les: light client protocol and API

1 files changed, 322 insertions, 0 deletions

diff --git a/les/handler_test.go b/les/handler_test.go
new file mode 100644
index 000000000..2aa7a5590
--- /dev/null
+++ b/les/handler_test.go
@@ -0,0 +1,322 @@
+package les
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+func expectResponse(r p2p.MsgReader, msgcode, reqID, bv uint64, data interface{}) error {
+	type resp struct {
+		ReqID, BV uint64
+		Data      interface{}
+	}
+	return p2p.ExpectMsg(r, msgcode, resp{reqID, bv, data})
+}
+
+// Tests that block headers can be retrieved from a remote chain based on user queries.
+func TestGetBlockHeadersLes1(t *testing.T) { testGetBlockHeaders(t, 1) }
+
+func testGetBlockHeaders(t *testing.T, protocol int) {
+	pm, _, _ := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Create a "random" unknown hash for testing
+	var unknown common.Hash
+	for i, _ := range unknown {
+		unknown[i] = byte(i)
+	}
+	// Create a batch of tests for various scenarios
+	limit := uint64(MaxHeaderFetch)
+	tests := []struct {
+		query  *getBlockHeadersData // The query to execute for header retrieval
+		expect []common.Hash        // The hashes of the block whose headers are expected
+	}{
+		// A single random block should be retrievable by hash and number too
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Hash: bc.GetBlockByNumber(limit / 2).Hash()}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(limit / 2).Hash()},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(limit / 2).Hash()},
+		},
+		// Multiple headers should be retrievable in both directions
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 + 1).Hash(),
+				bc.GetBlockByNumber(limit/2 + 2).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 - 1).Hash(),
+				bc.GetBlockByNumber(limit/2 - 2).Hash(),
+			},
+		},
+		// Multiple headers with skip lists should be retrievable
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 + 4).Hash(),
+				bc.GetBlockByNumber(limit/2 + 8).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 - 4).Hash(),
+				bc.GetBlockByNumber(limit/2 - 8).Hash(),
+			},
+		},
+		// The chain endpoints should be retrievable
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 0}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(0).Hash()},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64()}, Amount: 1},
+			[]common.Hash{bc.CurrentBlock().Hash()},
+		},
+		// Ensure protocol limits are honored
+		/*{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 1}, Amount: limit + 10, Reverse: true},
+			bc.GetBlockHashesFromHash(bc.CurrentBlock().Hash(), limit),
+		},*/
+		// Check that requesting more than available is handled gracefully
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 4}, Skip: 3, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 4).Hash(),
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64()).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 3, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(4).Hash(),
+				bc.GetBlockByNumber(0).Hash(),
+			},
+		},
+		// Check that requesting more than available is handled gracefully, even if mid skip
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 4}, Skip: 2, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 4).Hash(),
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 1).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 2, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(4).Hash(),
+				bc.GetBlockByNumber(1).Hash(),
+			},
+		},
+		// Check that non existing headers aren't returned
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Hash: unknown}, Amount: 1},
+			[]common.Hash{},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() + 1}, Amount: 1},
+			[]common.Hash{},
+		},
+	}
+	// Run each of the tests and verify the results against the chain
+	var reqID uint64
+	for i, tt := range tests {
+		// Collect the headers to expect in the response
+		headers := []*types.Header{}
+		for _, hash := range tt.expect {
+			headers = append(headers, bc.GetHeaderByHash(hash))
+		}
+		// Send the hash request and verify the response
+		reqID++
+		cost := peer.GetRequestCost(GetBlockHeadersMsg, int(tt.query.Amount))
+		sendRequest(peer.app, GetBlockHeadersMsg, reqID, cost, tt.query)
+		if err := expectResponse(peer.app, BlockHeadersMsg, reqID, testBufLimit, headers); err != nil {
+			t.Errorf("test %d: headers mismatch: %v", i, err)
+		}
+	}
+}
+
+// Tests that block contents can be retrieved from a remote chain based on their hashes.
+func TestGetBlockBodiesLes1(t *testing.T) { testGetBlockBodies(t, 1) }
+
+func testGetBlockBodies(t *testing.T, protocol int) {
+	pm, _, _ := newTestProtocolManagerMust(t, false, downloader.MaxBlockFetch+15, nil)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Create a batch of tests for various scenarios
+	limit := MaxBodyFetch
+	tests := []struct {
+		random    int           // Number of blocks to fetch randomly from the chain
+		explicit  []common.Hash // Explicitly requested blocks
+		available []bool        // Availability of explicitly requested blocks
+		expected  int           // Total number of existing blocks to expect
+	}{
+		{1, nil, nil, 1},         // A single random block should be retrievable
+		{10, nil, nil, 10},       // Multiple random blocks should be retrievable
+		{limit, nil, nil, limit}, // The maximum possible blocks should be retrievable
+		//{limit + 1, nil, nil, limit},                                  // No more than the possible block count should be returned
+		{0, []common.Hash{bc.Genesis().Hash()}, []bool{true}, 1},      // The genesis block should be retrievable
+		{0, []common.Hash{bc.CurrentBlock().Hash()}, []bool{true}, 1}, // The chains head block should be retrievable
+		{0, []common.Hash{common.Hash{}}, []bool{false}, 0},           // A non existent block should not be returned
+
+		// Existing and non-existing blocks interleaved should not cause problems
+		{0, []common.Hash{
+			common.Hash{},
+			bc.GetBlockByNumber(1).Hash(),
+			common.Hash{},
+			bc.GetBlockByNumber(10).Hash(),
+			common.Hash{},
+			bc.GetBlockByNumber(100).Hash(),
+			common.Hash{},
+		}, []bool{false, true, false, true, false, true, false}, 3},
+	}
+	// Run each of the tests and verify the results against the chain
+	var reqID uint64
+	for i, tt := range tests {
+		// Collect the hashes to request, and the response to expect
+		hashes, seen := []common.Hash{}, make(map[int64]bool)
+		bodies := []*types.Body{}
+
+		for j := 0; j < tt.random; j++ {
+			for {
+				num := rand.Int63n(int64(bc.CurrentBlock().NumberU64()))
+				if !seen[num] {
+					seen[num] = true
+
+					block := bc.GetBlockByNumber(uint64(num))
+					hashes = append(hashes, block.Hash())
+					if len(bodies) < tt.expected {
+						bodies = append(bodies, &types.Body{Transactions: block.Transactions(), Uncles: block.Uncles()})
+					}
+					break
+				}
+			}
+		}
+		for j, hash := range tt.explicit {
+			hashes = append(hashes, hash)
+			if tt.available[j] && len(bodies) < tt.expected {
+				block := bc.GetBlockByHash(hash)
+				bodies = append(bodies, &types.Body{Transactions: block.Transactions(), Uncles: block.Uncles()})
+			}
+		}
+		reqID++
+		// Send the hash request and verify the response
+		cost := peer.GetRequestCost(GetBlockBodiesMsg, len(hashes))
+		sendRequest(peer.app, GetBlockBodiesMsg, reqID, cost, hashes)
+		if err := expectResponse(peer.app, BlockBodiesMsg, reqID, testBufLimit, bodies); err != nil {
+			t.Errorf("test %d: bodies mismatch: %v", i, err)
+		}
+	}
+}
+
+// Tests that the contract codes can be retrieved based on account addresses.
+func TestGetCodeLes1(t *testing.T) { testGetCode(t, 1) }
+
+func testGetCode(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, _, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	var codereqs []*CodeReq
+	var codes [][]byte
+
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		header := bc.GetHeaderByNumber(i)
+		req := &CodeReq{
+			BHash:  header.Hash(),
+			AccKey: crypto.Keccak256(testContractAddr[:]),
+		}
+		codereqs = append(codereqs, req)
+		if i >= testContractDeployed {
+			codes = append(codes, testContractCodeDeployed)
+		}
+	}
+
+	cost := peer.GetRequestCost(GetCodeMsg, len(codereqs))
+	sendRequest(peer.app, GetCodeMsg, 42, cost, codereqs)
+	if err := expectResponse(peer.app, CodeMsg, 42, testBufLimit, codes); err != nil {
+		t.Errorf("codes mismatch: %v", err)
+	}
+}
+
+// Tests that the transaction receipts can be retrieved based on hashes.
+func TestGetReceiptLes1(t *testing.T) { testGetReceipt(t, 1) }
+
+func testGetReceipt(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, db, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Collect the hashes to request, and the response to expect
+	hashes, receipts := []common.Hash{}, []types.Receipts{}
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		block := bc.GetBlockByNumber(i)
+
+		hashes = append(hashes, block.Hash())
+		receipts = append(receipts, core.GetBlockReceipts(db, block.Hash(), block.NumberU64()))
+	}
+	// Send the hash request and verify the response
+	cost := peer.GetRequestCost(GetReceiptsMsg, len(hashes))
+	sendRequest(peer.app, GetReceiptsMsg, 42, cost, hashes)
+	if err := expectResponse(peer.app, ReceiptsMsg, 42, testBufLimit, receipts); err != nil {
+		t.Errorf("receipts mismatch: %v", err)
+	}
+}
+
+// Tests that trie merkle proofs can be retrieved
+func TestGetProofsLes1(t *testing.T) { testGetReceipt(t, 1) }
+
+func testGetProofs(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, db, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	var proofreqs []ProofReq
+	var proofs [][]rlp.RawValue
+
+	accounts := []common.Address{testBankAddress, acc1Addr, acc2Addr, common.Address{}}
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		header := bc.GetHeaderByNumber(i)
+		root := header.Root
+		trie, _ := trie.New(root, db)
+
+		for _, acc := range accounts {
+			req := ProofReq{
+				BHash: header.Hash(),
+				Key:   acc[:],
+			}
+			proofreqs = append(proofreqs, req)
+
+			proof := trie.Prove(crypto.Keccak256(acc[:]))
+			proofs = append(proofs, proof)
+		}
+	}
+	// Send the proof request and verify the response
+	cost := peer.GetRequestCost(GetProofsMsg, len(proofreqs))
+	sendRequest(peer.app, GetProofsMsg, 42, cost, proofreqs)
+	if err := expectResponse(peer.app, ProofsMsg, 42, testBufLimit, proofs); err != nil {
+		t.Errorf("proofs mismatch: %v", err)
+	}
+}