[Qemu-devel] [PATCH V4 05/12] net/net.c: Add vnet_hdr support in SocketReadState

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

Address Jason Wang's comments add vnet header length to SocketReadState.
We add a flag to dicide whether net_fill_rstate() to read
struct  {int size; int vnet_hdr_len; const uint8_t buf[];} or not.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
---
 include/net/net.h   |  9 +++++++--
 net/colo-compare.c  |  4 ++--
 net/filter-mirror.c |  2 +-
 net/net.c           | 36 ++++++++++++++++++++++++++++++++----
 net/socket.c        |  2 +-
 5 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 70edfc0..0763636 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -113,14 +113,19 @@ typedef struct NICState {
 } NICState;
 
 struct SocketReadState {
-    int state; /* 0 = getting length, 1 = getting data */
+    /* 0 = getting length, 1 = getting vnet header length, 2 = getting data */
+    int state;
     uint32_t index;
     uint32_t packet_len;
+    uint32_t vnet_hdr_len;
     uint8_t buf[NET_BUFSIZE];
     SocketReadStateFinalize *finalize;
 };
 
-int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size);
+int net_fill_rstate(SocketReadState *rs,
+                    const uint8_t *buf,
+                    int size,
+                    bool vnet_hdr);
 char *qemu_mac_strdup_printf(const uint8_t *macaddr);
 NetClientState *qemu_find_netdev(const char *id);
 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
diff --git a/net/colo-compare.c b/net/colo-compare.c
index 4ab80b1..332f57e 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -530,7 +530,7 @@ static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
     CompareState *s = COLO_COMPARE(opaque);
     int ret;
 
-    ret = net_fill_rstate(&s->pri_rs, buf, size);
+    ret = net_fill_rstate(&s->pri_rs, buf, size, false);
     if (ret == -1) {
         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
                                  NULL, NULL, true);
@@ -547,7 +547,7 @@ static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
     CompareState *s = COLO_COMPARE(opaque);
     int ret;
 
-    ret = net_fill_rstate(&s->sec_rs, buf, size);
+    ret = net_fill_rstate(&s->sec_rs, buf, size, false);
     if (ret == -1) {
         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
                                  NULL, NULL, true);
diff --git a/net/filter-mirror.c b/net/filter-mirror.c
index a65853c..4649416 100644
--- a/net/filter-mirror.c
+++ b/net/filter-mirror.c
@@ -134,7 +134,7 @@ static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
     MirrorState *s = FILTER_REDIRECTOR(nf);
     int ret;
 
-    ret = net_fill_rstate(&s->rs, buf, size);
+    ret = net_fill_rstate(&s->rs, buf, size, s->vnet_hdr);
 
     if (ret == -1) {
         qemu_chr_fe_set_handlers(&s->chr_in, NULL, NULL, NULL,
diff --git a/net/net.c b/net/net.c
index a00a0c9..a9c97cf 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1618,13 +1618,20 @@ void net_socket_rs_init(SocketReadState *rs,
  * 0: success
  * -1: error occurs
  */
-int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
+int net_fill_rstate(SocketReadState *rs,
+                    const uint8_t *buf,
+                    int size,
+                    bool vnet_hdr)
 {
     unsigned int l;
 
     while (size > 0) {
-        /* reassemble a packet from the network */
-        switch (rs->state) { /* 0 = getting length, 1 = getting data */
+        /* Reassemble a packet from the network.
+         * 0 = getting length.
+         * 1 = getting vnet header length.
+         * 2 = getting data.
+         */
+        switch (rs->state) {
         case 0:
             l = 4 - rs->index;
             if (l > size) {
@@ -1638,10 +1645,31 @@ int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
                 /* got length */
                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
                 rs->index = 0;
-                rs->state = 1;
+                if (vnet_hdr) {
+                    rs->state = 1;
+                } else {
+                    rs->state = 2;
+                    rs->vnet_hdr_len = 0;
+                }
             }
             break;
         case 1:
+            l = 4 - rs->index;
+            if (l > size) {
+                l = size;
+            }
+            memcpy(rs->buf + rs->index, buf, l);
+            buf += l;
+            size -= l;
+            rs->index += l;
+            if (rs->index == 4) {
+                /* got vnet header length */
+                rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
+                rs->index = 0;
+                rs->state = 2;
+            }
+            break;
+        case 2:
             l = rs->packet_len - rs->index;
             if (l > size) {
                 l = size;
diff --git a/net/socket.c b/net/socket.c
index b8c931e..4e58eff 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -182,7 +182,7 @@ static void net_socket_send(void *opaque)
     }
     buf = buf1;
 
-    ret = net_fill_rstate(&s->rs, buf, size);
+    ret = net_fill_rstate(&s->rs, buf, size, false);
 
     if (ret == -1) {
         goto eoc;
-- 
2.7.4