diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/ext2fs/finddev.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/lib/ext2fs/finddev.c b/lib/ext2fs/finddev.c new file mode 100644 index 0000000..cd85ef5 --- /dev/null +++ b/lib/ext2fs/finddev.c @@ -0,0 +1,218 @@ +/* + * 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 "config.h" +#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 +#ifdef HAVE_SYS_SYSMACROS_H +#include <sys/sysmacros.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 (ext2fsP_is_disk_device(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 |