From 1a94e38d254b3622d5d53f74b3b716b0fcab0ba8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 10 Feb 2017 12:08:23 +0100 Subject: [PATCH] netfilter: nf_tables: add NFTA_RULE_ID attribute This new attribute allows us to uniquely identify a rule in transaction. Robots may trigger an insertion followed by deletion in a batch, in that scenario we still don't have a public rule handle that we can use to delete the rule. This is similar to the NFTA_SET_ID attribute that allows us to refer to an anonymous set from a batch. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 3 +++ include/uapi/linux/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 26 ++++++++++++++++++++++++ 3 files changed, 31 insertions(+) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 21ce50e6d0c5..ac84686aaafb 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1202,10 +1202,13 @@ struct nft_trans { struct nft_trans_rule { struct nft_rule *rule; + u32 rule_id; }; #define nft_trans_rule(trans) \ (((struct nft_trans_rule *)trans->data)->rule) +#define nft_trans_rule_id(trans) \ + (((struct nft_trans_rule *)trans->data)->rule_id) struct nft_trans_set { struct nft_set *set; diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 207951516ede..05215d30fe5c 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -207,6 +207,7 @@ enum nft_chain_attributes { * @NFTA_RULE_COMPAT: compatibility specifications of the rule (NLA_NESTED: nft_rule_compat_attributes) * @NFTA_RULE_POSITION: numeric handle of the previous rule (NLA_U64) * @NFTA_RULE_USERDATA: user data (NLA_BINARY, NFT_USERDATA_MAXLEN) + * @NFTA_RULE_ID: uniquely identifies a rule in a transaction (NLA_U32) */ enum nft_rule_attributes { NFTA_RULE_UNSPEC, @@ -218,6 +219,7 @@ enum nft_rule_attributes { NFTA_RULE_POSITION, NFTA_RULE_USERDATA, NFTA_RULE_PAD, + NFTA_RULE_ID, __NFTA_RULE_MAX }; #define NFTA_RULE_MAX (__NFTA_RULE_MAX - 1) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 71c60a04b66b..6c782532615f 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -240,6 +240,10 @@ static struct nft_trans *nft_trans_rule_add(struct nft_ctx *ctx, int msg_type, if (trans == NULL) return NULL; + if (msg_type == NFT_MSG_NEWRULE && ctx->nla[NFTA_RULE_ID] != NULL) { + nft_trans_rule_id(trans) = + ntohl(nla_get_be32(ctx->nla[NFTA_RULE_ID])); + } nft_trans_rule(trans) = rule; list_add_tail(&trans->list, &ctx->net->nft.commit_list); @@ -2293,6 +2297,22 @@ err1: return err; } +static struct nft_rule *nft_rule_lookup_byid(const struct net *net, + const struct nlattr *nla) +{ + u32 id = ntohl(nla_get_be32(nla)); + struct nft_trans *trans; + + list_for_each_entry(trans, &net->nft.commit_list, list) { + struct nft_rule *rule = nft_trans_rule(trans); + + if (trans->msg_type == NFT_MSG_NEWRULE && + id == nft_trans_rule_id(trans)) + return rule; + } + return ERR_PTR(-ENOENT); +} + static int nf_tables_delrule(struct net *net, struct sock *nlsk, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nla[]) @@ -2330,6 +2350,12 @@ static int nf_tables_delrule(struct net *net, struct sock *nlsk, if (IS_ERR(rule)) return PTR_ERR(rule); + err = nft_delrule(&ctx, rule); + } else if (nla[NFTA_RULE_ID]) { + rule = nft_rule_lookup_byid(net, nla[NFTA_RULE_ID]); + if (IS_ERR(rule)) + return PTR_ERR(rule); + err = nft_delrule(&ctx, rule); } else { err = nft_delrule_by_chain(&ctx); -- 2.20.1