[Qemu-devel] [PATCH COLO-Frame v7 24/34] colo-nic: Handle secondary VM's original net device configure

[zhanghailiang]

For secondary VM, we need to reconfigure its original net devices,
Before go into COLO mode, we detach its original net devices (here is tap)
from its default configure (here is bridge), and
attach the net devices to forward bridge.
When exit from COLO mode, we resume its origianl configure.

Signed-off-by: zhanghailiang <address@hidden>
---
 include/net/colo-nic.h       |  2 ++
 net/colo-nic.c               | 52 ++++++++++++++++++++++++++++++++++-
 net/tap.c                    |  4 +++
 scripts/colo-proxy-script.sh | 65 ++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 116 insertions(+), 7 deletions(-)

diff --git a/include/net/colo-nic.h b/include/net/colo-nic.h
index 3941b6e..f1d9c25 100644
--- a/include/net/colo-nic.h
+++ b/include/net/colo-nic.h
@@ -20,6 +20,8 @@ typedef struct COLONicState {
     char nicname[128]; /* forward dev */
     char script[1024]; /* colo script */
     char ifname[128];  /* e.g. tap name */
+    char qemu_ifup[1024]; /* script that setup nic, e.g. /etc/qemu-ifup */
+    char *qemu_ifdown; /* script that cleanup nic e.g. /etc/qemu-ifdown */
 } COLONicState;
 
 void colo_add_nic_devices(COLONicState *cns);
diff --git a/net/colo-nic.c b/net/colo-nic.c
index 4ce08c0..4b53f72 100644
--- a/net/colo-nic.c
+++ b/net/colo-nic.c
@@ -58,17 +58,67 @@ static int launch_colo_script(COLONicState *cns, bool up, 
int side, int index)
     return 0;
 }
 
+/* For secondary VM, we need to cleanup its original configure
+ * when go into COLO state, when exit from COLO state, we need to
+ * resume its old configure
+*/
+static int handle_old_nic_configure(COLONicState *cns, int fd, bool cleanup)
+{
+    Error *err = NULL;
+    char *args[3];
+    char **parg;
+
+    parg = args;
+    *parg++ = cleanup ? cns->qemu_ifdown : (char *)cns->qemu_ifup;
+    *parg++ = (char *)cns->ifname;
+    *parg = NULL;
+    launch_script(args, fd, &err);
+    if (err) {
+        error_report_err(err);
+        return -1;
+    }
+    return 0;
+}
+
 QTAILQ_HEAD(, nic_device) nic_devices = QTAILQ_HEAD_INITIALIZER(nic_devices);
 
 static int colo_nic_configure(COLONicState *cns,
             bool up, int side, int index)
 {
+    NetClientState *nc = container_of(cns, NetClientState, cns);
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
     if (!cns && index <= 0) {
         error_report("Can not parse colo_script or forward_nic");
         return -1;
     }
 
-    return launch_colo_script(cns, up, side, index);
+    switch (side) {
+    case COLO_MODE_PRIMARY:
+        return launch_colo_script(cns, up, side, index);
+        break;
+    case COLO_MODE_SECONDARY:
+        if (!cns->qemu_ifup[0] || !cns->qemu_ifdown || !cns->qemu_ifdown[0]) {
+            error_report("ifup(e.g. /etc/qemu-ifup) and ifdown(e.g."
+                         "/etc/qemu-ifdown)script are needed for COLO");
+            return -1;
+        }
+        if (up) {
+            if (handle_old_nic_configure(cns, s->fd, true) < 0) {
+                return -1;
+            }
+            return launch_colo_script(cns, up, side, index);
+        } else {
+            if (launch_colo_script(cns, up, side, index) < 0) {
+                return -1;
+            }
+            return handle_old_nic_configure(cns, s->fd, false);
+        }
+        break;
+    default:
+        break;
+    }
+    return -1;
 }
 
 void colo_add_nic_devices(COLONicState *cns)
diff --git a/net/tap.c b/net/tap.c
index 0e3bdbd..ecd057f 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -644,6 +644,10 @@ static void net_init_tap_one(const NetdevTapOptions *tap, 
NetClientState *peer,
             snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
             snprintf(s->down_script_arg, sizeof(s->down_script_arg),
                      "%s", ifname);
+            nc->cns.qemu_ifdown = s->down_script;
+        }
+        if (strcmp(script, "no") != 0) {
+            strcpy(nc->cns.qemu_ifup, script);
         }
     }
 
diff --git a/scripts/colo-proxy-script.sh b/scripts/colo-proxy-script.sh
index 47c4fb5..03e3d98 100755
--- a/scripts/colo-proxy-script.sh
+++ b/scripts/colo-proxy-script.sh
@@ -9,8 +9,6 @@ action=$2
 phy_if=$3
 virt_if=$4
 index=$5
-br=br1
-failover_br=br0
 
 script_usage()
 {
@@ -52,9 +50,66 @@ primary_uninstall()
     /usr/local/sbin/arptables -D INPUT -i $phy_if -j MARK --set-mark $index
 }
 
+attach_forward_bridge()
+{
+    if brctl show |grep -q colobr ; then
+        colobr=`brctl show | grep colobr | awk '{print $1}' |tail -1`
+        if brctl show $colobr |grep -qw $phy_if ; then
+            ip link set $colobr up
+            brctl addif $colobr $virt_if
+            return 0
+        fi
+        for (( i=0; i<100; i++))
+        do
+            if [ "$colobr" == "colobr$i" ]; then
+                colobr=colobr$((i+1))
+                break
+            fi
+        done
+        if [ $i -eq 100 ]; then
+            echo "there are to many colobr"
+            colobr=
+            exit 1
+        fi
+    else
+        colobr=colobr0
+    fi
+
+    brctl addbr $colobr
+    ip link set dev $colobr up
+    brctl addif $colobr $phy_if
+    brctl addif $colobr $virt_if
+}
+
+detach_forward_bridge()
+{
+
+    bridges="`brctl show | grep -v -e 'bridge name' -e ^$'\t' |\
+            awk -F'\t' '{print $1}'`"
+    for bridge in $bridges
+    do
+        if brctl show $bridge |grep -qw $virt_if ; then
+                colobr=$bridge
+        fi
+    done
+
+    if [ "X$colobr" == "X" ]; then
+        return
+    fi
+    brctl delif $colobr $virt_if
+    has_slave=`brctl show $colobr |wc -l`
+    if [ $has_slave -ne 2 ]; then
+        return 0
+    fi
+
+    brctl delif $colobr $phy_if
+    ip link set $colobr down
+    brctl delbr $colobr
+}
+
 secondary_install()
 {
-    brctl addif $br $phy_if
+    attach_forward_bridge
 
     /usr/local/sbin/iptables -t mangle -I PREROUTING -m physdev --physdev-in \
         $virt_if -j SECCOLO --index $index
@@ -64,9 +119,7 @@ secondary_install()
 
 secondary_uninstall()
 {
-    brctl delif $br $phy_if
-    brctl delif $br $virt_if
-    brctl addif $failover_br $virt_if
+    detach_forward_bridge
 
     /usr/local/sbin/iptables -t mangle -D PREROUTING -m physdev --physdev-in \
         $virt_if -j SECCOLO --index $index
-- 
1.7.12.4