logging: support an "OFF" logging level

The only way to disable logging for a domain entirely is to
omit the domain from the "domains" list. For example:

  "level=INFO, domains=PLATFORM,..."

Now add an explicit level "OFF" to facilitate configuration like:

  "level=INFO, domains=ALL,WIFI_SCAN:OFF"

It also supports
  "level=OFF, domains=PLATFORM:INFO"
but this is for the most part equivalent to
  "level=INFO, domains=PLATFORM"

4 files changed, 16 insertions, 9 deletions

diff --git a/clients/cli/nmcli-completion b/clients/cli/nmcli-completion
index eb352d5269..4a55f3dbc6 100644
--- a/clients/cli/nmcli-completion
+++ b/clients/cli/nmcli-completion
@@ -306,7 +306,7 @@ _nmcli_compl_ARGS()
         case "${words[0]}" in
             level)
                 if [[ "${#words[@]}" -eq 2 ]]; then
-                    _nmcli_list "ERR WARN INFO DEBUG TRACE"
+                    _nmcli_list "OFF ERR WARN INFO DEBUG TRACE"
                    return 0
                 fi
                 ;;
diff --git a/man/NetworkManager.conf.xml.in b/man/NetworkManager.conf.xml.in
index 850e772fc1..30faab4d54 100644
--- a/man/NetworkManager.conf.xml.in
+++ b/man/NetworkManager.conf.xml.in
@@ -396,7 +396,7 @@ unmanaged-devices=mac:00:22:68:1c:59:b1;mac:00:1E:65:30:D1:C4;interface-name:eth
 	<varlistentry>
 	  <term><varname>level</varname></term>
 	  <listitem><para>The default logging verbosity level.
-	  One of <literal>ERR</literal>,
+	  One of <literal>OFF</literal>, <literal>ERR</literal>,
 	  <literal>WARN</literal>, <literal>INFO</literal>,
 	  <literal>DEBUG</literal>, <literal>TRACE</literal>.  The ERR
 	  level logs only critical errors.  WARN logs warnings that may
@@ -419,7 +419,7 @@ unmanaged-devices=mac:00:22:68:1c:59:b1;mac:00:1E:65:30:D1:C4;interface-name:eth
 	  ALL, DEFAULT, DHCP, IP.</para>
 	  <para>You can specify per-domain log level overrides by
 	  adding a colon and a log level to any domain. E.g.,
-	  "<literal>WIFI:DEBUG</literal>".</para></listitem>
+	  "<literal>WIFI:DEBUG,WIFI_SCAN:OFF</literal>".</para></listitem>
 	</varlistentry>
 	<varlistentry>
           <para>Domain descriptions:
diff --git a/src/nm-logging.c b/src/nm-logging.c
index a98972caa4..2398e8ae73 100644
--- a/src/nm-logging.c
+++ b/src/nm-logging.c
@@ -53,7 +53,7 @@ nm_log_handler (const gchar *log_domain,
 
 static NMLogLevel log_level = LOGL_INFO;
 static char *log_domains;
-static NMLogDomain logging[_LOGL_N];
+static NMLogDomain logging[_LOGL_N_REAL];
 static gboolean logging_set_up;
 enum {
 	LOG_BACKEND_GLIB,
@@ -82,6 +82,7 @@ static const LogLevelDesc level_desc[_LOGL_N] = {
 	[LOGL_INFO]  = { "INFO",  "<info>",  LOG_INFO,    G_LOG_LEVEL_MESSAGE, FALSE },
 	[LOGL_WARN]  = { "WARN",  "<warn>",  LOG_WARNING, G_LOG_LEVEL_WARNING, FALSE },
 	[LOGL_ERR]   = { "ERR",   "<error>", LOG_ERR,     G_LOG_LEVEL_WARNING, TRUE  },
+	[_LOGL_OFF]  = { "OFF",   NULL,      0,           0,                   FALSE },
 };
 
 static const LogDesc domain_descs[] = {
@@ -253,10 +254,12 @@ nm_logging_setup (const char  *level,
 			continue;
 		}
 
-		for (i = 0; i < domain_log_level; i++)
-			new_logging[i] &= ~bits;
-		for (i = domain_log_level; i < _LOGL_N; i++)
-			new_logging[i] |= bits;
+		for (i = 0; i < G_N_ELEMENTS (new_logging); i++) {
+			if (i < domain_log_level)
+				new_logging[i] &= ~bits;
+			else
+				new_logging[i] |= bits;
+		}
 	}
 	g_strfreev (tmp);
 
diff --git a/src/nm-logging.h b/src/nm-logging.h
index 9fbe62721d..a346a7a657 100644
--- a/src/nm-logging.h
+++ b/src/nm-logging.h
@@ -90,7 +90,11 @@ typedef enum  { /*< skip >*/
 	LOGL_WARN,
 	LOGL_ERR,
 
-	_LOGL_N, /* the number of logging levels */
+	_LOGL_N_REAL, /* the number of actual logging levels */
+
+	_LOGL_OFF = _LOGL_N_REAL, /* special logging level that is always disabled. */
+
+	_LOGL_N, /* the number of logging levels including "OFF" */
 } NMLogLevel;
 
 #define nm_log_err(domain, ...)     nm_log (LOGL_ERR,   (domain), __VA_ARGS__)