File: fragtest.c

package info (click to toggle)
fragroute 1.2-7
  • links: PTS
  • area: main
  • in suites: sarge
  • size: 692 kB
  • ctags: 520
  • sloc: ansic: 4,331; sh: 2,842; makefile: 74
file content (501 lines) | stat: -rw-r--r-- 12,427 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
/*
 * fragtest.c
 *
 * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
 *
 * $Id: fragtest.c,v 1.17 2002/04/07 22:55:20 dugsong Exp $
 */

#include "config.h"

#include <pcap.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mod.h"
#include "pcaputil.h"

#define TEST_PING		0x01
#define TEST_IP_OPT		0x02
#define TEST_IP_TRACERT		0x04
#define TEST_FRAG		0x08
#define TEST_FRAG_NEW		0x10
#define TEST_FRAG_OLD		0x20
#define TEST_FRAG_TIMEOUT	0x40

#define READ_TIMEOUT		2
#define FRAG_TIMEOUT		300

struct ft_ctx {
	struct addr		 src, dst;
	struct pktq		 pktq;
	ip_t			*ip;
	pcap_t			*pcap;
	rand_t			*rnd;
	int			 dloff;
};

extern struct mod mod_ip_frag;

static struct ft_ctx	 ctx;
static struct pkt	*ping;
static struct timeval	 read_tv = { READ_TIMEOUT, 0 };

static void
usage(void)
{
	fprintf(stderr, "Usage: fragtest TESTS ... <host>\n\n");
	fprintf(stderr, "  where TESTS is any combination of the following "
	    "(or \"all\"):\n\n");
	fprintf(stderr, "  ping\t\tprerequisite for all tests\n");
	fprintf(stderr, "  ip-opt\tdetermine supported IP options (BROKEN)\n");
	fprintf(stderr, "  ip-tracert\tdetermine path to target\n");
	fprintf(stderr, "  frag\t\ttry 8-byte IP fragments\n");
	fprintf(stderr, "  frag-new\ttry 8-byte fwd-overlapping IP "
	    "fragments, favoring new data (BROKEN)\n");
	fprintf(stderr, "  frag-old\ttry 8-byte fwd-overlapping IP "
	    "fragments, favoring old data\n");
	fprintf(stderr, "  frag-timeout\tdetermine IP fragment "
	    "reassembly timeout (BROKEN)\n");
	fprintf(stderr, "\n");
	exit(1);
}

static char *
timeval_ntoa(struct timeval *tv)
{
	static char buf[128];
	uint64_t usec;

	usec = (tv->tv_sec * 1000000) + tv->tv_usec;

	if (usec > 1000000) {
		snprintf(buf, sizeof(buf), "%d.%03d sec",
		    (int)(usec / 1000000), (int)(usec % 1000000));
	} else {
		snprintf(buf, sizeof(buf), "%d.%03d ms",
		    (int)(usec / 1000), (int)(usec % 1000));
	}
	return (buf);
}

static int
send_pkt(struct pkt *pkt)
{
	int i;

	i = ip_send(ctx.ip, pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
	pkt_free(pkt);
	return (i);
}

static void
send_pktq(struct pktq *pktq)
{
	struct pkt *pkt, *next;
	
	for (pkt = TAILQ_FIRST(pktq); pkt != TAILQ_END(pktq); pkt = next) {
		next = TAILQ_NEXT(pkt, pkt_next);
		TAILQ_REMOVE(pktq, pkt, pkt_next);
		send_pkt(pkt);
	}
}

static struct pkt *
recv_pkt(struct timeval *tv)
{
	struct pcap_pkthdr phdr;
	struct timeval now, start;
	struct pkt *pkt;
	u_char *p;
	long timeout_usec;
	int i;
	
	timeout_usec = tv->tv_sec * 1000000 + tv->tv_usec;
	gettimeofday(&start, NULL);
	
	/*
	 * XXX - can't select() on pcap_fileno on Solaris,
	 * seems to be unreliable on Linux as well. *sigh*
	 */
	for (;;) {
		gettimeofday(&now, NULL);
		
		if ((p = (u_char *)pcap_next(ctx.pcap, &phdr)) != NULL ||
		    (now.tv_sec - start.tv_sec) * 1000000 +
		    now.tv_usec - start.tv_usec > timeout_usec || (printf("a") && fflush(stdout)))
			break;
	}
	if (p == NULL)
		return (NULL);
	
	p += ctx.dloff;
	i = phdr.caplen - ctx.dloff;
	
	pkt = pkt_new();
	memcpy(pkt->pkt_eth_data, p, i);
	pkt->pkt_end = pkt->pkt_eth_data + i;
	pkt_decorate(pkt);
	
	tv->tv_sec = phdr.ts.tv_sec - start.tv_sec;
	tv->tv_usec = phdr.ts.tv_usec - start.tv_usec;
	
	return (pkt);
}

static int
test_ping(void)
{
	struct pkt *pkt;
	struct timeval tv;
	
	printf("ping: "); fflush(stdout);

	ping->pkt_icmp_msg->echo.icmp_id = rand_uint16(ctx.rnd);
	pkt = pkt_dup(ping);
	pkt->pkt_ip->ip_id = rand_uint16(ctx.rnd);
	ip_checksum(pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
	
	pcap_filter(ctx.pcap, "icmp[0] = 0 and src %s and dst %s",
	    addr_ntoa(&ctx.dst), addr_ntoa(&ctx.src));

	send_pkt(pkt);

	for (tv = read_tv; (pkt = recv_pkt(&tv)) != NULL; tv = read_tv) {
		if (memcmp(&pkt->pkt_icmp_msg->echo,
		    &ping->pkt_icmp_msg->echo, 8) == 0)
			break;
	}
	printf("%s\n", pkt ? timeval_ntoa(&tv) : "no reply");

	return (0);
}

static char *optnames[] = {
	"eol", "nop", "sec", "lsrr", "ts", "esec", "cipso", "rr",
	"satid", "ssrr", "zsu", "mtup", "mtur", "finn", "visa",
	"encode", "imitd", "eip", "tr", "addext", "rtralt", "sdb",
	"nsapa", "dps", "ump", NULL
};

static int
test_ip_opt(void)
{
	struct pkt *pkt;
	struct timeval tv;
	struct ip_opt opts[IP_OPT_MAX];
	int i, len, max;
	
	printf("ip-opt: "); fflush(stdout);
	
	memset(&opts, 0, sizeof(opts));
	max = 0;
	opts[max].opt_type = IP_OPT_SEC;
	opts[max].opt_len = IP_OPT_LEN + 9;
	max++;
	opts[max].opt_type = IP_OPT_LSRR;
	opts[max].opt_len = IP_OPT_LEN + 1 + 4;
	opts[max].opt_data.rr.ptr = 8;
	opts[max].opt_data.rr.iplist[0] = ping->pkt_ip->ip_src;
	max++;
	opts[max].opt_type = IP_OPT_TS;
	opts[max].opt_len = IP_OPT_LEN + 1 + 1 + 4;
	opts[max].opt_data.ts.ptr = 5;
	opts[max].opt_data.ts.flg = IP_OPT_TS_TSONLY;
	max++;
	opts[max].opt_type = IP_OPT_ESEC;
	opts[max].opt_len = IP_OPT_LEN;
	max++;
	opts[max].opt_type = IP_OPT_CIPSO;
	opts[max].opt_len = IP_OPT_LEN;
	max++;
	opts[max].opt_type = IP_OPT_RR;
	opts[max].opt_len = IP_OPT_LEN + 1 + 4;
	opts[max].opt_data.rr.ptr = 4;
	max++;
	opts[max].opt_type = IP_OPT_SATID;
	opts[max].opt_len = IP_OPT_LEN + 2;
	max++;
	opts[max].opt_type = IP_OPT_SSRR;
	opts[max].opt_len = IP_OPT_LEN + 1 + 4;
	opts[max].opt_data.rr.ptr = 8;
	opts[max].opt_data.rr.iplist[0] = ping->pkt_ip->ip_src;
	max++;
	
	pcap_filter(ctx.pcap, "icmp and src %s and dst %s",
	    addr_ntoa(&ctx.dst), addr_ntoa(&ctx.src));

	ping->pkt_icmp_msg->echo.icmp_id = rand_uint16(ctx.rnd);
	
	for (i = 0; i < max; i++) {
		pkt = pkt_dup(ping);
		pkt->pkt_ip->ip_id = rand_uint16(ctx.rnd);
		pkt->pkt_icmp_msg->echo.icmp_seq = opts[i].opt_type;
		len = ip_add_option(pkt->pkt_ip, PKT_BUF_LEN - ETH_HDR_LEN +
		    IP_HDR_LEN, IP_PROTO_IP, &opts[i], opts[i].opt_len);
		pkt->pkt_end += len;
		
		ip_checksum(pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
		
		send_pkt(pkt);
	}
	i = 0;
	for (tv = read_tv; (pkt = recv_pkt(&tv)) != NULL; tv = read_tv) {
		if (pkt->pkt_icmp->icmp_type == ICMP_ECHOREPLY &&
		    pkt->pkt_icmp_msg->echo.icmp_id ==
		    ping->pkt_icmp_msg->echo.icmp_id) {
			i = IP_OPT_NUMBER(pkt->pkt_icmp_msg->echo.icmp_seq);
			printf("%s ", optnames[i]);
			/* XXX: DEBUG */
			fflush(stdout);
		}
	}
	printf("%s\n", i ? "" : "none");
	
	return (0);
}

struct hop {
	struct addr	addr;
	struct icmp_hdr	icmp;
	int		rtt;
	int		ttl;
};

static int
test_ip_tracert(void)
{
	struct timeval tv;
	struct hop hops[IP_TTL_DEFAULT];
	struct pkt *pkt;
	struct icmp_msg_echo *echo;
	int i, hopcnt, max_ttl;

	printf("ip-tracert: "); fflush(stdout);

	pcap_filter(ctx.pcap, "icmp[0] = 0 and src %s and dst %s",
	    addr_ntoa(&ctx.dst), addr_ntoa(&ctx.src));
	
	ping->pkt_icmp_msg->echo.icmp_id = rand_uint16(ctx.rnd);
	pkt = pkt_dup(ping);
	pkt->pkt_ip->ip_id = rand_uint16(ctx.rnd);
	ip_checksum(pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
	
	send_pkt(pkt);
	tv = read_tv;
	
	if ((pkt = recv_pkt(&tv)) == NULL) {
		printf("no reply\n");
		return (0);
	}
	/* XXX - guess remote stack's starting TTL */
	for (i = 2; pkt->pkt_ip->ip_ttl > i; i <<= 1)
		;
	
	if ((max_ttl = i - pkt->pkt_ip->ip_ttl + 1) > IP_TTL_DEFAULT)
		max_ttl = IP_TTL_DEFAULT;

	printf("%s, %d hops max\n", ip_ntoa(&ping->pkt_ip->ip_dst), max_ttl);
	pcap_filter(ctx.pcap, "icmp and dst %s", addr_ntoa(&ctx.src));

	for (i = 1; i < max_ttl + 1; i++) {
		pkt = pkt_dup(ping);
		pkt->pkt_ip->ip_id = rand_uint16(ctx.rnd);
		pkt->pkt_ip->ip_ttl = i;
		pkt->pkt_icmp_msg->echo.icmp_seq = htons(i);
		ip_checksum(pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
		send_pkt(pkt);
		usleep(42);	/* XXX */
	}
	memset(&hops, 0, sizeof(hops));
	hopcnt = 0;
	
	for (tv = read_tv; (pkt = recv_pkt(&tv)) != NULL; tv = read_tv) {
		if ((pkt->pkt_icmp->icmp_type == ICMP_TIMEXCEED ||
		    pkt->pkt_icmp->icmp_type == ICMP_UNREACH) &&
		    pkt->pkt_end - pkt->pkt_eth_data >=
		    (IP_HDR_LEN + ICMP_LEN_MIN) * 2) {
			echo = (struct icmp_msg_echo *)
			    (pkt->pkt_icmp_msg->timexceed.icmp_ip +
				IP_HDR_LEN + ICMP_HDR_LEN);
		} else if (pkt->pkt_icmp->icmp_type == ICMP_ECHOREPLY) {
			echo = &pkt->pkt_icmp_msg->echo;
		} else
			continue;

		if (echo->icmp_id != ping->pkt_icmp_msg->echo.icmp_id)
			continue;
		
		i = ntohs(echo->icmp_seq);
		addr_pack(&hops[i].addr, ADDR_TYPE_IP, IP_ADDR_BITS,
		    &pkt->pkt_ip->ip_src, IP_ADDR_LEN);
		memcpy(&hops[i].icmp, pkt->pkt_icmp, ICMP_HDR_LEN);
		hops[i].ttl = pkt->pkt_ip->ip_ttl;
		hopcnt++;
		
		if (pkt->pkt_ip->ip_src == ping->pkt_ip->ip_dst)
			break;
	}
	for (i = 1; i < hopcnt + 1; i++) {
		if (hops[i].addr.addr_type == ADDR_TYPE_IP) {
			printf("%2d  %s (%d)\n",
			    i, addr_ntoa(&hops[i].addr), hops[i].ttl);
		} else
			printf("%2d  *\n", i);
	}
	return (0);
}

static int
test_frag(char *overlap, int drop)
{
	struct timeval tv, save_tv = read_tv;
	struct pkt *pkt;
	struct icmp_msg_echo *echo;
	char *frag_argv[4];

	if (overlap != NULL)
		printf("frag-%s: ", overlap);
	else if (drop)
		printf("frag-timeout (please wait): ");
	else
		printf("frag: ");
	fflush(stdout);

	ping->pkt_ip->ip_id = rand_uint16(ctx.rnd);
	ping->pkt_icmp_msg->echo.icmp_id = rand_uint16(ctx.rnd);
	pkt = pkt_dup(ping);
	ip_checksum(pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
	TAILQ_INSERT_TAIL(&ctx.pktq, pkt, pkt_next);
	
	frag_argv[0] = "ip_frag";
	frag_argv[1] = "8";
	frag_argv[2] = overlap;
	frag_argv[3] = NULL;
	
	mod_ip_frag.open(overlap ? 3 : 2, frag_argv);
	mod_ip_frag.apply(NULL, &ctx.pktq);

	if (drop) {
		pkt = TAILQ_LAST(&ctx.pktq, pktq);
		TAILQ_REMOVE(&ctx.pktq, pkt, pkt_next);
		pkt_free(pkt);
		save_tv.tv_sec = FRAG_TIMEOUT;
	}
	pcap_filter(ctx.pcap, "icmp[0] = %d and src %s and dst %s",
	    drop ? 11 : 0, addr_ntoa(&ctx.dst), addr_ntoa(&ctx.src));

	send_pktq(&ctx.pktq);

	for (tv = save_tv; (pkt = recv_pkt(&tv)) != NULL; tv = save_tv) {
		if (drop) {
			echo = (struct icmp_msg_echo *)
			    (pkt->pkt_icmp_msg->timexceed.icmp_ip +
				IP_HDR_LEN + ICMP_HDR_LEN);
		} else {
			echo = &pkt->pkt_icmp_msg->echo;
		}
		if (echo->icmp_id == ping->pkt_icmp_msg->echo.icmp_id)
			break;
	}
	printf("%s\n", pkt ? timeval_ntoa(&tv) : "no reply");
	
	return (0);
}

int
main(int argc, char *argv[])
{
	struct intf_entry ifent;
	intf_t *intf;
	int i, tests;
	char *cmd;
	
	if (argc < 3)
		usage();

	for (tests = 0, i = 1; i < argc - 1; i++) {
		cmd = argv[i];
		
		if (strcmp(cmd, "all") == 0)
			tests = ~0;
		else if (strcmp(cmd, "ping") == 0)
			tests |= TEST_PING;
		else if (strcmp(cmd, "ip-opt") == 0)
			tests |= TEST_IP_OPT;
		else if (strcmp(cmd, "ip-tracert") == 0)
			tests |= TEST_IP_TRACERT;
		else if (strcmp(cmd, "frag") == 0)
			tests |= TEST_FRAG;
		else if (strcmp(cmd, "frag-new") == 0)
			tests |= TEST_FRAG_NEW;
		else if (strcmp(cmd, "frag-old") == 0)
			tests |= TEST_FRAG_OLD;
		else if (strcmp(cmd, "frag-timeout") == 0)
			tests |= TEST_FRAG_TIMEOUT;
		else
			usage();
	}
	if (addr_aton(argv[i], &ctx.dst) < 0)
		err(1, "invalid host %s", argv[i]);

	if ((intf = intf_open()) == NULL)
		err(1, "couldn't open interface handle");

	ifent.intf_len = sizeof(ifent);
	
	if (intf_get_dst(intf, &ifent, &ctx.dst) < 0)
		err(1, "couldn't find interface for %s", addr_ntoa(&ctx.dst));
	
	memcpy(&ctx.src, &ifent.intf_addr, sizeof(ctx.src));
	ctx.src.addr_bits = IP_ADDR_BITS;
	
	intf_close(intf);
	
	if ((ctx.ip = ip_open()) == NULL)
		err(1, "couldn't open raw IP interface");

	if ((ctx.pcap = pcap_open(ifent.intf_name)) == NULL)
		err(1, "couldn't open %s for sniffing", ifent.intf_name);
	
	if ((ctx.dloff = pcap_dloff(ctx.pcap)) < 0)
		err(1, "couldn't determine link layer offset");
	
	ctx.rnd = rand_open();
	pkt_init(16);
	TAILQ_INIT(&ctx.pktq);

	ping = pkt_new();
	ip_pack_hdr(ping->pkt_ip, 0, IP_HDR_LEN + 8 + 24, 666, 0,
	    IP_TTL_DEFAULT, IP_PROTO_ICMP, ctx.src.addr_ip, ctx.dst.addr_ip);
	icmp_pack_hdr_echo(ping->pkt_icmp, ICMP_ECHO, ICMP_CODE_NONE,
	    666, 1, "AAAAAAAABBBBBBBBCCCCCCCC", 24);
	ping->pkt_end = ping->pkt_eth_data + IP_HDR_LEN + 8 + 24;
	pkt_decorate(ping);
	
	if ((tests & TEST_PING) != 0)
		test_ping();
	if ((tests & TEST_IP_OPT) != 0)
		test_ip_opt();
	if ((tests & TEST_IP_TRACERT) != 0)
		test_ip_tracert();
	if ((tests & TEST_FRAG) != 0)
		test_frag(NULL, 0);
	if ((tests & TEST_FRAG_NEW) != 0)
		test_frag("new", 0);
	if ((tests & TEST_FRAG_OLD) != 0)
		test_frag("old", 0);
	if ((tests & TEST_FRAG_TIMEOUT) != 0)
		test_frag(NULL, 1);

	rand_close(ctx.rnd);
	pcap_close(ctx.pcap);
	ip_close(ctx.ip);
	
	exit(0);
}