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Merge bitcoin#11363: net: Split socket create/connect
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3830b6e net: use CreateSocket for binds (Cory Fields)
df3bcf8 net: pass socket closing responsibility up to caller for outgoing connections (Cory Fields)
9e3b2f5 net: Move IsSelectableSocket check into socket creation (Cory Fields)
1729c29 net: split socket creation out of connection (Cory Fields)

Pull request description:

  Requirement for bitcoin#11227.

  We'll need to create sockets and perform the actual connect in separate steps, so break them up.

  bitcoin#11227 adds an RAII wrapper around connection attempts, as a belt-and-suspenders in case a CloseSocket is missed.

Tree-SHA512: de675bb718cc56d68893c303b8057ca062c7431eaa17ae7c4829caed119fa3f15b404d8f52aca22a6bca6e73a26fb79e898b335d090ab015bf6456cf417fc694
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@laanwj
laanwj committed Dec 13, 2017
2 parents ef8ba7d + 3830b6e commit ba2f195
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Showing 3 changed files with 63 additions and 82 deletions.
70 changes: 28 additions & 42 deletions src/net.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -415,39 +415,48 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
if (addrConnect.IsValid()) {
bool proxyConnectionFailed = false;

if (GetProxy(addrConnect.GetNetwork(), proxy))
if (GetProxy(addrConnect.GetNetwork(), proxy)) {
hSocket = CreateSocket(proxy.proxy);
if (hSocket == INVALID_SOCKET) {
return nullptr;
}
connected = ConnectThroughProxy(proxy, addrConnect.ToStringIP(), addrConnect.GetPort(), hSocket, nConnectTimeout, &proxyConnectionFailed);
else // no proxy needed (none set for target network)
} else {
// no proxy needed (none set for target network)
hSocket = CreateSocket(addrConnect);
if (hSocket == INVALID_SOCKET) {
return nullptr;
}
connected = ConnectSocketDirectly(addrConnect, hSocket, nConnectTimeout);
}
if (!proxyConnectionFailed) {
// If a connection to the node was attempted, and failure (if any) is not caused by a problem connecting to
// the proxy, mark this as an attempt.
addrman.Attempt(addrConnect, fCountFailure);
}
} else if (pszDest && GetNameProxy(proxy)) {
hSocket = CreateSocket(proxy.proxy);
if (hSocket == INVALID_SOCKET) {
return nullptr;
}
std::string host;
int port = default_port;
SplitHostPort(std::string(pszDest), port, host);
connected = ConnectThroughProxy(proxy, host, port, hSocket, nConnectTimeout, nullptr);
}
if (connected) {
if (!IsSelectableSocket(hSocket)) {
LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
CloseSocket(hSocket);
return nullptr;
}

// Add node
NodeId id = GetNewNodeId();
uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
CAddress addr_bind = GetBindAddress(hSocket);
CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, addr_bind, pszDest ? pszDest : "", false);
pnode->AddRef();

return pnode;
if (!connected) {
CloseSocket(hSocket);
return nullptr;
}

return nullptr;
// Add node
NodeId id = GetNewNodeId();
uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
CAddress addr_bind = GetBindAddress(hSocket);
CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, addr_bind, pszDest ? pszDest : "", false);
pnode->AddRef();

return pnode;
}

void CConnman::DumpBanlist()
Expand Down Expand Up @@ -2056,44 +2065,21 @@ bool CConnman::BindListenPort(const CService &addrBind, std::string& strError, b
return false;
}

SOCKET hListenSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
SOCKET hListenSocket = CreateSocket(addrBind);
if (hListenSocket == INVALID_SOCKET)
{
strError = strprintf("Error: Couldn't open socket for incoming connections (socket returned error %s)", NetworkErrorString(WSAGetLastError()));
LogPrintf("%s\n", strError);
return false;
}
if (!IsSelectableSocket(hListenSocket))
{
strError = "Error: Couldn't create a listenable socket for incoming connections";
LogPrintf("%s\n", strError);
return false;
}


#ifndef WIN32
#ifdef SO_NOSIGPIPE
// Different way of disabling SIGPIPE on BSD
setsockopt(hListenSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&nOne, sizeof(int));
#endif
// Allow binding if the port is still in TIME_WAIT state after
// the program was closed and restarted.
setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (void*)&nOne, sizeof(int));
// Disable Nagle's algorithm
setsockopt(hListenSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&nOne, sizeof(int));
#else
setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (const char*)&nOne, sizeof(int));
setsockopt(hListenSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&nOne, sizeof(int));
#endif

// Set to non-blocking, incoming connections will also inherit this
if (!SetSocketNonBlocking(hListenSocket, true)) {
CloseSocket(hListenSocket);
strError = strprintf("BindListenPort: Setting listening socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
LogPrintf("%s\n", strError);
return false;
}

// some systems don't have IPV6_V6ONLY but are always v6only; others do have the option
// and enable it by default or not. Try to enable it, if possible.
if (addrBind.IsIPv6()) {
Expand Down
70 changes: 32 additions & 38 deletions src/netbase.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -313,12 +313,11 @@ std::string Socks5ErrorString(uint8_t err)
}

/** Connect using SOCKS5 (as described in RFC1928) */
static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, const SOCKET& hSocket)
{
IntrRecvError recvr;
LogPrint(BCLog::NET, "SOCKS5 connecting %s\n", strDest);
if (strDest.size() > 255) {
CloseSocket(hSocket);
return error("Hostname too long");
}
// Accepted authentication methods
Expand All @@ -334,17 +333,14 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
}
ssize_t ret = send(hSocket, (const char*)vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vSocks5Init.size()) {
CloseSocket(hSocket);
return error("Error sending to proxy");
}
uint8_t pchRet1[2];
if ((recvr = InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
CloseSocket(hSocket);
LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
return false;
}
if (pchRet1[0] != SOCKSVersion::SOCKS5) {
CloseSocket(hSocket);
return error("Proxy failed to initialize");
}
if (pchRet1[1] == SOCKS5Method::USER_PASS && auth) {
Expand All @@ -359,23 +355,19 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
ret = send(hSocket, (const char*)vAuth.data(), vAuth.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vAuth.size()) {
CloseSocket(hSocket);
return error("Error sending authentication to proxy");
}
LogPrint(BCLog::PROXY, "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
uint8_t pchRetA[2];
if ((recvr = InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
CloseSocket(hSocket);
return error("Error reading proxy authentication response");
}
if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
CloseSocket(hSocket);
return error("Proxy authentication unsuccessful");
}
} else if (pchRet1[1] == SOCKS5Method::NOAUTH) {
// Perform no authentication
} else {
CloseSocket(hSocket);
return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
}
std::vector<uint8_t> vSocks5;
Expand All @@ -389,12 +381,10 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
vSocks5.push_back((port >> 0) & 0xFF);
ret = send(hSocket, (const char*)vSocks5.data(), vSocks5.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vSocks5.size()) {
CloseSocket(hSocket);
return error("Error sending to proxy");
}
uint8_t pchRet2[4];
if ((recvr = InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
CloseSocket(hSocket);
if (recvr == IntrRecvError::Timeout) {
/* If a timeout happens here, this effectively means we timed out while connecting
* to the remote node. This is very common for Tor, so do not print an
Expand All @@ -405,17 +395,14 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
}
}
if (pchRet2[0] != SOCKSVersion::SOCKS5) {
CloseSocket(hSocket);
return error("Proxy failed to accept request");
}
if (pchRet2[1] != SOCKS5Reply::SUCCEEDED) {
// Failures to connect to a peer that are not proxy errors
CloseSocket(hSocket);
LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
return false;
}
if (pchRet2[2] != 0x00) { // Reserved field must be 0
CloseSocket(hSocket);
return error("Error: malformed proxy response");
}
uint8_t pchRet3[256];
Expand All @@ -427,41 +414,42 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
{
recvr = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
if (recvr != IntrRecvError::OK) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
int nRecv = pchRet3[0];
recvr = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
break;
}
default: CloseSocket(hSocket); return error("Error: malformed proxy response");
default: return error("Error: malformed proxy response");
}
if (recvr != IntrRecvError::OK) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
if ((recvr = InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
LogPrint(BCLog::NET, "SOCKS5 connected %s\n", strDest);
return true;
}

bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
SOCKET CreateSocket(const CService &addrConnect)
{
hSocketRet = INVALID_SOCKET;

struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
return false;
LogPrintf("Cannot create socket for %s: unsupported network\n", addrConnect.ToString());
return INVALID_SOCKET;
}

SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
if (hSocket == INVALID_SOCKET)
return false;
return INVALID_SOCKET;

if (!IsSelectableSocket(hSocket)) {
CloseSocket(hSocket);
LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
return INVALID_SOCKET;
}

#ifdef SO_NOSIGPIPE
int set = 1;
Expand All @@ -475,9 +463,23 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
// Set to non-blocking
if (!SetSocketNonBlocking(hSocket, true)) {
CloseSocket(hSocket);
return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
LogPrintf("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
}
return hSocket;
}

bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocket, int nTimeout)
{
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
if (hSocket == INVALID_SOCKET) {
LogPrintf("Cannot connect to %s: invalid socket\n", addrConnect.ToString());
return false;
}
if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
return false;
}
if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
{
int nErr = WSAGetLastError();
Expand All @@ -492,13 +494,11 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
if (nRet == 0)
{
LogPrint(BCLog::NET, "connection to %s timeout\n", addrConnect.ToString());
CloseSocket(hSocket);
return false;
}
if (nRet == SOCKET_ERROR)
{
LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
socklen_t nRetSize = sizeof(nRet);
Expand All @@ -509,13 +509,11 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
#endif
{
LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
if (nRet != 0)
{
LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
CloseSocket(hSocket);
return false;
}
}
Expand All @@ -526,12 +524,9 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
#endif
{
LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
}

hSocketRet = hSocket;
return true;
}

Expand Down Expand Up @@ -583,9 +578,8 @@ bool IsProxy(const CNetAddr &addr) {
return false;
}

bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, const SOCKET& hSocket, int nTimeout, bool *outProxyConnectionFailed)
{
SOCKET hSocket = INVALID_SOCKET;
// first connect to proxy server
if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
if (outProxyConnectionFailed)
Expand All @@ -597,14 +591,14 @@ bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int
ProxyCredentials random_auth;
static std::atomic_int counter(0);
random_auth.username = random_auth.password = strprintf("%i", counter++);
if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket)) {
return false;
}
} else {
if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
if (!Socks5(strDest, (unsigned short)port, 0, hSocket)) {
return false;
}
}

hSocketRet = hSocket;
return true;
}
bool LookupSubNet(const char* pszName, CSubNet& ret)
Expand Down
5 changes: 3 additions & 2 deletions src/netbase.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,8 +51,9 @@ bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLoo
bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions);
CService LookupNumeric(const char *pszName, int portDefault = 0);
bool LookupSubNet(const char *pszName, CSubNet& subnet);
bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout);
bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed);
SOCKET CreateSocket(const CService &addrConnect);
bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocketRet, int nTimeout);
bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, const SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed);
/** Return readable error string for a network error code */
std::string NetworkErrorString(int err);
/** Close socket and set hSocket to INVALID_SOCKET */
Expand Down

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