/tmp/bitcoin/src/util/sock.cpp

Source
// Copyright (c) 2020-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <util/sock.h>

#include <compat/compat.h>
#include <span.h>
#include <tinyformat.h>
#include <util/check.h>
#include <util/log.h>
#include <util/syserror.h>
#include <util/threadinterrupt.h>
#include <util/time.h>

#include <algorithm>
#include <compare>
#include <exception>
#include <memory>
#include <stdexcept>
#include <string>
#include <utility>
#include <vector>

#ifdef USE_POLL
#include <poll.h>
#endif

Sock::Sock(SOCKET s) : m_socket(s) {}

Sock::Sock(Sock&& other)
{
    m_socket = other.m_socket;
    other.m_socket = INVALID_SOCKET;
}

Sock::~Sock() { Close(); }

Sock& Sock::operator=(Sock&& other)
{
    Close();
    m_socket = other.m_socket;
    other.m_socket = INVALID_SOCKET;
    return *this;
}

ssize_t Sock::Send(const void* data, size_t len, int flags) const
{
    return send(m_socket, static_cast<const char*>(data), len, flags);
}

ssize_t Sock::Recv(void* buf, size_t len, int flags) const
{
    return recv(m_socket, static_cast<char*>(buf), len, flags);
}

int Sock::Connect(const sockaddr* addr, socklen_t addr_len) const
{
    return connect(m_socket, addr, addr_len);
}

int Sock::Bind(const sockaddr* addr, socklen_t addr_len) const
{
    return bind(m_socket, addr, addr_len);
}

int Sock::Listen(int backlog) const
{
    return listen(m_socket, backlog);
}

std::unique_ptr<Sock> Sock::Accept(sockaddr* addr, socklen_t* addr_len) const
{
#ifdef WIN32
    static constexpr auto ERR = INVALID_SOCKET;
#else
    static constexpr auto ERR = SOCKET_ERROR;
#endif

    std::unique_ptr<Sock> sock;

    const auto socket = accept(m_socket, addr, addr_len);
    if (socket != ERR) {
        try {
            sock = std::make_unique<Sock>(socket);
        } catch (const std::exception&) {
#ifdef WIN32
            closesocket(socket);
#else
            close(socket);
#endif
        }
    }

    return sock;
}

int Sock::GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const
{
    return getsockopt(m_socket, level, opt_name, static_cast<char*>(opt_val), opt_len);
}

int Sock::SetSockOpt(int level, int opt_name, const void* opt_val, socklen_t opt_len) const
{
    return setsockopt(m_socket, level, opt_name, static_cast<const char*>(opt_val), opt_len);
}

int Sock::GetSockName(sockaddr* name, socklen_t* name_len) const
{
    return getsockname(m_socket, name, name_len);
}

bool Sock::SetNonBlocking() const
{
#ifdef WIN32
    u_long on{1};
    if (ioctlsocket(m_socket, FIONBIO, &on) == SOCKET_ERROR) {
        return false;
    }
#else
    const int flags{fcntl(m_socket, F_GETFL, 0)};
    if (flags == SOCKET_ERROR) {
        return false;
    }
    if (fcntl(m_socket, F_SETFL, flags | O_NONBLOCK) == SOCKET_ERROR) {
        return false;
    }
#endif
    return true;
}

bool Sock::IsSelectable() const
{
#if defined(USE_POLL) || defined(WIN32)
    return true;
#else
    return m_socket < FD_SETSIZE;
#endif
}

bool Sock::Wait(std::chrono::milliseconds timeout, Event requested, Event* occurred) const
{
    // We need a `shared_ptr` holding `this` for `WaitMany()`, but don't want
    // `this` to be destroyed when the `shared_ptr` goes out of scope at the
    // end of this function.
    // Create it with an aliasing shared_ptr that points to `this` without
    // owning it.
    std::shared_ptr<const Sock> shared{std::shared_ptr<const Sock>{}, this};

    EventsPerSock events_per_sock{std::make_pair(shared, Events{requested})};

    if (!WaitMany(timeout, events_per_sock)) {
        return false;
    }

    if (occurred != nullptr) {
        *occurred = events_per_sock.begin()->second.occurred;
    }

    return true;
}

bool Sock::WaitMany(std::chrono::milliseconds timeout, EventsPerSock& events_per_sock) const
{
#ifdef USE_POLL
    std::vector<pollfd> pfds;
    for (const auto& [sock, events] : events_per_sock) {
        pfds.emplace_back();
        auto& pfd = pfds.back();
        pfd.fd = sock->m_socket;
        if (events.requested & RECV) {
            pfd.events |= POLLIN;
        }
        if (events.requested & SEND) {
            pfd.events |= POLLOUT;
        }
    }

    if (poll(pfds.data(), pfds.size(), count_milliseconds(timeout)) == SOCKET_ERROR) {
        return false;
    }

    assert(pfds.size() == events_per_sock.size());
    size_t i{0};
    for (auto& [sock, events] : events_per_sock) {
        assert(sock->m_socket == static_cast<SOCKET>(pfds[i].fd));
        events.occurred = 0;
        if (pfds[i].revents & POLLIN) {
            events.occurred |= RECV;
        }
        if (pfds[i].revents & POLLOUT) {
            events.occurred |= SEND;
        }
        if (pfds[i].revents & (POLLERR | POLLHUP)) {
            events.occurred |= ERR;
        }
        ++i;
    }

    return true;
#else
    fd_set recv;
    fd_set send;
    fd_set err;
    FD_ZERO(&recv);
    FD_ZERO(&send);
    FD_ZERO(&err);
    SOCKET socket_max{0};

    for (const auto& [sock, events] : events_per_sock) {
        if (!sock->IsSelectable()) {
            return false;
        }
        const auto& s = sock->m_socket;
        if (events.requested & RECV) {
            FD_SET(s, &recv);
        }
        if (events.requested & SEND) {
            FD_SET(s, &send);
        }
        FD_SET(s, &err);
        socket_max = std::max(socket_max, s);
    }

    timeval tv = MillisToTimeval(timeout);

    if (select(socket_max + 1, &recv, &send, &err, &tv) == SOCKET_ERROR) {
        return false;
    }

    for (auto& [sock, events] : events_per_sock) {
        const auto& s = sock->m_socket;
        events.occurred = 0;
        if (FD_ISSET(s, &recv)) {
            events.occurred |= RECV;
        }
        if (FD_ISSET(s, &send)) {
            events.occurred |= SEND;
        }
        if (FD_ISSET(s, &err)) {
            events.occurred |= ERR;
        }
    }

    return true;
#endif /* USE_POLL */
}

void Sock::SendComplete(std::span<const unsigned char> data,
                        std::chrono::milliseconds timeout,
                        CThreadInterrupt& interrupt) const
{
    const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
    size_t sent{0};

    for (;;) {
        const ssize_t ret{Send(data.data() + sent, data.size() - sent, MSG_NOSIGNAL)};

        if (ret > 0) {
            sent += static_cast<size_t>(ret);
            if (sent == data.size()) {
                break;
            }
        } else {
            const int err{WSAGetLastError()};
            if (IOErrorIsPermanent(err)) {
                throw std::runtime_error(strprintf("send(): %s", NetworkErrorString(err)));
            }
        }

        const auto now = GetTime<std::chrono::milliseconds>();

        if (now >= deadline) {
            throw std::runtime_error(strprintf(
                "Send timeout (sent only %u of %u bytes before that)", sent, data.size()));
        }

        if (interrupt) {
            throw std::runtime_error(strprintf(
                "Send interrupted (sent only %u of %u bytes before that)", sent, data.size()));
        }

        // Wait for a short while (or the socket to become ready for sending) before retrying
        // if nothing was sent.
        const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
        (void)Wait(wait_time, SEND);
    }
}

void Sock::SendComplete(std::span<const char> data,
                        std::chrono::milliseconds timeout,
                        CThreadInterrupt& interrupt) const
{
    SendComplete(MakeUCharSpan(data), timeout, interrupt);
}

std::string Sock::RecvUntilTerminator(uint8_t terminator,
                                      std::chrono::milliseconds timeout,
                                      CThreadInterrupt& interrupt,
                                      size_t max_data) const
{
    const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
    std::string data;
    bool terminator_found{false};

    // We must not consume any bytes past the terminator from the socket.
    // One option is to read one byte at a time and check if we have read a terminator.
    // However that is very slow. Instead, we peek at what is in the socket and only read
    // as many bytes as possible without crossing the terminator.
    // Reading 64 MiB of random data with 262526 terminator chars takes 37 seconds to read
    // one byte at a time VS 0.71 seconds with the "peek" solution below. Reading one byte
    // at a time is about 50 times slower.

    for (;;) {
        if (data.size() >= max_data) {
            throw std::runtime_error(
                strprintf("Received too many bytes without a terminator (%u)", data.size()));
        }

        char buf[512];

        const ssize_t peek_ret{Recv(buf, std::min(sizeof(buf), max_data - data.size()), MSG_PEEK)};

        switch (peek_ret) {
        case -1: {
            const int err{WSAGetLastError()};
            if (IOErrorIsPermanent(err)) {
                throw std::runtime_error(strprintf("recv(): %s", NetworkErrorString(err)));
            }
            break;
        }
        case 0:
            throw std::runtime_error("Connection unexpectedly closed by peer");
        default:
            auto end = buf + peek_ret;
            auto terminator_pos = std::find(buf, end, terminator);
            terminator_found = terminator_pos != end;

            const size_t try_len{terminator_found ? terminator_pos - buf + 1 :
                                                    static_cast<size_t>(peek_ret)};

            const ssize_t read_ret{Recv(buf, try_len, 0)};

            if (read_ret < 0 || static_cast<size_t>(read_ret) != try_len) {
                throw std::runtime_error(
                    strprintf("recv() returned %u bytes on attempt to read %u bytes but previous "
                              "peek claimed %u bytes are available",
                              read_ret, try_len, peek_ret));
            }

            // Don't include the terminator in the output.
            const size_t append_len{terminator_found ? try_len - 1 : try_len};

            data.append(buf, buf + append_len);

            if (terminator_found) {
                return data;
            }
        }

        const auto now = GetTime<std::chrono::milliseconds>();

        if (now >= deadline) {
            throw std::runtime_error(strprintf(
                "Receive timeout (received %u bytes without terminator before that)", data.size()));
        }

        if (interrupt) {
            throw std::runtime_error(strprintf(
                "Receive interrupted (received %u bytes without terminator before that)",
                data.size()));
        }

        // Wait for a short while (or the socket to become ready for reading) before retrying.
        const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
        (void)Wait(wait_time, RECV);
    }
}

bool Sock::IsConnected(std::string& errmsg) const
{
    if (m_socket == INVALID_SOCKET) {
        errmsg = "not connected";
        return false;
    }

    char c;
    switch (Recv(&c, sizeof(c), MSG_PEEK)) {
    case -1: {
        const int err = WSAGetLastError();
        if (IOErrorIsPermanent(err)) {
            errmsg = NetworkErrorString(err);
            return false;
        }
        return true;
    }
    case 0:
        errmsg = "closed";
        return false;
    default:
        return true;
    }
}

void Sock::Close()
{
    if (m_socket == INVALID_SOCKET) {
        return;
    }
#ifdef WIN32
    int ret = closesocket(m_socket);
#else
    int ret = close(m_socket);
#endif
    if (ret) {
        LogWarning("Error closing socket %d: %s", m_socket, NetworkErrorString(WSAGetLastError()));
    }
    m_socket = INVALID_SOCKET;
}

bool Sock::operator==(SOCKET s) const
{
    return m_socket == s;
};

std::string NetworkErrorString(int err)
{
#if defined(WIN32)
    return Win32ErrorString(err);
#else
    // On BSD sockets implementations, NetworkErrorString is the same as SysErrorString.
    return SysErrorString(err);
#endif
}

Coverage Report

Created: 2026-05-30 09:47

Line	Count	Source
1		// Copyright (c) 2020-present The Bitcoin Core developers
2		// Distributed under the MIT software license, see the accompanying
3		// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5		#include <util/sock.h>
6
7		#include <compat/compat.h>
8		#include <span.h>
9		#include <tinyformat.h>
10		#include <util/check.h>
11		#include <util/log.h>
12		#include <util/syserror.h>
13		#include <util/threadinterrupt.h>
14		#include <util/time.h>
15
16		#include <algorithm>
17		#include <compare>
18		#include <exception>
19		#include <memory>
20		#include <stdexcept>
21		#include <string>
22		#include <utility>
23		#include <vector>
24
25		#ifdef USE_POLL
26		#include <poll.h>
27		#endif
28
29	3.80k	Sock::Sock(SOCKET s) : m_socket(s) {}
30
31		Sock::Sock(Sock&& other)
32	3	{
33	3	m_socket = other.m_socket;
34	3	other.m_socket = INVALID_SOCKET;
35	3	}
36
37	3.80k	Sock::~Sock() { Close(); }
38
39		Sock& Sock::operator=(Sock&& other)
40	4	{
41	4	Close();
42	4	m_socket = other.m_socket;
43	4	other.m_socket = INVALID_SOCKET;
44	4	return *this;
45	4	}
46
47		ssize_t Sock::Send(const void* data, size_t len, int flags) const
48	323k	{
49	323k	return send(m_socket, static_cast<const char*>(data), len, flags);
50	323k	}
51
52		ssize_t Sock::Recv(void* buf, size_t len, int flags) const
53	161k	{
54	161k	return recv(m_socket, static_cast<char*>(buf), len, flags);
55	161k	}
56
57		int Sock::Connect(const sockaddr* addr, socklen_t addr_len) const
58	1.75k	{
59	1.75k	return connect(m_socket, addr, addr_len);
60	1.75k	}
61
62		int Sock::Bind(const sockaddr* addr, socklen_t addr_len) const
63	1.00k	{
64	1.00k	return bind(m_socket, addr, addr_len);
65	1.00k	}
66
67		int Sock::Listen(int backlog) const
68	995	{
69	995	return listen(m_socket, backlog);
70	995	}
71
72		std::unique_ptr<Sock> Sock::Accept(sockaddr* addr, socklen_t* addr_len) const
73	1.01k	{
74		#ifdef WIN32
75		static constexpr auto ERR = INVALID_SOCKET;
76		#else
77	1.01k	static constexpr auto ERR = SOCKET_ERROR;
78	1.01k	#endif
79
80	1.01k	std::unique_ptr<Sock> sock;
81
82	1.01k	const auto socket = accept(m_socket, addr, addr_len);
83	1.01k	if (socket != ERR) {
84	1.01k	try {
85	1.01k	sock = std::make_unique<Sock>(socket);
86	1.01k	} catch (const std::exception&) {
87		#ifdef WIN32
88		closesocket(socket);
89		#else
90	0	close(socket);
91	0	#endif
92	0	}
93	1.01k	}
94
95	1.01k	return sock;
96	1.01k	}
97
98		int Sock::GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const
99	1.74k	{
100	1.74k	return getsockopt(m_socket, level, opt_name, static_cast<char*>(opt_val), opt_len);
101	1.74k	}
102
103		int Sock::SetSockOpt(int level, int opt_name, const void* opt_val, socklen_t opt_len) const
104	4.76k	{
105	4.76k	return setsockopt(m_socket, level, opt_name, static_cast<const char*>(opt_val), opt_len);
106	4.76k	}
107
108		int Sock::GetSockName(sockaddr* name, socklen_t* name_len) const
109	1.60k	{
110	1.60k	return getsockname(m_socket, name, name_len);
111	1.60k	}
112
113		bool Sock::SetNonBlocking() const
114	2.75k	{
115		#ifdef WIN32
116		u_long on{1};
117		if (ioctlsocket(m_socket, FIONBIO, &on) == SOCKET_ERROR) {
118		return false;
119		}
120		#else
121	2.75k	const int flags{fcntl(m_socket, F_GETFL, 0)};
122	2.75k	if (flags == SOCKET_ERROR) {
123	0	return false;
124	0	}
125	2.75k	if (fcntl(m_socket, F_SETFL, flags \| O_NONBLOCK) == SOCKET_ERROR) {
126	0	return false;
127	0	}
128	2.75k	#endif
129	2.75k	return true;
130	2.75k	}
131
132		bool Sock::IsSelectable() const
133	3.76k	{
134	3.76k	#if defined(USE_POLL) \|\| defined(WIN32)
135	3.76k	return true;
136		#else
137		return m_socket < FD_SETSIZE;
138		#endif
139	3.76k	}
140
141		bool Sock::Wait(std::chrono::milliseconds timeout, Event requested, Event* occurred) const
142	4.17k	{
143		// We need a `shared_ptr` holding `this` for `WaitMany()`, but don't want
144		// `this` to be destroyed when the `shared_ptr` goes out of scope at the
145		// end of this function.
146		// Create it with an aliasing shared_ptr that points to `this` without
147		// owning it.
148	4.17k	std::shared_ptr<const Sock> shared{std::shared_ptr<const Sock>{}, this};
149
150	4.17k	EventsPerSock events_per_sock{std::make_pair(shared, Events{requested})};
151
152	4.17k	if (!WaitMany(timeout, events_per_sock)) {
153	0	return false;
154	0	}
155
156	4.17k	if (occurred != nullptr) {
157	4.04k	*occurred = events_per_sock.begin()->second.occurred;
158	4.04k	}
159
160	4.17k	return true;
161	4.17k	}
162
163		bool Sock::WaitMany(std::chrono::milliseconds timeout, EventsPerSock& events_per_sock) const
164	306k	{
165	306k	#ifdef USE_POLL
166	306k	std::vector<pollfd> pfds;
167	815k	for (const auto& [sock, events] : events_per_sock) {
168	815k	pfds.emplace_back();
169	815k	auto& pfd = pfds.back();
170	815k	pfd.fd = sock->m_socket;
171	815k	if (events.requested & RECV) {
172	814k	pfd.events \|= POLLIN;
173	814k	}
174	815k	if (events.requested & SEND) {
175	3.12k	pfd.events \|= POLLOUT;
176	3.12k	}
177	815k	}
178
179	306k	if (poll(pfds.data(), pfds.size(), count_milliseconds(timeout)) == SOCKET_ERROR) {
180	0	return false;
181	0	}
182
183	306k	assert(pfds.size() == events_per_sock.size());
184	306k	size_t i{0};
185	815k	for (auto& [sock, events] : events_per_sock) {
186	815k	assert(sock->m_socket == static_cast<SOCKET>(pfds[i].fd));
187	815k	events.occurred = 0;
188	815k	if (pfds[i].revents & POLLIN) {
189	162k	events.occurred \|= RECV;
190	162k	}
191	815k	if (pfds[i].revents & POLLOUT) {
192	3.10k	events.occurred \|= SEND;
193	3.10k	}
194	815k	if (pfds[i].revents & (POLLERR \| POLLHUP)) {
195	74	events.occurred \|= ERR;
196	74	}
197	815k	++i;
198	815k	}
199
200	306k	return true;
201		#else
202		fd_set recv;
203		fd_set send;
204		fd_set err;
205		FD_ZERO(&recv);
206		FD_ZERO(&send);
207		FD_ZERO(&err);
208		SOCKET socket_max{0};
209
210		for (const auto& [sock, events] : events_per_sock) {
211		if (!sock->IsSelectable()) {
212		return false;
213		}
214		const auto& s = sock->m_socket;
215		if (events.requested & RECV) {
216		FD_SET(s, &recv);
217		}
218		if (events.requested & SEND) {
219		FD_SET(s, &send);
220		}
221		FD_SET(s, &err);
222		socket_max = std::max(socket_max, s);
223		}
224
225		timeval tv = MillisToTimeval(timeout);
226
227		if (select(socket_max + 1, &recv, &send, &err, &tv) == SOCKET_ERROR) {
228		return false;
229		}
230
231		for (auto& [sock, events] : events_per_sock) {
232		const auto& s = sock->m_socket;
233		events.occurred = 0;
234		if (FD_ISSET(s, &recv)) {
235		events.occurred \|= RECV;
236		}
237		if (FD_ISSET(s, &send)) {
238		events.occurred \|= SEND;
239		}
240		if (FD_ISSET(s, &err)) {
241		events.occurred \|= ERR;
242		}
243		}
244
245		return true;
246		#endif /* USE_POLL */
247	306k	}
248
249		void Sock::SendComplete(std::span<const unsigned char> data,
250		std::chrono::milliseconds timeout,
251		CThreadInterrupt& interrupt) const
252	175	{
253	175	const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
254	175	size_t sent{0};
255
256	175	for (;;) {
257	175	const ssize_t ret{Send(data.data() + sent, data.size() - sent, MSG_NOSIGNAL)};
258
259	175	if (ret > 0) {
260	175	sent += static_cast<size_t>(ret);
261	175	if (sent == data.size()) {
262	175	break;
263	175	}
264	175	} else {
265	0	const int err{WSAGetLastError()};
266	0	if (IOErrorIsPermanent(err)) {
267	0	throw std::runtime_error(strprintf("send(): %s", NetworkErrorString(err)));
268	0	}
269	0	}
270
271	0	const auto now = GetTime<std::chrono::milliseconds>();
272
273	0	if (now >= deadline) {
274	0	throw std::runtime_error(strprintf(
275	0	"Send timeout (sent only %u of %u bytes before that)", sent, data.size()));
276	0	}
277
278	0	if (interrupt) {
279	0	throw std::runtime_error(strprintf(
280	0	"Send interrupted (sent only %u of %u bytes before that)", sent, data.size()));
281	0	}
282
283		// Wait for a short while (or the socket to become ready for sending) before retrying
284		// if nothing was sent.
285	0	const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
286	0	(void)Wait(wait_time, SEND);
287	0	}
288	175	}
289
290		void Sock::SendComplete(std::span<const char> data,
291		std::chrono::milliseconds timeout,
292		CThreadInterrupt& interrupt) const
293	49	{
294	49	SendComplete(MakeUCharSpan(data), timeout, interrupt);
295	49	}
296
297		std::string Sock::RecvUntilTerminator(uint8_t terminator,
298		std::chrono::milliseconds timeout,
299		CThreadInterrupt& interrupt,
300		size_t max_data) const
301	38	{
302	38	const auto deadline = GetTime<std::chrono::milliseconds>() + timeout;
303	38	std::string data;
304	38	bool terminator_found{false};
305
306		// We must not consume any bytes past the terminator from the socket.
307		// One option is to read one byte at a time and check if we have read a terminator.
308		// However that is very slow. Instead, we peek at what is in the socket and only read
309		// as many bytes as possible without crossing the terminator.
310		// Reading 64 MiB of random data with 262526 terminator chars takes 37 seconds to read
311		// one byte at a time VS 0.71 seconds with the "peek" solution below. Reading one byte
312		// at a time is about 50 times slower.
313
314	169	for (;;) {
315	169	if (data.size() >= max_data) {
316	2	throw std::runtime_error(
317	2	strprintf("Received too many bytes without a terminator (%u)", data.size()));
318	2	}
319
320	167	char buf[512];
321
322	167	const ssize_t peek_ret{Recv(buf, std::min(sizeof(buf), max_data - data.size()), MSG_PEEK)};
323
324	167	switch (peek_ret) {
325	0	case -1: {
326	0	const int err{WSAGetLastError()};
327	0	if (IOErrorIsPermanent(err)) {
328	0	throw std::runtime_error(strprintf("recv(): %s", NetworkErrorString(err)));
329	0	}
330	0	break;
331	0	}
332	0	case 0:
333	0	throw std::runtime_error("Connection unexpectedly closed by peer");
334	167	default:
335	167	auto end = buf + peek_ret;
336	167	auto terminator_pos = std::find(buf, end, terminator);
337	167	terminator_found = terminator_pos != end;
338
339	167	const size_t try_len{terminator_found ? terminator_pos - buf + 1 :
340	167	static_cast<size_t>(peek_ret)};
341
342	167	const ssize_t read_ret{Recv(buf, try_len, 0)};
343
344	167	if (read_ret < 0 \|\| static_cast<size_t>(read_ret) != try_len) {
345	0	throw std::runtime_error(
346	0	strprintf("recv() returned %u bytes on attempt to read %u bytes but previous "
347	0	"peek claimed %u bytes are available",
348	0	read_ret, try_len, peek_ret));
349	0	}
350
351		// Don't include the terminator in the output.
352	167	const size_t append_len{terminator_found ? try_len - 1 : try_len};
353
354	167	data.append(buf, buf + append_len);
355
356	167	if (terminator_found) {
357	36	return data;
358	36	}
359	167	}
360
361	131	const auto now = GetTime<std::chrono::milliseconds>();
362
363	131	if (now >= deadline) {
364	0	throw std::runtime_error(strprintf(
365	0	"Receive timeout (received %u bytes without terminator before that)", data.size()));
366	0	}
367
368	131	if (interrupt) {
369	0	throw std::runtime_error(strprintf(
370	0	"Receive interrupted (received %u bytes without terminator before that)",
371	0	data.size()));
372	0	}
373
374		// Wait for a short while (or the socket to become ready for reading) before retrying.
375	131	const auto wait_time = std::min(deadline - now, std::chrono::milliseconds{MAX_WAIT_FOR_IO});
376	131	(void)Wait(wait_time, RECV);
377	131	}
378	38	}
379
380		bool Sock::IsConnected(std::string& errmsg) const
381	78	{
382	78	if (m_socket == INVALID_SOCKET) {
383	0	errmsg = "not connected";
384	0	return false;
385	0	}
386
387	78	char c;
388	78	switch (Recv(&c, sizeof(c), MSG_PEEK)) {
389	19	case -1: {
390	19	const int err = WSAGetLastError();
391	19	if (IOErrorIsPermanent(err)) {
392	0	errmsg = NetworkErrorString(err);
393	0	return false;
394	0	}
395	19	return true;
396	19	}
397	0	case 0:
398	0	errmsg = "closed";
399	0	return false;
400	59	default:
401	59	return true;
402	78	}
403	78	}
404
405		void Sock::Close()
406	3.81k	{
407	3.81k	if (m_socket == INVALID_SOCKET) {
408	34	return;
409	34	}
410		#ifdef WIN32
411		int ret = closesocket(m_socket);
412		#else
413	3.77k	int ret = close(m_socket);
414	3.77k	#endif
415	3.77k	if (ret) {
416	0	LogWarning("Error closing socket %d: %s", m_socket, NetworkErrorString(WSAGetLastError()));
417	0	}
418	3.77k	m_socket = INVALID_SOCKET;
419	3.77k	}
420
421		bool Sock::operator==(SOCKET s) const
422	4	{
423	4	return m_socket == s;
424	4	};
425
426		std::string NetworkErrorString(int err)
427	71	{
428		#if defined(WIN32)
429		return Win32ErrorString(err);
430		#else
431		// On BSD sockets implementations, NetworkErrorString is the same as SysErrorString.
432	71	return SysErrorString(err);
433	71	#endif
434	71	}