1 /**

     2  * Relational pipes

     3  * Copyright © 2022 František Kučera (Frantovo.cz, GlobalCode.info)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, version 3 of the License.

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    16  */

    17 #include <string>

    18 #include <cstring>

    19 #include <unistd.h>

    20 #include <stdexcept>

    21 #include <arpa/inet.h>

    22 #include <sys/types.h>

    23 #include <sys/socket.h>

    24 #include <sys/un.h>

    25 #include <netinet/in.h>

    26 #include <vector>

    27 #include <memory>

    28 #include <regex>

    29 #include <iostream>

    30 #include <netdb.h>

    31 

    32 #include "Socket.h"

    33 

    34 namespace relpipe {

    35 namespace in {

    36 namespace socket {

    37 

    38 using namespace relpipe::in::socket::options;

    39 

    40 static const std::string findOption(SocketOptions options, std::string name, bool required = false, const std::string defaultValue = "") {

    41 	for (auto o : options) if (o.name == name) return o.value;

    42 	if (required) throw std::invalid_argument("Option " + name + " is required but was not found");

    43 	else return defaultValue;

    44 }

    45 

    46 class FD {

    47 private:

    48 	int fd;

    49 public:

    50 

    51 	FD(int fd) : fd(fd) {

    52 	};

    53 

    54 	virtual ~FD() {

    55 		close(fd);

    56 	}

    57 

    58 	int getFD() {

    59 		return fd;

    60 	}

    61 };

    62 

    63 static void check(int result, std::string message) {

    64 	if (result == 0); // OK

    65 	else throw std::logic_error("Got error result: " + message + ": " + strerror(errno) + " (result=" + std::to_string(result) + ", errno=" + std::to_string(errno) + ")");

    66 }

    67 

    68 class AddressInfos {

    69 private:

    70 	std::shared_ptr<addrinfo> addrInfo;

    71 

    72 	AddressInfos(addrinfo* addrInfo) : addrInfo(std::shared_ptr<addrinfo>(addrInfo, freeaddrinfo)) {

    73 	}

    74 

    75 public:

    76 

    77 	virtual ~AddressInfos() {

    78 	}

    79 

    80 	class AddressInfo {

    81 	private:

    82 		std::shared_ptr<addrinfo> parent; // to avoid premature deletion of the whole structure

    83 	public:

    84 		const addrinfo * const ai;

    85 

    86 		AddressInfo(const addrinfo * const ai, std::shared_ptr<addrinfo> parent) : ai(ai), parent(parent) {

    87 		}

    88 

    89 		const std::string toString() const {

    90 			char buffer[INET6_ADDRSTRLEN] = {0};

    91 			if (ai->ai_family == AF_INET) return inet_ntop(ai->ai_family, &((sockaddr_in const *) ai->ai_addr)->sin_addr, buffer, sizeof (buffer)); // TODO: check 0 result

    92 			else if (ai->ai_family == AF_INET6) return inet_ntop(ai->ai_family, &((sockaddr_in6 const *) ai->ai_addr)->sin6_addr, buffer, sizeof (buffer)); // TODO: check 0 result

    93 			else return "unknown address family: " + std::to_string(ai->ai_family);

    94 		}

    95 	};

    96 

    97 	static AddressInfos getAddressInfos(const std::string& host, const std::string& port, int socketType = SOCK_STREAM, int protocol = IPPROTO_TCP) {

    98 		struct addrinfo query;

    99 		memset(&query, sizeof (query), 0);

   100 		query.ai_family = AF_UNSPEC;

   101 		query.ai_socktype = socketType;

   102 		query.ai_protocol = protocol;

   103 		query.ai_flags = AI_ALL;

   104 

   105 		struct addrinfo* addrInfo;

   106 		check(getaddrinfo(host.c_str(), port.c_str(), &query, &addrInfo), "getaddrinfo");

   107 

   108 		return AddressInfos(addrInfo);

   109 	}

   110 

   111 	const std::size_t size() const {

   112 		std::size_t size = 0;

   113 		for (addrinfo* ai = addrInfo.get(); ai; ai = ai->ai_next) size++;

   114 		return size;

   115 	}

   116 

   117 	const AddressInfo operator[](std::size_t index) const {

   118 		for (addrinfo* ai = addrInfo.get(); ai; index--) {

   119 			if (index == 0) return AddressInfo(ai, addrInfo);

   120 			else ai = ai->ai_next;

   121 		}

   122 

   123 		throw std::out_of_range("invalid index for AddressInfo: " + std::to_string(index));

   124 	}

   125 

   126 };

   127 

   128 template<class SocketClass, class... MoreArgs> static std::shared_ptr<SocketClass> openClientSocket(const SocketOptions& options, int socketType, int protocol, MoreArgs... moreArgs) {

   129 	AddressInfos remoteAddresses = AddressInfos::getAddressInfos(

   130 			findOption(options, OPTION_HOST, true),

   131 			findOption(options, OPTION_PORT, true),

   132 			socketType,

   133 			protocol);

   134 

   135 	return std::shared_ptr<SocketClass>(new SocketClass(remoteAddresses[0], moreArgs...));

   136 }

   137 

   138 /**

   139  * abstract class for sockets that use sendmsg() / recvmsg()

   140  */

   141 class MSGSocket : public Socket {

   142 protected:

   143 	FD socket;

   144 

   145 	void sendmsg(const std::string& message) {

   146 		iovec iov[1];

   147 		msghdr msg = {};

   148 		msg.msg_iov = iov;

   149 		msg.msg_iov[0].iov_base = (void*) message.c_str();

   150 		msg.msg_iov[0].iov_len = message.size();

   151 		msg.msg_iovlen = sizeof (iov) / sizeof (iov[0]);

   152 		ssize_t written = ::sendmsg(socket.getFD(), &msg, 0);

   153 		if (written != message.size()) throw std::logic_error("writing to the socket failed");

   154 	}

   155 public:

   156 

   157 	MSGSocket(int socket) : socket(socket) {

   158 	}

   159 

   160 	void send(const OutgoingMessage& message) {

   161 		sendmsg(message.data);

   162 	}

   163 

   164 };

   165 

   166 class UDPClientSocket : public Socket {

   167 private:

   168 	AddressInfos::AddressInfo remoteAddress;

   169 	useconds_t delay = 0;

   170 	FD socket;

   171 

   172 public:

   173 

   174 	UDPClientSocket(AddressInfos::AddressInfo remoteAddress) : remoteAddress(remoteAddress), socket(::socket(remoteAddress.ai->ai_family, remoteAddress.ai->ai_socktype, remoteAddress.ai->ai_protocol)) {

   175 	}

   176 

   177 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   178 		auto socket = openClientSocket<UDPClientSocket>(options, SOCK_DGRAM, IPPROTO_UDP);

   179 		socket->delay = std::stol(findOption(options, OPTION_DELAY, false, "0")); // TODO: Move to SocketHandler? Or delete.

   180 		return socket;

   181 	}

   182 

   183 	void send(const OutgoingMessage& message) override {

   184 		auto ai = remoteAddress.ai;

   185 		sendto(socket.getFD(), message.data.c_str(), message.data.size(), 0, ai->ai_addr, ai->ai_addrlen);

   186 		if (delay) usleep(delay);

   187 	}

   188 

   189 	const IncomingMessage receive() override {

   190 		// TODO: UDP receive()

   191 		return IncomingMessage("TODO: receive() a message");

   192 	}

   193 };

   194 

   195 class UDPServerSocket : public Socket {

   196 private:

   197 	AddressInfos::AddressInfo localAddress;

   198 	sockaddr_in6 remoteAddressForSending = {};

   199 	useconds_t delay = 0;

   200 	FD socket;

   201 

   202 public:

   203 

   204 	UDPServerSocket(AddressInfos::AddressInfo remoteAddress) : localAddress(remoteAddress), socket(::socket(remoteAddress.ai->ai_family, remoteAddress.ai->ai_socktype, remoteAddress.ai->ai_protocol)) {

   205 	}

   206 

   207 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   208 		auto socket = openClientSocket<UDPServerSocket>(options, SOCK_DGRAM, IPPROTO_UDP);

   209 		auto ai = socket->localAddress.ai;

   210 		int reuseAddr = true;

   211 		check(::setsockopt(socket->socket.getFD(), SOL_SOCKET, SO_REUSEADDR, &reuseAddr, sizeof (reuseAddr)), "setsockopt SO_REUSEADDR");

   212 		check(::bind(socket->socket.getFD(), ai->ai_addr, ai->ai_addrlen), "bind");

   213 		return socket;

   214 	}

   215 

   216 	void send(const OutgoingMessage& message) override {

   217 		// receive a message first to get a remote address:

   218 		char buffer[8192];

   219 		memset((char *) &remoteAddressForSending, 0, sizeof (remoteAddressForSending));

   220 		socklen_t remoteAddressSize = sizeof (remoteAddressForSending);

   221 		ssize_t msgSize = recvfrom(socket.getFD(), buffer, sizeof (buffer), 0, (sockaddr*) & remoteAddressForSending, &remoteAddressSize);

   222 

   223 		// respond with our messsage:

   224 		sendto(socket.getFD(), message.data.c_str(), message.data.size(), 0, (sockaddr*) & remoteAddressForSending, remoteAddressSize);

   225 	}

   226 

   227 	const IncomingMessage receive() override {

   228 		char buffer[8192];

   229 		sockaddr_in6 remoteAddress;

   230 		memset((char *) &remoteAddress, 0, sizeof (remoteAddress));

   231 		socklen_t remoteAddressSize = sizeof (remoteAddress);

   232 		ssize_t msgSize = recvfrom(socket.getFD(), buffer, sizeof (buffer), 0, (sockaddr*) & remoteAddress, &remoteAddressSize);

   233 		check(msgSize < 0, "recvfrom");

   234 

   235 		IncomingMessage message(std::string(buffer, std::min(sizeof (buffer), (size_t) msgSize)));

   236 

   237 		// TODO: move to a common method

   238 		char hostBuffer[INET6_ADDRSTRLEN] = {0};

   239 		if (remoteAddress.sin6_family == AF_INET) {

   240 			sockaddr_in* remoteAddress4 = (sockaddr_in*) & remoteAddress;

   241 			message.remoteHost = inet_ntop(remoteAddress4->sin_family, &remoteAddress4->sin_addr, hostBuffer, sizeof (hostBuffer)); // TODO: check 0 result

   242 			message.remotePort = remoteAddress4->sin_port;

   243 		} else if (remoteAddress.sin6_family == AF_INET6) {

   244 			message.remoteHost = inet_ntop(remoteAddress.sin6_family, &remoteAddress.sin6_addr, hostBuffer, sizeof (hostBuffer)); // TODO: check 0 result

   245 			message.remotePort = remoteAddress.sin6_port;

   246 		}

   247 

   248 		return message;

   249 	}

   250 };

   251 

   252 class TCPClientSocket : public Socket {

   253 private:

   254 	AddressInfos::AddressInfo remoteAddress;

   255 

   256 public:

   257 

   258 	TCPClientSocket(AddressInfos::AddressInfo remoteAddress) : remoteAddress(remoteAddress) {

   259 	}

   260 

   261 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   262 		return openClientSocket<TCPClientSocket>(options, SOCK_STREAM, IPPROTO_TCP);

   263 	}

   264 

   265 	void send(const OutgoingMessage& message) override {

   266 		auto ai = remoteAddress.ai;

   267 		FD s(::socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol));

   268 		check(::connect(s.getFD(), ai->ai_addr, ai->ai_addrlen), "connect socket");

   269 		ssize_t written = ::write(s.getFD(), message.data.c_str(), message.data.size());

   270 		if (written != message.data.size()) throw std::logic_error("writing to the socket failed");

   271 		// TODO: partial writes, repeat

   272 	}

   273 

   274 	const IncomingMessage receive() override {

   275 		// TODO: TCP receive()

   276 		return IncomingMessage("TODO: receive() a message");

   277 	}

   278 };

   279 

   280 class TCPServerSocket : public Socket {

   281 private:

   282 	AddressInfos::AddressInfo localAddress;

   283 	FD socket;

   284 public:

   285 

   286 	TCPServerSocket(AddressInfos::AddressInfo localAddress) : localAddress(localAddress), socket(::socket(localAddress.ai->ai_family, localAddress.ai->ai_socktype, localAddress.ai->ai_protocol)) {

   287 	}

   288 

   289 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   290 		auto socket = openClientSocket<TCPServerSocket>(options, SOCK_STREAM, IPPROTO_TCP);

   291 		auto ai = socket->localAddress.ai;

   292 		int reuseAddr = true;

   293 		check(::setsockopt(socket->socket.getFD(), SOL_SOCKET, SO_REUSEADDR, &reuseAddr, sizeof (reuseAddr)), "setsockopt SO_REUSEADDR");

   294 		check(::bind(socket->socket.getFD(), ai->ai_addr, ai->ai_addrlen), "bind");

   295 		check(::listen(socket->socket.getFD(), 10), "listen"); // TODO: configurable backlog connection count?

   296 		return socket;

   297 	}

   298 

   299 	void send(const OutgoingMessage& message) override {

   300 		FD clientSocket(accept(socket.getFD(), nullptr, 0));

   301 		ssize_t written = ::write(clientSocket.getFD(), message.data.c_str(), message.data.size());

   302 		if (written != message.data.size()) throw std::logic_error("writing to the socket failed");

   303 		// TODO: partial writes, repeat

   304 	}

   305 

   306 	const IncomingMessage receive() override {

   307 		// TODO: TCP receive()

   308 		return IncomingMessage("TODO: receive() a message");

   309 	}

   310 };

   311 

   312 class SCTPClientSocket : public MSGSocket {

   313 private:

   314 	AddressInfos::AddressInfo remoteAddress;

   315 public:

   316 

   317 	SCTPClientSocket(AddressInfos::AddressInfo remoteAddress) : remoteAddress(remoteAddress), MSGSocket(::socket(remoteAddress.ai->ai_family, remoteAddress.ai->ai_socktype, remoteAddress.ai->ai_protocol)) {

   318 	}

   319 

   320 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   321 		auto socket = openClientSocket<SCTPClientSocket>(options, SOCK_STREAM, IPPROTO_SCTP);

   322 		check(::connect(socket->socket.getFD(), socket->remoteAddress.ai->ai_addr, socket->remoteAddress.ai->ai_addrlen), "connect socket");

   323 		return socket;

   324 	}

   325 

   326 	const IncomingMessage receive() override {

   327 		// TODO: SCTP receive()

   328 		return IncomingMessage("TODO: receive() a message");

   329 	}

   330 };

   331 

   332 class UDSClientSocket : public MSGSocket {

   333 public:

   334 

   335 	UDSClientSocket(int fd) : MSGSocket(fd) {

   336 	}

   337 

   338 	static std::shared_ptr<Socket> open(const SocketOptions& options) {

   339 		struct sockaddr_un address;

   340 		std::string path = findOption(options, OPTION_PATH);

   341 

   342 		memset(&address, 0x00, sizeof (address));

   343 		address.sun_family = AF_UNIX;

   344 		strncpy(address.sun_path, path.c_str(), path.size());

   345 

   346 		int fd = ::socket(AF_UNIX, SOCK_STREAM, 0);

   347 

   348 		auto socket = std::make_shared<UDSClientSocket>(fd);

   349 		check(::connect(socket->socket.getFD(), (const sockaddr*) &address, sizeof (address)), "connect socket");

   350 

   351 

   352 		if (findOption(options, "debug") == "true") { // TODO: undocumented feature → standardize or remove

   353 			struct ucred credentials;

   354 			socklen_t credentialsLength = sizeof (credentials);

   355 			memset(&credentials, 0x00, credentialsLength);

   356 			getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &credentials, &credentialsLength);

   357 

   358 			printf("uds.fd = %d\n", fd);

   359 			printf("uds.path = %s\n", address.sun_path);

   360 			printf("uds.server.pid = %d\n", credentials.pid);

   361 			printf("uds.server.uid = %d\n", credentials.uid);

   362 			printf("uds.server.gid = %d\n", credentials.gid);

   363 		}

   364 

   365 

   366 		return socket;

   367 	}

   368 

   369 	const IncomingMessage receive() override {

   370 		// TODO: UDS receive()

   371 		return IncomingMessage("TODO: receive() a message");

   372 	}

   373 };

   374 

   375 template<const char* protocol, const char* role, const char* mode, typename SocketClass>

   376 class TemplateSocketFactory : public SocketFactory {

   377 public:

   378 

   379 	bool canHandle(const SocketOptions& options) override {

   380 		return findOption(options, OPTION_PROTOCOL) == protocol

   381 				&& findOption(options, OPTION_ROLE) == role

   382 				&& findOption(options, OPTION_MODE) == mode;

   383 	}

   384 

   385 	std::shared_ptr<Socket> open(const SocketOptions& options) override {

   386 		return SocketClass::open(options);

   387 	}

   388 };

   389 

   390 static std::vector<std::shared_ptr<SocketFactory>> factories

   391 {

   392 	std::make_shared<TemplateSocketFactory<PROTOCOL_TCP, ROLE_CLIENT, MODE_STREAM, TCPClientSocket >> (),

   393 	std::make_shared<TemplateSocketFactory<PROTOCOL_TCP, ROLE_SERVER, MODE_STREAM, TCPServerSocket >> (),

   394 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDP, ROLE_CLIENT, MODE_DATAGRAM, UDPClientSocket >> (),

   395 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDP, ROLE_SERVER, MODE_DATAGRAM, UDPServerSocket >> (),

   396 	std::make_shared<TemplateSocketFactory<PROTOCOL_SCTP, ROLE_CLIENT, MODE_STREAM, SCTPClientSocket >> (),

   397 	std::make_shared<TemplateSocketFactory<PROTOCOL_SCTP, ROLE_SERVER, MODE_STREAM, UDPClientSocket >> (), // TODO: correct class

   398 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDS, ROLE_CLIENT, MODE_STREAM, UDSClientSocket >> (),

   399 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDS, ROLE_CLIENT, MODE_DATAGRAM, UDSClientSocket >> (), // TODO: correct class

   400 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDS, ROLE_SERVER, MODE_STREAM, UDSClientSocket >> (), // TODO: correct class

   401 	std::make_shared<TemplateSocketFactory<PROTOCOL_UDS, ROLE_SERVER, MODE_DATAGRAM, UDSClientSocket >> (), // TODO: correct class

   402 };

   403 

   404 std::shared_ptr<SocketFactory> SocketFactory::find(const SocketOptions& options) {

   405 	for (auto f : factories) if (f->canHandle(options)) return f;

   406 	throw std::logic_error("Unable to find a SocketFactory"); // TODO: add relevant options?

   407 }

   408 

   409 

   410 }

   411 }

   412 }