analyze: add 'condition' verb

We didn't have a straightforward way to parse and evaluate those strings.
Prompted by #12881.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2019-06-26 14:58:45 +02:00
parent b1d5246d29
commit edfea9fe0d
7 changed files with 212 additions and 2 deletions

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@ -83,6 +83,12 @@
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">unit-paths</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">condition</arg>
<arg choice="plain"><replaceable>CONDITION</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
@ -348,6 +354,33 @@ $ eog targets.svg</programlisting>
to retrieve the actual list that the manager uses, with any empty directories omitted.</para>
</refsect2>
<refsect2>
<title><command>systemd-analyze condition <replaceable>CONDITION</replaceable>...</command></title>
<para>This command will evaluate <varname noindex='true'>Condition*=...</varname> and
<varname noindex='true'>Assert*=...</varname> assignments, and print their values, and
the resulting value of the combined condition set. See
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for a list of available conditions and asserts.</para>
<example>
<title>Evaluate conditions that check kernel versions</title>
<programlisting>$ systemd-analyze condition 'ConditionKernelVersion = ! &lt;4.0' \
'ConditionKernelVersion = &gt;=5.1' \
'ConditionACPower=|false' \
'ConditionArchitecture=|!arm' \
'AssertPathExists=/etc/os-release'
test.service: AssertPathExists=/etc/os-release succeeded.
Asserts succeeded.
test.service: ConditionArchitecture=|!arm succeeded.
test.service: ConditionACPower=|false failed.
test.service: ConditionKernelVersion=&gt;=5.1 succeeded.
test.service: ConditionKernelVersion=!&lt;4.0 succeeded.
Conditions succeeded.</programlisting>
</example>
</refsect2>
<refsect2>
<title><command>systemd-analyze syscall-filter <optional><replaceable>SET</replaceable>...</optional></command></title>

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@ -1030,7 +1030,9 @@
exclamation mark, the pipe symbol must be passed first, the exclamation second. Except for
<varname>ConditionPathIsSymbolicLink=</varname>, all path checks follow symlinks. If any of these
options is assigned the empty string, the list of conditions is reset completely, all previous
condition settings (of any kind) will have no effect.</para>
condition settings (of any kind) will have no effect. The <command>condition</command> verb of
<citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
can be used to test condition and assert expressions.</para>
<para><varname>ConditionArchitecture=</varname> may be used to
check whether the system is running on a specific
@ -1326,7 +1328,11 @@
<para>Note that neither assertion nor condition expressions result in unit state changes. Also note that both
are checked at the time the job is to be executed, i.e. long after depending jobs and it itself were
queued. Thus, neither condition nor assertion expressions are suitable for conditionalizing unit
dependencies.</para></listitem>
dependencies.</para>
<para>The <command>condition</command> verb of
<citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
can be used to test condition and assert expressions.</para></listitem>
</varlistentry>
<varlistentry>

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@ -0,0 +1,155 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <stdlib.h>
#include "analyze-condition.h"
#include "condition.h"
#include "conf-parser.h"
#include "load-fragment.h"
#include "service.h"
typedef struct condition_definition {
const char *name;
ConfigParserCallback parser;
ConditionType type;
} condition_definition;
static const condition_definition condition_definitions[] = {
{ "ConditionPathExists", config_parse_unit_condition_path, CONDITION_PATH_EXISTS },
{ "ConditionPathExistsGlob", config_parse_unit_condition_path, CONDITION_PATH_EXISTS_GLOB },
{ "ConditionPathIsDirectory", config_parse_unit_condition_path, CONDITION_PATH_IS_DIRECTORY },
{ "ConditionPathIsSymbolicLink", config_parse_unit_condition_path, CONDITION_PATH_IS_SYMBOLIC_LINK },
{ "ConditionPathIsMountPoint", config_parse_unit_condition_path, CONDITION_PATH_IS_MOUNT_POINT },
{ "ConditionPathIsReadWrite", config_parse_unit_condition_path, CONDITION_PATH_IS_READ_WRITE },
{ "ConditionDirectoryNotEmpty", config_parse_unit_condition_path, CONDITION_DIRECTORY_NOT_EMPTY },
{ "ConditionFileNotEmpty", config_parse_unit_condition_path, CONDITION_FILE_NOT_EMPTY },
{ "ConditionFileIsExecutable", config_parse_unit_condition_path, CONDITION_FILE_IS_EXECUTABLE },
{ "ConditionNeedsUpdate", config_parse_unit_condition_path, CONDITION_NEEDS_UPDATE },
{ "ConditionFirstBoot", config_parse_unit_condition_string, CONDITION_FIRST_BOOT },
{ "ConditionKernelCommandLine", config_parse_unit_condition_string, CONDITION_KERNEL_COMMAND_LINE },
{ "ConditionKernelVersion", config_parse_unit_condition_string, CONDITION_KERNEL_VERSION },
{ "ConditionArchitecture", config_parse_unit_condition_string, CONDITION_ARCHITECTURE },
{ "ConditionVirtualization", config_parse_unit_condition_string, CONDITION_VIRTUALIZATION },
{ "ConditionSecurity", config_parse_unit_condition_string, CONDITION_SECURITY },
{ "ConditionCapability", config_parse_unit_condition_string, CONDITION_CAPABILITY },
{ "ConditionHost", config_parse_unit_condition_string, CONDITION_HOST },
{ "ConditionACPower", config_parse_unit_condition_string, CONDITION_AC_POWER },
{ "ConditionUser", config_parse_unit_condition_string, CONDITION_USER },
{ "ConditionGroup", config_parse_unit_condition_string, CONDITION_GROUP },
{ "ConditionControlGroupController", config_parse_unit_condition_string, CONDITION_CONTROL_GROUP_CONTROLLER },
{ "AssertPathExists", config_parse_unit_condition_path, CONDITION_PATH_EXISTS },
{ "AssertPathExistsGlob", config_parse_unit_condition_path, CONDITION_PATH_EXISTS_GLOB },
{ "AssertPathIsDirectory", config_parse_unit_condition_path, CONDITION_PATH_IS_DIRECTORY },
{ "AssertPathIsSymbolicLink", config_parse_unit_condition_path, CONDITION_PATH_IS_SYMBOLIC_LINK },
{ "AssertPathIsMountPoint", config_parse_unit_condition_path, CONDITION_PATH_IS_MOUNT_POINT },
{ "AssertPathIsReadWrite", config_parse_unit_condition_path, CONDITION_PATH_IS_READ_WRITE },
{ "AssertDirectoryNotEmpty", config_parse_unit_condition_path, CONDITION_DIRECTORY_NOT_EMPTY },
{ "AssertFileNotEmpty", config_parse_unit_condition_path, CONDITION_FILE_NOT_EMPTY },
{ "AssertFileIsExecutable", config_parse_unit_condition_path, CONDITION_FILE_IS_EXECUTABLE },
{ "AssertNeedsUpdate", config_parse_unit_condition_path, CONDITION_NEEDS_UPDATE },
{ "AssertFirstBoot", config_parse_unit_condition_string, CONDITION_FIRST_BOOT },
{ "AssertKernelCommandLine", config_parse_unit_condition_string, CONDITION_KERNEL_COMMAND_LINE },
{ "AssertKernelVersion", config_parse_unit_condition_string, CONDITION_KERNEL_VERSION },
{ "AssertArchitecture", config_parse_unit_condition_string, CONDITION_ARCHITECTURE },
{ "AssertVirtualization", config_parse_unit_condition_string, CONDITION_VIRTUALIZATION },
{ "AssertSecurity", config_parse_unit_condition_string, CONDITION_SECURITY },
{ "AssertCapability", config_parse_unit_condition_string, CONDITION_CAPABILITY },
{ "AssertHost", config_parse_unit_condition_string, CONDITION_HOST },
{ "AssertACPower", config_parse_unit_condition_string, CONDITION_AC_POWER },
{ "AssertUser", config_parse_unit_condition_string, CONDITION_USER },
{ "AssertGroup", config_parse_unit_condition_string, CONDITION_GROUP },
{ "AssertControlGroupController", config_parse_unit_condition_string, CONDITION_CONTROL_GROUP_CONTROLLER },
/* deprecated, but we should still parse them */
{ "ConditionNull", config_parse_unit_condition_null, 0 },
{ "AssertNull", config_parse_unit_condition_null, 0 },
};
static int parse_condition(Unit *u, const char *line) {
const char *p;
Condition **target;
if ((p = startswith(line, "Condition")))
target = &u->conditions;
else if ((p = startswith(line, "Assert")))
target = &u->asserts;
else
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot parse \"%s\".", line);
for (size_t i = 0; i < ELEMENTSOF(condition_definitions); i++) {
const condition_definition *c = &condition_definitions[i];
p = startswith(line, c->name);
if (!p)
continue;
p += strspn(p, WHITESPACE);
if (*p != '=')
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected \"=\" in \"%s\".", line);
p += 1 + strspn(p + 1, WHITESPACE);
return c->parser(NULL, "(stdin)", 0, NULL, 0, c->name, c->type, p, target, u);
}
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot parse \"%s\".", line);
}
_printf_(7, 8)
static int log_helper(void *userdata, int level, int error, const char *file, int line, const char *func, const char *format, ...) {
Unit *u = userdata;
va_list ap;
int r;
assert(u);
/* "upgrade" debug messages */
level = MIN(LOG_INFO, level);
va_start(ap, format);
r = log_object_internalv(level, error, file, line, func,
NULL,
u->id,
NULL,
NULL,
format, ap);
va_end(ap);
return r;
}
int verify_conditions(char **lines, UnitFileScope scope) {
_cleanup_(manager_freep) Manager *m = NULL;
Unit *u;
char **line;
int r, q = 1;
r = manager_new(scope, MANAGER_TEST_RUN_MINIMAL, &m);
if (r < 0)
return log_error_errno(r, "Failed to initialize manager: %m");
log_debug("Starting manager...");
r = manager_startup(m, NULL, NULL);
if (r < 0)
return r;
r = unit_new_for_name(m, sizeof(Service), "test.service", &u);
if (r < 0)
return log_error_errno(r, "Failed to create test.service: %m");
STRV_FOREACH(line, lines) {
r = parse_condition(u, *line);
if (r < 0)
return r;
}
r = condition_test_list(u->asserts, assert_type_to_string, log_helper, u);
if (u->asserts)
log_notice("Asserts %s.", r > 0 ? "succeeded" : "failed");
q = condition_test_list(u->conditions, condition_type_to_string, log_helper, u);
if (u->conditions)
log_notice("Conditions %s.", q > 0 ? "succeeded" : "failed");
return r > 0 && q > 0 ? 0 : -EIO;
}

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@ -0,0 +1,6 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include "install.h"
int verify_conditions(char **lines, UnitFileScope scope);

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@ -13,6 +13,7 @@
#include "sd-bus.h"
#include "alloc-util.h"
#include "analyze-condition.h"
#include "analyze-security.h"
#include "analyze-verify.h"
#include "build.h"
@ -1897,6 +1898,10 @@ static int service_watchdogs(int argc, char *argv[], void *userdata) {
return 0;
}
static int do_condition(int argc, char *argv[], void *userdata) {
return verify_conditions(strv_skip(argv, 1), arg_scope);
}
static int do_verify(int argc, char *argv[], void *userdata) {
return verify_units(strv_skip(argv, 1), arg_scope, arg_man, arg_generators);
}
@ -1955,6 +1960,7 @@ static int help(int argc, char *argv[], void *userdata) {
" cat-config Show configuration file and drop-ins\n"
" unit-paths List load directories for units\n"
" syscall-filter [NAME...] Print list of syscalls in seccomp filter\n"
" condition CONDITION... Evaluate conditions and asserts\n"
" verify FILE... Check unit files for correctness\n"
" service-watchdogs [BOOL] Get/set service watchdog state\n"
" calendar SPEC... Validate repetitive calendar time events\n"
@ -2157,6 +2163,7 @@ static int run(int argc, char *argv[]) {
{ "cat-config", 2, VERB_ANY, 0, cat_config },
{ "unit-paths", 1, 1, 0, dump_unit_paths },
{ "syscall-filter", VERB_ANY, VERB_ANY, 0, dump_syscall_filters },
{ "condition", 2, VERB_ANY, 0, do_condition },
{ "verify", 2, VERB_ANY, 0, do_verify },
{ "calendar", 2, VERB_ANY, 0, test_calendar },
{ "timestamp", 2, VERB_ANY, 0, test_timestamp },

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@ -2,6 +2,8 @@
systemd_analyze_sources = files('''
analyze.c
analyze-condition.c
analyze-condition.h
analyze-verify.c
analyze-verify.h
analyze-security.c

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@ -254,6 +254,7 @@ Unit.SuccessAction, config_parse_emergency_action, 0,
Unit.FailureActionExitStatus, config_parse_exit_status, 0, offsetof(Unit, failure_action_exit_status)
Unit.SuccessActionExitStatus, config_parse_exit_status, 0, offsetof(Unit, success_action_exit_status)
Unit.RebootArgument, config_parse_unit_string_printf, 0, offsetof(Unit, reboot_arg)
m4_dnl Also add any conditions to condition_definitions[] in src/analyze/analyze-condition.c.
Unit.ConditionPathExists, config_parse_unit_condition_path, CONDITION_PATH_EXISTS, offsetof(Unit, conditions)
Unit.ConditionPathExistsGlob, config_parse_unit_condition_path, CONDITION_PATH_EXISTS_GLOB, offsetof(Unit, conditions)
Unit.ConditionPathIsDirectory, config_parse_unit_condition_path, CONDITION_PATH_IS_DIRECTORY, offsetof(Unit, conditions)