net/net.c: Add vnet_hdr support in SocketReadState

We add a flag to decide whether net_fill_rstate() need read
the vnet_hdr_len or not.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/net.h

@@ -112,9 +112,13 @@ 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;
+    /* This flag decide whether to read the vnet_hdr_len field */
+    bool vnet_hdr;
     uint32_t index;
     uint32_t packet_len;
+    uint32_t vnet_hdr_len;
     uint8_t buf[NET_BUFSIZE];
     SocketReadStateFinalize *finalize;
 };
@@ -177,7 +181,8 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,
 void print_net_client(Monitor *mon, NetClientState *nc);
 void hmp_info_network(Monitor *mon, const QDict *qdict);
 void net_socket_rs_init(SocketReadState *rs,
-                        SocketReadStateFinalize *finalize);
+                        SocketReadStateFinalize *finalize,
+                        bool vnet_hdr);
 
 /* NIC info */
 

net/colo-compare.c

@@ -743,8 +743,8 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
         return;
     }
 
-    net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
+    net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, false);
-    net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
+    net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, false);
 
     g_queue_init(&s->conn_list);
 

net/filter-mirror.c

@@ -229,7 +229,7 @@ static void filter_redirector_setup(NetFilterState *nf, Error **errp)
         }
     }
 
-    net_socket_rs_init(&s->rs, redirector_rs_finalize);
+    net_socket_rs_init(&s->rs, redirector_rs_finalize, false);
 
     if (s->indev) {
         chr = qemu_chr_find(s->indev);

net/net.c

@@ -1616,11 +1616,14 @@ QemuOptsList qemu_net_opts = {
 };
 
 void net_socket_rs_init(SocketReadState *rs,
-                        SocketReadStateFinalize *finalize)
+                        SocketReadStateFinalize *finalize,
+                        bool vnet_hdr)
 {
     rs->state = 0;
+    rs->vnet_hdr = vnet_hdr;
     rs->index = 0;
     rs->packet_len = 0;
+    rs->vnet_hdr_len = 0;
     memset(rs->buf, 0, sizeof(rs->buf));
     rs->finalize = finalize;
 }
@@ -1635,8 +1638,12 @@ int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
     unsigned int l;
 
     while (size > 0) {
-        /* reassemble a packet from the network */
+        /* Reassemble a packet from the network.
-        switch (rs->state) { /* 0 = getting length, 1 = getting data */
+         * 0 = getting length.
+         * 1 = getting vnet header length.
+         * 2 = getting data.
+         */
+        switch (rs->state) {
         case 0:
             l = 4 - rs->index;
             if (l > size) {
@@ -1650,10 +1657,31 @@ 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 (rs->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;

net/socket.c

@@ -174,7 +174,7 @@ static void net_socket_send(void *opaque)
         closesocket(s->fd);
 
         s->fd = -1;
-        net_socket_rs_init(&s->rs, net_socket_rs_finalize);
+        net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
         s->nc.link_down = true;
         memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
 
@@ -366,7 +366,7 @@ static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
     s->fd = fd;
     s->listen_fd = -1;
     s->send_fn = net_socket_send_dgram;
-    net_socket_rs_init(&s->rs, net_socket_rs_finalize);
+    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
     net_socket_read_poll(s, true);
 
     /* mcast: save bound address as dst */
@@ -417,7 +417,7 @@ static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
 
     s->fd = fd;
     s->listen_fd = -1;
-    net_socket_rs_init(&s->rs, net_socket_rs_finalize);
+    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 
     /* Disable Nagle algorithm on TCP sockets to reduce latency */
     socket_set_nodelay(fd);
@@ -522,7 +522,7 @@ static int net_socket_listen_init(NetClientState *peer,
     s->fd = -1;
     s->listen_fd = fd;
     s->nc.link_down = true;
-    net_socket_rs_init(&s->rs, net_socket_rs_finalize);
+    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 
     qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
     return 0;