Return from the test and utility examples via exit()

All the core examples have been modified not to return from main
by the means of the return statement, but rather via exit() function,
which was done to make the examples more bare metal friendly.

This commit, for the sake of consistency, introduces the modifications
to the test and utility examples. These, while less likely to be used
in the low level environments, won't suffer from such a change.

programs/test/benchmark.c

@@ -43,7 +43,7 @@
 int main( void )
 {
     mbedtls_printf("MBEDTLS_TIMING_C not defined.\n");
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 #else
 
@@ -999,7 +999,7 @@ int main( int argc, char *argv[] )
     fflush( stdout ); getchar();
 #endif
 
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 
 #endif /* MBEDTLS_TIMING_C */

programs/test/udp_proxy.c

@@ -42,6 +42,7 @@
 #define mbedtls_printf          printf
 #define mbedtls_calloc          calloc
 #define mbedtls_free            free
+#define mbedtls_exit            exit
 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
 #endif /* MBEDTLS_PLATFORM_C */
@@ -50,7 +51,7 @@
 int main( void )
 {
     mbedtls_printf( "MBEDTLS_NET_C not defined.\n" );
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 #else
 
@@ -964,7 +965,7 @@ exit:
     fflush( stdout ); getchar();
 #endif
 
-    return( exit_code );
+    mbedtls_exit( exit_code );
 }
 
 #endif /* MBEDTLS_NET_C */

programs/test/zeroize.c

@@ -42,6 +42,7 @@
 #else
 #include <stdlib.h>
 #define mbedtls_printf     printf
+#define mbedtls_exit       exit
 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
 #endif
@@ -72,14 +73,14 @@ int main( int argc, char** argv )
     {
         mbedtls_printf( "This program takes exactly 1 agument\n" );
         usage();
-        return( exit_code );
+        mbedtls_exit( exit_code );
     }
 
     fp = fopen( argv[1], "r" );
     if( fp == NULL )
     {
         mbedtls_printf( "Could not open file '%s'\n", argv[1] );
-        return( exit_code );
+        mbedtls_exit( exit_code );
     }
 
     while( ( c = fgetc( fp ) ) != EOF && p < end - 1 )
@@ -97,5 +98,5 @@ int main( int argc, char** argv )
     fclose( fp );
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
 
-    return( exit_code );
+    mbedtls_exit( exit_code );
 }

programs/util/pem2der.c

@@ -61,7 +61,7 @@
 int main( void )
 {
     mbedtls_printf("MBEDTLS_BASE64_C and/or MBEDTLS_FS_IO not defined.\n");
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 #else
 
@@ -290,6 +290,6 @@ exit:
     fflush( stdout ); getchar();
 #endif
 
-    return( exit_code );
+    mbedtls_exit( exit_code );
 }
 #endif /* MBEDTLS_BASE64_C && MBEDTLS_FS_IO */

programs/util/strerror.c

@@ -29,7 +29,9 @@
 #include "mbedtls/platform.h"
 #else
 #include <stdio.h>
+#include <stdlib.h>
 #define mbedtls_printf     printf
+#define mbedtls_exit       exit
 #endif
 
 #if defined(MBEDTLS_ERROR_C) || defined(MBEDTLS_ERROR_STRERROR_DUMMY)
@@ -48,7 +50,7 @@
 int main( void )
 {
     mbedtls_printf("MBEDTLS_ERROR_C and/or MBEDTLS_ERROR_STRERROR_DUMMY not defined.\n");
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 #else
 int main( int argc, char *argv[] )
@@ -59,7 +61,7 @@ int main( int argc, char *argv[] )
     if( argc != 2 )
     {
         mbedtls_printf( USAGE );
-        return( 0 );
+        mbedtls_exit( 0 );
     }
 
     val = strtol( argv[1], &end, 10 );
@@ -87,6 +89,6 @@ int main( int argc, char *argv[] )
     fflush( stdout ); getchar();
 #endif
 
-    return( val );
+    mbedtls_exit( val );
 }
 #endif /* MBEDTLS_ERROR_C */