pxemenu.c

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/*
 * Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <byteswap.h>
#include <curses.h>
#include <console.h>
#include <gpxe/dhcp.h>
#include <gpxe/keys.h>
#include <gpxe/timer.h>
#include <gpxe/process.h>
#include <usr/dhcpmgmt.h>
#include <usr/autoboot.h>

/** @file
 *
 * PXE Boot Menus
 *
 */

/* Colour pairs */
#define CPAIR_NORMAL    1
#define CPAIR_SELECT    2

/** A PXE boot menu item */
struct pxe_menu_item {
        /** Boot Server type */
        unsigned int type;
        /** Description */
        char *desc;
};

/**
 * A PXE boot menu
 *
 * This structure encapsulates the menu information provided via DHCP
 * options.
 */
struct pxe_menu {
        /** Prompt string (optional) */
        const char *prompt;
        /** Timeout (in seconds)
         *
         * Negative indicates no timeout (i.e. wait indefinitely)
         */
        int timeout;
        /** Number of menu items */
        unsigned int num_items;
        /** Selected menu item */
        unsigned int selection;
        /** Menu items */
        struct pxe_menu_item items[0];
};

/**
 * Parse and allocate PXE boot menu
 *
 * @v menu              PXE boot menu to fill in
 * @ret rc              Return status code
 *
 * It is the callers responsibility to eventually free the allocated
 * boot menu.
 */
static int pxe_menu_parse ( struct pxe_menu **menu ) {
        struct setting pxe_boot_menu_prompt_setting =
                { .tag = DHCP_PXE_BOOT_MENU_PROMPT };
        struct setting pxe_boot_menu_setting =
                { .tag = DHCP_PXE_BOOT_MENU };
        uint8_t raw_menu[256];
        int raw_prompt_len;
        int raw_menu_len;
        struct dhcp_pxe_boot_menu *raw_menu_item;
        struct dhcp_pxe_boot_menu_prompt *raw_menu_prompt;
        void *raw_menu_end;
        unsigned int num_menu_items;
        unsigned int i;
        int rc;

        /* Fetch raw menu */
        memset ( raw_menu, 0, sizeof ( raw_menu ) );
        if ( ( raw_menu_len = fetch_setting ( NULL, &pxe_boot_menu_setting,
                                              raw_menu,
                                              sizeof ( raw_menu ) ) ) < 0 ) {
                rc = raw_menu_len;
                DBG ( "Could not retrieve raw PXE boot menu: %s\n",
                      strerror ( rc ) );
                return rc;
        }
        if ( raw_menu_len >= ( int ) sizeof ( raw_menu ) ) {
                DBG ( "Raw PXE boot menu too large for buffer\n" );
                return -ENOSPC;
        }
        raw_menu_end = ( raw_menu + raw_menu_len );

        /* Fetch raw prompt length */
        raw_prompt_len = fetch_setting_len ( NULL,
                                             &pxe_boot_menu_prompt_setting );
        if ( raw_prompt_len < 0 )
                raw_prompt_len = 0;

        /* Count menu items */
        num_menu_items = 0;
        raw_menu_item = ( ( void * ) raw_menu );
        while ( 1 ) {
                if ( ( ( ( void * ) raw_menu_item ) +
                       sizeof ( *raw_menu_item ) ) > raw_menu_end )
                        break;
                if ( ( ( ( void * ) raw_menu_item ) +
                       sizeof ( *raw_menu_item ) +
                       raw_menu_item->desc_len ) > raw_menu_end )
                        break;
                num_menu_items++;
                raw_menu_item = ( ( ( void * ) raw_menu_item ) +
                                  sizeof ( *raw_menu_item ) +
                                  raw_menu_item->desc_len );
        }

        /* Allocate space for parsed menu */
        *menu = zalloc ( sizeof ( **menu ) +
                         ( num_menu_items * sizeof ( (*menu)->items[0] ) ) +
                         raw_menu_len + 1 /* NUL */ +
                         raw_prompt_len + 1 /* NUL */ );
        if ( ! *menu ) {
                DBG ( "Could not allocate PXE boot menu\n" );
                return -ENOMEM;
        }

        /* Fill in parsed menu */
        (*menu)->num_items = num_menu_items;
        raw_menu_item = ( ( ( void * ) (*menu) ) + sizeof ( **menu ) +
                          ( num_menu_items * sizeof ( (*menu)->items[0] ) ) );
        memcpy ( raw_menu_item, raw_menu, raw_menu_len );
        for ( i = 0 ; i < num_menu_items ; i++ ) {
                (*menu)->items[i].type = le16_to_cpu ( raw_menu_item->type );
                (*menu)->items[i].desc = raw_menu_item->desc;
                /* Set type to 0; this ensures that the description
                 * for the previous menu item is NUL-terminated.
                 * (Final item is NUL-terminated anyway.)
                 */
                raw_menu_item->type = 0;
                raw_menu_item = ( ( ( void * ) raw_menu_item ) +
                                  sizeof ( *raw_menu_item ) +
                                  raw_menu_item->desc_len );
        }
        if ( raw_prompt_len ) {
                raw_menu_prompt = ( ( ( void * ) raw_menu_item ) +
                                    1 /* NUL */ );
                fetch_setting ( NULL, &pxe_boot_menu_prompt_setting,
                                raw_menu_prompt, raw_prompt_len );
                (*menu)->timeout =
                        ( ( raw_menu_prompt->timeout == 0xff ) ?
                          -1 : raw_menu_prompt->timeout );
                (*menu)->prompt = raw_menu_prompt->prompt;
        } else {
                (*menu)->timeout = -1;
        }

        return 0;
}

/**
 * Draw PXE boot menu item
 *
 * @v menu              PXE boot menu
 * @v index             Index of item to draw
 * @v selected          Item is selected
 */
static void pxe_menu_draw_item ( struct pxe_menu *menu,
                                 unsigned int index, int selected ) {
        char buf[COLS+1];
        size_t len;
        unsigned int row;

        /* Prepare space-padded row content */
        len = snprintf ( buf, sizeof ( buf ), " %c. %s",
                         ( 'A' + index ), menu->items[index].desc );
        while ( len < ( sizeof ( buf ) - 1 ) )
                buf[len++] = ' ';
        buf[ sizeof ( buf ) - 1 ] = '\0';

        /* Draw row */
        row = ( LINES - menu->num_items + index );
        color_set ( ( selected ? CPAIR_SELECT : CPAIR_NORMAL ), NULL );
        mvprintw ( row, 0, "%s", buf );
        move ( row, 1 );
}

/**
 * Make selection from PXE boot menu
 *
 * @v menu              PXE boot menu
 * @ret rc              Return status code
 */
static int pxe_menu_select ( struct pxe_menu *menu ) {
        int key;
        unsigned int key_selection;
        unsigned int i;
        int rc = 0;

        /* Initialise UI */
        initscr();
        start_color();
        init_pair ( CPAIR_NORMAL, COLOR_WHITE, COLOR_BLACK );
        init_pair ( CPAIR_SELECT, COLOR_BLACK, COLOR_WHITE );
        color_set ( CPAIR_NORMAL, NULL );

        /* Draw initial menu */
        for ( i = 0 ; i < menu->num_items ; i++ )
                printf ( "\n" );
        for ( i = 0 ; i < menu->num_items ; i++ )
                pxe_menu_draw_item ( menu, ( menu->num_items - i - 1 ), 0 );

        while ( 1 ) {

                /* Highlight currently selected item */
                pxe_menu_draw_item ( menu, menu->selection, 1 );

                /* Wait for keyboard input */
                while ( ! iskey() )
                        step();
                key = getkey();

                /* Unhighlight currently selected item */
                pxe_menu_draw_item ( menu, menu->selection, 0 );

                /* Act upon key */
                if ( ( key == CR ) || ( key == LF ) ) {
                        pxe_menu_draw_item ( menu, menu->selection, 1 );
                        break;
                } else if ( ( key == CTRL_C ) || ( key == ESC ) ) {
                        rc = -ECANCELED;
                        break;
                } else if ( key == KEY_UP ) {
                        if ( menu->selection > 0 )
                                menu->selection--;
                } else if ( key == KEY_DOWN ) {
                        if ( menu->selection < ( menu->num_items - 1 ) )
                                menu->selection++;
                } else if ( ( key < KEY_MIN ) &&
                            ( ( key_selection = ( toupper ( key ) - 'A' ) )
                              < menu->num_items ) ) {
                        menu->selection = key_selection;
                        pxe_menu_draw_item ( menu, menu->selection, 1 );
                        break;
                }
        }

        /* Shut down UI */
        endwin();

        return rc;
}

/**
 * Prompt for (and make selection from) PXE boot menu
 *
 * @v menu              PXE boot menu
 * @ret rc              Return status code
 */
static int pxe_menu_prompt_and_select ( struct pxe_menu *menu ) {
        unsigned long start = currticks();
        unsigned long now;
        unsigned long elapsed;
        size_t len = 0;
        int key;
        int rc = 0;

        /* Display menu immediately, if specified to do so */
        if ( menu->timeout < 0 ) {
                if ( menu->prompt )
                        printf ( "%s\n", menu->prompt );
                return pxe_menu_select ( menu );
        }

        /* Display prompt, if specified */
        if ( menu->prompt )
                printf ( "%s", menu->prompt );

        /* Wait for timeout, if specified */
        while ( menu->timeout > 0 ) {
                if ( ! len )
                        len = printf ( " (%d)", menu->timeout );
                if ( iskey() ) {
                        key = getkey();
                        if ( key == KEY_F8 ) {
                                /* Display menu */
                                printf ( "\n" );
                                return pxe_menu_select ( menu );
                        } else if ( ( key == CTRL_C ) || ( key == ESC ) ) {
                                /* Abort */
                                rc = -ECANCELED;
                                break;
                        } else {
                                /* Stop waiting */
                                break;
                        }
                }
                now = currticks();
                elapsed = ( now - start );
                if ( elapsed >= TICKS_PER_SEC ) {
                        menu->timeout -= 1;
                        do {
                                printf ( "\b \b" );
                        } while ( --len );
                        start = now;
                }
        }

        /* Return with default option selected */
        printf ( "\n" );
        return rc;
}

/**
 * Boot using PXE boot menu
 *
 * @ret rc              Return status code
 *
 * Note that a success return status indicates that a PXE boot menu
 * item has been selected, and that the DHCP session should perform a
 * boot server request/ack.
 */
int pxe_menu_boot ( struct net_device *netdev ) {
        struct pxe_menu *menu;
        unsigned int pxe_type;
        struct settings *pxebs_settings;
        struct in_addr next_server;
        char filename[256];
        int rc;

        /* Parse and allocate boot menu */
        if ( ( rc = pxe_menu_parse ( &menu ) ) != 0 )
                return rc;

        /* Make selection from boot menu */
        if ( ( rc = pxe_menu_prompt_and_select ( menu ) ) != 0 ) {
                free ( menu );
                return rc;
        }
        pxe_type = menu->items[menu->selection].type;

        /* Free boot menu */
        free ( menu );

        /* Return immediately if local boot selected */
        if ( ! pxe_type )
                return 0;

        /* Attempt PXE Boot Server Discovery */
        if ( ( rc = pxebs ( netdev, pxe_type ) ) != 0 )
                return rc;

        /* Attempt boot */
        pxebs_settings = find_settings ( PXEBS_SETTINGS_NAME );
        assert ( pxebs_settings );
        fetch_ipv4_setting ( pxebs_settings, &next_server_setting,
                             &next_server );
        fetch_string_setting ( pxebs_settings, &filename_setting,
                               filename, sizeof ( filename ) );
        return boot_next_server_and_filename ( next_server, filename );
}