1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */ 2*4882a593Smuzhiyun #ifndef _PPP_CHANNEL_H_ 3*4882a593Smuzhiyun #define _PPP_CHANNEL_H_ 4*4882a593Smuzhiyun /* 5*4882a593Smuzhiyun * Definitions for the interface between the generic PPP code 6*4882a593Smuzhiyun * and a PPP channel. 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * A PPP channel provides a way for the generic PPP code to send 9*4882a593Smuzhiyun * and receive packets over some sort of communications medium. 10*4882a593Smuzhiyun * Packets are stored in sk_buffs and have the 2-byte PPP protocol 11*4882a593Smuzhiyun * number at the start, but not the address and control bytes. 12*4882a593Smuzhiyun * 13*4882a593Smuzhiyun * Copyright 1999 Paul Mackerras. 14*4882a593Smuzhiyun * 15*4882a593Smuzhiyun * ==FILEVERSION 20000322== 16*4882a593Smuzhiyun */ 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun #include <linux/list.h> 19*4882a593Smuzhiyun #include <linux/skbuff.h> 20*4882a593Smuzhiyun #include <linux/poll.h> 21*4882a593Smuzhiyun #include <net/net_namespace.h> 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun struct ppp_channel; 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun struct ppp_channel_ops { 26*4882a593Smuzhiyun /* Send a packet (or multilink fragment) on this channel. 27*4882a593Smuzhiyun Returns 1 if it was accepted, 0 if not. */ 28*4882a593Smuzhiyun int (*start_xmit)(struct ppp_channel *, struct sk_buff *); 29*4882a593Smuzhiyun /* Handle an ioctl call that has come in via /dev/ppp. */ 30*4882a593Smuzhiyun int (*ioctl)(struct ppp_channel *, unsigned int, unsigned long); 31*4882a593Smuzhiyun }; 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun struct ppp_channel { 34*4882a593Smuzhiyun void *private; /* channel private data */ 35*4882a593Smuzhiyun const struct ppp_channel_ops *ops; /* operations for this channel */ 36*4882a593Smuzhiyun int mtu; /* max transmit packet size */ 37*4882a593Smuzhiyun int hdrlen; /* amount of headroom channel needs */ 38*4882a593Smuzhiyun void *ppp; /* opaque to channel */ 39*4882a593Smuzhiyun int speed; /* transfer rate (bytes/second) */ 40*4882a593Smuzhiyun /* the following is not used at present */ 41*4882a593Smuzhiyun int latency; /* overhead time in milliseconds */ 42*4882a593Smuzhiyun }; 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun #ifdef __KERNEL__ 45*4882a593Smuzhiyun /* Called by the channel when it can send some more data. */ 46*4882a593Smuzhiyun extern void ppp_output_wakeup(struct ppp_channel *); 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun /* Called by the channel to process a received PPP packet. 49*4882a593Smuzhiyun The packet should have just the 2-byte PPP protocol header. */ 50*4882a593Smuzhiyun extern void ppp_input(struct ppp_channel *, struct sk_buff *); 51*4882a593Smuzhiyun 52*4882a593Smuzhiyun /* Called by the channel when an input error occurs, indicating 53*4882a593Smuzhiyun that we may have missed a packet. */ 54*4882a593Smuzhiyun extern void ppp_input_error(struct ppp_channel *, int code); 55*4882a593Smuzhiyun 56*4882a593Smuzhiyun /* Attach a channel to a given PPP unit in specified net. */ 57*4882a593Smuzhiyun extern int ppp_register_net_channel(struct net *, struct ppp_channel *); 58*4882a593Smuzhiyun 59*4882a593Smuzhiyun /* Attach a channel to a given PPP unit. */ 60*4882a593Smuzhiyun extern int ppp_register_channel(struct ppp_channel *); 61*4882a593Smuzhiyun 62*4882a593Smuzhiyun /* Detach a channel from its PPP unit (e.g. on hangup). */ 63*4882a593Smuzhiyun extern void ppp_unregister_channel(struct ppp_channel *); 64*4882a593Smuzhiyun 65*4882a593Smuzhiyun /* Get the channel number for a channel */ 66*4882a593Smuzhiyun extern int ppp_channel_index(struct ppp_channel *); 67*4882a593Smuzhiyun 68*4882a593Smuzhiyun /* Get the unit number associated with a channel, or -1 if none */ 69*4882a593Smuzhiyun extern int ppp_unit_number(struct ppp_channel *); 70*4882a593Smuzhiyun 71*4882a593Smuzhiyun /* Get the device name associated with a channel, or NULL if none */ 72*4882a593Smuzhiyun extern char *ppp_dev_name(struct ppp_channel *); 73*4882a593Smuzhiyun 74*4882a593Smuzhiyun /* 75*4882a593Smuzhiyun * SMP locking notes: 76*4882a593Smuzhiyun * The channel code must ensure that when it calls ppp_unregister_channel, 77*4882a593Smuzhiyun * nothing is executing in any of the procedures above, for that 78*4882a593Smuzhiyun * channel. The generic layer will ensure that nothing is executing 79*4882a593Smuzhiyun * in the start_xmit and ioctl routines for the channel by the time 80*4882a593Smuzhiyun * that ppp_unregister_channel returns. 81*4882a593Smuzhiyun */ 82*4882a593Smuzhiyun 83*4882a593Smuzhiyun #endif /* __KERNEL__ */ 84*4882a593Smuzhiyun #endif 85