| blob | f95b2fdc66bac2ea062872b1726bc86e7e8873fc |
1 /*\r
2 * ldisc.c: PuTTY line discipline. Sits between the input coming\r
3 * from keypresses in the window, and the output channel leading to\r
4 * the back end. Implements echo and/or local line editing,\r
5 * depending on what's currently configured.\r
6 */\r
7 \r
8 #include <stdio.h>\r
9 #include <ctype.h>\r
10 #include <assert.h>\r
11 \r
12 #include "putty.h"\r
13 #include "terminal.h"\r
14 #include "ldisc.h"\r
15 \r
16 #define ECHOING (ldisc->localecho == FORCE_ON || \\r
17 (ldisc->localecho == AUTO && \\r
18 (ldisc->back->ldisc(ldisc->backhandle, LD_ECHO) || \\r
19 term_ldisc(ldisc->term, LD_ECHO))))\r
20 #define EDITING (ldisc->localedit == FORCE_ON || \\r
21 (ldisc->localedit == AUTO && \\r
22 (ldisc->back->ldisc(ldisc->backhandle, LD_EDIT) || \\r
23 term_ldisc(ldisc->term, LD_EDIT))))\r
24 \r
25 static void c_write(Ldisc ldisc, char *buf, int len)\r
26 {\r
27 from_backend(ldisc->frontend, 0, buf, len);\r
28 }\r
29 \r
30 static int plen(Ldisc ldisc, unsigned char c)\r
31 {\r
32 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term)))\r
33 return 1;\r
34 else if (c < 128)\r
35 return 2; /* ^x for some x */\r
36 else if (in_utf(ldisc->term) && c >= 0xC0)\r
37 return 1; /* UTF-8 introducer character\r
38 * (FIXME: combining / wide chars) */\r
39 else if (in_utf(ldisc->term) && c >= 0x80 && c < 0xC0)\r
40 return 0; /* UTF-8 followup character */\r
41 else\r
42 return 4; /* <XY> hex representation */\r
43 }\r
44 \r
45 static void pwrite(Ldisc ldisc, unsigned char c)\r
46 {\r
47 if ((c >= 32 && c <= 126) ||\r
48 (!in_utf(ldisc->term) && c >= 0xA0) ||\r
49 (in_utf(ldisc->term) && c >= 0x80)) {\r
50 c_write(ldisc, (char *)&c, 1);\r
51 } else if (c < 128) {\r
52 char cc[2];\r
53 cc[1] = (c == 127 ? '?' : c + 0x40);\r
54 cc[0] = '^';\r
55 c_write(ldisc, cc, 2);\r
56 } else {\r
57 char cc[5];\r
58 sprintf(cc, "<%02X>", c);\r
59 c_write(ldisc, cc, 4);\r
60 }\r
61 }\r
62 \r
63 static int char_start(Ldisc ldisc, unsigned char c)\r
64 {\r
65 if (in_utf(ldisc->term))\r
66 return (c < 0x80 || c >= 0xC0);\r
67 else\r
68 return 1;\r
69 }\r
70 \r
71 static void bsb(Ldisc ldisc, int n)\r
72 {\r
73 while (n--)\r
74 c_write(ldisc, "\010 \010", 3);\r
75 }\r
76 \r
77 #define CTRL(x) (x^'@')\r
78 #define KCTRL(x) ((x^'@') | 0x100)\r
79 \r
80 void *ldisc_create(Conf *conf, Terminal *term,\r
81 Backend *back, void *backhandle,\r
82 void *frontend)\r
83 {\r
84 Ldisc ldisc = snew(struct ldisc_tag);\r
85 \r
86 ldisc->buf = NULL;\r
87 ldisc->buflen = 0;\r
88 ldisc->bufsiz = 0;\r
89 ldisc->quotenext = 0;\r
90 \r
91 ldisc->back = back;\r
92 ldisc->backhandle = backhandle;\r
93 ldisc->term = term;\r
94 ldisc->frontend = frontend;\r
95 \r
96 ldisc_configure(ldisc, conf);\r
97 \r
98 /* Link ourselves into the backend and the terminal */\r
99 if (term)\r
100 term->ldisc = ldisc;\r
101 if (back)\r
102 back->provide_ldisc(backhandle, ldisc);\r
103 \r
104 return ldisc;\r
105 }\r
106 \r
107 void ldisc_configure(void *handle, Conf *conf)\r
108 {\r
109 Ldisc ldisc = (Ldisc) handle;\r
110 \r
111 ldisc->telnet_keyboard = conf_get_int(conf, CONF_telnet_keyboard);\r
112 ldisc->telnet_newline = conf_get_int(conf, CONF_telnet_newline);\r
113 ldisc->protocol = conf_get_int(conf, CONF_protocol);\r
114 ldisc->localecho = conf_get_int(conf, CONF_localecho);\r
115 ldisc->localedit = conf_get_int(conf, CONF_localedit);\r
116 }\r
117 \r
118 void ldisc_free(void *handle)\r
119 {\r
120 Ldisc ldisc = (Ldisc) handle;\r
121 \r
122 if (ldisc->term)\r
123 ldisc->term->ldisc = NULL;\r
124 if (ldisc->back)\r
125 ldisc->back->provide_ldisc(ldisc->backhandle, NULL);\r
126 if (ldisc->buf)\r
127 sfree(ldisc->buf);\r
128 sfree(ldisc);\r
129 }\r
130 \r
131 void ldisc_send(void *handle, char *buf, int len, int interactive)\r
132 {\r
133 Ldisc ldisc = (Ldisc) handle;\r
134 int keyflag = 0;\r
135 /*\r
136 * Called with len=0 when the options change. We must inform\r
137 * the front end in case it needs to know.\r
138 */\r
139 if (len == 0) {\r
140 ldisc_update(ldisc->frontend, ECHOING, EDITING);\r
141 return;\r
142 }\r
143 \r
144 /*\r
145 * If that wasn't true, then we expect ldisc->term to be non-NULL\r
146 * hereafter. (The only front ends which have an ldisc but no term\r
147 * are those which do networking but no terminal emulation, in\r
148 * which case they need the above if statement to handle\r
149 * ldisc_updates passed from the back ends, but should never send\r
150 * any actual input through this function.)\r
151 */\r
152 assert(ldisc->term);\r
153 \r
154 /*\r
155 * Notify the front end that something was pressed, in case\r
156 * it's depending on finding out (e.g. keypress termination for\r
157 * Close On Exit). \r
158 */\r
159 frontend_keypress(ldisc->frontend);\r
160 \r
161 if (interactive) {\r
162 /*\r
163 * Interrupt a paste from the clipboard, if one was in\r
164 * progress when the user pressed a key. This is easier than\r
165 * buffering the current piece of data and saving it until the\r
166 * terminal has finished pasting, and has the potential side\r
167 * benefit of permitting a user to cancel an accidental huge\r
168 * paste.\r
169 */\r
170 term_nopaste(ldisc->term);\r
171 }\r
172 \r
173 /*\r
174 * Less than zero means null terminated special string.\r
175 */\r
176 if (len < 0) {\r
177 len = strlen(buf);\r
178 keyflag = KCTRL('@');\r
179 }\r
180 /*\r
181 * Either perform local editing, or just send characters.\r
182 */\r
183 if (EDITING) {\r
184 while (len--) {\r
185 int c;\r
186 c = (unsigned char)(*buf++) + keyflag;\r
187 if (!interactive && c == '\r')\r
188 c += KCTRL('@');\r
189 switch (ldisc->quotenext ? ' ' : c) {\r
190 /*\r
191 * ^h/^?: delete, and output BSBs, to return to\r
192 * last character boundary (in UTF-8 mode this may\r
193 * be more than one byte)\r
194 * ^w: delete, and output BSBs, to return to last\r
195 * space/nonspace boundary\r
196 * ^u: delete, and output BSBs, to return to BOL\r
197 * ^c: Do a ^u then send a telnet IP\r
198 * ^z: Do a ^u then send a telnet SUSP\r
199 * ^\: Do a ^u then send a telnet ABORT\r
200 * ^r: echo "^R\n" and redraw line\r
201 * ^v: quote next char\r
202 * ^d: if at BOL, end of file and close connection,\r
203 * else send line and reset to BOL\r
204 * ^m: send line-plus-\r\n and reset to BOL\r
205 */\r
206 case KCTRL('H'):\r
207 case KCTRL('?'): /* backspace/delete */\r
208 if (ldisc->buflen > 0) {\r
209 do {\r
210 if (ECHOING)\r
211 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
212 ldisc->buflen--;\r
213 } while (!char_start(ldisc, ldisc->buf[ldisc->buflen]));\r
214 }\r
215 break;\r
216 case CTRL('W'): /* delete word */\r
217 while (ldisc->buflen > 0) {\r
218 if (ECHOING)\r
219 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
220 ldisc->buflen--;\r
221 if (ldisc->buflen > 0 &&\r
222 isspace((unsigned char)ldisc->buf[ldisc->buflen-1]) &&\r
223 !isspace((unsigned char)ldisc->buf[ldisc->buflen]))\r
224 break;\r
225 }\r
226 break;\r
227 case CTRL('U'): /* delete line */\r
228 case CTRL('C'): /* Send IP */\r
229 case CTRL('\\'): /* Quit */\r
230 case CTRL('Z'): /* Suspend */\r
231 while (ldisc->buflen > 0) {\r
232 if (ECHOING)\r
233 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
234 ldisc->buflen--;\r
235 }\r
236 ldisc->back->special(ldisc->backhandle, TS_EL);\r
237 /*\r
238 * We don't send IP, SUSP or ABORT if the user has\r
239 * configured telnet specials off! This breaks\r
240 * talkers otherwise.\r
241 */\r
242 if (!ldisc->telnet_keyboard)\r
243 goto default_case;\r
244 if (c == CTRL('C'))\r
245 ldisc->back->special(ldisc->backhandle, TS_IP);\r
246 if (c == CTRL('Z'))\r
247 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
248 if (c == CTRL('\\'))\r
249 ldisc->back->special(ldisc->backhandle, TS_ABORT);\r
250 break;\r
251 case CTRL('R'): /* redraw line */\r
252 if (ECHOING) {\r
253 int i;\r
254 c_write(ldisc, "^R\r\n", 4);\r
255 for (i = 0; i < ldisc->buflen; i++)\r
256 pwrite(ldisc, ldisc->buf[i]);\r
257 }\r
258 break;\r
259 case CTRL('V'): /* quote next char */\r
260 ldisc->quotenext = TRUE;\r
261 break;\r
262 case CTRL('D'): /* logout or send */\r
263 if (ldisc->buflen == 0) {\r
264 ldisc->back->special(ldisc->backhandle, TS_EOF);\r
265 } else {\r
266 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
267 ldisc->buflen = 0;\r
268 }\r
269 break;\r
270 /*\r
271 * This particularly hideous bit of code from RDB\r
272 * allows ordinary ^M^J to do the same thing as\r
273 * magic-^M when in Raw protocol. The line `case\r
274 * KCTRL('M'):' is _inside_ the if block. Thus:\r
275 * \r
276 * - receiving regular ^M goes straight to the\r
277 * default clause and inserts as a literal ^M.\r
278 * - receiving regular ^J _not_ directly after a\r
279 * literal ^M (or not in Raw protocol) fails the\r
280 * if condition, leaps to the bottom of the if,\r
281 * and falls through into the default clause\r
282 * again.\r
283 * - receiving regular ^J just after a literal ^M\r
284 * in Raw protocol passes the if condition,\r
285 * deletes the literal ^M, and falls through\r
286 * into the magic-^M code\r
287 * - receiving a magic-^M empties the line buffer,\r
288 * signals end-of-line in one of the various\r
289 * entertaining ways, and _doesn't_ fall out of\r
290 * the bottom of the if and through to the\r
291 * default clause because of the break.\r
292 */\r
293 case CTRL('J'):\r
294 if (ldisc->protocol == PROT_RAW &&\r
295 ldisc->buflen > 0 && ldisc->buf[ldisc->buflen - 1] == '\r') {\r
296 if (ECHOING)\r
297 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
298 ldisc->buflen--;\r
299 /* FALLTHROUGH */\r
300 case KCTRL('M'): /* send with newline */\r
301 if (ldisc->buflen > 0)\r
302 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
303 if (ldisc->protocol == PROT_RAW)\r
304 ldisc->back->send(ldisc->backhandle, "\r\n", 2);\r
305 else if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
306 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
307 else\r
308 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
309 if (ECHOING)\r
310 c_write(ldisc, "\r\n", 2);\r
311 ldisc->buflen = 0;\r
312 break;\r
313 }\r
314 /* FALLTHROUGH */\r
315 default: /* get to this label from ^V handler */\r
316 default_case:\r
317 if (ldisc->buflen >= ldisc->bufsiz) {\r
318 ldisc->bufsiz = ldisc->buflen + 256;\r
319 ldisc->buf = sresize(ldisc->buf, ldisc->bufsiz, char);\r
320 }\r
321 ldisc->buf[ldisc->buflen++] = c;\r
322 if (ECHOING)\r
323 pwrite(ldisc, (unsigned char) c);\r
324 ldisc->quotenext = FALSE;\r
325 break;\r
326 }\r
327 }\r
328 } else {\r
329 if (ldisc->buflen != 0) {\r
330 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
331 while (ldisc->buflen > 0) {\r
332 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
333 ldisc->buflen--;\r
334 }\r
335 }\r
336 if (len > 0) {\r
337 if (ECHOING)\r
338 c_write(ldisc, buf, len);\r
339 if (keyflag && ldisc->protocol == PROT_TELNET && len == 1) {\r
340 switch (buf[0]) {\r
341 case CTRL('M'):\r
342 if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
343 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
344 else\r
345 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
346 break;\r
347 case CTRL('?'):\r
348 case CTRL('H'):\r
349 if (ldisc->telnet_keyboard) {\r
350 ldisc->back->special(ldisc->backhandle, TS_EC);\r
351 break;\r
352 }\r
353 case CTRL('C'):\r
354 if (ldisc->telnet_keyboard) {\r
355 ldisc->back->special(ldisc->backhandle, TS_IP);\r
356 break;\r
357 }\r
358 case CTRL('Z'):\r
359 if (ldisc->telnet_keyboard) {\r
360 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
361 break;\r
362 }\r
363 \r
364 default:\r
365 ldisc->back->send(ldisc->backhandle, buf, len);\r
366 break;\r
367 }\r
368 } else\r
369 ldisc->back->send(ldisc->backhandle, buf, len);\r
370 }\r
371 }\r
372 }\r