summaryrefslogtreecommitdiffstats
path: root/source3/lib/background.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--source3/lib/background.c256
1 files changed, 256 insertions, 0 deletions
diff --git a/source3/lib/background.c b/source3/lib/background.c
new file mode 100644
index 0000000..cf6cc3a
--- /dev/null
+++ b/source3/lib/background.c
@@ -0,0 +1,256 @@
+/*
+ Unix SMB/CIFS implementation.
+ Regular background jobs as forked helpers
+ Copyright (C) Volker Lendecke 2012
+
+ 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 "lib/util/tevent_ntstatus.h"
+#include "lib/async_req/async_sock.h"
+#include "include/messages.h"
+#include "background.h"
+
+struct background_job_state {
+ struct tevent_context *ev;
+ struct messaging_context *msg;
+ uint32_t *trigger_msgs;
+ size_t num_trigger_msgs;
+ bool parent_longlived;
+ int (*fn)(void *private_data);
+ void *private_data;
+
+ struct tevent_req *wakeup_req;
+ int pipe_fd;
+ struct tevent_req *pipe_req;
+};
+
+static int background_job_state_destructor(struct background_job_state *s);
+static void background_job_waited(struct tevent_req *subreq);
+static void background_job_done(struct tevent_req *subreq);
+static bool background_job_trigger(
+ struct messaging_rec *rec, void *private_data);
+
+struct tevent_req *background_job_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct messaging_context *msg,
+ uint32_t *trigger_msgs,
+ size_t num_trigger_msgs,
+ time_t initial_wait_sec,
+ int (*fn)(void *private_data),
+ void *private_data)
+{
+ struct tevent_req *req, *subreq;
+ struct background_job_state *state;
+ size_t i;
+
+ req = tevent_req_create(mem_ctx, &state,
+ struct background_job_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ state->ev = ev;
+ state->msg = msg;
+
+ if (num_trigger_msgs != 0) {
+ state->trigger_msgs = (uint32_t *)talloc_memdup(
+ state, trigger_msgs,
+ sizeof(uint32_t) * num_trigger_msgs);
+ if (tevent_req_nomem(state->trigger_msgs, req)) {
+ return tevent_req_post(req, ev);
+ }
+ state->num_trigger_msgs = num_trigger_msgs;
+ }
+
+ state->fn = fn;
+ state->private_data = private_data;
+
+ state->pipe_fd = -1;
+ talloc_set_destructor(state, background_job_state_destructor);
+
+ for (i=0; i<num_trigger_msgs; i++) {
+ subreq = messaging_filtered_read_send(
+ state, ev, msg, background_job_trigger, state);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ }
+
+ subreq = tevent_wakeup_send(
+ state, state->ev, timeval_current_ofs(initial_wait_sec, 0));
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(subreq, background_job_waited, req);
+ state->wakeup_req = subreq;
+ return req;
+}
+
+static int background_job_state_destructor(struct background_job_state *state)
+{
+ TALLOC_FREE(state->pipe_req);
+ if (state->pipe_fd != -1) {
+ close(state->pipe_fd);
+ state->pipe_fd = -1;
+ }
+
+ return 0;
+}
+
+static bool background_job_trigger(
+ struct messaging_rec *rec, void *private_data)
+{
+ struct background_job_state *state = talloc_get_type_abort(
+ private_data, struct background_job_state);
+ size_t i;
+
+ if (state->wakeup_req == NULL) {
+ return false;
+ }
+ for (i=0; i<state->num_trigger_msgs; i++) {
+ if (rec->msg_type == state->trigger_msgs[i]) {
+ break;
+ }
+ }
+ if (i == state->num_trigger_msgs) {
+ return false;
+ }
+ if (!tevent_req_set_endtime(state->wakeup_req, state->ev,
+ timeval_zero())) {
+ DEBUG(10, ("tevent_req_set_endtime failed\n"));
+ }
+ return false;
+}
+
+static void background_job_waited(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct background_job_state *state = tevent_req_data(
+ req, struct background_job_state);
+ int fds[2];
+ int res;
+ bool ret;
+
+ ret = tevent_wakeup_recv(subreq);
+ TALLOC_FREE(subreq);
+ state->wakeup_req = NULL;
+ if (!ret) {
+ tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
+ return;
+ }
+
+ res = pipe(fds);
+ if (res == -1) {
+ tevent_req_nterror(req, map_nt_error_from_unix(errno));
+ return;
+ }
+
+ res = fork();
+ if (res == -1) {
+ int err = errno;
+ close(fds[0]);
+ close(fds[1]);
+ tevent_req_nterror(req, map_nt_error_from_unix(err));
+ return;
+ }
+
+ if (res == 0) {
+ /* child */
+
+ NTSTATUS status;
+ ssize_t written;
+
+ close(fds[0]);
+
+ status = reinit_after_fork(state->msg, state->ev, true);
+ if (NT_STATUS_IS_OK(status)) {
+ res = state->fn(state->private_data);
+ } else {
+ res = -1;
+ }
+ written = write(fds[1], &res, sizeof(res));
+ if (written == -1) {
+ _exit(1);
+ }
+
+ /*
+ * No TALLOC_FREE here, messaging_parent_dgm_cleanup_init for
+ * example calls background_job_send with "messaging_context"
+ * as talloc parent. Thus "state" will be freed with the
+ * following talloc_free will have removed "state" when it
+ * returns. TALLOC_FREE will then write a NULL into free'ed
+ * memory. talloc_free() is required although we immediately
+ * exit, the messaging_context's destructor will want to clean
+ * up.
+ */
+ talloc_free(state->msg);
+ _exit(0);
+ }
+
+ /* parent */
+
+ close(fds[1]);
+ state->pipe_fd = fds[0];
+
+ subreq = read_packet_send(state, state->ev, state->pipe_fd,
+ sizeof(int), NULL, NULL);
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+ tevent_req_set_callback(subreq, background_job_done, req);
+ state->pipe_req = subreq;
+}
+
+static void background_job_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct background_job_state *state = tevent_req_data(
+ req, struct background_job_state);
+ ssize_t ret;
+ uint8_t *buf;
+ int err;
+ int wait_secs;
+
+ state->pipe_req = NULL;
+
+ ret = read_packet_recv(subreq, talloc_tos(), &buf, &err);
+ TALLOC_FREE(subreq);
+ if (ret == -1) {
+ tevent_req_nterror(req, map_nt_error_from_unix(err));
+ return;
+ }
+ close(state->pipe_fd);
+ state->pipe_fd = -1;
+ memcpy(&wait_secs, buf, sizeof(wait_secs));
+ if (wait_secs == -1) {
+ tevent_req_done(req);
+ return;
+ }
+ subreq = tevent_wakeup_send(
+ state, state->ev, timeval_current_ofs(wait_secs, 0));
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+ tevent_req_set_callback(subreq, background_job_waited, req);
+ state->wakeup_req = subreq;
+}
+
+NTSTATUS background_job_recv(struct tevent_req *req)
+{
+ return tevent_req_simple_recv_ntstatus(req);
+}