From e4adf93eb99dc60e37b9ab40d787609854d80f9c Mon Sep 17 00:00:00 2001
From: Alex Bligh <alex@alex.org.uk>
Date: Sun, 22 May 2011 19:20:49 +0100
Subject: [PATCH] Add nbd-trdump - utilty to dump traces

---
 nbd-trdump.c |  102 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 nbd-trdump.c

diff --git a/nbd-trdump.c b/nbd-trdump.c
new file mode 100644
index 0000000..49f4f9e
--- /dev/null
+++ b/nbd-trdump.c
@@ -0,0 +1,102 @@
+/*
+ * nbd-trdump.c
+ *
+ * Takes an nbd transaction log file on stdin and translates it into something
+ * comprehensible
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <unistd.h>
+#include "config.h"
+#include "cliserv.h"
+#include "nbd.h"
+
+static inline void doread(int f, void *buf, size_t len) {
+        ssize_t res;
+
+        while(len>0) {
+                if((res=read(f, buf, len)) <=0) {
+                        if (!res)
+				exit(0);
+			perror ("Error reading transactions");
+			exit(1);
+                }
+                len-=res;
+                buf+=res;
+        }
+}
+
+int main(int argc, char**argv) {
+	struct nbd_request req;
+	struct nbd_reply rep;
+	uint32_t magic;
+	uint64_t handle;
+	uint32_t error;
+	uint32_t command;
+	uint32_t len;
+	uint64_t offset;
+	char * ctext;
+	int readfd = 0; /* stdin */
+
+	while (1) {
+		/* Read a request or reply from the transaction file */
+		doread(readfd, &magic, sizeof(magic));
+		magic = ntohl(magic);
+		switch (magic) {
+		case NBD_REQUEST_MAGIC:
+			doread(readfd, sizeof(magic)+(char *)(&req), sizeof(struct nbd_request)-sizeof(magic));
+			handle = ntohll(*((long long int *)(req.handle)));
+			offset = ntohll(req.from);
+			len = ntohl(req.len);
+			command = ntohl(req.type);
+			
+			switch (command & NBD_CMD_MASK_COMMAND) {
+			case NBD_CMD_READ:
+				ctext="NBD_CMD_READ";
+				break;
+			case NBD_CMD_WRITE:
+				ctext="NBD_CMD_WRITE";
+				break;
+			case NBD_CMD_DISC:
+				ctext="NBD_CMD_DISC";
+				break;
+			case NBD_CMD_FLUSH:
+				ctext="NBD_CMD_FLUSH";
+				break;
+			default:
+				ctext="UNKNOWN";
+				break;
+			}
+			printf("> H=%016llx C=0x%08x (%13s+%4s) O=%016llx L=%08x\n",
+			       (long long unsigned int) handle,
+			       command,
+			       ctext,
+			       (command & NBD_CMD_FLAG_FUA)?"FUA":"NONE",
+			       (long long unsigned int) offset,
+			       len);
+			
+			break;
+		case NBD_REPLY_MAGIC:
+			doread(readfd, sizeof(magic)+(char *)(&rep), sizeof(struct nbd_reply)-sizeof(magic));
+			handle = ntohll(*((long long int *)(rep.handle)));
+			error = ntohl(rep.error);
+			
+			printf("< H=%016llx E=0x%08x\n",
+			       (long long unsigned int) handle,
+			       error);
+			break;
+			
+		default:
+			printf("? Unknown transaction type %08x\n",magic);
+			break;
+		}
+		
+	}
+	/* never reached */
+	return 0;
+}
-- 
1.7.10.4