Merge branch 'master+websocket'

1 files changed, 405 insertions, 0 deletions

diff --git a/src/modules/m_websocket.cpp b/src/modules/m_websocket.cpp
new file mode 100644
index 000000000..399b0b017
--- /dev/null
+++ b/src/modules/m_websocket.cpp
@@ -0,0 +1,405 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2016 Attila Molnar <attilamolnar@hush.com>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "inspircd.h"
+#include "iohook.h"
+#include "modules/hash.h"
+
+static const char MagicGUID[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+static const char whitespace[] = " \t\r\n";
+static dynamic_reference_nocheck<HashProvider>* sha1;
+
+class WebSocketHookProvider : public IOHookProvider
+{
+ public:
+	WebSocketHookProvider(Module* mod)
+		: IOHookProvider(mod, "websocket", IOHookProvider::IOH_UNKNOWN, true)
+	{
+	}
+
+	void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE;
+
+	void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
+	{
+	}
+};
+
+class WebSocketHook : public IOHookMiddle
+{
+	class HTTPHeaderFinder
+	{
+		std::string::size_type bpos;
+		std::string::size_type len;
+
+	 public:
+		bool Find(const std::string& req, const char* header, std::string::size_type headerlen, std::string::size_type maxpos)
+		{
+			std::string::size_type keybegin = req.find(header);
+			if ((keybegin == std::string::npos) || (keybegin > maxpos) || (keybegin == 0) || (req[keybegin-1] != '\n'))
+				return false;
+
+			keybegin += headerlen;
+
+			bpos = req.find_first_not_of(whitespace, keybegin, sizeof(whitespace)-1);
+			if ((bpos == std::string::npos) || (bpos > maxpos))
+				return false;
+
+			const std::string::size_type epos = req.find_first_of(whitespace, bpos, sizeof(whitespace)-1);
+			len = epos - bpos;
+
+			return true;
+		}
+
+		std::string ExtractValue(const std::string& req) const
+		{
+			return std::string(req, bpos, len);
+		}
+	};
+
+	enum OpCode
+	{
+		OP_CONTINUATION = 0x00,
+		OP_TEXT = 0x01,
+		OP_BINARY = 0x02,
+		OP_CLOSE = 0x08,
+		OP_PING = 0x09,
+		OP_PONG = 0x0a
+	};
+
+	enum State
+	{
+		STATE_HTTPREQ,
+		STATE_ESTABLISHED
+	};
+
+	static const unsigned char WS_MASKBIT = (1 << 7);
+	static const unsigned char WS_FINBIT = (1 << 7);
+	static const unsigned char WS_PAYLOAD_LENGTH_MAGIC_LARGE = 126;
+	static const unsigned char WS_PAYLOAD_LENGTH_MAGIC_HUGE = 127;
+	static const size_t WS_MAX_PAYLOAD_LENGTH_SMALL = 125;
+	static const size_t WS_MAX_PAYLOAD_LENGTH_LARGE = 65535;
+	static const size_t MAXHEADERSIZE = sizeof(uint64_t) + 2;
+
+	// Clients sending ping or pong frames faster than this are killed
+	static const time_t MINPINGPONGDELAY = 10;
+
+	State state;
+	time_t lastpingpong;
+
+	static size_t FillHeader(unsigned char* outbuf, size_t sendlength, OpCode opcode)
+	{
+		size_t pos = 0;
+		outbuf[pos++] = WS_FINBIT | opcode;
+
+		if (sendlength <= WS_MAX_PAYLOAD_LENGTH_SMALL)
+		{
+			outbuf[pos++] = sendlength;
+		}
+		else if (sendlength <= WS_MAX_PAYLOAD_LENGTH_LARGE)
+		{
+			outbuf[pos++] = WS_PAYLOAD_LENGTH_MAGIC_LARGE;
+			outbuf[pos++] = (sendlength >> 8) & 0xff;
+			outbuf[pos++] = sendlength & 0xff;
+		}
+		else
+		{
+			outbuf[pos++] = WS_PAYLOAD_LENGTH_MAGIC_HUGE;
+			const uint64_t len = sendlength;
+			for (int i = sizeof(uint64_t)-1; i >= 0; i--)
+				outbuf[pos++] = ((len >> i*8) & 0xff);
+		}
+
+		return pos;
+	}
+
+	static StreamSocket::SendQueue::Element PrepareSendQElem(size_t size, OpCode opcode)
+	{
+		unsigned char header[MAXHEADERSIZE];
+		const size_t n = FillHeader(header, size, opcode);
+
+		return StreamSocket::SendQueue::Element(reinterpret_cast<const char*>(header), n);
+	}
+
+	int HandleAppData(StreamSocket* sock, std::string& appdataout, bool allowlarge)
+	{
+		std::string& myrecvq = GetRecvQ();
+		// Need 1 byte opcode, minimum 1 byte len, 4 bytes masking key
+		if (myrecvq.length() < 6)
+			return 0;
+
+		const std::string& cmyrecvq = myrecvq;
+		unsigned char len1 = (unsigned char)cmyrecvq[1];
+		if (!(len1 & WS_MASKBIT))
+		{
+			sock->SetError("WebSocket protocol violation: unmasked client frame");
+			return -1;
+		}
+
+		len1 &= ~WS_MASKBIT;
+
+		// Assume the length is a single byte, if not, update values later
+		unsigned int len = len1;
+		unsigned int payloadstartoffset = 6;
+		const unsigned char* maskkey = reinterpret_cast<const unsigned char*>(&cmyrecvq[2]);
+
+		if (len1 == WS_PAYLOAD_LENGTH_MAGIC_LARGE)
+		{
+			// allowlarge is false for control frames according to the RFC meaning large pings, etc. are not allowed
+			if (!allowlarge)
+			{
+				sock->SetError("WebSocket protocol violation: large control frame");
+				return -1;
+			}
+
+			// Large frame, has 2 bytes len after the magic byte indicating the length
+			// Need 1 byte opcode, 3 bytes len, 4 bytes masking key
+			if (myrecvq.length() < 8)
+				return 0;
+
+			unsigned char len2 = (unsigned char)cmyrecvq[2];
+			unsigned char len3 = (unsigned char)cmyrecvq[3];
+			len = (len2 << 8) | len3;
+
+			if (len <= WS_MAX_PAYLOAD_LENGTH_SMALL)
+			{
+				sock->SetError("WebSocket protocol violation: non-minimal length encoding used");
+				return -1;
+			}
+
+			maskkey += 2;
+			payloadstartoffset += 2;
+		}
+		else if (len1 == WS_PAYLOAD_LENGTH_MAGIC_HUGE)
+		{
+			sock->SetError("WebSocket: Huge frames are not supported");
+			return -1;
+		}
+
+		if (myrecvq.length() < payloadstartoffset + len)
+			return 0;
+
+		unsigned int maskkeypos = 0;
+		const std::string::iterator endit = myrecvq.begin() + payloadstartoffset + len;
+		for (std::string::const_iterator i = myrecvq.begin() + payloadstartoffset; i != endit; ++i)
+		{
+			const unsigned char c = (unsigned char)*i;
+			appdataout.push_back(c ^ maskkey[maskkeypos++]);
+			maskkeypos %= 4;
+		}
+
+		myrecvq.erase(myrecvq.begin(), endit);
+		return 1;
+	}
+
+	int HandlePingPongFrame(StreamSocket* sock, bool isping)
+	{
+		if (lastpingpong + MINPINGPONGDELAY >= ServerInstance->Time())
+		{
+			sock->SetError("WebSocket: Ping/pong flood");
+			return -1;
+		}
+
+		lastpingpong = ServerInstance->Time();
+
+		std::string appdata;
+		const int result = HandleAppData(sock, appdata, false);
+		// If it's a pong stop here regardless of the result so we won't generate a reply
+		if ((result <= 0) || (!isping))
+			return result;
+
+		StreamSocket::SendQueue::Element elem = PrepareSendQElem(appdata.length(), OP_PONG);
+		elem.append(appdata);
+		GetSendQ().push_back(elem);
+
+		SocketEngine::ChangeEventMask(sock, FD_ADD_TRIAL_WRITE);
+		return 1;
+	}
+
+	int HandleWS(StreamSocket* sock, std::string& destrecvq)
+	{
+		if (GetRecvQ().empty())
+			return 0;
+
+		unsigned char opcode = (unsigned char)GetRecvQ().c_str()[0];
+		opcode &= ~WS_FINBIT;
+
+		switch (opcode)
+		{
+			case OP_CONTINUATION:
+			case OP_TEXT:
+			case OP_BINARY:
+			{
+				return HandleAppData(sock, destrecvq, true);
+			}
+
+			case OP_PING:
+			{
+				return HandlePingPongFrame(sock, true);
+			}
+
+			case OP_PONG:
+			{
+				// A pong frame may be sent unsolicited, so we have to handle it.
+				// It may carry application data which we need to remove from the recvq as well.
+				return HandlePingPongFrame(sock, false);
+			}
+
+			case OP_CLOSE:
+			{
+				sock->SetError("Connection closed");
+				return -1;
+			}
+
+			default:
+			{
+				sock->SetError("WebSocket: Invalid opcode");
+				return -1;
+			}
+		}
+	}
+
+	void FailHandshake(StreamSocket* sock, const char* httpreply, const char* sockerror)
+	{
+		GetSendQ().push_back(StreamSocket::SendQueue::Element(httpreply));
+		sock->DoWrite();
+		sock->SetError(sockerror);
+	}
+
+	int HandleHTTPReq(StreamSocket* sock)
+	{
+		std::string& recvq = GetRecvQ();
+		const std::string::size_type reqend = recvq.find("\r\n\r\n");
+		if (reqend == std::string::npos)
+			return 0;
+
+		HTTPHeaderFinder keyheader;
+		if (!keyheader.Find(recvq, "Sec-WebSocket-Key:", 18, reqend))
+		{
+			FailHandshake(sock, "HTTP/1.1 501 Not Implemented\r\nConnection: close\r\n\r\n", "WebSocket: Received HTTP request which is not a websocket upgrade");
+			return -1;
+		}
+
+		if (!*sha1)
+		{
+			FailHandshake(sock, "HTTP/1.1 503 Service Unavailable\r\nConnection: close\r\n\r\n", "WebSocket: SHA-1 provider missing");
+			return -1;
+		}
+
+		state = STATE_ESTABLISHED;
+
+		std::string key = keyheader.ExtractValue(recvq);
+		key.append(MagicGUID);
+
+		std::string reply = "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: ";
+		reply.append(BinToBase64((*sha1)->GenerateRaw(key), NULL, '=')).append("\r\n\r\n");
+		GetSendQ().push_back(StreamSocket::SendQueue::Element(reply));
+
+		SocketEngine::ChangeEventMask(sock, FD_ADD_TRIAL_WRITE);
+
+		recvq.erase(0, reqend + 4);
+
+		return 1;
+	}
+
+ public:
+	WebSocketHook(IOHookProvider* Prov, StreamSocket* sock)
+		: IOHookMiddle(Prov)
+		, state(STATE_HTTPREQ)
+		, lastpingpong(0)
+	{
+		sock->AddIOHook(this);
+	}
+
+	int OnStreamSocketWrite(StreamSocket* sock, StreamSocket::SendQueue& uppersendq) CXX11_OVERRIDE
+	{
+		StreamSocket::SendQueue& mysendq = GetSendQ();
+
+		// Return 1 to allow sending back an error HTTP response
+		if (state != STATE_ESTABLISHED)
+			return (mysendq.empty() ? 0 : 1);
+
+		if (!uppersendq.empty())
+		{
+			StreamSocket::SendQueue::Element elem = PrepareSendQElem(uppersendq.bytes(), OP_BINARY);
+			mysendq.push_back(elem);
+			mysendq.moveall(uppersendq);
+		}
+
+		return 1;
+	}
+
+	int OnStreamSocketRead(StreamSocket* sock, std::string& destrecvq) CXX11_OVERRIDE
+	{
+		if (state == STATE_HTTPREQ)
+		{
+			int httpret = HandleHTTPReq(sock);
+			if (httpret <= 0)
+				return httpret;
+		}
+
+		int wsret;
+		do
+		{
+			wsret = HandleWS(sock, destrecvq);
+		}
+		while ((!GetRecvQ().empty()) && (wsret > 0));
+
+		return wsret;
+	}
+
+	void OnStreamSocketClose(StreamSocket* sock) CXX11_OVERRIDE
+	{
+	}
+};
+
+void WebSocketHookProvider::OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
+{
+	new WebSocketHook(this, sock);
+}
+
+class ModuleWebSocket : public Module
+{
+	dynamic_reference_nocheck<HashProvider> hash;
+	WebSocketHookProvider hookprov;
+
+ public:
+	ModuleWebSocket()
+		: hash(this, "hash/sha1")
+		, hookprov(this)
+	{
+		sha1 = &hash;
+	}
+
+	void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
+	{
+		if (target_type != TYPE_USER)
+			return;
+
+		LocalUser* user = IS_LOCAL(static_cast<User*>(item));
+		if ((user) && (user->eh.GetModHook(this)))
+			ServerInstance->Users.QuitUser(user, "WebSocket module unloading");
+	}
+
+	Version GetVersion() CXX11_OVERRIDE
+	{
+		return Version("Provides RFC 6455 WebSocket support", VF_VENDOR);
+	}
+};
+
+MODULE_INIT(ModuleWebSocket)