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-rw-r--r--lib/addns/dnssock.c377
1 files changed, 377 insertions, 0 deletions
diff --git a/lib/addns/dnssock.c b/lib/addns/dnssock.c
new file mode 100644
index 0000000000..7c8bd418e5
--- /dev/null
+++ b/lib/addns/dnssock.c
@@ -0,0 +1,377 @@
+/*
+ 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 "dns.h"
+#include <sys/time.h>
+#include <unistd.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 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 *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 len = htons(buf->offset);
+ DNS_ERROR err;
+
+ err = write_all(conn->s, (uint8 *)&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 *data, size_t len)
+{
+ size_t total = 0;
+ fd_set rfds;
+ struct timeval tv;
+
+ while (total < len) {
+ ssize_t ret;
+ int fd_ready;
+
+ FD_ZERO( &rfds );
+ FD_SET( fd, &rfds );
+
+ /* 10 second timeout */
+ tv.tv_sec = 10;
+ tv.tv_usec = 0;
+
+ fd_ready = select( fd+1, &rfds, NULL, NULL, &tv );
+ 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 len;
+
+ if (!(buf = TALLOC_ZERO_P(mem_ctx, struct dns_buffer))) {
+ return ERROR_DNS_NO_MEMORY;
+ }
+
+ err = read_all(conn->s, (uint8 *)&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, 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_P(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, 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(conn, 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;
+}
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