xref: /freebsd/sys/dev/sfxge/common/efx_bootcfg.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
1 /*-
2  * Copyright (c) 2009-2016 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 <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include "efx.h"
35 #include "efx_impl.h"
36 
37 #if EFSYS_OPT_BOOTCFG
38 
39 /*
40  * Maximum size of BOOTCFG block across all nics as understood by SFCgPXE.
41  * A multiple of 0x100 so trailing 0xff characters don't contrinbute to the
42  * checksum.
43  */
44 #define	BOOTCFG_MAX_SIZE 0x1000
45 
46 #define	DHCP_END (uint8_t)0xff
47 #define	DHCP_PAD (uint8_t)0
48 
49 static	__checkReturn		uint8_t
50 efx_bootcfg_csum(
51 	__in			efx_nic_t *enp,
52 	__in_bcount(size)	caddr_t data,
53 	__in			size_t size)
54 {
55 	_NOTE(ARGUNUSED(enp))
56 
57 	unsigned int pos;
58 	uint8_t checksum = 0;
59 
60 	for (pos = 0; pos < size; pos++)
61 		checksum += data[pos];
62 	return (checksum);
63 }
64 
65 static	__checkReturn		efx_rc_t
66 efx_bootcfg_verify(
67 	__in			efx_nic_t *enp,
68 	__in_bcount(size)	caddr_t data,
69 	__in			size_t size,
70 	__out_opt		size_t *usedp)
71 {
72 	size_t offset = 0;
73 	size_t used = 0;
74 	efx_rc_t rc;
75 
76 	/* Start parsing tags immediately after the checksum */
77 	for (offset = 1; offset < size; ) {
78 		uint8_t tag;
79 		uint8_t length;
80 
81 		/* Consume tag */
82 		tag = data[offset];
83 		if (tag == DHCP_END) {
84 			offset++;
85 			used = offset;
86 			break;
87 		}
88 		if (tag == DHCP_PAD) {
89 			offset++;
90 			continue;
91 		}
92 
93 		/* Consume length */
94 		if (offset + 1 >= size) {
95 			rc = ENOSPC;
96 			goto fail1;
97 		}
98 		length = data[offset + 1];
99 
100 		/* Consume *length */
101 		if (offset + 1 + length >= size) {
102 			rc = ENOSPC;
103 			goto fail2;
104 		}
105 
106 		offset += 2 + length;
107 		used = offset;
108 	}
109 
110 	/* Checksum the entire sector, including bytes after any DHCP_END */
111 	if (efx_bootcfg_csum(enp, data, size) != 0) {
112 		rc = EINVAL;
113 		goto fail3;
114 	}
115 
116 	if (usedp != NULL)
117 		*usedp = used;
118 
119 	return (0);
120 
121 fail3:
122 	EFSYS_PROBE(fail3);
123 fail2:
124 	EFSYS_PROBE(fail2);
125 fail1:
126 	EFSYS_PROBE1(fail1, efx_rc_t, rc);
127 
128 	return (rc);
129 }
130 
131 				efx_rc_t
132 efx_bootcfg_read(
133 	__in			efx_nic_t *enp,
134 	__out_bcount(size)	caddr_t data,
135 	__in			size_t size)
136 {
137 	uint8_t *payload = NULL;
138 	size_t used_bytes;
139 	size_t sector_length;
140 	efx_rc_t rc;
141 
142 	rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
143 	if (rc != 0)
144 		goto fail1;
145 
146 	/*
147 	 * We need to read the entire BOOTCFG area to ensure we read all the
148 	 * tags, because legacy bootcfg sectors are not guaranteed to end with
149 	 * a DHCP_END character. If the user hasn't supplied a sufficiently
150 	 * large buffer then use our own buffer.
151 	 */
152 	if (sector_length > BOOTCFG_MAX_SIZE)
153 		sector_length = BOOTCFG_MAX_SIZE;
154 	if (sector_length > size) {
155 		EFSYS_KMEM_ALLOC(enp->en_esip, sector_length, payload);
156 		if (payload == NULL) {
157 			rc = ENOMEM;
158 			goto fail2;
159 		}
160 	} else
161 		payload = (uint8_t *)data;
162 
163 	if ((rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, NULL)) != 0)
164 		goto fail3;
165 
166 	rc = efx_nvram_read_chunk(enp, EFX_NVRAM_BOOTROM_CFG, 0,
167 				    (caddr_t)payload, sector_length);
168 
169 	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
170 
171 	if (rc != 0)
172 		goto fail4;
173 
174 	/* Verify that the area is correctly formatted and checksummed */
175 	rc = efx_bootcfg_verify(enp, (caddr_t)payload, sector_length,
176 				    &used_bytes);
177 	if (rc != 0 || used_bytes == 0) {
178 		payload[0] = (uint8_t)~DHCP_END;
179 		payload[1] = DHCP_END;
180 		used_bytes = 2;
181 	}
182 
183 	EFSYS_ASSERT(used_bytes >= 2);	/* checksum and DHCP_END */
184 	EFSYS_ASSERT(used_bytes <= sector_length);
185 
186 	/*
187 	 * Legacy bootcfg sectors don't terminate with a DHCP_END character.
188 	 * Modify the returned payload so it does. BOOTCFG_MAX_SIZE is by
189 	 * definition large enough for any valid (per-port) bootcfg sector,
190 	 * so reinitialise the sector if there isn't room for the character.
191 	 */
192 	if (payload[used_bytes - 1] != DHCP_END) {
193 		if (used_bytes + 1 > sector_length) {
194 			payload[0] = 0;
195 			used_bytes = 1;
196 		}
197 
198 		payload[used_bytes] = DHCP_END;
199 		++used_bytes;
200 	}
201 
202 	/*
203 	 * Verify that the user supplied buffer is large enough for the
204 	 * entire used bootcfg area, then copy into the user supplied buffer.
205 	 */
206 	if (used_bytes > size) {
207 		rc = ENOSPC;
208 		goto fail5;
209 	}
210 	if (sector_length > size) {
211 		memcpy(data, payload, used_bytes);
212 		EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
213 	}
214 
215 	/* Zero out the unused portion of the user buffer */
216 	if (used_bytes < size)
217 		(void) memset(data + used_bytes, 0, size - used_bytes);
218 
219 	/*
220 	 * The checksum includes trailing data after any DHCP_END character,
221 	 * which we've just modified (by truncation or appending DHCP_END).
222 	 */
223 	data[0] -= efx_bootcfg_csum(enp, data, size);
224 
225 	return (0);
226 
227 fail5:
228 	EFSYS_PROBE(fail5);
229 fail4:
230 	EFSYS_PROBE(fail4);
231 fail3:
232 	EFSYS_PROBE(fail3);
233 
234 	if (sector_length > size)
235 		EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
236 fail2:
237 	EFSYS_PROBE(fail2);
238 fail1:
239 	EFSYS_PROBE1(fail1, efx_rc_t, rc);
240 
241 	return (rc);
242 }
243 
244 				efx_rc_t
245 efx_bootcfg_write(
246 	__in			efx_nic_t *enp,
247 	__in_bcount(size)	caddr_t data,
248 	__in			size_t size)
249 {
250 	uint8_t *chunk;
251 	uint8_t checksum;
252 	size_t sector_length;
253 	size_t chunk_length;
254 	size_t used_bytes;
255 	size_t offset;
256 	size_t remaining;
257 	efx_rc_t rc;
258 
259 	rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
260 	if (rc != 0)
261 		goto fail1;
262 
263 	if (sector_length > BOOTCFG_MAX_SIZE)
264 		sector_length = BOOTCFG_MAX_SIZE;
265 
266 	if ((rc = efx_bootcfg_verify(enp, data, size, &used_bytes)) != 0)
267 		goto fail2;
268 
269 	/* The caller *must* terminate their block with a DHCP_END character */
270 	EFSYS_ASSERT(used_bytes >= 2);		/* checksum and DHCP_END */
271 	if ((uint8_t)data[used_bytes - 1] != DHCP_END) {
272 		rc = ENOENT;
273 		goto fail3;
274 	}
275 
276 	/* Check that the hardware has support for this much data */
277 	if (used_bytes > MIN(sector_length, BOOTCFG_MAX_SIZE)) {
278 		rc = ENOSPC;
279 		goto fail4;
280 	}
281 
282 	rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, &chunk_length);
283 	if (rc != 0)
284 		goto fail5;
285 
286 	EFSYS_KMEM_ALLOC(enp->en_esip, chunk_length, chunk);
287 	if (chunk == NULL) {
288 		rc = ENOMEM;
289 		goto fail6;
290 	}
291 
292 	if ((rc = efx_nvram_erase(enp, EFX_NVRAM_BOOTROM_CFG)) != 0)
293 		goto fail7;
294 
295 	/*
296 	 * Write the entire sector_length bytes of data in chunks. Zero out
297 	 * all data following the DHCP_END, and adjust the checksum
298 	 */
299 	checksum = efx_bootcfg_csum(enp, data, used_bytes);
300 	for (offset = 0; offset < sector_length; offset += remaining) {
301 		remaining = MIN(chunk_length, sector_length - offset);
302 
303 		/* Fill chunk */
304 		(void) memset(chunk, 0x0, chunk_length);
305 		if (offset < used_bytes)
306 			memcpy(chunk, data + offset,
307 			    MIN(remaining, used_bytes - offset));
308 
309 		/* Adjust checksum */
310 		if (offset == 0)
311 			chunk[0] -= checksum;
312 
313 		if ((rc = efx_nvram_write_chunk(enp, EFX_NVRAM_BOOTROM_CFG,
314 			    offset, (caddr_t)chunk, remaining)) != 0)
315 			goto fail8;
316 	}
317 
318 	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
319 
320 	EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
321 
322 	return (0);
323 
324 fail8:
325 	EFSYS_PROBE(fail8);
326 fail7:
327 	EFSYS_PROBE(fail7);
328 
329 	EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
330 fail6:
331 	EFSYS_PROBE(fail6);
332 
333 	efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
334 fail5:
335 	EFSYS_PROBE(fail5);
336 fail4:
337 	EFSYS_PROBE(fail4);
338 fail3:
339 	EFSYS_PROBE(fail3);
340 fail2:
341 	EFSYS_PROBE(fail2);
342 fail1:
343 	EFSYS_PROBE1(fail1, efx_rc_t, rc);
344 
345 	return (rc);
346 }
347 
348 #endif	/* EFSYS_OPT_BOOTCFG */
349