1 files changed, 106 insertions, 0 deletions
diff --git a/src/util/maildirlock.c b/src/util/maildirlock.c
new file mode 100644
index 0000000..89fbacc
--- /dev/null
+++ b/src/util/maildirlock.c
@@ -0,0 +1,106 @@
+/* Copyright (c) 2008-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "lib-signals.h"
+#include "ioloop.h"
+#include "write-full.h"
+#include "file-dotlock.h"
+#include "index/maildir/maildir-uidlist.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+
+static struct dotlock_settings dotlock_settings = {
+	.stale_timeout = MAILDIR_UIDLIST_LOCK_STALE_TIMEOUT,
+	.use_io_notify = TRUE
+};
+
+static struct ioloop *ioloop;
+
+static void sig_die(const siginfo_t *si ATTR_UNUSED, void *context ATTR_UNUSED)
+{
+	io_loop_stop(ioloop);
+}
+
+static int maildir_lock(const char *path, unsigned int timeout,
+			struct dotlock **dotlock_r)
+{
+	dotlock_settings.timeout = timeout;
+	dotlock_settings.use_excl_lock = getenv("DOTLOCK_USE_EXCL") != NULL;
+	dotlock_settings.nfs_flush = getenv("MAIL_NFS_STORAGE") != NULL;
+
+	path = t_strconcat(path, "/" MAILDIR_UIDLIST_NAME, NULL);
+	return file_dotlock_create(&dotlock_settings, path, 0, dotlock_r);
+}
+
+int main(int argc, const char *argv[])
+{
+	struct dotlock *dotlock;
+	unsigned int timeout;
+	pid_t pid;
+	int fd[2], ret;
+	char c;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: maildirlock <path> <timeout>\n"
+			" - SIGTERM will release the lock.\n");
+		return 1;
+	}
+	if (pipe(fd) != 0) {
+		fprintf(stderr, "pipe() failed: %s", strerror(errno));
+		return 1;
+	}
+
+	pid = fork();
+	if (pid == (pid_t)-1) {
+		fprintf(stderr, "fork() failed: %s", strerror(errno));
+		return 1;
+	}
+
+	/* call lib_init() only after fork so that PID gets set correctly */
+	lib_init();
+	lib_signals_init();
+	ioloop = io_loop_create();
+	lib_signals_set_handler(SIGINT, LIBSIG_FLAG_DELAYED, sig_die, NULL);
+	lib_signals_set_handler(SIGTERM, LIBSIG_FLAG_DELAYED, sig_die, NULL);
+
+	if (pid != 0) {
+		i_close_fd(&fd[1]);
+		ret = read(fd[0], &c, 1);
+		if (ret < 0) {
+			i_error("read(pipe) failed: %m");
+			return 1;
+		}
+		if (ret != 1) {
+			/* locking timed out */
+			return 1;
+		}
+
+		printf("%s", dec2str(pid));
+		return 0;
+	}
+
+	/* child process - stdout has to be closed so that caller knows when
+	   to stop reading it. */
+	if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0)
+		i_fatal("dup2() failed: %m");
+
+	if (str_to_uint(argv[2], &timeout) < 0)
+		i_fatal("Invalid timeout value: %s", argv[2]);
+	if (maildir_lock(argv[1], timeout, &dotlock) <= 0)
+		return 1;
+
+	/* locked - send a byte */
+	if (write_full(fd[1], "", 1) < 0)
+		i_fatal("write(pipe) failed: %m");
+
+	io_loop_run(ioloop);
+
+	file_dotlock_delete(&dotlock);
+	lib_signals_deinit();
+
+	io_loop_destroy(&ioloop);
+	lib_deinit();
+	return 0;
+}