From be88b819ecec075187ac313b8ab15d8ed8004b54 Mon Sep 17 00:00:00 2001 From: Jan Synacek Date: Wed, 11 Sep 2019 12:35:18 +0200 Subject: [PATCH] udev: introduce CONST key name Currently, there is no way to match against system-wide constants, such as architecture or virtualization type, without forking helper binaries. That potentially results in a huge number of spawned processes which output always the same answer. This patch introduces a special CONST keyword which takes a hard-coded string as its key and returns a value assigned to that key. Currently implemented are CONST{arch} and CONST{virt}, which can be used to match against the system's architecture and virtualization type. (based on commit 4801d8afe2ff1c1c075c9f0bc5631612172e0bb7) Resolves: #1748051 --- man/udev.xml | 26 ++++++++++++++++++++++++++ rules/40-redhat.rules | 4 ++-- src/udev/udev-rules.c | 39 +++++++++++++++++++++++++++++++++++++++ test/rule-syntax-check.py | 2 +- 4 files changed, 68 insertions(+), 3 deletions(-) diff --git a/man/udev.xml b/man/udev.xml index a948ea79a9..fc02edd214 100644 --- a/man/udev.xml +++ b/man/udev.xml @@ -240,6 +240,32 @@ + + CONST{key} + + Match against a system-wide constant. Supported keys are: + + + arch + + System's architecture. See in + systemd.unit5 + for possible values. + + + + virt + + System's virtualization environment. See + systemd-detect-virt1 + for possible values. + + + + Unknown keys will never match. + + + TAG diff --git a/rules/40-redhat.rules b/rules/40-redhat.rules index 2c690e522e..83d823e172 100644 --- a/rules/40-redhat.rules +++ b/rules/40-redhat.rules @@ -6,10 +6,10 @@ SUBSYSTEM=="cpu", ACTION=="add", TEST=="online", ATTR{online}=="0", ATTR{online} # Memory hotadd request SUBSYSTEM!="memory", GOTO="memory_hotplug_end" ACTION!="add", GOTO="memory_hotplug_end" -PROGRAM="/bin/uname -p", RESULT=="s390*", GOTO="memory_hotplug_end" +CONST{arch}=="s390*", GOTO="memory_hotplug_end" ENV{.state}="online" -PROGRAM="/bin/systemd-detect-virt", RESULT=="none", ENV{.state}="online_movable" +CONST{virt}=="none", ENV{.state}="online_movable" ATTR{state}=="offline", ATTR{state}="$env{.state}" LABEL="memory_hotplug_end" diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c index c9a0197534..9211f563b1 100644 --- a/src/udev/udev-rules.c +++ b/src/udev/udev-rules.c @@ -29,12 +29,14 @@ #include #include +#include "architecture.h" #include "udev.h" #include "path-util.h" #include "conf-files.h" #include "strbuf.h" #include "strv.h" #include "util.h" +#include "virt.h" #define PREALLOC_TOKEN 2048 @@ -123,6 +125,7 @@ enum token_type { TK_M_DEVLINK, /* val */ TK_M_NAME, /* val */ TK_M_ENV, /* val, attr */ + TK_M_CONST, /* val, attr */ TK_M_TAG, /* val */ TK_M_SUBSYSTEM, /* val */ TK_M_DRIVER, /* val */ @@ -257,6 +260,7 @@ static const char *token_str(enum token_type type) { [TK_M_DEVLINK] = "M DEVLINK", [TK_M_NAME] = "M NAME", [TK_M_ENV] = "M ENV", + [TK_M_CONST] = "M CONST", [TK_M_TAG] = "M TAG", [TK_M_SUBSYSTEM] = "M SUBSYSTEM", [TK_M_DRIVER] = "M DRIVER", @@ -365,6 +369,7 @@ static void dump_token(struct udev_rules *rules, struct token *token) { case TK_M_ATTR: case TK_M_ATTRS: case TK_M_ENV: + case TK_M_CONST: case TK_A_ATTR: case TK_A_ENV: log_debug("%s %s '%s' '%s'(%s)", @@ -905,6 +910,7 @@ static int rule_add_key(struct rule_tmp *rule_tmp, enum token_type type, token->key.builtin_cmd = *(enum udev_builtin_cmd *)data; break; case TK_M_ENV: + case TK_M_CONST: case TK_M_ATTR: case TK_M_ATTRS: case TK_A_ATTR: @@ -1264,6 +1270,22 @@ static int add_rule(struct udev_rules *rules, char *line, continue; } + if (startswith(key, "CONST{")) { + attr = get_key_attribute(rules->udev, key + STRLEN("CONST")); + if (attr == NULL || !STR_IN_SET(attr, "arch", "virt")) { + log_error("error parsing CONST attribute"); + goto invalid; + } + if (op == OP_REMOVE) { + log_error("invalid CONST operation"); + goto invalid; + } + if (op < OP_MATCH_MAX) { + if (rule_add_key(&rule_tmp, TK_M_CONST, op, value, attr) != 0) + goto invalid; + } + continue; + } if (streq(key, "TAG")) { if (op < OP_MATCH_MAX) rule_add_key(&rule_tmp, TK_M_TAG, op, value, NULL); @@ -1959,6 +1981,23 @@ int udev_rules_apply_to_event(struct udev_rules *rules, goto nomatch; break; } + case TK_M_CONST: { + const char *key_name = rules_str(rules, cur->key.attr_off); + const char *value = NULL; + int q; + + if (streq(key_name, "arch")) { + q = uname_architecture(); + value = architecture_to_string(q); + } else if (streq(key_name, "virt")) { + q = detect_virtualization(&value); + } else + assert_not_reached("Invalid CONST key"); + + if (match_key(rules, cur, value)) + goto nomatch; + break; + } case TK_M_TAG: { struct udev_list_entry *list_entry; bool match = false; diff --git a/test/rule-syntax-check.py b/test/rule-syntax-check.py index 80bbe65bea..c6d003b167 100644 --- a/test/rule-syntax-check.py +++ b/test/rule-syntax-check.py @@ -34,7 +34,7 @@ else: rules_files = glob(os.path.join(rules_dir, '*.rules')) no_args_tests = re.compile('(ACTION|DEVPATH|KERNELS?|NAME|SYMLINK|SUBSYSTEMS?|DRIVERS?|TAG|RESULT|TEST)\s*(?:=|!)=\s*"([^"]*)"$') -args_tests = re.compile('(ATTRS?|ENV|TEST){([a-zA-Z0-9/_.*%-]+)}\s*(?:=|!)=\s*"([^"]*)"$') +args_tests = re.compile('(ATTRS?|ENV|CONST|TEST){([a-zA-Z0-9/_.*%-]+)}\s*(?:=|!)=\s*"([^"]*)"$') no_args_assign = re.compile('(NAME|SYMLINK|OWNER|GROUP|MODE|TAG|PROGRAM|RUN|LABEL|GOTO|WAIT_FOR|OPTIONS|IMPORT)\s*(?:\+=|:=|=)\s*"([^"]*)"$') args_assign = re.compile('(ATTR|ENV|IMPORT|RUN){([a-zA-Z0-9/_.*%-]+)}\s*(=|\+=)\s*"([^"]*)"$')