1 /**
2 * libqcproto: Vypress/QChat protocol interface library
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19 /*
20 * QCS: qChat 1.6/VypressChat link interface
21 *
22 * link module
23 *
24 * (c) Saulius Menkevicius 2001-2004
25 */
26
27 #include <assert.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <errno.h>
32
33 #ifdef _WIN32
34 /* Win32 system */
35 #include <windows.h>
36 #include <winsock2.h>
37 #include <ws2tcpip.h>
38 #else
39 /* UNIX system */
40 #include <sys/types.h>
41 #include <netinet/in.h>
42 #include <sys/socket.h>
43 #include <sys/time.h>
44 #include <unistd.h>
45 #include <netdb.h>
46 #endif
47
48 #include "qcproto.h"
49 #include "link.h"
50 #include "supp.h"
51 #include "p_vypress.h"
52 #include "p_qchat.h"
53
54 #define VALID_ID(id) (id!=NULL)
55 #define ERRRET(err) if(1){errno=(err);return(0);}
56 #define ACTIVE_LINK(l) ((l)->rx >=0)
57 #define INVALIDATE(l) ((l)->rx=-1)
58
59 /* static variables */
60 static int link_count = 0;
61
62 /* internal routines */
63
64 /* link_bind_rx:
65 * binds link->rx to link->port
66 * returns:
67 * non-0 on error
68 */
69 static int
link_bind_rx(link_data * link)70 link_bind_rx(link_data * link)
71 {
72 struct sockaddr_in sa;
73
74 sa.sin_family = PF_INET;
75 sa.sin_addr.s_addr = htonl(INADDR_ANY);
76 sa.sin_port = htons(link->port);
77
78 return bind(link->rx, (struct sockaddr*)&sa, sizeof(sa))==-1;
79 }
80
81 /* link_setup_broadcast:
82 * setups link->tx to broadcast mode
83 * returns:
84 * non-0 on error
85 */
86 static int
link_setup_broadcast(link_data * link)87 link_setup_broadcast(link_data * link)
88 {
89 const int int_true = 1;
90
91 return setsockopt(link->tx, SOL_SOCKET, SO_BROADCAST,
92 (void*)&int_true, sizeof(int_true)
93 ) == -1;
94 }
95
96 /* link_setup_multicast:
97 * setups link->tx to multicast mode
98 * returns:
99 * non-0 on error
100 */
101 static int
link_setup_multicast(link_data * link)102 link_setup_multicast(link_data * link)
103 {
104 struct ip_mreq mreq;
105 unsigned char opt;
106
107 /* set IP_MULTICAST_LOOP to 1, so our host receives
108 * the messages we send
109 */
110 opt = 1;
111 if(setsockopt( link->tx, IPPROTO_IP, IP_MULTICAST_LOOP,
112 (void*)&opt, sizeof(opt)) != 0)
113 return 1;
114
115 /* set IP_MULTICAST_TTL to 32, that is the packets
116 * will go through 32 routers before getting scrapped
117 */
118 opt = 32;
119 if(setsockopt( link->tx, IPPROTO_IP, IP_MULTICAST_TTL,
120 (void*)&opt, sizeof(opt)) != 0)
121 return 1;
122
123
124 /* set our group membership */
125 mreq.imr_multiaddr.s_addr = htonl(link->broadcast_addr);
126 mreq.imr_interface.s_addr = INADDR_ANY;
127 if(setsockopt( link->rx, IPPROTO_IP, IP_ADD_MEMBERSHIP,
128 (void*)&mreq, sizeof(mreq)) != 0)
129 return 1;
130
131 return 0; /* multicast setup */
132 }
133
134 /** API implementation */
qcs_open(enum qcs_proto proto,enum qcs_proto_opt proto_opt,unsigned long broadcast_addr,unsigned short port)135 qcs_link qcs_open(
136 enum qcs_proto proto,
137 enum qcs_proto_opt proto_opt,
138 unsigned long broadcast_addr,
139 unsigned short port)
140 {
141 const int int_true = 1;
142 int error;
143 link_data * link;
144
145 /* check params */
146 if(proto >= QCS_PROTO_NUM)
147 ERRRET(ENOSYS);
148
149 /* alloc and setup `link_data' struct */
150 link = malloc(sizeof(link_data));
151 if(link==NULL)
152 ERRRET(ENOMEM);
153
154 link->proto = proto;
155 link->port = port ? port: 8167;
156 link->broadcast_addr = broadcast_addr;
157
158 /* alloc sockets */
159 link->tx = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
160 if(link->tx < 0) {
161 free(link);
162 #ifdef WIN32
163 errno = EINVAL;
164 #endif
165 return NULL;
166 }
167
168 /* setup rx */
169 link->rx = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
170 if(link->rx < 1) {
171 close(link->tx);
172 free(link);
173 #ifdef WIN32
174 errno = EINVAL;
175 #endif
176 return NULL;
177 }
178
179 #ifdef WIN32
180 /* on win32, we can setup the rx socket so, that we can use
181 * multiple clients on the same pc simultaneously
182 */
183 setsockopt(link->rx, SOL_SOCKET, SO_REUSEADDR,
184 (void*)&int_true, sizeof(int_true));
185 #endif
186 /* bind the rx socket to the port specified
187 */
188 if(link_bind_rx(link)) {
189 close(link->rx);
190 close(link->tx);
191 free(link);
192 #ifdef WIN32
193 errno = EINVAL;
194 #endif
195 return NULL;
196 }
197
198 /* setup link to multicast/broadcast mode, as specified
199 */
200 if(proto_opt & QCS_PROTO_OPT_MULTICAST)
201 error = link_setup_multicast(link);
202 else error = link_setup_broadcast(link);
203 if(error) {
204 close(link->tx);
205 close(link->rx);
206 free(link);
207 #ifdef WIN32
208 errno = ENOSYS;
209 #endif
210 return NULL;
211 }
212
213 /* increase link count */
214 link_count ++;
215
216 /* return success */
217 return (qcs_link)link;
218 }
219
qcs_close(qcs_link link_id)220 int qcs_close(qcs_link link_id)
221 {
222 link_data * link = (link_data *)link_id;
223
224 /* check if link is valid */
225 if(!VALID_ID(link_id)) ERRRET(EINVAL);
226 if(!ACTIVE_LINK(link)) ERRRET(EINVAL);
227
228 /* shutdown sockets and free the struct */
229 close(link->rx);
230 close(link->tx);
231 free(link);
232
233 link_count--;
234 if( link_count==0 ) {
235 /* clean up duplicate buffer */
236 qcs__cleanup_dup();
237 }
238
239 return 1;
240 }
241
qcs_rxsocket(qcs_link link_id,int * p_rxsocket)242 int qcs_rxsocket(
243 qcs_link link_id,
244 int * p_rxsocket )
245 {
246 link_data * link = (link_data*)link_id;
247
248 if(!VALID_ID(link_id)) ERRRET(EINVAL);
249 if(!ACTIVE_LINK(link)) ERRRET(EINVAL);
250
251 *p_rxsocket = link->rx;
252 return 1;
253 }
254
qcs_waitinput(qcs_link link_id,int timeout_ms)255 int qcs_waitinput(
256 qcs_link link_id,
257 int timeout_ms )
258 {
259 link_data * link = (link_data *) link_id;
260 struct timeval tv;
261 fd_set fds;
262
263 // check if link is valid
264 if(!VALID_ID(link_id)) ERRRET(EINVAL);
265 if(!ACTIVE_LINK(link)) ERRRET(EINVAL);
266
267 // fill structs & select()
268 if(timeout_ms < 0) {
269 tv.tv_sec = 0;
270 tv.tv_usec = 0;
271 } else {
272 tv.tv_sec = timeout_ms / 1000;
273 tv.tv_usec = (timeout_ms % 1000) * 1000;
274 }
275
276 FD_ZERO(&fds);
277 FD_SET(link->rx, &fds);
278
279 return select(FD_SETSIZE, &fds, NULL, NULL, &tv);
280 }
281
qcs_send(qcs_link link_id,const qcs_msg * msg)282 int qcs_send(
283 qcs_link link_id,
284 const qcs_msg * msg )
285 {
286 char * datagram;
287 ssize_t datagram_len, datagram_sent;
288 struct sockaddr_in sab;
289 link_data * link = (link_data *)link_id;
290
291 // check link
292 if(!VALID_ID(link_id)) ERRRET(EINVAL);
293 if(!ACTIVE_LINK(link)) ERRRET(EINVAL);
294
295 // build proto message
296 switch(link->proto) {
297 case QCS_PROTO_VYPRESS:
298 datagram = qcs__make_vypress_msg(msg, &datagram_len);
299 break;
300 case QCS_PROTO_QCHAT:
301 datagram = qcs__make_qchat_msg(msg, &datagram_len);
302 break;
303 default:
304 ERRRET(ENOSYS);
305 break;
306 }
307 if(datagram==NULL)
308 ERRRET(EINVAL);
309
310 sab.sin_family = PF_INET;
311 sab.sin_port = htons(link->port);
312 sab.sin_addr.s_addr = htonl(link->broadcast_addr);
313 datagram_sent = sendto(
314 link->tx, datagram, datagram_len, 0,
315 (struct sockaddr*)&sab, sizeof(sab));
316
317 free(datagram);
318
319 if(datagram_sent != datagram_len)
320 ERRRET(ENETUNREACH);
321
322 return 1;
323 }
324
qcs_recv(qcs_link link_id,qcs_msg * msg)325 int qcs_recv(
326 qcs_link link_id,
327 qcs_msg * msg )
328 {
329 link_data * link = (link_data *)link_id;
330 char * buff;
331
332 struct sockaddr_in sa;
333 socklen_t sa_len;
334 ssize_t dgram_size;
335 int parse_ok;
336
337 if(msg==NULL) ERRRET(EINVAL);
338
339 if(!VALID_ID(link_id)) ERRRET(EINVAL);
340 if(!ACTIVE_LINK(link)) ERRRET(EINVAL);
341
342 buff = (char*) malloc(QCP_MAXUDPSIZE+0x10);
343 if(buff==NULL) ERRRET(ENOMEM);
344
345 /* receive data of the message */
346 sa_len = sizeof(sa);
347 dgram_size = recvfrom(
348 link->rx, (void*)buff, QCP_MAXUDPSIZE, 0,
349 (struct sockaddr*)&sa, &sa_len
350 );
351
352 /* fill in message source address */
353 msg->src_ip = ntohl(sa.sin_addr.s_addr);
354
355 /* check if msg is too long for us to process:
356 * just strip it down. we guess this was the last
357 * ascii field, in proto msg, that was soo long.
358 */
359 if(dgram_size > QCP_MAXUDPSIZE)
360 *(char*)(buff+QCP_MAXUDPSIZE-1) = '\0';
361
362 /* failure */
363 if(dgram_size < 0) {
364 free(buff);
365 return 0;
366 }
367
368 /* parse the message */
369 switch(link->proto) {
370 case QCS_PROTO_QCHAT:
371 parse_ok = qcs__parse_qchat_msg(buff, dgram_size, msg);
372 break;
373 case QCS_PROTO_VYPRESS:
374 parse_ok = qcs__parse_vypress_msg(buff, dgram_size, msg);
375 break;
376 default: break;
377 }
378
379 /* cleanup */
380 free((void*)buff);
381 return parse_ok;
382 }
383
qcs_newmsg()384 qcs_msg * qcs_newmsg()
385 {
386 qcs_msg * msg = malloc(sizeof(qcs_msg));
387 if(msg==NULL)
388 return NULL;
389
390 msg->msg = QCS_MSG_INVALID;
391 msg->umode = QCS_UMODE_INVALID;
392 msg->uactive = 1;
393 msg->src = msg->dst = msg->text = msg->supp = msg->chan = NULL;
394
395 return msg;
396 }
397
qcs_deletemsg(qcs_msg * msg)398 void qcs_deletemsg( qcs_msg * msg )
399 {
400 if(msg==NULL) return;
401
402 if( msg->src ) free( msg->src );
403 if( msg->dst ) free( msg->dst );
404 if( msg->text ) free( msg->text );
405 if( msg->supp ) free( msg->supp );
406 if( msg->chan ) free( msg->chan );
407
408 free( msg );
409 }
410
qcs_msgset(qcs_msg * msg,enum qcs_textid which,const char * new_text)411 int qcs_msgset(
412 qcs_msg * msg,
413 enum qcs_textid which,
414 const char * new_text )
415 {
416 char ** ptext, * new_p;
417 size_t slen;
418
419 if(!msg) {
420 errno = EINVAL;
421 return 0;
422 }
423
424 switch(which) {
425 case QCS_SRC: ptext = &msg->src; break;
426 case QCS_DST: ptext = &msg->dst; break;
427 case QCS_TEXT: ptext = &msg->text; break;
428 case QCS_SUPP: ptext = &msg->supp; break;
429 case QCS_CHAN: ptext = &msg->chan; break;
430 default:
431 errno = EINVAL;
432 return 0;
433 }
434
435 if(*ptext==NULL && new_text==NULL) {
436 /* we have nothing to set here */
437 return 1;
438 }
439
440 /* try to allocate new space, if we have to
441 * before we damage something
442 */
443 if(new_text) {
444 slen = strlen(new_text);
445 new_p = malloc(slen + 1);
446 if(new_p==NULL) {
447 /* return -- out of mem */
448 errno = ENOMEM;
449 return 0;
450 }
451 memcpy((void*)new_p, (void*)new_text, slen + 1);
452 }
453
454 /* clear previous text */
455 if(*ptext!=NULL) {
456 free((void*)*ptext);
457 *ptext = NULL;
458
459 /* return if we have nothing to set */
460 if(new_text==NULL) {
461 return 1;
462 }
463 }
464
465 /* set new text */
466 *ptext = new_p;
467
468 return 1;
469 }
470