diff options
Diffstat (limited to 'src/gpt-auto-generator')
| -rw-r--r-- | src/gpt-auto-generator/gpt-auto-generator.c | 746 |
1 files changed, 746 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 0000000..d9e29c4 --- /dev/null +++ b/src/gpt-auto-generator/gpt-auto-generator.c @@ -0,0 +1,746 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <blkid.h> +#include <stdlib.h> +#include <sys/statfs.h> +#include <unistd.h> + +#include "sd-device.h" +#include "sd-id128.h" + +#include "alloc-util.h" +#include "blkid-util.h" +#include "blockdev-util.h" +#include "btrfs-util.h" +#include "device-util.h" +#include "dirent-util.h" +#include "dissect-image.h" +#include "efivars.h" +#include "fd-util.h" +#include "fileio.h" +#include "fstab-util.h" +#include "generator.h" +#include "gpt.h" +#include "missing.h" +#include "mkdir.h" +#include "mountpoint-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "proc-cmdline.h" +#include "special.h" +#include "specifier.h" +#include "stat-util.h" +#include "string-util.h" +#include "strv.h" +#include "unit-name.h" +#include "util.h" +#include "virt.h" + +static const char *arg_dest = NULL; +static bool arg_enabled = true; +static bool arg_root_enabled = true; +static int arg_root_rw = -1; + +static int add_cryptsetup(const char *id, const char *what, bool rw, bool require, char **device) { + _cleanup_free_ char *e = NULL, *n = NULL, *d = NULL, *id_escaped = NULL, *what_escaped = NULL; + _cleanup_fclose_ FILE *f = NULL; + const char *p; + int r; + + assert(id); + assert(what); + + r = unit_name_from_path(what, ".device", &d); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name: %m"); + + e = unit_name_escape(id); + if (!e) + return log_oom(); + + r = unit_name_build("systemd-cryptsetup", e, ".service", &n); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name: %m"); + + id_escaped = specifier_escape(id); + if (!id_escaped) + return log_oom(); + + what_escaped = specifier_escape(what); + if (!what_escaped) + return log_oom(); + + p = strjoina(arg_dest, "/", n); + f = fopen(p, "wxe"); + if (!f) + return log_error_errno(errno, "Failed to create unit file %s: %m", p); + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "Description=Cryptography Setup for %%I\n" + "Documentation=man:systemd-gpt-auto-generator(8) man:systemd-cryptsetup@.service(8)\n" + "DefaultDependencies=no\n" + "Conflicts=umount.target\n" + "BindsTo=dev-mapper-%%i.device %s\n" + "Before=umount.target cryptsetup.target\n" + "After=%s\n" + "IgnoreOnIsolate=true\n" + "[Service]\n" + "Type=oneshot\n" + "RemainAfterExit=yes\n" + "TimeoutSec=0\n" /* the binary handles timeouts anyway */ + "KeyringMode=shared\n" /* make sure we can share cached keys among instances */ + "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '' '%s'\n" + "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n", + d, d, + id_escaped, what_escaped, rw ? "" : "read-only", + id_escaped); + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write file %s: %m", p); + + r = generator_add_symlink(arg_dest, d, "wants", n); + if (r < 0) + return r; + + if (require) { + const char *dmname; + + r = generator_add_symlink(arg_dest, "cryptsetup.target", "requires", n); + if (r < 0) + return r; + + dmname = strjoina("dev-mapper-", e, ".device"); + r = generator_add_symlink(arg_dest, dmname, "requires", n); + if (r < 0) + return r; + } + + p = strjoina(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf"); + mkdir_parents_label(p, 0755); + r = write_string_file(p, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "JobTimeoutSec=0\n", + WRITE_STRING_FILE_CREATE); /* the binary handles timeouts anyway */ + if (r < 0) + return log_error_errno(r, "Failed to write device drop-in: %m"); + + if (device) { + char *ret; + + ret = strappend("/dev/mapper/", id); + if (!ret) + return log_oom(); + + *device = ret; + } + + return 0; +} + +static int add_mount( + const char *id, + const char *what, + const char *where, + const char *fstype, + bool rw, + const char *options, + const char *description, + const char *post) { + + _cleanup_free_ char *unit = NULL, *crypto_what = NULL, *p = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + /* Note that we don't apply specifier escaping on the input strings here, since we know they are not configured + * externally, but all originate from our own sources here, and hence we know they contain no % characters that + * could potentially be understood as specifiers. */ + + assert(id); + assert(what); + assert(where); + assert(description); + + log_debug("Adding %s: %s %s", where, what, strna(fstype)); + + if (streq_ptr(fstype, "crypto_LUKS")) { + + r = add_cryptsetup(id, what, rw, true, &crypto_what); + if (r < 0) + return r; + + what = crypto_what; + fstype = NULL; + } + + r = unit_name_from_path(where, ".mount", &unit); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name: %m"); + + p = strjoin(arg_dest, "/", unit); + if (!p) + return log_oom(); + + f = fopen(p, "wxe"); + if (!f) + return log_error_errno(errno, "Failed to create unit file %s: %m", unit); + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "Description=%s\n" + "Documentation=man:systemd-gpt-auto-generator(8)\n", + description); + + if (post) + fprintf(f, "Before=%s\n", post); + + r = generator_write_fsck_deps(f, arg_dest, what, where, fstype); + if (r < 0) + return r; + + fprintf(f, + "\n" + "[Mount]\n" + "What=%s\n" + "Where=%s\n", + what, where); + + if (fstype) + fprintf(f, "Type=%s\n", fstype); + + if (options) + fprintf(f, "Options=%s,%s\n", options, rw ? "rw" : "ro"); + else + fprintf(f, "Options=%s\n", rw ? "rw" : "ro"); + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write unit file %s: %m", p); + + if (post) + return generator_add_symlink(arg_dest, post, "requires", unit); + return 0; +} + +static int path_is_busy(const char *where) { + int r; + + /* already a mountpoint; generators run during reload */ + r = path_is_mount_point(where, NULL, AT_SYMLINK_FOLLOW); + if (r > 0) + return false; + + /* the directory might not exist on a stateless system */ + if (r == -ENOENT) + return false; + + if (r < 0) + return log_warning_errno(r, "Cannot check if \"%s\" is a mount point: %m", where); + + /* not a mountpoint but it contains files */ + r = dir_is_empty(where); + if (r < 0) + return log_warning_errno(r, "Cannot check if \"%s\" is empty: %m", where); + if (r > 0) + return false; + + log_debug("\"%s\" already populated, ignoring.", where); + return true; +} + +static int add_partition_mount( + DissectedPartition *p, + const char *id, + const char *where, + const char *description) { + + int r; + assert(p); + + r = path_is_busy(where); + if (r != 0) + return r < 0 ? r : 0; + + return add_mount( + id, + p->node, + where, + p->fstype, + p->rw, + NULL, + description, + SPECIAL_LOCAL_FS_TARGET); +} + +static int add_swap(const char *path) { + _cleanup_free_ char *name = NULL, *unit = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(path); + + /* Disable the swap auto logic if at least one swap is defined in /etc/fstab, see #6192. */ + r = fstab_has_fstype("swap"); + if (r < 0) + return log_error_errno(r, "Failed to parse fstab: %m"); + if (r > 0) { + log_debug("swap specified in fstab, ignoring."); + return 0; + } + + log_debug("Adding swap: %s", path); + + r = unit_name_from_path(path, ".swap", &name); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name: %m"); + + unit = strjoin(arg_dest, "/", name); + if (!unit) + return log_oom(); + + f = fopen(unit, "wxe"); + if (!f) + return log_error_errno(errno, "Failed to create unit file %s: %m", unit); + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "Description=Swap Partition\n" + "Documentation=man:systemd-gpt-auto-generator(8)\n\n" + "[Swap]\n" + "What=%s\n", + path); + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write unit file %s: %m", unit); + + return generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET, "wants", name); +} + +#if ENABLE_EFI +static int add_automount( + const char *id, + const char *what, + const char *where, + const char *fstype, + bool rw, + const char *options, + const char *description, + usec_t timeout) { + + _cleanup_free_ char *unit = NULL; + _cleanup_fclose_ FILE *f = NULL; + const char *opt = "noauto", *p; + int r; + + assert(id); + assert(where); + assert(description); + + if (options) + opt = strjoina(options, ",", opt); + + r = add_mount(id, + what, + where, + fstype, + rw, + opt, + description, + NULL); + if (r < 0) + return r; + + r = unit_name_from_path(where, ".automount", &unit); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name: %m"); + + p = strjoina(arg_dest, "/", unit); + f = fopen(p, "wxe"); + if (!f) + return log_error_errno(errno, "Failed to create unit file %s: %m", unit); + + fprintf(f, + "# Automatically generated by systemd-gpt-auto-generator\n\n" + "[Unit]\n" + "Description=%s\n" + "Documentation=man:systemd-gpt-auto-generator(8)\n" + "[Automount]\n" + "Where=%s\n" + "TimeoutIdleSec="USEC_FMT"\n", + description, + where, + timeout / USEC_PER_SEC); + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write unit file %s: %m", p); + + return generator_add_symlink(arg_dest, SPECIAL_LOCAL_FS_TARGET, "wants", unit); +} + +static int add_esp(DissectedPartition *p) { + const char *esp; + int r; + + assert(p); + + if (in_initrd()) { + log_debug("In initrd, ignoring the ESP."); + return 0; + } + + /* If /efi exists we'll use that. Otherwise we'll use /boot, as that's usually the better choice */ + esp = access("/efi/", F_OK) >= 0 ? "/efi" : "/boot"; + + /* We create an .automount which is not overridden by the .mount from the fstab generator. */ + r = fstab_is_mount_point(esp); + if (r < 0) + return log_error_errno(r, "Failed to parse fstab: %m"); + if (r > 0) { + log_debug("%s specified in fstab, ignoring.", esp); + return 0; + } + + r = path_is_busy(esp); + if (r != 0) + return r < 0 ? r : 0; + + if (is_efi_boot()) { + sd_id128_t loader_uuid; + + /* If this is an EFI boot, be extra careful, and only mount the ESP if it was the ESP used for booting. */ + + r = efi_loader_get_device_part_uuid(&loader_uuid); + if (r == -ENOENT) { + log_debug("EFI loader partition unknown."); + return 0; + } + if (r < 0) + return log_error_errno(r, "Failed to read ESP partition UUID: %m"); + + if (!sd_id128_equal(p->uuid, loader_uuid)) { + log_debug("Partition for %s does not appear to be the partition we are booted from.", esp); + return 0; + } + } else + log_debug("Not an EFI boot, skipping ESP check."); + + return add_automount("boot", + p->node, + esp, + p->fstype, + true, + "umask=0077", + "EFI System Partition Automount", + 120 * USEC_PER_SEC); +} +#else +static int add_esp(DissectedPartition *p) { + return 0; +} +#endif + +static int add_root_rw(DissectedPartition *p) { + const char *path; + int r; + + assert(p); + + if (in_initrd()) { + log_debug("In initrd, not generating drop-in for systemd-remount-fs.service."); + return 0; + } + + if (arg_root_rw >= 0) { + log_debug("Parameter ro/rw specified on kernel command line, not generating drop-in for systemd-remount-fs.service."); + return 0; + } + + if (!p->rw) { + log_debug("Root partition marked read-only in GPT partition table, not generating drop-in for systemd-remount-fs.service."); + return 0; + } + + path = strjoina(arg_dest, "/systemd-remount-fs.service.d/50-remount-rw.conf"); + (void) mkdir_parents(path, 0755); + + r = write_string_file(path, + "# Automatically generated by systemd-gpt-generator\n\n" + "[Unit]\n" + "ConditionPathExists=\n\n" /* We need to turn off the ConditionPathExist= in the main unit file */ + "[Service]\n" + "Environment=SYSTEMD_REMOUNT_ROOT_RW=1\n", + WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_NOFOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to write drop-in file %s: %m", path); + + return 0; +} + +static int open_parent(dev_t devnum, int *ret) { + _cleanup_(sd_device_unrefp) sd_device *d = NULL; + const char *name, *devtype, *node; + sd_device *parent; + dev_t pn; + int fd, r; + + assert(ret); + + r = sd_device_new_from_devnum(&d, 'b', devnum); + if (r < 0) + return log_debug_errno(r, "Failed to open device: %m"); + + if (sd_device_get_devname(d, &name) < 0) { + r = sd_device_get_syspath(d, &name); + if (r < 0) { + log_device_debug_errno(d, r, "Device %u:%u does not have a name, ignoring: %m", major(devnum), minor(devnum)); + return 0; + } + } + + r = sd_device_get_parent(d, &parent); + if (r < 0) { + log_device_debug_errno(d, r, "Not a partitioned device, ignoring: %m"); + return 0; + } + + /* Does it have a devtype? */ + r = sd_device_get_devtype(parent, &devtype); + if (r < 0) { + log_device_debug_errno(parent, r, "Parent doesn't have a device type, ignoring: %m"); + return 0; + } + + /* Is this a disk or a partition? We only care for disks... */ + if (!streq(devtype, "disk")) { + log_device_debug(parent, "Parent isn't a raw disk, ignoring."); + return 0; + } + + /* Does it have a device node? */ + r = sd_device_get_devname(parent, &node); + if (r < 0) { + log_device_debug_errno(parent, r, "Parent device does not have device node, ignoring: %m"); + return 0; + } + + log_device_debug(d, "Root device %s.", node); + + r = sd_device_get_devnum(parent, &pn); + if (r < 0) { + log_device_debug_errno(parent, r, "Parent device is not a proper block device, ignoring: %m"); + return 0; + } + + fd = open(node, O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) + return log_error_errno(errno, "Failed to open %s: %m", node); + + *ret = fd; + return 1; +} + +static int enumerate_partitions(dev_t devnum) { + _cleanup_close_ int fd = -1; + _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; + int r, k; + + r = open_parent(devnum, &fd); + if (r <= 0) + return r; + + r = dissect_image(fd, NULL, 0, DISSECT_IMAGE_GPT_ONLY|DISSECT_IMAGE_NO_UDEV, &m); + if (r == -ENOPKG) { + log_debug_errno(r, "No suitable partition table found, ignoring."); + return 0; + } + if (r < 0) + return log_error_errno(r, "Failed to dissect: %m"); + + if (m->partitions[PARTITION_SWAP].found) { + k = add_swap(m->partitions[PARTITION_SWAP].node); + if (k < 0) + r = k; + } + + if (m->partitions[PARTITION_ESP].found) { + k = add_esp(m->partitions + PARTITION_ESP); + if (k < 0) + r = k; + } + + if (m->partitions[PARTITION_HOME].found) { + k = add_partition_mount(m->partitions + PARTITION_HOME, "home", "/home", "Home Partition"); + if (k < 0) + r = k; + } + + if (m->partitions[PARTITION_SRV].found) { + k = add_partition_mount(m->partitions + PARTITION_SRV, "srv", "/srv", "Server Data Partition"); + if (k < 0) + r = k; + } + + if (m->partitions[PARTITION_ROOT].found) { + k = add_root_rw(m->partitions + PARTITION_ROOT); + if (k < 0) + r = k; + } + + return r; +} + +static int parse_proc_cmdline_item(const char *key, const char *value, void *data) { + int r; + + assert(key); + + if (proc_cmdline_key_streq(key, "systemd.gpt_auto") || + proc_cmdline_key_streq(key, "rd.systemd.gpt_auto")) { + + r = value ? parse_boolean(value) : 1; + if (r < 0) + log_warning_errno(r, "Failed to parse gpt-auto switch \"%s\", ignoring: %m", value); + else + arg_enabled = r; + + } else if (proc_cmdline_key_streq(key, "root")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + /* Disable root disk logic if there's a root= value + * specified (unless it happens to be "gpt-auto") */ + + arg_root_enabled = streq(value, "gpt-auto"); + + } else if (proc_cmdline_key_streq(key, "roothash")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + /* Disable root disk logic if there's roothash= defined (i.e. verity enabled) */ + + arg_root_enabled = false; + + } else if (proc_cmdline_key_streq(key, "rw") && !value) + arg_root_rw = true; + else if (proc_cmdline_key_streq(key, "ro") && !value) + arg_root_rw = false; + + return 0; +} + +#if ENABLE_EFI +static int add_root_cryptsetup(void) { + + /* If a device /dev/gpt-auto-root-luks appears, then make it pull in systemd-cryptsetup-root.service, which + * sets it up, and causes /dev/gpt-auto-root to appear which is all we are looking for. */ + + return add_cryptsetup("root", "/dev/gpt-auto-root-luks", true, false, NULL); +} +#endif + +static int add_root_mount(void) { + +#if ENABLE_EFI + int r; + + if (!is_efi_boot()) { + log_debug("Not a EFI boot, not creating root mount."); + return 0; + } + + r = efi_loader_get_device_part_uuid(NULL); + if (r == -ENOENT) { + log_debug("EFI loader partition unknown, exiting."); + return 0; + } else if (r < 0) + return log_error_errno(r, "Failed to read ESP partition UUID: %m"); + + /* OK, we have an ESP partition, this is fantastic, so let's + * wait for a root device to show up. A udev rule will create + * the link for us under the right name. */ + + if (in_initrd()) { + r = generator_write_initrd_root_device_deps(arg_dest, "/dev/gpt-auto-root"); + if (r < 0) + return 0; + + r = add_root_cryptsetup(); + if (r < 0) + return r; + } + + return add_mount( + "root", + "/dev/gpt-auto-root", + in_initrd() ? "/sysroot" : "/", + NULL, + arg_root_rw > 0, + NULL, + "Root Partition", + in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET); +#else + return 0; +#endif +} + +static int add_mounts(void) { + dev_t devno; + int r; + + r = get_block_device_harder("/", &devno); + if (r < 0) + return log_error_errno(r, "Failed to determine block device of root file system: %m"); + if (r == 0) { + r = get_block_device_harder("/usr", &devno); + if (r < 0) + return log_error_errno(r, "Failed to determine block device of /usr file system: %m"); + if (r == 0) { + log_debug("Neither root nor /usr file system are on a (single) block device."); + return 0; + } + } + + return enumerate_partitions(devno); +} + +static int run(const char *dest, const char *dest_early, const char *dest_late) { + int r, k; + + assert_se(arg_dest = dest_late); + + if (detect_container() > 0) { + log_debug("In a container, exiting."); + return 0; + } + + r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0); + if (r < 0) + log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m"); + + if (!arg_enabled) { + log_debug("Disabled, exiting."); + return 0; + } + + if (arg_root_enabled) + r = add_root_mount(); + + if (!in_initrd()) { + k = add_mounts(); + if (r >= 0) + r = k; + } + + return r; +} + +DEFINE_MAIN_GENERATOR_FUNCTION(run); |