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-rw-r--r--src/gpt-auto-generator/gpt-auto-generator.c746
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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-13 13:25:25 +0000