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linux/net/dccp/ccid.h
Gerrit Renker 6179983ad3 [DCCP]: Introducing CCMPS
This introduces a CCMPS field for setting a CCID-specific upper bound on the application payload
size, as is defined in RFC 4340, section 14.

Only the TX CCID is considered in setting this limit, since the RX CCID generates comparatively
small (DCCP-Ack) feedback packets. The CCMPS field includes network and transport layer header
lengths. The only current CCMPS customer is CCID4 (via RFC 4828).

A wrapper is used to allow querying the CCMPS even at times where the CCID modules may not have
been fully negotiated yet.

In dccp_sync_mss() the variable `mss_now' has been renamed into `cur_mps', to reflect that we are
dealing with an MPS, but not an MSS.
Since the DCCP code closely follows the TCP code, the identifiers `dccp_sync_mss' and
`dccps_mss_cache' have been kept, as they have direct TCP counterparts.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:57:59 -08:00

214 lines
7.0 KiB
C

#ifndef _CCID_H
#define _CCID_H
/*
* net/dccp/ccid.h
*
* An implementation of the DCCP protocol
* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* CCID infrastructure
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <net/sock.h>
#include <linux/compiler.h>
#include <linux/dccp.h>
#include <linux/list.h>
#include <linux/module.h>
#define CCID_MAX 255
struct tcp_info;
/**
* struct ccid_operations - Interface to Congestion-Control Infrastructure
*
* @ccid_id: numerical CCID ID (up to %CCID_MAX, cf. table 5 in RFC 4340, 10.)
* @ccid_ccmps: the CCMPS including network/transport headers (0 when disabled)
* @ccid_name: alphabetical identifier string for @ccid_id
* @ccid_owner: module which implements/owns this CCID
* @ccid_hc_{r,t}x_slab: memory pool for the receiver/sender half-connection
* @ccid_hc_{r,t}x_obj_size: size of the receiver/sender half-connection socket
*
* @ccid_hc_{r,t}x_init: CCID-specific initialisation routine (before startup)
* @ccid_hc_{r,t}x_exit: CCID-specific cleanup routine (before destruction)
* @ccid_hc_rx_packet_recv: implements the HC-receiver side
* @ccid_hc_{r,t}x_parse_options: parsing routine for CCID/HC-specific options
* @ccid_hc_{r,t}x_insert_options: insert routine for CCID/HC-specific options
* @ccid_hc_tx_packet_recv: implements feedback processing for the HC-sender
* @ccid_hc_tx_send_packet: implements the sending part of the HC-sender
* @ccid_hc_tx_packet_sent: does accounting for packets in flight by HC-sender
* @ccid_hc_{r,t}x_get_info: INET_DIAG information for HC-receiver/sender
* @ccid_hc_{r,t}x_getsockopt: socket options specific to HC-receiver/sender
*/
struct ccid_operations {
unsigned char ccid_id;
__u32 ccid_ccmps;
const char *ccid_name;
struct module *ccid_owner;
struct kmem_cache *ccid_hc_rx_slab,
*ccid_hc_tx_slab;
__u32 ccid_hc_rx_obj_size,
ccid_hc_tx_obj_size;
/* Interface Routines */
int (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk);
int (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk);
void (*ccid_hc_rx_exit)(struct sock *sk);
void (*ccid_hc_tx_exit)(struct sock *sk);
void (*ccid_hc_rx_packet_recv)(struct sock *sk,
struct sk_buff *skb);
int (*ccid_hc_rx_parse_options)(struct sock *sk,
unsigned char option,
unsigned char len, u16 idx,
unsigned char* value);
int (*ccid_hc_rx_insert_options)(struct sock *sk,
struct sk_buff *skb);
void (*ccid_hc_tx_packet_recv)(struct sock *sk,
struct sk_buff *skb);
int (*ccid_hc_tx_parse_options)(struct sock *sk,
unsigned char option,
unsigned char len, u16 idx,
unsigned char* value);
int (*ccid_hc_tx_send_packet)(struct sock *sk,
struct sk_buff *skb);
void (*ccid_hc_tx_packet_sent)(struct sock *sk,
int more, unsigned int len);
void (*ccid_hc_rx_get_info)(struct sock *sk,
struct tcp_info *info);
void (*ccid_hc_tx_get_info)(struct sock *sk,
struct tcp_info *info);
int (*ccid_hc_rx_getsockopt)(struct sock *sk,
const int optname, int len,
u32 __user *optval,
int __user *optlen);
int (*ccid_hc_tx_getsockopt)(struct sock *sk,
const int optname, int len,
u32 __user *optval,
int __user *optlen);
};
extern int ccid_register(struct ccid_operations *ccid_ops);
extern int ccid_unregister(struct ccid_operations *ccid_ops);
struct ccid {
struct ccid_operations *ccid_ops;
char ccid_priv[0];
};
static inline void *ccid_priv(const struct ccid *ccid)
{
return (void *)ccid->ccid_priv;
}
extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx,
gfp_t gfp);
extern struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk,
gfp_t gfp);
extern struct ccid *ccid_hc_tx_new(unsigned char id, struct sock *sk,
gfp_t gfp);
extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk);
extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk);
static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
struct sk_buff *skb)
{
int rc = 0;
if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
rc = ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb);
return rc;
}
static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
int more, unsigned int len)
{
if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, more, len);
}
static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
struct sk_buff *skb)
{
if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
}
static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
struct sk_buff *skb)
{
if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
}
static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
unsigned char option,
unsigned char len, u16 idx,
unsigned char* value)
{
int rc = 0;
if (ccid->ccid_ops->ccid_hc_tx_parse_options != NULL)
rc = ccid->ccid_ops->ccid_hc_tx_parse_options(sk, option, len, idx,
value);
return rc;
}
static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
unsigned char option,
unsigned char len, u16 idx,
unsigned char* value)
{
int rc = 0;
if (ccid->ccid_ops->ccid_hc_rx_parse_options != NULL)
rc = ccid->ccid_ops->ccid_hc_rx_parse_options(sk, option, len, idx, value);
return rc;
}
static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
struct sk_buff *skb)
{
if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
return 0;
}
static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
struct tcp_info *info)
{
if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
}
static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
struct tcp_info *info)
{
if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
}
static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
const int optname, int len,
u32 __user *optval, int __user *optlen)
{
int rc = -ENOPROTOOPT;
if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
optval, optlen);
return rc;
}
static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
const int optname, int len,
u32 __user *optval, int __user *optlen)
{
int rc = -ENOPROTOOPT;
if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,
optval, optlen);
return rc;
}
#endif /* _CCID_H */