/* * ldisc.c: PuTTY line discipline. Sits between the input coming * from keypresses in the window, and the output channel leading to * the back end. Implements echo and/or local line editing, * depending on what's currently configured. */ #include <stdio.h> #include <ctype.h> #include "putty.h" #include "terminal.h" #include "ldisc.h" #define ECHOING (ldisc->cfg->localecho == FORCE_ON || \ (ldisc->cfg->localecho == AUTO && \ (ldisc->back->ldisc(ldisc->backhandle, LD_ECHO) || \ term_ldisc(ldisc->term, LD_ECHO)))) #define EDITING (ldisc->cfg->localedit == FORCE_ON || \ (ldisc->cfg->localedit == AUTO && \ (ldisc->back->ldisc(ldisc->backhandle, LD_EDIT) || \ term_ldisc(ldisc->term, LD_EDIT)))) static void c_write(Ldisc ldisc, char *buf, int len) { from_backend(ldisc->frontend, 0, buf, len); } static int plen(Ldisc ldisc, unsigned char c) { if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf(ldisc->term))) return 1; else if (c < 128) return 2; /* ^x for some x */ else if (in_utf(ldisc->term) && c >= 0xC0) return 1; /* UTF-8 introducer character * (FIXME: combining / wide chars) */ else if (in_utf(ldisc->term) && c >= 0x80 && c < 0xC0) return 0; /* UTF-8 followup character */ else return 4; /* <XY> hex representation */ } static void pwrite(Ldisc ldisc, unsigned char c) { if ((c >= 32 && c <= 126) || (!in_utf(ldisc->term) && c >= 0xA0) || (in_utf(ldisc->term) && c >= 0x80)) { c_write(ldisc, (char *)&c, 1); } else if (c < 128) { char cc[2]; cc[1] = (c == 127 ? '?' : c + 0x40); cc[0] = '^'; c_write(ldisc, cc, 2); } else { char cc[5]; sprintf(cc, "<%02X>", c); c_write(ldisc, cc, 4); } } static int char_start(Ldisc ldisc, unsigned char c) { if (in_utf(ldisc->term)) return (c < 0x80 || c >= 0xC0); else return 1; } static void bsb(Ldisc ldisc, int n) { while (n--) c_write(ldisc, "\010 \010", 3); } #define CTRL(x) (x^'@') #define KCTRL(x) ((x^'@') | 0x100) void *ldisc_create(Config *mycfg, Terminal *term, Backend *back, void *backhandle, void *frontend) { Ldisc ldisc = snew(struct ldisc_tag); ldisc->buf = NULL; ldisc->buflen = 0; ldisc->bufsiz = 0; ldisc->quotenext = 0; ldisc->cfg = mycfg; ldisc->back = back; ldisc->backhandle = backhandle; ldisc->term = term; ldisc->frontend = frontend; /* Link ourselves into the backend and the terminal */ if (term) term->ldisc = ldisc; if (back) back->provide_ldisc(backhandle, ldisc); return ldisc; } void ldisc_free(void *handle) { Ldisc ldisc = (Ldisc) handle; if (ldisc->term) ldisc->term->ldisc = NULL; if (ldisc->back) ldisc->back->provide_ldisc(ldisc->backhandle, NULL); if (ldisc->buf) sfree(ldisc->buf); sfree(ldisc); } void ldisc_send(void *handle, char *buf, int len, int interactive) { Ldisc ldisc = (Ldisc) handle; int keyflag = 0; /* * Called with len=0 when the options change. We must inform * the front end in case it needs to know. */ if (len == 0) { ldisc_update(ldisc->frontend, ECHOING, EDITING); return; } /* * Notify the front end that something was pressed, in case * it's depending on finding out (e.g. keypress termination for * Close On Exit). */ frontend_keypress(ldisc->frontend); /* * Less than zero means null terminated special string. */ if (len < 0) { len = strlen(buf); keyflag = KCTRL('@'); } /* * Either perform local editing, or just send characters. */ if (EDITING) { while (len--) { int c; c = (unsigned char)(*buf++) + keyflag; if (!interactive && c == '\r') c += KCTRL('@'); switch (ldisc->quotenext ? ' ' : c) { /* * ^h/^?: delete, and output BSBs, to return to * last character boundary (in UTF-8 mode this may * be more than one byte) * ^w: delete, and output BSBs, to return to last * space/nonspace boundary * ^u: delete, and output BSBs, to return to BOL * ^c: Do a ^u then send a telnet IP * ^z: Do a ^u then send a telnet SUSP * ^\: Do a ^u then send a telnet ABORT * ^r: echo "^R\n" and redraw line * ^v: quote next char * ^d: if at BOL, end of file and close connection, * else send line and reset to BOL * ^m: send line-plus-\r\n and reset to BOL */ case KCTRL('H'): case KCTRL('?'): /* backspace/delete */ if (ldisc->buflen > 0) { do { if (ECHOING) bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1])); ldisc->buflen--; } while (!char_start(ldisc, ldisc->buf[ldisc->buflen])); } break; case CTRL('W'): /* delete word */ while (ldisc->buflen > 0) { if (ECHOING) bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1])); ldisc->buflen--; if (ldisc->buflen > 0 && isspace((unsigned char)ldisc->buf[ldisc->buflen-1]) && !isspace((unsigned char)ldisc->buf[ldisc->buflen])) break; } break; case CTRL('U'): /* delete line */ case CTRL('C'): /* Send IP */ case CTRL('\\'): /* Quit */ case CTRL('Z'): /* Suspend */ while (ldisc->buflen > 0) { if (ECHOING) bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1])); ldisc->buflen--; } ldisc->back->special(ldisc->backhandle, TS_EL); /* * We don't send IP, SUSP or ABORT if the user has * configured telnet specials off! This breaks * talkers otherwise. */ if (!ldisc->cfg->telnet_keyboard) goto default_case; if (c == CTRL('C')) ldisc->back->special(ldisc->backhandle, TS_IP); if (c == CTRL('Z')) ldisc->back->special(ldisc->backhandle, TS_SUSP); if (c == CTRL('\\')) ldisc->back->special(ldisc->backhandle, TS_ABORT); break; case CTRL('R'): /* redraw line */ if (ECHOING) { int i; c_write(ldisc, "^R\r\n", 4); for (i = 0; i < ldisc->buflen; i++) pwrite(ldisc, ldisc->buf[i]); } break; case CTRL('V'): /* quote next char */ ldisc->quotenext = TRUE; break; case CTRL('D'): /* logout or send */ if (ldisc->buflen == 0) { ldisc->back->special(ldisc->backhandle, TS_EOF); } else { ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen); ldisc->buflen = 0; } break; /* * This particularly hideous bit of code from RDB * allows ordinary ^M^J to do the same thing as * magic-^M when in Raw protocol. The line `case * KCTRL('M'):' is _inside_ the if block. Thus: * * - receiving regular ^M goes straight to the * default clause and inserts as a literal ^M. * - receiving regular ^J _not_ directly after a * literal ^M (or not in Raw protocol) fails the * if condition, leaps to the bottom of the if, * and falls through into the default clause * again. * - receiving regular ^J just after a literal ^M * in Raw protocol passes the if condition, * deletes the literal ^M, and falls through * into the magic-^M code * - receiving a magic-^M empties the line buffer, * signals end-of-line in one of the various * entertaining ways, and _doesn't_ fall out of * the bottom of the if and through to the * default clause because of the break. */ case CTRL('J'): if (ldisc->cfg->protocol == PROT_RAW && ldisc->buflen > 0 && ldisc->buf[ldisc->buflen - 1] == '\r') { if (ECHOING) bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1])); ldisc->buflen--; /* FALLTHROUGH */ case KCTRL('M'): /* send with newline */ if (ldisc->buflen > 0) ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen); if (ldisc->cfg->protocol == PROT_RAW) ldisc->back->send(ldisc->backhandle, "\r\n", 2); else if (ldisc->cfg->protocol == PROT_TELNET && ldisc->cfg->telnet_newline) ldisc->back->special(ldisc->backhandle, TS_EOL); else ldisc->back->send(ldisc->backhandle, "\r", 1); if (ECHOING) c_write(ldisc, "\r\n", 2); ldisc->buflen = 0; break; } /* FALLTHROUGH */ default: /* get to this label from ^V handler */ default_case: if (ldisc->buflen >= ldisc->bufsiz) { ldisc->bufsiz = ldisc->buflen + 256; ldisc->buf = sresize(ldisc->buf, ldisc->bufsiz, char); } ldisc->buf[ldisc->buflen++] = c; if (ECHOING) pwrite(ldisc, (unsigned char) c); ldisc->quotenext = FALSE; break; } } } else { if (ldisc->buflen != 0) { ldisc->back->send(ldisc->backhandle, ldisc->buf, ldisc->buflen); while (ldisc->buflen > 0) { bsb(ldisc, plen(ldisc, ldisc->buf[ldisc->buflen - 1])); ldisc->buflen--; } } if (len > 0) { if (ECHOING) c_write(ldisc, buf, len); if (keyflag && ldisc->cfg->protocol == PROT_TELNET && len == 1) { switch (buf[0]) { case CTRL('M'): if (ldisc->cfg->protocol == PROT_TELNET && ldisc->cfg->telnet_newline) ldisc->back->special(ldisc->backhandle, TS_EOL); else ldisc->back->send(ldisc->backhandle, "\r", 1); break; case CTRL('?'): case CTRL('H'): if (ldisc->cfg->telnet_keyboard) { ldisc->back->special(ldisc->backhandle, TS_EC); break; } case CTRL('C'): if (ldisc->cfg->telnet_keyboard) { ldisc->back->special(ldisc->backhandle, TS_IP); break; } case CTRL('Z'): if (ldisc->cfg->telnet_keyboard) { ldisc->back->special(ldisc->backhandle, TS_SUSP); break; } default: ldisc->back->send(ldisc->backhandle, buf, len); break; } } else ldisc->back->send(ldisc->backhandle, buf, len); } } }