async libwbclient infrastructure

1 files changed, 774 insertions, 0 deletions

diff --git a/source3/lib/wbclient.c b/source3/lib/wbclient.c
new file mode 100644
index 0000000000..d58c934c07
--- /dev/null
+++ b/source3/lib/wbclient.c
@@ -0,0 +1,774 @@
+/*
+   Unix SMB/CIFS implementation.
+   Infrastructure for async winbind requests
+   Copyright (C) Volker Lendecke 2008
+
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "winbindd/winbindd.h"
+#include "winbindd/winbindd_proto.h"
+
+static int make_nonstd_fd(int fd)
+{
+	int i;
+	int sys_errno = 0;
+	int fds[3];
+	int num_fds = 0;
+
+	if (fd == -1) {
+		return -1;
+	}
+	while (fd < 3) {
+		fds[num_fds++] = fd;
+		fd = dup(fd);
+		if (fd == -1) {
+			sys_errno = errno;
+			break;
+		}
+	}
+	for (i=0; i<num_fds; i++) {
+		close(fds[i]);
+	}
+	if (fd == -1) {
+		errno = sys_errno;
+	}
+	return fd;
+}
+
+/****************************************************************************
+ Set a fd into blocking/nonblocking mode. Uses POSIX O_NONBLOCK if available,
+ else
+ if SYSV use O_NDELAY
+ if BSD use FNDELAY
+ Set close on exec also.
+****************************************************************************/
+
+static int make_safe_fd(int fd)
+{
+	int result, flags;
+	int new_fd = make_nonstd_fd(fd);
+
+	if (new_fd == -1) {
+		goto fail;
+	}
+
+	/* Socket should be nonblocking. */
+
+#ifdef O_NONBLOCK
+#define FLAG_TO_SET O_NONBLOCK
+#else
+#ifdef SYSV
+#define FLAG_TO_SET O_NDELAY
+#else /* BSD */
+#define FLAG_TO_SET FNDELAY
+#endif
+#endif
+
+	if ((flags = fcntl(new_fd, F_GETFL)) == -1) {
+		goto fail;
+	}
+
+	flags |= FLAG_TO_SET;
+	if (fcntl(new_fd, F_SETFL, flags) == -1) {
+		goto fail;
+	}
+
+#undef FLAG_TO_SET
+
+	/* Socket should be closed on exec() */
+#ifdef FD_CLOEXEC
+	result = flags = fcntl(new_fd, F_GETFD, 0);
+	if (flags >= 0) {
+		flags |= FD_CLOEXEC;
+		result = fcntl( new_fd, F_SETFD, flags );
+	}
+	if (result < 0) {
+		goto fail;
+	}
+#endif
+	return new_fd;
+
+ fail:
+	if (new_fd != -1) {
+		int sys_errno = errno;
+		close(new_fd);
+		errno = sys_errno;
+	}
+	return -1;
+}
+
+static bool winbind_closed_fd(int fd)
+{
+	struct timeval tv;
+	fd_set r_fds;
+
+	if (fd == -1) {
+		return true;
+	}
+
+	FD_ZERO(&r_fds);
+	FD_SET(fd, &r_fds);
+	ZERO_STRUCT(tv);
+
+	if ((select(fd+1, &r_fds, NULL, NULL, &tv) == -1)
+	    || FD_ISSET(fd, &r_fds)) {
+		return true;
+	}
+
+	return false;
+}
+
+struct wb_context {
+	struct async_req_queue *queue;
+	int fd;
+	bool is_priv;
+};
+
+struct wb_context *wb_context_init(TALLOC_CTX *mem_ctx)
+{
+	struct wb_context *result;
+
+	result = talloc(mem_ctx, struct wb_context);
+	if (result == NULL) {
+		return NULL;
+	}
+	result->queue = async_req_queue_init(result);
+	if (result->queue == NULL) {
+		TALLOC_FREE(result);
+		return NULL;
+	}
+	result->fd = -1;
+	return result;
+}
+
+static struct async_req *wb_connect_send(TALLOC_CTX *mem_ctx,
+					 struct event_context *ev,
+					 struct wb_context *wb_ctx,
+					 const char *dir)
+{
+	struct async_req *req;
+	struct sockaddr_un sunaddr;
+	struct stat st;
+	char *path = NULL;
+	NTSTATUS status;
+
+	if (wb_ctx->fd != -1) {
+		close(wb_ctx->fd);
+		wb_ctx->fd = -1;
+	}
+
+	/* Check permissions on unix socket directory */
+
+	if (lstat(dir, &st) == -1) {
+		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+		goto post_status;
+	}
+
+	if (!S_ISDIR(st.st_mode) ||
+	    (st.st_uid != 0 && st.st_uid != geteuid())) {
+		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+		goto post_status;
+	}
+
+	/* Connect to socket */
+
+	path = talloc_asprintf(talloc_tos(), "%s/%s", dir,
+			       WINBINDD_SOCKET_NAME);
+	if (path == NULL) {
+		goto nomem;
+	}
+
+	sunaddr.sun_family = AF_UNIX;
+	strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path));
+	TALLOC_FREE(path);
+
+	/* If socket file doesn't exist, don't bother trying to connect
+	   with retry.  This is an attempt to make the system usable when
+	   the winbindd daemon is not running. */
+
+	if ((lstat(sunaddr.sun_path, &st) == -1)
+	    || !S_ISSOCK(st.st_mode)
+	    || (st.st_uid != 0 && st.st_uid != geteuid())) {
+		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+		goto post_status;
+	}
+
+	wb_ctx->fd = make_safe_fd(socket(AF_UNIX, SOCK_STREAM, 0));
+	if (wb_ctx->fd == -1) {
+		status = map_nt_error_from_unix(errno);
+		goto post_status;
+	}
+
+	req = async_connect_send(mem_ctx, ev, wb_ctx->fd,
+				 (struct sockaddr *)&sunaddr,
+				 sizeof(sunaddr));
+	if (req == NULL) {
+		goto nomem;
+	}
+	if (!async_req_set_timeout(req, ev, timeval_set(30, 0))) {
+		TALLOC_FREE(req);
+		goto nomem;
+	}
+
+	return req;
+
+ nomem:
+	status = NT_STATUS_NO_MEMORY;
+ post_status:
+	req = async_req_new(mem_ctx);
+	if (req == NULL) {
+		return NULL;
+	}
+	if (async_post_status(req, ev, status)) {
+		return req;
+	}
+	TALLOC_FREE(req);
+	return NULL;
+}
+
+static NTSTATUS wb_connect_recv(struct async_req *req)
+{
+	int dummy;
+
+	return async_connect_recv(req, &dummy);
+}
+
+static struct winbindd_request *winbindd_request_copy(
+	TALLOC_CTX *mem_ctx,
+	const struct winbindd_request *req)
+{
+	struct winbindd_request *result;
+
+	result = (struct winbindd_request *)TALLOC_MEMDUP(
+		mem_ctx, req, sizeof(struct winbindd_request));
+	if (result == NULL) {
+		return NULL;
+	}
+
+	if (result->extra_len == 0) {
+		return result;
+	}
+
+	result->extra_data.data = (char *)TALLOC_MEMDUP(
+		result, result->extra_data.data, result->extra_len);
+	if (result->extra_data.data == NULL) {
+		TALLOC_FREE(result);
+		return NULL;
+	}
+	return result;
+}
+
+struct wb_int_trans_state {
+	struct event_context *ev;
+	int fd;
+	struct winbindd_request *wb_req;
+	struct winbindd_response *wb_resp;
+};
+
+static void wb_int_trans_write_done(struct async_req *subreq);
+static void wb_int_trans_read_done(struct async_req *subreq);
+
+static struct async_req *wb_int_trans_send(TALLOC_CTX *mem_ctx,
+					   struct event_context *ev, int fd,
+					   struct winbindd_request *wb_req)
+{
+	struct async_req *result;
+	struct async_req *subreq;
+	struct wb_int_trans_state *state;
+
+	result = async_req_new(mem_ctx);
+	if (result == NULL) {
+		return NULL;
+	}
+	state = talloc(result, struct wb_int_trans_state);
+	if (state == NULL) {
+		goto fail;
+	}
+	result->private_data = state;
+
+	if (winbind_closed_fd(fd)) {
+		if (!async_post_status(result, ev,
+				       NT_STATUS_PIPE_DISCONNECTED)) {
+			goto fail;
+		}
+		return result;
+	}
+
+	state->ev = ev;
+	state->fd = fd;
+	state->wb_req = wb_req;
+
+	state->wb_req->length = sizeof(struct winbindd_request);
+	state->wb_req->pid = getpid();
+
+	subreq = wb_req_write_send(state, state->ev, state->fd, state->wb_req);
+	if (subreq == NULL) {
+		goto fail;
+	}
+	subreq->async.fn = wb_int_trans_write_done;
+	subreq->async.priv = result;
+
+	return result;
+
+ fail:
+	TALLOC_FREE(result);
+	return NULL;
+}
+
+static void wb_int_trans_write_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_int_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_int_trans_state);
+	NTSTATUS status;
+
+	status = wb_req_write_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		async_req_error(req, status);
+		return;
+	}
+
+	subreq = wb_resp_read_send(state, state->ev, state->fd);
+	if (subreq == NULL) {
+		async_req_error(req, NT_STATUS_NO_MEMORY);
+	}
+	subreq->async.fn = wb_int_trans_read_done;
+	subreq->async.priv = req;
+}
+
+static void wb_int_trans_read_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_int_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_int_trans_state);
+	NTSTATUS status;
+
+	status = wb_resp_read_recv(subreq, state, &state->wb_resp);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		async_req_error(req, status);
+		return;
+	}
+
+	async_req_done(req);
+}
+
+static NTSTATUS wb_int_trans_recv(struct async_req *req,
+				  TALLOC_CTX *mem_ctx,
+				  struct winbindd_response **presponse)
+{
+	struct wb_int_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_int_trans_state);
+	NTSTATUS status;
+
+	if (async_req_is_error(req, &status)) {
+		return status;
+	}
+
+	*presponse = talloc_move(mem_ctx, &state->wb_resp);
+	return NT_STATUS_OK;
+}
+
+static const char *winbindd_socket_dir(void)
+{
+#ifdef SOCKET_WRAPPER
+	const char *env_dir;
+
+	env_dir = getenv(WINBINDD_SOCKET_DIR_ENVVAR);
+	if (env_dir) {
+		return env_dir;
+	}
+#endif
+
+	return WINBINDD_SOCKET_DIR;
+}
+
+struct wb_open_pipe_state {
+	struct wb_context *wb_ctx;
+	struct event_context *ev;
+	bool need_priv;
+	struct winbindd_request wb_req;
+};
+
+static void wb_open_pipe_connect_nonpriv_done(struct async_req *subreq);
+static void wb_open_pipe_ping_done(struct async_req *subreq);
+static void wb_open_pipe_getpriv_done(struct async_req *subreq);
+static void wb_open_pipe_connect_priv_done(struct async_req *subreq);
+
+static struct async_req *wb_open_pipe_send(TALLOC_CTX *mem_ctx,
+					   struct event_context *ev,
+					   struct wb_context *wb_ctx,
+					   bool need_priv)
+{
+	struct async_req *result;
+	struct async_req *subreq;
+	struct wb_open_pipe_state *state;
+
+	result = async_req_new(mem_ctx);
+	if (result == NULL) {
+		return NULL;
+	}
+	state = talloc(result, struct wb_open_pipe_state);
+	if (state == NULL) {
+		goto fail;
+	}
+	result->private_data = state;
+
+	state->wb_ctx = wb_ctx;
+	state->ev = ev;
+	state->need_priv = need_priv;
+
+	if (wb_ctx->fd != -1) {
+		close(wb_ctx->fd);
+		wb_ctx->fd = -1;
+	}
+
+	subreq = wb_connect_send(state, ev, wb_ctx, winbindd_socket_dir());
+	if (subreq == NULL) {
+		goto fail;
+	}
+
+	subreq->async.fn = wb_open_pipe_connect_nonpriv_done;
+	subreq->async.priv = result;
+	return result;
+
+ fail:
+	TALLOC_FREE(result);
+	return NULL;
+}
+
+static void wb_open_pipe_connect_nonpriv_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_open_pipe_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_open_pipe_state);
+	NTSTATUS status;
+
+	status = wb_connect_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		state->wb_ctx->is_priv = true;
+		async_req_error(req, status);
+		return;
+	}
+
+	ZERO_STRUCT(state->wb_req);
+	state->wb_req.cmd = WINBINDD_INTERFACE_VERSION;
+
+	subreq = wb_int_trans_send(state, state->ev, state->wb_ctx->fd,
+				   &state->wb_req);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+
+	subreq->async.fn = wb_open_pipe_ping_done;
+	subreq->async.priv = req;
+}
+
+static void wb_open_pipe_ping_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_open_pipe_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_open_pipe_state);
+	struct winbindd_response *wb_resp;
+	NTSTATUS status;
+
+	status = wb_int_trans_recv(subreq, state, &wb_resp);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		async_req_error(req, status);
+		return;
+	}
+
+	if (!state->need_priv) {
+		async_req_done(req);
+		return;
+	}
+
+	state->wb_req.cmd = WINBINDD_PRIV_PIPE_DIR;
+
+	subreq = wb_int_trans_send(state, state->ev, state->wb_ctx->fd,
+				   &state->wb_req);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+
+	subreq->async.fn = wb_open_pipe_getpriv_done;
+	subreq->async.priv = req;
+}
+
+static void wb_open_pipe_getpriv_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_open_pipe_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_open_pipe_state);
+	struct winbindd_response *wb_resp = NULL;
+	NTSTATUS status;
+
+	status = wb_int_trans_recv(subreq, state, &wb_resp);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		async_req_error(req, status);
+		return;
+	}
+
+	close(state->wb_ctx->fd);
+	state->wb_ctx->fd = -1;
+
+	subreq = wb_connect_send(state, state->ev, state->wb_ctx,
+				 (char *)wb_resp->extra_data.data);
+	TALLOC_FREE(wb_resp);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+
+	subreq->async.fn = wb_open_pipe_connect_priv_done;
+	subreq->async.priv = req;
+}
+
+static void wb_open_pipe_connect_priv_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_open_pipe_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_open_pipe_state);
+	NTSTATUS status;
+
+	status = wb_connect_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		async_req_error(req, status);
+		return;
+	}
+	state->wb_ctx->is_priv = true;
+	async_req_done(req);
+}
+
+static NTSTATUS wb_open_pipe_recv(struct async_req *req)
+{
+	return async_req_simple_recv(req);
+}
+
+struct wb_trans_state {
+	struct wb_trans_state *prev, *next;
+	struct wb_context *wb_ctx;
+	struct event_context *ev;
+	struct winbindd_request *wb_req;
+	struct winbindd_response *wb_resp;
+	int num_retries;
+	bool need_priv;
+};
+
+static void wb_trans_connect_done(struct async_req *subreq);
+static void wb_trans_done(struct async_req *subreq);
+static void wb_trans_retry_wait_done(struct async_req *subreq);
+
+static void wb_trigger_trans(struct async_req *req)
+{
+	struct wb_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_trans_state);
+	struct async_req *subreq;
+
+	if ((state->wb_ctx->fd == -1)
+	    || (state->need_priv && !state->wb_ctx->is_priv)) {
+
+		subreq = wb_open_pipe_send(state, state->ev, state->wb_ctx,
+					   state->need_priv);
+		if (async_req_nomem(subreq, req)) {
+			return;
+		}
+		subreq->async.fn = wb_trans_connect_done;
+		subreq->async.priv = req;
+		return;
+	}
+
+	subreq = wb_int_trans_send(state, state->ev, state->wb_ctx->fd,
+				   state->wb_req);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+	subreq->async.fn = wb_trans_done;
+	subreq->async.priv = req;
+}
+
+struct async_req *wb_trans_send(TALLOC_CTX *mem_ctx, struct event_context *ev,
+				struct wb_context *wb_ctx, bool need_priv,
+				const struct winbindd_request *wb_req)
+{
+	struct async_req *result;
+	struct wb_trans_state *state;
+
+	result = async_req_new(mem_ctx);
+	if (result == NULL) {
+		return NULL;
+	}
+	state = talloc(result, struct wb_trans_state);
+	if (state == NULL) {
+		goto fail;
+	}
+	result->private_data = state;
+
+	state->wb_ctx = wb_ctx;
+	state->ev = ev;
+	state->wb_req = winbindd_request_copy(state, wb_req);
+	if (state->wb_req == NULL) {
+		goto fail;
+	}
+	state->num_retries = 10;
+	state->need_priv = need_priv;
+
+	if (!async_req_enqueue(wb_ctx->queue, ev, result, wb_trigger_trans)) {
+		goto fail;
+	}
+	return result;
+
+ fail:
+	TALLOC_FREE(result);
+	return NULL;
+}
+
+static bool wb_trans_retry(struct async_req *req,
+			   struct wb_trans_state *state,
+			   NTSTATUS status)
+{
+	struct async_req *subreq;
+
+	if (NT_STATUS_IS_OK(status)) {
+		return false;
+	}
+
+	if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)
+	    || NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
+		/*
+		 * Winbind not around or we can't connect to the pipe. Fail
+		 * immediately.
+		 */
+		async_req_error(req, status);
+		return true;
+	}
+
+	state->num_retries -= 1;
+	if (state->num_retries == 0) {
+		async_req_error(req, status);
+		return true;
+	}
+
+	/*
+	 * The transfer as such failed, retry after one second
+	 */
+
+	if (state->wb_ctx->fd != -1) {
+		close(state->wb_ctx->fd);
+		state->wb_ctx->fd = -1;
+	}
+
+	subreq = async_wait_send(state, state->ev, timeval_set(1, 0));
+	if (async_req_nomem(subreq, req)) {
+		return true;
+	}
+
+	subreq->async.fn = wb_trans_retry_wait_done;
+	subreq->async.priv = req;
+	return true;
+}
+
+static void wb_trans_retry_wait_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_trans_state);
+	NTSTATUS status;
+
+	status = async_wait_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
+		async_req_error(req, status);
+		return;
+	}
+
+	subreq = wb_open_pipe_send(state, state->ev, state->wb_ctx,
+				   state->need_priv);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+	subreq->async.fn = wb_trans_connect_done;
+	subreq->async.priv = req;
+}
+
+static void wb_trans_connect_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_trans_state);
+	NTSTATUS status;
+
+	status = wb_open_pipe_recv(subreq);
+	TALLOC_FREE(subreq);
+
+	if (wb_trans_retry(req, state, status)) {
+		return;
+	}
+
+	subreq = wb_int_trans_send(state, state->ev, state->wb_ctx->fd,
+				   state->wb_req);
+	if (async_req_nomem(subreq, req)) {
+		return;
+	}
+
+	subreq->async.fn = wb_trans_done;
+	subreq->async.priv = req;
+}
+
+static void wb_trans_done(struct async_req *subreq)
+{
+	struct async_req *req = talloc_get_type_abort(
+		subreq->async.priv, struct async_req);
+	struct wb_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_trans_state);
+	NTSTATUS status;
+
+	status = wb_int_trans_recv(subreq, state, &state->wb_resp);
+	TALLOC_FREE(subreq);
+
+	if (wb_trans_retry(req, state, status)) {
+		return;
+	}
+
+	async_req_done(req);
+}
+
+NTSTATUS wb_trans_recv(struct async_req *req, TALLOC_CTX *mem_ctx,
+		       struct winbindd_response **presponse)
+{
+	struct wb_trans_state *state = talloc_get_type_abort(
+		req->private_data, struct wb_trans_state);
+	NTSTATUS status;
+
+	if (async_req_is_error(req, &status)) {
+		return status;
+	}
+
+	*presponse = talloc_move(mem_ctx, &state->wb_resp);
+	return NT_STATUS_OK;
+}