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.
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->term, 0, buf, len);
29 static int plen(Ldisc ldisc, unsigned char c)
31 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term)))
34 return 2; /* ^x for some x */
36 return 4; /* <XY> for hex XY */
39 static void pwrite(Ldisc ldisc, unsigned char c)
41 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term))) {
42 c_write(ldisc, (char *)&c, 1);
45 cc[1] = (c == 127 ? '?' : c + 0x40);
47 c_write(ldisc, cc, 2);
50 sprintf(cc, "<%02X>", c);
51 c_write(ldisc, cc, 4);
55 static void bsb(Ldisc ldisc, int n)
58 c_write(ldisc, "\010 \010", 3);
61 #define CTRL(x) (x^'@')
62 #define KCTRL(x) ((x^'@') | 0x100)
64 void *ldisc_create(Config *mycfg, Terminal *term,
65 Backend *back, void *backhandle,
68 Ldisc ldisc = smalloc(sizeof(*ldisc));
77 ldisc->backhandle = backhandle;
79 ldisc->frontend = frontend;
81 /* Link ourselves into the backend and the terminal */
85 back->provide_ldisc(backhandle, ldisc);
90 void ldisc_free(void *handle)
92 Ldisc ldisc = (Ldisc) handle;
95 ldisc->term->ldisc = NULL;
97 ldisc->back->provide_ldisc(ldisc->backhandle, NULL);
103 void ldisc_send(void *handle, char *buf, int len, int interactive)
105 Ldisc ldisc = (Ldisc) handle;
108 * Called with len=0 when the options change. We must inform
109 * the front end in case it needs to know.
112 ldisc_update(ldisc->frontend, ECHOING, EDITING);
116 * Notify the front end that something was pressed, in case
117 * it's depending on finding out (e.g. keypress termination for
120 frontend_keypress(ldisc->frontend);
123 * Less than zero means null terminated special string.
127 keyflag = KCTRL('@');
130 * Either perform local editing, or just send characters.
135 c = *buf++ + keyflag;
136 if (!interactive && c == '\r')
138 switch (ldisc->quotenext ? ' ' : c) {
140 * ^h/^?: delete one char and output one BSB
141 * ^w: delete, and output BSBs, to return to last
142 * space/nonspace boundary
143 * ^u: delete, and output BSBs, to return to BOL
144 * ^c: Do a ^u then send a telnet IP
145 * ^z: Do a ^u then send a telnet SUSP
146 * ^\: Do a ^u then send a telnet ABORT
147 * ^r: echo "^R\n" and redraw line
148 * ^v: quote next char
149 * ^d: if at BOL, end of file and close connection,
150 * else send line and reset to BOL
151 * ^m: send line-plus-\r\n and reset to BOL
154 case KCTRL('?'): /* backspace/delete */
155 if (ldisc->buflen > 0) {
157 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
161 case CTRL('W'): /* delete word */
162 while (ldisc->buflen > 0) {
164 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
166 if (ldisc->buflen > 0 &&
167 isspace(ldisc->buf[ldisc->buflen - 1]) &&
168 !isspace(ldisc->buf[ldisc->buflen]))
172 case CTRL('U'): /* delete line */
173 case CTRL('C'): /* Send IP */
174 case CTRL('\\'): /* Quit */
175 case CTRL('Z'): /* Suspend */
176 while (ldisc->buflen > 0) {
178 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
181 ldisc->back->special(ldisc->backhandle, TS_EL);
183 * We don't send IP, SUSP or ABORT if the user has
184 * configured telnet specials off! This breaks
187 if (!ldisc->cfg->telnet_keyboard)
190 ldisc->back->special(ldisc->backhandle, TS_IP);
192 ldisc->back->special(ldisc->backhandle, TS_SUSP);
194 ldisc->back->special(ldisc->backhandle, TS_ABORT);
196 case CTRL('R'): /* redraw line */
199 c_write(ldisc, "^R\r\n", 4);
200 for (i = 0; i < ldisc->buflen; i++)
201 pwrite(ldisc, ldisc->buf[i]);
204 case CTRL('V'): /* quote next char */
205 ldisc->quotenext = TRUE;
207 case CTRL('D'): /* logout or send */
208 if (ldisc->buflen == 0) {
209 ldisc->back->special(ldisc->backhandle, TS_EOF);
211 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
216 * This particularly hideous bit of code from RDB
217 * allows ordinary ^M^J to do the same thing as
218 * magic-^M when in Raw protocol. The line `case
219 * KCTRL('M'):' is _inside_ the if block. Thus:
221 * - receiving regular ^M goes straight to the
222 * default clause and inserts as a literal ^M.
223 * - receiving regular ^J _not_ directly after a
224 * literal ^M (or not in Raw protocol) fails the
225 * if condition, leaps to the bottom of the if,
226 * and falls through into the default clause
228 * - receiving regular ^J just after a literal ^M
229 * in Raw protocol passes the if condition,
230 * deletes the literal ^M, and falls through
231 * into the magic-^M code
232 * - receiving a magic-^M empties the line buffer,
233 * signals end-of-line in one of the various
234 * entertaining ways, and _doesn't_ fall out of
235 * the bottom of the if and through to the
236 * default clause because of the break.
239 if (ldisc->cfg->protocol == PROT_RAW &&
240 ldisc->buflen > 0 && ldisc->buf[ldisc->buflen - 1] == '\r') {
242 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
245 case KCTRL('M'): /* send with newline */
246 if (ldisc->buflen > 0)
247 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
248 if (ldisc->cfg->protocol == PROT_RAW)
249 ldisc->back->send(ldisc->backhandle, "\r\n", 2);
250 else if (ldisc->cfg->protocol == PROT_TELNET && ldisc->cfg->telnet_newline)
251 ldisc->back->special(ldisc->backhandle, TS_EOL);
253 ldisc->back->send(ldisc->backhandle, "\r", 1);
255 c_write(ldisc, "\r\n", 2);
260 default: /* get to this label from ^V handler */
262 if (ldisc->buflen >= ldisc->bufsiz) {
263 ldisc->bufsiz = ldisc->buflen + 256;
264 ldisc->buf = srealloc(ldisc->buf, ldisc->bufsiz);
266 ldisc->buf[ldisc->buflen++] = c;
268 pwrite(ldisc, (unsigned char) c);
269 ldisc->quotenext = FALSE;
274 if (ldisc->buflen != 0) {
275 ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen);
276 while (ldisc->buflen > 0) {
277 bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1]));
283 c_write(ldisc, buf, len);
284 if (keyflag && ldisc->cfg->protocol == PROT_TELNET && len == 1) {
287 if (ldisc->cfg->protocol == PROT_TELNET && ldisc->cfg->telnet_newline)
288 ldisc->back->special(ldisc->backhandle, TS_EOL);
290 ldisc->back->send(ldisc->backhandle, "\r", 1);
294 if (ldisc->cfg->telnet_keyboard) {
295 ldisc->back->special(ldisc->backhandle, TS_EC);
299 if (ldisc->cfg->telnet_keyboard) {
300 ldisc->back->special(ldisc->backhandle, TS_IP);
304 if (ldisc->cfg->telnet_keyboard) {
305 ldisc->back->special(ldisc->backhandle, TS_SUSP);
310 ldisc->back->send(ldisc->backhandle, buf, len);
314 ldisc->back->send(ldisc->backhandle, buf, len);