From fa6dc0152cf920b440370b080b925b4c9cf2bbad Mon Sep 17 00:00:00 2001
From: Adam Cozzette <acozzette@cs.hmc.edu>
Date: Sun, 9 Oct 2011 22:30:30 -0700
Subject: [PATCH] Committing various changes.

---
 abuse.c    | 23 +++++++++++++++++++----
 abuse.h    |  6 +++---
 abusexmp.c | 16 +++++++++++++---
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/abuse.c b/abuse.c
index 88f0585..da976bd 100644
--- a/abuse.c
+++ b/abuse.c
@@ -36,8 +36,7 @@ int abuse_main(int argc, char *argv[], const struct abuse_operations *aop, void
     int sp[2];
     int nbd, sk, err, tmp_fd;
     u_int64_t from;
-    u_int32_t len;
-    int bytes_written, bytes_read;
+    u_int32_t len, bytes_read, bytes_written;
     char *dev_file;
     struct nbd_request request;
     struct nbd_reply reply;
@@ -92,27 +91,43 @@ int abuse_main(int argc, char *argv[], const struct abuse_operations *aop, void
 
         len = ntohl(request.len);
         from = ntohll(request.from);
-        (void) from;
         assert(request.magic == htonl(NBD_REQUEST_MAGIC));
 
         switch(ntohl(request.type)) {
+            /* I may at some point need to deal with the the fact that the
+             * official nbd server has a maximum buffer size, and divides up
+             * oversized requests into multiple pieces. This applies to reads
+             * and writes.
+             */
             case NBD_CMD_READ:
                 chunk = malloc(len + sizeof(struct nbd_reply));
                 aop->read((char *)chunk + sizeof(struct nbd_reply), len, from);
                 memcpy(chunk, &reply, sizeof(struct nbd_reply));
                 bytes_written = write(sk, chunk, len + sizeof(struct nbd_reply));
+                assert(bytes_written == len + sizeof(struct nbd_reply));
                 fprintf(stderr, "Wrote %d bytes.\n", bytes_written);
-                /* assert(bytes_written == len + sizeof(struct nbd_reply)); */
                 free(chunk);
                 break;
             case NBD_CMD_WRITE:
+                chunk = malloc(len);
+                bytes_read = read(sk, &chunk, len);
+                assert(bytes_read == len);
+                aop->write(chunk, len, from);
+                free(chunk);
+                bytes_written = write(sk, &reply, sizeof(struct nbd_reply));
+                assert(bytes_written == sizeof(struct nbd_reply));
                 break;
             case NBD_CMD_DISC:
+                aop->disc();
                 break;
             case NBD_CMD_FLUSH:
+                aop->flush();
                 break;
             case NBD_CMD_TRIM:
+                aop->trim();
                 break;
+            default:
+                assert(0);
         }
     }
 
diff --git a/abuse.h b/abuse.h
index 999f421..a4b2bfd 100644
--- a/abuse.h
+++ b/abuse.h
@@ -6,9 +6,9 @@
 struct abuse_operations {
     int (*read)(void *buf, u_int32_t len, u_int64_t offset);
     int (*write)(const void *buf, u_int32_t len, u_int64_t offset);
-    void (*disc)();
-    void (*flush)();
-    void (*trim)();
+    int (*disc)();
+    int (*flush)();
+    int (*trim)();
 
     u_int64_t size;
 };
diff --git a/abusexmp.c b/abusexmp.c
index 0b8992d..a5e334c 100644
--- a/abusexmp.c
+++ b/abusexmp.c
@@ -3,21 +3,31 @@
 
 #include "abuse.h"
 
+static void *data;
+
 static int xmp_read(void *buf, u_int32_t len, u_int64_t offset)
 {
-    (void) offset;
-
+    /* memcpy(buf, (char *)data + offset, len); */
     memset(buf, 0, len);
 
     return 0;
 }
 
+static int xmp_write(const void *buf, u_int32_t len, u_int64_t offset)
+{
+    memcpy((char *)data + offset, buf, len);
+    return 0;
+}
+
 static struct abuse_operations aop = {
     .read = xmp_read,
-    .size = 1024,
+    .write = xmp_write,
+    .size = 128 * 1024 * 1024,
 };
 
 int main(int argc, char *argv[])
 {
+    data = malloc(aop.size);
+
     return abuse_main(argc, argv, &aop, NULL);
 }