bgp: T3759: "l2vpn evpn" and ipv4/ipv6 safi route-targets differ

The "l2vpn evpn" address-family route-target command only accepts a single
route-target value consisting of (A.B.C.D:MN|EF:OPQR|GHJK:MN). The
"ipv4-unicast or ipv6-unicast" address-family route-target command for VPNs
support multiple, whitespace separated route-target values.

This commit adds a new custom validator named "bgp-route-target" with a --single
and a --multi option to pass one or more route-target values.

7 files changed, 141 insertions, 62 deletions

diff --git a/interface-definitions/include/bgp/afi-l2vpn-common.xml.i b/interface-definitions/include/bgp/afi-l2vpn-common.xml.i
index a9a833851..8deb189ab 100644
--- a/interface-definitions/include/bgp/afi-l2vpn-common.xml.i
+++ b/interface-definitions/include/bgp/afi-l2vpn-common.xml.i
@@ -17,9 +17,42 @@
     <help>Route Target</help>
   </properties>
   <children>
-    #include <include/bgp/route-target-both.xml.i>
-    #include <include/bgp/route-target-export.xml.i>
-    #include <include/bgp/route-target-import.xml.i>
+    <leafNode name="both">
+      <properties>
+        <help>Route Target both import and export</help>
+        <valueHelp>
+          <format>txt</format>
+          <description>Route target (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+        </valueHelp>
+        <constraint>
+          <validator name="bgp-route-target" argument="--single"/>
+        </constraint>
+      </properties>
+    </leafNode>
+    <leafNode name="import">
+      <properties>
+        <help>Route Target import</help>
+        <valueHelp>
+          <format>txt</format>
+          <description>Route target (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+        </valueHelp>
+        <constraint>
+          <validator name="bgp-route-target" argument="--single"/>
+        </constraint>
+      </properties>
+    </leafNode>
+    <leafNode name="export">
+      <properties>
+        <help>Route Target export</help>
+        <valueHelp>
+          <format>txt</format>
+          <description>Route target (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+        </valueHelp>
+        <constraint>
+          <validator name="bgp-route-target" argument="--single"/>
+        </constraint>
+      </properties>
+    </leafNode>
   </children>
 </node>
 <!-- include end -->
diff --git a/interface-definitions/include/bgp/afi-route-target-vpn.xml.i b/interface-definitions/include/bgp/afi-route-target-vpn.xml.i
new file mode 100644
index 000000000..1dc184a02
--- /dev/null
+++ b/interface-definitions/include/bgp/afi-route-target-vpn.xml.i
@@ -0,0 +1,52 @@
+<!-- include start from bgp/route-target-both.xml.i -->
+<node name="route-target">
+  <properties>
+    <help>Specify route distinguisher</help>
+  </properties>
+  <children>
+    <node name="vpn">
+      <properties>
+        <help>Between current address-family and VPN</help>
+      </properties>
+      <children>
+        <leafNode name="both">
+          <properties>
+            <help>Route Target both import and export</help>
+            <valueHelp>
+              <format>txt</format>
+              <description>Space separated route target list (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+            </valueHelp>
+            <constraint>
+              <validator name="bgp-route-target" argument="--multi"/>
+            </constraint>
+          </properties>
+        </leafNode>
+        <leafNode name="import">
+          <properties>
+            <help>Route Target import</help>
+            <valueHelp>
+              <format>txt</format>
+              <description>Space separated route target list (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+            </valueHelp>
+            <constraint>
+              <validator name="bgp-route-target" argument="--multi"/>
+            </constraint>
+          </properties>
+        </leafNode>
+        <leafNode name="export">
+          <properties>
+            <help>Route Target export</help>
+            <valueHelp>
+              <format>txt</format>
+              <description>Space separated route target list (A.B.C.D:MN|EF:OPQR|GHJK:MN)</description>
+            </valueHelp>
+            <constraint>
+              <validator name="bgp-route-target" argument="--multi"/>
+            </constraint>
+          </properties>
+        </leafNode>
+      </children>
+    </node>
+  </children>
+</node>
+<!-- include end -->
diff --git a/interface-definitions/include/bgp/protocol-common-config.xml.i b/interface-definitions/include/bgp/protocol-common-config.xml.i
index a971c52b8..2b22bac7d 100644
--- a/interface-definitions/include/bgp/protocol-common-config.xml.i
+++ b/interface-definitions/include/bgp/protocol-common-config.xml.i
@@ -119,23 +119,7 @@
         </tagNode>
         #include <include/bgp/afi-rd.xml.i>
         #include <include/bgp/afi-route-map-vpn.xml.i>
-        <node name="route-target">
-          <properties>
-            <help>Specify route distinguisher</help>
-          </properties>
-          <children>
-            <node name="vpn">
-              <properties>
-                <help>Between current address-family and VPN</help>
-              </properties>
-              <children>
-                #include <include/bgp/route-target-both.xml.i>
-                #include <include/bgp/route-target-export.xml.i>
-                #include <include/bgp/route-target-import.xml.i>
-              </children>
-            </node>
-          </children>
-        </node>
+        #include <include/bgp/afi-route-target-vpn.xml.i>
         <node name="redistribute">
           <properties>
             <help>Redistribute routes from other protocols into BGP</help>
@@ -520,6 +504,7 @@
         </tagNode>
         #include <include/bgp/afi-rd.xml.i>
         #include <include/bgp/afi-route-map-vpn.xml.i>
+        #include <include/bgp/afi-route-target-vpn.xml.i>
         <node name="redistribute">
           <properties>
             <help>Redistribute routes from other protocols into BGP</help>
diff --git a/interface-definitions/include/bgp/route-target-both.xml.i b/interface-definitions/include/bgp/route-target-both.xml.i
deleted file mode 100644
index d77878812..000000000
--- a/interface-definitions/include/bgp/route-target-both.xml.i
+++ /dev/null
@@ -1,14 +0,0 @@
-<!-- include start from bgp/route-target-both.xml.i -->
-<leafNode name="both">
-  <properties>
-    <help>Route Target both import and export</help>
-    <valueHelp>
-      <format>txt</format>
-      <description>Route target (x.x.x.x:yyy|xxxx:yyyy)</description>
-    </valueHelp>
-    <constraint>
-      <regex>^((25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)(\.(25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)){3}|[0-9]{1,10}):[0-9]{1,5}$</regex>
-    </constraint>
-  </properties>
-</leafNode>
-<!-- include end -->
diff --git a/interface-definitions/include/bgp/route-target-export.xml.i b/interface-definitions/include/bgp/route-target-export.xml.i
deleted file mode 100644
index 0431f0fcb..000000000
--- a/interface-definitions/include/bgp/route-target-export.xml.i
+++ /dev/null
@@ -1,14 +0,0 @@
-<!-- include start from bgp/route-target-export.xml.i -->
-<leafNode name="export">
-  <properties>
-    <help>Route Target export</help>
-    <valueHelp>
-      <format>txt</format>
-      <description>Route target (x.x.x.x:yyy|xxxx:yyyy)</description>
-    </valueHelp>
-    <constraint>
-      <regex>^((25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)(\.(25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)){3}|[0-9]{1,10}):[0-9]{1,5}$</regex>
-    </constraint>
-  </properties>
-</leafNode>
-<!-- include end -->
diff --git a/interface-definitions/include/bgp/route-target-import.xml.i b/interface-definitions/include/bgp/route-target-import.xml.i
deleted file mode 100644
index aa861c428..000000000
--- a/interface-definitions/include/bgp/route-target-import.xml.i
+++ /dev/null
@@ -1,14 +0,0 @@
-<!-- include start from bgp/route-target-import.xml.i -->
-<leafNode name="import">
-  <properties>
-    <help>Route Target import</help>
-    <valueHelp>
-      <format>txt</format>
-      <description>Route target (x.x.x.x:yyy|xxxx:yyyy)</description>
-    </valueHelp>
-    <constraint>
-      <regex>^((25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)(\.(25[0-5]|2[0-4][0-9]|[1][0-9][0-9]|[1-9][0-9]|[0-9]?)){3}|[0-9]{1,10}):[0-9]{1,5}$</regex>
-    </constraint>
-  </properties>
-</leafNode>
-<!-- include end -->
diff --git a/src/validators/bgp-route-target b/src/validators/bgp-route-target
new file mode 100755
index 000000000..e7e4d403f
--- /dev/null
+++ b/src/validators/bgp-route-target
@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from argparse import ArgumentParser
+from vyos.template import is_ipv4
+
+parser = ArgumentParser()
+group = parser.add_mutually_exclusive_group()
+group.add_argument('--single', action='store', help='Validate and allow only one route-target')
+group.add_argument('--multi', action='store', help='Validate multiple, whitespace separated route-targets')
+args = parser.parse_args()
+
+def is_valid_rt(rt):
+    # every route target needs to have a colon and must consists of two parts
+    value = rt.split(':')
+    if len(value) != 2:
+        return False
+    # A route target must either be only numbers, or the first part must be an
+    # IPv4 address
+    if (is_ipv4(value[0]) or value[0].isdigit()) and value[1].isdigit():
+        return True
+    return False
+
+if __name__ == '__main__':
+    if args.single:
+        if not is_valid_rt(args.single):
+            exit(1)
+
+    elif args.multi:
+        for rt in args.multi.split(' '):
+            if not is_valid_rt(rt):
+                exit(1)
+
+    else:
+        parser.print_help()
+        exit(1)
+
+    exit(0)