bootstrap-initrd

mount-stub.c (1775B)

// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _GNU_SOURCE
#include <errno.h>
#include <getopt.h>    // getopt_long
#include <stdio.h>     // fprintf
#include <string.h>    // strerror
#include <sys/mount.h> // mount
static void
usage()
{
	fprintf(stderr, "\
Usage: mount [-t fstype] device mountpoint\n\
       mount [--bind|--rbind|--move] source destination\n\
");
}
int
main(int argc, char *argv[])
{
	char *fstype = NULL;
	int mnt_flags = 0;
	int opt_bind_move = 0;
	struct option longopts[] = {
	    /* options exclusive to another, so mnt_flags can be set directly */
	    {"bind", no_argument, &opt_bind_move, MS_BIND},
	    {"rbind", no_argument, &opt_bind_move, MS_BIND | MS_REC},
	    {"move", no_argument, &opt_bind_move, MS_MOVE},
	};
	int c = -1;
	while((c = getopt_long(argc, argv, ":t:", longopts, NULL)) != -1)
	{
		switch(c)
		{
		case 0:
			break;
		case 't':
			fstype = optarg;
			break;
		}
	}
	argc -= optind;
	argv += optind;
	if(opt_bind_move != 0)
	{
		if(argc != 2)
		{
			fprintf(stderr, "mount: Expected 2 arguments, got %d\n", argc);
			usage();
			return 1;
		}
		char *src = argv[0];
		char *dest = argv[1];
		int ret = mount(src, dest, NULL, opt_bind_move, NULL);
		if(ret != 0)
		{
			fprintf(stderr, "mount: Failed mounting %s to %s: %s\n", src, dest, strerror(errno));
			return 1;
		}
		return 0;
	}
	if(argc != 2)
	{
		fprintf(stderr, "mount: Expected 2 arguments, got %d\n", argc);
		usage();
		return 1;
	}
	char *src = argv[0];
	char *dest = argv[1];
	int ret = mount(src, dest, fstype, mnt_flags, NULL);
	if(ret != 0)
	{
		fprintf(stderr, "mount: Failed mounting %s to %s: %s\n", src, dest, strerror(errno));
		return 1;
	}
	return 0;
}