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[puttycyg-ng.git] / ldisc.c
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1 /*
2 * ldisc.c: PuTTY line discipline. Sits between the input coming
3 * from keypresses in the window, and the output channel leading to
4 * the back end. Implements echo and/or local line editing,
5 * depending on what's currently configured.
6 */
8 #include <stdio.h>
9 #include <ctype.h>
11 #include "putty.h"
12 #include "terminal.h"
13 #include "ldisc.h"
15 #define ECHOING (ldisc->cfg->localecho == FORCE_ON || \
16 (ldisc->cfg->localecho == AUTO && \
17 (ldisc->back->ldisc(ldisc->backhandle, LD_ECHO) || \
18 term_ldisc(ldisc->term, LD_ECHO))))
19 #define EDITING (ldisc->cfg->localedit == FORCE_ON || \
20 (ldisc->cfg->localedit == AUTO && \
21 (ldisc->back->ldisc(ldisc->backhandle, LD_EDIT) || \
22 term_ldisc(ldisc->term, LD_EDIT))))
24 static void c_write(Ldisc ldisc, char *buf, int len)
26 from_backend(ldisc->frontend, 0, buf, len);
29 static int plen(Ldisc ldisc, unsigned char c)
31 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term)))
32 return 1;
33 else if (c < 128)
34 return 2; /* ^x for some x */
35 else if (in_utf(ldisc->term) && c >= 0xC0)
36 return 1; /* UTF-8 introducer character
37 * (FIXME: combining / wide chars) */
38 else if (in_utf(ldisc->term) && c >= 0x80 && c < 0xC0)
39 return 0; /* UTF-8 followup character */
40 else
41 return 4; /* <XY> hex representation */
44 static void pwrite(Ldisc ldisc, unsigned char c)
46 if ((c >= 32 && c <= 126) ||
47 (!in_utf(ldisc->term) && c >= 0xA0) ||
48 (in_utf(ldisc->term) && c >= 0x80)) {
49 c_write(ldisc, (char *)&c, 1);
50 } else if (c < 128) {
51 char cc[2];
52 cc[1] = (c == 127 ? '?' : c + 0x40);
53 cc[0] = '^';
54 c_write(ldisc, cc, 2);
55 } else {
56 char cc[5];
57 sprintf(cc, "<%02X>", c);
58 c_write(ldisc, cc, 4);
62 static int char_start(Ldisc ldisc, unsigned char c)
64 if (in_utf(ldisc->term))
65 return (c < 0x80 || c >= 0xC0);
66 else
67 return 1;
70 static void bsb(Ldisc ldisc, int n)
72 while (n--)
73 c_write(ldisc, "\010 \010", 3);
76 #define CTRL(x) (x^'@')
77 #define KCTRL(x) ((x^'@') | 0x100)
79 void *ldisc_create(Config *mycfg, Terminal *term,
80 Backend *back, void *backhandle,
81 void *frontend)
83 Ldisc ldisc = snew(struct ldisc_tag);
85 ldisc->buf = NULL;
86 ldisc->buflen = 0;
87 ldisc->bufsiz = 0;
88 ldisc->quotenext = 0;
90 ldisc->cfg = mycfg;
91 ldisc->back = back;
92 ldisc->backhandle = backhandle;
93 ldisc->term = term;
94 ldisc->frontend = frontend;
96 /* Link ourselves into the backend and the terminal */
97 if (term)
98 term->ldisc = ldisc;
99 if (back)
100 back->provide_ldisc(backhandle, ldisc);
102 return ldisc;
105 void ldisc_free(void *handle)
107 Ldisc ldisc = (Ldisc) handle;
109 if (ldisc->term)
110 ldisc->term->ldisc = NULL;
111 if (ldisc->back)
112 ldisc->back->provide_ldisc(ldisc->backhandle, NULL);
113 if (ldisc->buf)
114 sfree(ldisc->buf);
115 sfree(ldisc);
118 void ldisc_send(void *handle, char *buf, int len, int interactive)
120 Ldisc ldisc = (Ldisc) handle;
121 int keyflag = 0;
123 * Called with len=0 when the options change. We must inform
124 * the front end in case it needs to know.
126 if (len == 0) {
127 ldisc_update(ldisc->frontend, ECHOING, EDITING);
128 return;
131 * Notify the front end that something was pressed, in case
132 * it's depending on finding out (e.g. keypress termination for
133 * Close On Exit).
135 frontend_keypress(ldisc->frontend);
138 * Less than zero means null terminated special string.
140 if (len < 0) {
141 len = strlen(buf);
142 keyflag = KCTRL('@');
145 * Either perform local editing, or just send characters.
147 if (EDITING) {
148 while (len--) {
149 int c;
150 c = *buf++ + keyflag;
151 if (!interactive && c == '\r')
152 c += KCTRL('@');
153 switch (ldisc->quotenext ? ' ' : c) {
155 * ^h/^?: delete, and output BSBs, to return to
156 * last character boundary (in UTF-8 mode this may
157 * be more than one byte)
158 * ^w: delete, and output BSBs, to return to last
159 * space/nonspace boundary
160 * ^u: delete, and output BSBs, to return to BOL
161 * ^c: Do a ^u then send a telnet IP
162 * ^z: Do a ^u then send a telnet SUSP
163 * ^\: Do a ^u then send a telnet ABORT
164 * ^r: echo "^R\n" and redraw line
165 * ^v: quote next char
166 * ^d: if at BOL, end of file and close connection,
167 * else send line and reset to BOL
168 * ^m: send line-plus-\r\n and reset to BOL
170 case KCTRL('H'):
171 case KCTRL('?'): /* backspace/delete */
172 if (ldisc->buflen > 0) {
173 do {
174 if (ECHOING)
175 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
176 ldisc->buflen--;
177 } while (!char_start(ldisc, ldisc->buf[ldisc->buflen]));
179 break;
180 case CTRL('W'): /* delete word */
181 while (ldisc->buflen > 0) {
182 if (ECHOING)
183 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
184 ldisc->buflen--;
185 if (ldisc->buflen > 0 &&
186 isspace((unsigned char)ldisc->buf[ldisc->buflen-1]) &&
187 !isspace((unsigned char)ldisc->buf[ldisc->buflen]))
188 break;
190 break;
191 case CTRL('U'): /* delete line */
192 case CTRL('C'): /* Send IP */
193 case CTRL('\\'): /* Quit */
194 case CTRL('Z'): /* Suspend */
195 while (ldisc->buflen > 0) {
196 if (ECHOING)
197 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
198 ldisc->buflen--;
200 ldisc->back->special(ldisc->backhandle, TS_EL);
202 * We don't send IP, SUSP or ABORT if the user has
203 * configured telnet specials off! This breaks
204 * talkers otherwise.
206 if (!ldisc->cfg->telnet_keyboard)
207 goto default_case;
208 if (c == CTRL('C'))
209 ldisc->back->special(ldisc->backhandle, TS_IP);
210 if (c == CTRL('Z'))
211 ldisc->back->special(ldisc->backhandle, TS_SUSP);
212 if (c == CTRL('\\'))
213 ldisc->back->special(ldisc->backhandle, TS_ABORT);
214 break;
215 case CTRL('R'): /* redraw line */
216 if (ECHOING) {
217 int i;
218 c_write(ldisc, "^R\r\n", 4);
219 for (i = 0; i < ldisc->buflen; i++)
220 pwrite(ldisc, ldisc->buf[i]);
222 break;
223 case CTRL('V'): /* quote next char */
224 ldisc->quotenext = TRUE;
225 break;
226 case CTRL('D'): /* logout or send */
227 if (ldisc->buflen == 0) {
228 ldisc->back->special(ldisc->backhandle, TS_EOF);
229 } else {
230 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
231 ldisc->buflen = 0;
233 break;
235 * This particularly hideous bit of code from RDB
236 * allows ordinary ^M^J to do the same thing as
237 * magic-^M when in Raw protocol. The line `case
238 * KCTRL('M'):' is _inside_ the if block. Thus:
240 * - receiving regular ^M goes straight to the
241 * default clause and inserts as a literal ^M.
242 * - receiving regular ^J _not_ directly after a
243 * literal ^M (or not in Raw protocol) fails the
244 * if condition, leaps to the bottom of the if,
245 * and falls through into the default clause
246 * again.
247 * - receiving regular ^J just after a literal ^M
248 * in Raw protocol passes the if condition,
249 * deletes the literal ^M, and falls through
250 * into the magic-^M code
251 * - receiving a magic-^M empties the line buffer,
252 * signals end-of-line in one of the various
253 * entertaining ways, and _doesn't_ fall out of
254 * the bottom of the if and through to the
255 * default clause because of the break.
257 case CTRL('J'):
259 if (ECHOING)
260 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
261 ldisc->buflen--;
262 /* FALLTHROUGH */
263 case KCTRL('M'): /* send with newline */
264 if (ldisc->buflen > 0)
265 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
266 else
267 ldisc->back->send(ldisc->backhandle, "\r", 1);
268 if (ECHOING)
269 c_write(ldisc, "\r\n", 2);
270 ldisc->buflen = 0;
271 break;
273 /* FALLTHROUGH */
274 default: /* get to this label from ^V handler */
275 default_case:
276 if (ldisc->buflen >= ldisc->bufsiz) {
277 ldisc->bufsiz = ldisc->buflen + 256;
278 ldisc->buf = sresize(ldisc->buf, ldisc->bufsiz, char);
280 ldisc->buf[ldisc->buflen++] = c;
281 if (ECHOING)
282 pwrite(ldisc, (unsigned char) c);
283 ldisc->quotenext = FALSE;
284 break;
287 } else {
288 if (ldisc->buflen != 0) {
289 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
290 while (ldisc->buflen > 0) {
291 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
292 ldisc->buflen--;
295 if (len > 0) {
296 if (ECHOING)
297 c_write(ldisc, buf, len);
298 ldisc->back->send(ldisc->backhandle, buf, len);