static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level) { struct dirent *entry; struct stat st; char *ptr; char *result = NULL; DIR *dir; int space; /* Ignore strange nested directories */ if (dir_level > max_level) return NULL; path[PATH_MAX - 1] = '\0'; ptr = path + strlen(path); *ptr++ = '/'; *ptr = '\0'; space = PATH_MAX - (ptr - path); dir = opendir(path); if (!dir) return NULL; while((entry = readdir(dir))) { if (entry->d_name[0] == '.' || !strncmp(entry->d_name, "..", 2)) continue; if (dir_level == 0 && (!strcmp(entry->d_name, "shm") || !strcmp(entry->d_name, "fd") || !strcmp(entry->d_name, "char") || !strcmp(entry->d_name, "pts"))) continue; strncpy(ptr, entry->d_name, space); if (stat(path, &st) < 0) continue; if (S_ISDIR(st.st_mode)) { result = __lookup_dev(path, dev, dir_level + 1, max_level); if (result) break; } else if (S_ISBLK(st.st_mode)) { /* workaround: ignore dm-X devices, these are internal kernel names */ if (dir_level == 0 && dm_is_dm_kernel_name(entry->d_name)) continue; if (st.st_rdev == dev) { result = strdup(path); break; } } } closedir(dir); return result; }
/* * Returns string pointing to device in /dev according to "major:minor" dev_id */ char *crypt_lookup_dev(const char *dev_id) { int major, minor; char link[PATH_MAX], path[PATH_MAX], *devname, *devpath = NULL; struct stat st; ssize_t len; if (sscanf(dev_id, "%d:%d", &major, &minor) != 2) return NULL; if (snprintf(path, sizeof(path), "/sys/dev/block/%s", dev_id) < 0) return NULL; len = readlink(path, link, sizeof(link)); if (len < 0) { /* Without /sys use old scan */ if (stat("/sys/dev/block", &st) < 0) return lookup_dev_old(major, minor); return NULL; } link[len] = '\0'; devname = strrchr(link, '/'); if (!devname) return NULL; devname++; if (dm_is_dm_kernel_name(devname)) devpath = dm_device_path(major, minor); else if (snprintf(path, sizeof(path), "/dev/%s", devname) > 0) devpath = strdup(path); /* * Check that path is correct. */ if (devpath && ((stat(devpath, &st) < 0) || !S_ISBLK(st.st_mode) || (st.st_rdev != makedev(major, minor)))) { free(devpath); /* Should never happen unless user mangles with dev nodes. */ return lookup_dev_old(major, minor); } return devpath; }
/* Try to find partition which match offset and size on top level device */ char *crypt_get_partition_device(const char *dev_path, uint64_t offset, uint64_t size) { char link[PATH_MAX], path[PATH_MAX], part_path[PATH_MAX], *devname; char *result = NULL; struct stat st; size_t devname_len; ssize_t len; struct dirent *entry; DIR *dir; uint64_t part_offset, part_size; if (stat(dev_path, &st) < 0) return NULL; if (!S_ISBLK(st.st_mode)) return NULL; if (snprintf(path, sizeof(path), "/sys/dev/block/%d:%d", major(st.st_rdev), minor(st.st_rdev)) < 0) return NULL; len = readlink(path, link, sizeof(link) - 1); if (len < 0) return NULL; /* Get top level disk name for sysfs search */ link[len] = '\0'; devname = strrchr(link, '/'); if (!devname) return NULL; devname++; /* DM devices do not use kernel partitions. */ if (dm_is_dm_kernel_name(devname)) return NULL; dir = opendir(path); if (!dir) return NULL; devname_len = strlen(devname); while((entry = readdir(dir))) { if (strncmp(entry->d_name, devname, devname_len)) continue; if (snprintf(part_path, sizeof(part_path), "%s/%s", path, entry->d_name) < 0) continue; if (stat(part_path, &st) < 0) continue; if (S_ISDIR(st.st_mode)) { if (!_path_get_uint64(part_path, &part_offset, "start") || !_path_get_uint64(part_path, &part_size, "size")) continue; if (part_offset == offset && part_size == size && snprintf(part_path, sizeof(part_path), "/dev/%s", entry->d_name) > 0) { result = strdup(part_path); break; } } } closedir(dir); return result; }