1 files changed, 313 insertions, 0 deletions
diff --git a/lib/fileutils.c b/lib/fileutils.c
new file mode 100644
index 0000000..7779e10
--- /dev/null
+++ b/lib/fileutils.c
@@ -0,0 +1,313 @@
+/*
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Copyright (C) 2012 Sami Kerola <kerolasa@iki.fi>
+ * Copyright (C) 2012-2020 Karel Zak <kzak@redhat.com>
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <string.h>
+
+#include "c.h"
+#include "all-io.h"
+#include "fileutils.h"
+#include "pathnames.h"
+
+int mkstemp_cloexec(char *template)
+{
+#ifdef HAVE_MKOSTEMP
+	return mkostemp(template, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC);
+#else
+	int fd, old_flags, errno_save;
+
+	fd = mkstemp(template);
+	if (fd < 0)
+		return fd;
+
+	old_flags = fcntl(fd, F_GETFD, 0);
+	if (old_flags < 0)
+		goto unwind;
+	if (fcntl(fd, F_SETFD, old_flags | O_CLOEXEC) < 0)
+		goto unwind;
+
+	return fd;
+
+unwind:
+	errno_save = errno;
+	unlink(template);
+	close(fd);
+	errno = errno_save;
+
+	return -1;
+#endif
+}
+
+/* Create open temporary file in safe way.  Please notice that the
+ * file permissions are -rw------- by default. */
+int xmkstemp(char **tmpname, const char *dir, const char *prefix)
+{
+	char *localtmp;
+	const char *tmpenv;
+	mode_t old_mode;
+	int fd, rc;
+
+	/* Some use cases must be capable of being moved atomically
+	 * with rename(2), which is the reason why dir is here.  */
+	tmpenv = dir ? dir : getenv("TMPDIR");
+	if (!tmpenv)
+		tmpenv = _PATH_TMP;
+
+	rc = asprintf(&localtmp, "%s/%s.XXXXXX", tmpenv, prefix);
+	if (rc < 0)
+		return -1;
+
+	old_mode = umask(077);
+	fd = mkstemp_cloexec(localtmp);
+	umask(old_mode);
+	if (fd == -1) {
+		free(localtmp);
+		localtmp = NULL;
+	}
+	*tmpname = localtmp;
+	return fd;
+}
+
+#ifdef F_DUPFD_CLOEXEC
+int dup_fd_cloexec(int oldfd, int lowfd)
+#else
+int dup_fd_cloexec(int oldfd, int lowfd  __attribute__((__unused__)))
+#endif
+{
+	int fd, flags, errno_save;
+
+#ifdef F_DUPFD_CLOEXEC
+	fd = fcntl(oldfd, F_DUPFD_CLOEXEC, lowfd);
+	if (fd >= 0)
+		return fd;
+#endif
+
+	fd = dup(oldfd);
+	if (fd < 0)
+		return fd;
+
+	flags = fcntl(fd, F_GETFD);
+	if (flags < 0)
+		goto unwind;
+	if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0)
+		goto unwind;
+
+	return fd;
+
+unwind:
+	errno_save = errno;
+	close(fd);
+	errno = errno_save;
+
+	return -1;
+}
+
+/*
+ * portable getdtablesize()
+ */
+unsigned int get_fd_tabsize(void)
+{
+	int m;
+
+#if defined(HAVE_GETDTABLESIZE)
+	m = getdtablesize();
+#elif defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
+	struct rlimit rl;
+
+	getrlimit(RLIMIT_NOFILE, &rl);
+	m = rl.rlim_cur;
+#elif defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
+	m = sysconf(_SC_OPEN_MAX);
+#else
+	m = OPEN_MAX;
+#endif
+	return m;
+}
+
+void ul_close_all_fds(unsigned int first, unsigned int last)
+{
+	struct dirent *d;
+	DIR *dir;
+
+	dir = opendir(_PATH_PROC_FDDIR);
+	if (dir) {
+		while ((d = xreaddir(dir))) {
+			char *end;
+			unsigned int fd;
+			int dfd;
+
+			errno = 0;
+			fd = strtoul(d->d_name, &end, 10);
+
+			if (errno || end == d->d_name || !end || *end)
+				continue;
+			dfd = dirfd(dir);
+			if (dfd < 0)
+				continue;
+			if ((unsigned int)dfd == fd)
+				continue;
+			if (fd < first || last < fd)
+				continue;
+			close(fd);
+		}
+		closedir(dir);
+	} else {
+		unsigned fd, tbsz = get_fd_tabsize();
+
+		for (fd = 0; fd < tbsz; fd++) {
+			if (first <= fd && fd <= last)
+				close(fd);
+		}
+	}
+}
+
+#ifdef TEST_PROGRAM_FILEUTILS
+int main(int argc, char *argv[])
+{
+	if (argc < 2)
+		errx(EXIT_FAILURE, "Usage %s --{mkstemp,close-fds,copy-file}", argv[0]);
+
+	if (strcmp(argv[1], "--mkstemp") == 0) {
+		FILE *f;
+		char *tmpname = NULL;
+
+		f = xfmkstemp(&tmpname, NULL, "test");
+		unlink(tmpname);
+		free(tmpname);
+		fclose(f);
+
+	} else if (strcmp(argv[1], "--close-fds") == 0) {
+		ignore_result( dup(STDIN_FILENO) );
+		ignore_result( dup(STDIN_FILENO) );
+		ignore_result( dup(STDIN_FILENO) );
+
+# ifdef HAVE_CLOSE_RANGE
+		if (close_range(STDERR_FILENO + 1, ~0U, 0) < 0)
+# endif
+			ul_close_all_fds(STDERR_FILENO + 1, ~0U);
+
+	} else if (strcmp(argv[1], "--copy-file") == 0) {
+		int ret = ul_copy_file(STDIN_FILENO, STDOUT_FILENO);
+		if (ret == UL_COPY_READ_ERROR)
+			err(EXIT_FAILURE, "read");
+		else if (ret == UL_COPY_WRITE_ERROR)
+			err(EXIT_FAILURE, "write");
+	}
+	return EXIT_SUCCESS;
+}
+#endif
+
+
+int ul_mkdir_p(const char *path, mode_t mode)
+{
+	char *p, *dir;
+	int rc = 0;
+
+	if (!path || !*path)
+		return -EINVAL;
+
+	dir = p = strdup(path);
+	if (!dir)
+		return -ENOMEM;
+
+	if (*p == '/')
+		p++;
+
+	while (p && *p) {
+		char *e = strchr(p, '/');
+		if (e)
+			*e = '\0';
+		if (*p) {
+			rc = mkdir(dir, mode);
+			if (rc && errno != EEXIST)
+				break;
+			rc = 0;
+		}
+		if (!e)
+			break;
+		*e = '/';
+		p = e + 1;
+	}
+
+	free(dir);
+	return rc;
+}
+
+/* returns basename and keeps dirname in the @path, if @path is "/" (root)
+ * then returns empty string */
+char *stripoff_last_component(char *path)
+{
+	char *p = path ? strrchr(path, '/') : NULL;
+
+	if (!p)
+		return NULL;
+	*p = '\0';
+	return p + 1;
+}
+
+static int copy_file_simple(int from, int to)
+{
+	ssize_t nr;
+	char buf[BUFSIZ];
+
+	while ((nr = read_all(from, buf, sizeof(buf))) > 0)
+		if (write_all(to, buf, nr) == -1)
+			return UL_COPY_WRITE_ERROR;
+	if (nr < 0)
+		return UL_COPY_READ_ERROR;
+#ifdef HAVE_EXPLICIT_BZERO
+	explicit_bzero(buf, sizeof(buf));
+#endif
+	return 0;
+}
+
+/* Copies the contents of a file. Returns -1 on read error, -2 on write error. */
+int ul_copy_file(int from, int to)
+{
+#ifdef HAVE_SENDFILE
+	struct stat st;
+	ssize_t nw;
+
+	if (fstat(from, &st) == -1)
+		return UL_COPY_READ_ERROR;
+	if (!S_ISREG(st.st_mode))
+		return copy_file_simple(from, to);
+	if (sendfile_all(to, from, NULL, st.st_size) < 0)
+		return copy_file_simple(from, to);
+	/* ensure we either get an EOF or an error */
+	while ((nw = sendfile_all(to, from, NULL, 16*1024*1024)) != 0)
+		if (nw < 0)
+			return copy_file_simple(from, to);
+	return 0;
+#else
+	return copy_file_simple(from, to);
+#endif
+}
+
+int ul_reopen(int fd, int flags)
+{
+	ssize_t ssz;
+	char buf[PATH_MAX];
+	char fdpath[ sizeof(_PATH_PROC_FDDIR) + sizeof(stringify_value(INT_MAX)) ];
+
+	snprintf(fdpath, sizeof(fdpath), _PATH_PROC_FDDIR "/%d", fd);
+
+	ssz = readlink(fdpath, buf, sizeof(buf) - 1);
+	if (ssz < 0)
+		return -errno;
+
+	assert(ssz > 0);
+
+	buf[ssz] = '\0';
+
+	return open(buf, flags);
+}