From 002f2176532093753cb6ced61e5ea7b8904c6cae Mon Sep 17 00:00:00 2001 From: "Jose M. Guisado Gomez" Date: Mon, 28 Sep 2020 14:27:10 +0200 Subject: netfilter: nf_tables: add userdata attributes to nft_chain Enables storing userdata for nft_chain. Field udata points to user data and udlen stores its length. Adds new attribute flag NFTA_CHAIN_USERDATA. Signed-off-by: Jose M. Guisado Gomez Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 2 ++ include/uapi/linux/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 33 ++++++++++++++++++++++++-------- 3 files changed, 29 insertions(+), 8 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index c4c526507ddb..0bd2a081ae39 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -945,6 +945,8 @@ struct nft_chain { bound:1, genmask:2; char *name; + u16 udlen; + u8 *udata; /* Only used during control plane commit phase: */ struct nft_rule **rules_next; diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 3c2469b43742..352ee51707a1 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -208,6 +208,7 @@ enum nft_chain_flags { * @NFTA_CHAIN_COUNTERS: counter specification of the chain (NLA_NESTED: nft_counter_attributes) * @NFTA_CHAIN_FLAGS: chain flags * @NFTA_CHAIN_ID: uniquely identifies a chain in a transaction (NLA_U32) + * @NFTA_CHAIN_USERDATA: user data (NLA_BINARY) */ enum nft_chain_attributes { NFTA_CHAIN_UNSPEC, @@ -222,6 +223,7 @@ enum nft_chain_attributes { NFTA_CHAIN_PAD, NFTA_CHAIN_FLAGS, NFTA_CHAIN_ID, + NFTA_CHAIN_USERDATA, __NFTA_CHAIN_MAX }; #define NFTA_CHAIN_MAX (__NFTA_CHAIN_MAX - 1) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0473316aa392..3cfff31e4818 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1304,6 +1304,8 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { [NFTA_CHAIN_COUNTERS] = { .type = NLA_NESTED }, [NFTA_CHAIN_FLAGS] = { .type = NLA_U32 }, [NFTA_CHAIN_ID] = { .type = NLA_U32 }, + [NFTA_CHAIN_USERDATA] = { .type = NLA_BINARY, + .len = NFT_USERDATA_MAXLEN }, }; static const struct nla_policy nft_hook_policy[NFTA_HOOK_MAX + 1] = { @@ -1445,6 +1447,10 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, if (nla_put_be32(skb, NFTA_CHAIN_USE, htonl(chain->use))) goto nla_put_failure; + if (chain->udata && + nla_put(skb, NFTA_CHAIN_USERDATA, chain->udlen, chain->udata)) + goto nla_put_failure; + nlmsg_end(skb, nlh); return 0; @@ -1682,9 +1688,11 @@ void nf_tables_chain_destroy(struct nft_ctx *ctx) free_percpu(rcu_dereference_raw(basechain->stats)); } kfree(chain->name); + kfree(chain->udata); kfree(basechain); } else { kfree(chain->name); + kfree(chain->udata); kfree(chain); } } @@ -2038,7 +2046,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, } else { if (!(flags & NFT_CHAIN_BINDING)) { err = -EINVAL; - goto err1; + goto err_destroy_chain; } snprintf(name, sizeof(name), "__chain%llu", ++chain_id); @@ -2047,13 +2055,22 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, if (!chain->name) { err = -ENOMEM; - goto err1; + goto err_destroy_chain; + } + + if (nla[NFTA_CHAIN_USERDATA]) { + chain->udata = nla_memdup(nla[NFTA_CHAIN_USERDATA], GFP_KERNEL); + if (chain->udata == NULL) { + err = -ENOMEM; + goto err_destroy_chain; + } + chain->udlen = nla_len(nla[NFTA_CHAIN_USERDATA]); } rules = nf_tables_chain_alloc_rules(chain, 0); if (!rules) { err = -ENOMEM; - goto err1; + goto err_destroy_chain; } *rules = NULL; @@ -2062,12 +2079,12 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, err = nf_tables_register_hook(net, table, chain); if (err < 0) - goto err1; + goto err_destroy_chain; trans = nft_trans_chain_add(ctx, NFT_MSG_NEWCHAIN); if (IS_ERR(trans)) { err = PTR_ERR(trans); - goto err2; + goto err_unregister_hook; } nft_trans_chain_policy(trans) = NFT_CHAIN_POLICY_UNSET; @@ -2077,15 +2094,15 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, err = nft_chain_add(table, chain); if (err < 0) { nft_trans_destroy(trans); - goto err2; + goto err_unregister_hook; } table->use++; return 0; -err2: +err_unregister_hook: nf_tables_unregister_hook(net, table, chain); -err1: +err_destroy_chain: nf_tables_chain_destroy(ctx); return err; -- cgit v1.2.3