)
|
|
{
|
|
return close(conn->s);
|
|
}
|
|
|
|
/********************************************************************
|
|
********************************************************************/
|
|
|
|
static DNS_ERROR dns_tcp_open( const char *nameserver,
|
|
TALLOC_CTX *mem_ctx,
|
|
struct dns_connection **result )
|
|
{
|
|
uint32_t ulAddress;
|
|
struct hostent *pHost;
|
|
struct sockaddr_in s_in;
|
|
struct dns_connection *conn;
|
|
int res;
|
|
|
|
if (!(conn = talloc(mem_ctx, struct dns_connection))) {
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
|
|
if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
|
|
if ( (pHost = gethostbyname( nameserver )) == NULL ) {
|
|
TALLOC_FREE(conn);
|
|
return ERROR_DNS_INVALID_NAME_SERVER;
|
|
}
|
|
memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
|
|
}
|
|
|
|
conn->s = socket( PF_INET, SOCK_STREAM, 0 );
|
|
if (conn->s == -1) {
|
|
TALLOC_FREE(conn);
|
|
return ERROR_DNS_CONNECTION_FAILED;
|
|
}
|
|
|
|
talloc_set_destructor(conn, destroy_dns_connection);
|
|
|
|
s_in.sin_family = AF_INET;
|
|
s_in.sin_addr.s_addr = ulAddress;
|
|
s_in.sin_port = htons( DNS_TCP_PORT );
|
|
|
|
res = connect(conn->s, (struct sockaddr*)&s_in, sizeof( s_in ));
|
|
if (res == -1) {
|
|
TALLOC_FREE(conn);
|
|
return ERROR_DNS_CONNECTION_FAILED;
|
|
}
|
|
|
|
conn->hType = DNS_TCP;
|
|
|
|
*result = conn;
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
/********************************************************************
|
|
********************************************************************/
|
|
|
|
static DNS_ERROR dns_udp_open( const char *nameserver,
|
|
TALLOC_CTX *mem_ctx,
|
|
struct dns_connection **result )
|
|
{
|
|
unsigned long ulAddress;
|
|
struct hostent *pHost;
|
|
struct sockaddr_in RecvAddr;
|
|
struct dns_connection *conn;
|
|
|
|
if (!(conn = talloc(NULL, struct dns_connection))) {
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
|
|
if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
|
|
if ( (pHost = gethostbyname( nameserver )) == NULL ) {
|
|
TALLOC_FREE(conn);
|
|
return ERROR_DNS_INVALID_NAME_SERVER;
|
|
}
|
|
memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
|
|
}
|
|
|
|
/* Create a socket for sending data */
|
|
|
|
conn->s = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
|
|
if (conn->s == -1) {
|
|
TALLOC_FREE(conn);
|
|
return ERROR_DNS_CONNECTION_FAILED;
|
|
}
|
|
|
|
talloc_set_destructor(conn, destroy_dns_connection);
|
|
|
|
/* Set up the RecvAddr structure with the IP address of
|
|
the receiver (in this example case "123.456.789.1")
|
|
and the specified port number. */
|
|
|
|
ZERO_STRUCT(RecvAddr);
|
|
RecvAddr.sin_family = AF_INET;
|
|
RecvAddr.sin_port = htons( DNS_UDP_PORT );
|
|
RecvAddr.sin_addr.s_addr = ulAddress;
|
|
|
|
conn->hType = DNS_UDP;
|
|
memcpy( &conn->RecvAddr, &RecvAddr, sizeof( struct sockaddr_in ) );
|
|
|
|
*result = conn;
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
/********************************************************************
|
|
********************************************************************/
|
|
|
|
DNS_ERROR dns_open_connection( const char *nameserver, int32_t dwType,
|
|
TALLOC_CTX *mem_ctx,
|
|
struct dns_connection **conn )
|
|
{
|
|
switch ( dwType ) {
|
|
case DNS_TCP:
|
|
return dns_tcp_open( nameserver, mem_ctx, conn );
|
|
case DNS_UDP:
|
|
return dns_udp_open( nameserver, mem_ctx, conn );
|
|
}
|
|
|
|
return ERROR_DNS_INVALID_PARAMETER;
|
|
}
|
|
|
|
static DNS_ERROR write_all(int fd, uint8_t *data, size_t len)
|
|
{
|
|
size_t total = 0;
|
|
|
|
while (total < len) {
|
|
|
|
ssize_t ret = write(fd, data + total, len - total);
|
|
|
|
if (ret <= 0) {
|
|
/*
|
|
* EOF or error
|
|
*/
|
|
return ERROR_DNS_SOCKET_ERROR;
|
|
}
|
|
|
|
total += ret;
|
|
}
|
|
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
static DNS_ERROR dns_send_tcp(struct dns_connection *conn,
|
|
const struct dns_buffer *buf)
|
|
{
|
|
uint16_t len = htons(buf->offset);
|
|
DNS_ERROR err;
|
|
|
|
err = write_all(conn->s, (uint8_t *)&len, sizeof(len));
|
|
if (!ERR_DNS_IS_OK(err)) return err;
|
|
|
|
return write_all(conn->s, buf->data, buf->offset);
|
|
}
|
|
|
|
static DNS_ERROR dns_send_udp(struct dns_connection *conn,
|
|
const struct dns_buffer *buf)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = sendto(conn->s, buf->data, buf->offset, 0,
|
|
(struct sockaddr *)&conn->RecvAddr,
|
|
sizeof(conn->RecvAddr));
|
|
|
|
if (ret != buf->offset) {
|
|
return ERROR_DNS_SOCKET_ERROR;
|
|
}
|
|
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
DNS_ERROR dns_send(struct dns_connection *conn, const struct dns_buffer *buf)
|
|
{
|
|
if (conn->hType == DNS_TCP) {
|
|
return dns_send_tcp(conn, buf);
|
|
}
|
|
|
|
if (conn->hType == DNS_UDP) {
|
|
return dns_send_udp(conn, buf);
|
|
}
|
|
|
|
return ERROR_DNS_INVALID_PARAMETER;
|
|
}
|
|
|
|
static DNS_ERROR read_all(int fd, uint8_t *data, size_t len)
|
|
{
|
|
size_t total = 0;
|
|
|
|
while (total < len) {
|
|
struct pollfd pfd;
|
|
ssize_t ret;
|
|
int fd_ready;
|
|
|
|
ZERO_STRUCT(pfd);
|
|
pfd.fd = fd;
|
|
pfd.events = POLLIN|POLLHUP;
|
|
|
|
fd_ready = poll(&pfd, 1, 10000);
|
|
if ( fd_ready == 0 ) {
|
|
/* read timeout */
|
|
return ERROR_DNS_SOCKET_ERROR;
|
|
}
|
|
|
|
ret = read(fd, data + total, len - total);
|
|
if (ret <= 0) {
|
|
/* EOF or error */
|
|
return ERROR_DNS_SOCKET_ERROR;
|
|
}
|
|
|
|
total += ret;
|
|
}
|
|
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
static DNS_ERROR dns_receive_tcp(TALLOC_CTX *mem_ctx,
|
|
struct dns_connection *conn,
|
|
struct dns_buffer **presult)
|
|
{
|
|
struct dns_buffer *buf;
|
|
DNS_ERROR err;
|
|
uint16_t len;
|
|
|
|
if (!(buf = talloc_zero(mem_ctx, struct dns_buffer))) {
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
|
|
err = read_all(conn->s, (uint8_t *)&len, sizeof(len));
|
|
if (!ERR_DNS_IS_OK(err)) {
|
|
return err;
|
|
}
|
|
|
|
buf->size = ntohs(len);
|
|
|
|
if (buf->size) {
|
|
if (!(buf->data = talloc_array(buf, uint8_t, buf->size))) {
|
|
TALLOC_FREE(buf);
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
} else {
|
|
buf->data = NULL;
|
|
}
|
|
|
|
err = read_all(conn->s, buf->data, buf->size);
|
|
if (!ERR_DNS_IS_OK(err)) {
|
|
TALLOC_FREE(buf);
|
|
return err;
|
|
}
|
|
|
|
*presult = buf;
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
static DNS_ERROR dns_receive_udp(TALLOC_CTX *mem_ctx,
|
|
struct dns_connection *conn,
|
|
struct dns_buffer **presult)
|
|
{
|
|
struct dns_buffer *buf;
|
|
ssize_t received;
|
|
|
|
if (!(buf = talloc_zero(mem_ctx, struct dns_buffer))) {
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
|
|
/*
|
|
* UDP based DNS can only be 512 bytes
|
|
*/
|
|
|
|
if (!(buf->data = talloc_array(buf, uint8_t, 512))) {
|
|
TALLOC_FREE(buf);
|
|
return ERROR_DNS_NO_MEMORY;
|
|
}
|
|
|
|
received = recv(conn->s, (void *)buf->data, 512, 0);
|
|
|
|
if (received == -1) {
|
|
TALLOC_FREE(buf);
|
|
return ERROR_DNS_SOCKET_ERROR;
|
|
}
|
|
|
|
if (received > 512) {
|
|
TALLOC_FREE(buf);
|
|
return ERROR_DNS_BAD_RESPONSE;
|
|
}
|
|
|
|
buf->size = received;
|
|
buf->offset = 0;
|
|
|
|
*presult = buf;
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|
|
|
|
DNS_ERROR dns_receive(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
|
|
struct dns_buffer **presult)
|
|
{
|
|
if (conn->hType == DNS_TCP) {
|
|
return dns_receive_tcp(mem_ctx, conn, presult);
|
|
}
|
|
|
|
if (conn->hType == DNS_UDP) {
|
|
return dns_receive_udp(mem_ctx, conn, presult);
|
|
}
|
|
|
|
return ERROR_DNS_INVALID_PARAMETER;
|
|
}
|
|
|
|
DNS_ERROR dns_transaction(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
|
|
const struct dns_request *req,
|
|
struct dns_request **resp)
|
|
{
|
|
struct dns_buffer *buf = NULL;
|
|
DNS_ERROR err;
|
|
|
|
err = dns_marshall_request(mem_ctx, req, &buf);
|
|
if (!ERR_DNS_IS_OK(err)) goto error;
|
|
|
|
err = dns_send(conn, buf);
|
|
if (!ERR_DNS_IS_OK(err)) goto error;
|
|
TALLOC_FREE(buf);
|
|
|
|
err = dns_receive(mem_ctx, conn, &buf);
|
|
if (!ERR_DNS_IS_OK(err)) goto error;
|
|
|
|
err = dns_unmarshall_request(mem_ctx, buf, resp);
|
|
|
|
error:
|
|
TALLOC_FREE(buf);
|
|
return err;
|
|
}
|
|
|
|
DNS_ERROR dns_update_transaction(TALLOC_CTX *mem_ctx,
|
|
struct dns_connection *conn,
|
|
struct dns_update_request *up_req,
|
|
struct dns_update_request **up_resp)
|
|
{
|
|
struct dns_request *resp;
|
|
DNS_ERROR err;
|
|
|
|
err = dns_transaction(mem_ctx, conn, dns_update2request(up_req),
|
|
&resp);
|
|
|
|
if (!ERR_DNS_IS_OK(err)) return err;
|
|
|
|
*up_resp = dns_request2update(resp);
|
|
return ERROR_DNS_SUCCESS;
|
|
}
|