From 43da04a593d8b2626f1cf4b56efe9402f6b53652 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 28 Nov 2016 00:05:44 +0100 Subject: [PATCH] netfilter: nf_tables: atomic dump and reset for stateful objects This patch adds a new NFT_MSG_GETOBJ_RESET command perform an atomic dump-and-reset of the stateful object. This also comes with add support for atomic dump and reset for counter and quota objects. 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 | 29 ++++++++---- net/netfilter/nft_counter.c | 56 ++++++++++++++++++++---- net/netfilter/nft_quota.c | 18 +++++--- 5 files changed, 85 insertions(+), 23 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 903cd618f50e..6f7d6a1dc09c 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -997,7 +997,8 @@ struct nft_object_type { struct nft_object *obj); void (*destroy)(struct nft_object *obj); int (*dump)(struct sk_buff *skb, - const struct nft_object *obj); + struct nft_object *obj, + bool reset); }; int nft_register_obj(struct nft_object_type *obj_type); diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 3d47582caa80..399eac1eee91 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -89,6 +89,7 @@ enum nft_verdicts { * @NFT_MSG_NEWOBJ: create a stateful object (enum nft_obj_attributes) * @NFT_MSG_GETOBJ: get a stateful object (enum nft_obj_attributes) * @NFT_MSG_DELOBJ: delete a stateful object (enum nft_obj_attributes) + * @NFT_MSG_GETOBJ_RESET: get and reset a stateful object (enum nft_obj_attributes) */ enum nf_tables_msg_types { NFT_MSG_NEWTABLE, @@ -112,6 +113,7 @@ enum nf_tables_msg_types { NFT_MSG_NEWOBJ, NFT_MSG_GETOBJ, NFT_MSG_DELOBJ, + NFT_MSG_GETOBJ_RESET, NFT_MSG_MAX, }; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 2ae717c5dcb8..bfc015af366a 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3972,14 +3972,14 @@ err1: } static int nft_object_dump(struct sk_buff *skb, unsigned int attr, - const struct nft_object *obj) + struct nft_object *obj, bool reset) { struct nlattr *nest; nest = nla_nest_start(skb, attr); if (!nest) goto nla_put_failure; - if (obj->type->dump(skb, obj) < 0) + if (obj->type->dump(skb, obj, reset) < 0) goto nla_put_failure; nla_nest_end(skb, nest); return 0; @@ -4096,7 +4096,7 @@ err1: static int nf_tables_fill_obj_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_object *obj) + struct nft_object *obj, bool reset) { struct nfgenmsg *nfmsg; struct nlmsghdr *nlh; @@ -4115,7 +4115,7 @@ static int nf_tables_fill_obj_info(struct sk_buff *skb, struct net *net, nla_put_string(skb, NFTA_OBJ_NAME, obj->name) || nla_put_be32(skb, NFTA_OBJ_TYPE, htonl(obj->type->type)) || nla_put_be32(skb, NFTA_OBJ_USE, htonl(obj->use)) || - nft_object_dump(skb, NFTA_OBJ_DATA, obj)) + nft_object_dump(skb, NFTA_OBJ_DATA, obj, reset)) goto nla_put_failure; nlmsg_end(skb, nlh); @@ -4131,10 +4131,14 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); const struct nft_af_info *afi; const struct nft_table *table; - const struct nft_object *obj; unsigned int idx = 0, s_idx = cb->args[0]; struct net *net = sock_net(skb->sk); int family = nfmsg->nfgen_family; + struct nft_object *obj; + bool reset = false; + + if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET) + reset = true; rcu_read_lock(); cb->seq = net->nft.base_seq; @@ -4156,7 +4160,7 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) cb->nlh->nlmsg_seq, NFT_MSG_NEWOBJ, NLM_F_MULTI | NLM_F_APPEND, - afi->family, table, obj) < 0) + afi->family, table, obj, reset) < 0) goto done; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); @@ -4183,6 +4187,7 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, const struct nft_table *table; struct nft_object *obj; struct sk_buff *skb2; + bool reset = false; u32 objtype; int err; @@ -4214,9 +4219,12 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, if (!skb2) return -ENOMEM; + if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET) + reset = true; + err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid, nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0, - family, table, obj); + family, table, obj, reset); if (err < 0) goto err; @@ -4291,7 +4299,7 @@ static int nf_tables_obj_notify(const struct nft_ctx *ctx, err = nf_tables_fill_obj_info(skb, ctx->net, ctx->portid, ctx->seq, event, 0, ctx->afi->family, ctx->table, - obj); + obj, false); if (err < 0) { kfree_skb(skb); goto err; @@ -4482,6 +4490,11 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = { .attr_count = NFTA_OBJ_MAX, .policy = nft_obj_policy, }, + [NFT_MSG_GETOBJ_RESET] = { + .call = nf_tables_getobj, + .attr_count = NFTA_OBJ_MAX, + .policy = nft_obj_policy, + }, }; static void nft_chain_commit_update(struct nft_trans *trans) diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c index 6f3dd429f865..f6a02c5071c2 100644 --- a/net/netfilter/nft_counter.c +++ b/net/netfilter/nft_counter.c @@ -100,10 +100,10 @@ static void nft_counter_obj_destroy(struct nft_object *obj) nft_counter_do_destroy(priv); } -static void nft_counter_fetch(const struct nft_counter_percpu __percpu *counter, +static void nft_counter_fetch(struct nft_counter_percpu __percpu *counter, struct nft_counter *total) { - const struct nft_counter_percpu *cpu_stats; + struct nft_counter_percpu *cpu_stats; u64 bytes, packets; unsigned int seq; int cpu; @@ -122,12 +122,52 @@ static void nft_counter_fetch(const struct nft_counter_percpu __percpu *counter, } } +static u64 __nft_counter_reset(u64 *counter) +{ + u64 ret, old; + + do { + old = *counter; + ret = cmpxchg64(counter, old, 0); + } while (ret != old); + + return ret; +} + +static void nft_counter_reset(struct nft_counter_percpu __percpu *counter, + struct nft_counter *total) +{ + struct nft_counter_percpu *cpu_stats; + u64 bytes, packets; + unsigned int seq; + int cpu; + + memset(total, 0, sizeof(*total)); + for_each_possible_cpu(cpu) { + bytes = packets = 0; + + cpu_stats = per_cpu_ptr(counter, cpu); + do { + seq = u64_stats_fetch_begin_irq(&cpu_stats->syncp); + packets += __nft_counter_reset(&cpu_stats->counter.packets); + bytes += __nft_counter_reset(&cpu_stats->counter.bytes); + } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq)); + + total->packets += packets; + total->bytes += bytes; + } +} + static int nft_counter_do_dump(struct sk_buff *skb, - const struct nft_counter_percpu_priv *priv) + const struct nft_counter_percpu_priv *priv, + bool reset) { struct nft_counter total; - nft_counter_fetch(priv->counter, &total); + if (reset) + nft_counter_reset(priv->counter, &total); + else + nft_counter_fetch(priv->counter, &total); if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes), NFTA_COUNTER_PAD) || @@ -141,11 +181,11 @@ nla_put_failure: } static int nft_counter_obj_dump(struct sk_buff *skb, - const struct nft_object *obj) + struct nft_object *obj, bool reset) { - const struct nft_counter_percpu_priv *priv = nft_obj_data(obj); + struct nft_counter_percpu_priv *priv = nft_obj_data(obj); - return nft_counter_do_dump(skb, priv); + return nft_counter_do_dump(skb, priv, reset); } static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = { @@ -178,7 +218,7 @@ static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_counter_percpu_priv *priv = nft_expr_priv(expr); - return nft_counter_do_dump(skb, priv); + return nft_counter_do_dump(skb, priv, false); } static int nft_counter_init(const struct nft_ctx *ctx, diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c index 0d344209803a..5d25f57497cb 100644 --- a/net/netfilter/nft_quota.c +++ b/net/netfilter/nft_quota.c @@ -83,12 +83,17 @@ static int nft_quota_obj_init(const struct nlattr * const tb[], return nft_quota_do_init(tb, priv); } -static int nft_quota_do_dump(struct sk_buff *skb, const struct nft_quota *priv) +static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv, + bool reset) { u32 flags = priv->invert ? NFT_QUOTA_F_INV : 0; u64 consumed; - consumed = atomic64_read(&priv->consumed); + if (reset) + consumed = atomic64_xchg(&priv->consumed, 0); + else + consumed = atomic64_read(&priv->consumed); + /* Since we inconditionally increment consumed quota for each packet * that we see, don't go over the quota boundary in what we send to * userspace. @@ -108,11 +113,12 @@ nla_put_failure: return -1; } -static int nft_quota_obj_dump(struct sk_buff *skb, const struct nft_object *obj) +static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj, + bool reset) { struct nft_quota *priv = nft_obj_data(obj); - return nft_quota_do_dump(skb, priv); + return nft_quota_do_dump(skb, priv, reset); } static struct nft_object_type nft_quota_obj __read_mostly = { @@ -146,9 +152,9 @@ static int nft_quota_init(const struct nft_ctx *ctx, static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr) { - const struct nft_quota *priv = nft_expr_priv(expr); + struct nft_quota *priv = nft_expr_priv(expr); - return nft_quota_do_dump(skb, priv); + return nft_quota_do_dump(skb, priv, false); } static struct nft_expr_type nft_quota_type; -- 2.39.5