mount/lomount.c

/* Taken from Ted's losetup.c - Mitch <m.dsouza@mrc-apu.cam.ac.uk> */
/* Added vfs mount options - aeb - 960223 */
/* Removed lomount - aeb - 960224 */

/* 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
 * - added Native Language Support
 * Sun Mar 21 1999 - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 * - fixed strerr(errno) in gettext calls
 */

#define PROC_DEVICES	"/proc/devices"

/*
 * losetup.c - setup and control loop devices
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/sysmacros.h>

#include "loop.h"
#include "lomount.h"
#include "xstrncpy.h"
#include "nls.h"

extern int verbose;
extern char *xstrdup (const char *s);	/* not: #include "sundries.h" */
extern void error (const char *fmt, ...);	/* idem */

#ifdef LOOP_SET_FD
struct crypt_type_struct {
	int id;
	char *name;
} crypt_type_tbl[] = {
	{ LO_CRYPT_NONE, "no" },
	{ LO_CRYPT_NONE, "none" },
	{ LO_CRYPT_XOR, "xor" },
	{ LO_CRYPT_DES, "DES" },
	{ -1, NULL   }
};

static int 
crypt_type (const char *name) {
	int i;

	if (name) {
		for (i = 0; crypt_type_tbl[i].id != -1; i++)
			if (!strcasecmp (name, crypt_type_tbl[i].name))
				return crypt_type_tbl[i].id;
	}
	return -1;
}

#ifdef MAIN
static char *
crypt_name (int id) {
	int i;

	for (i = 0; crypt_type_tbl[i].id != -1; i++)
		if (id == crypt_type_tbl[i].id)
			return crypt_type_tbl[i].name;
	return "undefined";
}

static int
show_loop (char *device) {
	struct loop_info loopinfo;
	int fd;

	if ((fd = open (device, O_RDONLY)) < 0) {
		int errsv = errno;
		fprintf(stderr, _("loop: can't open device %s: %s\n"),
			device, strerror (errsv));
		return 2;
	}
	if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) < 0) {
		int errsv = errno;
		fprintf(stderr, _("loop: can't get info on device %s: %s\n"),
			device, strerror (errsv));
		close (fd);
		return 1;
	}
	printf (_("%s: [%04x]:%ld (%s) offset %d, %s encryption\n"),
		device, loopinfo.lo_device, loopinfo.lo_inode,
		loopinfo.lo_name, loopinfo.lo_offset,
		crypt_name (loopinfo.lo_encrypt_type));
	close (fd);

	return 0;
}
#endif

int
is_loop_device (const char *device) {
	struct stat statbuf;
	int loopmajor;
#if 1
	loopmajor = 7;
#else
	FILE *procdev;
	char line[100], *cp;

	loopmajor = 0;
	if ((procdev = fopen(PROC_DEVICES, "r")) != NULL) {
		while (fgets (line, sizeof(line), procdev)) {
			if ((cp = strstr (line, " loop\n")) != NULL) {
				*cp='\0';
				loopmajor=atoi(line);
				break;
			}
		}
		fclose(procdev);
	}
#endif
	return (loopmajor && stat(device, &statbuf) == 0 &&
		S_ISBLK(statbuf.st_mode) &&
		major(statbuf.st_rdev) == loopmajor);
}

#define SIZE(a) (sizeof(a)/sizeof(a[0]))

char *
find_unused_loop_device (void) {
	/* Just creating a device, say in /tmp, is probably a bad idea -
	   people might have problems with backup or so.
	   So, we just try /dev/loop[0-7]. */
	char dev[20];
	char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };
	int i, j, fd, somedev = 0, someloop = 0, loop_known = 0;
	struct stat statbuf;
	struct loop_info loopinfo;
	FILE *procdev;

	for (j = 0; j < SIZE(loop_formats); j++) {
	    for(i = 0; i < 256; i++) {
		sprintf(dev, loop_formats[j], i);
		if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
			somedev++;
			fd = open (dev, O_RDONLY);
			if (fd >= 0) {
				if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)
					someloop++;		/* in use */
				else if (errno == ENXIO) {
					close (fd);
					return xstrdup(dev);/* probably free */
				}
				close (fd);
			}
			continue;/* continue trying as long as devices exist */
		}
		break;
	    }
	}

	/* Nothing found. Why not? */
	if ((procdev = fopen(PROC_DEVICES, "r")) != NULL) {
		char line[100];
		while (fgets (line, sizeof(line), procdev))
			if (strstr (line, " loop\n")) {
				loop_known = 1;
				break;
			}
		fclose(procdev);
		if (!loop_known)
			loop_known = -1;
	}

	if (!somedev)
		error(_("mount: could not find any device /dev/loop#"));
	else if (!someloop) {
	    if (loop_known == 1)
		error(_(
		    "mount: Could not find any loop device.\n"
		    "       Maybe /dev/loop# has a wrong major number?"));
	    else if (loop_known == -1)
		error(_(
		    "mount: Could not find any loop device, and, according to %s,\n"
		    "       this kernel does not know about the loop device.\n"
		    "       (If so, then recompile or `insmod loop.o'.)"),
		      PROC_DEVICES);
	    else
		error(_(
		    "mount: Could not find any loop device. Maybe this kernel does not know\n"
		    "       about the loop device (then recompile or `insmod loop.o'), or\n"
		    "       maybe /dev/loop# has the wrong major number?"));
	} else
		error(_("mount: could not find any free loop device"));
	return 0;
}

int
set_loop (const char *device, const char *file, int offset,
	  const char *encryption, int *loopro) {
	struct loop_info loopinfo;
	int fd, ffd, mode, i;
	char *pass;

	mode = (*loopro ? O_RDONLY : O_RDWR);
	if ((ffd = open (file, mode)) < 0) {
		if (!*loopro && errno == EROFS)
			ffd = open (file, mode = O_RDONLY);
		if (ffd < 0) {
			perror (file);
			return 1;
		}
	}
	if ((fd = open (device, mode)) < 0) {
		perror (device);
		return 1;
	}
	*loopro = (mode == O_RDONLY);

	memset (&loopinfo, 0, sizeof (loopinfo));
	xstrncpy (loopinfo.lo_name, file, LO_NAME_SIZE);
	if (encryption && (loopinfo.lo_encrypt_type = crypt_type (encryption))
	    < 0) {
		fprintf (stderr, _("Unsupported encryption type %s\n"),
			 encryption);
		return 1;
	}
	loopinfo.lo_offset = offset;

#ifdef MCL_FUTURE  
	/*
	 * Oh-oh, sensitive data coming up. Better lock into memory to prevent
	 * passwd etc being swapped out and left somewhere on disk.
	 */
                                                
	if(mlockall(MCL_CURRENT | MCL_FUTURE)) {
		perror("memlock");
		fprintf(stderr, _("Couldn't lock into memory, exiting.\n"));
		exit(1);
	}
#endif

	switch (loopinfo.lo_encrypt_type) {
	case LO_CRYPT_NONE:
		loopinfo.lo_encrypt_key_size = 0;
		break;
	case LO_CRYPT_XOR:
		pass = getpass (_("Password: "));
		xstrncpy (loopinfo.lo_encrypt_key, pass, LO_KEY_SIZE);
		loopinfo.lo_encrypt_key_size = strlen(loopinfo.lo_encrypt_key);
		break;
	case LO_CRYPT_DES:
		pass = getpass (_("Password: "));
		strncpy (loopinfo.lo_encrypt_key, pass, 8);
		loopinfo.lo_encrypt_key[8] = 0;
		loopinfo.lo_encrypt_key_size = 8;
		pass = getpass (_("Init (up to 16 hex digits): "));
		for (i = 0; i < 16 && pass[i]; i++)
			if (isxdigit (pass[i])) {
				loopinfo.lo_init[i >> 3] |= (pass[i] > '9' ?
				  (islower (pass[i]) ? toupper (pass[i]) :
				   pass[i])-'A'+10 : pass[i]-'0') << (i&7) * 4;
			} else {
				fprintf (stderr, _("Non-hex digit '%c'.\n"),
					 pass[i]);
				return 1;
			}
		break;
	default:
		fprintf (stderr,
			 _("Don't know how to get key for encryption system %d\n"),
			 loopinfo.lo_encrypt_type);
		return 1;
	}
	if (ioctl (fd, LOOP_SET_FD, ffd) < 0) {
		perror ("ioctl: LOOP_SET_FD");
		return 1;
	}
	if (ioctl (fd, LOOP_SET_STATUS, &loopinfo) < 0) {
		(void) ioctl (fd, LOOP_CLR_FD, 0);
		perror ("ioctl: LOOP_SET_STATUS");
		return 1;
	}
	close (fd);
	close (ffd);
	if (verbose > 1)
		printf(_("set_loop(%s,%s,%d): success\n"),
		       device, file, offset);
	return 0;
}

int 
del_loop (const char *device) {
	int fd;

	if ((fd = open (device, O_RDONLY)) < 0) {
		int errsv = errno;
		fprintf(stderr, _("loop: can't delete device %s: %s\n"),
			device, strerror (errsv));
		return 1;
	}
	if (ioctl (fd, LOOP_CLR_FD, 0) < 0) {
		perror ("ioctl: LOOP_CLR_FD");
		return 1;
	}
	close (fd);
	if (verbose > 1)
		printf(_("del_loop(%s): success\n"), device);
	return 0;
}

#else /* no LOOP_SET_FD defined */
static void
mutter(void) {
	fprintf(stderr,
		_("This mount was compiled without loop support. "
		  "Please recompile.\n"));
}  

int
set_loop (const char *device, const char *file, int offset,
	  const char *encryption, int *loopro) {
	mutter();
	return 1;
}

int
del_loop (const char *device) {
	mutter();
	return 1;
}

char *
find_unused_loop_device (void) {
	mutter();
	return 0;
}

#endif

#ifdef MAIN

#ifdef LOOP_SET_FD

#include <getopt.h>
#include <stdarg.h>

int verbose = 0;
static char *progname;

static void
usage(void) {
	fprintf(stderr, _("usage:\n\
  %s loop_device                                      # give info\n\
  %s -d loop_device                                   # delete\n\
  %s [ -e encryption ] [ -o offset ] loop_device file # setup\n"),
		progname, progname, progname);
	exit(1);
}

char *
xstrdup (const char *s) {
	char *t;

	if (s == NULL)
		return NULL;

	t = strdup (s);

	if (t == NULL) {
		fprintf(stderr, _("not enough memory"));
		exit(1);
	}

	return t;
}

void
error (const char *fmt, ...) {
	va_list args;

	va_start (args, fmt);
	vfprintf (stderr, fmt, args);
	va_end (args);
	fprintf (stderr, "\n");
}

int
main(int argc, char **argv) {
	char *offset, *encryption;
	int delete,off,c;
	int res = 0;
	int ro = 0;

	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);

	delete = off = 0;
	offset = encryption = NULL;
	progname = argv[0];
	while ((c = getopt(argc,argv,"de:o:v")) != -1) {
		switch (c) {
		case 'd':
			delete = 1;
			break;
		case 'e':
			encryption = optarg;
			break;
		case 'o':
			offset = optarg;
			break;
		case 'v':
			verbose = 1;
			break;
		default:
			usage();
		}
	}
	if (argc == 1) usage();
	if ((delete && (argc != optind+1 || encryption || offset)) ||
	    (!delete && (argc < optind+1 || argc > optind+2)))
		usage();
	if (argc == optind+1) {
		if (delete)
			res = del_loop(argv[optind]);
		else
			res = show_loop(argv[optind]);
	} else {
		if (offset && sscanf(offset,"%d",&off) != 1)
			usage();
		res = set_loop(argv[optind],argv[optind+1],off,encryption,&ro);
	}
	return res;
}

#else /* LOOP_SET_FD not defined */

int
main(int argc, char **argv) {
	fprintf(stderr,
		_("No loop support was available at compile time. "
		  "Please recompile.\n"));
	return -1;
}
#endif
#endif