Add test for converting network XML to iptables rules

Using the virCommand dry run capability, capture iptables rules
created by various network XML documents.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

tests/testutils.c

@@ -855,6 +855,57 @@ int virtTestClearLineRegex(const char *pattern,
 }
 
 
+/*
+ * @cmdset contains a list of command line args, eg
+ *
+ * "/usr/sbin/iptables --table filter --insert INPUT --in-interface virbr0 --protocol tcp --destination-port 53 --jump ACCEPT
+ *  /usr/sbin/iptables --table filter --insert INPUT --in-interface virbr0 --protocol udp --destination-port 53 --jump ACCEPT
+ *  /usr/sbin/iptables --table filter --insert FORWARD --in-interface virbr0 --jump REJECT
+ *  /usr/sbin/iptables --table filter --insert FORWARD --out-interface virbr0 --jump REJECT
+ *  /usr/sbin/iptables --table filter --insert FORWARD --in-interface virbr0 --out-interface virbr0 --jump ACCEPT"
+ *
+ * And we're munging it in-place to strip the path component
+ * of the command line, to produce
+ *
+ * "iptables --table filter --insert INPUT --in-interface virbr0 --protocol tcp --destination-port 53 --jump ACCEPT
+ *  iptables --table filter --insert INPUT --in-interface virbr0 --protocol udp --destination-port 53 --jump ACCEPT
+ *  iptables --table filter --insert FORWARD --in-interface virbr0 --jump REJECT
+ *  iptables --table filter --insert FORWARD --out-interface virbr0 --jump REJECT
+ *  iptables --table filter --insert FORWARD --in-interface virbr0 --out-interface virbr0 --jump ACCEPT"
+ */
+void virtTestClearCommandPath(char *cmdset)
+{
+    size_t offset = 0;
+    char *lineStart = cmdset;
+    char *lineEnd = strchr(lineStart, '\n');
+
+    while (lineStart) {
+        char *dirsep;
+        char *movestart;
+        size_t movelen;
+        dirsep = strchr(lineStart, ' ');
+        if (dirsep) {
+            while (dirsep > lineStart && *dirsep != '/')
+                dirsep--;
+            if (*dirsep == '/')
+                dirsep++;
+            movestart = dirsep;
+        } else {
+            movestart = lineStart;
+        }
+        movelen = lineEnd ? lineEnd - movestart : strlen(movestart);
+
+        if (movelen) {
+            memmove(cmdset + offset, movestart, movelen + 1);
+            offset += movelen + 1;
+        }
+        lineStart = lineEnd ? lineEnd + 1 : NULL;
+        lineEnd = lineStart ? strchr(lineStart, '\n') : NULL;
+    }
+    cmdset[offset] = '\0';
+}
+
+
 virCapsPtr virTestGenericCapsInit(void)
 {
     virCapsPtr caps;