// Copyright 2015 CNI authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"encoding/json"
	"fmt"
	"net"
	"syscall"

	"github.com/containernetworking/cni/pkg/skel"
	"github.com/containernetworking/cni/pkg/types"
	"github.com/containernetworking/cni/pkg/types/current"
	"github.com/containernetworking/plugins/pkg/ns"
	"github.com/containernetworking/plugins/pkg/testutils"

	"github.com/vishvananda/netlink"

	"github.com/containernetworking/plugins/plugins/ipam/host-local/backend/allocator"
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

const MASTER_NAME = "eth0"

type Net struct {
	Name          string                 `json:"name"`
	CNIVersion    string                 `json:"cniVersion"`
	Type          string                 `json:"type,omitempty"`
	Master        string                 `json:"master"`
	VlanId        int                    `json:"vlanId"`
	MTU           int                    `json:"mtu"`
	IPAM          *allocator.IPAMConfig  `json:"ipam"`
	DNS           types.DNS              `json:"dns"`
	RawPrevResult map[string]interface{} `json:"prevResult,omitempty"`
	PrevResult    current.Result         `json:"-"`
}

func buildOneConfig(netName string, cniVersion string, orig *Net, prevResult types.Result) (*Net, error) {
	var err error

	inject := map[string]interface{}{
		"name":       netName,
		"cniVersion": cniVersion,
	}
	// Add previous plugin result
	if prevResult != nil {
		inject["prevResult"] = prevResult
	}

	// Ensure every config uses the same name and version
	config := make(map[string]interface{})

	confBytes, err := json.Marshal(orig)
	if err != nil {
		return nil, err
	}

	err = json.Unmarshal(confBytes, &config)
	if err != nil {
		return nil, fmt.Errorf("unmarshal existing network bytes: %s", err)
	}

	for key, value := range inject {
		config[key] = value
	}

	newBytes, err := json.Marshal(config)
	if err != nil {
		return nil, err
	}

	conf := &Net{}
	if err := json.Unmarshal(newBytes, &conf); err != nil {
		return nil, fmt.Errorf("error parsing configuration: %s", err)
	}

	return conf, nil

}

var _ = Describe("vlan Operations", func() {
	var originalNS ns.NetNS

	BeforeEach(func() {
		// Create a new NetNS so we don't modify the host
		var err error
		originalNS, err = testutils.NewNS()
		Expect(err).NotTo(HaveOccurred())

		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			// Add master
			err = netlink.LinkAdd(&netlink.Dummy{
				LinkAttrs: netlink.LinkAttrs{
					Name: MASTER_NAME,
				},
			})
			Expect(err).NotTo(HaveOccurred())
			m, err := netlink.LinkByName(MASTER_NAME)
			Expect(err).NotTo(HaveOccurred())
			err = netlink.LinkSetUp(m)
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	AfterEach(func() {
		Expect(originalNS.Close()).To(Succeed())
		Expect(testutils.UnmountNS(originalNS)).To(Succeed())
	})

	It("creates an vlan link in a non-default namespace with given MTU", func() {
		conf := &NetConf{
			NetConf: types.NetConf{
				CNIVersion: "0.3.0",
				Name:       "testConfig",
				Type:       "vlan",
			},
			Master: MASTER_NAME,
			VlanId: 33,
			MTU:    1500,
		}

		// Create vlan in other namespace
		targetNs, err := testutils.NewNS()
		Expect(err).NotTo(HaveOccurred())
		defer targetNs.Close()

		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			_, err := createVlan(conf, "foobar0", targetNs)
			Expect(err).NotTo(HaveOccurred())
			return nil
		})

		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link exists in the target namespace
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName("foobar0")
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().Name).To(Equal("foobar0"))
			Expect(link.Attrs().MTU).To(Equal(1500))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	It("creates an vlan link in a non-default namespace with master's MTU", func() {
		conf := &NetConf{
			NetConf: types.NetConf{
				CNIVersion: "0.3.0",
				Name:       "testConfig",
				Type:       "vlan",
			},
			Master: MASTER_NAME,
			VlanId: 33,
		}

		// Create vlan in other namespace
		targetNs, err := testutils.NewNS()
		Expect(err).NotTo(HaveOccurred())
		defer targetNs.Close()

		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			m, err := netlink.LinkByName(MASTER_NAME)
			Expect(err).NotTo(HaveOccurred())
			err = netlink.LinkSetMTU(m, 1200)
			Expect(err).NotTo(HaveOccurred())

			_, err = createVlan(conf, "foobar0", targetNs)
			Expect(err).NotTo(HaveOccurred())
			return nil
		})

		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link exists in the target namespace
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName("foobar0")
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().Name).To(Equal("foobar0"))
			Expect(link.Attrs().MTU).To(Equal(1200))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	It("configures and deconfigures an vlan link with ADD/DEL", func() {
		const IFNAME = "eth0"

		conf := fmt.Sprintf(`{
    "cniVersion": "0.3.0",
    "name": "mynet",
    "type": "vlan",
    "master": "%s",
    "ipam": {
        "type": "host-local",
        "subnet": "10.1.2.0/24"
    }
}`, MASTER_NAME)

		targetNs, err := testutils.NewNS()
		Expect(err).NotTo(HaveOccurred())
		defer targetNs.Close()

		args := &skel.CmdArgs{
			ContainerID: "dummy",
			Netns:       targetNs.Path(),
			IfName:      IFNAME,
			StdinData:   []byte(conf),
		}

		var result *current.Result
		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			r, _, err := testutils.CmdAddWithArgs(args, func() error {
				return cmdAdd(args)
			})
			Expect(err).NotTo(HaveOccurred())

			result, err = current.GetResult(r)
			Expect(err).NotTo(HaveOccurred())

			Expect(len(result.Interfaces)).To(Equal(1))
			Expect(result.Interfaces[0].Name).To(Equal(IFNAME))
			Expect(len(result.IPs)).To(Equal(1))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link exists in the target namespace
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName(IFNAME)
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().Name).To(Equal(IFNAME))

			hwaddr, err := net.ParseMAC(result.Interfaces[0].Mac)
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().HardwareAddr).To(Equal(hwaddr))

			addrs, err := netlink.AddrList(link, syscall.AF_INET)
			Expect(err).NotTo(HaveOccurred())
			Expect(len(addrs)).To(Equal(1))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			err = testutils.CmdDelWithArgs(args, func() error {
				return cmdDel(args)
			})
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link has been deleted
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName(IFNAME)
			Expect(err).To(HaveOccurred())
			Expect(link).To(BeNil())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// DEL can be called multiple times, make sure no error is returned
		// if the device is already removed.
		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			err = testutils.CmdDelWithArgs(args, func() error {
				return cmdDel(args)
			})
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	It("configures and deconfigures an CNI V4 vlan link with ADD/CHECK/DEL", func() {
		const IFNAME = "eth0"

		conf := fmt.Sprintf(`{
    "cniVersion": "0.4.0",
    "name": "vlanTestv4",
    "type": "vlan",
    "master": "%s",
    "vlanId": 1234,
    "ipam": {
        "type": "host-local",
        "subnet": "10.1.2.0/24"
    }
}`, MASTER_NAME)

		targetNs, err := testutils.NewNS()
		Expect(err).NotTo(HaveOccurred())
		defer targetNs.Close()

		args := &skel.CmdArgs{
			ContainerID: "dummy",
			Netns:       targetNs.Path(),
			IfName:      IFNAME,
			StdinData:   []byte(conf),
		}

		var result *current.Result
		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			r, _, err := testutils.CmdAddWithArgs(args, func() error {
				return cmdAdd(args)
			})
			Expect(err).NotTo(HaveOccurred())

			result, err = current.GetResult(r)
			Expect(err).NotTo(HaveOccurred())

			Expect(len(result.Interfaces)).To(Equal(1))
			Expect(result.Interfaces[0].Name).To(Equal(IFNAME))
			Expect(len(result.IPs)).To(Equal(1))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link exists in the target namespace
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName(IFNAME)
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().Name).To(Equal(IFNAME))

			hwaddr, err := net.ParseMAC(result.Interfaces[0].Mac)
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().HardwareAddr).To(Equal(hwaddr))

			addrs, err := netlink.AddrList(link, syscall.AF_INET)
			Expect(err).NotTo(HaveOccurred())
			Expect(len(addrs)).To(Equal(1))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// call CmdCheck
		n := &Net{}
		err = json.Unmarshal([]byte(conf), &n)
		Expect(err).NotTo(HaveOccurred())

		n.IPAM, _, err = allocator.LoadIPAMConfig([]byte(conf), "")
		Expect(err).NotTo(HaveOccurred())

		cniVersion := "0.4.0"
		newConf, err := buildOneConfig("vlanTestv4", cniVersion, n, result)
		Expect(err).NotTo(HaveOccurred())

		confString, err := json.Marshal(newConf)
		Expect(err).NotTo(HaveOccurred())

		args.StdinData = confString

		// CNI Check host-device in the target namespace
		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()
			var err error
			err = testutils.CmdCheckWithArgs(args, func() error { return cmdCheck(args) })
			return err
		})
		Expect(err).NotTo(HaveOccurred())

		args.StdinData = []byte(conf)

		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			err = testutils.CmdDelWithArgs(args, func() error {
				return cmdDel(args)
			})
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// Make sure vlan link has been deleted
		err = targetNs.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			link, err := netlink.LinkByName(IFNAME)
			Expect(err).To(HaveOccurred())
			Expect(link).To(BeNil())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	Describe("fails to create vlan link with invalid MTU", func() {
		conf := `{
    "cniVersion": "0.3.1",
    "name": "mynet",
    "type": "vlan",
    "master": "%s",
    "mtu": %d,
    "ipam": {
        "type": "host-local",
        "subnet": "10.1.2.0/24"
    }
}`
		BeforeEach(func() {
			var err error
			err = originalNS.Do(func(ns.NetNS) error {
				defer GinkgoRecover()

				// set master link's MTU to 1500
				link, err := netlink.LinkByName(MASTER_NAME)
				Expect(err).NotTo(HaveOccurred())
				err = netlink.LinkSetMTU(link, 1500)
				Expect(err).NotTo(HaveOccurred())

				return nil
			})
			Expect(err).NotTo(HaveOccurred())
		})

		It("fails to create vlan link with greater MTU than master interface", func() {
			var err error

			args := &skel.CmdArgs{
				ContainerID: "dummy",
				Netns:       "/var/run/netns/test",
				IfName:      "eth0",
				StdinData:   []byte(fmt.Sprintf(conf, MASTER_NAME, 1600)),
			}

			_ = originalNS.Do(func(netNS ns.NetNS) error {
				defer GinkgoRecover()

				_, _, err = testutils.CmdAddWithArgs(args, func() error {
					return cmdAdd(args)
				})
				Expect(err).To(Equal(fmt.Errorf("invalid MTU 1600, must be [0, master MTU(1500)]")))
				return nil
			})
		})

		It("fails to create vlan link with negative MTU", func() {
			var err error

			args := &skel.CmdArgs{
				ContainerID: "dummy",
				Netns:       "/var/run/netns/test",
				IfName:      "eth0",
				StdinData:   []byte(fmt.Sprintf(conf, MASTER_NAME, -100)),
			}

			_ = originalNS.Do(func(netNS ns.NetNS) error {
				defer GinkgoRecover()

				_, _, err = testutils.CmdAddWithArgs(args, func() error {
					return cmdAdd(args)
				})
				Expect(err).To(Equal(fmt.Errorf("invalid MTU -100, must be [0, master MTU(1500)]")))
				return nil
			})
		})
	})
})
