| blob | a2dc9d2c0c93871d083467030b4d36838a8600c9 |
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, const 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_echoedit_update(void *handle)\r
132 {\r
133 Ldisc ldisc = (Ldisc) handle;\r
134 frontend_echoedit_update(ldisc->frontend, ECHOING, EDITING);\r
135 }\r
136 \r
137 void ldisc_send(void *handle, const char *buf, int len, int interactive)\r
138 {\r
139 Ldisc ldisc = (Ldisc) handle;\r
140 int keyflag = 0;\r
141 \r
142 assert(ldisc->term);\r
143 assert(len);\r
144 \r
145 /*\r
146 * Notify the front end that something was pressed, in case\r
147 * it's depending on finding out (e.g. keypress termination for\r
148 * Close On Exit). \r
149 */\r
150 frontend_keypress(ldisc->frontend);\r
151 \r
152 if (interactive) {\r
153 /*\r
154 * Interrupt a paste from the clipboard, if one was in\r
155 * progress when the user pressed a key. This is easier than\r
156 * buffering the current piece of data and saving it until the\r
157 * terminal has finished pasting, and has the potential side\r
158 * benefit of permitting a user to cancel an accidental huge\r
159 * paste.\r
160 */\r
161 term_nopaste(ldisc->term);\r
162 }\r
163 \r
164 /*\r
165 * Less than zero means null terminated special string.\r
166 */\r
167 if (len < 0) {\r
168 len = strlen(buf);\r
169 keyflag = KCTRL('@');\r
170 }\r
171 /*\r
172 * Either perform local editing, or just send characters.\r
173 */\r
174 if (EDITING) {\r
175 while (len--) {\r
176 int c;\r
177 c = (unsigned char)(*buf++) + keyflag;\r
178 if (!interactive && c == '\r')\r
179 c += KCTRL('@');\r
180 switch (ldisc->quotenext ? ' ' : c) {\r
181 /*\r
182 * ^h/^?: delete, and output BSBs, to return to\r
183 * last character boundary (in UTF-8 mode this may\r
184 * be more than one byte)\r
185 * ^w: delete, and output BSBs, to return to last\r
186 * space/nonspace boundary\r
187 * ^u: delete, and output BSBs, to return to BOL\r
188 * ^c: Do a ^u then send a telnet IP\r
189 * ^z: Do a ^u then send a telnet SUSP\r
190 * ^\: Do a ^u then send a telnet ABORT\r
191 * ^r: echo "^R\n" and redraw line\r
192 * ^v: quote next char\r
193 * ^d: if at BOL, end of file and close connection,\r
194 * else send line and reset to BOL\r
195 * ^m: send line-plus-\r\n and reset to BOL\r
196 */\r
197 case KCTRL('H'):\r
198 case KCTRL('?'): /* backspace/delete */\r
199 if (ldisc->buflen > 0) {\r
200 do {\r
201 if (ECHOING)\r
202 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
203 ldisc->buflen--;\r
204 } while (!char_start(ldisc, ldisc->buf[ldisc->buflen]));\r
205 }\r
206 break;\r
207 case CTRL('W'): /* delete word */\r
208 while (ldisc->buflen > 0) {\r
209 if (ECHOING)\r
210 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
211 ldisc->buflen--;\r
212 if (ldisc->buflen > 0 &&\r
213 isspace((unsigned char)ldisc->buf[ldisc->buflen-1]) &&\r
214 !isspace((unsigned char)ldisc->buf[ldisc->buflen]))\r
215 break;\r
216 }\r
217 break;\r
218 case CTRL('U'): /* delete line */\r
219 case CTRL('C'): /* Send IP */\r
220 case CTRL('\\'): /* Quit */\r
221 case CTRL('Z'): /* Suspend */\r
222 while (ldisc->buflen > 0) {\r
223 if (ECHOING)\r
224 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
225 ldisc->buflen--;\r
226 }\r
227 ldisc->back->special(ldisc->backhandle, TS_EL);\r
228 /*\r
229 * We don't send IP, SUSP or ABORT if the user has\r
230 * configured telnet specials off! This breaks\r
231 * talkers otherwise.\r
232 */\r
233 if (!ldisc->telnet_keyboard)\r
234 goto default_case;\r
235 if (c == CTRL('C'))\r
236 ldisc->back->special(ldisc->backhandle, TS_IP);\r
237 if (c == CTRL('Z'))\r
238 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
239 if (c == CTRL('\\'))\r
240 ldisc->back->special(ldisc->backhandle, TS_ABORT);\r
241 break;\r
242 case CTRL('R'): /* redraw line */\r
243 if (ECHOING) {\r
244 int i;\r
245 c_write(ldisc, "^R\r\n", 4);\r
246 for (i = 0; i < ldisc->buflen; i++)\r
247 pwrite(ldisc, ldisc->buf[i]);\r
248 }\r
249 break;\r
250 case CTRL('V'): /* quote next char */\r
251 ldisc->quotenext = TRUE;\r
252 break;\r
253 case CTRL('D'): /* logout or send */\r
254 if (ldisc->buflen == 0) {\r
255 ldisc->back->special(ldisc->backhandle, TS_EOF);\r
256 } else {\r
257 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
258 ldisc->buflen = 0;\r
259 }\r
260 break;\r
261 /*\r
262 * This particularly hideous bit of code from RDB\r
263 * allows ordinary ^M^J to do the same thing as\r
264 * magic-^M when in Raw protocol. The line `case\r
265 * KCTRL('M'):' is _inside_ the if block. Thus:\r
266 * \r
267 * - receiving regular ^M goes straight to the\r
268 * default clause and inserts as a literal ^M.\r
269 * - receiving regular ^J _not_ directly after a\r
270 * literal ^M (or not in Raw protocol) fails the\r
271 * if condition, leaps to the bottom of the if,\r
272 * and falls through into the default clause\r
273 * again.\r
274 * - receiving regular ^J just after a literal ^M\r
275 * in Raw protocol passes the if condition,\r
276 * deletes the literal ^M, and falls through\r
277 * into the magic-^M code\r
278 * - receiving a magic-^M empties the line buffer,\r
279 * signals end-of-line in one of the various\r
280 * entertaining ways, and _doesn't_ fall out of\r
281 * the bottom of the if and through to the\r
282 * default clause because of the break.\r
283 */\r
284 case CTRL('J'):\r
285 if (ldisc->protocol == PROT_RAW &&\r
286 ldisc->buflen > 0 && ldisc->buf[ldisc->buflen - 1] == '\r') {\r
287 if (ECHOING)\r
288 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
289 ldisc->buflen--;\r
290 /* FALLTHROUGH */\r
291 case KCTRL('M'): /* send with newline */\r
292 if (ldisc->buflen > 0)\r
293 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
294 if (ldisc->protocol == PROT_RAW)\r
295 ldisc->back->send(ldisc->backhandle, "\r\n", 2);\r
296 else if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
297 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
298 else\r
299 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
300 if (ECHOING)\r
301 c_write(ldisc, "\r\n", 2);\r
302 ldisc->buflen = 0;\r
303 break;\r
304 }\r
305 /* FALLTHROUGH */\r
306 default: /* get to this label from ^V handler */\r
307 default_case:\r
308 if (ldisc->buflen >= ldisc->bufsiz) {\r
309 ldisc->bufsiz = ldisc->buflen + 256;\r
310 ldisc->buf = sresize(ldisc->buf, ldisc->bufsiz, char);\r
311 }\r
312 ldisc->buf[ldisc->buflen++] = c;\r
313 if (ECHOING)\r
314 pwrite(ldisc, (unsigned char) c);\r
315 ldisc->quotenext = FALSE;\r
316 break;\r
317 }\r
318 }\r
319 } else {\r
320 if (ldisc->buflen != 0) {\r
321 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
322 while (ldisc->buflen > 0) {\r
323 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
324 ldisc->buflen--;\r
325 }\r
326 }\r
327 if (len > 0) {\r
328 if (ECHOING)\r
329 c_write(ldisc, buf, len);\r
330 if (keyflag && ldisc->protocol == PROT_TELNET && len == 1) {\r
331 switch (buf[0]) {\r
332 case CTRL('M'):\r
333 if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
334 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
335 else\r
336 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
337 break;\r
338 case CTRL('?'):\r
339 case CTRL('H'):\r
340 if (ldisc->telnet_keyboard) {\r
341 ldisc->back->special(ldisc->backhandle, TS_EC);\r
342 break;\r
343 }\r
344 case CTRL('C'):\r
345 if (ldisc->telnet_keyboard) {\r
346 ldisc->back->special(ldisc->backhandle, TS_IP);\r
347 break;\r
348 }\r
349 case CTRL('Z'):\r
350 if (ldisc->telnet_keyboard) {\r
351 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
352 break;\r
353 }\r
354 \r
355 default:\r
356 ldisc->back->send(ldisc->backhandle, buf, len);\r
357 break;\r
358 }\r
359 } else\r
360 ldisc->back->send(ldisc->backhandle, buf, len);\r
361 }\r
362 }\r
363 }\r