Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 526 insertions, 0 deletions

diff --git a/src/veritysetup/veritysetup-generator.c b/src/veritysetup/veritysetup-generator.c
new file mode 100644
index 0000000..d55d4aa
--- /dev/null
+++ b/src/veritysetup/veritysetup-generator.c
@@ -0,0 +1,526 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fstab-util.h"
+#include "generator.h"
+#include "hexdecoct.h"
+#include "id128-util.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "proc-cmdline.h"
+#include "specifier.h"
+#include "string-util.h"
+#include "unit-name.h"
+
+#define SYSTEMD_VERITYSETUP_SERVICE_ROOT "systemd-veritysetup@root.service"
+#define SYSTEMD_VERITYSETUP_SERVICE_USR "systemd-veritysetup@usr.service"
+
+static const char *arg_dest = NULL;
+static bool arg_enabled = true;
+static bool arg_read_veritytab = true;
+static const char *arg_veritytab = NULL;
+static char *arg_root_hash = NULL;
+static char *arg_root_data_what = NULL;
+static char *arg_root_hash_what = NULL;
+static char *arg_root_options = NULL;
+static char *arg_usr_hash = NULL;
+static char *arg_usr_data_what = NULL;
+static char *arg_usr_hash_what = NULL;
+static char *arg_usr_options = NULL;
+
+STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_data_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_hash_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_options, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_hash, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_data_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_hash_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_options, freep);
+
+static int create_special_device(
+                const char *name,
+                const char *service,
+                const char *roothash,
+                const char *data_what,
+                const char *hash_what,
+                const char *options) {
+
+        _cleanup_free_ char *u = NULL, *v = NULL, *d = NULL, *e = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        /* Creates a systemd-veritysetup@.service instance for the special kernel cmdline specified root + usr devices. */
+
+        assert(name);
+        assert(service);
+
+        /* If all three pieces of information are missing, then verity is turned off */
+        if (!roothash && !data_what && !hash_what)
+                return 0;
+
+        /* if one of them is missing however, the data is simply incomplete and this is an error */
+        if (!roothash)
+                log_error("Verity information for %s incomplete, root hash unspecified.", name);
+        if (!data_what)
+                log_error("Verity information for %s incomplete, data device unspecified.", name);
+        if (!hash_what)
+                log_error("Verity information for %s incomplete, hash device unspecified.", name);
+
+        if (!roothash || !data_what || !hash_what)
+                return -EINVAL;
+
+        log_debug("Using %s verity data device %s, hash device %s, options %s, and hash %s.", name, data_what, hash_what, options, roothash);
+
+        u = fstab_node_to_udev_node(data_what);
+        if (!u)
+                return log_oom();
+        v = fstab_node_to_udev_node(hash_what);
+        if (!v)
+                return log_oom();
+
+        r = unit_name_from_path(u, ".device", &d);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+        r = unit_name_from_path(v, ".device", &e);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        r = generator_open_unit_file(arg_dest, NULL, service, &f);
+        if (r < 0)
+                return r;
+
+        r = generator_write_veritysetup_unit_section(f, "/proc/cmdline");
+        if (r < 0)
+                return r;
+
+        fprintf(f,
+                "Before=veritysetup.target\n"
+                "BindsTo=%s %s\n"
+                "After=%s %s\n",
+                d, e,
+                d, e);
+
+        r = generator_write_veritysetup_service_section(f, name, u, v, roothash, options);
+        if (r < 0)
+                return r;
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write file unit %s: %m", service);
+
+        r = generator_add_symlink(arg_dest, "veritysetup.target", "requires", service);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int create_root_device(void) {
+        return create_special_device("root", SYSTEMD_VERITYSETUP_SERVICE_ROOT, arg_root_hash, arg_root_data_what, arg_root_hash_what, arg_root_options);
+}
+
+static int create_usr_device(void) {
+        return create_special_device("usr", SYSTEMD_VERITYSETUP_SERVICE_USR, arg_usr_hash, arg_usr_data_what, arg_usr_hash_what, arg_usr_options);
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+        int r;
+
+        assert(key);
+
+        if (streq(key, "systemd.verity")) {
+
+                r = value ? parse_boolean(value) : 1;
+                if (r < 0)
+                        log_warning("Failed to parse verity= kernel command line switch %s. Ignoring.", value);
+                else
+                        arg_enabled = r;
+
+        } else if (streq(key, "veritytab")) {
+
+                r = value ? parse_boolean(value) : 1;
+                if (r < 0)
+                        log_warning("Failed to parse veritytab= kernel command line switch %s. Ignoring.", value);
+                else
+                        arg_read_veritytab = r;
+
+        } else if (streq(key, "roothash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_root_hash, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_root_data")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_root_data_what, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_root_hash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_root_hash_what, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_root_options")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_root_options, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (streq(key, "usrhash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_usr_hash, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_usr_data")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_usr_data_what, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_usr_hash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_usr_hash_what, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_usr_options")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_usr_options, value);
+                if (r < 0)
+                        return log_oom();
+
+        }
+
+        return 0;
+}
+
+static int determine_device(
+                const char *name,
+                const char *hash,
+                char **data_what,
+                char **hash_what) {
+
+        sd_id128_t data_uuid, verity_uuid;
+        _cleanup_free_ void *m = NULL;
+        size_t l;
+        int r;
+
+        assert(name);
+        assert(data_what);
+        assert(hash_what);
+
+        if (!hash)
+                return 0;
+
+        if (*data_what && *hash_what)
+                return 0;
+
+        r = unhexmem(hash, strlen(hash), &m, &l);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse hash: %s", hash);
+        if (l < sizeof(sd_id128_t)) {
+                log_debug("Root hash for %s is shorter than 128 bits (32 characters), ignoring for discovering verity partition.", name);
+                return 0;
+        }
+
+        if (!*data_what) {
+                memcpy(&data_uuid, m, sizeof(data_uuid));
+
+                *data_what = path_join("/dev/disk/by-partuuid", SD_ID128_TO_UUID_STRING(data_uuid));
+                if (!*data_what)
+                        return log_oom();
+        }
+
+        if (!*hash_what) {
+                memcpy(&verity_uuid, (uint8_t*) m + l - sizeof(verity_uuid), sizeof(verity_uuid));
+
+                *hash_what = path_join("/dev/disk/by-partuuid", SD_ID128_TO_UUID_STRING(verity_uuid));
+                if (!*hash_what)
+                        return log_oom();
+        }
+
+        log_info("Using data device %s and hash device %s for %s.", *data_what, *hash_what, name);
+
+        return 1;
+}
+
+static int determine_devices(void) {
+        int r;
+
+        r = determine_device("root", arg_root_hash, &arg_root_data_what, &arg_root_hash_what);
+        if (r < 0)
+                return r;
+
+        return determine_device("usr", arg_usr_hash, &arg_usr_data_what, &arg_usr_hash_what);
+}
+
+static bool attach_in_initrd(const char *name, const char *options) {
+        assert(name);
+
+        /* Imply x-initrd.attach in case the volume name is among those defined in the Discoverable Partition
+         * Specification for partitions that we require to be mounted during the initrd → host transition,
+         * i.e. for the root fs itself, and /usr/. This mirrors similar behaviour in
+         * systemd-fstab-generator. */
+
+        return fstab_test_option(options, "x-initrd.attach\0") ||
+                STR_IN_SET(name, "root", "usr");
+}
+
+static int create_veritytab_device(
+                const char *name,
+                const char *data_device,
+                const char *hash_device,
+                const char *roothash,
+                const char *options,
+                const char *source) {
+
+        _cleanup_free_ char *n = NULL, *dd = NULL, *du = NULL, *hd = NULL, *hu = NULL, *e = NULL,
+                            *du_escaped = NULL, *hu_escaped = NULL, *name_escaped = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        const char *dmname;
+        bool noauto, nofail, netdev, need_loop = false;
+        int r;
+
+        /* Creates a systemd-veritysetup@.service instance for volumes specified in /etc/veritytab. */
+
+        assert(name);
+        assert(data_device);
+        assert(hash_device);
+        assert(roothash);
+
+        noauto = fstab_test_yes_no_option(options, "noauto\0" "auto\0");
+        nofail = fstab_test_yes_no_option(options, "nofail\0" "fail\0");
+        netdev = fstab_test_option(options, "_netdev\0");
+
+        name_escaped = specifier_escape(name);
+        if (!name_escaped)
+                return log_oom();
+
+        e = unit_name_escape(name);
+        if (!e)
+                return log_oom();
+
+        du = fstab_node_to_udev_node(data_device);
+        if (!du)
+                return log_oom();
+
+        hu = fstab_node_to_udev_node(hash_device);
+        if (!hu)
+                return log_oom();
+
+        r = unit_name_build("systemd-veritysetup", e, ".service", &n);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        du_escaped = specifier_escape(du);
+        if (!du_escaped)
+                return log_oom();
+
+        hu_escaped = specifier_escape(hu);
+        if (!hu_escaped)
+                return log_oom();
+
+        r = unit_name_from_path(du, ".device", &dd);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        r = unit_name_from_path(hu, ".device", &hd);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        r = generator_open_unit_file(arg_dest, NULL, n, &f);
+        if (r < 0)
+                return r;
+
+        r = generator_write_veritysetup_unit_section(f, source);
+        if (r < 0)
+                return r;
+
+        if (netdev)
+                fprintf(f, "After=remote-fs-pre.target\n");
+
+        /* If initrd takes care of attaching the disk then it should also detach it during shutdown. */
+        if (!attach_in_initrd(name, options))
+                fprintf(f,
+                        "Conflicts=umount.target\n"
+                        "Before=umount.target\n");
+
+        if (!nofail)
+                fprintf(f,
+                        "Before=%s\n",
+                        netdev ? "remote-veritysetup.target" : "veritysetup.target");
+
+        if (path_startswith(du, "/dev/"))
+                fprintf(f,
+                        "BindsTo=%s\n"
+                        "After=%s\n",
+                        dd, dd);
+        else {
+                fprintf(f, "RequiresMountsFor=%s\n", du_escaped);
+                need_loop = true;
+        }
+
+        if (path_startswith(hu, "/dev/"))
+                fprintf(f,
+                        "BindsTo=%s\n"
+                        "After=%s\n",
+                        hd, hd);
+        else {
+                fprintf(f, "RequiresMountsFor=%s\n", hu_escaped);
+                need_loop = true;
+        }
+
+        if (need_loop)
+                /* For loopback devices make sure to explicitly load loop.ko, as this code might run very
+                 * early where device nodes created via systemd-tmpfiles-setup-dev.service might not be
+                 * around yet. Hence let's sync on the module itself. */
+                fprintf(f,
+                        "Wants=modprobe@loop.service\n"
+                        "After=modprobe@loop.service\n");
+
+        r = generator_write_veritysetup_service_section(f, name, du, hu, roothash, options);
+        if (r < 0)
+                return r;
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write unit file %s: %m", n);
+
+        if (!noauto) {
+                r = generator_add_symlink(arg_dest,
+                                          netdev ? "remote-veritysetup.target" : "veritysetup.target",
+                                          nofail ? "wants" : "requires", n);
+                if (r < 0)
+                        return r;
+        }
+
+        dmname = strjoina("dev-mapper-", e, ".device");
+        return generator_add_symlink(arg_dest, dmname, "requires", n);
+}
+
+static int add_veritytab_devices(void) {
+        _cleanup_fclose_ FILE *f = NULL;
+        unsigned veritytab_line = 0;
+        int r;
+
+        if (!arg_read_veritytab)
+                return 0;
+
+        r = fopen_unlocked(arg_veritytab, "re", &f);
+        if (r < 0) {
+                if (errno != ENOENT)
+                        log_error_errno(errno, "Failed to open %s: %m", arg_veritytab);
+                return 0;
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL, *name = NULL, *data_device = NULL, *hash_device = NULL,
+                                    *roothash = NULL, *options = NULL;
+                char *data_uuid, *hash_uuid;
+
+                r = read_stripped_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to read %s: %m", arg_veritytab);
+                if (r == 0)
+                        break;
+
+                veritytab_line++;
+
+                if (IN_SET(line[0], 0, '#'))
+                        continue;
+
+                r = sscanf(line, "%ms %ms %ms %ms %ms", &name, &data_device, &hash_device, &roothash, &options);
+                if (!IN_SET(r, 4, 5)) {
+                        log_error("Failed to parse %s:%u, ignoring.", arg_veritytab, veritytab_line);
+                        continue;
+                }
+
+                data_uuid = startswith(data_device, "UUID=");
+                if (!data_uuid)
+                        data_uuid = path_startswith(data_device, "/dev/disk/by-uuid/");
+
+                hash_uuid = startswith(hash_device, "UUID=");
+                if (!hash_uuid)
+                        hash_uuid = path_startswith(hash_device, "/dev/disk/by-uuid/");
+
+                r = create_veritytab_device(
+                                name,
+                                data_device,
+                                hash_device,
+                                roothash,
+                                options,
+                                arg_veritytab);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
+        int r;
+
+        assert_se(arg_dest = dest);
+
+        arg_veritytab = getenv("SYSTEMD_VERITYTAB") ?: "/etc/veritytab";
+
+        r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to parse kernel command line: %m");
+
+        if (!arg_enabled)
+                return 0;
+
+        r = add_veritytab_devices();
+        if (r < 0)
+                return r;
+
+        r = determine_devices();
+        if (r < 0)
+                return r;
+
+        r = create_root_device();
+        if (r < 0)
+                return r;
+
+        return create_usr_device();
+}
+
+DEFINE_MAIN_GENERATOR_FUNCTION(run);