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Re: [Qemu-devel] [PATCH v3 2/2] rtl8139: add vlan tag extraction
From: |
Blue Swirl |
Subject: |
Re: [Qemu-devel] [PATCH v3 2/2] rtl8139: add vlan tag extraction |
Date: |
Sat, 26 Feb 2011 18:58:23 +0200 |
On Sat, Feb 26, 2011 at 2:40 AM, Benjamin Poirier
<address@hidden> wrote:
> Add support to the emulated hardware to extract vlan tags in packets
> going from the network to the guest.
>
> Signed-off-by: Benjamin Poirier <address@hidden>
> Cc: Igor V. Kovalenko <address@hidden>
> Cc: Jason Wang <address@hidden>
> Cc: Michael S. Tsirkin <address@hidden>
>
> --
>
> AFAIK, extraction is optional to get vlans working. The driver
> requests rx detagging but should not assume that it was done. Under
> Linux, the mac layer will catch the vlan ethertype. I only added this
> part for completeness (to emulate the hardware more truthfully.)
> ---
> hw/rtl8139.c | 89
> +++++++++++++++++++++++++++++++++++++++++-----------------
> 1 files changed, 63 insertions(+), 26 deletions(-)
>
> diff --git a/hw/rtl8139.c b/hw/rtl8139.c
> index 35ccd3d..f3aaebc 100644
> --- a/hw/rtl8139.c
> +++ b/hw/rtl8139.c
> @@ -835,10 +835,11 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc,
> const uint8_t *buf,
> RTL8139State *s = DO_UPCAST(NICState, nc, nc)->opaque;
> int size_ = buf_size + (dot1q_buf ? VLAN_HDR_LEN : 0);
> int size = size_;
> + const uint8_t *next_part;
> + size_t next_part_size;
>
> uint32_t packet_header = 0;
>
> - uint8_t buf1[60];
> static const uint8_t broadcast_macaddr[6] =
> { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
>
> @@ -950,21 +951,6 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc,
> const uint8_t *buf,
> }
> }
>
> - /* if too small buffer, then expand it */
> - if (size < MIN_BUF_SIZE) {
> - if (unlikely(dot1q_buf)) {
> - memcpy(buf1, buf, 2 * ETHER_ADDR_LEN);
> - memcpy(buf1 + 2 * ETHER_ADDR_LEN, dot1q_buf, VLAN_HDR_LEN);
> - memcpy(buf1 + 2 * ETHER_ADDR_LEN + VLAN_HDR_LEN, buf + 2 *
> - ETHER_ADDR_LEN, buf_size - 2 * ETHER_ADDR_LEN);
> - } else {
> - memcpy(buf1, buf, size);
> - }
> - memset(buf1 + size, 0, MIN_BUF_SIZE - size);
> - buf = buf1;
> - size = MIN_BUF_SIZE;
> - }
> -
> if (rtl8139_cp_receiver_enabled(s))
> {
> DEBUG_PRINT(("RTL8139: in C+ Rx mode ================\n"));
> @@ -1025,6 +1011,44 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc,
> const uint8_t *buf,
>
> uint32_t rx_space = rxdw0 & CP_RX_BUFFER_SIZE_MASK;
>
> + /* write VLAN info to descriptor variables */
> + /* next_part starts right after the vlan header (if any), at the
> + * ethertype for the payload */
> + next_part = &buf[ETHER_ADDR_LEN * 2];
> + if (s->CpCmd & CPlusRxVLAN && (dot1q_buf || be16_to_cpup((uint16_t *)
> + &buf[ETHER_ADDR_LEN * 2]) == ETHERTYPE_VLAN)) {
> + if (!dot1q_buf) {
> + /* the tag is in the buffer */
> + dot1q_buf = &buf[ETHER_ADDR_LEN * 2];
> + next_part += VLAN_HDR_LEN;
> + }
> + size -= VLAN_HDR_LEN;
> +
> + rxdw1 &= ~CP_RX_VLAN_TAG_MASK;
> + /* BE + ~le_to_cpu()~ + cpu_to_le() = BE */
> + rxdw1 |= CP_RX_TAVA | le16_to_cpup((uint16_t *)
> + &buf[ETHER_HDR_LEN]);
> +
> + DEBUG_PRINT(("RTL8139: C+ Rx mode : extracted vlan tag with tci:
> "
> + "%u\n", be16_to_cpup((uint16_t *) &buf[ETHER_HDR_LEN])));
> + } else {
> + /* reset VLAN tag flag */
> + rxdw1 &= ~CP_RX_TAVA;
> + }
> + next_part_size = buf + buf_size - next_part;
> +
> + /* if too small buffer, then expand it */
> + if (size < MIN_BUF_SIZE) {
> + size_t tmp_size = MIN_BUF_SIZE - ETHER_ADDR_LEN * 2;
> + uint8_t *tmp = alloca(tmp_size);
Don't use alloca() but qemu_malloc() or a static buffer.
> +
> + memcpy(tmp, next_part, next_part_size);
> + memset(tmp + next_part_size, 0, tmp_size - next_part_size);
> + next_part = tmp;
> + next_part_size = tmp_size;
> + size = MIN_BUF_SIZE;
> + }
> +
> /* TODO: scatter the packet over available receive ring descriptors
> space */
>
> if (size+4 > rx_space)
> @@ -1049,14 +1073,11 @@ static ssize_t rtl8139_do_receive(VLANClientState
> *nc, const uint8_t *buf,
> if (unlikely(dot1q_buf)) {
> cpu_physical_memory_write(rx_addr, buf, 2 * ETHER_ADDR_LEN);
> val = rtl8139_crc32(0, buf, 2 * ETHER_ADDR_LEN);
> - cpu_physical_memory_write(rx_addr + 2 * ETHER_ADDR_LEN,
> dot1q_buf,
> - VLAN_HDR_LEN);
> val = rtl8139_crc32(val, dot1q_buf, VLAN_HDR_LEN);
> - cpu_physical_memory_write(rx_addr + 2 * ETHER_ADDR_LEN +
> - VLAN_HDR_LEN, buf + 2 * ETHER_ADDR_LEN, buf_size - 2 *
> - ETHER_ADDR_LEN);
> - val = rtl8139_crc32(val, buf + 2 * ETHER_ADDR_LEN, buf_size - 2 *
> - ETHER_ADDR_LEN);
> + cpu_physical_memory_write(rx_addr + 2 * ETHER_ADDR_LEN,
> next_part,
> + next_part_size);
> + val = rtl8139_crc32(val, buf + 2 * ETHER_ADDR_LEN,
> + next_part_size);
> } else {
> cpu_physical_memory_write(rx_addr, buf, size);
> val = rtl8139_crc32(0, buf, size);
> @@ -1115,9 +1136,6 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc,
> const uint8_t *buf,
> rxdw0 &= ~CP_RX_BUFFER_SIZE_MASK;
> rxdw0 |= (size+4);
>
> - /* reset VLAN tag flag */
> - rxdw1 &= ~CP_RX_TAVA;
> -
> /* update ring data */
> val = cpu_to_le32(rxdw0);
> cpu_physical_memory_write(cplus_rx_ring_desc, (uint8_t *)&val, 4);
> @@ -1144,6 +1162,25 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc,
> const uint8_t *buf,
> {
> DEBUG_PRINT(("RTL8139: in ring Rx mode ================\n"));
>
> + /* if too small buffer, then expand it */
> + if (size < MIN_BUF_SIZE) {
> + uint8_t *tmp;
> +
> + tmp = alloca(MIN_BUF_SIZE);
Ditto.
Note to self: HACKING forgets to forbid alloca, should be fixed.