From 04200975255f0089cb7e0d7e30c98cbafc423b17 Mon Sep 17 00:00:00 2001 From: Nick Rosbrook Date: Fri, 21 Aug 2026 14:30:50 -0400 Subject: [PATCH 1/3] varlink: introduce io.systemd.service.GetLogLevel We already have io.systemd.service.SetLogLevel. Add a getter so that CLI tools with `log-level` subcommands can be more easily implemented with varlink. Bind this method to all services that already bind io.systemd.service.SetLogLevel. --- src/home/homed-manager.c | 1 + src/hostname/hostnamed.c | 1 + src/import/importd.c | 1 + src/journal/journald-varlink.c | 1 + src/login/logind-varlink.c | 1 + src/machine/machined-varlink.c | 1 + src/network/networkd-manager-varlink.c | 1 + src/oom/oomd-manager.c | 1 + src/resolve/resolved-varlink.c | 1 + src/shared/varlink-io.systemd.service.c | 22 ++++++++++++++++++++++ src/shared/varlink-io.systemd.service.h | 1 + src/udev/udev-varlink.c | 1 + 12 files changed, 33 insertions(+) diff --git a/src/home/homed-manager.c b/src/home/homed-manager.c index d6ed1673b2..9e5550f1c0 100644 --- a/src/home/homed-manager.c +++ b/src/home/homed-manager.c @@ -1084,6 +1084,7 @@ static int manager_bind_varlink(Manager *m) { "io.systemd.UserDatabase.GetMemberships", vl_method_get_memberships, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); diff --git a/src/hostname/hostnamed.c b/src/hostname/hostnamed.c index 2784697ab5..5c190b373c 100644 --- a/src/hostname/hostnamed.c +++ b/src/hostname/hostnamed.c @@ -2634,6 +2634,7 @@ static int connect_varlink(Context *c) { "io.systemd.Hostname.SetTags", vl_method_set_tags, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to bind Varlink method calls: %m"); diff --git a/src/import/importd.c b/src/import/importd.c index 3a1ad8b502..b77515a264 100644 --- a/src/import/importd.c +++ b/src/import/importd.c @@ -2024,6 +2024,7 @@ static int manager_connect_varlink(Manager *m) { "io.systemd.Import.Pull", vl_method_pull, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to bind Varlink method calls: %m"); diff --git a/src/journal/journald-varlink.c b/src/journal/journald-varlink.c index 411b6af3f8..577830ff93 100644 --- a/src/journal/journald-varlink.c +++ b/src/journal/journald-varlink.c @@ -206,6 +206,7 @@ int manager_open_varlink(Manager *m, const char *socket, int fd) { "io.systemd.Journal.RelinquishVar", vl_method_relinquish_var, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return r; diff --git a/src/login/logind-varlink.c b/src/login/logind-varlink.c index 45f21b360e..d7f803826f 100644 --- a/src/login/logind-varlink.c +++ b/src/login/logind-varlink.c @@ -903,6 +903,7 @@ int manager_varlink_init(Manager *m, int fd) { "io.systemd.Shutdown.SoftReboot", vl_method_soft_reboot, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); diff --git a/src/machine/machined-varlink.c b/src/machine/machined-varlink.c index b136ccf2a2..ae121395c0 100644 --- a/src/machine/machined-varlink.c +++ b/src/machine/machined-varlink.c @@ -838,6 +838,7 @@ static int manager_varlink_init_machine(Manager *m) { "io.systemd.MachineImage.CleanPool", vl_method_clean_pool, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); diff --git a/src/network/networkd-manager-varlink.c b/src/network/networkd-manager-varlink.c index 19f7b4813d..c48faec31e 100644 --- a/src/network/networkd-manager-varlink.c +++ b/src/network/networkd-manager-varlink.c @@ -331,6 +331,7 @@ int manager_varlink_init(Manager *m, int fd) { "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.Reload", vl_method_reload, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); diff --git a/src/oom/oomd-manager.c b/src/oom/oomd-manager.c index 2fafa6904d..10343f6c55 100644 --- a/src/oom/oomd-manager.c +++ b/src/oom/oomd-manager.c @@ -1279,6 +1279,7 @@ static int manager_varlink_init(Manager *m, int fd) { "io.systemd.oom.ReportManagedOOMCGroups", process_managed_oom_request, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); diff --git a/src/resolve/resolved-varlink.c b/src/resolve/resolved-varlink.c index 32cd910514..d29bd92ac5 100644 --- a/src/resolve/resolved-varlink.c +++ b/src/resolve/resolved-varlink.c @@ -1547,6 +1547,7 @@ static int varlink_main_server_init(Manager *m) { "io.systemd.Resolve.ResolveRecord", vl_method_resolve_record, "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.SetLogLevel", varlink_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment, "io.systemd.Resolve.BrowseServices", vl_method_browse_services, "io.systemd.Resolve.DumpDNSConfiguration", vl_method_dump_dns_configuration); diff --git a/src/shared/varlink-io.systemd.service.c b/src/shared/varlink-io.systemd.service.c index 698a3d41eb..6e44e608a8 100644 --- a/src/shared/varlink-io.systemd.service.c +++ b/src/shared/varlink-io.systemd.service.c @@ -21,6 +21,11 @@ static SD_VARLINK_DEFINE_METHOD( SD_VARLINK_FIELD_COMMENT("The maximum log level, using BSD syslog log level integers."), SD_VARLINK_DEFINE_INPUT(level, SD_VARLINK_INT, SD_VARLINK_NULLABLE)); +static SD_VARLINK_DEFINE_METHOD( + GetLogLevel, + SD_VARLINK_FIELD_COMMENT("The current maximum log level, using BSD syslog level integers."), + SD_VARLINK_DEFINE_OUTPUT(level, SD_VARLINK_INT, 0)); + static SD_VARLINK_DEFINE_METHOD( GetEnvironment, SD_VARLINK_FIELD_COMMENT("Returns the current environment block, i.e. the contents of environ[]."), @@ -39,6 +44,8 @@ SD_VARLINK_DEFINE_INTERFACE( &vl_method_Reload, SD_VARLINK_SYMBOL_COMMENT("Sets the maximum log level."), &vl_method_SetLogLevel, + SD_VARLINK_SYMBOL_COMMENT("Gets the maximum log level."), + &vl_method_GetLogLevel, SD_VARLINK_SYMBOL_COMMENT("Get current environment block."), &vl_method_GetEnvironment, SD_VARLINK_SYMBOL_COMMENT("Returned if the environment block is currently not in a valid state."), @@ -91,6 +98,21 @@ int varlink_method_set_log_level(sd_varlink *link, sd_json_variant *parameters, return sd_varlink_reply(link, NULL); } +int varlink_method_get_log_level(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata) { + int r; + + assert(link); + assert(parameters); + + r = sd_varlink_dispatch(link, parameters, /* dispatch_table= */ NULL, /* userdata= */ NULL); + if (r != 0) + return r; + + log_debug("Received io.systemd.service.GetLogLevel()"); + + return sd_varlink_replybo(link, SD_JSON_BUILD_PAIR_INTEGER("level", log_get_max_level())); +} + int varlink_method_get_environment(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata) { uid_t uid; int r; diff --git a/src/shared/varlink-io.systemd.service.h b/src/shared/varlink-io.systemd.service.h index a68d58d6d4..7ad9781ab8 100644 --- a/src/shared/varlink-io.systemd.service.h +++ b/src/shared/varlink-io.systemd.service.h @@ -8,4 +8,5 @@ extern const sd_varlink_interface vl_interface_io_systemd_service; int varlink_method_ping(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata); int varlink_method_set_log_level(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata); +int varlink_method_get_log_level(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata); int varlink_method_get_environment(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata); diff --git a/src/udev/udev-varlink.c b/src/udev/udev-varlink.c index 70567dc58a..fb5fa390f3 100644 --- a/src/udev/udev-varlink.c +++ b/src/udev/udev-varlink.c @@ -218,6 +218,7 @@ int manager_start_varlink_server(Manager *manager, int fd) { "io.systemd.service.Ping", varlink_method_ping, "io.systemd.service.Reload", vl_method_reload, "io.systemd.service.SetLogLevel", vl_method_set_log_level, + "io.systemd.service.GetLogLevel", varlink_method_get_log_level, "io.systemd.service.GetEnvironment", varlink_method_get_environment, "io.systemd.Udev.SetTrace", vl_method_set_trace, "io.systemd.Udev.SetChildrenMax", vl_method_set_children_max, From 071f10991cf5b70cbfb6dd60242858b5d7728ea3 Mon Sep 17 00:00:00 2001 From: Nick Rosbrook Date: Fri, 21 Aug 2026 15:58:10 -0400 Subject: [PATCH 2/3] shared: add varlink_{get,set}_log_level_string helpers to verb-log-control.c Most of the time, the CLI tools that will use this helper are dealing with the string representation of log levels, so just add string-based helpers for now. --- src/shared/verb-log-control.c | 66 +++++++++++++++++++++++++++++++++++ src/shared/verb-log-control.h | 3 ++ 2 files changed, 69 insertions(+) diff --git a/src/shared/verb-log-control.c b/src/shared/verb-log-control.c index 304dd5431b..c46b62eec8 100644 --- a/src/shared/verb-log-control.c +++ b/src/shared/verb-log-control.c @@ -1,13 +1,17 @@ /* SPDX-License-Identifier: LGPL-2.1-or-later */ #include "sd-bus.h" +#include "sd-json.h" +#include "sd-varlink.h" #include "alloc-util.h" #include "bus-error.h" #include "bus-locator.h" +#include "json-util.h" #include "log.h" #include "string-util.h" #include "syslog-util.h" +#include "varlink-util.h" #include "verb-log-control.h" int verb_log_control_common(sd_bus *bus, const char *destination, const char *verb, const char *value) { @@ -52,3 +56,65 @@ int verb_log_control_common(sd_bus *bus, const char *destination, const char *ve return 0; } + +int varlink_get_log_level_string(sd_varlink *vl, char **ret) { + int r; + + assert(vl); + assert(ret); + + sd_json_variant *reply = NULL; + r = varlink_call_and_log( + vl, + "io.systemd.service.GetLogLevel", + /* parameters= */ NULL, + &reply); + if (r < 0) + return r; + + int level; + static const sd_json_dispatch_field dispatch_table[] = { + { "level", _SD_JSON_VARIANT_TYPE_INVALID, json_dispatch_log_level, 0, SD_JSON_MANDATORY|SD_JSON_STRICT }, + {} + }; + + r = sd_json_dispatch(reply, dispatch_table, SD_JSON_LOG|SD_JSON_ALLOW_EXTENSIONS, &level); + if (r < 0) + return r; + + _cleanup_free_ char *level_str = NULL; + r = log_level_to_string_alloc(level, &level_str); + if (r < 0) + return log_error_errno(r, "Failed to convert log level to string: %m"); + + *ret = TAKE_PTR(level_str); + return 0; +} + +int varlink_set_log_level_string(sd_varlink *vl, const char *value) { + int r; + + assert(vl); + + _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL; + if (value) { + int level = log_level_from_string(value); + if (level < 0) + return log_error_errno(level, "Failed to convert log level '%s': %m", value); + + r = sd_json_variant_new_integer(&v, level); + } else + r = sd_json_variant_new_null(&v); + if (r < 0) + return log_error_errno(r, "Failed to create JSON variant: %m"); + + r = varlink_callbo_and_log( + vl, + "io.systemd.service.SetLogLevel", + /* reply= */ NULL, + SD_JSON_BUILD_PAIR_VARIANT("level", v)); + if (r < 0) + return r; + + return 0; +} diff --git a/src/shared/verb-log-control.h b/src/shared/verb-log-control.h index 71c5f6c58d..c1324a229e 100644 --- a/src/shared/verb-log-control.h +++ b/src/shared/verb-log-control.h @@ -4,3 +4,6 @@ #include "forward.h" int verb_log_control_common(sd_bus *bus, const char *destination, const char *verb, const char *value); + +int varlink_get_log_level_string(sd_varlink *vl, char **ret); +int varlink_set_log_level_string(sd_varlink *vl, const char *value); From cf31d92de3c4e76e659917d7c8f12b943b514ec7 Mon Sep 17 00:00:00 2001 From: Nick Rosbrook Date: Fri, 21 Aug 2026 16:18:28 -0400 Subject: [PATCH 3/3] resolvectl: implement log-level with varlink methods --- src/resolve/resolvectl.c | 25 ++++++++++++++++++++----- test/units/TEST-75-RESOLVED.sh | 5 +++++ 2 files changed, 25 insertions(+), 5 deletions(-) diff --git a/src/resolve/resolvectl.c b/src/resolve/resolvectl.c index 4afd9958c8..9e97a90cf5 100644 --- a/src/resolve/resolvectl.c +++ b/src/resolve/resolvectl.c @@ -3171,16 +3171,31 @@ static int verb_revert_link(int argc, char *argv[], uintptr_t _data, void *userd VERB(verb_log_level, "log-level", "[LEVEL]", VERB_ANY, 2, 0, "Get/set logging threshold for systemd-resolved"); static int verb_log_level(int argc, char *argv[], uintptr_t _data, void *userdata) { - _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; int r; - r = acquire_bus(&bus); + _cleanup_(sd_varlink_unrefp) sd_varlink *vl = NULL; + r = sd_varlink_connect_address(&vl, "/run/systemd/resolve/io.systemd.Resolve"); if (r < 0) - return r; + return log_error_errno(r, "Failed to connect to /run/systemd/resolve/io.systemd.Resolve: %m"); - assert(IN_SET(argc, 1, 2)); + if (argc == 1) { + /* Show current log level */ + _cleanup_free_ char *level_str = NULL; + r = varlink_get_log_level_string(vl, &level_str); + if (r < 0) + return r; - return verb_log_control_common(bus, "org.freedesktop.resolve1", argv[0], argc == 2 ? argv[1] : NULL); + puts(level_str); + + } else if (argc == 2) { + /* Set new log level */ + r = varlink_set_log_level_string(vl, argv[1]); + if (r < 0) + return r; + } else + assert_not_reached(); + + return 0; } static int parse_protocol(const char *arg) { diff --git a/test/units/TEST-75-RESOLVED.sh b/test/units/TEST-75-RESOLVED.sh index 172dff245d..899c5a6b81 100755 --- a/test/units/TEST-75-RESOLVED.sh +++ b/test/units/TEST-75-RESOLVED.sh @@ -336,6 +336,11 @@ manual_testcase_01_resolvectl() { assert_in '_localdnsstub' "$(dig @127.0.0.53 -x 127.0.0.53)" assert_in '127.0.0.54' "$(dig @127.0.0.53 _localdnsproxy)" assert_in '_localdnsproxy' "$(dig @127.0.0.53 -x 127.0.0.54)" + + resolvectl log-level warning + assert_eq "$(resolvectl log-level)" "warning" + resolvectl log-level debug + assert_eq "$(resolvectl log-level)" "debug" } # Tests for mDNS and LLMNR settings