pccrc.c File Reference

Peer Content Caching and Retrieval: Content Identification [MS-PCCRC]. More...

#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>

Go to the source code of this file.

Data Structures
struct	peerdist_info_v2_cursor
	A segment cursor. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static const char *	peerdist_info_hash_ntoa (const struct peerdist_info *info, const void *hash)
	Transcribe hash value (for debugging) More...
static int	peerdist_info_get (const struct peerdist_info *info, void *data, size_t offset, size_t len)
	Get raw data. More...
static void	peerdist_info_segment_hash (struct peerdist_info_segment *segment, const void *hash, const void *secret)
	Populate segment hashes. More...
static int	peerdist_info_v1_blocks (const struct peerdist_info *info, size_t offset)
	Get number of blocks within a block description. More...
static ssize_t	peerdist_info_v1_block_offset (const struct peerdist_info *info, unsigned int index)
	Locate block description. More...
static int	peerdist_info_v1 (struct peerdist_info *info)
	Populate content information. More...
static int	peerdist_info_v1_segment (struct peerdist_info_segment *segment)
	Populate content information segment. More...
static int	peerdist_info_v1_block (struct peerdist_info_block *block)
	Populate content information block. More...
static void	peerdist_info_v2_cursor_init (struct peerdist_info_v2_cursor *cursor)
	Initialise segment cursor. More...
static int	peerdist_info_v2_cursor_next (const struct peerdist_info *info, struct peerdist_info_v2_cursor *cursor)
	Update segment cursor to next segment description. More...
static int	peerdist_info_v2_segments (const struct peerdist_info *info, size_t *len)
	Get number of segments and total length. More...
static int	peerdist_info_v2 (struct peerdist_info *info)
	Populate content information. More...
static int	peerdist_info_v2_segment (struct peerdist_info_segment *segment)
	Populate content information segment. More...
static int	peerdist_info_v2_block (struct peerdist_info_block *block)
	Populate content information block. More...
int	peerdist_info (userptr_t data, size_t len, struct peerdist_info *info)
	Populate content information. More...
int	peerdist_info_segment (const struct peerdist_info *info, struct peerdist_info_segment *segment, unsigned int index)
	Populate content information segment. More...
int	peerdist_info_block (const struct peerdist_info_segment *segment, struct peerdist_info_block *block, unsigned int index)
	Populate content information block. More...

Variables
static struct peerdist_info_operations	peerdist_info_v1_operations
	Content information version 1 operations. More...
static struct peerdist_info_operations	peerdist_info_v2_operations
	Content information version 2 operations. More...

Detailed Description

Peer Content Caching and Retrieval: Content Identification [MS-PCCRC].

Definition in file pccrc.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

peerdist_info_hash_ntoa()

static const char* peerdist_info_hash_ntoa ( const struct peerdist_info *  info, const void *  hash  )

inlinestatic

Transcribe hash value (for debugging)

Parameters

info	Content information
hash	Hash value

Return values

string

Hash value string

Definition at line 56 of file pccrc.c.

                                                                               {
        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;
}

References assert(), base16_encoded_len(), digestsize, hash, info, NULL, and PEERDIST_DIGEST_MAX_SIZE.

Referenced by peerdist_info_block(), and peerdist_info_segment().

peerdist_info_get()

static int peerdist_info_get ( const struct peerdist_info *  info, void *  data, size_t  offset, size_t  len  )

static

Get raw data.

Parameters

info	Content information
data	Data buffer
offset	Starting offset
len	Length

Return values

rc	Return status code

Definition at line 79 of file pccrc.c.

                                                           {

        /* 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;
}

References copy_from_user(), data, DBGC, ERANGE, info, len, and offset.

Referenced by peerdist_info(), peerdist_info_v1(), peerdist_info_v1_block(), peerdist_info_v1_blocks(), peerdist_info_v1_segment(), peerdist_info_v2(), peerdist_info_v2_cursor_next(), and peerdist_info_v2_segment().

peerdist_info_segment_hash()

static void peerdist_info_segment_hash ( struct peerdist_info_segment *  segment, const void *  hash, const void *  secret  )

static

Populate segment hashes.

Parameters

segment	Content information segment to fill in
hash	Segment hash of data
secret	Segment secret

Definition at line 103 of file pccrc.c.

                                                                               {
        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 );
}

References assert(), ctx, digestsize, hash, hmac_ctxsize(), hmac_final(), hmac_init(), hmac_update(), info, magic, memcpy(), PEERDIST_SEGMENT_ID_MAGIC, and segment.

Referenced by peerdist_info_v1_segment(), and peerdist_info_v2_segment().

peerdist_info_v1_blocks()

static int peerdist_info_v1_blocks ( const struct peerdist_info *  info, size_t  offset  )

static

Get number of blocks within a block description.

Parameters

info	Content information
offset	Block description offset

Return values

blocks

Number of blocks, or negative error

Definition at line 143 of file pccrc.c.

                                                     {
        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;
}

References peerdist_info_v1_block::blocks, info, le32_to_cpu, offset, peerdist_info_get(), raw, and rc.

Referenced by peerdist_info_v1_block_offset(), and peerdist_info_v1_segment().

peerdist_info_v1_block_offset()

static ssize_t peerdist_info_v1_block_offset ( const struct peerdist_info *  info, unsigned int  index  )

static

Locate block description.

Parameters

info	Content information
index	Segment index

Return values

offset

Block description offset, or negative error

Definition at line 167 of file pccrc.c.

                                                                    {
        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;
}

References assert(), peerdist_info_v1_block::blocks, DBGC, digestsize, index, info, offset, peerdist_info_v1_block_t, peerdist_info_v1_blocks(), peerdist_info_v1_segment_t, rc, peerdist_info_v1::segments, and strerror().

Referenced by peerdist_info_v1_block(), and peerdist_info_v1_segment().

peerdist_info_v1()

static int peerdist_info_v1 ( struct peerdist_info *  info )

static

Populate content information.

Parameters

info	Content information to fill in

Return values

rc	Return status code

Definition at line 209 of file pccrc.c.

                                                           {
        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;
}

References assert(), cpu_to_le16, cpu_to_le32, DBGC, DBGC2, peerdist_range::end, ENOTSUP, first, peerdist_info_segment::index, info, le32_to_cpu, NULL, peerdist_info_get(), PEERDIST_INFO_V1, PEERDIST_INFO_V1_HASH_SHA256, PEERDIST_INFO_V1_HASH_SHA384, PEERDIST_INFO_V1_HASH_SHA512, peerdist_info_segment::range, raw, rc, sha256_algorithm, sha384_algorithm, sha512_algorithm, peerdist_range::start, and strerror().

peerdist_info_v1_segment()

static int peerdist_info_v1_segment ( struct peerdist_info_segment *  segment )

static

Populate content information segment.

Parameters

segment

Content information segment to fill in

Return values

rc	Return status code

Definition at line 289 of file pccrc.c.

                                                                              {
        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;
}

References assert(), DBGC, digestsize, index, info, le32_to_cpu, le64_to_cpu, peerdist_info_get(), peerdist_info_segment_hash(), peerdist_info_v1_block_offset(), peerdist_info_v1_blocks(), peerdist_info_v1_segment_t, raw, rc, segment, and strerror().

peerdist_info_v1_block()

static int peerdist_info_v1_block ( struct peerdist_info_block *  block )

static

Populate content information block.

Parameters

block

Content information block to fill in

Return values

rc	Return status code

Definition at line 350 of file pccrc.c.

                                                                        {
        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;
}

References assert(), block, DBGC, digestsize, hash, info, offsetof, peerdist_info_get(), peerdist_info_v1_block_offset(), peerdist_info_v1_block_t, raw, rc, segment, strerror(), and typeof().

peerdist_info_v2_cursor_init()

static void peerdist_info_v2_cursor_init ( struct peerdist_info_v2_cursor *  cursor )

inlinestatic

Initialise segment cursor.

Parameters

cursor

Segment cursor

Definition at line 420 of file pccrc.c.

                                                                        {

        /* Initialise cursor */
        cursor->offset = ( sizeof ( struct peerdist_info_v2 ) +
                           sizeof ( struct peerdist_info_v2_chunk ) );
        cursor->remaining = 0;
        cursor->len = 0;
}

References peerdist_info_v2_cursor::len, peerdist_info_v2_cursor::offset, and peerdist_info_v2_cursor::remaining.

Referenced by peerdist_info_v2_segment(), and peerdist_info_v2_segments().

peerdist_info_v2_cursor_next()

static int peerdist_info_v2_cursor_next ( const struct peerdist_info *  info, struct peerdist_info_v2_cursor *  cursor  )

static

Update segment cursor to next segment description.

Parameters

info	Content information
offset	Current offset
remaining	Number of segments remaining within this chunk

Return values

rc	Return status code

Definition at line 438 of file pccrc.c.

                                                                        {
        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;
}

References be32_to_cpu, digestsize, info, peerdist_info_v2_chunk::len, peerdist_info_v2_cursor::len, peerdist_info_v2_cursor::offset, peerdist_info_get(), peerdist_info_v2_segment_t, raw, rc, and peerdist_info_v2_cursor::remaining.

Referenced by peerdist_info_v2_segment(), and peerdist_info_v2_segments().

peerdist_info_v2_segments()

static int peerdist_info_v2_segments ( const struct peerdist_info *  info, size_t *  len  )

static

Get number of segments and total length.

Parameters

info	Content information
len	Length to fill in

Return values

rc	Number of segments, or negative error

Definition at line 482 of file pccrc.c.

                                                     {
        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;
}

References DBGC, info, len, peerdist_info_v2_cursor::len, peerdist_info_v2_cursor::offset, peerdist_info_v2_cursor_init(), peerdist_info_v2_cursor_next(), rc, and strerror().

Referenced by peerdist_info_v2().

peerdist_info_v2()

static int peerdist_info_v2 ( struct peerdist_info *  info )

static

Populate content information.

Parameters

info	Content information to fill in

Return values

rc	Return status code

Definition at line 514 of file pccrc.c.

                                                           {
        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;
}

References assert(), be32_to_cpu, be64_to_cpu, cpu_to_le16, DBGC, DBGC2, ENOTSUP, info, len, NULL, peerdist_info_get(), PEERDIST_INFO_V2, PEERDIST_INFO_V2_HASH_SHA512_TRUNC, peerdist_info_v2_segments(), raw, rc, sha512_algorithm, and strerror().

peerdist_info_v2_segment()

static int peerdist_info_v2_segment ( struct peerdist_info_segment *  segment )

static

Populate content information segment.

Parameters

segment

Content information segment to fill in

Return values

rc	Return status code

Definition at line 575 of file pccrc.c.

                                                                              {
        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;
}

References assert(), be32_to_cpu, DBGC, digestsize, index, info, len, peerdist_info_v2_cursor::len, peerdist_info_v2_cursor::offset, peerdist_info_get(), peerdist_info_segment_hash(), peerdist_info_v2_cursor_init(), peerdist_info_v2_cursor_next(), peerdist_info_v2_segment_t, raw, rc, segment, and strerror().

peerdist_info_v2_block()

static int peerdist_info_v2_block ( struct peerdist_info_block *  block )

static

Populate content information block.

Parameters

block

Content information block to fill in

Return values

rc	Return status code

Definition at line 633 of file pccrc.c.

                                                                        {
        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;
}

References assert(), block, digestsize, info, memcpy(), and segment.

peerdist_info()

int peerdist_info	(	userptr_t	data,
		size_t	len,
		struct peerdist_info *	info
	)

Populate content information.

Parameters

data	Raw data
len	Length of raw data
info	Content information to fill in

Return values

rc	Return status code

Definition at line 670 of file pccrc.c.

                                                                             {
        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;
}

References assert(), cpu_to_le16, data, DBGC, DBGC2, ENOTSUP, info, len, memset(), NULL, peerdist_info_get(), PEERDIST_INFO_V1, peerdist_info_v1_operations, PEERDIST_INFO_V2, peerdist_info_v2_operations, rc, strerror(), and version.

peerdist_info_segment()

int peerdist_info_segment	(	const struct peerdist_info *	info,
		struct peerdist_info_segment *	segment,
		unsigned int	index
	)

Populate content information segment.

Parameters

info	Content information
segment	Content information segment to fill in
index	Segment index

Return values

rc	Return status code

Definition at line 723 of file pccrc.c.

                                                 {
        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;
}

References assert(), DBGC, DBGC2, ERANGE, index, info, memset(), NULL, peerdist_info_hash_ntoa(), rc, and segment.

peerdist_info_block()

int peerdist_info_block	(	const struct peerdist_info_segment *	segment,
		struct peerdist_info_block *	block,
		unsigned int	index
	)

Populate content information block.

Parameters

segment	Content information segment
block	Content information block to fill in
index	Block index

Return values

rc	Return status code

Definition at line 767 of file pccrc.c.

                                               {
        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;
}

References assert(), block, DBGC, DBGC2, end, ERANGE, index, info, memset(), NULL, peerdist_info_hash_ntoa(), rc, segment, start, peerdist_range::start, and peerdist_info::trim.

Variable Documentation

peerdist_info_v1_operations

struct peerdist_info_operations peerdist_info_v1_operations

static

Initial value:

= {
        .info = peerdist_info_v1,
        .segment = peerdist_info_v1_segment,
        .block = peerdist_info_v1_block,
}

Content information version 1 operations.

Definition at line 391 of file pccrc.c.

Referenced by peerdist_info().

peerdist_info_v2_operations

struct peerdist_info_operations peerdist_info_v2_operations

static

Initial value:

= {
        .block = peerdist_info_v2_block,
        .segment = peerdist_info_v2_segment,
        .info = peerdist_info_v2,
}

Content information version 2 operations.

Definition at line 649 of file pccrc.c.

Referenced by peerdist_info().