Commit 2e6599cb authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
Browse files

[NET] Generalise TCP's struct open_request minisock infrastructure 



Kept this first changeset minimal, without changing existing names to
ease peer review.

Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:

->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
  a specific protocol

The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.

I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.

Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)

Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1944972d

include/linux/ip.h

+21 −0
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ 
#ifdef __KERNEL__

#include <linux/config.h>

#include <linux/types.h>

#include <net/request_sock.h>

#include <net/sock.h>

#include <linux/igmp.h>

#include <net/flow.h>
@@ -107,6 +108,26 @@ struct ip_options { 


#define optlength(opt) (sizeof(struct ip_options) + opt->optlen)



struct inet_request_sock {

	struct open_request	req;

	u32			loc_addr;

	u32			rmt_addr;

	u16			rmt_port;

	u16			snd_wscale : 4, 

				rcv_wscale : 4, 

				tstamp_ok  : 1,

				sack_ok	   : 1,

				wscale_ok  : 1,

				ecn_ok	   : 1,

				acked	   : 1;

	struct ip_options	*opt;

};



static inline struct inet_request_sock *inet_rsk(const struct open_request *sk)

{

	return (struct inet_request_sock *)sk;

}



struct ipv6_pinfo;



struct inet_sock {

include/linux/ipv6.h

+13 −0
Original line number Diff line number Diff line
@@ -193,6 +193,19 @@ struct inet6_skb_parm { 


#define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))



struct tcp6_request_sock {

	struct tcp_request_sock	req;

	struct in6_addr		loc_addr;

	struct in6_addr		rmt_addr;

	struct sk_buff		*pktopts;

	int			iif;

};



static inline struct tcp6_request_sock *tcp6_rsk(const struct open_request *sk)

{

	return (struct tcp6_request_sock *)sk;

}



/**

 * struct ipv6_pinfo - ipv6 private area

 *

include/linux/tcp.h

+11 −0
Original line number Diff line number Diff line
@@ -230,6 +230,17 @@ struct tcp_options_received { 
	__u16	mss_clamp;	/* Maximal mss, negotiated at connection setup */

};



struct tcp_request_sock {

	struct inet_request_sock req;

	__u32			 rcv_isn;

	__u32			 snt_isn;

};



static inline struct tcp_request_sock *tcp_rsk(const struct open_request *req)

{

	return (struct tcp_request_sock *)req;

}



struct tcp_sock {

	/* inet_sock has to be the first member of tcp_sock */

	struct inet_sock	inet;

include/net/request_sock.h

0 → 100644
+77 −0
Original line number Diff line number Diff line 
/*

 * NET		Generic infrastructure for Network protocols.

 *

 *		Definitions for request_sock 

 *

 * Authors:	Arnaldo Carvalho de Melo <acme@conectiva.com.br>

 *

 * 		From code originally in include/net/tcp.h

 *

 *		This program is free software; you can redistribute it and/or

 *		modify it under the terms of the GNU General Public License

 *		as published by the Free Software Foundation; either version

 *		2 of the License, or (at your option) any later version.

 */

#ifndef _REQUEST_SOCK_H

#define _REQUEST_SOCK_H



#include <linux/slab.h>

#include <linux/types.h>

#include <net/sock.h>



struct open_request;

struct sk_buff;

struct dst_entry;

struct proto;



struct or_calltable {

	int		family;

	kmem_cache_t	*slab;

	int		obj_size;

	int		(*rtx_syn_ack)(struct sock *sk,

				       struct open_request *req,

				       struct dst_entry *dst);

	void		(*send_ack)(struct sk_buff *skb,

				    struct open_request *req);

	void		(*send_reset)(struct sk_buff *skb);

	void		(*destructor)(struct open_request *req);

};



/* struct open_request - mini sock to represent a connection request

 */

struct open_request {

	struct open_request		*dl_next; /* Must be first member! */

	u16				mss;

	u8				retrans;

	u8				__pad;

	/* The following two fields can be easily recomputed I think -AK */

	u32				window_clamp; /* window clamp at creation time */

	u32				rcv_wnd;	  /* rcv_wnd offered first time */

	u32				ts_recent;

	unsigned long			expires;

	struct or_calltable		*class;

	struct sock			*sk;

};



static inline struct open_request *tcp_openreq_alloc(struct or_calltable *class)

{

	struct open_request *req = kmem_cache_alloc(class->slab, SLAB_ATOMIC);



	if (req != NULL)

		req->class = class;



	return req;

}



static inline void tcp_openreq_fastfree(struct open_request *req)

{

	kmem_cache_free(req->class->slab, req);

}



static inline void tcp_openreq_free(struct open_request *req)

{

	req->class->destructor(req);

	tcp_openreq_fastfree(req);

}



#endif /* _REQUEST_SOCK_H */

include/net/sock.h

+4 −0
Original line number Diff line number Diff line
@@ -484,6 +484,8 @@ extern void sk_stream_kill_queues(struct sock *sk); 


extern int sk_wait_data(struct sock *sk, long *timeo);



struct or_calltable;



/* Networking protocol blocks we attach to sockets.

 * socket layer -> transport layer interface

 * transport -> network interface is defined by struct inet_proto
@@ -547,6 +549,8 @@ struct proto { 
	kmem_cache_t		*slab;

	unsigned int		obj_size;



	struct or_calltable	*rsk_prot;



	struct module		*owner;



	char			name[32];

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