summaryrefslogtreecommitdiffstats
path: root/src/osd/modules/file/posixsocket.cpp
blob: 4770e91c6a9093ad28864e6078e97d949335baee (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
// license:BSD-3-Clause
// copyright-holders:Olivier Galibert, R. Belmont, Vas Crabb
//============================================================
//
//  sdlsocket.c - SDL socket (inet, unix domain) access
//  functions
//
//  SDLMAME by Olivier Galibert and R. Belmont
//
//============================================================

#include "posixfile.h"

#include <cassert>
#include <cerrno>
#include <cstdio>
#include <cstring>

#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include <unistd.h>


namespace {

char const *const posixfile_socket_identifier  = "socket.";
char const *const posixfile_domain_identifier  = "domain.";


class posix_osd_socket : public osd_file
{
public:
	posix_osd_socket(posix_osd_socket const &) = delete;
	posix_osd_socket(posix_osd_socket &&) = delete;
	posix_osd_socket& operator=(posix_osd_socket const &) = delete;
	posix_osd_socket& operator=(posix_osd_socket &&) = delete;

	posix_osd_socket(int sock, bool listening) noexcept
		: m_sock(sock)
		, m_listening(listening)
	{
		assert(m_sock >= 0);
	}

	virtual ~posix_osd_socket()
	{
		::close(m_sock);
	}

	virtual std::error_condition read(void *buffer, std::uint64_t offset, std::uint32_t count, std::uint32_t &actual) noexcept override
	{
		fd_set readfds;
		FD_ZERO(&readfds);
		FD_SET(m_sock, &readfds);

		struct timeval timeout;
		timeout.tv_sec = timeout.tv_usec = 0;

		if (::select(m_sock + 1, &readfds, nullptr, nullptr, &timeout) < 0)
		{
			return std::error_condition(errno, std::generic_category());
		}
		else if (FD_ISSET(m_sock, &readfds))
		{
			if (!m_listening)
			{
				// connected socket
				ssize_t const result = ::read(m_sock, buffer, count);
				if (result < 0)
				{
					return std::error_condition(errno, std::generic_category());
				}
				else
				{
					actual = std::uint32_t(size_t(result));
					return std::error_condition();
				}
			}
			else
			{
				// listening socket
				int const accepted = ::accept(m_sock, nullptr, nullptr);
				if (accepted < 0)
				{
					return std::error_condition(errno, std::generic_category());
				}
				else
				{
					::close(m_sock);
					m_sock = accepted;
					m_listening = false;
					actual = 0;

					return std::error_condition();
				}
			}
		}
		else
		{
			// no data available
			actual = 0;
			return std::error_condition();
		}
	}

	virtual std::error_condition write(void const *buffer, std::uint64_t offset, std::uint32_t count, std::uint32_t &actual) noexcept override
	{
		ssize_t const result = ::write(m_sock, buffer, count);
		if (result < 0)
			return std::error_condition(errno, std::generic_category());

		actual = std::uint32_t(size_t(result));
		return std::error_condition();
	}

	virtual std::error_condition truncate(std::uint64_t offset) noexcept override
	{
		// doesn't make sense on socket
		return std::errc::bad_file_descriptor;
	}

	virtual std::error_condition flush() noexcept override
	{
		// there's no simple way to flush buffers on a socket anyway
		return std::error_condition();
	}

private:
	int     m_sock;
	bool    m_listening;
};


template <typename T>
std::error_condition create_socket(T const &sa, int sock, std::uint32_t openflags, osd_file::ptr &file, std::uint64_t &filesize) noexcept
{
	osd_file::ptr result;
	if (openflags & OPEN_FLAG_CREATE)
	{
		// listening socket support
		// bind socket...
		if (::bind(sock, reinterpret_cast<struct sockaddr const *>(&sa), sizeof(sa)) < 0)
		{
			std::error_condition binderr(errno, std::generic_category());
			::close(sock);
			return binderr;
		}

		// start to listen...
		if (::listen(sock, 1) < 0)
		{
			std::error_condition lstnerr(errno, std::generic_category());
			::close(sock);
			return lstnerr;
		}

		// mark socket as "listening"
		result.reset(new (std::nothrow) posix_osd_socket(sock, true));
	}
	else
	{
		if (::connect(sock, reinterpret_cast<struct sockaddr const *>(&sa), sizeof(sa)) < 0)
		{
			std::error_condition connerr(errno, std::generic_category());
			::close(sock);
			return connerr;
		}
		result.reset(new (std::nothrow) posix_osd_socket(sock, false));
	}

	if (!result)
	{
		::close(sock);
		return std::errc::not_enough_memory;
	}
	file = std::move(result);
	filesize = 0;
	return std::error_condition();
}

} // anonymous namespace


/*
    Checks whether the path is a socket specification. A valid socket
    specification has the format "socket." host ":" port. Host may be simple
    or fully qualified. Port must be between 1 and 65535.
*/
bool posix_check_socket_path(std::string const &path) noexcept
{
	if (strncmp(path.c_str(), posixfile_socket_identifier, strlen(posixfile_socket_identifier)) == 0 &&
		strchr(path.c_str(), ':') != nullptr) return true;
	return false;
}


bool posix_check_domain_path(std::string const &path) noexcept
{
	if (strncmp(path.c_str(), posixfile_domain_identifier, strlen(posixfile_domain_identifier)) == 0)
		return true;
	return false;
}


std::error_condition posix_open_socket(std::string const &path, std::uint32_t openflags, osd_file::ptr &file, std::uint64_t &filesize) noexcept
{
	char hostname[256];
	int port;
	std::sscanf(&path[strlen(posixfile_socket_identifier)], "%255[^:]:%d", hostname, &port);

	struct hostent const *const localhost = ::gethostbyname(hostname);
	if (!localhost)
		return std::errc::no_such_file_or_directory;

	struct sockaddr_in sai;
	memset(&sai, 0, sizeof(sai));
	sai.sin_family = AF_INET;
	sai.sin_port = htons(port);
	sai.sin_addr = *reinterpret_cast<struct in_addr *>(localhost->h_addr);

	int const sock = ::socket(AF_INET, SOCK_STREAM, 0);
	if (sock < 0)
		return std::error_condition(errno, std::generic_category());

	int const flag = 1;
	if ((::setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<const char *>(&flag), sizeof(flag)) < 0) ||
		(::setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<const char *>(&flag), sizeof(flag)) < 0))
	{
		std::error_condition sockopterr(errno, std::generic_category());
		::close(sock);
		return sockopterr;
	}

	return create_socket(sai, sock, openflags, file, filesize);
}


std::error_condition posix_open_domain(std::string const &path, std::uint32_t openflags, osd_file::ptr &file, std::uint64_t &filesize) noexcept
{
	struct sockaddr_un sau;
	memset(&sau, 0, sizeof(sau));
	sau.sun_family = AF_UNIX;
	strncpy(sau.sun_path, &path.c_str()[strlen(posixfile_domain_identifier)], sizeof(sau.sun_path)-1);

	int const sock = ::socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock < 0)
		return std::error_condition(errno, std::generic_category());

	if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
	{
		std::error_condition cntlerr(errno, std::generic_category());
		::close(sock);
		return cntlerr;
	}

	return create_socket(sau, sock, openflags, file, filesize);
}