4:07 p.m.
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