From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Tue, 4 Feb 2020 07:42:50 +0000 (+0100)
Subject: network,udev: refuse .link and .network settings with no matches
X-Git-Tag: v245-rc1~19^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F14761%2Fhead;p=thirdparty%2Fsystemd.git

network,udev: refuse .link and .network settings with no matches

Two releases ago we started warning about this, and I think it is now to turn
this into a hard error. People get bitten by this every once in a while, and
there doesn't see to be any legitimate use case where the same .link or
.network files should be applied to _all_ interfaces, since in particular that
configuration would apply both to lo and any other interfaces. And if for
whatever reason that is actually desired, OriginalName=* or Name=* can be
easily added to silence the warning and achieve the effect.

(The case described in #12098 is particularly nasty: 'echo -n >foo.network'
creates a mask file, 'echo >foo.network' creates a "match all" file.)

Fixes #717, #12098 for realz now.
---

diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 4fd48be52a0..ed59584fd1f 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -164,10 +164,10 @@ int network_verify(Network *network) {
             strv_isempty(network->match_path) && strv_isempty(network->match_driver) &&
             strv_isempty(network->match_type) && strv_isempty(network->match_name) &&
             strv_isempty(network->match_property) && strv_isempty(network->match_ssid) && !network->conditions)
-                log_warning("%s: No valid settings found in the [Match] section. "
-                            "The file will match all interfaces. "
-                            "If that is intended, please add Name=* in the [Match] section.",
-                            network->filename);
+                return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
+                                         "%s: No valid settings found in the [Match] section, ignoring file. "
+                                         "To match all interfaces, add Name=* in the [Match] section.",
+                                         network->filename);
 
         /* skip out early if configuration does not match the environment */
         if (!condition_test_list(network->conditions, NULL, NULL, NULL))
diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c
index 4a44edfc014..dfe9b9f3130 100644
--- a/src/udev/net/link-config.c
+++ b/src/udev/net/link-config.c
@@ -165,11 +165,12 @@ int link_load_one(link_config_ctx *ctx, const char *filename) {
 
         if (set_isempty(link->match_mac) && set_isempty(link->match_permanent_mac) &&
             strv_isempty(link->match_path) && strv_isempty(link->match_driver) && strv_isempty(link->match_type) &&
-            strv_isempty(link->match_name) && strv_isempty(link->match_property) && !link->conditions)
-                log_warning("%s: No valid settings found in the [Match] section. "
-                            "The file will match all interfaces. "
-                            "If that is intended, please add OriginalName=* in the [Match] section.",
+            strv_isempty(link->match_name) && strv_isempty(link->match_property) && !link->conditions) {
+                log_warning("%s: No valid settings found in the [Match] section, ignoring file. "
+                            "To match all interfaces, add OriginalName=* in the [Match] section.",
                             filename);
+                return 0;
+        }
 
         if (!condition_test_list(link->conditions, NULL, NULL, NULL)) {
                 log_debug("%s: Conditions do not match the system environment, skipping.", filename);