| /* |
| * 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 Library |
| * General Public License, version 2. |
| * %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" |
| #include "ext2fsP.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; |
| int level = 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; |
| /* Avoid infinite loop */ |
| if (++level >= EXT2FS_MAX_NESTED_LINKS) |
| break; |
| } |
| } |
| 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 |