freebsd-dev/usr.sbin/jail/jaillex.l
2019-09-10 07:25:37 +00:00

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%{
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2011 James Gritton
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "jailp.h"
#include "y.tab.h"
extern int yynerrs;
static ssize_t text2lval(size_t triml, size_t trimr, int tovar);
static int instr;
static int lineno = 1;
#define YY_DECL int yylex(void)
%}
%option noyywrap
%option noinput
%option nounput
%start _ DQ
%%
/* Whitespace or equivalent */
<_>[ \t]+ instr = 0;
<_>#.* ;
<_>\/\/.* ;
<_>\/\*([^*]|(\*+([^*\/])))*\*+\/ {
const char *s;
for (s = yytext; s < yytext + yyleng; s++)
if (*s == '\n')
lineno++;
instr = 0;
}
<_>\n {
lineno++;
instr = 0;
}
/* Reserved tokens */
<_>\+= {
instr = 0;
return PLEQ;
}
<_>[,;={}] {
instr = 0;
return yytext[0];
}
/* Atomic (unquoted) strings */
<_,DQ>[A-Za-z0-9_!%&()\-.:<>?@\[\]^`|~]+ |
<_,DQ>\\(.|\n|[0-7]{1,3}|x[0-9A-Fa-f]{1,2}) |
<_,DQ>[$*+/\\] {
(void)text2lval(0, 0, 0);
return instr ? STR1 : (instr = 1, STR);
}
/* Single and double quoted strings */
<_>'([^\'\\]|\\(.|\n))*' {
(void)text2lval(1, 1, 0);
return instr ? STR1 : (instr = 1, STR);
}
<_>\"([^"\\]|\\(.|\n))*\" |
<DQ>[^\"$\\]([^"\\]|\\(.|\n))*\" {
size_t skip;
ssize_t atvar;
skip = yytext[0] == '"' ? 1 : 0;
atvar = text2lval(skip, 1, 1);
if (atvar < 0)
BEGIN _;
else {
/*
* The string has a variable inside it.
* Go into DQ mode to get the variable
* and then the rest of the string.
*/
BEGIN DQ;
yyless(atvar);
}
return instr ? STR1 : (instr = 1, STR);
}
<DQ>\" BEGIN _;
/* Variables, single-word or bracketed */
<_,DQ>$[A-Za-z_][A-Za-z_0-9]* {
(void)text2lval(1, 0, 0);
return instr ? VAR1 : (instr = 1, VAR);
}
<_>$\{([^\n{}]|\\(.|\n))*\} |
<DQ>$\{([^\n\"{}]|\\(.|\n))*\} {
(void)text2lval(2, 1, 0);
return instr ? VAR1 : (instr = 1, VAR);
}
/* Partially formed bits worth complaining about */
<_>\/\*([^*]|(\*+([^*\/])))*\** {
warnx("%s line %d: unterminated comment",
cfname, lineno);
yynerrs++;
}
<_>'([^\n'\\]|\\.)* |
<_>\"([^\n\"\\]|\\.)* {
warnx("%s line %d: unterminated string",
cfname, lineno);
yynerrs++;
}
<_>$\{([^\n{}]|\\.)* |
<DQ>$\{([^\n\"{}]|\\.)* {
warnx("%s line %d: unterminated variable",
cfname, lineno);
yynerrs++;
}
/* A hack because "<0>" rules aren't allowed */
<_>. return yytext[0];
.|\n {
BEGIN _;
yyless(0);
}
%%
void
yyerror(const char *s)
{
if (!yytext)
warnx("%s line %d: %s", cfname, lineno, s);
else if (!yytext[0])
warnx("%s: unexpected EOF", cfname);
else
warnx("%s line %d: %s: %s", cfname, lineno, yytext, s);
}
/*
* Copy string from yytext to yylval, handling backslash escapes,
* and optionally stopping at the beginning of a variable.
*/
static ssize_t
text2lval(size_t triml, size_t trimr, int tovar)
{
char *d;
const char *s, *se;
yylval.cs = d = emalloc(yyleng - trimr - triml + 1);
se = yytext + (yyleng - trimr);
for (s = yytext + triml; s < se; s++, d++) {
if (*s != '\\') {
if (tovar && *s == '$') {
*d = '\0';
return s - yytext;
}
if (*s == '\n')
lineno++;
*d = *s;
continue;
}
s++;
if (*s >= '0' && *s <= '7') {
*d = *s - '0';
if (s + 1 < se && s[1] >= '0' && s[1] <= '7') {
*d = 010 * *d + (*++s - '0');
if (s + 1 < se && s[1] >= '0' && s[1] <= '7')
*d = 010 * *d + (*++s - '0');
}
continue;
}
switch (*s) {
case 'a': *d = '\a'; break;
case 'b': *d = '\b'; break;
case 'f': *d = '\f'; break;
case 'n': *d = '\n'; break;
case 'r': *d = '\r'; break;
case 't': *d = '\t'; break;
case 'v': *d = '\v'; break;
case '\n': d--; lineno++; break;
default: *d = *s; break;
case 'x':
*d = 0;
if (s + 1 >= se)
break;
if (s[1] >= '0' && s[1] <= '9')
*d = *++s - '0';
else if (s[1] >= 'A' && s[1] <= 'F')
*d = *++s + (0xA - 'A');
else if (s[1] >= 'a' && s[1] <= 'f')
*d = *++s + (0xa - 'a');
else
break;
if (s + 1 >= se)
break;
if (s[1] >= '0' && s[1] <= '9')
*d = *d * 0x10 + (*++s - '0');
else if (s[1] >= 'A' && s[1] <= 'F')
*d = *d * 0x10 + (*++s + (0xA - 'A'));
else if (s[1] >= 'a' && s[1] <= 'f')
*d = *d * 0x10 + (*++s + (0xa - 'a'));
}
}
*d = '\0';
return -1;
}