[pxe] Remove userptr_t from PXE file API implementation

Simplify the PXE file API implementation by assuming that all string
buffers are directly accessible via pointer dereferences.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/x86/interface/pxe/pxe_file.c b/src/arch/x86/interface/pxe/pxe_file.c
index 6bb9f525f645fe197b734079d3fd205f828d4694..b934e8fefbd8c92d20035c982a08ea8c4f95ad10 100644 (file)
--- a/src/arch/x86/interface/pxe/pxe_file.c
+++ b/src/arch/x86/interface/pxe/pxe_file.c
@@ -53,30 +53,20 @@ FEATURE ( FEATURE_MISC, "PXEXT", DHCP_EB_FEATURE_PXE_EXT, 2 );
  *
  */
 static PXENV_EXIT_t pxenv_file_open ( struct s_PXENV_FILE_OPEN *file_open ) {
-       userptr_t filename;
-       size_t filename_len;
+       const char *filename;
        int fd;
 
        DBG ( "PXENV_FILE_OPEN" );
 
-       /* Copy name from external program, and open it */
+       /* Open specified filename */
        filename = real_to_virt ( file_open->FileName.segment,
                                  file_open->FileName.offset );
-       filename_len = strlen ( filename );
-       {
-               char uri_string[ filename_len + 1 ];
-
-               copy_from_user ( uri_string, filename, 0,
-                                sizeof ( uri_string ) );
-               DBG ( " %s", uri_string );
-               fd = open ( uri_string );
-       }
-
+       DBG ( " %s", filename );
+       fd = open ( filename );
        if ( fd < 0 ) {
                file_open->Status = PXENV_STATUS ( fd );
                return PXENV_EXIT_FAILURE;
        }
-
        DBG ( " as file %d", fd );
 
        file_open->FileHandle = fd;
@@ -210,27 +200,18 @@ pxenv_get_file_size ( struct s_PXENV_GET_FILE_SIZE *get_file_size ) {
  *
  */
 static PXENV_EXIT_t pxenv_file_exec ( struct s_PXENV_FILE_EXEC *file_exec ) {
-       userptr_t command;
-       size_t command_len;
+       const char *command;
        int rc;
 
        DBG ( "PXENV_FILE_EXEC" );
 
-       /* Copy name from external program, and exec it */
+       /* Execute specified command */
        command = real_to_virt ( file_exec->Command.segment,
                                 file_exec->Command.offset );
-       command_len = strlen ( command );
-       {
-               char command_string[ command_len + 1 ];
-
-               copy_from_user ( command_string, command, 0,
-                                sizeof ( command_string ) );
-               DBG ( " %s", command_string );
-
-               if ( ( rc = system ( command_string ) ) != 0 ) {
-                       file_exec->Status = PXENV_STATUS ( rc );
-                       return PXENV_EXIT_FAILURE;
-               }
+       DBG ( " %s", command );
+       if ( ( rc = system ( command ) ) != 0 ) {
+               file_exec->Status = PXENV_STATUS ( rc );
+               return PXENV_EXIT_FAILURE;
        }
 
        file_exec->Status = PXENV_STATUS_SUCCESS;
@@ -251,8 +232,7 @@ static PXENV_EXIT_t pxenv_file_exec ( struct s_PXENV_FILE_EXEC *file_exec ) {
  */
 static PXENV_EXIT_t
 pxenv_file_cmdline ( struct s_PXENV_FILE_CMDLINE *file_cmdline ) {
-       userptr_t buffer;
-       size_t max_len;
+       char *buffer;
        size_t len;
 
        DBG ( "PXENV_FILE_CMDLINE to %04x:%04x+%04x \"%s\"\n",
@@ -262,12 +242,12 @@ pxenv_file_cmdline ( struct s_PXENV_FILE_CMDLINE *file_cmdline ) {
        buffer = real_to_virt ( file_cmdline->Buffer.segment,
                                file_cmdline->Buffer.offset );
        len = file_cmdline->BufferSize;
-       max_len = ( pxe_cmdline ?
-                   ( strlen ( pxe_cmdline ) + 1 /* NUL */ ) : 0 );
-       if ( len > max_len )
-               len = max_len;
-       copy_to_user ( buffer, 0, pxe_cmdline, len );
-       file_cmdline->BufferSize = max_len;
+       if ( pxe_cmdline ) {
+               len = snprintf ( buffer, len, "%s", pxe_cmdline );
+               file_cmdline->BufferSize = ( len + 1 /* NUL */ );
+       } else {
+               file_cmdline->BufferSize = 0;
+       }
 
        file_cmdline->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;