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, int interactive)
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 if (!interactive && c == '\r')
91 switch (term_quotenext ? ' ' : c) {
93 * ^h/^?: delete one char and output one BSB
94 * ^w: delete, and output BSBs, to return to last
95 * space/nonspace boundary
96 * ^u: delete, and output BSBs, to return to BOL
97 * ^c: Do a ^u then send a telnet IP
98 * ^z: Do a ^u then send a telnet SUSP
99 * ^\: Do a ^u then send a telnet ABORT
100 * ^r: echo "^R\n" and redraw line
101 * ^v: quote next char
102 * ^d: if at BOL, end of file and close connection,
103 * else send line and reset to BOL
104 * ^m: send line-plus-\r\n and reset to BOL
107 case KCTRL('?'): /* backspace/delete */
108 if (term_buflen > 0) {
110 bsb(plen(term_buf[term_buflen - 1]));
114 case CTRL('W'): /* delete word */
115 while (term_buflen > 0) {
117 bsb(plen(term_buf[term_buflen - 1]));
119 if (term_buflen > 0 &&
120 isspace(term_buf[term_buflen - 1]) &&
121 !isspace(term_buf[term_buflen]))
125 case CTRL('U'): /* delete line */
126 case CTRL('C'): /* Send IP */
127 case CTRL('\\'): /* Quit */
128 case CTRL('Z'): /* Suspend */
129 while (term_buflen > 0) {
131 bsb(plen(term_buf[term_buflen - 1]));
134 back->special(TS_EL);
136 back->special(TS_IP);
138 back->special(TS_SUSP);
140 back->special(TS_ABORT);
142 case CTRL('R'): /* redraw line */
145 c_write("^R\r\n", 4);
146 for (i = 0; i < term_buflen; i++)
150 case CTRL('V'): /* quote next char */
151 term_quotenext = TRUE;
153 case CTRL('D'): /* logout or send */
154 if (term_buflen == 0) {
155 back->special(TS_EOF);
157 back->send(term_buf, term_buflen);
162 * This particularly hideous bit of code from RDB
163 * allows ordinary ^M^J to do the same thing as
164 * magic-^M when in Raw protocol. The line `case
165 * KCTRL('M'):' is _inside_ the if block. Thus:
167 * - receiving regular ^M goes straight to the
168 * default clause and inserts as a literal ^M.
169 * - receiving regular ^J _not_ directly after a
170 * literal ^M (or not in Raw protocol) fails the
171 * if condition, leaps to the bottom of the if,
172 * and falls through into the default clause
174 * - receiving regular ^J just after a literal ^M
175 * in Raw protocol passes the if condition,
176 * deletes the literal ^M, and falls through
177 * into the magic-^M code
178 * - receiving a magic-^M empties the line buffer,
179 * signals end-of-line in one of the various
180 * entertaining ways, and _doesn't_ fall out of
181 * the bottom of the if and through to the
182 * default clause because of the break.
185 if (cfg.protocol == PROT_RAW &&
186 term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
188 bsb(plen(term_buf[term_buflen - 1]));
191 case KCTRL('M'): /* send with newline */
193 back->send(term_buf, term_buflen);
194 if (cfg.protocol == PROT_RAW)
195 back->send("\r\n", 2);
196 else if (cfg.protocol == PROT_TELNET)
197 back->special(TS_EOL);
206 default: /* get to this label from ^V handler */
207 if (term_buflen >= term_bufsiz) {
208 term_bufsiz = term_buflen + 256;
209 term_buf = saferealloc(term_buf, term_bufsiz);
211 term_buf[term_buflen++] = c;
213 pwrite((unsigned char) c);
214 term_quotenext = FALSE;
219 if (term_buflen != 0) {
220 back->send(term_buf, term_buflen);
221 while (term_buflen > 0) {
222 bsb(plen(term_buf[term_buflen - 1]));
229 if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
232 back->special(TS_EOL);
236 if (cfg.telnet_keyboard) {
237 back->special(TS_EC);
241 if (cfg.telnet_keyboard) {
242 back->special(TS_IP);
246 if (cfg.telnet_keyboard) {
247 back->special(TS_SUSP);
252 back->send(buf, len);
256 back->send(buf, len);