From 59c466dd68e796f3a7a0709d90c72ce2d84e29c2 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 26 Feb 2018 10:15:21 +0100 Subject: [PATCH] netfilter: nf_flow_table: add a new flow state for tearing down offloading On cleanup, this will be treated differently from FLOW_OFFLOAD_DYING: If FLOW_OFFLOAD_DYING is set, the connection is going away, so both the offload state and the connection tracking entry will be deleted. If FLOW_OFFLOAD_TEARDOWN is set, the connection remains alive, but the offload state is torn down. This is useful for cases that require more complex state tracking / timeout handling on TCP, or if the connection has been idle for too long. Support for sending flows back to the slow path will be implemented in a following patch Signed-off-by: Felix Fietkau Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_flow_table.h | 2 ++ net/netfilter/nf_flow_table_core.c | 22 ++++++++++++++-------- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h index 5aa4952..ba9fa45 100644 --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -68,6 +68,7 @@ struct flow_offload_tuple_rhash { #define FLOW_OFFLOAD_SNAT 0x1 #define FLOW_OFFLOAD_DNAT 0x2 #define FLOW_OFFLOAD_DYING 0x4 +#define FLOW_OFFLOAD_TEARDOWN 0x8 struct flow_offload { struct flow_offload_tuple_rhash tuplehash[FLOW_OFFLOAD_DIR_MAX]; @@ -103,6 +104,7 @@ void nf_flow_table_cleanup(struct net *net, struct net_device *dev); int nf_flow_table_init(struct nf_flowtable *flow_table); void nf_flow_table_free(struct nf_flowtable *flow_table); +void flow_offload_teardown(struct flow_offload *flow); static inline void flow_offload_dead(struct flow_offload *flow) { flow->flags |= FLOW_OFFLOAD_DYING; diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c index 0d38f20..5a81e4f 100644 --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -174,6 +174,12 @@ static void flow_offload_del(struct nf_flowtable *flow_table, flow_offload_free(flow); } +void flow_offload_teardown(struct flow_offload *flow) +{ + flow->flags |= FLOW_OFFLOAD_TEARDOWN; +} +EXPORT_SYMBOL_GPL(flow_offload_teardown); + struct flow_offload_tuple_rhash * flow_offload_lookup(struct nf_flowtable *flow_table, struct flow_offload_tuple *tuple) @@ -226,11 +232,6 @@ static inline bool nf_flow_has_expired(const struct flow_offload *flow) return (__s32)(flow->timeout - (u32)jiffies) <= 0; } -static inline bool nf_flow_is_dying(const struct flow_offload *flow) -{ - return flow->flags & FLOW_OFFLOAD_DYING; -} - static int nf_flow_offload_gc_step(struct nf_flowtable *flow_table) { struct flow_offload_tuple_rhash *tuplehash; @@ -258,7 +259,8 @@ static int nf_flow_offload_gc_step(struct nf_flowtable *flow_table) flow = container_of(tuplehash, struct flow_offload, tuplehash[0]); if (nf_flow_has_expired(flow) || - nf_flow_is_dying(flow)) + (flow->flags & (FLOW_OFFLOAD_DYING | + FLOW_OFFLOAD_TEARDOWN))) flow_offload_del(flow_table, flow); } out: @@ -419,10 +421,14 @@ static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data) { struct net_device *dev = data; - if (dev && flow->tuplehash[0].tuple.iifidx != dev->ifindex) + if (!dev) { + flow_offload_teardown(flow); return; + } - flow_offload_dead(flow); + if (flow->tuplehash[0].tuple.iifidx == dev->ifindex || + flow->tuplehash[1].tuple.iifidx == dev->ifindex) + flow_offload_dead(flow); } static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable, -- 2.7.4