mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-06-21 15:43:21 +02:00
Qingfang Deng
bb8539e0e6
ppp_dev_name() holds the RCU read lock internally to protect pch->ppp. However, as it returns netdev->name to the caller, the caller should also hold either RCU or RTNL lock to prevent the netdev from being freed. The only two references of the function is in the L2TP driver, both of which already hold RCU. So remove the internal RCU lock and document that callers must hold RCU. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260316092824.479149-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
91 lines
3.0 KiB
C
91 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 *);
|
|
|
|
/* 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.
|
|
* Caller must hold RCU read lock.
|
|
*/
|
|
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
|