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.
14 #define ECHOING (cfg.localecho == LD_YES || \
15 (cfg.localecho == LD_BACKEND && \
16 (back->ldisc(backhandle, LD_ECHO) || \
17 term_ldisc(term, LD_ECHO))))
18 #define EDITING (cfg.localedit == LD_YES || \
19 (cfg.localedit == LD_BACKEND && \
20 (back->ldisc(backhandle, LD_EDIT) || \
21 term_ldisc(term, LD_EDIT))))
23 static void c_write(char *buf, int len)
25 from_backend(term, 0, buf, len);
28 static char *term_buf = NULL;
29 static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
31 static int plen(unsigned char c)
33 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(term)))
36 return 2; /* ^x for some x */
38 return 4; /* <XY> for hex XY */
41 static void pwrite(unsigned char c)
43 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(term))) {
47 cc[1] = (c == 127 ? '?' : c + 0x40);
52 sprintf(cc, "<%02X>", c);
57 static void bsb(int n)
60 c_write("\010 \010", 3);
63 #define CTRL(x) (x^'@')
64 #define KCTRL(x) ((x^'@') | 0x100)
66 void ldisc_send(char *buf, int len, int interactive)
70 * Called with len=0 when the options change. We must inform
71 * the front end in case it needs to know.
74 void ldisc_update(int echo, int edit);
75 ldisc_update(ECHOING, EDITING);
79 * Notify the front end that something was pressed, in case
80 * it's depending on finding out (e.g. keypress termination for
85 * Less than zero means null terminated special string.
92 * Either perform local editing, or just send characters.
98 if (!interactive && c == '\r')
100 switch (term_quotenext ? ' ' : c) {
102 * ^h/^?: delete one char and output one BSB
103 * ^w: delete, and output BSBs, to return to last
104 * space/nonspace boundary
105 * ^u: delete, and output BSBs, to return to BOL
106 * ^c: Do a ^u then send a telnet IP
107 * ^z: Do a ^u then send a telnet SUSP
108 * ^\: Do a ^u then send a telnet ABORT
109 * ^r: echo "^R\n" and redraw line
110 * ^v: quote next char
111 * ^d: if at BOL, end of file and close connection,
112 * else send line and reset to BOL
113 * ^m: send line-plus-\r\n and reset to BOL
116 case KCTRL('?'): /* backspace/delete */
117 if (term_buflen > 0) {
119 bsb(plen(term_buf[term_buflen - 1]));
123 case CTRL('W'): /* delete word */
124 while (term_buflen > 0) {
126 bsb(plen(term_buf[term_buflen - 1]));
128 if (term_buflen > 0 &&
129 isspace(term_buf[term_buflen - 1]) &&
130 !isspace(term_buf[term_buflen]))
134 case CTRL('U'): /* delete line */
135 case CTRL('C'): /* Send IP */
136 case CTRL('\\'): /* Quit */
137 case CTRL('Z'): /* Suspend */
138 while (term_buflen > 0) {
140 bsb(plen(term_buf[term_buflen - 1]));
143 back->special(backhandle, TS_EL);
145 * We don't send IP, SUSP or ABORT if the user has
146 * configured telnet specials off! This breaks
149 if (!cfg.telnet_keyboard)
152 back->special(backhandle, TS_IP);
154 back->special(backhandle, TS_SUSP);
156 back->special(backhandle, TS_ABORT);
158 case CTRL('R'): /* redraw line */
161 c_write("^R\r\n", 4);
162 for (i = 0; i < term_buflen; i++)
166 case CTRL('V'): /* quote next char */
167 term_quotenext = TRUE;
169 case CTRL('D'): /* logout or send */
170 if (term_buflen == 0) {
171 back->special(backhandle, TS_EOF);
173 back->send(backhandle, term_buf, term_buflen);
178 * This particularly hideous bit of code from RDB
179 * allows ordinary ^M^J to do the same thing as
180 * magic-^M when in Raw protocol. The line `case
181 * KCTRL('M'):' is _inside_ the if block. Thus:
183 * - receiving regular ^M goes straight to the
184 * default clause and inserts as a literal ^M.
185 * - receiving regular ^J _not_ directly after a
186 * literal ^M (or not in Raw protocol) fails the
187 * if condition, leaps to the bottom of the if,
188 * and falls through into the default clause
190 * - receiving regular ^J just after a literal ^M
191 * in Raw protocol passes the if condition,
192 * deletes the literal ^M, and falls through
193 * into the magic-^M code
194 * - receiving a magic-^M empties the line buffer,
195 * signals end-of-line in one of the various
196 * entertaining ways, and _doesn't_ fall out of
197 * the bottom of the if and through to the
198 * default clause because of the break.
201 if (cfg.protocol == PROT_RAW &&
202 term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
204 bsb(plen(term_buf[term_buflen - 1]));
207 case KCTRL('M'): /* send with newline */
209 back->send(backhandle, term_buf, term_buflen);
210 if (cfg.protocol == PROT_RAW)
211 back->send(backhandle, "\r\n", 2);
212 else if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
213 back->special(backhandle, TS_EOL);
215 back->send(backhandle, "\r", 1);
222 default: /* get to this label from ^V handler */
224 if (term_buflen >= term_bufsiz) {
225 term_bufsiz = term_buflen + 256;
226 term_buf = saferealloc(term_buf, term_bufsiz);
228 term_buf[term_buflen++] = c;
230 pwrite((unsigned char) c);
231 term_quotenext = FALSE;
236 if (term_buflen != 0) {
237 back->send(backhandle, term_buf, term_buflen);
238 while (term_buflen > 0) {
239 bsb(plen(term_buf[term_buflen - 1]));
246 if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
249 if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
250 back->special(backhandle, TS_EOL);
252 back->send(backhandle, "\r", 1);
256 if (cfg.telnet_keyboard) {
257 back->special(backhandle, TS_EC);
261 if (cfg.telnet_keyboard) {
262 back->special(backhandle, TS_IP);
266 if (cfg.telnet_keyboard) {
267 back->special(backhandle, TS_SUSP);
272 back->send(backhandle, buf, len);
276 back->send(backhandle, buf, len);