Re: [Qemu-devel] [PATCH V4 03/12] net/filter-mirror.c: Make filter_mirror_send support vnet support.

[Zhang Chen]

On 05/15/2017 11:28 AM, Jason Wang wrote:

On 2017年05月12日 09:41, Zhang Chen wrote:

In this patch, if vnet_hdr=on 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 | 35 ++++++++++++++++++++++++++++++-----
  1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/net/filter-mirror.c b/net/filter-mirror.c
index 3766414..64323fc 100644
--- a/net/filter-mirror.c
+++ b/net/filter-mirror.c
@@ -44,10 +44,11 @@ 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;
      uint32_t len = 0;
@@ -59,14 +60,38 @@ 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;
      }
  +    if (s->vnet_hdr) {
+        /*
+         * If vnet_hdr = on, we send vnet header len to make other
+         * module(like colo-compare) know how to parse net
+         * packet correctly.
+         */
+        ssize_t vnet_hdr_len;
+
+        if (nf->netdev->using_vnet_hdr) {
+            vnet_hdr_len = nf->netdev->vnet_hdr_len;
+        } else if (nf->netdev->peer->using_vnet_hdr) {
+            vnet_hdr_len = nf->netdev->peer->vnet_hdr_len;

Still questionable here, may need a comment to explain.

OK, I will add comments in next version.

+        } else {
+            error_report("filter get vnet_hdr_len failed");

Why need error here, could we just use zero?

Yes,we can.

Thanks
Zhang Chen

Thanks

+            goto err;
+        }
+
+        len = htonl(vnet_hdr_len);

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

+        if (ret != sizeof(len)) {
+            goto err;
+        }
+    }
+
      buf = g_malloc(size);
      iov_to_buf(iov, iovcnt, 0, buf, size);
-    ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)buf, size);
+    ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
      g_free(buf);
      if (ret != size) {
          goto err;

@@ -142,7 +167,7 @@ static ssize_t filter_mirror_receive_iov(NetFilterState *nf,

      MirrorState *s = FILTER_MIRROR(nf);
      int ret;
  -    ret = filter_mirror_send(&s->chr_out, iov, iovcnt);
+    ret = filter_mirror_send(s, iov, iovcnt);
      if (ret) {
          error_report("filter_mirror_send failed(%s)", strerror(-ret));
      }

@@ -165,7 +190,7 @@ static ssize_t filter_redirector_receive_iov(NetFilterState *nf,

      int ret;
        if (qemu_chr_fe_get_driver(&s->chr_out)) {
-        ret = filter_mirror_send(&s->chr_out, iov, iovcnt);
+        ret = filter_mirror_send(s, iov, iovcnt);
          if (ret) {

error_report("filter_mirror_send failed(%s)", strerror(-ret));

          }

.

--
Thanks
Zhang Chen