| blob | 7ed42a37ca39d3e89cc7f4f0465ebfb53bbce3b7 |
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 \r
11 #include "putty.h"\r
12 #include "terminal.h"\r
13 #include "ldisc.h"\r
14 \r
15 #define ECHOING (ldisc->localecho == FORCE_ON || \\r
16 (ldisc->localecho == AUTO && \\r
17 (ldisc->back->ldisc(ldisc->backhandle, LD_ECHO) || \\r
18 term_ldisc(ldisc->term, LD_ECHO))))\r
19 #define EDITING (ldisc->localedit == FORCE_ON || \\r
20 (ldisc->localedit == AUTO && \\r
21 (ldisc->back->ldisc(ldisc->backhandle, LD_EDIT) || \\r
22 term_ldisc(ldisc->term, LD_EDIT))))\r
23 \r
24 static void c_write(Ldisc ldisc, char *buf, int len)\r
25 {\r
26 from_backend(ldisc->frontend, 0, buf, len);\r
27 }\r
28 \r
29 static int plen(Ldisc ldisc, unsigned char c)\r
30 {\r
31 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term)))\r
32 return 1;\r
33 else if (c < 128)\r
34 return 2; /* ^x for some x */\r
35 else if (in_utf(ldisc->term) && c >= 0xC0)\r
36 return 1; /* UTF-8 introducer character\r
37 * (FIXME: combining / wide chars) */\r
38 else if (in_utf(ldisc->term) && c >= 0x80 && c < 0xC0)\r
39 return 0; /* UTF-8 followup character */\r
40 else\r
41 return 4; /* <XY> hex representation */\r
42 }\r
43 \r
44 static void pwrite(Ldisc ldisc, unsigned char c)\r
45 {\r
46 if ((c >= 32 && c <= 126) ||\r
47 (!in_utf(ldisc->term) && c >= 0xA0) ||\r
48 (in_utf(ldisc->term) && c >= 0x80)) {\r
49 c_write(ldisc, (char *)&c, 1);\r
50 } else if (c < 128) {\r
51 char cc[2];\r
52 cc[1] = (c == 127 ? '?' : c + 0x40);\r
53 cc[0] = '^';\r
54 c_write(ldisc, cc, 2);\r
55 } else {\r
56 char cc[5];\r
57 sprintf(cc, "<%02X>", c);\r
58 c_write(ldisc, cc, 4);\r
59 }\r
60 }\r
61 \r
62 static int char_start(Ldisc ldisc, unsigned char c)\r
63 {\r
64 if (in_utf(ldisc->term))\r
65 return (c < 0x80 || c >= 0xC0);\r
66 else\r
67 return 1;\r
68 }\r
69 \r
70 static void bsb(Ldisc ldisc, int n)\r
71 {\r
72 while (n--)\r
73 c_write(ldisc, "\010 \010", 3);\r
74 }\r
75 \r
76 #define CTRL(x) (x^'@')\r
77 #define KCTRL(x) ((x^'@') | 0x100)\r
78 \r
79 void *ldisc_create(Conf *conf, Terminal *term,\r
80 Backend *back, void *backhandle,\r
81 void *frontend)\r
82 {\r
83 Ldisc ldisc = snew(struct ldisc_tag);\r
84 \r
85 ldisc->buf = NULL;\r
86 ldisc->buflen = 0;\r
87 ldisc->bufsiz = 0;\r
88 ldisc->quotenext = 0;\r
89 \r
90 ldisc->back = back;\r
91 ldisc->backhandle = backhandle;\r
92 ldisc->term = term;\r
93 ldisc->frontend = frontend;\r
94 \r
95 ldisc_configure(ldisc, conf);\r
96 \r
97 /* Link ourselves into the backend and the terminal */\r
98 if (term)\r
99 term->ldisc = ldisc;\r
100 if (back)\r
101 back->provide_ldisc(backhandle, ldisc);\r
102 \r
103 return ldisc;\r
104 }\r
105 \r
106 void ldisc_configure(void *handle, Conf *conf)\r
107 {\r
108 Ldisc ldisc = (Ldisc) handle;\r
109 \r
110 ldisc->telnet_keyboard = conf_get_int(conf, CONF_telnet_keyboard);\r
111 ldisc->telnet_newline = conf_get_int(conf, CONF_telnet_newline);\r
112 ldisc->protocol = conf_get_int(conf, CONF_protocol);\r
113 ldisc->localecho = conf_get_int(conf, CONF_localecho);\r
114 ldisc->localedit = conf_get_int(conf, CONF_localedit);\r
115 }\r
116 \r
117 void ldisc_free(void *handle)\r
118 {\r
119 Ldisc ldisc = (Ldisc) handle;\r
120 \r
121 if (ldisc->term)\r
122 ldisc->term->ldisc = NULL;\r
123 if (ldisc->back)\r
124 ldisc->back->provide_ldisc(ldisc->backhandle, NULL);\r
125 if (ldisc->buf)\r
126 sfree(ldisc->buf);\r
127 sfree(ldisc);\r
128 }\r
129 \r
130 void ldisc_send(void *handle, char *buf, int len, int interactive)\r
131 {\r
132 Ldisc ldisc = (Ldisc) handle;\r
133 int keyflag = 0;\r
134 /*\r
135 * Called with len=0 when the options change. We must inform\r
136 * the front end in case it needs to know.\r
137 */\r
138 if (len == 0) {\r
139 ldisc_update(ldisc->frontend, ECHOING, EDITING);\r
140 return;\r
141 }\r
142 /*\r
143 * Notify the front end that something was pressed, in case\r
144 * it's depending on finding out (e.g. keypress termination for\r
145 * Close On Exit). \r
146 */\r
147 frontend_keypress(ldisc->frontend);\r
148 \r
149 /*\r
150 * Less than zero means null terminated special string.\r
151 */\r
152 if (len < 0) {\r
153 len = strlen(buf);\r
154 keyflag = KCTRL('@');\r
155 }\r
156 /*\r
157 * Either perform local editing, or just send characters.\r
158 */\r
159 if (EDITING) {\r
160 while (len--) {\r
161 int c;\r
162 c = (unsigned char)(*buf++) + keyflag;\r
163 if (!interactive && c == '\r')\r
164 c += KCTRL('@');\r
165 switch (ldisc->quotenext ? ' ' : c) {\r
166 /*\r
167 * ^h/^?: delete, and output BSBs, to return to\r
168 * last character boundary (in UTF-8 mode this may\r
169 * be more than one byte)\r
170 * ^w: delete, and output BSBs, to return to last\r
171 * space/nonspace boundary\r
172 * ^u: delete, and output BSBs, to return to BOL\r
173 * ^c: Do a ^u then send a telnet IP\r
174 * ^z: Do a ^u then send a telnet SUSP\r
175 * ^\: Do a ^u then send a telnet ABORT\r
176 * ^r: echo "^R\n" and redraw line\r
177 * ^v: quote next char\r
178 * ^d: if at BOL, end of file and close connection,\r
179 * else send line and reset to BOL\r
180 * ^m: send line-plus-\r\n and reset to BOL\r
181 */\r
182 case KCTRL('H'):\r
183 case KCTRL('?'): /* backspace/delete */\r
184 if (ldisc->buflen > 0) {\r
185 do {\r
186 if (ECHOING)\r
187 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
188 ldisc->buflen--;\r
189 } while (!char_start(ldisc, ldisc->buf[ldisc->buflen]));\r
190 }\r
191 break;\r
192 case CTRL('W'): /* delete word */\r
193 while (ldisc->buflen > 0) {\r
194 if (ECHOING)\r
195 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
196 ldisc->buflen--;\r
197 if (ldisc->buflen > 0 &&\r
198 isspace((unsigned char)ldisc->buf[ldisc->buflen-1]) &&\r
199 !isspace((unsigned char)ldisc->buf[ldisc->buflen]))\r
200 break;\r
201 }\r
202 break;\r
203 case CTRL('U'): /* delete line */\r
204 case CTRL('C'): /* Send IP */\r
205 case CTRL('\\'): /* Quit */\r
206 case CTRL('Z'): /* Suspend */\r
207 while (ldisc->buflen > 0) {\r
208 if (ECHOING)\r
209 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
210 ldisc->buflen--;\r
211 }\r
212 ldisc->back->special(ldisc->backhandle, TS_EL);\r
213 /*\r
214 * We don't send IP, SUSP or ABORT if the user has\r
215 * configured telnet specials off! This breaks\r
216 * talkers otherwise.\r
217 */\r
218 if (!ldisc->telnet_keyboard)\r
219 goto default_case;\r
220 if (c == CTRL('C'))\r
221 ldisc->back->special(ldisc->backhandle, TS_IP);\r
222 if (c == CTRL('Z'))\r
223 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
224 if (c == CTRL('\\'))\r
225 ldisc->back->special(ldisc->backhandle, TS_ABORT);\r
226 break;\r
227 case CTRL('R'): /* redraw line */\r
228 if (ECHOING) {\r
229 int i;\r
230 c_write(ldisc, "^R\r\n", 4);\r
231 for (i = 0; i < ldisc->buflen; i++)\r
232 pwrite(ldisc, ldisc->buf[i]);\r
233 }\r
234 break;\r
235 case CTRL('V'): /* quote next char */\r
236 ldisc->quotenext = TRUE;\r
237 break;\r
238 case CTRL('D'): /* logout or send */\r
239 if (ldisc->buflen == 0) {\r
240 ldisc->back->special(ldisc->backhandle, TS_EOF);\r
241 } else {\r
242 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
243 ldisc->buflen = 0;\r
244 }\r
245 break;\r
246 /*\r
247 * This particularly hideous bit of code from RDB\r
248 * allows ordinary ^M^J to do the same thing as\r
249 * magic-^M when in Raw protocol. The line `case\r
250 * KCTRL('M'):' is _inside_ the if block. Thus:\r
251 * \r
252 * - receiving regular ^M goes straight to the\r
253 * default clause and inserts as a literal ^M.\r
254 * - receiving regular ^J _not_ directly after a\r
255 * literal ^M (or not in Raw protocol) fails the\r
256 * if condition, leaps to the bottom of the if,\r
257 * and falls through into the default clause\r
258 * again.\r
259 * - receiving regular ^J just after a literal ^M\r
260 * in Raw protocol passes the if condition,\r
261 * deletes the literal ^M, and falls through\r
262 * into the magic-^M code\r
263 * - receiving a magic-^M empties the line buffer,\r
264 * signals end-of-line in one of the various\r
265 * entertaining ways, and _doesn't_ fall out of\r
266 * the bottom of the if and through to the\r
267 * default clause because of the break.\r
268 */\r
269 case CTRL('J'):\r
270 if (ldisc->protocol == PROT_RAW &&\r
271 ldisc->buflen > 0 && ldisc->buf[ldisc->buflen - 1] == '\r') {\r
272 if (ECHOING)\r
273 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
274 ldisc->buflen--;\r
275 /* FALLTHROUGH */\r
276 case KCTRL('M'): /* send with newline */\r
277 if (ldisc->buflen > 0)\r
278 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
279 if (ldisc->protocol == PROT_RAW)\r
280 ldisc->back->send(ldisc->backhandle, "\r\n", 2);\r
281 else if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
282 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
283 else\r
284 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
285 if (ECHOING)\r
286 c_write(ldisc, "\r\n", 2);\r
287 ldisc->buflen = 0;\r
288 break;\r
289 }\r
290 /* FALLTHROUGH */\r
291 default: /* get to this label from ^V handler */\r
292 default_case:\r
293 if (ldisc->buflen >= ldisc->bufsiz) {\r
294 ldisc->bufsiz = ldisc->buflen + 256;\r
295 ldisc->buf = sresize(ldisc->buf, ldisc->bufsiz, char);\r
296 }\r
297 ldisc->buf[ldisc->buflen++] = c;\r
298 if (ECHOING)\r
299 pwrite(ldisc, (unsigned char) c);\r
300 ldisc->quotenext = FALSE;\r
301 break;\r
302 }\r
303 }\r
304 } else {\r
305 if (ldisc->buflen != 0) {\r
306 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);\r
307 while (ldisc->buflen > 0) {\r
308 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));\r
309 ldisc->buflen--;\r
310 }\r
311 }\r
312 if (len > 0) {\r
313 if (ECHOING)\r
314 c_write(ldisc, buf, len);\r
315 if (keyflag && ldisc->protocol == PROT_TELNET && len == 1) {\r
316 switch (buf[0]) {\r
317 case CTRL('M'):\r
318 if (ldisc->protocol == PROT_TELNET && ldisc->telnet_newline)\r
319 ldisc->back->special(ldisc->backhandle, TS_EOL);\r
320 else\r
321 ldisc->back->send(ldisc->backhandle, "\r", 1);\r
322 break;\r
323 case CTRL('?'):\r
324 case CTRL('H'):\r
325 if (ldisc->telnet_keyboard) {\r
326 ldisc->back->special(ldisc->backhandle, TS_EC);\r
327 break;\r
328 }\r
329 case CTRL('C'):\r
330 if (ldisc->telnet_keyboard) {\r
331 ldisc->back->special(ldisc->backhandle, TS_IP);\r
332 break;\r
333 }\r
334 case CTRL('Z'):\r
335 if (ldisc->telnet_keyboard) {\r
336 ldisc->back->special(ldisc->backhandle, TS_SUSP);\r
337 break;\r
338 }\r
339 \r
340 default:\r
341 ldisc->back->send(ldisc->backhandle, buf, len);\r
342 break;\r
343 }\r
344 } else\r
345 ldisc->back->send(ldisc->backhandle, buf, len);\r
346 }\r
347 }\r
348 }\r