1 /* -----------------------------------------------------------------------------
2 * Copyright (c) 2011 Ozmo Inc
3 * Released under the GNU General Public License Version 2 (GPLv2).
4 * -----------------------------------------------------------------------------
5 */
6 #include <linux/module.h>
7 #include <linux/fs.h>
8 #include <linux/cdev.h>
9 #include <linux/uaccess.h>
10 #include <linux/netdevice.h>
11 #include <linux/etherdevice.h>
12 #include <linux/poll.h>
13 #include <linux/sched.h>
14 #include "ozconfig.h"
15 #include "ozprotocol.h"
16 #include "oztrace.h"
17 #include "ozappif.h"
18 #include "ozeltbuf.h"
19 #include "ozpd.h"
20 #include "ozproto.h"
21 #include "ozevent.h"
22 #include "ozcdev.h"
23 /*------------------------------------------------------------------------------
24 */
25 #define OZ_RD_BUF_SZ 256
26 struct oz_cdev {
27 dev_t devnum;
28 struct cdev cdev;
29 wait_queue_head_t rdq;
30 spinlock_t lock;
31 u8 active_addr[ETH_ALEN];
32 struct oz_pd *active_pd;
33 };
34
35 /* Per PD context for the serial service stored in the PD. */
36 struct oz_serial_ctx {
37 atomic_t ref_count;
38 u8 tx_seq_num;
39 u8 rx_seq_num;
40 u8 rd_buf[OZ_RD_BUF_SZ];
41 int rd_in;
42 int rd_out;
43 };
44 /*------------------------------------------------------------------------------
45 */
46 static struct oz_cdev g_cdev;
47 static struct class *g_oz_class;
48 /*------------------------------------------------------------------------------
49 * Context: process and softirq
50 */
oz_cdev_claim_ctx(struct oz_pd * pd)51 static struct oz_serial_ctx *oz_cdev_claim_ctx(struct oz_pd *pd)
52 {
53 struct oz_serial_ctx *ctx;
54 spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
55 ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
56 if (ctx)
57 atomic_inc(&ctx->ref_count);
58 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
59 return ctx;
60 }
61 /*------------------------------------------------------------------------------
62 * Context: softirq or process
63 */
oz_cdev_release_ctx(struct oz_serial_ctx * ctx)64 static void oz_cdev_release_ctx(struct oz_serial_ctx *ctx)
65 {
66 if (atomic_dec_and_test(&ctx->ref_count)) {
67 oz_trace("Dealloc serial context.\n");
68 kfree(ctx);
69 }
70 }
71 /*------------------------------------------------------------------------------
72 * Context: process
73 */
oz_cdev_open(struct inode * inode,struct file * filp)74 static int oz_cdev_open(struct inode *inode, struct file *filp)
75 {
76 struct oz_cdev *dev;
77 oz_trace("oz_cdev_open()\n");
78 oz_trace("major = %d minor = %d\n", imajor(inode), iminor(inode));
79 dev = container_of(inode->i_cdev, struct oz_cdev, cdev);
80 filp->private_data = dev;
81 return 0;
82 }
83 /*------------------------------------------------------------------------------
84 * Context: process
85 */
oz_cdev_release(struct inode * inode,struct file * filp)86 static int oz_cdev_release(struct inode *inode, struct file *filp)
87 {
88 oz_trace("oz_cdev_release()\n");
89 return 0;
90 }
91 /*------------------------------------------------------------------------------
92 * Context: process
93 */
oz_cdev_read(struct file * filp,char __user * buf,size_t count,loff_t * fpos)94 static ssize_t oz_cdev_read(struct file *filp, char __user *buf, size_t count,
95 loff_t *fpos)
96 {
97 int n;
98 int ix;
99
100 struct oz_pd *pd;
101 struct oz_serial_ctx *ctx;
102
103 spin_lock_bh(&g_cdev.lock);
104 pd = g_cdev.active_pd;
105 if (pd)
106 oz_pd_get(pd);
107 spin_unlock_bh(&g_cdev.lock);
108 if (pd == NULL)
109 return -1;
110 ctx = oz_cdev_claim_ctx(pd);
111 if (ctx == NULL)
112 goto out2;
113 n = ctx->rd_in - ctx->rd_out;
114 if (n < 0)
115 n += OZ_RD_BUF_SZ;
116 if (count > n)
117 count = n;
118 ix = ctx->rd_out;
119 n = OZ_RD_BUF_SZ - ix;
120 if (n > count)
121 n = count;
122 if (copy_to_user(buf, &ctx->rd_buf[ix], n)) {
123 count = 0;
124 goto out1;
125 }
126 ix += n;
127 if (ix == OZ_RD_BUF_SZ)
128 ix = 0;
129 if (n < count) {
130 if (copy_to_user(&buf[n], ctx->rd_buf, count-n)) {
131 count = 0;
132 goto out1;
133 }
134 ix = count-n;
135 }
136 ctx->rd_out = ix;
137 out1:
138 oz_cdev_release_ctx(ctx);
139 out2:
140 oz_pd_put(pd);
141 return count;
142 }
143 /*------------------------------------------------------------------------------
144 * Context: process
145 */
oz_cdev_write(struct file * filp,const char __user * buf,size_t count,loff_t * fpos)146 static ssize_t oz_cdev_write(struct file *filp, const char __user *buf,
147 size_t count, loff_t *fpos)
148 {
149 struct oz_pd *pd;
150 struct oz_elt_buf *eb;
151 struct oz_elt_info *ei;
152 struct oz_elt *elt;
153 struct oz_app_hdr *app_hdr;
154 struct oz_serial_ctx *ctx;
155
156 spin_lock_bh(&g_cdev.lock);
157 pd = g_cdev.active_pd;
158 if (pd)
159 oz_pd_get(pd);
160 spin_unlock_bh(&g_cdev.lock);
161 if (pd == NULL)
162 return -1;
163 eb = &pd->elt_buff;
164 ei = oz_elt_info_alloc(eb);
165 if (ei == NULL) {
166 count = 0;
167 goto out;
168 }
169 elt = (struct oz_elt *)ei->data;
170 app_hdr = (struct oz_app_hdr *)(elt+1);
171 elt->length = sizeof(struct oz_app_hdr) + count;
172 elt->type = OZ_ELT_APP_DATA;
173 ei->app_id = OZ_APPID_SERIAL;
174 ei->length = elt->length + sizeof(struct oz_elt);
175 app_hdr->app_id = OZ_APPID_SERIAL;
176 if (copy_from_user(app_hdr+1, buf, count))
177 goto out;
178 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
179 ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
180 if (ctx) {
181 app_hdr->elt_seq_num = ctx->tx_seq_num++;
182 if (ctx->tx_seq_num == 0)
183 ctx->tx_seq_num = 1;
184 spin_lock(&eb->lock);
185 if (oz_queue_elt_info(eb, 0, 0, ei) == 0)
186 ei = NULL;
187 spin_unlock(&eb->lock);
188 }
189 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
190 out:
191 if (ei) {
192 count = 0;
193 spin_lock_bh(&eb->lock);
194 oz_elt_info_free(eb, ei);
195 spin_unlock_bh(&eb->lock);
196 }
197 oz_pd_put(pd);
198 return count;
199 }
200 /*------------------------------------------------------------------------------
201 * Context: process
202 */
oz_set_active_pd(const u8 * addr)203 static int oz_set_active_pd(const u8 *addr)
204 {
205 int rc = 0;
206 struct oz_pd *pd;
207 struct oz_pd *old_pd;
208 pd = oz_pd_find(addr);
209 if (pd) {
210 spin_lock_bh(&g_cdev.lock);
211 memcpy(g_cdev.active_addr, addr, ETH_ALEN);
212 old_pd = g_cdev.active_pd;
213 g_cdev.active_pd = pd;
214 spin_unlock_bh(&g_cdev.lock);
215 if (old_pd)
216 oz_pd_put(old_pd);
217 } else {
218 if (is_zero_ether_addr(addr)) {
219 spin_lock_bh(&g_cdev.lock);
220 pd = g_cdev.active_pd;
221 g_cdev.active_pd = NULL;
222 memset(g_cdev.active_addr, 0,
223 sizeof(g_cdev.active_addr));
224 spin_unlock_bh(&g_cdev.lock);
225 if (pd)
226 oz_pd_put(pd);
227 } else {
228 rc = -1;
229 }
230 }
231 return rc;
232 }
233 /*------------------------------------------------------------------------------
234 * Context: process
235 */
oz_cdev_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)236 static long oz_cdev_ioctl(struct file *filp, unsigned int cmd,
237 unsigned long arg)
238 {
239 int rc = 0;
240 if (_IOC_TYPE(cmd) != OZ_IOCTL_MAGIC)
241 return -ENOTTY;
242 if (_IOC_NR(cmd) > OZ_IOCTL_MAX)
243 return -ENOTTY;
244 if (_IOC_DIR(cmd) & _IOC_READ)
245 rc = !access_ok(VERIFY_WRITE, (void __user *)arg,
246 _IOC_SIZE(cmd));
247 else if (_IOC_DIR(cmd) & _IOC_WRITE)
248 rc = !access_ok(VERIFY_READ, (void __user *)arg,
249 _IOC_SIZE(cmd));
250 if (rc)
251 return -EFAULT;
252 switch (cmd) {
253 case OZ_IOCTL_GET_PD_LIST: {
254 struct oz_pd_list list;
255 oz_trace("OZ_IOCTL_GET_PD_LIST\n");
256 memset(&list, 0, sizeof(list));
257 list.count = oz_get_pd_list(list.addr, OZ_MAX_PDS);
258 if (copy_to_user((void __user *)arg, &list,
259 sizeof(list)))
260 return -EFAULT;
261 }
262 break;
263 case OZ_IOCTL_SET_ACTIVE_PD: {
264 u8 addr[ETH_ALEN];
265 oz_trace("OZ_IOCTL_SET_ACTIVE_PD\n");
266 if (copy_from_user(addr, (void __user *)arg, ETH_ALEN))
267 return -EFAULT;
268 rc = oz_set_active_pd(addr);
269 }
270 break;
271 case OZ_IOCTL_GET_ACTIVE_PD: {
272 u8 addr[ETH_ALEN];
273 oz_trace("OZ_IOCTL_GET_ACTIVE_PD\n");
274 spin_lock_bh(&g_cdev.lock);
275 memcpy(addr, g_cdev.active_addr, ETH_ALEN);
276 spin_unlock_bh(&g_cdev.lock);
277 if (copy_to_user((void __user *)arg, addr, ETH_ALEN))
278 return -EFAULT;
279 }
280 break;
281 case OZ_IOCTL_ADD_BINDING:
282 case OZ_IOCTL_REMOVE_BINDING: {
283 struct oz_binding_info b;
284 if (copy_from_user(&b, (void __user *)arg,
285 sizeof(struct oz_binding_info))) {
286 return -EFAULT;
287 }
288 /* Make sure name is null terminated. */
289 b.name[OZ_MAX_BINDING_LEN-1] = 0;
290 if (cmd == OZ_IOCTL_ADD_BINDING)
291 oz_binding_add(b.name);
292 else
293 oz_binding_remove(b.name);
294 }
295 break;
296 }
297 return rc;
298 }
299 /*------------------------------------------------------------------------------
300 * Context: process
301 */
oz_cdev_poll(struct file * filp,poll_table * wait)302 static unsigned int oz_cdev_poll(struct file *filp, poll_table *wait)
303 {
304 unsigned int ret = 0;
305 struct oz_cdev *dev = filp->private_data;
306 oz_trace("Poll called wait = %p\n", wait);
307 spin_lock_bh(&dev->lock);
308 if (dev->active_pd) {
309 struct oz_serial_ctx *ctx = oz_cdev_claim_ctx(dev->active_pd);
310 if (ctx) {
311 if (ctx->rd_in != ctx->rd_out)
312 ret |= POLLIN | POLLRDNORM;
313 oz_cdev_release_ctx(ctx);
314 }
315 }
316 spin_unlock_bh(&dev->lock);
317 if (wait)
318 poll_wait(filp, &dev->rdq, wait);
319 return ret;
320 }
321 /*------------------------------------------------------------------------------
322 */
323 static const struct file_operations oz_fops = {
324 .owner = THIS_MODULE,
325 .open = oz_cdev_open,
326 .release = oz_cdev_release,
327 .read = oz_cdev_read,
328 .write = oz_cdev_write,
329 .unlocked_ioctl = oz_cdev_ioctl,
330 .poll = oz_cdev_poll
331 };
332 /*------------------------------------------------------------------------------
333 * Context: process
334 */
oz_cdev_register(void)335 int oz_cdev_register(void)
336 {
337 int err;
338 struct device *dev;
339 memset(&g_cdev, 0, sizeof(g_cdev));
340 err = alloc_chrdev_region(&g_cdev.devnum, 0, 1, "ozwpan");
341 if (err < 0)
342 goto out3;
343 oz_trace("Alloc dev number %d:%d\n", MAJOR(g_cdev.devnum),
344 MINOR(g_cdev.devnum));
345 cdev_init(&g_cdev.cdev, &oz_fops);
346 g_cdev.cdev.owner = THIS_MODULE;
347 g_cdev.cdev.ops = &oz_fops;
348 spin_lock_init(&g_cdev.lock);
349 init_waitqueue_head(&g_cdev.rdq);
350 err = cdev_add(&g_cdev.cdev, g_cdev.devnum, 1);
351 if (err < 0) {
352 oz_trace("Failed to add cdev\n");
353 goto out2;
354 }
355 g_oz_class = class_create(THIS_MODULE, "ozmo_wpan");
356 if (IS_ERR(g_oz_class)) {
357 oz_trace("Failed to register ozmo_wpan class\n");
358 goto out1;
359 }
360 dev = device_create(g_oz_class, NULL, g_cdev.devnum, NULL, "ozwpan");
361 if (IS_ERR(dev)) {
362 oz_trace("Failed to create sysfs entry for cdev\n");
363 goto out1;
364 }
365 return 0;
366 out1:
367 cdev_del(&g_cdev.cdev);
368 out2:
369 unregister_chrdev_region(g_cdev.devnum, 1);
370 out3:
371 return err;
372 }
373 /*------------------------------------------------------------------------------
374 * Context: process
375 */
oz_cdev_deregister(void)376 int oz_cdev_deregister(void)
377 {
378 cdev_del(&g_cdev.cdev);
379 unregister_chrdev_region(g_cdev.devnum, 1);
380 if (g_oz_class) {
381 device_destroy(g_oz_class, g_cdev.devnum);
382 class_destroy(g_oz_class);
383 }
384 return 0;
385 }
386 /*------------------------------------------------------------------------------
387 * Context: process
388 */
oz_cdev_init(void)389 int oz_cdev_init(void)
390 {
391 oz_event_log(OZ_EVT_SERVICE, 1, OZ_APPID_SERIAL, NULL, 0);
392 oz_app_enable(OZ_APPID_SERIAL, 1);
393 return 0;
394 }
395 /*------------------------------------------------------------------------------
396 * Context: process
397 */
oz_cdev_term(void)398 void oz_cdev_term(void)
399 {
400 oz_event_log(OZ_EVT_SERVICE, 2, OZ_APPID_SERIAL, NULL, 0);
401 oz_app_enable(OZ_APPID_SERIAL, 0);
402 }
403 /*------------------------------------------------------------------------------
404 * Context: softirq-serialized
405 */
oz_cdev_start(struct oz_pd * pd,int resume)406 int oz_cdev_start(struct oz_pd *pd, int resume)
407 {
408 struct oz_serial_ctx *ctx;
409 struct oz_serial_ctx *old_ctx;
410 oz_event_log(OZ_EVT_SERVICE, 3, OZ_APPID_SERIAL, NULL, resume);
411 if (resume) {
412 oz_trace("Serial service resumed.\n");
413 return 0;
414 }
415 ctx = kzalloc(sizeof(struct oz_serial_ctx), GFP_ATOMIC);
416 if (ctx == NULL)
417 return -ENOMEM;
418 atomic_set(&ctx->ref_count, 1);
419 ctx->tx_seq_num = 1;
420 spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
421 old_ctx = pd->app_ctx[OZ_APPID_SERIAL-1];
422 if (old_ctx) {
423 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
424 kfree(ctx);
425 } else {
426 pd->app_ctx[OZ_APPID_SERIAL-1] = ctx;
427 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
428 }
429 spin_lock(&g_cdev.lock);
430 if ((g_cdev.active_pd == NULL) &&
431 (memcmp(pd->mac_addr, g_cdev.active_addr, ETH_ALEN) == 0)) {
432 oz_pd_get(pd);
433 g_cdev.active_pd = pd;
434 oz_trace("Active PD arrived.\n");
435 }
436 spin_unlock(&g_cdev.lock);
437 oz_trace("Serial service started.\n");
438 return 0;
439 }
440 /*------------------------------------------------------------------------------
441 * Context: softirq or process
442 */
oz_cdev_stop(struct oz_pd * pd,int pause)443 void oz_cdev_stop(struct oz_pd *pd, int pause)
444 {
445 struct oz_serial_ctx *ctx;
446 oz_event_log(OZ_EVT_SERVICE, 4, OZ_APPID_SERIAL, NULL, pause);
447 if (pause) {
448 oz_trace("Serial service paused.\n");
449 return;
450 }
451 spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
452 ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
453 pd->app_ctx[OZ_APPID_SERIAL-1] = NULL;
454 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
455 if (ctx)
456 oz_cdev_release_ctx(ctx);
457 spin_lock(&g_cdev.lock);
458 if (pd == g_cdev.active_pd)
459 g_cdev.active_pd = NULL;
460 else
461 pd = NULL;
462 spin_unlock(&g_cdev.lock);
463 if (pd) {
464 oz_pd_put(pd);
465 oz_trace("Active PD departed.\n");
466 }
467 oz_trace("Serial service stopped.\n");
468 }
469 /*------------------------------------------------------------------------------
470 * Context: softirq-serialized
471 */
oz_cdev_rx(struct oz_pd * pd,struct oz_elt * elt)472 void oz_cdev_rx(struct oz_pd *pd, struct oz_elt *elt)
473 {
474 struct oz_serial_ctx *ctx;
475 struct oz_app_hdr *app_hdr;
476 u8 *data;
477 int len;
478 int space;
479 int copy_sz;
480 int ix;
481
482 ctx = oz_cdev_claim_ctx(pd);
483 if (ctx == NULL) {
484 oz_trace("Cannot claim serial context.\n");
485 return;
486 }
487
488 app_hdr = (struct oz_app_hdr *)(elt+1);
489 /* If sequence number is non-zero then check it is not a duplicate.
490 */
491 if (app_hdr->elt_seq_num != 0) {
492 if (((ctx->rx_seq_num - app_hdr->elt_seq_num) & 0x80) == 0) {
493 /* Reject duplicate element. */
494 oz_trace("Duplicate element:%02x %02x\n",
495 app_hdr->elt_seq_num, ctx->rx_seq_num);
496 goto out;
497 }
498 }
499 ctx->rx_seq_num = app_hdr->elt_seq_num;
500 len = elt->length - sizeof(struct oz_app_hdr);
501 data = ((u8 *)(elt+1)) + sizeof(struct oz_app_hdr);
502 if (len <= 0)
503 goto out;
504 space = ctx->rd_out - ctx->rd_in - 1;
505 if (space < 0)
506 space += OZ_RD_BUF_SZ;
507 if (len > space) {
508 oz_trace("Not enough space:%d %d\n", len, space);
509 len = space;
510 }
511 ix = ctx->rd_in;
512 copy_sz = OZ_RD_BUF_SZ - ix;
513 if (copy_sz > len)
514 copy_sz = len;
515 memcpy(&ctx->rd_buf[ix], data, copy_sz);
516 len -= copy_sz;
517 ix += copy_sz;
518 if (ix == OZ_RD_BUF_SZ)
519 ix = 0;
520 if (len) {
521 memcpy(ctx->rd_buf, data+copy_sz, len);
522 ix = len;
523 }
524 ctx->rd_in = ix;
525 wake_up(&g_cdev.rdq);
526 out:
527 oz_cdev_release_ctx(ctx);
528 }
529