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

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

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.fnst@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);
+    }
+
+    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;
@@ -141,7 +159,7 @@ 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));
     }
@@ -164,7 +182,7 @@ 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));
         }
-- 
2.7.4