From d1be257a85234f139c073f7c41f845065dd7246e Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Thu, 22 Nov 2012 13:33:23 +0100
Subject: [PATCH] util: refactor iptables command construction into multiple
 steps

Instead of creating an iptables command in one shot, do it in steps
so we can add conditional options like physdev and protocol.

This removes code duplication while keeping existing behaviour.

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
---
 src/util/iptables.c | 130 +++++++++++++++++++++++-----------------------------
 1 file changed, 58 insertions(+), 72 deletions(-)

diff --git a/src/util/iptables.c b/src/util/iptables.c
index 00a1c29..407ca3a 100644
--- a/src/util/iptables.c
+++ b/src/util/iptables.c
@@ -127,15 +127,10 @@ iptRulesNew(const char *table,
     return NULL;
 }
 
-static int ATTRIBUTE_SENTINEL
-iptablesAddRemoveRule(iptRules *rules, int family, int action,
-                      const char *arg, ...)
+static virCommandPtr
+iptablesCommandNew(iptRules *rules, int family, int action)
 {
-    va_list args;
-    int ret;
     virCommandPtr cmd = NULL;
-    const char *s;
-
 #if HAVE_FIREWALLD
     virIpTablesInitialize();
     if (firewall_cmd_path) {
@@ -152,16 +147,36 @@ iptablesAddRemoveRule(iptRules *rules, int family, int action,
 
     virCommandAddArgList(cmd, "--table", rules->table,
                          action == ADD ? "--insert" : "--delete",
-                         rules->chain, arg, NULL);
+                         rules->chain, NULL);
+    return cmd;
+}
+
+static int
+iptablesCommandRunAndFree(virCommandPtr cmd)
+{
+    int ret;
+    ret = virCommandRun(cmd, NULL);
+    virCommandFree(cmd);
+    return ret;
+}
+
+static int ATTRIBUTE_SENTINEL
+iptablesAddRemoveRule(iptRules *rules, int family, int action,
+                      const char *arg, ...)
+{
+    va_list args;
+    virCommandPtr cmd = NULL;
+    const char *s;
+
+    cmd = iptablesCommandNew(rules, family, action);
+    virCommandAddArg(cmd, arg);
 
     va_start(args, arg);
     while ((s = va_arg(args, const char *)))
         virCommandAddArg(cmd, s);
     va_end(args);
 
-    ret = virCommandRun(cmd, NULL);
-    virCommandFree(cmd);
-    return ret;
+    return iptablesCommandRunAndFree(cmd);
 }
 
 /**
@@ -370,28 +385,24 @@ iptablesForwardAllowOut(iptablesContext *ctx,
 {
     int ret;
     char *networkstr;
+    virCommandPtr cmd = NULL;
 
     if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
         return -1;
 
-    if (physdev && physdev[0]) {
-        ret = iptablesAddRemoveRule(ctx->forward_filter,
-                                    VIR_SOCKET_ADDR_FAMILY(netaddr),
-                                    action,
-                                    "--source", networkstr,
-                                    "--in-interface", iface,
-                                    "--out-interface", physdev,
-                                    "--jump", "ACCEPT",
-                                    NULL);
-    } else {
-        ret = iptablesAddRemoveRule(ctx->forward_filter,
-                                    VIR_SOCKET_ADDR_FAMILY(netaddr),
-                                    action,
-                                    "--source", networkstr,
-                                    "--in-interface", iface,
-                                    "--jump", "ACCEPT",
-                                    NULL);
-    }
+    cmd = iptablesCommandNew(ctx->forward_filter,
+                             VIR_SOCKET_ADDR_FAMILY(netaddr),
+                             action);
+    virCommandAddArgList(cmd,
+                         "--source", networkstr,
+			 "--in-interface", iface, NULL);
+
+    if (physdev && physdev[0])
+        virCommandAddArgList(cmd, "--out-interface", physdev, NULL);
+
+    virCommandAddArgList(cmd, "--jump", "ACCEPT", NULL);
+
+    ret = iptablesCommandRunAndFree(cmd);
     VIR_FREE(networkstr);
     return ret;
 }
@@ -797,6 +808,7 @@ iptablesForwardMasquerade(iptablesContext *ctx,
 {
     int ret;
     char *networkstr;
+    virCommandPtr cmd = NULL;
 
     if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
         return -1;
@@ -810,49 +822,23 @@ iptablesForwardMasquerade(iptablesContext *ctx,
         return -1;
     }
 
-    if (protocol && protocol[0]) {
-        if (physdev && physdev[0]) {
-            ret = iptablesAddRemoveRule(ctx->nat_postrouting,
-                                        AF_INET,
-                                        action,
-                                        "--source", networkstr,
-                                        "-p", protocol,
-                                        "!", "--destination", networkstr,
-                                        "--out-interface", physdev,
-                                        "--jump", "MASQUERADE",
-                                        "--to-ports", "1024-65535",
-                                        NULL);
-        } else {
-            ret = iptablesAddRemoveRule(ctx->nat_postrouting,
-                                        AF_INET,
-                                        action,
-                                        "--source", networkstr,
-                                        "-p", protocol,
-                                        "!", "--destination", networkstr,
-                                        "--jump", "MASQUERADE",
-                                        "--to-ports", "1024-65535",
-                                        NULL);
-        }
-    } else {
-        if (physdev && physdev[0]) {
-            ret = iptablesAddRemoveRule(ctx->nat_postrouting,
-                                        AF_INET,
-                                        action,
-                                        "--source", networkstr,
-                                        "!", "--destination", networkstr,
-                                        "--out-interface", physdev,
-                                        "--jump", "MASQUERADE",
-                                        NULL);
-        } else {
-            ret = iptablesAddRemoveRule(ctx->nat_postrouting,
-                                        AF_INET,
-                                        action,
-                                        "--source", networkstr,
-                                        "!", "--destination", networkstr,
-                                        "--jump", "MASQUERADE",
-                                        NULL);
-        }
-    }
+    cmd = iptablesCommandNew(ctx->nat_postrouting, AF_INET, action);
+    virCommandAddArgList(cmd, "--source", networkstr, NULL);
+
+    if (protocol && protocol[0])
+        virCommandAddArgList(cmd, "-p", protocol, NULL);
+
+    virCommandAddArgList(cmd, "!", "--destination", networkstr, NULL);
+
+    if (physdev && physdev[0])
+        virCommandAddArgList(cmd, "--out-interface", physdev, NULL);
+
+    virCommandAddArgList(cmd, "--jump", "MASQUERADE", NULL);
+
+    if (protocol && protocol[0])
+        virCommandAddArgList(cmd, "--to-ports", "1024-65535", NULL);
+
+    ret = iptablesCommandRunAndFree(cmd);
     VIR_FREE(networkstr);
     return ret;
 }
-- 
1.8.0.1