main.c revision 190633 
1/*
2 * Copyright (c) 2002-2003 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: head/sbin/ipfw/main.c 190633 2009-04-01 20:23:47Z piso $
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
36static void
37help(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|reset|\n"
47"		reverse|proxy_only|redirect_addr linkspec|\n"
48"		redirect_port linkspec|redirect_proto linkspec}\n"
49"set [disable N... enable N...] | move [rule] X to Y | swap X Y | show\n"
50"set N {show|list|zero|resetlog|delete} [N{,N}] | flush\n"
51"table N {add ip[/bits] [value] | delete ip[/bits] | flush | list}\n"
52"table all {flush | list}\n"
53"\n"
54"RULE-BODY:	check-state [PARAMS] | ACTION [PARAMS] ADDR [OPTION_LIST]\n"
55"ACTION:	check-state | allow | count | deny | unreach{,6} CODE |\n"
56"               skipto N | {divert|tee} PORT | forward ADDR |\n"
57"               pipe N | queue N | nat N | setfib FIB | reass\n"
58"PARAMS: 	[log [logamount LOGLIMIT]] [altq QUEUE_NAME]\n"
59"ADDR:		[ MAC dst src ether_type ] \n"
60"		[ ip from IPADDR [ PORT ] to IPADDR [ PORTLIST ] ]\n"
61"		[ ipv6|ip6 from IP6ADDR [ PORT ] to IP6ADDR [ PORTLIST ] ]\n"
62"IPADDR:	[not] { any | me | ip/bits{x,y,z} | table(t[,v]) | IPLIST }\n"
63"IP6ADDR:	[not] { any | me | me6 | ip6/bits | IP6LIST }\n"
64"IP6LIST:	{ ip6 | ip6/bits }[,IP6LIST]\n"
65"IPLIST:	{ ip | ip/bits | ip:mask }[,IPLIST]\n"
66"OPTION_LIST:	OPTION [OPTION_LIST]\n"
67"OPTION:	bridged | diverted | diverted-loopback | diverted-output |\n"
68"	{dst-ip|src-ip} IPADDR | {dst-ip6|src-ip6|dst-ipv6|src-ipv6} IP6ADDR |\n"
69"	{dst-port|src-port} LIST |\n"
70"	estab | frag | {gid|uid} N | icmptypes LIST | in | out | ipid LIST |\n"
71"	iplen LIST | ipoptions SPEC | ipprecedence | ipsec | iptos SPEC |\n"
72"	ipttl LIST | ipversion VER | keep-state | layer2 | limit ... |\n"
73"	icmp6types LIST | ext6hdr LIST | flow-id N[,N] | fib FIB |\n"
74"	mac ... | mac-type LIST | proto LIST | {recv|xmit|via} {IF|IPADDR} |\n"
75"	setup | {tcpack|tcpseq|tcpwin} NN | tcpflags SPEC | tcpoptions SPEC |\n"
76"	tcpdatalen LIST | verrevpath | versrcreach | antispoof\n"
77);
78
79	exit(0);
80}
81
82/*
83 * Free a the (locally allocated) copy of command line arguments.
84 */
85static void
86free_args(int ac, char **av)
87{
88	int i;
89
90	for (i=0; i < ac; i++)
91		free(av[i]);
92	free(av);
93}
94
95/*
96 * Called with the arguments, including program name because getopt
97 * wants it to be present.
98 * Returns 0 if successful, 1 if empty command, errx() in case of errors.
99 */
100static int
101ipfw_main(int oldac, char **oldav)
102{
103	int ch, ac, save_ac;
104	const char *errstr;
105	char **av, **save_av;
106	int do_acct = 0;		/* Show packet/byte count */
107	int try_next = 0;		/* set if pipe cmd not found */
108
109#define WHITESP		" \t\f\v\n\r"
110	if (oldac < 2)
111		return 1;	/* need at least one argument */
112
113	if (oldac == 2) {
114		/*
115		 * If we are called with a single string, try to split it into
116		 * arguments for subsequent parsing.
117		 * But first, remove spaces after a ',', by copying the string
118		 * in-place.
119		 */
120		char *arg = oldav[1];	/* The string is the first arg. */
121		int l = strlen(arg);
122		int copy = 0;		/* 1 if we need to copy, 0 otherwise */
123		int i, j;
124
125		for (i = j = 0; i < l; i++) {
126			if (arg[i] == '#')	/* comment marker */
127				break;
128			if (copy) {
129				arg[j++] = arg[i];
130				copy = !index("," WHITESP, arg[i]);
131			} else {
132				copy = !index(WHITESP, arg[i]);
133				if (copy)
134					arg[j++] = arg[i];
135			}
136		}
137		if (!copy && j > 0)	/* last char was a 'blank', remove it */
138			j--;
139		l = j;			/* the new argument length */
140		arg[j++] = '\0';
141		if (l == 0)		/* empty string! */
142			return 1;
143
144		/*
145		 * First, count number of arguments. Because of the previous
146		 * processing, this is just the number of blanks plus 1.
147		 */
148		for (i = 0, ac = 1; i < l; i++)
149			if (index(WHITESP, arg[i]) != NULL)
150				ac++;
151
152		/*
153		 * Allocate the argument list, including one entry for
154		 * the program name because getopt expects it.
155		 */
156		av = safe_calloc(ac + 1, sizeof(char *));
157
158		/*
159		 * Second, copy arguments from arg[] to av[]. For each one,
160		 * j is the initial character, i is the one past the end.
161		 */
162		for (ac = 1, i = j = 0; i < l; i++)
163			if (index(WHITESP, arg[i]) != NULL || i == l-1) {
164				if (i == l-1)
165					i++;
166				av[ac] = safe_calloc(i-j+1, 1);
167				bcopy(arg+j, av[ac], i-j);
168				ac++;
169				j = i + 1;
170			}
171	} else {
172		/*
173		 * If an argument ends with ',' join with the next one.
174		 */
175		int first, i, l;
176
177		av = safe_calloc(oldac, sizeof(char *));
178		for (first = i = ac = 1, l = 0; i < oldac; i++) {
179			char *arg = oldav[i];
180			int k = strlen(arg);
181
182			l += k;
183			if (arg[k-1] != ',' || i == oldac-1) {
184				/* Time to copy. */
185				av[ac] = safe_calloc(l+1, 1);
186				for (l=0; first <= i; first++) {
187					strcat(av[ac]+l, oldav[first]);
188					l += strlen(oldav[first]);
189				}
190				ac++;
191				l = 0;
192				first = i+1;
193			}
194		}
195	}
196
197	av[0] = strdup(oldav[0]);	/* copy progname from the caller */
198	/* Set the force flag for non-interactive processes */
199	if (!co.do_force)
200		co.do_force = !isatty(STDIN_FILENO);
201
202	/* Save arguments for final freeing of memory. */
203	save_ac = ac;
204	save_av = av;
205
206	optind = optreset = 1;	/* restart getopt() */
207	while ((ch = getopt(ac, av, "abcdefhinNqs:STtv")) != -1)
208		switch (ch) {
209		case 'a':
210			do_acct = 1;
211			break;
212
213		case 'b':
214			co.comment_only = 1;
215			co.do_compact = 1;
216			break;
217
218		case 'c':
219			co.do_compact = 1;
220			break;
221
222		case 'd':
223			co.do_dynamic = 1;
224			break;
225
226		case 'e':
227			co.do_expired = 1;
228			break;
229
230		case 'f':
231			co.do_force = 1;
232			break;
233
234		case 'h': /* help */
235			free_args(save_ac, save_av);
236			help();
237			break;	/* NOTREACHED */
238
239		case 'i':
240			co.do_value_as_ip = 1;
241			break;
242
243		case 'n':
244			co.test_only = 1;
245			break;
246
247		case 'N':
248			co.do_resolv = 1;
249			break;
250
251		case 'q':
252			co.do_quiet = 1;
253			break;
254
255		case 's': /* sort */
256			co.do_sort = atoi(optarg);
257			break;
258
259		case 'S':
260			co.show_sets = 1;
261			break;
262
263		case 't':
264			co.do_time = 1;
265			break;
266
267		case 'T':
268			co.do_time = 2;	/* numeric timestamp */
269			break;
270
271		case 'v': /* verbose */
272			co.verbose = 1;
273			break;
274
275		default:
276			free_args(save_ac, save_av);
277			return 1;
278		}
279
280	ac -= optind;
281	av += optind;
282	NEED1("bad arguments, for usage summary ``ipfw''");
283
284	/*
285	 * An undocumented behaviour of ipfw1 was to allow rule numbers first,
286	 * e.g. "100 add allow ..." instead of "add 100 allow ...".
287	 * In case, swap first and second argument to get the normal form.
288	 */
289	if (ac > 1 && isdigit(*av[0])) {
290		char *p = av[0];
291
292		av[0] = av[1];
293		av[1] = p;
294	}
295
296	/*
297	 * Optional: pipe, queue or nat.
298	 */
299	co.do_nat = 0;
300	co.do_pipe = 0;
301	if (!strncmp(*av, "nat", strlen(*av)))
302 	        co.do_nat = 1;
303 	else if (!strncmp(*av, "pipe", strlen(*av)))
304		co.do_pipe = 1;
305	else if (_substrcmp(*av, "queue") == 0)
306		co.do_pipe = 2;
307	else if (!strncmp(*av, "set", strlen(*av))) {
308		if (ac > 1 && isdigit(av[1][0])) {
309			co.use_set = strtonum(av[1], 0, resvd_set_number,
310					&errstr);
311			if (errstr)
312				errx(EX_DATAERR,
313				    "invalid set number %s\n", av[1]);
314			ac -= 2; av += 2; co.use_set++;
315		}
316	}
317
318	if (co.do_pipe || co.do_nat) {
319		ac--;
320		av++;
321	}
322	NEED1("missing command");
323
324	/*
325	 * For pipes, queues and nats we normally say 'nat|pipe NN config'
326	 * but the code is easier to parse as 'nat|pipe config NN'
327	 * so we swap the two arguments.
328	 */
329	if ((co.do_pipe || co.do_nat) && ac > 1 && isdigit(*av[0])) {
330		char *p = av[0];
331
332		av[0] = av[1];
333		av[1] = p;
334	}
335
336	if (co.use_set == 0) {
337		if (_substrcmp(*av, "add") == 0)
338			ipfw_add(ac, av);
339		else if (co.do_nat && _substrcmp(*av, "show") == 0)
340 			ipfw_show_nat(ac, av);
341		else if (co.do_pipe && _substrcmp(*av, "config") == 0)
342			ipfw_config_pipe(ac, av);
343		else if (co.do_nat && _substrcmp(*av, "config") == 0)
344 			ipfw_config_nat(ac, av);
345		else if (_substrcmp(*av, "set") == 0)
346			ipfw_sets_handler(ac, av);
347		else if (_substrcmp(*av, "table") == 0)
348			ipfw_table_handler(ac, av);
349		else if (_substrcmp(*av, "enable") == 0)
350			ipfw_sysctl_handler(ac, av, 1);
351		else if (_substrcmp(*av, "disable") == 0)
352			ipfw_sysctl_handler(ac, av, 0);
353		else
354			try_next = 1;
355	}
356
357	if (co.use_set || try_next) {
358		if (_substrcmp(*av, "delete") == 0)
359			ipfw_delete(ac, av);
360		else if (_substrcmp(*av, "flush") == 0)
361			ipfw_flush(co.do_force);
362		else if (_substrcmp(*av, "zero") == 0)
363			ipfw_zero(ac, av, 0 /* IP_FW_ZERO */);
364		else if (_substrcmp(*av, "resetlog") == 0)
365			ipfw_zero(ac, av, 1 /* IP_FW_RESETLOG */);
366		else if (_substrcmp(*av, "print") == 0 ||
367		         _substrcmp(*av, "list") == 0)
368			ipfw_list(ac, av, do_acct);
369		else if (_substrcmp(*av, "show") == 0)
370			ipfw_list(ac, av, 1 /* show counters */);
371		else
372			errx(EX_USAGE, "bad command `%s'", *av);
373	}
374
375	/* Free memory allocated in the argument parsing. */
376	free_args(save_ac, save_av);
377	return 0;
378}
379
380
381static void
382ipfw_readfile(int ac, char *av[])
383{
384#define MAX_ARGS	32
385	char	buf[BUFSIZ];
386	char *progname = av[0];		/* original program name */
387	const char *cmd = NULL;		/* preprocessor name, if any */
388	const char *filename = av[ac-1]; /* file to read */
389	int	c, lineno=0;
390	FILE	*f = NULL;
391	pid_t	preproc = 0;
392
393	while ((c = getopt(ac, av, "cfNnp:qS")) != -1) {
394		switch(c) {
395		case 'c':
396			co.do_compact = 1;
397			break;
398
399		case 'f':
400			co.do_force = 1;
401			break;
402
403		case 'N':
404			co.do_resolv = 1;
405			break;
406
407		case 'n':
408			co.test_only = 1;
409			break;
410
411		case 'p':
412			/*
413			 * ipfw -p cmd [args] filename
414			 *
415			 * We are done with getopt(). All arguments
416			 * except the filename go to the preprocessor,
417			 * so we need to do the following:
418			 * - check that a filename is actually present;
419			 * - advance av by optind-1 to skip arguments
420			 *   already processed;
421			 * - decrease ac by optind, to remove the args
422			 *   already processed and the final filename;
423			 * - set the last entry in av[] to NULL so
424			 *   popen() can detect the end of the array;
425			 * - set optind=ac to let getopt() terminate.
426			 */
427			if (optind == ac)
428				errx(EX_USAGE, "no filename argument");
429			cmd = optarg;
430			av[ac-1] = NULL;
431			av += optind - 1;
432			ac -= optind;
433			optind = ac;
434			break;
435
436		case 'q':
437			co.do_quiet = 1;
438			break;
439
440		case 'S':
441			co.show_sets = 1;
442			break;
443
444		default:
445			errx(EX_USAGE, "bad arguments, for usage"
446			     " summary ``ipfw''");
447		}
448
449	}
450
451	if (cmd == NULL && ac != optind + 1)
452		errx(EX_USAGE, "extraneous filename arguments %s", av[ac-1]);
453
454	if ((f = fopen(filename, "r")) == NULL)
455		err(EX_UNAVAILABLE, "fopen: %s", filename);
456
457	if (cmd != NULL) {			/* pipe through preprocessor */
458		int pipedes[2];
459
460		if (pipe(pipedes) == -1)
461			err(EX_OSERR, "cannot create pipe");
462
463		preproc = fork();
464		if (preproc == -1)
465			err(EX_OSERR, "cannot fork");
466
467		if (preproc == 0) {
468			/*
469			 * Child, will run the preprocessor with the
470			 * file on stdin and the pipe on stdout.
471			 */
472			if (dup2(fileno(f), 0) == -1
473			    || dup2(pipedes[1], 1) == -1)
474				err(EX_OSERR, "dup2()");
475			fclose(f);
476			close(pipedes[1]);
477			close(pipedes[0]);
478			execvp(cmd, av);
479			err(EX_OSERR, "execvp(%s) failed", cmd);
480		} else { /* parent, will reopen f as the pipe */
481			fclose(f);
482			close(pipedes[1]);
483			if ((f = fdopen(pipedes[0], "r")) == NULL) {
484				int savederrno = errno;
485
486				(void)kill(preproc, SIGTERM);
487				errno = savederrno;
488				err(EX_OSERR, "fdopen()");
489			}
490		}
491	}
492
493	while (fgets(buf, BUFSIZ, f)) {		/* read commands */
494		char linename[10];
495		char *args[2];
496
497		lineno++;
498		sprintf(linename, "Line %d", lineno);
499		setprogname(linename); /* XXX */
500		args[0] = progname;
501		args[1] = buf;
502		ipfw_main(2, args);
503	}
504	fclose(f);
505	if (cmd != NULL) {
506		int status;
507
508		if (waitpid(preproc, &status, 0) == -1)
509			errx(EX_OSERR, "waitpid()");
510		if (WIFEXITED(status) && WEXITSTATUS(status) != EX_OK)
511			errx(EX_UNAVAILABLE,
512			    "preprocessor exited with status %d",
513			    WEXITSTATUS(status));
514		else if (WIFSIGNALED(status))
515			errx(EX_UNAVAILABLE,
516			    "preprocessor exited with signal %d",
517			    WTERMSIG(status));
518	}
519}
520
521int
522main(int ac, char *av[])
523{
524	/*
525	 * If the last argument is an absolute pathname, interpret it
526	 * as a file to be preprocessed.
527	 */
528
529	if (ac > 1 && av[ac - 1][0] == '/' && access(av[ac - 1], R_OK) == 0)
530		ipfw_readfile(ac, av);
531	else {
532		if (ipfw_main(ac, av)) {
533			errx(EX_USAGE,
534			    "usage: ipfw [options]\n"
535			    "do \"ipfw -h\" or \"man ipfw\" for details");
536		}
537	}
538	return EX_OK;
539}
540