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1 /*
2  * Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 FILE_LICENCE ( GPL2_OR_LATER );
20 
21 #include <stdint.h>
22 #include <stdlib.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <errno.h>
26 #include <ctype.h>
27 #include <byteswap.h>
28 #include <curses.h>
29 #include <console.h>
30 #include <gpxe/dhcp.h>
31 #include <gpxe/keys.h>
32 #include <gpxe/timer.h>
33 #include <gpxe/process.h>
34 #include <usr/dhcpmgmt.h>
35 #include <usr/autoboot.h>
36 
37 /** @file
38  *
39  * PXE Boot Menus
40  *
41  */
42 
43 /* Colour pairs */
44 #define CPAIR_NORMAL	1
45 #define CPAIR_SELECT	2
46 
47 /** A PXE boot menu item */
48 struct pxe_menu_item {
49 	/** Boot Server type */
50 	unsigned int type;
51 	/** Description */
52 	char *desc;
53 };
54 
55 /**
56  * A PXE boot menu
57  *
58  * This structure encapsulates the menu information provided via DHCP
59  * options.
60  */
61 struct pxe_menu {
62 	/** Prompt string (optional) */
63 	const char *prompt;
64 	/** Timeout (in seconds)
65 	 *
66 	 * Negative indicates no timeout (i.e. wait indefinitely)
67 	 */
68 	int timeout;
69 	/** Number of menu items */
70 	unsigned int num_items;
71 	/** Selected menu item */
72 	unsigned int selection;
73 	/** Menu items */
74 	struct pxe_menu_item items[0];
75 };
76 
77 /**
78  * Parse and allocate PXE boot menu
79  *
80  * @v menu		PXE boot menu to fill in
81  * @ret rc		Return status code
82  *
83  * It is the callers responsibility to eventually free the allocated
84  * boot menu.
85  */
pxe_menu_parse(struct pxe_menu ** menu)86 static int pxe_menu_parse ( struct pxe_menu **menu ) {
87 	struct setting pxe_boot_menu_prompt_setting =
88 		{ .tag = DHCP_PXE_BOOT_MENU_PROMPT };
89 	struct setting pxe_boot_menu_setting =
90 		{ .tag = DHCP_PXE_BOOT_MENU };
91 	uint8_t raw_menu[256];
92 	int raw_prompt_len;
93 	int raw_menu_len;
94 	struct dhcp_pxe_boot_menu *raw_menu_item;
95 	struct dhcp_pxe_boot_menu_prompt *raw_menu_prompt;
96 	void *raw_menu_end;
97 	unsigned int num_menu_items;
98 	unsigned int i;
99 	int rc;
100 
101 	/* Fetch raw menu */
102 	memset ( raw_menu, 0, sizeof ( raw_menu ) );
103 	if ( ( raw_menu_len = fetch_setting ( NULL, &pxe_boot_menu_setting,
104 					      raw_menu,
105 					      sizeof ( raw_menu ) ) ) < 0 ) {
106 		rc = raw_menu_len;
107 		DBG ( "Could not retrieve raw PXE boot menu: %s\n",
108 		      strerror ( rc ) );
109 		return rc;
110 	}
111 	if ( raw_menu_len >= ( int ) sizeof ( raw_menu ) ) {
112 		DBG ( "Raw PXE boot menu too large for buffer\n" );
113 		return -ENOSPC;
114 	}
115 	raw_menu_end = ( raw_menu + raw_menu_len );
116 
117 	/* Fetch raw prompt length */
118 	raw_prompt_len = fetch_setting_len ( NULL,
119 					     &pxe_boot_menu_prompt_setting );
120 	if ( raw_prompt_len < 0 )
121 		raw_prompt_len = 0;
122 
123 	/* Count menu items */
124 	num_menu_items = 0;
125 	raw_menu_item = ( ( void * ) raw_menu );
126 	while ( 1 ) {
127 		if ( ( ( ( void * ) raw_menu_item ) +
128 		       sizeof ( *raw_menu_item ) ) > raw_menu_end )
129 			break;
130 		if ( ( ( ( void * ) raw_menu_item ) +
131 		       sizeof ( *raw_menu_item ) +
132 		       raw_menu_item->desc_len ) > raw_menu_end )
133 			break;
134 		num_menu_items++;
135 		raw_menu_item = ( ( ( void * ) raw_menu_item ) +
136 				  sizeof ( *raw_menu_item ) +
137 				  raw_menu_item->desc_len );
138 	}
139 
140 	/* Allocate space for parsed menu */
141 	*menu = zalloc ( sizeof ( **menu ) +
142 			 ( num_menu_items * sizeof ( (*menu)->items[0] ) ) +
143 			 raw_menu_len + 1 /* NUL */ +
144 			 raw_prompt_len + 1 /* NUL */ );
145 	if ( ! *menu ) {
146 		DBG ( "Could not allocate PXE boot menu\n" );
147 		return -ENOMEM;
148 	}
149 
150 	/* Fill in parsed menu */
151 	(*menu)->num_items = num_menu_items;
152 	raw_menu_item = ( ( ( void * ) (*menu) ) + sizeof ( **menu ) +
153 			  ( num_menu_items * sizeof ( (*menu)->items[0] ) ) );
154 	memcpy ( raw_menu_item, raw_menu, raw_menu_len );
155 	for ( i = 0 ; i < num_menu_items ; i++ ) {
156 		(*menu)->items[i].type = le16_to_cpu ( raw_menu_item->type );
157 		(*menu)->items[i].desc = raw_menu_item->desc;
158 		/* Set type to 0; this ensures that the description
159 		 * for the previous menu item is NUL-terminated.
160 		 * (Final item is NUL-terminated anyway.)
161 		 */
162 		raw_menu_item->type = 0;
163 		raw_menu_item = ( ( ( void * ) raw_menu_item ) +
164 				  sizeof ( *raw_menu_item ) +
165 				  raw_menu_item->desc_len );
166 	}
167 	if ( raw_prompt_len ) {
168 		raw_menu_prompt = ( ( ( void * ) raw_menu_item ) +
169 				    1 /* NUL */ );
170 		fetch_setting ( NULL, &pxe_boot_menu_prompt_setting,
171 				raw_menu_prompt, raw_prompt_len );
172 		(*menu)->timeout =
173 			( ( raw_menu_prompt->timeout == 0xff ) ?
174 			  -1 : raw_menu_prompt->timeout );
175 		(*menu)->prompt = raw_menu_prompt->prompt;
176 	} else {
177 		(*menu)->timeout = -1;
178 	}
179 
180 	return 0;
181 }
182 
183 /**
184  * Draw PXE boot menu item
185  *
186  * @v menu		PXE boot menu
187  * @v index		Index of item to draw
188  * @v selected		Item is selected
189  */
pxe_menu_draw_item(struct pxe_menu * menu,unsigned int index,int selected)190 static void pxe_menu_draw_item ( struct pxe_menu *menu,
191 				 unsigned int index, int selected ) {
192 	char buf[COLS+1];
193 	size_t len;
194 	unsigned int row;
195 
196 	/* Prepare space-padded row content */
197 	len = snprintf ( buf, sizeof ( buf ), " %c. %s",
198 			 ( 'A' + index ), menu->items[index].desc );
199 	while ( len < ( sizeof ( buf ) - 1 ) )
200 		buf[len++] = ' ';
201 	buf[ sizeof ( buf ) - 1 ] = '\0';
202 
203 	/* Draw row */
204 	row = ( LINES - menu->num_items + index );
205 	color_set ( ( selected ? CPAIR_SELECT : CPAIR_NORMAL ), NULL );
206 	mvprintw ( row, 0, "%s", buf );
207 	move ( row, 1 );
208 }
209 
210 /**
211  * Make selection from PXE boot menu
212  *
213  * @v menu		PXE boot menu
214  * @ret rc		Return status code
215  */
pxe_menu_select(struct pxe_menu * menu)216 static int pxe_menu_select ( struct pxe_menu *menu ) {
217 	int key;
218 	unsigned int key_selection;
219 	unsigned int i;
220 	int rc = 0;
221 
222 	/* Initialise UI */
223 	initscr();
224 	start_color();
225 	init_pair ( CPAIR_NORMAL, COLOR_WHITE, COLOR_BLACK );
226 	init_pair ( CPAIR_SELECT, COLOR_BLACK, COLOR_WHITE );
227 	color_set ( CPAIR_NORMAL, NULL );
228 
229 	/* Draw initial menu */
230 	for ( i = 0 ; i < menu->num_items ; i++ )
231 		printf ( "\n" );
232 	for ( i = 0 ; i < menu->num_items ; i++ )
233 		pxe_menu_draw_item ( menu, ( menu->num_items - i - 1 ), 0 );
234 
235 	while ( 1 ) {
236 
237 		/* Highlight currently selected item */
238 		pxe_menu_draw_item ( menu, menu->selection, 1 );
239 
240 		/* Wait for keyboard input */
241 		while ( ! iskey() )
242 			step();
243 		key = getkey();
244 
245 		/* Unhighlight currently selected item */
246 		pxe_menu_draw_item ( menu, menu->selection, 0 );
247 
248 		/* Act upon key */
249 		if ( ( key == CR ) || ( key == LF ) ) {
250 			pxe_menu_draw_item ( menu, menu->selection, 1 );
251 			break;
252 		} else if ( ( key == CTRL_C ) || ( key == ESC ) ) {
253 			rc = -ECANCELED;
254 			break;
255 		} else if ( key == KEY_UP ) {
256 			if ( menu->selection > 0 )
257 				menu->selection--;
258 		} else if ( key == KEY_DOWN ) {
259 			if ( menu->selection < ( menu->num_items - 1 ) )
260 				menu->selection++;
261 		} else if ( ( key < KEY_MIN ) &&
262 			    ( ( key_selection = ( toupper ( key ) - 'A' ) )
263 			      < menu->num_items ) ) {
264 			menu->selection = key_selection;
265 			pxe_menu_draw_item ( menu, menu->selection, 1 );
266 			break;
267 		}
268 	}
269 
270 	/* Shut down UI */
271 	endwin();
272 
273 	return rc;
274 }
275 
276 /**
277  * Prompt for (and make selection from) PXE boot menu
278  *
279  * @v menu		PXE boot menu
280  * @ret rc		Return status code
281  */
pxe_menu_prompt_and_select(struct pxe_menu * menu)282 static int pxe_menu_prompt_and_select ( struct pxe_menu *menu ) {
283 	unsigned long start = currticks();
284 	unsigned long now;
285 	unsigned long elapsed;
286 	size_t len = 0;
287 	int key;
288 	int rc = 0;
289 
290 	/* Display menu immediately, if specified to do so */
291 	if ( menu->timeout < 0 ) {
292 		if ( menu->prompt )
293 			printf ( "%s\n", menu->prompt );
294 		return pxe_menu_select ( menu );
295 	}
296 
297 	/* Display prompt, if specified */
298 	if ( menu->prompt )
299 		printf ( "%s", menu->prompt );
300 
301 	/* Wait for timeout, if specified */
302 	while ( menu->timeout > 0 ) {
303 		if ( ! len )
304 			len = printf ( " (%d)", menu->timeout );
305 		if ( iskey() ) {
306 			key = getkey();
307 			if ( key == KEY_F8 ) {
308 				/* Display menu */
309 				printf ( "\n" );
310 				return pxe_menu_select ( menu );
311 			} else if ( ( key == CTRL_C ) || ( key == ESC ) ) {
312 				/* Abort */
313 				rc = -ECANCELED;
314 				break;
315 			} else {
316 				/* Stop waiting */
317 				break;
318 			}
319 		}
320 		now = currticks();
321 		elapsed = ( now - start );
322 		if ( elapsed >= TICKS_PER_SEC ) {
323 			menu->timeout -= 1;
324 			do {
325 				printf ( "\b \b" );
326 			} while ( --len );
327 			start = now;
328 		}
329 	}
330 
331 	/* Return with default option selected */
332 	printf ( "\n" );
333 	return rc;
334 }
335 
336 /**
337  * Boot using PXE boot menu
338  *
339  * @ret rc		Return status code
340  *
341  * Note that a success return status indicates that a PXE boot menu
342  * item has been selected, and that the DHCP session should perform a
343  * boot server request/ack.
344  */
pxe_menu_boot(struct net_device * netdev)345 int pxe_menu_boot ( struct net_device *netdev ) {
346 	struct pxe_menu *menu;
347 	unsigned int pxe_type;
348 	struct settings *pxebs_settings;
349 	struct in_addr next_server;
350 	char filename[256];
351 	int rc;
352 
353 	/* Parse and allocate boot menu */
354 	if ( ( rc = pxe_menu_parse ( &menu ) ) != 0 )
355 		return rc;
356 
357 	/* Make selection from boot menu */
358 	if ( ( rc = pxe_menu_prompt_and_select ( menu ) ) != 0 ) {
359 		free ( menu );
360 		return rc;
361 	}
362 	pxe_type = menu->items[menu->selection].type;
363 
364 	/* Free boot menu */
365 	free ( menu );
366 
367 	/* Return immediately if local boot selected */
368 	if ( ! pxe_type )
369 		return 0;
370 
371 	/* Attempt PXE Boot Server Discovery */
372 	if ( ( rc = pxebs ( netdev, pxe_type ) ) != 0 )
373 		return rc;
374 
375 	/* Attempt boot */
376 	pxebs_settings = find_settings ( PXEBS_SETTINGS_NAME );
377 	assert ( pxebs_settings );
378 	fetch_ipv4_setting ( pxebs_settings, &next_server_setting,
379 			     &next_server );
380 	fetch_string_setting ( pxebs_settings, &filename_setting,
381 			       filename, sizeof ( filename ) );
382 	return boot_next_server_and_filename ( next_server, filename );
383 }
384