xref: /f-stack/tools/ipfw/main.c (revision b9e91cfd)
1 /*
2  * Copyright (c) 2002-2003,2010 Luigi Rizzo
3  * Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
4  * Copyright (c) 1994 Ugen J.S.Antsilevich
5  *
6  * Idea and grammar partially left from:
7  * Copyright (c) 1993 Daniel Boulet
8  *
9  * Redistribution and use in source forms, with and without modification,
10  * are permitted provided that this entire comment appears intact.
11  *
12  * Redistribution in binary form may occur without any restrictions.
13  * Obviously, it would be nice if you gave credit where credit is due
14  * but requiring it would be too onerous.
15  *
16  * This software is provided ``AS IS'' without any warranties of any kind.
17  *
18  * Command line interface for IP firewall facility
19  *
20  * $FreeBSD$
21  */
22 
23 #include <sys/wait.h>
24 #include <ctype.h>
25 #include <err.h>
26 #include <errno.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sysexits.h>
32 #include <unistd.h>
33 
34 #ifdef FSTACK
35 #include <stdint.h>
36 #include "ff_ipc.h"
37 #endif
38 
39 #include "ipfw2.h"
40 
41 static void
42 help(void)
43 {
44 	fprintf(stderr,
45 "ipfw syntax summary (but please do read the ipfw(8) manpage):\n\n"
46 #ifndef FSTACK
47 "\tipfw [-abcdefhnNqStTv] <command>\n\n"
48 #else
49 "\tipfw -P <f-stack proc_id> [-abcdefhnNqStTv] <command>\n\n"
50 #endif
51 "where <command> is one of the following:\n\n"
52 "add [num] [set N] [prob x] RULE-BODY\n"
53 "{pipe|queue} N config PIPE-BODY\n"
54 "[pipe|queue] {zero|delete|show} [N{,N}]\n"
55 "nat N config {ip IPADDR|if IFNAME|log|deny_in|same_ports|unreg_only|reset|\n"
56 "		reverse|proxy_only|redirect_addr linkspec|\n"
57 "		redirect_port linkspec|redirect_proto linkspec}\n"
58 "set [disable N... enable N...] | move [rule] X to Y | swap X Y | show\n"
59 "set N {show|list|zero|resetlog|delete} [N{,N}] | flush\n"
60 "table N {add ip[/bits] [value] | delete ip[/bits] | flush | list}\n"
61 "table all {flush | list}\n"
62 "\n"
63 "RULE-BODY:	check-state [PARAMS] | ACTION [PARAMS] ADDR [OPTION_LIST]\n"
64 "ACTION:	check-state | allow | count | deny | unreach{,6} CODE |\n"
65 "               skipto N | {divert|tee} PORT | forward ADDR |\n"
66 "               pipe N | queue N | nat N | setfib FIB | reass\n"
67 "PARAMS: 	[log [logamount LOGLIMIT]] [altq QUEUE_NAME]\n"
68 "ADDR:		[ MAC dst src ether_type ] \n"
69 "		[ ip from IPADDR [ PORT ] to IPADDR [ PORTLIST ] ]\n"
70 "		[ ipv6|ip6 from IP6ADDR [ PORT ] to IP6ADDR [ PORTLIST ] ]\n"
71 "IPADDR:	[not] { any | me | ip/bits{x,y,z} | table(t[,v]) | IPLIST }\n"
72 "IP6ADDR:	[not] { any | me | me6 | ip6/bits | IP6LIST }\n"
73 "IP6LIST:	{ ip6 | ip6/bits }[,IP6LIST]\n"
74 "IPLIST:	{ ip | ip/bits | ip:mask }[,IPLIST]\n"
75 "OPTION_LIST:	OPTION [OPTION_LIST]\n"
76 "OPTION:	bridged | diverted | diverted-loopback | diverted-output |\n"
77 "	{dst-ip|src-ip} IPADDR | {dst-ip6|src-ip6|dst-ipv6|src-ipv6} IP6ADDR |\n"
78 "	{dst-port|src-port} LIST |\n"
79 "	estab | frag | {gid|uid} N | icmptypes LIST | in | out | ipid LIST |\n"
80 "	iplen LIST | ipoptions SPEC | ipprecedence | ipsec | iptos SPEC |\n"
81 "	ipttl LIST | ipversion VER | keep-state | layer2 | limit ... |\n"
82 "	icmp6types LIST | ext6hdr LIST | flow-id N[,N] | fib FIB |\n"
83 "	mac ... | mac-type LIST | proto LIST | {recv|xmit|via} {IF|IPADDR} |\n"
84 "	setup | {tcpack|tcpseq|tcpwin} NN | tcpflags SPEC | tcpoptions SPEC |\n"
85 "	tcpdatalen LIST | verrevpath | versrcreach | antispoof\n"
86 );
87 
88 	exit(0);
89 }
90 
91 /*
92  * Called with the arguments, including program name because getopt
93  * wants it to be present.
94  * Returns 0 if successful, 1 if empty command, errx() in case of errors.
95  * First thing we do is process parameters creating an argv[] array
96  * which includes the program name and a NULL entry at the end.
97  * If we are called with a single string, we split it on whitespace.
98  * Also, arguments with a trailing ',' are joined to the next one.
99  * The pointers (av[]) and data are in a single chunk of memory.
100  * av[0] points to the original program name, all other entries
101  * point into the allocated chunk.
102  */
103 static int
104 ipfw_main(int oldac, char **oldav)
105 {
106 	int ch, ac;
107 	const char *errstr;
108 	char **av, **save_av;
109 	int do_acct = 0;		/* Show packet/byte count */
110 	int try_next = 0;		/* set if pipe cmd not found */
111 	int av_size;			/* compute the av size */
112 	char *av_p;			/* used to build the av list */
113 
114 #define WHITESP		" \t\f\v\n\r"
115 	if (oldac < 2)
116 		return 1;	/* need at least one argument */
117 
118 	if (oldac == 2) {
119 		/*
120 		 * If we are called with one argument, try to split it into
121 		 * words for subsequent parsing. Spaces after a ',' are
122 		 * removed by copying the string in-place.
123 		 */
124 		char *arg = oldav[1];	/* The string is the first arg. */
125 		int l = strlen(arg);
126 		int copy = 0;		/* 1 if we need to copy, 0 otherwise */
127 		int i, j;
128 
129 		for (i = j = 0; i < l; i++) {
130 			if (arg[i] == '#')	/* comment marker */
131 				break;
132 			if (copy) {
133 				arg[j++] = arg[i];
134 				copy = !strchr("," WHITESP, arg[i]);
135 			} else {
136 				copy = !strchr(WHITESP, arg[i]);
137 				if (copy)
138 					arg[j++] = arg[i];
139 			}
140 		}
141 		if (!copy && j > 0)	/* last char was a 'blank', remove it */
142 			j--;
143 		l = j;			/* the new argument length */
144 		arg[j++] = '\0';
145 		if (l == 0)		/* empty string! */
146 			return 1;
147 
148 		/*
149 		 * First, count number of arguments. Because of the previous
150 		 * processing, this is just the number of blanks plus 1.
151 		 */
152 		for (i = 0, ac = 1; i < l; i++)
153 			if (strchr(WHITESP, arg[i]) != NULL)
154 				ac++;
155 
156 		/*
157 		 * Allocate the argument list structure as a single block
158 		 * of memory, containing pointers and the argument
159 		 * strings. We include one entry for the program name
160 		 * because getopt expects it, and a NULL at the end
161 		 * to simplify further parsing.
162 		 */
163 		ac++;		/* add 1 for the program name */
164 		av_size = (ac+1) * sizeof(char *) + l + 1;
165 		av = safe_calloc(av_size, 1);
166 
167 		/*
168 		 * Init the argument pointer to the end of the array
169 		 * and copy arguments from arg[] to av[]. For each one,
170 		 * j is the initial character, i is the one past the end.
171 		 */
172 		av_p = (char *)&av[ac+1];
173 		for (ac = 1, i = j = 0; i < l; i++) {
174 			if (strchr(WHITESP, arg[i]) != NULL || i == l-1) {
175 				if (i == l-1)
176 					i++;
177 				bcopy(arg+j, av_p, i-j);
178 				av[ac] = av_p;
179 				av_p += i-j;	/* the length of the string */
180 				*av_p++ = '\0';
181 				ac++;
182 				j = i + 1;
183 			}
184 		}
185 	} else {
186 		/*
187 		 * If an argument ends with ',' join with the next one.
188 		 */
189 		int first, i, l=0;
190 
191 		/*
192 		 * Allocate the argument list structure as a single block
193 		 * of memory, containing both pointers and the argument
194 		 * strings. We include some space for the program name
195 		 * because getopt expects it.
196 		 * We add an extra pointer to the end of the array,
197 		 * to make simpler further parsing.
198 		 */
199 		for (i=0; i<oldac; i++)
200 			l += strlen(oldav[i]);
201 
202 		av_size = (oldac+1) * sizeof(char *) + l + oldac;
203 		av = safe_calloc(av_size, 1);
204 
205 		/*
206 		 * Init the argument pointer to the end of the array
207 		 * and copy arguments from arg[] to av[]
208 		 */
209 		av_p = (char *)&av[oldac+1];
210 		for (first = i = ac = 1, l = 0; i < oldac; i++) {
211 			char *arg = oldav[i];
212 			int k = strlen(arg);
213 
214 			l += k;
215 			if (arg[k-1] != ',' || i == oldac-1) {
216 				/* Time to copy. */
217 				av[ac] = av_p;
218 				for (l=0; first <= i; first++) {
219 					strcat(av_p, oldav[first]);
220 					av_p += strlen(oldav[first]);
221 				}
222 				*av_p++ = '\0';
223 				ac++;
224 				l = 0;
225 				first = i+1;
226 			}
227 		}
228 	}
229 
230 	/*
231 	 * set the progname pointer to the original string
232 	 * and terminate the array with null
233 	 */
234 	av[0] = oldav[0];
235 	av[ac] = NULL;
236 
237 	/* Set the force flag for non-interactive processes */
238 	if (!co.do_force)
239 		co.do_force = !isatty(STDIN_FILENO);
240 
241 #ifdef EMULATE_SYSCTL /* sysctl emulation */
242 	if ( ac >= 2 && !strcmp(av[1], "sysctl")) {
243 		char *s;
244 		int i;
245 
246 		if (ac != 3) {
247 			printf(	"sysctl emulation usage:\n"
248 				"	ipfw sysctl name[=value]\n"
249 				"	ipfw sysctl -a\n");
250 			return 0;
251 		}
252 		s = strchr(av[2], '=');
253 		if (s == NULL) {
254 			s = !strcmp(av[2], "-a") ? NULL : av[2];
255 			sysctlbyname(s, NULL, NULL, NULL, 0);
256 		} else {	/* ipfw sysctl x.y.z=value */
257 			/* assume an INT value, will extend later */
258 			if (s[1] == '\0') {
259 				printf("ipfw sysctl: missing value\n\n");
260 				return 0;
261 			}
262 			*s = '\0';
263 			i = strtol(s+1, NULL, 0);
264 			sysctlbyname(av[2], NULL, NULL, &i, sizeof(int));
265 		}
266 		return 0;
267 	}
268 #endif
269 
270 	/* Save arguments for final freeing of memory. */
271 	save_av = av;
272 
273 	optind = optreset = 1;	/* restart getopt() */
274 #ifndef FSTACK
275 	while ((ch = getopt(ac, av, "abcdefhinNp:qs:STtv")) != -1)
276 #else
277 	while ((ch = getopt(ac, av, "abcdefhinNp:qs:STtvP:")) != -1)
278 #endif
279 		switch (ch) {
280 		case 'a':
281 			do_acct = 1;
282 			break;
283 
284 		case 'b':
285 			co.comment_only = 1;
286 			co.do_compact = 1;
287 			break;
288 
289 		case 'c':
290 			co.do_compact = 1;
291 			break;
292 
293 		case 'd':
294 			co.do_dynamic = 1;
295 			break;
296 
297 		case 'e':
298 			co.do_expired = 1;
299 			break;
300 
301 		case 'f':
302 			co.do_force = 1;
303 			break;
304 
305 		case 'h': /* help */
306 			free(save_av);
307 			help();
308 			break;	/* NOTREACHED */
309 
310 		case 'i':
311 			co.do_value_as_ip = 1;
312 			break;
313 
314 		case 'n':
315 			co.test_only = 1;
316 			break;
317 
318 		case 'N':
319 			co.do_resolv = 1;
320 			break;
321 
322 		case 'p':
323 			errx(EX_USAGE, "An absolute pathname must be used "
324 			    "with -p option.");
325 			/* NOTREACHED */
326 
327 		case 'q':
328 			co.do_quiet = 1;
329 			break;
330 
331 		case 's': /* sort */
332 			co.do_sort = atoi(optarg);
333 			break;
334 
335 		case 'S':
336 			co.show_sets = 1;
337 			break;
338 
339 		case 't':
340 			co.do_time = 1;
341 			break;
342 
343 		case 'T':
344 			co.do_time = 2;	/* numeric timestamp */
345 			break;
346 
347 		case 'v': /* verbose */
348 			co.verbose = 1;
349 			break;
350 #ifdef FSTACK
351 		case 'P':
352 			ff_set_proc_id(atoi(optarg));
353 			break;
354 #endif
355 		default:
356 			free(save_av);
357 			return 1;
358 		}
359 
360 	ac -= optind;
361 	av += optind;
362 	NEED1("bad arguments, for usage summary ``ipfw''");
363 
364 	/*
365 	 * An undocumented behaviour of ipfw1 was to allow rule numbers first,
366 	 * e.g. "100 add allow ..." instead of "add 100 allow ...".
367 	 * In case, swap first and second argument to get the normal form.
368 	 */
369 	if (ac > 1 && isdigit(*av[0])) {
370 		char *p = av[0];
371 
372 		av[0] = av[1];
373 		av[1] = p;
374 	}
375 
376 	/*
377 	 * Optional: pipe, queue or nat.
378 	 */
379 	co.do_nat = 0;
380 	co.do_pipe = 0;
381 	co.use_set = 0;
382 	if (!strncmp(*av, "nat", strlen(*av)))
383  		co.do_nat = 1;
384  	else if (!strncmp(*av, "pipe", strlen(*av)))
385 		co.do_pipe = 1;
386 	else if (_substrcmp(*av, "queue") == 0)
387 		co.do_pipe = 2;
388 	else if (_substrcmp(*av, "flowset") == 0)
389 		co.do_pipe = 2;
390 	else if (_substrcmp(*av, "sched") == 0)
391 		co.do_pipe = 3;
392 	else if (!strncmp(*av, "set", strlen(*av))) {
393 		if (ac > 1 && isdigit(av[1][0])) {
394 			co.use_set = strtonum(av[1], 0, resvd_set_number,
395 					&errstr);
396 			if (errstr)
397 				errx(EX_DATAERR,
398 				    "invalid set number %s\n", av[1]);
399 			ac -= 2; av += 2; co.use_set++;
400 		}
401 	}
402 
403 	if (co.do_pipe || co.do_nat) {
404 		ac--;
405 		av++;
406 	}
407 	NEED1("missing command");
408 
409 	/*
410 	 * For pipes, queues and nats we normally say 'nat|pipe NN config'
411 	 * but the code is easier to parse as 'nat|pipe config NN'
412 	 * so we swap the two arguments.
413 	 */
414 	if ((co.do_pipe || co.do_nat) && ac > 1 && isdigit(*av[0])) {
415 		char *p = av[0];
416 
417 		av[0] = av[1];
418 		av[1] = p;
419 	}
420 
421 	if (co.use_set == 0) {
422 		if (_substrcmp(*av, "add") == 0)
423 			ipfw_add(av);
424 		else if (co.do_nat && _substrcmp(*av, "show") == 0)
425  			ipfw_show_nat(ac, av);
426 		else if (co.do_pipe && _substrcmp(*av, "config") == 0)
427 #ifdef DUMMYNET
428 			ipfw_config_pipe(ac, av);
429 #else
430 		{
431 			errx(EX_UNAVAILABLE, "ipfw_config_pipe not supported");
432 		}
433 #endif
434 		else if (co.do_nat && _substrcmp(*av, "config") == 0)
435  			ipfw_config_nat(ac, av);
436 		else if (_substrcmp(*av, "set") == 0)
437 			ipfw_sets_handler(av);
438 		else if (_substrcmp(*av, "table") == 0)
439 			ipfw_table_handler(ac, av);
440 		else if (_substrcmp(*av, "enable") == 0)
441 			ipfw_sysctl_handler(av, 1);
442 		else if (_substrcmp(*av, "disable") == 0)
443 			ipfw_sysctl_handler(av, 0);
444 		else
445 			try_next = 1;
446 	}
447 
448 	if (co.use_set || try_next) {
449 		if (_substrcmp(*av, "delete") == 0)
450 			ipfw_delete(av);
451 		else if (_substrcmp(*av, "flush") == 0)
452 			ipfw_flush(co.do_force);
453 		else if (_substrcmp(*av, "zero") == 0)
454 			ipfw_zero(ac, av, 0 /* IP_FW_ZERO */);
455 		else if (_substrcmp(*av, "resetlog") == 0)
456 			ipfw_zero(ac, av, 1 /* IP_FW_RESETLOG */);
457 		else if (_substrcmp(*av, "print") == 0 ||
458 			 _substrcmp(*av, "list") == 0)
459 			ipfw_list(ac, av, do_acct);
460 		else if (_substrcmp(*av, "show") == 0)
461 			ipfw_list(ac, av, 1 /* show counters */);
462 		else if (_substrcmp(*av, "table") == 0)
463 			ipfw_table_handler(ac, av);
464 		else if (_substrcmp(*av, "internal") == 0)
465 			ipfw_internal_handler(ac, av);
466 		else
467 			errx(EX_USAGE, "bad command `%s'", *av);
468 	}
469 
470 	/* Free memory allocated in the argument parsing. */
471 	free(save_av);
472 	return 0;
473 }
474 
475 
476 static void
477 ipfw_readfile(int ac, char *av[])
478 {
479 #define MAX_ARGS	32
480 	char buf[4096];
481 	char *progname = av[0];		/* original program name */
482 	const char *cmd = NULL;		/* preprocessor name, if any */
483 	const char *filename = av[ac-1]; /* file to read */
484 	int	c, lineno=0;
485 	FILE	*f = NULL;
486 	pid_t	preproc = 0;
487 
488 #ifndef FSTACK
489 	while ((c = getopt(ac, av, "cfNnp:qS")) != -1) {
490 #else
491 	while ((c = getopt(ac, av, "cfNnp:qSP:")) != -1) {
492 #endif
493 		switch(c) {
494 		case 'c':
495 			co.do_compact = 1;
496 			break;
497 
498 		case 'f':
499 			co.do_force = 1;
500 			break;
501 
502 		case 'N':
503 			co.do_resolv = 1;
504 			break;
505 
506 		case 'n':
507 			co.test_only = 1;
508 			break;
509 
510 		case 'p':
511 			/*
512 			 * ipfw -p cmd [args] filename
513 			 *
514 			 * We are done with getopt(). All arguments
515 			 * except the filename go to the preprocessor,
516 			 * so we need to do the following:
517 			 * - check that a filename is actually present;
518 			 * - advance av by optind-1 to skip arguments
519 			 *   already processed;
520 			 * - decrease ac by optind, to remove the args
521 			 *   already processed and the final filename;
522 			 * - set the last entry in av[] to NULL so
523 			 *   popen() can detect the end of the array;
524 			 * - set optind=ac to let getopt() terminate.
525 			 */
526 			if (optind == ac)
527 				errx(EX_USAGE, "no filename argument");
528 			cmd = optarg;
529 			av[ac-1] = NULL;
530 			av += optind - 1;
531 			ac -= optind;
532 			optind = ac;
533 			break;
534 
535 		case 'q':
536 			co.do_quiet = 1;
537 			break;
538 
539 		case 'S':
540 			co.show_sets = 1;
541 			break;
542 
543 #ifdef FSTACK
544 		case 'P':
545 			ff_set_proc_id(atoi(optarg));
546 			break;
547 #endif
548 
549 		default:
550 			errx(EX_USAGE, "bad arguments, for usage"
551 			     " summary ``ipfw''");
552 		}
553 
554 	}
555 
556 	if (cmd == NULL && ac != optind + 1)
557 		errx(EX_USAGE, "extraneous filename arguments %s", av[ac-1]);
558 
559 	if ((f = fopen(filename, "r")) == NULL)
560 		err(EX_UNAVAILABLE, "fopen: %s", filename);
561 
562 	if (cmd != NULL) {			/* pipe through preprocessor */
563 		int pipedes[2];
564 
565 		if (pipe(pipedes) == -1)
566 			err(EX_OSERR, "cannot create pipe");
567 
568 		preproc = fork();
569 		if (preproc == -1)
570 			err(EX_OSERR, "cannot fork");
571 
572 		if (preproc == 0) {
573 			/*
574 			 * Child, will run the preprocessor with the
575 			 * file on stdin and the pipe on stdout.
576 			 */
577 			if (dup2(fileno(f), 0) == -1
578 			    || dup2(pipedes[1], 1) == -1)
579 				err(EX_OSERR, "dup2()");
580 			fclose(f);
581 			close(pipedes[1]);
582 			close(pipedes[0]);
583 			execvp(cmd, av);
584 			err(EX_OSERR, "execvp(%s) failed", cmd);
585 		} else { /* parent, will reopen f as the pipe */
586 			fclose(f);
587 			close(pipedes[1]);
588 			if ((f = fdopen(pipedes[0], "r")) == NULL) {
589 				int savederrno = errno;
590 
591 				(void)kill(preproc, SIGTERM);
592 				errno = savederrno;
593 				err(EX_OSERR, "fdopen()");
594 			}
595 		}
596 	}
597 
598 	while (fgets(buf, sizeof(buf), f)) {		/* read commands */
599 		char linename[20];
600 		char *args[2];
601 
602 		lineno++;
603 		snprintf(linename, sizeof(linename), "Line %d", lineno);
604 #ifndef FSTACK
605 		setprogname(linename); /* XXX */
606 #endif
607 		args[0] = progname;
608 		args[1] = buf;
609 		ipfw_main(2, args);
610 	}
611 	fclose(f);
612 	if (cmd != NULL) {
613 		int status;
614 
615 		if (waitpid(preproc, &status, 0) == -1)
616 			errx(EX_OSERR, "waitpid()");
617 		if (WIFEXITED(status) && WEXITSTATUS(status) != EX_OK)
618 			errx(EX_UNAVAILABLE,
619 			    "preprocessor exited with status %d",
620 			    WEXITSTATUS(status));
621 		else if (WIFSIGNALED(status))
622 			errx(EX_UNAVAILABLE,
623 			    "preprocessor exited with signal %d",
624 			    WTERMSIG(status));
625 	}
626 }
627 
628 int
629 main(int ac, char *av[])
630 {
631 #if defined(_WIN32) && defined(TCC)
632 	{
633 		WSADATA wsaData;
634 		int ret=0;
635 		unsigned short wVersionRequested = MAKEWORD(2, 2);
636 		ret = WSAStartup(wVersionRequested, &wsaData);
637 		if (ret != 0) {
638 			/* Tell the user that we could not find a usable */
639 			/* Winsock DLL.				  */
640 			printf("WSAStartup failed with error: %d\n", ret);
641 			return 1;
642 		}
643 	}
644 #endif
645 	/*
646 	 * If the last argument is an absolute pathname, interpret it
647 	 * as a file to be preprocessed.
648 	 */
649 #ifdef FSTACK
650 	ff_ipc_init();
651 #endif
652 	if (ac > 1 && av[ac - 1][0] == '/') {
653 		if (access(av[ac - 1], R_OK) == 0)
654 			ipfw_readfile(ac, av);
655 		else
656 			err(EX_USAGE, "pathname: %s", av[ac - 1]);
657 	} else {
658 		if (ipfw_main(ac, av)) {
659 			errx(EX_USAGE,
660 			    "usage: ipfw [options]\n"
661 			    "do \"ipfw -h\" or \"man ipfw\" for details");
662 		}
663 	}
664 	return EX_OK;
665 }
666