[PATCH v2 04/13] iptables: Fix chain tail handling

[Daniel Wagner]

From: Daniel Wagner <daniel.wag...@bmw-carit.de>

find_chain_tail() returns the list element after the chain end.
If we return the real last element of the chain we can simplify
the code considerable.

This allows a simple bug fix in the next patch.
---
 src/iptables.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/iptables.c b/src/iptables.c
index 088168a..fe568ad 100644
--- a/src/iptables.c
+++ b/src/iptables.c
@@ -376,7 +376,7 @@ static GList *find_chain_head(struct connman_iptables 
*table,
 static GList *find_chain_tail(struct connman_iptables *table,
                                const char *chain_name)
 {
-       struct connman_iptables_entry *tail;
+       struct connman_iptables_entry *entry;
        GList *chain_head, *list;
 
        chain_head = find_chain_head(table, chain_name);
@@ -385,10 +385,12 @@ static GList *find_chain_tail(struct connman_iptables 
*table,
 
        /* Then we look for the next chain */
        for (list = chain_head->next; list; list = list->next) {
-               tail = list->data;
+               entry = list->data;
+
+               if (is_chain(table, entry) == FALSE)
+                       continue;
 
-               if (is_chain(table, tail))
-                       return list;
+               return g_list_previous(list);
        }
 
        /* Nothing found, we return the table end */
@@ -529,6 +531,10 @@ static int iptables_flush_chain(struct connman_iptables 
*table,
        if (chain_tail == NULL)
                return -EINVAL;
 
+       /* Is chain already emtpy ?*/
+       if (chain_head == chain_tail)
+               return 0;
+
        entry = chain_head->data;
        builtin = entry->builtin;
 
@@ -537,10 +543,7 @@ static int iptables_flush_chain(struct connman_iptables 
*table,
        else
                list = chain_head->next;
 
-       if (list == chain_tail->prev)
-               return 0;
-
-       while (list != chain_tail->prev) {
+       while (list != chain_tail) {
                entry = list->data;
                next = g_list_next(list);
 
@@ -666,13 +669,10 @@ static int iptables_delete_chain(struct connman_iptables 
*table,
        if (chain_tail == NULL)
                return -EINVAL;
 
-       /* Chain must be flushed */
-       if (chain_head->next != chain_tail->prev)
-               return -EINVAL;
-
+       entry = chain_head->data;
        remove_table_entry(table, entry);
 
-       entry = chain_tail->prev->data;
+       entry = chain_tail->data;
        remove_table_entry(table, entry);
 
        update_offsets(table);
-- 
1.8.1.3.566.gaa39828

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