This patch allows users to add devices to an existing netdev chain. Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- include/net/netfilter/nf_tables.h | 6 ++ net/netfilter/nf_tables_api.c | 133 +++++++++++++++++++----------- 2 files changed, 90 insertions(+), 49 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index e69ce23566ea..a2b1cb8e3985 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1574,6 +1574,8 @@ struct nft_trans_chain { struct nft_stats __percpu *stats; u8 policy; u32 chain_id; + struct nft_base_chain *basechain; + struct list_head hook_list; }; #define nft_trans_chain_update(trans) \ @@ -1586,6 +1588,10 @@ struct nft_trans_chain { (((struct nft_trans_chain *)trans->data)->policy) #define nft_trans_chain_id(trans) \ (((struct nft_trans_chain *)trans->data)->chain_id) +#define nft_trans_basechain(trans) \ + (((struct nft_trans_chain *)trans->data)->basechain) +#define nft_trans_chain_hooks(trans) \ + (((struct nft_trans_chain *)trans->data)->hook_list) struct nft_trans_table { bool update; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b436752cf3ec..dc7ba9d31c4c 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2018,7 +2018,7 @@ static int nft_chain_parse_netdev(struct net *net, static int nft_chain_parse_hook(struct net *net, const struct nlattr * const nla[], struct nft_chain_hook *hook, u8 family, - struct netlink_ext_ack *extack, bool autoload) + struct netlink_ext_ack *extack, bool add) { struct nftables_pernet *nft_net = nft_pernet(net); struct nlattr *ha[NFTA_HOOK_MAX + 1]; @@ -2034,12 +2034,19 @@ static int nft_chain_parse_hook(struct net *net, if (err < 0) return err; - if (ha[NFTA_HOOK_HOOKNUM] == NULL || - ha[NFTA_HOOK_PRIORITY] == NULL) - return -EINVAL; + if (add) { + if (!ha[NFTA_HOOK_HOOKNUM] || + !ha[NFTA_HOOK_PRIORITY]) + return -EINVAL; - hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])); - hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY])); + hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])); + hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY])); + } else { + if (ha[NFTA_HOOK_HOOKNUM]) + hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])); + if (ha[NFTA_HOOK_PRIORITY]) + hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY])); + } type = __nft_chain_type_get(family, NFT_CHAIN_T_DEFAULT); if (!type) @@ -2047,7 +2054,7 @@ static int nft_chain_parse_hook(struct net *net, if (nla[NFTA_CHAIN_TYPE]) { type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE], - family, autoload); + family, add); if (IS_ERR(type)) { NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]); return PTR_ERR(type); @@ -2156,12 +2163,8 @@ static int nft_basechain_init(struct nft_base_chain *basechain, u8 family, list_splice_init(&hook->list, &basechain->hook_list); list_for_each_entry(h, &basechain->hook_list, list) nft_basechain_hook_init(&h->ops, family, hook, chain); - - basechain->ops.hooknum = hook->num; - basechain->ops.priority = hook->priority; - } else { - nft_basechain_hook_init(&basechain->ops, family, hook, chain); } + nft_basechain_hook_init(&basechain->ops, family, hook, chain); chain->flags |= NFT_CHAIN_BASE | flags; basechain->policy = NF_ACCEPT; @@ -2333,42 +2336,27 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, return err; } -static bool nft_hook_list_equal(struct list_head *hook_list1, - struct list_head *hook_list2) -{ - struct nft_hook *hook; - int n = 0, m = 0; - - n = 0; - list_for_each_entry(hook, hook_list2, list) { - if (!nft_hook_list_find(hook_list1, hook)) - return false; - - n++; - } - list_for_each_entry(hook, hook_list1, list) - m++; - - return n == m; -} - static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, u32 flags, const struct nlattr *attr, struct netlink_ext_ack *extack) { const struct nlattr * const *nla = ctx->nla; + struct nft_base_chain *basechain = NULL; struct nft_table *table = ctx->table; struct nft_chain *chain = ctx->chain; - struct nft_base_chain *basechain; struct nft_stats *stats = NULL; struct nft_chain_hook hook; + struct nft_hook *h, *next; struct nf_hook_ops *ops; struct nft_trans *trans; + bool unregister = false; int err; if (chain->flags ^ flags) return -EOPNOTSUPP; + INIT_LIST_HEAD(&hook.list); + if (nla[NFTA_CHAIN_HOOK]) { if (!nft_is_base_chain(chain)) { NL_SET_BAD_ATTR(extack, attr); @@ -2386,12 +2374,18 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, return -EEXIST; } - if (nft_base_chain_netdev(ctx->family, hook.num)) { - if (!nft_hook_list_equal(&basechain->hook_list, - &hook.list)) { - nft_chain_release_hook(&hook); - NL_SET_BAD_ATTR(extack, attr); - return -EEXIST; + if (nft_base_chain_netdev(ctx->family, basechain->ops.hooknum)) { + list_for_each_entry_safe(h, next, &hook.list, list) { + h->ops.pf = basechain->ops.pf; + h->ops.hooknum = basechain->ops.hooknum; + h->ops.priority = basechain->ops.priority; + h->ops.priv = basechain->ops.priv; + h->ops.hook = basechain->ops.hook; + + if (nft_hook_list_find(&basechain->hook_list, h)) { + list_del(&h->list); + kfree(h); + } } } else { ops = &basechain->ops; @@ -2402,7 +2396,6 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, return -EEXIST; } } - nft_chain_release_hook(&hook); } if (nla[NFTA_CHAIN_HANDLE] && @@ -2413,24 +2406,43 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, nla[NFTA_CHAIN_NAME], genmask); if (!IS_ERR(chain2)) { NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_NAME]); - return -EEXIST; + err = -EEXIST; + goto err_hooks; } } if (nla[NFTA_CHAIN_COUNTERS]) { - if (!nft_is_base_chain(chain)) - return -EOPNOTSUPP; + if (!nft_is_base_chain(chain)) { + err = -EOPNOTSUPP; + goto err_hooks; + } stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]); - if (IS_ERR(stats)) - return PTR_ERR(stats); + if (IS_ERR(stats)) { + err = PTR_ERR(stats); + goto err_hooks; + } + } + + if (!(table->flags & NFT_TABLE_F_DORMANT) && + nft_is_base_chain(chain) && + !list_empty(&hook.list)) { + basechain = nft_base_chain(chain); + ops = &basechain->ops; + + if (nft_base_chain_netdev(table->family, basechain->ops.hooknum)) { + err = nft_netdev_register_hooks(ctx->net, &hook.list); + if (err < 0) + goto err_hooks; + } } + unregister = true; err = -ENOMEM; trans = nft_trans_alloc(ctx, NFT_MSG_NEWCHAIN, sizeof(struct nft_trans_chain)); if (trans == NULL) - goto err; + goto err_trans; nft_trans_chain_stats(trans) = stats; nft_trans_chain_update(trans) = true; @@ -2449,7 +2461,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, err = -ENOMEM; name = nla_strdup(nla[NFTA_CHAIN_NAME], GFP_KERNEL_ACCOUNT); if (!name) - goto err; + goto err_trans; err = -EEXIST; list_for_each_entry(tmp, &nft_net->commit_list, list) { @@ -2460,18 +2472,33 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, strcmp(name, nft_trans_chain_name(tmp)) == 0) { NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_NAME]); kfree(name); - goto err; + goto err_trans; } } nft_trans_chain_name(trans) = name; } + + nft_trans_basechain(trans) = basechain; + INIT_LIST_HEAD(&nft_trans_chain_hooks(trans)); + list_splice(&hook.list, &nft_trans_chain_hooks(trans)); + nft_trans_commit_list_add_tail(ctx->net, trans); return 0; -err: + +err_trans: free_percpu(stats); kfree(trans); +err_hooks: + list_for_each_entry_safe(h, next, &hook.list, list) { + if (unregister) + nf_unregister_net_hook(ctx->net, &h->ops); + list_del(&h->list); + kfree_rcu(h, rcu); + } + module_put(hook.type->owner); + return err; } @@ -8993,6 +9020,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) if (nft_trans_chain_update(trans)) { nft_chain_commit_update(trans); nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN); + list_splice(&nft_trans_chain_hooks(trans), + &nft_trans_basechain(trans)->hook_list); /* trans destroyed after rcu grace period */ } else { nft_chain_commit_drop_policy(trans); @@ -9159,7 +9188,10 @@ static void nf_tables_abort_release(struct nft_trans *trans) nf_tables_table_destroy(&trans->ctx); break; case NFT_MSG_NEWCHAIN: - nf_tables_chain_destroy(&trans->ctx); + if (nft_trans_chain_update(trans)) + nft_hooks_destroy(&nft_trans_chain_hooks(trans)); + else + nf_tables_chain_destroy(&trans->ctx); break; case NFT_MSG_NEWRULE: nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans)); @@ -9221,6 +9253,9 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) break; case NFT_MSG_NEWCHAIN: if (nft_trans_chain_update(trans)) { + nft_netdev_unregister_hooks(net, + &nft_trans_chain_hooks(trans), + true); free_percpu(nft_trans_chain_stats(trans)); kfree(nft_trans_chain_name(trans)); nft_trans_destroy(trans); -- 2.30.2