diff options
Diffstat (limited to 'src/shared/condition.c')
| -rw-r--r-- | src/shared/condition.c | 1340 |
1 files changed, 1340 insertions, 0 deletions
diff --git a/src/shared/condition.c b/src/shared/condition.c new file mode 100644 index 0000000..a23d6a3 --- /dev/null +++ b/src/shared/condition.c @@ -0,0 +1,1340 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <fnmatch.h> +#include <limits.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/utsname.h> +#include <time.h> +#include <unistd.h> + +#include "sd-id128.h" + +#include "alloc-util.h" +#include "apparmor-util.h" +#include "architecture.h" +#include "audit-util.h" +#include "blockdev-util.h" +#include "cap-list.h" +#include "cgroup-util.h" +#include "compare-operator.h" +#include "condition.h" +#include "cpu-set-util.h" +#include "creds-util.h" +#include "efi-api.h" +#include "env-file.h" +#include "env-util.h" +#include "extract-word.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.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 "os-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "percent-util.h" +#include "proc-cmdline.h" +#include "process-util.h" +#include "psi-util.h" +#include "selinux-util.h" +#include "smack-util.h" +#include "special.h" +#include "stat-util.h" +#include "string-table.h" +#include "string-util.h" +#include "tomoyo-util.h" +#include "tpm2-util.h" +#include "udev-util.h" +#include "uid-alloc-range.h" +#include "user-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); + + 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; +} + +Condition* condition_free(Condition *c) { + assert(c); + + free(c->parameter); + return mfree(c); +} + +Condition* condition_free_list_type(Condition *head, ConditionType type) { + LIST_FOREACH(conditions, c, 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, char **env) { + _cleanup_free_ char *line = NULL; + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_KERNEL_COMMAND_LINE); + + r = proc_cmdline(&line); + if (r < 0) + return r; + + bool equal = strchr(c->parameter, '='); + + for (const char *p = line;;) { + _cleanup_free_ char *word = NULL; + bool found; + + r = extract_first_word(&p, &word, NULL, EXTRACT_UNQUOTE|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; +} + +static int condition_test_credential(Condition *c, char **env) { + int (*gd)(const char **ret); + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_CREDENTIAL); + + /* For now we'll do a very simple existence check and are happy with either a regular or an encrypted + * credential. Given that we check the syntax of the argument we have the option to later maybe allow + * contents checks too without breaking compatibility, but for now let's be minimalistic. */ + + if (!credential_name_valid(c->parameter)) /* credentials with invalid names do not exist */ + return false; + + FOREACH_POINTER(gd, get_credentials_dir, get_encrypted_credentials_dir) { + _cleanup_free_ char *j = NULL; + const char *cd; + + r = gd(&cd); + if (r == -ENXIO) /* no env var set */ + continue; + if (r < 0) + return r; + + j = path_join(cd, c->parameter); + if (!j) + return -ENOMEM; + + if (laccess(j, F_OK) >= 0) + return true; /* yay! */ + if (errno != ENOENT) + return -errno; + + /* not found in this dir */ + } + + return false; +} + +static int condition_test_kernel_version(Condition *c, char **env) { + CompareOperator operator; + struct utsname u; + bool first = true; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_KERNEL_VERSION); + + assert_se(uname(&u) >= 0); + + for (const char *p = c->parameter;;) { + _cleanup_free_ char *word = NULL; + const char *s; + int r; + + r = extract_first_word(&p, &word, NULL, EXTRACT_UNQUOTE); + if (r < 0) + return log_debug_errno(r, "Failed to parse condition string \"%s\": %m", p); + if (r == 0) + break; + + s = strstrip(word); + operator = parse_compare_operator(&s, COMPARE_ALLOW_FNMATCH|COMPARE_EQUAL_BY_STRING); + if (operator < 0) /* No prefix? Then treat as glob string */ + operator = COMPARE_FNMATCH_EQUAL; + + s += strspn(s, WHITESPACE); + if (isempty(s)) { + if (first) { + /* For backwards compatibility, allow whitespace between the operator and + * value, without quoting, but only in the first expression. */ + word = mfree(word); + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + return log_debug_errno(r, "Failed to parse condition string \"%s\": %m", p); + if (r == 0) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected end of expression: %s", p); + s = word; + } else + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected end of expression: %s", p); + } + + r = version_or_fnmatch_compare(operator, u.release, s); + if (r < 0) + return r; + if (!r) + return false; + + first = false; + } + + return true; +} + +static int condition_test_osrelease(Condition *c, char **env) { + int r; + + assert(c); + assert(c->type == CONDITION_OS_RELEASE); + + for (const char *parameter = ASSERT_PTR(c->parameter);;) { + _cleanup_free_ char *key = NULL, *condition = NULL, *actual_value = NULL; + CompareOperator operator; + const char *word; + + r = extract_first_word(¶meter, &condition, NULL, EXTRACT_UNQUOTE); + if (r < 0) + return log_debug_errno(r, "Failed to parse parameter: %m"); + if (r == 0) + break; + + /* parse_compare_operator() needs the string to start with the comparators */ + word = condition; + r = extract_first_word(&word, &key, COMPARE_OPERATOR_WITH_FNMATCH_CHARS, EXTRACT_RETAIN_SEPARATORS); + if (r < 0) + return log_debug_errno(r, "Failed to parse parameter: %m"); + /* The os-release spec mandates env-var-like key names */ + if (r == 0 || isempty(word) || !env_name_is_valid(key)) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to parse parameter, key/value format expected: %m"); + + /* Do not allow whitespace after the separator, as that's not a valid os-release format */ + operator = parse_compare_operator(&word, COMPARE_ALLOW_FNMATCH|COMPARE_EQUAL_BY_STRING); + if (operator < 0 || isempty(word) || strchr(WHITESPACE, *word) != NULL) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to parse parameter, key/value format expected: %m"); + + r = parse_os_release(NULL, key, &actual_value); + if (r < 0) + return log_debug_errno(r, "Failed to parse os-release: %m"); + + r = version_or_fnmatch_compare(operator, actual_value, word); + if (r < 0) + return r; + if (!r) + return false; + } + + return true; +} + +static int condition_test_memory(Condition *c, char **env) { + CompareOperator operator; + 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; + operator = parse_compare_operator(&p, 0); + if (operator < 0) + operator = COMPARE_GREATER_OR_EQUAL; /* default to >= check, if nothing is specified. */ + + r = parse_size(p, 1024, &k); + if (r < 0) + return log_debug_errno(r, "Failed to parse size '%s': %m", p); + + return test_order(CMP(m, k), operator); +} + +static int condition_test_cpus(Condition *c, char **env) { + CompareOperator operator; + 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; + operator = parse_compare_operator(&p, 0); + if (operator < 0) + operator = COMPARE_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), operator); +} + +static int condition_test_user(Condition *c, char **env) { + uid_t id; + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_USER); + + /* Do the quick&easy comparisons first, and only parse the UID later. */ + if (streq(c->parameter, "root")) + return getuid() == 0 || geteuid() == 0; + if (streq(c->parameter, NOBODY_USER_NAME)) + return getuid() == UID_NOBODY || geteuid() == UID_NOBODY; + if (streq(c->parameter, "@system")) + return uid_is_system(getuid()) || uid_is_system(geteuid()); + + r = parse_uid(c->parameter, &id); + if (r >= 0) + return id == getuid() || id == geteuid(); + + if (getpid_cached() == 1) /* We already checked for "root" above, and we know that + * PID 1 is running as root, hence we know it cannot match. */ + return false; + + /* getusername_malloc() may do an nss lookup, which is not allowed in PID 1. */ + _cleanup_free_ char *username = getusername_malloc(); + if (!username) + return -ENOMEM; + + if (streq(username, c->parameter)) + return 1; + + const char *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, char **env) { + int r; + CGroupMask system_mask, wanted_mask = 0; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_CONTROL_GROUP_CONTROLLER); + + if (streq(c->parameter, "v2")) + return cg_all_unified(); + if (streq(c->parameter, "v1")) { + r = cg_all_unified(); + if (r < 0) + return r; + return !r; + } + + 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, char **env) { + 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, char **env) { + Virtualization v; + int b; + + 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 != VIRTUALIZATION_NONE); + + /* 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, char **env) { + Architecture 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; +} + +#define DTCOMPAT_FILE "/proc/device-tree/compatible" +static int condition_test_firmware_devicetree_compatible(const char *dtcarg) { + int r; + _cleanup_free_ char *dtcompat = NULL; + _cleanup_strv_free_ char **dtcompatlist = NULL; + size_t size; + + r = read_full_virtual_file(DTCOMPAT_FILE, &dtcompat, &size); + if (r < 0) { + /* if the path doesn't exist it is incompatible */ + if (r != -ENOENT) + log_debug_errno(r, "Failed to open() '%s', assuming machine is incompatible: %m", DTCOMPAT_FILE); + return false; + } + + /* Not sure this can happen, but play safe. */ + if (size == 0) { + log_debug("%s has zero length, assuming machine is incompatible", DTCOMPAT_FILE); + return false; + } + + /* /proc/device-tree/compatible consists of one or more strings, each ending in '\0'. + * So the last character in dtcompat must be a '\0'. */ + if (dtcompat[size - 1] != '\0') { + log_debug("%s is in an unknown format, assuming machine is incompatible", DTCOMPAT_FILE); + return false; + } + + dtcompatlist = strv_parse_nulstr(dtcompat, size); + if (!dtcompatlist) + return -ENOMEM; + + return strv_contains(dtcompatlist, dtcarg); +} + +static int condition_test_firmware_smbios_field(const char *expression) { + _cleanup_free_ char *field = NULL, *expected_value = NULL, *actual_value = NULL; + CompareOperator operator; + int r; + + assert(expression); + + /* Parse SMBIOS field */ + r = extract_first_word(&expression, &field, COMPARE_OPERATOR_WITH_FNMATCH_CHARS, EXTRACT_RETAIN_SEPARATORS); + if (r < 0) + return r; + if (r == 0 || isempty(expression)) + return -EINVAL; + + /* Remove trailing spaces from SMBIOS field */ + delete_trailing_chars(field, WHITESPACE); + + /* Parse operator */ + operator = parse_compare_operator(&expression, COMPARE_ALLOW_FNMATCH|COMPARE_EQUAL_BY_STRING); + if (operator < 0) + return operator; + + /* Parse expected value */ + r = extract_first_word(&expression, &expected_value, NULL, EXTRACT_UNQUOTE); + if (r < 0) + return r; + if (r == 0 || !isempty(expression)) + return -EINVAL; + + /* Read actual value from sysfs */ + if (!filename_is_valid(field)) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid SMBIOS field name"); + + const char *p = strjoina("/sys/class/dmi/id/", field); + r = read_virtual_file(p, SIZE_MAX, &actual_value, NULL); + if (r < 0) { + log_debug_errno(r, "Failed to read %s: %m", p); + if (r == -ENOENT) + return false; + return r; + } + + /* Remove trailing newline */ + delete_trailing_chars(actual_value, WHITESPACE); + + /* Finally compare actual and expected value */ + return version_or_fnmatch_compare(operator, actual_value, expected_value); +} + +static int condition_test_firmware(Condition *c, char **env) { + sd_char *arg; + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_FIRMWARE); + + if (streq(c->parameter, "device-tree")) { + if (access("/sys/firmware/devicetree/", F_OK) < 0) { + if (errno != ENOENT) + log_debug_errno(errno, "Unexpected error when checking for /sys/firmware/devicetree/: %m"); + return false; + } else + return true; + } else if ((arg = startswith(c->parameter, "device-tree-compatible("))) { + _cleanup_free_ char *dtc_arg = NULL; + char *end; + + end = strrchr(arg, ')'); + if (!end || *(end + 1) != '\0') { + log_debug("Malformed ConditionFirmware=%s", c->parameter); + return false; + } + + dtc_arg = strndup(arg, end - arg); + if (!dtc_arg) + return -ENOMEM; + + return condition_test_firmware_devicetree_compatible(dtc_arg); + } else if (streq(c->parameter, "uefi")) + return is_efi_boot(); + else if ((arg = startswith(c->parameter, "smbios-field("))) { + _cleanup_free_ char *smbios_arg = NULL; + char *end; + + end = strrchr(arg, ')'); + if (!end || *(end + 1) != '\0') + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Malformed ConditionFirmware=%s: %m", c->parameter); + + smbios_arg = strndup(arg, end - arg); + if (!smbios_arg) + return log_oom_debug(); + + r = condition_test_firmware_smbios_field(smbios_arg); + if (r < 0) + return log_debug_errno(r, "Malformed ConditionFirmware=%s: %m", c->parameter); + return r; + } else { + log_debug("Unsupported Firmware condition \"%s\"", c->parameter); + return false; + } +} + +static int condition_test_host(Condition *c, char **env) { + _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; + + r = fnmatch(c->parameter, h, FNM_CASEFOLD); + if (r == FNM_NOMATCH) + return false; + if (r != 0) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "fnmatch() failed."); + + return true; +} + +static int condition_test_ac_power(Condition *c, char **env) { + 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 has_tpm2(void) { + /* Checks whether the kernel has the TPM subsystem enabled and the firmware reports support. Note + * we don't check for actual TPM devices, since we might not have loaded the driver for it yet, i.e. + * during early boot where we very likely want to use this condition check). + * + * Note that we don't check if we ourselves are built with TPM2 support here! */ + + return FLAGS_SET(tpm2_support(), TPM2_SUPPORT_SUBSYSTEM|TPM2_SUPPORT_FIRMWARE); +} + +static int condition_test_security(Condition *c, char **env) { + 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(); + if (streq(c->parameter, "tpm2")) + return has_tpm2(); + + return false; +} + +static int condition_test_capability(Condition *c, char **env) { + 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; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + break; + + const char *p = startswith(line, "CapBnd:"); + if (p) { + if (sscanf(p, "%llx", &capabilities) != 1) + return -EIO; + + break; + } + } + + return !!(capabilities & (1ULL << value)); +} + +static int condition_test_needs_update(Condition *c, char **env) { + struct stat usr, other; + const char *p; + bool b; + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_NEEDS_UPDATE); + + r = proc_cmdline_get_bool("systemd.condition-needs-update", &b); + if (r < 0) + log_debug_errno(r, "Failed to parse systemd.condition-needs-update= kernel command line argument, ignoring: %m"); + if (r > 0) + return b; + + if (in_initrd()) { + log_debug("We are in an initrd, not doing any updates."); + return false; + } + + if (!path_is_absolute(c->parameter)) { + log_debug("Specified condition parameter '%s' is not absolute, assuming an update is needed.", c->parameter); + return true; + } + + /* If the file system is read-only we shouldn't suggest an update */ + r = path_is_read_only_fs(c->parameter); + if (r < 0) + log_debug_errno(r, "Failed to determine if '%s' is read-only, ignoring: %m", c->parameter); + if (r > 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. */ + + p = strjoina(c->parameter, "/.updated"); + if (lstat(p, &other) < 0) { + if (errno != ENOENT) + log_debug_errno(errno, "Failed to stat() '%s', assuming an update is needed: %m", p); + return true; + } + + if (lstat("/usr/", &usr) < 0) { + log_debug_errno(errno, "Failed to stat() /usr/, assuming an update is needed: %m"); + 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) + return usr.st_mtim.tv_nsec > other.st_mtim.tv_nsec; + + _cleanup_free_ char *timestamp_str = NULL; + r = parse_env_file(NULL, p, "TIMESTAMP_NSEC", ×tamp_str); + if (r < 0) { + log_debug_errno(r, "Failed to parse timestamp file '%s', using mtime: %m", p); + return true; + } + if (isempty(timestamp_str)) { + log_debug("No data in timestamp file '%s', using mtime.", p); + return true; + } + + uint64_t timestamp; + r = safe_atou64(timestamp_str, ×tamp); + if (r < 0) { + log_debug_errno(r, "Failed to parse timestamp value '%s' in file '%s', using mtime: %m", timestamp_str, p); + return true; + } + + return timespec_load_nsec(&usr.st_mtim) > timestamp; +} + +static int condition_test_first_boot(Condition *c, char **env) { + int r, q; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_FIRST_BOOT); + + r = parse_boolean(c->parameter); + if (r < 0) + return r; + + q = access("/run/systemd/first-boot", F_OK); + if (q < 0 && errno != ENOENT) + log_debug_errno(errno, "Failed to check if /run/systemd/first-boot exists, assuming no: %m"); + + return (q >= 0) == r; +} + +static int condition_test_environment(Condition *c, char **env) { + bool equal; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_ENVIRONMENT); + + equal = strchr(c->parameter, '='); + + STRV_FOREACH(i, env) { + bool found; + + if (equal) + found = streq(c->parameter, *i); + else { + const char *f; + + f = startswith(*i, c->parameter); + found = f && IN_SET(*f, 0, '='); + } + + if (found) + return true; + } + + return false; +} + +static int condition_test_path_exists(Condition *c, char **env) { + 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, char **env) { + 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, char **env) { + 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, char **env) { + 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, char **env) { + 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, char **env) { + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_PATH_IS_READ_WRITE); + + r = path_is_read_only_fs(c->parameter); + + return r <= 0 && r != -ENOENT; +} + +static int condition_test_cpufeature(Condition *c, char **env) { + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_CPU_FEATURE); + + return has_cpu_with_flag(ascii_strlower(c->parameter)); +} + +static int condition_test_path_is_encrypted(Condition *c, char **env) { + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_PATH_IS_ENCRYPTED); + + r = path_is_encrypted(c->parameter); + if (r < 0 && r != -ENOENT) + log_debug_errno(r, "Failed to determine if '%s' is encrypted: %m", c->parameter); + + return r > 0; +} + +static int condition_test_directory_not_empty(Condition *c, char **env) { + int r; + + assert(c); + assert(c->parameter); + assert(c->type == CONDITION_DIRECTORY_NOT_EMPTY); + + r = dir_is_empty(c->parameter, /* ignore_hidden_or_backup= */ true); + return r <= 0 && !IN_SET(r, -ENOENT, -ENOTDIR); +} + +static int condition_test_file_not_empty(Condition *c, char **env) { + 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, char **env) { + 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_psi(Condition *c, char **env) { + _cleanup_free_ char *first = NULL, *second = NULL, *third = NULL, *fourth = NULL, *pressure_path = NULL; + const char *p, *value, *pressure_type; + loadavg_t *current, limit; + ResourcePressure pressure; + int r; + + assert(c); + assert(c->parameter); + assert(IN_SET(c->type, CONDITION_MEMORY_PRESSURE, CONDITION_CPU_PRESSURE, CONDITION_IO_PRESSURE)); + + if (!is_pressure_supported()) { + log_debug("Pressure Stall Information (PSI) is not supported, skipping."); + return 1; + } + + pressure_type = c->type == CONDITION_MEMORY_PRESSURE ? "memory" : + c->type == CONDITION_CPU_PRESSURE ? "cpu" : + "io"; + + p = c->parameter; + r = extract_many_words(&p, ":", 0, &first, &second, NULL); + if (r <= 0) + return log_debug_errno(r < 0 ? r : SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + /* If only one parameter is passed, then we look at the global system pressure rather than a specific cgroup. */ + if (r == 1) { + pressure_path = path_join("/proc/pressure", pressure_type); + if (!pressure_path) + return log_oom_debug(); + + value = first; + } else { + const char *controller = strjoina(pressure_type, ".pressure"); + _cleanup_free_ char *slice_path = NULL, *root_scope = NULL; + CGroupMask mask, required_mask; + char *slice, *e; + + required_mask = c->type == CONDITION_MEMORY_PRESSURE ? CGROUP_MASK_MEMORY : + c->type == CONDITION_CPU_PRESSURE ? CGROUP_MASK_CPU : + CGROUP_MASK_IO; + + slice = strstrip(first); + if (!slice) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + + r = cg_all_unified(); + if (r < 0) + return log_debug_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m"); + if (r == 0) { + log_debug("PSI condition check requires the unified cgroups hierarchy, skipping."); + return 1; + } + + r = cg_mask_supported(&mask); + if (r < 0) + return log_debug_errno(r, "Failed to get supported cgroup controllers: %m"); + + if (!FLAGS_SET(mask, required_mask)) { + log_debug("Cgroup %s controller not available, skipping PSI condition check.", pressure_type); + return 1; + } + + r = cg_slice_to_path(slice, &slice_path); + if (r < 0) + return log_debug_errno(r, "Cannot determine slice \"%s\" cgroup path: %m", slice); + + /* We might be running under the user manager, so get the root path and prefix it accordingly. */ + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, getpid_cached(), &root_scope); + if (r < 0) + return log_debug_errno(r, "Failed to get root cgroup path: %m"); + + /* Drop init.scope, we want the parent. We could get an empty or / path, but that's fine, + * just skip it in that case. */ + e = endswith(root_scope, "/" SPECIAL_INIT_SCOPE); + if (e) + *e = 0; + if (!empty_or_root(root_scope)) { + _cleanup_free_ char *slice_joined = NULL; + + slice_joined = path_join(root_scope, slice_path); + if (!slice_joined) + return log_oom_debug(); + + free_and_replace(slice_path, slice_joined); + } + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, slice_path, controller, &pressure_path); + if (r < 0) + return log_debug_errno(r, "Error getting cgroup pressure path from %s: %m", slice_path); + + value = second; + } + + /* If a value including a specific timespan (in the intervals allowed by the kernel), + * parse it, otherwise we assume just a plain percentage that will be checked if it is + * smaller or equal to the current pressure average over 5 minutes. */ + r = extract_many_words(&value, "/", 0, &third, &fourth, NULL); + if (r <= 0) + return log_debug_errno(r < 0 ? r : SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + if (r == 1) + current = &pressure.avg300; + else { + const char *timespan; + + timespan = skip_leading_chars(fourth, NULL); + if (!timespan) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + + if (startswith(timespan, "10sec")) + current = &pressure.avg10; + else if (startswith(timespan, "1min")) + current = &pressure.avg60; + else if (startswith(timespan, "5min")) + current = &pressure.avg300; + else + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + } + + value = strstrip(third); + if (!value) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse condition parameter %s: %m", c->parameter); + + r = parse_permyriad(value); + if (r < 0) + return log_debug_errno(r, "Failed to parse permyriad: %s", c->parameter); + + r = store_loadavg_fixed_point(r / 100LU, r % 100LU, &limit); + if (r < 0) + return log_debug_errno(r, "Failed to parse loadavg: %s", c->parameter); + + r = read_resource_pressure(pressure_path, PRESSURE_TYPE_FULL, &pressure); + if (r == -ENODATA) /* cpu.pressure 'full' was added recently, fall back to 'some'. */ + r = read_resource_pressure(pressure_path, PRESSURE_TYPE_SOME, &pressure); + if (r == -ENOENT) { + /* We already checked that /proc/pressure exists, so this means we were given a cgroup + * that doesn't exist or doesn't exist any longer. */ + log_debug("\"%s\" not found, skipping PSI check.", pressure_path); + return 1; + } + if (r < 0) + return log_debug_errno(r, "Error parsing pressure from %s: %m", pressure_path); + + return *current <= limit; +} + +int condition_test(Condition *c, char **env) { + + static int (*const condition_tests[_CONDITION_TYPE_MAX])(Condition *c, char **env) = { + [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_PATH_IS_ENCRYPTED] = condition_test_path_is_encrypted, + [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_CREDENTIAL] = condition_test_credential, + [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_FIRMWARE] = condition_test_firmware, + [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_CPUS] = condition_test_cpus, + [CONDITION_MEMORY] = condition_test_memory, + [CONDITION_ENVIRONMENT] = condition_test_environment, + [CONDITION_CPU_FEATURE] = condition_test_cpufeature, + [CONDITION_OS_RELEASE] = condition_test_osrelease, + [CONDITION_MEMORY_PRESSURE] = condition_test_psi, + [CONDITION_CPU_PRESSURE] = condition_test_psi, + [CONDITION_IO_PRESSURE] = condition_test_psi, + }; + + int r, b; + + assert(c); + assert(c->type >= 0); + assert(c->type < _CONDITION_TYPE_MAX); + + r = condition_tests[c->type](c, env); + 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, + char **env, + condition_to_string_t to_string, + condition_test_logger_t logger, + void *userdata) { + + 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, env); + + if (logger) { + if (r < 0) + logger(userdata, LOG_WARNING, r, PROJECT_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, PROJECT_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, condition_to_string_t to_string) { + assert(c); + assert(f); + assert(to_string); + + 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, condition_to_string_t to_string) { + 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_FIRMWARE] = "ConditionFirmware", + [CONDITION_VIRTUALIZATION] = "ConditionVirtualization", + [CONDITION_HOST] = "ConditionHost", + [CONDITION_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine", + [CONDITION_KERNEL_VERSION] = "ConditionKernelVersion", + [CONDITION_CREDENTIAL] = "ConditionCredential", + [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_PATH_IS_ENCRYPTED] = "ConditionPathIsEncrypted", + [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_CPUS] = "ConditionCPUs", + [CONDITION_MEMORY] = "ConditionMemory", + [CONDITION_ENVIRONMENT] = "ConditionEnvironment", + [CONDITION_CPU_FEATURE] = "ConditionCPUFeature", + [CONDITION_OS_RELEASE] = "ConditionOSRelease", + [CONDITION_MEMORY_PRESSURE] = "ConditionMemoryPressure", + [CONDITION_CPU_PRESSURE] = "ConditionCPUPressure", + [CONDITION_IO_PRESSURE] = "ConditionIOPressure", +}; + +DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType); + +static const char* const assert_type_table[_CONDITION_TYPE_MAX] = { + [CONDITION_ARCHITECTURE] = "AssertArchitecture", + [CONDITION_FIRMWARE] = "AssertFirmware", + [CONDITION_VIRTUALIZATION] = "AssertVirtualization", + [CONDITION_HOST] = "AssertHost", + [CONDITION_KERNEL_COMMAND_LINE] = "AssertKernelCommandLine", + [CONDITION_KERNEL_VERSION] = "AssertKernelVersion", + [CONDITION_CREDENTIAL] = "AssertCredential", + [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_PATH_IS_ENCRYPTED] = "AssertPathIsEncrypted", + [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_CPUS] = "AssertCPUs", + [CONDITION_MEMORY] = "AssertMemory", + [CONDITION_ENVIRONMENT] = "AssertEnvironment", + [CONDITION_CPU_FEATURE] = "AssertCPUFeature", + [CONDITION_OS_RELEASE] = "AssertOSRelease", + [CONDITION_MEMORY_PRESSURE] = "AssertMemoryPressure", + [CONDITION_CPU_PRESSURE] = "AssertCPUPressure", + [CONDITION_IO_PRESSURE] = "AssertIOPressure", +}; + +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); |