iptables: Refactoring how jumps are handled
[framework/connectivity/connman.git] / src / iptables.c
index 78ad210..48d7214 100644 (file)
@@ -315,10 +315,10 @@ static int iptables_add_entry(struct connman_iptables *table,
        entry_before = before->data;
 
        /*
-        * We've just insterted a new entry. All references before it
+        * We've just appended/insterted a new entry. All references
         * should be bumped accordingly.
         */
-       for (list = table->entries; list != before; list = list->next) {
+       for (list = table->entries; list; list = list->next) {
                tmp = list->data;
 
                if (!is_jump(tmp))
@@ -326,7 +326,7 @@ static int iptables_add_entry(struct connman_iptables *table,
 
                t = (struct xt_standard_target *)ipt_get_target(tmp->entry);
 
-               if (t->verdict >= entry_before->offset)
+               if (t->verdict > entry_before->offset)
                        t->verdict += entry->next_offset;
        }
 
@@ -517,13 +517,12 @@ static int iptables_delete_chain(struct connman_iptables *table, char *name)
 }
 
 static struct ipt_entry *
-new_rule(struct connman_iptables *table, struct ipt_ip *ip,
-               char *target_name, struct xtables_target *xt_t,
+new_rule(struct ipt_ip *ip, char *target_name,
+               struct xtables_target *xt_t,
                char *match_name, struct xtables_match *xt_m)
 {
        struct ipt_entry *new_entry;
        size_t match_size, target_size;
-       int is_builtin = is_builtin_target(target_name);
 
        if (xt_m)
                match_size = xt_m->m->u.match_size;
@@ -555,40 +554,8 @@ new_rule(struct connman_iptables *table, struct ipt_ip *ip,
        if (xt_t) {
                struct xt_entry_target *entry_target;
 
-               if (is_builtin) {
-                       struct xt_standard_target *target;
-
-                       target = (struct xt_standard_target *)(xt_t->t);
-                       strcpy(target->target.u.user.name, IPT_STANDARD_TARGET);
-                       target->verdict = target_to_verdict(target_name);
-               }
-
                entry_target = ipt_get_target(new_entry);
                memcpy(entry_target, xt_t->t, target_size);
-       } else {
-               struct connman_iptables_entry *target_rule;
-               struct xt_standard_target *target;
-               GList *chain_head;
-
-               /*
-                * This is a user defined target, i.e. a chain jump.
-                * We search for the chain head, and the target verdict
-                * is the first rule's offset on this chain.
-                * The offset is from the beginning of the table.
-                */
-
-               chain_head = find_chain_head(table, target_name);
-               if (chain_head == NULL || chain_head->next == NULL) {
-                       g_free(new_entry);
-                       return NULL;
-               }
-
-               target_rule = chain_head->next->data;
-
-               target = (struct xt_standard_target *)ipt_get_target(new_entry);
-               strcpy(target->target.u.user.name, IPT_STANDARD_TARGET);
-               target->target.u.user.target_size = target_size;
-               target->verdict = target_rule->offset;
        }
 
        return new_entry;
@@ -624,32 +591,27 @@ static void update_hooks(struct connman_iptables *table, GList *chain_head,
        }
 }
 
-static int
-iptables_add_rule(struct connman_iptables *table,
+static struct ipt_entry *prepare_rule_inclusion(struct connman_iptables *table,
                                struct ipt_ip *ip, char *chain_name,
                                char *target_name, struct xtables_target *xt_t,
-                               char *match_name, struct xtables_match *xt_m)
+                               char *match_name, struct xtables_match *xt_m,
+                               int *builtin)
 {
        GList *chain_tail, *chain_head;
        struct ipt_entry *new_entry;
        struct connman_iptables_entry *head;
-       int builtin = -1;
-
-       DBG("");
 
        chain_head = find_chain_head(table, chain_name);
        if (chain_head == NULL)
-               return -EINVAL;
+               return NULL;
 
        chain_tail = find_chain_tail(table, chain_name);
        if (chain_tail == NULL)
-               return -EINVAL;
+               return NULL;
 
-       new_entry = new_rule(table, ip,
-                               target_name, xt_t,
-                               match_name, xt_m);
+       new_entry = new_rule(ip, target_name, xt_t, match_name, xt_m);
        if (new_entry == NULL)
-               return -EINVAL;
+               return NULL;
 
        update_hooks(table, chain_head, new_entry);
 
@@ -660,13 +622,65 @@ iptables_add_rule(struct connman_iptables *table,
         */
        head = chain_head->data;
        if (head->builtin < 0)
-               builtin = -1;
+               *builtin = -1;
        else if (chain_head == chain_tail->prev) {
-               builtin = head->builtin;
+               *builtin = head->builtin;
                head->builtin = -1;
        }
 
-       return iptables_add_entry(table, new_entry, chain_tail->prev, builtin);
+       return new_entry;
+}
+
+static int iptables_append_rule(struct connman_iptables *table,
+                               struct ipt_ip *ip, char *chain_name,
+                               char *target_name, struct xtables_target *xt_t,
+                               char *match_name, struct xtables_match *xt_m)
+{
+       GList *chain_tail;
+       struct ipt_entry *new_entry;
+       int builtin = -1, ret;
+
+       DBG("");
+
+       chain_tail = find_chain_tail(table, chain_name);
+       if (chain_tail == NULL)
+               return -EINVAL;
+
+       new_entry = prepare_rule_inclusion(table, ip, chain_name,
+                       target_name, xt_t, match_name, xt_m, &builtin);
+       if (new_entry == NULL)
+               return -EINVAL;
+
+       ret = iptables_add_entry(table, new_entry, chain_tail->prev, builtin);
+       if (ret < 0)
+               g_free(new_entry);
+
+       return ret;
+}
+
+static int iptables_insert_rule(struct connman_iptables *table,
+                               struct ipt_ip *ip, char *chain_name,
+                               char *target_name, struct xtables_target *xt_t,
+                               char *match_name, struct xtables_match *xt_m)
+{
+       struct ipt_entry *new_entry;
+       int builtin = -1, ret;
+       GList *chain_head;
+
+       chain_head = find_chain_head(table, chain_name);
+       if (chain_head == NULL)
+               return -EINVAL;
+
+       new_entry = prepare_rule_inclusion(table, ip, chain_name,
+                       target_name, xt_t, match_name, xt_m, &builtin);
+       if (new_entry == NULL)
+               return -EINVAL;
+
+       ret = iptables_add_entry(table, new_entry, chain_head->next, builtin);
+       if (ret < 0)
+               g_free(new_entry);
+
+       return ret;
 }
 
 static struct ipt_replace *
@@ -997,9 +1011,75 @@ err:
        return NULL;
 }
 
+static struct xtables_target *prepare_target(struct connman_iptables *table,
+                                                       char *target_name)
+{
+       struct xtables_target *xt_t = NULL;
+       gboolean is_builtin, is_user_defined;
+       GList *chain_head = NULL;
+       size_t target_size;
+
+       is_builtin = FALSE;
+       is_user_defined = FALSE;
+
+       if (is_builtin_target(target_name))
+               is_builtin = TRUE;
+       else {
+               chain_head = find_chain_head(table, target_name);
+               if (chain_head != NULL && chain_head->next != NULL)
+                       is_user_defined = TRUE;
+       }
+
+       if (is_builtin || is_user_defined)
+               xt_t = xtables_find_target(IPT_STANDARD_TARGET,
+                                               XTF_LOAD_MUST_SUCCEED);
+       else
+               xt_t = xtables_find_target(target_name, XTF_TRY_LOAD);
+
+       if (xt_t == NULL)
+               return NULL;
+
+       target_size = ALIGN(sizeof(struct ipt_entry_target)) + xt_t->size;
+
+       xt_t->t = g_try_malloc0(target_size);
+       if (xt_t->t == NULL)
+               return NULL;
+
+       xt_t->t->u.target_size = target_size;
+
+       if (is_builtin || is_user_defined) {
+               struct xt_standard_target *target;
+
+               target = (struct xt_standard_target *)(xt_t->t);
+               strcpy(target->target.u.user.name, IPT_STANDARD_TARGET);
+
+               if (is_builtin == TRUE)
+                       target->verdict = target_to_verdict(target_name);
+               else if (is_user_defined == TRUE) {
+                       struct connman_iptables_entry *target_rule;
+
+                       if (chain_head == NULL) {
+                               g_free(xt_t->t);
+                               return NULL;
+                       }
+
+                       target_rule = chain_head->next->data;
+                       target->verdict = target_rule->offset;
+               }
+       } else {
+               strcpy(xt_t->t->u.user.name, target_name);
+               xt_t->t->u.user.revision = xt_t->revision;
+               if (xt_t->init != NULL)
+                       xt_t->init(xt_t->t);
+       }
+
+       return xt_t;
+}
+
 static struct option iptables_opts[] = {
        {.name = "append",        .has_arg = 1, .val = 'A'},
        {.name = "flush-chain",   .has_arg = 1, .val = 'F'},
+       {.name = "insert",        .has_arg = 1, .val = 'I'},
        {.name = "list",          .has_arg = 2, .val = 'L'},
        {.name = "new-chain",     .has_arg = 1, .val = 'N'},
        {.name = "delete-chain",  .has_arg = 1, .val = 'X'},
@@ -1029,7 +1109,7 @@ static int iptables_command(int argc, char *argv[])
        char *flush_chain, *delete_chain;
        int c, ret, in_len, out_len;
        size_t size;
-       gboolean dump, invert;
+       gboolean dump, invert, insert;
        struct in_addr src, dst;
 
        if (argc == 0)
@@ -1037,6 +1117,7 @@ static int iptables_command(int argc, char *argv[])
 
        dump = FALSE;
        invert = FALSE;
+       insert = FALSE;
        table_name = chain = new_chain = match_name = target_name = NULL;
        flush_chain = delete_chain = NULL;
        memset(&ip, 0, sizeof(struct ipt_ip));
@@ -1047,10 +1128,14 @@ static int iptables_command(int argc, char *argv[])
 
        optind = 0;
 
-       while ((c = getopt_long(argc, argv, "-A:F:L::N:X:d:j:i:m:o:s:t:",
+       while ((c = getopt_long(argc, argv, "-A:F:I:L::N: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 */
+                       if (chain)
+                               goto out;
+
                        chain = optarg;
                        break;
 
@@ -1058,6 +1143,15 @@ static int iptables_command(int argc, char *argv[])
                        flush_chain = optarg;
                        break;
 
+               case 'I':
+                       /* It is either -A, -D or -I at once */
+                       if (chain)
+                               goto out;
+
+                       chain = optarg;
+                       insert = TRUE;
+                       break;
+
                case 'L':
                        dump = TRUE;
                        break;
@@ -1098,33 +1192,6 @@ static int iptables_command(int argc, char *argv[])
 
                case 'j':
                        target_name = optarg;
-                       xt_t = xtables_find_target(target_name, XTF_TRY_LOAD);
-
-                       if (xt_t == NULL)
-                               break;
-
-                       size = ALIGN(sizeof(struct ipt_entry_target)) +
-                                                               xt_t->size;
-
-                       xt_t->t = g_try_malloc0(size);
-                       if (xt_t->t == NULL)
-                               goto out;
-                       xt_t->t->u.target_size = size;
-                       strcpy(xt_t->t->u.user.name, target_name);
-                       xt_t->t->u.user.revision = xt_t->revision;
-                       if (xt_t->init != NULL)
-                               xt_t->init(xt_t->t);
-                       iptables_globals.opts =
-                               xtables_merge_options(
-#if XTABLES_VERSION_CODE > 5
-                                                    iptables_globals.orig_opts,
-#endif
-                                                    iptables_globals.opts,
-                                                    xt_t->extra_opts,
-                                                    &xt_t->option_offset);
-                       if (iptables_globals.opts == NULL)
-                               goto out;
-
                        break;
 
                case 'm':
@@ -1260,16 +1327,38 @@ static int iptables_command(int argc, char *argv[])
        }
 
        if (chain) {
-               if (target_name == NULL)
-                       return -1;
+               xt_t = prepare_target(table, target_name);
+               if (xt_t == NULL)
+                       goto out;
+
+               iptables_globals.opts =
+                       xtables_merge_options(
+#if XTABLES_VERSION_CODE > 5
+                                       iptables_globals.orig_opts,
+#endif
+                                       iptables_globals.opts,
+                                       xt_t->extra_opts,
+                                       &xt_t->option_offset);
+               if (iptables_globals.opts == NULL)
+                       goto out;
 
-               DBG("Adding %s to %s (match %s)",
-                               target_name, chain, match_name);
+               if (insert == TRUE) {
+                       DBG("Inserting %s to %s (match %s)",
+                                       target_name, chain, match_name);
 
-               ret = iptables_add_rule(table, &ip, chain, target_name, xt_t,
-                                       match_name, xt_m);
+                       ret = iptables_insert_rule(table, &ip, chain,
+                                       target_name, xt_t, match_name, xt_m);
 
-               goto out;
+                       goto out;
+               } else {
+                       DBG("Adding %s to %s (match %s)",
+                                       target_name, chain, match_name);
+
+                       ret = iptables_append_rule(table, &ip, chain,
+                                       target_name, xt_t, match_name, xt_m);
+
+                       goto out;
+               }
        }
 
 out: