[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 <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 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;
	    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);
		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 */
		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);
	}
    }
}
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 <windows.h>
5bc238bb	9	#include <stdio.h>
1d470ad2	10	#include <ctype.h>
5bc238bb	11
	12	#include "putty.h"
	13
0965bee0	14	#define ECHOING (cfg.localecho == LD_YES \|\| \
	15	(cfg.localecho == LD_BACKEND && \
	16	(back->ldisc(LD_ECHO) \|\| term_ldisc(LD_ECHO))))
	17	#define EDITING (cfg.localedit == LD_YES \|\| \
	18	(cfg.localedit == LD_BACKEND && \
	19	(back->ldisc(LD_EDIT) \|\| term_ldisc(LD_EDIT))))
5bc238bb	20
32874aea	21	static void c_write(char *buf, int len)
32874aea	22	{
fe50e814	23	from_backend(0, buf, len);
	24	}
	25
5bc238bb	26	static char *term_buf = NULL;
	27	static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0;
	28
32874aea	29	static int plen(unsigned char c)
32874aea	30	{
8f22582c	31	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf))
32874aea	32	return 1;
5bc238bb	33	else if (c < 128)
32874aea	34	return 2; /* ^x for some x */
5bc238bb	35	else
32874aea	36	return 4; /* <XY> for hex XY */
5bc238bb	37	}
5bc238bb	38
32874aea	39	static void pwrite(unsigned char c)
32874aea	40	{
8f22582c	41	if ((c >= 32 && c <= 126) \|\| (c >= 160 && !in_utf)) {
32874aea	42	c_write(&c, 1);
5bc238bb	43	} else if (c < 128) {
32874aea	44	char cc[2];
	45	cc[1] = (c == 127 ? '?' : c + 0x40);
	46	cc[0] = '^';
	47	c_write(cc, 2);
5bc238bb	48	} else {
32874aea	49	char cc[5];
	50	sprintf(cc, "<%02X>", c);
	51	c_write(cc, 4);
5bc238bb	52	}
	53	}
	54
32874aea	55	static void bsb(int n)
32874aea	56	{
5bc238bb	57	while (n--)
	58	c_write("\010 \010", 3);
	59	}
	60
5d1d4279	61	#define CTRL(x) (x^'@')
a5f3e637	62	#define KCTRL(x) ((x^'@') \| 0x100)
5d1d4279	63
32874aea	64	void ldisc_send(char *buf, int len)
32874aea	65	{
a5f3e637	66	int keyflag = 0;
0965bee0	67	/*
	68	* Called with len=0 when the options change. We must inform
	69	* the front end in case it needs to know.
	70	*/
	71	if (len == 0) {
32874aea	72	void ldisc_update(int echo, int edit);
32874aea	73	ldisc_update(ECHOING, EDITING);
5bc238bb	74	}
0965bee0	75	/*
a5f3e637	76	* Less than zero means null terminated special string.
	77	*/
	78	if (len < 0) {
	79	len = strlen(buf);
	80	keyflag = KCTRL('@');
	81	}
	82	/*
0965bee0	83	* Either perform local editing, or just send characters.
	84	*/
	85	if (EDITING) {
32874aea	86	while (len--) {
a5f3e637	87	int c;
a5f3e637	88	c = *buf++ + keyflag;
32874aea	89	switch (term_quotenext ? ' ' : c) {
	90	/*
	91	* ^h/^?: delete one char and output one BSB
	92	* ^w: delete, and output BSBs, to return to last
	93	* space/nonspace boundary
	94	* ^u: delete, and output BSBs, to return to BOL
	95	* ^c: Do a ^u then send a telnet IP
	96	* ^z: Do a ^u then send a telnet SUSP
	97	* ^\: Do a ^u then send a telnet ABORT
	98	* ^r: echo "^R\n" and redraw line
	99	* ^v: quote next char
	100	* ^d: if at BOL, end of file and close connection,
	101	* else send line and reset to BOL
	102	* ^m: send line-plus-\r\n and reset to BOL
	103	*/
a5f3e637	104	case KCTRL('H'):
a5f3e637	105	case KCTRL('?'): /* backspace/delete */
32874aea	106	if (term_buflen > 0) {
	107	if (ECHOING)
	108	bsb(plen(term_buf[term_buflen - 1]));
	109	term_buflen--;
	110	}
	111	break;
	112	case CTRL('W'): /* delete word */
	113	while (term_buflen > 0) {
	114	if (ECHOING)
	115	bsb(plen(term_buf[term_buflen - 1]));
	116	term_buflen--;
	117	if (term_buflen > 0 &&
	118	isspace(term_buf[term_buflen - 1]) &&
	119	!isspace(term_buf[term_buflen]))
	120	break;
	121	}
	122	break;
	123	case CTRL('U'): /* delete line */
	124	case CTRL('C'): /* Send IP */
	125	case CTRL('\\'): /* Quit */
	126	case CTRL('Z'): /* Suspend */
	127	while (term_buflen > 0) {
	128	if (ECHOING)
	129	bsb(plen(term_buf[term_buflen - 1]));
	130	term_buflen--;
	131	}
	132	back->special(TS_EL);
	133	if (c == CTRL('C'))
	134	back->special(TS_IP);
	135	if (c == CTRL('Z'))
	136	back->special(TS_SUSP);
	137	if (c == CTRL('\\'))
	138	back->special(TS_ABORT);
	139	break;
	140	case CTRL('R'): /* redraw line */
	141	if (ECHOING) {
	142	int i;
	143	c_write("^R\r\n", 4);
	144	for (i = 0; i < term_buflen; i++)
	145	pwrite(term_buf[i]);
	146	}
	147	break;
	148	case CTRL('V'): /* quote next char */
	149	term_quotenext = TRUE;
	150	break;
	151	case CTRL('D'): /* logout or send */
	152	if (term_buflen == 0) {
	153	back->special(TS_EOF);
	154	} else {
	155	back->send(term_buf, term_buflen);
	156	term_buflen = 0;
	157	}
	158	break;
a5f3e637	159	/*
	160	* This particularly hideous bit of code from RDB
	161	* allows ordinary ^M^J to do the same thing as
	162	* magic-^M when in Raw protocol. The line `case
	163	* KCTRL('M'):' is _inside_ the if block. Thus:
	164	*
	165	* - receiving regular ^M goes straight to the
	166	* default clause and inserts as a literal ^M.
	167	* - receiving regular ^J _not_ directly after a
	168	* literal ^M (or not in Raw protocol) fails the
	169	* if condition, leaps to the bottom of the if,
	170	* and falls through into the default clause
	171	* again.
	172	* - receiving regular ^J just after a literal ^M
	173	* in Raw protocol passes the if condition,
	174	* deletes the literal ^M, and falls through
	175	* into the magic-^M code
	176	* - receiving a magic-^M empties the line buffer,
	177	* signals end-of-line in one of the various
	178	* entertaining ways, and _doesn't_ fall out of
	179	* the bottom of the if and through to the
	180	* default clause because of the break.
	181	*/
	182	case CTRL('J'):
	183	if (cfg.protocol == PROT_RAW &&
	184	term_buflen > 0 && term_buf[term_buflen - 1] == '\r') {
	185	if (ECHOING)
	186	bsb(plen(term_buf[term_buflen - 1]));
	187	term_buflen--;
	188	/* FALLTHROUGH */
	189	case KCTRL('M'): /* send with newline */
	190	if (term_buflen > 0)
	191	back->send(term_buf, term_buflen);
	192	if (cfg.protocol == PROT_RAW)
	193	back->send("\r\n", 2);
	194	else if (cfg.protocol == PROT_TELNET)
	195	back->special(TS_EOL);
	196	else
	197	back->send("\r", 1);
	198	if (ECHOING)
	199	c_write("\r\n", 2);
	200	term_buflen = 0;
	201	break;
	202	}
	203	/* FALLTHROUGH */
32874aea	204	default: /* get to this label from ^V handler */
	205	if (term_buflen >= term_bufsiz) {
	206	term_bufsiz = term_buflen + 256;
	207	term_buf = saferealloc(term_buf, term_bufsiz);
	208	}
	209	term_buf[term_buflen++] = c;
	210	if (ECHOING)
a5f3e637	211	pwrite((unsigned char) c);
32874aea	212	term_quotenext = FALSE;
	213	break;
	214	}
	215	}
0965bee0	216	} else {
32874aea	217	if (term_buflen != 0) {
	218	back->send(term_buf, term_buflen);
	219	while (term_buflen > 0) {
	220	bsb(plen(term_buf[term_buflen - 1]));
	221	term_buflen--;
	222	}
	223	}
	224	if (len > 0) {
	225	if (ECHOING)
	226	c_write(buf, len);
a5f3e637	227	if (keyflag && cfg.protocol == PROT_TELNET && len == 1) {
	228	switch (buf[0]) {
	229	case CTRL('M'):
	230	back->special(TS_EOL);
	231	break;
	232	case CTRL('?'):
	233	case CTRL('H'):
	234	if (cfg.telnet_keyboard) {
	235	back->special(TS_EC);
	236	break;
	237	}
	238	case CTRL('C'):
	239	if (cfg.telnet_keyboard) {
	240	back->special(TS_IP);
	241	break;
	242	}
	243	case CTRL('Z'):
	244	if (cfg.telnet_keyboard) {
	245	back->special(TS_SUSP);
	246	break;
	247	}
	248
	249	default:
	250	back->send(buf, len);
	251	break;
	252	}
	253	} else
	254	back->send(buf, len);
32874aea	255	}
5d1d4279	256	}
5bc238bb	257	}