// Hash returns the SHA3 hash of the envelope, calculating it if not yet done.
func (self *Envelope) Hash() common.Hash {
if (self.hash == common.Hash{}) {
enc, _ := rlp.EncodeToBytes(self)
self.hash = crypto.Sha3Hash(enc)
}
return self.hash
}
func (req *findnode) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
if expired(req.Expiration) {
return errExpired
}
if t.db.node(fromID) == nil {
// No bond exists, we don't process the packet. This prevents
// an attack vector where the discovery protocol could be used
// to amplify traffic in a DDOS attack. A malicious actor
// would send a findnode request with the IP address and UDP
// port of the target as the source address. The recipient of
// the findnode packet would then send a neighbors packet
// (which is a much bigger packet than findnode) to the victim.
return errUnknownNode
}
target := crypto.Sha3Hash(req.Target[:])
t.mutex.Lock()
closest := t.closest(target, bucketSize).entries
t.mutex.Unlock()
p := neighbors{Expiration: uint64(time.Now().Add(expiration).Unix())}
// Send neighbors in chunks with at most maxNeighbors per packet
// to stay below the 1280 byte limit.
for i, n := range closest {
p.Nodes = append(p.Nodes, nodeToRPC(n))
if len(p.Nodes) == maxNeighbors || i == len(closest)-1 {
t.send(from, neighborsPacket, p)
p.Nodes = p.Nodes[:0]
}
}
return nil
}
// NewProgram returns a new JIT program
func NewProgram(code []byte) *Program {
program := &Program{
Id: crypto.Sha3Hash(code),
mapping: make(map[uint64]uint64),
destinations: make(map[uint64]struct{}),
code: code,
}
programs.Add(program.Id, program)
return program
}
// NewNode creates a new node. It is mostly meant to be used for
// testing purposes.
func NewNode(id NodeID, ip net.IP, udpPort, tcpPort uint16) *Node {
if ipv4 := ip.To4(); ipv4 != nil {
ip = ipv4
}
return &Node{
IP: ip,
UDP: udpPort,
TCP: tcpPort,
ID: id,
sha: crypto.Sha3Hash(id[:]),
}
}
// node retrieves a node with a given id from the database.
func (db *nodeDB) node(id NodeID) *Node {
blob, err := db.lvl.Get(makeKey(id, nodeDBDiscoverRoot), nil)
if err != nil {
glog.V(logger.Detail).Infof("failed to retrieve node %v: %v", id, err)
return nil
}
node := new(Node)
if err := rlp.DecodeBytes(blob, node); err != nil {
glog.V(logger.Warn).Infof("failed to decode node RLP: %v", err)
return nil
}
node.sha = crypto.Sha3Hash(node.ID[:])
return node
}
func (self *HTTPClient) GetAuthContent(uri string, hash common.Hash) ([]byte, error) {
// retrieve content
content, err := self.Get(uri, "")
if err != nil {
return nil, err
}
// check hash to authenticate content
chash := crypto.Sha3Hash(content)
if chash != hash {
return nil, fmt.Errorf("content hash mismatch %x != %x (exp)", hash[:], chash[:])
}
return content, nil
}
// DecodeRLP decodes an Envelope from an RLP data stream.
func (self *Envelope) DecodeRLP(s *rlp.Stream) error {
raw, err := s.Raw()
if err != nil {
return err
}
// The decoding of Envelope uses the struct fields but also needs
// to compute the hash of the whole RLP-encoded envelope. This
// type has the same structure as Envelope but is not an
// rlp.Decoder so we can reuse the Envelope struct definition.
type rlpenv Envelope
if err := rlp.DecodeBytes(raw, (*rlpenv)(self)); err != nil {
return err
}
self.hash = crypto.Sha3Hash(raw)
return nil
}
// Resolve searches for a specific node with the given ID.
// It returns nil if the node could not be found.
func (tab *Table) Resolve(targetID NodeID) *Node {
// If the node is present in the local table, no
// network interaction is required.
hash := crypto.Sha3Hash(targetID[:])
tab.mutex.Lock()
cl := tab.closest(hash, 1)
tab.mutex.Unlock()
if len(cl.entries) > 0 && cl.entries[0].ID == targetID {
return cl.entries[0]
}
// Otherwise, do a network lookup.
result := tab.Lookup(targetID)
for _, n := range result {
if n.ID == targetID {
return n
}
}
return nil
}
// SetFallbackNodes sets the initial points of contact. These nodes
// are used to connect to the network if the table is empty and there
// are no known nodes in the database.
func (tab *Table) SetFallbackNodes(nodes []*Node) error {
for _, n := range nodes {
if err := n.validateComplete(); err != nil {
return fmt.Errorf("bad bootstrap/fallback node %q (%v)", n, err)
}
}
tab.mutex.Lock()
tab.nursery = make([]*Node, 0, len(nodes))
for _, n := range nodes {
cpy := *n
// Recompute cpy.sha because the node might not have been
// created by NewNode or ParseNode.
cpy.sha = crypto.Sha3Hash(n.ID[:])
tab.nursery = append(tab.nursery, &cpy)
}
tab.mutex.Unlock()
tab.refresh()
return nil
}
"github.com/gophergala2016/etherapis/etherapis/Godeps/_workspace/src/github.com/ethereum/go-ethereum/logger"
"github.com/gophergala2016/etherapis/etherapis/Godeps/_workspace/src/github.com/ethereum/go-ethereum/logger/glog"
"github.com/gophergala2016/etherapis/etherapis/Godeps/_workspace/src/github.com/ethereum/go-ethereum/rlp"
)
const defaultCacheCapacity = 800
var (
// The global cache stores decoded trie nodes by hash as they get loaded.
globalCache = newARC(defaultCacheCapacity)
// This is the known root hash of an empty trie.
emptyRoot = common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
// This is the known hash of an empty state trie entry.
emptyState = crypto.Sha3Hash(nil)
)
// ClearGlobalCache clears the global trie cache
func ClearGlobalCache() {
globalCache.Clear()
}
// Database must be implemented by backing stores for the trie.
type Database interface {
DatabaseWriter
// Get returns the value for key from the database.
Get(key []byte) (value []byte, err error)
}
// DatabaseWriter wraps the Put method of a backing store for the trie.
// Run loops and evaluates the contract's code with the given input data
func (self *Vm) Run(contract *Contract, input []byte) (ret []byte, err error) {
self.env.SetDepth(self.env.Depth() + 1)
defer self.env.SetDepth(self.env.Depth() - 1)
// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
defer func() {
if err != nil {
// In case of a VM exception (known exceptions) all gas consumed (panics NOT included).
contract.UseGas(contract.Gas)
ret = contract.Return(nil)
}
}()
if contract.CodeAddr != nil {
if p := Precompiled[contract.CodeAddr.Str()]; p != nil {
return self.RunPrecompiled(p, input, contract)
}
}
// Don't bother with the execution if there's no code.
if len(contract.Code) == 0 {
return contract.Return(nil), nil
}
var (
codehash = crypto.Sha3Hash(contract.Code) // codehash is used when doing jump dest caching
program *Program
)
if EnableJit {
// If the JIT is enabled check the status of the JIT program,
// if it doesn't exist compile a new program in a seperate
// goroutine or wait for compilation to finish if the JIT is
// forced.
switch GetProgramStatus(codehash) {
case progReady:
return RunProgram(GetProgram(codehash), self.env, contract, input)
case progUnknown:
if ForceJit {
// Create and compile program
program = NewProgram(contract.Code)
perr := CompileProgram(program)
if perr == nil {
return RunProgram(program, self.env, contract, input)
}
glog.V(logger.Info).Infoln("error compiling program", err)
} else {
// create and compile the program. Compilation
// is done in a seperate goroutine
program = NewProgram(contract.Code)
go func() {
err := CompileProgram(program)
if err != nil {
glog.V(logger.Info).Infoln("error compiling program", err)
return
}
}()
}
}
}
var (
caller = contract.caller
code = contract.Code
instrCount = 0
op OpCode // current opcode
mem = NewMemory() // bound memory
stack = newstack() // local stack
statedb = self.env.Db() // current state
// For optimisation reason we're using uint64 as the program counter.
// It's theoretically possible to go above 2^64. The YP defines the PC to be uint256. Pratically much less so feasible.
pc = uint64(0) // program counter
// jump evaluates and checks whether the given jump destination is a valid one
// if valid move the `pc` otherwise return an error.
jump = func(from uint64, to *big.Int) error {
if !contract.jumpdests.has(codehash, code, to) {
nop := contract.GetOp(to.Uint64())
return fmt.Errorf("invalid jump destination (%v) %v", nop, to)
}
pc = to.Uint64()
return nil
}
newMemSize *big.Int
cost *big.Int
)
contract.Input = input
// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
defer func() {
if err != nil {
self.log(pc, op, contract.Gas, cost, mem, stack, contract, err)
}
}()
if glog.V(logger.Debug) {
glog.Infof("running byte VM %x\n", codehash[:4])
tstart := time.Now()
defer func() {
glog.Infof("byte VM %x done. time: %v instrc: %v\n", codehash[:4], time.Since(tstart), instrCount)
}()
}
for ; ; instrCount++ {
/*
if EnableJit && it%100 == 0 {
if program != nil && progStatus(atomic.LoadInt32(&program.status)) == progReady {
// move execution
fmt.Println("moved", it)
glog.V(logger.Info).Infoln("Moved execution to JIT")
return runProgram(program, pc, mem, stack, self.env, contract, input)
}
}
*/
// Get the memory location of pc
op = contract.GetOp(pc)
// calculate the new memory size and gas price for the current executing opcode
newMemSize, cost, err = calculateGasAndSize(self.env, contract, caller, op, statedb, mem, stack)
if err != nil {
return nil, err
}
// Use the calculated gas. When insufficient gas is present, use all gas and return an
// Out Of Gas error
if !contract.UseGas(cost) {
return nil, OutOfGasError
}
// Resize the memory calculated previously
mem.Resize(newMemSize.Uint64())
// Add a log message
self.log(pc, op, contract.Gas, cost, mem, stack, contract, nil)
if opPtr := jumpTable[op]; opPtr.valid {
if opPtr.fn != nil {
opPtr.fn(instruction{}, &pc, self.env, contract, mem, stack)
} else {
switch op {
case PC:
opPc(instruction{data: new(big.Int).SetUint64(pc)}, &pc, self.env, contract, mem, stack)
case JUMP:
if err := jump(pc, stack.pop()); err != nil {
return nil, err
}
continue
case JUMPI:
pos, cond := stack.pop(), stack.pop()
if cond.Cmp(common.BigTrue) >= 0 {
if err := jump(pc, pos); err != nil {
return nil, err
}
continue
}
case RETURN:
offset, size := stack.pop(), stack.pop()
ret := mem.GetPtr(offset.Int64(), size.Int64())
return contract.Return(ret), nil
case SUICIDE:
opSuicide(instruction{}, nil, self.env, contract, mem, stack)
fallthrough
case STOP: // Stop the contract
return contract.Return(nil), nil
}
}
} else {
return nil, fmt.Errorf("Invalid opcode %x", op)
}
pc++
}
}
func makeSeedHash(epoch uint64) (sh common.Hash) {
for ; epoch > 0; epoch-- {
sh = crypto.Sha3Hash(sh[:])
}
return sh
}
func (tab *Table) lookup(targetID NodeID, refreshIfEmpty bool) []*Node {
var (
target = crypto.Sha3Hash(targetID[:])
asked = make(map[NodeID]bool)
seen = make(map[NodeID]bool)
reply = make(chan []*Node, alpha)
pendingQueries = 0
result *nodesByDistance
)
// don't query further if we hit ourself.
// unlikely to happen often in practice.
asked[tab.self.ID] = true
for {
tab.mutex.Lock()
// generate initial result set
result = tab.closest(target, bucketSize)
tab.mutex.Unlock()
if len(result.entries) > 0 || !refreshIfEmpty {
break
}
// The result set is empty, all nodes were dropped, refresh.
// We actually wait for the refresh to complete here. The very
// first query will hit this case and run the bootstrapping
// logic.
<-tab.refresh()
refreshIfEmpty = false
}
for {
// ask the alpha closest nodes that we haven't asked yet
for i := 0; i < len(result.entries) && pendingQueries < alpha; i++ {
n := result.entries[i]
if !asked[n.ID] {
asked[n.ID] = true
pendingQueries++
go func() {
// Find potential neighbors to bond with
r, err := tab.net.findnode(n.ID, n.addr(), targetID)
if err != nil {
// Bump the failure counter to detect and evacuate non-bonded entries
fails := tab.db.findFails(n.ID) + 1
tab.db.updateFindFails(n.ID, fails)
glog.V(logger.Detail).Infof("Bumping failures for %x: %d", n.ID[:8], fails)
if fails >= maxFindnodeFailures {
glog.V(logger.Detail).Infof("Evacuating node %x: %d findnode failures", n.ID[:8], fails)
tab.delete(n)
}
}
reply <- tab.bondall(r)
}()
}
}
if pendingQueries == 0 {
// we have asked all closest nodes, stop the search
break
}
// wait for the next reply
for _, n := range <-reply {
if n != nil && !seen[n.ID] {
seen[n.ID] = true
result.push(n, bucketSize)
}
}
pendingQueries--
}
return result.entries
}
