From 6869c4d8e066e21623c812c448a05f1ed931c9c6 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Tue, 9 Aug 2005 19:24:19 -0700 Subject: [NETFILTER]: reduce netfilter sk_buff enlargement As discussed at netconf'05, we're trying to save every bit in sk_buff. The patch below makes sk_buff 8 bytes smaller. I did some basic testing on my notebook and it seems to work. The only real in-tree user of nfcache was IPVS, who only needs a single bit. Unfortunately I couldn't find some other free bit in sk_buff to stuff that bit into, so I introduced a separate field for them. Maybe the IPVS guys can resolve that to further save space. Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and alike are only 6 values defined), but unfortunately the bluetooth code overloads pkt_type :( The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just came up with a way how to do it without any skb fields, so it's safe to remove it. - remove all never-implemented 'nfcache' code - don't have ipvs code abuse 'nfcache' field. currently get's their own compile-conditional skb->ipvs_property field. IPVS maintainers can decide to move this bit elswhere, but nfcache needs to die. - remove skb->nfcache field to save 4 bytes - move skb->nfctinfo into three unused bits to save further 4 bytes Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- include/linux/netfilter.h | 3 +++ include/linux/netfilter_decnet.h | 3 +++ include/linux/netfilter_ipv4.h | 3 +++ include/linux/netfilter_ipv6.h | 3 +++ include/linux/skbuff.h | 10 +++++----- 5 files changed, 17 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 2e2045482cb..ec60856408f 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -21,10 +21,13 @@ #define NF_STOP 5 #define NF_MAX_VERDICT NF_STOP +/* only for userspace compatibility */ +#ifndef __KERNEL__ /* Generic cache responses from hook functions. <= 0x2000 is used for protocol-flags. */ #define NFC_UNKNOWN 0x4000 #define NFC_ALTERED 0x8000 +#endif #ifdef __KERNEL__ #include diff --git a/include/linux/netfilter_decnet.h b/include/linux/netfilter_decnet.h index 3064eec9cb8..01897948415 100644 --- a/include/linux/netfilter_decnet.h +++ b/include/linux/netfilter_decnet.h @@ -9,6 +9,8 @@ #include +/* only for userspace compatibility */ +#ifndef __KERNEL__ /* IP Cache bits. */ /* Src IP address. */ #define NFC_DN_SRC 0x0001 @@ -18,6 +20,7 @@ #define NFC_DN_IF_IN 0x0004 /* Output device. */ #define NFC_DN_IF_OUT 0x0008 +#endif /* ! __KERNEL__ */ /* DECnet Hooks */ /* After promisc drops, checksum checks. */ diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h index 3ebc36afae1..552815b8193 100644 --- a/include/linux/netfilter_ipv4.h +++ b/include/linux/netfilter_ipv4.h @@ -8,6 +8,8 @@ #include #include +/* only for userspace compatibility */ +#ifndef __KERNEL__ /* IP Cache bits. */ /* Src IP address. */ #define NFC_IP_SRC 0x0001 @@ -35,6 +37,7 @@ #define NFC_IP_DST_PT 0x0400 /* Something else about the proto */ #define NFC_IP_PROTO_UNKNOWN 0x2000 +#endif /* ! __KERNEL__ */ /* IP Hooks */ /* After promisc drops, checksum checks. */ diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h index bee7a5ec7c6..20c069a5e4a 100644 --- a/include/linux/netfilter_ipv6.h +++ b/include/linux/netfilter_ipv6.h @@ -10,6 +10,8 @@ #include +/* only for userspace compatibility */ +#ifndef __KERNEL__ /* IP Cache bits. */ /* Src IP address. */ #define NFC_IP6_SRC 0x0001 @@ -38,6 +40,7 @@ #define NFC_IP6_DST_PT 0x0400 /* Something else about the proto */ #define NFC_IP6_PROTO_UNKNOWN 0x2000 +#endif /* ! __KERNEL__ */ /* IP6 Hooks */ diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2e40f4c9f7a..4b929c3c1a9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -190,7 +190,6 @@ struct skb_shared_info { * @end: End pointer * @destructor: Destruct function * @nfmark: Can be used for communication between hooks - * @nfcache: Cache info * @nfct: Associated connection, if any * @nfctinfo: Relationship of this skb to the connection * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c @@ -252,17 +251,18 @@ struct sk_buff { __u8 local_df:1, cloned:1, ip_summed:2, - nohdr:1; - /* 3 bits spare */ + nohdr:1, + nfctinfo:3; __u8 pkt_type; __be16 protocol; void (*destructor)(struct sk_buff *skb); #ifdef CONFIG_NETFILTER __u32 nfmark; - __u32 nfcache; - __u32 nfctinfo; struct nf_conntrack *nfct; +#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) + __u8 ipvs_property:1; +#endif #ifdef CONFIG_BRIDGE_NETFILTER struct nf_bridge_info *nf_bridge; #endif -- cgit v1.2.3-18-g5258