/* $KAME: advcap.c,v 1.11 2003/05/19 09:46:50 keiichi Exp $ */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1983 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* remcap - routines for dealing with the remote host data base
*
* derived from termcap
*/
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include "pathnames.h"
#ifndef BUFSIZ
#define BUFSIZ 1024
#endif
#define MAXHOP 32 /* max number of tc= indirections */
#define tgetent agetent
#define tnchktc anchktc
#define tnamatch anamatch
#define tgetnum agetnum
#define tgetflag agetflag
#define tgetstr agetstr
#if 0
#define V_TERMCAP "REMOTE"
#define V_TERM "HOST"
#endif
/*
* termcap - routines for dealing with the terminal capability data base
*
* BUG: Should use a "last" pointer in tbuf, so that searching
* for capabilities alphabetically would not be a n**2/2
* process when large numbers of capabilities are given.
* Note: If we add a last pointer now we will screw up the
* tc capability. We really should compile termcap.
*
* Essentially all the work here is scanning and decoding escapes
* in string capabilities. We don't use stdio because the editor
* doesn't, and because living w/o it is not hard.
*/
static char *tbuf;
static int hopcount; /* detect infinite loops in termcap, init 0 */
extern const char *conffile;
int tgetent(char *, char *);
int getent(char *, char *, const char *);
int tnchktc(void);
int tnamatch(char *);
static char *tskip(char *);
int64_t tgetnum(char *);
int tgetflag(char *);
char *tgetstr(char *, char **);
static char *tdecode(char *, char **);
/*
* Get an entry for terminal name in buffer bp,
* from the termcap file. Parse is very rudimentary;
* we just notice escaped newlines.
*/
int
tgetent(char *bp, char *name)
{
return (getent(bp, name, conffile));
}
int
getent(char *bp, char *name, const char *cfile)
{
int c;
int i = 0, cnt = 0;
char ibuf[BUFSIZ];
char *cp;
int tf;
tbuf = bp;
tf = 0;
/*
* TERMCAP can have one of two things in it. It can be the
* name of a file to use instead of /etc/termcap. In this
* case it better start with a "/". Or it can be an entry to
* use so we don't have to read the file. In this case it
* has to already have the newlines crunched out.
*/
if (cfile && *cfile)
tf = open(cfile, O_RDONLY);
if (tf < 0) {
syslog(LOG_INFO,
"<%s> open: %s", __func__, strerror(errno));
return (-2);
}
for (;;) {
cp = bp;
for (;;) {
if (i == cnt) {
cnt = read(tf, ibuf, BUFSIZ);
if (cnt <= 0) {
close(tf);
return (0);
}
i = 0;
}
c = ibuf[i++];
if (c == '\n') {
if (cp > bp && cp[-1] == '\\') {
cp--;
continue;
}
break;
}
if (cp >= bp + BUFSIZ - 1) {
write(STDERR_FILENO, "Remcap entry too long\n",
22);
break;
} else
*cp++ = c;
}
*cp = 0;
/*
* The real work for the match.
*/
if (tnamatch(name)) {
close(tf);
return (tnchktc());
}
}
}
/*
* tnchktc: check the last entry, see if it's tc=xxx. If so,
* recursively find xxx and append that entry (minus the names)
* to take the place of the tc=xxx entry. This allows termcap
* entries to say "like an HP2621 but doesn't turn on the labels".
* Note that this works because of the left to right scan.
*/
int
tnchktc(void)
{
char *p, *q;
char tcname[16]; /* name of similar terminal */
char tcbuf[BUFSIZ];
char *holdtbuf = tbuf;
int l;
p = tbuf + strlen(tbuf) - 2; /* before the last colon */
while (*--p != ':')
if (p < tbuf) {
write(STDERR_FILENO, "Bad remcap entry\n", 18);
return (0);
}
p++;
/* p now points to beginning of last field */
if (p[0] != 't' || p[1] != 'c')
return (1);
strlcpy(tcname, p + 3, sizeof tcname);
q = tcname;
while (*q && *q != ':')
q++;
*q = 0;
if (++hopcount > MAXHOP) {
write(STDERR_FILENO, "Infinite tc= loop\n", 18);
return (0);
}
if (getent(tcbuf, tcname, conffile) != 1) {
return (0);
}
for (q = tcbuf; *q++ != ':'; )
;
l = p - holdtbuf + strlen(q);
if (l > BUFSIZ) {
write(STDERR_FILENO, "Remcap entry too long\n", 23);
q[BUFSIZ - (p-holdtbuf)] = 0;
}
strcpy(p, q);
tbuf = holdtbuf;
return (1);
}
/*
* Tnamatch deals with name matching. The first field of the termcap
* entry is a sequence of names separated by |'s, so we compare
* against each such name. The normal : terminator after the last
* name (before the first field) stops us.
*/
int
tnamatch(char *np)
{
char *Np, *Bp;
Bp = tbuf;
if (*Bp == '#')
return (0);
for (;;) {
for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
continue;
if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
return (1);
while (*Bp && *Bp != ':' && *Bp != '|')
Bp++;
if (*Bp == 0 || *Bp == ':')
return (0);
Bp++;
}
}
/*
* Skip to the next field. Notice that this is very dumb, not
* knowing about \: escapes or any such. If necessary, :'s can be put
* into the termcap file in octal.
*/
static char *
tskip(char *bp)
{
int dquote;
dquote = 0;
while (*bp) {
switch (*bp) {
case ':':
if (!dquote)
goto breakbreak;
else
bp++;
break;
case '\\':
bp++;
if (isdigit(*bp)) {
while (isdigit(*bp++))
;
} else
bp++;
case '"':
dquote = (dquote ? 1 : 0);
bp++;
break;
default:
bp++;
break;
}
}
breakbreak:
if (*bp == ':')
bp++;
return (bp);
}
/*
* Return the (numeric) option id.
* Numeric options look like
* li#80
* i.e. the option string is separated from the numeric value by
* a # character. If the option is not found we return -1.
* Note that we handle octal numbers beginning with 0.
*/
int64_t
tgetnum(char *id)
{
int64_t i;
int base;
char *bp = tbuf;
for (;;) {
bp = tskip(bp);
if (*bp == 0)
return (-1);
if (strncmp(bp, id, strlen(id)) != 0)
continue;
bp += strlen(id);
if (*bp == '@')
return (-1);
if (*bp != '#')
continue;
bp++;
base = 10;
if (*bp == '0')
base = 8;
i = 0;
while (isdigit(*bp))
i *= base, i += *bp++ - '0';
return (i);
}
}
/*
* Handle a flag option.
* Flag options are given "naked", i.e. followed by a : or the end
* of the buffer. Return 1 if we find the option, or 0 if it is
* not given.
*/
int
tgetflag(char *id)
{
char *bp = tbuf;
for (;;) {
bp = tskip(bp);
if (!*bp)
return (0);
if (strncmp(bp, id, strlen(id)) == 0) {
bp += strlen(id);
if (!*bp || *bp == ':')
return (1);
else if (*bp == '@')
return (0);
}
}
}
/*
* Get a string valued option.
* These are given as
* cl=^Z
* Much decoding is done on the strings, and the strings are
* placed in area, which is a ref parameter which is updated.
* No checking on area overflow.
*/
char *
tgetstr(char *id, char **area)
{
char *bp = tbuf;
for (;;) {
bp = tskip(bp);
if (!*bp)
return (0);
if (strncmp(bp, id, strlen(id)) != 0)
continue;
bp += strlen(id);
if (*bp == '@')
return (0);
if (*bp != '=')
continue;
bp++;
return (tdecode(bp, area));
}
}
/*
* Tdecode does the grung work to decode the
* string capability escapes.
*/
static char *
tdecode(char *str, char **area)
{
char *cp;
int c;
const char *dp;
int i;
char term;
term = ':';
cp = *area;
again:
if (*str == '"') {
term = '"';
str++;
}
while ((c = *str++) && c != term) {
switch (c) {
case '^':
c = *str++ & 037;
break;
case '\\':
dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
c = *str++;
nextc:
if (*dp++ == c) {
c = *dp++;
break;
}
dp++;
if (*dp)
goto nextc;
if (isdigit(c)) {
c -= '0', i = 2;
do
c <<= 3, c |= *str++ - '0';
while (--i && isdigit(*str));
}
break;
}
*cp++ = c;
}
if (c == term && term != ':') {
term = ':';
goto again;
}
*cp++ = 0;
str = *area;
*area = cp;
return (str);
}
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