From abadb2f865d72a223d691fc68e006943ecadf0d9 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 20 May 2020 13:46:51 +0200 Subject: [PATCH] netfilter: nf_tables: delete devices from flowtable This patch allows users to delete devices from existing flowtables. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 1 + net/netfilter/nf_tables_api.c | 113 ++++++++++++++++++++++++++++++++------ 2 files changed, 98 insertions(+), 16 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 4f58c4411bb4..6f0f6fca9ac3 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1002,6 +1002,7 @@ struct nft_stats { struct nft_hook { struct list_head list; + bool inactive; struct nf_hook_ops ops; struct rcu_head rcu; }; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 98f2cbb97e39..1c2c3bb78fa0 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1669,6 +1669,7 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net, goto err_hook_dev; } hook->ops.dev = dev; + hook->inactive = false; return hook; @@ -1678,17 +1679,17 @@ err_hook_alloc: return ERR_PTR(err); } -static bool nft_hook_list_find(struct list_head *hook_list, - const struct nft_hook *this) +static struct nft_hook *nft_hook_list_find(struct list_head *hook_list, + const struct nft_hook *this) { struct nft_hook *hook; list_for_each_entry(hook, hook_list, list) { if (this->ops.dev == hook->ops.dev) - return true; + return hook; } - return false; + return NULL; } static int nf_tables_parse_netdev_hooks(struct net *net, @@ -6530,6 +6531,51 @@ err1: return err; } +static int nft_delflowtable_hook(struct nft_ctx *ctx, + struct nft_flowtable *flowtable) +{ + const struct nlattr * const *nla = ctx->nla; + struct nft_flowtable_hook flowtable_hook; + struct nft_hook *this, *next, *hook; + struct nft_trans *trans; + int err; + + err = nft_flowtable_parse_hook(ctx, nla[NFTA_FLOWTABLE_HOOK], + &flowtable_hook, &flowtable->data); + if (err < 0) + return err; + + list_for_each_entry_safe(this, next, &flowtable_hook.list, list) { + hook = nft_hook_list_find(&flowtable->hook_list, this); + if (!hook) { + err = -ENOENT; + goto err_flowtable_del_hook; + } + hook->inactive = true; + list_del(&this->list); + kfree(this); + } + + trans = nft_trans_alloc(ctx, NFT_MSG_DELFLOWTABLE, + sizeof(struct nft_trans_flowtable)); + if (!trans) + return -ENOMEM; + + nft_trans_flowtable(trans) = flowtable; + nft_trans_flowtable_update(trans) = true; + INIT_LIST_HEAD(&nft_trans_flowtable_hooks(trans)); + + list_add_tail(&trans->list, &ctx->net->nft.commit_list); + + return 0; + +err_flowtable_del_hook: + list_for_each_entry(hook, &flowtable_hook.list, list) + hook->inactive = false; + + return err; +} + static int nf_tables_delflowtable(struct net *net, struct sock *nlsk, struct sk_buff *skb, const struct nlmsghdr *nlh, @@ -6568,13 +6614,17 @@ static int nf_tables_delflowtable(struct net *net, struct sock *nlsk, NL_SET_BAD_ATTR(extack, attr); return PTR_ERR(flowtable); } + + nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla); + + if (nla[NFTA_FLOWTABLE_HOOK]) + return nft_delflowtable_hook(&ctx, flowtable); + if (flowtable->use > 0) { NL_SET_BAD_ATTR(extack, attr); return -EBUSY; } - nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla); - return nft_delflowtable(&ctx, flowtable); } @@ -7184,7 +7234,10 @@ static void nft_commit_release(struct nft_trans *trans) nft_obj_destroy(&trans->ctx, nft_trans_obj(trans)); break; case NFT_MSG_DELFLOWTABLE: - nf_tables_flowtable_destroy(nft_trans_flowtable(trans)); + if (nft_trans_flowtable_update(trans)) + nft_flowtable_hooks_destroy(&nft_trans_flowtable_hooks(trans)); + else + nf_tables_flowtable_destroy(nft_trans_flowtable(trans)); break; } @@ -7345,6 +7398,17 @@ static void nft_chain_del(struct nft_chain *chain) list_del_rcu(&chain->list); } +static void nft_flowtable_hooks_del(struct nft_flowtable *flowtable, + struct list_head *hook_list) +{ + struct nft_hook *hook, *next; + + list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) { + if (hook->inactive) + list_move(&hook->list, hook_list); + } +} + static void nf_tables_module_autoload_cleanup(struct net *net) { struct nft_module_request *req, *next; @@ -7570,13 +7634,24 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) nft_trans_destroy(trans); break; case NFT_MSG_DELFLOWTABLE: - list_del_rcu(&nft_trans_flowtable(trans)->list); - nf_tables_flowtable_notify(&trans->ctx, - nft_trans_flowtable(trans), - &nft_trans_flowtable(trans)->hook_list, - NFT_MSG_DELFLOWTABLE); - nft_unregister_flowtable_net_hooks(net, - &nft_trans_flowtable(trans)->hook_list); + if (nft_trans_flowtable_update(trans)) { + nft_flowtable_hooks_del(nft_trans_flowtable(trans), + &nft_trans_flowtable_hooks(trans)); + nf_tables_flowtable_notify(&trans->ctx, + nft_trans_flowtable(trans), + &nft_trans_flowtable_hooks(trans), + NFT_MSG_DELFLOWTABLE); + nft_unregister_flowtable_net_hooks(net, + &nft_trans_flowtable_hooks(trans)); + } else { + list_del_rcu(&nft_trans_flowtable(trans)->list); + nf_tables_flowtable_notify(&trans->ctx, + nft_trans_flowtable(trans), + &nft_trans_flowtable(trans)->hook_list, + NFT_MSG_DELFLOWTABLE); + nft_unregister_flowtable_net_hooks(net, + &nft_trans_flowtable(trans)->hook_list); + } break; } } @@ -7638,6 +7713,7 @@ static int __nf_tables_abort(struct net *net, bool autoload) { struct nft_trans *trans, *next; struct nft_trans_elem *te; + struct nft_hook *hook; list_for_each_entry_safe_reverse(trans, next, &net->nft.commit_list, list) { @@ -7746,8 +7822,13 @@ static int __nf_tables_abort(struct net *net, bool autoload) } break; case NFT_MSG_DELFLOWTABLE: - trans->ctx.table->use++; - nft_clear(trans->ctx.net, nft_trans_flowtable(trans)); + if (nft_trans_flowtable_update(trans)) { + list_for_each_entry(hook, &nft_trans_flowtable(trans)->hook_list, list) + hook->inactive = false; + } else { + trans->ctx.table->use++; + nft_clear(trans->ctx.net, nft_trans_flowtable(trans)); + } nft_trans_destroy(trans); break; } -- 2.11.0