hush/test.c
2000-04-15 16:34:54 +00:00

590 lines
11 KiB
C

/* vi: set sw=4 ts=4: */
/*
* test implementation for busybox
*
* Copyright (c) by a whole pile of folks:
*
* test(1); version 7-like -- author Erik Baalbergen
* modified by Eric Gisin to be used as built-in.
* modified by Arnold Robbins to add SVR3 compatibility
* (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
* modified by J.T. Conklin for NetBSD.
* modified by Herbert Xu to be used as built-in in ash.
* modified by Erik Andersen <andersee@debian.org> to be used
* in busybox.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Original copyright notice states:
* "This program is in the Public Domain."
*/
#include "internal.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
/* test(1) accepts the following grammar:
oexpr ::= aexpr | aexpr "-o" oexpr ;
aexpr ::= nexpr | nexpr "-a" aexpr ;
nexpr ::= primary | "!" primary
primary ::= unary-operator operand
| operand binary-operator operand
| operand
| "(" oexpr ")"
;
unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
"-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
binary-operator ::= "="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
"-nt"|"-ot"|"-ef";
operand ::= <any legal UNIX file name>
*/
enum token {
EOI,
FILRD,
FILWR,
FILEX,
FILEXIST,
FILREG,
FILDIR,
FILCDEV,
FILBDEV,
FILFIFO,
FILSOCK,
FILSYM,
FILGZ,
FILTT,
FILSUID,
FILSGID,
FILSTCK,
FILNT,
FILOT,
FILEQ,
FILUID,
FILGID,
STREZ,
STRNZ,
STREQ,
STRNE,
STRLT,
STRGT,
INTEQ,
INTNE,
INTGE,
INTGT,
INTLE,
INTLT,
UNOT,
BAND,
BOR,
LPAREN,
RPAREN,
OPERAND
};
enum token_types {
UNOP,
BINOP,
BUNOP,
BBINOP,
PAREN
};
struct t_op {
const char *op_text;
short op_num, op_type;
} const ops [] = {
{"-r", FILRD, UNOP},
{"-w", FILWR, UNOP},
{"-x", FILEX, UNOP},
{"-e", FILEXIST,UNOP},
{"-f", FILREG, UNOP},
{"-d", FILDIR, UNOP},
{"-c", FILCDEV,UNOP},
{"-b", FILBDEV,UNOP},
{"-p", FILFIFO,UNOP},
{"-u", FILSUID,UNOP},
{"-g", FILSGID,UNOP},
{"-k", FILSTCK,UNOP},
{"-s", FILGZ, UNOP},
{"-t", FILTT, UNOP},
{"-z", STREZ, UNOP},
{"-n", STRNZ, UNOP},
{"-h", FILSYM, UNOP}, /* for backwards compat */
{"-O", FILUID, UNOP},
{"-G", FILGID, UNOP},
{"-L", FILSYM, UNOP},
{"-S", FILSOCK,UNOP},
{"=", STREQ, BINOP},
{"!=", STRNE, BINOP},
{"<", STRLT, BINOP},
{">", STRGT, BINOP},
{"-eq", INTEQ, BINOP},
{"-ne", INTNE, BINOP},
{"-ge", INTGE, BINOP},
{"-gt", INTGT, BINOP},
{"-le", INTLE, BINOP},
{"-lt", INTLT, BINOP},
{"-nt", FILNT, BINOP},
{"-ot", FILOT, BINOP},
{"-ef", FILEQ, BINOP},
{"!", UNOT, BUNOP},
{"-a", BAND, BBINOP},
{"-o", BOR, BBINOP},
{"(", LPAREN, PAREN},
{")", RPAREN, PAREN},
{0, 0, 0}
};
char **t_wp;
struct t_op const *t_wp_op;
static gid_t *group_array = NULL;
static int ngroups;
static enum token t_lex();
static int oexpr();
static int aexpr();
static int nexpr();
static int binop();
static int primary();
static int filstat();
static int getn();
static int newerf();
static int olderf();
static int equalf();
static void syntax();
static int test_eaccess();
static int is_a_group_member();
static void initialize_group_array();
extern int
test_main(int argc, char** argv)
{
int res;
if (strcmp(argv[0], "[") == 0) {
if (strcmp(argv[--argc], "]"))
fatalError("missing ]");
argv[argc] = NULL;
}
if (strcmp(argv[1], "--help") == 0) {
usage("test EXPRESSION\n"
"or [ EXPRESSION ]\n\n"
"Checks file types and compares values returning an exit\n"
"code determined by the value of EXPRESSION.\n");
}
/* Implement special cases from POSIX.2, section 4.62.4 */
switch (argc) {
case 1:
exit( 1);
case 2:
exit (*argv[1] == '\0');
case 3:
if (argv[1][0] == '!' && argv[1][1] == '\0') {
exit (!(*argv[2] == '\0'));
}
break;
case 4:
if (argv[1][0] != '!' || argv[1][1] != '\0') {
if (t_lex(argv[2]),
t_wp_op && t_wp_op->op_type == BINOP) {
t_wp = &argv[1];
exit (binop() == 0);
}
}
break;
case 5:
if (argv[1][0] == '!' && argv[1][1] == '\0') {
if (t_lex(argv[3]),
t_wp_op && t_wp_op->op_type == BINOP) {
t_wp = &argv[2];
exit (!(binop() == 0));
}
}
break;
}
t_wp = &argv[1];
res = !oexpr(t_lex(*t_wp));
if (*t_wp != NULL && *++t_wp != NULL)
syntax(*t_wp, "unknown operand");
exit( res);
}
static void
syntax(op, msg)
char *op;
char *msg;
{
if (op && *op)
fatalError("%s: %s", op, msg);
else
fatalError("%s", msg);
}
static int
oexpr(n)
enum token n;
{
int res;
res = aexpr(n);
if (t_lex(*++t_wp) == BOR)
return oexpr(t_lex(*++t_wp)) || res;
t_wp--;
return res;
}
static int
aexpr(n)
enum token n;
{
int res;
res = nexpr(n);
if (t_lex(*++t_wp) == BAND)
return aexpr(t_lex(*++t_wp)) && res;
t_wp--;
return res;
}
static int
nexpr(n)
enum token n; /* token */
{
if (n == UNOT)
return !nexpr(t_lex(*++t_wp));
return primary(n);
}
static int
primary(n)
enum token n;
{
int res;
if (n == EOI)
syntax(NULL, "argument expected");
if (n == LPAREN) {
res = oexpr(t_lex(*++t_wp));
if (t_lex(*++t_wp) != RPAREN)
syntax(NULL, "closing paren expected");
return res;
}
if (t_wp_op && t_wp_op->op_type == UNOP) {
/* unary expression */
if (*++t_wp == NULL)
syntax(t_wp_op->op_text, "argument expected");
switch (n) {
case STREZ:
return strlen(*t_wp) == 0;
case STRNZ:
return strlen(*t_wp) != 0;
case FILTT:
return isatty(getn(*t_wp));
default:
return filstat(*t_wp, n);
}
}
if (t_lex(t_wp[1]), t_wp_op && t_wp_op->op_type == BINOP) {
return binop();
}
return strlen(*t_wp) > 0;
}
static int
binop()
{
const char *opnd1, *opnd2;
struct t_op const *op;
opnd1 = *t_wp;
(void) t_lex(*++t_wp);
op = t_wp_op;
if ((opnd2 = *++t_wp) == (char *)0)
syntax(op->op_text, "argument expected");
switch (op->op_num) {
case STREQ:
return strcmp(opnd1, opnd2) == 0;
case STRNE:
return strcmp(opnd1, opnd2) != 0;
case STRLT:
return strcmp(opnd1, opnd2) < 0;
case STRGT:
return strcmp(opnd1, opnd2) > 0;
case INTEQ:
return getn(opnd1) == getn(opnd2);
case INTNE:
return getn(opnd1) != getn(opnd2);
case INTGE:
return getn(opnd1) >= getn(opnd2);
case INTGT:
return getn(opnd1) > getn(opnd2);
case INTLE:
return getn(opnd1) <= getn(opnd2);
case INTLT:
return getn(opnd1) < getn(opnd2);
case FILNT:
return newerf (opnd1, opnd2);
case FILOT:
return olderf (opnd1, opnd2);
case FILEQ:
return equalf (opnd1, opnd2);
}
/* NOTREACHED */
return 1;
}
static int
filstat(nm, mode)
char *nm;
enum token mode;
{
struct stat s;
int i;
if (mode == FILSYM) {
#ifdef S_IFLNK
if (lstat(nm, &s) == 0) {
i = S_IFLNK;
goto filetype;
}
#endif
return 0;
}
if (stat(nm, &s) != 0)
return 0;
switch (mode) {
case FILRD:
return test_eaccess(nm, R_OK) == 0;
case FILWR:
return test_eaccess(nm, W_OK) == 0;
case FILEX:
return test_eaccess(nm, X_OK) == 0;
case FILEXIST:
return 1;
case FILREG:
i = S_IFREG;
goto filetype;
case FILDIR:
i = S_IFDIR;
goto filetype;
case FILCDEV:
i = S_IFCHR;
goto filetype;
case FILBDEV:
i = S_IFBLK;
goto filetype;
case FILFIFO:
#ifdef S_IFIFO
i = S_IFIFO;
goto filetype;
#else
return 0;
#endif
case FILSOCK:
#ifdef S_IFSOCK
i = S_IFSOCK;
goto filetype;
#else
return 0;
#endif
case FILSUID:
i = S_ISUID;
goto filebit;
case FILSGID:
i = S_ISGID;
goto filebit;
case FILSTCK:
i = S_ISVTX;
goto filebit;
case FILGZ:
return s.st_size > 0L;
case FILUID:
return s.st_uid == geteuid();
case FILGID:
return s.st_gid == getegid();
default:
return 1;
}
filetype:
return ((s.st_mode & S_IFMT) == i);
filebit:
return ((s.st_mode & i) != 0);
}
static enum token
t_lex(s)
char *s;
{
struct t_op const *op = ops;
if (s == 0) {
t_wp_op = (struct t_op *)0;
return EOI;
}
while (op->op_text) {
if (strcmp(s, op->op_text) == 0) {
t_wp_op = op;
return op->op_num;
}
op++;
}
t_wp_op = (struct t_op *)0;
return OPERAND;
}
/* atoi with error detection */
static int
getn(s)
char *s;
{
char *p;
long r;
errno = 0;
r = strtol(s, &p, 10);
if (errno != 0)
fatalError("%s: out of range", s);
while (isspace(*p))
p++;
if (*p)
fatalError("%s: bad number", s);
return (int) r;
}
static int
newerf (f1, f2)
char *f1, *f2;
{
struct stat b1, b2;
return (stat (f1, &b1) == 0 &&
stat (f2, &b2) == 0 &&
b1.st_mtime > b2.st_mtime);
}
static int
olderf (f1, f2)
char *f1, *f2;
{
struct stat b1, b2;
return (stat (f1, &b1) == 0 &&
stat (f2, &b2) == 0 &&
b1.st_mtime < b2.st_mtime);
}
static int
equalf (f1, f2)
char *f1, *f2;
{
struct stat b1, b2;
return (stat (f1, &b1) == 0 &&
stat (f2, &b2) == 0 &&
b1.st_dev == b2.st_dev &&
b1.st_ino == b2.st_ino);
}
/* Do the same thing access(2) does, but use the effective uid and gid,
and don't make the mistake of telling root that any file is
executable. */
static int
test_eaccess (path, mode)
char *path;
int mode;
{
struct stat st;
int euid = geteuid();
if (stat (path, &st) < 0)
return (-1);
if (euid == 0) {
/* Root can read or write any file. */
if (mode != X_OK)
return (0);
/* Root can execute any file that has any one of the execute
bits set. */
if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
return (0);
}
if (st.st_uid == euid) /* owner */
mode <<= 6;
else if (is_a_group_member (st.st_gid))
mode <<= 3;
if (st.st_mode & mode)
return (0);
return (-1);
}
static void
initialize_group_array ()
{
ngroups = getgroups(0, NULL);
if ((group_array = realloc(group_array, ngroups * sizeof(gid_t))) == NULL)
fatalError("Out of space");
getgroups(ngroups, group_array);
}
/* Return non-zero if GID is one that we have in our groups list. */
static int
is_a_group_member (gid)
gid_t gid;
{
register int i;
/* Short-circuit if possible, maybe saving a call to getgroups(). */
if (gid == getgid() || gid == getegid())
return (1);
if (ngroups == 0)
initialize_group_array ();
/* Search through the list looking for GID. */
for (i = 0; i < ngroups; i++)
if (gid == group_array[i])
return (1);
return (0);
}