1/* Linux ISDN subsystem, sync PPP, interface to ipppd
2 *
3 * Copyright 1994-1999  by Fritz Elfert (fritz@isdn4linux.de)
4 * Copyright 1995,96    Thinking Objects Software GmbH Wuerzburg
5 * Copyright 1995,96    by Michael Hipp (Michael.Hipp@student.uni-tuebingen.de)
6 * Copyright 2000-2002  by Kai Germaschewski (kai@germaschewski.name)
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 */
12#ifndef _LINUX_ISDN_PPP_H
13#define _LINUX_ISDN_PPP_H
14
15
16
17
18#ifdef CONFIG_IPPP_FILTER
19#include <linux/filter.h>
20#endif
21#include <uapi/linux/isdn_ppp.h>
22
23#define DECOMP_ERR_NOMEM	(-10)
24
25#define MP_END_FRAG    0x40
26#define MP_BEGIN_FRAG  0x80
27
28#define MP_MAX_QUEUE_LEN	16
29
30/*
31 * We need a way for the decompressor to influence the generation of CCP
32 * Reset-Requests in a variety of ways. The decompressor is already returning
33 * a lot of information (generated skb length, error conditions) so we use
34 * another parameter. This parameter is a pointer to a structure which is
35 * to be marked valid by the decompressor and only in this case is ever used.
36 * Furthermore, the only case where this data is used is when the decom-
37 * pressor returns DECOMP_ERROR.
38 *
39 * We use this same struct for the reset entry of the compressor to commu-
40 * nicate to its caller how to deal with sending of a Reset Ack. In this
41 * case, expra is not used, but other options still apply (suppressing
42 * sending with rsend, appending arbitrary data, etc).
43 */
44
45#define IPPP_RESET_MAXDATABYTES	32
46
47struct isdn_ppp_resetparams {
48  unsigned char valid:1;	/* rw Is this structure filled at all ? */
49  unsigned char rsend:1;	/* rw Should we send one at all ? */
50  unsigned char idval:1;	/* rw Is the id field valid ? */
51  unsigned char dtval:1;	/* rw Is the data field valid ? */
52  unsigned char expra:1;	/* rw Is an Ack expected for this Req ? */
53  unsigned char id;		/* wo Send CCP ResetReq with this id */
54  unsigned short maxdlen;	/* ro Max bytes to be stored in data field */
55  unsigned short dlen;		/* rw Bytes stored in data field */
56  unsigned char *data;		/* wo Data for ResetReq info field */
57};
58
59/*
60 * this is an 'old friend' from ppp-comp.h under a new name
61 * check the original include for more information
62 */
63struct isdn_ppp_compressor {
64  struct isdn_ppp_compressor *next, *prev;
65  struct module *owner;
66  int num; /* CCP compression protocol number */
67
68  void *(*alloc) (struct isdn_ppp_comp_data *);
69  void (*free) (void *state);
70  int  (*init) (void *state, struct isdn_ppp_comp_data *,
71		int unit,int debug);
72
73  /* The reset entry needs to get more exact information about the
74     ResetReq or ResetAck it was called with. The parameters are
75     obvious. If reset is called without a Req or Ack frame which
76     could be handed into it, code MUST be set to 0. Using rsparm,
77     the reset entry can control if and how a ResetAck is returned. */
78
79  void (*reset) (void *state, unsigned char code, unsigned char id,
80		 unsigned char *data, unsigned len,
81		 struct isdn_ppp_resetparams *rsparm);
82
83  int  (*compress) (void *state, struct sk_buff *in,
84		    struct sk_buff *skb_out, int proto);
85
86	int  (*decompress) (void *state,struct sk_buff *in,
87			    struct sk_buff *skb_out,
88			    struct isdn_ppp_resetparams *rsparm);
89
90  void (*incomp) (void *state, struct sk_buff *in,int proto);
91  void (*stat) (void *state, struct compstat *stats);
92};
93
94extern int isdn_ppp_register_compressor(struct isdn_ppp_compressor *);
95extern int isdn_ppp_unregister_compressor(struct isdn_ppp_compressor *);
96extern int isdn_ppp_dial_slave(char *);
97extern int isdn_ppp_hangup_slave(char *);
98
99typedef struct {
100  unsigned long seqerrs;
101  unsigned long frame_drops;
102  unsigned long overflows;
103  unsigned long max_queue_len;
104} isdn_mppp_stats;
105
106typedef struct {
107  int mp_mrru;                        /* unused                             */
108  struct sk_buff * frags;	/* fragments sl list -- use skb->next */
109  long frames;			/* number of frames in the frame list */
110  unsigned int seq;		/* last processed packet seq #: any packets
111  				 * with smaller seq # will be dropped
112				 * unconditionally */
113  spinlock_t lock;
114  int ref_ct;
115  /* statistics */
116  isdn_mppp_stats stats;
117} ippp_bundle;
118
119#define NUM_RCV_BUFFS     64
120
121struct ippp_buf_queue {
122  struct ippp_buf_queue *next;
123  struct ippp_buf_queue *last;
124  char *buf;                 /* NULL here indicates end of queue */
125  int len;
126};
127
128/* The data structure for one CCP reset transaction */
129enum ippp_ccp_reset_states {
130  CCPResetIdle,
131  CCPResetSentReq,
132  CCPResetRcvdReq,
133  CCPResetSentAck,
134  CCPResetRcvdAck
135};
136
137struct ippp_ccp_reset_state {
138  enum ippp_ccp_reset_states state;	/* State of this transaction */
139  struct ippp_struct *is;		/* Backlink to device stuff */
140  unsigned char id;			/* Backlink id index */
141  unsigned char ta:1;			/* The timer is active (flag) */
142  unsigned char expra:1;		/* We expect a ResetAck at all */
143  int dlen;				/* Databytes stored in data */
144  struct timer_list timer;		/* For timeouts/retries */
145  /* This is a hack but seems sufficient for the moment. We do not want
146     to have this be yet another allocation for some bytes, it is more
147     memory management overhead than the whole mess is worth. */
148  unsigned char data[IPPP_RESET_MAXDATABYTES];
149};
150
151/* The data structure keeping track of the currently outstanding CCP Reset
152   transactions. */
153struct ippp_ccp_reset {
154  struct ippp_ccp_reset_state *rs[256];	/* One per possible id */
155  unsigned char lastid;			/* Last id allocated by the engine */
156};
157
158struct ippp_struct {
159  struct ippp_struct *next_link;
160  int state;
161  spinlock_t buflock;
162  struct ippp_buf_queue rq[NUM_RCV_BUFFS]; /* packet queue for isdn_ppp_read() */
163  struct ippp_buf_queue *first;  /* pointer to (current) first packet */
164  struct ippp_buf_queue *last;   /* pointer to (current) last used packet in queue */
165  wait_queue_head_t wq;
166  struct task_struct *tk;
167  unsigned int mpppcfg;
168  unsigned int pppcfg;
169  unsigned int mru;
170  unsigned int mpmru;
171  unsigned int mpmtu;
172  unsigned int maxcid;
173  struct isdn_net_local_s *lp;
174  int unit;
175  int minor;
176  unsigned int last_link_seqno;
177  long mp_seqno;
178#ifdef CONFIG_ISDN_PPP_VJ
179  unsigned char *cbuf;
180  struct slcompress *slcomp;
181#endif
182#ifdef CONFIG_IPPP_FILTER
183  struct bpf_prog *pass_filter;   /* filter for packets to pass */
184  struct bpf_prog *active_filter; /* filter for pkts to reset idle */
185#endif
186  unsigned long debug;
187  struct isdn_ppp_compressor *compressor,*decompressor;
188  struct isdn_ppp_compressor *link_compressor,*link_decompressor;
189  void *decomp_stat,*comp_stat,*link_decomp_stat,*link_comp_stat;
190  struct ippp_ccp_reset *reset;	/* Allocated on demand, may never be needed */
191  unsigned long compflags;
192};
193
194#endif /* _LINUX_ISDN_PPP_H */
195