If config file can not be parsed, use compiled in BB_SUID_... values as a

fallback method

1 files changed, 71 insertions, 55 deletions

diff --git a/applets/applets.c b/applets/applets.c
index 2ab44059a..9dcfe6b85 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -53,8 +53,9 @@ static void check_suid ( struct BB_applet *app );
 #include "pwd.h"
 #include "grp.h"
 
-static void parse_error ( int line, const char *err );
-static void parse_config_file ( void );
+static int parse_config_file ( void );
+
+static int config_ok;
 
 #define CONFIG_FILE "/etc/busybox.conf"
 
@@ -119,7 +120,7 @@ void run_applet_by_name(const char *name, int argc, char **argv)
 
 #ifdef CONFIG_FEATURE_SUID_CONFIG
         if ( recurse_level == 0 )
-                parse_config_file ( );
+                config_ok = parse_config_file ( );
 #endif
 
         recurse_level++;
@@ -183,42 +184,53 @@ void check_suid ( struct BB_applet *applet )
         uid_t rgid = getgid ( );
                         
 #ifdef CONFIG_FEATURE_SUID_CONFIG
-        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 ( config_ok ) {
+                struct BB_suid_config *sct;
                 
-                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;
+                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!" );
+                        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
-                        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 { // default: drop all priviledges
-                setgid ( rgid );
-                setuid ( ruid );
+        else {
+                static int onetime = 0;
+                
+                if ( !onetime ) {
+                        onetime = 1;
+                        fprintf ( stderr, "Using fallback suid method\n" );
+                }
         }
-#else
+#endif
 
         if ( applet-> need_suid == _BB_SUID_ALWAYS ) {
                 if ( geteuid ( ) != 0 ) 
@@ -228,23 +240,20 @@ void check_suid ( struct BB_applet *applet )
                 setgid ( rgid ); // drop all priviledges
                 setuid ( ruid );
         }       
-#endif  
 }
 
 #ifdef CONFIG_FEATURE_SUID_CONFIG
 
-void parse_error ( int line, const char *err )
-{
-        char msg [512];
-        snprintf ( msg, sizeof( msg ) - 1, "Parse error in %s, line %d: %s", CONFIG_FILE, line, err );
 
-        error_msg_and_die ( msg );
-}
+#define parse_error(x)  { err=x; goto pe_label; }
 
 
-void parse_config_file ( void )
+int parse_config_file ( void )
 {
         struct stat st;
+        char *err = 0;
+        FILE *f = 0;
+        int lc = 0;
 
         suid_config = 0;
         
@@ -253,12 +262,11 @@ void parse_config_file ( void )
                 // 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
-                        FILE *f = fopen ( CONFIG_FILE, "r" );
+                        f = fopen ( CONFIG_FILE, "r" );
 
                         if ( f ) {
-                                char buffer [4096];
+                                char buffer [256];
                                 int section = 0;
-                                int lc = 0;
                                 
                                 while ( fgets ( buffer, sizeof( buffer ) - 1, f )) {
                                         char c = buffer [0];
@@ -280,7 +288,7 @@ void parse_config_file ( void )
                                                 p = strchr ( buffer, ']' );
                                                 
                                                 if ( !p || ( p == ( buffer + 1 )))  // no matching ] or empty []
-                                                        parse_error ( lc, "malformed section header" );
+                                                        parse_error ( "malformed section header" );
 
                                                 *p = 0;
                                                 
@@ -298,7 +306,7 @@ void parse_config_file ( void )
                                                                 p = strchr ( buffer, '=' ); // <key>[::space::]*=[::space::]*<value>
                                                                 
                                                                 if ( !p || ( p == ( buffer + 1 ))) // no = or key is empty
-                                                                        parse_error ( lc, "malformed keyword" );
+                                                                        parse_error ( "malformed keyword" );
                                                                 
                                                                 l = p - buffer;
                                                                 while ( isspace ( buffer [--l] )) { } // skip whitespace
@@ -321,7 +329,7 @@ void parse_config_file ( void )
                                                                                 case 's': sct-> m_mode |= S_ISUID; // no break
                                                                                 case 'x': sct-> m_mode |= S_IXUSR; break;
                                                                                 case '-': break;
-                                                                                default : parse_error ( lc, "invalid user mode" );
+                                                                                default : parse_error ( "invalid user mode" );
                                                                         }
                                                                                 
                                                                         switch ( *p++ ) {
@@ -329,7 +337,7 @@ void parse_config_file ( void )
                                                                                 case 'x': sct-> m_mode |= S_IXGRP; break;
                                                                                 case 'S': break;
                                                                                 case '-': break;
-                                                                                default : parse_error ( lc, "invalid group mode" );
+                                                                                default : parse_error ( "invalid group mode" );
                                                                         }
                                                                                 
                                                                         switch ( *p ) {
@@ -337,7 +345,7 @@ void parse_config_file ( void )
                                                                                 case 'x': sct-> m_mode |= S_IXOTH; break;
                                                                                 case 'T':
                                                                                 case '-': break;
-                                                                                default : parse_error ( lc, "invalid other mode" );
+                                                                                default : parse_error ( "invalid other mode" );
                                                                         }
                                                                                 
                                                                         while ( isspace ( *++p )) { } // skip whitespace
@@ -345,20 +353,20 @@ void parse_config_file ( void )
                                                                         if ( isdigit ( *p )) {
                                                                                 sct-> m_uid = strtol ( p, &p, 10 );
                                                                                 if ( *p++ != '.' )
-                                                                                        parse_error ( lc, "parsing <uid>.<gid>" );                                                                              
+                                                                                        parse_error ( "parsing <uid>.<gid>" );                                                                          
                                                                         }
                                                                         else {
                                                                                 struct passwd *pwd;
                                                                                 char *p2 = strchr ( p, '.' );
                                                                                 
                                                                                 if ( !p2 ) 
-                                                                                        parse_error ( lc, "parsing <uid>.<gid>" );                                                                              
+                                                                                        parse_error ( "parsing <uid>.<gid>" );                                                                          
         
                                                                                 *p2 = 0;
                                                                                 pwd = getpwnam ( p );
                                                 
                                                                                 if ( !pwd ) 
-                                                                                        parse_error ( lc, "invalid user name" );
+                                                                                        parse_error ( "invalid user name" );
                                                                                 
                                                                                 sct-> m_uid = pwd-> pw_uid;
                                                                                 p = p2 + 1;
@@ -369,7 +377,7 @@ void parse_config_file ( void )
                                                                                 struct group *grp = getgrnam ( p );
                                                 
                                                                                 if ( !grp ) 
-                                                                                        parse_error ( lc, "invalid group name" );
+                                                                                        parse_error ( "invalid group name" );
                                                                                 
                                                                                 sct-> m_gid = grp-> gr_gid;
                                                                         }                                                                                                                                               
@@ -381,12 +389,20 @@ void parse_config_file ( void )
                                                 }                                       
                                         }
                                         else
-                                                parse_error ( lc, "keyword not within section" );
+                                                parse_error ( "keyword not within section" );
                                 }                               
                                 fclose ( f );
                         }
                 }
         }
+        return 1;
+        
+pe_label:       
+        fprintf ( stderr, "Parse error in %s, line %d: %s\n", CONFIG_FILE, lc, err );
+
+        if ( f )
+                fclose ( f );
+        return 0;
 }
 
 #endif