1 /*
2  * DSS.1 Finite State Machine
3  * base: ITU-T Rec Q.931
4  *
5  * Copyright (C) 1996 Universidade de Lisboa
6  *
7  * Written by Pedro Roque Marques (roque@di.fc.ul.pt)
8  *
9  * This software may be used and distributed according to the terms of
10  * the GNU General Public License, incorporated herein by reference.
11  */
12 
13 /*
14  *        TODO: complete the FSM
15  *              move state/event descriptions to a user space logger
16  */
17 
18 #include <linux/string.h>
19 #include <linux/kernel.h>
20 
21 #include <linux/types.h>
22 #include <linux/mm.h>
23 #include <linux/skbuff.h>
24 
25 #include <linux/timer.h>
26 #include <asm/io.h>
27 
28 #include <linux/isdnif.h>
29 
30 #include "pcbit.h"
31 #include "edss1.h"
32 #include "layer2.h"
33 #include "callbacks.h"
34 
35 
36 const char * const isdn_state_table[] = {
37 	"Closed",
38 	"Call initiated",
39 	"Overlap sending",
40 	"Outgoing call proceeding",
41 	"NOT DEFINED",
42 	"Call delivered",
43 	"Call present",
44 	"Call received",
45 	"Connect request",
46 	"Incoming call proceeding",
47 	"Active",
48 	"Disconnect request",
49 	"Disconnect indication",
50 	"NOT DEFINED",
51 	"NOT DEFINED",
52 	"Suspend request",
53 	"NOT DEFINED",
54 	"Resume request",
55 	"NOT DEFINED",
56 	"Release Request",
57 	"NOT DEFINED",
58 	"NOT DEFINED",
59 	"NOT DEFINED",
60 	"NOT DEFINED",
61 	"NOT DEFINED",
62 	"Overlap receiving",
63 	"Select protocol on B-Channel",
64 	"Activate B-channel protocol"
65 };
66 
67 #ifdef DEBUG_ERRS
68 static
69 struct CauseValue {
70 	byte nr;
71 	char *descr;
72 } cvlist[] = {
73 	{0x01, "Unallocated (unassigned) number"},
74 	{0x02, "No route to specified transit network"},
75 	{0x03, "No route to destination"},
76 	{0x04, "Send special information tone"},
77 	{0x05, "Misdialled trunk prefix"},
78 	{0x06, "Channel unacceptable"},
79 	{0x07, "Channel awarded and being delivered in an established channel"},
80 	{0x08, "Preemption"},
81 	{0x09, "Preemption - circuit reserved for reuse"},
82 	{0x10, "Normal call clearing"},
83 	{0x11, "User busy"},
84 	{0x12, "No user responding"},
85 	{0x13, "No answer from user (user alerted)"},
86 	{0x14, "Subscriber absent"},
87 	{0x15, "Call rejected"},
88 	{0x16, "Number changed"},
89 	{0x1a, "non-selected user clearing"},
90 	{0x1b, "Destination out of order"},
91 	{0x1c, "Invalid number format (address incomplete)"},
92 	{0x1d, "Facility rejected"},
93 	{0x1e, "Response to Status enquiry"},
94 	{0x1f, "Normal, unspecified"},
95 	{0x22, "No circuit/channel available"},
96 	{0x26, "Network out of order"},
97 	{0x27, "Permanent frame mode connection out-of-service"},
98 	{0x28, "Permanent frame mode connection operational"},
99 	{0x29, "Temporary failure"},
100 	{0x2a, "Switching equipment congestion"},
101 	{0x2b, "Access information discarded"},
102 	{0x2c, "Requested circuit/channel not available"},
103 	{0x2e, "Precedence call blocked"},
104 	{0x2f, "Resource unavailable, unspecified"},
105 	{0x31, "Quality of service unavailable"},
106 	{0x32, "Requested facility not subscribed"},
107 	{0x35, "Outgoing calls barred within CUG"},
108 	{0x37, "Incoming calls barred within CUG"},
109 	{0x39, "Bearer capability not authorized"},
110 	{0x3a, "Bearer capability not presently available"},
111 	{0x3e, "Inconsistency in designated outgoing access information and subscriber class"},
112 	{0x3f, "Service or option not available, unspecified"},
113 	{0x41, "Bearer capability not implemented"},
114 	{0x42, "Channel type not implemented"},
115 	{0x43, "Requested facility not implemented"},
116 	{0x44, "Only restricted digital information bearer capability is available"},
117 	{0x4f, "Service or option not implemented"},
118 	{0x51, "Invalid call reference value"},
119 	{0x52, "Identified channel does not exist"},
120 	{0x53, "A suspended call exists, but this call identity does not"},
121 	{0x54, "Call identity in use"},
122 	{0x55, "No call suspended"},
123 	{0x56, "Call having the requested call identity has been cleared"},
124 	{0x57, "User not member of CUG"},
125 	{0x58, "Incompatible destination"},
126 	{0x5a, "Non-existent CUG"},
127 	{0x5b, "Invalid transit network selection"},
128 	{0x5f, "Invalid message, unspecified"},
129 	{0x60, "Mandatory information element is missing"},
130 	{0x61, "Message type non-existent or not implemented"},
131 	{0x62, "Message not compatible with call state or message type non-existent or not implemented"},
132 	{0x63, "Information element/parameter non-existent or not implemented"},
133 	{0x64, "Invalid information element contents"},
134 	{0x65, "Message not compatible with call state"},
135 	{0x66, "Recovery on timer expiry"},
136 	{0x67, "Parameter non-existent or not implemented - passed on"},
137 	{0x6e, "Message with unrecognized parameter discarded"},
138 	{0x6f, "Protocol error, unspecified"},
139 	{0x7f, "Interworking, unspecified"}
140 };
141 
142 #endif
143 
144 static struct isdn_event_desc {
145 	unsigned short ev;
146 	char *desc;
147 } isdn_event_table[] = {
148 	{EV_USR_SETUP_REQ,     "CC->L3: Setup Request"},
149 	{EV_USR_SETUP_RESP,    "CC->L3: Setup Response"},
150 	{EV_USR_PROCED_REQ,    "CC->L3: Proceeding Request"},
151 	{EV_USR_RELEASE_REQ,   "CC->L3: Release Request"},
152 
153 	{EV_NET_SETUP,        "NET->TE: setup "},
154 	{EV_NET_CALL_PROC,    "NET->TE: call proceeding"},
155 	{EV_NET_SETUP_ACK,    "NET->TE: setup acknowledge (more info needed)"},
156 	{EV_NET_CONN,         "NET->TE: connect"},
157 	{EV_NET_CONN_ACK,     "NET->TE: connect acknowledge"},
158 	{EV_NET_DISC,         "NET->TE: disconnect indication"},
159 	{EV_NET_RELEASE,      "NET->TE: release"},
160 	{EV_NET_RELEASE_COMP, "NET->TE: release complete"},
161 	{EV_NET_SELP_RESP,    "Board: Select B-channel protocol ack"},
162 	{EV_NET_ACTV_RESP,    "Board: Activate B-channel protocol ack"},
163 	{EV_TIMER,            "Timeout"},
164 	{0, "NULL"}
165 };
166 
strisdnevent(ushort ev)167 char *strisdnevent(ushort ev)
168 {
169 	struct isdn_event_desc *entry;
170 
171 	for (entry = isdn_event_table; entry->ev; entry++)
172 		if (entry->ev == ev)
173 			break;
174 
175 	return entry->desc;
176 }
177 
178 /*
179  * Euro ISDN finite state machine
180  */
181 
182 static struct fsm_timer_entry fsm_timers[] = {
183 	{ST_CALL_PROC, 10},
184 	{ST_DISC_REQ, 2},
185 	{ST_ACTIVE_SELP, 5},
186 	{ST_ACTIVE_ACTV, 5},
187 	{ST_INCM_PROC, 10},
188 	{ST_CONN_REQ, 2},
189 	{0xff, 0}
190 };
191 
192 static struct fsm_entry fsm_table[] = {
193 /* Connect Phase */
194 	/* Outgoing */
195 	{ST_NULL, ST_CALL_INIT, EV_USR_SETUP_REQ, cb_out_1},
196 
197 	{ST_CALL_INIT, ST_OVER_SEND, EV_NET_SETUP_ACK, cb_notdone},
198 	{ST_CALL_INIT, ST_CALL_PROC, EV_NET_CALL_PROC, NULL},
199 	{ST_CALL_INIT, ST_NULL, EV_NET_DISC, cb_out_2},
200 
201 	{ST_CALL_PROC, ST_ACTIVE_SELP, EV_NET_CONN, cb_out_2},
202 	{ST_CALL_PROC, ST_NULL, EV_NET_DISC, cb_disc_1},
203 	{ST_CALL_PROC, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
204 
205 	/* Incoming */
206 	{ST_NULL, ST_CALL_PRES, EV_NET_SETUP, NULL},
207 
208 	{ST_CALL_PRES, ST_INCM_PROC, EV_USR_PROCED_REQ, cb_in_1},
209 	{ST_CALL_PRES, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
210 
211 	{ST_INCM_PROC, ST_CONN_REQ, EV_USR_SETUP_RESP, cb_in_2},
212 	{ST_INCM_PROC, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
213 
214 	{ST_CONN_REQ, ST_ACTIVE_SELP, EV_NET_CONN_ACK, cb_in_3},
215 
216 	/* Active */
217 	{ST_ACTIVE, ST_NULL, EV_NET_DISC, cb_disc_1},
218 	{ST_ACTIVE, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
219 	{ST_ACTIVE, ST_NULL, EV_NET_RELEASE, cb_disc_3},
220 
221 	/* Disconnect */
222 
223 	{ST_DISC_REQ, ST_NULL, EV_NET_DISC, cb_disc_1},
224 	{ST_DISC_REQ, ST_NULL, EV_NET_RELEASE, cb_disc_3},
225 
226 	/* protocol selection */
227 	{ST_ACTIVE_SELP, ST_ACTIVE_ACTV, EV_NET_SELP_RESP, cb_selp_1},
228 	{ST_ACTIVE_SELP, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
229 
230 	{ST_ACTIVE_ACTV, ST_ACTIVE, EV_NET_ACTV_RESP, cb_open},
231 	{ST_ACTIVE_ACTV, ST_DISC_REQ, EV_USR_RELEASE_REQ, cb_disc_2},
232 
233 	/* Timers */
234 	{ST_CALL_PROC, ST_DISC_REQ, EV_TIMER, cb_disc_2},
235 	{ST_DISC_REQ, ST_NULL, EV_TIMER, cb_disc_3},
236 	{ST_ACTIVE_SELP, ST_DISC_REQ, EV_TIMER, cb_disc_2},
237 	{ST_ACTIVE_ACTV, ST_DISC_REQ, EV_TIMER, cb_disc_2},
238 	{ST_INCM_PROC, ST_DISC_REQ, EV_TIMER, cb_disc_2},
239 	{ST_CONN_REQ, ST_CONN_REQ, EV_TIMER, cb_in_2},
240 
241 	{0xff, 0, 0, NULL}
242 };
243 
244 
pcbit_fsm_timer(unsigned long data)245 static void pcbit_fsm_timer(unsigned long data)
246 {
247 	struct pcbit_dev *dev;
248 	struct pcbit_chan *chan;
249 
250 	chan = (struct pcbit_chan *) data;
251 
252 	del_timer(&chan->fsm_timer);
253 	chan->fsm_timer.function = NULL;
254 
255 	dev = chan2dev(chan);
256 
257 	if (dev == NULL) {
258 		printk(KERN_WARNING "pcbit: timer for unknown device\n");
259 		return;
260 	}
261 
262 	pcbit_fsm_event(dev, chan, EV_TIMER, NULL);
263 }
264 
265 
pcbit_fsm_event(struct pcbit_dev * dev,struct pcbit_chan * chan,unsigned short event,struct callb_data * data)266 void pcbit_fsm_event(struct pcbit_dev *dev, struct pcbit_chan *chan,
267 		     unsigned short event, struct callb_data *data)
268 {
269 	struct fsm_entry *action;
270 	struct fsm_timer_entry *tentry;
271 	unsigned long flags;
272 
273 	spin_lock_irqsave(&dev->lock, flags);
274 
275 	for (action = fsm_table; action->init != 0xff; action++)
276 		if (action->init == chan->fsm_state && action->event == event)
277 			break;
278 
279 	if (action->init == 0xff) {
280 
281 		spin_unlock_irqrestore(&dev->lock, flags);
282 		printk(KERN_DEBUG "fsm error: event %x on state %x\n",
283 		       event, chan->fsm_state);
284 		return;
285 	}
286 
287 	if (chan->fsm_timer.function) {
288 		del_timer(&chan->fsm_timer);
289 		chan->fsm_timer.function = NULL;
290 	}
291 
292 	chan->fsm_state = action->final;
293 
294 	pcbit_state_change(dev, chan, action->init, event, action->final);
295 
296 	for (tentry = fsm_timers; tentry->init != 0xff; tentry++)
297 		if (tentry->init == chan->fsm_state)
298 			break;
299 
300 	if (tentry->init != 0xff) {
301 		init_timer(&chan->fsm_timer);
302 		chan->fsm_timer.function = &pcbit_fsm_timer;
303 		chan->fsm_timer.data = (ulong) chan;
304 		chan->fsm_timer.expires = jiffies + tentry->timeout * HZ;
305 		add_timer(&chan->fsm_timer);
306 	}
307 
308 	spin_unlock_irqrestore(&dev->lock, flags);
309 
310 	if (action->callb)
311 		action->callb(dev, chan, data);
312 
313 }
314