ESP8266-based WiFi serial modem emulator ROM
telnet: Improve debugging, separate IAC vs. data tracing
This properly implements WONT/DONT support which we were lacking,
and fixes negotiation with NetBSD telnetd (such as sdf.org) by
responding to ENCRYPT with DONT rather than WONT.
+253
-98
+250
-97
telnet.cpp
+250
-97
telnet.cpp
···
20
20
WiFiClient telnet;
21
21
22
22
enum {
23
-
TELNET_STATE_DISCONNECTED = 1,
23
+
TELNET_STATE_DISCONNECTED = 0,
24
24
TELNET_STATE_CONNECTED,
25
25
TELNET_STATE_IAC,
26
-
TELNET_STATE_IAC_SB,
27
26
TELNET_STATE_IAC_WILL,
27
+
TELNET_STATE_IAC_WONT,
28
28
TELNET_STATE_IAC_DO,
29
+
TELNET_STATE_IAC_DONT,
30
+
TELNET_STATE_IAC_SB,
29
31
};
30
32
31
33
uint8_t telnet_state = TELNET_STATE_DISCONNECTED;
32
34
uint8_t telnet_sb[64];
33
35
uint8_t telnet_sb_len = 0;
34
-
bool telnet_echoing = true;
35
36
36
37
#define SE 240 /* end of sub-negotiation options */
37
38
#define SB 250 /* start of sub-negotiation options */
···
44
45
#define IS 0 /* sub-negotiation */
45
46
#define SEND 1 /* sub-negotiation */
46
47
48
+
#define IAC_BINARY 0 /* Transmit Binary */
47
49
#define IAC_ECHO 1 /* Echo Option */
48
50
#define IAC_SGA 3 /* Suppress Go Ahead Option */
49
51
#define IAC_STATUS 5 /* Status Option */
···
72
74
#define IAC_LINEMODE 34 /* Linemode Option */
73
75
#define IAC_XDISPLOC 35 /* X Display Location Option */
74
76
#define IAC_ENVIRON 36 /* Environment Option */
77
+
#define IAC_AUTH 37 /* Authentication */
78
+
#define IAC_ENCRYPT 38 /* Encryption Option */
75
79
#define IAC_NEWENV 39 /* Environment Option */
76
80
#define IAC_CHARSET 42 /* Charset Option */
77
81
#define IAC_COMPORT 44 /* Com Port Control Option */
78
82
79
-
#if DEBUG
80
-
#define TELNET_DEBUG(...) { outputf(__VA_ARGS__) }
83
+
#ifdef TELNET_IAC_TRACE
84
+
#define TELNET_IAC_DEBUG(...) { syslog.logf(LOG_INFO, __VA_ARGS__); delay(1); }
81
85
#else
82
-
#define TELNET_DEBUG(...) {}
86
+
#define TELNET_IAC_DEBUG(...) {}
83
87
#endif
84
88
85
-
void telnet_process_sb(void);
89
+
#ifdef TELNET_DATA_TRACE
90
+
#define TELNET_DATA_DEBUG(...) { syslog.logf(LOG_INFO, __VA_ARGS__); delay(1); }
91
+
#else
92
+
#define TELNET_DATA_DEBUG(...) {}
93
+
#endif
86
94
87
95
int
88
96
telnet_connect(char *host, uint16_t port)
89
97
{
90
-
if (telnet_state != TELNET_STATE_DISCONNECTED) {
91
-
outputf("can't telnet_connect, telnet_state %d\r\n",
92
-
telnet_state);
93
-
return 1;
94
-
}
98
+
if (telnet_state != TELNET_STATE_DISCONNECTED)
99
+
telnet_disconnect();
95
100
96
101
if (!telnet.connect(host, port))
97
102
return 1;
···
99
104
telnet.setNoDelay(true);
100
105
101
106
telnet_state = TELNET_STATE_CONNECTED;
102
-
telnet_echoing = true;
103
107
serial_dcd(true);
108
+
109
+
if (settings->telnet) {
110
+
/* start by sending things we support */
111
+
TELNET_IAC_DEBUG("%s: -> IAC DO SUPPRESS GO AHEAD", __func__);
112
+
telnet.printf("%c%c%c", IAC, DO, IAC_SGA);
113
+
TELNET_IAC_DEBUG("%s: -> IAC WILL TTYPE", __func__);
114
+
telnet.printf("%c%c%c", IAC, WILL, IAC_TTYPE);
115
+
TELNET_IAC_DEBUG("%s: -> IAC WILL NAWS", __func__);
116
+
telnet.printf("%c%c%c", IAC, WILL, IAC_NAWS);
117
+
TELNET_IAC_DEBUG("%s: -> IAC WILL TSPEED", __func__);
118
+
telnet.printf("%c%c%c", IAC, WILL, IAC_TSPEED);
119
+
TELNET_IAC_DEBUG("%s: -> IAC WONT LINEMODE", __func__);
120
+
telnet.printf("%c%c%c", IAC, WONT, IAC_LINEMODE);
121
+
TELNET_IAC_DEBUG("%s: -> IAC DO STATUS", __func__);
122
+
telnet.printf("%c%c%c", IAC, DO, IAC_STATUS);
123
+
}
124
+
104
125
return 0;
105
126
}
106
127
···
127
148
serial_dcd(false);
128
149
}
129
150
130
-
void
131
-
telnet_process_sb(void)
151
+
#ifdef TELNET_IAC_TRACE
152
+
static char iac_name[16];
153
+
char *
154
+
telnet_iac_name(char iac)
132
155
{
133
-
switch (telnet_sb[0]) {
134
-
case IAC_TTYPE:
135
-
if (telnet_sb[1] != SEND) {
136
-
TELNET_DEBUG("%s: server is telling us TYPE? ",
137
-
__func__);
138
-
goto dump_sb;
139
-
}
140
-
141
-
TELNET_DEBUG("%s: -> IAC SB TTYPE %s\r\n", __func__,
142
-
settings->telnet_tterm);
143
-
telnet.printf("%c%c%c%c", IAC, SB, IAC_TTYPE, IS);
144
-
for (size_t i = 0; i < sizeof(settings->telnet_tterm); i++) {
145
-
if (settings->telnet_tterm[i] == '\0')
146
-
break;
156
+
if (telnet_state == TELNET_STATE_CONNECTED && iac != IAC) {
157
+
sprintf(iac_name, "%d (%c)", iac, iac);
158
+
return iac_name;
159
+
}
147
160
148
-
if (settings->telnet_tterm[i] == IAC)
149
-
telnet.write(IAC);
150
-
telnet.write(settings->telnet_tterm[i]);
151
-
}
152
-
telnet.printf("%c%c", IAC, SE);
161
+
switch (iac) {
162
+
case IAC_ECHO:
163
+
sprintf(iac_name, "ECHO");
164
+
break;
165
+
case IAC_SGA:
166
+
sprintf(iac_name, "SGA");
167
+
break;
168
+
case IAC_STATUS:
169
+
sprintf(iac_name, "STATUS");
170
+
break;
171
+
case IAC_TTYPE:
172
+
sprintf(iac_name, "TTYPE");
153
173
break;
154
174
case IAC_NAWS:
155
-
if (telnet_sb[1] != SEND) {
156
-
TELNET_DEBUG("%s: server is telling us NAWS? ",
157
-
__func__);
158
-
goto dump_sb;
159
-
}
175
+
sprintf(iac_name, "NAWS");
176
+
break;
177
+
case IAC_TSPEED:
178
+
sprintf(iac_name, "TSPEED");
179
+
break;
180
+
case IAC_FLOWCTRL:
181
+
sprintf(iac_name, "FLOWCTRL");
182
+
break;
183
+
case IAC_LINEMODE:
184
+
sprintf(iac_name, "LINEMODE");
185
+
break;
186
+
case IAC_ENCRYPT:
187
+
sprintf(iac_name, "ENCRYPT");
188
+
break;
189
+
case IAC_AUTH:
190
+
sprintf(iac_name, "AUTH");
191
+
break;
192
+
case IAC_XDISPLOC:
193
+
sprintf(iac_name, "XDISPLOC");
194
+
break;
195
+
case IAC_NEWENV:
196
+
sprintf(iac_name, "NEWENV");
197
+
break;
198
+
case IAC_ENVIRON:
199
+
sprintf(iac_name, "OLD ENVIRON");
200
+
break;
201
+
case SE:
202
+
sprintf(iac_name, "SE");
203
+
break;
204
+
case SB:
205
+
sprintf(iac_name, "SB");
206
+
break;
207
+
case WILL:
208
+
sprintf(iac_name, "WILL");
209
+
break;
210
+
case WONT:
211
+
sprintf(iac_name, "WONT");
212
+
break;
213
+
case DO:
214
+
sprintf(iac_name, "DO");
215
+
break;
216
+
case DONT:
217
+
sprintf(iac_name, "DONT");
218
+
break;
219
+
case IAC:
220
+
sprintf(iac_name, "IAC");
221
+
break;
222
+
default:
223
+
sprintf(iac_name, "%d", iac);
224
+
break;
225
+
}
226
+
return iac_name;
227
+
}
228
+
#endif
229
+
230
+
void
231
+
telnet_send_ttype(void)
232
+
{
233
+
TELNET_IAC_DEBUG("%s: -> IAC SB TTYPE IS %s IAC SE", __func__,
234
+
settings->telnet_tterm);
235
+
telnet.printf("%c%c%c%c", IAC, SB, IAC_TTYPE, IS);
236
+
for (size_t i = 0; i < sizeof(settings->telnet_tterm); i++) {
237
+
if (settings->telnet_tterm[i] == '\0')
238
+
break;
239
+
240
+
if (settings->telnet_tterm[i] == IAC)
241
+
telnet.write(IAC);
242
+
telnet.write(settings->telnet_tterm[i]);
243
+
}
244
+
telnet.printf("%c%c", IAC, SE);
245
+
}
246
+
247
+
void
248
+
telnet_send_naws(void)
249
+
{
250
+
251
+
TELNET_IAC_DEBUG("%s: -> IAC SB NAWS IS %dx%d IAC SE", __func__,
252
+
settings->telnet_tts_w, settings->telnet_tts_h);
160
253
161
-
TELNET_DEBUG("%s: -> IAC SB NAWS %dx%d\r\n", __func__,
162
-
settings->telnet_tts_w, settings->telnet_tts_h);
254
+
telnet.printf("%c%c%c", IAC, SB, IAC_NAWS);
255
+
256
+
/* we only support 8-bit settings, but NAWS is 16-bit * */
257
+
telnet.write(0);
258
+
if (settings->telnet_tts_w == IAC)
259
+
telnet.write(IAC);
260
+
telnet.write(settings->telnet_tts_w);
163
261
164
-
telnet.printf("%c%c%c", IAC, SB, IAC_NAWS);
262
+
telnet.write(0);
263
+
if (settings->telnet_tts_h == IAC)
264
+
telnet.write(IAC);
265
+
telnet.write(settings->telnet_tts_h);
165
266
166
-
/* we only support 8-bit settings, but NAWS is 16-bit * */
167
-
telnet.write(0);
168
-
if (settings->telnet_tts_w == IAC)
169
-
telnet.write(IAC);
170
-
telnet.write(settings->telnet_tts_w);
267
+
telnet.printf("%c%c", IAC, SE);
268
+
}
171
269
172
-
telnet.write(0);
173
-
if (settings->telnet_tts_h == IAC)
174
-
telnet.write(IAC);
175
-
telnet.write(settings->telnet_tts_h);
270
+
void
271
+
telnet_send_tspeed(void)
272
+
{
273
+
TELNET_IAC_DEBUG("%s: -> IAC SB TSPEED IS %d,%d IAC SE", __func__,
274
+
Serial.baudRate(), Serial.baudRate());
176
275
177
-
telnet.printf("%c%c", IAC, SE);
178
-
break;
179
-
default:
180
-
TELNET_DEBUG("handle IAC SB:");
181
-
goto dump_sb;
182
-
}
276
+
telnet.printf("%c%c%c%d,%d", IAC, SB, IAC_TSPEED, Serial.baudRate(),
277
+
Serial.baudRate());
183
278
184
-
return;
185
-
dump_sb:
186
-
for (int i = 0; i < telnet_sb_len; i++)
187
-
TELNET_DEBUG(" %02d", telnet_sb[i]);
188
-
TELNET_DEBUG("\r\n");
279
+
telnet.printf("%c%c", IAC, SE);
189
280
}
190
281
191
282
int
···
196
287
if (!telnet.available())
197
288
return -1;
198
289
199
-
b = telnet.read();
200
-
201
-
if (telnet_state != TELNET_STATE_CONNECTED)
202
-
TELNET_DEBUG("telnet_state[%d]: 0x%x (%d)\r\n", telnet_state,
203
-
b, b);
204
-
205
290
/* when AT$NET=0, just pass everything as-is */
206
291
if (!settings->telnet)
207
-
return b;
292
+
return telnet.read();
293
+
294
+
b = telnet.peek();
295
+
if (telnet_state != TELNET_STATE_CONNECTED || b == IAC)
296
+
TELNET_IAC_DEBUG("telnet_read[%s]: %s",
297
+
(telnet_state == TELNET_STATE_CONNECTED ? "connected" :
298
+
(telnet_state == TELNET_STATE_IAC ? "IAC" :
299
+
(telnet_state == TELNET_STATE_IAC_WILL ? "WILL" :
300
+
(telnet_state == TELNET_STATE_IAC_WONT ? "WONT" :
301
+
(telnet_state == TELNET_STATE_IAC_DO ? "DO" :
302
+
(telnet_state == TELNET_STATE_IAC_DONT ? "DONT" :
303
+
(telnet_state == TELNET_STATE_IAC_SB ? "SB" : "?"))))))),
304
+
telnet_iac_name(b));
208
305
209
306
switch (telnet_state) {
210
307
case TELNET_STATE_CONNECTED:
308
+
b = telnet.read();
211
309
switch (b) {
212
310
case IAC:
213
311
telnet_state = TELNET_STATE_IAC;
···
217
315
}
218
316
break;
219
317
case TELNET_STATE_IAC:
318
+
/* don't consume byte yet */
220
319
switch (b) {
221
320
case IAC:
222
-
/* escaped IAC */
223
-
return b;
321
+
/* escaped IAC, return one IAC */
322
+
telnet_state = TELNET_STATE_CONNECTED;
323
+
return telnet.read();
224
324
case WILL:
225
325
/* server can do something */
226
326
telnet_state = TELNET_STATE_IAC_WILL;
327
+
break;
328
+
case WONT:
329
+
/* server will not do something */
330
+
telnet_state = TELNET_STATE_IAC_WONT;
227
331
break;
228
332
case DO:
229
333
/* server wants us to do something */
230
334
telnet_state = TELNET_STATE_IAC_DO;
231
335
break;
336
+
case DONT:
337
+
/* server wants us to not do something */
338
+
telnet_state = TELNET_STATE_IAC_DONT;
339
+
break;
232
340
case SB:
233
341
/* sub-negotiate */
234
342
telnet_state = TELNET_STATE_IAC_SB;
235
343
telnet_sb_len = 0;
236
344
break;
237
345
default:
346
+
/* something else, return the original IAC */
238
347
telnet_state = TELNET_STATE_CONNECTED;
348
+
return IAC;
349
+
/* this next non-IAC byte will get returned next */
239
350
}
351
+
/* consume byte */
352
+
telnet.read();
240
353
break;
241
354
case TELNET_STATE_IAC_SB:
242
355
/* keep reading until we see [^IAC] IAC SE */
356
+
b = telnet.read();
357
+
TELNET_IAC_DEBUG("telnet_read: SB[%d] %s",
358
+
telnet_sb_len, telnet_iac_name(b));
243
359
if (b == SE && telnet_sb_len > 0 &&
244
360
telnet_sb[telnet_sb_len - 1] == IAC) {
245
-
telnet_process_sb();
361
+
TELNET_IAC_DEBUG("telnet_read: processing SB");
362
+
if (telnet_sb[1] == SEND) {
363
+
switch (telnet_sb[0]) {
364
+
case IAC_TTYPE:
365
+
telnet_send_ttype();
366
+
break;
367
+
case IAC_NAWS:
368
+
telnet_send_naws();
369
+
break;
370
+
case IAC_TSPEED:
371
+
telnet_send_tspeed();
372
+
break;
373
+
default:
374
+
TELNET_IAC_DEBUG("unsupported IAC SB %s",
375
+
telnet_iac_name(telnet_sb[0]));
376
+
}
377
+
} else {
378
+
syslog.logf(LOG_WARNING, "%s: server is "
379
+
"telling us SB %d?", __func__, telnet_sb[0]);
380
+
}
246
381
telnet_state = TELNET_STATE_CONNECTED;
247
382
} else {
248
383
if (telnet_sb_len < sizeof(telnet_sb))
249
384
telnet_sb[telnet_sb_len++] = b;
250
385
else {
251
-
outputf("IAC SB overflow!\r\n");
386
+
syslog.logf(LOG_ERR, "IAC SB overflow!");
252
387
telnet_state = TELNET_STATE_CONNECTED;
388
+
telnet_sb_len = 0;
253
389
}
254
390
}
255
391
break;
256
392
case TELNET_STATE_IAC_WILL:
257
-
TELNET_DEBUG("telnet_read: IAC WILL %d\r\n", b);
258
-
switch (b) {
393
+
switch (b = telnet.read()) {
259
394
case IAC_ECHO:
260
-
TELNET_DEBUG("telnet_read: -> IAC DO ECHO\r\n");
395
+
TELNET_IAC_DEBUG("telnet_read: -> IAC DO ECHO");
261
396
telnet.printf("%c%c%c", IAC, DO, b);
262
397
break;
263
-
case IAC_TTYPE:
264
-
TELNET_DEBUG("telnet_read: -> IAC DO TTYPE\r\n");
398
+
case IAC_SGA:
399
+
TELNET_IAC_DEBUG("telnet_read: -> IAC DO SGA");
265
400
telnet.printf("%c%c%c", IAC, DO, b);
266
401
break;
267
-
case IAC_NAWS:
268
-
TELNET_DEBUG("telnet_read: -> IAC DO NAWS\r\n");
269
-
telnet.printf("%c%c%c", IAC, DO, b);
270
-
break;
271
-
case IAC_TSPEED:
272
-
TELNET_DEBUG("telnet_read: -> IAC DO TSPEED\r\n");
273
-
telnet.printf("%c%c%c", IAC, DO, b);
402
+
case IAC_ENCRYPT:
403
+
/* refuse with DONT to satisfy NetBSD's telnetd */
404
+
TELNET_IAC_DEBUG("telnet_read: -> IAC DONT ENCRYPT");
405
+
telnet.printf("%c%c%c", IAC, DONT, b);
274
406
break;
407
+
}
408
+
telnet_state = TELNET_STATE_CONNECTED;
409
+
break;
410
+
case TELNET_STATE_IAC_WONT:
411
+
switch (b = telnet.read()) {
275
412
default:
276
-
TELNET_DEBUG("telnet_read: -> IAC WONT %d\r\n", b);
277
-
telnet.printf("%c%c%c", IAC, WONT, b);
413
+
/* we don't care about any of these yet */
278
414
break;
279
415
}
280
416
telnet_state = TELNET_STATE_CONNECTED;
281
417
break;
282
418
case TELNET_STATE_IAC_DO:
419
+
b = telnet.read();
283
420
switch (b) {
284
-
case IAC_TTYPE:
285
-
TELNET_DEBUG("telnet_read: -> IAC WILL TTYPE\r\n");
421
+
case IAC_BINARY:
422
+
TELNET_IAC_DEBUG("telnet_read: -> IAC WILL BINARY");
286
423
telnet.printf("%c%c%c", IAC, WILL, b);
287
424
break;
288
425
case IAC_NAWS:
289
-
TELNET_DEBUG("telnet_read: -> IAC WILL NAWS\r\n");
290
-
telnet.printf("%c%c%c", IAC, WILL, b);
426
+
case IAC_TSPEED:
427
+
case IAC_TTYPE:
428
+
case IAC_FLOWCTRL:
291
429
break;
292
430
case IAC_LINEMODE:
293
431
/* refuse this, we want the server to handle input */
294
-
TELNET_DEBUG("telnet_read: -> IAC WONT LINEMODE\r\n");
432
+
/* FALLTHROUGH */
433
+
default:
434
+
TELNET_IAC_DEBUG("telnet_read: -> IAC WONT %s",
435
+
telnet_iac_name(b));
295
436
telnet.printf("%c%c%c", IAC, WONT, b);
296
437
break;
438
+
}
439
+
telnet_state = TELNET_STATE_CONNECTED;
440
+
break;
441
+
case TELNET_STATE_IAC_DONT:
442
+
switch (b = telnet.read()) {
297
443
default:
298
-
TELNET_DEBUG("telnet_read: -> IAC WONT %d\r\n", b);
299
-
telnet.printf("%c%c%c", IAC, WONT, b);
444
+
TELNET_IAC_DEBUG("telnet_read: IAC DONT %s",
445
+
telnet_iac_name(b));
300
446
break;
301
447
}
302
448
telnet_state = TELNET_STATE_CONNECTED;
303
449
break;
304
450
default:
305
-
TELNET_DEBUG("telnet_read: read 0x%x but in state %d\r\n", b,
451
+
b = telnet.read();
452
+
TELNET_IAC_DEBUG("telnet_read: read 0x%x but in state %d", b,
306
453
telnet_state);
307
454
break;
308
455
}
···
314
461
telnet_write(char b)
315
462
{
316
463
/* escape */
317
-
if (settings->telnet && b == IAC)
464
+
if (settings->telnet && b == IAC) {
465
+
TELNET_DATA_DEBUG("telnet_write: escaped IAC");
318
466
telnet.write(b);
467
+
}
319
468
469
+
TELNET_DATA_DEBUG("telnet_write: 0x%x", b);
320
470
return telnet.write(b);
321
471
}
322
472
···
327
477
328
478
for (size_t i = 0; i < s.length(); i++) {
329
479
/* escape */
330
-
if (settings->telnet && s.charAt(i) == IAC)
480
+
if (settings->telnet && s.charAt(i) == IAC) {
481
+
TELNET_DATA_DEBUG("telnet_write: escaped IAC");
331
482
s2 += IAC;
483
+
}
332
484
s2 += s.charAt(i);
485
+
TELNET_DATA_DEBUG("telnet_write: 0x%x", s.charAt(i));
333
486
}
334
487
335
488
return telnet.print(s2);
+3
-1
wifippp.h
+3
-1
wifippp.h
···
26
26
27
27
#define WIFIPPP_VERSION "0.1"
28
28
29
-
/* enable various debugging */
29
+
/* enable various debugging through syslog */
30
30
// #define AT_TRACE
31
31
// #define OUTPUT_TRACE
32
32
// #define PIXEL_TRACE
33
33
// #define PPP_TRACE
34
34
// #define SOCKS_TRACE
35
+
// #define TELNET_DATA_TRACE
36
+
// #define TELNET_IAC_TRACE
35
37
// #define UPDATE_TRACE
36
38
37
39
#define EEPROM_SIZE 512