1 #include "nonblocksockets.h"

     2 #include "logging.h"

     3 #include <stdlib.h>

     4 

     5 static uint32_t get_peer_ip(TCPsocket sock) {

     6 	IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);

     7 	return SDLNet_Read32(&addr->host);

     8 }

     9 

    10 static bool connection_is_local(TCPsocket sock) {

    11 	return get_peer_ip(sock) == (uint32_t)((127UL<<24)+1); // 127.0.0.1

    12 }

    13 

    14 void flib_nbsocket_close(NonBlockSocket *nbsockptr) {

    15 	NonBlockSocket nbsock = *nbsockptr;

    16 	if(nbsock!=NULL) {

    17 		SDLNet_DelSocket(nbsock->sockset, (SDLNet_GenericSocket)nbsock->sock);

    18 		SDLNet_TCP_Close(nbsock->sock);

    19 		SDLNet_FreeSocketSet(nbsock->sockset);

    20 	}

    21 	free(nbsock);

    22 	*nbsockptr = NULL;

    23 }

    24 

    25 NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly) {

    26 	NonBlockSocket result = NULL;

    27 	if(!listensocket) {

    28 		flib_log_e("Attempt to accept a connection on a NULL socket.");

    29 		return NULL;

    30 	}

    31 	while(result==NULL) {

    32 		TCPsocket sock = SDLNet_TCP_Accept(listensocket);

    33 		if(!sock) {

    34 			// No incoming connections

    35 			return NULL;

    36 		}

    37 		if(localOnly && !connection_is_local(sock)) {

    38 			flib_log_i("Rejected nonlocal connection attempt from %s", flib_format_ip(get_peer_ip(sock)));

    39 			SDLNet_TCP_Close(sock);

    40 		} else {

    41 			result = malloc(sizeof(_NonBlockSocket));

    42 			if(result==NULL) {

    43 				flib_log_e("Out of memory!");

    44 				SDLNet_TCP_Close(sock);

    45 				return NULL;

    46 			}

    47 			result->sock = sock;

    48 			result->sockset = SDLNet_AllocSocketSet(1);

    49 			if(result->sockset==NULL) {

    50 				flib_log_e("Out of memory!");

    51 				SDLNet_TCP_Close(sock);

    52 				free(result);

    53 				return NULL;

    54 			}

    55 			SDLNet_AddSocket(result->sockset, (SDLNet_GenericSocket)result->sock);

    56 		}

    57 	}

    58 	return result;

    59 }

    60 

    61 int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen) {

    62 	if(!sock) {

    63 		flib_log_e("Attempt to receive on a NULL socket.");

    64 		return -1;

    65 	}

    66 	int readySockets = SDLNet_CheckSockets(sock->sockset, 0);

    67 	if(readySockets>0) {

    68 		int size = SDLNet_TCP_Recv(sock->sock, data, maxlen);

    69 		return size>0 ? size : -1;

    70 	} else if(readySockets==0) {

    71 		return 0;

    72 	} else {

    73 		flib_log_e("Error in select system call: %s", SDLNet_GetError());

    74 		return -1;

    75 	}

    76 }