diff options
Diffstat (limited to 'mount_root.c')
| -rw-r--r-- | mount_root.c | 829 |
1 files changed, 0 insertions, 829 deletions
diff --git a/mount_root.c b/mount_root.c deleted file mode 100644 index 1927efa..0000000 --- a/mount_root.c +++ /dev/null @@ -1,829 +0,0 @@ -/* - * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org> - * Copyright (C) 2013 John Crispin <blogic@openwrt.org> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License version 2.1 - * as published by the Free Software Foundation - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - */ - -#include <stdio.h> -#include <string.h> -#include <getopt.h> -#include <syslog.h> -#include <errno.h> -#include <stdlib.h> -#include <fcntl.h> -#include <unistd.h> -#include <libgen.h> -#include <glob.h> -#include <dirent.h> - -#include <sys/stat.h> -#include <sys/types.h> -#include <sys/mount.h> -#include <sys/wait.h> - -#include <asm/byteorder.h> - -#include <mtd/mtd-user.h> - -#define DEBUG(level, fmt, ...) do { \ - if (debug >= level) \ - fprintf(stderr, "%s %s(%d): " fmt, argv0, __func__, __LINE__, ## __VA_ARGS__); \ - } while (0) - -#define LOG(fmt, ...) do { \ - syslog(LOG_INFO, fmt, ## __VA_ARGS__); \ - fprintf(stderr, "%s: "fmt, argv0, ## __VA_ARGS__); \ - } while (0) - -#define ERROR(fmt, ...) do { \ - syslog(LOG_ERR, fmt, ## __VA_ARGS__); \ - fprintf(stderr, "%s: "fmt, argv0, ## __VA_ARGS__); \ - } while (0) - -enum { - FS_NONE, - FS_JFFS2, - FS_DEADCODE, -}; - -static const char *argv0; - -/* this is a raw syscall - man 2 pivot_root */ -extern int pivot_root(const char *new_root, const char *put_old); - -static int debug = 0; - -static void foreachdir(const char *dir, int (*cb)(const char*)) -{ - char globdir[256]; - glob_t gl; - int j; - - if (dir[strlen(dir) - 1] == '/') - snprintf(globdir, 256, "%s*", dir); - else - snprintf(globdir, 256, "%s/*", dir); - - if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl)) - for (j = 0; j < gl.gl_pathc; j++) - foreachdir(gl.gl_pathv[j], cb); - - cb(dir); -} - -static int find_overlay_mount(char *overlay) -{ - FILE *fp = fopen("/proc/mounts", "r"); - static char line[256]; - int ret = -1; - - if(!fp) - return ret; - - while (ret && fgets(line, sizeof(line), fp)) - if (!strncmp(line, overlay, strlen(overlay))) - ret = 0; - - fclose(fp); - - return ret; -} - -static char* find_mount(char *mp) -{ - FILE *fp = fopen("/proc/mounts", "r"); - static char line[256]; - char *point = NULL; - - if(!fp) - return NULL; - - while (fgets(line, sizeof(line), fp)) { - char *s, *t = strstr(line, " "); - - if (!t) { - fclose(fp); - return NULL; - } - t++; - s = strstr(t, " "); - if (!s) { - fclose(fp); - return NULL; - } - *s = '\0'; - - if (!strcmp(t, mp)) { - fclose(fp); - return t; - } - } - - fclose(fp); - - return point; -} - -static char* find_mount_point(char *block, char *fs) -{ - FILE *fp = fopen("/proc/mounts", "r"); - static char line[256]; - int len = strlen(block); - char *point = NULL; - - if(!fp) - return NULL; - - while (fgets(line, sizeof(line), fp)) { - if (!strncmp(line, block, len)) { - char *p = &line[len + 1]; - char *t = strstr(p, " "); - - if (!t) { - fclose(fp); - return NULL; - } - - *t = '\0'; - t++; - - if (fs && strncmp(t, fs, strlen(fs))) { - fclose(fp); - ERROR("block is mounted with wrong fs\n"); - return NULL; - } - point = p; - break; - } - } - - fclose(fp); - - return point; -} - -static char* find_mtd_index(char *name) -{ - FILE *fp = fopen("/proc/mtd", "r"); - static char line[256]; - char *index = NULL; - - if(!fp) - return index; - - while (!index && fgets(line, sizeof(line), fp)) { - if (strstr(line, name)) { - char *eol = strstr(line, ":"); - - if (!eol) - continue; - - *eol = '\0'; - index = &line[3]; - DEBUG(1, "found %s -> index:%s\n", name, index); - } - } - - fclose(fp); - - return index; -} - -static int find_mtd_block(char *name, char *part, int plen) -{ - char *index = find_mtd_index(name); - - if (!index) - return -1; - - snprintf(part, plen, "/dev/mtdblock%s", index); - DEBUG(1, "found %s -> %s\n", name, part); - - return 0; -} - -static int find_mtd_char(char *name, char *part, int plen) -{ - char *index = find_mtd_index(name); - - if (!index) - return -1; - - snprintf(part, plen, "/dev/mtd%s", index); - DEBUG(1, "found %s -> %s\n", name, part); - - return 0; -} - -static int mtd_unlock(char *mtd) -{ - struct erase_info_user mtdlock; - struct mtd_info_user mtdinfo; - int fd = open(mtd, O_RDWR | O_SYNC); - int ret = -1; - - DEBUG(1, "%s\n", mtd); - - if (!fd) { - ERROR("failed to open %s: %s\n", mtd, strerror(errno)); - return -1; - } - - ret = ioctl(fd, MEMGETINFO, &mtdinfo); - if (ret) { - ERROR("ioctl(%s, MEMGETINFO) failed: %s\n", mtd, strerror(errno)); - goto err_out; - } - - mtdlock.start = 0; - mtdlock.length = mtdinfo.size; - ioctl(fd, MEMUNLOCK, &mtdlock); - -err_out: - close(fd); - - return ret; -} - -static int mtd_mount_jffs2(void) -{ - char rootfs_data[32]; - - if (mkdir("/tmp/overlay", 0755)) { - ERROR("failed to mkdir /tmp/overlay: %s\n", strerror(errno)); - return -1; - } - - if (find_mtd_block("rootfs_data", rootfs_data, sizeof(rootfs_data))) { - ERROR("rootfs_data does not exist\n"); - return -1; - } - - if (mount(rootfs_data, "/tmp/overlay", "jffs2", MS_NOATIME, NULL)) { - ERROR("failed to mount -t jffs2 %s /tmp/overlay: %s\n", rootfs_data, strerror(errno)); - return -1; - } - - find_mtd_char("rootfs_data", rootfs_data, sizeof(rootfs_data)); - - return mtd_unlock(rootfs_data); -} - -static int jffs2_ready(char *mtd) -{ - FILE *fp = fopen(mtd, "r"); - __u32 deadc0de; - __u16 jffs2; - size_t sz; - - if (!fp) { - ERROR("reading %s failed\n", mtd); - exit(-1); - } - - sz = fread(&deadc0de, sizeof(deadc0de), 1, fp); - fclose(fp); - - if (sz != 1) { - ERROR("reading %s failed: %s\n", mtd, strerror(errno)); - exit(-1); - } - - deadc0de = __be32_to_cpu(deadc0de); - jffs2 = __be16_to_cpu(deadc0de >> 16); - - if (jffs2 == 0x1985) { - LOG("jffs2 is ready\n"); - return FS_JFFS2; - } - - if (deadc0de == 0xdeadc0de) { - LOG("jffs2 is not ready - marker found\n"); - return FS_DEADCODE; - } - - ERROR("No jffs2 marker was found\n"); - - return FS_NONE; -} - -static int check_fs_exists(char *fs) -{ - FILE *fp = fopen("/proc/filesystems", "r"); - static char line[256]; - int ret = -1; - - DEBUG(2, "%s\n", fs); - - if (!fp) { - ERROR("opening /proc/filesystems failed: %s\n", strerror(errno)); - goto out; - } - - while (ret && fgets(line, sizeof(line), fp)) - if (strstr(line, fs)) - ret = 0; - - fclose(fp); - -out: - return ret; -} - -static int mount_move(char *oldroot, char *newroot, char *dir) -{ -#ifndef MS_MOVE -#define MS_MOVE (1 << 13) -#endif - struct stat s; - char olddir[64]; - char newdir[64]; - int ret; - - DEBUG(2, "%s %s %s\n", oldroot, newroot, dir); - - snprintf(olddir, sizeof(olddir), "%s%s", oldroot, dir); - snprintf(newdir, sizeof(newdir), "%s%s", newroot, dir); - - if (stat(olddir, &s) || !S_ISDIR(s.st_mode)) - return -1; - - if (stat(newdir, &s) || !S_ISDIR(s.st_mode)) - return -1; - - ret = mount(olddir, newdir, NULL, MS_NOATIME | MS_MOVE, NULL); - - if (ret) - DEBUG(1, "failed %s %s: %s\n", olddir, newdir, strerror(errno)); - - return ret; -} - -static int pivot(char *new, char *old) -{ - char pivotdir[64]; - int ret; - - DEBUG(2, "%s %s\n", new, old); - - if (mount_move("", new, "/proc")) - return -1; - - snprintf(pivotdir, sizeof(pivotdir), "%s%s", new, old); - - ret = pivot_root(new, pivotdir); - - if (ret < 0) { - ERROR("pivot_root failed %s %s: %s\n", new, pivotdir, strerror(errno)); - return -1; - } - - mount_move(old, "", "/dev"); - mount_move(old, "", "/tmp"); - mount_move(old, "", "/sys"); - mount_move(old, "", "/overlay"); - - return 0; -} - -static int fopivot(char *rw_root, char *ro_root) -{ - char overlay[64], lowerdir[64]; - - DEBUG(2, "%s %s\n", rw_root, ro_root); - - if (check_fs_exists("overlay")) { - ERROR("BUG: no suitable fs found\n"); - return -1; - } - - snprintf(overlay, sizeof(overlay), "overlayfs:%s", rw_root); - snprintf(lowerdir, sizeof(lowerdir), "lowerdir=/,upperdir=%s", rw_root); - - if (mount(overlay, "/mnt", "overlayfs", MS_NOATIME, lowerdir)) { - ERROR("mount failed: %s\n", strerror(errno)); - return -1; - } - - return pivot("/mnt", ro_root); -} - -static int ramoverlay(void) -{ - DEBUG(2, "\n"); - - mkdir("/tmp/root", 0755); - mount("tmpfs", "/tmp/root", "tmpfs", MS_NOATIME, "mode=0755"); - - return fopivot("/tmp/root", "/rom"); -} - -static int switch2jffs(void) -{ - char mtd[32]; - - if (!find_mtd_block("rootfs_patches", mtd, sizeof(mtd))) - return 0; - - if (find_mtd_block("rootfs_data", mtd, sizeof(mtd))) { - ERROR("no rootfs_data was found\n"); - return -1; - } - - if (mount(mtd, "/rom/overlay", "jffs2", MS_NOATIME, NULL)) { - ERROR("failed - mount -t jffs2 %s /rom/overlay: %s\n", mtd, strerror(errno)); - return -1; - } - - if (mount("none", "/", NULL, MS_NOATIME | MS_REMOUNT, 0)) { - ERROR("failed - mount -o remount,ro none: %s\n", strerror(errno)); - return -1; - } - - system("cp -a /tmp/root/* /rom/overlay"); - - if (pivot("/rom", "/mnt")) { - ERROR("failed - pivot /rom /mnt: %s\n", strerror(errno)); - return -1; - } - - if (mount_move("/mnt", "/tmp/root", "")) { - ERROR("failed - mount -o move /mnt /tmp/root %s\n", strerror(errno)); - return -1; - } - - return fopivot("/overlay", "/rom"); -} - -static int handle_whiteout(const char *dir) -{ - struct stat s; - char link[256]; - ssize_t sz; - struct dirent **namelist; - int n; - - n = scandir(dir, &namelist, NULL, NULL); - - if (n < 1) - return -1; - - while (n--) { - char file[256]; - - snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name); - if (!lstat(file, &s) && S_ISLNK(s.st_mode)) { - sz = readlink(file, link, sizeof(link) - 1); - if (sz > 0) { - char *orig; - - link[sz] = '\0'; - orig = strstr(&file[1], "/"); - if (orig && !strcmp(link, "(overlay-whiteout)")) { - DEBUG(1, "unlinking %s\n", orig); - unlink(orig); - } - } - } - free(namelist[n]); - } - free(namelist); - - return 0; -} - -static int mtd_erase(const char *mtd) -{ - int fd = open(mtd, O_RDWR | O_SYNC); - struct mtd_info_user i; - struct erase_info_user e; - int ret; - - if (!fd) { - ERROR("failed to open %s: %s\n", mtd, strerror(errno)); - return -1; - } - - ret = ioctl(fd, MEMGETINFO, &i); - if (ret) { - ERROR("ioctl(%s, MEMGETINFO) failed: %s\n", mtd, strerror(errno)); - return -1; - } - - e.length = i.erasesize; - for (e.start = 0; e.start < i.size; e.start += i.erasesize) { - ioctl(fd, MEMUNLOCK, &e); - if(ioctl(fd, MEMERASE, &e)) - ERROR("Failed to erase block on %s at 0x%x\n", mtd, e.start); - } - - close(fd); - return 0; -} - -static int ask_user(int argc, char **argv) -{ - if ((argc < 2) || strcmp(argv[1], "-y")) { - LOG("This will erase all settings and remove any installed packages. Are you sure? [N/y]\n"); - if (getchar() != 'y') - return -1; - } - return 0; - -} - -static int handle_rmdir(const char *dir) -{ - struct stat s; - struct dirent **namelist; - int n; - - n = scandir(dir, &namelist, NULL, NULL); - - if (n < 1) - return -1; - - while (n--) { - char file[256]; - - snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name); - if (!lstat(file, &s) && !S_ISDIR(s.st_mode)) { - DEBUG(1, "unlinking %s\n", file); - unlink(file); - } - free(namelist[n]); - } - free(namelist); - - DEBUG(1, "rmdir %s\n", dir); - rmdir(dir); - - return 0; -} - -static int main_jffs2reset(int argc, char **argv) -{ - char mtd[32]; - char *mp; - - if (ask_user(argc, argv)) - return -1; - - if (check_fs_exists("overlay")) { - ERROR("overlayfs not found\n"); - return -1; - } - - if (find_mtd_block("rootfs_data", mtd, sizeof(mtd))) { - ERROR("no rootfs_data was found\n"); - return -1; - } - - mp = find_mount_point(mtd, "jffs2"); - if (mp) { - LOG("%s is mounted as %s, only erasing files\n", mtd, mp); - foreachdir(mp, handle_rmdir); - mount(mp, "/", NULL, MS_REMOUNT, 0); - } else { - LOG("%s is not mounted, erasing it\n", mtd); - find_mtd_char("rootfs_data", mtd, sizeof(mtd)); - mtd_erase(mtd); - } - - return 0; -} - -static int main_jffs2mark(int argc, char **argv) -{ - FILE *fp; - __u32 deadc0de = __cpu_to_be32(0xdeadc0de); - char mtd[32]; - size_t sz; - - if (ask_user(argc, argv)) - return -1; - - if (find_mtd_block("rootfs_data", mtd, sizeof(mtd))) { - ERROR("no rootfs_data was found\n"); - return -1; - } - - fp = fopen(mtd, "w"); - LOG("%s - marking with deadc0de\n", mtd); - if (!fp) { - ERROR("opening %s failed\n", mtd); - return -1; - } - - sz = fwrite(&deadc0de, sizeof(deadc0de), 1, fp); - fclose(fp); - - if (sz != 1) { - ERROR("writing %s failed: %s\n", mtd, strerror(errno)); - return -1; - } - - return 0; - } -static int main_switch2jffs(int argc, char **argv) -{ - char mtd[32]; - char *mp; - int ret = -1; - - if (find_overlay_mount("overlayfs:/tmp/root")) - return -1; - - if (check_fs_exists("overlay")) { - ERROR("overlayfs not found\n"); - return ret; - } - - find_mtd_block("rootfs_data", mtd, sizeof(mtd)); - mp = find_mount_point(mtd, NULL); - if (mp) { - LOG("rootfs_data:%s is already mounted as %s\n", mtd, mp); - return -1; - } - - if (find_mtd_char("rootfs_data", mtd, sizeof(mtd))) { - ERROR("no rootfs_data was found\n"); - return ret; - } - - switch (jffs2_ready(mtd)) { - case FS_NONE: - ERROR("no jffs2 marker found\n"); - /* fall through */ - - case FS_DEADCODE: - ret = switch2jffs(); - if (!ret) { - DEBUG(1, "doing fo cleanup\n"); - umount2("/tmp/root", MNT_DETACH); - foreachdir("/overlay/", handle_whiteout); - } - break; - - case FS_JFFS2: - ret = mtd_mount_jffs2(); - if (ret) - break; - if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) { - ERROR("switching to jffs2 failed\n"); - ret = -1; - } - break; - } - - return ret; -} - -static int extroot(const char *prefix) -{ - char block_path[32]; - char kmod_loader[64]; - struct stat s; - pid_t pid; - - sprintf(block_path, "%s/sbin/block", prefix); - - if (stat(block_path, &s)) - { - sprintf(block_path, "/sbin/block"); - - if (stat(block_path, &s)) - return -1; - } - - sprintf(kmod_loader, "/sbin/kmodloader %s/etc/modules-boot.d/ %s", prefix, prefix); - system(kmod_loader); - - LOG("starting block executable %s\n", block_path); - - pid = fork(); - if (!pid) { - mkdir("/tmp/extroot", 0755); - execl(block_path, block_path, "extroot", NULL); - exit(-1); - } else if (pid > 0) { - int status; - - waitpid(pid, &status, 0); - if (!WEXITSTATUS(status)) { - if (find_mount("/tmp/extroot/mnt")) { - mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT | MS_RDONLY, 0); - - mkdir("/tmp/extroot/mnt/proc", 0755); - mkdir("/tmp/extroot/mnt/dev", 0755); - mkdir("/tmp/extroot/mnt/sys", 0755); - mkdir("/tmp/extroot/mnt/tmp", 0755); - mkdir("/tmp/extroot/mnt/rom", 0755); - - if (mount_move("/tmp/extroot", "", "/mnt")) { - ERROR("moving pivotroot failed - continue normal boot\n"); - umount("/tmp/extroot/mnt"); - } else if (pivot("/mnt", "/rom")) { - ERROR("switching to pivotroot failed - continue normal boot\n"); - umount("/mnt"); - } else { - umount("/tmp/overlay"); - rmdir("/tmp/overlay"); - rmdir("/tmp/extroot/mnt"); - rmdir("/tmp/extroot"); - return 0; - } - } else if (find_mount("/tmp/extroot/overlay")) { - if (mount_move("/tmp/extroot", "", "/overlay")) { - ERROR("moving extroot failed - continue normal boot\n"); - umount("/tmp/extroot/overlay"); - } else if (fopivot("/overlay", "/rom")) { - ERROR("switching to extroot failed - continue normal boot\n"); - umount("/overlay"); - } else { - umount("/tmp/overlay"); - rmdir("/tmp/overlay"); - rmdir("/tmp/extroot/overlay"); - rmdir("/tmp/extroot"); - return 0; - } - } else { - ERROR("block executable did not set up an overlay\n"); - } - } else { - ERROR("block executable failed with code %d\n", WEXITSTATUS(status)); - } - } - return -1; -} - -int main(int argc, char **argv) -{ - char *mp; - char mtd[32]; - - argv0 = basename(*argv); - - if (!strcmp(basename(*argv), "jffs2mark")) - return main_jffs2mark(argc, argv); - - if (!strcmp(basename(*argv), "jffs2reset")) - return main_jffs2reset(argc, argv); - - if (!strcmp(basename(*argv), "switch2jffs")) - return main_switch2jffs(argc, argv); - - if (!getenv("PREINIT")) - return -1; - - if (!find_mtd_block("rootfs_patches", mtd, sizeof(mtd))) { - ramoverlay(); - } else if (find_mtd_char("rootfs_data", mtd, sizeof(mtd))) { - if (!find_mtd_char("rootfs", mtd, sizeof(mtd))) - mtd_unlock(mtd); - LOG("mounting /dev/root\n"); - mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0); - } else { - if (!extroot("")) { - fprintf(stderr, "mount_root: switched to extroot\n"); - return 0; - } - - switch (jffs2_ready(mtd)) { - case FS_NONE: - case FS_DEADCODE: - return ramoverlay(); - - case FS_JFFS2: - find_mtd_block("rootfs_data", mtd, sizeof(mtd)); - mp = find_mount_point(mtd, NULL); - if (mp) { - LOG("rootfs_data:%s is already mounted as %s\n", mtd, mp); - return -1; - } - - mtd_mount_jffs2(); - - if (!extroot("/tmp/overlay")) { - fprintf(stderr, "mount_root: switched to extroot\n"); - return 0; - } - - DEBUG(1, "switching to jffs2\n"); - if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) { - ERROR("switching to jffs2 failed - fallback to ramoverlay\n"); - return ramoverlay(); - } - } - } - - return 0; -} |