[peerdist] Add support for constructing and decoding retrieval messages

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/pccrr.h

@@ -0,0 +1,376 @@
+#ifndef _IPXE_PCCRR_H
+#define _IPXE_PCCRR_H
+
+/** @file
+ *
+ * Peer Content Caching and Retrieval: Retrieval Protocol [MS-PCCRR]
+ *
+ * All fields are in network byte order.
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/uaccess.h>
+
+/** Magic retrieval URI path */
+#define PEERDIST_MAGIC_PATH "/116B50EB-ECE2-41ac-8429-9F9E963361B7/"
+
+/** Retrieval protocol version */
+union peerdist_msg_version {
+	/** Raw version number */
+	uint32_t raw;
+	/** Major:minor version number */
+	struct {
+		/** Minor version number */
+		uint16_t minor;
+		/** Major version number */
+		uint16_t major;
+	} __attribute__ (( packed ));
+} __attribute__ (( packed ));
+
+/** Retrieval protocol version 1.0 */
+#define PEERDIST_MSG_VERSION_1_0 0x00000001UL
+
+/** Retrieval protocol version 2.0 */
+#define PEERDIST_MSG_VERSION_2_0 0x00000002UL
+
+/** Retrieval protocol supported versions */
+struct peerdist_msg_versions {
+	/** Minimum supported protocol version */
+	union peerdist_msg_version min;
+	/** Maximum supported protocol version */
+	union peerdist_msg_version max;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block range */
+struct peerdist_msg_range {
+	/** First block in range */
+	uint32_t first;
+	/** Number of blocks in range */
+	uint32_t count;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol segment ID header */
+struct peerdist_msg_segment {
+	/** Digest size (i.e. length of segment ID) */
+	uint32_t digestsize;
+	/* Followed by a single variable-length ID and padding:
+	 *
+	 * uint8_t id[digestsize];
+	 * uint8_t pad[ (-digestsize) & 0x3 ];
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol segment ID
+ *
+ * @v digestsize	Digest size
+ */
+#define peerdist_msg_segment_t( digestsize )				\
+	struct {							\
+		struct peerdist_msg_segment segment;			\
+		uint8_t id[digestsize];					\
+		uint8_t pad[ ( -(digestsize) ) & 0x3 ];			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol block range list header */
+struct peerdist_msg_ranges {
+	/** Number of ranges */
+	uint32_t count;
+	/* Followed by an array of block ranges:
+	 *
+	 * struct peerdist_msg_range range[count];
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block range list
+ *
+ * @v count		Number of ranges
+ */
+#define peerdist_msg_ranges_t( count )					\
+	struct {							\
+		struct peerdist_msg_ranges ranges;			\
+		struct peerdist_msg_range range[count];			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol data block header */
+struct peerdist_msg_block {
+	/** Length of data block */
+	uint32_t len;
+	/* Followed by the (encrypted) data block:
+	 *
+	 * uint8_t data[len];
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol data block */
+#define peerdist_msg_block_t( len )					\
+	struct {							\
+		struct peerdist_msg_block block;			\
+		uint8_t data[len];					\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol initialisation vector header */
+struct peerdist_msg_iv {
+	/** Cipher block size */
+	uint32_t blksize;
+	/* Followed by the initialisation vector:
+	 *
+	 * uint8_t data[blksize];
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol initialisation vector */
+#define peerdist_msg_iv_t( blksize )					\
+	struct {							\
+		struct peerdist_msg_iv iv;				\
+		uint8_t data[blksize];					\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol useless VRF data header */
+struct peerdist_msg_useless_vrf {
+	/** Length of useless VRF data */
+	uint32_t len;
+	/* Followed by a variable-length useless VRF data block and
+	 * padding:
+	 *
+	 * uint8_t data[len];
+	 * uint8_t pad[ (-len) & 0x3 ];
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol useless VRF data */
+#define peerdist_msg_useless_vrf_t( vrf_len )				\
+	struct {							\
+		struct peerdist_msg_useless_vrf vrf;			\
+		uint8_t data[vrf_len];					\
+		uint8_t pad[ ( -(vrf_len) ) & 0x3 ];			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol message header */
+struct peerdist_msg_header {
+	/** Protocol version
+	 *
+	 * This is the protocol version in which the message type was
+	 * first defined.
+	 */
+	union peerdist_msg_version version;
+	/** Message type */
+	uint32_t type;
+	/** Message size (including this header) */
+	uint32_t len;
+	/** Cryptographic algorithm ID */
+	uint32_t algorithm;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol cryptographic algorithm IDs */
+enum peerdist_msg_algorithm {
+	/** No encryption */
+	PEERDIST_MSG_PLAINTEXT = 0x00000000UL,
+	/** AES-128 in CBC mode */
+	PEERDIST_MSG_AES_128_CBC = 0x00000001UL,
+	/** AES-192 in CBC mode */
+	PEERDIST_MSG_AES_192_CBC = 0x00000002UL,
+	/** AES-256 in CBC mode */
+	PEERDIST_MSG_AES_256_CBC = 0x00000003UL,
+};
+
+/** Retrieval protocol transport response header */
+struct peerdist_msg_transport_header {
+	/** Length (excluding this header)
+	 *
+	 * This seems to be identical in both purpose and value to the
+	 * length found within the message header, and therefore
+	 * serves no useful purpose.
+	 */
+	uint32_t len;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol negotiation request */
+struct peerdist_msg_nego_req {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/** Supported versions */
+	struct peerdist_msg_versions versions;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol negotiation request version */
+#define PEERDIST_MSG_NEGO_REQ_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol negotiation request type */
+#define PEERDIST_MSG_NEGO_REQ_TYPE 0x00000000UL
+
+/** Retrieval protocol negotiation response */
+struct peerdist_msg_nego_resp {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/** Supported versions */
+	struct peerdist_msg_versions versions;
+} __attribute__ (( packed ));
+
+/** Retrieval protocol negotiation response version */
+#define PEERDIST_MSG_NEGO_RESP_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol negotiation response type */
+#define PEERDIST_MSG_NEGO_RESP_TYPE 0x00000001UL
+
+/** Retrieval protocol block list request header */
+struct peerdist_msg_getblklist {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/* Followed by a segment ID and a block range list:
+	 *
+	 * peerdist_msg_segment_t(digestsize) segment;
+	 * peerdist_msg_ranges_t(count) ranges;
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block list request
+ *
+ * @v digestsize	Digest size
+ * @v count		Block range count
+ */
+#define peerdist_msg_getblklist_t( digestsize, count )			\
+	struct {							\
+		struct peerdist_msg_getblklist getblklist;		\
+		peerdist_msg_segment_t ( digestsize ) segment;		\
+		peerdist_msg_ranges_t ( count ) ranges;			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol block list request version */
+#define PEERDIST_MSG_GETBLKLIST_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol block list request type */
+#define PEERDIST_MSG_GETBLKLIST_TYPE 0x00000002UL
+
+/** Retrieval protocol block fetch request header */
+struct peerdist_msg_getblks {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/* Followed by a segment ID, a block range list, and a useless
+	 * VRF block:
+	 *
+	 * peerdist_msg_segment_t(digestsize) segment;
+	 * peerdist_msg_ranges_t(count) ranges;
+	 * peerdist_msg_vrf_t(vrf_len) vrf;
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block fetch request
+ *
+ * @v digestsize	Digest size
+ * @v count		Block range count
+ * @v vrf_len		Length of uselessness
+ */
+#define peerdist_msg_getblks_t( digestsize, count, vrf_len )		\
+	struct {							\
+		struct peerdist_msg_getblks getblks;			\
+		peerdist_msg_segment_t ( digestsize ) segment;		\
+		peerdist_msg_ranges_t ( count ) ranges;			\
+		peerdist_msg_useless_vrf_t ( vrf_len );			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol block fetch request version */
+#define PEERDIST_MSG_GETBLKS_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol block fetch request type */
+#define PEERDIST_MSG_GETBLKS_TYPE 0x00000003UL
+
+/** Retrieval protocol block list response header */
+struct peerdist_msg_blklist {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/* Followed by a segment ID, a block range list, and a next
+	 * block index:
+	 *
+	 * peerdist_msg_segment_t(digestsize) segment;
+	 * peerdist_msg_ranges_t(count) ranges;
+	 * uint32_t next;
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block list response
+ *
+ * @v digestsize	Digest size
+ * @v count		Block range count
+ */
+#define peerdist_msg_blklist_t( digestsize, count )			\
+	struct {							\
+		struct peerdist_msg_blklist blklist;			\
+		peerdist_msg_segment_t ( digestsize ) segment;		\
+		peerdist_msg_ranges_t ( count ) ranges;			\
+		uint32_t next;						\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol block list response version */
+#define PEERDIST_MSG_BLKLIST_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol block list response type */
+#define PEERDIST_MSG_BLKLIST_TYPE 0x00000004UL
+
+/** Retrieval protocol block fetch response header */
+struct peerdist_msg_blk {
+	/** Message header */
+	struct peerdist_msg_header hdr;
+	/* Followed by a segment ID, a block index, a next block
+	 * index, a data block, a useless VRF block, and an
+	 * initialisation vector:
+	 *
+	 * peerdist_msg_segment_t(digestsize) segment;
+	 * uint32_t index;
+	 * uint32_t next;
+	 * peerdist_msg_block_t(len) data;
+	 * peerdist_msg_useless_vrf_t(vrf_len) vrf;
+	 * peerdist_msg_iv_t(blksize) iv;
+	 */
+} __attribute__ (( packed ));
+
+/** Retrieval protocol block fetch response
+ *
+ * @v digestsize	Digest size
+ * @v len		Data block length
+ * @v vrf_len		Length of uselessness
+ * @v blksize		Cipher block size
+ */
+#define peerdist_msg_blk_t( digestsize, len, vrf_len, blksize )		\
+	struct {							\
+		struct peerdist_msg_blk blk;				\
+		peerdist_msg_segment_t ( digestsize ) segment;		\
+		uint32_t index;						\
+		uint32_t next;						\
+		peerdist_msg_block_t ( len ) block;			\
+		peerdist_msg_useless_vrf_t ( vrf_len ) vrf;		\
+		peerdist_msg_iv_t ( blksize ) iv;			\
+	} __attribute__ (( packed ))
+
+/** Retrieval protocol block fetch response version */
+#define PEERDIST_MSG_BLK_VERSION PEERDIST_MSG_VERSION_1_0
+
+/** Retrieval protocol block fetch response type */
+#define PEERDIST_MSG_BLK_TYPE 0x00000005UL
+
+/**
+ * Parse retrieval protocol block fetch response
+ *
+ * @v raw		Raw data
+ * @v raw_len		Length of raw data
+ * @v digestsize	Digest size
+ * @v blksize		Cipher block size
+ * @v blk		Structure to fill in
+ * @ret rc		Return status code
+ */
+#define peerdist_msg_blk( raw, raw_len, digestsize, blksize, blk ) ( {	\
+	assert ( sizeof ( (blk)->segment.id ) == (digestsize) );	\
+	assert ( sizeof ( (blk)->block.data ) == 0 );			\
+	assert ( sizeof ( (blk)->vrf.data ) == 0 );			\
+	assert ( sizeof ( (blk)->iv.data ) == blksize );		\
+	peerdist_msg_blk_untyped ( (raw), (raw_len), (digestsize),	\
+				   (blksize), blk );			\
+	} )
+
+extern int peerdist_msg_blk_untyped ( userptr_t raw, size_t raw_len,
+				      size_t digestsize, size_t blksize,
+				      void *out );
+
+#endif /* _IPXE_PCCRR_H */