Implemented writing to carrier file to enable it when bringing up an …

…interface

Fix for #4

Dockerfile

@@ -7,7 +7,7 @@ FROM ${USER_NAME}/nff-go-base
 
 LABEL RUN docker run -it --privileged -v /sys/bus/pci/drivers:/sys/bus/pci/drivers -v /sys/kernel/mm/hugepages:/sys/kernel/mm/hugepages -v /sys/devices/system/node:/sys/devices/system/node -v /dev:/dev --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE
 
-RUN apt-get install -y procps iproute2 iputils-ping apache2 wget; apt-get clean
+RUN apt-get install -y procps iproute2 iputils-ping net-tools apache2 wget; apt-get clean
 RUN dd if=/dev/zero of=/var/www/html/10k.bin bs=1 count=10240
 RUN dd if=/dev/zero of=/var/www/html/100k.bin bs=1 count=102400
 RUN dd if=/dev/zero of=/var/www/html/1m.bin bs=1 count=1048576

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/grpc-ecosystem/grpc-gateway v1.7.0 // indirect
 	github.com/intel-go/nff-go v0.7.3
 	github.com/microcosm-cc/bluemonday v1.0.2 // indirect
+	github.com/nsf/gocode v0.0.0-20181120081338-6cac7c69a41e // indirect
 	github.com/openzipkin/zipkin-go v0.1.5 // indirect
 	github.com/pkg/errors v0.8.1 // indirect
 	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 // indirect

go.sum

@@ -120,6 +120,8 @@ github.com/microcosm-cc/bluemonday v1.0.2/go.mod h1:iVP4YcDBq+n/5fb23BhYFvIMq/le
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86/go.mod h1:kHJEU3ofeGjhHklVoIGuVj85JJwZ6kWPaJwCIxgnFmo=
 github.com/neelance/sourcemap v0.0.0-20151028013722-8c68805598ab/go.mod h1:Qr6/a/Q4r9LP1IltGz7tA7iOK1WonHEYhu1HRBA7ZiM=
+github.com/nsf/gocode v0.0.0-20181120081338-6cac7c69a41e h1:ihaECqr05sBOt6hJAEIHzbE2RF47BK34Z0LbQnxDiYw=
+github.com/nsf/gocode v0.0.0-20181120081338-6cac7c69a41e/go.mod h1:6Q8/OMaaKAgTX7/jt2bOXVDrm1eJhoNd+iwzghR7jvs=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=

nat/util.go

@@ -238,14 +238,34 @@ func ParseAllKnownL4(pkt *packet.Packet, pktIPv4 *packet.IPv4Hdr, pktIPv6 *packe
 	}
 }
 
+const sysFsIfFormat = "/sys/devices/virtual/net/%s/carrier"
+
 func bringInterfaceUp(dev netlink.Link, name string) error {
-	err := netlink.LinkSetUp(dev)
+	var err error
+	err = netlink.LinkSetUp(dev)
 	if err != nil {
-		return fmt.Errorf("Failed to bring interface up", name, ":", err)
-	} else {
-		fmt.Println("Interface", name, "brought up successfully")
-		return nil
+		return fmt.Errorf("Failed to bring interface up \"%s\": %+v", name, err)
+	}
+
+	fname := fmt.Sprintf(sysFsIfFormat, name)
+	fmt.Println("NAME=", name)
+	fmt.Println("FILE NAME=", fname)
+	var file *os.File
+	file, err = os.OpenFile(fname, os.O_WRONLY, 0644)
+	if err != nil {
+		return fmt.Errorf("Failed to enable carrier for interface \"%s\" because file \"%s\" could not be open: %+v", name, fname, err)
+	}
+	_, err = file.Write([]byte("1"))
+	if err != nil {
+		return fmt.Errorf("Failed to write to carrier file \"%s\": %+v", fname, err)
+	}
+	err = file.Close()
+	if err != nil {
+		return fmt.Errorf("Failed to close carrier file \"%s\": %+v", fname, err)
 	}
+
+	fmt.Println("Interface", name, "brought up successfully")
+	return nil
 }
 
 func (port *ipPort) setLinkIPv4KNIAddress(ipv4addr, mask, oldaddr, oldmask uint32, bringup bool) error {
@@ -255,7 +275,7 @@ func (port *ipPort) setLinkIPv4KNIAddress(ipv4addr, mask, oldaddr, oldmask uint3
 
 	myKNI, err := netlink.LinkByName(port.KNIName)
 	if err != nil {
-		return fmt.Errorf("Failed to get KNI interface", port.KNIName, ":", err)
+		return fmt.Errorf("Failed to get KNI interface %s: %+v", port.KNIName, err)
 	}
 
 	if oldaddr != 0 {
@@ -270,7 +290,14 @@ func (port *ipPort) setLinkIPv4KNIAddress(ipv4addr, mask, oldaddr, oldmask uint3
 		fmt.Println("Removing address", addr, "on interface", port.KNIName)
 		err = netlink.AddrDel(myKNI, addr)
 		if err != nil {
-			return fmt.Errorf("Failed to remove address", addr, "from interface", port.KNIName, ":", err)
+			return fmt.Errorf("Failed to remove address %+v from interface \"%s\": %+v", addr, port.KNIName, err)
+		}
+	}
+
+	if bringup {
+		err = bringInterfaceUp(myKNI, port.KNIName)
+		if err != nil {
+			return err
 		}
 	}
 
@@ -285,13 +312,10 @@ func (port *ipPort) setLinkIPv4KNIAddress(ipv4addr, mask, oldaddr, oldmask uint3
 	fmt.Println("Setting address", addr, "on interface", port.KNIName)
 	err = netlink.AddrAdd(myKNI, addr)
 	if err != nil {
-		return fmt.Errorf("Failed to set interface", port.KNIName, "address", addr, ":", err)
+		return fmt.Errorf("Failed to set interface \"%s\" address %+v: %+v", port.KNIName, addr, err)
 	}
 
-	fmt.Println("Set address", addr, "on KNI interface", port.KNIName)
-	if bringup {
-		return bringInterfaceUp(myKNI, port.KNIName)
-	}
+	fmt.Println("Successfully set address", addr, "on KNI interface", port.KNIName)
 	return nil
 }
 
@@ -305,6 +329,13 @@ func (port *ipPort) setLinkIPv6KNIAddress(ipv6addr, mask, oldaddr, oldmask [comm
 		return fmt.Errorf("Failed to get KNI interface", port.KNIName, ":", err)
 	}
 
+	if bringup {
+		err = bringInterfaceUp(myKNI, port.KNIName)
+		if err != nil {
+			return err
+		}
+	}
+
 	if oldaddr != zeroIPv6Addr {
 		addr := &netlink.Addr{
 			IPNet: &net.IPNet{
@@ -328,12 +359,9 @@ func (port *ipPort) setLinkIPv6KNIAddress(ipv6addr, mask, oldaddr, oldmask [comm
 	fmt.Println("Setting address", addr)
 	err = netlink.AddrAdd(myKNI, addr)
 	if err != nil {
-		return fmt.Errorf("Failed to set interface", port.KNIName, "address", addr, ":", err)
+		return fmt.Errorf("Failed to set interface \"%s\" address %+v: %+v", port.KNIName, addr, err)
 	}
 
-	fmt.Println("Set address", addr, "on KNI interface", port.KNIName)
-	if bringup {
-		return bringInterfaceUp(myKNI, port.KNIName)
-	}
+	fmt.Println("Successfully set address", addr, "on KNI interface", port.KNIName)
 	return nil
 }