[Qemu-devel] [PATCH COLO-Frame v5 22/29] COLO: Handle nfnetlink message from proxy module

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

Proxy module will send message to qemu through nfnetlink.
Now, the message only contains the result of packets comparation.

We use a global variable 'packet_compare_different' to store the result.
And this variable should be accessed by using atomic related function,
such as 'atomic_set' 'atomic_xchg'.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
 net/colo-nic.c | 41 +++++++++++++++++++++++++++++++++++++++++
 trace-events   |  1 +
 2 files changed, 42 insertions(+)

diff --git a/net/colo-nic.c b/net/colo-nic.c
index f4e04af..9e08fe3 100644
--- a/net/colo-nic.c
+++ b/net/colo-nic.c
@@ -21,6 +21,7 @@
 #include "net/net.h"
 #include "net/colo-nic.h"
 #include "qemu/error-report.h"
+#include "trace.h"
 
 /* Remove the follow define after proxy is merged into kernel,
 * using #include <libnfnetlink/libnfnetlink.h> instead.
@@ -79,6 +80,7 @@ typedef struct nic_device {
 
 static struct nfnl_handle *nfnlh;
 static struct nfnl_subsys_handle *nfnlssh;
+static int32_t packet_compare_different; /* The result of packet comparing */
 
 QTAILQ_HEAD(, nic_device) nic_devices = QTAILQ_HEAD_INITIALIZER(nic_devices);
 
@@ -264,6 +266,38 @@ static int colo_proxy_send(enum nfnl_colo_msg_types msg_type,
     return ret;
 }
 
+static int __colo_rcv_pkt(struct nlmsghdr *nlh, struct nfattr *nfa[],
+                          void *data)
+{
+    /* struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); */
+    int32_t  result = ntohl(nfnl_get_data(nfa, NFNL_COLO_COMPARE_RESULT,
+                                          int32_t));
+
+    atomic_set(&packet_compare_different, result);
+    trace_colo_rcv_pkt(result);
+    return 0;
+}
+
+static struct nfnl_callback colo_nic_cb = {
+    .call   = &__colo_rcv_pkt,
+    .attr_count = NFNL_COLO_KERNEL_NOTIFY_MAX,
+};
+
+static void colo_proxy_recv(void *opaque)
+{
+    unsigned char *buf = g_malloc0(2048);
+    int len;
+    int ret;
+
+    len = nfnl_recv(nfnlh, buf, 2048);
+    ret = nfnl_handle_packet(nfnlh, (char *)buf, len);
+    if (ret < 0) {/* Notify colo thread the error */
+        atomic_set(&packet_compare_different, -1);
+        error_report("call nfnl_handle_packet failed");
+    }
+    g_free(buf);
+}
+
 static int check_proxy_ack(void)
 {
     unsigned char *buf = g_malloc0(2048);
@@ -319,6 +353,11 @@ int colo_proxy_init(enum colo_mode mode)
         goto err_out;
     }
 
+    ret = nfnl_callback_register(nfnlssh, NFCOLO_KERNEL_NOTIFY, &colo_nic_cb);
+    if (ret < 0) {
+        goto err_out;
+    }
+
     /* Netlink is not a reliable protocol, So it is necessary to request proxy
      * module to acknowledge in the first time.
      */
@@ -338,6 +377,8 @@ int colo_proxy_init(enum colo_mode mode)
         goto err_out;
     }
 
+   qemu_set_fd_handler(nfnl_fd(nfnlh), colo_proxy_recv, NULL, NULL);
+
     return 0;
 err_out:
     nfnl_close(nfnlh);
diff --git a/trace-events b/trace-events
index 1ce7bba..b1c263a 100644
--- a/trace-events
+++ b/trace-events
@@ -1450,6 +1450,7 @@ colo_info_load(const char *msg) "%s"
 colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
 colo_receive_message(const char *msg) "Receive '%s'"
 colo_do_failover(void) ""
+colo_rcv_pkt(int result) "Result of net packets comparing is different: %d"
 
 # kvm-all.c
 kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
-- 
1.7.12.4