This applies to all child processes making use of reinit_after_fork().
It is implemented by establishing a pipe between parent and child.
The child watches for EOF on the read end of the pipe, indidcating
an exited parent.
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>
char *clean_name(TALLOC_CTX *ctx, const char *s);
ssize_t write_data_at_offset(int fd, const char *buffer, size_t N, SMB_OFF_T pos);
int set_blocking(int fd, bool set);
+NTSTATUS init_before_fork(void);
NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx,
struct event_context *ev_ctx,
bool parent_longlived);
#endif
}
+static int reinit_after_fork_pipe[2] = { -1, -1 };
+
+NTSTATUS init_before_fork(void)
+{
+ int ret;
+
+ ret = pipe(reinit_after_fork_pipe);
+ if (ret == -1) {
+ NTSTATUS status;
+
+ status = map_nt_error_from_unix_common(errno);
+
+ DEBUG(0, ("Error creating child_pipe: %s\n",
+ nt_errstr(status)));
+
+ return status;
+ }
+
+ return NT_STATUS_OK;
+}
+
+/**
+ * Detect died parent by detecting EOF on the pipe
+ */
+static void reinit_after_fork_pipe_handler(struct tevent_context *ev,
+ struct tevent_fd *fde,
+ uint16_t flags,
+ void *private_data)
+{
+ char c;
+
+ if (read(reinit_after_fork_pipe[0], &c, 1) != 1) {
+ /*
+ * we have reached EOF on stdin, which means the
+ * parent has exited. Shutdown the server
+ */
+ (void)kill(getpid(), SIGTERM);
+ }
+}
+
NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx,
struct event_context *ev_ctx,
{
NTSTATUS status = NT_STATUS_OK;
+ if (reinit_after_fork_pipe[1] != -1) {
+ close(reinit_after_fork_pipe[1]);
+ reinit_after_fork_pipe[1] = -1;
+ }
+
/* Reset the state of the random
* number generation system, so
* children do not get the same random
smb_panic(__location__ ": Failed to re-initialise event context");
}
+ if (reinit_after_fork_pipe[0] != -1) {
+ struct tevent_fd *fde;
+
+ fde = tevent_add_fd(ev_ctx, ev_ctx /* TALLOC_CTX */,
+ reinit_after_fork_pipe[0], TEVENT_FD_READ,
+ reinit_after_fork_pipe_handler, NULL);
+ if (fde == NULL) {
+ smb_panic(__location__ ": Failed to add reinit_after_fork pipe event");
+ }
+ }
+
if (msg_ctx) {
/*
* For clustering, we need to re-init our ctdbd connection after the
exit(1);
}
+ /*
+ * Do not initialize the parent-child-pipe before becoming
+ * a daemon: this is used to detect a died parent in the child
+ * process.
+ */
+ status = init_before_fork();
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("init_before_fork failed: %s\n", nt_errstr(status)));
+ exit(1);
+ }
+
if (!nmbd_setup_sig_term_handler(msg))
exit(1);
if (!nmbd_setup_stdin_handler(msg, !Fork))
/* the list of current child processes */
struct smbd_child_pid *children;
size_t num_children;
+ /* pipe for detecting death of parent process in child: */
+ int child_pipe[2];
struct timed_event *cleanup_te;
};
exit(1);
}
+ /*
+ * Do not initialize the parent-child-pipe before becoming
+ * a daemon: this is used to detect a died parent in the child
+ * process.
+ */
+ status = init_before_fork();
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("init_before_fork failed: %s\n", nt_errstr(status)));
+ exit(1);
+ }
+
smbd_server_conn->msg_ctx = msg_ctx;
parent = talloc_zero(ev_ctx, struct smbd_parent_context);
exit(1);
}
+ /*
+ * Do not initialize the parent-child-pipe before becoming
+ * a daemon: this is used to detect a died parent in the child
+ * process.
+ */
+ status = init_before_fork();
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("init_before_fork failed: %s\n", nt_errstr(status)));
+ exit(1);
+ }
+
winbindd_register_handlers(!Fork);
status = init_system_info();