common/socket.c - third_party/libusbmuxd - Git at Google

 /*
  * socket.c
  *
  * Copyright (C) 2012-2018 Nikias Bassen <nikias@gmx.li>
  * Copyright (C) 2012 Martin Szulecki <m.szulecki@libimobiledevice.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif
 #include <stdio.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sys/time.h>
 #include <sys/stat.h>
 #ifdef WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include <windows.h>
 static int wsa_init = 0;
 #else
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <netdb.h>
 #include <arpa/inet.h>
 #include <fcntl.h>
 #endif
 #include "socket.h"

 #define RECV_TIMEOUT 20000
 #define CONNECT_TIMEOUT 5000

 static int verbose = 0;

 void socket_set_verbose(int level)
 {
 	verbose = level;
 }

 #ifndef WIN32
 int socket_create_unix(const char *filename)
 {
 	struct sockaddr_un name;
 	int sock;
 #ifdef SO_NOSIGPIPE
 	int yes = 1;
 #endif

 	// remove if still present
 	unlink(filename);

 	/* Create the socket. */
 	sock = socket(PF_UNIX, SOCK_STREAM, 0);
 	if (sock < 0) {
 		perror("socket");
 		return -1;
 	}

 #ifdef SO_NOSIGPIPE
 	if (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
 		perror("setsockopt()");
 		socket_close(sock);
 		return -1;
 	}
 #endif

 	/* Bind a name to the socket. */
 	name.sun_family = AF_UNIX;
 	strncpy(name.sun_path, filename, sizeof(name.sun_path));
 	name.sun_path[sizeof(name.sun_path) - 1] = '\0';

 	if (bind(sock, (struct sockaddr*)&name, sizeof(name)) < 0) {
 		perror("bind");
 		socket_close(sock);
 		return -1;
 	}

 	if (listen(sock, 10) < 0) {
 		perror("listen");
 		socket_close(sock);
 		return -1;
 	}

 	return sock;
 }

 int socket_connect_unix(const char *filename)
 {
 	struct sockaddr_un name;
 	int sfd = -1;
 	struct stat fst;
 #ifdef SO_NOSIGPIPE
 	int yes = 1;
 #endif
 	int bufsize = 0x20000;

 	// check if socket file exists...
 	if (stat(filename, &fst) != 0) {
 		if (verbose >= 2)
 			fprintf(stderr, "%s: stat '%s': %s\n", __func__, filename,
 					strerror(errno));
 		return -1;
 	}
 	// ... and if it is a unix domain socket
 	if (!S_ISSOCK(fst.st_mode)) {
 		if (verbose >= 2)
 			fprintf(stderr, "%s: File '%s' is not a socket!\n", __func__,
 					filename);
 		return -1;
 	}
 	// make a new socket
 	if ((sfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 		if (verbose >= 2)
 			fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
 		return -1;
 	}

 	if (setsockopt(sfd, SOL_SOCKET, SO_SNDBUF, (void*)&bufsize, sizeof(int)) == -1) {
 		perror("Could not set send buffer for socket");
 	}

 	if (setsockopt(sfd, SOL_SOCKET, SO_RCVBUF, (void*)&bufsize, sizeof(int)) == -1) {
 		perror("Could not set receive buffer for socket");
 	}

 #ifdef SO_NOSIGPIPE
 	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
 		perror("setsockopt()");
 		socket_close(sfd);
 		return -1;
 	}
 #endif
 	// and connect to 'filename'
 	name.sun_family = AF_UNIX;
 	strncpy(name.sun_path, filename, sizeof(name.sun_path));
 	name.sun_path[sizeof(name.sun_path) - 1] = 0;

 	if (connect(sfd, (struct sockaddr*)&name, sizeof(name)) < 0) {
 		socket_close(sfd);
 		if (verbose >= 2)
 			fprintf(stderr, "%s: connect: %s\n", __func__,
 					strerror(errno));
 		return -1;
 	}

 	return sfd;
 }
 #endif

 int socket_create(uint16_t port)
 {
 	int sfd = -1;
 	int yes = 1;
 #ifdef WIN32
 	WSADATA wsa_data;
 	if (!wsa_init) {
 		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
 			fprintf(stderr, "WSAStartup failed!\n");
 			ExitProcess(-1);
 		}
 		wsa_init = 1;
 	}
 #endif
 	struct sockaddr_in saddr;

 	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
 		perror("socket()");
 		return -1;
 	}

 	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
 		perror("setsockopt()");
 		socket_close(sfd);
 		return -1;
 	}

 #ifdef SO_NOSIGPIPE
 	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
 		perror("setsockopt()");
 		socket_close(sfd);
 		return -1;
 	}
 #endif

 	memset((void *) &saddr, 0, sizeof(saddr));
 	saddr.sin_family = AF_INET;
 	saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 	saddr.sin_port = htons(port);

 	if (0 > bind(sfd, (struct sockaddr *) &saddr, sizeof(saddr))) {
 		perror("bind()");
 		socket_close(sfd);
 		return -1;
 	}

 	if (listen(sfd, 1) == -1) {
 		perror("listen()");
 		socket_close(sfd);
 		return -1;
 	}

 	return sfd;
 }

 int socket_connect(const char *addr, uint16_t port)
 {
 	int sfd = -1;
 	int yes = 1;
 	int bufsize = 0x20000;
 	struct addrinfo hints;
 	struct addrinfo *result, *rp;
 	char portstr[8];
 	int res;
 #ifdef WIN32
 	u_long l_yes = 1;
 	u_long l_no = 0;
 	WSADATA wsa_data;
 	if (!wsa_init) {
 		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
 			fprintf(stderr, "WSAStartup failed!\n");
 			ExitProcess(-1);
 		}
 		wsa_init = 1;
 	}
 #else
 	int flags = 0;
 #endif

 	if (!addr) {
 		errno = EINVAL;
 		return -1;
 	}

 	memset(&hints, '\0', sizeof(struct addrinfo));
 	hints.ai_family = AF_UNSPEC;
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_flags = 0;
 	hints.ai_protocol = IPPROTO_TCP;

 	sprintf(portstr, "%d", port);

 	res = getaddrinfo(addr, portstr, &hints, &result);
 	if (res != 0) {
 		fprintf(stderr, "%s: getaddrinfo: %s\n", __func__, gai_strerror(res));
 		return -1;
 	}

 	for (rp = result; rp != NULL; rp = rp->ai_next) {
 		sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 		if (sfd == -1) {
 			continue;
 		}

 		if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
 			perror("setsockopt()");
 			close(sfd);
 			continue;
 		}

 #ifdef WIN32
 		ioctlsocket(sfd, FIONBIO, &l_yes);
 #else
 		fcntl(sfd, F_SETFL, O_NONBLOCK);
 #endif

 		if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1) {
 			break;
 		}
 #ifdef WIN32
 		if (WSAGetLastError() == WSAEWOULDBLOCK)
 #else
 		if (errno == EINPROGRESS)
 #endif
 		{
 			fd_set fds;
 			FD_ZERO(&fds);
 			FD_SET(sfd, &fds);

 			struct timeval timeout;
 			timeout.tv_sec = CONNECT_TIMEOUT / 1000;
 			timeout.tv_usec = (CONNECT_TIMEOUT - (timeout.tv_sec * 1000)) * 1000;
 			if (select(sfd + 1, NULL, &fds, NULL, &timeout) == 1) {
 				int so_error;
 				socklen_t len = sizeof(so_error);
 				getsockopt(sfd, SOL_SOCKET, SO_ERROR, (void*)&so_error, &len);
 				if (so_error == 0) {
 					break;
 				}
 			}
 		}
 		socket_close(sfd);
 	}

 	freeaddrinfo(result);

 	if (rp == NULL) {
 		if (verbose >= 2)
 			fprintf(stderr, "%s: Could not connect to %s:%d\n", __func__, addr, port);
 		return -1;
 	}

 #ifdef WIN32
 	ioctlsocket(sfd, FIONBIO, &l_no);
 #else
 	flags = fcntl(sfd, F_GETFL, 0);
 	fcntl(sfd, F_SETFL, flags & (~O_NONBLOCK));
 #endif

 #ifdef SO_NOSIGPIPE
 	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
 		perror("setsockopt()");
 		socket_close(sfd);
 		return -1;
 	}
 #endif

 	if (setsockopt(sfd, IPPROTO_TCP, TCP_NODELAY, (void*)&yes, sizeof(int)) == -1) {
 		perror("Could not set TCP_NODELAY on socket");
 	}

 	if (setsockopt(sfd, SOL_SOCKET, SO_SNDBUF, (void*)&bufsize, sizeof(int)) == -1) {
 		perror("Could not set send buffer for socket");
 	}

 	if (setsockopt(sfd, SOL_SOCKET, SO_RCVBUF, (void*)&bufsize, sizeof(int)) == -1) {
 		perror("Could not set receive buffer for socket");
 	}

 	return sfd;
 }

 int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout)
 {
 	fd_set fds;
 	int sret;
 	int eagain;
 	struct timeval to;
 	struct timeval *pto;

 	if (fd < 0) {
 		if (verbose >= 2)
 			fprintf(stderr, "ERROR: invalid fd in check_fd %d\n", fd);
 		return -1;
 	}

 	FD_ZERO(&fds);
 	FD_SET(fd, &fds);

 	if (timeout > 0) {
 		to.tv_sec = (time_t) (timeout / 1000);
 		to.tv_usec = (time_t) ((timeout - (to.tv_sec * 1000)) * 1000);
 		pto = &to;
 	} else {
 		pto = NULL;
 	}

 	sret = -1;

 	do {
 		eagain = 0;
 		switch (fdm) {
 		case FDM_READ:
 			sret = select(fd + 1, &fds, NULL, NULL, pto);
 			break;
 		case FDM_WRITE:
 			sret = select(fd + 1, NULL, &fds, NULL, pto);
 			break;
 		case FDM_EXCEPT:
 			sret = select(fd + 1, NULL, NULL, &fds, pto);
 			break;
 		default:
 			return -1;
 		}

 		if (sret < 0) {
 			switch (errno) {
 			case EINTR:
 				// interrupt signal in select
 				if (verbose >= 2)
 					fprintf(stderr, "%s: EINTR\n", __func__);
 				eagain = 1;
 				break;
 			case EAGAIN:
 				if (verbose >= 2)
 					fprintf(stderr, "%s: EAGAIN\n", __func__);
 				break;
 			default:
 				if (verbose >= 2)
 					fprintf(stderr, "%s: select failed: %s\n", __func__,
 							strerror(errno));
 				return -1;
 			}
 		}
 	} while (eagain);

 	return sret;
 }

 int socket_accept(int fd, uint16_t port)
 {
 #ifdef WIN32
 	int addr_len;
 #else
 	socklen_t addr_len;
 #endif
 	int result;
 	struct sockaddr_in addr;

 	memset(&addr, 0, sizeof(addr));
 	addr.sin_family = AF_INET;
 	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 	addr.sin_port = htons(port);

 	addr_len = sizeof(addr);
 	result = accept(fd, (struct sockaddr*)&addr, &addr_len);

 	return result;
 }

 int socket_shutdown(int fd, int how)
 {
 	return shutdown(fd, how);
 }

 int socket_close(int fd) {
 #ifdef WIN32
 	return closesocket(fd);
 #else
 	return close(fd);
 #endif
 }

 int socket_receive(int fd, void *data, size_t length)
 {
 	return socket_receive_timeout(fd, data, length, 0, RECV_TIMEOUT);
 }

 int socket_peek(int fd, void *data, size_t length)
 {
 	return socket_receive_timeout(fd, data, length, MSG_PEEK, RECV_TIMEOUT);
 }

 int socket_receive_timeout(int fd, void *data, size_t length, int flags,
 					 unsigned int timeout)
 {
 	int res;
 	int result;

 	// check if data is available
 	res = socket_check_fd(fd, FDM_READ, timeout);
 	if (res <= 0) {
 		return res;
 	}
 	// if we get here, there _is_ data available
 	result = recv(fd, data, length, flags);
 	if (res > 0 && result == 0) {
 		// but this is an error condition
 		if (verbose >= 3)
 			fprintf(stderr, "%s: fd=%d recv returned 0\n", __func__, fd);
 		return -EAGAIN;
 	}
 	if (result < 0) {
 		return -errno;
 	}
 	return result;
 }

 int socket_send(int fd, void *data, size_t length)
 {
 	int flags = 0;
 #ifdef MSG_NOSIGNAL
 	flags |= MSG_NOSIGNAL;
 #endif
 	return send(fd, data, length, flags);
 }
	/*
	* socket.c
	*
	* Copyright (C) 2012-2018 Nikias Bassen <nikias@gmx.li>
	* Copyright (C) 2012 Martin Szulecki <m.szulecki@libimobiledevice.org>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library 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
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#ifdef HAVE_CONFIG_H
	#include <config.h>
	#endif
	#include <stdio.h>
	#include <stddef.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <errno.h>
	#include <sys/time.h>
	#include <sys/stat.h>
	#ifdef WIN32
	#include <winsock2.h>
	#include <ws2tcpip.h>
	#include <windows.h>
	static int wsa_init = 0;
	#else
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <netinet/in.h>
	#include <netinet/tcp.h>
	#include <netdb.h>
	#include <arpa/inet.h>
	#include <fcntl.h>
	#endif
	#include "socket.h"

	#define RECV_TIMEOUT 20000
	#define CONNECT_TIMEOUT 5000

	static int verbose = 0;

	void socket_set_verbose(int level)
	{
	verbose = level;
	}

	#ifndef WIN32
	int socket_create_unix(const char *filename)
	{
	struct sockaddr_un name;
	int sock;
	#ifdef SO_NOSIGPIPE
	int yes = 1;
	#endif

	// remove if still present
	unlink(filename);

	/* Create the socket. */
	sock = socket(PF_UNIX, SOCK_STREAM, 0);
	if (sock < 0) {
	perror("socket");
	return -1;
	}

	#ifdef SO_NOSIGPIPE
	if (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	socket_close(sock);
	return -1;
	}
	#endif

	/* Bind a name to the socket. */
	name.sun_family = AF_UNIX;
	strncpy(name.sun_path, filename, sizeof(name.sun_path));
	name.sun_path[sizeof(name.sun_path) - 1] = '\0';

	if (bind(sock, (struct sockaddr*)&name, sizeof(name)) < 0) {
	perror("bind");
	socket_close(sock);
	return -1;
	}

	if (listen(sock, 10) < 0) {
	perror("listen");
	socket_close(sock);
	return -1;
	}

	return sock;
	}

	int socket_connect_unix(const char *filename)
	{
	struct sockaddr_un name;
	int sfd = -1;
	struct stat fst;
	#ifdef SO_NOSIGPIPE
	int yes = 1;
	#endif
	int bufsize = 0x20000;

	// check if socket file exists...
	if (stat(filename, &fst) != 0) {
	if (verbose >= 2)
	fprintf(stderr, "%s: stat '%s': %s\n", __func__, filename,
	strerror(errno));
	return -1;
	}
	// ... and if it is a unix domain socket
	if (!S_ISSOCK(fst.st_mode)) {
	if (verbose >= 2)
	fprintf(stderr, "%s: File '%s' is not a socket!\n", __func__,
	filename);
	return -1;
	}
	// make a new socket
	if ((sfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
	if (verbose >= 2)
	fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
	return -1;
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_SNDBUF, (void*)&bufsize, sizeof(int)) == -1) {
	perror("Could not set send buffer for socket");
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_RCVBUF, (void*)&bufsize, sizeof(int)) == -1) {
	perror("Could not set receive buffer for socket");
	}

	#ifdef SO_NOSIGPIPE
	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	socket_close(sfd);
	return -1;
	}
	#endif
	// and connect to 'filename'
	name.sun_family = AF_UNIX;
	strncpy(name.sun_path, filename, sizeof(name.sun_path));
	name.sun_path[sizeof(name.sun_path) - 1] = 0;

	if (connect(sfd, (struct sockaddr*)&name, sizeof(name)) < 0) {
	socket_close(sfd);
	if (verbose >= 2)
	fprintf(stderr, "%s: connect: %s\n", __func__,
	strerror(errno));
	return -1;
	}

	return sfd;
	}
	#endif

	int socket_create(uint16_t port)
	{
	int sfd = -1;
	int yes = 1;
	#ifdef WIN32
	WSADATA wsa_data;
	if (!wsa_init) {
	if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
	fprintf(stderr, "WSAStartup failed!\n");
	ExitProcess(-1);
	}
	wsa_init = 1;
	}
	#endif
	struct sockaddr_in saddr;

	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
	perror("socket()");
	return -1;
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	socket_close(sfd);
	return -1;
	}

	#ifdef SO_NOSIGPIPE
	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	socket_close(sfd);
	return -1;
	}
	#endif

	memset((void *) &saddr, 0, sizeof(saddr));
	saddr.sin_family = AF_INET;
	saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
	saddr.sin_port = htons(port);

	if (0 > bind(sfd, (struct sockaddr *) &saddr, sizeof(saddr))) {
	perror("bind()");
	socket_close(sfd);
	return -1;
	}

	if (listen(sfd, 1) == -1) {
	perror("listen()");
	socket_close(sfd);
	return -1;
	}

	return sfd;
	}

	int socket_connect(const char *addr, uint16_t port)
	{
	int sfd = -1;
	int yes = 1;
	int bufsize = 0x20000;
	struct addrinfo hints;
	struct addrinfo result, rp;
	char portstr[8];
	int res;
	#ifdef WIN32
	u_long l_yes = 1;
	u_long l_no = 0;
	WSADATA wsa_data;
	if (!wsa_init) {
	if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
	fprintf(stderr, "WSAStartup failed!\n");
	ExitProcess(-1);
	}
	wsa_init = 1;
	}
	#else
	int flags = 0;
	#endif

	if (!addr) {
	errno = EINVAL;
	return -1;
	}

	memset(&hints, '\0', sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = 0;
	hints.ai_protocol = IPPROTO_TCP;

	sprintf(portstr, "%d", port);

	res = getaddrinfo(addr, portstr, &hints, &result);
	if (res != 0) {
	fprintf(stderr, "%s: getaddrinfo: %s\n", __func__, gai_strerror(res));
	return -1;
	}

	for (rp = result; rp != NULL; rp = rp->ai_next) {
	sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
	if (sfd == -1) {
	continue;
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	close(sfd);
	continue;
	}

	#ifdef WIN32
	ioctlsocket(sfd, FIONBIO, &l_yes);
	#else
	fcntl(sfd, F_SETFL, O_NONBLOCK);
	#endif

	if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1) {
	break;
	}
	#ifdef WIN32
	if (WSAGetLastError() == WSAEWOULDBLOCK)
	#else
	if (errno == EINPROGRESS)
	#endif
	{
	fd_set fds;
	FD_ZERO(&fds);
	FD_SET(sfd, &fds);

	struct timeval timeout;
	timeout.tv_sec = CONNECT_TIMEOUT / 1000;
	timeout.tv_usec = (CONNECT_TIMEOUT - (timeout.tv_sec * 1000)) * 1000;
	if (select(sfd + 1, NULL, &fds, NULL, &timeout) == 1) {
	int so_error;
	socklen_t len = sizeof(so_error);
	getsockopt(sfd, SOL_SOCKET, SO_ERROR, (void*)&so_error, &len);
	if (so_error == 0) {
	break;
	}
	}
	}
	socket_close(sfd);
	}

	freeaddrinfo(result);

	if (rp == NULL) {
	if (verbose >= 2)
	fprintf(stderr, "%s: Could not connect to %s:%d\n", __func__, addr, port);
	return -1;
	}

	#ifdef WIN32
	ioctlsocket(sfd, FIONBIO, &l_no);
	#else
	flags = fcntl(sfd, F_GETFL, 0);
	fcntl(sfd, F_SETFL, flags & (~O_NONBLOCK));
	#endif

	#ifdef SO_NOSIGPIPE
	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
	perror("setsockopt()");
	socket_close(sfd);
	return -1;
	}
	#endif

	if (setsockopt(sfd, IPPROTO_TCP, TCP_NODELAY, (void*)&yes, sizeof(int)) == -1) {
	perror("Could not set TCP_NODELAY on socket");
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_SNDBUF, (void*)&bufsize, sizeof(int)) == -1) {
	perror("Could not set send buffer for socket");
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_RCVBUF, (void*)&bufsize, sizeof(int)) == -1) {
	perror("Could not set receive buffer for socket");
	}

	return sfd;
	}

	int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout)
	{
	fd_set fds;
	int sret;
	int eagain;
	struct timeval to;
	struct timeval *pto;

	if (fd < 0) {
	if (verbose >= 2)
	fprintf(stderr, "ERROR: invalid fd in check_fd %d\n", fd);
	return -1;
	}

	FD_ZERO(&fds);
	FD_SET(fd, &fds);

	if (timeout > 0) {
	to.tv_sec = (time_t) (timeout / 1000);
	to.tv_usec = (time_t) ((timeout - (to.tv_sec * 1000)) * 1000);
	pto = &to;
	} else {
	pto = NULL;
	}

	sret = -1;

	do {
	eagain = 0;
	switch (fdm) {
	case FDM_READ:
	sret = select(fd + 1, &fds, NULL, NULL, pto);
	break;
	case FDM_WRITE:
	sret = select(fd + 1, NULL, &fds, NULL, pto);
	break;
	case FDM_EXCEPT:
	sret = select(fd + 1, NULL, NULL, &fds, pto);
	break;
	default:
	return -1;
	}

	if (sret < 0) {
	switch (errno) {
	case EINTR:
	// interrupt signal in select
	if (verbose >= 2)
	fprintf(stderr, "%s: EINTR\n", __func__);
	eagain = 1;
	break;
	case EAGAIN:
	if (verbose >= 2)
	fprintf(stderr, "%s: EAGAIN\n", __func__);
	break;
	default:
	if (verbose >= 2)
	fprintf(stderr, "%s: select failed: %s\n", __func__,
	strerror(errno));
	return -1;
	}
	}
	} while (eagain);

	return sret;
	}

	int socket_accept(int fd, uint16_t port)
	{
	#ifdef WIN32
	int addr_len;
	#else
	socklen_t addr_len;
	#endif
	int result;
	struct sockaddr_in addr;

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
	addr.sin_port = htons(port);

	addr_len = sizeof(addr);
	result = accept(fd, (struct sockaddr*)&addr, &addr_len);

	return result;
	}

	int socket_shutdown(int fd, int how)
	{
	return shutdown(fd, how);
	}

	int socket_close(int fd) {
	#ifdef WIN32
	return closesocket(fd);
	#else
	return close(fd);
	#endif
	}

	int socket_receive(int fd, void *data, size_t length)
	{
	return socket_receive_timeout(fd, data, length, 0, RECV_TIMEOUT);
	}

	int socket_peek(int fd, void *data, size_t length)
	{
	return socket_receive_timeout(fd, data, length, MSG_PEEK, RECV_TIMEOUT);
	}

	int socket_receive_timeout(int fd, void *data, size_t length, int flags,
	unsigned int timeout)
	{
	int res;
	int result;

	// check if data is available
	res = socket_check_fd(fd, FDM_READ, timeout);
	if (res <= 0) {
	return res;
	}
	// if we get here, there _is_ data available
	result = recv(fd, data, length, flags);
	if (res > 0 && result == 0) {
	// but this is an error condition
	if (verbose >= 3)
	fprintf(stderr, "%s: fd=%d recv returned 0\n", __func__, fd);
	return -EAGAIN;
	}
	if (result < 0) {
	return -errno;
	}
	return result;
	}

	int socket_send(int fd, void *data, size_t length)
	{
	int flags = 0;
	#ifdef MSG_NOSIGNAL
	flags \|= MSG_NOSIGNAL;
	#endif
	return send(fd, data, length, flags);
	}