1/*
2 * Copyright (c) 2009-2015 Solarflare Communications Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 *    this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 *    this list of conditions and the following disclaimer in the documentation
12 *    and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
15 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
24 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * The views and conclusions contained in the software and documentation are
27 * those of the authors and should not be interpreted as representing official
28 * policies, either expressed or implied, of the FreeBSD Project.
29 */
30
31#include "efx.h"
32#include "efx_impl.h"
33
34#if EFSYS_OPT_BOOTCFG
35
36/*
37 * Maximum size of BOOTCFG block across all nics as understood by SFCgPXE.
38 * A multiple of 0x100 so trailing 0xff characters don't contrinbute to the
39 * checksum.
40 */
41#define	BOOTCFG_MAX_SIZE 0x1000
42
43#define	DHCP_END (uint8_t)0xff
44#define	DHCP_PAD (uint8_t)0
45
46static	__checkReturn		uint8_t
47efx_bootcfg_csum(
48	__in			efx_nic_t *enp,
49	__in_bcount(size)	caddr_t data,
50	__in			size_t size)
51{
52	_NOTE(ARGUNUSED(enp))
53
54	unsigned int pos;
55	uint8_t checksum = 0;
56
57	for (pos = 0; pos < size; pos++)
58		checksum += data[pos];
59	return (checksum);
60}
61
62static	__checkReturn		efx_rc_t
63efx_bootcfg_verify(
64	__in			efx_nic_t *enp,
65	__in_bcount(size)	caddr_t data,
66	__in			size_t size,
67	__out_opt		size_t *usedp)
68{
69	size_t offset = 0;
70	size_t used = 0;
71	efx_rc_t rc;
72
73	/* Start parsing tags immediatly after the checksum */
74	for (offset = 1; offset < size; ) {
75		uint8_t tag;
76		uint8_t length;
77
78		/* Consume tag */
79		tag = data[offset];
80		if (tag == DHCP_END) {
81			offset++;
82			used = offset;
83			break;
84		}
85		if (tag == DHCP_PAD) {
86			offset++;
87			continue;
88		}
89
90		/* Consume length */
91		if (offset + 1 >= size) {
92			rc = ENOSPC;
93			goto fail1;
94		}
95		length = data[offset + 1];
96
97		/* Consume *length */
98		if (offset + 1 + length >= size) {
99			rc = ENOSPC;
100			goto fail2;
101		}
102
103		offset += 2 + length;
104		used = offset;
105	}
106
107	/* Checksum the entire sector, including bytes after any DHCP_END */
108	if (efx_bootcfg_csum(enp, data, size) != 0) {
109		rc = EINVAL;
110		goto fail3;
111	}
112
113	if (usedp != NULL)
114		*usedp = used;
115
116	return (0);
117
118fail3:
119	EFSYS_PROBE(fail3);
120fail2:
121	EFSYS_PROBE(fail2);
122fail1:
123	EFSYS_PROBE1(fail1, efx_rc_t, rc);
124
125	return (rc);
126}
127
128				efx_rc_t
129efx_bootcfg_read(
130	__in			efx_nic_t *enp,
131	__out_bcount(size)	caddr_t data,
132	__in			size_t size)
133{
134	uint8_t *payload = NULL;
135	size_t used_bytes;
136	size_t sector_length;
137	efx_rc_t rc;
138
139	rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
140	if (rc != 0)
141		goto fail1;
142
143	/*
144	 * We need to read the entire BOOTCFG area to ensure we read all the
145	 * tags, because legacy bootcfg sectors are not guaranteed to end with
146	 * a DHCP_END character. If the user hasn't supplied a sufficiently
147	 * large buffer then use our own buffer.
148	 */
149	if (sector_length > BOOTCFG_MAX_SIZE)
150		sector_length = BOOTCFG_MAX_SIZE;
151	if (sector_length > size) {
152		EFSYS_KMEM_ALLOC(enp->en_esip, sector_length, payload);
153		if (payload == NULL) {
154			rc = ENOMEM;
155			goto fail2;
156		}
157	} else
158		payload = (uint8_t *)data;
159
160	if ((rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, NULL)) != 0)
161		goto fail3;
162
163	rc = efx_nvram_read_chunk(enp, EFX_NVRAM_BOOTROM_CFG, 0,
164				    (caddr_t)payload, sector_length);
165
166	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
167
168	if (rc != 0)
169		goto fail4;
170
171	/* Verify that the area is correctly formatted and checksummed */
172	rc = efx_bootcfg_verify(enp, (caddr_t)payload, sector_length,
173				    &used_bytes);
174	if (rc != 0 || used_bytes == 0) {
175		payload[0] = (uint8_t)~DHCP_END;
176		payload[1] = DHCP_END;
177		used_bytes = 2;
178	}
179
180	EFSYS_ASSERT(used_bytes >= 2);	/* checksum and DHCP_END */
181	EFSYS_ASSERT(used_bytes <= sector_length);
182
183	/*
184	 * Legacy bootcfg sectors don't terminate with a DHCP_END character.
185	 * Modify the returned payload so it does. BOOTCFG_MAX_SIZE is by
186	 * definition large enough for any valid (per-port) bootcfg sector,
187	 * so reinitialise the sector if there isn't room for the character.
188	 */
189	if (payload[used_bytes - 1] != DHCP_END) {
190		if (used_bytes + 1 > sector_length) {
191			payload[0] = 0;
192			used_bytes = 1;
193		}
194
195		payload[used_bytes] = DHCP_END;
196		++used_bytes;
197	}
198
199	/*
200	 * Verify that the user supplied buffer is large enough for the
201	 * entire used bootcfg area, then copy into the user supplied buffer.
202	 */
203	if (used_bytes > size) {
204		rc = ENOSPC;
205		goto fail5;
206	}
207	if (sector_length > size) {
208		(void) memcpy(data, payload, used_bytes);
209		EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
210	}
211
212	/* Zero out the unused portion of the user buffer */
213	if (used_bytes < size)
214		(void) memset(data + used_bytes, 0, size - used_bytes);
215
216	/*
217	 * The checksum includes trailing data after any DHCP_END character,
218	 * which we've just modified (by truncation or appending DHCP_END).
219	 */
220	data[0] -= efx_bootcfg_csum(enp, data, size);
221
222	return (0);
223
224fail5:
225	EFSYS_PROBE(fail5);
226fail4:
227	EFSYS_PROBE(fail4);
228fail3:
229	EFSYS_PROBE(fail3);
230
231	if (sector_length > size)
232		EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
233fail2:
234	EFSYS_PROBE(fail2);
235fail1:
236	EFSYS_PROBE1(fail1, efx_rc_t, rc);
237
238	return (rc);
239}
240
241				efx_rc_t
242efx_bootcfg_write(
243	__in			efx_nic_t *enp,
244	__in_bcount(size)	caddr_t data,
245	__in			size_t size)
246{
247	uint8_t *chunk;
248	uint8_t checksum;
249	size_t sector_length;
250	size_t chunk_length;
251	size_t used_bytes;
252	size_t offset;
253	size_t remaining;
254	efx_rc_t rc;
255
256	rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
257	if (rc != 0)
258		goto fail1;
259
260	if (sector_length > BOOTCFG_MAX_SIZE)
261		sector_length = BOOTCFG_MAX_SIZE;
262
263	if ((rc = efx_bootcfg_verify(enp, data, size, &used_bytes)) != 0)
264		goto fail2;
265
266	/* The caller *must* terminate their block with a DHCP_END character */
267	EFSYS_ASSERT(used_bytes >= 2);		/* checksum and DHCP_END */
268	if ((uint8_t)data[used_bytes - 1] != DHCP_END) {
269		rc = ENOENT;
270		goto fail3;
271	}
272
273	/* Check that the hardware has support for this much data */
274	if (used_bytes > MIN(sector_length, BOOTCFG_MAX_SIZE)) {
275		rc = ENOSPC;
276		goto fail4;
277	}
278
279	rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, &chunk_length);
280	if (rc != 0)
281		goto fail5;
282
283	EFSYS_KMEM_ALLOC(enp->en_esip, chunk_length, chunk);
284	if (chunk == NULL) {
285		rc = ENOMEM;
286		goto fail6;
287	}
288
289	if ((rc = efx_nvram_erase(enp, EFX_NVRAM_BOOTROM_CFG)) != 0)
290		goto fail7;
291
292	/*
293	 * Write the entire sector_length bytes of data in chunks. Zero out
294	 * all data following the DHCP_END, and adjust the checksum
295	 */
296	checksum = efx_bootcfg_csum(enp, data, used_bytes);
297	for (offset = 0; offset < sector_length; offset += remaining) {
298		remaining = MIN(chunk_length, sector_length - offset);
299
300		/* Fill chunk */
301		(void) memset(chunk, 0x0, chunk_length);
302		if (offset < used_bytes)
303			(void) memcpy(chunk, data + offset,
304			    MIN(remaining, used_bytes - offset));
305
306		/* Adjust checksum */
307		if (offset == 0)
308			chunk[0] -= checksum;
309
310		if ((rc = efx_nvram_write_chunk(enp, EFX_NVRAM_BOOTROM_CFG,
311			    offset, (caddr_t)chunk, remaining)) != 0)
312			goto fail8;
313	}
314
315	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
316
317	EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
318
319	return (0);
320
321fail8:
322	EFSYS_PROBE(fail8);
323fail7:
324	EFSYS_PROBE(fail7);
325
326	EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
327fail6:
328	EFSYS_PROBE(fail6);
329
330	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
331fail5:
332	EFSYS_PROBE(fail5);
333fail4:
334	EFSYS_PROBE(fail4);
335fail3:
336	EFSYS_PROBE(fail3);
337fail2:
338	EFSYS_PROBE(fail2);
339fail1:
340	EFSYS_PROBE1(fail1, efx_rc_t, rc);
341
342	return (rc);
343}
344
345#endif	/* EFSYS_OPT_BOOTCFG */
346