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BRPeer.c
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BRPeer.c
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//
// BRPeer.c
//
// Created by Aaron Voisine on 9/2/15.
// Copyright (c) 2015 breadwallet LLC.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#include "BRPeer.h"
#include "BRMerkleBlock.h"
#include "BRAddress.h"
#include "BRSet.h"
#include "BRArray.h"
#include "BRCrypto.h"
#include "BRInt.h"
#include <stdlib.h>
#include <float.h>
#include <inttypes.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define HEADER_LENGTH 24
#define MAX_MSG_LENGTH 0x02000000
#define MAX_GETDATA_HASHES 50000
#define ENABLED_SERVICES 0ULL // we don't provide full blocks to remote nodes
#define PROTOCOL_VERSION 70015
#define MIN_PROTO_VERSION 70002 // peers earlier than this protocol version not supported (need v0.9 txFee relay rules)
#define LOCAL_HOST ((UInt128) { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x01 })
#define CONNECT_TIMEOUT 3.0
#define MESSAGE_TIMEOUT 10.0
// the standard blockchain download protocol works as follows (for SPV mode):
// - local peer sends getblocks
// - remote peer reponds with inv containing up to 500 block hashes
// - local peer sends getdata with the block hashes
// - remote peer responds with multiple merkleblock and tx messages
// - remote peer sends inv containg 1 hash, of the most recent block
// - local peer sends getdata with the most recent block hash
// - remote peer responds with merkleblock
// - if local peer can't connect the most recent block to the chain (because it started more than 500 blocks behind), go
// back to first step and repeat until entire chain is downloaded
//
// we modify this sequence to improve sync performance and handle adding bip32 addresses to the bloom filter as needed:
// - local peer sends getheaders
// - remote peer responds with up to 2000 headers
// - local peer immediately sends getheaders again and then processes the headers
// - previous two steps repeat until a header within a week of earliestKeyTime is reached (further headers are ignored)
// - local peer sends getblocks
// - remote peer responds with inv containing up to 500 block hashes
// - local peer sends getdata with the block hashes
// - if there were 500 hashes, local peer sends getblocks again without waiting for remote peer
// - remote peer responds with multiple merkleblock and tx messages, followed by inv containing up to 500 block hashes
// - previous two steps repeat until an inv with fewer than 500 block hashes is received
// - local peer sends just getdata for the final set of fewer than 500 block hashes
// - remote peer responds with multiple merkleblock and tx messages
// - if at any point tx messages consume enough wallet addresses to drop below the bip32 chain gap limit, more addresses
// are generated and local peer sends filterload with an updated bloom filter
// - after filterload is sent, getdata is sent to re-request recent blocks that may contain new tx matching the filter
typedef enum {
inv_undefined = 0,
inv_tx = 1,
inv_block = 2,
inv_filtered_block = 3
} inv_type;
typedef struct {
BRPeer peer; // superstruct on top of BRPeer
uint32_t magicNumber;
char host[INET6_ADDRSTRLEN];
BRPeerStatus status;
int waitingForNetwork;
volatile int needsFilterUpdate;
uint64_t nonce, feePerKb;
char *useragent;
uint32_t version, lastblock, earliestKeyTime, currentBlockHeight;
double startTime, pingTime;
volatile double disconnectTime, mempoolTime;
int sentVerack, gotVerack, sentGetaddr, sentFilter, sentGetdata, sentMempool, sentGetblocks;
UInt256 lastBlockHash;
BRMerkleBlock *currentBlock;
UInt256 *currentBlockTxHashes, *knownBlockHashes, *knownTxHashes;
BRSet *knownTxHashSet;
volatile int socket;
void *info;
void (*connected)(void *info);
void (*disconnected)(void *info, int error);
void (*relayedPeers)(void *info, const BRPeer peers[], size_t peersCount);
void (*relayedTx)(void *info, BRTransaction *tx);
void (*hasTx)(void *info, UInt256 txHash);
void (*rejectedTx)(void *info, UInt256 txHash, uint8_t code);
void (*relayedBlock)(void *info, BRMerkleBlock *block);
void (*notfound)(void *info, const UInt256 txHashes[], size_t txCount, const UInt256 blockHashes[],
size_t blockCount);
void (*setFeePerKb)(void *info, uint64_t feePerKb);
BRTransaction *(*requestedTx)(void *info, UInt256 txHash);
int (*networkIsReachable)(void *info);
void (*threadCleanup)(void *info);
void **volatile pongInfo;
void (**volatile pongCallback)(void *info, int success);
void *volatile mempoolInfo;
void (*volatile mempoolCallback)(void *info, int success);
pthread_t thread;
} BRPeerContext;
void BRPeerSendVersionMessage(BRPeer *peer);
void BRPeerSendVerackMessage(BRPeer *peer);
void BRPeerSendAddr(BRPeer *peer);
inline static int _BRPeerIsIPv4(const BRPeer *peer)
{
return (peer->address.u64[0] == 0 && peer->address.u16[4] == 0 && peer->address.u16[5] == 0xffff);
}
static void _BRPeerAddKnownTxHashes(const BRPeer *peer, const UInt256 txHashes[], size_t txCount)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
UInt256 *knownTxHashes = ctx->knownTxHashes;
size_t i, j;
for (i = 0; i < txCount; i++) {
if (! BRSetContains(ctx->knownTxHashSet, &txHashes[i])) {
array_add(knownTxHashes, txHashes[i]);
if (ctx->knownTxHashes != knownTxHashes) { // check if knownTxHashes was moved to a new memory location
ctx->knownTxHashes = knownTxHashes;
BRSetClear(ctx->knownTxHashSet);
for (j = array_count(knownTxHashes); j > 0; j--) BRSetAdd(ctx->knownTxHashSet, &knownTxHashes[j - 1]);
}
else BRSetAdd(ctx->knownTxHashSet, &knownTxHashes[array_count(knownTxHashes) - 1]);
}
}
}
static void _BRPeerDidConnect(BRPeer *peer)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
if (ctx->status == BRPeerStatusConnecting && ctx->sentVerack && ctx->gotVerack) {
peer_log(peer, "handshake completed");
ctx->disconnectTime = DBL_MAX;
ctx->status = BRPeerStatusConnected;
peer_log(peer, "connected with lastblock: %"PRIu32, ctx->lastblock);
if (ctx->connected) ctx->connected(ctx->info);
}
}
static int _BRPeerAcceptVersionMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, strLen = 0, len = 0;
uint64_t recvServices, fromServices, nonce;
UInt128 recvAddr, fromAddr;
uint16_t recvPort, fromPort;
int r = 1;
if (85 > msgLen) {
peer_log(peer, "malformed version message, length is %zu, should be >= 85", msgLen);
r = 0;
}
else {
ctx->version = UInt32GetLE(&msg[off]);
off += sizeof(uint32_t);
peer->services = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
peer->timestamp = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
recvServices = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
recvAddr = UInt128Get(&msg[off]);
off += sizeof(UInt128);
recvPort = UInt16GetBE(&msg[off]);
off += sizeof(uint16_t);
fromServices = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
fromAddr = UInt128Get(&msg[off]);
off += sizeof(UInt128);
fromPort = UInt16GetBE(&msg[off]);
off += sizeof(uint16_t);
nonce = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
strLen = (size_t)BRVarInt(&msg[off], (off <= msgLen ? msgLen - off : 0), &len);
off += len;
if (off + strLen + sizeof(uint32_t) > msgLen) {
peer_log(peer, "malformed version message, length is %zu, should be %zu", msgLen,
off + strLen + sizeof(uint32_t));
r = 0;
}
else if (ctx->version < MIN_PROTO_VERSION) {
peer_log(peer, "protocol version %"PRIu32" not supported", ctx->version);
r = 0;
}
else {
array_clear(ctx->useragent);
array_add_array(ctx->useragent, &msg[off], strLen);
array_add(ctx->useragent, '\0');
off += strLen;
ctx->lastblock = UInt32GetLE(&msg[off]);
off += sizeof(uint32_t);
peer_log(peer, "got version %"PRIu32", services %"PRIx64", useragent:\"%s\"", ctx->version, peer->services,
ctx->useragent);
BRPeerSendVerackMessage(peer);
}
}
return r;
}
static int _BRPeerAcceptVerackMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
struct timeval tv;
int r = 1;
if (ctx->gotVerack) {
peer_log(peer, "got unexpected verack");
}
else {
gettimeofday(&tv, NULL);
ctx->pingTime = tv.tv_sec + (double)tv.tv_usec/1000000 - ctx->startTime; // use verack time as initial ping time
ctx->startTime = 0;
peer_log(peer, "got verack in %fs", ctx->pingTime);
ctx->gotVerack = 1;
_BRPeerDidConnect(peer);
}
return r;
}
// TODO: relay addresses
static int _BRPeerAcceptAddrMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, count = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off == 0 || off + count*30 > msgLen) {
peer_log(peer, "malformed addr message, length is %zu, should be %zu for %zu address(es)", msgLen,
BRVarIntSize(count) + 30*count, count);
r = 0;
}
else if (count > 1000) {
peer_log(peer, "dropping addr message, %zu is too many addresses, max is 1000", count);
}
else if (ctx->sentGetaddr) { // simple anti-tarpitting tactic, don't accept unsolicited addresses
BRPeer peers[count], p;
size_t peersCount = 0;
time_t now = time(NULL);
peer_log(peer, "got addr with %zu address(es)", count);
for (size_t i = 0; i < count; i++) {
p.timestamp = UInt32GetLE(&msg[off]);
off += sizeof(uint32_t);
p.services = UInt64GetLE(&msg[off]);
off += sizeof(uint64_t);
p.address = UInt128Get(&msg[off]);
off += sizeof(UInt128);
p.port = UInt16GetBE(&msg[off]);
off += sizeof(uint16_t);
if (! (p.services & SERVICES_NODE_NETWORK)) continue; // skip peers that don't carry full blocks
if (! _BRPeerIsIPv4(&p)) continue; // ignore IPv6 for now
// if address time is more than 10 min in the future or unknown, set to 5 days old
if (p.timestamp > now + 10*60 || p.timestamp == 0) p.timestamp = now - 5*24*60*60;
p.timestamp -= 2*60*60; // subtract two hours
peers[peersCount++] = p; // add it to the list
}
if (peersCount > 0 && ctx->relayedPeers) ctx->relayedPeers(ctx->info, peers, peersCount);
}
return r;
}
static int _BRPeerAcceptInvMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, count = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off == 0 || off + count*36 > msgLen) {
peer_log(peer, "malformed inv message, length is %zu, should be %zu for %zu item(s)", msgLen,
BRVarIntSize(count) + 36*count, count);
r = 0;
}
else if (count > MAX_GETDATA_HASHES) {
peer_log(peer, "dropping inv message, %zu is too many items, max is %d", count, MAX_GETDATA_HASHES);
}
else {
inv_type type;
const uint8_t *transactions[count], *blocks[count];
size_t i, j, txCount = 0, blockCount = 0;
peer_log(peer, "got inv with %zu item(s)", count);
for (i = 0; i < count; i++) {
type = UInt32GetLE(&msg[off]);
switch (type) { // inv messages only use inv_tx or inv_block
case inv_tx: transactions[txCount++] = &msg[off + sizeof(uint32_t)]; break;
case inv_block: blocks[blockCount++] = &msg[off + sizeof(uint32_t)]; break;
default: break;
}
off += 36;
}
if (txCount > 0 && ! ctx->sentFilter && ! ctx->sentMempool && ! ctx->sentGetblocks) {
peer_log(peer, "got inv message before loading a filter");
r = 0;
}
else if (txCount > 10000) { // sanity check
peer_log(peer, "too many transactions, disconnecting");
r = 0;
}
else if (ctx->currentBlockHeight > 0 && blockCount > 2 && blockCount < 500 &&
ctx->currentBlockHeight + array_count(ctx->knownBlockHashes) + blockCount < ctx->lastblock) {
peer_log(peer, "non-standard inv, %zu is fewer block hash(es) than expected", blockCount);
r = 0;
}
else {
if (! ctx->sentFilter && ! ctx->sentGetblocks) blockCount = 0;
if (blockCount == 1 && UInt256Eq(ctx->lastBlockHash, UInt256Get(blocks[0]))) blockCount = 0;
if (blockCount == 1) ctx->lastBlockHash = UInt256Get(blocks[0]);
UInt256 hash, blockHashes[blockCount], txHashes[txCount];
for (i = 0; i < blockCount; i++) {
blockHashes[i] = UInt256Get(blocks[i]);
// remember blockHashes in case we need to re-request them with an updated bloom filter
array_add(ctx->knownBlockHashes, blockHashes[i]);
}
while (array_count(ctx->knownBlockHashes) > MAX_GETDATA_HASHES) {
array_rm_range(ctx->knownBlockHashes, 0, array_count(ctx->knownBlockHashes)/3);
}
if (ctx->needsFilterUpdate) blockCount = 0;
for (i = 0, j = 0; i < txCount; i++) {
hash = UInt256Get(transactions[i]);
if (BRSetContains(ctx->knownTxHashSet, &hash)) {
if (ctx->hasTx) ctx->hasTx(ctx->info, hash);
}
else txHashes[j++] = hash;
}
_BRPeerAddKnownTxHashes(peer, txHashes, j);
if (j > 0 || blockCount > 0) BRPeerSendGetdata(peer, txHashes, j, blockHashes, blockCount);
// to improve chain download performance, if we received 500 block hashes, request the next 500 block hashes
if (blockCount >= 500) {
UInt256 locators[] = { blockHashes[blockCount - 1], blockHashes[0] };
BRPeerSendGetblocks(peer, locators, 2, UINT256_ZERO);
}
if (txCount > 0 && ctx->mempoolCallback) {
peer_log(peer, "got initial mempool response");
BRPeerSendPing(peer, ctx->mempoolInfo, ctx->mempoolCallback);
ctx->mempoolCallback = NULL;
ctx->mempoolTime = DBL_MAX;
}
}
}
return r;
}
static int _BRPeerAcceptTxMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
BRTransaction *tx = BRTransactionParse(msg, msgLen);
UInt256 txHash;
int r = 1;
if (! tx) {
peer_log(peer, "malformed tx message with length: %zu", msgLen);
r = 0;
}
else if (! ctx->sentFilter && ! ctx->sentGetdata) {
peer_log(peer, "got tx message before loading filter");
BRTransactionFree(tx);
r = 0;
}
else {
txHash = tx->txHash;
peer_log(peer, "got tx: %s", u256hex(txHash));
if (ctx->relayedTx) {
ctx->relayedTx(ctx->info, tx);
}
else BRTransactionFree(tx);
if (ctx->currentBlock) { // we're collecting tx messages for a merkleblock
for (size_t i = array_count(ctx->currentBlockTxHashes); i > 0; i--) {
if (! UInt256Eq(txHash, ctx->currentBlockTxHashes[i - 1])) continue;
array_rm(ctx->currentBlockTxHashes, i - 1);
break;
}
if (array_count(ctx->currentBlockTxHashes) == 0) { // we received the entire block including all matched tx
BRMerkleBlock *block = ctx->currentBlock;
ctx->currentBlock = NULL;
if (ctx->relayedBlock) ctx->relayedBlock(ctx->info, block);
}
}
}
return r;
}
static int _BRPeerAcceptHeadersMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, count = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off == 0 || off + 81*count > msgLen) {
peer_log(peer, "malformed headers message, length is %zu, should be %zu for %zu header(s)", msgLen,
BRVarIntSize(count) + 81*count, count);
r = 0;
}
else {
peer_log(peer, "got %zu header(s)", count);
// To improve chain download performance, if this message contains 2000 headers then request the next 2000
// headers immediately, and switch to requesting blocks when we receive a header newer than earliestKeyTime
uint32_t timestamp = (count > 0) ? UInt32GetLE(&msg[off + 81*(count - 1) + 68]) : 0;
if (count >= 2000 || (timestamp > 0 && timestamp + 7*24*60*60 + BLOCK_MAX_TIME_DRIFT >= ctx->earliestKeyTime)) {
size_t last = 0;
time_t now = time(NULL);
UInt256 locators[2];
BRSHA256_2(&locators[0], &msg[off + 81*(count - 1)], 80);
BRSHA256_2(&locators[1], &msg[off], 80);
if (timestamp > 0 && timestamp + 7*24*60*60 + BLOCK_MAX_TIME_DRIFT >= ctx->earliestKeyTime) {
// request blocks for the remainder of the chain
timestamp = (++last < count) ? UInt32GetLE(&msg[off + 81*last + 68]) : 0;
while (timestamp > 0 && timestamp + 7*24*60*60 + BLOCK_MAX_TIME_DRIFT < ctx->earliestKeyTime) {
timestamp = (++last < count) ? UInt32GetLE(&msg[off + 81*last + 68]) : 0;
}
BRSHA256_2(&locators[0], &msg[off + 81*(last - 1)], 80);
BRPeerSendGetblocks(peer, locators, 2, UINT256_ZERO);
}
else BRPeerSendGetheaders(peer, locators, 2, UINT256_ZERO);
for (size_t i = 0; r && i < count; i++) {
BRMerkleBlock *block = BRMerkleBlockParse(&msg[off + 81*i], 81);
if (! BRMerkleBlockIsValid(block, (uint32_t)now)) {
peer_log(peer, "invalid block header: %s", u256hex(block->blockHash));
BRMerkleBlockFree(block);
r = 0;
}
else if (ctx->relayedBlock) {
ctx->relayedBlock(ctx->info, block);
}
else BRMerkleBlockFree(block);
}
}
else {
peer_log(peer, "non-standard headers message, %zu is fewer header(s) than expected", count);
r = 0;
}
}
return r;
}
static int _BRPeerAcceptGetaddrMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
peer_log(peer, "got getaddr");
BRPeerSendAddr(peer);
return 1;
}
static int _BRPeerAcceptGetdataMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, count = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off == 0 || off + 36*count > msgLen) {
peer_log(peer, "malformed getdata message, length is %zu, should %zu for %zu item(s)", msgLen,
BRVarIntSize(count) + 36*count, count);
r = 0;
}
else if (count > MAX_GETDATA_HASHES) {
peer_log(peer, "dropping getdata message, %zu is too many items, max is %d", count, MAX_GETDATA_HASHES);
}
else {
struct inv_item { uint8_t item[36]; } *notfound = NULL;
BRTransaction *tx = NULL;
peer_log(peer, "got getdata with %zu item(s)", count);
for (size_t i = 0; i < count; i++) {
inv_type type = UInt32GetLE(&msg[off]);
UInt256 hash = UInt256Get(&msg[off + sizeof(uint32_t)]);
switch (type) {
case inv_tx:
if (ctx->requestedTx) tx = ctx->requestedTx(ctx->info, hash);
if (tx && BRTransactionSize(tx) < TX_MAX_SIZE) {
uint8_t buf[BRTransactionSerialize(tx, NULL, 0)];
size_t bufLen = BRTransactionSerialize(tx, buf, sizeof(buf));
char txHex[bufLen*2 + 1];
for (size_t j = 0; j < bufLen; j++) {
sprintf(&txHex[j*2], "%02x", buf[j]);
}
peer_log(peer, "publishing tx: %s", txHex);
BRPeerSendMessage(peer, buf, bufLen, MSG_TX);
break;
}
// fall through
default:
if (! notfound) array_new(notfound, 1);
array_add(notfound, *(struct inv_item *)&msg[off]);
break;
}
off += 36;
}
if (notfound) {
size_t bufLen = BRVarIntSize(array_count(notfound)) + 36*array_count(notfound), o = 0;
uint8_t *buf = malloc(bufLen);
assert(buf != NULL);
o += BRVarIntSet(&buf[o], (o <= bufLen ? bufLen - o : 0), array_count(notfound));
memcpy(&buf[o], notfound, 36*array_count(notfound));
o += 36*array_count(notfound);
array_free(notfound);
BRPeerSendMessage(peer, buf, o, MSG_NOTFOUND);
free(buf);
}
}
return r;
}
static int _BRPeerAcceptNotfoundMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, count = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off == 0 || off + 36*count > msgLen) {
peer_log(peer, "malformed notfound message, length is %zu, should be %zu for %zu item(s)", msgLen,
BRVarIntSize(count) + 36*count, count);
r = 0;
}
else if (count > MAX_GETDATA_HASHES) {
peer_log(peer, "dropping notfound message, %zu is too many items, max is %d", count, MAX_GETDATA_HASHES);
}
else {
inv_type type;
UInt256 *txHashes, *blockHashes, hash;
peer_log(peer, "got notfound with %zu item(s)", count);
array_new(txHashes, 1);
array_new(blockHashes, 1);
for (size_t i = 0; i < count; i++) {
type = UInt32GetLE(&msg[off]);
hash = UInt256Get(&msg[off + sizeof(uint32_t)]);
switch (type) {
case inv_tx: array_add(txHashes, hash); break;
case inv_filtered_block: // drop through
case inv_block: array_add(blockHashes, hash); break;
default: break;
}
off += 36;
}
if (ctx->notfound) {
ctx->notfound(ctx->info, txHashes, array_count(txHashes), blockHashes, array_count(blockHashes));
}
array_free(txHashes);
array_free(blockHashes);
}
return r;
}
static int _BRPeerAcceptPingMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
int r = 1;
if (sizeof(uint64_t) > msgLen) {
peer_log(peer, "malformed ping message, length is %zu, should be %zu", msgLen, sizeof(uint64_t));
r = 0;
}
else {
peer_log(peer, "got ping");
BRPeerSendMessage(peer, msg, msgLen, MSG_PONG);
}
return r;
}
static int _BRPeerAcceptPongMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
struct timeval tv;
double pingTime;
int r = 1;
if (sizeof(uint64_t) > msgLen) {
peer_log(peer, "malformed pong message, length is %zu, should be %zu", msgLen, sizeof(uint64_t));
r = 0;
}
else if (UInt64GetLE(msg) != ctx->nonce) {
peer_log(peer, "pong message has wrong nonce: %"PRIu64", expected: %"PRIu64, UInt64GetLE(msg), ctx->nonce);
r = 0;
}
else if (array_count(ctx->pongCallback) == 0) {
peer_log(peer, "got unexpected pong");
r = 0;
}
else {
if (ctx->startTime > 1) {
gettimeofday(&tv, NULL);
pingTime = tv.tv_sec + (double)tv.tv_usec/1000000 - ctx->startTime;
// 50% low pass filter on current ping time
ctx->pingTime = ctx->pingTime*0.5 + pingTime*0.5;
ctx->startTime = 0;
peer_log(peer, "got pong in %fs", pingTime);
}
else peer_log(peer, "got pong");
if (array_count(ctx->pongCallback) > 0) {
void (*pongCallback)(void *, int) = ctx->pongCallback[0];
void *pongInfo = ctx->pongInfo[0];
array_rm(ctx->pongCallback, 0);
array_rm(ctx->pongInfo, 0);
if (pongCallback) pongCallback(pongInfo, 1);
}
}
return r;
}
static int _BRPeerAcceptMerkleblockMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
// Bitcoin nodes don't support querying arbitrary transactions, only transactions not yet accepted in a block. After
// a merkleblock message, the remote node is expected to send tx messages for the tx referenced in the block. When a
// non-tx message is received we should have all the tx in the merkleblock.
BRPeerContext *ctx = (BRPeerContext *)peer;
BRMerkleBlock *block = BRMerkleBlockParse(msg, msgLen);
int r = 1;
if (! block) {
peer_log(peer, "malformed merkleblock message with length: %zu", msgLen);
r = 0;
}
else if (! BRMerkleBlockIsValid(block, (uint32_t)time(NULL))) {
peer_log(peer, "invalid merkleblock: %s", u256hex(block->blockHash));
BRMerkleBlockFree(block);
block = NULL;
r = 0;
}
else if (! ctx->sentFilter && ! ctx->sentGetdata) {
peer_log(peer, "got merkleblock message before loading a filter");
BRMerkleBlockFree(block);
block = NULL;
r = 0;
}
else {
size_t count = BRMerkleBlockTxHashes(block, NULL, 0);
UInt256 _hashes[(sizeof(UInt256)*count <= 0x1000) ? count : 0],
*hashes = (sizeof(UInt256)*count <= 0x1000) ? _hashes : malloc(count*sizeof(*hashes));
assert(hashes != NULL);
count = BRMerkleBlockTxHashes(block, hashes, count);
for (size_t i = count; i > 0; i--) { // reverse order for more efficient removal as tx arrive
if (BRSetContains(ctx->knownTxHashSet, &hashes[i - 1])) continue;
array_add(ctx->currentBlockTxHashes, hashes[i - 1]);
}
if (hashes != _hashes) free(hashes);
}
if (block) {
if (array_count(ctx->currentBlockTxHashes) > 0) { // wait til we get all tx messages before processing the block
ctx->currentBlock = block;
}
else if (ctx->relayedBlock) {
ctx->relayedBlock(ctx->info, block);
}
else BRMerkleBlockFree(block);
}
return r;
}
// described in BIP61: https://github.com/bitcoin/bips/blob/master/bip-0061.mediawiki
static int _BRPeerAcceptRejectMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
size_t off = 0, strLen = (size_t)BRVarInt(msg, msgLen, &off);
int r = 1;
if (off + strLen + sizeof(uint8_t) > msgLen) {
peer_log(peer, "malformed reject message, length is %zu, should be >= %zu", msgLen,
off + strLen + sizeof(uint8_t));
r = 0;
}
else {
char type[(strLen < 0x1000) ? strLen + 1 : 0x1000];
uint8_t code;
size_t len = 0, hashLen = 0;
strncpy(type, (const char *)&msg[off], sizeof(type) - 1);
type[sizeof(type) - 1] = '\0';
off += strLen;
code = msg[off++];
strLen = (size_t)BRVarInt(&msg[off], (off <= msgLen ? msgLen - off : 0), &len);
off += len;
if (strncmp(type, MSG_TX, sizeof(type)) == 0) hashLen = sizeof(UInt256);
if (off + strLen + hashLen > msgLen) {
peer_log(peer, "malformed reject message, length is %zu, should be >= %zu", msgLen, off + strLen + hashLen);
r = 0;
}
else {
char reason[(strLen < 0x1000) ? strLen + 1 : 0x1000];
UInt256 txHash = UINT256_ZERO;
strncpy(reason, (const char *)&msg[off], sizeof(reason) - 1);
reason[sizeof(reason) - 1] = '\0';
off += strLen;
if (hashLen == sizeof(UInt256)) txHash = UInt256Get(&msg[off]);
off += hashLen;
if (! UInt256IsZero(txHash)) {
peer_log(peer, "rejected %s code: 0x%x reason: \"%s\" txid: %s", type, code, reason, u256hex(txHash));
if (ctx->rejectedTx) ctx->rejectedTx(ctx->info, txHash, code);
}
else peer_log(peer, "rejected %s code: 0x%x reason: \"%s\"", type, code, reason);
}
}
return r;
}
// BIP133: https://github.com/bitcoin/bips/blob/master/bip-0133.mediawiki
static int _BRPeerAcceptFeeFilterMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
int r = 1;
if (sizeof(uint64_t) > msgLen) {
peer_log(peer, "malformed feefilter message, length is %zu, should be >= %zu", msgLen, sizeof(uint64_t));
r = 0;
}
else {
ctx->feePerKb = UInt64GetLE(msg);
peer_log(peer, "got feefilter with rate %"PRIu64, ctx->feePerKb);
if (ctx->setFeePerKb) ctx->setFeePerKb(ctx->info, ctx->feePerKb);
}
return r;
}
static int _BRPeerAcceptMessage(BRPeer *peer, const uint8_t *msg, size_t msgLen, const char *type)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
int r = 1;
if (ctx->currentBlock && strncmp(MSG_TX, type, 12) != 0) { // if we receive a non-tx message, merkleblock is done
peer_log(peer, "incomplete merkleblock %s, expected %zu more tx, got %s", u256hex(ctx->currentBlock->blockHash),
array_count(ctx->currentBlockTxHashes), type);
array_clear(ctx->currentBlockTxHashes);
ctx->currentBlock = NULL;
r = 0;
}
else if (strncmp(MSG_VERSION, type, 12) == 0) r = _BRPeerAcceptVersionMessage(peer, msg, msgLen);
else if (strncmp(MSG_VERACK, type, 12) == 0) r = _BRPeerAcceptVerackMessage(peer, msg, msgLen);
else if (strncmp(MSG_ADDR, type, 12) == 0) r = _BRPeerAcceptAddrMessage(peer, msg, msgLen);
else if (strncmp(MSG_INV, type, 12) == 0) r = _BRPeerAcceptInvMessage(peer, msg, msgLen);
else if (strncmp(MSG_TX, type, 12) == 0) r = _BRPeerAcceptTxMessage(peer, msg, msgLen);
else if (strncmp(MSG_HEADERS, type, 12) == 0) r = _BRPeerAcceptHeadersMessage(peer, msg, msgLen);
else if (strncmp(MSG_GETADDR, type, 12) == 0) r = _BRPeerAcceptGetaddrMessage(peer, msg, msgLen);
else if (strncmp(MSG_GETDATA, type, 12) == 0) r = _BRPeerAcceptGetdataMessage(peer, msg, msgLen);
else if (strncmp(MSG_NOTFOUND, type, 12) == 0) r = _BRPeerAcceptNotfoundMessage(peer, msg, msgLen);
else if (strncmp(MSG_PING, type, 12) == 0) r = _BRPeerAcceptPingMessage(peer, msg, msgLen);
else if (strncmp(MSG_PONG, type, 12) == 0) r = _BRPeerAcceptPongMessage(peer, msg, msgLen);
else if (strncmp(MSG_MERKLEBLOCK, type, 12) == 0) r = _BRPeerAcceptMerkleblockMessage(peer, msg, msgLen);
else if (strncmp(MSG_REJECT, type, 12) == 0) r = _BRPeerAcceptRejectMessage(peer, msg, msgLen);
else if (strncmp(MSG_FEEFILTER, type, 12) == 0) r = _BRPeerAcceptFeeFilterMessage(peer, msg, msgLen);
else peer_log(peer, "dropping %s, length %zu, not implemented", type, msgLen);
return r;
}
static int _BRPeerOpenSocket(BRPeer *peer, int domain, double timeout, int *error)
{
BRPeerContext *ctx = (BRPeerContext *)peer;
struct sockaddr_storage addr;
struct timeval tv;
fd_set fds;
socklen_t addrLen, optLen;
int count, arg = 0, err = 0, on = 1, r = 1;
ctx->socket = socket(domain, SOCK_STREAM, 0);
if (ctx->socket < 0) {
err = errno;
r = 0;
}
else {
tv.tv_sec = 1; // one second timeout for send/receive, so thread doesn't block for too long
tv.tv_usec = 0;
setsockopt(ctx->socket, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
setsockopt(ctx->socket, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
setsockopt(ctx->socket, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on));
#ifdef SO_NOSIGPIPE // BSD based systems have a SO_NOSIGPIPE socket option to supress SIGPIPE signals
setsockopt(ctx->socket, SOL_SOCKET, SO_NOSIGPIPE, &on, sizeof(on));
#endif
arg = fcntl(ctx->socket, F_GETFL, NULL);
if (arg < 0 || fcntl(ctx->socket, F_SETFL, arg | O_NONBLOCK) < 0) r = 0; // temporarily set socket non-blocking
if (! r) err = errno;
}
if (r) {
memset(&addr, 0, sizeof(addr));
if (domain == PF_INET6) {
((struct sockaddr_in6 *)&addr)->sin6_family = AF_INET6;
((struct sockaddr_in6 *)&addr)->sin6_addr = *(struct in6_addr *)&peer->address;
((struct sockaddr_in6 *)&addr)->sin6_port = htons(peer->port);
addrLen = sizeof(struct sockaddr_in6);
}
else {
((struct sockaddr_in *)&addr)->sin_family = AF_INET;
((struct sockaddr_in *)&addr)->sin_addr = *(struct in_addr *)&peer->address.u32[3];
((struct sockaddr_in *)&addr)->sin_port = htons(peer->port);
addrLen = sizeof(struct sockaddr_in);
}
if (connect(ctx->socket, (struct sockaddr *)&addr, addrLen) < 0) err = errno;
if (err == EINPROGRESS) {
err = 0;
optLen = sizeof(err);
tv.tv_sec = timeout;
tv.tv_usec = (long)(timeout*1000000) % 1000000;
FD_ZERO(&fds);
FD_SET(ctx->socket, &fds);
count = select(ctx->socket + 1, NULL, &fds, NULL, &tv);
if (count <= 0 || getsockopt(ctx->socket, SOL_SOCKET, SO_ERROR, &err, &optLen) < 0 || err) {
if (count == 0) err = ETIMEDOUT;
if (count < 0 || ! err) err = errno;
r = 0;
}
}
else if (err && domain == PF_INET6 && _BRPeerIsIPv4(peer)) {
return _BRPeerOpenSocket(peer, PF_INET, timeout, error); // fallback to IPv4
}
else if (err) r = 0;
if (r) peer_log(peer, "socket connected");
fcntl(ctx->socket, F_SETFL, arg); // restore socket non-blocking status
}
if (! r && err) peer_log(peer, "connect error: %s", strerror(err));
if (error && err) *error = err;
return r;
}
static void *_peerThreadRoutine(void *arg)
{
BRPeer *peer = arg;
BRPeerContext *ctx = arg;
int socket, error = 0;
pthread_cleanup_push(ctx->threadCleanup, ctx->info);
if (_BRPeerOpenSocket(peer, PF_INET6, CONNECT_TIMEOUT, &error)) {
struct timeval tv;
double time = 0, msgTimeout;
uint8_t header[HEADER_LENGTH], *payload = malloc(0x1000);
size_t len = 0, payloadLen = 0x1000;
ssize_t n = 0;
assert(payload != NULL);
gettimeofday(&tv, NULL);
ctx->startTime = tv.tv_sec + (double)tv.tv_usec/1000000;
BRPeerSendVersionMessage(peer);
while (ctx->socket >= 0 && ! error) {
len = 0;
socket = ctx->socket;
while (socket >= 0 && ! error && len < HEADER_LENGTH) {
n = read(socket, &header[len], sizeof(header) - len);
if (n > 0) len += n;
if (n == 0) error = ECONNRESET;
if (n < 0 && errno != EWOULDBLOCK) error = errno;
gettimeofday(&tv, NULL);
time = tv.tv_sec + (double)tv.tv_usec/1000000;
if (! error && time >= ctx->disconnectTime) error = ETIMEDOUT;
if (! error && time >= ctx->mempoolTime) {
peer_log(peer, "done waiting for mempool response");
BRPeerSendPing(peer, ctx->mempoolInfo, ctx->mempoolCallback);
ctx->mempoolCallback = NULL;
ctx->mempoolTime = DBL_MAX;
}
while (sizeof(uint32_t) <= len && UInt32GetLE(header) != ctx->magicNumber) {
memmove(header, &header[1], --len); // consume one byte at a time until we find the magic number
}
socket = ctx->socket;
}
if (error) {
peer_log(peer, "%s", strerror(error));
}
else if (header[15] != 0) { // verify header type field is NULL terminated
peer_log(peer, "malformed message header: type not NULL terminated");
error = EPROTO;
}
else if (len == HEADER_LENGTH) {
const char *type = (const char *)(&header[4]);
uint32_t msgLen = UInt32GetLE(&header[16]);
uint32_t checksum = UInt32GetLE(&header[20]);
UInt256 hash;
if (msgLen > MAX_MSG_LENGTH) { // check message length
peer_log(peer, "error reading %s, message length %"PRIu32" is too long", type, msgLen);
error = EPROTO;
}
else {
if (msgLen > payloadLen) payload = realloc(payload, (payloadLen = msgLen));
assert(payload != NULL);
len = 0;
socket = ctx->socket;
msgTimeout = time + MESSAGE_TIMEOUT;
while (socket >= 0 && ! error && len < msgLen) {
n = read(socket, &payload[len], msgLen - len);
if (n > 0) len += n;
if (n == 0) error = ECONNRESET;
if (n < 0 && errno != EWOULDBLOCK) error = errno;
gettimeofday(&tv, NULL);
time = tv.tv_sec + (double)tv.tv_usec/1000000;
if (n > 0) msgTimeout = time + MESSAGE_TIMEOUT;
if (! error && time >= msgTimeout) error = ETIMEDOUT;
socket = ctx->socket;
}
if (error) {