1 /** @file
2 *
3 * PXE Preboot API
4 *
5 */
6
7 /* PXE API interface for Etherboot.
8 *
9 * Copyright (C) 2004 Michael Brown <mbrown@fensystems.co.uk>.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of the
14 * License, or any later version.
15 *
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26 FILE_LICENCE ( GPL2_OR_LATER );
27
28 #include <stdint.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <gpxe/uaccess.h>
32 #include <gpxe/dhcp.h>
33 #include <gpxe/fakedhcp.h>
34 #include <gpxe/device.h>
35 #include <gpxe/netdevice.h>
36 #include <gpxe/isapnp.h>
37 #include <gpxe/init.h>
38 #include <gpxe/if_ether.h>
39 #include <basemem_packet.h>
40 #include <biosint.h>
41 #include "pxe.h"
42 #include "pxe_call.h"
43
44 /* Avoid dragging in isapnp.o unnecessarily */
45 uint16_t isapnp_read_port;
46
47 /** Zero-based versions of PXENV_GET_CACHED_INFO::PacketType */
48 enum pxe_cached_info_indices {
49 CACHED_INFO_DHCPDISCOVER = ( PXENV_PACKET_TYPE_DHCP_DISCOVER - 1 ),
50 CACHED_INFO_DHCPACK = ( PXENV_PACKET_TYPE_DHCP_ACK - 1 ),
51 CACHED_INFO_BINL = ( PXENV_PACKET_TYPE_CACHED_REPLY - 1 ),
52 NUM_CACHED_INFOS
53 };
54
55 /** A cached DHCP packet */
56 union pxe_cached_info {
57 struct dhcphdr dhcphdr;
58 /* This buffer must be *exactly* the size of a BOOTPLAYER_t
59 * structure, otherwise WinPE will die horribly. It takes the
60 * size of *our* buffer and feeds it in to us as the size of
61 * one of *its* buffers. If our buffer is larger than it
62 * expects, we therefore end up overwriting part of its data
63 * segment, since it tells us to do so. (D'oh!)
64 *
65 * Note that a BOOTPLAYER_t is not necessarily large enough to
66 * hold a DHCP packet; this is a flaw in the PXE spec.
67 */
68 BOOTPLAYER_t packet;
69 } __attribute__ (( packed ));
70
71 /** A PXE DHCP packet creator */
72 struct pxe_dhcp_packet_creator {
73 /** Create DHCP packet
74 *
75 * @v netdev Network device
76 * @v data Buffer for DHCP packet
77 * @v max_len Size of DHCP packet buffer
78 * @ret rc Return status code
79 */
80 int ( * create ) ( struct net_device *netdev, void *data,
81 size_t max_len );
82 };
83
84 /** PXE DHCP packet creators */
85 static struct pxe_dhcp_packet_creator pxe_dhcp_packet_creators[] = {
86 [CACHED_INFO_DHCPDISCOVER] = { create_fakedhcpdiscover },
87 [CACHED_INFO_DHCPACK] = { create_fakedhcpack },
88 [CACHED_INFO_BINL] = { create_fakepxebsack },
89 };
90
91 /* The case in which the caller doesn't supply a buffer is really
92 * awkward to support given that we have multiple sources of options,
93 * and that we don't actually store the DHCP packets. (We may not
94 * even have performed DHCP; we may have obtained all configuration
95 * from non-volatile stored options or from the command line.)
96 *
97 * Some NBPs rely on the buffers we provide being persistent, so we
98 * can't just use the temporary packet buffer. 4.5kB of base memory
99 * always wasted just because some clients are too lazy to provide
100 * their own buffers...
101 */
102 static union pxe_cached_info __bss16_array ( cached_info, [NUM_CACHED_INFOS] );
103 #define cached_info __use_data16 ( cached_info )
104
105 /**
106 * Set PXE cached TFTP filename
107 *
108 * @v filename TFTP filename
109 *
110 * This is a bug-for-bug compatibility hack needed in order to work
111 * with Microsoft Remote Installation Services (RIS). The filename
112 * used in a call to PXENV_RESTART_TFTP or PXENV_TFTP_READ_FILE must
113 * be returned as the DHCP filename in subsequent calls to
114 * PXENV_GET_CACHED_INFO.
115 */
pxe_set_cached_filename(const unsigned char * filename)116 void pxe_set_cached_filename ( const unsigned char *filename ) {
117 memcpy ( cached_info[CACHED_INFO_DHCPACK].dhcphdr.file, filename,
118 sizeof ( cached_info[CACHED_INFO_DHCPACK].dhcphdr.file ) );
119 memcpy ( cached_info[CACHED_INFO_BINL].dhcphdr.file, filename,
120 sizeof ( cached_info[CACHED_INFO_BINL].dhcphdr.file ) );
121 }
122
123 /**
124 * UNLOAD BASE CODE STACK
125 *
126 * @v None -
127 * @ret ...
128 *
129 */
pxenv_unload_stack(struct s_PXENV_UNLOAD_STACK * unload_stack)130 PXENV_EXIT_t pxenv_unload_stack ( struct s_PXENV_UNLOAD_STACK *unload_stack ) {
131 DBG ( "PXENV_UNLOAD_STACK" );
132
133 unload_stack->Status = PXENV_STATUS_SUCCESS;
134 return PXENV_EXIT_SUCCESS;
135 }
136
137 /* PXENV_GET_CACHED_INFO
138 *
139 * Status: working
140 */
pxenv_get_cached_info(struct s_PXENV_GET_CACHED_INFO * get_cached_info)141 PXENV_EXIT_t pxenv_get_cached_info ( struct s_PXENV_GET_CACHED_INFO
142 *get_cached_info ) {
143 struct pxe_dhcp_packet_creator *creator;
144 union pxe_cached_info *info;
145 unsigned int idx;
146 size_t len;
147 userptr_t buffer;
148 int rc;
149
150 DBG ( "PXENV_GET_CACHED_INFO %d", get_cached_info->PacketType );
151
152 DBG ( " to %04x:%04x+%x", get_cached_info->Buffer.segment,
153 get_cached_info->Buffer.offset, get_cached_info->BufferSize );
154
155 /* Sanity check */
156 idx = ( get_cached_info->PacketType - 1 );
157 if ( idx >= NUM_CACHED_INFOS ) {
158 DBG ( " bad PacketType" );
159 goto err;
160 }
161 info = &cached_info[idx];
162
163 /* Construct cached version of packet, if not already constructed. */
164 if ( ! info->dhcphdr.op ) {
165 /* Construct DHCP packet */
166 creator = &pxe_dhcp_packet_creators[idx];
167 if ( ( rc = creator->create ( pxe_netdev, info,
168 sizeof ( *info ) ) ) != 0 ) {
169 DBG ( " failed to build packet" );
170 goto err;
171 }
172 }
173
174 len = get_cached_info->BufferSize;
175 if ( len == 0 ) {
176 /* Point client at our cached buffer.
177 *
178 * To add to the fun, Intel decided at some point in
179 * the evolution of the PXE specification to add the
180 * BufferLimit field, which we are meant to fill in
181 * with the length of our packet buffer, so that the
182 * caller can safely modify the boot server reply
183 * packet stored therein. However, this field was not
184 * present in earlier versions of the PXE spec, and
185 * there is at least one PXE NBP (Altiris) which
186 * allocates only exactly enough space for this
187 * earlier, shorter version of the structure. If we
188 * actually fill in the BufferLimit field, we
189 * therefore risk trashing random areas of the
190 * caller's memory. If we *don't* fill it in, then
191 * the caller is at liberty to assume that whatever
192 * random value happened to be in that location
193 * represents the length of the buffer we've just
194 * passed back to it.
195 *
196 * Since older PXE stacks won't fill this field in
197 * anyway, it's probably safe to assume that no
198 * callers actually rely on it, so we choose to not
199 * fill it in.
200 */
201 get_cached_info->Buffer.segment = rm_ds;
202 get_cached_info->Buffer.offset = __from_data16 ( info );
203 get_cached_info->BufferSize = sizeof ( *info );
204 DBG ( " returning %04x:%04x+%04x['%x']",
205 get_cached_info->Buffer.segment,
206 get_cached_info->Buffer.offset,
207 get_cached_info->BufferSize,
208 get_cached_info->BufferLimit );
209 } else {
210 /* Copy packet to client buffer */
211 if ( len > sizeof ( *info ) )
212 len = sizeof ( *info );
213 if ( len < sizeof ( *info ) )
214 DBG ( " buffer may be too short" );
215 buffer = real_to_user ( get_cached_info->Buffer.segment,
216 get_cached_info->Buffer.offset );
217 copy_to_user ( buffer, 0, info, len );
218 get_cached_info->BufferSize = len;
219 }
220
221 get_cached_info->Status = PXENV_STATUS_SUCCESS;
222 return PXENV_EXIT_SUCCESS;
223
224 err:
225 get_cached_info->Status = PXENV_STATUS_OUT_OF_RESOURCES;
226 return PXENV_EXIT_FAILURE;
227 }
228
229 /* PXENV_RESTART_TFTP
230 *
231 * Status: working
232 */
pxenv_restart_tftp(struct s_PXENV_TFTP_READ_FILE * restart_tftp)233 PXENV_EXIT_t pxenv_restart_tftp ( struct s_PXENV_TFTP_READ_FILE
234 *restart_tftp ) {
235 PXENV_EXIT_t tftp_exit;
236
237 DBG ( "PXENV_RESTART_TFTP " );
238
239 /* Intel bug-for-bug hack */
240 pxe_set_cached_filename ( restart_tftp->FileName );
241
242 /* Words cannot describe the complete mismatch between the PXE
243 * specification and any possible version of reality...
244 */
245 restart_tftp->Buffer = PXE_LOAD_PHYS; /* Fixed by spec, apparently */
246 restart_tftp->BufferSize = ( 0xa0000 - PXE_LOAD_PHYS ); /* Near enough */
247 tftp_exit = pxenv_tftp_read_file ( restart_tftp );
248 if ( tftp_exit != PXENV_EXIT_SUCCESS )
249 return tftp_exit;
250
251 /* Fire up the new NBP */
252 restart_tftp->Status = pxe_start_nbp();
253
254 /* Not sure what "SUCCESS" actually means, since we can only
255 * return if the new NBP failed to boot...
256 */
257 return PXENV_EXIT_SUCCESS;
258 }
259
260 /* PXENV_START_UNDI
261 *
262 * Status: working
263 */
pxenv_start_undi(struct s_PXENV_START_UNDI * start_undi)264 PXENV_EXIT_t pxenv_start_undi ( struct s_PXENV_START_UNDI *start_undi ) {
265 unsigned int bus_type;
266 unsigned int location;
267 struct net_device *netdev;
268
269 DBG ( "PXENV_START_UNDI %04x:%04x:%04x",
270 start_undi->AX, start_undi->BX, start_undi->DX );
271
272 /* Determine bus type and location. Use a heuristic to decide
273 * whether we are PCI or ISAPnP
274 */
275 if ( ( start_undi->DX >= ISAPNP_READ_PORT_MIN ) &&
276 ( start_undi->DX <= ISAPNP_READ_PORT_MAX ) &&
277 ( start_undi->BX >= ISAPNP_CSN_MIN ) &&
278 ( start_undi->BX <= ISAPNP_CSN_MAX ) ) {
279 bus_type = BUS_TYPE_ISAPNP;
280 location = start_undi->BX;
281 /* Record ISAPnP read port for use by isapnp.c */
282 isapnp_read_port = start_undi->DX;
283 } else {
284 bus_type = BUS_TYPE_PCI;
285 location = start_undi->AX;
286 }
287
288 /* Probe for devices, etc. */
289 startup();
290
291 /* Look for a matching net device */
292 netdev = find_netdev_by_location ( bus_type, location );
293 if ( ! netdev ) {
294 DBG ( " no net device found" );
295 start_undi->Status = PXENV_STATUS_UNDI_CANNOT_INITIALIZE_NIC;
296 return PXENV_EXIT_FAILURE;
297 }
298 DBG ( " using netdev %s", netdev->name );
299
300 /* Activate PXE */
301 pxe_activate ( netdev );
302
303 start_undi->Status = PXENV_STATUS_SUCCESS;
304 return PXENV_EXIT_SUCCESS;
305 }
306
307 /* PXENV_STOP_UNDI
308 *
309 * Status: working
310 */
pxenv_stop_undi(struct s_PXENV_STOP_UNDI * stop_undi)311 PXENV_EXIT_t pxenv_stop_undi ( struct s_PXENV_STOP_UNDI *stop_undi ) {
312 DBG ( "PXENV_STOP_UNDI" );
313
314 /* Deactivate PXE */
315 pxe_deactivate();
316
317 /* Prepare for unload */
318 shutdown ( SHUTDOWN_BOOT );
319
320 /* Check to see if we still have any hooked interrupts */
321 if ( hooked_bios_interrupts != 0 ) {
322 DBG ( "PXENV_STOP_UNDI failed: %d interrupts still hooked\n",
323 hooked_bios_interrupts );
324 stop_undi->Status = PXENV_STATUS_KEEP_UNDI;
325 return PXENV_EXIT_FAILURE;
326 }
327
328 stop_undi->Status = PXENV_STATUS_SUCCESS;
329 return PXENV_EXIT_SUCCESS;
330 }
331
332 /* PXENV_START_BASE
333 *
334 * Status: won't implement (requires major structural changes)
335 */
pxenv_start_base(struct s_PXENV_START_BASE * start_base)336 PXENV_EXIT_t pxenv_start_base ( struct s_PXENV_START_BASE *start_base ) {
337 DBG ( "PXENV_START_BASE" );
338
339 start_base->Status = PXENV_STATUS_UNSUPPORTED;
340 return PXENV_EXIT_FAILURE;
341 }
342
343 /* PXENV_STOP_BASE
344 *
345 * Status: working
346 */
pxenv_stop_base(struct s_PXENV_STOP_BASE * stop_base)347 PXENV_EXIT_t pxenv_stop_base ( struct s_PXENV_STOP_BASE *stop_base ) {
348 DBG ( "PXENV_STOP_BASE" );
349
350 /* The only time we will be called is when the NBP is trying
351 * to shut down the PXE stack. There's nothing we need to do
352 * in this call.
353 */
354
355 stop_base->Status = PXENV_STATUS_SUCCESS;
356 return PXENV_EXIT_SUCCESS;
357 }
358