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1 /******************************************************************************/
2 /*                                                                            */
3 /*   Copyright (c) International Business Machines  Corp., 2006               */
4 /*                                                                            */
5 /*   This program is free software;  you can redistribute it and/or modify    */
6 /*   it under the terms of the GNU General Public License as published by     */
7 /*   the Free Software Foundation; either version 2 of the License, or        */
8 /*   (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                */
13 /*   the 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 
21 /*
22  * File:
23  *	ns-igmp_querier.c
24  *
25  * Description:
26  *	This utiltity sends IGMP queries.
27  *	(General Query, Multicast Address Specific Query
28  *	 or Multicast Address and Source Specific Query)
29  *
30  * Author:
31  *	Mitsuru Chinen <mitch@jp.ibm.com>
32  *
33  * History:
34  *	Apr 24 2006 - Created (Mitsuru Chinen)
35  *---------------------------------------------------------------------------*/
36 
37 /*
38  * Header Files
39  */
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <errno.h>
44 #include <netdb.h>
45 #include <signal.h>
46 #include <time.h>
47 #include <unistd.h>
48 #include <arpa/inet.h>
49 #include <net/if.h>
50 #include <netinet/in.h>
51 #include <netinet/igmp.h>
52 #include <sys/ioctl.h>
53 #include <sys/socket.h>
54 #include <sys/types.h>
55 
56 #include "ns-mcast.h"
57 #include "ns-traffic.h"
58 
59 /*
60  * Structure Definitions
61  */
62 struct igmp_info {
63 	uint32_t ifindex;
64 	struct igmpv3_query *query;
65 	double timeout;
66 	struct timespec interval;
67 };
68 
69 /*
70  * Gloval variables
71  */
72 char *program_name;		/* program name */
73 struct sigaction handler;	/* Behavior for a signal */
74 int catch_sighup;		/* When catch the SIGHUP, set to non-zero */
75 
76 /*
77  * Function: usage()
78  *
79  * Descripton:
80  *  Print the usage of this program. Then, terminate this program with
81  *  the specified exit value.
82  *
83  * Argument:
84  *  exit_value:	exit value
85  *
86  * Return value:
87  *  This function does not return.
88  */
usage(char * program_name,int exit_value)89 void usage(char *program_name, int exit_value)
90 {
91 	FILE *stream = stdout;	/* stream where the usage is output */
92 
93 	if (exit_value == EXIT_FAILURE)
94 		stream = stderr;
95 
96 	fprintf(stream, "%s [OPTION]\n"
97 		"\t-I ifname\tname of listening interface\n"
98 		"\t-m addr\tmulticast address\n"
99 		"\t-s addrs\tcomma separated array of Source Addresses\n"
100 		"\t-r value\tMax Resp Code\n"
101 		"\t-i value\tinterval [nanosec]\n"
102 		"\t-t value\ttimeout [sec]\n"
103 		"\t-o\t\tsend only one query\n"
104 		"\t-b\t\twork in the background\n"
105 		"\t-d\t\tdisplay debug informations\n"
106 		"\t-h\t\tdisplay this usage\n", program_name);
107 	exit(exit_value);
108 }
109 
110 /*
111  * Function: set_signal_flag()
112  *
113  * Description:
114  *  This function sets global variables accordig to signal
115  *
116  * Argument:
117  *  type: type of signal
118  *
119  * Return value:
120  *  None
121  */
set_signal_flag(int type)122 void set_signal_flag(int type)
123 {
124 	if (debug)
125 		fprintf(stderr, "Catch signal. type is %d\n", type);
126 
127 	switch (type) {
128 	case SIGHUP:
129 		catch_sighup = 1;
130 		handler.sa_handler = SIG_IGN;
131 		if (sigaction(type, &handler, NULL) < 0)
132 			fatal_error("sigaction()");
133 		break;
134 
135 	default:
136 		fprintf(stderr, "Unexpected signal (%d) is caught\n", type);
137 		exit(EXIT_FAILURE);
138 	}
139 }
140 
141 /*
142  * Function: create_query()
143  *
144  * Description:
145  *  This function create a igmpv3 query information.
146  *  This function allocates memory to store the information.
147  *
148  * Argument:
149  *   code:	Max Resp Code
150  *   maddr:	multicast address
151  *   saddrs:	comma separated array of the source addresses
152  *
153  * Return value:
154  *  pointer to allocated igmpv3_query structure
155  */
create_query(uint8_t code,char * maddr,char * saddrs)156 struct igmpv3_query *create_query(uint8_t code, char *maddr, char *saddrs)
157 {
158 	struct igmpv3_query *query;	/* pointer to igmpv3_query structure */
159 	uint16_t numsrc;	/* number of source address */
160 	size_t query_size;	/* size of igmpv3_query */
161 	struct in_addr ip;
162 	uint32_t idx;
163 	char *sp, *ep;
164 
165 	/* calculate the number of source address */
166 	if (saddrs == NULL) {
167 		numsrc = 0;
168 	} else {
169 		numsrc = 1;
170 		for (sp = saddrs; *sp != '\0'; sp++)
171 			if (*sp == ',')
172 				numsrc++;
173 	}
174 	if (debug)
175 		fprintf(stderr, "number of source address is %u\n", numsrc);
176 
177 	/* allocate memory for igmpv3_query structure */
178 	query_size = MY_IGMPV3_QUERY_SIZE(numsrc);
179 	query = (struct igmpv3_query *)calloc(1, query_size);
180 	if (query == NULL)
181 		fatal_error("calloc()");
182 
183 	/* substitute paramaters */
184 	query->type = IGMP_HOST_MEMBERSHIP_QUERY;
185 	query->code = code;
186 	query->csum = 0;	/* Calculate later */
187 	query->resv = 0;
188 	query->suppress = 0;
189 	query->qrv = 0;
190 	query->qqic = 0;
191 	query->nsrcs = htons(numsrc);
192 
193 	/* substitute multicast address */
194 	if (maddr == NULL) {
195 		query->group = htonl(INADDR_ANY);
196 	} else {
197 		if (inet_pton(AF_INET, maddr, &ip) <= 0) {
198 			fprintf(stderr,
199 				"multicast address is something wrong\n");
200 			return NULL;
201 		}
202 		query->group = ip.s_addr;
203 	}
204 
205 	/* substitute source addresses */
206 	sp = saddrs;
207 	for (idx = 0; idx < numsrc; idx++) {
208 		ep = strchr(sp, ',');
209 		if (ep != NULL)
210 			*ep = '\0';
211 		if (debug)
212 			fprintf(stderr, "source address[%u]: %s\n", idx, sp);
213 
214 		if (inet_pton(AF_INET, sp, &ip) <= 0) {
215 			fprintf(stderr,
216 				"source address list is something wrong\n");
217 			return NULL;
218 		}
219 		query->srcs[idx] = ip.s_addr;
220 		sp = ep + 1;
221 	}
222 
223 	/* Calculate checksum */
224 	query->csum = calc_checksum((u_int16_t *) query, query_size);
225 
226 	return query;
227 }
228 
229 /*
230  * Function: parse_options()
231  *
232  * Description:
233  *  This function parse the options
234  *
235  * Argument:
236  *   argc:  the number of argument
237  *   argv:  arguments
238  *  info_p: pointer to data of querier information
239  *   bg_p:  pointer to the flag of working in backgrond
240  *
241  * Return value:
242  *  None
243  */
parse_options(int argc,char * argv[],struct igmp_info * info_p,int * bg_p)244 void parse_options(int argc, char *argv[], struct igmp_info *info_p, int *bg_p)
245 {
246 	int optc;		/* option */
247 	unsigned long opt_ul;	/* option value in unsigned long */
248 	double opt_d;		/* option value in double */
249 	uint8_t max_resp;	/* Max Resp Code */
250 	char *maddr;		/* multicast address */
251 	char *saddrs;		/* comma separated array of source addresses */
252 
253 	max_resp = IGMP_MAX_HOST_REPORT_DELAY;
254 	maddr = NULL;
255 	saddrs = NULL;
256 
257 	while ((optc = getopt(argc, argv, "I:m:s:r:t:i:obdh")) != EOF) {
258 		switch (optc) {
259 		case 'I':
260 			info_p->ifindex = if_nametoindex(optarg);
261 			if (info_p->ifindex == 0) {
262 				fprintf(stderr,
263 					"specified interface is incorrect\n");
264 				usage(program_name, EXIT_FAILURE);
265 			}
266 			break;
267 
268 		case 'm':
269 			maddr = strdup(optarg);
270 			if (maddr == NULL)
271 				fatal_error("strdup()");
272 			break;
273 
274 		case 's':
275 			saddrs = strdup(optarg);
276 			if (saddrs == NULL)
277 				fatal_error("strdup()");
278 			break;
279 
280 		case 'r':
281 			opt_ul = strtoul(optarg, NULL, 0);
282 			if (opt_ul > 255) {
283 				fprintf(stderr,
284 					"Max Resp Code should be less then 256\n");
285 				usage(program_name, EXIT_FAILURE);
286 			}
287 			max_resp = opt_ul;
288 			break;
289 
290 		case 't':
291 			opt_d = strtod(optarg, NULL);
292 			if (opt_d < 0.0) {
293 				fprintf(stderr,
294 					"Timeout should be positive value\n");
295 				usage(program_name, EXIT_FAILURE);
296 			}
297 			info_p->timeout = opt_d;
298 			break;
299 
300 		case 'i':
301 			if (strtotimespec(optarg, &info_p->interval)) {
302 				fprintf(stderr,
303 					"Interval is something wrong\n");
304 				usage(program_name, EXIT_FAILURE);
305 			}
306 			break;
307 
308 		case 'o':
309 			info_p->timeout = -1.0;
310 			break;
311 
312 		case 'b':
313 			*bg_p = 1;
314 			break;
315 
316 		case 'd':
317 			debug = 1;
318 			break;
319 
320 		case 'h':
321 			usage(program_name, EXIT_SUCCESS);
322 			break;
323 
324 		default:
325 			usage(program_name, EXIT_FAILURE);
326 		}
327 	}
328 
329 	if (info_p->ifindex == 0) {
330 		fprintf(stderr, "specified interface seems incorrect\n");
331 		usage(program_name, EXIT_FAILURE);
332 	}
333 
334 	if ((info_p->query = create_query(max_resp, maddr, saddrs)) == NULL)
335 		usage(program_name, EXIT_FAILURE);
336 
337 	free(maddr);
338 	free(saddrs);
339 }
340 
341 /*
342  * Function: create_socket()
343  *
344  * Description:
345  *  This function creates a socket to send
346  *
347  * Argument:
348  *  info_p: pointer to data of igmp query information
349  *
350  * Return value:
351  *  file descriptor referencing the socket
352  */
create_socket(struct igmp_info * info_p)353 int create_socket(struct igmp_info *info_p)
354 {
355 	int sd;			/* socket file descriptor */
356 	int on;
357 	unsigned char opt[4] = { 0x94, 0x04, 0x00, 0x00 };	/* Router Alert */
358 	struct ip_mreqn mcast_req, *req_p = &mcast_req;
359 
360 	/* Create a socket */
361 	sd = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP);
362 	if (sd < 0)
363 		fatal_error("socket()");
364 
365 	/* Enable to reuse the socket */
366 	on = 1;
367 	if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int)))
368 		fatal_error("setsockopt(): enable to reuse the socket");
369 
370 	/* Add router alert option */
371 	if (setsockopt(sd, IPPROTO_IP, IP_OPTIONS, opt, sizeof(opt)))
372 		fatal_error("setsockopt(): socket options");
373 
374 	/* Specify the interface for outgoing datagrams */
375 	req_p->imr_multiaddr.s_addr = info_p->query->group;
376 	req_p->imr_address.s_addr = htonl(INADDR_ANY);
377 	req_p->imr_ifindex = info_p->ifindex;
378 	if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
379 		       req_p, sizeof(struct ip_mreqn))) {
380 		fatal_error("setsockopt(): specify the interface");
381 	}
382 
383 	return sd;
384 }
385 
386 /*
387  * Function: send_query()
388  *
389  * Description:
390  *  This function sends IGMP query
391  *
392  * Argument:
393  *  info_p: pointer to data of igmp query information
394  *
395  * Return value:
396  *  None
397  */
send_query(struct igmp_info * info_p)398 void send_query(struct igmp_info *info_p)
399 {
400 	int sd;
401 	int retval;
402 	double start_time;
403 	struct sockaddr_in to;
404 	size_t query_size;
405 
406 	/* Set singal hander for SIGHUP */
407 	handler.sa_handler = set_signal_flag;
408 	handler.sa_flags = 0;
409 	if (sigfillset(&handler.sa_mask) < 0)
410 		fatal_error("sigfillset()");
411 	if (sigaction(SIGHUP, &handler, NULL) < 0)
412 		fatal_error("sigaction()");
413 
414 	/* Specify multicast address to send */
415 	to.sin_family = AF_INET;
416 	to.sin_port = IPPROTO_IGMP;
417 	if (info_p->query->group == htonl(INADDR_ANY))
418 		to.sin_addr.s_addr = IGMP_ALL_HOSTS;
419 	else
420 		to.sin_addr.s_addr = info_p->query->group;
421 
422 	/* Create a socket */
423 	sd = create_socket(info_p);
424 
425 	/* loop for sending queries */
426 	start_time = time(NULL);
427 	query_size = MY_IGMPV3_QUERY_SIZE(ntohs(info_p->query->nsrcs));
428 	if (debug)
429 		fprintf(stderr, "query size is %zu\n", query_size);
430 
431 	for (;;) {
432 		retval = sendto(sd, info_p->query, query_size, 0,
433 				(struct sockaddr *)&to,
434 				sizeof(struct sockaddr_in));
435 		if (retval != query_size) {
436 			if (catch_sighup)
437 				break;
438 			else
439 				fatal_error("sendto()");
440 		}
441 
442 		/* Check timeout:
443 		   If timeout value is negative only send one datagram */
444 		if (info_p->timeout)
445 			if (info_p->timeout < difftime(time(NULL), start_time))
446 				break;
447 
448 		/* Wait in specified interval */
449 		nanosleep(&info_p->interval, NULL);
450 
451 		/* catch SIGHUP */
452 		if (catch_sighup)
453 			break;
454 
455 	}
456 
457 	close(sd);
458 }
459 
460 /*
461  *
462  *  Function: main()
463  *
464  */
main(int argc,char * argv[])465 int main(int argc, char *argv[])
466 {
467 	struct igmp_info mcast_rcv;
468 	int background = 0;
469 
470 	debug = 0;
471 	program_name = strdup(argv[0]);
472 
473 	memset(&mcast_rcv, '\0', sizeof(struct igmp_info));
474 	parse_options(argc, argv, &mcast_rcv, &background);
475 
476 	if (background)		/* Work in the background */
477 		if (daemon(0, 0) < 0)
478 			fatal_error("daemon()");
479 
480 	send_query(&mcast_rcv);
481 
482 	exit(EXIT_SUCCESS);
483 }
484