| /* 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 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) */ |
| /* the following is not used at present */ |
| int latency; /* overhead time in milliseconds */ |
| }; |
| |
| #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 |