7adc3830f9
If all of the entropy is in the local and foreign addresses, but xor'ing together would cancel out that entropy, the current hash performs poorly. Suggested by Cosmin Ratiu: Basically, the situation is as follows: There is a client machine and a server machine. Both create 15000 virtual interfaces, open up a socket for each pair of interfaces and do SIP traffic. By profiling I noticed that there is a lot of time spent walking the established hash chains with this particular setup. The addresses were distributed like this: client interfaces were 198.18.0.1/16 with increments of 1 and server interfaces were 198.18.128.1/16 with increments of 1. As I said, there were 15000 interfaces. Source and destination ports were 5060 for each connection. So in this case, ports don't matter for hashing purposes, and the bits from the address pairs used cancel each other, meaning there are no differences in the whole lot of pairs, so they all end up in the same hash chain. Signed-off-by: David S. Miller <davem@davemloft.net>
202 lines
5.1 KiB
C
202 lines
5.1 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for inet_sock
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*
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* Authors: Many, reorganised here by
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* Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _INET_SOCK_H
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#define _INET_SOCK_H
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/jhash.h>
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#include <net/flow.h>
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#include <net/sock.h>
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#include <net/request_sock.h>
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#include <net/route.h>
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/** struct ip_options - IP Options
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*
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* @faddr - Saved first hop address
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* @is_data - Options in __data, rather than skb
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* @is_strictroute - Strict source route
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* @srr_is_hit - Packet destination addr was our one
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* @is_changed - IP checksum more not valid
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* @rr_needaddr - Need to record addr of outgoing dev
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* @ts_needtime - Need to record timestamp
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* @ts_needaddr - Need to record addr of outgoing dev
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*/
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struct ip_options {
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__be32 faddr;
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unsigned char optlen;
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unsigned char srr;
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unsigned char rr;
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unsigned char ts;
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unsigned char is_data:1,
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is_strictroute:1,
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srr_is_hit:1,
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is_changed:1,
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rr_needaddr:1,
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ts_needtime:1,
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ts_needaddr:1;
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unsigned char router_alert;
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unsigned char cipso;
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unsigned char __pad2;
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unsigned char __data[0];
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};
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#define optlength(opt) (sizeof(struct ip_options) + opt->optlen)
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struct inet_request_sock {
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struct request_sock req;
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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u16 inet6_rsk_offset;
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/* 2 bytes hole, try to pack */
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#endif
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__be32 loc_addr;
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__be32 rmt_addr;
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__be16 rmt_port;
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u16 snd_wscale : 4,
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rcv_wscale : 4,
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tstamp_ok : 1,
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sack_ok : 1,
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wscale_ok : 1,
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ecn_ok : 1,
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acked : 1;
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struct ip_options *opt;
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};
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static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
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{
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return (struct inet_request_sock *)sk;
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}
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struct ip_mc_socklist;
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struct ipv6_pinfo;
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struct rtable;
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/** struct inet_sock - representation of INET sockets
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*
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* @sk - ancestor class
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* @pinet6 - pointer to IPv6 control block
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* @daddr - Foreign IPv4 addr
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* @rcv_saddr - Bound local IPv4 addr
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* @dport - Destination port
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* @num - Local port
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* @saddr - Sending source
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* @uc_ttl - Unicast TTL
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* @sport - Source port
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* @id - ID counter for DF pkts
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* @tos - TOS
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* @mc_ttl - Multicasting TTL
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* @is_icsk - is this an inet_connection_sock?
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* @mc_index - Multicast device index
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* @mc_list - Group array
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* @cork - info to build ip hdr on each ip frag while socket is corked
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*/
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struct inet_sock {
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/* sk and pinet6 has to be the first two members of inet_sock */
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struct sock sk;
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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struct ipv6_pinfo *pinet6;
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#endif
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/* Socket demultiplex comparisons on incoming packets. */
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__be32 daddr;
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__be32 rcv_saddr;
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__be16 dport;
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__u16 num;
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__be32 saddr;
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__s16 uc_ttl;
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__u16 cmsg_flags;
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struct ip_options *opt;
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__be16 sport;
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__u16 id;
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__u8 tos;
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__u8 mc_ttl;
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__u8 pmtudisc;
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__u8 recverr:1,
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is_icsk:1,
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freebind:1,
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hdrincl:1,
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mc_loop:1;
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int mc_index;
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__be32 mc_addr;
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struct ip_mc_socklist *mc_list;
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struct {
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unsigned int flags;
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unsigned int fragsize;
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struct ip_options *opt;
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struct rtable *rt;
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int length; /* Total length of all frames */
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__be32 addr;
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struct flowi fl;
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} cork;
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};
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#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
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#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */
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static inline struct inet_sock *inet_sk(const struct sock *sk)
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{
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return (struct inet_sock *)sk;
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}
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static inline void __inet_sk_copy_descendant(struct sock *sk_to,
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const struct sock *sk_from,
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const int ancestor_size)
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{
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memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
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sk_from->sk_prot->obj_size - ancestor_size);
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}
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#if !(defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE))
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static inline void inet_sk_copy_descendant(struct sock *sk_to,
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const struct sock *sk_from)
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{
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__inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
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}
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#endif
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extern int inet_sk_rebuild_header(struct sock *sk);
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extern u32 inet_ehash_secret;
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extern void build_ehash_secret(void);
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static inline unsigned int inet_ehashfn(const __be32 laddr, const __u16 lport,
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const __be32 faddr, const __be16 fport)
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{
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return jhash_3words((__force __u32) laddr,
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(__force __u32) faddr,
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((__u32) lport) << 16 | (__force __u32)fport,
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inet_ehash_secret);
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}
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static inline int inet_sk_ehashfn(const struct sock *sk)
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{
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const struct inet_sock *inet = inet_sk(sk);
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const __be32 laddr = inet->rcv_saddr;
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const __u16 lport = inet->num;
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const __be32 faddr = inet->daddr;
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const __be16 fport = inet->dport;
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return inet_ehashfn(laddr, lport, faddr, fport);
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}
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static inline int inet_iif(const struct sk_buff *skb)
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{
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return ((struct rtable *)skb->dst)->rt_iif;
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}
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#endif /* _INET_SOCK_H */
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