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1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/slab.h>
7#include <linux/tty.h>
8#include <linux/tty_flip.h>
9#include "chan.h"
10#include "os.h"
11#include "irq_kern.h"
12
13#ifdef CONFIG_NOCONFIG_CHAN
14static void *not_configged_init(char *str, int device,
15 const struct chan_opts *opts)
16{
17 printk(KERN_ERR "Using a channel type which is configured out of "
18 "UML\n");
19 return NULL;
20}
21
22static int not_configged_open(int input, int output, int primary, void *data,
23 char **dev_out)
24{
25 printk(KERN_ERR "Using a channel type which is configured out of "
26 "UML\n");
27 return -ENODEV;
28}
29
30static void not_configged_close(int fd, void *data)
31{
32 printk(KERN_ERR "Using a channel type which is configured out of "
33 "UML\n");
34}
35
36static int not_configged_read(int fd, char *c_out, void *data)
37{
38 printk(KERN_ERR "Using a channel type which is configured out of "
39 "UML\n");
40 return -EIO;
41}
42
43static int not_configged_write(int fd, const char *buf, int len, void *data)
44{
45 printk(KERN_ERR "Using a channel type which is configured out of "
46 "UML\n");
47 return -EIO;
48}
49
50static int not_configged_console_write(int fd, const char *buf, int len)
51{
52 printk(KERN_ERR "Using a channel type which is configured out of "
53 "UML\n");
54 return -EIO;
55}
56
57static int not_configged_window_size(int fd, void *data, unsigned short *rows,
58 unsigned short *cols)
59{
60 printk(KERN_ERR "Using a channel type which is configured out of "
61 "UML\n");
62 return -ENODEV;
63}
64
65static void not_configged_free(void *data)
66{
67 printk(KERN_ERR "Using a channel type which is configured out of "
68 "UML\n");
69}
70
71static const struct chan_ops not_configged_ops = {
72 .init = not_configged_init,
73 .open = not_configged_open,
74 .close = not_configged_close,
75 .read = not_configged_read,
76 .write = not_configged_write,
77 .console_write = not_configged_console_write,
78 .window_size = not_configged_window_size,
79 .free = not_configged_free,
80 .winch = 0,
81};
82#endif /* CONFIG_NOCONFIG_CHAN */
83
84static void tty_receive_char(struct tty_struct *tty, char ch)
85{
86 if (tty == NULL)
87 return;
88
89 if (I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
90 if (ch == STOP_CHAR(tty)) {
91 stop_tty(tty);
92 return;
93 }
94 else if (ch == START_CHAR(tty)) {
95 start_tty(tty);
96 return;
97 }
98 }
99
100 tty_insert_flip_char(tty, ch, TTY_NORMAL);
101}
102
103static int open_one_chan(struct chan *chan)
104{
105 int fd, err;
106
107 if (chan->opened)
108 return 0;
109
110 if (chan->ops->open == NULL)
111 fd = 0;
112 else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
113 chan->data, &chan->dev);
114 if (fd < 0)
115 return fd;
116
117 err = os_set_fd_block(fd, 0);
118 if (err) {
119 (*chan->ops->close)(fd, chan->data);
120 return err;
121 }
122
123 chan->fd = fd;
124
125 chan->opened = 1;
126 return 0;
127}
128
129static int open_chan(struct list_head *chans)
130{
131 struct list_head *ele;
132 struct chan *chan;
133 int ret, err = 0;
134
135 list_for_each(ele, chans) {
136 chan = list_entry(ele, struct chan, list);
137 ret = open_one_chan(chan);
138 if (chan->primary)
139 err = ret;
140 }
141 return err;
142}
143
144void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
145{
146 if (chan && chan->primary && chan->ops->winch)
147 register_winch(chan->fd, tty);
148}
149
150static void line_timer_cb(struct work_struct *work)
151{
152 struct line *line = container_of(work, struct line, task.work);
153
154 if (!line->throttled)
155 chan_interrupt(line, line->tty, line->driver->read_irq);
156}
157
158int enable_chan(struct line *line)
159{
160 struct list_head *ele;
161 struct chan *chan;
162 int err;
163
164 INIT_DELAYED_WORK(&line->task, line_timer_cb);
165
166 list_for_each(ele, &line->chan_list) {
167 chan = list_entry(ele, struct chan, list);
168 err = open_one_chan(chan);
169 if (err) {
170 if (chan->primary)
171 goto out_close;
172
173 continue;
174 }
175
176 if (chan->enabled)
177 continue;
178 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
179 chan);
180 if (err)
181 goto out_close;
182
183 chan->enabled = 1;
184 }
185
186 return 0;
187
188 out_close:
189 close_chan(line);
190 return err;
191}
192
193/* Items are added in IRQ context, when free_irq can't be called, and
194 * removed in process context, when it can.
195 * This handles interrupt sources which disappear, and which need to
196 * be permanently disabled. This is discovered in IRQ context, but
197 * the freeing of the IRQ must be done later.
198 */
199static DEFINE_SPINLOCK(irqs_to_free_lock);
200static LIST_HEAD(irqs_to_free);
201
202void free_irqs(void)
203{
204 struct chan *chan;
205 LIST_HEAD(list);
206 struct list_head *ele;
207 unsigned long flags;
208
209 spin_lock_irqsave(&irqs_to_free_lock, flags);
210 list_splice_init(&irqs_to_free, &list);
211 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
212
213 list_for_each(ele, &list) {
214 chan = list_entry(ele, struct chan, free_list);
215
216 if (chan->input && chan->enabled)
217 um_free_irq(chan->line->driver->read_irq, chan);
218 if (chan->output && chan->enabled)
219 um_free_irq(chan->line->driver->write_irq, chan);
220 chan->enabled = 0;
221 }
222}
223
224static void close_one_chan(struct chan *chan, int delay_free_irq)
225{
226 unsigned long flags;
227
228 if (!chan->opened)
229 return;
230
231 if (delay_free_irq) {
232 spin_lock_irqsave(&irqs_to_free_lock, flags);
233 list_add(&chan->free_list, &irqs_to_free);
234 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
235 }
236 else {
237 if (chan->input && chan->enabled)
238 um_free_irq(chan->line->driver->read_irq, chan);
239 if (chan->output && chan->enabled)
240 um_free_irq(chan->line->driver->write_irq, chan);
241 chan->enabled = 0;
242 }
243 if (chan->ops->close != NULL)
244 (*chan->ops->close)(chan->fd, chan->data);
245
246 chan->opened = 0;
247 chan->fd = -1;
248}
249
250void close_chan(struct line *line)
251{
252 struct chan *chan;
253
254 /* Close in reverse order as open in case more than one of them
255 * refers to the same device and they save and restore that device's
256 * state. Then, the first one opened will have the original state,
257 * so it must be the last closed.
258 */
259 list_for_each_entry_reverse(chan, &line->chan_list, list) {
260 close_one_chan(chan, 0);
261 }
262}
263
264void deactivate_chan(struct chan *chan, int irq)
265{
266 if (chan && chan->enabled)
267 deactivate_fd(chan->fd, irq);
268}
269
270void reactivate_chan(struct chan *chan, int irq)
271{
272 if (chan && chan->enabled)
273 reactivate_fd(chan->fd, irq);
274}
275
276int write_chan(struct chan *chan, const char *buf, int len,
277 int write_irq)
278{
279 int n, ret = 0;
280
281 if (len == 0 || !chan || !chan->ops->write)
282 return 0;
283
284 n = chan->ops->write(chan->fd, buf, len, chan->data);
285 if (chan->primary) {
286 ret = n;
287 if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
288 reactivate_fd(chan->fd, write_irq);
289 }
290 return ret;
291}
292
293int console_write_chan(struct chan *chan, const char *buf, int len)
294{
295 int n, ret = 0;
296
297 if (!chan || !chan->ops->console_write)
298 return 0;
299
300 n = chan->ops->console_write(chan->fd, buf, len);
301 if (chan->primary)
302 ret = n;
303 return ret;
304}
305
306int console_open_chan(struct line *line, struct console *co)
307{
308 int err;
309
310 err = open_chan(&line->chan_list);
311 if (err)
312 return err;
313
314 printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
315 co->index);
316 return 0;
317}
318
319int chan_window_size(struct line *line, unsigned short *rows_out,
320 unsigned short *cols_out)
321{
322 struct chan *chan;
323
324 chan = line->chan_in;
325 if (chan && chan->primary) {
326 if (chan->ops->window_size == NULL)
327 return 0;
328 return chan->ops->window_size(chan->fd, chan->data,
329 rows_out, cols_out);
330 }
331 chan = line->chan_out;
332 if (chan && chan->primary) {
333 if (chan->ops->window_size == NULL)
334 return 0;
335 return chan->ops->window_size(chan->fd, chan->data,
336 rows_out, cols_out);
337 }
338 return 0;
339}
340
341static void free_one_chan(struct chan *chan)
342{
343 list_del(&chan->list);
344
345 close_one_chan(chan, 0);
346
347 if (chan->ops->free != NULL)
348 (*chan->ops->free)(chan->data);
349
350 if (chan->primary && chan->output)
351 ignore_sigio_fd(chan->fd);
352 kfree(chan);
353}
354
355static void free_chan(struct list_head *chans)
356{
357 struct list_head *ele, *next;
358 struct chan *chan;
359
360 list_for_each_safe(ele, next, chans) {
361 chan = list_entry(ele, struct chan, list);
362 free_one_chan(chan);
363 }
364}
365
366static int one_chan_config_string(struct chan *chan, char *str, int size,
367 char **error_out)
368{
369 int n = 0;
370
371 if (chan == NULL) {
372 CONFIG_CHUNK(str, size, n, "none", 1);
373 return n;
374 }
375
376 CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
377
378 if (chan->dev == NULL) {
379 CONFIG_CHUNK(str, size, n, "", 1);
380 return n;
381 }
382
383 CONFIG_CHUNK(str, size, n, ":", 0);
384 CONFIG_CHUNK(str, size, n, chan->dev, 0);
385
386 return n;
387}
388
389static int chan_pair_config_string(struct chan *in, struct chan *out,
390 char *str, int size, char **error_out)
391{
392 int n;
393
394 n = one_chan_config_string(in, str, size, error_out);
395 str += n;
396 size -= n;
397
398 if (in == out) {
399 CONFIG_CHUNK(str, size, n, "", 1);
400 return n;
401 }
402
403 CONFIG_CHUNK(str, size, n, ",", 1);
404 n = one_chan_config_string(out, str, size, error_out);
405 str += n;
406 size -= n;
407 CONFIG_CHUNK(str, size, n, "", 1);
408
409 return n;
410}
411
412int chan_config_string(struct line *line, char *str, int size,
413 char **error_out)
414{
415 struct chan *in = line->chan_in, *out = line->chan_out;
416
417 if (in && !in->primary)
418 in = NULL;
419 if (out && !out->primary)
420 out = NULL;
421
422 return chan_pair_config_string(in, out, str, size, error_out);
423}
424
425struct chan_type {
426 char *key;
427 const struct chan_ops *ops;
428};
429
430static const struct chan_type chan_table[] = {
431 { "fd", &fd_ops },
432
433#ifdef CONFIG_NULL_CHAN
434 { "null", &null_ops },
435#else
436 { "null", ¬_configged_ops },
437#endif
438
439#ifdef CONFIG_PORT_CHAN
440 { "port", &port_ops },
441#else
442 { "port", ¬_configged_ops },
443#endif
444
445#ifdef CONFIG_PTY_CHAN
446 { "pty", &pty_ops },
447 { "pts", &pts_ops },
448#else
449 { "pty", ¬_configged_ops },
450 { "pts", ¬_configged_ops },
451#endif
452
453#ifdef CONFIG_TTY_CHAN
454 { "tty", &tty_ops },
455#else
456 { "tty", ¬_configged_ops },
457#endif
458
459#ifdef CONFIG_XTERM_CHAN
460 { "xterm", &xterm_ops },
461#else
462 { "xterm", ¬_configged_ops },
463#endif
464};
465
466static struct chan *parse_chan(struct line *line, char *str, int device,
467 const struct chan_opts *opts, char **error_out)
468{
469 const struct chan_type *entry;
470 const struct chan_ops *ops;
471 struct chan *chan;
472 void *data;
473 int i;
474
475 ops = NULL;
476 data = NULL;
477 for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
478 entry = &chan_table[i];
479 if (!strncmp(str, entry->key, strlen(entry->key))) {
480 ops = entry->ops;
481 str += strlen(entry->key);
482 break;
483 }
484 }
485 if (ops == NULL) {
486 *error_out = "No match for configured backends";
487 return NULL;
488 }
489
490 data = (*ops->init)(str, device, opts);
491 if (data == NULL) {
492 *error_out = "Configuration failed";
493 return NULL;
494 }
495
496 chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
497 if (chan == NULL) {
498 *error_out = "Memory allocation failed";
499 return NULL;
500 }
501 *chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
502 .free_list =
503 LIST_HEAD_INIT(chan->free_list),
504 .line = line,
505 .primary = 1,
506 .input = 0,
507 .output = 0,
508 .opened = 0,
509 .enabled = 0,
510 .fd = -1,
511 .ops = ops,
512 .data = data });
513 return chan;
514}
515
516int parse_chan_pair(char *str, struct line *line, int device,
517 const struct chan_opts *opts, char **error_out)
518{
519 struct list_head *chans = &line->chan_list;
520 struct chan *new;
521 char *in, *out;
522
523 if (!list_empty(chans)) {
524 line->chan_in = line->chan_out = NULL;
525 free_chan(chans);
526 INIT_LIST_HEAD(chans);
527 }
528
529 if (!str)
530 return 0;
531
532 out = strchr(str, ',');
533 if (out != NULL) {
534 in = str;
535 *out = '\0';
536 out++;
537 new = parse_chan(line, in, device, opts, error_out);
538 if (new == NULL)
539 return -1;
540
541 new->input = 1;
542 list_add(&new->list, chans);
543 line->chan_in = new;
544
545 new = parse_chan(line, out, device, opts, error_out);
546 if (new == NULL)
547 return -1;
548
549 list_add(&new->list, chans);
550 new->output = 1;
551 line->chan_out = new;
552 }
553 else {
554 new = parse_chan(line, str, device, opts, error_out);
555 if (new == NULL)
556 return -1;
557
558 list_add(&new->list, chans);
559 new->input = 1;
560 new->output = 1;
561 line->chan_in = line->chan_out = new;
562 }
563 return 0;
564}
565
566void chan_interrupt(struct line *line, struct tty_struct *tty, int irq)
567{
568 struct chan *chan = line->chan_in;
569 int err;
570 char c;
571
572 if (!chan || !chan->ops->read)
573 goto out;
574
575 do {
576 if (tty && !tty_buffer_request_room(tty, 1)) {
577 schedule_delayed_work(&line->task, 1);
578 goto out;
579 }
580 err = chan->ops->read(chan->fd, &c, chan->data);
581 if (err > 0)
582 tty_receive_char(tty, c);
583 } while (err > 0);
584
585 if (err == 0)
586 reactivate_fd(chan->fd, irq);
587 if (err == -EIO) {
588 if (chan->primary) {
589 if (tty != NULL)
590 tty_hangup(tty);
591 if (line->chan_out != chan)
592 close_one_chan(line->chan_out, 1);
593 }
594 close_one_chan(chan, 1);
595 if (chan->primary)
596 return;
597 }
598 out:
599 if (tty)
600 tty_flip_buffer_push(tty);
601}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
4 */
5
6#include <linux/slab.h>
7#include <linux/tty.h>
8#include <linux/tty_flip.h>
9#include "chan.h"
10#include <os.h>
11#include <irq_kern.h>
12
13#ifdef CONFIG_NOCONFIG_CHAN
14static void *not_configged_init(char *str, int device,
15 const struct chan_opts *opts)
16{
17 printk(KERN_ERR "Using a channel type which is configured out of "
18 "UML\n");
19 return NULL;
20}
21
22static int not_configged_open(int input, int output, int primary, void *data,
23 char **dev_out)
24{
25 printk(KERN_ERR "Using a channel type which is configured out of "
26 "UML\n");
27 return -ENODEV;
28}
29
30static void not_configged_close(int fd, void *data)
31{
32 printk(KERN_ERR "Using a channel type which is configured out of "
33 "UML\n");
34}
35
36static int not_configged_read(int fd, char *c_out, void *data)
37{
38 printk(KERN_ERR "Using a channel type which is configured out of "
39 "UML\n");
40 return -EIO;
41}
42
43static int not_configged_write(int fd, const char *buf, int len, void *data)
44{
45 printk(KERN_ERR "Using a channel type which is configured out of "
46 "UML\n");
47 return -EIO;
48}
49
50static int not_configged_console_write(int fd, const char *buf, int len)
51{
52 printk(KERN_ERR "Using a channel type which is configured out of "
53 "UML\n");
54 return -EIO;
55}
56
57static int not_configged_window_size(int fd, void *data, unsigned short *rows,
58 unsigned short *cols)
59{
60 printk(KERN_ERR "Using a channel type which is configured out of "
61 "UML\n");
62 return -ENODEV;
63}
64
65static void not_configged_free(void *data)
66{
67 printk(KERN_ERR "Using a channel type which is configured out of "
68 "UML\n");
69}
70
71static const struct chan_ops not_configged_ops = {
72 .init = not_configged_init,
73 .open = not_configged_open,
74 .close = not_configged_close,
75 .read = not_configged_read,
76 .write = not_configged_write,
77 .console_write = not_configged_console_write,
78 .window_size = not_configged_window_size,
79 .free = not_configged_free,
80 .winch = 0,
81};
82#endif /* CONFIG_NOCONFIG_CHAN */
83
84static int open_one_chan(struct chan *chan)
85{
86 int fd, err;
87
88 if (chan->opened)
89 return 0;
90
91 if (chan->ops->open == NULL)
92 fd = 0;
93 else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
94 chan->data, &chan->dev);
95 if (fd < 0)
96 return fd;
97
98 err = os_set_fd_block(fd, 0);
99 if (err) {
100 (*chan->ops->close)(fd, chan->data);
101 return err;
102 }
103
104 chan->fd = fd;
105
106 chan->opened = 1;
107 return 0;
108}
109
110static int open_chan(struct list_head *chans)
111{
112 struct list_head *ele;
113 struct chan *chan;
114 int ret, err = 0;
115
116 list_for_each(ele, chans) {
117 chan = list_entry(ele, struct chan, list);
118 ret = open_one_chan(chan);
119 if (chan->primary)
120 err = ret;
121 }
122 return err;
123}
124
125void chan_enable_winch(struct chan *chan, struct tty_port *port)
126{
127 if (chan && chan->primary && chan->ops->winch)
128 register_winch(chan->fd, port);
129}
130
131static void line_timer_cb(struct work_struct *work)
132{
133 struct line *line = container_of(work, struct line, task.work);
134
135 if (!line->throttled)
136 chan_interrupt(line, line->read_irq);
137}
138
139int enable_chan(struct line *line)
140{
141 struct list_head *ele;
142 struct chan *chan;
143 int err;
144
145 INIT_DELAYED_WORK(&line->task, line_timer_cb);
146
147 list_for_each(ele, &line->chan_list) {
148 chan = list_entry(ele, struct chan, list);
149 err = open_one_chan(chan);
150 if (err) {
151 if (chan->primary)
152 goto out_close;
153
154 continue;
155 }
156
157 if (chan->enabled)
158 continue;
159 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
160 chan);
161 if (err)
162 goto out_close;
163
164 chan->enabled = 1;
165 }
166
167 return 0;
168
169 out_close:
170 close_chan(line);
171 return err;
172}
173
174/* Items are added in IRQ context, when free_irq can't be called, and
175 * removed in process context, when it can.
176 * This handles interrupt sources which disappear, and which need to
177 * be permanently disabled. This is discovered in IRQ context, but
178 * the freeing of the IRQ must be done later.
179 */
180static DEFINE_SPINLOCK(irqs_to_free_lock);
181static LIST_HEAD(irqs_to_free);
182
183void free_irqs(void)
184{
185 struct chan *chan;
186 LIST_HEAD(list);
187 struct list_head *ele;
188 unsigned long flags;
189
190 spin_lock_irqsave(&irqs_to_free_lock, flags);
191 list_splice_init(&irqs_to_free, &list);
192 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
193
194 list_for_each(ele, &list) {
195 chan = list_entry(ele, struct chan, free_list);
196
197 if (chan->input && chan->enabled)
198 um_free_irq(chan->line->read_irq, chan);
199 if (chan->output && chan->enabled)
200 um_free_irq(chan->line->write_irq, chan);
201 chan->enabled = 0;
202 }
203}
204
205static void close_one_chan(struct chan *chan, int delay_free_irq)
206{
207 unsigned long flags;
208
209 if (!chan->opened)
210 return;
211
212 if (delay_free_irq) {
213 spin_lock_irqsave(&irqs_to_free_lock, flags);
214 list_add(&chan->free_list, &irqs_to_free);
215 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
216 } else {
217 if (chan->input && chan->enabled)
218 um_free_irq(chan->line->read_irq, chan);
219 if (chan->output && chan->enabled)
220 um_free_irq(chan->line->write_irq, chan);
221 chan->enabled = 0;
222 }
223 if (chan->ops->close != NULL)
224 (*chan->ops->close)(chan->fd, chan->data);
225
226 chan->opened = 0;
227 chan->fd = -1;
228}
229
230void close_chan(struct line *line)
231{
232 struct chan *chan;
233
234 /* Close in reverse order as open in case more than one of them
235 * refers to the same device and they save and restore that device's
236 * state. Then, the first one opened will have the original state,
237 * so it must be the last closed.
238 */
239 list_for_each_entry_reverse(chan, &line->chan_list, list) {
240 close_one_chan(chan, 0);
241 }
242}
243
244void deactivate_chan(struct chan *chan, int irq)
245{
246 if (chan && chan->enabled)
247 deactivate_fd(chan->fd, irq);
248}
249
250int write_chan(struct chan *chan, const char *buf, int len,
251 int write_irq)
252{
253 int n, ret = 0;
254
255 if (len == 0 || !chan || !chan->ops->write)
256 return 0;
257
258 n = chan->ops->write(chan->fd, buf, len, chan->data);
259 if (chan->primary) {
260 ret = n;
261 }
262 return ret;
263}
264
265int console_write_chan(struct chan *chan, const char *buf, int len)
266{
267 int n, ret = 0;
268
269 if (!chan || !chan->ops->console_write)
270 return 0;
271
272 n = chan->ops->console_write(chan->fd, buf, len);
273 if (chan->primary)
274 ret = n;
275 return ret;
276}
277
278int console_open_chan(struct line *line, struct console *co)
279{
280 int err;
281
282 err = open_chan(&line->chan_list);
283 if (err)
284 return err;
285
286 printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
287 co->index);
288 return 0;
289}
290
291int chan_window_size(struct line *line, unsigned short *rows_out,
292 unsigned short *cols_out)
293{
294 struct chan *chan;
295
296 chan = line->chan_in;
297 if (chan && chan->primary) {
298 if (chan->ops->window_size == NULL)
299 return 0;
300 return chan->ops->window_size(chan->fd, chan->data,
301 rows_out, cols_out);
302 }
303 chan = line->chan_out;
304 if (chan && chan->primary) {
305 if (chan->ops->window_size == NULL)
306 return 0;
307 return chan->ops->window_size(chan->fd, chan->data,
308 rows_out, cols_out);
309 }
310 return 0;
311}
312
313static void free_one_chan(struct chan *chan)
314{
315 list_del(&chan->list);
316
317 close_one_chan(chan, 0);
318
319 if (chan->ops->free != NULL)
320 (*chan->ops->free)(chan->data);
321
322 if (chan->primary && chan->output)
323 ignore_sigio_fd(chan->fd);
324 kfree(chan);
325}
326
327static void free_chan(struct list_head *chans)
328{
329 struct list_head *ele, *next;
330 struct chan *chan;
331
332 list_for_each_safe(ele, next, chans) {
333 chan = list_entry(ele, struct chan, list);
334 free_one_chan(chan);
335 }
336}
337
338static int one_chan_config_string(struct chan *chan, char *str, int size,
339 char **error_out)
340{
341 int n = 0;
342
343 if (chan == NULL) {
344 CONFIG_CHUNK(str, size, n, "none", 1);
345 return n;
346 }
347
348 CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
349
350 if (chan->dev == NULL) {
351 CONFIG_CHUNK(str, size, n, "", 1);
352 return n;
353 }
354
355 CONFIG_CHUNK(str, size, n, ":", 0);
356 CONFIG_CHUNK(str, size, n, chan->dev, 0);
357
358 return n;
359}
360
361static int chan_pair_config_string(struct chan *in, struct chan *out,
362 char *str, int size, char **error_out)
363{
364 int n;
365
366 n = one_chan_config_string(in, str, size, error_out);
367 str += n;
368 size -= n;
369
370 if (in == out) {
371 CONFIG_CHUNK(str, size, n, "", 1);
372 return n;
373 }
374
375 CONFIG_CHUNK(str, size, n, ",", 1);
376 n = one_chan_config_string(out, str, size, error_out);
377 str += n;
378 size -= n;
379 CONFIG_CHUNK(str, size, n, "", 1);
380
381 return n;
382}
383
384int chan_config_string(struct line *line, char *str, int size,
385 char **error_out)
386{
387 struct chan *in = line->chan_in, *out = line->chan_out;
388
389 if (in && !in->primary)
390 in = NULL;
391 if (out && !out->primary)
392 out = NULL;
393
394 return chan_pair_config_string(in, out, str, size, error_out);
395}
396
397struct chan_type {
398 char *key;
399 const struct chan_ops *ops;
400};
401
402static const struct chan_type chan_table[] = {
403 { "fd", &fd_ops },
404
405#ifdef CONFIG_NULL_CHAN
406 { "null", &null_ops },
407#else
408 { "null", ¬_configged_ops },
409#endif
410
411#ifdef CONFIG_PORT_CHAN
412 { "port", &port_ops },
413#else
414 { "port", ¬_configged_ops },
415#endif
416
417#ifdef CONFIG_PTY_CHAN
418 { "pty", &pty_ops },
419 { "pts", &pts_ops },
420#else
421 { "pty", ¬_configged_ops },
422 { "pts", ¬_configged_ops },
423#endif
424
425#ifdef CONFIG_TTY_CHAN
426 { "tty", &tty_ops },
427#else
428 { "tty", ¬_configged_ops },
429#endif
430
431#ifdef CONFIG_XTERM_CHAN
432 { "xterm", &xterm_ops },
433#else
434 { "xterm", ¬_configged_ops },
435#endif
436};
437
438static struct chan *parse_chan(struct line *line, char *str, int device,
439 const struct chan_opts *opts, char **error_out)
440{
441 const struct chan_type *entry;
442 const struct chan_ops *ops;
443 struct chan *chan;
444 void *data;
445 int i;
446
447 ops = NULL;
448 data = NULL;
449 for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
450 entry = &chan_table[i];
451 if (!strncmp(str, entry->key, strlen(entry->key))) {
452 ops = entry->ops;
453 str += strlen(entry->key);
454 break;
455 }
456 }
457 if (ops == NULL) {
458 *error_out = "No match for configured backends";
459 return NULL;
460 }
461
462 data = (*ops->init)(str, device, opts);
463 if (data == NULL) {
464 *error_out = "Configuration failed";
465 return NULL;
466 }
467
468 chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
469 if (chan == NULL) {
470 *error_out = "Memory allocation failed";
471 return NULL;
472 }
473 *chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
474 .free_list =
475 LIST_HEAD_INIT(chan->free_list),
476 .line = line,
477 .primary = 1,
478 .input = 0,
479 .output = 0,
480 .opened = 0,
481 .enabled = 0,
482 .fd = -1,
483 .ops = ops,
484 .data = data });
485 return chan;
486}
487
488int parse_chan_pair(char *str, struct line *line, int device,
489 const struct chan_opts *opts, char **error_out)
490{
491 struct list_head *chans = &line->chan_list;
492 struct chan *new;
493 char *in, *out;
494
495 if (!list_empty(chans)) {
496 line->chan_in = line->chan_out = NULL;
497 free_chan(chans);
498 INIT_LIST_HEAD(chans);
499 }
500
501 if (!str)
502 return 0;
503
504 out = strchr(str, ',');
505 if (out != NULL) {
506 in = str;
507 *out = '\0';
508 out++;
509 new = parse_chan(line, in, device, opts, error_out);
510 if (new == NULL)
511 return -1;
512
513 new->input = 1;
514 list_add(&new->list, chans);
515 line->chan_in = new;
516
517 new = parse_chan(line, out, device, opts, error_out);
518 if (new == NULL)
519 return -1;
520
521 list_add(&new->list, chans);
522 new->output = 1;
523 line->chan_out = new;
524 }
525 else {
526 new = parse_chan(line, str, device, opts, error_out);
527 if (new == NULL)
528 return -1;
529
530 list_add(&new->list, chans);
531 new->input = 1;
532 new->output = 1;
533 line->chan_in = line->chan_out = new;
534 }
535 return 0;
536}
537
538void chan_interrupt(struct line *line, int irq)
539{
540 struct tty_port *port = &line->port;
541 struct chan *chan = line->chan_in;
542 int err;
543 char c;
544
545 if (!chan || !chan->ops->read)
546 goto out;
547
548 do {
549 if (!tty_buffer_request_room(port, 1)) {
550 schedule_delayed_work(&line->task, 1);
551 goto out;
552 }
553 err = chan->ops->read(chan->fd, &c, chan->data);
554 if (err > 0)
555 tty_insert_flip_char(port, c, TTY_NORMAL);
556 } while (err > 0);
557
558 if (err == -EIO) {
559 if (chan->primary) {
560 tty_port_tty_hangup(&line->port, false);
561 if (line->chan_out != chan)
562 close_one_chan(line->chan_out, 1);
563 }
564 close_one_chan(chan, 1);
565 if (chan->primary)
566 return;
567 }
568 out:
569 tty_flip_buffer_push(port);
570}