]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - net/netfilter/nf_tables_api.c
Merge remote-tracking branch 'gpio/for-next'
[karo-tx-linux.git] / net / netfilter / nf_tables_api.c
index 0f140663ec71b2133108d07af3506a2c5e89edbd..dcddc49c0e08363044195695138543e4277f83f0 100644 (file)
@@ -978,6 +978,8 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
 
        INIT_LIST_HEAD(&chain->rules);
        chain->handle = nf_tables_alloc_handle(table);
+       chain->net = net;
+       chain->table = table;
        nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN);
 
        if (!(table->flags & NFT_TABLE_F_DORMANT) &&
@@ -1371,6 +1373,41 @@ err:
        return err;
 }
 
+static inline bool
+nft_rule_is_active(struct net *net, const struct nft_rule *rule)
+{
+       return (rule->genmask & (1 << net->nft.gencursor)) == 0;
+}
+
+static inline int gencursor_next(struct net *net)
+{
+       return net->nft.gencursor+1 == 1 ? 1 : 0;
+}
+
+static inline int
+nft_rule_is_active_next(struct net *net, const struct nft_rule *rule)
+{
+       return (rule->genmask & (1 << gencursor_next(net))) == 0;
+}
+
+static inline void
+nft_rule_activate_next(struct net *net, struct nft_rule *rule)
+{
+       /* Now inactive, will be active in the future */
+       rule->genmask = (1 << net->nft.gencursor);
+}
+
+static inline void
+nft_rule_disactivate_next(struct net *net, struct nft_rule *rule)
+{
+       rule->genmask = (1 << gencursor_next(net));
+}
+
+static inline void nft_rule_clear(struct net *net, struct nft_rule *rule)
+{
+       rule->genmask = 0;
+}
+
 static int nf_tables_dump_rules(struct sk_buff *skb,
                                struct netlink_callback *cb)
 {
@@ -1382,6 +1419,8 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
        unsigned int idx = 0, s_idx = cb->args[0];
        struct net *net = sock_net(skb->sk);
        int family = nfmsg->nfgen_family;
+       u8 genctr = ACCESS_ONCE(net->nft.genctr);
+       u8 gencursor = ACCESS_ONCE(net->nft.gencursor);
 
        list_for_each_entry(afi, &net->nft.af_info, list) {
                if (family != NFPROTO_UNSPEC && family != afi->family)
@@ -1390,6 +1429,8 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
                list_for_each_entry(table, &afi->tables, list) {
                        list_for_each_entry(chain, &table->chains, list) {
                                list_for_each_entry(rule, &chain->rules, list) {
+                                       if (!nft_rule_is_active(net, rule))
+                                               goto cont;
                                        if (idx < s_idx)
                                                goto cont;
                                        if (idx > s_idx)
@@ -1408,6 +1449,10 @@ cont:
                }
        }
 done:
+       /* Invalidate this dump, a transition to the new generation happened */
+       if (gencursor != net->nft.gencursor || genctr != net->nft.genctr)
+               return -EBUSY;
+
        cb->args[0] = idx;
        return skb->len;
 }
@@ -1492,6 +1537,25 @@ static void nf_tables_rule_destroy(struct nft_rule *rule)
 
 static struct nft_expr_info *info;
 
+static struct nft_rule_trans *
+nf_tables_trans_add(struct nft_rule *rule, const struct nft_ctx *ctx)
+{
+       struct nft_rule_trans *rupd;
+
+       rupd = kmalloc(sizeof(struct nft_rule_trans), GFP_KERNEL);
+       if (rupd == NULL)
+              return NULL;
+
+       rupd->chain = ctx->chain;
+       rupd->table = ctx->table;
+       rupd->rule = rule;
+       rupd->family = ctx->afi->family;
+       rupd->nlh = ctx->nlh;
+       list_add_tail(&rupd->list, &ctx->net->nft.commit_list);
+
+       return rupd;
+}
+
 static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
                             const struct nlmsghdr *nlh,
                             const struct nlattr * const nla[])
@@ -1502,6 +1566,7 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
        struct nft_table *table;
        struct nft_chain *chain;
        struct nft_rule *rule, *old_rule = NULL;
+       struct nft_rule_trans *repl = NULL;
        struct nft_expr *expr;
        struct nft_ctx ctx;
        struct nlattr *tmp;
@@ -1576,6 +1641,8 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
        if (rule == NULL)
                goto err1;
 
+       nft_rule_activate_next(net, rule);
+
        rule->handle = handle;
        rule->dlen   = size;
 
@@ -1589,8 +1656,18 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
        }
 
        if (nlh->nlmsg_flags & NLM_F_REPLACE) {
-               list_replace_rcu(&old_rule->list, &rule->list);
-               nf_tables_rule_destroy(old_rule);
+               if (nft_rule_is_active_next(net, old_rule)) {
+                       repl = nf_tables_trans_add(old_rule, &ctx);
+                       if (repl == NULL) {
+                               err = -ENOMEM;
+                               goto err2;
+                       }
+                       nft_rule_disactivate_next(net, old_rule);
+                       list_add_tail(&rule->list, &old_rule->list);
+               } else {
+                       err = -ENOENT;
+                       goto err2;
+               }
        } else if (nlh->nlmsg_flags & NLM_F_APPEND)
                if (old_rule)
                        list_add_rcu(&rule->list, &old_rule->list);
@@ -1603,11 +1680,20 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
                        list_add_rcu(&rule->list, &chain->rules);
        }
 
-       nf_tables_rule_notify(skb, nlh, table, chain, rule, NFT_MSG_NEWRULE,
-                             nlh->nlmsg_flags & (NLM_F_APPEND | NLM_F_REPLACE),
-                             nfmsg->nfgen_family);
+       if (nf_tables_trans_add(rule, &ctx) == NULL) {
+               err = -ENOMEM;
+               goto err3;
+       }
        return 0;
 
+err3:
+       list_del_rcu(&rule->list);
+       if (repl) {
+               list_del_rcu(&repl->rule->list);
+               list_del(&repl->list);
+               nft_rule_clear(net, repl->rule);
+               kfree(repl);
+       }
 err2:
        nf_tables_rule_destroy(rule);
 err1:
@@ -1618,6 +1704,19 @@ err1:
        return err;
 }
 
+static int
+nf_tables_delrule_one(struct nft_ctx *ctx, struct nft_rule *rule)
+{
+       /* You cannot delete the same rule twice */
+       if (nft_rule_is_active_next(ctx->net, rule)) {
+               if (nf_tables_trans_add(rule, ctx) == NULL)
+                       return -ENOMEM;
+               nft_rule_disactivate_next(ctx->net, rule);
+               return 0;
+       }
+       return -ENOENT;
+}
+
 static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
                             const struct nlmsghdr *nlh,
                             const struct nlattr * const nla[])
@@ -1628,7 +1727,8 @@ static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
        const struct nft_table *table;
        struct nft_chain *chain;
        struct nft_rule *rule, *tmp;
-       int family = nfmsg->nfgen_family;
+       int family = nfmsg->nfgen_family, err = 0;
+       struct nft_ctx ctx;
 
        afi = nf_tables_afinfo_lookup(net, family, false);
        if (IS_ERR(afi))
@@ -1642,31 +1742,95 @@ static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
        if (IS_ERR(chain))
                return PTR_ERR(chain);
 
+       nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
+
        if (nla[NFTA_RULE_HANDLE]) {
                rule = nf_tables_rule_lookup(chain, nla[NFTA_RULE_HANDLE]);
                if (IS_ERR(rule))
                        return PTR_ERR(rule);
 
-               /* List removal must be visible before destroying expressions */
-               list_del_rcu(&rule->list);
-
-               nf_tables_rule_notify(skb, nlh, table, chain, rule,
-                                     NFT_MSG_DELRULE, 0, family);
-               nf_tables_rule_destroy(rule);
+               err = nf_tables_delrule_one(&ctx, rule);
        } else {
                /* Remove all rules in this chain */
                list_for_each_entry_safe(rule, tmp, &chain->rules, list) {
-                       list_del_rcu(&rule->list);
+                       err = nf_tables_delrule_one(&ctx, rule);
+                       if (err < 0)
+                               break;
+               }
+       }
+
+       return err;
+}
+
+static int nf_tables_commit(struct sk_buff *skb)
+{
+       struct net *net = sock_net(skb->sk);
+       struct nft_rule_trans *rupd, *tmp;
 
-                       nf_tables_rule_notify(skb, nlh, table, chain, rule,
-                                             NFT_MSG_DELRULE, 0, family);
-                       nf_tables_rule_destroy(rule);
+       /* Bump generation counter, invalidate any dump in progress */
+       net->nft.genctr++;
+
+       /* A new generation has just started */
+       net->nft.gencursor = gencursor_next(net);
+
+       /* Make sure all packets have left the previous generation before
+        * purging old rules.
+        */
+       synchronize_rcu();
+
+       list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
+               /* Delete this rule from the dirty list */
+               list_del(&rupd->list);
+
+               /* This rule was inactive in the past and just became active.
+                * Clear the next bit of the genmask since its meaning has
+                * changed, now it is the future.
+                */
+               if (nft_rule_is_active(net, rupd->rule)) {
+                       nft_rule_clear(net, rupd->rule);
+                       nf_tables_rule_notify(skb, rupd->nlh, rupd->table,
+                                             rupd->chain, rupd->rule,
+                                             NFT_MSG_NEWRULE, 0,
+                                             rupd->family);
+                       kfree(rupd);
+                       continue;
                }
+
+               /* This rule is in the past, get rid of it */
+               list_del_rcu(&rupd->rule->list);
+               nf_tables_rule_notify(skb, rupd->nlh, rupd->table, rupd->chain,
+                                     rupd->rule, NFT_MSG_DELRULE, 0,
+                                     rupd->family);
+               nf_tables_rule_destroy(rupd->rule);
+               kfree(rupd);
        }
 
        return 0;
 }
 
+static int nf_tables_abort(struct sk_buff *skb)
+{
+       struct net *net = sock_net(skb->sk);
+       struct nft_rule_trans *rupd, *tmp;
+
+       list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
+               /* Delete all rules from the dirty list */
+               list_del(&rupd->list);
+
+               if (!nft_rule_is_active_next(net, rupd->rule)) {
+                       nft_rule_clear(net, rupd->rule);
+                       kfree(rupd);
+                       continue;
+               }
+
+               /* This rule is inactive, get rid of it */
+               list_del_rcu(&rupd->rule->list);
+               nf_tables_rule_destroy(rupd->rule);
+               kfree(rupd);
+       }
+       return 0;
+}
+
 /*
  * Sets
  */
@@ -2634,7 +2798,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
                .policy         = nft_chain_policy,
        },
        [NFT_MSG_NEWRULE] = {
-               .call           = nf_tables_newrule,
+               .call_batch     = nf_tables_newrule,
                .attr_count     = NFTA_RULE_MAX,
                .policy         = nft_rule_policy,
        },
@@ -2644,7 +2808,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
                .policy         = nft_rule_policy,
        },
        [NFT_MSG_DELRULE] = {
-               .call           = nf_tables_delrule,
+               .call_batch     = nf_tables_delrule,
                .attr_count     = NFTA_RULE_MAX,
                .policy         = nft_rule_policy,
        },
@@ -2685,6 +2849,8 @@ static const struct nfnetlink_subsystem nf_tables_subsys = {
        .subsys_id      = NFNL_SUBSYS_NFTABLES,
        .cb_count       = NFT_MSG_MAX,
        .cb             = nf_tables_cb,
+       .commit         = nf_tables_commit,
+       .abort          = nf_tables_abort,
 };
 
 /*
@@ -3056,6 +3222,7 @@ EXPORT_SYMBOL_GPL(nft_data_dump);
 static int nf_tables_init_net(struct net *net)
 {
        INIT_LIST_HEAD(&net->nft.af_info);
+       INIT_LIST_HEAD(&net->nft.commit_list);
        return 0;
 }