1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *	Declarations of X.25 Packet Layer type objects.
4  *
5  * 	History
6  *	nov/17/96	Jonathan Naylor	  Initial version.
7  *	mar/20/00	Daniela Squassoni Disabling/enabling of facilities
8  *					  negotiation.
9  */
10 
11 #ifndef _X25_H
12 #define _X25_H
13 #include <linux/x25.h>
14 #include <linux/slab.h>
15 #include <linux/refcount.h>
16 #include <net/sock.h>
17 
18 #define	X25_ADDR_LEN			16
19 
20 #define	X25_MAX_L2_LEN			18	/* 802.2 LLC */
21 
22 #define	X25_STD_MIN_LEN			3
23 #define	X25_EXT_MIN_LEN			4
24 
25 #define	X25_GFI_SEQ_MASK		0x30
26 #define	X25_GFI_STDSEQ			0x10
27 #define	X25_GFI_EXTSEQ			0x20
28 
29 #define	X25_Q_BIT			0x80
30 #define	X25_D_BIT			0x40
31 #define	X25_STD_M_BIT			0x10
32 #define	X25_EXT_M_BIT			0x01
33 
34 #define	X25_CALL_REQUEST		0x0B
35 #define	X25_CALL_ACCEPTED		0x0F
36 #define	X25_CLEAR_REQUEST		0x13
37 #define	X25_CLEAR_CONFIRMATION		0x17
38 #define	X25_DATA			0x00
39 #define	X25_INTERRUPT			0x23
40 #define	X25_INTERRUPT_CONFIRMATION	0x27
41 #define	X25_RR				0x01
42 #define	X25_RNR				0x05
43 #define	X25_REJ				0x09
44 #define	X25_RESET_REQUEST		0x1B
45 #define	X25_RESET_CONFIRMATION		0x1F
46 #define	X25_REGISTRATION_REQUEST	0xF3
47 #define	X25_REGISTRATION_CONFIRMATION	0xF7
48 #define	X25_RESTART_REQUEST		0xFB
49 #define	X25_RESTART_CONFIRMATION	0xFF
50 #define	X25_DIAGNOSTIC			0xF1
51 #define	X25_ILLEGAL			0xFD
52 
53 /* Define the various conditions that may exist */
54 
55 #define	X25_COND_ACK_PENDING	0x01
56 #define	X25_COND_OWN_RX_BUSY	0x02
57 #define	X25_COND_PEER_RX_BUSY	0x04
58 
59 /* Define Link State constants. */
60 enum {
61 	X25_STATE_0,		/* Ready */
62 	X25_STATE_1,		/* Awaiting Call Accepted */
63 	X25_STATE_2,		/* Awaiting Clear Confirmation */
64 	X25_STATE_3,		/* Data Transfer */
65 	X25_STATE_4		/* Awaiting Reset Confirmation */
66 };
67 
68 enum {
69 	X25_LINK_STATE_0,
70 	X25_LINK_STATE_1,
71 	X25_LINK_STATE_2,
72 	X25_LINK_STATE_3
73 };
74 
75 #define X25_DEFAULT_T20		(180 * HZ)		/* Default T20 value */
76 #define X25_DEFAULT_T21		(200 * HZ)		/* Default T21 value */
77 #define X25_DEFAULT_T22		(180 * HZ)		/* Default T22 value */
78 #define	X25_DEFAULT_T23		(180 * HZ)		/* Default T23 value */
79 #define	X25_DEFAULT_T2		(3   * HZ)		/* Default ack holdback value */
80 
81 #define	X25_DEFAULT_WINDOW_SIZE	2			/* Default Window Size	*/
82 #define	X25_DEFAULT_PACKET_SIZE	X25_PS128		/* Default Packet Size */
83 #define	X25_DEFAULT_THROUGHPUT	0x0A			/* Deafult Throughput */
84 #define	X25_DEFAULT_REVERSE	0x00			/* Default Reverse Charging */
85 
86 #define X25_SMODULUS 		8
87 #define	X25_EMODULUS		128
88 
89 /*
90  *	X.25 Facilities constants.
91  */
92 
93 #define	X25_FAC_CLASS_MASK	0xC0
94 
95 #define	X25_FAC_CLASS_A		0x00
96 #define	X25_FAC_CLASS_B		0x40
97 #define	X25_FAC_CLASS_C		0x80
98 #define	X25_FAC_CLASS_D		0xC0
99 
100 #define	X25_FAC_REVERSE		0x01			/* also fast select */
101 #define	X25_FAC_THROUGHPUT	0x02
102 #define	X25_FAC_PACKET_SIZE	0x42
103 #define	X25_FAC_WINDOW_SIZE	0x43
104 
105 #define X25_MAX_FAC_LEN 	60
106 #define	X25_MAX_CUD_LEN		128
107 
108 #define X25_FAC_CALLING_AE 	0xCB
109 #define X25_FAC_CALLED_AE 	0xC9
110 
111 #define X25_MARKER 		0x00
112 #define X25_DTE_SERVICES 	0x0F
113 #define X25_MAX_AE_LEN 		40			/* Max num of semi-octets in AE - OSI Nw */
114 #define X25_MAX_DTE_FACIL_LEN	21			/* Max length of DTE facility params */
115 
116 /* Bitset in x25_sock->flags for misc flags */
117 #define X25_Q_BIT_FLAG		0
118 #define X25_INTERRUPT_FLAG	1
119 #define X25_ACCPT_APPRV_FLAG	2
120 
121 /**
122  *	struct x25_route - x25 routing entry
123  *	@node - entry in x25_list_lock
124  *	@address - Start of address range
125  *	@sigdigits - Number of sig digits
126  *	@dev - More than one for MLP
127  *	@refcnt - reference counter
128  */
129 struct x25_route {
130 	struct list_head	node;
131 	struct x25_address	address;
132 	unsigned int		sigdigits;
133 	struct net_device	*dev;
134 	refcount_t		refcnt;
135 };
136 
137 struct x25_neigh {
138 	struct list_head	node;
139 	struct net_device	*dev;
140 	unsigned int		state;
141 	unsigned int		extended;
142 	struct sk_buff_head	queue;
143 	unsigned long		t20;
144 	struct timer_list	t20timer;
145 	unsigned long		global_facil_mask;
146 	refcount_t		refcnt;
147 };
148 
149 struct x25_sock {
150 	struct sock		sk;
151 	struct x25_address	source_addr, dest_addr;
152 	struct x25_neigh	*neighbour;
153 	unsigned int		lci, cudmatchlength;
154 	unsigned char		state, condition;
155 	unsigned short		vs, vr, va, vl;
156 	unsigned long		t2, t21, t22, t23;
157 	unsigned short		fraglen;
158 	unsigned long		flags;
159 	struct sk_buff_head	ack_queue;
160 	struct sk_buff_head	fragment_queue;
161 	struct sk_buff_head	interrupt_in_queue;
162 	struct sk_buff_head	interrupt_out_queue;
163 	struct timer_list	timer;
164 	struct x25_causediag	causediag;
165 	struct x25_facilities	facilities;
166 	struct x25_dte_facilities dte_facilities;
167 	struct x25_calluserdata	calluserdata;
168 	unsigned long 		vc_facil_mask;	/* inc_call facilities mask */
169 };
170 
171 struct x25_forward {
172 	struct list_head	node;
173 	unsigned int		lci;
174 	struct net_device	*dev1;
175 	struct net_device	*dev2;
176 	atomic_t		refcnt;
177 };
178 
x25_sk(const struct sock * sk)179 static inline struct x25_sock *x25_sk(const struct sock *sk)
180 {
181 	return (struct x25_sock *)sk;
182 }
183 
184 /* af_x25.c */
185 extern int  sysctl_x25_restart_request_timeout;
186 extern int  sysctl_x25_call_request_timeout;
187 extern int  sysctl_x25_reset_request_timeout;
188 extern int  sysctl_x25_clear_request_timeout;
189 extern int  sysctl_x25_ack_holdback_timeout;
190 extern int  sysctl_x25_forward;
191 
192 int x25_parse_address_block(struct sk_buff *skb,
193 			    struct x25_address *called_addr,
194 			    struct x25_address *calling_addr);
195 
196 int x25_addr_ntoa(unsigned char *, struct x25_address *, struct x25_address *);
197 int x25_addr_aton(unsigned char *, struct x25_address *, struct x25_address *);
198 struct sock *x25_find_socket(unsigned int, struct x25_neigh *);
199 void x25_destroy_socket_from_timer(struct sock *);
200 int x25_rx_call_request(struct sk_buff *, struct x25_neigh *, unsigned int);
201 void x25_kill_by_neigh(struct x25_neigh *);
202 
203 /* x25_dev.c */
204 void x25_send_frame(struct sk_buff *, struct x25_neigh *);
205 int x25_lapb_receive_frame(struct sk_buff *, struct net_device *,
206 			   struct packet_type *, struct net_device *);
207 void x25_establish_link(struct x25_neigh *);
208 void x25_terminate_link(struct x25_neigh *);
209 
210 /* x25_facilities.c */
211 int x25_parse_facilities(struct sk_buff *, struct x25_facilities *,
212 			 struct x25_dte_facilities *, unsigned long *);
213 int x25_create_facilities(unsigned char *, struct x25_facilities *,
214 			  struct x25_dte_facilities *, unsigned long);
215 int x25_negotiate_facilities(struct sk_buff *, struct sock *,
216 			     struct x25_facilities *,
217 			     struct x25_dte_facilities *);
218 void x25_limit_facilities(struct x25_facilities *, struct x25_neigh *);
219 
220 /* x25_forward.c */
221 void x25_clear_forward_by_lci(unsigned int lci);
222 void x25_clear_forward_by_dev(struct net_device *);
223 int x25_forward_data(int, struct x25_neigh *, struct sk_buff *);
224 int x25_forward_call(struct x25_address *, struct x25_neigh *, struct sk_buff *,
225 		     int);
226 
227 /* x25_in.c */
228 int x25_process_rx_frame(struct sock *, struct sk_buff *);
229 int x25_backlog_rcv(struct sock *, struct sk_buff *);
230 
231 /* x25_link.c */
232 void x25_link_control(struct sk_buff *, struct x25_neigh *, unsigned short);
233 void x25_link_device_up(struct net_device *);
234 void x25_link_device_down(struct net_device *);
235 void x25_link_established(struct x25_neigh *);
236 void x25_link_terminated(struct x25_neigh *);
237 void x25_transmit_clear_request(struct x25_neigh *, unsigned int,
238 				unsigned char);
239 void x25_transmit_link(struct sk_buff *, struct x25_neigh *);
240 int x25_subscr_ioctl(unsigned int, void __user *);
241 struct x25_neigh *x25_get_neigh(struct net_device *);
242 void x25_link_free(void);
243 
244 /* x25_neigh.c */
x25_neigh_hold(struct x25_neigh * nb)245 static __inline__ void x25_neigh_hold(struct x25_neigh *nb)
246 {
247 	refcount_inc(&nb->refcnt);
248 }
249 
x25_neigh_put(struct x25_neigh * nb)250 static __inline__ void x25_neigh_put(struct x25_neigh *nb)
251 {
252 	if (refcount_dec_and_test(&nb->refcnt))
253 		kfree(nb);
254 }
255 
256 /* x25_out.c */
257 int x25_output(struct sock *, struct sk_buff *);
258 void x25_kick(struct sock *);
259 void x25_enquiry_response(struct sock *);
260 
261 /* x25_route.c */
262 struct x25_route *x25_get_route(struct x25_address *addr);
263 struct net_device *x25_dev_get(char *);
264 void x25_route_device_down(struct net_device *dev);
265 int x25_route_ioctl(unsigned int, void __user *);
266 void x25_route_free(void);
267 
x25_route_hold(struct x25_route * rt)268 static __inline__ void x25_route_hold(struct x25_route *rt)
269 {
270 	refcount_inc(&rt->refcnt);
271 }
272 
x25_route_put(struct x25_route * rt)273 static __inline__ void x25_route_put(struct x25_route *rt)
274 {
275 	if (refcount_dec_and_test(&rt->refcnt))
276 		kfree(rt);
277 }
278 
279 /* x25_subr.c */
280 void x25_clear_queues(struct sock *);
281 void x25_frames_acked(struct sock *, unsigned short);
282 void x25_requeue_frames(struct sock *);
283 int x25_validate_nr(struct sock *, unsigned short);
284 void x25_write_internal(struct sock *, int);
285 int x25_decode(struct sock *, struct sk_buff *, int *, int *, int *, int *,
286 	       int *);
287 void x25_disconnect(struct sock *, int, unsigned char, unsigned char);
288 
289 /* x25_timer.c */
290 void x25_init_timers(struct sock *sk);
291 void x25_start_heartbeat(struct sock *);
292 void x25_start_t2timer(struct sock *);
293 void x25_start_t21timer(struct sock *);
294 void x25_start_t22timer(struct sock *);
295 void x25_start_t23timer(struct sock *);
296 void x25_stop_heartbeat(struct sock *);
297 void x25_stop_timer(struct sock *);
298 unsigned long x25_display_timer(struct sock *);
299 void x25_check_rbuf(struct sock *);
300 
301 /* sysctl_net_x25.c */
302 #ifdef CONFIG_SYSCTL
303 int x25_register_sysctl(void);
304 void x25_unregister_sysctl(void);
305 #else
x25_register_sysctl(void)306 static inline int x25_register_sysctl(void) { return 0; };
x25_unregister_sysctl(void)307 static inline void x25_unregister_sysctl(void) {};
308 #endif /* CONFIG_SYSCTL */
309 
310 struct x25_skb_cb {
311 	unsigned int flags;
312 };
313 #define X25_SKB_CB(s) ((struct x25_skb_cb *) ((s)->cb))
314 
315 extern struct hlist_head x25_list;
316 extern rwlock_t x25_list_lock;
317 extern struct list_head x25_route_list;
318 extern rwlock_t x25_route_list_lock;
319 extern struct list_head x25_forward_list;
320 extern rwlock_t x25_forward_list_lock;
321 extern struct list_head x25_neigh_list;
322 extern rwlock_t x25_neigh_list_lock;
323 
324 int x25_proc_init(void);
325 void x25_proc_exit(void);
326 #endif
327