remove unused stuff from daemonise

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 162 insertions, 244 deletions

diff --git a/src/daemonise.c b/src/daemonise.c
index 822e0ed..be7e33e 100644
--- a/src/daemonise.c
+++ b/src/daemonise.c
@@ -19,7 +19,10 @@
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  * 
- * This file is copied from <http://github.com/maandree/slibc>.
+ * This file is copied from <http://github.com/maandree/slibc>,
+ * but with unused stuff removed. It has also been slightly modified
+ * and changed code style (these "slight" modifications do not change
+ * the behaviour.)
  */
 #define _POSIX_C_SOURCE  200809L
 #include "daemonise.h"
@@ -36,6 +39,9 @@
 #include <sys/resource.h>
 
 
+#define t(...)  do { if (__VA_ARGS__) goto fail; }  while (0)
+#define S(...)  (saved_errno = errno, __VA_ARGS__, errno = saved_errno)
+
 
 /**
  * The process's environment variables.
@@ -58,31 +64,28 @@ static char* __pidfile = NULL;
  * 
  * @throws  Any error specified for dup(3).
  */
-static int dup_at_least_3(int old)
+static int
+dup_at_least_3(int old)
 {
-  int intermediary[3];
-  int i = 0, saved_errno;
-  
-  do
-    {
-      if (old = dup(old), old == -1)
-	goto fail;
-      assert(i < 3);
-      if (i >= 3)
-	abort();
-      intermediary[i++] = old;
-    }
-  while (old < 3);
-  i--;
-  
- fail:
-  saved_errno = errno;
-  while (i--)
-    close(intermediary[i]);
-  errno = saved_errno;
-  return old;
-}
+	int intermediary[3];
+	int i = 0, saved_errno;
+
+	do {
+		t (old = dup(old), old == -1);
+		assert(i < 3);
+		if (i >= 3)
+			abort();
+		intermediary[i++] = old;
+	} while (old < 3);
+	i--;
 
+fail:
+	saved_errno = errno;
+	while (i--)
+		close(intermediary[i]);
+	errno = saved_errno;
+	return old;
+}
 
 
 /**
@@ -154,39 +157,15 @@ static int dup_at_least_3(int old)
  * 
  * @param   name   The name of the daemon. Use a hardcoded value,
  *                 not the process name. Must not be `NULL`.
- * @param   flags  Flags to modify the behaviour of the function.
- *                 A bitwise OR combination of the constants:
- *                 -  `DAEMONISE_NO_CLOSE`
- *                 -  `DAEMONISE_NO_SIG_DFL`
- *                 -  `DAEMONISE_KEEP_SIGMASK`
- *                 -  `DAEMONISE_KEEP_ENVIRON`
- *                 -  `DAEMONISE_KEEP_UMASK`
- *                 -  `DAEMONISE_NO_PID_FILE`
- *                 -  `DAEMONISE_KEEP_STDERR`
- *                 -  `DAEMONISE_CLOSE_STDERR`
- *                 -  `DAEMONISE_KEEP_STDIN`
- *                 -  `DAEMONISE_KEEP_STDOUT`
- *                 -  `DAEMONISE_KEEP_FDS`
- *                 -  `DAEMONISE_NEW_PID`
- * @param   ...    Enabled if `DAEMONISE_KEEP_FDS` is used,
- *                 do not add anything if `DAEMONISE_KEEP_FDS`
- *                 is unused. This is a `-1`-terminated list
- *                 of file descritors to keep open. 0, 1, and 2
- *                 are implied by `DAEMONISE_KEEP_STDIN`,
- *                 `DAEMONISE_KEEP_STDOUT`, and `DAEMONISE_KEEP_STDERR`,
- *                 respectively. All arguments are of type `int`.
+ * @param   ...    This is a `-1`-terminated list
+ *                 of file descritors to keep open.
+ *                 All arguments are of type `int`.
  * @return         Zero on success, -1 on error.
  * 
  * @throws  EEXIST  The PID file already exists on the system.
  *                  Unless your daemon supervisor removs old
  *                  PID files, this could mean that the daemon
  *                  has exited without removing the PID file.
- * @throws  EINVAL  `flags` contains an unsupported bit, both
- *                  `DAEMONISE_KEEP_STDERR` and `DAEMONISE_CLOSE_STDERR`
- *                  are set, both `DAEMONISE_NO_PID_FILE` and
- *                  `DAEMONISE_NEW_PID`, or both `DAEMONISE_CLOSE_STDERR`
- *                  and `DAEMONISE_KEEP_FDS` are set whilst `2` is
- *                  in the list of file descriptor not to close.
  * @throws          Any error specified for signal(3).
  * @throws          Any error specified for sigemptyset(3).
  * @throws          Any error specified for sigprocmask(3).
@@ -201,197 +180,138 @@ static int dup_at_least_3(int old)
  * 
  * @since  Always.
  */
-int daemonise(const char* name, int flags, ...)
+int daemonise(const char* name, ...)
 {
-#define t(...)  do { if (__VA_ARGS__) goto fail; }  while (0)
-  
-  struct rlimit rlimit;
-  int pipe_rw[2] = { -1, -1 };
-  sigset_t set;
-  char** r;
-  char** w;
-  char* run;
-  int i, closeerr, fd = -1;
-  char* keep = NULL;
-  int keepmax = 0;
-  pid_t pid;
-  va_list args;
-  int saved_errno;
-  
-  
-  /* Validate flags. */
-  if (flags & (int)~(2048L * 2 - 1))
-    return errno = EINVAL, -1;
-  if ((flags & DAEMONISE_KEEP_STDERR) && (flags & DAEMONISE_CLOSE_STDERR))
-      return errno = EINVAL, -1;
-  if ((flags & DAEMONISE_NO_PID_FILE) && (flags & DAEMONISE_NEW_PID))
-      return errno = EINVAL, -1;
-  
-  
-  /* Find out which file descriptors not too close. */
-  if (flags & DAEMONISE_KEEP_FDS)
-    {
-      va_start(args, flags);
-      while ((fd = va_arg(args, int)) >= 0)
-	if ((fd > 2) && (keepmax < fd))
-	  keepmax = fd;
-      fd = -1;
-      va_end(args);
-      keep = calloc((size_t)keepmax + 1, sizeof(char));
-      t (keep == NULL);
-      va_start(args, flags);
-      while ((fd = va_arg(args, int)) >= 0)
-	switch (fd)
-	  {
-	  case 0:  flags |= DAEMONISE_KEEP_STDIN;   break;
-	  case 1:  flags |= DAEMONISE_KEEP_STDOUT;  break;
-	  case 2:  flags |= DAEMONISE_KEEP_STDERR;
-	    if (flags & DAEMONISE_CLOSE_STDERR)
-	      return free(keep), errno = EINVAL, -1;
-	    break;
-	  default:
-	    keep[fd] = 1;
-	    break;
-	  }
-      fd = -1;
-      va_end(args);
-    }
-  /* We assume that the maximum file descriptor is not extremely large.
-   * We also assume the number of file descriptors too keep is very small,
-   * but this does not affect us. */
-  
-  /* Close all files except stdin, stdout, and stderr. */
-  if ((flags & DAEMONISE_NO_CLOSE) == 0)
-    {
-      if (getrlimit(RLIMIT_NOFILE, &rlimit))
-	rlimit.rlim_cur = 4 << 10;
-      for (i = 3; (rlim_t)i < rlimit.rlim_cur; i++)
-	/* File descriptors with numbers above and including
-	 * `rlimit.rlim_cur` cannot be created. They cause EBADF. */
-	if ((i > keepmax) || (keep[i] == 0))
-	  close(i);
-    }
-  free(keep), keep = NULL;
-  
-  /* Reset all signal handlers. */
-  if ((flags & DAEMONISE_NO_SIG_DFL) == 0)
-    for (i = 1; i < _NSIG; i++)
-      if (signal(i, SIG_DFL) == SIG_ERR)
-	t (errno != EINVAL);
-  
-  /* Set signal mask. */
-  if ((flags & DAEMONISE_KEEP_SIGMASK) == 0)
-    {
-      t (sigemptyset(&set));
-      t (sigprocmask(SIG_SETMASK, &set, NULL));
-    }
-  
-  /* Remove malformatted environment entires. */
-  if (((flags & DAEMONISE_KEEP_ENVIRON) == 0) && (environ != NULL))
-    {
-      for (r = w = environ; *r; r++)
-	if (strchr(*r, '=')) /* It happens that this is not the case! (Thank you PAM!) */
-	  *w++ = *r;
-      *w = NULL;
-    }
-  
-  /* Zero umask. */
-  if ((flags & DAEMONISE_KEEP_UMASK) == 0)
-    umask(0);
-  
-  /* Change current working directory to '/'. */
-  t (chdir("/"));
-  
-  /* Create a channel for letting the original process know when to exit. */
-  if (pipe(pipe_rw))
-    t ((pipe_rw[0] = pipe_rw[1] = -1));
-  t (fd = dup_at_least_3(pipe_rw[0]), fd == -1);
-  close(pipe_rw[0]);
-  pipe_rw[0] = fd;
-  t (fd = dup_at_least_3(pipe_rw[1]), fd == -1);
-  close(pipe_rw[1]);
-  pipe_rw[1] = fd;
-  
-  /* Become a background process. */
-  t (pid = fork(), pid == -1);
-  close(pipe_rw[!!pid]), pipe_rw[!!pid] = 1;
-  if (pid)
-    exit(read(pipe_rw[0], &fd, (size_t)1) <= 0);
-  
-  /* Temporarily become session leader. */
-  t (setsid() == -1);
+	struct rlimit rlimit;
+	int pipe_rw[2] = { -1, -1 };
+	sigset_t set;
+	char** r;
+	char** w;
+	char* run;
+	int i, closeerr, fd = -1;
+	char* keep = NULL;
+	int keepmax = 0;
+	pid_t pid;
+	va_list args;
+	int saved_errno;
+
+	/* Find out which file descriptors not too close. */
+	va_start(args, name);
+	while ((fd = va_arg(args, int)) >= 0)
+		keepmax = fd;
+	fd = -1;
+	va_end(args);
+	keep = calloc((size_t)keepmax + 1, sizeof(char));
+	t (keep == NULL);
+	va_start(args, name);
+	while ((fd = va_arg(args, int)) >= 0)
+		keep[fd] = 1;
+	fd = -1;
+	va_end(args);
+	/* We assume that the maximum file descriptor is not extremely large.
+	 * We also assume the number of file descriptors too keep is very small,
+	 * but this does not affect us. */
   
-  /* Fork again. */
-  t (pid = fork(), pid == -1);
-  if (pid > 0)
-    exit(0);
+	/* Close all files except stdin, stdout, and stderr. */
+	if (getrlimit(RLIMIT_NOFILE, &rlimit))
+		rlimit.rlim_cur = 4 << 10;
+	for (i = 3; (rlim_t)i < rlimit.rlim_cur; i++)
+		/* File descriptors with numbers above and including
+		 * `rlimit.rlim_cur` cannot be created. They cause EBADF. */
+		if ((i > keepmax) || (keep[i] == 0))
+			close(i);
+	free(keep), keep = NULL;
+
+	/* Reset all signal handlers. */
+	for (i = 1; i < _NSIG; i++)
+		if (signal(i, SIG_DFL) == SIG_ERR)
+			t (errno != EINVAL);
+
+	/* Set signal mask. */
+	t (sigemptyset(&set));
+	t (sigprocmask(SIG_SETMASK, &set, NULL));
+
+	/* Remove malformatted environment entires. */
+	if (environ) {
+		for (r = w = environ; *r; r++)
+			if (strchr(*r, '=')) /* It happens that this is not the case! (Thank you PAM!) */
+				*w++ = *r;
+		*w = NULL;
+	}
+
+	/* Zero umask. */
+	umask(0);
+
+	/* Change current working directory to '/'. */
+	t (chdir("/"));
+
+	/* Create a channel for letting the original process know when to exit. */
+	if (pipe(pipe_rw))
+		t ((pipe_rw[0] = pipe_rw[1] = -1));
+	t (fd = dup_at_least_3(pipe_rw[0]), fd == -1);
+	close(pipe_rw[0]);
+	pipe_rw[0] = fd;
+	t (fd = dup_at_least_3(pipe_rw[1]), fd == -1);
+	close(pipe_rw[1]);
+	pipe_rw[1] = fd;
   
-  /* Create PID file. */
-  if (flags & DAEMONISE_NO_PID_FILE)
-    goto no_pid_file;
-  run = getenv("XDG_RUNTIME_DIR");
-  if (run && *run)
-    {
-      __pidfile = malloc(sizeof("/.pid") + (strlen(run) + strlen(name)) * sizeof(char));
-      t (__pidfile == NULL);
-      stpcpy(stpcpy(stpcpy(stpcpy(__pidfile, run), "/"), name), ".pid");
-    }
-  else
-    {
-      __pidfile = malloc(sizeof("/run/.pid") + strlen(name) * sizeof(char));
-      t (__pidfile == NULL);
-      stpcpy(stpcpy(stpcpy(__pidfile, "/run/"), name), ".pid");
-    }
-  fd = open(__pidfile, O_WRONLY | O_CREAT | ((flags & DAEMONISE_NEW_PID) ? 0 : O_EXCL), 0644);
-  if (fd == -1)
-    {
-      saved_errno = errno;
-      free(__pidfile), __pidfile = NULL;
-      errno = saved_errno;
-      goto fail;
-    }
-  pid = getpid();
-  t (dprintf(fd, "%lli\n", (long long int)pid) < 0);
-  t (close(fd) && (errno != EINTR));
- no_pid_file:
+	/* Become a background process. */
+	t (pid = fork(), pid == -1);
+	close(pipe_rw[!!pid]), pipe_rw[!!pid] = 1;
+	if (pid)
+		exit(read(pipe_rw[0], &fd, (size_t)1) <= 0);
   
-  /* Redirect to '/dev/null'. */
-  if (flags & DAEMONISE_KEEP_STDERR)
-    closeerr = 0;
-  else if (flags & DAEMONISE_CLOSE_STDERR)
-    closeerr = 1;
-  else
-    closeerr = (isatty(2) || (errno == EBADF));
-  t (fd = open("/dev/null", O_RDWR), fd == -1);
-  if ((flags & DAEMONISE_KEEP_STDIN) == 0)   if (fd != 0)  close(0);
-  if ((flags & DAEMONISE_KEEP_STDOUT) == 0)  if (fd != 1)  close(1);
-  if (closeerr)                              if (fd != 2)  close(2);
-  if ((flags & DAEMONISE_KEEP_STDIN) == 0)   t (dup2(fd, 0) == -1);
-  if ((flags & DAEMONISE_KEEP_STDOUT) == 0)  t (dup2(fd, 1) == -1);
-  if (closeerr)                              t (dup2(fd, 2) == -1);
-  if (fd > 2)
-    close(fd);
-  fd = -1;
+	/* Temporarily become session leader. */
+	t (setsid() == -1);
   
-  /* We are done! Let the original process exit. */
-  if ((write(pipe_rw[1], &fd, (size_t)1) <= 0) ||
-      (close(pipe_rw[1]) && (errno != EINTR)))
-    {
-      if (flags & DAEMONISE_KEEP_STDERR)
-	return -1;
-      undaemonise();
-      abort(); /* Do not overcomplicate things, just abort in this unlikely event. */
-    }
+	/* Fork again. */
+	t (pid = fork(), pid == -1);
+	if (pid > 0)
+		exit(0);
   
-  return 0;
- fail:
-  saved_errno = errno;
-  if (pipe_rw[0] >= 0)  close(pipe_rw[0]);
-  if (pipe_rw[1] >= 0)  close(pipe_rw[1]);
-  if (fd         >= 0)  close(fd);
-  free(keep);
-  errno = saved_errno;
-  return -1;
+	/* Create PID file. */
+	run = getenv("XDG_RUNTIME_DIR");
+	if (run && *run) {
+		__pidfile = malloc(sizeof("/.pid") + (strlen(run) + strlen(name)) * sizeof(char));
+		t (__pidfile == NULL);
+		stpcpy(stpcpy(stpcpy(stpcpy(__pidfile, run), "/"), name), ".pid");
+	} else {
+		__pidfile = malloc(sizeof("/run/.pid") + strlen(name) * sizeof(char));
+		t (__pidfile == NULL);
+		stpcpy(stpcpy(stpcpy(__pidfile, "/run/"), name), ".pid");
+	}
+	fd = open(__pidfile, O_WRONLY | O_CREAT, 0644);
+	if (fd == -1) {
+		S(free(__pidfile), __pidfile = NULL);
+		goto fail;
+	}
+	pid = getpid();
+	t (dprintf(fd, "%lli\n", (long long int)pid) < 0);
+	t (close(fd) && (errno != EINTR));
+
+	/* Redirect to '/dev/null'. */
+	closeerr = (isatty(2) || (errno == EBADF));
+	t (fd = open("/dev/null", O_RDWR), fd == -1);
+	if (fd != 0)  close(0);
+	if (fd != 1)  close(1);
+	if (closeerr)  if (fd != 2)  close(2);
+	t (dup2(fd, 0) == -1);
+	t (dup2(fd, 1) == -1);
+	if (closeerr)  t (dup2(fd, 2) == -1);
+	if (fd > 2)
+		close(fd);
+	fd = -1;
+
+	/* We are done! Let the original process exit. */
+	if ((write(pipe_rw[1], &fd, (size_t)1) <= 0) ||
+	    (close(pipe_rw[1]) && (errno != EINTR))) {
+		undaemonise();
+		abort(); /* Do not overcomplicate things, just abort in this unlikely event. */
+	}
+
+	return 0;
+fail:
+	return S(close(pipe_rw[0]), close(pipe_rw[1]), close(fd), free(keep)), -1;
 }
 
 
@@ -412,13 +332,11 @@ int daemonise(const char* name, int flags, ...)
  */
 int undaemonise(void)
 {
-  int r, saved_errno;
-  if (__pidfile == NULL)
-    return 0;
-  r = unlink(__pidfile);
-  saved_errno = errno;
-  free(__pidfile), __pidfile = NULL;
-  errno = saved_errno;
-  return r;
+	int r, saved_errno;
+	if (__pidfile == NULL)
+		return 0;
+	r = unlink(__pidfile);
+	S(free(__pidfile), __pidfile = NULL);
+	return r;
 }