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-rw-r--r--lib/addns/dnssock.c420
1 files changed, 420 insertions, 0 deletions
diff --git a/lib/addns/dnssock.c b/lib/addns/dnssock.c
new file mode 100644
index 0000000..11f2e00
--- /dev/null
+++ b/lib/addns/dnssock.c
@@ -0,0 +1,420 @@
+/*
+ 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"
+#include "../lib/util/debug.h"
+
+static int destroy_dns_connection(struct dns_connection *conn)
+{
+ return close(conn->s);
+}
+
+/********************************************************************
+********************************************************************/
+
+static DNS_ERROR dns_open_helper(const char *nameserver,
+ const char *service,
+ struct addrinfo *hints,
+ TALLOC_CTX *mem_ctx,
+ struct dns_connection **ret_conn)
+{
+ int ret;
+ struct addrinfo *rp;
+ struct addrinfo *ai_result = NULL;
+ struct dns_connection *conn = NULL;
+
+ if (!(conn = talloc(mem_ctx, struct dns_connection))) {
+ return ERROR_DNS_NO_MEMORY;
+ }
+
+ ret = getaddrinfo(nameserver, service, hints, &ai_result);
+ if (ret != 0) {
+ DEBUG(1,("dns_tcp_open: getaddrinfo: %s\n", gai_strerror(ret)));
+ TALLOC_FREE(conn);
+ return ERROR_DNS_INVALID_NAME_SERVER;
+ }
+
+ for (rp = ai_result; rp != NULL; rp = rp->ai_next) {
+ conn->s = socket(rp->ai_family,
+ rp->ai_socktype,
+ rp->ai_protocol);
+ if (conn->s == -1) {
+ continue;
+ }
+ do {
+ ret = connect(conn->s, rp->ai_addr, rp->ai_addrlen);
+ } while ((ret == -1) && (errno == EINTR));
+ if (ret != -1) {
+ /* Successful connect */
+ break;
+ }
+ close(conn->s);
+ }
+
+ freeaddrinfo(ai_result);
+
+ if (rp == NULL) {
+ TALLOC_FREE(conn);
+ return ERROR_DNS_CONNECTION_FAILED;
+ }
+
+ talloc_set_destructor(conn, destroy_dns_connection);
+
+ *ret_conn = conn;
+ return ERROR_DNS_SUCCESS;
+}
+
+static DNS_ERROR dns_tcp_open( const char *nameserver,
+ TALLOC_CTX *mem_ctx,
+ struct dns_connection **result )
+{
+ struct addrinfo hints;
+ struct dns_connection *conn;
+ DNS_ERROR dns_ret;
+ char service[16];
+
+ snprintf(service, sizeof(service), "%d", DNS_TCP_PORT);
+
+ memset(&hints, 0, sizeof(struct addrinfo));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+ hints.ai_flags = 0;
+ hints.ai_protocol = IPPROTO_TCP;
+
+ dns_ret = dns_open_helper(nameserver, service, &hints, mem_ctx, &conn);
+ if (!ERR_DNS_IS_OK(dns_ret)) {
+ return dns_ret;
+ }
+
+ 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 )
+{
+ struct addrinfo hints;
+ struct sockaddr_storage RecvAddr;
+ struct dns_connection *conn = NULL;
+ DNS_ERROR dns_ret;
+ socklen_t RecvAddrLen;
+ char service[16];
+
+ snprintf(service, sizeof(service), "%d", DNS_UDP_PORT);
+
+ memset(&hints, 0, sizeof(struct addrinfo));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_DGRAM;
+ hints.ai_flags = 0;
+ hints.ai_protocol = IPPROTO_UDP;
+
+ dns_ret = dns_open_helper(nameserver, service, &hints, mem_ctx, &conn);
+ if (!ERR_DNS_IS_OK(dns_ret)) {
+ TALLOC_FREE(conn);
+ return dns_ret;
+ }
+
+ /* Set up the RecvAddr structure with the IP address of
+ the receiver and the specified port number. */
+
+ RecvAddrLen = sizeof(RecvAddr);
+ if (getpeername(conn->s,
+ (struct sockaddr *)&RecvAddr,
+ &RecvAddrLen) == -1) {
+ return ERROR_DNS_CONNECTION_FAILED;
+ }
+
+ conn->hType = DNS_UDP;
+ memcpy(&conn->RecvAddr, &RecvAddr, sizeof(struct sockaddr_storage));
+
+ *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;
+
+ do {
+ ret = write(fd, data + total, len - total);
+ } while ((ret == -1) && (errno == EINTR));
+
+ 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;
+
+ do {
+ ret = send(conn->s, buf->data, buf->offset, 0);
+ } while ((ret == -1) && (errno == EINTR));
+
+ 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 == -1) {
+ if (errno == EINTR) {
+ continue;
+ }
+ return ERROR_DNS_SOCKET_ERROR;
+ }
+ if ( fd_ready == 0 ) {
+ /* read timeout */
+ return ERROR_DNS_SOCKET_ERROR;
+ }
+
+ do {
+ ret = read(fd, data + total, len - total);
+ } while ((ret == -1) && (errno == EINTR));
+
+ 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 == 0) {
+ *presult = buf;
+ return ERROR_DNS_SUCCESS;
+ }
+
+ if (!(buf->data = talloc_array(buf, uint8_t, buf->size))) {
+ TALLOC_FREE(buf);
+ return ERROR_DNS_NO_MEMORY;
+ }
+
+ err = read_all(conn->s, buf->data, talloc_get_size(buf->data));
+ 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;
+ }
+
+ do {
+ received = recv(conn->s, (void *)buf->data, 512, 0);
+ } while ((received == -1) && (errno == EINTR));
+
+ 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;
+}
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