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-rw-r--r--e2fslib/finddev.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/e2fslib/finddev.c b/e2fslib/finddev.c
new file mode 100644
index 0000000..2e9d70a
--- /dev/null
+++ b/e2fslib/finddev.c
@@ -0,0 +1,208 @@
+/*
+ * finddev.c -- this routine attempts to find a particular device in
+ * /dev
+ *
+ * Copyright (C) 2000 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#include <dirent.h>
+#if HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#if HAVE_SYS_MKDEV_H
+#include <sys/mkdev.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+struct dir_list {
+ char *name;
+ struct dir_list *next;
+};
+
+/*
+ * This function adds an entry to the directory list
+ */
+static void add_to_dirlist(const char *name, struct dir_list **list)
+{
+ struct dir_list *dp;
+
+ dp = malloc(sizeof(struct dir_list));
+ if (!dp)
+ return;
+ dp->name = malloc(strlen(name)+1);
+ if (!dp->name) {
+ free(dp);
+ return;
+ }
+ strcpy(dp->name, name);
+ dp->next = *list;
+ *list = dp;
+}
+
+/*
+ * This function frees a directory list
+ */
+static void free_dirlist(struct dir_list **list)
+{
+ struct dir_list *dp, *next;
+
+ for (dp = *list; dp; dp = next) {
+ next = dp->next;
+ free(dp->name);
+ free(dp);
+ }
+ *list = 0;
+}
+
+static int scan_dir(char *dirname, dev_t device, struct dir_list **list,
+ char **ret_path)
+{
+ DIR *dir;
+ struct dirent *dp;
+ char path[1024], *cp;
+ int dirlen;
+ struct stat st;
+
+ dirlen = strlen(dirname);
+ if ((dir = opendir(dirname)) == NULL)
+ return errno;
+ dp = readdir(dir);
+ while (dp) {
+ if (dirlen + strlen(dp->d_name) + 2 >= sizeof(path))
+ goto skip_to_next;
+ if (dp->d_name[0] == '.' &&
+ ((dp->d_name[1] == 0) ||
+ ((dp->d_name[1] == '.') && (dp->d_name[2] == 0))))
+ goto skip_to_next;
+ sprintf(path, "%s/%s", dirname, dp->d_name);
+ if (stat(path, &st) < 0)
+ goto skip_to_next;
+ if (S_ISDIR(st.st_mode))
+ add_to_dirlist(path, list);
+ if (S_ISBLK(st.st_mode) && st.st_rdev == device) {
+ cp = malloc(strlen(path)+1);
+ if (!cp) {
+ closedir(dir);
+ return ENOMEM;
+ }
+ strcpy(cp, path);
+ *ret_path = cp;
+ goto success;
+ }
+ skip_to_next:
+ dp = readdir(dir);
+ }
+success:
+ closedir(dir);
+ return 0;
+}
+
+/*
+ * This function finds the pathname to a block device with a given
+ * device number. It returns a pointer to allocated memory to the
+ * pathname on success, and NULL on failure.
+ */
+char *ext2fs_find_block_device(dev_t device)
+{
+ struct dir_list *list = 0, *new_list = 0;
+ struct dir_list *current;
+ char *ret_path = 0;
+
+ /*
+ * Add the starting directories to search...
+ */
+ add_to_dirlist("/devices", &list);
+ add_to_dirlist("/devfs", &list);
+ add_to_dirlist("/dev", &list);
+
+ while (list) {
+ current = list;
+ list = list->next;
+#ifdef DEBUG
+ printf("Scanning directory %s\n", current->name);
+#endif
+ scan_dir(current->name, device, &new_list, &ret_path);
+ free(current->name);
+ free(current);
+ if (ret_path)
+ break;
+ /*
+ * If we're done checking at this level, descend to
+ * the next level of subdirectories. (breadth-first)
+ */
+ if (list == 0) {
+ list = new_list;
+ new_list = 0;
+ }
+ }
+ free_dirlist(&list);
+ free_dirlist(&new_list);
+ return ret_path;
+}
+
+
+#ifdef DEBUG
+int main(int argc, char** argv)
+{
+ char *devname, *tmp;
+ int major, minor;
+ dev_t device;
+ const char *errmsg = "Couldn't parse %s: %s\n";
+
+ if ((argc != 2) && (argc != 3)) {
+ fprintf(stderr, "Usage: %s device_number\n", argv[0]);
+ fprintf(stderr, "\t: %s major minor\n", argv[0]);
+ exit(1);
+ }
+ if (argc == 2) {
+ device = strtoul(argv[1], &tmp, 0);
+ if (*tmp) {
+ fprintf(stderr, errmsg, "device number", argv[1]);
+ exit(1);
+ }
+ } else {
+ major = strtoul(argv[1], &tmp, 0);
+ if (*tmp) {
+ fprintf(stderr, errmsg, "major number", argv[1]);
+ exit(1);
+ }
+ minor = strtoul(argv[2], &tmp, 0);
+ if (*tmp) {
+ fprintf(stderr, errmsg, "minor number", argv[2]);
+ exit(1);
+ }
+ device = makedev(major, minor);
+ printf("Looking for device 0x%04x (%d:%d)\n", device,
+ major, minor);
+ }
+ devname = ext2fs_find_block_device(device);
+ if (devname) {
+ printf("Found device! %s\n", devname);
+ free(devname);
+ } else {
+ printf("Couldn't find device.\n");
+ }
+ return 0;
+}
+
+#endif