Re: [Qemu-devel] [PATCH V3 04/10] net/filter-mirror.c: Add filter-mirror and filter-redirector vnet support.

[Jason Wang]

On 2017年05月03日 11:18, Zhang Chen wrote:

On 05/02/2017 12:47 PM, Jason Wang wrote:

On 2017年04月28日 17:47, Zhang Chen wrote:

In this patch, we change the send packet format from

struct {int size; const uint8_t buf[];} to {int size; int vnet_hdr_len; const uint8_t buf[];}. make other module(like colo-compare) know how to parse net packet correctly.

Signed-off-by: Zhang Chen <zhangchen.f...@cn.fujitsu.com>
---
  net/filter-mirror.c | 28 +++++++++++++++++++++++-----
  1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/net/filter-mirror.c b/net/filter-mirror.c
index 72fa7c2..bb9ecf3 100644
--- a/net/filter-mirror.c
+++ b/net/filter-mirror.c
@@ -43,12 +43,14 @@ typedef struct MirrorState {
      SocketReadState rs;
  } MirrorState;
  -static int filter_mirror_send(CharBackend *chr_out,
+static int filter_mirror_send(MirrorState *s,
                                const struct iovec *iov,
                                int iovcnt)
  {
+    NetFilterState *nf = NETFILTER(s);
      int ret = 0;
      ssize_t size = 0;
+    ssize_t vnet_hdr_len;
      uint32_t len = 0;
      char *buf;

@@ -58,14 +60,30 @@ static int filter_mirror_send(CharBackend *chr_out,

      }
        len = htonl(size);

- ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)&len, sizeof(len)); + ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));

+    if (ret != sizeof(len)) {
+        goto err;
+    }
+
+    /*
+     * We send vnet header len make other module(like colo-compare)
+     * know how to parse net packet correctly.
+     */
+    if (qemu_get_using_vnet_hdr(nf->netdev)) {
+        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev);
+    } else {
+        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev->peer);
+    }

Any reason to query peer here?

That's depend on using NetClientState, If we using nf->netdev that need to query, Otherwise we query nf->netdev->peer, then we can get the real vnet_hdr_len in my test.

Thanks

Zhang Chen

Confused, I think nf->netdev won't be a nic?

Thanks