// This file is part of SmallBASIC
//
// Network library (byte-stream sockets)
//
// This program is distributed under the terms of the GPL v2.0 or later
// Download the GNU Public License (GPL) from www.gnu.org
//
// Copyright(C) 2000 Nicholas Christopoulos
#include "common/sys.h"
#include "common/inet.h"
#include "common/device.h"
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(_Win32)
static int inetlib_init = 0;
#else
#include <sys/ioctl.h>
#include <netdb.h>
#include <netinet/in.h>
#endif
#ifndef socklen_t
#define socklen_t int
#endif
// the length of time (usec) to block waiting for an event
#define BLOCK_INTERVAL 250000
/**
* prepare to use the network
*/
int net_init() {
#if defined(_Win32)
if (!inetlib_init) {
inetlib_init = 1;
WSADATA wsadata;
if (WSAStartup(MAKEWORD(2, 0), &wsadata)) {
return 0;
}
return 1;
}
#endif
return 1;
}
/**
* stop using the network
*/
int net_close() {
#if defined(_Win32)
if (inetlib_init) {
WSACleanup();
inetlib_init = 0;
}
#endif
return 1;
}
/**
* sends a string to socket
*/
void net_print(socket_t s, const char *str) {
send(s, str, strlen(str), 0);
}
/**
* sends a string to socket
*/
void net_printf(socket_t s, const char *fmt, ...) {
char buf[1025];
va_list argp;
va_start(argp, fmt);
vsnprintf(buf, sizeof(buf), fmt, argp);
va_end(argp);
net_print(s, buf);
}
/**
* read the specified number of bytes from the socket
*/
int net_read(socket_t s, char *buf, int size) {
fd_set readfds;
struct timeval tv;
int rv;
// clear the set
FD_ZERO(&readfds);
while (1) {
FD_SET(s, &readfds);
tv.tv_sec = 0;
tv.tv_usec = BLOCK_INTERVAL;
rv = select(s + 1, &readfds, NULL, NULL, &tv);
if (rv == -1) {
// an error occured
return 0;
} else if (rv == 0) {
// timeout occured
if (0 != dev_events(0)) {
s = 0;
break;
}
} else {
// ready to read
return recv(s, buf, size, 0);
}
}
return 0;
}
/**
* read a string from a socket until a char from delim str found.
*/
int net_input(socket_t s, char *buf, int size, const char *delim) {
// wait for remote input without eating cpu
fd_set readfds;
struct timeval tv;
char ch;
int count = 0;
// clear the set
FD_ZERO(&readfds);
while (1) {
tv.tv_sec = 0;
tv.tv_usec = BLOCK_INTERVAL; // time is reset in select() call in linux
FD_SET(s, &readfds);
int rv = select(s + 1, &readfds, NULL, NULL, &tv);
if (rv == -1) {
return 0; // an error occured
} else if (rv == 0) {
// timeout occured - check for program break
if (0 != dev_events(0)) {
return 0;
}
} else if (FD_ISSET(s, &readfds)) {
// ready for reading
break;
}
}
FD_ZERO(&readfds);
memset(buf, 0, size);
while (count < size) {
int bytes = net_read(s, &ch, 1);
if (bytes <= 0) {
return count; // no more data
} else {
if (ch == 0) {
return count;
}
if (delim) {
if ((strchr(delim, ch) != NULL)) {
return count; // delimiter found
}
}
if (ch != '\015') { // ignore it
buf[count] = ch;
count += bytes; // actually ++
}
}
}
return count;
}
/**
* return true if there something waiting
*/
int net_peek(socket_t s) {
#if defined(_Win32)
unsigned long bytes;
ioctlsocket(s, FIONREAD, &bytes);
return (bytes > 0);
#else
int bytes;
ioctl(s, FIONREAD, &bytes);
return (bytes > 0);
#endif
}
/**
* connect to server and returns the socket
*/
socket_t net_connect(const char *server_name, int server_port) {
socket_t sock;
dword inaddr;
struct sockaddr_in ad;
struct hostent *hp;
net_init();
memset(&ad, 0, sizeof(ad));
ad.sin_family = AF_INET;
if ((inaddr = inet_addr(server_name)) == INADDR_NONE) {
hp = gethostbyname(server_name);
if (hp == NULL) {
return -1;
}
memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);
} else {
memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
}
ad.sin_port = htons(server_port);
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock <= 0) {
return sock;
}
if (connect(sock, (struct sockaddr *)&ad, sizeof(ad)) < 0) {
return -1;
}
return sock;
}
/**
* listen for an incoming connection on the given port and
* returns the socket once a connection has been established
*/
socket_t net_listen(int server_port) {
int listener;
struct sockaddr_in addr, remoteaddr;
socket_t s;
fd_set readfds;
struct timeval tv;
int rv;
int yes = 1;
// more info about listen sockets:
// http://beej.us/guide/bgnet/output/htmlsingle/bgnet.html#acceptman
net_init();
listener = socket(PF_INET, SOCK_STREAM, 0);
if (listener <= 0) {
return listener;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(server_port); // clients connect to this port
addr.sin_addr.s_addr = INADDR_ANY; // autoselect IP address
// prevent address already in use bind errors
if (setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, (const char*)&yes, sizeof(int)) == -1) {
return -1;
}
// set s up to be a server (listening) socket
if (bind(listener, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
return -1;
}
if (listen(listener, 1) == -1) {
return -1;
}
// clear the set
FD_ZERO(&readfds);
while (1) {
tv.tv_sec = 0; // block at 1 second intervals
tv.tv_usec = 500000; // time is reset in select() call in linux
FD_SET(listener, &readfds);
rv = select(listener + 1, &readfds, NULL, NULL, &tv);
if (rv == -1) {
s = 0;
break; // an error occured
} else if (rv == 0) {
// timeout occured - check for program break
if (0 != dev_events(0)) {
s = 0;
break;
}
} else if (FD_ISSET(listener, &readfds)) {
// connection is ready
socklen_t remoteaddr_len = sizeof(remoteaddr);
s = accept(listener, (struct sockaddr *)&remoteaddr, &remoteaddr_len);
break;
}
}
FD_ZERO(&readfds);
net_disconnect(listener);
return s;
}
/**
* disconnect the given network connection
*/
void net_disconnect(socket_t s) {
#if defined(_Win32)
closesocket(s);
#else
close(s);
#endif
}
