linux-loongson/include/linux/ppp_channel.h
Qingfang Deng 95d0d094ba ppp: use IFF_NO_QUEUE in virtual interfaces
For PPPoE, PPTP, and PPPoL2TP, the start_xmit() function directly
forwards packets to the underlying network stack and never returns
anything other than 1. So these interfaces do not require a qdisc,
and the IFF_NO_QUEUE flag should be set.

Introduces a direct_xmit flag in struct ppp_channel to indicate when
IFF_NO_QUEUE should be applied. The flag is set in ppp_connect_channel()
for relevant protocols.

While at it, remove the usused latency member from struct ppp_channel.

Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250301135517.695809-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-04 17:11:17 -08:00

89 lines
3.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _PPP_CHANNEL_H_
#define _PPP_CHANNEL_H_
/*
* Definitions for the interface between the generic PPP code
* and a PPP channel.
*
* A PPP channel provides a way for the generic PPP code to send
* and receive packets over some sort of communications medium.
* Packets are stored in sk_buffs and have the 2-byte PPP protocol
* number at the start, but not the address and control bytes.
*
* Copyright 1999 Paul Mackerras.
*
* ==FILEVERSION 20000322==
*/
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/poll.h>
#include <net/net_namespace.h>
struct net_device_path;
struct net_device_path_ctx;
struct ppp_channel;
struct ppp_channel_ops {
/* Send a packet (or multilink fragment) on this channel.
Returns 1 if it was accepted, 0 if not. */
int (*start_xmit)(struct ppp_channel *, struct sk_buff *);
/* Handle an ioctl call that has come in via /dev/ppp. */
int (*ioctl)(struct ppp_channel *, unsigned int, unsigned long);
int (*fill_forward_path)(struct net_device_path_ctx *,
struct net_device_path *,
const struct ppp_channel *);
};
struct ppp_channel {
void *private; /* channel private data */
const struct ppp_channel_ops *ops; /* operations for this channel */
int mtu; /* max transmit packet size */
int hdrlen; /* amount of headroom channel needs */
void *ppp; /* opaque to channel */
int speed; /* transfer rate (bytes/second) */
bool direct_xmit; /* no qdisc, xmit directly */
};
#ifdef __KERNEL__
/* Called by the channel when it can send some more data. */
extern void ppp_output_wakeup(struct ppp_channel *);
/* Called by the channel to process a received PPP packet.
The packet should have just the 2-byte PPP protocol header. */
extern void ppp_input(struct ppp_channel *, struct sk_buff *);
/* Called by the channel when an input error occurs, indicating
that we may have missed a packet. */
extern void ppp_input_error(struct ppp_channel *, int code);
/* Attach a channel to a given PPP unit in specified net. */
extern int ppp_register_net_channel(struct net *, struct ppp_channel *);
/* Attach a channel to a given PPP unit. */
extern int ppp_register_channel(struct ppp_channel *);
/* Detach a channel from its PPP unit (e.g. on hangup). */
extern void ppp_unregister_channel(struct ppp_channel *);
/* Get the channel number for a channel */
extern int ppp_channel_index(struct ppp_channel *);
/* Get the unit number associated with a channel, or -1 if none */
extern int ppp_unit_number(struct ppp_channel *);
/* Get the device name associated with a channel, or NULL if none */
extern char *ppp_dev_name(struct ppp_channel *);
/*
* SMP locking notes:
* The channel code must ensure that when it calls ppp_unregister_channel,
* nothing is executing in any of the procedures above, for that
* channel. The generic layer will ensure that nothing is executing
* in the start_xmit and ioctl routines for the channel by the time
* that ppp_unregister_channel returns.
*/
#endif /* __KERNEL__ */
#endif