Merge remote-tracking branch 'remotes/philmd-gitlab/tags/renesas-20201027' into staging
[qemu.git] / hw / char / terminal3270.c
1 /*
2 * Terminal 3270 implementation
3 *
4 * Copyright 2017 IBM Corp.
5 *
6 * Authors: Yang Chen <bjcyang@linux.vnet.ibm.com>
7 * Jing Liu <liujbjl@linux.vnet.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or (at
10 * your option) any later version. See the COPYING file in the top-level
11 * directory.
12 */
13
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qemu/module.h"
17 #include "chardev/char-fe.h"
18 #include "hw/qdev-properties.h"
19 #include "hw/s390x/3270-ccw.h"
20 #include "qom/object.h"
21
22 /* Enough spaces for different window sizes. */
23 #define INPUT_BUFFER_SIZE 1000
24 /*
25 * 1 for header, 1024*2 for datastream, 2 for tail
26 * Reserve enough spaces for telnet IAC escape.
27 */
28 #define OUTPUT_BUFFER_SIZE 2051
29
30 struct Terminal3270 {
31 EmulatedCcw3270Device cdev;
32 CharBackend chr;
33 uint8_t inv[INPUT_BUFFER_SIZE];
34 uint8_t outv[OUTPUT_BUFFER_SIZE];
35 int in_len;
36 bool handshake_done;
37 guint timer_tag;
38 };
39 typedef struct Terminal3270 Terminal3270;
40
41 #define TYPE_TERMINAL_3270 "x-terminal3270"
42 DECLARE_INSTANCE_CHECKER(Terminal3270, TERMINAL_3270,
43 TYPE_TERMINAL_3270)
44
45 static int terminal_can_read(void *opaque)
46 {
47 Terminal3270 *t = opaque;
48
49 return INPUT_BUFFER_SIZE - t->in_len;
50 }
51
52 static void terminal_timer_cancel(Terminal3270 *t)
53 {
54 if (t->timer_tag) {
55 g_source_remove(t->timer_tag);
56 t->timer_tag = 0;
57 }
58 }
59
60 /*
61 * Protocol handshake done,
62 * signal guest by an unsolicited DE irq.
63 */
64 static void TN3270_handshake_done(Terminal3270 *t)
65 {
66 CcwDevice *ccw_dev = CCW_DEVICE(t);
67 SubchDev *sch = ccw_dev->sch;
68
69 t->handshake_done = true;
70 sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
71 css_conditional_io_interrupt(sch);
72 }
73
74 /*
75 * Called when the interval is timeout to detect
76 * if the client is still alive by Timing Mark.
77 */
78 static gboolean send_timing_mark_cb(gpointer opaque)
79 {
80 Terminal3270 *t = opaque;
81 const uint8_t timing[] = {0xff, 0xfd, 0x06};
82
83 qemu_chr_fe_write_all(&t->chr, timing, sizeof(timing));
84 return true;
85 }
86
87 /*
88 * Receive inbound data from socket.
89 * For data given to guest, drop the data boundary IAC, IAC_EOR.
90 * TODO:
91 * Using "Reset" key on x3270 may result multiple commands in one packet.
92 * This usually happens when the user meets a poor traffic of the network.
93 * As of now, for such case, we simply terminate the connection,
94 * and we should come back here later with a better solution.
95 */
96 static void terminal_read(void *opaque, const uint8_t *buf, int size)
97 {
98 Terminal3270 *t = opaque;
99 CcwDevice *ccw_dev = CCW_DEVICE(t);
100 SubchDev *sch = ccw_dev->sch;
101 int end;
102
103 assert(size <= (INPUT_BUFFER_SIZE - t->in_len));
104
105 terminal_timer_cancel(t);
106 t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
107 memcpy(&t->inv[t->in_len], buf, size);
108 t->in_len += size;
109 if (t->in_len < 2) {
110 return;
111 }
112
113 if (!t->handshake_done) {
114 /*
115 * Receiving Terminal Type is the last step of handshake.
116 * The data format: IAC SB Terminal-Type IS <terminal type> IAC SE
117 * The code for Terminal-Type is 0x18, for IS is 0.
118 * Simply check the data format and mark handshake_done.
119 */
120 if (t->in_len > 6 && t->inv[2] == 0x18 && t->inv[3] == 0x0 &&
121 t->inv[t->in_len - 2] == IAC && t->inv[t->in_len - 1] == IAC_SE) {
122 TN3270_handshake_done(t);
123 t->in_len = 0;
124 }
125 return;
126 }
127
128 for (end = 0; end < t->in_len - 1; end++) {
129 if (t->inv[end] == IAC && t->inv[end + 1] == IAC_EOR) {
130 break;
131 }
132 }
133 if (end == t->in_len - 2) {
134 /* Data is valid for consuming. */
135 t->in_len -= 2;
136 sch->curr_status.scsw.dstat = SCSW_DSTAT_ATTENTION;
137 css_conditional_io_interrupt(sch);
138 } else if (end < t->in_len - 2) {
139 /* "Reset" key is used. */
140 qemu_chr_fe_disconnect(&t->chr);
141 } else {
142 /* Gathering data. */
143 return;
144 }
145 }
146
147 static void chr_event(void *opaque, QEMUChrEvent event)
148 {
149 Terminal3270 *t = opaque;
150 CcwDevice *ccw_dev = CCW_DEVICE(t);
151 SubchDev *sch = ccw_dev->sch;
152
153 /* Ensure the initial status correct, always reset them. */
154 t->in_len = 0;
155 t->handshake_done = false;
156 terminal_timer_cancel(t);
157
158 switch (event) {
159 case CHR_EVENT_OPENED:
160 /*
161 * 3270 does handshake firstly by the negotiate options in
162 * char-socket.c. Once qemu receives the terminal-type of the
163 * client, mark handshake done and trigger everything rolling again.
164 */
165 t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
166 break;
167 case CHR_EVENT_CLOSED:
168 sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
169 css_conditional_io_interrupt(sch);
170 break;
171 case CHR_EVENT_BREAK:
172 case CHR_EVENT_MUX_IN:
173 case CHR_EVENT_MUX_OUT:
174 /* Ignore */
175 break;
176 }
177 }
178
179 static void terminal_init(EmulatedCcw3270Device *dev, Error **errp)
180 {
181 Terminal3270 *t = TERMINAL_3270(dev);
182 static bool terminal_available;
183
184 if (terminal_available) {
185 error_setg(errp, "Multiple 3270 terminals are not supported.");
186 return;
187 }
188 terminal_available = true;
189 qemu_chr_fe_set_handlers(&t->chr, terminal_can_read,
190 terminal_read, chr_event, NULL, t, NULL, true);
191 }
192
193 static inline CcwDataStream *get_cds(Terminal3270 *t)
194 {
195 return &(CCW_DEVICE(&t->cdev)->sch->cds);
196 }
197
198 static int read_payload_3270(EmulatedCcw3270Device *dev)
199 {
200 Terminal3270 *t = TERMINAL_3270(dev);
201 int len;
202
203 len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
204 ccw_dstream_write_buf(get_cds(t), t->inv, len);
205 t->in_len -= len;
206
207 return len;
208 }
209
210 /* TN3270 uses binary transmission, which needs escape IAC to IAC IAC */
211 static int insert_IAC_escape_char(uint8_t *outv, int out_len)
212 {
213 int IAC_num = 0, new_out_len, i, j;
214
215 for (i = 0; i < out_len; i++) {
216 if (outv[i] == IAC) {
217 IAC_num++;
218 }
219 }
220 if (IAC_num == 0) {
221 return out_len;
222 }
223 new_out_len = out_len + IAC_num;
224 for (i = out_len - 1, j = new_out_len - 1; j > i && i >= 0; i--, j--) {
225 outv[j] = outv[i];
226 if (outv[i] == IAC) {
227 outv[--j] = IAC;
228 }
229 }
230 return new_out_len;
231 }
232
233 /*
234 * Write 3270 outbound to socket.
235 * Return the count of 3270 data field if succeeded, zero if failed.
236 */
237 static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd)
238 {
239 Terminal3270 *t = TERMINAL_3270(dev);
240 int retval = 0;
241 int count = ccw_dstream_avail(get_cds(t));
242 int bound = (OUTPUT_BUFFER_SIZE - 3) / 2;
243 int len = MIN(count, bound);
244 int out_len = 0;
245
246 if (!t->handshake_done) {
247 if (!(t->outv[0] == IAC && t->outv[1] != IAC)) {
248 /*
249 * Before having finished 3270 negotiation,
250 * sending outbound data except protocol options is prohibited.
251 */
252 return 0;
253 }
254 }
255 if (!qemu_chr_fe_backend_connected(&t->chr)) {
256 /* We just say we consumed all data if there's no backend. */
257 return count;
258 }
259
260 t->outv[out_len++] = cmd;
261 do {
262 ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len);
263 count = ccw_dstream_avail(get_cds(t));
264 out_len += len;
265
266 out_len = insert_IAC_escape_char(t->outv, out_len);
267 if (!count) {
268 t->outv[out_len++] = IAC;
269 t->outv[out_len++] = IAC_EOR;
270 }
271 retval = qemu_chr_fe_write_all(&t->chr, t->outv, out_len);
272 len = MIN(count, bound);
273 out_len = 0;
274 } while (len && retval >= 0);
275 return (retval <= 0) ? 0 : get_cds(t)->count;
276 }
277
278 static Property terminal_properties[] = {
279 DEFINE_PROP_CHR("chardev", Terminal3270, chr),
280 DEFINE_PROP_END_OF_LIST(),
281 };
282
283 static const VMStateDescription terminal3270_vmstate = {
284 .name = TYPE_TERMINAL_3270,
285 .unmigratable = 1,
286 };
287
288 static void terminal_class_init(ObjectClass *klass, void *data)
289 {
290 DeviceClass *dc = DEVICE_CLASS(klass);
291 EmulatedCcw3270Class *ck = EMULATED_CCW_3270_CLASS(klass);
292
293 device_class_set_props(dc, terminal_properties);
294 dc->vmsd = &terminal3270_vmstate;
295 ck->init = terminal_init;
296 ck->read_payload_3270 = read_payload_3270;
297 ck->write_payload_3270 = write_payload_3270;
298 }
299
300 static const TypeInfo ccw_terminal_info = {
301 .name = TYPE_TERMINAL_3270,
302 .parent = TYPE_EMULATED_CCW_3270,
303 .instance_size = sizeof(Terminal3270),
304 .class_init = terminal_class_init,
305 .class_size = sizeof(EmulatedCcw3270Class),
306 };
307
308 static void register_types(void)
309 {
310 type_register_static(&ccw_terminal_info);
311 }
312
313 type_init(register_types)