NBD_MODE_EXPORT_NAME, /* newstyle but only OPT_EXPORT_NAME safe */
NBD_MODE_SIMPLE, /* newstyle but only simple replies */
NBD_MODE_STRUCTURED, /* newstyle, structured replies enabled */
- /* TODO add NBD_MODE_EXTENDED */
+ NBD_MODE_EXTENDED, /* newstyle, extended headers enabled */
} NBDMode;
/* Transmission phase structs */
uint32_t length; /* length of payload */
} QEMU_PACKED NBDStructuredReplyChunk;
+typedef struct NBDExtendedReplyChunk {
+ uint32_t magic; /* NBD_EXTENDED_REPLY_MAGIC */
+ uint16_t flags; /* combination of NBD_REPLY_FLAG_* */
+ uint16_t type; /* NBD_REPLY_TYPE_* */
+ uint64_t cookie; /* request handle */
+ uint64_t offset; /* request offset */
+ uint64_t length; /* length of payload */
+} QEMU_PACKED NBDExtendedReplyChunk;
+
typedef union NBDReply {
NBDSimpleReply simple;
NBDStructuredReplyChunk structured;
+ NBDExtendedReplyChunk extended;
struct {
/*
- * @magic and @cookie fields have the same offset and size both in
- * simple reply and structured reply chunk, so let them be accessible
- * without ".simple." or ".structured." specification
+ * @magic and @cookie fields have the same offset and size in all
+ * forms of replies, so let them be accessible without ".simple.",
+ * ".structured.", or ".extended." specifications.
*/
uint32_t magic;
uint32_t _skip;
uint64_t cookie;
- } QEMU_PACKED;
+ };
} NBDReply;
+QEMU_BUILD_BUG_ON(offsetof(NBDReply, simple.cookie) !=
+ offsetof(NBDReply, cookie));
+QEMU_BUILD_BUG_ON(offsetof(NBDReply, structured.cookie) !=
+ offsetof(NBDReply, cookie));
+QEMU_BUILD_BUG_ON(offsetof(NBDReply, extended.cookie) !=
+ offsetof(NBDReply, cookie));
/* Header of chunk for NBD_REPLY_TYPE_OFFSET_DATA */
typedef struct NBDStructuredReadData {
typedef struct NBDStructuredMeta {
/* header's length >= 12 (at least one extent) */
uint32_t context_id;
- /* extents follows */
+ /* NBDExtent32 extents[] follows, array length implied by header */
} QEMU_PACKED NBDStructuredMeta;
-/* Extent chunk for NBD_REPLY_TYPE_BLOCK_STATUS */
-typedef struct NBDExtent {
+/* Extent array element for NBD_REPLY_TYPE_BLOCK_STATUS */
+typedef struct NBDExtent32 {
uint32_t length;
uint32_t flags; /* NBD_STATE_* */
-} QEMU_PACKED NBDExtent;
+} QEMU_PACKED NBDExtent32;
+
+/* Header of NBD_REPLY_TYPE_BLOCK_STATUS_EXT */
+typedef struct NBDExtendedMeta {
+ /* header's length >= 24 (at least one extent) */
+ uint32_t context_id;
+ uint32_t count; /* header length must be count * 16 + 8 */
+ /* NBDExtent64 extents[count] follows */
+} QEMU_PACKED NBDExtendedMeta;
+
+/* Extent array element for NBD_REPLY_TYPE_BLOCK_STATUS_EXT */
+typedef struct NBDExtent64 {
+ uint64_t length;
+ uint64_t flags; /* NBD_STATE_* */
+} QEMU_PACKED NBDExtent64;
+
+/* Client payload for limiting NBD_CMD_BLOCK_STATUS reply */
+typedef struct NBDBlockStatusPayload {
+ uint64_t effect_length;
+ /* uint32_t ids[] follows, array length implied by header */
+} QEMU_PACKED NBDBlockStatusPayload;
/* Transmission (export) flags: sent from server to client during handshake,
but describe what will happen during transmission */
NBD_FLAG_SEND_RESIZE_BIT = 9, /* Send resize */
NBD_FLAG_SEND_CACHE_BIT = 10, /* Send CACHE (prefetch) */
NBD_FLAG_SEND_FAST_ZERO_BIT = 11, /* FAST_ZERO flag for WRITE_ZEROES */
+ NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT = 12, /* PAYLOAD flag for BLOCK_STATUS */
};
-#define NBD_FLAG_HAS_FLAGS (1 << NBD_FLAG_HAS_FLAGS_BIT)
-#define NBD_FLAG_READ_ONLY (1 << NBD_FLAG_READ_ONLY_BIT)
-#define NBD_FLAG_SEND_FLUSH (1 << NBD_FLAG_SEND_FLUSH_BIT)
-#define NBD_FLAG_SEND_FUA (1 << NBD_FLAG_SEND_FUA_BIT)
-#define NBD_FLAG_ROTATIONAL (1 << NBD_FLAG_ROTATIONAL_BIT)
-#define NBD_FLAG_SEND_TRIM (1 << NBD_FLAG_SEND_TRIM_BIT)
-#define NBD_FLAG_SEND_WRITE_ZEROES (1 << NBD_FLAG_SEND_WRITE_ZEROES_BIT)
-#define NBD_FLAG_SEND_DF (1 << NBD_FLAG_SEND_DF_BIT)
-#define NBD_FLAG_CAN_MULTI_CONN (1 << NBD_FLAG_CAN_MULTI_CONN_BIT)
-#define NBD_FLAG_SEND_RESIZE (1 << NBD_FLAG_SEND_RESIZE_BIT)
-#define NBD_FLAG_SEND_CACHE (1 << NBD_FLAG_SEND_CACHE_BIT)
-#define NBD_FLAG_SEND_FAST_ZERO (1 << NBD_FLAG_SEND_FAST_ZERO_BIT)
+#define NBD_FLAG_HAS_FLAGS (1 << NBD_FLAG_HAS_FLAGS_BIT)
+#define NBD_FLAG_READ_ONLY (1 << NBD_FLAG_READ_ONLY_BIT)
+#define NBD_FLAG_SEND_FLUSH (1 << NBD_FLAG_SEND_FLUSH_BIT)
+#define NBD_FLAG_SEND_FUA (1 << NBD_FLAG_SEND_FUA_BIT)
+#define NBD_FLAG_ROTATIONAL (1 << NBD_FLAG_ROTATIONAL_BIT)
+#define NBD_FLAG_SEND_TRIM (1 << NBD_FLAG_SEND_TRIM_BIT)
+#define NBD_FLAG_SEND_WRITE_ZEROES (1 << NBD_FLAG_SEND_WRITE_ZEROES_BIT)
+#define NBD_FLAG_SEND_DF (1 << NBD_FLAG_SEND_DF_BIT)
+#define NBD_FLAG_CAN_MULTI_CONN (1 << NBD_FLAG_CAN_MULTI_CONN_BIT)
+#define NBD_FLAG_SEND_RESIZE (1 << NBD_FLAG_SEND_RESIZE_BIT)
+#define NBD_FLAG_SEND_CACHE (1 << NBD_FLAG_SEND_CACHE_BIT)
+#define NBD_FLAG_SEND_FAST_ZERO (1 << NBD_FLAG_SEND_FAST_ZERO_BIT)
+#define NBD_FLAG_BLOCK_STAT_PAYLOAD (1 << NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT)
/* New-style handshake (global) flags, sent from server to client, and
control what will happen during handshake phase. */
#define NBD_OPT_STRUCTURED_REPLY (8)
#define NBD_OPT_LIST_META_CONTEXT (9)
#define NBD_OPT_SET_META_CONTEXT (10)
+#define NBD_OPT_EXTENDED_HEADERS (11)
/* Option reply types. */
#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) | (value))
#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */
+#define NBD_REP_ERR_TOO_BIG NBD_REP_ERR(9) /* Payload size overflow */
+#define NBD_REP_ERR_EXT_HEADER_REQD NBD_REP_ERR(10) /* Need extended headers */
/* Info types, used during NBD_REP_INFO */
#define NBD_INFO_EXPORT 0
#define NBD_INFO_BLOCK_SIZE 3
/* Request flags, sent from client to server during transmission phase */
-#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
-#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
-#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */
-#define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS
- * reply chunk */
-#define NBD_CMD_FLAG_FAST_ZERO (1 << 4) /* fail if WRITE_ZEROES is not fast */
+#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
+#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
+#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */
+#define NBD_CMD_FLAG_REQ_ONE (1 << 3) \
+ /* only one extent in BLOCK_STATUS reply chunk */
+#define NBD_CMD_FLAG_FAST_ZERO (1 << 4) /* fail if WRITE_ZEROES is not fast */
+#define NBD_CMD_FLAG_PAYLOAD_LEN (1 << 5) \
+ /* length describes payload, not effect; only with ext header */
/* Supported request types */
enum {
*/
#define NBD_MAX_STRING_SIZE 4096
-/* Two types of reply structures */
+/* Two types of request structures, a given client will only use 1 */
+#define NBD_REQUEST_MAGIC 0x25609513
+#define NBD_EXTENDED_REQUEST_MAGIC 0x21e41c71
+
+/*
+ * Three types of reply structures, but what a client expects depends
+ * on NBD_OPT_STRUCTURED_REPLY and NBD_OPT_EXTENDED_HEADERS.
+ */
#define NBD_SIMPLE_REPLY_MAGIC 0x67446698
#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
+#define NBD_EXTENDED_REPLY_MAGIC 0x6e8a278c
-/* Structured reply flags */
+/* Chunk reply flags (for structured and extended replies) */
#define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */
-/* Structured reply types */
+/* Chunk reply types */
#define NBD_REPLY_ERR(value) ((1 << 15) | (value))
-#define NBD_REPLY_TYPE_NONE 0
-#define NBD_REPLY_TYPE_OFFSET_DATA 1
-#define NBD_REPLY_TYPE_OFFSET_HOLE 2
-#define NBD_REPLY_TYPE_BLOCK_STATUS 5
-#define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1)
-#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)
+#define NBD_REPLY_TYPE_NONE 0
+#define NBD_REPLY_TYPE_OFFSET_DATA 1
+#define NBD_REPLY_TYPE_OFFSET_HOLE 2
+#define NBD_REPLY_TYPE_BLOCK_STATUS 5
+#define NBD_REPLY_TYPE_BLOCK_STATUS_EXT 6
+#define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1)
+#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)
/* Extent flags for base:allocation in NBD_REPLY_TYPE_BLOCK_STATUS */
#define NBD_STATE_HOLE (1 << 0)