[u/mdw/putty] / ldisc.c

/*
 * 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"

#define ECHOING (cfg.localecho == LD_YES || \
                 (cfg.localecho == LD_BACKEND && \
                      (back->ldisc(backhandle, LD_ECHO) || \
			   term_ldisc(term, LD_ECHO))))
#define EDITING (cfg.localedit == LD_YES || \
                 (cfg.localedit == LD_BACKEND && \
                      (back->ldisc(backhandle, LD_EDIT) || \
			   term_ldisc(term, LD_EDIT))))

static void c_write(char *buf, int len)
{
    from_backend(term, 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(term)))
	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(term))) {
	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);
	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();
    /*
     * 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(backhandle, 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(backhandle, TS_IP);
		if (c == CTRL('Z'))
		    back->special(backhandle, TS_SUSP);
		if (c == CTRL('\\'))
		    back->special(backhandle, 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(backhandle, TS_EOF);
		} else {
		    back->send(backhandle, 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(backhandle, term_buf, term_buflen);
		    if (cfg.protocol == PROT_RAW)
			back->send(backhandle, "\r\n", 2);
		    else if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
			back->special(backhandle, TS_EOL);
		    else
			back->send(backhandle, "\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(backhandle, 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'):
		    if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
			back->special(backhandle, TS_EOL);
		    else
			back->send(backhandle, "\r", 1);
		    break;
		  case CTRL('?'):
		  case CTRL('H'):
		    if (cfg.telnet_keyboard) {
			back->special(backhandle, TS_EC);
			break;
		    }
		  case CTRL('C'):
		    if (cfg.telnet_keyboard) {
			back->special(backhandle, TS_IP);
			break;
		    }
		  case CTRL('Z'):
		    if (cfg.telnet_keyboard) {
			back->special(backhandle, TS_SUSP);
			break;
		    }

		  default:
		    back->send(backhandle, buf, len);
		    break;
		}
	    } else
		back->send(backhandle, buf, len);
	}
    }
}
Commit	Line	Data
0965bee0	1	/*
	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.
	6	*/
	7
5bc238bb	8	#include <stdio.h>
1d470ad2	9	#include <ctype.h>
5bc238bb	10
5bc238bb	11	#include "putty.h"
887035a5	12	#include "terminal.h"
5bc238bb	13
0965bee0	14	#define ECHOING (cfg.localecho == LD_YES \|\| \
0965bee0	15	(cfg.localecho == LD_BACKEND && \
51470298	16	(back->ldisc(backhandle, LD_ECHO) \|\| \
51470298	17	term_ldisc(term, LD_ECHO))))
0965bee0	18	#define EDITING (cfg.localedit == LD_YES \|\| \
0965bee0	19	(cfg.localedit == LD_BACKEND && \
51470298	20	(back->ldisc(backhandle, LD_EDIT) \|\| \
51470298	21	term_ldisc(term, LD_EDIT))))
5bc238bb	22
32874aea	23	static void c_write(char *buf, int len)
32874aea	24	{
887035a5	25	from_backend(term, 0, buf, len);
fe50e814	26	}
fe50e814	27
5bc238bb	28	static char *term_buf = NULL;
	29	static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
	30
32874aea	31	static int plen(unsigned char c)
32874aea	32	{
887035a5	33	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf(term)))
32874aea	34	return 1;
5bc238bb	35	else if (c < 128)
32874aea	36	return 2; /* ^x for some x */
5bc238bb	37	else
32874aea	38	return 4; /* <XY> for hex XY */
5bc238bb	39	}
5bc238bb	40
32874aea	41	static void pwrite(unsigned char c)
32874aea	42	{
887035a5	43	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf(term))) {
32874aea	44	c_write(&c, 1);
5bc238bb	45	} else if (c < 128) {
32874aea	46	char cc[2];
	47	cc[1] = (c == 127 ? '?' : c + 0x40);
	48	cc[0] = '^';
	49	c_write(cc, 2);
5bc238bb	50	} else {
32874aea	51	char cc[5];
	52	sprintf(cc, "<%02X>", c);
	53	c_write(cc, 4);
5bc238bb	54	}
	55	}
	56
32874aea	57	static void bsb(int n)
32874aea	58	{
5bc238bb	59	while (n--)
	60	c_write("\010 \010", 3);
	61	}
	62
5d1d4279	63	#define CTRL(x) (x^'@')
a5f3e637	64	#define KCTRL(x) ((x^'@') \| 0x100)
5d1d4279	65
760e88b2	66	void ldisc_send(char *buf, int len, int interactive)
32874aea	67	{
a5f3e637	68	int keyflag = 0;
0965bee0	69	/*
	70	* Called with len=0 when the options change. We must inform
	71	* the front end in case it needs to know.
	72	*/
	73	if (len == 0) {
32874aea	74	void ldisc_update(int echo, int edit);
32874aea	75	ldisc_update(ECHOING, EDITING);
887035a5	76	return;
5bc238bb	77	}
0965bee0	78	/*
ab2c86b9	79	* Notify the front end that something was pressed, in case
	80	* it's depending on finding out (e.g. keypress termination for
	81	* Close On Exit).
	82	*/
	83	frontend_keypress();
	84	/*
a5f3e637	85	* Less than zero means null terminated special string.
	86	*/
	87	if (len < 0) {
	88	len = strlen(buf);
	89	keyflag = KCTRL('@');
	90	}
	91	/*
0965bee0	92	* Either perform local editing, or just send characters.
	93	*/
	94	if (EDITING) {
32874aea	95	while (len--) {
a5f3e637	96	int c;
a5f3e637	97	c = *buf++ + keyflag;
760e88b2	98	if (!interactive && c == '\r')
760e88b2	99	c += KCTRL('@');
32874aea	100	switch (term_quotenext ? ' ' : c) {
	101	/*
	102	* ^h/^?: delete one char and output one BSB
	103	* ^w: delete, and output BSBs, to return to last
	104	* space/nonspace boundary
	105	* ^u: delete, and output BSBs, to return to BOL
	106	* ^c: Do a ^u then send a telnet IP
	107	* ^z: Do a ^u then send a telnet SUSP
	108	* ^\: Do a ^u then send a telnet ABORT
	109	* ^r: echo "^R\n" and redraw line
	110	* ^v: quote next char
	111	* ^d: if at BOL, end of file and close connection,
	112	* else send line and reset to BOL
	113	* ^m: send line-plus-\r\n and reset to BOL
	114	*/
a5f3e637	115	case KCTRL('H'):
a5f3e637	116	case KCTRL('?'): /* backspace/delete */
32874aea	117	if (term_buflen > 0) {
	118	if (ECHOING)
	119	bsb(plen(term_buf[term_buflen - 1]));
	120	term_buflen--;
	121	}
	122	break;
	123	case CTRL('W'): /* delete word */
	124	while (term_buflen > 0) {
	125	if (ECHOING)
	126	bsb(plen(term_buf[term_buflen - 1]));
	127	term_buflen--;
	128	if (term_buflen > 0 &&
	129	isspace(term_buf[term_buflen - 1]) &&
	130	!isspace(term_buf[term_buflen]))
	131	break;
	132	}
	133	break;
	134	case CTRL('U'): /* delete line */
	135	case CTRL('C'): /* Send IP */
	136	case CTRL('\\'): /* Quit */
	137	case CTRL('Z'): /* Suspend */
	138	while (term_buflen > 0) {
	139	if (ECHOING)
	140	bsb(plen(term_buf[term_buflen - 1]));
	141	term_buflen--;
	142	}
51470298	143	back->special(backhandle, TS_EL);
2a8a449c	144	/*
	145	* We don't send IP, SUSP or ABORT if the user has
	146	* configured telnet specials off! This breaks
	147	* talkers otherwise.
	148	*/
	149	if (!cfg.telnet_keyboard)
	150	goto default_case;
32874aea	151	if (c == CTRL('C'))
51470298	152	back->special(backhandle, TS_IP);
32874aea	153	if (c == CTRL('Z'))
51470298	154	back->special(backhandle, TS_SUSP);
32874aea	155	if (c == CTRL('\\'))
51470298	156	back->special(backhandle, TS_ABORT);
32874aea	157	break;
	158	case CTRL('R'): /* redraw line */
	159	if (ECHOING) {
	160	int i;
	161	c_write("^R\r\n", 4);
	162	for (i = 0; i < term_buflen; i++)
	163	pwrite(term_buf[i]);
	164	}
	165	break;
	166	case CTRL('V'): /* quote next char */
	167	term_quotenext = TRUE;
	168	break;
	169	case CTRL('D'): /* logout or send */
	170	if (term_buflen == 0) {
51470298	171	back->special(backhandle, TS_EOF);
32874aea	172	} else {
51470298	173	back->send(backhandle, term_buf, term_buflen);
32874aea	174	term_buflen = 0;
	175	}
	176	break;
a5f3e637	177	/*
	178	* This particularly hideous bit of code from RDB
	179	* allows ordinary ^M^J to do the same thing as
	180	* magic-^M when in Raw protocol. The line `case
	181	* KCTRL('M'):' is _inside_ the if block. Thus:
	182	*
	183	* - receiving regular ^M goes straight to the
	184	* default clause and inserts as a literal ^M.
	185	* - receiving regular ^J _not_ directly after a
	186	* literal ^M (or not in Raw protocol) fails the
	187	* if condition, leaps to the bottom of the if,
	188	* and falls through into the default clause
	189	* again.
	190	* - receiving regular ^J just after a literal ^M
	191	* in Raw protocol passes the if condition,
	192	* deletes the literal ^M, and falls through
	193	* into the magic-^M code
	194	* - receiving a magic-^M empties the line buffer,
	195	* signals end-of-line in one of the various
	196	* entertaining ways, and _doesn't_ fall out of
	197	* the bottom of the if and through to the
	198	* default clause because of the break.
	199	*/
	200	case CTRL('J'):
	201	if (cfg.protocol == PROT_RAW &&
	202	term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
	203	if (ECHOING)
	204	bsb(plen(term_buf[term_buflen - 1]));
	205	term_buflen--;
	206	/* FALLTHROUGH */
	207	case KCTRL('M'): /* send with newline */
	208	if (term_buflen > 0)
51470298	209	back->send(backhandle, term_buf, term_buflen);
a5f3e637	210	if (cfg.protocol == PROT_RAW)
51470298	211	back->send(backhandle, "\r\n", 2);
eee63b77	212	else if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
51470298	213	back->special(backhandle, TS_EOL);
a5f3e637	214	else
51470298	215	back->send(backhandle, "\r", 1);
a5f3e637	216	if (ECHOING)
	217	c_write("\r\n", 2);
	218	term_buflen = 0;
	219	break;
	220	}
	221	/* FALLTHROUGH */
32874aea	222	default: /* get to this label from ^V handler */
2a8a449c	223	default_case:
32874aea	224	if (term_buflen >= term_bufsiz) {
	225	term_bufsiz = term_buflen + 256;
	226	term_buf = saferealloc(term_buf, term_bufsiz);
	227	}
	228	term_buf[term_buflen++] = c;
	229	if (ECHOING)
a5f3e637	230	pwrite((unsigned char) c);
32874aea	231	term_quotenext = FALSE;
	232	break;
	233	}
	234	}
0965bee0	235	} else {
32874aea	236	if (term_buflen != 0) {
51470298	237	back->send(backhandle, term_buf, term_buflen);
32874aea	238	while (term_buflen > 0) {
	239	bsb(plen(term_buf[term_buflen - 1]));
	240	term_buflen--;
	241	}
	242	}
	243	if (len > 0) {
	244	if (ECHOING)
	245	c_write(buf, len);
a5f3e637	246	if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
	247	switch (buf[0]) {
	248	case CTRL('M'):
eee63b77	249	if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
51470298	250	back->special(backhandle, TS_EOL);
eee63b77	251	else
51470298	252	back->send(backhandle, "\r", 1);
a5f3e637	253	break;
	254	case CTRL('?'):
	255	case CTRL('H'):
	256	if (cfg.telnet_keyboard) {
51470298	257	back->special(backhandle, TS_EC);
a5f3e637	258	break;
	259	}
	260	case CTRL('C'):
	261	if (cfg.telnet_keyboard) {
51470298	262	back->special(backhandle, TS_IP);
a5f3e637	263	break;
	264	}
	265	case CTRL('Z'):
	266	if (cfg.telnet_keyboard) {
51470298	267	back->special(backhandle, TS_SUSP);
a5f3e637	268	break;
	269	}
	270
	271	default:
51470298	272	back->send(backhandle, buf, len);
a5f3e637	273	break;
	274	}
	275	} else
51470298	276	back->send(backhandle, buf, len);
32874aea	277	}
5d1d4279	278	}
5bc238bb	279	}