SWPTP-1516: use macro to populate default config help text

src/include/sfptpd_config.h

@@ -449,6 +449,21 @@
 /** Maximum section name length in config files */
 #define SFPTPD_CONFIG_SECTION_NAME_MAX (64)
 
+/** Produce help text for default config value. */
+#define SFPTPD_CONFIG_DFL(val) _Generic((val), \
+	bool: (val) ? "Enabled by default" : "Disabled by default", \
+	default: "Default is " STRINGIFY(val))
+
+/** Produce help text for default config value with compat for pre-C23
+ *  compilers (can be removed when gcc-10 become baseline) */
+#define SFPTPD_CONFIG_DFL_BOOL(val) _Generic((val), \
+	int: (val) ? "Enabled by default" : "Disabled by default", \
+	default: SFPTPD_CONFIG_DFL(val))
+
+/** Produce help text for default string config quoted macro values */
+#define SFPTPD_CONFIG_DFL_STR(val) _Generic((val), \
+	char *: "Defaults to " val)
+
 /** Enumeration of different config section categories. */
 enum sfptpd_config_category {
 
@@ -555,6 +570,8 @@ typedef struct sfptpd_config_option {
 	enum sfptpd_config_scope scope;
 	int (*parse)(struct sfptpd_config_section *, const char *option,
 		     unsigned int num_params, const char * const *params);
+	const char *dfl;
+	const char *unit;
 	bool hidden;
 	bool confidential;
 } sfptpd_config_option_t;

src/include/sfptpd_general_config.h

@@ -23,7 +23,7 @@
 #define SFPTPD_DEFAULT_STATS_LOG                   (SFPTPD_STATS_LOG_OFF)
 #define SFPTPD_DEFAULT_STATE_PATH                  SFPTPD_STATE_PATH
 #define SFPTPD_DEFAULT_CONTROL_PATH                SFPTPD_CONTROL_SOCKET_PATH
-#define SFPTPD_DEFAULT_TRACE_LEVEL                 (0)
+#define SFPTPD_DEFAULT_TRACE_LEVEL                 0
 #define SFPTPD_DEFAULT_SYNC_INTERVAL               -4
 #define SFPTPD_DEFAULT_CLOCK_CTRL                  (SFPTPD_CLOCK_CTRL_SLEW_AND_STEP)
 #define SFPTPD_DEFAULT_STEP_THRESHOLD_NS           (SFPTPD_SERVO_CLOCK_STEP_THRESHOLD_S * ONE_BILLION)
@@ -33,6 +33,7 @@
 #define SFPTPD_DEFAULT_CLUSTERING_GUARD            (false)
 #define SFPTPD_DEFAULT_CLUSTERING_GUARD_THRESHOLD  1
 #define SFPTPD_DEFAULT_PERSISTENT_CLOCK_CORRECTION (true)
+#define SFPTPD_DEFAULT_DISABLE_ON_EXIT             (true)
 #define SFPTPD_DEFAULT_DISCIPLINE_ALL_CLOCKS       (true)
 #define SFPTPD_DEFAULT_NON_SFC_NICS                (false)
 #define SFPTPD_DEFAULT_ASSUME_ONE_PHC_PER_NIC      (false)

src/sfptpd_config.c

@@ -119,11 +119,16 @@ static void config_display_help(void)
 		printf("%s:\n", set->description);
 
 		for (j = 0; j < set->num_options; j++) {
-			if (!set->options[j].hidden) {
-				printf("%-28s %-30s %s\n",
-				       set->options[j].option,
-				       set->options[j].params,
-				       set->options[j].description);
+			const sfptpd_config_option_t *opt = set->options + j;
+			if (!opt->hidden) {
+				printf("%-28s %-30s %s%s%s%s%s\n",
+				       opt->option,
+				       opt->params,
+				       opt->description,
+				       opt->dfl ? ". " : "",
+				       opt->dfl ? opt->dfl : "",
+				       opt->dfl && opt->unit ? " " : "",
+				       opt->dfl && opt->unit ? opt->unit : "");
 			}
 		}
 

src/sfptpd_general_config.c

@@ -150,103 +150,115 @@ static const sfptpd_config_option_t config_general_options[] =
 		parse_phc_pps_methods},
 	{"selection_holdoff_interval", "NUMBER",
 		"Specifies how long to wait after detecting a better instance "
-		"before selecting it. Default is "
-		STRINGIFY(SFPTPD_DEFAULT_SELECTION_HOLDOFF_INTERVAL) " seconds.",
+		"before selecting it",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_selection_holdoff_interval},
+		parse_selection_holdoff_interval,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_SELECTION_HOLDOFF_INTERVAL),
+		.unit = "seconds"},
 	{"message_log", "<syslog | stderr | filename>",
-		"Specifies where to send messages generated by the application. By default messages are sent to stderr",
+		"Specifies where to send messages generated by the application",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_message_log},
+		parse_message_log,
+		.dfl = "By default messages are sent to stderr"},
 	{"stats_log", "<off | stdout | filename>",
-		"Specifies if and where to log statistics generated by the application. By default statistics logging is disabled",
+		"Specifies if and where to log statistics generated by the application",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_stats_log},
+		parse_stats_log,
+		.dfl = "By default statistics logging is disabled"},
 	{"user", "USER [GROUP]",
 		"Drop to the user and group named USER and GROUP retaining "
 		"essential capabilities. Group defaults to USER's if not "
 		"specified",
 		~1, SFPTPD_CONFIG_SCOPE_GLOBAL,
 		parse_user},
 	{"daemon", "",
-		"Run as a daemon. Disabled by default",
+		"Run as a daemon.",
 		0, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_daemon},
+		parse_daemon,
+		.dfl = "Disabled by default"},
 	{"lock", "<off | on>",
-		"Specify whether to use a lock file to stop multiple simultaneous instances of the daemon. Enabled by default",
+		"Specify whether to use a lock file to stop multiple simultaneous instances of the daemon",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_lock},
+		parse_lock,
+		.dfl = "Enabled by default"},
 	{"state_path", "<path>",
-		"Directory in which to store sfptpd state data. Defaults to " SFPTPD_DEFAULT_STATE_PATH,
+		"Directory in which to store sfptpd state data",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_state_path},
+		parse_state_path,
+		.dfl = SFPTPD_CONFIG_DFL_STR(SFPTPD_DEFAULT_STATE_PATH)},
 	{"control_path", "<path>",
-		"Path for Unix domain control socket. Defaults to " SFPTPD_DEFAULT_CONTROL_PATH,
+		"Path for Unix domain control socket",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_control_path},
+		parse_control_path,
+		.dfl = SFPTPD_CONFIG_DFL_STR(SFPTPD_DEFAULT_CONTROL_PATH)},
 	{"sync_interval", "NUMBER",
 		"Specifies the interval in 2^NUMBER seconds at which the clocks "
 		"are synchronized to the local reference clock, where NUMBER is "
 		"in the range ["
 		STRINGIFY(SFPTPD_MIN_SYNC_INTERVAL) ","
-		STRINGIFY(SFPTPD_MAX_SYNC_INTERVAL) "]. The default is "
-		STRINGIFY(SFPTPD_DEFAULT_SYNC_INTERVAL) ".",
+		STRINGIFY(SFPTPD_MAX_SYNC_INTERVAL) "]",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_sync_interval},
+		parse_sync_interval,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_SYNC_INTERVAL)},
 	{"local_sync_threshold", "NUMBER",
 		"Threshold in nanoseconds of the offset between the system clock and a NIC clock over a "
 		STRINGIFY(SFPTPD_STATS_CONVERGENCE_MIN_PERIOD_DEFAULT)
-		"s period to be considered in sync (converged). The default is "
-		STRINGIFY(SFPTPD_STATS_CONVERGENCE_MAX_OFFSET_DEFAULT) ".",
+		"s period to be considered in sync",
 		1, SFPTPD_CONFIG_SCOPE_INSTANCE,
-		parse_sync_threshold},
+		parse_sync_threshold,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_STATS_CONVERGENCE_MAX_OFFSET_DEFAULT)},
 	{"clock_control", "<slew-and-step | step-at-startup | no-step | no-adjust | step-forward | step-on-first-lock>",
-		"Specifies how the clocks are controlled. By default clocks are stepped and slewed as necessary",
+		"Specifies how the clocks are controlled",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_clock_control},
+		parse_clock_control,
+		.dfl = "By default clocks are stepped and slewed as necessary"},
 	{"step_threshold", "NUMBER",
-		"Threshold in seconds of the offset between the clock and its reference clock for sfptpd to step. The default is "
-		STRINGIFY(SFPTPD_SERVO_CLOCK_STEP_THRESHOLD_S) ".",
+		"Threshold in seconds of the offset between the clock and its reference clock for sfptpd to step.",
 		1, SFPTPD_CONFIG_SCOPE_INSTANCE,
-		parse_step_threshold},
+		parse_step_threshold,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_SERVO_CLOCK_STEP_THRESHOLD_S)},
 	{"epoch_guard", "<alarm-only | prevent-sync | correct-clock>",
-		"Guards against propagation of times near the epoch. The default is correct-clock",
+		"Guards against propagation of times near the epoch",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_epoch_guard},
+		parse_epoch_guard,
+		.dfl = "The default is correct-clock"},
 	{"clock_list", "[<name | mac-address | clock-id | ifname>]*",
-		"Specifies the set of clocks that sfptpd should discipline. By default all clocks are disciplined",
+		"Specifies the set of clocks that sfptpd should discipline",
 		~0, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_clock_list},
+		parse_clock_list,
+		.dfl = "By default all clocks are disciplined"},
 	{"clock_readonly", "[<name | mac-address | clock-id | ifname>]",
 		"Specifies a set of clocks that sfptpd should never step or slew, under any circumstance. Use with care.",
 		~1, SFPTPD_CONFIG_SCOPE_GLOBAL,
 		parse_clock_readonly},
 	{"persistent_clock_correction", "<off | on>",
-		"Specifies whether to used saved clock frequency corrections when disciplining clocks. Enabled by default",
+		"Specifies whether to used saved clock frequency corrections when disciplining clocks",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_persistent_clock_correction},
+		parse_persistent_clock_correction,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_PERSISTENT_CLOCK_CORRECTION)},
 	{"non_solarflare_nics", "<off | on>",
 		"Specify whether to use timestamping and hardware clock "
-		"capabilities of non-Solarflare adapters. Disabled by default",
+		"capabilities of non-Solarflare adapters",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_non_solarflare_nics},
+		parse_non_solarflare_nics,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_NON_SFC_NICS)},
 	{"non_xilinx_nics", "<off | on>",
-		"Specify whether to use timestamping and hardware clock "
-		"capabilities of non-Xilinx adapters. Disabled by default",
+		"Alias for non_solarflace_nics",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
 		parse_non_solarflare_nics,
 		.hidden = true},
 	{"assume_one_phc_per_nic", "<off | on>",
 		"Specify whether multiple reported clock devices on a NIC "
-		"should be assumed to represent the same underlying clock. "
-		"Enabled by default",
+		"should be assumed to represent the same underlying clock",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_assume_one_phc_per_nic},
+		parse_assume_one_phc_per_nic,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_ASSUME_ONE_PHC_PER_NIC)},
 	{"avoid_efx_ioctl", "<off | on>",
 		"Specify whether to avoid private SIOCEFX ioctl for Solarflare "
-		"adapters where possible. Disabled by default",
+		"adapters where possible",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
 		parse_avoid_efx_ioctl,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(false),
 		.hidden = true},
 	{"phc_diff_methods", "<sys-offset-precise | efx | pps | sys-offset-ext | sys-offset | read-time>*",
 		"Define the list of PHC diff methods used",
@@ -259,60 +271,65 @@ static const sfptpd_config_option_t config_general_options[] =
 	{"timestamping_disable_on_exit", "<off | on>",
 		"Specifies whether timestamping should be disabled when daemon exits",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_timestamping_disable_on_exit},
+		parse_timestamping_disable_on_exit,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_DISABLE_ON_EXIT)},
 	{"pid_filter_p", "NUMBER",
-		"Secondary servo PID filter proportional term coefficient. Default value is "
-		STRINGIFY(SFPTPD_DEFAULT_SERVO_K_PROPORTIONAL) ".",
+		"Secondary servo PID filter proportional term coefficient",
 		1, SFPTPD_CONFIG_SCOPE_INSTANCE,
-		parse_pid_filter_kp},
+		parse_pid_filter_kp,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_SERVO_K_PROPORTIONAL)},
 	{"pid_filter_i", "NUMBER",
-		"Secondary servo PID filter integral term coefficient. Default value is "
-		STRINGIFY(SFPTPD_DEFAULT_SERVO_K_INTEGRAL) ".",
+		"Secondary servo PID filter integral term coefficient",
 		1, SFPTPD_CONFIG_SCOPE_INSTANCE,
-		parse_pid_filter_ki},
+		parse_pid_filter_ki,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_SERVO_K_INTEGRAL)},
 	{"trace_level", "[<general | threading | bic | netlink | ntp | servo | clocks>] NUMBER",
-		"Specifies a module trace level, if built with trace enabled. If module name is omitted, will set the 'general' module trace level. Default is 0 - no trace",
+		"Specifies a module (of 'general' if omitted) trace level from 0 (none) to 6 (excessive)",
 		~1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_trace_level},
+		parse_trace_level,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_TRACE_LEVEL)},
 	{"test_mode", "",
-		"Enables features to aid testing. Disabled by default",
+		"Enables features to aid testing",
 		0, SFPTPD_CONFIG_SCOPE_GLOBAL,
 		parse_test_mode,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_TEST_MODE),
 		.hidden = true},
 	{"json_stats", "<filename>",
-		"Output realtime module statistics in JSON-lines format to this file (http://jsonlines.org). Disabled by default.",
-		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_json_stats},
+		"Output realtime module statistics in JSON-lines format to this file (http://jsonlines.org)",
+		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_json_stats,
+		.dfl = "Disabled by default"},
 	{"json_remote_monitor", "<filename>",
-		"Output realtime information collected by the PTP remote monitor in "
-		"JSON-lines format to this file (http://jsonlines.org). "
-		"Disabled by default. DEPRECATED since v3.7.0.",
-		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_json_remote_monitor},
+		"Write JSON lines to this file for data collected by the PTP "
+		"remote monitor (which is DEPRECATED in favour of sfptpmon)",
+		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_json_remote_monitor,
+		.dfl = "Disabled by default"},
 	{"hotplug_detection_mode", "<netlink | auto>",
-		"Deprecated option to configure how the daemon should detect "
-		"hotplug insertion and removal of interfaces and bond changes. "
-		"Netlink is used exclusively for this now and any other option "
-		"is ignored.",
+		"obsolete option to control how interface and bond changes are "
+		"detected. The option value is ignored and netlink used.",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_hotplug_detection_mode},
 	{"reporting_intervals", "<save_state|stats_log INTERVAL>*",
 		"Specifies period between saving state files and/or writing "
-		"stats log output. Default is: \"save_state "
-		STRINGIFY(SFPTPD_DEFAULT_STATE_SAVE_INTERVAL) " stats_log "
-		STRINGIFY(SFPTPD_DEFAULT_STATISTICS_LOGGING_INTERVAL) "\"",
+		"stats log output",
 		~2, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_reporting_intervals},
+		parse_reporting_intervals,
+		.dfl = "Default is: \"save_state "
+		STRINGIFY(SFPTPD_DEFAULT_STATE_SAVE_INTERVAL) " stats_log "
+		STRINGIFY(SFPTPD_DEFAULT_STATISTICS_LOGGING_INTERVAL) "\""},
 	{"netlink_rescan_interval", "NUMBER",
 		"Specifies period between rescanning the link table with netlink. "
-		"Periodic rescans are disabled with zero. Default is "
-		STRINGIFY(SFPTPD_DEFAULT_NETLINK_RESCAN_INTERVAL) " seconds.",
+		"Periodic rescans are disabled with zero",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_netlink_rescan_interval},
+		parse_netlink_rescan_interval,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_NETLINK_RESCAN_INTERVAL),
+		.unit = "seconds"},
 	{"netlink_coalesce_ms", "NUMBER",
 		"Specifies period after a significant change is communicated "
 		"by netlink to wait for further changes to avoid excessive "
-		"perturbation. Coalescing is disabled with zero. Default is "
-		STRINGIFY(SFPTPD_DEFAULT_NETLINK_COALESCE_MS) " ms.",
+		"perturbation. Coalescing is disabled with zero",
 		1, SFPTPD_CONFIG_SCOPE_GLOBAL,
-		parse_netlink_coalesce_ms},
+		parse_netlink_coalesce_ms,
+		.dfl = SFPTPD_CONFIG_DFL(SFPTPD_DEFAULT_NETLINK_COALESCE_MS),
+		.unit =  "ms"},
 	{"clustering", "discriminator <INSTANCE> <THRESHOLD> <NO_DISCRIMINATOR_SCORE>",
 		"Implements clustering based on MODE. Currently only supports "
 		"discriminator mode, which disqualifies sync instances that differ "
@@ -334,32 +351,32 @@ static const sfptpd_config_option_t config_general_options[] =
 		"or diagnostic use cases.",
 		~1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_ignore_critical},
 	{"rtc_adjust", "<off | on>",
-		"Specify whether to let the kernel sync the RTC clock. "
-		"Enabled by default",
-		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_rtc_adjust},
+		"Specify whether to let the kernel sync the RTC clock",
+		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_rtc_adjust,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(SFPTPD_DEFAULT_RTC_ADJUST)},
 	{"clock_display_fmts", "SHORT-FMT LONG-FMT HWID-FMT FNAM-FMT",
 		"Define formats for displaying clock properties, "
 		"of max expansion "
 		STRINGIFY(SFPTPD_CLOCK_SHORT_NAME_SIZE) ", "
 		STRINGIFY(SFPTPD_CLOCK_FULL_NAME_SIZE) ", "
 		STRINGIFY(SFPTPD_CLOCK_HW_ID_STRING_SIZE) " and "
-		STRINGIFY(SFPTPD_CLOCK_HW_ID_STRING_SIZE) " respectively. "
-		"Default is "
-		SFPTPD_DEFAULT_CLOCK_SHORT_FMT " "
-		SFPTPD_DEFAULT_CLOCK_LONG_FMT " "
-		SFPTPD_DEFAULT_CLOCK_HWID_FMT " "
-		SFPTPD_DEFAULT_CLOCK_FNAM_FMT ".",
-		4, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_clock_display_fmts},
+		STRINGIFY(SFPTPD_CLOCK_HW_ID_STRING_SIZE) " respectively. ",
+		4, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_clock_display_fmts,
+		.dfl = "Default is "
+			SFPTPD_DEFAULT_CLOCK_SHORT_FMT " "
+			SFPTPD_DEFAULT_CLOCK_LONG_FMT " "
+			SFPTPD_DEFAULT_CLOCK_HWID_FMT " "
+			SFPTPD_DEFAULT_CLOCK_FNAM_FMT "."},
 	{"unique_clockid_bits", "<OCTETS | pid | hostid | rand>",
 		"Colon-delimited octets providing the unique bits that pad the "
 		"LSBs of an EUI-64 clock identity constructed from an EUI-48 "
-		"MAC address. Default is "
-		SFPTPD_DEFAULT_UNIQUE_CLOCKID_BITS ".",
-		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_unique_clockid_bits},
+		"MAC address",
+		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_unique_clockid_bits,
+		.dfl = SFPTPD_CONFIG_DFL_STR(SFPTPD_DEFAULT_UNIQUE_CLOCKID_BITS)},
 	{"legacy_clockids", "<off | on>",
-		"Use legacy 1588-2008 clock ids of the form :::ff:fe:::. "
-		"Default is off.",
-		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_legacy_clockids},
+		"Use legacy 1588-2008 clock ids of the form :::ff:fe:::",
+		1, SFPTPD_CONFIG_SCOPE_GLOBAL, parse_legacy_clockids,
+		.dfl = SFPTPD_CONFIG_DFL_BOOL(false)},
 };
 
 static const sfptpd_config_option_set_t config_general_option_set =
@@ -1684,7 +1701,7 @@ static struct sfptpd_config_section *general_config_create(const char *name,
 		new->rtc_adjust = SFPTPD_DEFAULT_RTC_ADJUST;
 
 		new->timestamping.all = false;
-		new->timestamping.disable_on_exit = true;
+		new->timestamping.disable_on_exit = SFPTPD_DEFAULT_DISABLE_ON_EXIT;
 		new->timestamping.num_interfaces = 0;
 
 		new->convergence_threshold = 0.0;