Function pidfile_open

tools/libutil/pidfile.c:102–219

}

struct pidfh *
pidfile_open(const char *pathp, mode_t mode, pid_t *pidptr)
{
	char path[MAXPATHLEN];
	struct pidfh *pfh;
	struct stat sb;
	int error, fd, dirfd, dirlen, filenamelen, count;
	struct timespec rqtp;
	cap_rights_t caprights;

	pfh = malloc(sizeof(*pfh));
	if (pfh == NULL)
		return (NULL);

	if (pathp == NULL) {
		dirlen = snprintf(pfh->pf_dir, sizeof(pfh->pf_dir),
		    "/var/run/");
		filenamelen = snprintf(pfh->pf_filename,
		    sizeof(pfh->pf_filename), "%s.pid", getprogname());
	} else {
		if (strlcpy(path, pathp, sizeof(path)) >= sizeof(path)) {
			free(pfh);
			errno = ENAMETOOLONG;
			return (NULL);
		}
		dirlen = strlcpy(pfh->pf_dir, dirname(path),
		    sizeof(pfh->pf_dir));
		(void)strlcpy(path, pathp, sizeof(path));
		filenamelen = strlcpy(pfh->pf_filename, basename(path),
		    sizeof(pfh->pf_filename));
	}

	if (dirlen >= (int)sizeof(pfh->pf_dir) ||
	    filenamelen >= (int)sizeof(pfh->pf_filename)) {
		free(pfh);
		errno = ENAMETOOLONG;
		return (NULL);
	}

	dirfd = open(pfh->pf_dir, O_CLOEXEC | O_DIRECTORY | O_NONBLOCK);
	if (dirfd == -1) {
		error = errno;
		free(pfh);
		errno = error;
		return (NULL);
	}

	/*
	 * Open the PID file and obtain exclusive lock.
	 * We truncate PID file here only to remove old PID immediately,
	 * PID file will be truncated again in pidfile_write(), so
	 * pidfile_write() can be called multiple times.
	 */
	fd = flopenat(dirfd, pfh->pf_filename,
	    O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NONBLOCK, mode);
	if (fd == -1) {
		if (errno == EWOULDBLOCK) {
			if (pidptr == NULL) {