fix bugs and improve debugging

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

7 files changed, 65 insertions, 24 deletions

diff --git a/src/client.c b/src/client.c
index a0f58e3..9e5600e 100644
--- a/src/client.c
+++ b/src/client.c
@@ -65,7 +65,7 @@ send_command(enum command cmd, size_t n, const char *restrict msg)
 	dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run");
 	if (strlen(dir) + sizeof("/" PACKAGE "/socket") > sizeof(address.sun_path))
 		t ((errno = ENAMETOOLONG));
-	stpcpy(stpcpy(address.sun_path, dir), "/" PACKAGE "/state"); /* Yes, "state", It is temporary. */
+	stpcpy(stpcpy(address.sun_path, dir), "/" PACKAGE "/lock"); /* Yes, "lock", It is temporary. */
 	address.sun_family = AF_UNIX;
 
 	/* Any daemon listening? */
diff --git a/src/common.h b/src/common.h
index 375cf49..1401c37 100644
--- a/src/common.h
+++ b/src/common.h
@@ -35,7 +35,13 @@
  * 
  * @param  ...  The statement.
  */
-# define t(...)  do { if (__VA_ARGS__) goto fail; } while (0)
+# ifdef DEBUG
+#  define t(...)  do { if ((__VA_ARGS__) ? (failed__ = #__VA_ARGS__) : 0) { (perror)(failed__); goto fail; } } while (0)
+static const char *failed__ = NULL;
+#  define perror(_)  ((void)(_))
+# else
+#  define t(...)  do { if (__VA_ARGS__) goto fail; } while (0)
+# endif
 #endif
 
 
diff --git a/src/daemon.c b/src/daemon.c
index 830beca..977e845 100644
--- a/src/daemon.c
+++ b/src/daemon.c
@@ -218,8 +218,7 @@ reopen(int fd, int oflag)
 		return -1;
 	if (dup2(r, fd) == -1)
 		return saved_errno = errno, close(r), errno = saved_errno, -1;
-	close(fd);
-	return 0;
+	return close(r), 0;
 }
 
 
diff --git a/src/daemon.h b/src/daemon.h
index c36e314..567e268 100644
--- a/src/daemon.h
+++ b/src/daemon.h
@@ -55,6 +55,11 @@
  */
 #define REAL_FILENO  6
 
+/**
+ * The file descriptor for the lock file.
+ */
+#define LOCK_FILENO  7
+
 
 /**
  * Command: queue a job.
@@ -84,7 +89,13 @@
  * 
  * @param  ...  The statement.
  */
-# define t(...)  do { if (__VA_ARGS__) goto fail; } while (0)
+# ifdef DEBUG
+#  define t(...)  do { if ((__VA_ARGS__) ? (failed__ = #__VA_ARGS__) : 0) { (perror)(failed__); goto fail; } } while (0)
+static const char *failed__ = NULL;
+#  define perror(_)  ((void)(_))
+# else
+#  define t(...)  do { if (__VA_ARGS__) goto fail; } while (0)
+# endif
 #endif
 
 
diff --git a/src/satd-diminished.c b/src/satd-diminished.c
index 5316398..f0df567 100644
--- a/src/satd-diminished.c
+++ b/src/satd-diminished.c
@@ -113,10 +113,10 @@ fork_again:
 			goto child_fail;
 		}
 		if (command < 0) {
-			close(SOCK_FILENO);
+			close(SOCK_FILENO), close(LOCK_FILENO);
 			execve(image, argv, envp);
 		} else {
-			close(BOOT_FILENO), close(REAL_FILENO);
+			close(BOOT_FILENO), close(REAL_FILENO), close(LOCK_FILENO);
 			if (dup2(fd, SOCK_FILENO) != -1)
 				close(fd), fd = SOCK_FILENO, execve(image, argv, envp);
 		}
diff --git a/src/satd-timer.c b/src/satd-timer.c
index 4550465..310c23d 100644
--- a/src/satd-timer.c
+++ b/src/satd-timer.c
@@ -63,6 +63,8 @@ main(int argc, char *argv[])
 	struct job **job;
 	int rc = 0;
 
+	t (reopen(STATE_FILENO, O_RDWR));
+
 	/* Get current expiration time. */
 	t (timerfd_gettime(BOOT_FILENO, &bootspec));
 	t (timerfd_gettime(REAL_FILENO, &realspec));
@@ -88,6 +90,7 @@ done:
 	for (job = jobs; *job; job++)
 		free(*job);
 	free(jobs);
+	close(STATE_FILENO);
 	return rc;
 fail:
 	perror(argv[0]);
diff --git a/src/satd.c b/src/satd.c
index 0b8160c..5b0eaf6 100644
--- a/src/satd.c
+++ b/src/satd.c
@@ -48,7 +48,7 @@ USAGE("[-f]")
 
 
 /**
- * Create the socket, but not its directory.
+ * Create the socket.
  * 
  * @param   address  Output parameter for the socket address.
  * @return           The file descriptor for the socket, -1 on error.
@@ -89,11 +89,7 @@ fail:
 
 
 /**
- * Create the state file, and its directory.
- * 
- * This will also check that the daemon is not
- * running. The daemon holds a shared lock on
- * the state file.
+ * Create the state file.
  * 
  * @return  A file descriptor to the state file, -1 on error.
  */
@@ -102,34 +98,58 @@ create_state(void)
 {
 	const char *dir;
 	char *path;
-	char *p;
-	int fd, saved_errno;
+	int fd = -1, saved_errno;
 
 	/* Create directory. */
 	dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run");
 	t (!(path = malloc(strlen(dir) * sizeof(char) + sizeof("/" PACKAGE "/state"))));
+	stpcpy(stpcpy(path, dir), "/" PACKAGE "/state");
+	t (fd = open(path, O_RDWR | O_CREAT /* but not O_EXCL or O_TRUNC */, S_IRUSR | S_IWUSR), fd == -1);
+
+fail:
+	saved_errno = errno;
+	free(path);
+	errno = saved_errno;
+	return fd;
+}
+
+
+/**
+ * Create and lock the lock file, and its directory.
+ * 
+ * @return  A file descriptor to the lock file, -1 on error.
+ */
+static int
+create_lock(void)
+{
+	const char *dir;
+	char *path;
+	char *p;
+	int fd = -1, saved_errno;
+
+	/* Create directory. */
+	dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run");
+	t (!(path = malloc(strlen(dir) * sizeof(char) + sizeof("/" PACKAGE "/lock"))));
 	p = stpcpy(stpcpy(path, dir), "/" PACKAGE);
 	t (mkdir(path, S_IRWXU) && (errno != EEXIST));
 
 	/* Open file. */
-	stpcpy(p, "/state");
-	t (fd = open(path, O_RDWR | O_CREAT /* but not O_EXCL */, S_IRUSR | S_IWUSR), fd == -1);
-	free(path), path = NULL;
+	stpcpy(p, "/lock");
+	t (fd = open(path, O_RDWR | O_CREAT /* but not O_EXCL or O_TRUNC */, S_IRUSR | S_IWUSR), fd == -1);
 
 	/* Check that the daemon is not running, and mark it as running. */
 	if (flock(fd, LOCK_EX | LOCK_NB)) {
-		t (errno != EWOULDBLOCK);
+		t (fd = -1, errno != EWOULDBLOCK);
 		fprintf(stderr, "%s: the daemon's state file is already in use.\n", argv0);
 		errno = 0;
 		goto fail;
 	}
 
-	return fd;
 fail:
 	saved_errno = errno;
 	free(path);
 	errno = saved_errno;
-	return -1;
+	return fd;
 }
 
 
@@ -230,7 +250,7 @@ main(int argc, char *argv[])
 	t (path = path ? path : hookpath(PRE, SUF), !path && errno)
 
 	struct sockaddr_un address;
-	int sock = -1, state = -1, boot = -1, real = -1, foreground = 0;
+	int sock = -1, state = -1, boot = -1, real = -1, lock = -1, foreground = 0;
 	char *path = NULL;
 	struct itimerspec spec;
 
@@ -250,7 +270,8 @@ main(int argc, char *argv[])
 		free(path), path = NULL;
 	}
 
-	/* Open/create state file, and create socket. */
+	/* Open/create lock file and state file, and create socket. */
+	GET_FD(lock,  LOCK_FILENO,  create_lock());
 	GET_FD(state, STATE_FILENO, create_state());
 	GET_FD(sock,  SOCK_FILENO,  create_socket(&address));
 
@@ -271,7 +292,7 @@ main(int argc, char *argv[])
 #endif
 
 	/* Daemonise. */
-	t (foreground ? 0 : daemonise("satd", DAEMONISE_KEEP_FDS | DAEMONISE_NEW_PID, 3, 4, 5, 6, -1));
+	t (foreground ? 0 : daemonise("satd", DAEMONISE_KEEP_FDS | DAEMONISE_NEW_PID, 3, 4, 5, 6, 7, -1));
 
 	/* Change to a process image without all this initialisation text. */
 	execl(LIBEXECDIR "/" PACKAGE "/satd-diminished", argv0, address.sun_path, NULL);
@@ -287,6 +308,7 @@ fail:
 	if (state >= 0)  close(state);
 	if (boot  >= 0)  close(boot);
 	if (real  >= 0)  close(real);
+	if (lock  >= 0)  close(lock);
 	undaemonise();
 	return 1;
 }