1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * z/VM IUCV hypervisor console (HVC) device driver |
4 | * |
5 | * This HVC device driver provides terminal access using |
6 | * z/VM IUCV communication paths. |
7 | * |
8 | * Copyright IBM Corp. 2008, 2013 |
9 | * |
10 | * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> |
11 | */ |
12 | #define KMSG_COMPONENT "hvc_iucv" |
13 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
14 | |
15 | #include <linux/types.h> |
16 | #include <linux/slab.h> |
17 | #include <asm/ebcdic.h> |
18 | #include <linux/ctype.h> |
19 | #include <linux/delay.h> |
20 | #include <linux/device.h> |
21 | #include <linux/init.h> |
22 | #include <linux/mempool.h> |
23 | #include <linux/moduleparam.h> |
24 | #include <linux/tty.h> |
25 | #include <linux/wait.h> |
26 | #include <net/iucv/iucv.h> |
27 | |
28 | #include "hvc_console.h" |
29 | |
30 | |
31 | /* General device driver settings */ |
32 | #define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS |
33 | #define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) |
34 | |
35 | /* IUCV TTY message */ |
36 | #define MSG_VERSION 0x02 /* Message version */ |
37 | #define MSG_TYPE_ERROR 0x01 /* Error message */ |
38 | #define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ |
39 | #define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ |
40 | #define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ |
41 | #define MSG_TYPE_DATA 0x10 /* Terminal data */ |
42 | |
43 | struct iucv_tty_msg { |
44 | u8 version; /* Message version */ |
45 | u8 type; /* Message type */ |
46 | #define MSG_MAX_DATALEN ((u16)(~0)) |
47 | u16 datalen; /* Payload length */ |
48 | u8 data[]; /* Payload buffer */ |
49 | } __attribute__((packed)); |
50 | #define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) |
51 | |
52 | enum iucv_state_t { |
53 | IUCV_DISCONN = 0, |
54 | IUCV_CONNECTED = 1, |
55 | IUCV_SEVERED = 2, |
56 | }; |
57 | |
58 | enum tty_state_t { |
59 | TTY_CLOSED = 0, |
60 | TTY_OPENED = 1, |
61 | }; |
62 | |
63 | struct hvc_iucv_private { |
64 | struct hvc_struct *hvc; /* HVC struct reference */ |
65 | u8 srv_name[8]; /* IUCV service name (ebcdic) */ |
66 | unsigned char is_console; /* Linux console usage flag */ |
67 | enum iucv_state_t iucv_state; /* IUCV connection status */ |
68 | enum tty_state_t tty_state; /* TTY status */ |
69 | struct iucv_path *path; /* IUCV path pointer */ |
70 | spinlock_t lock; /* hvc_iucv_private lock */ |
71 | #define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ |
72 | void *sndbuf; /* send buffer */ |
73 | size_t sndbuf_len; /* length of send buffer */ |
74 | #define QUEUE_SNDBUF_DELAY (HZ / 25) |
75 | struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ |
76 | wait_queue_head_t sndbuf_waitq; /* wait for send completion */ |
77 | struct list_head tty_outqueue; /* outgoing IUCV messages */ |
78 | struct list_head tty_inqueue; /* incoming IUCV messages */ |
79 | struct device *dev; /* device structure */ |
80 | u8 info_path[16]; /* IUCV path info (dev attr) */ |
81 | }; |
82 | |
83 | struct iucv_tty_buffer { |
84 | struct list_head list; /* list pointer */ |
85 | struct iucv_message msg; /* store an IUCV message */ |
86 | size_t offset; /* data buffer offset */ |
87 | struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ |
88 | }; |
89 | |
90 | /* IUCV callback handler */ |
91 | static int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *); |
92 | static void hvc_iucv_path_severed(struct iucv_path *, u8 *); |
93 | static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); |
94 | static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); |
95 | |
96 | |
97 | /* Kernel module parameter: use one terminal device as default */ |
98 | static unsigned long hvc_iucv_devices = 1; |
99 | |
100 | /* Array of allocated hvc iucv tty lines... */ |
101 | static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; |
102 | #define IUCV_HVC_CON_IDX (0) |
103 | /* List of z/VM user ID filter entries (struct iucv_vmid_filter) */ |
104 | #define MAX_VMID_FILTER (500) |
105 | #define FILTER_WILDCARD_CHAR '*' |
106 | static size_t hvc_iucv_filter_size; |
107 | static void *hvc_iucv_filter; |
108 | static const char *hvc_iucv_filter_string; |
109 | static DEFINE_RWLOCK(hvc_iucv_filter_lock); |
110 | |
111 | /* Kmem cache and mempool for iucv_tty_buffer elements */ |
112 | static struct kmem_cache *hvc_iucv_buffer_cache; |
113 | static mempool_t *hvc_iucv_mempool; |
114 | |
115 | /* IUCV handler callback functions */ |
116 | static struct iucv_handler hvc_iucv_handler = { |
117 | .path_pending = hvc_iucv_path_pending, |
118 | .path_severed = hvc_iucv_path_severed, |
119 | .message_complete = hvc_iucv_msg_complete, |
120 | .message_pending = hvc_iucv_msg_pending, |
121 | }; |
122 | |
123 | |
124 | /** |
125 | * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. |
126 | * @num: The HVC virtual terminal number (vtermno) |
127 | * |
128 | * This function returns the struct hvc_iucv_private instance that corresponds |
129 | * to the HVC virtual terminal number specified as parameter @num. |
130 | */ |
131 | static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) |
132 | { |
133 | if (num > hvc_iucv_devices) |
134 | return NULL; |
135 | return hvc_iucv_table[num]; |
136 | } |
137 | |
138 | /** |
139 | * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. |
140 | * @size: Size of the internal buffer used to store data. |
141 | * @flags: Memory allocation flags passed to mempool. |
142 | * |
143 | * This function allocates a new struct iucv_tty_buffer element and, optionally, |
144 | * allocates an internal data buffer with the specified size @size. |
145 | * The internal data buffer is always allocated with GFP_DMA which is |
146 | * required for receiving and sending data with IUCV. |
147 | * Note: The total message size arises from the internal buffer size and the |
148 | * members of the iucv_tty_msg structure. |
149 | * The function returns NULL if memory allocation has failed. |
150 | */ |
151 | static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) |
152 | { |
153 | struct iucv_tty_buffer *bufp; |
154 | |
155 | bufp = mempool_alloc(pool: hvc_iucv_mempool, gfp_mask: flags); |
156 | if (!bufp) |
157 | return NULL; |
158 | memset(bufp, 0, sizeof(*bufp)); |
159 | |
160 | if (size > 0) { |
161 | bufp->msg.length = MSG_SIZE(size); |
162 | bufp->mbuf = kmalloc(size: bufp->msg.length, flags: flags | GFP_DMA); |
163 | if (!bufp->mbuf) { |
164 | mempool_free(element: bufp, pool: hvc_iucv_mempool); |
165 | return NULL; |
166 | } |
167 | bufp->mbuf->version = MSG_VERSION; |
168 | bufp->mbuf->type = MSG_TYPE_DATA; |
169 | bufp->mbuf->datalen = (u16) size; |
170 | } |
171 | return bufp; |
172 | } |
173 | |
174 | /** |
175 | * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. |
176 | * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. |
177 | */ |
178 | static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) |
179 | { |
180 | kfree(objp: bufp->mbuf); |
181 | mempool_free(element: bufp, pool: hvc_iucv_mempool); |
182 | } |
183 | |
184 | /** |
185 | * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. |
186 | * @list: List containing struct iucv_tty_buffer elements. |
187 | */ |
188 | static void destroy_tty_buffer_list(struct list_head *list) |
189 | { |
190 | struct iucv_tty_buffer *ent, *next; |
191 | |
192 | list_for_each_entry_safe(ent, next, list, list) { |
193 | list_del(entry: &ent->list); |
194 | destroy_tty_buffer(bufp: ent); |
195 | } |
196 | } |
197 | |
198 | /** |
199 | * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. |
200 | * @priv: Pointer to struct hvc_iucv_private |
201 | * @buf: HVC buffer for writing received terminal data. |
202 | * @count: HVC buffer size. |
203 | * @has_more_data: Pointer to an int variable. |
204 | * |
205 | * The function picks up pending messages from the input queue and receives |
206 | * the message data that is then written to the specified buffer @buf. |
207 | * If the buffer size @count is less than the data message size, the |
208 | * message is kept on the input queue and @has_more_data is set to 1. |
209 | * If all message data has been written, the message is removed from |
210 | * the input queue. |
211 | * |
212 | * The function returns the number of bytes written to the terminal, zero if |
213 | * there are no pending data messages available or if there is no established |
214 | * IUCV path. |
215 | * If the IUCV path has been severed, then -EPIPE is returned to cause a |
216 | * hang up (that is issued by the HVC layer). |
217 | */ |
218 | static int hvc_iucv_write(struct hvc_iucv_private *priv, |
219 | char *buf, int count, int *has_more_data) |
220 | { |
221 | struct iucv_tty_buffer *rb; |
222 | int written; |
223 | int rc; |
224 | |
225 | /* immediately return if there is no IUCV connection */ |
226 | if (priv->iucv_state == IUCV_DISCONN) |
227 | return 0; |
228 | |
229 | /* if the IUCV path has been severed, return -EPIPE to inform the |
230 | * HVC layer to hang up the tty device. */ |
231 | if (priv->iucv_state == IUCV_SEVERED) |
232 | return -EPIPE; |
233 | |
234 | /* check if there are pending messages */ |
235 | if (list_empty(head: &priv->tty_inqueue)) |
236 | return 0; |
237 | |
238 | /* receive an iucv message and flip data to the tty (ldisc) */ |
239 | rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); |
240 | |
241 | written = 0; |
242 | if (!rb->mbuf) { /* message not yet received ... */ |
243 | /* allocate mem to store msg data; if no memory is available |
244 | * then leave the buffer on the list and re-try later */ |
245 | rb->mbuf = kmalloc(size: rb->msg.length, GFP_ATOMIC | GFP_DMA); |
246 | if (!rb->mbuf) |
247 | return -ENOMEM; |
248 | |
249 | rc = __iucv_message_receive(path: priv->path, msg: &rb->msg, flags: 0, |
250 | buffer: rb->mbuf, size: rb->msg.length, NULL); |
251 | switch (rc) { |
252 | case 0: /* Successful */ |
253 | break; |
254 | case 2: /* No message found */ |
255 | case 9: /* Message purged */ |
256 | break; |
257 | default: |
258 | written = -EIO; |
259 | } |
260 | /* remove buffer if an error has occurred or received data |
261 | * is not correct */ |
262 | if (rc || (rb->mbuf->version != MSG_VERSION) || |
263 | (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) |
264 | goto out_remove_buffer; |
265 | } |
266 | |
267 | switch (rb->mbuf->type) { |
268 | case MSG_TYPE_DATA: |
269 | written = min_t(int, rb->mbuf->datalen - rb->offset, count); |
270 | memcpy(buf, rb->mbuf->data + rb->offset, written); |
271 | if (written < (rb->mbuf->datalen - rb->offset)) { |
272 | rb->offset += written; |
273 | *has_more_data = 1; |
274 | goto out_written; |
275 | } |
276 | break; |
277 | |
278 | case MSG_TYPE_WINSIZE: |
279 | if (rb->mbuf->datalen != sizeof(struct winsize)) |
280 | break; |
281 | /* The caller must ensure that the hvc is locked, which |
282 | * is the case when called from hvc_iucv_get_chars() */ |
283 | __hvc_resize(hp: priv->hvc, ws: *((struct winsize *) rb->mbuf->data)); |
284 | break; |
285 | |
286 | case MSG_TYPE_ERROR: /* ignored ... */ |
287 | case MSG_TYPE_TERMENV: /* ignored ... */ |
288 | case MSG_TYPE_TERMIOS: /* ignored ... */ |
289 | break; |
290 | } |
291 | |
292 | out_remove_buffer: |
293 | list_del(entry: &rb->list); |
294 | destroy_tty_buffer(bufp: rb); |
295 | *has_more_data = !list_empty(head: &priv->tty_inqueue); |
296 | |
297 | out_written: |
298 | return written; |
299 | } |
300 | |
301 | /** |
302 | * hvc_iucv_get_chars() - HVC get_chars operation. |
303 | * @vtermno: HVC virtual terminal number. |
304 | * @buf: Pointer to a buffer to store data |
305 | * @count: Size of buffer available for writing |
306 | * |
307 | * The HVC thread calls this method to read characters from the back-end. |
308 | * If an IUCV communication path has been established, pending IUCV messages |
309 | * are received and data is copied into buffer @buf up to @count bytes. |
310 | * |
311 | * Locking: The routine gets called under an irqsave() spinlock; and |
312 | * the routine locks the struct hvc_iucv_private->lock to call |
313 | * helper functions. |
314 | */ |
315 | static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) |
316 | { |
317 | struct hvc_iucv_private *priv = hvc_iucv_get_private(num: vtermno); |
318 | int written; |
319 | int has_more_data; |
320 | |
321 | if (count <= 0) |
322 | return 0; |
323 | |
324 | if (!priv) |
325 | return -ENODEV; |
326 | |
327 | spin_lock(lock: &priv->lock); |
328 | has_more_data = 0; |
329 | written = hvc_iucv_write(priv, buf, count, has_more_data: &has_more_data); |
330 | spin_unlock(lock: &priv->lock); |
331 | |
332 | /* if there are still messages on the queue... schedule another run */ |
333 | if (has_more_data) |
334 | hvc_kick(); |
335 | |
336 | return written; |
337 | } |
338 | |
339 | /** |
340 | * hvc_iucv_queue() - Buffer terminal data for sending. |
341 | * @priv: Pointer to struct hvc_iucv_private instance. |
342 | * @buf: Buffer containing data to send. |
343 | * @count: Size of buffer and amount of data to send. |
344 | * |
345 | * The function queues data for sending. To actually send the buffered data, |
346 | * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). |
347 | * The function returns the number of data bytes that has been buffered. |
348 | * |
349 | * If the device is not connected, data is ignored and the function returns |
350 | * @count. |
351 | * If the buffer is full, the function returns 0. |
352 | * If an existing IUCV communicaton path has been severed, -EPIPE is returned |
353 | * (that can be passed to HVC layer to cause a tty hangup). |
354 | */ |
355 | static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, |
356 | int count) |
357 | { |
358 | size_t len; |
359 | |
360 | if (priv->iucv_state == IUCV_DISCONN) |
361 | return count; /* ignore data */ |
362 | |
363 | if (priv->iucv_state == IUCV_SEVERED) |
364 | return -EPIPE; |
365 | |
366 | len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); |
367 | if (!len) |
368 | return 0; |
369 | |
370 | memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); |
371 | priv->sndbuf_len += len; |
372 | |
373 | if (priv->iucv_state == IUCV_CONNECTED) |
374 | schedule_delayed_work(dwork: &priv->sndbuf_work, QUEUE_SNDBUF_DELAY); |
375 | |
376 | return len; |
377 | } |
378 | |
379 | /** |
380 | * hvc_iucv_send() - Send an IUCV message containing terminal data. |
381 | * @priv: Pointer to struct hvc_iucv_private instance. |
382 | * |
383 | * If an IUCV communication path has been established, the buffered output data |
384 | * is sent via an IUCV message and the number of bytes sent is returned. |
385 | * Returns 0 if there is no established IUCV communication path or |
386 | * -EPIPE if an existing IUCV communicaton path has been severed. |
387 | */ |
388 | static int hvc_iucv_send(struct hvc_iucv_private *priv) |
389 | { |
390 | struct iucv_tty_buffer *sb; |
391 | int rc, len; |
392 | |
393 | if (priv->iucv_state == IUCV_SEVERED) |
394 | return -EPIPE; |
395 | |
396 | if (priv->iucv_state == IUCV_DISCONN) |
397 | return -EIO; |
398 | |
399 | if (!priv->sndbuf_len) |
400 | return 0; |
401 | |
402 | /* allocate internal buffer to store msg data and also compute total |
403 | * message length */ |
404 | sb = alloc_tty_buffer(size: priv->sndbuf_len, GFP_ATOMIC); |
405 | if (!sb) |
406 | return -ENOMEM; |
407 | |
408 | memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); |
409 | sb->mbuf->datalen = (u16) priv->sndbuf_len; |
410 | sb->msg.length = MSG_SIZE(sb->mbuf->datalen); |
411 | |
412 | list_add_tail(new: &sb->list, head: &priv->tty_outqueue); |
413 | |
414 | rc = __iucv_message_send(path: priv->path, msg: &sb->msg, flags: 0, srccls: 0, |
415 | buffer: (void *) sb->mbuf, size: sb->msg.length); |
416 | if (rc) { |
417 | /* drop the message here; however we might want to handle |
418 | * 0x03 (msg limit reached) by trying again... */ |
419 | list_del(entry: &sb->list); |
420 | destroy_tty_buffer(bufp: sb); |
421 | } |
422 | len = priv->sndbuf_len; |
423 | priv->sndbuf_len = 0; |
424 | |
425 | return len; |
426 | } |
427 | |
428 | /** |
429 | * hvc_iucv_sndbuf_work() - Send buffered data over IUCV |
430 | * @work: Work structure. |
431 | * |
432 | * This work queue function sends buffered output data over IUCV and, |
433 | * if not all buffered data could be sent, reschedules itself. |
434 | */ |
435 | static void hvc_iucv_sndbuf_work(struct work_struct *work) |
436 | { |
437 | struct hvc_iucv_private *priv; |
438 | |
439 | priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); |
440 | |
441 | spin_lock_bh(lock: &priv->lock); |
442 | hvc_iucv_send(priv); |
443 | spin_unlock_bh(lock: &priv->lock); |
444 | } |
445 | |
446 | /** |
447 | * hvc_iucv_put_chars() - HVC put_chars operation. |
448 | * @vtermno: HVC virtual terminal number. |
449 | * @buf: Pointer to an buffer to read data from |
450 | * @count: Size of buffer available for reading |
451 | * |
452 | * The HVC thread calls this method to write characters to the back-end. |
453 | * The function calls hvc_iucv_queue() to queue terminal data for sending. |
454 | * |
455 | * Locking: The method gets called under an irqsave() spinlock; and |
456 | * locks struct hvc_iucv_private->lock. |
457 | */ |
458 | static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) |
459 | { |
460 | struct hvc_iucv_private *priv = hvc_iucv_get_private(num: vtermno); |
461 | int queued; |
462 | |
463 | if (count <= 0) |
464 | return 0; |
465 | |
466 | if (!priv) |
467 | return -ENODEV; |
468 | |
469 | spin_lock(lock: &priv->lock); |
470 | queued = hvc_iucv_queue(priv, buf, count); |
471 | spin_unlock(lock: &priv->lock); |
472 | |
473 | return queued; |
474 | } |
475 | |
476 | /** |
477 | * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. |
478 | * @hp: Pointer to the HVC device (struct hvc_struct) |
479 | * @id: Additional data (originally passed to hvc_alloc): the index of an struct |
480 | * hvc_iucv_private instance. |
481 | * |
482 | * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private |
483 | * instance that is derived from @id. Always returns 0. |
484 | * |
485 | * Locking: struct hvc_iucv_private->lock, spin_lock_bh |
486 | */ |
487 | static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) |
488 | { |
489 | struct hvc_iucv_private *priv; |
490 | |
491 | priv = hvc_iucv_get_private(num: id); |
492 | if (!priv) |
493 | return 0; |
494 | |
495 | spin_lock_bh(lock: &priv->lock); |
496 | priv->tty_state = TTY_OPENED; |
497 | spin_unlock_bh(lock: &priv->lock); |
498 | |
499 | return 0; |
500 | } |
501 | |
502 | /** |
503 | * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. |
504 | * @priv: Pointer to the struct hvc_iucv_private instance. |
505 | */ |
506 | static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) |
507 | { |
508 | destroy_tty_buffer_list(list: &priv->tty_outqueue); |
509 | destroy_tty_buffer_list(list: &priv->tty_inqueue); |
510 | |
511 | priv->tty_state = TTY_CLOSED; |
512 | priv->iucv_state = IUCV_DISCONN; |
513 | |
514 | priv->sndbuf_len = 0; |
515 | } |
516 | |
517 | /** |
518 | * tty_outqueue_empty() - Test if the tty outq is empty |
519 | * @priv: Pointer to struct hvc_iucv_private instance. |
520 | */ |
521 | static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) |
522 | { |
523 | int rc; |
524 | |
525 | spin_lock_bh(lock: &priv->lock); |
526 | rc = list_empty(head: &priv->tty_outqueue); |
527 | spin_unlock_bh(lock: &priv->lock); |
528 | |
529 | return rc; |
530 | } |
531 | |
532 | /** |
533 | * flush_sndbuf_sync() - Flush send buffer and wait for completion |
534 | * @priv: Pointer to struct hvc_iucv_private instance. |
535 | * |
536 | * The routine cancels a pending sndbuf work, calls hvc_iucv_send() |
537 | * to flush any buffered terminal output data and waits for completion. |
538 | */ |
539 | static void flush_sndbuf_sync(struct hvc_iucv_private *priv) |
540 | { |
541 | int sync_wait; |
542 | |
543 | cancel_delayed_work_sync(dwork: &priv->sndbuf_work); |
544 | |
545 | spin_lock_bh(lock: &priv->lock); |
546 | hvc_iucv_send(priv); /* force sending buffered data */ |
547 | sync_wait = !list_empty(head: &priv->tty_outqueue); /* anything queued ? */ |
548 | spin_unlock_bh(lock: &priv->lock); |
549 | |
550 | if (sync_wait) |
551 | wait_event_timeout(priv->sndbuf_waitq, |
552 | tty_outqueue_empty(priv), HZ/10); |
553 | } |
554 | |
555 | /** |
556 | * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up |
557 | * @priv: Pointer to hvc_iucv_private structure |
558 | * |
559 | * This routine severs an existing IUCV communication path and hangs |
560 | * up the underlying HVC terminal device. |
561 | * The hang-up occurs only if an IUCV communication path is established; |
562 | * otherwise there is no need to hang up the terminal device. |
563 | * |
564 | * The IUCV HVC hang-up is separated into two steps: |
565 | * 1. After the IUCV path has been severed, the iucv_state is set to |
566 | * IUCV_SEVERED. |
567 | * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the |
568 | * IUCV_SEVERED state causes the tty hang-up in the HVC layer. |
569 | * |
570 | * If the tty has not yet been opened, clean up the hvc_iucv_private |
571 | * structure to allow re-connects. |
572 | * If the tty has been opened, let get_chars() return -EPIPE to signal |
573 | * the HVC layer to hang up the tty and, if so, wake up the HVC thread |
574 | * to call get_chars()... |
575 | * |
576 | * Special notes on hanging up a HVC terminal instantiated as console: |
577 | * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) |
578 | * 2. do_tty_hangup() calls tty->ops->close() for console_filp |
579 | * => no hangup notifier is called by HVC (default) |
580 | * 2. hvc_close() returns because of tty_hung_up_p(filp) |
581 | * => no delete notifier is called! |
582 | * Finally, the back-end is not being notified, thus, the tty session is |
583 | * kept active (TTY_OPEN) to be ready for re-connects. |
584 | * |
585 | * Locking: spin_lock(&priv->lock) w/o disabling bh |
586 | */ |
587 | static void hvc_iucv_hangup(struct hvc_iucv_private *priv) |
588 | { |
589 | struct iucv_path *path; |
590 | |
591 | path = NULL; |
592 | spin_lock(lock: &priv->lock); |
593 | if (priv->iucv_state == IUCV_CONNECTED) { |
594 | path = priv->path; |
595 | priv->path = NULL; |
596 | priv->iucv_state = IUCV_SEVERED; |
597 | if (priv->tty_state == TTY_CLOSED) |
598 | hvc_iucv_cleanup(priv); |
599 | else |
600 | /* console is special (see above) */ |
601 | if (priv->is_console) { |
602 | hvc_iucv_cleanup(priv); |
603 | priv->tty_state = TTY_OPENED; |
604 | } else |
605 | hvc_kick(); |
606 | } |
607 | spin_unlock(lock: &priv->lock); |
608 | |
609 | /* finally sever path (outside of priv->lock due to lock ordering) */ |
610 | if (path) { |
611 | iucv_path_sever(path, NULL); |
612 | iucv_path_free(path); |
613 | } |
614 | } |
615 | |
616 | /** |
617 | * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. |
618 | * @hp: Pointer to the HVC device (struct hvc_struct) |
619 | * @id: Additional data (originally passed to hvc_alloc): |
620 | * the index of an struct hvc_iucv_private instance. |
621 | * |
622 | * This routine notifies the HVC back-end that a tty hangup (carrier loss, |
623 | * virtual or otherwise) has occurred. |
624 | * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) |
625 | * to keep an existing IUCV communication path established. |
626 | * (Background: vhangup() is called from user space (by getty or login) to |
627 | * disable writing to the tty by other applications). |
628 | * If the tty has been opened and an established IUCV path has been severed |
629 | * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). |
630 | * |
631 | * Locking: struct hvc_iucv_private->lock |
632 | */ |
633 | static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) |
634 | { |
635 | struct hvc_iucv_private *priv; |
636 | |
637 | priv = hvc_iucv_get_private(num: id); |
638 | if (!priv) |
639 | return; |
640 | |
641 | flush_sndbuf_sync(priv); |
642 | |
643 | spin_lock_bh(lock: &priv->lock); |
644 | /* NOTE: If the hangup was scheduled by ourself (from the iucv |
645 | * path_servered callback [IUCV_SEVERED]), we have to clean up |
646 | * our structure and to set state to TTY_CLOSED. |
647 | * If the tty was hung up otherwise (e.g. vhangup()), then we |
648 | * ignore this hangup and keep an established IUCV path open... |
649 | * (...the reason is that we are not able to connect back to the |
650 | * client if we disconnect on hang up) */ |
651 | priv->tty_state = TTY_CLOSED; |
652 | |
653 | if (priv->iucv_state == IUCV_SEVERED) |
654 | hvc_iucv_cleanup(priv); |
655 | spin_unlock_bh(lock: &priv->lock); |
656 | } |
657 | |
658 | /** |
659 | * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS |
660 | * @hp: Pointer the HVC device (struct hvc_struct) |
661 | * @active: True to raise or false to lower DTR/RTS lines |
662 | * |
663 | * This routine notifies the HVC back-end to raise or lower DTR/RTS |
664 | * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to |
665 | * drop the IUCV connection (similar to hang up the modem). |
666 | */ |
667 | static void hvc_iucv_dtr_rts(struct hvc_struct *hp, bool active) |
668 | { |
669 | struct hvc_iucv_private *priv; |
670 | struct iucv_path *path; |
671 | |
672 | /* Raising the DTR/RTS is ignored as IUCV connections can be |
673 | * established at any times. |
674 | */ |
675 | if (active) |
676 | return; |
677 | |
678 | priv = hvc_iucv_get_private(num: hp->vtermno); |
679 | if (!priv) |
680 | return; |
681 | |
682 | /* Lowering the DTR/RTS lines disconnects an established IUCV |
683 | * connection. |
684 | */ |
685 | flush_sndbuf_sync(priv); |
686 | |
687 | spin_lock_bh(lock: &priv->lock); |
688 | path = priv->path; /* save reference to IUCV path */ |
689 | priv->path = NULL; |
690 | priv->iucv_state = IUCV_DISCONN; |
691 | spin_unlock_bh(lock: &priv->lock); |
692 | |
693 | /* Sever IUCV path outside of priv->lock due to lock ordering of: |
694 | * priv->lock <--> iucv_table_lock */ |
695 | if (path) { |
696 | iucv_path_sever(path, NULL); |
697 | iucv_path_free(path); |
698 | } |
699 | } |
700 | |
701 | /** |
702 | * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. |
703 | * @hp: Pointer to the HVC device (struct hvc_struct) |
704 | * @id: Additional data (originally passed to hvc_alloc): |
705 | * the index of an struct hvc_iucv_private instance. |
706 | * |
707 | * This routine notifies the HVC back-end that the last tty device fd has been |
708 | * closed. The function cleans up tty resources. The clean-up of the IUCV |
709 | * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios |
710 | * control setting. |
711 | * |
712 | * Locking: struct hvc_iucv_private->lock |
713 | */ |
714 | static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) |
715 | { |
716 | struct hvc_iucv_private *priv; |
717 | |
718 | priv = hvc_iucv_get_private(num: id); |
719 | if (!priv) |
720 | return; |
721 | |
722 | flush_sndbuf_sync(priv); |
723 | |
724 | spin_lock_bh(lock: &priv->lock); |
725 | destroy_tty_buffer_list(list: &priv->tty_outqueue); |
726 | destroy_tty_buffer_list(list: &priv->tty_inqueue); |
727 | priv->tty_state = TTY_CLOSED; |
728 | priv->sndbuf_len = 0; |
729 | spin_unlock_bh(lock: &priv->lock); |
730 | } |
731 | |
732 | /** |
733 | * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID |
734 | * @ipvmid: Originating z/VM user ID (right padded with blanks) |
735 | * |
736 | * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to |
737 | * connect, otherwise non-zero. |
738 | */ |
739 | static int hvc_iucv_filter_connreq(u8 ipvmid[8]) |
740 | { |
741 | const char *wildcard, *filter_entry; |
742 | size_t i, len; |
743 | |
744 | /* Note: default policy is ACCEPT if no filter is set */ |
745 | if (!hvc_iucv_filter_size) |
746 | return 0; |
747 | |
748 | for (i = 0; i < hvc_iucv_filter_size; i++) { |
749 | filter_entry = hvc_iucv_filter + (8 * i); |
750 | |
751 | /* If a filter entry contains the filter wildcard character, |
752 | * reduce the length to match the leading portion of the user |
753 | * ID only (wildcard match). Characters following the wildcard |
754 | * are ignored. |
755 | */ |
756 | wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); |
757 | len = (wildcard) ? wildcard - filter_entry : 8; |
758 | if (0 == memcmp(p: ipvmid, q: filter_entry, size: len)) |
759 | return 0; |
760 | } |
761 | return 1; |
762 | } |
763 | |
764 | /** |
765 | * hvc_iucv_path_pending() - IUCV handler to process a connection request. |
766 | * @path: Pending path (struct iucv_path) |
767 | * @ipvmid: z/VM system identifier of originator |
768 | * @ipuser: User specified data for this path |
769 | * (AF_IUCV: port/service name and originator port) |
770 | * |
771 | * The function uses the @ipuser data to determine if the pending path belongs |
772 | * to a terminal managed by this device driver. |
773 | * If the path belongs to this driver, ensure that the terminal is not accessed |
774 | * multiple times (only one connection to a terminal is allowed). |
775 | * If the terminal is not yet connected, the pending path is accepted and is |
776 | * associated to the appropriate struct hvc_iucv_private instance. |
777 | * |
778 | * Returns 0 if @path belongs to a terminal managed by the this device driver; |
779 | * otherwise returns -ENODEV in order to dispatch this path to other handlers. |
780 | * |
781 | * Locking: struct hvc_iucv_private->lock |
782 | */ |
783 | static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid, |
784 | u8 *ipuser) |
785 | { |
786 | struct hvc_iucv_private *priv, *tmp; |
787 | u8 wildcard[9] = "lnxhvc " ; |
788 | int i, rc, find_unused; |
789 | u8 nuser_data[16]; |
790 | u8 vm_user_id[9]; |
791 | |
792 | ASCEBC(wildcard, sizeof(wildcard)); |
793 | find_unused = !memcmp(p: wildcard, q: ipuser, size: 8); |
794 | |
795 | /* First, check if the pending path request is managed by this |
796 | * IUCV handler: |
797 | * - find a disconnected device if ipuser contains the wildcard |
798 | * - find the device that matches the terminal ID in ipuser |
799 | */ |
800 | priv = NULL; |
801 | for (i = 0; i < hvc_iucv_devices; i++) { |
802 | tmp = hvc_iucv_table[i]; |
803 | if (!tmp) |
804 | continue; |
805 | |
806 | if (find_unused) { |
807 | spin_lock(lock: &tmp->lock); |
808 | if (tmp->iucv_state == IUCV_DISCONN) |
809 | priv = tmp; |
810 | spin_unlock(lock: &tmp->lock); |
811 | |
812 | } else if (!memcmp(p: tmp->srv_name, q: ipuser, size: 8)) |
813 | priv = tmp; |
814 | if (priv) |
815 | break; |
816 | } |
817 | if (!priv) |
818 | return -ENODEV; |
819 | |
820 | /* Enforce that ipvmid is allowed to connect to us */ |
821 | read_lock(&hvc_iucv_filter_lock); |
822 | rc = hvc_iucv_filter_connreq(ipvmid); |
823 | read_unlock(&hvc_iucv_filter_lock); |
824 | if (rc) { |
825 | iucv_path_sever(path, userdata: ipuser); |
826 | iucv_path_free(path); |
827 | memcpy(vm_user_id, ipvmid, 8); |
828 | vm_user_id[8] = 0; |
829 | pr_info("A connection request from z/VM user ID %s " |
830 | "was refused\n" , vm_user_id); |
831 | return 0; |
832 | } |
833 | |
834 | spin_lock(lock: &priv->lock); |
835 | |
836 | /* If the terminal is already connected or being severed, then sever |
837 | * this path to enforce that there is only ONE established communication |
838 | * path per terminal. */ |
839 | if (priv->iucv_state != IUCV_DISCONN) { |
840 | iucv_path_sever(path, userdata: ipuser); |
841 | iucv_path_free(path); |
842 | goto out_path_handled; |
843 | } |
844 | |
845 | /* accept path */ |
846 | memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ |
847 | memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ |
848 | path->msglim = 0xffff; /* IUCV MSGLIMIT */ |
849 | path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ |
850 | rc = iucv_path_accept(path, handler: &hvc_iucv_handler, userdata: nuser_data, private: priv); |
851 | if (rc) { |
852 | iucv_path_sever(path, userdata: ipuser); |
853 | iucv_path_free(path); |
854 | goto out_path_handled; |
855 | } |
856 | priv->path = path; |
857 | priv->iucv_state = IUCV_CONNECTED; |
858 | |
859 | /* store path information */ |
860 | memcpy(priv->info_path, ipvmid, 8); |
861 | memcpy(priv->info_path + 8, ipuser + 8, 8); |
862 | |
863 | /* flush buffered output data... */ |
864 | schedule_delayed_work(dwork: &priv->sndbuf_work, delay: 5); |
865 | |
866 | out_path_handled: |
867 | spin_unlock(lock: &priv->lock); |
868 | return 0; |
869 | } |
870 | |
871 | /** |
872 | * hvc_iucv_path_severed() - IUCV handler to process a path sever. |
873 | * @path: Pending path (struct iucv_path) |
874 | * @ipuser: User specified data for this path |
875 | * (AF_IUCV: port/service name and originator port) |
876 | * |
877 | * This function calls the hvc_iucv_hangup() function for the |
878 | * respective IUCV HVC terminal. |
879 | * |
880 | * Locking: struct hvc_iucv_private->lock |
881 | */ |
882 | static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser) |
883 | { |
884 | struct hvc_iucv_private *priv = path->private; |
885 | |
886 | hvc_iucv_hangup(priv); |
887 | } |
888 | |
889 | /** |
890 | * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. |
891 | * @path: Pending path (struct iucv_path) |
892 | * @msg: Pointer to the IUCV message |
893 | * |
894 | * The function puts an incoming message on the input queue for later |
895 | * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). |
896 | * If the tty has not yet been opened, the message is rejected. |
897 | * |
898 | * Locking: struct hvc_iucv_private->lock |
899 | */ |
900 | static void hvc_iucv_msg_pending(struct iucv_path *path, |
901 | struct iucv_message *msg) |
902 | { |
903 | struct hvc_iucv_private *priv = path->private; |
904 | struct iucv_tty_buffer *rb; |
905 | |
906 | /* reject messages that exceed max size of iucv_tty_msg->datalen */ |
907 | if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { |
908 | iucv_message_reject(path, msg); |
909 | return; |
910 | } |
911 | |
912 | spin_lock(lock: &priv->lock); |
913 | |
914 | /* reject messages if tty has not yet been opened */ |
915 | if (priv->tty_state == TTY_CLOSED) { |
916 | iucv_message_reject(path, msg); |
917 | goto unlock_return; |
918 | } |
919 | |
920 | /* allocate tty buffer to save iucv msg only */ |
921 | rb = alloc_tty_buffer(size: 0, GFP_ATOMIC); |
922 | if (!rb) { |
923 | iucv_message_reject(path, msg); |
924 | goto unlock_return; /* -ENOMEM */ |
925 | } |
926 | rb->msg = *msg; |
927 | |
928 | list_add_tail(new: &rb->list, head: &priv->tty_inqueue); |
929 | |
930 | hvc_kick(); /* wake up hvc thread */ |
931 | |
932 | unlock_return: |
933 | spin_unlock(lock: &priv->lock); |
934 | } |
935 | |
936 | /** |
937 | * hvc_iucv_msg_complete() - IUCV handler to process message completion |
938 | * @path: Pending path (struct iucv_path) |
939 | * @msg: Pointer to the IUCV message |
940 | * |
941 | * The function is called upon completion of message delivery to remove the |
942 | * message from the outqueue. Additional delivery information can be found |
943 | * msg->audit: rejected messages (0x040000 (IPADRJCT)), and |
944 | * purged messages (0x010000 (IPADPGNR)). |
945 | * |
946 | * Locking: struct hvc_iucv_private->lock |
947 | */ |
948 | static void hvc_iucv_msg_complete(struct iucv_path *path, |
949 | struct iucv_message *msg) |
950 | { |
951 | struct hvc_iucv_private *priv = path->private; |
952 | struct iucv_tty_buffer *ent, *next; |
953 | LIST_HEAD(list_remove); |
954 | |
955 | spin_lock(lock: &priv->lock); |
956 | list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) |
957 | if (ent->msg.id == msg->id) { |
958 | list_move(list: &ent->list, head: &list_remove); |
959 | break; |
960 | } |
961 | wake_up(&priv->sndbuf_waitq); |
962 | spin_unlock(lock: &priv->lock); |
963 | destroy_tty_buffer_list(list: &list_remove); |
964 | } |
965 | |
966 | static ssize_t hvc_iucv_dev_termid_show(struct device *dev, |
967 | struct device_attribute *attr, |
968 | char *buf) |
969 | { |
970 | struct hvc_iucv_private *priv = dev_get_drvdata(dev); |
971 | size_t len; |
972 | |
973 | len = sizeof(priv->srv_name); |
974 | memcpy(buf, priv->srv_name, len); |
975 | EBCASC(buf, len); |
976 | buf[len++] = '\n'; |
977 | return len; |
978 | } |
979 | |
980 | static ssize_t hvc_iucv_dev_state_show(struct device *dev, |
981 | struct device_attribute *attr, |
982 | char *buf) |
983 | { |
984 | struct hvc_iucv_private *priv = dev_get_drvdata(dev); |
985 | return sprintf(buf, fmt: "%u:%u\n" , priv->iucv_state, priv->tty_state); |
986 | } |
987 | |
988 | static ssize_t hvc_iucv_dev_peer_show(struct device *dev, |
989 | struct device_attribute *attr, |
990 | char *buf) |
991 | { |
992 | struct hvc_iucv_private *priv = dev_get_drvdata(dev); |
993 | char vmid[9], ipuser[9]; |
994 | |
995 | memset(vmid, 0, sizeof(vmid)); |
996 | memset(ipuser, 0, sizeof(ipuser)); |
997 | |
998 | spin_lock_bh(lock: &priv->lock); |
999 | if (priv->iucv_state == IUCV_CONNECTED) { |
1000 | memcpy(vmid, priv->info_path, 8); |
1001 | memcpy(ipuser, priv->info_path + 8, 8); |
1002 | } |
1003 | spin_unlock_bh(lock: &priv->lock); |
1004 | EBCASC(ipuser, 8); |
1005 | |
1006 | return sprintf(buf, fmt: "%s:%s\n" , vmid, ipuser); |
1007 | } |
1008 | |
1009 | |
1010 | /* HVC operations */ |
1011 | static const struct hv_ops hvc_iucv_ops = { |
1012 | .get_chars = hvc_iucv_get_chars, |
1013 | .put_chars = hvc_iucv_put_chars, |
1014 | .notifier_add = hvc_iucv_notifier_add, |
1015 | .notifier_del = hvc_iucv_notifier_del, |
1016 | .notifier_hangup = hvc_iucv_notifier_hangup, |
1017 | .dtr_rts = hvc_iucv_dtr_rts, |
1018 | }; |
1019 | |
1020 | /* IUCV HVC device attributes */ |
1021 | static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); |
1022 | static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); |
1023 | static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); |
1024 | static struct attribute *hvc_iucv_dev_attrs[] = { |
1025 | &dev_attr_termid.attr, |
1026 | &dev_attr_state.attr, |
1027 | &dev_attr_peer.attr, |
1028 | NULL, |
1029 | }; |
1030 | static struct attribute_group hvc_iucv_dev_attr_group = { |
1031 | .attrs = hvc_iucv_dev_attrs, |
1032 | }; |
1033 | static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { |
1034 | &hvc_iucv_dev_attr_group, |
1035 | NULL, |
1036 | }; |
1037 | |
1038 | |
1039 | /** |
1040 | * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance |
1041 | * @id: hvc_iucv_table index |
1042 | * @is_console: Flag if the instance is used as Linux console |
1043 | * |
1044 | * This function allocates a new hvc_iucv_private structure and stores |
1045 | * the instance in hvc_iucv_table at index @id. |
1046 | * Returns 0 on success; otherwise non-zero. |
1047 | */ |
1048 | static int __init hvc_iucv_alloc(int id, unsigned int is_console) |
1049 | { |
1050 | struct hvc_iucv_private *priv; |
1051 | char name[9]; |
1052 | int rc; |
1053 | |
1054 | priv = kzalloc(size: sizeof(struct hvc_iucv_private), GFP_KERNEL); |
1055 | if (!priv) |
1056 | return -ENOMEM; |
1057 | |
1058 | spin_lock_init(&priv->lock); |
1059 | INIT_LIST_HEAD(list: &priv->tty_outqueue); |
1060 | INIT_LIST_HEAD(list: &priv->tty_inqueue); |
1061 | INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); |
1062 | init_waitqueue_head(&priv->sndbuf_waitq); |
1063 | |
1064 | priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); |
1065 | if (!priv->sndbuf) { |
1066 | kfree(objp: priv); |
1067 | return -ENOMEM; |
1068 | } |
1069 | |
1070 | /* set console flag */ |
1071 | priv->is_console = is_console; |
1072 | |
1073 | /* allocate hvc device */ |
1074 | priv->hvc = hvc_alloc(vtermno: id, /* PAGE_SIZE */ |
1075 | data: id, ops: &hvc_iucv_ops, outbuf_size: 256); |
1076 | if (IS_ERR(ptr: priv->hvc)) { |
1077 | rc = PTR_ERR(ptr: priv->hvc); |
1078 | goto out_error_hvc; |
1079 | } |
1080 | |
1081 | /* notify HVC thread instead of using polling */ |
1082 | priv->hvc->irq_requested = 1; |
1083 | |
1084 | /* setup iucv related information */ |
1085 | snprintf(buf: name, size: 9, fmt: "lnxhvc%-2d" , id); |
1086 | memcpy(priv->srv_name, name, 8); |
1087 | ASCEBC(priv->srv_name, 8); |
1088 | |
1089 | /* create and setup device */ |
1090 | priv->dev = kzalloc(size: sizeof(*priv->dev), GFP_KERNEL); |
1091 | if (!priv->dev) { |
1092 | rc = -ENOMEM; |
1093 | goto out_error_dev; |
1094 | } |
1095 | dev_set_name(dev: priv->dev, name: "hvc_iucv%d" , id); |
1096 | dev_set_drvdata(dev: priv->dev, data: priv); |
1097 | priv->dev->bus = &iucv_bus; |
1098 | priv->dev->parent = iucv_root; |
1099 | priv->dev->groups = hvc_iucv_dev_attr_groups; |
1100 | priv->dev->release = (void (*)(struct device *)) kfree; |
1101 | rc = device_register(dev: priv->dev); |
1102 | if (rc) { |
1103 | put_device(dev: priv->dev); |
1104 | goto out_error_dev; |
1105 | } |
1106 | |
1107 | hvc_iucv_table[id] = priv; |
1108 | return 0; |
1109 | |
1110 | out_error_dev: |
1111 | hvc_remove(hp: priv->hvc); |
1112 | out_error_hvc: |
1113 | free_page((unsigned long) priv->sndbuf); |
1114 | kfree(objp: priv); |
1115 | |
1116 | return rc; |
1117 | } |
1118 | |
1119 | /** |
1120 | * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances |
1121 | */ |
1122 | static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) |
1123 | { |
1124 | hvc_remove(hp: priv->hvc); |
1125 | device_unregister(dev: priv->dev); |
1126 | free_page((unsigned long) priv->sndbuf); |
1127 | kfree(objp: priv); |
1128 | } |
1129 | |
1130 | /** |
1131 | * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID |
1132 | * @filter: String containing a comma-separated list of z/VM user IDs |
1133 | * @dest: Location where to store the parsed z/VM user ID |
1134 | */ |
1135 | static const char *hvc_iucv_parse_filter(const char *filter, char *dest) |
1136 | { |
1137 | const char *nextdelim, *residual; |
1138 | size_t len; |
1139 | |
1140 | nextdelim = strchr(filter, ','); |
1141 | if (nextdelim) { |
1142 | len = nextdelim - filter; |
1143 | residual = nextdelim + 1; |
1144 | } else { |
1145 | len = strlen(filter); |
1146 | residual = filter + len; |
1147 | } |
1148 | |
1149 | if (len == 0) |
1150 | return ERR_PTR(error: -EINVAL); |
1151 | |
1152 | /* check for '\n' (if called from sysfs) */ |
1153 | if (filter[len - 1] == '\n') |
1154 | len--; |
1155 | |
1156 | /* prohibit filter entries containing the wildcard character only */ |
1157 | if (len == 1 && *filter == FILTER_WILDCARD_CHAR) |
1158 | return ERR_PTR(error: -EINVAL); |
1159 | |
1160 | if (len > 8) |
1161 | return ERR_PTR(error: -EINVAL); |
1162 | |
1163 | /* pad with blanks and save upper case version of user ID */ |
1164 | memset(dest, ' ', 8); |
1165 | while (len--) |
1166 | dest[len] = toupper(filter[len]); |
1167 | return residual; |
1168 | } |
1169 | |
1170 | /** |
1171 | * hvc_iucv_setup_filter() - Set up z/VM user ID filter |
1172 | * @filter: String consisting of a comma-separated list of z/VM user IDs |
1173 | * |
1174 | * The function parses the @filter string and creates an array containing |
1175 | * the list of z/VM user ID filter entries. |
1176 | * Return code 0 means success, -EINVAL if the filter is syntactically |
1177 | * incorrect, -ENOMEM if there was not enough memory to allocate the |
1178 | * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. |
1179 | */ |
1180 | static int hvc_iucv_setup_filter(const char *val) |
1181 | { |
1182 | const char *residual; |
1183 | int err; |
1184 | size_t size, count; |
1185 | void *array, *old_filter; |
1186 | |
1187 | count = strlen(val); |
1188 | if (count == 0 || (count == 1 && val[0] == '\n')) { |
1189 | size = 0; |
1190 | array = NULL; |
1191 | goto out_replace_filter; /* clear filter */ |
1192 | } |
1193 | |
1194 | /* count user IDs in order to allocate sufficient memory */ |
1195 | size = 1; |
1196 | residual = val; |
1197 | while ((residual = strchr(residual, ',')) != NULL) { |
1198 | residual++; |
1199 | size++; |
1200 | } |
1201 | |
1202 | /* check if the specified list exceeds the filter limit */ |
1203 | if (size > MAX_VMID_FILTER) |
1204 | return -ENOSPC; |
1205 | |
1206 | array = kcalloc(n: size, size: 8, GFP_KERNEL); |
1207 | if (!array) |
1208 | return -ENOMEM; |
1209 | |
1210 | count = size; |
1211 | residual = val; |
1212 | while (*residual && count) { |
1213 | residual = hvc_iucv_parse_filter(filter: residual, |
1214 | dest: array + ((size - count) * 8)); |
1215 | if (IS_ERR(ptr: residual)) { |
1216 | err = PTR_ERR(ptr: residual); |
1217 | kfree(objp: array); |
1218 | goto out_err; |
1219 | } |
1220 | count--; |
1221 | } |
1222 | |
1223 | out_replace_filter: |
1224 | write_lock_bh(&hvc_iucv_filter_lock); |
1225 | old_filter = hvc_iucv_filter; |
1226 | hvc_iucv_filter_size = size; |
1227 | hvc_iucv_filter = array; |
1228 | write_unlock_bh(&hvc_iucv_filter_lock); |
1229 | kfree(objp: old_filter); |
1230 | |
1231 | err = 0; |
1232 | out_err: |
1233 | return err; |
1234 | } |
1235 | |
1236 | /** |
1237 | * param_set_vmidfilter() - Set z/VM user ID filter parameter |
1238 | * @val: String consisting of a comma-separated list of z/VM user IDs |
1239 | * @kp: Kernel parameter pointing to hvc_iucv_filter array |
1240 | * |
1241 | * The function sets up the z/VM user ID filter specified as comma-separated |
1242 | * list of user IDs in @val. |
1243 | * Note: If it is called early in the boot process, @val is stored and |
1244 | * parsed later in hvc_iucv_init(). |
1245 | */ |
1246 | static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) |
1247 | { |
1248 | int rc; |
1249 | |
1250 | if (!MACHINE_IS_VM || !hvc_iucv_devices) |
1251 | return -ENODEV; |
1252 | |
1253 | if (!val) |
1254 | return -EINVAL; |
1255 | |
1256 | rc = 0; |
1257 | if (slab_is_available()) |
1258 | rc = hvc_iucv_setup_filter(val); |
1259 | else |
1260 | hvc_iucv_filter_string = val; /* defer... */ |
1261 | return rc; |
1262 | } |
1263 | |
1264 | /** |
1265 | * param_get_vmidfilter() - Get z/VM user ID filter |
1266 | * @buffer: Buffer to store z/VM user ID filter, |
1267 | * (buffer size assumption PAGE_SIZE) |
1268 | * @kp: Kernel parameter pointing to the hvc_iucv_filter array |
1269 | * |
1270 | * The function stores the filter as a comma-separated list of z/VM user IDs |
1271 | * in @buffer. Typically, sysfs routines call this function for attr show. |
1272 | */ |
1273 | static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) |
1274 | { |
1275 | int rc; |
1276 | size_t index, len; |
1277 | void *start, *end; |
1278 | |
1279 | if (!MACHINE_IS_VM || !hvc_iucv_devices) |
1280 | return -ENODEV; |
1281 | |
1282 | rc = 0; |
1283 | read_lock_bh(&hvc_iucv_filter_lock); |
1284 | for (index = 0; index < hvc_iucv_filter_size; index++) { |
1285 | start = hvc_iucv_filter + (8 * index); |
1286 | end = memchr(p: start, c: ' ', size: 8); |
1287 | len = (end) ? end - start : 8; |
1288 | memcpy(buffer + rc, start, len); |
1289 | rc += len; |
1290 | buffer[rc++] = ','; |
1291 | } |
1292 | read_unlock_bh(&hvc_iucv_filter_lock); |
1293 | if (rc) |
1294 | buffer[--rc] = '\0'; /* replace last comma and update rc */ |
1295 | return rc; |
1296 | } |
1297 | |
1298 | #define param_check_vmidfilter(name, p) __param_check(name, p, void) |
1299 | |
1300 | static const struct kernel_param_ops param_ops_vmidfilter = { |
1301 | .set = param_set_vmidfilter, |
1302 | .get = param_get_vmidfilter, |
1303 | }; |
1304 | |
1305 | /** |
1306 | * hvc_iucv_init() - z/VM IUCV HVC device driver initialization |
1307 | */ |
1308 | static int __init hvc_iucv_init(void) |
1309 | { |
1310 | int rc; |
1311 | unsigned int i; |
1312 | |
1313 | if (!hvc_iucv_devices) |
1314 | return -ENODEV; |
1315 | |
1316 | if (!MACHINE_IS_VM) { |
1317 | pr_notice("The z/VM IUCV HVC device driver cannot " |
1318 | "be used without z/VM\n" ); |
1319 | rc = -ENODEV; |
1320 | goto out_error; |
1321 | } |
1322 | |
1323 | if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { |
1324 | pr_err("%lu is not a valid value for the hvc_iucv= " |
1325 | "kernel parameter\n" , hvc_iucv_devices); |
1326 | rc = -EINVAL; |
1327 | goto out_error; |
1328 | } |
1329 | |
1330 | /* parse hvc_iucv_allow string and create z/VM user ID filter list */ |
1331 | if (hvc_iucv_filter_string) { |
1332 | rc = hvc_iucv_setup_filter(val: hvc_iucv_filter_string); |
1333 | switch (rc) { |
1334 | case 0: |
1335 | break; |
1336 | case -ENOMEM: |
1337 | pr_err("Allocating memory failed with " |
1338 | "reason code=%d\n" , 3); |
1339 | goto out_error; |
1340 | case -EINVAL: |
1341 | pr_err("hvc_iucv_allow= does not specify a valid " |
1342 | "z/VM user ID list\n" ); |
1343 | goto out_error; |
1344 | case -ENOSPC: |
1345 | pr_err("hvc_iucv_allow= specifies too many " |
1346 | "z/VM user IDs\n" ); |
1347 | goto out_error; |
1348 | default: |
1349 | goto out_error; |
1350 | } |
1351 | } |
1352 | |
1353 | hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, |
1354 | size: sizeof(struct iucv_tty_buffer), |
1355 | align: 0, flags: 0, NULL); |
1356 | if (!hvc_iucv_buffer_cache) { |
1357 | pr_err("Allocating memory failed with reason code=%d\n" , 1); |
1358 | rc = -ENOMEM; |
1359 | goto out_error; |
1360 | } |
1361 | |
1362 | hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, |
1363 | kc: hvc_iucv_buffer_cache); |
1364 | if (!hvc_iucv_mempool) { |
1365 | pr_err("Allocating memory failed with reason code=%d\n" , 2); |
1366 | kmem_cache_destroy(s: hvc_iucv_buffer_cache); |
1367 | rc = -ENOMEM; |
1368 | goto out_error; |
1369 | } |
1370 | |
1371 | /* register the first terminal device as console |
1372 | * (must be done before allocating hvc terminal devices) */ |
1373 | rc = hvc_instantiate(vtermno: 0, IUCV_HVC_CON_IDX, ops: &hvc_iucv_ops); |
1374 | if (rc) { |
1375 | pr_err("Registering HVC terminal device as " |
1376 | "Linux console failed\n" ); |
1377 | goto out_error_memory; |
1378 | } |
1379 | |
1380 | /* allocate hvc_iucv_private structs */ |
1381 | for (i = 0; i < hvc_iucv_devices; i++) { |
1382 | rc = hvc_iucv_alloc(id: i, is_console: (i == IUCV_HVC_CON_IDX) ? 1 : 0); |
1383 | if (rc) { |
1384 | pr_err("Creating a new HVC terminal device " |
1385 | "failed with error code=%d\n" , rc); |
1386 | goto out_error_hvc; |
1387 | } |
1388 | } |
1389 | |
1390 | /* register IUCV callback handler */ |
1391 | rc = iucv_register(handler: &hvc_iucv_handler, smp: 0); |
1392 | if (rc) { |
1393 | pr_err("Registering IUCV handlers failed with error code=%d\n" , |
1394 | rc); |
1395 | goto out_error_hvc; |
1396 | } |
1397 | |
1398 | return 0; |
1399 | |
1400 | out_error_hvc: |
1401 | for (i = 0; i < hvc_iucv_devices; i++) |
1402 | if (hvc_iucv_table[i]) |
1403 | hvc_iucv_destroy(priv: hvc_iucv_table[i]); |
1404 | out_error_memory: |
1405 | mempool_destroy(pool: hvc_iucv_mempool); |
1406 | kmem_cache_destroy(s: hvc_iucv_buffer_cache); |
1407 | out_error: |
1408 | kfree(objp: hvc_iucv_filter); |
1409 | hvc_iucv_devices = 0; /* ensure that we do not provide any device */ |
1410 | return rc; |
1411 | } |
1412 | |
1413 | /** |
1414 | * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter |
1415 | * @val: Parameter value (numeric) |
1416 | */ |
1417 | static int __init hvc_iucv_config(char *val) |
1418 | { |
1419 | if (kstrtoul(s: val, base: 10, res: &hvc_iucv_devices)) |
1420 | pr_warn("hvc_iucv= invalid parameter value '%s'\n" , val); |
1421 | return 1; |
1422 | } |
1423 | |
1424 | |
1425 | device_initcall(hvc_iucv_init); |
1426 | __setup("hvc_iucv=" , hvc_iucv_config); |
1427 | core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); |
1428 | |