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