summaryrefslogtreecommitdiffstats
path: root/iotbzh-CAN-binding.c
blob: e96796c0b15f8189915413550e6509ee08cfdf0f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
/*
 * Copyright (C) 2015, 2016 "IoT.bzh"
 * Author "Romain Forlot" <romain.forlot@iot.bzh>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#define _GNU_SOURCE

#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <sys/time.h>
#include <linux/can.h>
#include <math.h>
#include <fcntl.h>
#include <systemd/sd-event.h>
#include <errno.h>

#include <json-c/json.h>
#include <openxc.pb.h>

#include <afb/afb-binding.h>
#include <afb/afb-service-itf.h>

/*****************************************************************************************/
/*****************************************************************************************/
/**											**/
/**											**/
/**	   SECTION: GLOBAL VARIABLES							**/
/**											**/
/**											**/
/*****************************************************************************************/
/*****************************************************************************************/

/* max. number of CAN interfaces given on the cmdline */
#define MAXSOCK 16

/* buffer sizes for CAN frame string representations */
#define CL_ID (sizeof("12345678##1"))
#define CL_DATA sizeof(".AA")
#define CL_BINDATA sizeof(".10101010")

 /* CAN FD ASCII hex short representation with DATA_SEPERATORs */
#define CL_CFSZ (2*CL_ID + 64*CL_DATA)

/*
 * the type of position expected
 *
 * here, this type is the selection of protocol
 */
enum type {
	type_OBDII,
	type_CAN,
	type_DEFAULT = type_CAN,
	type_INVALID = -1
};

#define type_size sizeof(enum type)-2

/*
 * each generated event
 */
struct event {
	struct event *next;	/* link for the same period */
	const char *name;	/* name of the event */
	struct afb_event event;	/* the event for the binder */
	enum type type;		/* the type of data expected */
	int id;			/* id of the event for unsubscribe */
};

struct can_handler {
	int socket;
	char *device;
	struct sockaddr_can txAddress;
};

static __u32 dropcnt[MAXSOCK];
static __u32 last_dropcnt[MAXSOCK];
char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
struct timeval tv;
struct iovec iov;
struct msghdr msg;
struct cmsghdr *cmsg;
struct canfd_frame can_frame;

/*****************************************************************************************/
/*****************************************************************************************/
/**											**/
/**											**/
/**	   SECTION: UTILITY FUNCTIONS							**/
/**											**/
/**											**/
/*****************************************************************************************/
/*****************************************************************************************/
/*
 * Interface between the daemon and the binding
 */
static const struct afb_binding_interface *interface;

/*
 * @brief Retry a function 3 times
 *
 * @param int function(): function that return an int wihtout any parameter
 *
 * @ return : 0 if ok, -1 if failed
 *
 */
static int retry( int(*func)());
static int retry( int(*func)())
{
	int i;

	for (i=0;i<4;i++)
	{
		if ( (*func)() >= 0)
		{
			return 0;
		}
		usleep(100000);
	}
	return -1;
}

/*****************************************************************************************/
/*****************************************************************************************/
/**											**/
/**											**/
/**	   SECTION: HANDLE CAN DEVICE							**/
/**											**/
/**											**/
/*****************************************************************************************/
/*****************************************************************************************/
/*
 * names of the types
 */
static const char * const type_NAMES[type_size] = {
	"OBDII",
	"CAN"
};


// Initialize default can_handler values
static struct can_handler can_handler = {
	.socket = -1,
	.device = "vcan0"
};

/*
 * Parse the CAN frame data payload as a CAN packet
 * TODO: parse as an OpenXC Can Message
 */
int can_frame_parse(openxc_CanMessage *can_message, struct can_frame *can_frame)
{

}


/*
 * open the can socket
 */
static int open_can_dev()
{
	struct ifreq ifr;
	struct timeval timeout = {1,0};

	DEBUG(interface, "open_can_dev: CAN Handler socket : %d", can_handler.socket);
	close(can_handler.socket);

	can_handler.socket = socket(PF_CAN, SOCK_RAW, CAN_RAW);
	if (can_handler.socket < 0)
	{
		ERROR(interface, "open_can_dev: socket could not be created");
	}
	else
	{
		// Set timeout for read
		setsockopt(can_handler.socket, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));
		// Attempts to open a socket to CAN bus
		strcpy(ifr.ifr_name, can_handler.device);
		if(ioctl(can_handler.socket, SIOCGIFINDEX, &ifr) < 0)
		{
			ERROR(interface, "open_can_dev: ioctl failed");
		}
		else
		{
			can_handler.txAddress.can_family = AF_CAN;
			can_handler.txAddress.can_ifindex = ifr.ifr_ifindex;

			// And bind it to txAddress
			if (bind(can_handler.socket, (struct sockaddr *)&can_handler.txAddress, sizeof(can_handler.txAddress)) < 0)
			{
				ERROR(interface, "open_can_dev: bind failed");
			}
			else
			{
				fcntl(can_handler.socket, F_SETFL, O_NONBLOCK);
				return 0;
			}
		}
		close(can_handler.socket);
		can_handler.socket = -1;
	}
	return -1;
}

static int write_can()
{
	int rc = 0;

	rc = can_handler.socket;
	if (rc >= 0)
	{
/*
 * TODO change old hvac write can frame to generic on_event
 */
		rc = sendto(can_handler.socket, &can_frame, sizeof(struct can_frame), 0,
			    (struct sockaddr*)&can_handler.txAddress, sizeof(can_handler.txAddress));
		if (rc < 0)
		{
			ERROR(interface, "Sending CAN frame failed.");
		}
	}
	else
	{
		ERROR(interface, "socket not initialized. Attempt to reopen can device socket.");
		retry(open_can_dev);
	}
	return rc;
}

/*
 * Read on CAN bus and return how much bytes has been read.
 */
static int read_can(openxc_CanMessage *can_message)
{
	int byte_read, maxdlen;
	iov.iov_base = &can_frame;
	msg.msg_name = &can_handler.txAddress;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = &ctrlmsg;

	byte_read = recvmsg(can_handler.socket, &msg, 0);

	if (byte_read < 0)
	{
		if (errno == ENETDOWN) {
			ERROR(interface, "%s: interface down", can_handler.device);
		}
		ERROR(interface, "Error reading CAN bus");
		return -1;
	}

	// CAN frame integrity check
	if ((size_t)byte_read == CAN_MTU)
		maxdlen = CAN_MAX_DLEN;
	else if ((size_t)byte_read == CANFD_MTU)
		maxdlen = CANFD_MAX_DLEN;
	else
	{
		ERROR(interface, "CAN frame incomplete");
		return -2;
	}

	for (	cmsg = CMSG_FIRSTHDR(&msg);
		cmsg && (cmsg->cmsg_level == SOL_SOCKET);
		cmsg = CMSG_NXTHDR(&msg,cmsg))
	{
		if (cmsg->cmsg_type == SO_TIMESTAMP)
			tv = *(struct timeval *)CMSG_DATA(cmsg);
			else if (cmsg->cmsg_type == SO_RXQ_OVFL)
				dropcnt[can_handler.socket] = *(__u32 *)CMSG_DATA(cmsg);
	}

	// Check if there is a new CAN frame dropped.
	if (dropcnt[can_handler.socket] != last_dropcnt[can_handler.socket])
	{
		__u32 frames = dropcnt[can_handler.socket] - last_dropcnt[can_handler.socket];
		WARNING(interface, "DROPCOUNT: dropped %d CAN frame%s on '%s' socket (total drops %d)",
			frames, (frames > 1)?"s":"", can_handler.device, dropcnt[can_handler.socket]);
			if (log)
				WARNING(interface, "DROPCOUNT: dropped %d CAN frame%s on '%s' socket (total drops %d)\n",
					frames, (frames > 1)?"s":"", can_handler.device, dropcnt[can_handler.socket]);

			last_dropcnt[can_handler.socket] = dropcnt[can_handler.socket];
	}

	can_message->has_id = true;
	can_message->id = msg.id; // TODO make the parsing to extract id from data and only return left data into msg.msg_iov
	can_message->has_data = true;
	can_message->data = msg.msg_iov;
}

/***************************************************************************************/
/***************************************************************************************/
/**                                                                                   **/
/**                                                                                   **/
/**       SECTION: MANAGING EVENTS                                                    **/
/**                                                                                   **/
/**                                                                                   **/
/***************************************************************************************/
/***************************************************************************************/
static int connect_to_event_loop();

/*
 * called on an event on the CAN bus
 */
static int on_event(sd_event_source *s, int fd, uint32_t revents, void *userdata)
{
	openxc_CanMessage can_message;

	/* read available data */
	if ((revents & EPOLLIN) != 0)
	{
		read_can(&can_message);
//		event_send();
	}

	/* check if error or hangup */
	if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
	{
		sd_event_source_unref(s);
		close(fd);
		connect_to_event_loop();
	}

	return 0;
}

/*
 * get or create an event handler for the type
 * TODO: implement function and handle retrieve or create an event as needed
 */
static struct event *event_get(enum type type)
{

}

static struct event *event_of_id(int id)
{

}

/*****************************************************************************************/
/*****************************************************************************************/
/**											**/
/**											**/
/**	   SECTION: BINDING VERBS IMPLEMENTATION					**/
/**											**/
/**											**/
/*****************************************************************************************/
/*****************************************************************************************/
/*
 * Returns the type corresponding to the given name
 */
static enum type type_of_name(const char *name)
{
	enum type result;
	if (name == NULL)
		return type_DEFAULT;
	for (result = 0 ; result < type_size; result++)
		if (strcmp(type_NAMES[result], name) == 0)
			return result;
	return type_INVALID;
}

/*
 * extract a valid type from the request
 */
static int get_type_for_req(struct afb_req req, enum type *type)
{
	if ((*type = type_of_name(afb_req_value(req, "type"))) != type_INVALID)
		return 1;
	afb_req_fail(req, "unknown-type", NULL);
	return 0;
}

/*
 * subscribe to notification of new CAN messages
 *
 * parameters of the subscription are:
 *
 *    TODO type: string:  choose between CAN and OBDII messages formats.
 *
 * returns an object with 2 fields:
 *
 *    name:   string:  the name of the event without its prefix
 *    id:     integer: a numeric identifier of the event to be used for unsubscribing
 */
static void subscribe(struct afb_req req)
{
	enum type type;
	const char *period;
	struct event *event;
	struct json_object *json;

	if (get_type_for_req(req, &type))
	{
		event = event_get(type);
		if (event == NULL)
			afb_req_fail(req, "out-of-memory", NULL);
		else if (afb_req_subscribe(req, event->event) != 0)
			afb_req_fail_f(req, "failed", "afb_req_subscribe returned an error: %m");
		else
		{
			json = json_object_new_object();
			json_object_object_add(json, "name", json_object_new_string(event->name));
			json_object_object_add(json, "id", json_object_new_int(event->id));
			afb_req_success(req, json, NULL);
		}
	}
}

/*
 * unsubscribe a previous subscription
 *
 * parameters of the unsubscription are:
 *
 *    id:   integer: the numeric identifier of the event as returned when subscribing
 */
static void unsubscribe(struct afb_req req)
{
	const char *id;
	struct event *event;

	id = afb_req_value(req, "id");
	if (id == NULL)
		afb_req_fail(req, "missing-id", NULL);
	else
	{
		event = event_of_id(atoi(id));
		if (event == NULL)
			afb_req_fail(req, "bad-id", NULL);
		else
		{
			afb_req_unsubscribe(req, event->event);
			afb_req_success(req, NULL, NULL);
		}
	}
}

static int connect_to_event_loop()
{
	sd_event_source *source;
	int rc;

	retry(open_can_dev);

	if (can_handler.socket < 0)
	{
		return can_handler.socket;
	}

	rc = sd_event_add_io(afb_daemon_get_event_loop(interface->daemon), &source, can_handler.socket, EPOLLIN, on_event, NULL);
	if (rc < 0)
	{
		close(can_handler.socket);
		ERROR(interface, "Can't connect CAN bus %s to the event loop", can_handler.device);
	} else
	{
		NOTICE(interface, "Connected CAN bus %s to the event loop", can_handler.device);
	}

	return rc;
}


// TODO: Have to change session management flag to AFB_SESSION_CHECK to use token auth
static const struct afb_verb_desc_v1 verbs[]=
{
  { .name= "subscribe",    .session= AFB_SESSION_NONE, .callback= subscribe,    .info= "subscribe to notification of CAN bus messages." },
  { .name= "unsubscribe",  .session= AFB_SESSION_NONE, .callback= unsubscribe,  .info= "unsubscribe a previous subscription." },
	{NULL}
};

static const struct afb_binding binding_desc = {
	.type = AFB_BINDING_VERSION_1,
	.v1 = {
		.info = "CAN bus service",
		.prefix = "can",
		.verbs = verbs
	}
};

const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
{
	interface = itf;

	return &binding_desc;
}

int afbBindingV1ServiceInit(struct afb_service service)
{
	return connect_to_event_loop();
}