diff options
author | Pablo Neira Ayuso <pablo@netfilter.org> | 2020-06-30 20:21:36 +0300 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2020-07-04 02:22:14 +0300 |
commit | d0e2c7de92c7f2b3d355ad76b0bb9fc43d1beb87 (patch) | |
tree | aeb58859a40e1b8478a275c2fd534b5bf56cad10 | |
parent | 04b7db414490ea9254d0c1d8930ea9571f8ce9f0 (diff) | |
download | linux-d0e2c7de92c7f2b3d355ad76b0bb9fc43d1beb87.tar.xz |
netfilter: nf_tables: add NFT_CHAIN_BINDING
This new chain flag specifies that:
* the kernel dynamically allocates the chain name, if no chain name
is specified.
* If the immediate expression that refers to this chain is removed,
then this bound chain (and its content) is destroyed.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r-- | include/net/netfilter/nf_tables.h | 13 | ||||
-rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 1 | ||||
-rw-r--r-- | net/netfilter/nf_tables_api.c | 86 | ||||
-rw-r--r-- | net/netfilter/nft_immediate.c | 51 |
4 files changed, 138 insertions, 13 deletions
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 6d1e7da6e00a..822c26766330 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -899,6 +899,8 @@ static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule) return (void *)&rule->data[rule->dlen]; } +void nf_tables_rule_release(const struct nft_ctx *ctx, struct nft_rule *rule); + static inline void nft_set_elem_update_expr(const struct nft_set_ext *ext, struct nft_regs *regs, const struct nft_pktinfo *pkt) @@ -944,7 +946,8 @@ struct nft_chain { struct nft_table *table; u64 handle; u32 use; - u8 flags:6, + u8 flags:5, + bound:1, genmask:2; char *name; @@ -989,6 +992,14 @@ int nft_chain_validate_dependency(const struct nft_chain *chain, int nft_chain_validate_hooks(const struct nft_chain *chain, unsigned int hook_flags); +static inline bool nft_chain_is_bound(struct nft_chain *chain) +{ + return (chain->flags & NFT_CHAIN_BINDING) && chain->bound; +} + +void nft_chain_del(struct nft_chain *chain); +void nf_tables_chain_destroy(struct nft_ctx *ctx); + struct nft_stats { u64 bytes; u64 pkts; diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 2cf7cc3b50c1..e00b4ae6174e 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -187,6 +187,7 @@ enum nft_table_attributes { enum nft_chain_flags { NFT_CHAIN_BASE = (1 << 0), NFT_CHAIN_HW_OFFLOAD = (1 << 1), + NFT_CHAIN_BINDING = (1 << 2), }; /** diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a7cb9c07802b..b8a970dad213 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1056,6 +1056,9 @@ static int nft_flush_table(struct nft_ctx *ctx) if (!nft_is_active_next(ctx->net, chain)) continue; + if (nft_chain_is_bound(chain)) + continue; + ctx->chain = chain; err = nft_delrule_by_chain(ctx); @@ -1098,6 +1101,9 @@ static int nft_flush_table(struct nft_ctx *ctx) if (!nft_is_active_next(ctx->net, chain)) continue; + if (nft_chain_is_bound(chain)) + continue; + ctx->chain = chain; err = nft_delchain(ctx); @@ -1413,13 +1419,12 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, lockdep_commit_lock_is_held(net)); if (nft_dump_stats(skb, stats)) goto nla_put_failure; - - if ((chain->flags & NFT_CHAIN_HW_OFFLOAD) && - nla_put_be32(skb, NFTA_CHAIN_FLAGS, - htonl(NFT_CHAIN_HW_OFFLOAD))) - goto nla_put_failure; } + if (chain->flags && + nla_put_be32(skb, NFTA_CHAIN_FLAGS, htonl(chain->flags))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_CHAIN_USE, htonl(chain->use))) goto nla_put_failure; @@ -1621,7 +1626,7 @@ static void nf_tables_chain_free_chain_rules(struct nft_chain *chain) kvfree(chain->rules_next); } -static void nf_tables_chain_destroy(struct nft_ctx *ctx) +void nf_tables_chain_destroy(struct nft_ctx *ctx) { struct nft_chain *chain = ctx->chain; struct nft_hook *hook, *next; @@ -1928,6 +1933,8 @@ static int nft_chain_add(struct nft_table *table, struct nft_chain *chain) return 0; } +static u64 chain_id; + static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, u8 policy, u32 flags) { @@ -1936,6 +1943,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, struct nft_base_chain *basechain; struct nft_stats __percpu *stats; struct net *net = ctx->net; + char name[NFT_NAME_MAXLEN]; struct nft_trans *trans; struct nft_chain *chain; struct nft_rule **rules; @@ -1947,6 +1955,9 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, if (nla[NFTA_CHAIN_HOOK]) { struct nft_chain_hook hook; + if (flags & NFT_CHAIN_BINDING) + return -EOPNOTSUPP; + err = nft_chain_parse_hook(net, nla, &hook, family, true); if (err < 0) return err; @@ -1976,16 +1987,33 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, return err; } } else { + if (flags & NFT_CHAIN_BASE) + return -EINVAL; + if (flags & NFT_CHAIN_HW_OFFLOAD) + return -EOPNOTSUPP; + chain = kzalloc(sizeof(*chain), GFP_KERNEL); if (chain == NULL) return -ENOMEM; + + chain->flags = flags; } ctx->chain = chain; INIT_LIST_HEAD(&chain->rules); chain->handle = nf_tables_alloc_handle(table); chain->table = table; - chain->name = nla_strdup(nla[NFTA_CHAIN_NAME], GFP_KERNEL); + + if (nla[NFTA_CHAIN_NAME]) { + chain->name = nla_strdup(nla[NFTA_CHAIN_NAME], GFP_KERNEL); + } else { + if (!(flags & NFT_CHAIN_BINDING)) + return -EINVAL; + + snprintf(name, sizeof(name), "__chain%llu", ++chain_id); + chain->name = kstrdup(name, GFP_KERNEL); + } + if (!chain->name) { err = -ENOMEM; goto err1; @@ -2976,8 +3004,7 @@ static void nf_tables_rule_destroy(const struct nft_ctx *ctx, kfree(rule); } -static void nf_tables_rule_release(const struct nft_ctx *ctx, - struct nft_rule *rule) +void nf_tables_rule_release(const struct nft_ctx *ctx, struct nft_rule *rule) { nft_rule_expr_deactivate(ctx, rule, NFT_TRANS_RELEASE); nf_tables_rule_destroy(ctx, rule); @@ -3075,6 +3102,9 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk, NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]); return PTR_ERR(chain); } + if (nft_chain_is_bound(chain)) + return -EOPNOTSUPP; + } else if (nla[NFTA_RULE_CHAIN_ID]) { chain = nft_chain_lookup_byid(net, nla[NFTA_RULE_CHAIN_ID]); if (IS_ERR(chain)) { @@ -3294,6 +3324,8 @@ static int nf_tables_delrule(struct net *net, struct sock *nlsk, NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]); return PTR_ERR(chain); } + if (nft_chain_is_bound(chain)) + return -EOPNOTSUPP; } nft_ctx_init(&ctx, net, skb, nlh, family, table, chain, nla); @@ -5330,11 +5362,24 @@ static int nf_tables_newsetelem(struct net *net, struct sock *nlsk, */ void nft_data_hold(const struct nft_data *data, enum nft_data_types type) { + struct nft_chain *chain; + struct nft_rule *rule; + if (type == NFT_DATA_VERDICT) { switch (data->verdict.code) { case NFT_JUMP: case NFT_GOTO: - data->verdict.chain->use++; + chain = data->verdict.chain; + chain->use++; + + if (!nft_chain_is_bound(chain)) + break; + + chain->table->use++; + list_for_each_entry(rule, &chain->rules, list) + chain->use++; + + nft_chain_add(chain->table, chain); break; } } @@ -7474,7 +7519,7 @@ static void nft_obj_del(struct nft_object *obj) list_del_rcu(&obj->list); } -static void nft_chain_del(struct nft_chain *chain) +void nft_chain_del(struct nft_chain *chain) { struct nft_table *table = chain->table; @@ -7825,6 +7870,10 @@ static int __nf_tables_abort(struct net *net, bool autoload) kfree(nft_trans_chain_name(trans)); nft_trans_destroy(trans); } else { + if (nft_chain_is_bound(trans->ctx.chain)) { + nft_trans_destroy(trans); + break; + } trans->ctx.table->use--; nft_chain_del(trans->ctx.chain); nf_tables_unregister_hook(trans->ctx.net, @@ -8321,10 +8370,23 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, static void nft_verdict_uninit(const struct nft_data *data) { + struct nft_chain *chain; + struct nft_rule *rule; + switch (data->verdict.code) { case NFT_JUMP: case NFT_GOTO: - data->verdict.chain->use--; + chain = data->verdict.chain; + chain->use--; + + if (!nft_chain_is_bound(chain)) + break; + + chain->table->use--; + list_for_each_entry(rule, &chain->rules, list) + chain->use--; + + nft_chain_del(chain); break; } } diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c index c7f0ef73d939..9e556638bb32 100644 --- a/net/netfilter/nft_immediate.c +++ b/net/netfilter/nft_immediate.c @@ -54,6 +54,23 @@ static int nft_immediate_init(const struct nft_ctx *ctx, if (err < 0) goto err1; + if (priv->dreg == NFT_REG_VERDICT) { + struct nft_chain *chain = priv->data.verdict.chain; + + switch (priv->data.verdict.code) { + case NFT_JUMP: + case NFT_GOTO: + if (nft_chain_is_bound(chain)) { + err = -EBUSY; + goto err1; + } + chain->bound = true; + break; + default: + break; + } + } + return 0; err1: @@ -81,6 +98,39 @@ static void nft_immediate_deactivate(const struct nft_ctx *ctx, return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg)); } +static void nft_immediate_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + const struct nft_immediate_expr *priv = nft_expr_priv(expr); + const struct nft_data *data = &priv->data; + struct nft_ctx chain_ctx; + struct nft_chain *chain; + struct nft_rule *rule; + + if (priv->dreg != NFT_REG_VERDICT) + return; + + switch (data->verdict.code) { + case NFT_JUMP: + case NFT_GOTO: + chain = data->verdict.chain; + + if (!nft_chain_is_bound(chain)) + break; + + chain_ctx = *ctx; + chain_ctx.chain = chain; + + list_for_each_entry(rule, &chain->rules, list) + nf_tables_rule_release(&chain_ctx, rule); + + nf_tables_chain_destroy(&chain_ctx); + break; + default: + break; + } +} + static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_immediate_expr *priv = nft_expr_priv(expr); @@ -170,6 +220,7 @@ static const struct nft_expr_ops nft_imm_ops = { .init = nft_immediate_init, .activate = nft_immediate_activate, .deactivate = nft_immediate_deactivate, + .destroy = nft_immediate_destroy, .dump = nft_immediate_dump, .validate = nft_immediate_validate, .offload = nft_immediate_offload, |