s390x/sclpconsole-lm: truncate input if line is too long
[qemu.git] / hw / char / sclpconsole-lm.c
1 /*
2 * SCLP event types
3 * Operations Command - Line Mode input
4 * Message - Line Mode output
5 *
6 * Copyright IBM, Corp. 2013
7 *
8 * Authors:
9 * Heinz Graalfs <graalfs@linux.vnet.ibm.com>
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
12 * option) any later version. See the COPYING file in the top-level directory.
13 *
14 */
15
16 #include "hw/qdev.h"
17 #include "qemu/thread.h"
18 #include "qemu/error-report.h"
19 #include "sysemu/char.h"
20
21 #include "hw/s390x/sclp.h"
22 #include "hw/s390x/event-facility.h"
23 #include "hw/s390x/ebcdic.h"
24
25 #define SIZE_BUFFER 4096
26 #define NEWLINE "\n"
27
28 typedef struct OprtnsCommand {
29 EventBufferHeader header;
30 MDMSU message_unit;
31 char data[0];
32 } QEMU_PACKED OprtnsCommand;
33
34 /* max size for line-mode data in 4K SCCB page */
35 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
36
37 typedef struct SCLPConsoleLM {
38 SCLPEvent event;
39 CharDriverState *chr;
40 bool echo; /* immediate echo of input if true */
41 uint32_t write_errors; /* errors writing to char layer */
42 uint32_t length; /* length of byte stream in buffer */
43 uint8_t buf[SIZE_CONSOLE_BUFFER];
44 } SCLPConsoleLM;
45
46 /*
47 * Character layer call-back functions
48 *
49 * Allow 1 character at a time
50 *
51 * Accumulate bytes from character layer in console buffer,
52 * event_pending is set when a newline character is encountered
53 *
54 * The maximum command line length is limited by the maximum
55 * space available in an SCCB. Line mode console input is sent
56 * truncated to the guest in case it doesn't fit into the SCCB.
57 */
58
59 static int chr_can_read(void *opaque)
60 {
61 SCLPConsoleLM *scon = opaque;
62
63 if (scon->event.event_pending) {
64 return 0;
65 }
66 return 1;
67 }
68
69 static void chr_read(void *opaque, const uint8_t *buf, int size)
70 {
71 SCLPConsoleLM *scon = opaque;
72
73 assert(size == 1);
74
75 if (*buf == '\r' || *buf == '\n') {
76 scon->event.event_pending = true;
77 sclp_service_interrupt(0);
78 return;
79 }
80 if (scon->length == SIZE_CONSOLE_BUFFER) {
81 /* Eat the character, but still process CR and LF. */
82 return;
83 }
84 scon->buf[scon->length] = *buf;
85 scon->length += 1;
86 if (scon->echo) {
87 qemu_chr_fe_write(scon->chr, buf, size);
88 }
89 }
90
91 /* functions to be called by event facility */
92
93 static bool can_handle_event(uint8_t type)
94 {
95 return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
96 }
97
98 static unsigned int send_mask(void)
99 {
100 return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
101 }
102
103 static unsigned int receive_mask(void)
104 {
105 return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
106 }
107
108 /*
109 * Triggered by SCLP's read_event_data
110 * - convert ASCII byte stream to EBCDIC and
111 * - copy converted data into provided (SCLP) buffer
112 */
113 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
114 int avail)
115 {
116 int len;
117
118 SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
119
120 len = cons->length;
121 /* data need to fit into provided SCLP buffer */
122 if (len > avail) {
123 return 1;
124 }
125
126 ebcdic_put(buf, (char *)&cons->buf, len);
127 *size = len;
128 cons->length = 0;
129 /* data provided and no more data pending */
130 event->event_pending = false;
131 return 0;
132 }
133
134 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
135 int *slen)
136 {
137 int avail, rc;
138 size_t src_len;
139 uint8_t *to;
140 OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
141
142 if (!event->event_pending) {
143 /* no data pending */
144 return 0;
145 }
146
147 to = (uint8_t *)&oc->data;
148 avail = *slen - sizeof(OprtnsCommand);
149 rc = get_console_data(event, to, &src_len, avail);
150 if (rc) {
151 /* data didn't fit, try next SCCB */
152 return 1;
153 }
154
155 oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
156 oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
157
158 oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
159 oc->message_unit.cpmsu.length =
160 cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
161
162 oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
163 oc->message_unit.text_command.length =
164 cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
165
166 oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
167 oc->message_unit.self_def_text_message.length =
168 cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
169
170 oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
171 oc->message_unit.text_message.length =
172 cpu_to_be16(sizeof(GdsSubvector) + src_len);
173
174 oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
175 oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
176 *slen = avail - src_len;
177
178 return 1;
179 }
180
181 /*
182 * Triggered by SCLP's write_event_data
183 * - write console data to character layer
184 * returns < 0 if an error occurred
185 */
186 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
187 {
188 int ret = 0;
189 const uint8_t *buf_offset;
190
191 SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
192
193 if (!scon->chr) {
194 /* If there's no backend, we can just say we consumed all data. */
195 return len;
196 }
197
198 buf_offset = buf;
199 while (len > 0) {
200 ret = qemu_chr_fe_write(scon->chr, buf, len);
201 if (ret == 0) {
202 /* a pty doesn't seem to be connected - no error */
203 len = 0;
204 } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
205 len -= ret;
206 buf_offset += ret;
207 } else {
208 len = 0;
209 }
210 }
211
212 return ret;
213 }
214
215 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
216 {
217 int rc;
218 int len;
219 uint8_t buffer[SIZE_BUFFER];
220
221 len = be16_to_cpu(mdbo->length);
222 len -= sizeof(mdbo->length) + sizeof(mdbo->type)
223 + sizeof(mdbo->mto.line_type_flags)
224 + sizeof(mdbo->mto.alarm_control)
225 + sizeof(mdbo->mto._reserved);
226
227 assert(len <= SIZE_BUFFER);
228
229 /* convert EBCDIC SCLP contents to ASCII console message */
230 ascii_put(buffer, mdbo->mto.message, len);
231 rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
232 if (rc < 0) {
233 return rc;
234 }
235 return write_console_data(event, buffer, len);
236 }
237
238 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
239 {
240 int len;
241 int written;
242 int errors = 0;
243 MDBO *mdbo;
244 SclpMsg *data = (SclpMsg *) ebh;
245 SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
246
247 len = be16_to_cpu(data->mdb.header.length);
248 if (len < sizeof(data->mdb.header)) {
249 return SCLP_RC_INCONSISTENT_LENGTHS;
250 }
251 len -= sizeof(data->mdb.header);
252
253 /* first check message buffers */
254 mdbo = data->mdb.mdbo;
255 while (len > 0) {
256 if (be16_to_cpu(mdbo->length) > len
257 || be16_to_cpu(mdbo->length) == 0) {
258 return SCLP_RC_INCONSISTENT_LENGTHS;
259 }
260 len -= be16_to_cpu(mdbo->length);
261 mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
262 }
263
264 /* then execute */
265 len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
266 mdbo = data->mdb.mdbo;
267 while (len > 0) {
268 switch (be16_to_cpu(mdbo->type)) {
269 case MESSAGE_TEXT:
270 /* message text object */
271 written = process_mdb(event, mdbo);
272 if (written < 0) {
273 /* character layer error */
274 errors++;
275 }
276 break;
277 default: /* ignore */
278 break;
279 }
280 len -= be16_to_cpu(mdbo->length);
281 mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
282 }
283 if (errors) {
284 scon->write_errors += errors;
285 }
286 data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
287
288 return SCLP_RC_NORMAL_COMPLETION;
289 }
290
291 /* functions for live migration */
292
293 static const VMStateDescription vmstate_sclplmconsole = {
294 .name = "sclplmconsole",
295 .version_id = 0,
296 .minimum_version_id = 0,
297 .fields = (VMStateField[]) {
298 VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
299 VMSTATE_UINT32(write_errors, SCLPConsoleLM),
300 VMSTATE_UINT32(length, SCLPConsoleLM),
301 VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
302 VMSTATE_END_OF_LIST()
303 }
304 };
305
306 /* qemu object creation and initialization functions */
307
308 /* tell character layer our call-back functions */
309
310 static int console_init(SCLPEvent *event)
311 {
312 static bool console_available;
313
314 SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
315
316 if (console_available) {
317 error_report("Multiple line-mode operator consoles are not supported");
318 return -1;
319 }
320 console_available = true;
321
322 if (scon->chr) {
323 qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
324 }
325
326 return 0;
327 }
328
329 static int console_exit(SCLPEvent *event)
330 {
331 return 0;
332 }
333
334 static void console_reset(DeviceState *dev)
335 {
336 SCLPEvent *event = SCLP_EVENT(dev);
337 SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
338
339 event->event_pending = false;
340 scon->length = 0;
341 scon->write_errors = 0;
342 }
343
344 static Property console_properties[] = {
345 DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
346 DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
347 DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
348 DEFINE_PROP_END_OF_LIST(),
349 };
350
351 static void console_class_init(ObjectClass *klass, void *data)
352 {
353 DeviceClass *dc = DEVICE_CLASS(klass);
354 SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
355
356 dc->props = console_properties;
357 dc->reset = console_reset;
358 dc->vmsd = &vmstate_sclplmconsole;
359 ec->init = console_init;
360 ec->exit = console_exit;
361 ec->get_send_mask = send_mask;
362 ec->get_receive_mask = receive_mask;
363 ec->can_handle_event = can_handle_event;
364 ec->read_event_data = read_event_data;
365 ec->write_event_data = write_event_data;
366 }
367
368 static const TypeInfo sclp_console_info = {
369 .name = "sclplmconsole",
370 .parent = TYPE_SCLP_EVENT,
371 .instance_size = sizeof(SCLPConsoleLM),
372 .class_init = console_class_init,
373 .class_size = sizeof(SCLPEventClass),
374 };
375
376 static void register_types(void)
377 {
378 type_register_static(&sclp_console_info);
379 }
380
381 type_init(register_types)