mirror of
https://github.com/sheumann/hush.git
synced 2024-11-05 06:07:00 +00:00
423 lines
10 KiB
C
423 lines
10 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Utility routines.
|
|
*
|
|
* Copyright (C) tons of folks. Tracking down who wrote what
|
|
* isn't something I'm going to worry about... If you wrote something
|
|
* here, please feel free to acknowledge your work.
|
|
*
|
|
* 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
|
|
*
|
|
* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
|
|
* Permission has been granted to redistribute this code under the GPL.
|
|
*
|
|
*/
|
|
|
|
#include <unistd.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "busybox.h"
|
|
|
|
#undef APPLET
|
|
#undef APPLET_NOUSAGE
|
|
#undef PROTOTYPES
|
|
#include "applets.h"
|
|
|
|
struct BB_applet *applet_using;
|
|
|
|
/* The -1 arises because of the {0,NULL,0,-1} entry above. */
|
|
const size_t NUM_APPLETS = (sizeof (applets) / sizeof (struct BB_applet) - 1);
|
|
|
|
|
|
#ifdef CONFIG_FEATURE_SUID
|
|
|
|
static void check_suid ( struct BB_applet *app );
|
|
|
|
#ifdef CONFIG_FEATURE_SUID_CONFIG
|
|
|
|
#include <sys/stat.h>
|
|
#include <ctype.h>
|
|
#include "pwd_.h"
|
|
#include "grp_.h"
|
|
|
|
static int parse_config_file ( void );
|
|
|
|
static int config_ok;
|
|
|
|
#define CONFIG_FILE "/etc/busybox.conf"
|
|
|
|
// applets [] is const, so we have to define this "override" structure
|
|
struct BB_suid_config {
|
|
struct BB_applet *m_applet;
|
|
|
|
uid_t m_uid;
|
|
gid_t m_gid;
|
|
mode_t m_mode;
|
|
|
|
struct BB_suid_config *m_next;
|
|
};
|
|
|
|
static struct BB_suid_config *suid_config;
|
|
|
|
#endif // CONFIG_FEATURE_SUID_CONFIG
|
|
|
|
#endif // CONFIG_FEATURE_SUID
|
|
|
|
|
|
|
|
extern void show_usage(void)
|
|
{
|
|
const char *format_string;
|
|
const char *usage_string = usage_messages;
|
|
int i;
|
|
|
|
for (i = applet_using - applets; i > 0; ) {
|
|
if (!*usage_string++) {
|
|
--i;
|
|
}
|
|
}
|
|
format_string = "%s\n\nUsage: %s %s\n\n";
|
|
if(*usage_string == 0)
|
|
format_string = "%s\n\nNo help available.\n\n";
|
|
fprintf(stderr, format_string,
|
|
full_version, applet_using->name, usage_string);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
static int applet_name_compare(const void *x, const void *y)
|
|
{
|
|
const char *name = x;
|
|
const struct BB_applet *applet = y;
|
|
|
|
return strcmp(name, applet->name);
|
|
}
|
|
|
|
extern const size_t NUM_APPLETS;
|
|
|
|
struct BB_applet *find_applet_by_name(const char *name)
|
|
{
|
|
return bsearch(name, applets, NUM_APPLETS, sizeof(struct BB_applet),
|
|
applet_name_compare);
|
|
}
|
|
|
|
void run_applet_by_name(const char *name, int argc, char **argv)
|
|
{
|
|
static int recurse_level = 0;
|
|
extern int been_there_done_that; /* From busybox.c */
|
|
|
|
#ifdef CONFIG_FEATURE_SUID_CONFIG
|
|
if ( recurse_level == 0 )
|
|
config_ok = parse_config_file ( );
|
|
#endif
|
|
|
|
recurse_level++;
|
|
/* Do a binary search to find the applet entry given the name. */
|
|
if ((applet_using = find_applet_by_name(name)) != NULL) {
|
|
applet_name = applet_using->name;
|
|
if (argv[1] && strcmp(argv[1], "--help") == 0) {
|
|
if (strcmp(applet_using->name, "busybox")==0) {
|
|
if(argv[2])
|
|
applet_using = find_applet_by_name(argv[2]);
|
|
else
|
|
applet_using = NULL;
|
|
}
|
|
if(applet_using)
|
|
show_usage();
|
|
been_there_done_that=1;
|
|
busybox_main(0, NULL);
|
|
}
|
|
#ifdef CONFIG_FEATURE_SUID
|
|
check_suid ( applet_using );
|
|
#endif
|
|
|
|
exit((*(applet_using->main)) (argc, argv));
|
|
}
|
|
/* Just in case they have renamed busybox - Check argv[1] */
|
|
if (recurse_level == 1) {
|
|
run_applet_by_name("busybox", argc, argv);
|
|
}
|
|
recurse_level--;
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_FEATURE_SUID
|
|
|
|
#ifdef CONFIG_FEATURE_SUID_CONFIG
|
|
|
|
// check if u is member of group g
|
|
static int ingroup ( uid_t u, gid_t g )
|
|
{
|
|
struct group *grp = getgrgid ( g );
|
|
|
|
if ( grp ) {
|
|
char **mem;
|
|
|
|
for ( mem = grp-> gr_mem; *mem; mem++ ) {
|
|
struct passwd *pwd = getpwnam ( *mem );
|
|
|
|
if ( pwd && ( pwd-> pw_uid == u ))
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
void check_suid ( struct BB_applet *applet )
|
|
{
|
|
uid_t ruid = getuid ( ); // real [ug]id
|
|
uid_t rgid = getgid ( );
|
|
|
|
#ifdef CONFIG_FEATURE_SUID_CONFIG
|
|
if ( config_ok ) {
|
|
struct BB_suid_config *sct;
|
|
|
|
for ( sct = suid_config; sct; sct = sct-> m_next ) {
|
|
if ( sct-> m_applet == applet )
|
|
break;
|
|
}
|
|
if ( sct ) {
|
|
mode_t m = sct-> m_mode;
|
|
|
|
if ( sct-> m_uid == ruid ) // same uid
|
|
m >>= 6;
|
|
else if (( sct-> m_gid == rgid ) || ingroup ( ruid, sct-> m_gid )) // same group / in group
|
|
m >>= 3;
|
|
|
|
if (!( m & S_IXOTH )) // is x bit not set ?
|
|
error_msg_and_die ( "You have no permission to run this applet!" );
|
|
|
|
if (( sct-> m_mode & ( S_ISGID | S_IXGRP )) == ( S_ISGID | S_IXGRP )) { // *both* have to be set for sgid
|
|
if ( setegid ( sct-> m_gid ))
|
|
error_msg_and_die ( "BusyBox binary has insufficient rights to set proper GID for applet!" );
|
|
}
|
|
else
|
|
setgid ( rgid ); // no sgid -> drop
|
|
|
|
if ( sct-> m_mode & S_ISUID ) {
|
|
if ( seteuid ( sct-> m_uid ))
|
|
error_msg_and_die ( "BusyBox binary has insufficient rights to set proper UID for applet!" );
|
|
}
|
|
else
|
|
setuid ( ruid ); // no suid -> drop
|
|
}
|
|
else { // default: drop all priviledges
|
|
setgid ( rgid );
|
|
setuid ( ruid );
|
|
}
|
|
return;
|
|
}
|
|
else {
|
|
#ifndef CONFIG_FEATURE_SUID_CONFIG_QUIET
|
|
static int onetime = 0;
|
|
|
|
if ( !onetime ) {
|
|
onetime = 1;
|
|
fprintf ( stderr, "Using fallback suid method\n" );
|
|
}
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
if ( applet-> need_suid == _BB_SUID_ALWAYS ) {
|
|
if ( geteuid ( ) != 0 )
|
|
error_msg_and_die ( "This applet requires root priviledges!" );
|
|
}
|
|
else if ( applet-> need_suid == _BB_SUID_NEVER ) {
|
|
setgid ( rgid ); // drop all priviledges
|
|
setuid ( ruid );
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_FEATURE_SUID_CONFIG
|
|
|
|
|
|
#define parse_error(x) { err=x; goto pe_label; }
|
|
|
|
|
|
int parse_config_file ( void )
|
|
{
|
|
struct stat st;
|
|
char *err = 0;
|
|
FILE *f = 0;
|
|
int lc = 0;
|
|
|
|
suid_config = 0;
|
|
|
|
// is there a config file ?
|
|
if ( stat ( CONFIG_FILE, &st ) == 0 ) {
|
|
// is it owned by root with no write perm. for group and others ?
|
|
if ( S_ISREG( st. st_mode ) && ( st. st_uid == 0 ) && (!( st. st_mode & ( S_IWGRP | S_IWOTH )))) {
|
|
// that's ok .. then try to open it
|
|
f = fopen ( CONFIG_FILE, "r" );
|
|
|
|
if ( f ) {
|
|
char buffer [256];
|
|
int section = 0;
|
|
|
|
while ( fgets ( buffer, sizeof( buffer ) - 1, f )) {
|
|
char c = buffer [0];
|
|
char *p;
|
|
|
|
lc++;
|
|
|
|
p = strchr ( buffer, '#' );
|
|
if ( p )
|
|
*p = 0;
|
|
p = buffer + xstrlen ( buffer );
|
|
while (( p > buffer ) && isspace ( *--p ))
|
|
*p = 0;
|
|
|
|
if ( p == buffer )
|
|
continue;
|
|
|
|
if ( c == '[' ) {
|
|
p = strchr ( buffer, ']' );
|
|
|
|
if ( !p || ( p == ( buffer + 1 ))) // no matching ] or empty []
|
|
parse_error ( "malformed section header" );
|
|
|
|
*p = 0;
|
|
|
|
if ( strcasecmp ( buffer + 1, "SUID" ) == 0 )
|
|
section = 1;
|
|
else
|
|
section = -1; // unknown section - just skip
|
|
}
|
|
else if ( section ) {
|
|
switch ( section ) {
|
|
case 1: { // SUID
|
|
int l;
|
|
struct BB_applet *applet;
|
|
|
|
p = strchr ( buffer, '=' ); // <key>[::space::]*=[::space::]*<value>
|
|
|
|
if ( !p || ( p == ( buffer + 1 ))) // no = or key is empty
|
|
parse_error ( "malformed keyword" );
|
|
|
|
l = p - buffer;
|
|
while ( isspace ( buffer [--l] )) { } // skip whitespace
|
|
|
|
buffer [l+1] = 0;
|
|
|
|
if (( applet = find_applet_by_name ( buffer ))) {
|
|
struct BB_suid_config *sct = xmalloc ( sizeof( struct BB_suid_config ));
|
|
|
|
sct-> m_applet = applet;
|
|
sct-> m_next = suid_config;
|
|
suid_config = sct;
|
|
|
|
while ( isspace ( *++p )) { } // skip whitespace
|
|
|
|
sct-> m_mode = 0;
|
|
|
|
switch ( *p++ ) {
|
|
case 'S': sct-> m_mode |= S_ISUID; break;
|
|
case 's': sct-> m_mode |= S_ISUID; // no break
|
|
case 'x': sct-> m_mode |= S_IXUSR; break;
|
|
case '-': break;
|
|
default : parse_error ( "invalid user mode" );
|
|
}
|
|
|
|
switch ( *p++ ) {
|
|
case 's': sct-> m_mode |= S_ISGID; // no break
|
|
case 'x': sct-> m_mode |= S_IXGRP; break;
|
|
case 'S': break;
|
|
case '-': break;
|
|
default : parse_error ( "invalid group mode" );
|
|
}
|
|
|
|
switch ( *p ) {
|
|
case 't':
|
|
case 'x': sct-> m_mode |= S_IXOTH; break;
|
|
case 'T':
|
|
case '-': break;
|
|
default : parse_error ( "invalid other mode" );
|
|
}
|
|
|
|
while ( isspace ( *++p )) { } // skip whitespace
|
|
|
|
if ( isdigit ( *p )) {
|
|
sct-> m_uid = strtol ( p, &p, 10 );
|
|
if ( *p++ != '.' )
|
|
parse_error ( "parsing <uid>.<gid>" );
|
|
}
|
|
else {
|
|
struct passwd *pwd;
|
|
char *p2 = strchr ( p, '.' );
|
|
|
|
if ( !p2 )
|
|
parse_error ( "parsing <uid>.<gid>" );
|
|
|
|
*p2 = 0;
|
|
pwd = getpwnam ( p );
|
|
|
|
if ( !pwd )
|
|
parse_error ( "invalid user name" );
|
|
|
|
sct-> m_uid = pwd-> pw_uid;
|
|
p = p2 + 1;
|
|
}
|
|
if ( isdigit ( *p ))
|
|
sct-> m_gid = strtol ( p, &p, 10 );
|
|
else {
|
|
struct group *grp = getgrnam ( p );
|
|
|
|
if ( !grp )
|
|
parse_error ( "invalid group name" );
|
|
|
|
sct-> m_gid = grp-> gr_gid;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
default: // unknown - skip
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
parse_error ( "keyword not within section" );
|
|
}
|
|
fclose ( f );
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0; // no config file or not readable (not an error)
|
|
|
|
pe_label:
|
|
fprintf ( stderr, "Parse error in %s, line %d: %s\n", CONFIG_FILE, lc, err );
|
|
|
|
if ( f )
|
|
fclose ( f );
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif
|
|
|
|
/* END CODE */
|
|
/*
|
|
Local Variables:
|
|
c-file-style: "linux"
|
|
c-basic-offset: 4
|
|
tab-width: 4
|
|
End:
|
|
*/
|