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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-icmpv4_sender.c
24  *
25  * Description:
26  *	This is ICMPv4 echo request sender.
27  *	This utility is also able to set illegal information in the IP header
28  *
29  * Author:
30  *	Mitsuru Chinen <mitch@jp.ibm.com>
31  *
32  * History:
33  *	Mar 5 2006 - Created (Mitsuru Chinen)
34  *---------------------------------------------------------------------------*/
35 
36 /*
37  * Header Files
38  */
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <errno.h>
43 #include <netdb.h>
44 #include <signal.h>
45 #include <time.h>
46 #include <unistd.h>
47 #include <sys/ioctl.h>
48 #include <sys/socket.h>
49 #include <arpa/inet.h>
50 #include <net/ethernet.h>
51 #include <net/if_arp.h>
52 
53 #include "ns-traffic.h"
54 
55 /*
56  * Structure Definitions
57  */
58 struct icmpv4_fake {
59 	struct ip4_datagram pkt;
60 	char *src_ifname;
61 	struct sockaddr_ll saddr_ll;
62 	struct sockaddr_ll daddr_ll;
63 	struct in_addr saddr;
64 	struct in_addr daddr;
65 	unsigned short int pkt_size;
66 	unsigned short int data_size;
67 	double timeout;
68 
69 	u_int16_t fake_flag;
70 };
71 
72 /*
73  * Gloval variables
74  */
75 char *program_name;		/* program name */
76 struct sigaction handler;	/* Behavior for a signal */
77 int catch_sighup;		/* When catch the SIGHUP, set to non-zero */
78 
79 /*
80  * Function: usage()
81  *
82  * Descripton:
83  *  Print the usage of this program. Then, terminate this program with
84  *  the specified exit value.
85  *
86  * Argument:
87  *  exit_value:	exit value
88  *
89  * Return value:
90  *  This function does not return.
91  */
usage(char * program_name,int exit_value)92 void usage(char *program_name, int exit_value)
93 {
94 	FILE *stream = stdout;	/* stream where the usage is output */
95 
96 	if (exit_value == EXIT_FAILURE)
97 		stream = stderr;
98 
99 	fprintf(stream, "%s [OPTION]\n"
100 		"\t-I if_name\tInterface name of the source host\n"
101 		"\t-S ip_addr\tIPv4 address of the source host\n"
102 		"\t-M mac_addr\tMAC address of the destination host\n"
103 		"\t-D ip_addr\tIPv4 address of the destination host\n"
104 		"\t-s packetsize\tnumber of data bytes (exclude header)\n"
105 		"\t-t value\ttimeout [sec]\n"
106 		"\t-d\t\tdisplay debug informations\n"
107 		"\t-h\t\tdisplay this usage\n"
108 		"\n"
109 		"\t[options for fake]\n"
110 		"\t  -c\tbreak checksum\n"
111 		"\t  -f\tbreak fragment information\n"
112 		"\t  -i\tbreak IPv4 destination address\n"
113 		"\t  -l\tbreak header length\n"
114 		"\t  -L\tbreak total length\n"
115 		"\t  -p\tbreak protocol number\n"
116 		"\t  -v\tbreak IP version\n", program_name);
117 	exit(exit_value);
118 }
119 
120 /*
121  * Function: set_signal_flag()
122  *
123  * Description:
124  *  This function sets global variables accordig to signal
125  *
126  * Argument:
127  *  type: type of signal
128  *
129  * Return value:
130  *  None
131  */
set_signal_flag(int type)132 void set_signal_flag(int type)
133 {
134 	if (debug)
135 		fprintf(stderr, "Catch signal. type is %d\n", type);
136 
137 	switch (type) {
138 	case SIGHUP:
139 		catch_sighup = 1;
140 		handler.sa_handler = SIG_IGN;
141 		if (sigaction(type, &handler, NULL) < 0)
142 			fatal_error("sigaction()");
143 		break;
144 
145 	default:
146 		fprintf(stderr, "Unexpected signal (%d) is caught\n", type);
147 		exit(EXIT_FAILURE);
148 	}
149 }
150 
151 /*
152  * Function: parse_options()
153  *
154  * Description:
155  *  This function parse the options, then modify the fake icmp data
156  *
157  * Argument:
158  *   argc:  the number of argument
159  *   argv:  arguments
160  *  fake_p: pointer to data of fake icmp data to modify
161  *
162  * Return value:
163  *  None
164  */
parse_options(int argc,char * argv[],struct icmpv4_fake * fake_p)165 void parse_options(int argc, char *argv[], struct icmpv4_fake *fake_p)
166 {
167 	int optc;		/* option */
168 	unsigned long opt_ul;	/* option value in unsigned long */
169 	double opt_d;		/* option value in double */
170 	struct in_addr opt_addr;	/* option value in struct in_addr */
171 	struct sockaddr_ll opt_addr_ll;	/* option value in struct sockaddr_ll */
172 	int is_specified_src_ifname = 0;
173 	int is_specified_saddr = 0;
174 	int is_specified_daddr_ll = 0;
175 	int is_specified_daddr = 0;
176 
177 	while ((optc = getopt(argc, argv, "I:S:M:D:s:t:dhcfilLpv")) != EOF) {
178 		switch (optc) {
179 		case 'I':
180 			fake_p->src_ifname = strdup(optarg);
181 			if (fake_p->src_ifname == NULL)
182 				fatal_error("strdup() failed.");
183 			is_specified_src_ifname = 1;
184 			break;
185 
186 		case 'S':
187 			if (inet_pton(AF_INET, optarg, &opt_addr) <= 0) {
188 				fprintf(stderr, "Source address is wrong\n");
189 				usage(program_name, EXIT_FAILURE);
190 			}
191 			fake_p->saddr = opt_addr;
192 			is_specified_saddr = 1;
193 			break;
194 
195 		case 'M':
196 			if (eth_pton(AF_INET, optarg, &opt_addr_ll)) {
197 				fprintf(stderr,
198 					"Destination MAC address is wrong\n");
199 				usage(program_name, EXIT_FAILURE);
200 			}
201 			fake_p->daddr_ll = opt_addr_ll;
202 			is_specified_daddr_ll = 1;
203 			break;
204 
205 		case 'D':
206 			if (inet_pton(AF_INET, optarg, &opt_addr) <= 0) {
207 				fprintf(stderr,
208 					"Destination address is wrong\n");
209 				usage(program_name, EXIT_FAILURE);
210 			}
211 			fake_p->daddr = opt_addr;
212 			is_specified_daddr = 1;
213 			break;
214 
215 		case 's':
216 			opt_ul = strtoul(optarg, NULL, 0);
217 			if (opt_ul > ICMPV4_DATA_MAXSIZE) {
218 				fprintf(stderr,
219 					"Data size sholud be less than %d\n",
220 					ICMPV4_DATA_MAXSIZE + 1);
221 				usage(program_name, EXIT_FAILURE);
222 			}
223 			fake_p->data_size = opt_ul;
224 			break;
225 
226 		case 't':
227 			opt_d = strtod(optarg, NULL);
228 			if (opt_d < 0.0) {
229 				fprintf(stderr,
230 					"Timeout should be positive value\n");
231 				usage(program_name, EXIT_FAILURE);
232 			}
233 			fake_p->timeout = opt_d;
234 			break;
235 
236 		case 'd':
237 			debug = 1;
238 			break;
239 
240 		case 'h':
241 			usage(program_name, EXIT_SUCCESS);
242 			break;
243 
244 			/* Options for fake */
245 		case 'c':
246 			fake_p->fake_flag |= FAKE_CHECK;
247 			break;
248 
249 		case 'f':
250 			fake_p->fake_flag |= FAKE_FRAGMENT;
251 			break;
252 
253 		case 'i':
254 			fake_p->fake_flag |= FAKE_DADDR;
255 			break;
256 
257 		case 'l':
258 			fake_p->fake_flag |= FAKE_IHL;
259 			break;
260 
261 		case 'L':
262 			fake_p->fake_flag |= FAKE_TOT_LEN;
263 			break;
264 
265 		case 'p':
266 			fake_p->fake_flag |= FAKE_PROTOCOL;
267 			break;
268 
269 		case 'v':
270 			fake_p->fake_flag |= FAKE_VERSION;
271 			break;
272 
273 		default:
274 			usage(program_name, EXIT_FAILURE);
275 		}
276 	}
277 
278 	if (!is_specified_src_ifname) {
279 		fprintf(stderr,
280 			"Interface name of the source host is not specified\n");
281 		usage(program_name, EXIT_FAILURE);
282 	}
283 
284 	if (!is_specified_saddr) {
285 		fprintf(stderr, "Source IP address is not specified\n");
286 		usage(program_name, EXIT_FAILURE);
287 	}
288 
289 	if (!is_specified_daddr_ll) {
290 		fprintf(stderr, "Destination MAC address is not specified\n");
291 		usage(program_name, EXIT_FAILURE);
292 	}
293 
294 	if (!is_specified_daddr) {
295 		fprintf(stderr, "Destination IP address is not specified\n");
296 		usage(program_name, EXIT_FAILURE);
297 	}
298 }
299 
300 /*
301  * Function: complete_eth_addrs()
302  *
303  * Description:
304  *  This function sets the source and destination ethernet address completely
305  *
306  * Argument:
307  *  fake_p: pointer to data of fake icmp structure
308  *
309  * Return value:
310  *  None
311  *
312  */
complete_eth_addrs(struct icmpv4_fake * fake_p)313 void complete_eth_addrs(struct icmpv4_fake *fake_p)
314 {
315 	int sock_fd;		/* Socket for ioctl() */
316 	struct ifreq ifinfo;	/* Interface information */
317 
318 	if ((sock_fd = socket(AF_PACKET, SOCK_DGRAM, 0)) < 0)
319 		fatal_error("socket()");
320 
321 	/* Source */
322 	fake_p->saddr_ll.sll_family = AF_PACKET;	/* Always AF_PACKET */
323 	fake_p->saddr_ll.sll_protocol = htons(ETH_P_IP);	/* IPv4 */
324 	fake_p->saddr_ll.sll_hatype = ARPHRD_ETHER;	/* Header type */
325 	fake_p->saddr_ll.sll_pkttype = PACKET_HOST;	/* Packet type */
326 	fake_p->saddr_ll.sll_halen = ETH_ALEN;	/* Length of address */
327 
328 	/* Get the MAC address of the interface at source host */
329 	get_ifinfo(&ifinfo, sock_fd, fake_p->src_ifname, SIOCGIFHWADDR);
330 	memcpy(fake_p->saddr_ll.sll_addr, ifinfo.ifr_hwaddr.sa_data, ETH_ALEN);
331 
332 	/* Get the interface index */
333 	get_ifinfo(&ifinfo, sock_fd, fake_p->src_ifname, SIOCGIFINDEX);
334 	fake_p->saddr_ll.sll_ifindex = ifinfo.ifr_ifindex;
335 	fake_p->daddr_ll.sll_ifindex = ifinfo.ifr_ifindex;
336 
337 	close(sock_fd);
338 }
339 
340 /*
341  * Function: create_clean_packet()
342  *
343  * Description:
344  *  This function creates icmpv4 packet without any fakes
345  *
346  * Argument:
347  *  fake_p: pointer to data of fake icmp structure
348  *
349  * Return value:
350  *  None
351  */
create_clean_packet(struct icmpv4_fake * fake_p)352 void create_clean_packet(struct icmpv4_fake *fake_p)
353 {
354 	struct ip4_datagram pkt;	/* sending IPv4 packet */
355 	struct icmp4_segment *icmp_p;	/* ICMPv4 part of sending packet */
356 	unsigned short int pkt_size;
357 
358 	memset(&pkt, '\0', sizeof(struct ip4_datagram));
359 	pkt_size = sizeof(struct iphdr)	/* IP header */
360 	    +sizeof(struct icmphdr)	/* ICMP header */
361 	    +fake_p->data_size;	/* ICMP payload */
362 
363 	icmp_p = (struct icmp4_segment *)&(pkt.payload);
364 
365 	/* IPv4 Header */
366 	pkt.hdr.version = 4;
367 	pkt.hdr.ihl = sizeof(struct iphdr) / 4;
368 	pkt.hdr.tos = 0;
369 	pkt.hdr.tot_len = htons(pkt_size);
370 	pkt.hdr.id = htons(IPV4_PACKET_ID);
371 	pkt.hdr.frag_off = htons(IPV4_DEFAULT_FLAG);
372 	pkt.hdr.ttl = IPV4_DEFAULT_TTL;
373 	pkt.hdr.protocol = IPPROTO_ICMP;
374 	pkt.hdr.check = 0;	/* Calculate later */
375 	pkt.hdr.saddr = fake_p->saddr.s_addr;
376 	pkt.hdr.daddr = fake_p->daddr.s_addr;
377 
378 	/* ICMPv4 Header */
379 	icmp_p->hdr.type = ICMP_ECHO;
380 	icmp_p->hdr.code = 0;
381 	icmp_p->hdr.checksum = 0;	/* Calculate later */
382 	icmp_p->hdr.un.echo.id = htons(ICMP_ECHO_ID);
383 	icmp_p->hdr.un.echo.sequence = htons(1);
384 
385 	/* ICMPv4 Payload */
386 	fill_payload(icmp_p->data, fake_p->data_size);
387 
388 	/* Calcualte checksums */
389 	pkt.hdr.check = calc_checksum((u_int16_t *) (&pkt.hdr),
390 				      sizeof(struct iphdr));
391 	icmp_p->hdr.checksum = calc_checksum((u_int16_t *) icmp_p,
392 					     sizeof(struct icmphdr) +
393 					     fake_p->data_size);
394 
395 	/* Store the clean packet data */
396 	fake_p->pkt = pkt;
397 	fake_p->pkt_size = pkt_size;
398 }
399 
400 /*
401  * Function: thrust_fakes()
402  *
403  * Description:
404  *  This function thrust fake information to the icmp packet
405  *
406  * Argument:
407  *     pkt   : Payload of the Ethernet frame (Namely, IPv6 packet
408  *  fake_flag: Flag which represents what information would be faked
409  *
410  * Return value:
411  *  None
412  */
thrust_fakes(struct ip4_datagram * pkt,u_int16_t fake_flag)413 void thrust_fakes(struct ip4_datagram *pkt, u_int16_t fake_flag)
414 {
415 	int rand_val;
416 	size_t bitsize;
417 	u_int32_t seed;
418 
419 	if (debug)
420 		fprintf(stderr, "fake_flag = %2x\n", fake_flag);
421 
422 	if (fake_flag & FAKE_VERSION) {	/* version */
423 		bitsize = 4;
424 		seed = bit_change_seed(bitsize, 1);
425 		pkt->hdr.version ^= seed;
426 	}
427 
428 	if (fake_flag & FAKE_IHL) {	/* header length */
429 		bitsize = 4;
430 		seed = bit_change_seed(bitsize, 1);
431 		pkt->hdr.ihl ^= seed;
432 	}
433 
434 	if (fake_flag & FAKE_TOT_LEN) {	/* total length */
435 		bitsize = sizeof(pkt->hdr.tot_len) * 8;
436 		seed = bit_change_seed(bitsize, bitsize / 8);
437 		pkt->hdr.tot_len ^= seed;
438 	}
439 
440 	if (fake_flag & FAKE_FRAGMENT) {	/* fragment information */
441 		/* Set reserved flag */
442 		rand_val = rand() / ((RAND_MAX + 1U) / 16);
443 		if (!rand_val) {
444 			if (debug)
445 				fprintf(stderr, "Up reserved bit\n");
446 			pkt->hdr.frag_off |= htonl(0x80000000);
447 		}
448 
449 		/* Set more fragments flag */
450 		rand_val = rand() / ((RAND_MAX + 1U) / 3);
451 		if (!rand_val) {
452 			if (debug)
453 				fprintf(stderr, "Set more fragments flag\n");
454 			pkt->hdr.frag_off |= htons(0x2000);
455 		}
456 
457 		/* Unset unfragmented flag */
458 		rand_val = rand() / ((RAND_MAX + 1U) / 3);
459 		if (!rand_val) {
460 			if (debug)
461 				fprintf(stderr, "Unset unfragmented flag\n");
462 			pkt->hdr.frag_off &= htons(0xbfff);
463 		}
464 
465 		/* Set fragment offset */
466 		rand_val = rand() / ((RAND_MAX + 1U) / 3);
467 		if (!rand_val) {
468 			bitsize = 13;
469 			seed = bit_change_seed(bitsize, 0);
470 			if (debug)
471 				fprintf(stderr, "Set fragment offset %02x\n",
472 					seed);
473 			pkt->hdr.frag_off |= htons(seed);
474 		}
475 	}
476 
477 	if (fake_flag & FAKE_PROTOCOL) {	/* protocol */
478 		rand_val = rand() / ((RAND_MAX + 1U) / 5);
479 		switch (rand_val) {
480 		case 1:
481 		case 2:
482 			if (debug)
483 				fprintf(stderr, "Bit reverse\n");
484 			bitsize = sizeof(pkt->hdr.protocol) * 8;
485 			seed = bit_change_seed(bitsize, 0);
486 			pkt->hdr.protocol ^= seed;
487 			break;
488 
489 		case 3:
490 		case 4:
491 			if (debug)
492 				fprintf(stderr, "Unknown Protocol\n");
493 			if (rand_val) {
494 				int number;
495 				int counter;
496 				for (counter = 0; counter <= 0xff; counter++) {
497 					number =
498 					    rand() / ((RAND_MAX + 1U) / 0x100);
499 					if (getprotobynumber(number) == NULL) {
500 						pkt->hdr.protocol = number;
501 						break;
502 					}
503 				}
504 			}
505 			break;
506 
507 		default:
508 			if (debug)
509 				fprintf(stderr, "Do nothing\n");
510 			break;
511 		}
512 	}
513 
514 	if (fake_flag & FAKE_DADDR) {	/* destination address */
515 		bitsize = sizeof(pkt->hdr.daddr) * 8;
516 		seed = bit_change_seed(bitsize, bitsize / 8);
517 		pkt->hdr.daddr ^= seed;
518 	}
519 
520 	/* Recalculate checksum once */
521 	pkt->hdr.check = 0;
522 	pkt->hdr.check =
523 	    calc_checksum((u_int16_t *) & (pkt->hdr), sizeof(struct iphdr));
524 
525 	if (fake_flag & FAKE_CHECK) {	/* checksum */
526 		bitsize = sizeof(pkt->hdr.check) * 8;
527 		seed = bit_change_seed(bitsize, bitsize / 8);
528 		pkt->hdr.check ^= seed;
529 	}
530 }
531 
532 /*
533  * Function: send_packet()
534  *
535  * Description:
536  *  This function sends icmpv4 packet
537  *
538  * Argument:
539  *  fake_p: pointer to data of fake icmp structure
540  *
541  * Return value:
542  *  None
543  */
send_packets(struct icmpv4_fake * fake_p)544 void send_packets(struct icmpv4_fake *fake_p)
545 {
546 	int sock_fd;
547 	int retval;
548 	struct ip4_datagram pkt;
549 	double start_time;
550 
551 	/* Open a socket */
552 	sock_fd = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
553 	if (sock_fd < 0)
554 		fatal_error("socket()");
555 
556 	/* Bind the socket to the physical address */
557 	retval = bind(sock_fd, (struct sockaddr *)&(fake_p->saddr_ll),
558 		      sizeof(struct sockaddr_ll));
559 	if (retval < 0)
560 		fatal_error("bind()");
561 
562 	/* Set singal hander for SIGHUP */
563 	handler.sa_handler = set_signal_flag;
564 	handler.sa_flags = 0;
565 	if (sigfillset(&handler.sa_mask) < 0)
566 		fatal_error("sigfillset()");
567 	if (sigaction(SIGHUP, &handler, NULL) < 0)
568 		fatal_error("sigfillset()");
569 
570 	/*
571 	 * loop for sending packets
572 	 */
573 	pkt = fake_p->pkt;
574 	start_time = time(NULL);
575 
576 	for (;;) {
577 		if (fake_p->fake_flag) {
578 			pkt = fake_p->pkt;
579 			thrust_fakes(&pkt, fake_p->fake_flag);
580 		}
581 
582 		retval = sendto(sock_fd, &pkt, fake_p->pkt_size, 0,
583 				(struct sockaddr *)&(fake_p->daddr_ll),
584 				sizeof(struct sockaddr_ll));
585 		if (retval < 0)
586 			fatal_error("sendto()");
587 
588 		if (fake_p->timeout)	/* timeout */
589 			if (fake_p->timeout < difftime(time(NULL), start_time))
590 				break;
591 
592 		if (catch_sighup)	/* catch SIGHUP */
593 			break;
594 	}
595 
596 	/* Close the socket */
597 	close(sock_fd);
598 }
599 
600 /*
601  *
602  *  Function: main()
603  *
604  */
main(int argc,char * argv[])605 int main(int argc, char *argv[])
606 {
607 	struct icmpv4_fake fake_data;
608 
609 	debug = 0;
610 	program_name = strdup(argv[0]);
611 	srand(getpid());
612 
613 	memset(&fake_data, '\0', sizeof(struct icmpv4_fake));
614 	parse_options(argc, argv, &fake_data);
615 
616 	complete_eth_addrs(&fake_data);
617 	create_clean_packet(&fake_data);
618 
619 	send_packets(&fake_data);
620 
621 	exit(EXIT_SUCCESS);
622 }
623