From 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 19 Apr 2007 20:29:13 -0700 Subject: [SK_BUFF]: Convert skb->tail to sk_buff_data_t So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes on 64bit architectures, allowing us to combine the 4 bytes hole left by the layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4 64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN... :-) Many calculations that previously required that skb->{transport,network, mac}_header be first converted to a pointer now can be done directly, being meaningful as offsets or pointers. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- include/linux/netfilter/nfnetlink.h | 4 +-- include/linux/netlink.h | 2 +- include/linux/rtnetlink.h | 6 ++-- include/linux/skbuff.h | 57 +++++++++++++++++++++++++++++-------- include/net/inet_ecn.h | 6 ++-- include/net/netlink.h | 8 +++--- include/net/pkt_cls.h | 2 +- 7 files changed, 58 insertions(+), 27 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 6179648a014..e1ea5dfbbbd 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -62,11 +62,11 @@ struct nfattr #define NFA_DATA(nfa) ((void *)(((char *)(nfa)) + NFA_LENGTH(0))) #define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0)) #define NFA_NEST(skb, type) \ -({ struct nfattr *__start = (struct nfattr *) (skb)->tail; \ +({ struct nfattr *__start = (struct nfattr *)skb_tail_pointer(skb); \ NFA_PUT(skb, (NFNL_NFA_NEST | type), 0, NULL); \ __start; }) #define NFA_NEST_END(skb, start) \ -({ (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \ +({ (start)->nfa_len = skb_tail_pointer(skb) - (unsigned char *)(start); \ (skb)->len; }) #define NFA_NEST_CANCEL(skb, start) \ ({ if (start) \ diff --git a/include/linux/netlink.h b/include/linux/netlink.h index a9d3ad5bc80..68a632b372e 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -229,7 +229,7 @@ __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags) (cb)->nlh->nlmsg_seq, type, len, flags) #define NLMSG_END(skb, nlh) \ -({ (nlh)->nlmsg_len = (skb)->tail - (unsigned char *) (nlh); \ +({ (nlh)->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)(nlh); \ (skb)->len; }) #define NLMSG_CANCEL(skb, nlh) \ diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 4a629ea70cc..3a4cb242ecd 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -605,7 +605,7 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi #define RTA_PUT_NOHDR(skb, attrlen, data) \ ({ RTA_APPEND(skb, RTA_ALIGN(attrlen), data); \ - memset(skb->tail - (RTA_ALIGN(attrlen) - attrlen), 0, \ + memset(skb_tail_pointer(skb) - (RTA_ALIGN(attrlen) - attrlen), 0, \ RTA_ALIGN(attrlen) - attrlen); }) #define RTA_PUT_U8(skb, attrtype, value) \ @@ -637,12 +637,12 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi RTA_PUT(skb, attrtype, 0, NULL); #define RTA_NEST(skb, type) \ -({ struct rtattr *__start = (struct rtattr *) (skb)->tail; \ +({ struct rtattr *__start = (struct rtattr *)skb_tail_pointer(skb); \ RTA_PUT(skb, type, 0, NULL); \ __start; }) #define RTA_NEST_END(skb, start) \ -({ (start)->rta_len = ((skb)->tail - (unsigned char *) (start)); \ +({ (start)->rta_len = skb_tail_pointer(skb) - (unsigned char *)(start); \ (skb)->len; }) #define RTA_NEST_CANCEL(skb, start) \ diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2e740550062..e1c2392ecb5 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -246,9 +246,6 @@ struct sk_buff { int iif; /* 4 byte hole on 64 bit*/ - sk_buff_data_t transport_header; - sk_buff_data_t network_header; - sk_buff_data_t mac_header; struct dst_entry *dst; struct sec_path *sp; @@ -303,13 +300,16 @@ struct sk_buff { __u32 mark; + sk_buff_data_t transport_header; + sk_buff_data_t network_header; + sk_buff_data_t mac_header; /* These elements must be at the end, see alloc_skb() for details. */ - unsigned int truesize; - atomic_t users; + sk_buff_data_t tail; unsigned char *head, *data, - *tail, *end; + unsigned int truesize; + atomic_t users; }; #ifdef __KERNEL__ @@ -812,12 +812,45 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i, #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list) #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) +#ifdef NET_SKBUFF_DATA_USES_OFFSET +static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) +{ + return skb->head + skb->tail; +} + +static inline void skb_reset_tail_pointer(struct sk_buff *skb) +{ + skb->tail = skb->data - skb->head; +} + +static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) +{ + skb_reset_tail_pointer(skb); + skb->tail += offset; +} +#else /* NET_SKBUFF_DATA_USES_OFFSET */ +static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) +{ + return skb->tail; +} + +static inline void skb_reset_tail_pointer(struct sk_buff *skb) +{ + skb->tail = skb->data; +} + +static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) +{ + skb->tail = skb->data + offset; +} +#endif /* NET_SKBUFF_DATA_USES_OFFSET */ + /* * Add data to an sk_buff */ static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) { - unsigned char *tmp = skb->tail; + unsigned char *tmp = skb_tail_pointer(skb); SKB_LINEAR_ASSERT(skb); skb->tail += len; skb->len += len; @@ -835,11 +868,11 @@ static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) */ static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len) { - unsigned char *tmp = skb->tail; + unsigned char *tmp = skb_tail_pointer(skb); SKB_LINEAR_ASSERT(skb); skb->tail += len; skb->len += len; - if (unlikely(skb->tail>skb->end)) + if (unlikely(skb_tail_pointer(skb) > skb->end)) skb_over_panic(skb, len, current_text_addr()); return tmp; } @@ -935,7 +968,7 @@ static inline int skb_headroom(const struct sk_buff *skb) */ static inline int skb_tailroom(const struct sk_buff *skb) { - return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; + return skb_is_nonlinear(skb) ? 0 : skb->end - skb_tail_pointer(skb); } /** @@ -1127,8 +1160,8 @@ static inline void __skb_trim(struct sk_buff *skb, unsigned int len) WARN_ON(1); return; } - skb->len = len; - skb->tail = skb->data + len; + skb->len = len; + skb_set_tail_pointer(skb, len); } /** diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h index 06a2c69a89e..de8399a7977 100644 --- a/include/net/inet_ecn.h +++ b/include/net/inet_ecn.h @@ -114,14 +114,12 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb) { switch (skb->protocol) { case __constant_htons(ETH_P_IP): - if (skb_network_header(skb) + sizeof(struct iphdr) <= - skb->tail) + if (skb->network_header + sizeof(struct iphdr) <= skb->tail) return IP_ECN_set_ce(ip_hdr(skb)); break; case __constant_htons(ETH_P_IPV6): - if (skb_network_header(skb) + sizeof(struct ipv6hdr) <= - skb->tail) + if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail) return IP6_ECN_set_ce(ipv6_hdr(skb)); break; } diff --git a/include/net/netlink.h b/include/net/netlink.h index bcaf67b7a19..2c7ab107f20 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -525,7 +525,7 @@ static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) */ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) { - nlh->nlmsg_len = skb->tail - (unsigned char *) nlh; + nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; return skb->len; } @@ -538,7 +538,7 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) */ static inline void *nlmsg_get_pos(struct sk_buff *skb) { - return skb->tail; + return skb_tail_pointer(skb); } /** @@ -940,7 +940,7 @@ static inline unsigned long nla_get_msecs(struct nlattr *nla) */ static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) { - struct nlattr *start = (struct nlattr *) skb->tail; + struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); if (nla_put(skb, attrtype, 0, NULL) < 0) return NULL; @@ -960,7 +960,7 @@ static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) */ static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) { - start->nla_len = skb->tail - (unsigned char *) start; + start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; return skb->len; } diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index dcb3a91f136..4129df70807 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -337,7 +337,7 @@ static inline unsigned char * tcf_get_base_ptr(struct sk_buff *skb, int layer) static inline int tcf_valid_offset(const struct sk_buff *skb, const unsigned char *ptr, const int len) { - return unlikely((ptr + len) < skb->tail && ptr > skb->head); + return unlikely((ptr + len) < skb_tail_pointer(skb) && ptr > skb->head); } #ifdef CONFIG_NET_CLS_IND -- cgit v1.2.3