script.c File Reference

gPXE scripts More...

#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <gpxe/image.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
struct image_type script_image_type	__image_type (PROBE_NORMAL)
	Script image type.
static int	script_exec (struct image *image)
	Execute script.
static int	script_load (struct image *image)
	Load script into memory.

---

Detailed Description

gPXE scripts

Definition in file script.c.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

struct image_type script_image_type __image_type

(

PROBE_NORMAL

)

[read]

Script image type.

static int script_exec

(

struct image *

image

)

[static]

Execute script.

Parameters:

image

Script

Return values:

rc

Return status code

Definition at line 42 of file script.c.

References copy_from_user(), image::data, DBG, image::len, memchr_user(), offset, register_image(), strerror(), system(), and unregister_image().

                                               {
        size_t offset = 0;
        off_t eol;
        size_t len;
        int rc;

        /* Temporarily de-register image, so that a "boot" command
         * doesn't throw us into an execution loop.
         */
        unregister_image ( image );

        while ( offset < image->len ) {
        
                /* Find length of next line, excluding any terminating '\n' */
                eol = memchr_user ( image->data, offset, '\n',
                                    ( image->len - offset ) );
                if ( eol < 0 )
                        eol = image->len;
                len = ( eol - offset );

                /* Copy line, terminate with NUL, and execute command */
                {
                        char cmdbuf[ len + 1 ];

                        copy_from_user ( cmdbuf, image->data, offset, len );
                        cmdbuf[len] = '\0';
                        DBG ( "$ %s\n", cmdbuf );
                        if ( ( rc = system ( cmdbuf ) ) != 0 ) {
                                DBG ( "Command \"%s\" failed: %s\n",
                                      cmdbuf, strerror ( rc ) );
                                goto done;
                        }
                }
                
                /* Move to next line */
                offset += ( len + 1 );
        }

        rc = 0;
 done:
        /* Re-register image and return */
        register_image ( image );
        return rc;
}

static int script_load

(

struct image *

image

)

[static]

Load script into memory.

Parameters:

image

Script

Return values:

rc

Return status code

Definition at line 93 of file script.c.

References copy_from_user(), image::data, DBG, ENOEXEC, isspace(), image::len, memcmp(), test, and image::type.

                                               {
        static const char magic[] = "#!gpxe";
        char test[ sizeof ( magic ) - 1 /* NUL */ + 1 /* terminating space */];

        /* Sanity check */
        if ( image->len < sizeof ( test ) ) {
                DBG ( "Too short to be a script\n" );
                return -ENOEXEC;
        }

        /* Check for magic signature */
        copy_from_user ( test, image->data, 0, sizeof ( test ) );
        if ( ( memcmp ( test, magic, ( sizeof ( test ) - 1 ) ) != 0 ) ||
             ! isspace ( test[ sizeof ( test ) - 1 ] ) ) {
                DBG ( "Invalid magic signature\n" );
                return -ENOEXEC;
        }

        /* This is a script */
        image->type = &script_image_type;

        /* We don't actually load it anywhere; we will pick the lines
         * out of the image as we need them.
         */

        return 0;
}