X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Flosetup.c;h=21108d0bfb372fced9e0925ebd1a0037b12c21d4;hb=93c32f2dd2b9d7c06bc46be8adac704c08929da8;hp=6b9a810f283bc338b1f70178db36c9a34b41ca6d;hpb=956a5693603be076a7a2b0bacc22eea4a3b93cbe;p=oweals%2Fbusybox.git

diff --git a/util-linux/losetup.c b/util-linux/losetup.c
index 6b9a810f2..21108d0bf 100644
--- a/util-linux/losetup.c
+++ b/util-linux/losetup.c
@@ -4,60 +4,103 @@
  *
  * Copyright (C) 2002  Matt Kraai.
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include <getopt.h>
-#include <stdlib.h>
+//usage:#define losetup_trivial_usage
+//usage:       "[-r] [-o OFS] LOOPDEV FILE - associate loop devices\n"
+//usage:       "	losetup -d LOOPDEV - disassociate\n"
+//usage:       "	losetup [-f] - show"
+//usage:#define losetup_full_usage "\n\n"
+//usage:       "	-o OFS	Start OFS bytes into FILE"
+//usage:     "\n	-r	Read-only"
+//usage:     "\n	-f	Show first free loop device"
+//usage:
+//usage:#define losetup_notes_usage
+//usage:       "No arguments will display all current associations.\n"
+//usage:       "One argument (losetup /dev/loop1) will display the current association\n"
+//usage:       "(if any), or disassociate it (with -d). The display shows the offset\n"
+//usage:       "and filename of the file the loop device is currently bound to.\n\n"
+//usage:       "Two arguments (losetup /dev/loop1 file.img) create a new association,\n"
+//usage:       "with an optional offset (-o 12345). Encryption is not yet supported.\n"
+//usage:       "losetup -f will show the first loop free loop device\n\n"
 
-#include "busybox.h"
+#include "libbb.h"
 
-int losetup_main(int argc, char **argv)
+int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int losetup_main(int argc UNUSED_PARAM, char **argv)
 {
-	unsigned long opt;
+	unsigned opt;
+	int n;
 	char *opt_o;
-	int offset = 0;
+	unsigned long long offset = 0;
+	enum {
+		OPT_d = (1 << 0),
+		OPT_o = (1 << 1),
+		OPT_f = (1 << 2),
+		OPT_r = (1 << 3), /* must be last */
+	};
 
-	opt = bb_getopt_ulflags(argc, argv, "do:", &opt_o);
-	argc -= optind;
+	/* max 2 args, -d,-o,-f opts are mutually exclusive */
+	opt_complementary = "?2:d--of:o--df:f--do";
+	opt = getopt32(argv, "do:fr", &opt_o);
 	argv += optind;
 
-	if (opt == 0x3) // -d + -o (illegal)
-		bb_show_usage();
+	if (opt == OPT_o)
+		offset = xatoull(opt_o);
 
-	if (opt == 0x1) { // -d
-		/* detach takes exactly one argument */
-		if (argc != 1)
+	if (opt == OPT_d) {
+		/* -d BLOCKDEV */
+		if (!argv[0] || argv[1])
 			bb_show_usage();
-		if (!del_loop(argv[0]))
-			return EXIT_SUCCESS;
-		bb_perror_nomsg_and_die();
+		if (del_loop(argv[0]))
+			bb_simple_perror_msg_and_die(argv[0]);
+		return EXIT_SUCCESS;
 	}
 
-	if (opt == 0x2) // -o
-		offset = bb_xparse_number(opt_o, NULL);
+	if (argv[0]) {
+		char *s;
 
-	/* -o or no option */
+		if (opt == OPT_f) /* -f should not have arguments */
+			bb_show_usage();
 
-	if (argc == 2) {
-		if (set_loop(&argv[0], argv[1], offset) < 0)
-			bb_perror_nomsg_and_die();
-	} else if (argc == 1) {
-		char *s = query_loop(argv[0]);
-		if (!s) bb_perror_nomsg_and_die();
+		if (argv[1]) {
+			/* [-r] [-o OFS] BLOCKDEV FILE */
+			if (set_loop(&argv[0], argv[1], offset, (opt / OPT_r)) < 0)
+				bb_simple_perror_msg_and_die(argv[0]);
+			return EXIT_SUCCESS;
+		}
+		/* [-r] [-o OFS] BLOCKDEV */
+		s = query_loop(argv[0]);
+		if (!s)
+			bb_simple_perror_msg_and_die(argv[0]);
 		printf("%s: %s\n", argv[0], s);
-		if (ENABLE_FEATURE_CLEAN_UP) free(s);
-	} else {
-		char dev[11] = "/dev/loop0";
-		char c;
-		for (c = '0'; c <= '9'; ++c) {
-			char *s;
-			dev[9] = c;
-			s = query_loop(dev);
-			if (s) {
-				printf("%s: %s\n", dev, s);
-				if (ENABLE_FEATURE_CLEAN_UP) free(s);
+		if (ENABLE_FEATURE_CLEAN_UP)
+			free(s);
+		return EXIT_SUCCESS;
+	}
+
+	/* [-r] [-o OFS|-f] with no params */
+	n = 0;
+	while (1) {
+		char *s;
+		char dev[LOOP_NAMESIZE];
+
+		sprintf(dev, LOOP_FORMAT, n);
+		s = query_loop(dev);
+		n++;
+		if (!s) {
+			if (n > 9 && errno && errno != ENXIO)
+				return EXIT_SUCCESS;
+			if (opt == OPT_f) {
+				puts(dev);
+				return EXIT_SUCCESS;
 			}
+		} else {
+			if (opt != OPT_f)
+				printf("%s: %s\n", dev, s);
+			if (ENABLE_FEATURE_CLEAN_UP)
+				free(s);
 		}
 	}
 	return EXIT_SUCCESS;