From: Hani Benhabiles <kroosec@gmail.com>
Date: Sun, 18 May 2014 10:50:05 +0000 (+0100)
Subject: nbd: Don't validate from and len in NBD_CMD_DISC.
X-Git-Tag: TizenStudio_2.0_p2.3.2~208^2~730^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8c5d1abbb79193dca8e4823ef53d8d1e650362ae;p=sdk%2Femulator%2Fqemu.git

nbd: Don't validate from and len in NBD_CMD_DISC.

These values aren't used in this case.

Currently, the from field in the request sent by the nbd kernel module leading
to a false error message when ending the connection with the client.

$ qemu-nbd some.img -v
// After nbd-client -d /dev/nbd0
nbd.c:nbd_trip():L1031: From: 18446744073709551104, Len: 0, Size: 20971520,
Offset: 0
nbd.c:nbd_trip():L1032: requested operation past EOF--bad client?
nbd.c:nbd_receive_request():L638: read failed

Signed-off-by: Hani Benhabiles <kroosec@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/nbd.c b/nbd.c
index e0d032c..8d8bc40 100644
--- a/nbd.c
+++ b/nbd.c
@@ -1001,6 +1001,7 @@ static void nbd_trip(void *opaque)
     struct nbd_request request;
     struct nbd_reply reply;
     ssize_t ret;
+    uint32_t command;
 
     TRACE("Reading request.");
     if (client->closing) {
@@ -1023,8 +1024,8 @@ static void nbd_trip(void *opaque)
         reply.error = -ret;
         goto error_reply;
     }
-
-    if ((request.from + request.len) > exp->size) {
+    command = request.type & NBD_CMD_MASK_COMMAND;
+    if (command != NBD_CMD_DISC && (request.from + request.len) > exp->size) {
             LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
             ", Offset: %" PRIu64 "\n",
                     request.from, request.len,
@@ -1033,7 +1034,7 @@ static void nbd_trip(void *opaque)
         goto invalid_request;
     }
 
-    switch (request.type & NBD_CMD_MASK_COMMAND) {
+    switch (command) {
     case NBD_CMD_READ:
         TRACE("Request type is READ");