diff options
Diffstat (limited to 'include/block/nbd.h')
| -rw-r--r-- | include/block/nbd.h | 142 |
1 files changed, 98 insertions, 44 deletions
diff --git a/include/block/nbd.h b/include/block/nbd.h index f672b76173..8a765e78df 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -60,20 +60,22 @@ typedef enum NBDMode { 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 - * - * Note: these are _NOT_ the same as the network representation of an NBD - * request and reply! +/* Transmission phase structs */ + +/* + * Note: NBDRequest is _NOT_ the same as the network representation of an NBD + * request! */ typedef struct NBDRequest { uint64_t cookie; - uint64_t from; - uint32_t len; + uint64_t from; /* Offset touched by the command */ + uint64_t len; /* Effect length; 32 bit limit without extended headers */ uint16_t flags; /* NBD_CMD_FLAG_* */ - uint16_t type; /* NBD_CMD_* */ + uint16_t type; /* NBD_CMD_* */ + NBDMode mode; /* Determines which network representation to use */ } NBDRequest; typedef struct NBDSimpleReply { @@ -91,20 +93,36 @@ typedef struct NBDStructuredReplyChunk { 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 { @@ -131,14 +149,34 @@ typedef struct NBDStructuredError { 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 */ @@ -156,20 +194,22 @@ enum { 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. */ @@ -192,6 +232,7 @@ enum { #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)) @@ -209,6 +250,8 @@ enum { #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 @@ -217,12 +260,14 @@ enum { #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 { @@ -248,22 +293,31 @@ 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) @@ -305,7 +359,7 @@ typedef struct NBDExportInfo { /* In-out fields, set by client before nbd_receive_negotiate() and * updated by server results during nbd_receive_negotiate() */ - bool structured_reply; + NBDMode mode; /* input maximum mode tolerated; output actual mode chosen */ bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */ /* Set by server results during nbd_receive_negotiate() and |