Eventually nbdkit will install this as a public header file and we will be able to consume it from $includedir. In the mean time synchronize with the copy in nbdkit. --- lib/nbd-protocol.h | 57 +++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 29 deletions(-) diff --git a/lib/nbd-protocol.h b/lib/nbd-protocol.h index 699aa22..7df411a 100644 --- a/lib/nbd-protocol.h +++ b/lib/nbd-protocol.h @@ -30,21 +30,22 @@ * SUCH DAMAGE. */ -/* This is derived from nbdkit's common/protocol/protocol.h. In time - * we expect that this library, nbdkit (and maybe others) should use - * the exact same header. - */ - #ifndef NBD_PROTOCOL_H #define NBD_PROTOCOL_H #include <stdint.h> /* Note that all NBD fields are sent on the wire in network byte - * order, so we must use beXXtoh or htobeXX when reading or writing + * order, so you must use beXXtoh or htobeXX when reading or writing * these structures. */ +#if defined(__GNUC__) || defined(__clang__) +#define NBD_ATTRIBUTE_PACKED __attribute__((__packed__)) +#else +#define NBD_ATTRIBUTE_PACKED +#endif + #define NBD_MAX_STRING 4096 /* Maximum length of a string field */ /* Old-style handshake. */ @@ -55,7 +56,7 @@ struct nbd_old_handshake { uint16_t gflags; /* global flags */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_OLD_VERSION UINT64_C(0x420281861253) @@ -64,7 +65,7 @@ struct nbd_new_handshake { char nbdmagic[8]; /* "NBDMAGIC" */ uint64_t version; /* NBD_NEW_VERSION */ uint16_t gflags; /* global flags */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_NEW_VERSION UINT64_C(0x49484156454F5054) @@ -74,14 +75,14 @@ struct nbd_new_option { uint32_t option; /* NBD_OPT_* */ uint32_t optlen; /* option data length */ /* option data follows */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Newstyle handshake OPT_EXPORT_NAME reply message. */ struct nbd_export_name_option_reply { uint64_t exportsize; /* size of export */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* optional zeroes */ -} __attribute__((packed));; +} NBD_ATTRIBUTE_PACKED;; /* Fixed newstyle handshake reply message. */ struct nbd_fixed_new_option_reply { @@ -89,14 +90,13 @@ struct nbd_fixed_new_option_reply { uint32_t option; /* option we are replying to */ uint32_t reply; /* NBD_REP_* */ uint32_t replylen; -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_REP_MAGIC UINT64_C(0x3e889045565a9) -/* Global flags. Exposed by the generator as LIBNBD_HANDSHAKE_FLAG_* instead +/* Global flags. */ #define NBD_FLAG_FIXED_NEWSTYLE 1 #define NBD_FLAG_NO_ZEROES 2 - */ /* Per-export flags. */ #define NBD_FLAG_HAS_FLAGS (1 << 0) @@ -146,19 +146,19 @@ struct nbd_fixed_new_option_reply_info_export { uint16_t info; /* NBD_INFO_EXPORT */ uint64_t exportsize; /* size of export */ uint16_t eflags; /* per-export flags */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* NBD_REP_META_CONTEXT reply (follows fixed_new_option_reply). */ struct nbd_fixed_new_option_reply_meta_context { uint32_t context_id; /* metadata context ID */ /* followed by a string */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* NBD_REPLY_TYPE_BLOCK_STATUS block descriptor. */ struct nbd_block_descriptor { uint32_t length; /* length of block */ uint32_t status_flags; /* block type (hole etc) */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* New-style handshake server reply when using NBD_OPT_EXPORT_NAME. * Modern clients use NBD_OPT_GO instead of this. @@ -167,7 +167,7 @@ struct nbd_new_handshake_finish { uint64_t exportsize; uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Request (client -> server). */ struct nbd_request { @@ -177,14 +177,14 @@ struct nbd_request { uint64_t handle; /* Opaque handle. */ uint64_t offset; /* Request offset. */ uint32_t count; /* Request length. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Simple reply (server -> client). */ struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Structured reply (server -> client). */ struct nbd_structured_reply { @@ -193,23 +193,23 @@ struct nbd_structured_reply { uint16_t type; /* NBD_REPLY_TYPE_* */ uint64_t handle; /* Opaque handle. */ uint32_t length; /* Length of payload which follows. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_offset_data { uint64_t offset; /* offset */ /* Followed by data. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_offset_hole { uint64_t offset; uint32_t length; /* Length of hole. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; struct nbd_structured_reply_error { uint32_t error; /* NBD_E* error number */ uint16_t len; /* Length of human readable error. */ /* Followed by human readable error string, and possibly more structure. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; #define NBD_REQUEST_MAGIC 0x25609513 #define NBD_SIMPLE_REPLY_MAGIC 0x67446698 @@ -239,12 +239,11 @@ struct nbd_structured_reply_error { #define NBD_CMD_WRITE_ZEROES 6 #define NBD_CMD_BLOCK_STATUS 7 -/* Command flags. Exposed by the generator as LIBNBD_CMD_FLAG_* instead -#define NBD_CMD_FLAG_FUA (1<<0) -#define NBD_CMD_FLAG_NO_HOLE (1<<1) -#define NBD_CMD_FLAG_DF (1<<2) -#define NBD_CMD_FLAG_REQ_ONE (1<<3) -*/ +#define NBD_CMD_FLAG_FUA (1<<0) +#define NBD_CMD_FLAG_NO_HOLE (1<<1) +#define NBD_CMD_FLAG_DF (1<<2) +#define NBD_CMD_FLAG_REQ_ONE (1<<3) +#define NBD_CMD_FLAG_FAST_ZERO (1<<4) /* NBD error codes. */ #define NBD_SUCCESS 0 -- 2.23.0