path: root/swarm/pss/forwarding_test.go

package pss

import (
    "fmt"
    "math/rand"
    "testing"
    "time"

    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/enode"
    "github.com/ethereum/go-ethereum/p2p/protocols"
    "github.com/ethereum/go-ethereum/swarm/network"
    "github.com/ethereum/go-ethereum/swarm/pot"
    whisper "github.com/ethereum/go-ethereum/whisper/whisperv6"
)

type testCase struct {
    name      string
    recipient []byte
    peers     []pot.Address
    expected  []int
    exclusive bool
    nFails    int
    success   bool
    errors    string
}

var testCases []testCase

// the purpose of this test is to see that pss.forward() function correctly
// selects the peers for message forwarding, depending on the message address
// and kademlia constellation.
func TestForwardBasic(t *testing.T) {
    baseAddrBytes := make([]byte, 32)
    for i := 0; i < len(baseAddrBytes); i++ {
        baseAddrBytes[i] = 0xFF
    }
    var c testCase
    base := pot.NewAddressFromBytes(baseAddrBytes)
    var peerAddresses []pot.Address
    const depth = 10
    for i := 0; i <= depth; i++ {
        // add two peers for each proximity order
        a := pot.RandomAddressAt(base, i)
        peerAddresses = append(peerAddresses, a)
        a = pot.RandomAddressAt(base, i)
        peerAddresses = append(peerAddresses, a)
    }

    // skip one level, add one peer at one level deeper.
    // as a result, we will have an edge case of three peers in nearest neighbours' bin.
    peerAddresses = append(peerAddresses, pot.RandomAddressAt(base, depth+2))

    kad := network.NewKademlia(base[:], network.NewKadParams())
    ps := createPss(t, kad)
    defer ps.Stop()
    addPeers(kad, peerAddresses)

    const firstNearest = depth * 2 // shallowest peer in the nearest neighbours' bin
    nearestNeighbours := []int{firstNearest, firstNearest + 1, firstNearest + 2}
    var all []int // indices of all the peers
    for i := 0; i < len(peerAddresses); i++ {
        all = append(all, i)
    }

    for i := 0; i < len(peerAddresses); i++ {
        // send msg directly to the known peers (recipient address == peer address)
        c = testCase{
            name:      fmt.Sprintf("Send direct to known, id: [%d]", i),
            recipient: peerAddresses[i][:],
            peers:     peerAddresses,
            expected:  []int{i},
            exclusive: false,
        }
        testCases = append(testCases, c)
    }

    for i := 0; i < firstNearest; i++ {
        // send random messages with proximity orders, corresponding to PO of each bin,
        // with one peer being closer to the recipient address
        a := pot.RandomAddressAt(peerAddresses[i], 64)
        c = testCase{
            name:      fmt.Sprintf("Send random to each PO, id: [%d]", i),
            recipient: a[:],
            peers:     peerAddresses,
            expected:  []int{i},
            exclusive: false,
        }
        testCases = append(testCases, c)
    }

    for i := 0; i < firstNearest; i++ {
        // send random messages with proximity orders, corresponding to PO of each bin,
        // with random proximity relative to the recipient address
        po := i / 2
        a := pot.RandomAddressAt(base, po)
        c = testCase{
            name:      fmt.Sprintf("Send direct to known, id: [%d]", i),
            recipient: a[:],
            peers:     peerAddresses,
            expected:  []int{po * 2, po*2 + 1},
            exclusive: true,
        }
        testCases = append(testCases, c)
    }

    for i := firstNearest; i < len(peerAddresses); i++ {
        // recipient address falls into the nearest neighbours' bin
        a := pot.RandomAddressAt(base, i)
        c = testCase{
            name:      fmt.Sprintf("recipient address falls into the nearest neighbours' bin, id: [%d]", i),
            recipient: a[:],
            peers:     peerAddresses,
            expected:  nearestNeighbours,
            exclusive: false,
        }
        testCases = append(testCases, c)
    }

    // send msg with proximity order much deeper than the deepest nearest neighbour
    a2 := pot.RandomAddressAt(base, 77)
    c = testCase{
        name:      "proximity order much deeper than the deepest nearest neighbour",
        recipient: a2[:],
        peers:     peerAddresses,
        expected:  nearestNeighbours,
        exclusive: false,
    }
    testCases = append(testCases, c)

    // test with partial addresses
    const part = 12

    for i := 0; i < firstNearest; i++ {
        // send messages with partial address falling into different proximity orders
        po := i / 2
        if i%8 != 0 {
            c = testCase{
                name:      fmt.Sprintf("partial address falling into different proximity orders, id: [%d]", i),
                recipient: peerAddresses[i][:i],
                peers:     peerAddresses,
                expected:  []int{po * 2, po*2 + 1},
                exclusive: true,
            }
            testCases = append(testCases, c)
        }
        c = testCase{
            name:      fmt.Sprintf("extended partial address falling into different proximity orders, id: [%d]", i),
            recipient: peerAddresses[i][:part],
            peers:     peerAddresses,
            expected:  []int{po * 2, po*2 + 1},
            exclusive: true,
        }
        testCases = append(testCases, c)
    }

    for i := firstNearest; i < len(peerAddresses); i++ {
        // partial address falls into the nearest neighbours' bin
        c = testCase{
            name:      fmt.Sprintf("partial address falls into the nearest neighbours' bin, id: [%d]", i),
            recipient: peerAddresses[i][:part],
            peers:     peerAddresses,
            expected:  nearestNeighbours,
            exclusive: false,
        }
        testCases = append(testCases, c)
    }

    // partial address with proximity order deeper than any of the nearest neighbour
    a3 := pot.RandomAddressAt(base, part)
    c = testCase{
        name:      "partial address with proximity order deeper than any of the nearest neighbour",
        recipient: a3[:part],
        peers:     peerAddresses,
        expected:  nearestNeighbours,
        exclusive: false,
    }
    testCases = append(testCases, c)

    // special cases where partial address matches a large group of peers

    // zero bytes of address is given, msg should be delivered to all the peers
    c = testCase{
        name:      "zero bytes of address is given",
        recipient: []byte{},
        peers:     peerAddresses,
        expected:  all,
        exclusive: false,
    }
    testCases = append(testCases, c)

    // luminous radius of 8 bits, proximity order 8
    indexAtPo8 := 16
    c = testCase{
        name:      "luminous radius of 8 bits",
        recipient: []byte{0xFF},
        peers:     peerAddresses,
        expected:  all[indexAtPo8:],
        exclusive: false,
    }
    testCases = append(testCases, c)

    // luminous radius of 256 bits, proximity order 8
    a4 := pot.Address{}
    a4[0] = 0xFF
    c = testCase{
        name:      "luminous radius of 256 bits",
        recipient: a4[:],
        peers:     peerAddresses,
        expected:  []int{indexAtPo8, indexAtPo8 + 1},
        exclusive: true,
    }
    testCases = append(testCases, c)

    // check correct behaviour in case send fails
    for i := 2; i < firstNearest-3; i += 2 {
        po := i / 2
        // send random messages with proximity orders, corresponding to PO of each bin,
        // with different numbers of failed attempts.
        // msg should be received by only one of the deeper peers.
        a := pot.RandomAddressAt(base, po)
        c = testCase{
            name:      fmt.Sprintf("Send direct to known, id: [%d]", i),
            recipient: a[:],
            peers:     peerAddresses,
            expected:  all[i+1:],
            exclusive: true,
            nFails:    rand.Int()%3 + 2,
        }
        testCases = append(testCases, c)
    }

    for _, c := range testCases {
        testForwardMsg(t, ps, &c)
    }
}

// this function tests the forwarding of a single message. the recipient address is passed as param,
// along with addresses of all peers, and indices of those peers which are expected to receive the message.
func testForwardMsg(t *testing.T, ps *Pss, c *testCase) {
    recipientAddr := c.recipient
    peers := c.peers
    expected := c.expected
    exclusive := c.exclusive
    nFails := c.nFails
    tries := 0 // number of previous failed tries

    resultMap := make(map[pot.Address]int)

    defer func() { sendFunc = sendMsg }()
    sendFunc = func(_ *Pss, sp *network.Peer, _ *PssMsg) bool {
        if tries < nFails {
            tries++
            return false
        }
        a := pot.NewAddressFromBytes(sp.Address())
        resultMap[a]++
        return true
    }

    msg := newTestMsg(recipientAddr)
    ps.forward(msg)

    // check test results
    var fail bool
    precision := len(recipientAddr)
    if precision > 4 {
        precision = 4
    }
    s := fmt.Sprintf("test [%s]\nmsg address: %x..., radius: %d", c.name, recipientAddr[:precision], 8*len(recipientAddr))

    // false negatives (expected message didn't reach peer)
    if exclusive {
        var cnt int
        for _, i := range expected {
            a := peers[i]
            cnt += resultMap[a]
            resultMap[a] = 0
        }
        if cnt != 1 {
            s += fmt.Sprintf("\n%d messages received by %d peers with indices: [%v]", cnt, len(expected), expected)
            fail = true
        }
    } else {
        for _, i := range expected {
            a := peers[i]
            received := resultMap[a]
            if received != 1 {
                s += fmt.Sprintf("\npeer number %d [%x...] received %d messages", i, a[:4], received)
                fail = true
            }
            resultMap[a] = 0
        }
    }

    // false positives (unexpected message reached peer)
    for k, v := range resultMap {
        if v != 0 {
            // find the index of the false positive peer
            var j int
            for j = 0; j < len(peers); j++ {
                if peers[j] == k {
                    break
                }
            }
            s += fmt.Sprintf("\npeer number %d [%x...] received %d messages", j, k[:4], v)
            fail = true
        }
    }

    if fail {
        t.Fatal(s)
    }
}

func addPeers(kad *network.Kademlia, addresses []pot.Address) {
    for _, a := range addresses {
        p := newTestDiscoveryPeer(a, kad)
        kad.On(p)
    }
}

func createPss(t *testing.T, kad *network.Kademlia) *Pss {
    privKey, err := crypto.GenerateKey()
    pssp := NewPssParams().WithPrivateKey(privKey)
    ps, err := NewPss(kad, pssp)
    if err != nil {
        t.Fatal(err.Error())
    }
    return ps
}

func newTestDiscoveryPeer(addr pot.Address, kad *network.Kademlia) *network.Peer {
    rw := &p2p.MsgPipeRW{}
    p := p2p.NewPeer(enode.ID{}, "test", []p2p.Cap{})
    pp := protocols.NewPeer(p, rw, &protocols.Spec{})
    bp := &network.BzzPeer{
        Peer: pp,
        BzzAddr: &network.BzzAddr{
            OAddr: addr.Bytes(),
            UAddr: []byte(fmt.Sprintf("%x", addr[:])),
        },
    }
    return network.NewPeer(bp, kad)
}

func newTestMsg(addr []byte) *PssMsg {
    msg := newPssMsg(&msgParams{})
    msg.To = addr[:]
    msg.Expire = uint32(time.Now().Add(time.Second * 60).Unix())
    msg.Payload = &whisper.Envelope{
        Topic: [4]byte{},
        Data:  []byte("i have nothing to hide"),
    }
    return msg
}