Edit File: ppp_channel.h
#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. * * 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. * * ==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); }; 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