diff options
Diffstat (limited to 'src/gpt-auto-generator/gpt-auto-generator.c')
| -rw-r--r-- | src/gpt-auto-generator/gpt-auto-generator.c | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c new file mode 100644 index 0000000000..ca54925da4 --- /dev/null +++ b/src/gpt-auto-generator/gpt-auto-generator.c @@ -0,0 +1,527 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2013 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <unistd.h> +#include <stdlib.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <sys/statfs.h> +#include <blkid.h> + +#ifdef HAVE_LINUX_BTRFS_H +#include <linux/btrfs.h> +#endif + +#include "path-util.h" +#include "util.h" +#include "mkdir.h" +#include "missing.h" +#include "sd-id128.h" +#include "libudev.h" +#include "special.h" +#include "unit-name.h" + +/* TODO: + * + * - Properly handle cryptsetup partitions + * - Define new partition type for encrypted swap + * - Make /home automount rather than mount + * + */ + +static const char *arg_dest = "/tmp"; + +static inline void blkid_free_probep(blkid_probe *b) { + if (*b) + blkid_free_probe(*b); +} +#define _cleanup_blkid_freep_probe_ _cleanup_(blkid_free_probep) + +static int verify_gpt_partition(const char *node, sd_id128_t *type, unsigned *nr, char **fstype) { + _cleanup_blkid_freep_probe_ blkid_probe b = NULL; + const char *v; + int r; + + errno = 0; + b = blkid_new_probe_from_filename(node); + if (!b) + return errno != 0 ? -errno : -ENOMEM; + + blkid_probe_enable_superblocks(b, 1); + blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE); + blkid_probe_enable_partitions(b, 1); + blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); + + errno = 0; + r = blkid_do_safeprobe(b); + if (r == -2) + return -ENODEV; + else if (r == 1) + return -ENODEV; + else if (r != 0) + return errno ? -errno : -EIO; + + errno = 0; + r = blkid_probe_lookup_value(b, "PART_ENTRY_SCHEME", &v, NULL); + if (r != 0) + /* return 0 if we're not on GPT */ + return errno ? -errno : 0; + + if (strcmp(v, "gpt") != 0) + return 0; + + if (type) { + errno = 0; + r = blkid_probe_lookup_value(b, "PART_ENTRY_TYPE", &v, NULL); + if (r != 0) + return errno ? -errno : -EIO; + + r = sd_id128_from_string(v, type); + if (r < 0) + return r; + } + + if (nr) { + errno = 0; + r = blkid_probe_lookup_value(b, "PART_ENTRY_NUMBER", &v, NULL); + if (r != 0) + return errno ? -errno : -EIO; + + r = safe_atou(v, nr); + if (r < 0) + return r; + } + + + if (fstype) { + char *fst; + + errno = 0; + r = blkid_probe_lookup_value(b, "TYPE", &v, NULL); + if (r != 0) + *fstype = NULL; + else { + fst = strdup(v); + if (!fst) + return -ENOMEM; + + *fstype = fst; + } + } + + return 1; +} + +static int add_swap(const char *path, const char *fstype) { + _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL; + _cleanup_fclose_ FILE *f = NULL; + + log_debug("Adding swap: %s %s", path, fstype); + + name = unit_name_from_path(path, ".swap"); + if (!name) + return log_oom(); + + unit = strjoin(arg_dest, "/", name, NULL); + if (!unit) + return log_oom(); + + f = fopen(unit, "wxe"); + if (!f) { + log_error("Failed to create unit file %s: %m", unit); + return -errno; + } + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "DefaultDependencies=no\n" + "Conflicts=" SPECIAL_UMOUNT_TARGET "\n" + "Before=" SPECIAL_UMOUNT_TARGET " " SPECIAL_SWAP_TARGET "\n\n" + "[Swap]\n" + "What=%s\n", + path); + + fflush(f); + if (ferror(f)) { + log_error("Failed to write unit file %s: %m", unit); + return -errno; + } + + lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL); + if (!lnk) + return log_oom(); + + mkdir_parents_label(lnk, 0755); + if (symlink(unit, lnk) < 0) { + log_error("Failed to create symlink %s: %m", lnk); + return -errno; + } + + return 0; +} + +static int add_home(const char *path, const char *fstype) { + _cleanup_free_ char *unit = NULL, *lnk = NULL; + _cleanup_fclose_ FILE *f = NULL; + + if (dir_is_empty("/home") <= 0) + return 0; + + log_debug("Adding home: %s %s", path, fstype); + + unit = strappend(arg_dest, "/home.mount"); + if (!unit) + return log_oom(); + + f = fopen(unit, "wxe"); + if (!f) { + log_error("Failed to create unit file %s: %m", unit); + return -errno; + } + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "DefaultDependencies=no\n" + "After=" SPECIAL_LOCAL_FS_PRE_TARGET "\n" + "Conflicts=" SPECIAL_UMOUNT_TARGET "\n" + "Before=" SPECIAL_UMOUNT_TARGET " " SPECIAL_LOCAL_FS_TARGET "\n\n" + "[Mount]\n" + "What=%s\n" + "Where=/home\n" + "Type=%s\n" + "FsckPassNo=2\n", + path, fstype); + + fflush(f); + if (ferror(f)) { + log_error("Failed to write unit file %s: %m", unit); + return -errno; + } + + lnk = strjoin(arg_dest, "/" SPECIAL_LOCAL_FS_TARGET ".requires/home.mount", NULL); + if (!lnk) + return log_oom(); + + + mkdir_parents_label(lnk, 0755); + if (symlink(unit, lnk) < 0) { + log_error("Failed to create symlink %s: %m", lnk); + return -errno; + } + + return 0; +} + +static int enumerate_partitions(struct udev *udev, dev_t dev) { + struct udev_enumerate *e = NULL; + struct udev_device *parent = NULL, *d = NULL; + struct udev_list_entry *first, *item; + unsigned home_nr = (unsigned) -1; + _cleanup_free_ char *home = NULL, *home_fstype = NULL; + int r; + + e = udev_enumerate_new(udev); + if (!e) { + r = log_oom(); + goto finish; + } + + d = udev_device_new_from_devnum(udev, 'b', dev); + if (!d) { + r = log_oom(); + goto finish; + } + + parent = udev_device_get_parent(d); + if (!parent) { + r = log_oom(); + goto finish; + } + + r = udev_enumerate_add_match_parent(e, parent); + if (r < 0) { + r = log_oom(); + goto finish; + } + + r = udev_enumerate_add_match_subsystem(e, "block"); + if (r < 0) { + r = log_oom(); + goto finish; + } + + r = udev_enumerate_scan_devices(e); + if (r < 0) { + log_error("Failed to enumerate partitions on /dev/block/%u:%u: %s", + major(dev), minor(dev), strerror(-r)); + goto finish; + } + + first = udev_enumerate_get_list_entry(e); + udev_list_entry_foreach(item, first) { + _cleanup_free_ char *fstype = NULL; + const char *node = NULL; + struct udev_device *q; + sd_id128_t type_id; + unsigned nr; + + q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); + if (!q) { + r = log_oom(); + goto finish; + } + + if (udev_device_get_devnum(q) == udev_device_get_devnum(d)) + goto skip; + + if (udev_device_get_devnum(q) == udev_device_get_devnum(parent)) + goto skip; + + node = udev_device_get_devnode(q); + if (!node) { + r = log_oom(); + goto finish; + } + + r = verify_gpt_partition(node, &type_id, &nr, &fstype); + if (r < 0) { + log_error("Failed to verify GPT partition %s: %s", + node, strerror(-r)); + udev_device_unref(q); + goto finish; + } + if (r == 0) + goto skip; + + if (sd_id128_equal(type_id, SD_ID128_MAKE(06,57,fd,6d,a4,ab,43,c4,84,e5,09,33,c8,4b,4f,4f))) + add_swap(node, fstype); + else if (sd_id128_equal(type_id, SD_ID128_MAKE(93,3a,c7,e1,2e,b4,4f,13,b8,44,0e,14,e2,ae,f9,15))) { + + if (!home || nr < home_nr) { + free(home); + home = strdup(node); + if (!home) { + r = log_oom(); + goto finish; + } + + home_nr = nr; + + free(home_fstype); + home_fstype = fstype; + fstype = NULL; + } + } + + skip: + udev_device_unref(q); + } + + if (home && home_fstype) + add_home(home, home_fstype); + +finish: + if (d) + udev_device_unref(d); + + if (e) + udev_enumerate_unref(e); + + + return r; +} + +static int get_btrfs_block_device(const char *path, dev_t *dev) { + struct btrfs_ioctl_fs_info_args fsi; + _cleanup_close_ int fd = -1; + uint64_t id; + + assert(path); + assert(dev); + + fd = open(path, O_DIRECTORY|O_CLOEXEC); + if (fd < 0) + return -errno; + + zero(fsi); + if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0) + return -errno; + + /* We won't do this for btrfs RAID */ + if (fsi.num_devices != 1) + return 0; + + for (id = 1; id <= fsi.max_id; id++) { + struct btrfs_ioctl_dev_info_args di; + struct stat st; + + zero(di); + di.devid = id; + + if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) { + if (errno == ENODEV) + continue; + + return -errno; + } + + if (stat((char*) di.path, &st) < 0) + return -errno; + + if (!S_ISBLK(st.st_mode)) + return -ENODEV; + + if (major(st.st_rdev) == 0) + return -ENODEV; + + *dev = st.st_rdev; + return 1; + } + + return -ENODEV; +} + +static int get_block_device(const char *path, dev_t *dev) { + struct stat st; + struct statfs sfs; + + assert(path); + assert(dev); + + if (lstat("/", &st)) + return -errno; + + if (major(st.st_dev) != 0) { + *dev = st.st_dev; + return 1; + } + + if (statfs("/", &sfs) < 0) + return -errno; + + if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC)) + return get_btrfs_block_device(path, dev); + + return 0; +} + +static int devno_to_devnode(struct udev *udev, dev_t devno, char **ret) { + struct udev_device *d = NULL; + const char *t; + char *n; + int r; + + d = udev_device_new_from_devnum(udev, 'b', devno); + if (!d) { + r = log_oom(); + goto finish; + } + + t = udev_device_get_devnode(d); + if (!t) { + r = -ENODEV; + goto finish; + } + + n = strdup(t); + if (!n) { + r = -ENOMEM; + goto finish; + } + + *ret = n; + r = 0; + +finish: + if (d) + udev_device_unref(d); + + return r; +} + +int main(int argc, char *argv[]) { + _cleanup_free_ char *node = NULL; + struct udev *udev = NULL; + dev_t devno; + int r; + + if (argc > 1 && argc != 4) { + log_error("This program takes three or no arguments."); + r = -EINVAL; + goto finish; + } + + if (argc > 1) + arg_dest = argv[3]; + + log_set_target(LOG_TARGET_SAFE); + log_parse_environment(); + log_open(); + + umask(0022); + + if (in_initrd()) { + r = 0; + goto finish; + } + + r = get_block_device("/", &devno); + if (r < 0) { + log_error("Failed to determine block device of root file system: %s", strerror(-r)); + goto finish; + } + if (r == 0) { + log_debug("Root file system not on a (single) block device."); + goto finish; + } + + udev = udev_new(); + if (!udev) { + r = log_oom(); + goto finish; + } + + r = devno_to_devnode(udev, devno, &node); + if (r < 0) { + log_error("Failed to determine block device node from major/minor: %s", strerror(-r)); + goto finish; + } + + log_debug("Root device %s.", node); + + r = verify_gpt_partition(node, NULL, NULL, NULL); + if (r < 0) { + log_error("Failed to verify GPT partition %s: %s", node, strerror(-r)); + goto finish; + } + if (r == 0) + goto finish; + + r = enumerate_partitions(udev, devno); + +finish: + if (udev) + udev_unref(udev); + + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} |