/*
* 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 <windows.h>
#include <stdio.h>
#include <ctype.h>
#include "putty.h"
#define ECHOING (cfg.localecho == LD_YES || \
(cfg.localecho == LD_BACKEND && \
(back->ldisc(LD_ECHO) || term_ldisc(LD_ECHO))))
#define EDITING (cfg.localedit == LD_YES || \
(cfg.localedit == LD_BACKEND && \
(back->ldisc(LD_EDIT) || term_ldisc(LD_EDIT))))
static void c_write(char *buf, int len)
{
from_backend(0, buf, len);
}
static char *term_buf = NULL;
static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
static int plen(unsigned char c)
{
if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf))
return 1;
else if (c < 128)
return 2; /* ^x for some x */
else
return 4; /* <XY> for hex XY */
}
static void pwrite(unsigned char c)
{
if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf)) {
c_write(&c, 1);
} else if (c < 128) {
char cc[2];
cc[1] = (c == 127 ? '?' : c + 0x40);
cc[0] = '^';
c_write(cc, 2);
} else {
char cc[5];
sprintf(cc, "<%02X>", c);
c_write(cc, 4);
}
}
static void bsb(int n)
{
while (n--)
c_write("\010 \010", 3);
}
#define CTRL(x) (x^'@')
#define KCTRL(x) ((x^'@') | 0x100)
void ldisc_send(char *buf, int len, int interactive)
{
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) {
void ldisc_update(int echo, int edit);
ldisc_update(ECHOING, EDITING);
}
/*
* 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 = *buf++ + keyflag;
if (!interactive && c == '\r')
c += KCTRL('@');
switch (term_quotenext ? ' ' : c) {
/*
* ^h/^?: delete one char and output one BSB
* ^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 (term_buflen > 0) {
if (ECHOING)
bsb(plen(term_buf[term_buflen - 1]));
term_buflen--;
}
break;
case CTRL('W'): /* delete word */
while (term_buflen > 0) {
if (ECHOING)
bsb(plen(term_buf[term_buflen - 1]));
term_buflen--;
if (term_buflen > 0 &&
isspace(term_buf[term_buflen - 1]) &&
!isspace(term_buf[term_buflen]))
break;
}
break;
case CTRL('U'): /* delete line */
case CTRL('C'): /* Send IP */
case CTRL('\\'): /* Quit */
case CTRL('Z'): /* Suspend */
while (term_buflen > 0) {
if (ECHOING)
bsb(plen(term_buf[term_buflen - 1]));
term_buflen--;
}
back->special(TS_EL);
/*
* We don't send IP, SUSP or ABORT if the user has
* configured telnet specials off! This breaks
* talkers otherwise.
*/
if (!cfg.telnet_keyboard)
goto default_case;
if (c == CTRL('C'))
back->special(TS_IP);
if (c == CTRL('Z'))
back->special(TS_SUSP);
if (c == CTRL('\\'))
back->special(TS_ABORT);
break;
case CTRL('R'): /* redraw line */
if (ECHOING) {
int i;
c_write("^R\r\n", 4);
for (i = 0; i < term_buflen; i++)
pwrite(term_buf[i]);
}
break;
case CTRL('V'): /* quote next char */
term_quotenext = TRUE;
break;
case CTRL('D'): /* logout or send */
if (term_buflen == 0) {
back->special(TS_EOF);
} else {
back->send(term_buf, term_buflen);
term_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 (cfg.protocol == PROT_RAW &&
term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
if (ECHOING)
bsb(plen(term_buf[term_buflen - 1]));
term_buflen--;
/* FALLTHROUGH */
case KCTRL('M'): /* send with newline */
if (term_buflen > 0)
back->send(term_buf, term_buflen);
if (cfg.protocol == PROT_RAW)
back->send("\r\n", 2);
else if (cfg.protocol == PROT_TELNET)
back->special(TS_EOL);
else
back->send("\r", 1);
if (ECHOING)
c_write("\r\n", 2);
term_buflen = 0;
break;
}
/* FALLTHROUGH */
default: /* get to this label from ^V handler */
default_case:
if (term_buflen >= term_bufsiz) {
term_bufsiz = term_buflen + 256;
term_buf = saferealloc(term_buf, term_bufsiz);
}
term_buf[term_buflen++] = c;
if (ECHOING)
pwrite((unsigned char) c);
term_quotenext = FALSE;
break;
}
}
} else {
if (term_buflen != 0) {
back->send(term_buf, term_buflen);
while (term_buflen > 0) {
bsb(plen(term_buf[term_buflen - 1]));
term_buflen--;
}
}
if (len > 0) {
if (ECHOING)
c_write(buf, len);
if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
switch (buf[0]) {
case CTRL('M'):
back->special(TS_EOL);
break;
case CTRL('?'):
case CTRL('H'):
if (cfg.telnet_keyboard) {
back->special(TS_EC);
break;
}
case CTRL('C'):
if (cfg.telnet_keyboard) {
back->special(TS_IP);
break;
}
case CTRL('Z'):
if (cfg.telnet_keyboard) {
back->special(TS_SUSP);
break;
}
default:
back->send(buf, len);
break;
}
} else
back->send(buf, len);
}
}
}