#include <config.h>
#include "daemon.h"
+#include "daemon-private.h"
#include <stdio.h>
#include <stdlib.h>
#include "poll-loop.h"
#include "vlog.h"
-VLOG_DEFINE_THIS_MODULE(daemon);
+VLOG_DEFINE_THIS_MODULE(daemon_windows);
static bool service_create; /* Was --service specified? */
static bool service_started; /* Have we dispatched service to start? */
* unexpectedly? */
static bool monitor;
+bool detach; /* Was --detach specified? */
+static bool detached; /* Running as the child process. */
+static HANDLE write_handle; /* End of pipe to write to parent. */
+
+char *pidfile; /* --pidfile: Name of pidfile (null if none). */
+static FILE *filep_pidfile; /* File pointer to access the pidfile. */
+
/* Handle to the Services Manager and the created service. */
static SC_HANDLE manager, service;
static void init_service_status(void);
static void set_config_failure_actions(void);
+static bool detach_process(int argc, char *argv[]);
+
extern int main(int argc, char *argv[]);
void
{NULL, NULL}
};
+ /* If one of the command line option is "--detach", we create
+ * a new process in case of parent, wait for child to start and exit.
+ * In case of the child, we just return. We should not be creating a
+ * service in either case. */
+ if (detach_process(argc, argv)) {
+ return;
+ }
+
/* 'service_started' is 'false' when service_start() is called the first
* time. It is 'true', when it is called the second time by the Windows
* services manager. */
}
}
-\f
-/* Stub functions to handle daemonize related calls in non-windows platform. */
-bool
-get_detach()
+/* When a daemon is passed the --detach option, we create a new
+ * process and pass an additional non-documented option called --pipe-handle.
+ * Through this option, the parent passes one end of a pipe handle. */
+void
+set_pipe_handle(const char *pipe_handle)
{
- return false;
+ write_handle = (HANDLE) atoi(pipe_handle);
}
-void
-daemon_save_fd(int fd OVS_UNUSED)
+/* If one of the command line option is "--detach", creates
+ * a new process in case of parent, waits for child to start and exits.
+ * In case of the child, returns. */
+static bool
+detach_process(int argc, char *argv[])
{
+ SECURITY_ATTRIBUTES sa;
+ STARTUPINFO si;
+ PROCESS_INFORMATION pi;
+ HANDLE read_pipe, write_pipe;
+ char *buffer;
+ int error, i;
+ char ch;
+
+ /* We are only interested in the '--detach' and '--pipe-handle'. */
+ for (i = 0; i < argc; i ++) {
+ if (!strcmp(argv[i], "--detach")) {
+ detach = true;
+ } else if (!strncmp(argv[i], "--pipe-handle", 13)) {
+ /* If running as a child, return. */
+ detached = true;
+ return true;
+ }
+ }
+
+ /* Nothing to do if the option --detach is not set. */
+ if (!detach) {
+ return false;
+ }
+
+ /* Set the security attribute such that a process created will
+ * inherit the pipe handles. */
+ sa.nLength = sizeof(sa);
+ sa.lpSecurityDescriptor = NULL;
+ sa.bInheritHandle = TRUE;
+
+ /* Create an anonymous pipe to communicate with the child. */
+ error = CreatePipe(&read_pipe, &write_pipe, &sa, 0);
+ if (!error) {
+ VLOG_FATAL("CreatePipe failed (%s)", ovs_lasterror_to_string());
+ }
+
+ GetStartupInfo(&si);
+
+ /* To the child, we pass an extra argument '--pipe-handle=write_pipe' */
+ buffer = xasprintf("%s %s=%ld", GetCommandLine(), "--pipe-handle",
+ write_pipe);
+
+ /* Create a detached child */
+ error = CreateProcess(NULL, buffer, NULL, NULL, TRUE, DETACHED_PROCESS,
+ NULL, NULL, &si, &pi);
+ if (!error) {
+ VLOG_FATAL("CreateProcess failed (%s)", ovs_lasterror_to_string());
+ }
+
+ /* Close one end of the pipe in the parent. */
+ CloseHandle(write_pipe);
+
+ /* Block and wait for child to say it is ready. */
+ error = ReadFile(read_pipe, &ch, 1, NULL, NULL);
+ if (!error) {
+ VLOG_FATAL("Failed to read from child (%s)",
+ ovs_lasterror_to_string());
+ }
+ /* The child has successfully started and is ready. */
+ exit(0);
}
-void
-daemonize(void)
+static void
+unlink_pidfile(void)
{
+ if (filep_pidfile) {
+ fclose(filep_pidfile);
+ }
+ if (pidfile) {
+ unlink(pidfile);
+ }
+}
+
+/* If a pidfile has been configured, creates it and stores the running
+ * process's pid in it. Ensures that the pidfile will be deleted when the
+ * process exits. */
+static void
+make_pidfile(void)
+{
+ int error;
+
+ error = GetFileAttributes(pidfile);
+ if (error != INVALID_FILE_ATTRIBUTES) {
+ /* pidfile exists. Try to unlink() it. */
+ error = unlink(pidfile);
+ if (error) {
+ VLOG_FATAL("Failed to delete existing pidfile %s (%s)", pidfile,
+ ovs_strerror(errno));
+ }
+ }
+
+ filep_pidfile = fopen(pidfile, "w");
+ if (filep_pidfile == NULL) {
+ VLOG_FATAL("failed to open %s (%s)", pidfile, ovs_strerror(errno));
+ }
+
+ fatal_signal_add_hook(unlink_pidfile, NULL, NULL, true);
+
+ fprintf(filep_pidfile, "%d\n", _getpid());
+ if (fflush(filep_pidfile) == EOF) {
+ VLOG_FATAL("Failed to write into the pidfile %s", pidfile);
+ }
+
+ /* Don't close the pidfile till the process exits. */
}
void daemonize_start(void)
{
+ if (pidfile) {
+ make_pidfile();
+ }
}
void
daemonize_complete(void)
{
+ /* If running as a child because '--detach' option was specified,
+ * communicate with the parent to inform that the child is ready. */
+ if (detached) {
+ int error;
+
+ close_standard_fds();
+
+ error = WriteFile(write_handle, "a", 1, NULL, NULL);
+ if (!error) {
+ VLOG_FATAL("Failed to communicate with the parent (%s)",
+ ovs_lasterror_to_string());
+ }
+ }
+
service_complete();
}
+
+/* Returns the file name that would be used for a pidfile if 'name' were
+ * provided to set_pidfile(). The caller must free the returned string. */
+char *
+make_pidfile_name(const char *name)
+{
+ if (name && strchr(name, ':')) {
+ return strdup(name);
+ } else {
+ return xasprintf("%s/%s.pid", ovs_rundir(), program_name);
+ }
+}