[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"

#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 && cfg.telnet_newline)
			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'):
		    if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
			back->special(TS_EOL);
		    else
			back->send("\r", 1);
		    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);
	}
    }
}
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
	11	#include "putty.h"
	12
0965bee0	13	#define ECHOING (cfg.localecho == LD_YES \|\| \
	14	(cfg.localecho == LD_BACKEND && \
	15	(back->ldisc(LD_ECHO) \|\| term_ldisc(LD_ECHO))))
	16	#define EDITING (cfg.localedit == LD_YES \|\| \
	17	(cfg.localedit == LD_BACKEND && \
	18	(back->ldisc(LD_EDIT) \|\| term_ldisc(LD_EDIT))))
5bc238bb	19
32874aea	20	static void c_write(char *buf, int len)
32874aea	21	{
fe50e814	22	from_backend(0, buf, len);
	23	}
	24
5bc238bb	25	static char *term_buf = NULL;
	26	static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
	27
32874aea	28	static int plen(unsigned char c)
32874aea	29	{
8f22582c	30	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf))
32874aea	31	return 1;
5bc238bb	32	else if (c < 128)
32874aea	33	return 2; /* ^x for some x */
5bc238bb	34	else
32874aea	35	return 4; /* <XY> for hex XY */
5bc238bb	36	}
5bc238bb	37
32874aea	38	static void pwrite(unsigned char c)
32874aea	39	{
8f22582c	40	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf)) {
32874aea	41	c_write(&c, 1);
5bc238bb	42	} else if (c < 128) {
32874aea	43	char cc[2];
	44	cc[1] = (c == 127 ? '?' : c + 0x40);
	45	cc[0] = '^';
	46	c_write(cc, 2);
5bc238bb	47	} else {
32874aea	48	char cc[5];
	49	sprintf(cc, "<%02X>", c);
	50	c_write(cc, 4);
5bc238bb	51	}
	52	}
	53
32874aea	54	static void bsb(int n)
32874aea	55	{
5bc238bb	56	while (n--)
	57	c_write("\010 \010", 3);
	58	}
	59
5d1d4279	60	#define CTRL(x) (x^'@')
a5f3e637	61	#define KCTRL(x) ((x^'@') \| 0x100)
5d1d4279	62
760e88b2	63	void ldisc_send(char *buf, int len, int interactive)
32874aea	64	{
a5f3e637	65	int keyflag = 0;
0965bee0	66	/*
	67	* Called with len=0 when the options change. We must inform
	68	* the front end in case it needs to know.
	69	*/
	70	if (len == 0) {
32874aea	71	void ldisc_update(int echo, int edit);
32874aea	72	ldisc_update(ECHOING, EDITING);
5bc238bb	73	}
0965bee0	74	/*
a5f3e637	75	* Less than zero means null terminated special string.
	76	*/
	77	if (len < 0) {
	78	len = strlen(buf);
	79	keyflag = KCTRL('@');
	80	}
	81	/*
0965bee0	82	* Either perform local editing, or just send characters.
	83	*/
	84	if (EDITING) {
32874aea	85	while (len--) {
a5f3e637	86	int c;
a5f3e637	87	c = *buf++ + keyflag;
760e88b2	88	if (!interactive && c == '\r')
760e88b2	89	c += KCTRL('@');
32874aea	90	switch (term_quotenext ? ' ' : c) {
	91	/*
	92	* ^h/^?: delete one char and output one BSB
	93	* ^w: delete, and output BSBs, to return to last
	94	* space/nonspace boundary
	95	* ^u: delete, and output BSBs, to return to BOL
	96	* ^c: Do a ^u then send a telnet IP
	97	* ^z: Do a ^u then send a telnet SUSP
	98	* ^\: Do a ^u then send a telnet ABORT
	99	* ^r: echo "^R\n" and redraw line
	100	* ^v: quote next char
	101	* ^d: if at BOL, end of file and close connection,
	102	* else send line and reset to BOL
	103	* ^m: send line-plus-\r\n and reset to BOL
	104	*/
a5f3e637	105	case KCTRL('H'):
a5f3e637	106	case KCTRL('?'): /* backspace/delete */
32874aea	107	if (term_buflen > 0) {
	108	if (ECHOING)
	109	bsb(plen(term_buf[term_buflen - 1]));
	110	term_buflen--;
	111	}
	112	break;
	113	case CTRL('W'): /* delete word */
	114	while (term_buflen > 0) {
	115	if (ECHOING)
	116	bsb(plen(term_buf[term_buflen - 1]));
	117	term_buflen--;
	118	if (term_buflen > 0 &&
	119	isspace(term_buf[term_buflen - 1]) &&
	120	!isspace(term_buf[term_buflen]))
	121	break;
	122	}
	123	break;
	124	case CTRL('U'): /* delete line */
	125	case CTRL('C'): /* Send IP */
	126	case CTRL('\\'): /* Quit */
	127	case CTRL('Z'): /* Suspend */
	128	while (term_buflen > 0) {
	129	if (ECHOING)
	130	bsb(plen(term_buf[term_buflen - 1]));
	131	term_buflen--;
	132	}
	133	back->special(TS_EL);
2a8a449c	134	/*
	135	* We don't send IP, SUSP or ABORT if the user has
	136	* configured telnet specials off! This breaks
	137	* talkers otherwise.
	138	*/
	139	if (!cfg.telnet_keyboard)
	140	goto default_case;
32874aea	141	if (c == CTRL('C'))
	142	back->special(TS_IP);
	143	if (c == CTRL('Z'))
	144	back->special(TS_SUSP);
	145	if (c == CTRL('\\'))
	146	back->special(TS_ABORT);
	147	break;
	148	case CTRL('R'): /* redraw line */
	149	if (ECHOING) {
	150	int i;
	151	c_write("^R\r\n", 4);
	152	for (i = 0; i < term_buflen; i++)
	153	pwrite(term_buf[i]);
	154	}
	155	break;
	156	case CTRL('V'): /* quote next char */
	157	term_quotenext = TRUE;
	158	break;
	159	case CTRL('D'): /* logout or send */
	160	if (term_buflen == 0) {
	161	back->special(TS_EOF);
	162	} else {
	163	back->send(term_buf, term_buflen);
	164	term_buflen = 0;
	165	}
	166	break;
a5f3e637	167	/*
	168	* This particularly hideous bit of code from RDB
	169	* allows ordinary ^M^J to do the same thing as
	170	* magic-^M when in Raw protocol. The line `case
	171	* KCTRL('M'):' is _inside_ the if block. Thus:
	172	*
	173	* - receiving regular ^M goes straight to the
	174	* default clause and inserts as a literal ^M.
	175	* - receiving regular ^J _not_ directly after a
	176	* literal ^M (or not in Raw protocol) fails the
	177	* if condition, leaps to the bottom of the if,
	178	* and falls through into the default clause
	179	* again.
	180	* - receiving regular ^J just after a literal ^M
	181	* in Raw protocol passes the if condition,
	182	* deletes the literal ^M, and falls through
	183	* into the magic-^M code
	184	* - receiving a magic-^M empties the line buffer,
	185	* signals end-of-line in one of the various
	186	* entertaining ways, and _doesn't_ fall out of
	187	* the bottom of the if and through to the
	188	* default clause because of the break.
	189	*/
	190	case CTRL('J'):
	191	if (cfg.protocol == PROT_RAW &&
	192	term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
	193	if (ECHOING)
	194	bsb(plen(term_buf[term_buflen - 1]));
	195	term_buflen--;
	196	/* FALLTHROUGH */
	197	case KCTRL('M'): /* send with newline */
	198	if (term_buflen > 0)
	199	back->send(term_buf, term_buflen);
	200	if (cfg.protocol == PROT_RAW)
	201	back->send("\r\n", 2);
eee63b77	202	else if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
a5f3e637	203	back->special(TS_EOL);
	204	else
	205	back->send("\r", 1);
	206	if (ECHOING)
	207	c_write("\r\n", 2);
	208	term_buflen = 0;
	209	break;
	210	}
	211	/* FALLTHROUGH */
32874aea	212	default: /* get to this label from ^V handler */
2a8a449c	213	default_case:
32874aea	214	if (term_buflen >= term_bufsiz) {
	215	term_bufsiz = term_buflen + 256;
	216	term_buf = saferealloc(term_buf, term_bufsiz);
	217	}
	218	term_buf[term_buflen++] = c;
	219	if (ECHOING)
a5f3e637	220	pwrite((unsigned char) c);
32874aea	221	term_quotenext = FALSE;
	222	break;
	223	}
	224	}
0965bee0	225	} else {
32874aea	226	if (term_buflen != 0) {
	227	back->send(term_buf, term_buflen);
	228	while (term_buflen > 0) {
	229	bsb(plen(term_buf[term_buflen - 1]));
	230	term_buflen--;
	231	}
	232	}
	233	if (len > 0) {
	234	if (ECHOING)
	235	c_write(buf, len);
a5f3e637	236	if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
	237	switch (buf[0]) {
	238	case CTRL('M'):
eee63b77	239	if (cfg.protocol == PROT_TELNET && cfg.telnet_newline)
	240	back->special(TS_EOL);
	241	else
	242	back->send("\r", 1);
a5f3e637	243	break;
	244	case CTRL('?'):
	245	case CTRL('H'):
	246	if (cfg.telnet_keyboard) {
	247	back->special(TS_EC);
	248	break;
	249	}
	250	case CTRL('C'):
	251	if (cfg.telnet_keyboard) {
	252	back->special(TS_IP);
	253	break;
	254	}
	255	case CTRL('Z'):
	256	if (cfg.telnet_keyboard) {
	257	back->special(TS_SUSP);
	258	break;
	259	}
	260
	261	default:
	262	back->send(buf, len);
	263	break;
	264	}
	265	} else
	266	back->send(buf, len);
32874aea	267	}
5d1d4279	268	}
5bc238bb	269	}