Re: [Qemu-devel] [PATCH 2/2] nbd: Don't validate from and len in NBD_CMD_DISC.

[Paolo Bonzini <pbonzini@redhat.com>]

Il 18/05/2014 12:50, Hani Benhabiles ha scritto:
> 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 <hani@linux.com>
> ---
>  nbd.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/nbd.c b/nbd.c
> index e5084b6..dc076d7 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 type;
>
>      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) {
> +    type = request.type & NBD_CMD_MASK_COMMAND;
> +    if (type != 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 (type) {
>      case NBD_CMD_READ:
>          TRACE("Request type is READ");
>
>

Applied after renaming the variable from type to command (for 
consistency with e.g. nbd_co_receive_request).

Paolo