| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _PPP_CHANNEL_H_ |
| 2 | #define _PPP_CHANNEL_H_ |
| 3 | /* |
| 4 | * Definitions for the interface between the generic PPP code |
| 5 | * and a PPP channel. |
| 6 | * |
| 7 | * A PPP channel provides a way for the generic PPP code to send |
| 8 | * and receive packets over some sort of communications medium. |
| 9 | * Packets are stored in sk_buffs and have the 2-byte PPP protocol |
| 10 | * number at the start, but not the address and control bytes. |
| 11 | * |
| 12 | * Copyright 1999 Paul Mackerras. |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or |
| 15 | * modify it under the terms of the GNU General Public License |
| 16 | * as published by the Free Software Foundation; either version |
| 17 | * 2 of the License, or (at your option) any later version. |
| 18 | * |
| 19 | * ==FILEVERSION 20000322== |
| 20 | */ |
| 21 | |
| 22 | #include <linux/list.h> |
| 23 | #include <linux/skbuff.h> |
| 24 | #include <linux/poll.h> |
| 25 | |
| 26 | struct ppp_channel; |
| 27 | |
| 28 | struct ppp_channel_ops { |
| 29 | /* Send a packet (or multilink fragment) on this channel. |
| 30 | Returns 1 if it was accepted, 0 if not. */ |
| 31 | int (*start_xmit)(struct ppp_channel *, struct sk_buff *); |
| 32 | /* Handle an ioctl call that has come in via /dev/ppp. */ |
| 33 | int (*ioctl)(struct ppp_channel *, unsigned int, unsigned long); |
| 34 | }; |
| 35 | |
| 36 | struct ppp_channel { |
| 37 | void *private; /* channel private data */ |
| 38 | struct ppp_channel_ops *ops; /* operations for this channel */ |
| 39 | int mtu; /* max transmit packet size */ |
| 40 | int hdrlen; /* amount of headroom channel needs */ |
| 41 | void *ppp; /* opaque to channel */ |
| 42 | /* the following are not used at present */ |
| 43 | int speed; /* transfer rate (bytes/second) */ |
| 44 | int latency; /* overhead time in milliseconds */ |
| 45 | }; |
| 46 | |
| 47 | #ifdef __KERNEL__ |
| 48 | /* Called by the channel when it can send some more data. */ |
| 49 | extern void ppp_output_wakeup(struct ppp_channel *); |
| 50 | |
| 51 | /* Called by the channel to process a received PPP packet. |
| 52 | The packet should have just the 2-byte PPP protocol header. */ |
| 53 | extern void ppp_input(struct ppp_channel *, struct sk_buff *); |
| 54 | |
| 55 | /* Called by the channel when an input error occurs, indicating |
| 56 | that we may have missed a packet. */ |
| 57 | extern void ppp_input_error(struct ppp_channel *, int code); |
| 58 | |
| 59 | /* Attach a channel to a given PPP unit. */ |
| 60 | extern int ppp_register_channel(struct ppp_channel *); |
| 61 | |
| 62 | /* Detach a channel from its PPP unit (e.g. on hangup). */ |
| 63 | extern void ppp_unregister_channel(struct ppp_channel *); |
| 64 | |
| 65 | /* Get the channel number for a channel */ |
| 66 | extern int ppp_channel_index(struct ppp_channel *); |
| 67 | |
| 68 | /* Get the unit number associated with a channel, or -1 if none */ |
| 69 | extern int ppp_unit_number(struct ppp_channel *); |
| 70 | |
| 71 | /* |
| 72 | * SMP locking notes: |
| 73 | * The channel code must ensure that when it calls ppp_unregister_channel, |
| 74 | * nothing is executing in any of the procedures above, for that |
| 75 | * channel. The generic layer will ensure that nothing is executing |
| 76 | * in the start_xmit and ioctl routines for the channel by the time |
| 77 | * that ppp_unregister_channel returns. |
| 78 | */ |
| 79 | |
| 80 | #endif /* __KERNEL__ */ |
| 81 | #endif |