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(LD_ECHO) || term_ldisc(LD_ECHO))))
17 #define EDITING (cfg.localedit == LD_YES || \
18 (cfg.localedit == LD_BACKEND && \
19 (back->ldisc(LD_EDIT) || term_ldisc(LD_EDIT))))
21 static void c_write(char *buf, int len)
23 from_backend(0, buf, len);
26 static char *term_buf = NULL;
27 static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
29 static int plen(unsigned char c)
31 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf))
34 return 2; /* ^x for some x */
36 return 4; /* <XY> for hex XY */
39 static void pwrite(unsigned char c)
41 if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf)) {
45 cc[1] = (c == 127 ? '?' : c + 0x40);
50 sprintf(cc, "<%02X>", c);
55 static void bsb(int n)
58 c_write("\010 \010", 3);
61 #define CTRL(x) (x^'@')
62 #define KCTRL(x) ((x^'@') | 0x100)
64 void ldisc_send(char *buf, int len)
68 * Called with len=0 when the options change. We must inform
69 * the front end in case it needs to know.
72 void ldisc_update(int echo, int edit);
73 ldisc_update(ECHOING, EDITING);
76 * Less than zero means null terminated special string.
83 * Either perform local editing, or just send characters.
89 switch (term_quotenext ? ' ' : c) {
91 * ^h/^?: delete one char and output one BSB
92 * ^w: delete, and output BSBs, to return to last
93 * space/nonspace boundary
94 * ^u: delete, and output BSBs, to return to BOL
95 * ^c: Do a ^u then send a telnet IP
96 * ^z: Do a ^u then send a telnet SUSP
97 * ^\: Do a ^u then send a telnet ABORT
98 * ^r: echo "^R\n" and redraw line
100 * ^d: if at BOL, end of file and close connection,
101 * else send line and reset to BOL
102 * ^m: send line-plus-\r\n and reset to BOL
105 case KCTRL('?'): /* backspace/delete */
106 if (term_buflen > 0) {
108 bsb(plen(term_buf[term_buflen - 1]));
112 case CTRL('W'): /* delete word */
113 while (term_buflen > 0) {
115 bsb(plen(term_buf[term_buflen - 1]));
117 if (term_buflen > 0 &&
118 isspace(term_buf[term_buflen - 1]) &&
119 !isspace(term_buf[term_buflen]))
123 case CTRL('U'): /* delete line */
124 case CTRL('C'): /* Send IP */
125 case CTRL('\\'): /* Quit */
126 case CTRL('Z'): /* Suspend */
127 while (term_buflen > 0) {
129 bsb(plen(term_buf[term_buflen - 1]));
132 back->special(TS_EL);
134 back->special(TS_IP);
136 back->special(TS_SUSP);
138 back->special(TS_ABORT);
140 case CTRL('R'): /* redraw line */
143 c_write("^R\r\n", 4);
144 for (i = 0; i < term_buflen; i++)
148 case CTRL('V'): /* quote next char */
149 term_quotenext = TRUE;
151 case CTRL('D'): /* logout or send */
152 if (term_buflen == 0) {
153 back->special(TS_EOF);
155 back->send(term_buf, term_buflen);
160 * This particularly hideous bit of code from RDB
161 * allows ordinary ^M^J to do the same thing as
162 * magic-^M when in Raw protocol. The line `case
163 * KCTRL('M'):' is _inside_ the if block. Thus:
165 * - receiving regular ^M goes straight to the
166 * default clause and inserts as a literal ^M.
167 * - receiving regular ^J _not_ directly after a
168 * literal ^M (or not in Raw protocol) fails the
169 * if condition, leaps to the bottom of the if,
170 * and falls through into the default clause
172 * - receiving regular ^J just after a literal ^M
173 * in Raw protocol passes the if condition,
174 * deletes the literal ^M, and falls through
175 * into the magic-^M code
176 * - receiving a magic-^M empties the line buffer,
177 * signals end-of-line in one of the various
178 * entertaining ways, and _doesn't_ fall out of
179 * the bottom of the if and through to the
180 * default clause because of the break.
183 if (cfg.protocol == PROT_RAW &&
184 term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
186 bsb(plen(term_buf[term_buflen - 1]));
189 case KCTRL('M'): /* send with newline */
191 back->send(term_buf, term_buflen);
192 if (cfg.protocol == PROT_RAW)
193 back->send("\r\n", 2);
194 else if (cfg.protocol == PROT_TELNET)
195 back->special(TS_EOL);
204 default: /* get to this label from ^V handler */
205 if (term_buflen >= term_bufsiz) {
206 term_bufsiz = term_buflen + 256;
207 term_buf = saferealloc(term_buf, term_bufsiz);
209 term_buf[term_buflen++] = c;
211 pwrite((unsigned char) c);
212 term_quotenext = FALSE;
217 if (term_buflen != 0) {
218 back->send(term_buf, term_buflen);
219 while (term_buflen > 0) {
220 bsb(plen(term_buf[term_buflen - 1]));
227 if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
230 back->special(TS_EOL);
234 if (cfg.telnet_keyboard) {
235 back->special(TS_EC);
239 if (cfg.telnet_keyboard) {
240 back->special(TS_IP);
244 if (cfg.telnet_keyboard) {
245 back->special(TS_SUSP);
250 back->send(buf, len);
254 back->send(buf, len);