iptables: add capability to check for an existing rule

diff --git a/src/iptables.c b/src/iptables.c
index 3767e48..5b6b590 100644 (file)
--- a/src/iptables.c
+++ b/src/iptables.c
@@ -902,6 +902,28 @@ static int iptables_delete_rule(struct connman_iptables *table,
        return 0;
 }
 
+static int iptables_compare_rule(struct connman_iptables *table,
+                               struct ipt_ip *ip, char *chain_name,
+                               char *target_name, struct xtables_target *xt_t,
+                               struct xtables_match *xt_m,
+                               struct xtables_rule_match *xt_rm)
+{
+       struct connman_iptables_entry *entry;
+       GList *found;
+
+       found = find_existing_rule(table, ip, chain_name, target_name,
+                                                       xt_t, xt_m, xt_rm);
+       if (found == NULL)
+               return -EINVAL;
+
+       entry = found->data;
+       if (entry == NULL)
+               return -EINVAL;
+
+       return 0;
+}
+
+
 static int iptables_change_policy(struct connman_iptables *table,
                                        char *chain_name, char *policy)
 {
@@ -1277,6 +1299,7 @@ err:
 
 static struct option iptables_opts[] = {
        {.name = "append",        .has_arg = 1, .val = 'A'},
+       {.name = "compare",       .has_arg = 1, .val = 'C'},
        {.name = "delete",        .has_arg = 1, .val = 'D'},
        {.name = "flush-chain",   .has_arg = 1, .val = 'F'},
        {.name = "insert",        .has_arg = 1, .val = 'I'},
@@ -1453,7 +1476,7 @@ static int iptables_command(int argc, char *argv[])
        char *table_name, *chain, *new_chain, *match_name, *target_name;
        char *flush_chain, *delete_chain, *policy;
        int c, ret, in_len, out_len;
-       gboolean dump, invert, insert, delete;
+       gboolean dump, invert, insert, delete, compare;
        struct in_addr src, dst;
 
        if (argc == 0)
@@ -1463,6 +1486,7 @@ static int iptables_command(int argc, char *argv[])
        invert = FALSE;
        insert = FALSE;
        delete = FALSE;
+       compare = FALSE;
        table_name = chain = new_chain = match_name = target_name = NULL;
        flush_chain = delete_chain = policy = NULL;
        memset(&ip, 0, sizeof(struct ipt_ip));
@@ -1477,19 +1501,29 @@ static int iptables_command(int argc, char *argv[])
 
        optind = 0;
 
-       while ((c = getopt_long(argc, argv, "-A:F:I:L::N:P:X:d:j:i:m:o:s:t:",
+       while ((c = getopt_long(argc, argv,
+                                       "-A:C:D:F:I:L::N:P:X:d:j:i:m:o:s:t:",
                                        iptables_globals.opts, NULL)) != -1) {
                switch (c) {
                case 'A':
-                       /* It is either -A, -D or -I at once */
+                       /* It is either -A, -C, -D or -I at once */
                        if (chain)
                                goto out;
 
                        chain = optarg;
                        break;
 
+               case 'C':
+                       /* It is either -A, -C, -D or -I at once */
+                       if (chain)
+                               goto out;
+
+                       chain = optarg;
+                       compare = TRUE;
+                       break;
+
                case 'D':
-                       /* It is either -A, -D or -I at once */
+                       /* It is either -A, -C, -D or -I at once */
                        if (chain)
                                goto out;
 
@@ -1502,7 +1536,7 @@ static int iptables_command(int argc, char *argv[])
                        break;
 
                case 'I':
-                       /* It is either -A, -D or -I at once */
+                       /* It is either -A, -C, -D or -I at once */
                        if (chain)
                                goto out;
 
@@ -1755,6 +1789,12 @@ static int iptables_command(int argc, char *argv[])
                if (xt_t == NULL)
                        goto out;
 
+               if (compare == TRUE) {
+                       ret = iptables_compare_rule(table, &ip, chain,
+                                       target_name, xt_t, xt_m, xt_rm);
+                       goto out;
+               }
+
                if (delete == TRUE) {
                        DBG("Deleting %s to %s (match %s)\n",
                                        target_name, chain, match_name);