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e1eaea46 AC |
1 | /* |
2 | * n_gsm.c GSM 0710 tty multiplexor | |
3 | * Copyright (c) 2009/10 Intel Corporation | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
17 | * | |
18 | * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE * | |
19 | * | |
20 | * TO DO: | |
21 | * Mostly done: ioctls for setting modes/timing | |
5f9a31d6 | 22 | * Partly done: hooks so you can pull off frames to non tty devs |
e1eaea46 | 23 | * Restart DLCI 0 when it closes ? |
e1eaea46 AC |
24 | * Improve the tx engine |
25 | * Resolve tx side locking by adding a queue_head and routing | |
26 | * all control traffic via it | |
27 | * General tidy/document | |
28 | * Review the locking/move to refcounts more (mux now moved to an | |
29 | * alloc/free model ready) | |
30 | * Use newest tty open/close port helpers and install hooks | |
31 | * What to do about power functions ? | |
32 | * Termios setting and negotiation | |
33 | * Do we need a 'which mux are you' ioctl to correlate mux and tty sets | |
34 | * | |
35 | */ | |
36 | ||
37 | #include <linux/types.h> | |
38 | #include <linux/major.h> | |
39 | #include <linux/errno.h> | |
40 | #include <linux/signal.h> | |
41 | #include <linux/fcntl.h> | |
42 | #include <linux/sched.h> | |
43 | #include <linux/interrupt.h> | |
44 | #include <linux/tty.h> | |
e1eaea46 AC |
45 | #include <linux/ctype.h> |
46 | #include <linux/mm.h> | |
47 | #include <linux/string.h> | |
48 | #include <linux/slab.h> | |
49 | #include <linux/poll.h> | |
50 | #include <linux/bitops.h> | |
51 | #include <linux/file.h> | |
52 | #include <linux/uaccess.h> | |
53 | #include <linux/module.h> | |
54 | #include <linux/timer.h> | |
55 | #include <linux/tty_flip.h> | |
56 | #include <linux/tty_driver.h> | |
57 | #include <linux/serial.h> | |
58 | #include <linux/kfifo.h> | |
59 | #include <linux/skbuff.h> | |
bcd5abe2 RG |
60 | #include <net/arp.h> |
61 | #include <linux/ip.h> | |
62 | #include <linux/netdevice.h> | |
63 | #include <linux/etherdevice.h> | |
e1eaea46 AC |
64 | #include <linux/gsmmux.h> |
65 | ||
66 | static int debug; | |
67 | module_param(debug, int, 0600); | |
68 | ||
69 | #define T1 (HZ/10) | |
70 | #define T2 (HZ/3) | |
71 | #define N2 3 | |
72 | ||
73 | /* Use long timers for testing at low speed with debug on */ | |
74 | #ifdef DEBUG_TIMING | |
75 | #define T1 HZ | |
76 | #define T2 (2 * HZ) | |
77 | #endif | |
78 | ||
5f9a31d6 | 79 | /* |
25985edc | 80 | * Semi-arbitrary buffer size limits. 0710 is normally run with 32-64 byte |
5f9a31d6 AC |
81 | * limits so this is plenty |
82 | */ | |
bcd5abe2 RG |
83 | #define MAX_MRU 1500 |
84 | #define MAX_MTU 1500 | |
85 | #define GSM_NET_TX_TIMEOUT (HZ*10) | |
86 | ||
87 | /** | |
88 | * struct gsm_mux_net - network interface | |
89 | * @struct gsm_dlci* dlci | |
90 | * @struct net_device_stats stats; | |
91 | * | |
92 | * Created when net interface is initialized. | |
93 | **/ | |
94 | struct gsm_mux_net { | |
95 | struct kref ref; | |
96 | struct gsm_dlci *dlci; | |
97 | struct net_device_stats stats; | |
98 | }; | |
99 | ||
100 | #define STATS(net) (((struct gsm_mux_net *)netdev_priv(net))->stats) | |
e1eaea46 AC |
101 | |
102 | /* | |
103 | * Each block of data we have queued to go out is in the form of | |
25985edc | 104 | * a gsm_msg which holds everything we need in a link layer independent |
e1eaea46 AC |
105 | * format |
106 | */ | |
107 | ||
108 | struct gsm_msg { | |
109 | struct gsm_msg *next; | |
110 | u8 addr; /* DLCI address + flags */ | |
111 | u8 ctrl; /* Control byte + flags */ | |
112 | unsigned int len; /* Length of data block (can be zero) */ | |
113 | unsigned char *data; /* Points into buffer but not at the start */ | |
114 | unsigned char buffer[0]; | |
115 | }; | |
116 | ||
117 | /* | |
118 | * Each active data link has a gsm_dlci structure associated which ties | |
119 | * the link layer to an optional tty (if the tty side is open). To avoid | |
120 | * complexity right now these are only ever freed up when the mux is | |
121 | * shut down. | |
122 | * | |
123 | * At the moment we don't free DLCI objects until the mux is torn down | |
124 | * this avoid object life time issues but might be worth review later. | |
125 | */ | |
126 | ||
127 | struct gsm_dlci { | |
128 | struct gsm_mux *gsm; | |
129 | int addr; | |
130 | int state; | |
131 | #define DLCI_CLOSED 0 | |
132 | #define DLCI_OPENING 1 /* Sending SABM not seen UA */ | |
133 | #define DLCI_OPEN 2 /* SABM/UA complete */ | |
134 | #define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */ | |
6ab8fba7 | 135 | struct kref ref; /* freed from port or mux close */ |
bcd5abe2 | 136 | struct mutex mutex; |
e1eaea46 AC |
137 | |
138 | /* Link layer */ | |
139 | spinlock_t lock; /* Protects the internal state */ | |
140 | struct timer_list t1; /* Retransmit timer for SABM and UA */ | |
141 | int retries; | |
142 | /* Uplink tty if active */ | |
143 | struct tty_port port; /* The tty bound to this DLCI if there is one */ | |
144 | struct kfifo *fifo; /* Queue fifo for the DLCI */ | |
145 | struct kfifo _fifo; /* For new fifo API porting only */ | |
146 | int adaption; /* Adaption layer in use */ | |
bcd5abe2 | 147 | int prev_adaption; |
e1eaea46 AC |
148 | u32 modem_rx; /* Our incoming virtual modem lines */ |
149 | u32 modem_tx; /* Our outgoing modem lines */ | |
150 | int dead; /* Refuse re-open */ | |
151 | /* Flow control */ | |
152 | int throttled; /* Private copy of throttle state */ | |
153 | int constipated; /* Throttle status for outgoing */ | |
154 | /* Packetised I/O */ | |
155 | struct sk_buff *skb; /* Frame being sent */ | |
156 | struct sk_buff_head skb_list; /* Queued frames */ | |
157 | /* Data handling callback */ | |
158 | void (*data)(struct gsm_dlci *dlci, u8 *data, int len); | |
bcd5abe2 RG |
159 | void (*prev_data)(struct gsm_dlci *dlci, u8 *data, int len); |
160 | struct net_device *net; /* network interface, if created */ | |
e1eaea46 AC |
161 | }; |
162 | ||
163 | /* DLCI 0, 62/63 are special or reseved see gsmtty_open */ | |
164 | ||
165 | #define NUM_DLCI 64 | |
166 | ||
167 | /* | |
168 | * DLCI 0 is used to pass control blocks out of band of the data | |
169 | * flow (and with a higher link priority). One command can be outstanding | |
170 | * at a time and we use this structure to manage them. They are created | |
171 | * and destroyed by the user context, and updated by the receive paths | |
172 | * and timers | |
173 | */ | |
174 | ||
175 | struct gsm_control { | |
176 | u8 cmd; /* Command we are issuing */ | |
177 | u8 *data; /* Data for the command in case we retransmit */ | |
178 | int len; /* Length of block for retransmission */ | |
179 | int done; /* Done flag */ | |
180 | int error; /* Error if any */ | |
181 | }; | |
182 | ||
183 | /* | |
184 | * Each GSM mux we have is represented by this structure. If we are | |
185 | * operating as an ldisc then we use this structure as our ldisc | |
186 | * state. We need to sort out lifetimes and locking with respect | |
187 | * to the gsm mux array. For now we don't free DLCI objects that | |
188 | * have been instantiated until the mux itself is terminated. | |
189 | * | |
190 | * To consider further: tty open versus mux shutdown. | |
191 | */ | |
192 | ||
193 | struct gsm_mux { | |
194 | struct tty_struct *tty; /* The tty our ldisc is bound to */ | |
195 | spinlock_t lock; | |
d50f6dca | 196 | unsigned int num; |
6ab8fba7 | 197 | struct kref ref; |
e1eaea46 AC |
198 | |
199 | /* Events on the GSM channel */ | |
200 | wait_queue_head_t event; | |
201 | ||
202 | /* Bits for GSM mode decoding */ | |
203 | ||
204 | /* Framing Layer */ | |
205 | unsigned char *buf; | |
206 | int state; | |
207 | #define GSM_SEARCH 0 | |
208 | #define GSM_START 1 | |
209 | #define GSM_ADDRESS 2 | |
210 | #define GSM_CONTROL 3 | |
211 | #define GSM_LEN 4 | |
212 | #define GSM_DATA 5 | |
213 | #define GSM_FCS 6 | |
214 | #define GSM_OVERRUN 7 | |
c2f2f000 AC |
215 | #define GSM_LEN0 8 |
216 | #define GSM_LEN1 9 | |
217 | #define GSM_SSOF 10 | |
e1eaea46 AC |
218 | unsigned int len; |
219 | unsigned int address; | |
220 | unsigned int count; | |
221 | int escape; | |
222 | int encoding; | |
223 | u8 control; | |
224 | u8 fcs; | |
c2f2f000 | 225 | u8 received_fcs; |
e1eaea46 AC |
226 | u8 *txframe; /* TX framing buffer */ |
227 | ||
228 | /* Methods for the receiver side */ | |
229 | void (*receive)(struct gsm_mux *gsm, u8 ch); | |
230 | void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag); | |
231 | /* And transmit side */ | |
232 | int (*output)(struct gsm_mux *mux, u8 *data, int len); | |
233 | ||
234 | /* Link Layer */ | |
235 | unsigned int mru; | |
236 | unsigned int mtu; | |
237 | int initiator; /* Did we initiate connection */ | |
238 | int dead; /* Has the mux been shut down */ | |
239 | struct gsm_dlci *dlci[NUM_DLCI]; | |
240 | int constipated; /* Asked by remote to shut up */ | |
241 | ||
242 | spinlock_t tx_lock; | |
243 | unsigned int tx_bytes; /* TX data outstanding */ | |
244 | #define TX_THRESH_HI 8192 | |
245 | #define TX_THRESH_LO 2048 | |
246 | struct gsm_msg *tx_head; /* Pending data packets */ | |
247 | struct gsm_msg *tx_tail; | |
248 | ||
249 | /* Control messages */ | |
250 | struct timer_list t2_timer; /* Retransmit timer for commands */ | |
251 | int cretries; /* Command retry counter */ | |
252 | struct gsm_control *pending_cmd;/* Our current pending command */ | |
253 | spinlock_t control_lock; /* Protects the pending command */ | |
254 | ||
255 | /* Configuration */ | |
256 | int adaption; /* 1 or 2 supported */ | |
257 | u8 ftype; /* UI or UIH */ | |
258 | int t1, t2; /* Timers in 1/100th of a sec */ | |
259 | int n2; /* Retry count */ | |
260 | ||
261 | /* Statistics (not currently exposed) */ | |
262 | unsigned long bad_fcs; | |
263 | unsigned long malformed; | |
264 | unsigned long io_error; | |
265 | unsigned long bad_size; | |
266 | unsigned long unsupported; | |
267 | }; | |
268 | ||
269 | ||
270 | /* | |
271 | * Mux objects - needed so that we can translate a tty index into the | |
272 | * relevant mux and DLCI. | |
273 | */ | |
274 | ||
275 | #define MAX_MUX 4 /* 256 minors */ | |
276 | static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */ | |
277 | static spinlock_t gsm_mux_lock; | |
278 | ||
d50f6dca RG |
279 | static struct tty_driver *gsm_tty_driver; |
280 | ||
e1eaea46 AC |
281 | /* |
282 | * This section of the driver logic implements the GSM encodings | |
283 | * both the basic and the 'advanced'. Reliable transport is not | |
284 | * supported. | |
285 | */ | |
286 | ||
287 | #define CR 0x02 | |
288 | #define EA 0x01 | |
289 | #define PF 0x10 | |
290 | ||
291 | /* I is special: the rest are ..*/ | |
292 | #define RR 0x01 | |
293 | #define UI 0x03 | |
294 | #define RNR 0x05 | |
295 | #define REJ 0x09 | |
296 | #define DM 0x0F | |
297 | #define SABM 0x2F | |
298 | #define DISC 0x43 | |
299 | #define UA 0x63 | |
300 | #define UIH 0xEF | |
301 | ||
302 | /* Channel commands */ | |
303 | #define CMD_NSC 0x09 | |
304 | #define CMD_TEST 0x11 | |
305 | #define CMD_PSC 0x21 | |
306 | #define CMD_RLS 0x29 | |
307 | #define CMD_FCOFF 0x31 | |
308 | #define CMD_PN 0x41 | |
309 | #define CMD_RPN 0x49 | |
310 | #define CMD_FCON 0x51 | |
311 | #define CMD_CLD 0x61 | |
312 | #define CMD_SNC 0x69 | |
313 | #define CMD_MSC 0x71 | |
314 | ||
315 | /* Virtual modem bits */ | |
316 | #define MDM_FC 0x01 | |
317 | #define MDM_RTC 0x02 | |
318 | #define MDM_RTR 0x04 | |
319 | #define MDM_IC 0x20 | |
320 | #define MDM_DV 0x40 | |
321 | ||
322 | #define GSM0_SOF 0xF9 | |
5f9a31d6 | 323 | #define GSM1_SOF 0x7E |
e1eaea46 AC |
324 | #define GSM1_ESCAPE 0x7D |
325 | #define GSM1_ESCAPE_BITS 0x20 | |
326 | #define XON 0x11 | |
327 | #define XOFF 0x13 | |
328 | ||
329 | static const struct tty_port_operations gsm_port_ops; | |
330 | ||
331 | /* | |
332 | * CRC table for GSM 0710 | |
333 | */ | |
334 | ||
335 | static const u8 gsm_fcs8[256] = { | |
336 | 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, | |
337 | 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B, | |
338 | 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, | |
339 | 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, | |
340 | 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, | |
341 | 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43, | |
342 | 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, | |
343 | 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F, | |
344 | 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, | |
345 | 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B, | |
346 | 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, | |
347 | 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, | |
348 | 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, | |
349 | 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33, | |
350 | 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, | |
351 | 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F, | |
352 | 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, | |
353 | 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B, | |
354 | 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, | |
355 | 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, | |
356 | 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, | |
357 | 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3, | |
358 | 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, | |
359 | 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF, | |
360 | 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, | |
361 | 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB, | |
362 | 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, | |
363 | 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, | |
364 | 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, | |
365 | 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3, | |
366 | 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, | |
367 | 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF | |
368 | }; | |
369 | ||
370 | #define INIT_FCS 0xFF | |
371 | #define GOOD_FCS 0xCF | |
372 | ||
373 | /** | |
374 | * gsm_fcs_add - update FCS | |
375 | * @fcs: Current FCS | |
376 | * @c: Next data | |
377 | * | |
378 | * Update the FCS to include c. Uses the algorithm in the specification | |
379 | * notes. | |
380 | */ | |
381 | ||
382 | static inline u8 gsm_fcs_add(u8 fcs, u8 c) | |
383 | { | |
384 | return gsm_fcs8[fcs ^ c]; | |
385 | } | |
386 | ||
387 | /** | |
388 | * gsm_fcs_add_block - update FCS for a block | |
389 | * @fcs: Current FCS | |
390 | * @c: buffer of data | |
391 | * @len: length of buffer | |
392 | * | |
393 | * Update the FCS to include c. Uses the algorithm in the specification | |
394 | * notes. | |
395 | */ | |
396 | ||
397 | static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len) | |
398 | { | |
399 | while (len--) | |
400 | fcs = gsm_fcs8[fcs ^ *c++]; | |
401 | return fcs; | |
402 | } | |
403 | ||
404 | /** | |
405 | * gsm_read_ea - read a byte into an EA | |
406 | * @val: variable holding value | |
407 | * c: byte going into the EA | |
408 | * | |
409 | * Processes one byte of an EA. Updates the passed variable | |
410 | * and returns 1 if the EA is now completely read | |
411 | */ | |
412 | ||
413 | static int gsm_read_ea(unsigned int *val, u8 c) | |
414 | { | |
415 | /* Add the next 7 bits into the value */ | |
416 | *val <<= 7; | |
417 | *val |= c >> 1; | |
418 | /* Was this the last byte of the EA 1 = yes*/ | |
419 | return c & EA; | |
420 | } | |
421 | ||
422 | /** | |
423 | * gsm_encode_modem - encode modem data bits | |
424 | * @dlci: DLCI to encode from | |
425 | * | |
426 | * Returns the correct GSM encoded modem status bits (6 bit field) for | |
427 | * the current status of the DLCI and attached tty object | |
428 | */ | |
429 | ||
430 | static u8 gsm_encode_modem(const struct gsm_dlci *dlci) | |
431 | { | |
432 | u8 modembits = 0; | |
433 | /* FC is true flow control not modem bits */ | |
434 | if (dlci->throttled) | |
435 | modembits |= MDM_FC; | |
436 | if (dlci->modem_tx & TIOCM_DTR) | |
437 | modembits |= MDM_RTC; | |
438 | if (dlci->modem_tx & TIOCM_RTS) | |
439 | modembits |= MDM_RTR; | |
440 | if (dlci->modem_tx & TIOCM_RI) | |
441 | modembits |= MDM_IC; | |
442 | if (dlci->modem_tx & TIOCM_CD) | |
443 | modembits |= MDM_DV; | |
444 | return modembits; | |
445 | } | |
446 | ||
447 | /** | |
448 | * gsm_print_packet - display a frame for debug | |
449 | * @hdr: header to print before decode | |
450 | * @addr: address EA from the frame | |
451 | * @cr: C/R bit from the frame | |
452 | * @control: control including PF bit | |
453 | * @data: following data bytes | |
454 | * @dlen: length of data | |
455 | * | |
456 | * Displays a packet in human readable format for debugging purposes. The | |
457 | * style is based on amateur radio LAP-B dump display. | |
458 | */ | |
459 | ||
460 | static void gsm_print_packet(const char *hdr, int addr, int cr, | |
461 | u8 control, const u8 *data, int dlen) | |
462 | { | |
463 | if (!(debug & 1)) | |
464 | return; | |
465 | ||
5f9a31d6 | 466 | pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]); |
e1eaea46 AC |
467 | |
468 | switch (control & ~PF) { | |
469 | case SABM: | |
5f9a31d6 | 470 | pr_cont("SABM"); |
e1eaea46 AC |
471 | break; |
472 | case UA: | |
5f9a31d6 | 473 | pr_cont("UA"); |
e1eaea46 AC |
474 | break; |
475 | case DISC: | |
5f9a31d6 | 476 | pr_cont("DISC"); |
e1eaea46 AC |
477 | break; |
478 | case DM: | |
5f9a31d6 | 479 | pr_cont("DM"); |
e1eaea46 AC |
480 | break; |
481 | case UI: | |
5f9a31d6 | 482 | pr_cont("UI"); |
e1eaea46 AC |
483 | break; |
484 | case UIH: | |
5f9a31d6 | 485 | pr_cont("UIH"); |
e1eaea46 AC |
486 | break; |
487 | default: | |
488 | if (!(control & 0x01)) { | |
5f9a31d6 AC |
489 | pr_cont("I N(S)%d N(R)%d", |
490 | (control & 0x0E) >> 1, (control & 0xE) >> 5); | |
e1eaea46 | 491 | } else switch (control & 0x0F) { |
5f9a31d6 AC |
492 | case RR: |
493 | pr_cont("RR(%d)", (control & 0xE0) >> 5); | |
494 | break; | |
495 | case RNR: | |
496 | pr_cont("RNR(%d)", (control & 0xE0) >> 5); | |
497 | break; | |
498 | case REJ: | |
499 | pr_cont("REJ(%d)", (control & 0xE0) >> 5); | |
500 | break; | |
501 | default: | |
502 | pr_cont("[%02X]", control); | |
e1eaea46 AC |
503 | } |
504 | } | |
505 | ||
506 | if (control & PF) | |
5f9a31d6 | 507 | pr_cont("(P)"); |
e1eaea46 | 508 | else |
5f9a31d6 | 509 | pr_cont("(F)"); |
e1eaea46 AC |
510 | |
511 | if (dlen) { | |
512 | int ct = 0; | |
513 | while (dlen--) { | |
5f9a31d6 AC |
514 | if (ct % 8 == 0) { |
515 | pr_cont("\n"); | |
516 | pr_debug(" "); | |
517 | } | |
518 | pr_cont("%02X ", *data++); | |
e1eaea46 AC |
519 | ct++; |
520 | } | |
521 | } | |
5f9a31d6 | 522 | pr_cont("\n"); |
e1eaea46 AC |
523 | } |
524 | ||
525 | ||
526 | /* | |
527 | * Link level transmission side | |
528 | */ | |
529 | ||
530 | /** | |
531 | * gsm_stuff_packet - bytestuff a packet | |
532 | * @ibuf: input | |
533 | * @obuf: output | |
534 | * @len: length of input | |
535 | * | |
536 | * Expand a buffer by bytestuffing it. The worst case size change | |
537 | * is doubling and the caller is responsible for handing out | |
538 | * suitable sized buffers. | |
539 | */ | |
540 | ||
541 | static int gsm_stuff_frame(const u8 *input, u8 *output, int len) | |
542 | { | |
543 | int olen = 0; | |
544 | while (len--) { | |
545 | if (*input == GSM1_SOF || *input == GSM1_ESCAPE | |
546 | || *input == XON || *input == XOFF) { | |
547 | *output++ = GSM1_ESCAPE; | |
548 | *output++ = *input++ ^ GSM1_ESCAPE_BITS; | |
549 | olen++; | |
550 | } else | |
551 | *output++ = *input++; | |
552 | olen++; | |
553 | } | |
554 | return olen; | |
555 | } | |
556 | ||
e1eaea46 AC |
557 | /** |
558 | * gsm_send - send a control frame | |
559 | * @gsm: our GSM mux | |
560 | * @addr: address for control frame | |
561 | * @cr: command/response bit | |
562 | * @control: control byte including PF bit | |
563 | * | |
564 | * Format up and transmit a control frame. These do not go via the | |
565 | * queueing logic as they should be transmitted ahead of data when | |
566 | * they are needed. | |
567 | * | |
568 | * FIXME: Lock versus data TX path | |
569 | */ | |
570 | ||
571 | static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) | |
572 | { | |
573 | int len; | |
574 | u8 cbuf[10]; | |
575 | u8 ibuf[3]; | |
576 | ||
577 | switch (gsm->encoding) { | |
578 | case 0: | |
579 | cbuf[0] = GSM0_SOF; | |
580 | cbuf[1] = (addr << 2) | (cr << 1) | EA; | |
581 | cbuf[2] = control; | |
582 | cbuf[3] = EA; /* Length of data = 0 */ | |
583 | cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3); | |
584 | cbuf[5] = GSM0_SOF; | |
585 | len = 6; | |
586 | break; | |
587 | case 1: | |
588 | case 2: | |
589 | /* Control frame + packing (but not frame stuffing) in mode 1 */ | |
590 | ibuf[0] = (addr << 2) | (cr << 1) | EA; | |
591 | ibuf[1] = control; | |
592 | ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2); | |
593 | /* Stuffing may double the size worst case */ | |
594 | len = gsm_stuff_frame(ibuf, cbuf + 1, 3); | |
595 | /* Now add the SOF markers */ | |
596 | cbuf[0] = GSM1_SOF; | |
597 | cbuf[len + 1] = GSM1_SOF; | |
598 | /* FIXME: we can omit the lead one in many cases */ | |
599 | len += 2; | |
600 | break; | |
601 | default: | |
602 | WARN_ON(1); | |
603 | return; | |
604 | } | |
605 | gsm->output(gsm, cbuf, len); | |
606 | gsm_print_packet("-->", addr, cr, control, NULL, 0); | |
607 | } | |
608 | ||
609 | /** | |
610 | * gsm_response - send a control response | |
611 | * @gsm: our GSM mux | |
612 | * @addr: address for control frame | |
613 | * @control: control byte including PF bit | |
614 | * | |
615 | * Format up and transmit a link level response frame. | |
616 | */ | |
617 | ||
618 | static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) | |
619 | { | |
620 | gsm_send(gsm, addr, 0, control); | |
621 | } | |
622 | ||
623 | /** | |
624 | * gsm_command - send a control command | |
625 | * @gsm: our GSM mux | |
626 | * @addr: address for control frame | |
627 | * @control: control byte including PF bit | |
628 | * | |
629 | * Format up and transmit a link level command frame. | |
630 | */ | |
631 | ||
632 | static inline void gsm_command(struct gsm_mux *gsm, int addr, int control) | |
633 | { | |
634 | gsm_send(gsm, addr, 1, control); | |
635 | } | |
636 | ||
637 | /* Data transmission */ | |
638 | ||
639 | #define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */ | |
640 | ||
641 | /** | |
642 | * gsm_data_alloc - allocate data frame | |
643 | * @gsm: GSM mux | |
644 | * @addr: DLCI address | |
645 | * @len: length excluding header and FCS | |
646 | * @ctrl: control byte | |
647 | * | |
648 | * Allocate a new data buffer for sending frames with data. Space is left | |
649 | * at the front for header bytes but that is treated as an implementation | |
650 | * detail and not for the high level code to use | |
651 | */ | |
652 | ||
653 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, | |
654 | u8 ctrl) | |
655 | { | |
656 | struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN, | |
657 | GFP_ATOMIC); | |
658 | if (m == NULL) | |
659 | return NULL; | |
660 | m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */ | |
661 | m->len = len; | |
662 | m->addr = addr; | |
663 | m->ctrl = ctrl; | |
664 | m->next = NULL; | |
665 | return m; | |
666 | } | |
667 | ||
668 | /** | |
669 | * gsm_data_kick - poke the queue | |
670 | * @gsm: GSM Mux | |
671 | * | |
672 | * The tty device has called us to indicate that room has appeared in | |
673 | * the transmit queue. Ram more data into the pipe if we have any | |
674 | * | |
675 | * FIXME: lock against link layer control transmissions | |
676 | */ | |
677 | ||
678 | static void gsm_data_kick(struct gsm_mux *gsm) | |
679 | { | |
680 | struct gsm_msg *msg = gsm->tx_head; | |
681 | int len; | |
682 | int skip_sof = 0; | |
683 | ||
684 | /* FIXME: We need to apply this solely to data messages */ | |
685 | if (gsm->constipated) | |
686 | return; | |
687 | ||
688 | while (gsm->tx_head != NULL) { | |
689 | msg = gsm->tx_head; | |
690 | if (gsm->encoding != 0) { | |
691 | gsm->txframe[0] = GSM1_SOF; | |
692 | len = gsm_stuff_frame(msg->data, | |
693 | gsm->txframe + 1, msg->len); | |
694 | gsm->txframe[len + 1] = GSM1_SOF; | |
695 | len += 2; | |
696 | } else { | |
697 | gsm->txframe[0] = GSM0_SOF; | |
698 | memcpy(gsm->txframe + 1 , msg->data, msg->len); | |
699 | gsm->txframe[msg->len + 1] = GSM0_SOF; | |
700 | len = msg->len + 2; | |
701 | } | |
702 | ||
0a77c4f9 JP |
703 | if (debug & 4) |
704 | print_hex_dump_bytes("gsm_data_kick: ", | |
705 | DUMP_PREFIX_OFFSET, | |
706 | gsm->txframe, len); | |
e1eaea46 AC |
707 | |
708 | if (gsm->output(gsm, gsm->txframe + skip_sof, | |
709 | len - skip_sof) < 0) | |
710 | break; | |
711 | /* FIXME: Can eliminate one SOF in many more cases */ | |
712 | gsm->tx_head = msg->next; | |
713 | if (gsm->tx_head == NULL) | |
714 | gsm->tx_tail = NULL; | |
715 | gsm->tx_bytes -= msg->len; | |
716 | kfree(msg); | |
717 | /* For a burst of frames skip the extra SOF within the | |
718 | burst */ | |
719 | skip_sof = 1; | |
720 | } | |
721 | } | |
722 | ||
723 | /** | |
724 | * __gsm_data_queue - queue a UI or UIH frame | |
725 | * @dlci: DLCI sending the data | |
726 | * @msg: message queued | |
727 | * | |
728 | * Add data to the transmit queue and try and get stuff moving | |
729 | * out of the mux tty if not already doing so. The Caller must hold | |
730 | * the gsm tx lock. | |
731 | */ | |
732 | ||
733 | static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
734 | { | |
735 | struct gsm_mux *gsm = dlci->gsm; | |
736 | u8 *dp = msg->data; | |
737 | u8 *fcs = dp + msg->len; | |
738 | ||
739 | /* Fill in the header */ | |
740 | if (gsm->encoding == 0) { | |
741 | if (msg->len < 128) | |
742 | *--dp = (msg->len << 1) | EA; | |
743 | else { | |
be7a7411 KM |
744 | *--dp = (msg->len >> 7); /* bits 7 - 15 */ |
745 | *--dp = (msg->len & 127) << 1; /* bits 0 - 6 */ | |
e1eaea46 AC |
746 | } |
747 | } | |
748 | ||
749 | *--dp = msg->ctrl; | |
750 | if (gsm->initiator) | |
751 | *--dp = (msg->addr << 2) | 2 | EA; | |
752 | else | |
753 | *--dp = (msg->addr << 2) | EA; | |
754 | *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp); | |
755 | /* Ugly protocol layering violation */ | |
756 | if (msg->ctrl == UI || msg->ctrl == (UI|PF)) | |
757 | *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len); | |
758 | *fcs = 0xFF - *fcs; | |
759 | ||
760 | gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl, | |
761 | msg->data, msg->len); | |
762 | ||
763 | /* Move the header back and adjust the length, also allow for the FCS | |
764 | now tacked on the end */ | |
765 | msg->len += (msg->data - dp) + 1; | |
766 | msg->data = dp; | |
767 | ||
768 | /* Add to the actual output queue */ | |
769 | if (gsm->tx_tail) | |
770 | gsm->tx_tail->next = msg; | |
771 | else | |
772 | gsm->tx_head = msg; | |
773 | gsm->tx_tail = msg; | |
774 | gsm->tx_bytes += msg->len; | |
775 | gsm_data_kick(gsm); | |
776 | } | |
777 | ||
778 | /** | |
779 | * gsm_data_queue - queue a UI or UIH frame | |
780 | * @dlci: DLCI sending the data | |
781 | * @msg: message queued | |
782 | * | |
783 | * Add data to the transmit queue and try and get stuff moving | |
784 | * out of the mux tty if not already doing so. Take the | |
785 | * the gsm tx lock and dlci lock. | |
786 | */ | |
787 | ||
788 | static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
789 | { | |
790 | unsigned long flags; | |
791 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); | |
792 | __gsm_data_queue(dlci, msg); | |
793 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); | |
794 | } | |
795 | ||
796 | /** | |
797 | * gsm_dlci_data_output - try and push data out of a DLCI | |
798 | * @gsm: mux | |
799 | * @dlci: the DLCI to pull data from | |
800 | * | |
801 | * Pull data from a DLCI and send it into the transmit queue if there | |
802 | * is data. Keep to the MRU of the mux. This path handles the usual tty | |
803 | * interface which is a byte stream with optional modem data. | |
804 | * | |
805 | * Caller must hold the tx_lock of the mux. | |
806 | */ | |
807 | ||
808 | static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) | |
809 | { | |
810 | struct gsm_msg *msg; | |
811 | u8 *dp; | |
268e526b | 812 | int len, total_size, size; |
e1eaea46 AC |
813 | int h = dlci->adaption - 1; |
814 | ||
268e526b MK |
815 | total_size = 0; |
816 | while(1) { | |
817 | len = kfifo_len(dlci->fifo); | |
818 | if (len == 0) | |
819 | return total_size; | |
820 | ||
821 | /* MTU/MRU count only the data bits */ | |
822 | if (len > gsm->mtu) | |
823 | len = gsm->mtu; | |
824 | ||
825 | size = len + h; | |
826 | ||
827 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); | |
828 | /* FIXME: need a timer or something to kick this so it can't | |
829 | get stuck with no work outstanding and no buffer free */ | |
830 | if (msg == NULL) | |
831 | return -ENOMEM; | |
832 | dp = msg->data; | |
833 | switch (dlci->adaption) { | |
834 | case 1: /* Unstructured */ | |
835 | break; | |
836 | case 2: /* Unstructed with modem bits. Always one byte as we never | |
837 | send inline break data */ | |
838 | *dp++ = gsm_encode_modem(dlci); | |
839 | break; | |
840 | } | |
841 | WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len); | |
842 | __gsm_data_queue(dlci, msg); | |
843 | total_size += size; | |
e1eaea46 | 844 | } |
e1eaea46 | 845 | /* Bytes of data we used up */ |
268e526b | 846 | return total_size; |
e1eaea46 AC |
847 | } |
848 | ||
849 | /** | |
850 | * gsm_dlci_data_output_framed - try and push data out of a DLCI | |
851 | * @gsm: mux | |
852 | * @dlci: the DLCI to pull data from | |
853 | * | |
854 | * Pull data from a DLCI and send it into the transmit queue if there | |
855 | * is data. Keep to the MRU of the mux. This path handles framed data | |
856 | * queued as skbuffs to the DLCI. | |
857 | * | |
858 | * Caller must hold the tx_lock of the mux. | |
859 | */ | |
860 | ||
861 | static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, | |
862 | struct gsm_dlci *dlci) | |
863 | { | |
864 | struct gsm_msg *msg; | |
865 | u8 *dp; | |
866 | int len, size; | |
867 | int last = 0, first = 0; | |
868 | int overhead = 0; | |
869 | ||
870 | /* One byte per frame is used for B/F flags */ | |
871 | if (dlci->adaption == 4) | |
872 | overhead = 1; | |
873 | ||
874 | /* dlci->skb is locked by tx_lock */ | |
875 | if (dlci->skb == NULL) { | |
876 | dlci->skb = skb_dequeue(&dlci->skb_list); | |
877 | if (dlci->skb == NULL) | |
878 | return 0; | |
879 | first = 1; | |
880 | } | |
881 | len = dlci->skb->len + overhead; | |
882 | ||
883 | /* MTU/MRU count only the data bits */ | |
884 | if (len > gsm->mtu) { | |
885 | if (dlci->adaption == 3) { | |
886 | /* Over long frame, bin it */ | |
887 | kfree_skb(dlci->skb); | |
888 | dlci->skb = NULL; | |
889 | return 0; | |
890 | } | |
891 | len = gsm->mtu; | |
892 | } else | |
893 | last = 1; | |
894 | ||
895 | size = len + overhead; | |
896 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); | |
897 | ||
898 | /* FIXME: need a timer or something to kick this so it can't | |
899 | get stuck with no work outstanding and no buffer free */ | |
900 | if (msg == NULL) | |
901 | return -ENOMEM; | |
902 | dp = msg->data; | |
903 | ||
904 | if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ | |
905 | /* Flag byte to carry the start/end info */ | |
906 | *dp++ = last << 7 | first << 6 | 1; /* EA */ | |
907 | len--; | |
908 | } | |
57f2104f RG |
909 | memcpy(dp, dlci->skb->data, len); |
910 | skb_pull(dlci->skb, len); | |
e1eaea46 | 911 | __gsm_data_queue(dlci, msg); |
bcd5abe2 RG |
912 | if (last) { |
913 | kfree_skb(dlci->skb); | |
e1eaea46 | 914 | dlci->skb = NULL; |
bcd5abe2 | 915 | } |
e1eaea46 AC |
916 | return size; |
917 | } | |
918 | ||
919 | /** | |
920 | * gsm_dlci_data_sweep - look for data to send | |
921 | * @gsm: the GSM mux | |
922 | * | |
923 | * Sweep the GSM mux channels in priority order looking for ones with | |
924 | * data to send. We could do with optimising this scan a bit. We aim | |
925 | * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit | |
926 | * TX_THRESH_LO we get called again | |
927 | * | |
928 | * FIXME: We should round robin between groups and in theory you can | |
929 | * renegotiate DLCI priorities with optional stuff. Needs optimising. | |
930 | */ | |
931 | ||
932 | static void gsm_dlci_data_sweep(struct gsm_mux *gsm) | |
933 | { | |
934 | int len; | |
935 | /* Priority ordering: We should do priority with RR of the groups */ | |
936 | int i = 1; | |
e1eaea46 | 937 | |
e1eaea46 AC |
938 | while (i < NUM_DLCI) { |
939 | struct gsm_dlci *dlci; | |
940 | ||
941 | if (gsm->tx_bytes > TX_THRESH_HI) | |
942 | break; | |
943 | dlci = gsm->dlci[i]; | |
944 | if (dlci == NULL || dlci->constipated) { | |
945 | i++; | |
946 | continue; | |
947 | } | |
bcd5abe2 | 948 | if (dlci->adaption < 3 && !dlci->net) |
e1eaea46 AC |
949 | len = gsm_dlci_data_output(gsm, dlci); |
950 | else | |
951 | len = gsm_dlci_data_output_framed(gsm, dlci); | |
952 | if (len < 0) | |
e73790a5 | 953 | break; |
e1eaea46 AC |
954 | /* DLCI empty - try the next */ |
955 | if (len == 0) | |
956 | i++; | |
957 | } | |
e1eaea46 AC |
958 | } |
959 | ||
960 | /** | |
961 | * gsm_dlci_data_kick - transmit if possible | |
962 | * @dlci: DLCI to kick | |
963 | * | |
964 | * Transmit data from this DLCI if the queue is empty. We can't rely on | |
965 | * a tty wakeup except when we filled the pipe so we need to fire off | |
966 | * new data ourselves in other cases. | |
967 | */ | |
968 | ||
969 | static void gsm_dlci_data_kick(struct gsm_dlci *dlci) | |
970 | { | |
971 | unsigned long flags; | |
972 | ||
973 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); | |
974 | /* If we have nothing running then we need to fire up */ | |
bcd5abe2 RG |
975 | if (dlci->gsm->tx_bytes == 0) { |
976 | if (dlci->net) | |
977 | gsm_dlci_data_output_framed(dlci->gsm, dlci); | |
978 | else | |
979 | gsm_dlci_data_output(dlci->gsm, dlci); | |
980 | } else if (dlci->gsm->tx_bytes < TX_THRESH_LO) | |
e1eaea46 AC |
981 | gsm_dlci_data_sweep(dlci->gsm); |
982 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); | |
983 | } | |
984 | ||
985 | /* | |
986 | * Control message processing | |
987 | */ | |
988 | ||
989 | ||
990 | /** | |
991 | * gsm_control_reply - send a response frame to a control | |
992 | * @gsm: gsm channel | |
993 | * @cmd: the command to use | |
994 | * @data: data to follow encoded info | |
995 | * @dlen: length of data | |
996 | * | |
997 | * Encode up and queue a UI/UIH frame containing our response. | |
998 | */ | |
999 | ||
1000 | static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data, | |
1001 | int dlen) | |
1002 | { | |
1003 | struct gsm_msg *msg; | |
1004 | msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); | |
093d8046 KM |
1005 | if (msg == NULL) |
1006 | return; | |
e1eaea46 AC |
1007 | msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ |
1008 | msg->data[1] = (dlen << 1) | EA; | |
1009 | memcpy(msg->data + 2, data, dlen); | |
1010 | gsm_data_queue(gsm->dlci[0], msg); | |
1011 | } | |
1012 | ||
1013 | /** | |
1014 | * gsm_process_modem - process received modem status | |
1015 | * @tty: virtual tty bound to the DLCI | |
1016 | * @dlci: DLCI to affect | |
1017 | * @modem: modem bits (full EA) | |
1018 | * | |
1019 | * Used when a modem control message or line state inline in adaption | |
1020 | * layer 2 is processed. Sort out the local modem state and throttles | |
1021 | */ | |
1022 | ||
1023 | static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, | |
7263287a | 1024 | u32 modem, int clen) |
e1eaea46 AC |
1025 | { |
1026 | int mlines = 0; | |
7263287a RG |
1027 | u8 brk = 0; |
1028 | ||
1029 | /* The modem status command can either contain one octet (v.24 signals) | |
1030 | or two octets (v.24 signals + break signals). The length field will | |
1031 | either be 2 or 3 respectively. This is specified in section | |
1032 | 5.4.6.3.7 of the 27.010 mux spec. */ | |
1033 | ||
1034 | if (clen == 2) | |
1035 | modem = modem & 0x7f; | |
1036 | else { | |
1037 | brk = modem & 0x7f; | |
1038 | modem = (modem >> 7) & 0x7f; | |
1039 | }; | |
e1eaea46 AC |
1040 | |
1041 | /* Flow control/ready to communicate */ | |
1042 | if (modem & MDM_FC) { | |
1043 | /* Need to throttle our output on this device */ | |
1044 | dlci->constipated = 1; | |
1045 | } | |
1046 | if (modem & MDM_RTC) { | |
1047 | mlines |= TIOCM_DSR | TIOCM_DTR; | |
1048 | dlci->constipated = 0; | |
1049 | gsm_dlci_data_kick(dlci); | |
1050 | } | |
1051 | /* Map modem bits */ | |
1052 | if (modem & MDM_RTR) | |
1053 | mlines |= TIOCM_RTS | TIOCM_CTS; | |
1054 | if (modem & MDM_IC) | |
1055 | mlines |= TIOCM_RI; | |
1056 | if (modem & MDM_DV) | |
1057 | mlines |= TIOCM_CD; | |
1058 | ||
1059 | /* Carrier drop -> hangup */ | |
1060 | if (tty) { | |
1061 | if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) | |
1062 | if (!(tty->termios->c_cflag & CLOCAL)) | |
1063 | tty_hangup(tty); | |
1064 | if (brk & 0x01) | |
1065 | tty_insert_flip_char(tty, 0, TTY_BREAK); | |
1066 | } | |
1067 | dlci->modem_rx = mlines; | |
1068 | } | |
1069 | ||
1070 | /** | |
1071 | * gsm_control_modem - modem status received | |
1072 | * @gsm: GSM channel | |
1073 | * @data: data following command | |
1074 | * @clen: command length | |
1075 | * | |
1076 | * We have received a modem status control message. This is used by | |
1077 | * the GSM mux protocol to pass virtual modem line status and optionally | |
1078 | * to indicate break signals. Unpack it, convert to Linux representation | |
1079 | * and if need be stuff a break message down the tty. | |
1080 | */ | |
1081 | ||
1082 | static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen) | |
1083 | { | |
1084 | unsigned int addr = 0; | |
1085 | unsigned int modem = 0; | |
1086 | struct gsm_dlci *dlci; | |
1087 | int len = clen; | |
1088 | u8 *dp = data; | |
1089 | struct tty_struct *tty; | |
1090 | ||
1091 | while (gsm_read_ea(&addr, *dp++) == 0) { | |
1092 | len--; | |
1093 | if (len == 0) | |
1094 | return; | |
1095 | } | |
1096 | /* Must be at least one byte following the EA */ | |
1097 | len--; | |
1098 | if (len <= 0) | |
1099 | return; | |
1100 | ||
1101 | addr >>= 1; | |
1102 | /* Closed port, or invalid ? */ | |
1103 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1104 | return; | |
1105 | dlci = gsm->dlci[addr]; | |
1106 | ||
1107 | while (gsm_read_ea(&modem, *dp++) == 0) { | |
1108 | len--; | |
1109 | if (len == 0) | |
1110 | return; | |
1111 | } | |
1112 | tty = tty_port_tty_get(&dlci->port); | |
7263287a | 1113 | gsm_process_modem(tty, dlci, modem, clen); |
e1eaea46 AC |
1114 | if (tty) { |
1115 | tty_wakeup(tty); | |
1116 | tty_kref_put(tty); | |
1117 | } | |
1118 | gsm_control_reply(gsm, CMD_MSC, data, clen); | |
1119 | } | |
1120 | ||
1121 | /** | |
1122 | * gsm_control_rls - remote line status | |
1123 | * @gsm: GSM channel | |
1124 | * @data: data bytes | |
1125 | * @clen: data length | |
1126 | * | |
1127 | * The modem sends us a two byte message on the control channel whenever | |
1128 | * it wishes to send us an error state from the virtual link. Stuff | |
1129 | * this into the uplink tty if present | |
1130 | */ | |
1131 | ||
1132 | static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen) | |
1133 | { | |
1134 | struct tty_struct *tty; | |
1135 | unsigned int addr = 0 ; | |
1136 | u8 bits; | |
1137 | int len = clen; | |
1138 | u8 *dp = data; | |
1139 | ||
1140 | while (gsm_read_ea(&addr, *dp++) == 0) { | |
1141 | len--; | |
1142 | if (len == 0) | |
1143 | return; | |
1144 | } | |
1145 | /* Must be at least one byte following ea */ | |
1146 | len--; | |
1147 | if (len <= 0) | |
1148 | return; | |
1149 | addr >>= 1; | |
1150 | /* Closed port, or invalid ? */ | |
1151 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1152 | return; | |
1153 | /* No error ? */ | |
1154 | bits = *dp; | |
1155 | if ((bits & 1) == 0) | |
1156 | return; | |
1157 | /* See if we have an uplink tty */ | |
1158 | tty = tty_port_tty_get(&gsm->dlci[addr]->port); | |
1159 | ||
1160 | if (tty) { | |
1161 | if (bits & 2) | |
1162 | tty_insert_flip_char(tty, 0, TTY_OVERRUN); | |
1163 | if (bits & 4) | |
1164 | tty_insert_flip_char(tty, 0, TTY_PARITY); | |
1165 | if (bits & 8) | |
1166 | tty_insert_flip_char(tty, 0, TTY_FRAME); | |
1167 | tty_flip_buffer_push(tty); | |
1168 | tty_kref_put(tty); | |
1169 | } | |
1170 | gsm_control_reply(gsm, CMD_RLS, data, clen); | |
1171 | } | |
1172 | ||
1173 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci); | |
1174 | ||
1175 | /** | |
1176 | * gsm_control_message - DLCI 0 control processing | |
1177 | * @gsm: our GSM mux | |
1178 | * @command: the command EA | |
1179 | * @data: data beyond the command/length EAs | |
1180 | * @clen: length | |
1181 | * | |
1182 | * Input processor for control messages from the other end of the link. | |
1183 | * Processes the incoming request and queues a response frame or an | |
1184 | * NSC response if not supported | |
1185 | */ | |
1186 | ||
1187 | static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, | |
1188 | u8 *data, int clen) | |
1189 | { | |
1190 | u8 buf[1]; | |
1191 | switch (command) { | |
1192 | case CMD_CLD: { | |
1193 | struct gsm_dlci *dlci = gsm->dlci[0]; | |
1194 | /* Modem wishes to close down */ | |
1195 | if (dlci) { | |
1196 | dlci->dead = 1; | |
1197 | gsm->dead = 1; | |
1198 | gsm_dlci_begin_close(dlci); | |
1199 | } | |
1200 | } | |
1201 | break; | |
1202 | case CMD_TEST: | |
1203 | /* Modem wishes to test, reply with the data */ | |
1204 | gsm_control_reply(gsm, CMD_TEST, data, clen); | |
1205 | break; | |
1206 | case CMD_FCON: | |
1207 | /* Modem wants us to STFU */ | |
1208 | gsm->constipated = 1; | |
1209 | gsm_control_reply(gsm, CMD_FCON, NULL, 0); | |
1210 | break; | |
1211 | case CMD_FCOFF: | |
1212 | /* Modem can accept data again */ | |
1213 | gsm->constipated = 0; | |
1214 | gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); | |
1215 | /* Kick the link in case it is idling */ | |
1216 | gsm_data_kick(gsm); | |
1217 | break; | |
1218 | case CMD_MSC: | |
1219 | /* Out of band modem line change indicator for a DLCI */ | |
1220 | gsm_control_modem(gsm, data, clen); | |
1221 | break; | |
1222 | case CMD_RLS: | |
1223 | /* Out of band error reception for a DLCI */ | |
1224 | gsm_control_rls(gsm, data, clen); | |
1225 | break; | |
1226 | case CMD_PSC: | |
1227 | /* Modem wishes to enter power saving state */ | |
1228 | gsm_control_reply(gsm, CMD_PSC, NULL, 0); | |
1229 | break; | |
1230 | /* Optional unsupported commands */ | |
1231 | case CMD_PN: /* Parameter negotiation */ | |
25985edc LDM |
1232 | case CMD_RPN: /* Remote port negotiation */ |
1233 | case CMD_SNC: /* Service negotiation command */ | |
e1eaea46 AC |
1234 | default: |
1235 | /* Reply to bad commands with an NSC */ | |
1236 | buf[0] = command; | |
1237 | gsm_control_reply(gsm, CMD_NSC, buf, 1); | |
1238 | break; | |
1239 | } | |
1240 | } | |
1241 | ||
1242 | /** | |
1243 | * gsm_control_response - process a response to our control | |
1244 | * @gsm: our GSM mux | |
1245 | * @command: the command (response) EA | |
1246 | * @data: data beyond the command/length EA | |
1247 | * @clen: length | |
1248 | * | |
1249 | * Process a response to an outstanding command. We only allow a single | |
1250 | * control message in flight so this is fairly easy. All the clean up | |
1251 | * is done by the caller, we just update the fields, flag it as done | |
1252 | * and return | |
1253 | */ | |
1254 | ||
1255 | static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, | |
1256 | u8 *data, int clen) | |
1257 | { | |
1258 | struct gsm_control *ctrl; | |
1259 | unsigned long flags; | |
1260 | ||
1261 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1262 | ||
1263 | ctrl = gsm->pending_cmd; | |
1264 | /* Does the reply match our command */ | |
1265 | command |= 1; | |
1266 | if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { | |
1267 | /* Our command was replied to, kill the retry timer */ | |
1268 | del_timer(&gsm->t2_timer); | |
1269 | gsm->pending_cmd = NULL; | |
1270 | /* Rejected by the other end */ | |
1271 | if (command == CMD_NSC) | |
1272 | ctrl->error = -EOPNOTSUPP; | |
1273 | ctrl->done = 1; | |
1274 | wake_up(&gsm->event); | |
1275 | } | |
1276 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1277 | } | |
1278 | ||
1279 | /** | |
5f9a31d6 | 1280 | * gsm_control_transmit - send control packet |
e1eaea46 AC |
1281 | * @gsm: gsm mux |
1282 | * @ctrl: frame to send | |
1283 | * | |
1284 | * Send out a pending control command (called under control lock) | |
1285 | */ | |
1286 | ||
1287 | static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) | |
1288 | { | |
ed43b47b | 1289 | struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1, gsm->ftype); |
e1eaea46 AC |
1290 | if (msg == NULL) |
1291 | return; | |
1292 | msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */ | |
1293 | memcpy(msg->data + 1, ctrl->data, ctrl->len); | |
1294 | gsm_data_queue(gsm->dlci[0], msg); | |
1295 | } | |
1296 | ||
1297 | /** | |
1298 | * gsm_control_retransmit - retransmit a control frame | |
1299 | * @data: pointer to our gsm object | |
1300 | * | |
1301 | * Called off the T2 timer expiry in order to retransmit control frames | |
1302 | * that have been lost in the system somewhere. The control_lock protects | |
1303 | * us from colliding with another sender or a receive completion event. | |
1304 | * In that situation the timer may still occur in a small window but | |
1305 | * gsm->pending_cmd will be NULL and we just let the timer expire. | |
1306 | */ | |
1307 | ||
1308 | static void gsm_control_retransmit(unsigned long data) | |
1309 | { | |
1310 | struct gsm_mux *gsm = (struct gsm_mux *)data; | |
1311 | struct gsm_control *ctrl; | |
1312 | unsigned long flags; | |
1313 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1314 | ctrl = gsm->pending_cmd; | |
1315 | if (ctrl) { | |
1316 | gsm->cretries--; | |
1317 | if (gsm->cretries == 0) { | |
1318 | gsm->pending_cmd = NULL; | |
1319 | ctrl->error = -ETIMEDOUT; | |
1320 | ctrl->done = 1; | |
1321 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1322 | wake_up(&gsm->event); | |
1323 | return; | |
1324 | } | |
1325 | gsm_control_transmit(gsm, ctrl); | |
1326 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); | |
1327 | } | |
1328 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1329 | } | |
1330 | ||
1331 | /** | |
1332 | * gsm_control_send - send a control frame on DLCI 0 | |
1333 | * @gsm: the GSM channel | |
1334 | * @command: command to send including CR bit | |
1335 | * @data: bytes of data (must be kmalloced) | |
1336 | * @len: length of the block to send | |
1337 | * | |
1338 | * Queue and dispatch a control command. Only one command can be | |
1339 | * active at a time. In theory more can be outstanding but the matching | |
1340 | * gets really complicated so for now stick to one outstanding. | |
1341 | */ | |
1342 | ||
1343 | static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, | |
1344 | unsigned int command, u8 *data, int clen) | |
1345 | { | |
1346 | struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), | |
1347 | GFP_KERNEL); | |
1348 | unsigned long flags; | |
1349 | if (ctrl == NULL) | |
1350 | return NULL; | |
1351 | retry: | |
1352 | wait_event(gsm->event, gsm->pending_cmd == NULL); | |
1353 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1354 | if (gsm->pending_cmd != NULL) { | |
1355 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1356 | goto retry; | |
1357 | } | |
1358 | ctrl->cmd = command; | |
1359 | ctrl->data = data; | |
1360 | ctrl->len = clen; | |
1361 | gsm->pending_cmd = ctrl; | |
1362 | gsm->cretries = gsm->n2; | |
1363 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); | |
1364 | gsm_control_transmit(gsm, ctrl); | |
1365 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1366 | return ctrl; | |
1367 | } | |
1368 | ||
1369 | /** | |
1370 | * gsm_control_wait - wait for a control to finish | |
1371 | * @gsm: GSM mux | |
1372 | * @control: control we are waiting on | |
1373 | * | |
1374 | * Waits for the control to complete or time out. Frees any used | |
1375 | * resources and returns 0 for success, or an error if the remote | |
1376 | * rejected or ignored the request. | |
1377 | */ | |
1378 | ||
1379 | static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) | |
1380 | { | |
1381 | int err; | |
1382 | wait_event(gsm->event, control->done == 1); | |
1383 | err = control->error; | |
1384 | kfree(control); | |
1385 | return err; | |
1386 | } | |
1387 | ||
1388 | ||
1389 | /* | |
1390 | * DLCI level handling: Needs krefs | |
1391 | */ | |
1392 | ||
1393 | /* | |
1394 | * State transitions and timers | |
1395 | */ | |
1396 | ||
1397 | /** | |
1398 | * gsm_dlci_close - a DLCI has closed | |
1399 | * @dlci: DLCI that closed | |
1400 | * | |
1401 | * Perform processing when moving a DLCI into closed state. If there | |
1402 | * is an attached tty this is hung up | |
1403 | */ | |
1404 | ||
1405 | static void gsm_dlci_close(struct gsm_dlci *dlci) | |
1406 | { | |
1407 | del_timer(&dlci->t1); | |
1408 | if (debug & 8) | |
5f9a31d6 | 1409 | pr_debug("DLCI %d goes closed.\n", dlci->addr); |
e1eaea46 AC |
1410 | dlci->state = DLCI_CLOSED; |
1411 | if (dlci->addr != 0) { | |
1412 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); | |
1413 | if (tty) { | |
1414 | tty_hangup(tty); | |
1415 | tty_kref_put(tty); | |
1416 | } | |
1417 | kfifo_reset(dlci->fifo); | |
1418 | } else | |
1419 | dlci->gsm->dead = 1; | |
1420 | wake_up(&dlci->gsm->event); | |
1421 | /* A DLCI 0 close is a MUX termination so we need to kick that | |
1422 | back to userspace somehow */ | |
1423 | } | |
1424 | ||
1425 | /** | |
1426 | * gsm_dlci_open - a DLCI has opened | |
1427 | * @dlci: DLCI that opened | |
1428 | * | |
1429 | * Perform processing when moving a DLCI into open state. | |
1430 | */ | |
1431 | ||
1432 | static void gsm_dlci_open(struct gsm_dlci *dlci) | |
1433 | { | |
1434 | /* Note that SABM UA .. SABM UA first UA lost can mean that we go | |
1435 | open -> open */ | |
1436 | del_timer(&dlci->t1); | |
1437 | /* This will let a tty open continue */ | |
1438 | dlci->state = DLCI_OPEN; | |
1439 | if (debug & 8) | |
5f9a31d6 | 1440 | pr_debug("DLCI %d goes open.\n", dlci->addr); |
e1eaea46 AC |
1441 | wake_up(&dlci->gsm->event); |
1442 | } | |
1443 | ||
1444 | /** | |
1445 | * gsm_dlci_t1 - T1 timer expiry | |
1446 | * @dlci: DLCI that opened | |
1447 | * | |
1448 | * The T1 timer handles retransmits of control frames (essentially of | |
1449 | * SABM and DISC). We resend the command until the retry count runs out | |
1450 | * in which case an opening port goes back to closed and a closing port | |
1451 | * is simply put into closed state (any further frames from the other | |
1452 | * end will get a DM response) | |
1453 | */ | |
1454 | ||
1455 | static void gsm_dlci_t1(unsigned long data) | |
1456 | { | |
1457 | struct gsm_dlci *dlci = (struct gsm_dlci *)data; | |
1458 | struct gsm_mux *gsm = dlci->gsm; | |
1459 | ||
1460 | switch (dlci->state) { | |
1461 | case DLCI_OPENING: | |
1462 | dlci->retries--; | |
1463 | if (dlci->retries) { | |
1464 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); | |
1465 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1466 | } else | |
1467 | gsm_dlci_close(dlci); | |
1468 | break; | |
1469 | case DLCI_CLOSING: | |
1470 | dlci->retries--; | |
1471 | if (dlci->retries) { | |
1472 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); | |
1473 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1474 | } else | |
1475 | gsm_dlci_close(dlci); | |
1476 | break; | |
1477 | } | |
1478 | } | |
1479 | ||
1480 | /** | |
1481 | * gsm_dlci_begin_open - start channel open procedure | |
1482 | * @dlci: DLCI to open | |
1483 | * | |
1484 | * Commence opening a DLCI from the Linux side. We issue SABM messages | |
1485 | * to the modem which should then reply with a UA, at which point we | |
1486 | * will move into open state. Opening is done asynchronously with retry | |
1487 | * running off timers and the responses. | |
1488 | */ | |
1489 | ||
1490 | static void gsm_dlci_begin_open(struct gsm_dlci *dlci) | |
1491 | { | |
1492 | struct gsm_mux *gsm = dlci->gsm; | |
1493 | if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING) | |
1494 | return; | |
1495 | dlci->retries = gsm->n2; | |
1496 | dlci->state = DLCI_OPENING; | |
1497 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); | |
1498 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1499 | } | |
1500 | ||
1501 | /** | |
1502 | * gsm_dlci_begin_close - start channel open procedure | |
1503 | * @dlci: DLCI to open | |
1504 | * | |
1505 | * Commence closing a DLCI from the Linux side. We issue DISC messages | |
1506 | * to the modem which should then reply with a UA, at which point we | |
1507 | * will move into closed state. Closing is done asynchronously with retry | |
1508 | * off timers. We may also receive a DM reply from the other end which | |
1509 | * indicates the channel was already closed. | |
1510 | */ | |
1511 | ||
1512 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci) | |
1513 | { | |
1514 | struct gsm_mux *gsm = dlci->gsm; | |
1515 | if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING) | |
1516 | return; | |
1517 | dlci->retries = gsm->n2; | |
1518 | dlci->state = DLCI_CLOSING; | |
1519 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); | |
1520 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1521 | } | |
1522 | ||
1523 | /** | |
1524 | * gsm_dlci_data - data arrived | |
1525 | * @dlci: channel | |
1526 | * @data: block of bytes received | |
1527 | * @len: length of received block | |
1528 | * | |
1529 | * A UI or UIH frame has arrived which contains data for a channel | |
1530 | * other than the control channel. If the relevant virtual tty is | |
1531 | * open we shovel the bits down it, if not we drop them. | |
1532 | */ | |
1533 | ||
7263287a | 1534 | static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int clen) |
e1eaea46 AC |
1535 | { |
1536 | /* krefs .. */ | |
1537 | struct tty_port *port = &dlci->port; | |
1538 | struct tty_struct *tty = tty_port_tty_get(port); | |
1539 | unsigned int modem = 0; | |
7263287a | 1540 | int len = clen; |
e1eaea46 AC |
1541 | |
1542 | if (debug & 16) | |
5f9a31d6 | 1543 | pr_debug("%d bytes for tty %p\n", len, tty); |
e1eaea46 AC |
1544 | if (tty) { |
1545 | switch (dlci->adaption) { | |
5f9a31d6 AC |
1546 | /* Unsupported types */ |
1547 | /* Packetised interruptible data */ | |
1548 | case 4: | |
1549 | break; | |
1550 | /* Packetised uininterruptible voice/data */ | |
1551 | case 3: | |
1552 | break; | |
1553 | /* Asynchronous serial with line state in each frame */ | |
1554 | case 2: | |
1555 | while (gsm_read_ea(&modem, *data++) == 0) { | |
1556 | len--; | |
1557 | if (len == 0) | |
1558 | return; | |
1559 | } | |
7263287a | 1560 | gsm_process_modem(tty, dlci, modem, clen); |
5f9a31d6 AC |
1561 | /* Line state will go via DLCI 0 controls only */ |
1562 | case 1: | |
1563 | default: | |
1564 | tty_insert_flip_string(tty, data, len); | |
1565 | tty_flip_buffer_push(tty); | |
e1eaea46 AC |
1566 | } |
1567 | tty_kref_put(tty); | |
1568 | } | |
1569 | } | |
1570 | ||
1571 | /** | |
1572 | * gsm_dlci_control - data arrived on control channel | |
1573 | * @dlci: channel | |
1574 | * @data: block of bytes received | |
1575 | * @len: length of received block | |
1576 | * | |
1577 | * A UI or UIH frame has arrived which contains data for DLCI 0 the | |
1578 | * control channel. This should contain a command EA followed by | |
1579 | * control data bytes. The command EA contains a command/response bit | |
1580 | * and we divide up the work accordingly. | |
1581 | */ | |
1582 | ||
1583 | static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len) | |
1584 | { | |
1585 | /* See what command is involved */ | |
1586 | unsigned int command = 0; | |
1587 | while (len-- > 0) { | |
1588 | if (gsm_read_ea(&command, *data++) == 1) { | |
1589 | int clen = *data++; | |
1590 | len--; | |
1591 | /* FIXME: this is properly an EA */ | |
1592 | clen >>= 1; | |
1593 | /* Malformed command ? */ | |
1594 | if (clen > len) | |
1595 | return; | |
1596 | if (command & 1) | |
1597 | gsm_control_message(dlci->gsm, command, | |
1598 | data, clen); | |
1599 | else | |
1600 | gsm_control_response(dlci->gsm, command, | |
1601 | data, clen); | |
1602 | return; | |
1603 | } | |
1604 | } | |
1605 | } | |
1606 | ||
1607 | /* | |
1608 | * Allocate/Free DLCI channels | |
1609 | */ | |
1610 | ||
1611 | /** | |
1612 | * gsm_dlci_alloc - allocate a DLCI | |
1613 | * @gsm: GSM mux | |
1614 | * @addr: address of the DLCI | |
1615 | * | |
1616 | * Allocate and install a new DLCI object into the GSM mux. | |
1617 | * | |
1618 | * FIXME: review locking races | |
1619 | */ | |
1620 | ||
1621 | static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) | |
1622 | { | |
1623 | struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC); | |
1624 | if (dlci == NULL) | |
1625 | return NULL; | |
1626 | spin_lock_init(&dlci->lock); | |
6ab8fba7 | 1627 | kref_init(&dlci->ref); |
bcd5abe2 | 1628 | mutex_init(&dlci->mutex); |
e1eaea46 AC |
1629 | dlci->fifo = &dlci->_fifo; |
1630 | if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) { | |
1631 | kfree(dlci); | |
1632 | return NULL; | |
1633 | } | |
1634 | ||
1635 | skb_queue_head_init(&dlci->skb_list); | |
1636 | init_timer(&dlci->t1); | |
1637 | dlci->t1.function = gsm_dlci_t1; | |
1638 | dlci->t1.data = (unsigned long)dlci; | |
1639 | tty_port_init(&dlci->port); | |
1640 | dlci->port.ops = &gsm_port_ops; | |
1641 | dlci->gsm = gsm; | |
1642 | dlci->addr = addr; | |
1643 | dlci->adaption = gsm->adaption; | |
1644 | dlci->state = DLCI_CLOSED; | |
1645 | if (addr) | |
1646 | dlci->data = gsm_dlci_data; | |
1647 | else | |
1648 | dlci->data = gsm_dlci_command; | |
1649 | gsm->dlci[addr] = dlci; | |
1650 | return dlci; | |
1651 | } | |
1652 | ||
1653 | /** | |
6ab8fba7 RG |
1654 | * gsm_dlci_free - free DLCI |
1655 | * @dlci: DLCI to free | |
1656 | * | |
1657 | * Free up a DLCI. | |
1658 | * | |
1659 | * Can sleep. | |
1660 | */ | |
1661 | static void gsm_dlci_free(struct kref *ref) | |
1662 | { | |
1663 | struct gsm_dlci *dlci = container_of(ref, struct gsm_dlci, ref); | |
1664 | ||
1665 | del_timer_sync(&dlci->t1); | |
1666 | dlci->gsm->dlci[dlci->addr] = NULL; | |
1667 | kfifo_free(dlci->fifo); | |
1668 | while ((dlci->skb = skb_dequeue(&dlci->skb_list))) | |
1669 | kfree_skb(dlci->skb); | |
1670 | kfree(dlci); | |
1671 | } | |
1672 | ||
1673 | static inline void dlci_get(struct gsm_dlci *dlci) | |
1674 | { | |
1675 | kref_get(&dlci->ref); | |
1676 | } | |
1677 | ||
1678 | static inline void dlci_put(struct gsm_dlci *dlci) | |
1679 | { | |
1680 | kref_put(&dlci->ref, gsm_dlci_free); | |
1681 | } | |
1682 | ||
1683 | /** | |
1684 | * gsm_dlci_release - release DLCI | |
e1eaea46 AC |
1685 | * @dlci: DLCI to destroy |
1686 | * | |
6ab8fba7 RG |
1687 | * Release a DLCI. Actual free is deferred until either |
1688 | * mux is closed or tty is closed - whichever is last. | |
e1eaea46 AC |
1689 | * |
1690 | * Can sleep. | |
1691 | */ | |
6ab8fba7 | 1692 | static void gsm_dlci_release(struct gsm_dlci *dlci) |
e1eaea46 AC |
1693 | { |
1694 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); | |
1695 | if (tty) { | |
1696 | tty_vhangup(tty); | |
1697 | tty_kref_put(tty); | |
1698 | } | |
6ab8fba7 | 1699 | dlci_put(dlci); |
e1eaea46 AC |
1700 | } |
1701 | ||
e1eaea46 AC |
1702 | /* |
1703 | * LAPBish link layer logic | |
1704 | */ | |
1705 | ||
1706 | /** | |
1707 | * gsm_queue - a GSM frame is ready to process | |
1708 | * @gsm: pointer to our gsm mux | |
1709 | * | |
1710 | * At this point in time a frame has arrived and been demangled from | |
1711 | * the line encoding. All the differences between the encodings have | |
1712 | * been handled below us and the frame is unpacked into the structures. | |
1713 | * The fcs holds the header FCS but any data FCS must be added here. | |
1714 | */ | |
1715 | ||
1716 | static void gsm_queue(struct gsm_mux *gsm) | |
1717 | { | |
1718 | struct gsm_dlci *dlci; | |
1719 | u8 cr; | |
1720 | int address; | |
1721 | /* We have to sneak a look at the packet body to do the FCS. | |
1722 | A somewhat layering violation in the spec */ | |
1723 | ||
1724 | if ((gsm->control & ~PF) == UI) | |
1725 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len); | |
9db4e438 MK |
1726 | if (gsm->encoding == 0){ |
1727 | /* WARNING: gsm->received_fcs is used for gsm->encoding = 0 only. | |
1728 | In this case it contain the last piece of data | |
1729 | required to generate final CRC */ | |
1730 | gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); | |
1731 | } | |
e1eaea46 AC |
1732 | if (gsm->fcs != GOOD_FCS) { |
1733 | gsm->bad_fcs++; | |
1734 | if (debug & 4) | |
5f9a31d6 | 1735 | pr_debug("BAD FCS %02x\n", gsm->fcs); |
e1eaea46 AC |
1736 | return; |
1737 | } | |
1738 | address = gsm->address >> 1; | |
1739 | if (address >= NUM_DLCI) | |
1740 | goto invalid; | |
1741 | ||
1742 | cr = gsm->address & 1; /* C/R bit */ | |
1743 | ||
1744 | gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); | |
1745 | ||
1746 | cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */ | |
1747 | dlci = gsm->dlci[address]; | |
1748 | ||
1749 | switch (gsm->control) { | |
1750 | case SABM|PF: | |
1751 | if (cr == 0) | |
1752 | goto invalid; | |
1753 | if (dlci == NULL) | |
1754 | dlci = gsm_dlci_alloc(gsm, address); | |
1755 | if (dlci == NULL) | |
1756 | return; | |
1757 | if (dlci->dead) | |
1758 | gsm_response(gsm, address, DM); | |
1759 | else { | |
1760 | gsm_response(gsm, address, UA); | |
1761 | gsm_dlci_open(dlci); | |
1762 | } | |
1763 | break; | |
1764 | case DISC|PF: | |
1765 | if (cr == 0) | |
1766 | goto invalid; | |
1767 | if (dlci == NULL || dlci->state == DLCI_CLOSED) { | |
1768 | gsm_response(gsm, address, DM); | |
1769 | return; | |
1770 | } | |
1771 | /* Real close complete */ | |
1772 | gsm_response(gsm, address, UA); | |
1773 | gsm_dlci_close(dlci); | |
1774 | break; | |
1775 | case UA: | |
1776 | case UA|PF: | |
1777 | if (cr == 0 || dlci == NULL) | |
1778 | break; | |
1779 | switch (dlci->state) { | |
1780 | case DLCI_CLOSING: | |
1781 | gsm_dlci_close(dlci); | |
1782 | break; | |
1783 | case DLCI_OPENING: | |
1784 | gsm_dlci_open(dlci); | |
1785 | break; | |
1786 | } | |
1787 | break; | |
1788 | case DM: /* DM can be valid unsolicited */ | |
1789 | case DM|PF: | |
1790 | if (cr) | |
1791 | goto invalid; | |
1792 | if (dlci == NULL) | |
1793 | return; | |
1794 | gsm_dlci_close(dlci); | |
1795 | break; | |
1796 | case UI: | |
1797 | case UI|PF: | |
1798 | case UIH: | |
1799 | case UIH|PF: | |
1800 | #if 0 | |
1801 | if (cr) | |
1802 | goto invalid; | |
1803 | #endif | |
1804 | if (dlci == NULL || dlci->state != DLCI_OPEN) { | |
1805 | gsm_command(gsm, address, DM|PF); | |
1806 | return; | |
1807 | } | |
1808 | dlci->data(dlci, gsm->buf, gsm->len); | |
1809 | break; | |
1810 | default: | |
1811 | goto invalid; | |
1812 | } | |
1813 | return; | |
1814 | invalid: | |
1815 | gsm->malformed++; | |
1816 | return; | |
1817 | } | |
1818 | ||
1819 | ||
1820 | /** | |
1821 | * gsm0_receive - perform processing for non-transparency | |
1822 | * @gsm: gsm data for this ldisc instance | |
1823 | * @c: character | |
1824 | * | |
1825 | * Receive bytes in gsm mode 0 | |
1826 | */ | |
1827 | ||
1828 | static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) | |
1829 | { | |
c2f2f000 AC |
1830 | unsigned int len; |
1831 | ||
e1eaea46 AC |
1832 | switch (gsm->state) { |
1833 | case GSM_SEARCH: /* SOF marker */ | |
1834 | if (c == GSM0_SOF) { | |
1835 | gsm->state = GSM_ADDRESS; | |
1836 | gsm->address = 0; | |
1837 | gsm->len = 0; | |
1838 | gsm->fcs = INIT_FCS; | |
1839 | } | |
c2f2f000 AC |
1840 | break; |
1841 | case GSM_ADDRESS: /* Address EA */ | |
e1eaea46 AC |
1842 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
1843 | if (gsm_read_ea(&gsm->address, c)) | |
1844 | gsm->state = GSM_CONTROL; | |
1845 | break; | |
1846 | case GSM_CONTROL: /* Control Byte */ | |
1847 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
1848 | gsm->control = c; | |
c2f2f000 | 1849 | gsm->state = GSM_LEN0; |
e1eaea46 | 1850 | break; |
c2f2f000 | 1851 | case GSM_LEN0: /* Length EA */ |
e1eaea46 AC |
1852 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
1853 | if (gsm_read_ea(&gsm->len, c)) { | |
1854 | if (gsm->len > gsm->mru) { | |
1855 | gsm->bad_size++; | |
1856 | gsm->state = GSM_SEARCH; | |
1857 | break; | |
1858 | } | |
1859 | gsm->count = 0; | |
c2f2f000 AC |
1860 | if (!gsm->len) |
1861 | gsm->state = GSM_FCS; | |
1862 | else | |
1863 | gsm->state = GSM_DATA; | |
1864 | break; | |
e1eaea46 | 1865 | } |
c2f2f000 AC |
1866 | gsm->state = GSM_LEN1; |
1867 | break; | |
1868 | case GSM_LEN1: | |
1869 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
1870 | len = c; | |
1871 | gsm->len |= len << 7; | |
1872 | if (gsm->len > gsm->mru) { | |
1873 | gsm->bad_size++; | |
1874 | gsm->state = GSM_SEARCH; | |
1875 | break; | |
e1eaea46 | 1876 | } |
c2f2f000 AC |
1877 | gsm->count = 0; |
1878 | if (!gsm->len) | |
1879 | gsm->state = GSM_FCS; | |
1880 | else | |
1881 | gsm->state = GSM_DATA; | |
e1eaea46 AC |
1882 | break; |
1883 | case GSM_DATA: /* Data */ | |
1884 | gsm->buf[gsm->count++] = c; | |
1885 | if (gsm->count == gsm->len) | |
1886 | gsm->state = GSM_FCS; | |
1887 | break; | |
1888 | case GSM_FCS: /* FCS follows the packet */ | |
c2f2f000 | 1889 | gsm->received_fcs = c; |
e1eaea46 | 1890 | gsm_queue(gsm); |
c2f2f000 AC |
1891 | gsm->state = GSM_SSOF; |
1892 | break; | |
1893 | case GSM_SSOF: | |
1894 | if (c == GSM0_SOF) { | |
1895 | gsm->state = GSM_SEARCH; | |
1896 | break; | |
1897 | } | |
e1eaea46 AC |
1898 | break; |
1899 | } | |
1900 | } | |
1901 | ||
1902 | /** | |
c2f2f000 | 1903 | * gsm1_receive - perform processing for non-transparency |
e1eaea46 AC |
1904 | * @gsm: gsm data for this ldisc instance |
1905 | * @c: character | |
1906 | * | |
1907 | * Receive bytes in mode 1 (Advanced option) | |
1908 | */ | |
1909 | ||
1910 | static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) | |
1911 | { | |
1912 | if (c == GSM1_SOF) { | |
1913 | /* EOF is only valid in frame if we have got to the data state | |
1914 | and received at least one byte (the FCS) */ | |
1915 | if (gsm->state == GSM_DATA && gsm->count) { | |
1916 | /* Extract the FCS */ | |
1917 | gsm->count--; | |
1918 | gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); | |
1919 | gsm->len = gsm->count; | |
1920 | gsm_queue(gsm); | |
1921 | gsm->state = GSM_START; | |
1922 | return; | |
1923 | } | |
1924 | /* Any partial frame was a runt so go back to start */ | |
1925 | if (gsm->state != GSM_START) { | |
1926 | gsm->malformed++; | |
1927 | gsm->state = GSM_START; | |
1928 | } | |
1929 | /* A SOF in GSM_START means we are still reading idling or | |
1930 | framing bytes */ | |
1931 | return; | |
1932 | } | |
1933 | ||
1934 | if (c == GSM1_ESCAPE) { | |
1935 | gsm->escape = 1; | |
1936 | return; | |
1937 | } | |
1938 | ||
1939 | /* Only an unescaped SOF gets us out of GSM search */ | |
1940 | if (gsm->state == GSM_SEARCH) | |
1941 | return; | |
1942 | ||
1943 | if (gsm->escape) { | |
1944 | c ^= GSM1_ESCAPE_BITS; | |
1945 | gsm->escape = 0; | |
1946 | } | |
1947 | switch (gsm->state) { | |
1948 | case GSM_START: /* First byte after SOF */ | |
1949 | gsm->address = 0; | |
1950 | gsm->state = GSM_ADDRESS; | |
1951 | gsm->fcs = INIT_FCS; | |
1952 | /* Drop through */ | |
1953 | case GSM_ADDRESS: /* Address continuation */ | |
1954 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
1955 | if (gsm_read_ea(&gsm->address, c)) | |
1956 | gsm->state = GSM_CONTROL; | |
1957 | break; | |
1958 | case GSM_CONTROL: /* Control Byte */ | |
1959 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
1960 | gsm->control = c; | |
1961 | gsm->count = 0; | |
1962 | gsm->state = GSM_DATA; | |
1963 | break; | |
1964 | case GSM_DATA: /* Data */ | |
5f9a31d6 | 1965 | if (gsm->count > gsm->mru) { /* Allow one for the FCS */ |
e1eaea46 AC |
1966 | gsm->state = GSM_OVERRUN; |
1967 | gsm->bad_size++; | |
1968 | } else | |
1969 | gsm->buf[gsm->count++] = c; | |
1970 | break; | |
1971 | case GSM_OVERRUN: /* Over-long - eg a dropped SOF */ | |
1972 | break; | |
1973 | } | |
1974 | } | |
1975 | ||
1976 | /** | |
1977 | * gsm_error - handle tty error | |
1978 | * @gsm: ldisc data | |
1979 | * @data: byte received (may be invalid) | |
1980 | * @flag: error received | |
1981 | * | |
1982 | * Handle an error in the receipt of data for a frame. Currently we just | |
1983 | * go back to hunting for a SOF. | |
1984 | * | |
1985 | * FIXME: better diagnostics ? | |
1986 | */ | |
1987 | ||
1988 | static void gsm_error(struct gsm_mux *gsm, | |
1989 | unsigned char data, unsigned char flag) | |
1990 | { | |
1991 | gsm->state = GSM_SEARCH; | |
1992 | gsm->io_error++; | |
1993 | } | |
1994 | ||
1995 | /** | |
1996 | * gsm_cleanup_mux - generic GSM protocol cleanup | |
1997 | * @gsm: our mux | |
1998 | * | |
1999 | * Clean up the bits of the mux which are the same for all framing | |
2000 | * protocols. Remove the mux from the mux table, stop all the timers | |
2001 | * and then shut down each device hanging up the channels as we go. | |
2002 | */ | |
2003 | ||
2004 | void gsm_cleanup_mux(struct gsm_mux *gsm) | |
2005 | { | |
2006 | int i; | |
2007 | struct gsm_dlci *dlci = gsm->dlci[0]; | |
2008 | struct gsm_msg *txq; | |
f17141fd | 2009 | struct gsm_control *gc; |
e1eaea46 AC |
2010 | |
2011 | gsm->dead = 1; | |
2012 | ||
2013 | spin_lock(&gsm_mux_lock); | |
2014 | for (i = 0; i < MAX_MUX; i++) { | |
2015 | if (gsm_mux[i] == gsm) { | |
2016 | gsm_mux[i] = NULL; | |
2017 | break; | |
2018 | } | |
2019 | } | |
2020 | spin_unlock(&gsm_mux_lock); | |
2021 | WARN_ON(i == MAX_MUX); | |
2022 | ||
f17141fd AC |
2023 | /* In theory disconnecting DLCI 0 is sufficient but for some |
2024 | modems this is apparently not the case. */ | |
2025 | if (dlci) { | |
2026 | gc = gsm_control_send(gsm, CMD_CLD, NULL, 0); | |
2027 | if (gc) | |
2028 | gsm_control_wait(gsm, gc); | |
2029 | } | |
e1eaea46 AC |
2030 | del_timer_sync(&gsm->t2_timer); |
2031 | /* Now we are sure T2 has stopped */ | |
2032 | if (dlci) { | |
2033 | dlci->dead = 1; | |
2034 | gsm_dlci_begin_close(dlci); | |
2035 | wait_event_interruptible(gsm->event, | |
2036 | dlci->state == DLCI_CLOSED); | |
2037 | } | |
2038 | /* Free up any link layer users */ | |
2039 | for (i = 0; i < NUM_DLCI; i++) | |
2040 | if (gsm->dlci[i]) | |
6ab8fba7 | 2041 | gsm_dlci_release(gsm->dlci[i]); |
e1eaea46 AC |
2042 | /* Now wipe the queues */ |
2043 | for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) { | |
2044 | gsm->tx_head = txq->next; | |
2045 | kfree(txq); | |
2046 | } | |
2047 | gsm->tx_tail = NULL; | |
2048 | } | |
2049 | EXPORT_SYMBOL_GPL(gsm_cleanup_mux); | |
2050 | ||
2051 | /** | |
2052 | * gsm_activate_mux - generic GSM setup | |
2053 | * @gsm: our mux | |
2054 | * | |
2055 | * Set up the bits of the mux which are the same for all framing | |
2056 | * protocols. Add the mux to the mux table so it can be opened and | |
2057 | * finally kick off connecting to DLCI 0 on the modem. | |
2058 | */ | |
2059 | ||
2060 | int gsm_activate_mux(struct gsm_mux *gsm) | |
2061 | { | |
2062 | struct gsm_dlci *dlci; | |
2063 | int i = 0; | |
2064 | ||
2065 | init_timer(&gsm->t2_timer); | |
2066 | gsm->t2_timer.function = gsm_control_retransmit; | |
2067 | gsm->t2_timer.data = (unsigned long)gsm; | |
2068 | init_waitqueue_head(&gsm->event); | |
2069 | spin_lock_init(&gsm->control_lock); | |
2070 | spin_lock_init(&gsm->tx_lock); | |
2071 | ||
2072 | if (gsm->encoding == 0) | |
2073 | gsm->receive = gsm0_receive; | |
2074 | else | |
2075 | gsm->receive = gsm1_receive; | |
2076 | gsm->error = gsm_error; | |
2077 | ||
2078 | spin_lock(&gsm_mux_lock); | |
2079 | for (i = 0; i < MAX_MUX; i++) { | |
2080 | if (gsm_mux[i] == NULL) { | |
d50f6dca | 2081 | gsm->num = i; |
e1eaea46 AC |
2082 | gsm_mux[i] = gsm; |
2083 | break; | |
2084 | } | |
2085 | } | |
2086 | spin_unlock(&gsm_mux_lock); | |
2087 | if (i == MAX_MUX) | |
2088 | return -EBUSY; | |
2089 | ||
2090 | dlci = gsm_dlci_alloc(gsm, 0); | |
2091 | if (dlci == NULL) | |
2092 | return -ENOMEM; | |
2093 | gsm->dead = 0; /* Tty opens are now permissible */ | |
2094 | return 0; | |
2095 | } | |
2096 | EXPORT_SYMBOL_GPL(gsm_activate_mux); | |
2097 | ||
2098 | /** | |
2099 | * gsm_free_mux - free up a mux | |
2100 | * @mux: mux to free | |
2101 | * | |
6ab8fba7 | 2102 | * Dispose of allocated resources for a dead mux |
e1eaea46 AC |
2103 | */ |
2104 | void gsm_free_mux(struct gsm_mux *gsm) | |
2105 | { | |
2106 | kfree(gsm->txframe); | |
2107 | kfree(gsm->buf); | |
2108 | kfree(gsm); | |
2109 | } | |
2110 | EXPORT_SYMBOL_GPL(gsm_free_mux); | |
2111 | ||
6ab8fba7 RG |
2112 | /** |
2113 | * gsm_free_muxr - free up a mux | |
2114 | * @mux: mux to free | |
2115 | * | |
2116 | * Dispose of allocated resources for a dead mux | |
2117 | */ | |
2118 | static void gsm_free_muxr(struct kref *ref) | |
2119 | { | |
2120 | struct gsm_mux *gsm = container_of(ref, struct gsm_mux, ref); | |
2121 | gsm_free_mux(gsm); | |
2122 | } | |
2123 | ||
2124 | static inline void mux_get(struct gsm_mux *gsm) | |
2125 | { | |
2126 | kref_get(&gsm->ref); | |
2127 | } | |
2128 | ||
2129 | static inline void mux_put(struct gsm_mux *gsm) | |
2130 | { | |
2131 | kref_put(&gsm->ref, gsm_free_muxr); | |
2132 | } | |
2133 | ||
e1eaea46 AC |
2134 | /** |
2135 | * gsm_alloc_mux - allocate a mux | |
2136 | * | |
2137 | * Creates a new mux ready for activation. | |
2138 | */ | |
2139 | ||
2140 | struct gsm_mux *gsm_alloc_mux(void) | |
2141 | { | |
2142 | struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); | |
2143 | if (gsm == NULL) | |
2144 | return NULL; | |
2145 | gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL); | |
2146 | if (gsm->buf == NULL) { | |
2147 | kfree(gsm); | |
2148 | return NULL; | |
2149 | } | |
2150 | gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL); | |
2151 | if (gsm->txframe == NULL) { | |
2152 | kfree(gsm->buf); | |
2153 | kfree(gsm); | |
2154 | return NULL; | |
2155 | } | |
2156 | spin_lock_init(&gsm->lock); | |
6ab8fba7 | 2157 | kref_init(&gsm->ref); |
e1eaea46 AC |
2158 | |
2159 | gsm->t1 = T1; | |
2160 | gsm->t2 = T2; | |
2161 | gsm->n2 = N2; | |
2162 | gsm->ftype = UIH; | |
e1eaea46 AC |
2163 | gsm->adaption = 1; |
2164 | gsm->encoding = 1; | |
2165 | gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ | |
2166 | gsm->mtu = 64; | |
2167 | gsm->dead = 1; /* Avoid early tty opens */ | |
2168 | ||
2169 | return gsm; | |
2170 | } | |
2171 | EXPORT_SYMBOL_GPL(gsm_alloc_mux); | |
2172 | ||
e1eaea46 AC |
2173 | /** |
2174 | * gsmld_output - write to link | |
2175 | * @gsm: our mux | |
2176 | * @data: bytes to output | |
2177 | * @len: size | |
2178 | * | |
2179 | * Write a block of data from the GSM mux to the data channel. This | |
2180 | * will eventually be serialized from above but at the moment isn't. | |
2181 | */ | |
2182 | ||
2183 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) | |
2184 | { | |
2185 | if (tty_write_room(gsm->tty) < len) { | |
2186 | set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); | |
2187 | return -ENOSPC; | |
2188 | } | |
0a77c4f9 JP |
2189 | if (debug & 4) |
2190 | print_hex_dump_bytes("gsmld_output: ", DUMP_PREFIX_OFFSET, | |
2191 | data, len); | |
e1eaea46 AC |
2192 | gsm->tty->ops->write(gsm->tty, data, len); |
2193 | return len; | |
2194 | } | |
2195 | ||
2196 | /** | |
2197 | * gsmld_attach_gsm - mode set up | |
2198 | * @tty: our tty structure | |
2199 | * @gsm: our mux | |
2200 | * | |
2201 | * Set up the MUX for basic mode and commence connecting to the | |
2202 | * modem. Currently called from the line discipline set up but | |
2203 | * will need moving to an ioctl path. | |
2204 | */ | |
2205 | ||
2206 | static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) | |
2207 | { | |
d50f6dca RG |
2208 | int ret, i; |
2209 | int base = gsm->num << 6; /* Base for this MUX */ | |
e1eaea46 AC |
2210 | |
2211 | gsm->tty = tty_kref_get(tty); | |
2212 | gsm->output = gsmld_output; | |
2213 | ret = gsm_activate_mux(gsm); | |
2214 | if (ret != 0) | |
2215 | tty_kref_put(gsm->tty); | |
d50f6dca RG |
2216 | else { |
2217 | /* Don't register device 0 - this is the control channel and not | |
2218 | a usable tty interface */ | |
2219 | for (i = 1; i < NUM_DLCI; i++) | |
2220 | tty_register_device(gsm_tty_driver, base + i, NULL); | |
2221 | } | |
e1eaea46 AC |
2222 | return ret; |
2223 | } | |
2224 | ||
2225 | ||
2226 | /** | |
2227 | * gsmld_detach_gsm - stop doing 0710 mux | |
70f23fd6 | 2228 | * @tty: tty attached to the mux |
e1eaea46 AC |
2229 | * @gsm: mux |
2230 | * | |
2231 | * Shutdown and then clean up the resources used by the line discipline | |
2232 | */ | |
2233 | ||
2234 | static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) | |
2235 | { | |
d50f6dca RG |
2236 | int i; |
2237 | int base = gsm->num << 6; /* Base for this MUX */ | |
2238 | ||
e1eaea46 | 2239 | WARN_ON(tty != gsm->tty); |
d50f6dca RG |
2240 | for (i = 1; i < NUM_DLCI; i++) |
2241 | tty_unregister_device(gsm_tty_driver, base + i); | |
e1eaea46 AC |
2242 | gsm_cleanup_mux(gsm); |
2243 | tty_kref_put(gsm->tty); | |
2244 | gsm->tty = NULL; | |
2245 | } | |
2246 | ||
55db4c64 LT |
2247 | static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
2248 | char *fp, int count) | |
e1eaea46 AC |
2249 | { |
2250 | struct gsm_mux *gsm = tty->disc_data; | |
2251 | const unsigned char *dp; | |
2252 | char *f; | |
2253 | int i; | |
2254 | char buf[64]; | |
2255 | char flags; | |
2256 | ||
0a77c4f9 JP |
2257 | if (debug & 4) |
2258 | print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET, | |
2259 | cp, count); | |
e1eaea46 AC |
2260 | |
2261 | for (i = count, dp = cp, f = fp; i; i--, dp++) { | |
2262 | flags = *f++; | |
2263 | switch (flags) { | |
2264 | case TTY_NORMAL: | |
2265 | gsm->receive(gsm, *dp); | |
2266 | break; | |
2267 | case TTY_OVERRUN: | |
2268 | case TTY_BREAK: | |
2269 | case TTY_PARITY: | |
2270 | case TTY_FRAME: | |
2271 | gsm->error(gsm, *dp, flags); | |
2272 | break; | |
2273 | default: | |
5f9a31d6 | 2274 | WARN_ONCE("%s: unknown flag %d\n", |
e1eaea46 AC |
2275 | tty_name(tty, buf), flags); |
2276 | break; | |
2277 | } | |
2278 | } | |
2279 | /* FASYNC if needed ? */ | |
2280 | /* If clogged call tty_throttle(tty); */ | |
2281 | } | |
2282 | ||
2283 | /** | |
2284 | * gsmld_chars_in_buffer - report available bytes | |
2285 | * @tty: tty device | |
2286 | * | |
2287 | * Report the number of characters buffered to be delivered to user | |
2288 | * at this instant in time. | |
2289 | * | |
2290 | * Locking: gsm lock | |
2291 | */ | |
2292 | ||
2293 | static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty) | |
2294 | { | |
2295 | return 0; | |
2296 | } | |
2297 | ||
2298 | /** | |
2299 | * gsmld_flush_buffer - clean input queue | |
2300 | * @tty: terminal device | |
2301 | * | |
2302 | * Flush the input buffer. Called when the line discipline is | |
2303 | * being closed, when the tty layer wants the buffer flushed (eg | |
2304 | * at hangup). | |
2305 | */ | |
2306 | ||
2307 | static void gsmld_flush_buffer(struct tty_struct *tty) | |
2308 | { | |
2309 | } | |
2310 | ||
2311 | /** | |
2312 | * gsmld_close - close the ldisc for this tty | |
2313 | * @tty: device | |
2314 | * | |
2315 | * Called from the terminal layer when this line discipline is | |
2316 | * being shut down, either because of a close or becsuse of a | |
2317 | * discipline change. The function will not be called while other | |
2318 | * ldisc methods are in progress. | |
2319 | */ | |
2320 | ||
2321 | static void gsmld_close(struct tty_struct *tty) | |
2322 | { | |
2323 | struct gsm_mux *gsm = tty->disc_data; | |
2324 | ||
2325 | gsmld_detach_gsm(tty, gsm); | |
2326 | ||
2327 | gsmld_flush_buffer(tty); | |
2328 | /* Do other clean up here */ | |
6ab8fba7 | 2329 | mux_put(gsm); |
e1eaea46 AC |
2330 | } |
2331 | ||
2332 | /** | |
2333 | * gsmld_open - open an ldisc | |
2334 | * @tty: terminal to open | |
2335 | * | |
2336 | * Called when this line discipline is being attached to the | |
2337 | * terminal device. Can sleep. Called serialized so that no | |
2338 | * other events will occur in parallel. No further open will occur | |
2339 | * until a close. | |
2340 | */ | |
2341 | ||
2342 | static int gsmld_open(struct tty_struct *tty) | |
2343 | { | |
2344 | struct gsm_mux *gsm; | |
2345 | ||
2346 | if (tty->ops->write == NULL) | |
2347 | return -EINVAL; | |
2348 | ||
2349 | /* Attach our ldisc data */ | |
2350 | gsm = gsm_alloc_mux(); | |
2351 | if (gsm == NULL) | |
2352 | return -ENOMEM; | |
2353 | ||
2354 | tty->disc_data = gsm; | |
2355 | tty->receive_room = 65536; | |
2356 | ||
2357 | /* Attach the initial passive connection */ | |
2358 | gsm->encoding = 1; | |
2359 | return gsmld_attach_gsm(tty, gsm); | |
2360 | } | |
2361 | ||
2362 | /** | |
2363 | * gsmld_write_wakeup - asynchronous I/O notifier | |
2364 | * @tty: tty device | |
2365 | * | |
2366 | * Required for the ptys, serial driver etc. since processes | |
2367 | * that attach themselves to the master and rely on ASYNC | |
2368 | * IO must be woken up | |
2369 | */ | |
2370 | ||
2371 | static void gsmld_write_wakeup(struct tty_struct *tty) | |
2372 | { | |
2373 | struct gsm_mux *gsm = tty->disc_data; | |
328be395 | 2374 | unsigned long flags; |
e1eaea46 AC |
2375 | |
2376 | /* Queue poll */ | |
2377 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
2378 | gsm_data_kick(gsm); | |
328be395 DC |
2379 | if (gsm->tx_bytes < TX_THRESH_LO) { |
2380 | spin_lock_irqsave(&gsm->tx_lock, flags); | |
e1eaea46 | 2381 | gsm_dlci_data_sweep(gsm); |
328be395 DC |
2382 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
2383 | } | |
e1eaea46 AC |
2384 | } |
2385 | ||
2386 | /** | |
2387 | * gsmld_read - read function for tty | |
2388 | * @tty: tty device | |
2389 | * @file: file object | |
2390 | * @buf: userspace buffer pointer | |
2391 | * @nr: size of I/O | |
2392 | * | |
2393 | * Perform reads for the line discipline. We are guaranteed that the | |
2394 | * line discipline will not be closed under us but we may get multiple | |
2395 | * parallel readers and must handle this ourselves. We may also get | |
2396 | * a hangup. Always called in user context, may sleep. | |
2397 | * | |
2398 | * This code must be sure never to sleep through a hangup. | |
2399 | */ | |
2400 | ||
2401 | static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, | |
2402 | unsigned char __user *buf, size_t nr) | |
2403 | { | |
2404 | return -EOPNOTSUPP; | |
2405 | } | |
2406 | ||
2407 | /** | |
2408 | * gsmld_write - write function for tty | |
2409 | * @tty: tty device | |
2410 | * @file: file object | |
2411 | * @buf: userspace buffer pointer | |
2412 | * @nr: size of I/O | |
2413 | * | |
2414 | * Called when the owner of the device wants to send a frame | |
2415 | * itself (or some other control data). The data is transferred | |
2416 | * as-is and must be properly framed and checksummed as appropriate | |
2417 | * by userspace. Frames are either sent whole or not at all as this | |
2418 | * avoids pain user side. | |
2419 | */ | |
2420 | ||
2421 | static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, | |
2422 | const unsigned char *buf, size_t nr) | |
2423 | { | |
2424 | int space = tty_write_room(tty); | |
2425 | if (space >= nr) | |
2426 | return tty->ops->write(tty, buf, nr); | |
2427 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
2428 | return -ENOBUFS; | |
2429 | } | |
2430 | ||
2431 | /** | |
2432 | * gsmld_poll - poll method for N_GSM0710 | |
2433 | * @tty: terminal device | |
2434 | * @file: file accessing it | |
2435 | * @wait: poll table | |
2436 | * | |
2437 | * Called when the line discipline is asked to poll() for data or | |
2438 | * for special events. This code is not serialized with respect to | |
2439 | * other events save open/close. | |
2440 | * | |
2441 | * This code must be sure never to sleep through a hangup. | |
2442 | * Called without the kernel lock held - fine | |
2443 | */ | |
2444 | ||
2445 | static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file, | |
2446 | poll_table *wait) | |
2447 | { | |
2448 | unsigned int mask = 0; | |
2449 | struct gsm_mux *gsm = tty->disc_data; | |
2450 | ||
2451 | poll_wait(file, &tty->read_wait, wait); | |
2452 | poll_wait(file, &tty->write_wait, wait); | |
2453 | if (tty_hung_up_p(file)) | |
2454 | mask |= POLLHUP; | |
2455 | if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) | |
2456 | mask |= POLLOUT | POLLWRNORM; | |
2457 | if (gsm->dead) | |
2458 | mask |= POLLHUP; | |
2459 | return mask; | |
2460 | } | |
2461 | ||
2462 | static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm, | |
2463 | struct gsm_config *c) | |
2464 | { | |
2465 | int need_close = 0; | |
2466 | int need_restart = 0; | |
2467 | ||
2468 | /* Stuff we don't support yet - UI or I frame transport, windowing */ | |
5f9a31d6 | 2469 | if ((c->adaption != 1 && c->adaption != 2) || c->k) |
e1eaea46 AC |
2470 | return -EOPNOTSUPP; |
2471 | /* Check the MRU/MTU range looks sane */ | |
2472 | if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) | |
2473 | return -EINVAL; | |
2474 | if (c->n2 < 3) | |
2475 | return -EINVAL; | |
2476 | if (c->encapsulation > 1) /* Basic, advanced, no I */ | |
2477 | return -EINVAL; | |
2478 | if (c->initiator > 1) | |
2479 | return -EINVAL; | |
2480 | if (c->i == 0 || c->i > 2) /* UIH and UI only */ | |
2481 | return -EINVAL; | |
2482 | /* | |
2483 | * See what is needed for reconfiguration | |
2484 | */ | |
2485 | ||
2486 | /* Timing fields */ | |
2487 | if (c->t1 != 0 && c->t1 != gsm->t1) | |
2488 | need_restart = 1; | |
2489 | if (c->t2 != 0 && c->t2 != gsm->t2) | |
2490 | need_restart = 1; | |
2491 | if (c->encapsulation != gsm->encoding) | |
2492 | need_restart = 1; | |
2493 | if (c->adaption != gsm->adaption) | |
2494 | need_restart = 1; | |
2495 | /* Requires care */ | |
2496 | if (c->initiator != gsm->initiator) | |
2497 | need_close = 1; | |
2498 | if (c->mru != gsm->mru) | |
2499 | need_restart = 1; | |
2500 | if (c->mtu != gsm->mtu) | |
2501 | need_restart = 1; | |
2502 | ||
2503 | /* | |
2504 | * Close down what is needed, restart and initiate the new | |
2505 | * configuration | |
2506 | */ | |
2507 | ||
2508 | if (need_close || need_restart) { | |
2509 | gsm_dlci_begin_close(gsm->dlci[0]); | |
2510 | /* This will timeout if the link is down due to N2 expiring */ | |
2511 | wait_event_interruptible(gsm->event, | |
2512 | gsm->dlci[0]->state == DLCI_CLOSED); | |
2513 | if (signal_pending(current)) | |
2514 | return -EINTR; | |
2515 | } | |
2516 | if (need_restart) | |
2517 | gsm_cleanup_mux(gsm); | |
2518 | ||
2519 | gsm->initiator = c->initiator; | |
2520 | gsm->mru = c->mru; | |
91f78f36 | 2521 | gsm->mtu = c->mtu; |
e1eaea46 AC |
2522 | gsm->encoding = c->encapsulation; |
2523 | gsm->adaption = c->adaption; | |
820e62ef | 2524 | gsm->n2 = c->n2; |
e1eaea46 AC |
2525 | |
2526 | if (c->i == 1) | |
2527 | gsm->ftype = UIH; | |
2528 | else if (c->i == 2) | |
2529 | gsm->ftype = UI; | |
2530 | ||
2531 | if (c->t1) | |
2532 | gsm->t1 = c->t1; | |
2533 | if (c->t2) | |
2534 | gsm->t2 = c->t2; | |
2535 | ||
2536 | /* FIXME: We need to separate activation/deactivation from adding | |
2537 | and removing from the mux array */ | |
2538 | if (need_restart) | |
2539 | gsm_activate_mux(gsm); | |
2540 | if (gsm->initiator && need_close) | |
2541 | gsm_dlci_begin_open(gsm->dlci[0]); | |
2542 | return 0; | |
2543 | } | |
2544 | ||
2545 | static int gsmld_ioctl(struct tty_struct *tty, struct file *file, | |
2546 | unsigned int cmd, unsigned long arg) | |
2547 | { | |
2548 | struct gsm_config c; | |
2549 | struct gsm_mux *gsm = tty->disc_data; | |
2550 | ||
2551 | switch (cmd) { | |
2552 | case GSMIOC_GETCONF: | |
2553 | memset(&c, 0, sizeof(c)); | |
2554 | c.adaption = gsm->adaption; | |
2555 | c.encapsulation = gsm->encoding; | |
2556 | c.initiator = gsm->initiator; | |
2557 | c.t1 = gsm->t1; | |
2558 | c.t2 = gsm->t2; | |
2559 | c.t3 = 0; /* Not supported */ | |
2560 | c.n2 = gsm->n2; | |
2561 | if (gsm->ftype == UIH) | |
2562 | c.i = 1; | |
2563 | else | |
2564 | c.i = 2; | |
5f9a31d6 | 2565 | pr_debug("Ftype %d i %d\n", gsm->ftype, c.i); |
e1eaea46 AC |
2566 | c.mru = gsm->mru; |
2567 | c.mtu = gsm->mtu; | |
2568 | c.k = 0; | |
2569 | if (copy_to_user((void *)arg, &c, sizeof(c))) | |
2570 | return -EFAULT; | |
2571 | return 0; | |
2572 | case GSMIOC_SETCONF: | |
2573 | if (copy_from_user(&c, (void *)arg, sizeof(c))) | |
2574 | return -EFAULT; | |
2575 | return gsmld_config(tty, gsm, &c); | |
2576 | default: | |
2577 | return n_tty_ioctl_helper(tty, file, cmd, arg); | |
2578 | } | |
2579 | } | |
2580 | ||
bcd5abe2 RG |
2581 | /* |
2582 | * Network interface | |
2583 | * | |
2584 | */ | |
2585 | ||
2586 | static int gsm_mux_net_open(struct net_device *net) | |
2587 | { | |
2588 | pr_debug("%s called\n", __func__); | |
2589 | netif_start_queue(net); | |
2590 | return 0; | |
2591 | } | |
2592 | ||
2593 | static int gsm_mux_net_close(struct net_device *net) | |
2594 | { | |
2595 | netif_stop_queue(net); | |
2596 | return 0; | |
2597 | } | |
2598 | ||
2599 | static struct net_device_stats *gsm_mux_net_get_stats(struct net_device *net) | |
2600 | { | |
2601 | return &((struct gsm_mux_net *)netdev_priv(net))->stats; | |
2602 | } | |
2603 | static void dlci_net_free(struct gsm_dlci *dlci) | |
2604 | { | |
2605 | if (!dlci->net) { | |
2606 | WARN_ON(1); | |
2607 | return; | |
2608 | } | |
2609 | dlci->adaption = dlci->prev_adaption; | |
2610 | dlci->data = dlci->prev_data; | |
2611 | free_netdev(dlci->net); | |
2612 | dlci->net = NULL; | |
2613 | } | |
2614 | static void net_free(struct kref *ref) | |
2615 | { | |
2616 | struct gsm_mux_net *mux_net; | |
2617 | struct gsm_dlci *dlci; | |
2618 | ||
2619 | mux_net = container_of(ref, struct gsm_mux_net, ref); | |
2620 | dlci = mux_net->dlci; | |
2621 | ||
2622 | if (dlci->net) { | |
2623 | unregister_netdev(dlci->net); | |
2624 | dlci_net_free(dlci); | |
2625 | } | |
2626 | } | |
2627 | ||
6ab8fba7 RG |
2628 | static inline void muxnet_get(struct gsm_mux_net *mux_net) |
2629 | { | |
2630 | kref_get(&mux_net->ref); | |
2631 | } | |
2632 | ||
2633 | static inline void muxnet_put(struct gsm_mux_net *mux_net) | |
2634 | { | |
2635 | kref_put(&mux_net->ref, net_free); | |
2636 | } | |
2637 | ||
bcd5abe2 RG |
2638 | static int gsm_mux_net_start_xmit(struct sk_buff *skb, |
2639 | struct net_device *net) | |
2640 | { | |
2641 | struct gsm_mux_net *mux_net = (struct gsm_mux_net *)netdev_priv(net); | |
2642 | struct gsm_dlci *dlci = mux_net->dlci; | |
6ab8fba7 | 2643 | muxnet_get(mux_net); |
bcd5abe2 RG |
2644 | |
2645 | skb_queue_head(&dlci->skb_list, skb); | |
2646 | STATS(net).tx_packets++; | |
2647 | STATS(net).tx_bytes += skb->len; | |
2648 | gsm_dlci_data_kick(dlci); | |
2649 | /* And tell the kernel when the last transmit started. */ | |
2650 | net->trans_start = jiffies; | |
6ab8fba7 | 2651 | muxnet_put(mux_net); |
bcd5abe2 RG |
2652 | return NETDEV_TX_OK; |
2653 | } | |
2654 | ||
2655 | /* called when a packet did not ack after watchdogtimeout */ | |
2656 | static void gsm_mux_net_tx_timeout(struct net_device *net) | |
2657 | { | |
2658 | /* Tell syslog we are hosed. */ | |
2659 | dev_dbg(&net->dev, "Tx timed out.\n"); | |
2660 | ||
2661 | /* Update statistics */ | |
2662 | STATS(net).tx_errors++; | |
2663 | } | |
2664 | ||
2665 | static void gsm_mux_rx_netchar(struct gsm_dlci *dlci, | |
2666 | unsigned char *in_buf, int size) | |
2667 | { | |
2668 | struct net_device *net = dlci->net; | |
2669 | struct sk_buff *skb; | |
2670 | struct gsm_mux_net *mux_net = (struct gsm_mux_net *)netdev_priv(net); | |
6ab8fba7 | 2671 | muxnet_get(mux_net); |
bcd5abe2 RG |
2672 | |
2673 | /* Allocate an sk_buff */ | |
2674 | skb = dev_alloc_skb(size + NET_IP_ALIGN); | |
2675 | if (!skb) { | |
2676 | /* We got no receive buffer. */ | |
2677 | STATS(net).rx_dropped++; | |
6ab8fba7 | 2678 | muxnet_put(mux_net); |
bcd5abe2 RG |
2679 | return; |
2680 | } | |
2681 | skb_reserve(skb, NET_IP_ALIGN); | |
2682 | memcpy(skb_put(skb, size), in_buf, size); | |
2683 | ||
2684 | skb->dev = net; | |
2685 | skb->protocol = __constant_htons(ETH_P_IP); | |
2686 | ||
2687 | /* Ship it off to the kernel */ | |
2688 | netif_rx(skb); | |
2689 | ||
2690 | /* update out statistics */ | |
2691 | STATS(net).rx_packets++; | |
2692 | STATS(net).rx_bytes += size; | |
6ab8fba7 | 2693 | muxnet_put(mux_net); |
bcd5abe2 RG |
2694 | return; |
2695 | } | |
2696 | ||
2697 | int gsm_change_mtu(struct net_device *net, int new_mtu) | |
2698 | { | |
2699 | struct gsm_mux_net *mux_net = (struct gsm_mux_net *)netdev_priv(net); | |
2700 | if ((new_mtu < 8) || (new_mtu > mux_net->dlci->gsm->mtu)) | |
2701 | return -EINVAL; | |
2702 | net->mtu = new_mtu; | |
2703 | return 0; | |
2704 | } | |
2705 | ||
2706 | static void gsm_mux_net_init(struct net_device *net) | |
2707 | { | |
2708 | static const struct net_device_ops gsm_netdev_ops = { | |
2709 | .ndo_open = gsm_mux_net_open, | |
2710 | .ndo_stop = gsm_mux_net_close, | |
2711 | .ndo_start_xmit = gsm_mux_net_start_xmit, | |
2712 | .ndo_tx_timeout = gsm_mux_net_tx_timeout, | |
2713 | .ndo_get_stats = gsm_mux_net_get_stats, | |
2714 | .ndo_change_mtu = gsm_change_mtu, | |
2715 | }; | |
2716 | ||
2717 | net->netdev_ops = &gsm_netdev_ops; | |
2718 | ||
2719 | /* fill in the other fields */ | |
2720 | net->watchdog_timeo = GSM_NET_TX_TIMEOUT; | |
2721 | net->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; | |
2722 | net->type = ARPHRD_NONE; | |
2723 | net->tx_queue_len = 10; | |
2724 | } | |
2725 | ||
2726 | ||
2727 | /* caller holds the dlci mutex */ | |
2728 | static void gsm_destroy_network(struct gsm_dlci *dlci) | |
2729 | { | |
2730 | struct gsm_mux_net *mux_net; | |
2731 | ||
2732 | pr_debug("destroy network interface"); | |
2733 | if (!dlci->net) | |
2734 | return; | |
2735 | mux_net = (struct gsm_mux_net *)netdev_priv(dlci->net); | |
6ab8fba7 | 2736 | muxnet_put(mux_net); |
bcd5abe2 RG |
2737 | } |
2738 | ||
2739 | ||
2740 | /* caller holds the dlci mutex */ | |
2741 | static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) | |
2742 | { | |
2743 | char *netname; | |
2744 | int retval = 0; | |
2745 | struct net_device *net; | |
2746 | struct gsm_mux_net *mux_net; | |
2747 | ||
2748 | if (!capable(CAP_NET_ADMIN)) | |
2749 | return -EPERM; | |
2750 | ||
2751 | /* Already in a non tty mode */ | |
2752 | if (dlci->adaption > 2) | |
2753 | return -EBUSY; | |
2754 | ||
2755 | if (nc->protocol != htons(ETH_P_IP)) | |
2756 | return -EPROTONOSUPPORT; | |
2757 | ||
2758 | if (nc->adaption != 3 && nc->adaption != 4) | |
2759 | return -EPROTONOSUPPORT; | |
2760 | ||
2761 | pr_debug("create network interface"); | |
2762 | ||
2763 | netname = "gsm%d"; | |
2764 | if (nc->if_name[0] != '\0') | |
2765 | netname = nc->if_name; | |
2766 | net = alloc_netdev(sizeof(struct gsm_mux_net), | |
2767 | netname, | |
2768 | gsm_mux_net_init); | |
2769 | if (!net) { | |
2770 | pr_err("alloc_netdev failed"); | |
2771 | return -ENOMEM; | |
2772 | } | |
2773 | net->mtu = dlci->gsm->mtu; | |
2774 | mux_net = (struct gsm_mux_net *)netdev_priv(net); | |
2775 | mux_net->dlci = dlci; | |
2776 | kref_init(&mux_net->ref); | |
2777 | strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */ | |
2778 | ||
2779 | /* reconfigure dlci for network */ | |
2780 | dlci->prev_adaption = dlci->adaption; | |
2781 | dlci->prev_data = dlci->data; | |
2782 | dlci->adaption = nc->adaption; | |
2783 | dlci->data = gsm_mux_rx_netchar; | |
2784 | dlci->net = net; | |
2785 | ||
2786 | pr_debug("register netdev"); | |
2787 | retval = register_netdev(net); | |
2788 | if (retval) { | |
2789 | pr_err("network register fail %d\n", retval); | |
2790 | dlci_net_free(dlci); | |
2791 | return retval; | |
2792 | } | |
2793 | return net->ifindex; /* return network index */ | |
2794 | } | |
e1eaea46 AC |
2795 | |
2796 | /* Line discipline for real tty */ | |
2797 | struct tty_ldisc_ops tty_ldisc_packet = { | |
2798 | .owner = THIS_MODULE, | |
2799 | .magic = TTY_LDISC_MAGIC, | |
2800 | .name = "n_gsm", | |
2801 | .open = gsmld_open, | |
2802 | .close = gsmld_close, | |
2803 | .flush_buffer = gsmld_flush_buffer, | |
2804 | .chars_in_buffer = gsmld_chars_in_buffer, | |
2805 | .read = gsmld_read, | |
2806 | .write = gsmld_write, | |
2807 | .ioctl = gsmld_ioctl, | |
2808 | .poll = gsmld_poll, | |
2809 | .receive_buf = gsmld_receive_buf, | |
2810 | .write_wakeup = gsmld_write_wakeup | |
2811 | }; | |
2812 | ||
2813 | /* | |
2814 | * Virtual tty side | |
2815 | */ | |
2816 | ||
2817 | #define TX_SIZE 512 | |
2818 | ||
2819 | static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) | |
2820 | { | |
2821 | u8 modembits[5]; | |
2822 | struct gsm_control *ctrl; | |
2823 | int len = 2; | |
2824 | ||
2825 | if (brk) | |
2826 | len++; | |
2827 | ||
2828 | modembits[0] = len << 1 | EA; /* Data bytes */ | |
2829 | modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */ | |
2830 | modembits[2] = gsm_encode_modem(dlci) << 1 | EA; | |
2831 | if (brk) | |
2832 | modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */ | |
2833 | ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1); | |
2834 | if (ctrl == NULL) | |
2835 | return -ENOMEM; | |
2836 | return gsm_control_wait(dlci->gsm, ctrl); | |
2837 | } | |
2838 | ||
2839 | static int gsm_carrier_raised(struct tty_port *port) | |
2840 | { | |
2841 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
2842 | /* Not yet open so no carrier info */ | |
2843 | if (dlci->state != DLCI_OPEN) | |
2844 | return 0; | |
2845 | if (debug & 2) | |
2846 | return 1; | |
2847 | return dlci->modem_rx & TIOCM_CD; | |
2848 | } | |
2849 | ||
2850 | static void gsm_dtr_rts(struct tty_port *port, int onoff) | |
2851 | { | |
2852 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
2853 | unsigned int modem_tx = dlci->modem_tx; | |
2854 | if (onoff) | |
2855 | modem_tx |= TIOCM_DTR | TIOCM_RTS; | |
2856 | else | |
2857 | modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); | |
2858 | if (modem_tx != dlci->modem_tx) { | |
2859 | dlci->modem_tx = modem_tx; | |
2860 | gsmtty_modem_update(dlci, 0); | |
2861 | } | |
2862 | } | |
2863 | ||
2864 | static const struct tty_port_operations gsm_port_ops = { | |
2865 | .carrier_raised = gsm_carrier_raised, | |
2866 | .dtr_rts = gsm_dtr_rts, | |
2867 | }; | |
2868 | ||
2869 | ||
2870 | static int gsmtty_open(struct tty_struct *tty, struct file *filp) | |
2871 | { | |
2872 | struct gsm_mux *gsm; | |
2873 | struct gsm_dlci *dlci; | |
2874 | struct tty_port *port; | |
2875 | unsigned int line = tty->index; | |
2876 | unsigned int mux = line >> 6; | |
2877 | ||
2878 | line = line & 0x3F; | |
2879 | ||
2880 | if (mux >= MAX_MUX) | |
2881 | return -ENXIO; | |
2882 | /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */ | |
2883 | if (gsm_mux[mux] == NULL) | |
2884 | return -EUNATCH; | |
2885 | if (line == 0 || line > 61) /* 62/63 reserved */ | |
2886 | return -ECHRNG; | |
2887 | gsm = gsm_mux[mux]; | |
2888 | if (gsm->dead) | |
2889 | return -EL2HLT; | |
2890 | dlci = gsm->dlci[line]; | |
2891 | if (dlci == NULL) | |
2892 | dlci = gsm_dlci_alloc(gsm, line); | |
2893 | if (dlci == NULL) | |
2894 | return -ENOMEM; | |
2895 | port = &dlci->port; | |
2896 | port->count++; | |
2897 | tty->driver_data = dlci; | |
6ab8fba7 RG |
2898 | dlci_get(dlci); |
2899 | dlci_get(dlci->gsm->dlci[0]); | |
2900 | mux_get(dlci->gsm); | |
e1eaea46 AC |
2901 | tty_port_tty_set(port, tty); |
2902 | ||
2903 | dlci->modem_rx = 0; | |
2904 | /* We could in theory open and close before we wait - eg if we get | |
2905 | a DM straight back. This is ok as that will have caused a hangup */ | |
2906 | set_bit(ASYNCB_INITIALIZED, &port->flags); | |
2907 | /* Start sending off SABM messages */ | |
2908 | gsm_dlci_begin_open(dlci); | |
2909 | /* And wait for virtual carrier */ | |
2910 | return tty_port_block_til_ready(port, tty, filp); | |
2911 | } | |
2912 | ||
2913 | static void gsmtty_close(struct tty_struct *tty, struct file *filp) | |
2914 | { | |
2915 | struct gsm_dlci *dlci = tty->driver_data; | |
6ab8fba7 RG |
2916 | struct gsm_mux *gsm; |
2917 | ||
e1eaea46 AC |
2918 | if (dlci == NULL) |
2919 | return; | |
bcd5abe2 RG |
2920 | mutex_lock(&dlci->mutex); |
2921 | gsm_destroy_network(dlci); | |
2922 | mutex_unlock(&dlci->mutex); | |
6ab8fba7 | 2923 | gsm = dlci->gsm; |
e1eaea46 | 2924 | if (tty_port_close_start(&dlci->port, tty, filp) == 0) |
6ab8fba7 | 2925 | goto out; |
e1eaea46 AC |
2926 | gsm_dlci_begin_close(dlci); |
2927 | tty_port_close_end(&dlci->port, tty); | |
2928 | tty_port_tty_set(&dlci->port, NULL); | |
6ab8fba7 RG |
2929 | out: |
2930 | dlci_put(dlci); | |
2931 | dlci_put(gsm->dlci[0]); | |
2932 | mux_put(gsm); | |
e1eaea46 AC |
2933 | } |
2934 | ||
2935 | static void gsmtty_hangup(struct tty_struct *tty) | |
2936 | { | |
2937 | struct gsm_dlci *dlci = tty->driver_data; | |
2938 | tty_port_hangup(&dlci->port); | |
2939 | gsm_dlci_begin_close(dlci); | |
2940 | } | |
2941 | ||
2942 | static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf, | |
2943 | int len) | |
2944 | { | |
2945 | struct gsm_dlci *dlci = tty->driver_data; | |
2946 | /* Stuff the bytes into the fifo queue */ | |
2947 | int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock); | |
2948 | /* Need to kick the channel */ | |
2949 | gsm_dlci_data_kick(dlci); | |
2950 | return sent; | |
2951 | } | |
2952 | ||
2953 | static int gsmtty_write_room(struct tty_struct *tty) | |
2954 | { | |
2955 | struct gsm_dlci *dlci = tty->driver_data; | |
2956 | return TX_SIZE - kfifo_len(dlci->fifo); | |
2957 | } | |
2958 | ||
2959 | static int gsmtty_chars_in_buffer(struct tty_struct *tty) | |
2960 | { | |
2961 | struct gsm_dlci *dlci = tty->driver_data; | |
2962 | return kfifo_len(dlci->fifo); | |
2963 | } | |
2964 | ||
2965 | static void gsmtty_flush_buffer(struct tty_struct *tty) | |
2966 | { | |
2967 | struct gsm_dlci *dlci = tty->driver_data; | |
2968 | /* Caution needed: If we implement reliable transport classes | |
2969 | then the data being transmitted can't simply be junked once | |
2970 | it has first hit the stack. Until then we can just blow it | |
2971 | away */ | |
2972 | kfifo_reset(dlci->fifo); | |
2973 | /* Need to unhook this DLCI from the transmit queue logic */ | |
2974 | } | |
2975 | ||
2976 | static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout) | |
2977 | { | |
2978 | /* The FIFO handles the queue so the kernel will do the right | |
2979 | thing waiting on chars_in_buffer before calling us. No work | |
2980 | to do here */ | |
2981 | } | |
2982 | ||
60b33c13 | 2983 | static int gsmtty_tiocmget(struct tty_struct *tty) |
e1eaea46 AC |
2984 | { |
2985 | struct gsm_dlci *dlci = tty->driver_data; | |
2986 | return dlci->modem_rx; | |
2987 | } | |
2988 | ||
20b9d177 | 2989 | static int gsmtty_tiocmset(struct tty_struct *tty, |
e1eaea46 AC |
2990 | unsigned int set, unsigned int clear) |
2991 | { | |
2992 | struct gsm_dlci *dlci = tty->driver_data; | |
2993 | unsigned int modem_tx = dlci->modem_tx; | |
2994 | ||
cf16807b | 2995 | modem_tx &= ~clear; |
e1eaea46 AC |
2996 | modem_tx |= set; |
2997 | ||
2998 | if (modem_tx != dlci->modem_tx) { | |
2999 | dlci->modem_tx = modem_tx; | |
3000 | return gsmtty_modem_update(dlci, 0); | |
3001 | } | |
3002 | return 0; | |
3003 | } | |
3004 | ||
3005 | ||
6caa76b7 | 3006 | static int gsmtty_ioctl(struct tty_struct *tty, |
e1eaea46 AC |
3007 | unsigned int cmd, unsigned long arg) |
3008 | { | |
bcd5abe2 RG |
3009 | struct gsm_dlci *dlci = tty->driver_data; |
3010 | struct gsm_netconfig nc; | |
3011 | int index; | |
3012 | ||
3013 | switch (cmd) { | |
3014 | case GSMIOC_ENABLE_NET: | |
3015 | if (copy_from_user(&nc, (void __user *)arg, sizeof(nc))) | |
3016 | return -EFAULT; | |
3017 | nc.if_name[IFNAMSIZ-1] = '\0'; | |
3018 | /* return net interface index or error code */ | |
3019 | mutex_lock(&dlci->mutex); | |
3020 | index = gsm_create_network(dlci, &nc); | |
3021 | mutex_unlock(&dlci->mutex); | |
3022 | if (copy_to_user((void __user *)arg, &nc, sizeof(nc))) | |
3023 | return -EFAULT; | |
3024 | return index; | |
3025 | case GSMIOC_DISABLE_NET: | |
3026 | if (!capable(CAP_NET_ADMIN)) | |
3027 | return -EPERM; | |
3028 | mutex_lock(&dlci->mutex); | |
3029 | gsm_destroy_network(dlci); | |
3030 | mutex_unlock(&dlci->mutex); | |
3031 | return 0; | |
3032 | default: | |
3033 | return -ENOIOCTLCMD; | |
3034 | } | |
e1eaea46 AC |
3035 | } |
3036 | ||
3037 | static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old) | |
3038 | { | |
3039 | /* For the moment its fixed. In actual fact the speed information | |
3040 | for the virtual channel can be propogated in both directions by | |
3041 | the RPN control message. This however rapidly gets nasty as we | |
3042 | then have to remap modem signals each way according to whether | |
3043 | our virtual cable is null modem etc .. */ | |
3044 | tty_termios_copy_hw(tty->termios, old); | |
3045 | } | |
3046 | ||
3047 | static void gsmtty_throttle(struct tty_struct *tty) | |
3048 | { | |
3049 | struct gsm_dlci *dlci = tty->driver_data; | |
3050 | if (tty->termios->c_cflag & CRTSCTS) | |
3051 | dlci->modem_tx &= ~TIOCM_DTR; | |
3052 | dlci->throttled = 1; | |
3053 | /* Send an MSC with DTR cleared */ | |
3054 | gsmtty_modem_update(dlci, 0); | |
3055 | } | |
3056 | ||
3057 | static void gsmtty_unthrottle(struct tty_struct *tty) | |
3058 | { | |
3059 | struct gsm_dlci *dlci = tty->driver_data; | |
3060 | if (tty->termios->c_cflag & CRTSCTS) | |
3061 | dlci->modem_tx |= TIOCM_DTR; | |
3062 | dlci->throttled = 0; | |
3063 | /* Send an MSC with DTR set */ | |
3064 | gsmtty_modem_update(dlci, 0); | |
3065 | } | |
3066 | ||
3067 | static int gsmtty_break_ctl(struct tty_struct *tty, int state) | |
3068 | { | |
3069 | struct gsm_dlci *dlci = tty->driver_data; | |
3070 | int encode = 0; /* Off */ | |
3071 | ||
3072 | if (state == -1) /* "On indefinitely" - we can't encode this | |
3073 | properly */ | |
3074 | encode = 0x0F; | |
3075 | else if (state > 0) { | |
3076 | encode = state / 200; /* mS to encoding */ | |
3077 | if (encode > 0x0F) | |
3078 | encode = 0x0F; /* Best effort */ | |
3079 | } | |
3080 | return gsmtty_modem_update(dlci, encode); | |
3081 | } | |
3082 | ||
e1eaea46 AC |
3083 | |
3084 | /* Virtual ttys for the demux */ | |
3085 | static const struct tty_operations gsmtty_ops = { | |
3086 | .open = gsmtty_open, | |
3087 | .close = gsmtty_close, | |
3088 | .write = gsmtty_write, | |
3089 | .write_room = gsmtty_write_room, | |
3090 | .chars_in_buffer = gsmtty_chars_in_buffer, | |
3091 | .flush_buffer = gsmtty_flush_buffer, | |
3092 | .ioctl = gsmtty_ioctl, | |
3093 | .throttle = gsmtty_throttle, | |
3094 | .unthrottle = gsmtty_unthrottle, | |
3095 | .set_termios = gsmtty_set_termios, | |
3096 | .hangup = gsmtty_hangup, | |
3097 | .wait_until_sent = gsmtty_wait_until_sent, | |
3098 | .tiocmget = gsmtty_tiocmget, | |
3099 | .tiocmset = gsmtty_tiocmset, | |
3100 | .break_ctl = gsmtty_break_ctl, | |
3101 | }; | |
3102 | ||
3103 | ||
3104 | ||
3105 | static int __init gsm_init(void) | |
3106 | { | |
3107 | /* Fill in our line protocol discipline, and register it */ | |
3108 | int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet); | |
3109 | if (status != 0) { | |
5f9a31d6 AC |
3110 | pr_err("n_gsm: can't register line discipline (err = %d)\n", |
3111 | status); | |
e1eaea46 AC |
3112 | return status; |
3113 | } | |
3114 | ||
3115 | gsm_tty_driver = alloc_tty_driver(256); | |
3116 | if (!gsm_tty_driver) { | |
3117 | tty_unregister_ldisc(N_GSM0710); | |
5f9a31d6 | 3118 | pr_err("gsm_init: tty allocation failed.\n"); |
e1eaea46 AC |
3119 | return -EINVAL; |
3120 | } | |
3121 | gsm_tty_driver->owner = THIS_MODULE; | |
3122 | gsm_tty_driver->driver_name = "gsmtty"; | |
3123 | gsm_tty_driver->name = "gsmtty"; | |
3124 | gsm_tty_driver->major = 0; /* Dynamic */ | |
3125 | gsm_tty_driver->minor_start = 0; | |
3126 | gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; | |
3127 | gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; | |
3128 | gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV | |
5f9a31d6 | 3129 | | TTY_DRIVER_HARDWARE_BREAK; |
e1eaea46 AC |
3130 | gsm_tty_driver->init_termios = tty_std_termios; |
3131 | /* Fixme */ | |
3132 | gsm_tty_driver->init_termios.c_lflag &= ~ECHO; | |
3133 | tty_set_operations(gsm_tty_driver, &gsmtty_ops); | |
3134 | ||
3135 | spin_lock_init(&gsm_mux_lock); | |
3136 | ||
3137 | if (tty_register_driver(gsm_tty_driver)) { | |
3138 | put_tty_driver(gsm_tty_driver); | |
3139 | tty_unregister_ldisc(N_GSM0710); | |
5f9a31d6 | 3140 | pr_err("gsm_init: tty registration failed.\n"); |
e1eaea46 AC |
3141 | return -EBUSY; |
3142 | } | |
5f9a31d6 AC |
3143 | pr_debug("gsm_init: loaded as %d,%d.\n", |
3144 | gsm_tty_driver->major, gsm_tty_driver->minor_start); | |
e1eaea46 AC |
3145 | return 0; |
3146 | } | |
3147 | ||
3148 | static void __exit gsm_exit(void) | |
3149 | { | |
3150 | int status = tty_unregister_ldisc(N_GSM0710); | |
3151 | if (status != 0) | |
5f9a31d6 AC |
3152 | pr_err("n_gsm: can't unregister line discipline (err = %d)\n", |
3153 | status); | |
e1eaea46 AC |
3154 | tty_unregister_driver(gsm_tty_driver); |
3155 | put_tty_driver(gsm_tty_driver); | |
e1eaea46 AC |
3156 | } |
3157 | ||
3158 | module_init(gsm_init); | |
3159 | module_exit(gsm_exit); | |
3160 | ||
3161 | ||
3162 | MODULE_LICENSE("GPL"); | |
3163 | MODULE_ALIAS_LDISC(N_GSM0710); |