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/*
* Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <errno.h>
#include <assert.h>
#include <ipxe/uaccess.h>
#include <ipxe/sha256.h>
#include <ipxe/sha512.h>
#include <ipxe/hmac.h>
#include <ipxe/base16.h>
#include <ipxe/pccrc.h>
/** @file
*
* Peer Content Caching and Retrieval: Content Identification [MS-PCCRC]
*
*/
/******************************************************************************
*
* Utility functions
*
******************************************************************************
*/
/**
* Transcribe hash value (for debugging)
*
* @v info Content information
* @v hash Hash value
* @ret string Hash value string
*/
static inline const char *
peerdist_info_hash_ntoa ( const struct peerdist_info *info, const void *hash ) {
static char buf[ ( 2 * PEERDIST_DIGEST_MAX_SIZE ) + 1 /* NUL */ ];
size_t digestsize = info->digestsize;
/* Sanity check */
assert ( info != NULL );
assert ( digestsize != 0 );
assert ( base16_encoded_len ( digestsize ) < sizeof ( buf ) );
/* Transcribe hash value */
base16_encode ( hash, digestsize, buf, sizeof ( buf ) );
return buf;
}
/**
* Get raw data
*
* @v info Content information
* @v data Data buffer
* @v offset Starting offset
* @v len Length
* @ret rc Return status code
*/
static int peerdist_info_get ( const struct peerdist_info *info, void *data,
size_t offset, size_t len ) {
/* Sanity check */
if ( ( offset > info->raw.len ) ||
( len > ( info->raw.len - offset ) ) ) {
DBGC ( info, "PCCRC %p data underrun at [%zx,%zx) of %zx\n",
info, offset, ( offset + len ), info->raw.len );
return -ERANGE;
}
/* Copy data */
copy_from_user ( data, info->raw.data, offset, len );
return 0;
}
/**
* Populate segment hashes
*
* @v segment Content information segment to fill in
* @v hash Segment hash of data
* @v secret Segment secret
*/
static void peerdist_info_segment_hash ( struct peerdist_info_segment *segment,
const void *hash, const void *secret ){
const struct peerdist_info *info = segment->info;
struct digest_algorithm *digest = info->digest;
uint8_t ctx[ hmac_ctxsize ( digest ) ];
size_t digestsize = info->digestsize;
static const uint16_t magic[] = PEERDIST_SEGMENT_ID_MAGIC;
/* Sanity check */
assert ( digestsize <= sizeof ( segment->hash ) );
assert ( digestsize <= sizeof ( segment->secret ) );
assert ( digestsize <= sizeof ( segment->id ) );
/* Get segment hash of data */
memcpy ( segment->hash, hash, digestsize );
/* Get segment secret */
memcpy ( segment->secret, secret, digestsize );
/* Calculate segment identifier */
hmac_init ( digest, ctx, segment->secret, digestsize );
hmac_update ( digest, ctx, segment->hash, digestsize );
hmac_update ( digest, ctx, magic, sizeof ( magic ) );
hmac_final ( digest, ctx, segment->id );
}
/******************************************************************************
*
* Content Information version 1
*
******************************************************************************
*/
/**
* Get number of blocks within a block description
*
* @v info Content information
* @v offset Block description offset
* @ret blocks Number of blocks, or negative error
*/
static int peerdist_info_v1_blocks ( const struct peerdist_info *info,
size_t offset ) {
struct peerdist_info_v1_block raw;
unsigned int blocks;
int rc;
/* Get block description header */
if ( ( rc = peerdist_info_get ( info, &raw, offset,
sizeof ( raw ) ) ) != 0 )
return rc;
/* Calculate number of blocks */
blocks = le32_to_cpu ( raw.blocks );
return blocks;
}
/**
* Locate block description
*
* @v info Content information
* @v index Segment index
* @ret offset Block description offset, or negative error
*/
static ssize_t peerdist_info_v1_block_offset ( const struct peerdist_info *info,
unsigned int index ) {
size_t digestsize = info->digestsize;
unsigned int i;
size_t offset;
int blocks;
int rc;
/* Sanity check */
assert ( index < info->segments );
/* Calculate offset of first block description */
offset = ( sizeof ( struct peerdist_info_v1 ) +
( info->segments *
sizeof ( peerdist_info_v1_segment_t ( digestsize ) ) ) );
/* Iterate over block descriptions until we find this segment */
for ( i = 0 ; i < index ; i++ ) {
/* Get number of blocks */
blocks = peerdist_info_v1_blocks ( info, offset );
if ( blocks < 0 ) {
rc = blocks;
DBGC ( info, "PCCRC %p segment %d could not get number "
"of blocks: %s\n", info, i, strerror ( rc ) );
return rc;
}
/* Move to next block description */
offset += sizeof ( peerdist_info_v1_block_t ( digestsize,
blocks ) );
}
return offset;
}
/**
* Populate content information
*
* @v info Content information to fill in
* @ret rc Return status code
*/
static int peerdist_info_v1 ( struct peerdist_info *info ) {
struct peerdist_info_v1 raw;
struct peerdist_info_segment first;
struct peerdist_info_segment last;
size_t first_skip;
size_t last_skip;
size_t last_read;
int rc;
/* Get raw header */
if ( ( rc = peerdist_info_get ( info, &raw, 0, sizeof ( raw ) ) ) != 0){
DBGC ( info, "PCCRC %p could not get V1 content information: "
"%s\n", info, strerror ( rc ) );
return rc;
}
assert ( raw.version.raw == cpu_to_le16 ( PEERDIST_INFO_V1 ) );
/* Determine hash algorithm */
switch ( raw.hash ) {
case cpu_to_le32 ( PEERDIST_INFO_V1_HASH_SHA256 ) :
info->digest = &sha256_algorithm;
break;
case cpu_to_le32 ( PEERDIST_INFO_V1_HASH_SHA384 ) :
info->digest = &sha384_algorithm;
break;
case cpu_to_le32 ( PEERDIST_INFO_V1_HASH_SHA512 ) :
info->digest = &sha512_algorithm;
break;
default:
DBGC ( info, "PCCRC %p unsupported hash algorithm %#08x\n",
info, le32_to_cpu ( raw.hash ) );
return -ENOTSUP;
}
info->digestsize = info->digest->digestsize;
assert ( info->digest != NULL );
DBGC2 ( info, "PCCRC %p using %s[%zd]\n",
info, info->digest->name, ( info->digestsize * 8 ) );
/* Calculate number of segments */
info->segments = le32_to_cpu ( raw.segments );
/* Get first segment */
if ( ( rc = peerdist_info_segment ( info, &first, 0 ) ) != 0 )
return rc;
/* Calculate range start offset */
info->range.start = first.range.start;
/* Calculate trimmed range start offset */
first_skip = le32_to_cpu ( raw.first );
info->trim.start = ( first.range.start + first_skip );
/* Get last segment */
if ( ( rc = peerdist_info_segment ( info, &last,
( info->segments - 1 ) ) ) != 0 )
return rc;
/* Calculate range end offset */
info->range.end = last.range.end;
/* Calculate trimmed range end offset */
if ( raw.last ) {
/* Explicit length to include from last segment is given */
last_read = le32_to_cpu ( raw.last );
last_skip = ( last.index ? 0 : first_skip );
info->trim.end = ( last.range.start + last_skip + last_read );
} else {
/* No explicit length given: range extends to end of segment */
info->trim.end = last.range.end;
}
return 0;
}
/**
* Populate content information segment
*
* @v segment Content information segment to fill in
* @ret rc Return status code
*/
static int peerdist_info_v1_segment ( struct peerdist_info_segment *segment ) {
const struct peerdist_info *info = segment->info;
size_t digestsize = info->digestsize;
peerdist_info_v1_segment_t ( digestsize ) raw;
ssize_t raw_offset;
int blocks;
int rc;
/* Sanity checks */
assert ( segment->index < info->segments );
/* Get raw description */
raw_offset = ( sizeof ( struct peerdist_info_v1 ) +
( segment->index * sizeof ( raw ) ) );
if ( ( rc = peerdist_info_get ( info, &raw, raw_offset,
sizeof ( raw ) ) ) != 0 ) {
DBGC ( info, "PCCRC %p segment %d could not get segment "
"description: %s\n", info, segment->index,
strerror ( rc ) );
return rc;
}
/* Calculate start offset of this segment */
segment->range.start = le64_to_cpu ( raw.segment.offset );
/* Calculate end offset of this segment */
segment->range.end = ( segment->range.start +
le32_to_cpu ( raw.segment.len ) );
/* Calculate block size of this segment */
segment->blksize = le32_to_cpu ( raw.segment.blksize );
/* Locate block description for this segment */
raw_offset = peerdist_info_v1_block_offset ( info, segment->index );
if ( raw_offset < 0 ) {
rc = raw_offset;
return rc;
}
/* Get number of blocks */
blocks = peerdist_info_v1_blocks ( info, raw_offset );
if ( blocks < 0 ) {
rc = blocks;
DBGC ( info, "PCCRC %p segment %d could not get number of "
"blocks: %s\n", info, segment->index, strerror ( rc ) );
return rc;
}
segment->blocks = blocks;
/* Calculate segment hashes */
peerdist_info_segment_hash ( segment, raw.hash, raw.secret );
return 0;
}
/**
* Populate content information block
*
* @v block Content information block to fill in
* @ret rc Return status code
*/
static int peerdist_info_v1_block ( struct peerdist_info_block *block ) {
const struct peerdist_info_segment *segment = block->segment;
const struct peerdist_info *info = segment->info;
size_t digestsize = info->digestsize;
peerdist_info_v1_block_t ( digestsize, segment->blocks ) raw;
ssize_t raw_offset;
int rc;
/* Sanity checks */
assert ( block->index < segment->blocks );
/* Calculate start offset of this block */
block->range.start = ( segment->range.start +
( block->index * segment->blksize ) );
/* Calculate end offset of this block */
block->range.end = ( block->range.start + segment->blksize );
if ( block->range.end > segment->range.end )
block->range.end = segment->range.end;
/* Locate block description */
raw_offset = peerdist_info_v1_block_offset ( info, segment->index );
if ( raw_offset < 0 ) {
rc = raw_offset;
return rc;
}
/* Get block hash */
raw_offset += offsetof ( typeof ( raw ), hash[block->index] );
if ( ( rc = peerdist_info_get ( info, block->hash, raw_offset,
digestsize ) ) != 0 ) {
DBGC ( info, "PCCRC %p segment %d block %d could not get "
"hash: %s\n", info, segment->index, block->index,
strerror ( rc ) );
return rc;
}
return 0;
}
/** Content information version 1 operations */
static struct peerdist_info_operations peerdist_info_v1_operations = {
.info = peerdist_info_v1,
.segment = peerdist_info_v1_segment,
.block = peerdist_info_v1_block,
};
/******************************************************************************
*
* Content Information version 2
*
******************************************************************************
*/
/** A segment cursor */
struct peerdist_info_v2_cursor {
/** Raw data offset */
size_t offset;
/** Number of segments remaining within this chunk */
unsigned int remaining;
/** Accumulated segment length */
size_t len;
};
/**
* Initialise segment cursor
*
* @v cursor Segment cursor
*/
static inline void
peerdist_info_v2_cursor_init ( struct peerdist_info_v2_cursor *cursor ) {
/* Initialise cursor */
cursor->offset = ( sizeof ( struct peerdist_info_v2 ) +
sizeof ( struct peerdist_info_v2_chunk ) );
cursor->remaining = 0;
cursor->len = 0;
}
/**
* Update segment cursor to next segment description
*
* @v info Content information
* @v offset Current offset
* @v remaining Number of segments remaining within this chunk
* @ret rc Return status code
*/
static int
peerdist_info_v2_cursor_next ( const struct peerdist_info *info,
struct peerdist_info_v2_cursor *cursor ) {
size_t digestsize = info->digestsize;
peerdist_info_v2_segment_t ( digestsize ) raw;
struct peerdist_info_v2_chunk chunk;
int rc;
/* Get chunk description if applicable */
if ( ! cursor->remaining ) {
/* Get chunk description */
if ( ( rc = peerdist_info_get ( info, &chunk,
( cursor->offset -
sizeof ( chunk ) ),
sizeof ( chunk ) ) ) != 0 )
return rc;
/* Update number of segments remaining */
cursor->remaining = ( be32_to_cpu ( chunk.len ) /
sizeof ( raw ) );
}
/* Get segment description header */
if ( ( rc = peerdist_info_get ( info, &raw.segment, cursor->offset,
sizeof ( raw.segment ) ) ) != 0 )
return rc;
/* Update cursor */
cursor->offset += sizeof ( raw );
cursor->remaining--;
if ( ! cursor->remaining )
cursor->offset += sizeof ( chunk );
cursor->len += be32_to_cpu ( raw.segment.len );
return 0;
}
/**
* Get number of segments and total length
*
* @v info Content information
* @v len Length to fill in
* @ret rc Number of segments, or negative error
*/
static int peerdist_info_v2_segments ( const struct peerdist_info *info,
size_t *len ) {
struct peerdist_info_v2_cursor cursor;
unsigned int segments;
int rc;
/* Iterate over all segments */
for ( peerdist_info_v2_cursor_init ( &cursor ), segments = 0 ;
cursor.offset < info->raw.len ; segments++ ) {
/* Update segment cursor */
if ( ( rc = peerdist_info_v2_cursor_next ( info,
&cursor ) ) != 0 ) {
DBGC ( info, "PCCRC %p segment %d could not update "
"segment cursor: %s\n",
info, segments, strerror ( rc ) );
return rc;
}
}
/* Record accumulated length */
*len = cursor.len;
return segments;
}
/**
* Populate content information
*
* @v info Content information to fill in
* @ret rc Return status code
*/
static int peerdist_info_v2 ( struct peerdist_info *info ) {
struct peerdist_info_v2 raw;
size_t len = 0;
int segments;
int rc;
/* Get raw header */
if ( ( rc = peerdist_info_get ( info, &raw, 0, sizeof ( raw ) ) ) != 0){
DBGC ( info, "PCCRC %p could not get V2 content information: "
"%s\n", info, strerror ( rc ) );
return rc;
}
assert ( raw.version.raw == cpu_to_le16 ( PEERDIST_INFO_V2 ) );
/* Determine hash algorithm */
switch ( raw.hash ) {
case PEERDIST_INFO_V2_HASH_SHA512_TRUNC :
info->digest = &sha512_algorithm;
info->digestsize = ( 256 / 8 );
break;
default:
DBGC ( info, "PCCRC %p unsupported hash algorithm %#02x\n",
info, raw.hash );
return -ENOTSUP;
}
assert ( info->digest != NULL );
DBGC2 ( info, "PCCRC %p using %s[%zd]\n",
info, info->digest->name, ( info->digestsize * 8 ) );
/* Calculate number of segments and total length */
segments = peerdist_info_v2_segments ( info, &len );
if ( segments < 0 ) {
rc = segments;
DBGC ( info, "PCCRC %p could not get segment count and length: "
"%s\n", info, strerror ( rc ) );
return rc;
}
info->segments = segments;
/* Calculate range start offset */
info->range.start = be64_to_cpu ( raw.offset );
/* Calculate trimmed range start offset */
info->trim.start = ( info->range.start + be32_to_cpu ( raw.first ) );
/* Calculate range end offset */
info->range.end = ( info->range.start + len );
/* Calculate trimmed range end offset */
info->trim.end = ( raw.len ? be64_to_cpu ( raw.len ) :
info->range.end );
return 0;
}
/**
* Populate content information segment
*
* @v segment Content information segment to fill in
* @ret rc Return status code
*/
static int peerdist_info_v2_segment ( struct peerdist_info_segment *segment ) {
const struct peerdist_info *info = segment->info;
size_t digestsize = info->digestsize;
peerdist_info_v2_segment_t ( digestsize ) raw;
struct peerdist_info_v2_cursor cursor;
unsigned int index;
size_t len;
int rc;
/* Sanity checks */
assert ( segment->index < info->segments );
/* Iterate over all segments before the target segment */
for ( peerdist_info_v2_cursor_init ( &cursor ), index = 0 ;
index < segment->index ; index++ ) {
/* Update segment cursor */
if ( ( rc = peerdist_info_v2_cursor_next ( info,
&cursor ) ) != 0 ) {
DBGC ( info, "PCCRC %p segment %d could not update "
"segment cursor: %s\n",
info, index, strerror ( rc ) );
return rc;
}
}
/* Get raw description */
if ( ( rc = peerdist_info_get ( info, &raw, cursor.offset,
sizeof ( raw ) ) ) != 0 ) {
DBGC ( info, "PCCRC %p segment %d could not get segment "
"description: %s\n",
info, segment->index, strerror ( rc ) );
return rc;
}
/* Calculate start offset of this segment */
segment->range.start = ( info->range.start + cursor.len );
/* Calculate end offset of this segment */
len = be32_to_cpu ( raw.segment.len );
segment->range.end = ( segment->range.start + len );
/* Model as a segment containing a single block */
segment->blocks = 1;
segment->blksize = len;
/* Calculate segment hashes */
peerdist_info_segment_hash ( segment, raw.hash, raw.secret );
return 0;
}
/**
* Populate content information block
*
* @v block Content information block to fill in
* @ret rc Return status code
*/
static int peerdist_info_v2_block ( struct peerdist_info_block *block ) {
const struct peerdist_info_segment *segment = block->segment;
const struct peerdist_info *info = segment->info;
size_t digestsize = info->digestsize;
/* Sanity checks */
assert ( block->index < segment->blocks );
/* Model as a block covering the whole segment */
memcpy ( &block->range, &segment->range, sizeof ( block->range ) );
memcpy ( block->hash, segment->hash, digestsize );
return 0;
}
/** Content information version 2 operations */
static struct peerdist_info_operations peerdist_info_v2_operations = {
.block = peerdist_info_v2_block,
.segment = peerdist_info_v2_segment,
.info = peerdist_info_v2,
};
/******************************************************************************
*
* Content Information
*
******************************************************************************
*/
/**
* Populate content information
*
* @v data Raw data
* @v len Length of raw data
* @v info Content information to fill in
* @ret rc Return status code
*/
int peerdist_info ( userptr_t data, size_t len, struct peerdist_info *info ) {
union peerdist_info_version version;
int rc;
/* Initialise structure */
memset ( info, 0, sizeof ( *info ) );
info->raw.data = data;
info->raw.len = len;
/* Get version */
if ( ( rc = peerdist_info_get ( info, &version, 0,
sizeof ( version ) ) ) != 0 ) {
DBGC ( info, "PCCRC %p could not get version: %s\n",
info, strerror ( rc ) );
return rc;
}
DBGC2 ( info, "PCCRC %p version %d.%d\n",
info, version.major, version.minor );
/* Determine version */
switch ( version.raw ) {
case cpu_to_le16 ( PEERDIST_INFO_V1 ) :
info->op = &peerdist_info_v1_operations;
break;
case cpu_to_le16 ( PEERDIST_INFO_V2 ) :
info->op = &peerdist_info_v2_operations;
break;
default:
DBGC ( info, "PCCRC %p unsupported version %d.%d\n",
info, version.major, version.minor );
return -ENOTSUP;
}
assert ( info->op != NULL );
assert ( info->op->info != NULL );
/* Populate content information */
if ( ( rc = info->op->info ( info ) ) != 0 )
return rc;
DBGC2 ( info, "PCCRC %p range [%08zx,%08zx) covers [%08zx,%08zx) with "
"%d segments\n", info, info->range.start, info->range.end,
info->trim.start, info->trim.end, info->segments );
return 0;
}
/**
* Populate content information segment
*
* @v info Content information
* @v segment Content information segment to fill in
* @v index Segment index
* @ret rc Return status code
*/
int peerdist_info_segment ( const struct peerdist_info *info,
struct peerdist_info_segment *segment,
unsigned int index ) {
int rc;
/* Sanity checks */
assert ( info != NULL );
assert ( info->op != NULL );
assert ( info->op->segment != NULL );
if ( index >= info->segments ) {
DBGC ( info, "PCCRC %p segment %d of [0,%d) out of range\n",
info, index, info->segments );
return -ERANGE;
}
/* Initialise structure */
memset ( segment, 0, sizeof ( *segment ) );
segment->info = info;
segment->index = index;
/* Populate content information segment */
if ( ( rc = info->op->segment ( segment ) ) != 0 )
return rc;
DBGC2 ( info, "PCCRC %p segment %d range [%08zx,%08zx) with %d "
"blocks\n", info, segment->index, segment->range.start,
segment->range.end, segment->blocks );
DBGC2 ( info, "PCCRC %p segment %d digest %s\n", info, segment->index,
peerdist_info_hash_ntoa ( info, segment->hash ) );
DBGC2 ( info, "PCCRC %p segment %d secret %s\n", info, segment->index,
peerdist_info_hash_ntoa ( info, segment->secret ) );
DBGC2 ( info, "PCCRC %p segment %d identf %s\n", info, segment->index,
peerdist_info_hash_ntoa ( info, segment->id ) );
return 0;
}
/**
* Populate content information block
*
* @v segment Content information segment
* @v block Content information block to fill in
* @v index Block index
* @ret rc Return status code
*/
int peerdist_info_block ( const struct peerdist_info_segment *segment,
struct peerdist_info_block *block,
unsigned int index ) {
const struct peerdist_info *info = segment->info;
size_t start;
size_t end;
int rc;
/* Sanity checks */
assert ( segment != NULL );
assert ( info != NULL );
assert ( info->op != NULL );
assert ( info->op->block != NULL );
if ( index >= segment->blocks ) {
DBGC ( info, "PCCRC %p segment %d block %d of [0,%d) out of "
"range\n", info, segment->index, index, segment->blocks);
return -ERANGE;
}
/* Initialise structure */
memset ( block, 0, sizeof ( *block ) );
block->segment = segment;
block->index = index;
/* Populate content information block */
if ( ( rc = info->op->block ( block ) ) != 0 )
return rc;
/* Calculate trimmed range */
start = block->range.start;
if ( start < info->trim.start )
start = info->trim.start;
end = block->range.end;
if ( end > info->trim.end )
end = info->trim.end;
if ( end < start )
end = start;
block->trim.start = start;
block->trim.end = end;
DBGC2 ( info, "PCCRC %p segment %d block %d hash %s\n",
info, segment->index, block->index,
peerdist_info_hash_ntoa ( info, block->hash ) );
DBGC2 ( info, "PCCRC %p segment %d block %d range [%08zx,%08zx) covers "
"[%08zx,%08zx)\n", info, segment->index, block->index,
block->range.start, block->range.end, block->trim.start,
block->trim.end );
return 0;
}