/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #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, &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; 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; } 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);