/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include #include #include #include #include #include #include #include #include #include "sd-id128.h" #include "alloc-util.h" #include "apparmor-util.h" #include "architecture.h" #include "audit-util.h" #include "cap-list.h" #include "cgroup-util.h" #include "condition.h" #include "cpu-set-util.h" #include "efivars.h" #include "env-file.h" #include "extract-word.h" #include "fd-util.h" #include "fileio.h" #include "glob-util.h" #include "hostname-util.h" #include "ima-util.h" #include "limits-util.h" #include "list.h" #include "macro.h" #include "mountpoint-util.h" #include "parse-util.h" #include "path-util.h" #include "proc-cmdline.h" #include "process-util.h" #include "selinux-util.h" #include "smack-util.h" #include "stat-util.h" #include "string-table.h" #include "string-util.h" #include "tomoyo-util.h" #include "user-util.h" #include "util.h" #include "virt.h" Condition* condition_new(ConditionType type, const char *parameter, bool trigger, bool negate) { Condition *c; assert(type >= 0); assert(type < _CONDITION_TYPE_MAX); assert((!parameter) == (type == CONDITION_NULL)); c = new(Condition, 1); if (!c) return NULL; *c = (Condition) { .type = type, .trigger = trigger, .negate = negate, }; if (parameter) { c->parameter = strdup(parameter); if (!c->parameter) return mfree(c); } return c; } void condition_free(Condition *c) { assert(c); free(c->parameter); free(c); } Condition* condition_free_list_type(Condition *head, ConditionType type) { Condition *c, *n; LIST_FOREACH_SAFE(conditions, c, n, head) if (type < 0 || c->type == type) { LIST_REMOVE(conditions, head, c); condition_free(c); } assert(type >= 0 || !head); return head; } static int condition_test_kernel_command_line(Condition *c) { _cleanup_free_ char *line = NULL; const char *p; bool equal; int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_KERNEL_COMMAND_LINE); r = proc_cmdline(&line); if (r < 0) return r; equal = strchr(c->parameter, '='); for (p = line;;) { _cleanup_free_ char *word = NULL; bool found; r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX); if (r < 0) return r; if (r == 0) break; if (equal) found = streq(word, c->parameter); else { const char *f; f = startswith(word, c->parameter); found = f && IN_SET(*f, 0, '='); } if (found) return true; } return false; } typedef enum { /* Listed in order of checking. Note that some comparators are prefixes of others, hence the longest * should be listed first. */ ORDER_LOWER_OR_EQUAL, ORDER_GREATER_OR_EQUAL, ORDER_LOWER, ORDER_GREATER, ORDER_EQUAL, ORDER_UNEQUAL, _ORDER_MAX, _ORDER_INVALID = -1 } OrderOperator; static OrderOperator parse_order(const char **s) { static const char *const prefix[_ORDER_MAX] = { [ORDER_LOWER_OR_EQUAL] = "<=", [ORDER_GREATER_OR_EQUAL] = ">=", [ORDER_LOWER] = "<", [ORDER_GREATER] = ">", [ORDER_EQUAL] = "=", [ORDER_UNEQUAL] = "!=", }; OrderOperator i; for (i = 0; i < _ORDER_MAX; i++) { const char *e; e = startswith(*s, prefix[i]); if (e) { *s = e; return i; } } return _ORDER_INVALID; } static bool test_order(int k, OrderOperator p) { switch (p) { case ORDER_LOWER: return k < 0; case ORDER_LOWER_OR_EQUAL: return k <= 0; case ORDER_EQUAL: return k == 0; case ORDER_UNEQUAL: return k != 0; case ORDER_GREATER_OR_EQUAL: return k >= 0; case ORDER_GREATER: return k > 0; default: assert_not_reached("unknown order"); } } static int condition_test_kernel_version(Condition *c) { OrderOperator order; struct utsname u; const char *p; assert(c); assert(c->parameter); assert(c->type == CONDITION_KERNEL_VERSION); assert_se(uname(&u) >= 0); p = c->parameter; order = parse_order(&p); /* No prefix? Then treat as glob string */ if (order < 0) return fnmatch(skip_leading_chars(c->parameter, NULL), u.release, 0) == 0; return test_order(str_verscmp(u.release, skip_leading_chars(p, NULL)), order); } static int condition_test_memory(Condition *c) { OrderOperator order; uint64_t m, k; const char *p; int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_MEMORY); m = physical_memory(); p = c->parameter; order = parse_order(&p); if (order < 0) order = ORDER_GREATER_OR_EQUAL; /* default to >= check, if nothing is specified. */ r = safe_atou64(p, &k); if (r < 0) return log_debug_errno(r, "Failed to parse size: %m"); return test_order(CMP(m, k), order); } static int condition_test_cpus(Condition *c) { OrderOperator order; const char *p; unsigned k; int r, n; assert(c); assert(c->parameter); assert(c->type == CONDITION_CPUS); n = cpus_in_affinity_mask(); if (n < 0) return log_debug_errno(n, "Failed to determine CPUs in affinity mask: %m"); p = c->parameter; order = parse_order(&p); if (order < 0) order = ORDER_GREATER_OR_EQUAL; /* default to >= check, if nothing is specified. */ r = safe_atou(p, &k); if (r < 0) return log_debug_errno(r, "Failed to parse number of CPUs: %m"); return test_order(CMP((unsigned) n, k), order); } static int condition_test_user(Condition *c) { uid_t id; int r; _cleanup_free_ char *username = NULL; const char *u; assert(c); assert(c->parameter); assert(c->type == CONDITION_USER); r = parse_uid(c->parameter, &id); if (r >= 0) return id == getuid() || id == geteuid(); if (streq("@system", c->parameter)) return uid_is_system(getuid()) || uid_is_system(geteuid()); username = getusername_malloc(); if (!username) return -ENOMEM; if (streq(username, c->parameter)) return 1; if (getpid_cached() == 1) return streq(c->parameter, "root"); u = c->parameter; r = get_user_creds(&u, &id, NULL, NULL, NULL, USER_CREDS_ALLOW_MISSING); if (r < 0) return 0; return id == getuid() || id == geteuid(); } static int condition_test_control_group_controller(Condition *c) { int r; CGroupMask system_mask, wanted_mask = 0; assert(c); assert(c->parameter); assert(c->type == CONDITION_CONTROL_GROUP_CONTROLLER); r = cg_mask_supported(&system_mask); if (r < 0) return log_debug_errno(r, "Failed to determine supported controllers: %m"); r = cg_mask_from_string(c->parameter, &wanted_mask); if (r < 0 || wanted_mask <= 0) { /* This won't catch the case that we have an unknown controller * mixed in with valid ones -- these are only assessed on the * validity of the valid controllers found. */ log_debug("Failed to parse cgroup string: %s", c->parameter); return 1; } return FLAGS_SET(system_mask, wanted_mask); } static int condition_test_group(Condition *c) { gid_t id; int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_GROUP); r = parse_gid(c->parameter, &id); if (r >= 0) return in_gid(id); /* Avoid any NSS lookups if we are PID1 */ if (getpid_cached() == 1) return streq(c->parameter, "root"); return in_group(c->parameter) > 0; } static int condition_test_virtualization(Condition *c) { int b, v; assert(c); assert(c->parameter); assert(c->type == CONDITION_VIRTUALIZATION); if (streq(c->parameter, "private-users")) return running_in_userns(); v = detect_virtualization(); if (v < 0) return v; /* First, compare with yes/no */ b = parse_boolean(c->parameter); if (b >= 0) return b == !!v; /* Then, compare categorization */ if (streq(c->parameter, "vm")) return VIRTUALIZATION_IS_VM(v); if (streq(c->parameter, "container")) return VIRTUALIZATION_IS_CONTAINER(v); /* Finally compare id */ return v != VIRTUALIZATION_NONE && streq(c->parameter, virtualization_to_string(v)); } static int condition_test_architecture(Condition *c) { int a, b; assert(c); assert(c->parameter); assert(c->type == CONDITION_ARCHITECTURE); a = uname_architecture(); if (a < 0) return a; if (streq(c->parameter, "native")) b = native_architecture(); else { b = architecture_from_string(c->parameter); if (b < 0) /* unknown architecture? Then it's definitely not ours */ return false; } return a == b; } static int condition_test_host(Condition *c) { _cleanup_free_ char *h = NULL; sd_id128_t x, y; int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_HOST); if (sd_id128_from_string(c->parameter, &x) >= 0) { r = sd_id128_get_machine(&y); if (r < 0) return r; return sd_id128_equal(x, y); } h = gethostname_malloc(); if (!h) return -ENOMEM; return fnmatch(c->parameter, h, FNM_CASEFOLD) == 0; } static int condition_test_ac_power(Condition *c) { int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_AC_POWER); r = parse_boolean(c->parameter); if (r < 0) return r; return (on_ac_power() != 0) == !!r; } static int condition_test_security(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_SECURITY); if (streq(c->parameter, "selinux")) return mac_selinux_use(); if (streq(c->parameter, "smack")) return mac_smack_use(); if (streq(c->parameter, "apparmor")) return mac_apparmor_use(); if (streq(c->parameter, "audit")) return use_audit(); if (streq(c->parameter, "ima")) return use_ima(); if (streq(c->parameter, "tomoyo")) return mac_tomoyo_use(); if (streq(c->parameter, "uefi-secureboot")) return is_efi_secure_boot(); return false; } static int condition_test_capability(Condition *c) { unsigned long long capabilities = (unsigned long long) -1; _cleanup_fclose_ FILE *f = NULL; int value, r; assert(c); assert(c->parameter); assert(c->type == CONDITION_CAPABILITY); /* If it's an invalid capability, we don't have it */ value = capability_from_name(c->parameter); if (value < 0) return -EINVAL; /* If it's a valid capability we default to assume * that we have it */ f = fopen("/proc/self/status", "re"); if (!f) return -errno; for (;;) { _cleanup_free_ char *line = NULL; const char *p; r = read_line(f, LONG_LINE_MAX, &line); if (r < 0) return r; if (r == 0) break; p = startswith(line, "CapBnd:"); if (p) { if (sscanf(line+7, "%llx", &capabilities) != 1) return -EIO; break; } } return !!(capabilities & (1ULL << value)); } static int condition_test_needs_update(Condition *c) { const char *p; struct stat usr, other; assert(c); assert(c->parameter); assert(c->type == CONDITION_NEEDS_UPDATE); /* If the file system is read-only we shouldn't suggest an update */ if (path_is_read_only_fs(c->parameter) > 0) return false; /* Any other failure means we should allow the condition to be true, * so that we rather invoke too many update tools than too * few. */ if (!path_is_absolute(c->parameter)) return true; p = strjoina(c->parameter, "/.updated"); if (lstat(p, &other) < 0) return true; if (lstat("/usr/", &usr) < 0) return true; /* * First, compare seconds as they are always accurate... */ if (usr.st_mtim.tv_sec != other.st_mtim.tv_sec) return usr.st_mtim.tv_sec > other.st_mtim.tv_sec; /* * ...then compare nanoseconds. * * A false positive is only possible when /usr's nanoseconds > 0 * (otherwise /usr cannot be strictly newer than the target file) * AND the target file's nanoseconds == 0 * (otherwise the filesystem supports nsec timestamps, see stat(2)). */ if (usr.st_mtim.tv_nsec > 0 && other.st_mtim.tv_nsec == 0) { _cleanup_free_ char *timestamp_str = NULL; uint64_t timestamp; int r; r = parse_env_file(NULL, p, "TIMESTAMP_NSEC", ×tamp_str); if (r < 0) { log_error_errno(r, "Failed to parse timestamp file '%s', using mtime: %m", p); return true; } else if (r == 0) { log_debug("No data in timestamp file '%s', using mtime", p); return true; } r = safe_atou64(timestamp_str, ×tamp); if (r < 0) { log_error_errno(r, "Failed to parse timestamp value '%s' in file '%s', using mtime: %m", timestamp_str, p); return true; } timespec_store(&other.st_mtim, timestamp); } return usr.st_mtim.tv_nsec > other.st_mtim.tv_nsec; } static int condition_test_first_boot(Condition *c) { int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_FIRST_BOOT); r = parse_boolean(c->parameter); if (r < 0) return r; return (access("/run/systemd/first-boot", F_OK) >= 0) == !!r; } static int condition_test_path_exists(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_EXISTS); return access(c->parameter, F_OK) >= 0; } static int condition_test_path_exists_glob(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_EXISTS_GLOB); return glob_exists(c->parameter) > 0; } static int condition_test_path_is_directory(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_IS_DIRECTORY); return is_dir(c->parameter, true) > 0; } static int condition_test_path_is_symbolic_link(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_IS_SYMBOLIC_LINK); return is_symlink(c->parameter) > 0; } static int condition_test_path_is_mount_point(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_IS_MOUNT_POINT); return path_is_mount_point(c->parameter, NULL, AT_SYMLINK_FOLLOW) > 0; } static int condition_test_path_is_read_write(Condition *c) { assert(c); assert(c->parameter); assert(c->type == CONDITION_PATH_IS_READ_WRITE); return path_is_read_only_fs(c->parameter) <= 0; } static int condition_test_directory_not_empty(Condition *c) { int r; assert(c); assert(c->parameter); assert(c->type == CONDITION_DIRECTORY_NOT_EMPTY); r = dir_is_empty(c->parameter); return r <= 0 && r != -ENOENT; } static int condition_test_file_not_empty(Condition *c) { struct stat st; assert(c); assert(c->parameter); assert(c->type == CONDITION_FILE_NOT_EMPTY); return (stat(c->parameter, &st) >= 0 && S_ISREG(st.st_mode) && st.st_size > 0); } static int condition_test_file_is_executable(Condition *c) { struct stat st; assert(c); assert(c->parameter); assert(c->type == CONDITION_FILE_IS_EXECUTABLE); return (stat(c->parameter, &st) >= 0 && S_ISREG(st.st_mode) && (st.st_mode & 0111)); } static int condition_test_null(Condition *c) { assert(c); assert(c->type == CONDITION_NULL); /* Note that during parsing we already evaluate the string and * store it in c->negate */ return true; } int condition_test(Condition *c) { static int (*const condition_tests[_CONDITION_TYPE_MAX])(Condition *c) = { [CONDITION_PATH_EXISTS] = condition_test_path_exists, [CONDITION_PATH_EXISTS_GLOB] = condition_test_path_exists_glob, [CONDITION_PATH_IS_DIRECTORY] = condition_test_path_is_directory, [CONDITION_PATH_IS_SYMBOLIC_LINK] = condition_test_path_is_symbolic_link, [CONDITION_PATH_IS_MOUNT_POINT] = condition_test_path_is_mount_point, [CONDITION_PATH_IS_READ_WRITE] = condition_test_path_is_read_write, [CONDITION_DIRECTORY_NOT_EMPTY] = condition_test_directory_not_empty, [CONDITION_FILE_NOT_EMPTY] = condition_test_file_not_empty, [CONDITION_FILE_IS_EXECUTABLE] = condition_test_file_is_executable, [CONDITION_KERNEL_COMMAND_LINE] = condition_test_kernel_command_line, [CONDITION_KERNEL_VERSION] = condition_test_kernel_version, [CONDITION_VIRTUALIZATION] = condition_test_virtualization, [CONDITION_SECURITY] = condition_test_security, [CONDITION_CAPABILITY] = condition_test_capability, [CONDITION_HOST] = condition_test_host, [CONDITION_AC_POWER] = condition_test_ac_power, [CONDITION_ARCHITECTURE] = condition_test_architecture, [CONDITION_NEEDS_UPDATE] = condition_test_needs_update, [CONDITION_FIRST_BOOT] = condition_test_first_boot, [CONDITION_USER] = condition_test_user, [CONDITION_GROUP] = condition_test_group, [CONDITION_CONTROL_GROUP_CONTROLLER] = condition_test_control_group_controller, [CONDITION_NULL] = condition_test_null, [CONDITION_CPUS] = condition_test_cpus, [CONDITION_MEMORY] = condition_test_memory, }; int r, b; assert(c); assert(c->type >= 0); assert(c->type < _CONDITION_TYPE_MAX); r = condition_tests[c->type](c); if (r < 0) { c->result = CONDITION_ERROR; return r; } b = (r > 0) == !c->negate; c->result = b ? CONDITION_SUCCEEDED : CONDITION_FAILED; return b; } bool condition_test_list(Condition *first, const char *(*to_string)(ConditionType t), condition_test_logger_t logger, void *userdata) { Condition *c; int triggered = -1; assert(!!logger == !!to_string); /* If the condition list is empty, then it is true */ if (!first) return true; /* Otherwise, if all of the non-trigger conditions apply and * if any of the trigger conditions apply (unless there are * none) we return true */ LIST_FOREACH(conditions, c, first) { int r; r = condition_test(c); if (logger) { if (r < 0) logger(userdata, LOG_WARNING, r, __FILE__, __LINE__, __func__, "Couldn't determine result for %s=%s%s%s, assuming failed: %m", to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter); else logger(userdata, LOG_DEBUG, 0, __FILE__, __LINE__, __func__, "%s=%s%s%s %s.", to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter, condition_result_to_string(c->result)); } if (!c->trigger && r <= 0) return false; if (c->trigger && triggered <= 0) triggered = r > 0; } return triggered != 0; } void condition_dump(Condition *c, FILE *f, const char *prefix, const char *(*to_string)(ConditionType t)) { assert(c); assert(f); prefix = strempty(prefix); fprintf(f, "%s\t%s: %s%s%s %s\n", prefix, to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter, condition_result_to_string(c->result)); } void condition_dump_list(Condition *first, FILE *f, const char *prefix, const char *(*to_string)(ConditionType t)) { Condition *c; LIST_FOREACH(conditions, c, first) condition_dump(c, f, prefix, to_string); } static const char* const condition_type_table[_CONDITION_TYPE_MAX] = { [CONDITION_ARCHITECTURE] = "ConditionArchitecture", [CONDITION_VIRTUALIZATION] = "ConditionVirtualization", [CONDITION_HOST] = "ConditionHost", [CONDITION_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine", [CONDITION_KERNEL_VERSION] = "ConditionKernelVersion", [CONDITION_SECURITY] = "ConditionSecurity", [CONDITION_CAPABILITY] = "ConditionCapability", [CONDITION_AC_POWER] = "ConditionACPower", [CONDITION_NEEDS_UPDATE] = "ConditionNeedsUpdate", [CONDITION_FIRST_BOOT] = "ConditionFirstBoot", [CONDITION_PATH_EXISTS] = "ConditionPathExists", [CONDITION_PATH_EXISTS_GLOB] = "ConditionPathExistsGlob", [CONDITION_PATH_IS_DIRECTORY] = "ConditionPathIsDirectory", [CONDITION_PATH_IS_SYMBOLIC_LINK] = "ConditionPathIsSymbolicLink", [CONDITION_PATH_IS_MOUNT_POINT] = "ConditionPathIsMountPoint", [CONDITION_PATH_IS_READ_WRITE] = "ConditionPathIsReadWrite", [CONDITION_DIRECTORY_NOT_EMPTY] = "ConditionDirectoryNotEmpty", [CONDITION_FILE_NOT_EMPTY] = "ConditionFileNotEmpty", [CONDITION_FILE_IS_EXECUTABLE] = "ConditionFileIsExecutable", [CONDITION_USER] = "ConditionUser", [CONDITION_GROUP] = "ConditionGroup", [CONDITION_CONTROL_GROUP_CONTROLLER] = "ConditionControlGroupController", [CONDITION_NULL] = "ConditionNull", [CONDITION_CPUS] = "ConditionCPUs", [CONDITION_MEMORY] = "ConditionMemory", }; DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType); static const char* const assert_type_table[_CONDITION_TYPE_MAX] = { [CONDITION_ARCHITECTURE] = "AssertArchitecture", [CONDITION_VIRTUALIZATION] = "AssertVirtualization", [CONDITION_HOST] = "AssertHost", [CONDITION_KERNEL_COMMAND_LINE] = "AssertKernelCommandLine", [CONDITION_KERNEL_VERSION] = "AssertKernelVersion", [CONDITION_SECURITY] = "AssertSecurity", [CONDITION_CAPABILITY] = "AssertCapability", [CONDITION_AC_POWER] = "AssertACPower", [CONDITION_NEEDS_UPDATE] = "AssertNeedsUpdate", [CONDITION_FIRST_BOOT] = "AssertFirstBoot", [CONDITION_PATH_EXISTS] = "AssertPathExists", [CONDITION_PATH_EXISTS_GLOB] = "AssertPathExistsGlob", [CONDITION_PATH_IS_DIRECTORY] = "AssertPathIsDirectory", [CONDITION_PATH_IS_SYMBOLIC_LINK] = "AssertPathIsSymbolicLink", [CONDITION_PATH_IS_MOUNT_POINT] = "AssertPathIsMountPoint", [CONDITION_PATH_IS_READ_WRITE] = "AssertPathIsReadWrite", [CONDITION_DIRECTORY_NOT_EMPTY] = "AssertDirectoryNotEmpty", [CONDITION_FILE_NOT_EMPTY] = "AssertFileNotEmpty", [CONDITION_FILE_IS_EXECUTABLE] = "AssertFileIsExecutable", [CONDITION_USER] = "AssertUser", [CONDITION_GROUP] = "AssertGroup", [CONDITION_CONTROL_GROUP_CONTROLLER] = "AssertControlGroupController", [CONDITION_NULL] = "AssertNull", [CONDITION_CPUS] = "AssertCPUs", [CONDITION_MEMORY] = "AssertMemory", }; DEFINE_STRING_TABLE_LOOKUP(assert_type, ConditionType); static const char* const condition_result_table[_CONDITION_RESULT_MAX] = { [CONDITION_UNTESTED] = "untested", [CONDITION_SUCCEEDED] = "succeeded", [CONDITION_FAILED] = "failed", [CONDITION_ERROR] = "error", }; DEFINE_STRING_TABLE_LOOKUP(condition_result, ConditionResult);