File: [local] / src / usr.bin / doas / parse.y (download)
Revision 1.1, Thu Jul 16 20:44:21 2015 UTC (8 years, 10 months ago) by tedu
Branch: MAIN
import doas. still subject to changes, large and small.
|
/* $OpenBSD: parse.y,v 1.1 2015/07/16 20:44:21 tedu Exp $ */
/*
* Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
%{
#include <sys/types.h>
#include <ctype.h>
#include <unistd.h>
#include <stdint.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <err.h>
#include "doas.h"
typedef struct {
union {
struct {
int action;
int options;
const char **envlist;
};
const char *str;
};
} yystype;
#define YYSTYPE yystype
FILE *yyfp;
struct rule **rules;
int nrules, maxrules;
%}
%token TPERMIT TDENY TAS TCMD
%token TNOPASS TKEEPENV
%token TSTRING
%%
grammar: /* empty */
| grammar '\n'
| grammar rule '\n'
;
rule: action ident target cmd {
struct rule *r;
r = calloc(1, sizeof(*r));
r->action = $1.action;
r->options = $1.options;
r->envlist = $1.envlist;
r->ident = $2.str;
r->target = $3.str;
r->cmd = $4.str;
if (nrules == maxrules) {
if (maxrules == 0)
maxrules = 63;
else
maxrules *= 2;
if (!(rules = reallocarray(rules, maxrules, sizeof(*rules))))
errx(1, "can't allocate rules");
}
rules[nrules++] = r;
} ;
action: TPERMIT options {
$$.action = PERMIT;
$$.options = $2.options;
$$.envlist = $2.envlist;
} | TDENY {
$$.action = DENY;
} ;
options: /* none */
| options option {
$$.options = $1.options | $2.options;
$$.envlist = $1.envlist;
if ($2.envlist) {
if ($$.envlist)
errx(1, "can't have two keepenv sections");
else
$$.envlist = $2.envlist;
}
} ;
option: TNOPASS {
$$.options = NOPASS;
} | TKEEPENV {
$$.options = KEEPENV;
} | TKEEPENV '{' envlist '}' {
$$.options = KEEPENV;
$$.envlist = $3.envlist;
} ;
envlist: /* empty */ {
if (!($$.envlist = calloc(1, sizeof(char *))))
errx(1, "can't allocate envlist");
} | envlist TSTRING {
int nenv = arraylen($1.envlist);
if (!($$.envlist = reallocarray($1.envlist, nenv + 2, sizeof(char *))))
errx(1, "can't allocate envlist");
$$.envlist[nenv] = $2.str;
$$.envlist[nenv + 1] = NULL;
}
ident: TSTRING {
$$.str = $1.str;
} ;
target: /* optional */ {
$$.str = NULL;
} | TAS TSTRING {
$$.str = $2.str;
} ;
cmd: /* optional */ {
$$.str = NULL;
} | TCMD TSTRING {
$$.str = $2.str;
} ;
%%
void
yyerror(const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
fprintf(stderr, "doas: ");
vfprintf(stderr, fmt, va);
fprintf(stderr, "\n");
va_end(va);
exit(1);
}
struct keyword {
const char *word;
int token;
} keywords[] = {
{ "deny", TDENY },
{ "permit", TPERMIT },
{ "as", TAS },
{ "cmd", TCMD },
{ "nopass", TNOPASS },
{ "keepenv", TKEEPENV },
};
int
yylex(void)
{
char buf[1024], *ebuf, *p, *str;
int i, c;
p = buf;
ebuf = buf + sizeof(buf);
while ((c = getc(yyfp)) == ' ' || c == '\t')
; /* skip spaces */
switch (c) {
case '\n':
case '{':
case '}':
return c;
case '#':
while ((c = getc(yyfp)) != '\n' && c != EOF)
; /* skip comments */
if (c == EOF)
return 0;
return c;
case EOF:
return 0;
case ':':
*p++ = c;
c = getc(yyfp);
break;
default:
break;
}
while (isalnum(c)) {
*p++ = c;
if (p == ebuf)
yyerror("too much stuff");
c = getc(yyfp);
}
*p = 0;
if (c != EOF)
ungetc(c, yyfp);
for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
if (strcmp(buf, keywords[i].word) == 0)
return keywords[i].token;
}
if ((str = strdup(buf)) == NULL)
err(1, "strdup");
yylval.str = str;
return TSTRING;
}