From 93b9103f7383d400616d222606c294e07b16e1aa Mon Sep 17 00:00:00 2001
From: Lars Müller
Date: Sat, 1 Mar 2008 18:30:38 +0000
Subject: Import dnbd* from the former openslx-contrib repo as of revision 92.

openslx-contrib is currently read only and will get removed in some
days.


git-svn-id: http://svn.openslx.org/svn/openslx/contrib/dnbd2/trunk@1592 95ad53e4-c205-0410-b2fa-d234c58c8868
---
 include/dnbd2.h | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100644 include/dnbd2.h

(limited to 'include')

diff --git a/include/dnbd2.h b/include/dnbd2.h
new file mode 100644
index 0000000..4035b11
--- /dev/null
+++ b/include/dnbd2.h
@@ -0,0 +1,131 @@
+/*
+ * libs/dnbd2.h - Stuff that applies to all programs.
+ */
+
+
+/*
+ * The Linux Kernel's minimum block request size is PAGE_SIZE.  We use
+ * the same block size to simplify things.  We don't care about other
+ * sizes because our software is platform dependant.
+ */
+#define DNBD2_BLOCK_SIZE 4096
+
+/*
+ * Commands the data-server understands.
+ */
+#define CMD_GET_BLOCK   1 /* Request a block. */
+#define CMD_GET_SIZE    2 /* Request the size of a Dataset. */
+#define CMD_GET_SERVERS 3 /* Request a list of alternative servers. */
+
+/*
+ * Maximum number of alternative data-servers per dataset.
+ */
+#define ALT_SERVERS_MAX 4
+
+/*
+ * Maximum lenght of strings including the ending \0.
+ */
+#define FILE_NAME_MAX  255
+#define LINE_SIZE_MAX  FILE_NAME_MAX
+
+/*
+ * Network byte order <-> Host byte order (64bits).
+ */
+#ifndef MODULE
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define ntohll(x) (x)
+#define htonll(x) (x)
+#else
+#define ntohll(x) bswap_64(x)
+#define htonll(x) bswap_64(x)
+#endif
+#endif
+
+
+/*
+ * Dataset
+ */
+typedef struct dataset {
+        char     path[FILE_NAME_MAX]; /* pathname to file or block-device */
+        uint16_t vid;                 /* Volume-ID */
+        uint16_t rid;                 /* Release-ID */
+} dataset_t;
+
+/*
+ * Structure to identify servers.
+ */
+#pragma pack(4)
+typedef struct dnbd2_server {
+        uint32_t ip;   /* IP   (network byte order) */
+        uint16_t port; /* Port (network byte order) */
+	uint16_t pad;  /* Padding - unused */
+} dnbd2_server_t;
+#pragma pack()
+
+/*
+ * Structure for requests:
+ *
+ *   <--------- 64 bits --------->
+ *
+ *   +---------------------------+
+ *   | cmd  | time | vid  | rid  |
+ *   |---------------------------|
+ *   |          offset           |
+ *   +---------------------------+
+ *
+ *   - cmd:  Command (defined above)
+ *   - time: Time of request
+ *   - vid:  Volume-ID
+ *   - rid:  Release-ID
+ *   - num:  Offset (for CMD_GET_BLOCK), otherwise undefined
+ */
+#pragma pack(1)
+typedef struct dnbd2_data_request {
+	uint16_t cmd;
+	uint16_t time;
+	uint16_t vid;
+	uint16_t rid;
+	uint64_t num;
+} dnbd2_data_request_t;
+#pragma pack()
+
+/*
+ * Structure for replies:
+ *
+ *   <--------- 64 bits --------->
+ *
+ *   +---------------------------+
+ *   | cmd  | time | vid  | rid  |
+ *   |---------------------------|
+ *   |   offset/size/n.servers   |
+ *   |---------------------------|
+ *   |                           |
+ *   |           (4KB)           |
+ *   |   Block/List of servers   |
+ *   |                           |
+ *   +---------------------------+
+ *
+ *   - req.cmd:  Always echoed
+ *   - req.time: Always echoed
+ *   - req.vid:  Always echoed
+ *   - req.rid:  Always echoed
+ *   - req.num:  Echoed (for CMD_GET_BLOCK) or
+ *               Dataset size (for CMD_GET_SIZE) or
+ *               Number of Servers (for CMD_GET_SERVERS)
+ *   - payload:  A block (for CMD_GET_BLOCK) or
+ *               Undefined (for CMD_GET_SIZE) or
+ *               List of Servers (for CMD_GET_SIZE)
+ */
+#pragma pack(1)
+typedef struct dnbd2_data_reply {
+	uint16_t cmd;
+	uint16_t time;
+	uint16_t vid;
+	uint16_t rid;
+	uint64_t num;
+	union {
+		uint8_t data[DNBD2_BLOCK_SIZE];
+		dnbd2_server_t server[ALT_SERVERS_MAX];
+	} payload;
+} dnbd2_data_reply_t;
+#pragma pack()
-- 
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