From b9703ed44ffbfba85c103b9de01886a225e14b38 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 21 Apr 2023 00:34:31 +0200 Subject: [PATCH] netfilter: nf_tables: support for adding new devices to an existing netdev chain This patch allows users to add devices to an existing netdev chain. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 6 + net/netfilter/nf_tables_api.c | 217 +++++++++++++++++++----------- 2 files changed, 142 insertions(+), 81 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 58a4d217faaf..3ed21d2d5659 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1609,6 +1609,8 @@ 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) \ @@ -1621,6 +1623,10 @@ 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 77975b4b0fdc..f8d8cace0c7d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1582,7 +1582,8 @@ nla_put_failure: } static int nft_dump_basechain_hook(struct sk_buff *skb, int family, - const struct nft_base_chain *basechain) + const struct nft_base_chain *basechain, + const struct list_head *hook_list) { const struct nf_hook_ops *ops = &basechain->ops; struct nft_hook *hook, *first = NULL; @@ -1599,7 +1600,11 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family, if (nft_base_chain_netdev(family, ops->hooknum)) { nest_devs = nla_nest_start_noflag(skb, NFTA_HOOK_DEVS); - list_for_each_entry(hook, &basechain->hook_list, list) { + + if (!hook_list) + hook_list = &basechain->hook_list; + + list_for_each_entry(hook, hook_list, list) { if (!first) first = hook; @@ -1624,7 +1629,8 @@ nla_put_failure: static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, u32 portid, u32 seq, int event, u32 flags, int family, const struct nft_table *table, - const struct nft_chain *chain) + const struct nft_chain *chain, + const struct list_head *hook_list) { struct nlmsghdr *nlh; @@ -1649,7 +1655,7 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, const struct nft_base_chain *basechain = nft_base_chain(chain); struct nft_stats __percpu *stats; - if (nft_dump_basechain_hook(skb, family, basechain)) + if (nft_dump_basechain_hook(skb, family, basechain, hook_list)) goto nla_put_failure; if (nla_put_be32(skb, NFTA_CHAIN_POLICY, @@ -1684,7 +1690,8 @@ nla_put_failure: return -1; } -static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event) +static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event, + const struct list_head *hook_list) { struct nftables_pernet *nft_net; struct sk_buff *skb; @@ -1704,7 +1711,7 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event) err = nf_tables_fill_chain_info(skb, ctx->net, ctx->portid, ctx->seq, event, flags, ctx->family, ctx->table, - ctx->chain); + ctx->chain, hook_list); if (err < 0) { kfree_skb(skb); goto err; @@ -1750,7 +1757,7 @@ static int nf_tables_dump_chains(struct sk_buff *skb, NFT_MSG_NEWCHAIN, NLM_F_MULTI, table->family, table, - chain) < 0) + chain, NULL) < 0) goto done; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); @@ -1804,7 +1811,7 @@ static int nf_tables_getchain(struct sk_buff *skb, const struct nfnl_info *info, err = nf_tables_fill_chain_info(skb2, net, NETLINK_CB(skb).portid, info->nlh->nlmsg_seq, NFT_MSG_NEWCHAIN, - 0, family, table, chain); + 0, family, table, chain, NULL); if (err < 0) goto err_fill_chain_info; @@ -2048,9 +2055,10 @@ static int nft_chain_parse_netdev(struct net *net, } static int nft_chain_parse_hook(struct net *net, + struct nft_base_chain *basechain, const struct nlattr * const nla[], struct nft_chain_hook *hook, u8 family, - struct netlink_ext_ack *extack, bool autoload) + struct netlink_ext_ack *extack) { struct nftables_pernet *nft_net = nft_pernet(net); struct nlattr *ha[NFTA_HOOK_MAX + 1]; @@ -2066,31 +2074,46 @@ 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 (!basechain) { + 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])); - type = __nft_chain_type_get(family, NFT_CHAIN_T_DEFAULT); - if (!type) - return -EOPNOTSUPP; + type = __nft_chain_type_get(family, NFT_CHAIN_T_DEFAULT); + if (!type) + return -EOPNOTSUPP; - if (nla[NFTA_CHAIN_TYPE]) { - type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE], - family, autoload); - if (IS_ERR(type)) { - NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]); - return PTR_ERR(type); + if (nla[NFTA_CHAIN_TYPE]) { + type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE], + family, true); + if (IS_ERR(type)) { + NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]); + return PTR_ERR(type); + } } - } - if (hook->num >= NFT_MAX_HOOKS || !(type->hook_mask & (1 << hook->num))) - return -EOPNOTSUPP; + if (hook->num >= NFT_MAX_HOOKS || !(type->hook_mask & (1 << hook->num))) + return -EOPNOTSUPP; - if (type->type == NFT_CHAIN_T_NAT && - hook->priority <= NF_IP_PRI_CONNTRACK) - return -EOPNOTSUPP; + if (type->type == NFT_CHAIN_T_NAT && + hook->priority <= NF_IP_PRI_CONNTRACK) + return -EOPNOTSUPP; + } else { + if (ha[NFTA_HOOK_HOOKNUM]) { + hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])); + if (hook->num != basechain->ops.hooknum) + return -EOPNOTSUPP; + } + if (ha[NFTA_HOOK_PRIORITY]) { + hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY])); + if (hook->priority != basechain->ops.priority) + return -EOPNOTSUPP; + } + + type = basechain->type; + } if (!try_module_get(type->owner)) { if (nla[NFTA_CHAIN_TYPE]) @@ -2184,12 +2207,8 @@ 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; @@ -2239,13 +2258,13 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, if (nla[NFTA_CHAIN_HOOK]) { struct nft_stats __percpu *stats = NULL; - struct nft_chain_hook hook; + struct nft_chain_hook hook = {}; if (flags & NFT_CHAIN_BINDING) return -EOPNOTSUPP; - err = nft_chain_parse_hook(net, nla, &hook, family, extack, - true); + err = nft_chain_parse_hook(net, NULL, nla, &hook, family, + extack); if (err < 0) return err; @@ -2359,65 +2378,57 @@ err_destroy_chain: 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_chain_hook hook = {}; 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); return -EEXIST; } - err = nft_chain_parse_hook(ctx->net, nla, &hook, ctx->family, - extack, false); + + basechain = nft_base_chain(chain); + err = nft_chain_parse_hook(ctx->net, basechain, nla, &hook, + ctx->family, extack); if (err < 0) return err; - basechain = nft_base_chain(chain); if (basechain->type != hook.type) { nft_chain_release_hook(&hook); NL_SET_BAD_ATTR(extack, attr); 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; @@ -2428,7 +2439,6 @@ 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] && @@ -2439,24 +2449,43 @@ 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; @@ -2475,7 +2504,7 @@ 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) { @@ -2486,18 +2515,35 @@ 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: + if (nla[NFTA_CHAIN_HOOK]) { + 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; } @@ -9244,19 +9290,22 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) case NFT_MSG_NEWCHAIN: if (nft_trans_chain_update(trans)) { nft_chain_commit_update(trans); - nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN); + nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, + &nft_trans_chain_hooks(trans)); + 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); nft_clear(net, trans->ctx.chain); - nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN); + nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, NULL); nft_trans_destroy(trans); } break; case NFT_MSG_DELCHAIN: case NFT_MSG_DESTROYCHAIN: nft_chain_del(trans->ctx.chain); - nf_tables_chain_notify(&trans->ctx, trans->msg_type); + nf_tables_chain_notify(&trans->ctx, trans->msg_type, NULL); nf_tables_unregister_hook(trans->ctx.net, trans->ctx.table, trans->ctx.chain); @@ -9423,7 +9472,10 @@ 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)); @@ -9486,6 +9538,9 @@ 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);