1 /*

     2  * Hedgewars, a free turn based strategy game

     3  * Copyright (C) 2012 Simeon Maxein <smaxein@googlemail.com>

     4  *

     5  * This program is free software; you can redistribute it and/or

     6  * modify it under the terms of the GNU General Public License

     7  * as published by the Free Software Foundation; either version 2

     8  * of the License, or (at your option) any later version.

     9  *

    10  * This program is distributed in the hope that it will be useful,

    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    13  * GNU General Public License for more details.

    14  *

    15  * You should have received a copy of the GNU General Public License

    16  * along with this program; if not, write to the Free Software

    17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

    18  */

    19 

    20 #include "netbase.h"

    21 #include "../util/buffer.h"

    22 #include "../util/logging.h"

    23 #include "../util/util.h"

    24 #include "../socket.h"

    25 

    26 #include <string.h>

    27 #include <stdbool.h>

    28 #include <stdlib.h>

    29 #include <stdio.h>

    30 

    31 #define NET_READBUFFER_LIMIT (1024*1024)

    32 

    33 struct _flib_netbase {

    34 	flib_vector *readBuffer;

    35 	flib_tcpsocket *sock;

    36 };

    37 

    38 flib_netbase *flib_netbase_create(const char *server, uint16_t port) {

    39 	if(log_badargs_if2(server==NULL, port==0)) {

    40 		return NULL;

    41 	}

    42 

    43 	flib_netbase *result = NULL;

    44 	flib_netbase *newNet =  flib_calloc(1, sizeof(flib_netbase));

    45 

    46 	if(newNet) {

    47 		newNet->readBuffer = flib_vector_create();

    48 		newNet->sock = flib_socket_connect(server, port);

    49 		if(newNet->readBuffer && newNet->sock) {

    50 			flib_log_i("Connected to server %s:%u", server, (unsigned)port);

    51 			result = newNet;

    52 			newNet = NULL;

    53 		}

    54 	}

    55 	flib_netbase_destroy(newNet);

    56 

    57 	return result;

    58 }

    59 

    60 void flib_netbase_destroy(flib_netbase *net) {

    61 	if(net) {

    62 		flib_socket_close(net->sock);

    63 		flib_vector_destroy(net->readBuffer);

    64 		free(net);

    65 	}

    66 }

    67 

    68 bool flib_netbase_connected(flib_netbase *net) {

    69 	if(!log_badargs_if(net==NULL) && net->sock) {

    70 		return true;

    71 	}

    72 	return false;

    73 }

    74 

    75 /**

    76  * Parses and returns a message, and removes it from the vector.

    77  */

    78 static flib_netmsg *parseMessage(flib_vector *vec) {

    79 	const uint8_t *partStart = flib_vector_data(vec);

    80 	const uint8_t *end = partStart+flib_vector_size(vec);

    81 	flib_netmsg *result = flib_netmsg_create();

    82 	if(!result) {

    83 		return NULL;

    84 	}

    85 

    86 	while(1) {

    87 		const uint8_t *partEnd = memchr(partStart, '\n', end-partStart);

    88 		if(!partEnd) {

    89 			// message incomplete

    90 			flib_netmsg_destroy(result);

    91 			return NULL;

    92 		} else if(partEnd-partStart == 0) {

    93 			// Zero-length part, message end marker. Remove the message from the vector.

    94 			uint8_t *vectorStart = flib_vector_data(vec);

    95 			size_t msgLen = partEnd+1-vectorStart;

    96 			memmove(vectorStart, partEnd+1, flib_vector_size(vec)-msgLen);

    97 			flib_vector_resize(vec, flib_vector_size(vec)-msgLen);

    98 			return result;

    99 		} else {

   100 			if(flib_netmsg_append_part(result, partStart, partEnd-partStart)) {

   101 				flib_netmsg_destroy(result);

   102 				return NULL;

   103 			}

   104 			partStart = partEnd+1; // Skip the '\n'

   105 		}

   106 	}

   107 	return NULL; // Never reached

   108 }

   109 

   110 /**

   111  * Receive some bytes and add them to the buffer.

   112  * Returns the number of bytes received.

   113  * Automatically closes the socket if an error occurs

   114  * and sets sock=NULL.

   115  */

   116 static int receiveToBuffer(flib_netbase *net) {

   117 	uint8_t buffer[256];

   118 	if(!net->sock) {

   119 		return 0;

   120 	} else if(flib_vector_size(net->readBuffer) > NET_READBUFFER_LIMIT) {

   121 		flib_log_e("Net connection closed: Net message too big");

   122 		flib_socket_close(net->sock);

   123 		net->sock = NULL;

   124 		return 0;

   125 	} else {

   126 		int size = flib_socket_nbrecv(net->sock, buffer, sizeof(buffer));

   127 		if(size>=0 && !flib_vector_append(net->readBuffer, buffer, size)) {

   128 			return size;

   129 		} else {

   130 			flib_socket_close(net->sock);

   131 			net->sock = NULL;

   132 			return 0;

   133 		}

   134 	}

   135 }

   136 

   137 flib_netmsg *flib_netbase_recv_message(flib_netbase *net) {

   138 	if(log_badargs_if(net==NULL)) {

   139 		return NULL;

   140 	}

   141 

   142 	flib_netmsg *msg;

   143 	while(!(msg=parseMessage(net->readBuffer))

   144 			&& receiveToBuffer(net)) {}

   145 

   146 	if(msg) {

   147 		return msg;

   148 	} else if(!net->sock && flib_vector_size(net->readBuffer)>0) {

   149 		// Connection is down and we didn't get a complete message, just flush the rest.

   150 		flib_vector_resize(net->readBuffer, 0);

   151 	}

   152 	return NULL;

   153 }

   154 

   155 static void logSentMsg(const uint8_t *data, size_t len) {

   156 	if(flib_log_isActive(FLIB_LOGLEVEL_DEBUG)) {

   157 		flib_log_d("[NET OUT][%03u]%*.*s",(unsigned)len, (unsigned)len, (unsigned)len, data);

   158 	}

   159 }

   160 

   161 int flib_netbase_send_raw(flib_netbase *net, const void *data, size_t len) {

   162 	if(log_badargs_if2(net==NULL, data==NULL && len>0)) {

   163 		return -1;

   164 	}

   165 	if(!net->sock) {

   166 		flib_log_w("flib_netbase_send_raw: Not connected.");

   167 		return -1;

   168 	}

   169 

   170 	if(flib_socket_send(net->sock, data, len) == len) {

   171 		logSentMsg(data, len);

   172 		return 0;

   173 	} else {

   174 		flib_log_w("Failed or incomplete write: net connection lost.");

   175 		flib_socket_close(net->sock);

   176 		net->sock = NULL;

   177 		return -1;

   178 	}

   179 }

   180 

   181 int flib_netbase_send_message(flib_netbase *net, const flib_netmsg *msg) {

   182 	if(log_badargs_if2(net==NULL, msg==NULL)) {

   183 		return -1;

   184 	}

   185 

   186 	size_t totalSize = 0;

   187 	for(int i=0; i<msg->partCount; i++) {

   188 		totalSize += strlen(msg->parts[i]) + 1;

   189 	}

   190 	totalSize++; // Last part ends in two '\n' instead of one

   191 

   192 	uint8_t *buffer = flib_malloc(totalSize);

   193 	if(!buffer) {

   194 		return -1;

   195 	}

   196 	size_t pos = 0;

   197 	for(int i=0; i<msg->partCount; i++) {

   198 		size_t partsize = strlen(msg->parts[i]);

   199 		memcpy(buffer+pos, msg->parts[i], partsize);

   200 		pos += partsize;

   201 		buffer[pos++] = '\n';

   202 	}

   203 	buffer[pos++] = '\n';

   204 	return flib_netbase_send_raw(net, buffer, pos);

   205 }

   206 

   207 int flib_netbase_sendf(flib_netbase *net, const char *format, ...) {

   208 	int result = -1;

   209 	if(!log_badargs_if2(net==NULL, format==NULL)) {

   210 		va_list argp;

   211 		va_start(argp, format);

   212 		char *buffer = flib_vasprintf(format, argp);

   213 		if(buffer) {

   214 			result = flib_netbase_send_raw(net, buffer, strlen(buffer));

   215 		}

   216 		free(buffer);

   217 		va_end(argp);

   218 	}

   219 	return result;

   220 }

   221 

   222 flib_netmsg *flib_netmsg_create() {

   223 	flib_netmsg *result = flib_calloc(1, sizeof(flib_netmsg));

   224 	if(result) {

   225 		result->partCount = 0;

   226 		result->parts = NULL;

   227 		return result;

   228 	} else {

   229 		return NULL;

   230 	}

   231 }

   232 

   233 void flib_netmsg_destroy(flib_netmsg *msg) {

   234 	if(msg) {

   235 		for(int i=0; i<msg->partCount; i++) {

   236 			free(msg->parts[i]);

   237 		}

   238 		free(msg->parts);

   239 		free(msg);

   240 	}

   241 }

   242 

   243 int flib_netmsg_append_part(flib_netmsg *msg, const void *part, size_t partlen) {

   244 	int result = -1;

   245 	if(!log_badargs_if2(msg==NULL, part==NULL && partlen>0)) {

   246 		char **newParts = realloc(msg->parts, (msg->partCount+1)*sizeof(*msg->parts));

   247 		if(newParts) {

   248 			msg->parts = newParts;

   249 			msg->parts[msg->partCount] = flib_malloc(partlen+1);

   250 			if(msg->parts[msg->partCount]) {

   251 				memcpy(msg->parts[msg->partCount], part, partlen);

   252 				msg->parts[msg->partCount][partlen] = 0;

   253 				msg->partCount++;

   254 				result = 0;

   255 			}

   256 		}

   257 	}

   258 	return result;

   259 }