xref: /freebsd/sbin/ipfw/main.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 #include "ipfw2.h"
35 
36 static void
37 help(void)
38 {
39 	fprintf(stderr,
40 "ipfw syntax summary (but please do read the ipfw(8) manpage):\n\n"
41 "\tipfw [-abcdefhnNqStTv] <command>\n\n"
42 "where <command> is one of the following:\n\n"
43 "add [num] [set N] [prob x] RULE-BODY\n"
44 "{pipe|queue} N config PIPE-BODY\n"
45 "[pipe|queue] {zero|delete|show} [N{,N}]\n"
46 "nat N config {ip IPADDR|if IFNAME|log|deny_in|same_ports|unreg_only|unreg_cgn|\n"
47 "		reset|reverse|proxy_only|redirect_addr linkspec|\n"
48 "		redirect_port linkspec|redirect_proto linkspec|\n"
49 "		port_range lower-upper}\n"
50 "set [disable N... enable N...] | move [rule] X to Y | swap X Y | show\n"
51 "set N {show|list|zero|resetlog|delete} [N{,N}] | flush\n"
52 "table N {add ip[/bits] [value] | delete ip[/bits] | flush | list}\n"
53 "table all {flush | list}\n"
54 "\n"
55 "RULE-BODY:	check-state [PARAMS] | ACTION [PARAMS] ADDR [OPTION_LIST]\n"
56 "ACTION:	check-state | allow | count | deny | unreach{,6} CODE |\n"
57 "               skipto N | {divert|tee} PORT | forward ADDR |\n"
58 "               pipe N | queue N | nat N | setfib FIB | reass\n"
59 "PARAMS: 	[log [logamount LOGLIMIT]] [altq QUEUE_NAME]\n"
60 "ADDR:		[ MAC dst src ether_type ] \n"
61 "		[ ip from IPADDR [ PORT ] to IPADDR [ PORTLIST ] ]\n"
62 "		[ ipv6|ip6 from IP6ADDR [ PORT ] to IP6ADDR [ PORTLIST ] ]\n"
63 "IPADDR:	[not] { any | me | ip/bits{x,y,z} | table(t[,v]) | IPLIST }\n"
64 "IP6ADDR:	[not] { any | me | me6 | ip6/bits | IP6LIST }\n"
65 "IP6LIST:	{ ip6 | ip6/bits }[,IP6LIST]\n"
66 "IPLIST:	{ ip | ip/bits | ip:mask }[,IPLIST]\n"
67 "OPTION_LIST:	OPTION [OPTION_LIST]\n"
68 "OPTION:	bridged | diverted | diverted-loopback | diverted-output |\n"
69 "	{dst-ip|src-ip} IPADDR | {dst-ip6|src-ip6|dst-ipv6|src-ipv6} IP6ADDR |\n"
70 "	{dst-port|src-port} LIST |\n"
71 "	estab | frag | {gid|uid} N | icmptypes LIST | in | out | ipid LIST |\n"
72 "	iplen LIST | ipoptions SPEC | ipprecedence | ipsec | iptos SPEC |\n"
73 "	ipttl LIST | ipversion VER | keep-state | layer2 | limit ... |\n"
74 "	icmp6types LIST | ext6hdr LIST | flow-id N[,N] | fib FIB |\n"
75 "	mac ... | mac-type LIST | proto LIST | {recv|xmit|via} {IF|IPADDR} |\n"
76 "	setup | {tcpack|tcpseq|tcpwin} NN | tcpflags SPEC | tcpoptions SPEC |\n"
77 "	tcpdatalen LIST | verrevpath | versrcreach | antispoof\n"
78 );
79 
80 	exit(0);
81 }
82 
83 /*
84  * Called with the arguments, including program name because getopt
85  * wants it to be present.
86  * Returns 0 if successful, 1 if empty command, errx() in case of errors.
87  * First thing we do is process parameters creating an argv[] array
88  * which includes the program name and a NULL entry at the end.
89  * If we are called with a single string, we split it on whitespace.
90  * Also, arguments with a trailing ',' are joined to the next one.
91  * The pointers (av[]) and data are in a single chunk of memory.
92  * av[0] points to the original program name, all other entries
93  * point into the allocated chunk.
94  */
95 static int
96 ipfw_main(int oldac, char **oldav)
97 {
98 	int ch, ac;
99 	const char *errstr;
100 	char **av, **save_av;
101 	int do_acct = 0;		/* Show packet/byte count */
102 	int try_next = 0;		/* set if pipe cmd not found */
103 	int av_size;			/* compute the av size */
104 	char *av_p;			/* used to build the av list */
105 
106 #define WHITESP		" \t\f\v\n\r"
107 	if (oldac < 2)
108 		return 1;	/* need at least one argument */
109 
110 	if (oldac == 2) {
111 		/*
112 		 * If we are called with one argument, try to split it into
113 		 * words for subsequent parsing. Spaces after a ',' are
114 		 * removed by copying the string in-place.
115 		 */
116 		char *arg = oldav[1];	/* The string is the first arg. */
117 		int l = strlen(arg);
118 		int copy = 0;		/* 1 if we need to copy, 0 otherwise */
119 		int i, j;
120 
121 		for (i = j = 0; i < l; i++) {
122 			if (arg[i] == '#')	/* comment marker */
123 				break;
124 			if (copy) {
125 				arg[j++] = arg[i];
126 				copy = !strchr("," WHITESP, arg[i]);
127 			} else {
128 				copy = !strchr(WHITESP, arg[i]);
129 				if (copy)
130 					arg[j++] = arg[i];
131 			}
132 		}
133 		if (!copy && j > 0)	/* last char was a 'blank', remove it */
134 			j--;
135 		l = j;			/* the new argument length */
136 		arg[j++] = '\0';
137 		if (l == 0)		/* empty string! */
138 			return 1;
139 
140 		/*
141 		 * First, count number of arguments. Because of the previous
142 		 * processing, this is just the number of blanks plus 1.
143 		 */
144 		for (i = 0, ac = 1; i < l; i++)
145 			if (strchr(WHITESP, arg[i]) != NULL)
146 				ac++;
147 
148 		/*
149 		 * Allocate the argument list structure as a single block
150 		 * of memory, containing pointers and the argument
151 		 * strings. We include one entry for the program name
152 		 * because getopt expects it, and a NULL at the end
153 		 * to simplify further parsing.
154 		 */
155 		ac++;		/* add 1 for the program name */
156 		av_size = (ac+1) * sizeof(char *) + l + 1;
157 		av = safe_calloc(av_size, 1);
158 
159 		/*
160 		 * Init the argument pointer to the end of the array
161 		 * and copy arguments from arg[] to av[]. For each one,
162 		 * j is the initial character, i is the one past the end.
163 		 */
164 		av_p = (char *)&av[ac+1];
165 		for (ac = 1, i = j = 0; i < l; i++) {
166 			if (strchr(WHITESP, arg[i]) != NULL || i == l-1) {
167 				if (i == l-1)
168 					i++;
169 				bcopy(arg+j, av_p, i-j);
170 				av[ac] = av_p;
171 				av_p += i-j;	/* the length of the string */
172 				*av_p++ = '\0';
173 				ac++;
174 				j = i + 1;
175 			}
176 		}
177 	} else {
178 		/*
179 		 * If an argument ends with ',' join with the next one.
180 		 */
181 		int first, i, l=0;
182 
183 		/*
184 		 * Allocate the argument list structure as a single block
185 		 * of memory, containing both pointers and the argument
186 		 * strings. We include some space for the program name
187 		 * because getopt expects it.
188 		 * We add an extra pointer to the end of the array,
189 		 * to make simpler further parsing.
190 		 */
191 		for (i=0; i<oldac; i++)
192 			l += strlen(oldav[i]);
193 
194 		av_size = (oldac+1) * sizeof(char *) + l + oldac;
195 		av = safe_calloc(av_size, 1);
196 
197 		/*
198 		 * Init the argument pointer to the end of the array
199 		 * and copy arguments from arg[] to av[]
200 		 */
201 		av_p = (char *)&av[oldac+1];
202 		for (first = i = ac = 1, l = 0; i < oldac; i++) {
203 			char *arg = oldav[i];
204 			int k = strlen(arg);
205 
206 			l += k;
207 			if (arg[k-1] != ',' || i == oldac-1) {
208 				/* Time to copy. */
209 				av[ac] = av_p;
210 				for (l=0; first <= i; first++) {
211 					strcat(av_p, oldav[first]);
212 					av_p += strlen(oldav[first]);
213 				}
214 				*av_p++ = '\0';
215 				ac++;
216 				l = 0;
217 				first = i+1;
218 			}
219 		}
220 	}
221 
222 	/*
223 	 * set the progname pointer to the original string
224 	 * and terminate the array with null
225 	 */
226 	av[0] = oldav[0];
227 	av[ac] = NULL;
228 
229 	/* Set the force flag for non-interactive processes */
230 	if (!g_co.do_force)
231 		g_co.do_force = !isatty(STDIN_FILENO);
232 
233 #ifdef EMULATE_SYSCTL /* sysctl emulation */
234 	if ( ac >= 2 && !strcmp(av[1], "sysctl")) {
235 		char *s;
236 		int i;
237 
238 		if (ac != 3) {
239 			printf(	"sysctl emulation usage:\n"
240 				"	ipfw sysctl name[=value]\n"
241 				"	ipfw sysctl -a\n");
242 			return 0;
243 		}
244 		s = strchr(av[2], '=');
245 		if (s == NULL) {
246 			s = !strcmp(av[2], "-a") ? NULL : av[2];
247 			sysctlbyname(s, NULL, NULL, NULL, 0);
248 		} else {	/* ipfw sysctl x.y.z=value */
249 			/* assume an INT value, will extend later */
250 			if (s[1] == '\0') {
251 				printf("ipfw sysctl: missing value\n\n");
252 				return 0;
253 			}
254 			*s = '\0';
255 			i = strtol(s+1, NULL, 0);
256 			sysctlbyname(av[2], NULL, NULL, &i, sizeof(int));
257 		}
258 		return 0;
259 	}
260 #endif
261 
262 	/* Save arguments for final freeing of memory. */
263 	save_av = av;
264 
265 	optind = optreset = 1;	/* restart getopt() */
266 	while ((ch = getopt(ac, av, "abcdDefhinNp:qs:STtv")) != -1)
267 		switch (ch) {
268 		case 'a':
269 			do_acct = 1;
270 			break;
271 
272 		case 'b':
273 			g_co.comment_only = 1;
274 			g_co.do_compact = 1;
275 			break;
276 
277 		case 'c':
278 			g_co.do_compact = 1;
279 			break;
280 
281 		case 'd':
282 			g_co.do_dynamic = 1;
283 			break;
284 
285 		case 'D':
286 			g_co.do_dynamic = 2;
287 			break;
288 
289 		case 'e':
290 			/* nop for compatibility */
291 			break;
292 
293 		case 'f':
294 			g_co.do_force = 1;
295 			break;
296 
297 		case 'h': /* help */
298 			free(save_av);
299 			help();
300 			break;	/* NOTREACHED */
301 
302 		case 'i':
303 			g_co.do_value_as_ip = 1;
304 			break;
305 
306 		case 'n':
307 			g_co.test_only = 1;
308 			break;
309 
310 		case 'N':
311 			g_co.do_resolv = 1;
312 			break;
313 
314 		case 'p':
315 			errx(EX_USAGE, "An absolute pathname must be used "
316 			    "with -p option.");
317 			/* NOTREACHED */
318 
319 		case 'q':
320 			g_co.do_quiet = 1;
321 			break;
322 
323 		case 's': /* sort */
324 			g_co.do_sort = atoi(optarg);
325 			break;
326 
327 		case 'S':
328 			g_co.show_sets = 1;
329 			break;
330 
331 		case 't':
332 			g_co.do_time = TIMESTAMP_STRING;
333 			break;
334 
335 		case 'T':
336 			g_co.do_time = TIMESTAMP_NUMERIC;
337 			break;
338 
339 		case 'v': /* verbose */
340 			g_co.verbose = 1;
341 			break;
342 
343 		default:
344 			free(save_av);
345 			return 1;
346 		}
347 
348 	ac -= optind;
349 	av += optind;
350 	NEED1("bad arguments, for usage summary ``ipfw''");
351 
352 	/*
353 	 * An undocumented behaviour of ipfw1 was to allow rule numbers first,
354 	 * e.g. "100 add allow ..." instead of "add 100 allow ...".
355 	 * In case, swap first and second argument to get the normal form.
356 	 */
357 	if (ac > 1 && isdigit(*av[0])) {
358 		char *p = av[0];
359 
360 		av[0] = av[1];
361 		av[1] = p;
362 	}
363 
364 	/*
365 	 * Optional: pipe, queue or nat.
366 	 */
367 	g_co.do_nat = 0;
368 	g_co.do_pipe = 0;
369 	g_co.use_set = 0;
370 	if (!strncmp(*av, "nat", strlen(*av)))
371 		g_co.do_nat = 1;
372 	else if (!strncmp(*av, "pipe", strlen(*av)))
373 		g_co.do_pipe = 1;
374 	else if (_substrcmp(*av, "queue") == 0)
375 		g_co.do_pipe = 2;
376 	else if (_substrcmp(*av, "flowset") == 0)
377 		g_co.do_pipe = 2;
378 	else if (_substrcmp(*av, "sched") == 0)
379 		g_co.do_pipe = 3;
380 	else if (!strncmp(*av, "set", strlen(*av))) {
381 		if (ac > 1 && isdigit(av[1][0])) {
382 			g_co.use_set = strtonum(av[1], 0, resvd_set_number,
383 					&errstr);
384 			if (errstr)
385 				errx(EX_DATAERR,
386 				    "invalid set number %s\n", av[1]);
387 			ac -= 2; av += 2; g_co.use_set++;
388 		}
389 	}
390 
391 	if (g_co.do_pipe || g_co.do_nat) {
392 		ac--;
393 		av++;
394 	}
395 	NEED1("missing command");
396 
397 	/*
398 	 * For pipes, queues and nats we normally say 'nat|pipe NN config'
399 	 * but the code is easier to parse as 'nat|pipe config NN'
400 	 * so we swap the two arguments.
401 	 */
402 	if ((g_co.do_pipe || g_co.do_nat) && ac > 1 && isdigit(*av[0])) {
403 		char *p = av[0];
404 
405 		av[0] = av[1];
406 		av[1] = p;
407 	}
408 
409 	if (g_co.use_set == 0) {
410 		if (_substrcmp(*av, "add") == 0)
411 			ipfw_add(av);
412 		else if (g_co.do_nat && _substrcmp(*av, "show") == 0)
413  			ipfw_show_nat(ac, av);
414 		else if (g_co.do_pipe && _substrcmp(*av, "config") == 0)
415 			ipfw_config_pipe(ac, av);
416 		else if (g_co.do_nat && _substrcmp(*av, "config") == 0)
417  			ipfw_config_nat(ac, av);
418 		else if (_substrcmp(*av, "set") == 0)
419 			ipfw_sets_handler(av);
420 		else if (_substrcmp(*av, "table") == 0)
421 			ipfw_table_handler(ac, av);
422 		else if (_substrcmp(*av, "enable") == 0)
423 			ipfw_sysctl_handler(av, 1);
424 		else if (_substrcmp(*av, "disable") == 0)
425 			ipfw_sysctl_handler(av, 0);
426 		else
427 			try_next = 1;
428 	}
429 
430 	if (g_co.use_set || try_next) {
431 		if (_substrcmp(*av, "delete") == 0)
432 			ipfw_delete(av);
433 		else if (!strncmp(*av, "nat64clat", strlen(*av)))
434 			ipfw_nat64clat_handler(ac, av);
435 		else if (!strncmp(*av, "nat64stl", strlen(*av)))
436 			ipfw_nat64stl_handler(ac, av);
437 		else if (!strncmp(*av, "nat64lsn", strlen(*av)))
438 			ipfw_nat64lsn_handler(ac, av);
439 		else if (!strncmp(*av, "nptv6", strlen(*av)))
440 			ipfw_nptv6_handler(ac, av);
441 		else if (_substrcmp(*av, "flush") == 0)
442 			ipfw_flush(g_co.do_force);
443 		else if (_substrcmp(*av, "zero") == 0)
444 			ipfw_zero(ac, av, 0 /* IP_FW_ZERO */);
445 		else if (_substrcmp(*av, "resetlog") == 0)
446 			ipfw_zero(ac, av, 1 /* IP_FW_RESETLOG */);
447 		else if (_substrcmp(*av, "print") == 0 ||
448 			 _substrcmp(*av, "list") == 0)
449 			ipfw_list(ac, av, do_acct);
450 		else if (_substrcmp(*av, "show") == 0)
451 			ipfw_list(ac, av, 1 /* show counters */);
452 		else if (_substrcmp(*av, "table") == 0)
453 			ipfw_table_handler(ac, av);
454 		else if (_substrcmp(*av, "internal") == 0)
455 			ipfw_internal_handler(ac, av);
456 		else
457 			errx(EX_USAGE, "bad command `%s'", *av);
458 	}
459 
460 	/* Free memory allocated in the argument parsing. */
461 	free(save_av);
462 	return 0;
463 }
464 
465 
466 static void
467 ipfw_readfile(int ac, char *av[])
468 {
469 #define MAX_ARGS	32
470 	char buf[4096];
471 	char *progname = av[0];		/* original program name */
472 	const char *cmd = NULL;		/* preprocessor name, if any */
473 	const char *filename = av[ac-1]; /* file to read */
474 	int	c, lineno=0;
475 	FILE	*f = NULL;
476 	pid_t	preproc = 0;
477 
478 	while ((c = getopt(ac, av, "cfNnp:qS")) != -1) {
479 		switch(c) {
480 		case 'c':
481 			g_co.do_compact = 1;
482 			break;
483 
484 		case 'f':
485 			g_co.do_force = 1;
486 			break;
487 
488 		case 'N':
489 			g_co.do_resolv = 1;
490 			break;
491 
492 		case 'n':
493 			g_co.test_only = 1;
494 			break;
495 
496 		case 'p':
497 			/*
498 			 * ipfw -p cmd [args] filename
499 			 *
500 			 * We are done with getopt(). All arguments
501 			 * except the filename go to the preprocessor,
502 			 * so we need to do the following:
503 			 * - check that a filename is actually present;
504 			 * - advance av by optind-1 to skip arguments
505 			 *   already processed;
506 			 * - decrease ac by optind, to remove the args
507 			 *   already processed and the final filename;
508 			 * - set the last entry in av[] to NULL so
509 			 *   popen() can detect the end of the array;
510 			 * - set optind=ac to let getopt() terminate.
511 			 */
512 			if (optind == ac)
513 				errx(EX_USAGE, "no filename argument");
514 			cmd = optarg;
515 			av[ac-1] = NULL;
516 			av += optind - 1;
517 			ac -= optind;
518 			optind = ac;
519 			break;
520 
521 		case 'q':
522 			g_co.do_quiet = 1;
523 			break;
524 
525 		case 'S':
526 			g_co.show_sets = 1;
527 			break;
528 
529 		default:
530 			errx(EX_USAGE, "bad arguments, for usage"
531 			     " summary ``ipfw''");
532 		}
533 
534 	}
535 
536 	if (cmd == NULL && ac != optind + 1)
537 		errx(EX_USAGE, "extraneous filename arguments %s", av[ac-1]);
538 
539 	if ((f = fopen(filename, "r")) == NULL)
540 		err(EX_UNAVAILABLE, "fopen: %s", filename);
541 
542 	if (cmd != NULL) {			/* pipe through preprocessor */
543 		int pipedes[2];
544 
545 		if (pipe(pipedes) == -1)
546 			err(EX_OSERR, "cannot create pipe");
547 
548 		preproc = fork();
549 		if (preproc == -1)
550 			err(EX_OSERR, "cannot fork");
551 
552 		if (preproc == 0) {
553 			/*
554 			 * Child, will run the preprocessor with the
555 			 * file on stdin and the pipe on stdout.
556 			 */
557 			if (dup2(fileno(f), 0) == -1
558 			    || dup2(pipedes[1], 1) == -1)
559 				err(EX_OSERR, "dup2()");
560 			fclose(f);
561 			close(pipedes[1]);
562 			close(pipedes[0]);
563 			execvp(cmd, av);
564 			err(EX_OSERR, "execvp(%s) failed", cmd);
565 		} else { /* parent, will reopen f as the pipe */
566 			fclose(f);
567 			close(pipedes[1]);
568 			if ((f = fdopen(pipedes[0], "r")) == NULL) {
569 				int savederrno = errno;
570 
571 				(void)kill(preproc, SIGTERM);
572 				errno = savederrno;
573 				err(EX_OSERR, "fdopen()");
574 			}
575 		}
576 	}
577 
578 	while (fgets(buf, sizeof(buf), f)) {		/* read commands */
579 		char linename[20];
580 		char *args[2];
581 
582 		lineno++;
583 		snprintf(linename, sizeof(linename), "Line %d", lineno);
584 		setprogname(linename); /* XXX */
585 		args[0] = progname;
586 		args[1] = buf;
587 		ipfw_main(2, args);
588 	}
589 	fclose(f);
590 	if (cmd != NULL) {
591 		int status;
592 
593 		if (waitpid(preproc, &status, 0) == -1)
594 			errx(EX_OSERR, "waitpid()");
595 		if (WIFEXITED(status) && WEXITSTATUS(status) != EX_OK)
596 			errx(EX_UNAVAILABLE,
597 			    "preprocessor exited with status %d",
598 			    WEXITSTATUS(status));
599 		else if (WIFSIGNALED(status))
600 			errx(EX_UNAVAILABLE,
601 			    "preprocessor exited with signal %d",
602 			    WTERMSIG(status));
603 	}
604 }
605 
606 int
607 main(int ac, char *av[])
608 {
609 #if defined(_WIN32) && defined(TCC)
610 	{
611 		WSADATA wsaData;
612 		int ret=0;
613 		unsigned short wVersionRequested = MAKEWORD(2, 2);
614 		ret = WSAStartup(wVersionRequested, &wsaData);
615 		if (ret != 0) {
616 			/* Tell the user that we could not find a usable */
617 			/* Winsock DLL.				  */
618 			printf("WSAStartup failed with error: %d\n", ret);
619 			return 1;
620 		}
621 	}
622 #endif
623 	/*
624 	 * If the last argument is an absolute pathname, interpret it
625 	 * as a file to be preprocessed.
626 	 */
627 
628 	if (ac > 1 && av[ac - 1][0] == '/') {
629 		if (access(av[ac - 1], R_OK) == 0)
630 			ipfw_readfile(ac, av);
631 		else
632 			err(EX_USAGE, "pathname: %s", av[ac - 1]);
633 	} else {
634 		if (ipfw_main(ac, av)) {
635 			errx(EX_USAGE,
636 			    "usage: ipfw [options]\n"
637 			    "do \"ipfw -h\" or \"man ipfw\" for details");
638 		}
639 	}
640 	return EX_OK;
641 }
642