1 files changed, 190 insertions, 0 deletions

diff --git a/losetup.c b/losetup.c
new file mode 100644
index 000000000..2908dbc88
--- /dev/null
+++ b/losetup.c
@@ -0,0 +1,190 @@
+/*
+ * losetup.c - setup and control loop devices
+ */
+
+
+#include "internal.h"
+
+const char      losetup_usage[] = "losetup\n"
+"\n"
+"\tlosetup loop_device                          give info\n"
+"\tlosetup -d loop_device                               delete\n"
+"\tlosetup [ -o offset ] loop_device file               setup\n";
+
+/* from mount-2.6d */
+
+/*
+ * losetup.c - setup and control loop devices
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+/* #include "loop.h" */
+
+/*
+ * include/linux/loop.h
+ *
+ * Written by Theodore Ts'o, 3/29/93.
+ *
+ * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
+ * permitted under the GNU Public License.
+ */
+
+#define LO_NAME_SIZE    64
+#define LO_KEY_SIZE     32
+       
+struct loop_info {
+        int             lo_number;      /* ioctl r/o */
+        dev_t           lo_device;      /* ioctl r/o */
+        unsigned long   lo_inode;       /* ioctl r/o */
+        dev_t           lo_rdevice;     /* ioctl r/o */
+        int             lo_offset;
+        int             lo_encrypt_type;
+        int             lo_encrypt_key_size;    /* ioctl w/o */
+        int             lo_flags;       /* ioctl r/o */
+        char            lo_name[LO_NAME_SIZE];
+        unsigned char   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+        unsigned long   lo_init[2];
+        char            reserved[4];
+};
+
+/*
+ * IOCTL commands --- we will commandeer 0x4C ('L')
+ */
+
+#define LOOP_SET_FD     0x4C00
+#define LOOP_CLR_FD     0x4C01
+#define LOOP_SET_STATUS 0x4C02
+#define LOOP_GET_STATUS 0x4C03
+
+/* #include "lomount.h" */
+
+extern int set_loop (const char *, const char *, int, int *);
+extern int del_loop (const char *);
+
+static void show_loop(const char *device)
+{
+        struct  loop_info       loopinfo;
+        int                     fd;
+        
+        if ((fd = open(device, O_RDWR)) < 0) {
+                perror(device);
+                return;
+        }
+        if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) < 0) {
+                perror("Cannot get loop info");
+                close(fd);
+                return;
+        }
+        printf("%s: [%04x]:%ld (%s) offset %d\n",
+               device, (unsigned int)loopinfo.lo_device, loopinfo.lo_inode,
+               loopinfo.lo_name, loopinfo.lo_offset);
+        close(fd);
+}
+
+
+int set_loop(const char *device, const char *file, int offset, int *loopro)
+{
+        struct loop_info loopinfo;
+        int     fd, ffd, mode;
+        
+        mode = *loopro ? O_RDONLY : O_RDWR;
+        if ((ffd = open (file, mode)) < 0 && !*loopro
+            && (errno != EROFS || (ffd = open (file, mode = O_RDONLY)) < 0)) {
+          perror (file);
+          return 1;
+        }
+        if ((fd = open (device, mode)) < 0) {
+          close(ffd);
+          perror (device);
+          return 1;
+        }
+        *loopro = (mode == O_RDONLY);
+
+        memset(&loopinfo, 0, sizeof(loopinfo));
+        strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
+        loopinfo.lo_name[LO_NAME_SIZE-1] = 0;
+
+        loopinfo.lo_offset = offset;
+
+        loopinfo.lo_encrypt_key_size = 0;
+        if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
+                perror("ioctl: LOOP_SET_FD");
+                exit(1);
+        }
+        if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
+                (void) ioctl(fd, LOOP_CLR_FD, 0);
+                perror("ioctl: LOOP_SET_STATUS");
+                exit(1);
+        }
+        close(fd);
+        close(ffd);
+        return 0;
+}
+
+int del_loop(const char *device)
+{
+        int fd;
+
+        if ((fd = open(device, O_RDONLY)) < 0) {
+                perror(device);
+                exit(1);
+        }
+        if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
+                perror("ioctl: LOOP_CLR_FD");
+                exit(1);
+        }
+        close(fd);
+        return(0);
+}
+
+
+static int losetup_usage_fn(void)
+{
+        fprintf(stderr, losetup_usage);
+        exit(1);
+}
+
+int losetup_main(struct FileInfo * i, int argc, char * * argv)
+{
+        char *offset;
+        int delete,off,c;
+        int ro = 0;
+
+        delete = off = 0;
+        offset = NULL;
+        while ((c = getopt(argc,argv,"do:")) != EOF) {
+                switch (c) {
+                        case 'd':
+                                delete = 1;
+                                break;
+                        case 'o':
+                                offset = optarg;
+                                break;
+                        default:
+                                losetup_usage_fn();
+                }
+        }
+        if (argc == 1) losetup_usage_fn();
+        if ((delete && (argc != optind+1 || offset)) ||
+            (!delete && (argc < optind+1 || argc > optind+2)))
+                losetup_usage_fn();
+        if (argc == optind+1)
+                if (delete)
+                        del_loop(argv[optind]);
+                else
+                        show_loop(argv[optind]);
+        else {
+                if (offset && sscanf(offset,"%d",&off) != 1)
+                        losetup_usage_fn();
+                set_loop(argv[optind],argv[optind+1],off,&ro);
+        }
+        return 0;
+}