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 @@
struct nbd_request request;
struct nbd_reply reply;
ssize_t ret;
+ uint32_t command;
TRACE("Reading request.");
if (client->closing) {
@@ -1023,8 +1024,8 @@
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 @@
goto invalid_request;
}
- switch (request.type & NBD_CMD_MASK_COMMAND) {
+ switch (command) {
case NBD_CMD_READ:
TRACE("Request type is READ");
