freebsd-nq/sys/dev/sfxge/common/efx_bootcfg.c
Andrew Rybchenko 460cb5684c sfxge: add prefast annotation to common code return types
Using a typedef for common code return types (rather than "int")
allows the Prefast static analyser to understand when a function
has been successful (and thus when its postconditions must hold).

This greatly reduces then number of false positives reported by
prefast for error paths in common code functions.

Submitted by:   Andy Moreton <amoreton at solarflare.com>
Sponsored by:   Solarflare Communications, Inc.
MFC after:      2 days
2015-11-29 05:42:49 +00:00

351 lines
8.4 KiB
C

/*-
* Copyright (c) 2009-2015 Solarflare Communications Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are
* those of the authors and should not be interpreted as representing official
* policies, either expressed or implied, of the FreeBSD Project.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "efsys.h"
#include "efx.h"
#include "efx_types.h"
#include "efx_impl.h"
#if EFSYS_OPT_BOOTCFG
/*
* Maximum size of BOOTCFG block across all nics as understood by SFCgPXE.
* A multiple of 0x100 so trailing 0xff characters don't contrinbute to the
* checksum.
*/
#define BOOTCFG_MAX_SIZE 0x1000
#define DHCP_END (uint8_t)0xff
#define DHCP_PAD (uint8_t)0
static __checkReturn uint8_t
efx_bootcfg_csum(
__in efx_nic_t *enp,
__in_bcount(size) caddr_t data,
__in size_t size)
{
_NOTE(ARGUNUSED(enp))
unsigned int pos;
uint8_t checksum = 0;
for (pos = 0; pos < size; pos++)
checksum += data[pos];
return (checksum);
}
static __checkReturn efx_rc_t
efx_bootcfg_verify(
__in efx_nic_t *enp,
__in_bcount(size) caddr_t data,
__in size_t size,
__out_opt size_t *usedp)
{
size_t offset = 0;
size_t used = 0;
efx_rc_t rc;
/* Start parsing tags immediatly after the checksum */
for (offset = 1; offset < size; ) {
uint8_t tag;
uint8_t length;
/* Consume tag */
tag = data[offset];
if (tag == DHCP_END) {
offset++;
used = offset;
break;
}
if (tag == DHCP_PAD) {
offset++;
continue;
}
/* Consume length */
if (offset + 1 >= size) {
rc = ENOSPC;
goto fail1;
}
length = data[offset + 1];
/* Consume *length */
if (offset + 1 + length >= size) {
rc = ENOSPC;
goto fail2;
}
offset += 2 + length;
used = offset;
}
/* Checksum the entire sector, including bytes after any DHCP_END */
if (efx_bootcfg_csum(enp, data, size) != 0) {
rc = EINVAL;
goto fail3;
}
if (usedp != NULL)
*usedp = used;
return (0);
fail3:
EFSYS_PROBE(fail3);
fail2:
EFSYS_PROBE(fail2);
fail1:
EFSYS_PROBE1(fail1, efx_rc_t, rc);
return (rc);
}
efx_rc_t
efx_bootcfg_read(
__in efx_nic_t *enp,
__out_bcount(size) caddr_t data,
__in size_t size)
{
uint8_t *payload = NULL;
size_t used_bytes;
size_t sector_length;
efx_rc_t rc;
rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
if (rc != 0)
goto fail1;
/*
* We need to read the entire BOOTCFG area to ensure we read all the
* tags, because legacy bootcfg sectors are not guaranteed to end with
* a DHCP_END character. If the user hasn't supplied a sufficiently
* large buffer then use our own buffer.
*/
if (sector_length > BOOTCFG_MAX_SIZE)
sector_length = BOOTCFG_MAX_SIZE;
if (sector_length > size) {
EFSYS_KMEM_ALLOC(enp->en_esip, sector_length, payload);
if (payload == NULL) {
rc = ENOMEM;
goto fail2;
}
} else
payload = (uint8_t *)data;
if ((rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, NULL)) != 0)
goto fail3;
rc = efx_nvram_read_chunk(enp, EFX_NVRAM_BOOTROM_CFG, 0,
(caddr_t)payload, sector_length);
efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
if (rc != 0)
goto fail4;
/* Verify that the area is correctly formatted and checksummed */
rc = efx_bootcfg_verify(enp, (caddr_t)payload, sector_length,
&used_bytes);
if (rc != 0 || used_bytes == 0) {
payload[0] = (uint8_t)~DHCP_END;
payload[1] = DHCP_END;
used_bytes = 2;
}
EFSYS_ASSERT(used_bytes >= 2); /* checksum and DHCP_END */
EFSYS_ASSERT(used_bytes <= sector_length);
/*
* Legacy bootcfg sectors don't terminate with a DHCP_END character.
* Modify the returned payload so it does. BOOTCFG_MAX_SIZE is by
* definition large enough for any valid (per-port) bootcfg sector,
* so reinitialise the sector if there isn't room for the character.
*/
if (payload[used_bytes - 1] != DHCP_END) {
if (used_bytes + 1 > sector_length) {
payload[0] = 0;
used_bytes = 1;
}
payload[used_bytes] = DHCP_END;
++used_bytes;
}
/*
* Verify that the user supplied buffer is large enough for the
* entire used bootcfg area, then copy into the user supplied buffer.
*/
if (used_bytes > size) {
rc = ENOSPC;
goto fail5;
}
if (sector_length > size) {
memcpy(data, payload, used_bytes);
EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
}
/* Zero out the unused portion of the user buffer */
if (used_bytes < size)
(void) memset(data + used_bytes, 0, size - used_bytes);
/*
* The checksum includes trailing data after any DHCP_END character,
* which we've just modified (by truncation or appending DHCP_END).
*/
data[0] -= efx_bootcfg_csum(enp, data, size);
return (0);
fail5:
EFSYS_PROBE(fail5);
fail4:
EFSYS_PROBE(fail4);
fail3:
EFSYS_PROBE(fail3);
if (sector_length > size)
EFSYS_KMEM_FREE(enp->en_esip, sector_length, payload);
fail2:
EFSYS_PROBE(fail2);
fail1:
EFSYS_PROBE1(fail1, efx_rc_t, rc);
return (rc);
}
efx_rc_t
efx_bootcfg_write(
__in efx_nic_t *enp,
__in_bcount(size) caddr_t data,
__in size_t size)
{
uint8_t *chunk;
uint8_t checksum;
size_t sector_length;
size_t chunk_length;
size_t used_bytes;
size_t offset;
size_t remaining;
efx_rc_t rc;
rc = efx_nvram_size(enp, EFX_NVRAM_BOOTROM_CFG, &sector_length);
if (rc != 0)
goto fail1;
if (sector_length > BOOTCFG_MAX_SIZE)
sector_length = BOOTCFG_MAX_SIZE;
if ((rc = efx_bootcfg_verify(enp, data, size, &used_bytes)) != 0)
goto fail2;
/* The caller *must* terminate their block with a DHCP_END character */
EFSYS_ASSERT(used_bytes >= 2); /* checksum and DHCP_END */
if ((uint8_t)data[used_bytes - 1] != DHCP_END) {
rc = ENOENT;
goto fail3;
}
/* Check that the hardware has support for this much data */
if (used_bytes > MIN(sector_length, BOOTCFG_MAX_SIZE)) {
rc = ENOSPC;
goto fail4;
}
rc = efx_nvram_rw_start(enp, EFX_NVRAM_BOOTROM_CFG, &chunk_length);
if (rc != 0)
goto fail5;
EFSYS_KMEM_ALLOC(enp->en_esip, chunk_length, chunk);
if (chunk == NULL) {
rc = ENOMEM;
goto fail6;
}
if ((rc = efx_nvram_erase(enp, EFX_NVRAM_BOOTROM_CFG)) != 0)
goto fail7;
/*
* Write the entire sector_length bytes of data in chunks. Zero out
* all data following the DHCP_END, and adjust the checksum
*/
checksum = efx_bootcfg_csum(enp, data, used_bytes);
for (offset = 0; offset < sector_length; offset += remaining) {
remaining = MIN(chunk_length, sector_length - offset);
/* Fill chunk */
(void) memset(chunk, 0x0, chunk_length);
if (offset < used_bytes)
memcpy(chunk, data + offset,
MIN(remaining, used_bytes - offset));
/* Adjust checksum */
if (offset == 0)
chunk[0] -= checksum;
if ((rc = efx_nvram_write_chunk(enp, EFX_NVRAM_BOOTROM_CFG,
offset, (caddr_t)chunk, remaining)) != 0)
goto fail8;
}
efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
return (0);
fail8:
EFSYS_PROBE(fail8);
fail7:
EFSYS_PROBE(fail7);
EFSYS_KMEM_FREE(enp->en_esip, chunk_length, chunk);
fail6:
EFSYS_PROBE(fail6);
efx_nvram_rw_finish(enp, EFX_NVRAM_BOOTROM_CFG);
fail5:
EFSYS_PROBE(fail5);
fail4:
EFSYS_PROBE(fail4);
fail3:
EFSYS_PROBE(fail3);
fail2:
EFSYS_PROBE(fail2);
fail1:
EFSYS_PROBE1(fail1, efx_rc_t, rc);
return (rc);
}
#endif /* EFSYS_OPT_BOOTCFG */