On Sat, Apr 30, 2011 at 10:40:07PM +0200, Stefan Weil wrote:
> QEMU sends frames smaller than 60 bytes to ethernet nics.
> This should be fixed in the networking code because normally
> such frames are rejected by real NICs and their emulations.
> To avoid this behaviour, other NIC emulations pad received
> frames. This patch enables this workaround for eepro100, too.
>
> All related code is marked with CONFIG_PAD_RECEIVED_FRAMES,
> so emulation of the correct handling for short frames can
> be restored as soon as QEMU's networking code is fixed.
>
> Signed-off-by: Stefan Weil <w...@mail.berlios.de>
Applied, I tweaked the comment a bit as we don't intend
to change it in qemu. But go ahead and keep the ifdef around
if you like.
> ---
> hw/eepro100.c | 25 ++++++++++++++++++++++++-
> 1 files changed, 24 insertions(+), 1 deletions(-)
>
> diff --git a/hw/eepro100.c b/hw/eepro100.c
> index 82c6369..2104bc0 100644
> --- a/hw/eepro100.c
> +++ b/hw/eepro100.c
> @@ -48,6 +48,14 @@
> #include "eeprom93xx.h"
> #include "sysemu.h"
>
> +/* QEMU sends frames smaller than 60 bytes to ethernet nics.
> + * This should be fixed in the networking code because normally
> + * such frames are rejected by real nics and their emulations.
> + * To avoid this behaviour, other nic emulations pad received
> + * frames. The following definition enables this workaround for
> + * eepro100, too. */
> +#define CONFIG_PAD_RECEIVED_FRAMES
> +
> #define KiB 1024
>
> /* Debug EEPRO100 card. */
> @@ -1656,19 +1664,32 @@ static ssize_t nic_receive(VLANClientState *nc, const
> uint8_t * buf, size_t size
> */
> EEPRO100State *s = DO_UPCAST(NICState, nc, nc)->opaque;
> uint16_t rfd_status = 0xa000;
> +#if defined(CONFIG_PAD_RECEIVED_FRAMES)
> + uint8_t min_buf[60];
> +#endif
> static const uint8_t broadcast_macaddr[6] =
> { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
>
> +#if defined(CONFIG_PAD_RECEIVED_FRAMES)
> + /* Pad to minimum Ethernet frame length */
> + if (size < sizeof(min_buf)) {
> + memcpy(min_buf, buf, size);
> + memset(&min_buf[size], 0, sizeof(min_buf) - size);
> + buf = min_buf;
> + size = sizeof(min_buf);
> + }
> +#endif
> +
> if (s->configuration[8] & 0x80) {
> /* CSMA is disabled. */
> logout("%p received while CSMA is disabled\n", s);
> return -1;
> +#if !defined(CONFIG_PAD_RECEIVED_FRAMES)
> } else if (size < 64 && (s->configuration[7] & BIT(0))) {
> /* Short frame and configuration byte 7/0 (discard short receive)
> set:
> * Short frame is discarded */
> logout("%p received short frame (%zu byte)\n", s, size);
> s->statistics.rx_short_frame_errors++;
> -#if 0
> return -1;
> #endif
> } else if ((size > MAX_ETH_FRAME_SIZE + 4) && !(s->configuration[18] &
> BIT(3))) {
> @@ -1747,9 +1768,11 @@ static ssize_t nic_receive(VLANClientState *nc, const
> uint8_t * buf, size_t size
> "(%zu bytes); data truncated\n", rfd_size, size);
> size = rfd_size;
> }
> +#if !defined(CONFIG_PAD_RECEIVED_FRAMES)
> if (size < 64) {
> rfd_status |= 0x0080;
> }
> +#endif
> TRACE(OTHER, logout("command 0x%04x, link 0x%08x, addr 0x%08x, size
> %u\n",
> rfd_command, rx.link, rx.rx_buf_addr, rfd_size));
> stw_phys(s->ru_base + s->ru_offset + offsetof(eepro100_rx_t, status),
> --
> 1.7.2.5
