ip6tables-restore.c revision ee80faf4438102395bc4034894b6468453181be9 
1/* Code to restore the iptables state, from file by ip6tables-save.
2 * Author:  Andras Kis-Szabo <kisza@sch.bme.hu>
3 *
4 * based on iptables-restore
5 * Authors:
6 *      Harald Welte <laforge@gnumonks.org>
7 *      Rusty Russell <rusty@linuxcare.com.au>
8 * This code is distributed under the terms of GNU GPL v2
9 */
10
11#include <getopt.h>
12#include <sys/errno.h>
13#include <stdbool.h>
14#include <string.h>
15#include <stdio.h>
16#include <stdlib.h>
17#include "ip6tables.h"
18#include "xtables.h"
19#include "libiptc/libip6tc.h"
20#include "ip6tables-multi.h"
21
22#ifdef DEBUG
23#define DEBUGP(x, args...) fprintf(stderr, x, ## args)
24#else
25#define DEBUGP(x, args...)
26#endif
27
28static int binary = 0, counters = 0, verbose = 0, noflush = 0;
29
30/* Keeping track of external matches and targets.  */
31static const struct option options[] = {
32	{.name = "binary",   .has_arg = false, .val = 'b'},
33	{.name = "counters", .has_arg = false, .val = 'c'},
34	{.name = "verbose",  .has_arg = false, .val = 'v'},
35	{.name = "test",     .has_arg = false, .val = 't'},
36	{.name = "help",     .has_arg = false, .val = 'h'},
37	{.name = "noflush",  .has_arg = false, .val = 'n'},
38	{.name = "modprobe", .has_arg = true,  .val = 'M'},
39	{NULL},
40};
41
42static void print_usage(const char *name, const char *version) __attribute__((noreturn));
43
44static void print_usage(const char *name, const char *version)
45{
46	fprintf(stderr, "Usage: %s [-b] [-c] [-v] [-t] [-h]\n"
47			"	   [ --binary ]\n"
48			"	   [ --counters ]\n"
49			"	   [ --verbose ]\n"
50			"	   [ --test ]\n"
51			"	   [ --help ]\n"
52			"	   [ --noflush ]\n"
53			"          [ --modprobe=<command>]\n", name);
54
55	exit(1);
56}
57
58static struct ip6tc_handle *create_handle(const char *tablename)
59{
60	struct ip6tc_handle *handle;
61
62	handle = ip6tc_init(tablename);
63
64	if (!handle) {
65		/* try to insmod the module if iptc_init failed */
66		xtables_load_ko(xtables_modprobe_program, false);
67		handle = ip6tc_init(tablename);
68	}
69
70	if (!handle) {
71		xtables_error(PARAMETER_PROBLEM, "%s: unable to initialize "
72			"table '%s'\n", ip6tables_globals.program_name,
73			tablename);
74		exit(1);
75	}
76	return handle;
77}
78
79static int parse_counters(char *string, struct ip6t_counters *ctr)
80{
81	unsigned long long pcnt, bcnt;
82	int ret;
83
84	ret = sscanf(string, "[%llu:%llu]", &pcnt, &bcnt);
85	ctr->pcnt = pcnt;
86	ctr->bcnt = bcnt;
87	return ret == 2;
88}
89
90/* global new argv and argc */
91static char *newargv[255];
92static int newargc;
93
94/* function adding one argument to newargv, updating newargc
95 * returns true if argument added, false otherwise */
96static int add_argv(char *what) {
97	DEBUGP("add_argv: %s\n", what);
98	if (what && newargc + 1 < ARRAY_SIZE(newargv)) {
99		newargv[newargc] = strdup(what);
100		newargc++;
101		return 1;
102	} else {
103		xtables_error(PARAMETER_PROBLEM,
104			"Parser cannot handle more arguments\n");
105		return 0;
106	}
107}
108
109static void free_argv(void) {
110	int i;
111
112	for (i = 0; i < newargc; i++)
113		free(newargv[i]);
114}
115
116#ifdef IPTABLES_MULTI
117int ip6tables_restore_main(int argc, char *argv[])
118#else
119int main(int argc, char *argv[])
120#endif
121{
122	struct ip6tc_handle *handle = NULL;
123	char buffer[10240];
124	int c;
125	char curtable[IP6T_TABLE_MAXNAMELEN + 1];
126	FILE *in;
127	int in_table = 0, testing = 0;
128
129	line = 0;
130
131	ip6tables_globals.program_name = "ip6tables-restore";
132	c = xtables_init_all(&ip6tables_globals, NFPROTO_IPV6);
133	if (c < 0) {
134		fprintf(stderr, "%s/%s Failed to initialize xtables\n",
135				ip6tables_globals.program_name,
136				ip6tables_globals.program_version);
137		exit(1);
138	}
139#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
140	init_extensions();
141	init_extensions6();
142#endif
143
144	while ((c = getopt_long(argc, argv, "bcvthnM:", options, NULL)) != -1) {
145		switch (c) {
146			case 'b':
147				binary = 1;
148				break;
149			case 'c':
150				counters = 1;
151				break;
152			case 'v':
153				verbose = 1;
154				break;
155			case 't':
156				testing = 1;
157				break;
158			case 'h':
159				print_usage("ip6tables-restore",
160					    IPTABLES_VERSION);
161				break;
162			case 'n':
163				noflush = 1;
164				break;
165			case 'M':
166				xtables_modprobe_program = optarg;
167				break;
168		}
169	}
170
171	if (optind == argc - 1) {
172		in = fopen(argv[optind], "re");
173		if (!in) {
174			fprintf(stderr, "Can't open %s: %s\n", argv[optind],
175				strerror(errno));
176			exit(1);
177		}
178	}
179	else if (optind < argc) {
180		fprintf(stderr, "Unknown arguments found on commandline\n");
181		exit(1);
182	}
183	else in = stdin;
184
185	/* Grab standard input. */
186	while (fgets(buffer, sizeof(buffer), in)) {
187		int ret = 0;
188
189		line++;
190		if (buffer[0] == '\n')
191			continue;
192		else if (buffer[0] == '#') {
193			if (verbose)
194				fputs(buffer, stdout);
195			continue;
196		} else if ((strcmp(buffer, "COMMIT\n") == 0) && (in_table)) {
197			if (!testing) {
198				DEBUGP("Calling commit\n");
199				ret = ip6tc_commit(handle);
200				ip6tc_free(handle);
201				handle = NULL;
202			} else {
203				DEBUGP("Not calling commit, testing\n");
204				ret = 1;
205			}
206			in_table = 0;
207		} else if ((buffer[0] == '*') && (!in_table)) {
208			/* New table */
209			char *table;
210
211			table = strtok(buffer+1, " \t\n");
212			DEBUGP("line %u, table '%s'\n", line, table);
213			if (!table) {
214				xtables_error(PARAMETER_PROBLEM,
215					"%s: line %u table name invalid\n",
216					ip6tables_globals.program_name,
217					line);
218				exit(1);
219			}
220			strncpy(curtable, table, IP6T_TABLE_MAXNAMELEN);
221			curtable[IP6T_TABLE_MAXNAMELEN] = '\0';
222
223			if (handle)
224				ip6tc_free(handle);
225
226			handle = create_handle(table);
227			if (noflush == 0) {
228				DEBUGP("Cleaning all chains of table '%s'\n",
229					table);
230				for_each_chain6(flush_entries6, verbose, 1,
231						handle);
232
233				DEBUGP("Deleting all user-defined chains "
234				       "of table '%s'\n", table);
235				for_each_chain6(delete_chain6, verbose, 0,
236						handle);
237			}
238
239			ret = 1;
240			in_table = 1;
241
242		} else if ((buffer[0] == ':') && (in_table)) {
243			/* New chain. */
244			char *policy, *chain;
245
246			chain = strtok(buffer+1, " \t\n");
247			DEBUGP("line %u, chain '%s'\n", line, chain);
248			if (!chain) {
249				xtables_error(PARAMETER_PROBLEM,
250					   "%s: line %u chain name invalid\n",
251					   ip6tables_globals.program_name,
252					   line);
253				exit(1);
254			}
255
256			if (strlen(chain) >= XT_EXTENSION_MAXNAMELEN)
257				xtables_error(PARAMETER_PROBLEM,
258					   "Invalid chain name `%s' "
259					   "(%u chars max)",
260					   chain, XT_EXTENSION_MAXNAMELEN - 1);
261
262			if (ip6tc_builtin(chain, handle) <= 0) {
263				if (noflush && ip6tc_is_chain(chain, handle)) {
264					DEBUGP("Flushing existing user defined chain '%s'\n", chain);
265					if (!ip6tc_flush_entries(chain, handle))
266						xtables_error(PARAMETER_PROBLEM,
267							   "error flushing chain "
268							   "'%s':%s\n", chain,
269							   strerror(errno));
270				} else {
271					DEBUGP("Creating new chain '%s'\n", chain);
272					if (!ip6tc_create_chain(chain, handle))
273						xtables_error(PARAMETER_PROBLEM,
274							   "error creating chain "
275							   "'%s':%s\n", chain,
276							   strerror(errno));
277				}
278			}
279
280			policy = strtok(NULL, " \t\n");
281			DEBUGP("line %u, policy '%s'\n", line, policy);
282			if (!policy) {
283				xtables_error(PARAMETER_PROBLEM,
284					   "%s: line %u policy invalid\n",
285					   ip6tables_globals.program_name,
286					   line);
287				exit(1);
288			}
289
290			if (strcmp(policy, "-") != 0) {
291				struct ip6t_counters count;
292
293				if (counters) {
294					char *ctrs;
295					ctrs = strtok(NULL, " \t\n");
296
297					if (!ctrs || !parse_counters(ctrs, &count))
298						xtables_error(PARAMETER_PROBLEM,
299							  "invalid policy counters "
300							  "for chain '%s'\n", chain);
301
302				} else {
303					memset(&count, 0,
304					       sizeof(struct ip6t_counters));
305				}
306
307				DEBUGP("Setting policy of chain %s to %s\n",
308					chain, policy);
309
310				if (!ip6tc_set_policy(chain, policy, &count,
311						     handle))
312					xtables_error(OTHER_PROBLEM,
313						"Can't set policy `%s'"
314						" on `%s' line %u: %s\n",
315						policy, chain, line,
316						ip6tc_strerror(errno));
317			}
318
319			ret = 1;
320
321		} else if (in_table) {
322			int a;
323			char *ptr = buffer;
324			char *pcnt = NULL;
325			char *bcnt = NULL;
326			char *parsestart;
327
328			/* the parser */
329			char *curchar;
330			int quote_open, escaped;
331			size_t param_len;
332
333			/* reset the newargv */
334			newargc = 0;
335
336			if (buffer[0] == '[') {
337				/* we have counters in our input */
338				ptr = strchr(buffer, ']');
339				if (!ptr)
340					xtables_error(PARAMETER_PROBLEM,
341						   "Bad line %u: need ]\n",
342						   line);
343
344				pcnt = strtok(buffer+1, ":");
345				if (!pcnt)
346					xtables_error(PARAMETER_PROBLEM,
347						   "Bad line %u: need :\n",
348						   line);
349
350				bcnt = strtok(NULL, "]");
351				if (!bcnt)
352					xtables_error(PARAMETER_PROBLEM,
353						   "Bad line %u: need ]\n",
354						   line);
355
356				/* start command parsing after counter */
357				parsestart = ptr + 1;
358			} else {
359				/* start command parsing at start of line */
360				parsestart = buffer;
361			}
362
363			add_argv(argv[0]);
364			add_argv("-t");
365			add_argv(curtable);
366
367			if (counters && pcnt && bcnt) {
368				add_argv("--set-counters");
369				add_argv((char *) pcnt);
370				add_argv((char *) bcnt);
371			}
372
373			/* After fighting with strtok enough, here's now
374			 * a 'real' parser. According to Rusty I'm now no
375			 * longer a real hacker, but I can live with that */
376
377			quote_open = 0;
378			escaped = 0;
379			param_len = 0;
380
381			for (curchar = parsestart; *curchar; curchar++) {
382				char param_buffer[1024];
383
384				if (quote_open) {
385					if (escaped) {
386						param_buffer[param_len++] = *curchar;
387						escaped = 0;
388						continue;
389					} else if (*curchar == '\\') {
390						escaped = 1;
391						continue;
392					} else if (*curchar == '"') {
393						quote_open = 0;
394						*curchar = ' ';
395					} else {
396						param_buffer[param_len++] = *curchar;
397						continue;
398					}
399				} else {
400					if (*curchar == '"') {
401						quote_open = 1;
402						continue;
403					}
404				}
405
406				if (*curchar == ' '
407				    || *curchar == '\t'
408				    || * curchar == '\n') {
409					if (!param_len) {
410						/* two spaces? */
411						continue;
412					}
413
414					param_buffer[param_len] = '\0';
415
416					/* check if table name specified */
417					if (!strncmp(param_buffer, "-t", 2)
418                                            || !strncmp(param_buffer, "--table", 8)) {
419						xtables_error(PARAMETER_PROBLEM,
420						   "Line %u seems to have a "
421						   "-t table option.\n", line);
422						exit(1);
423					}
424
425					add_argv(param_buffer);
426					param_len = 0;
427				} else {
428					/* regular character, copy to buffer */
429					param_buffer[param_len++] = *curchar;
430
431					if (param_len >= sizeof(param_buffer))
432						xtables_error(PARAMETER_PROBLEM,
433						   "Parameter too long!");
434				}
435			}
436
437			DEBUGP("calling do_command6(%u, argv, &%s, handle):\n",
438				newargc, curtable);
439
440			for (a = 0; a < newargc; a++)
441				DEBUGP("argv[%u]: %s\n", a, newargv[a]);
442
443			ret = do_command6(newargc, newargv,
444					 &newargv[2], &handle);
445
446			free_argv();
447			fflush(stdout);
448		}
449		if (!ret) {
450			fprintf(stderr, "%s: line %u failed\n",
451					ip6tables_globals.program_name,
452					line);
453			exit(1);
454		}
455	}
456	if (in_table) {
457		fprintf(stderr, "%s: COMMIT expected at line %u\n",
458				ip6tables_globals.program_name,
459				line + 1);
460		exit(1);
461	}
462
463	fclose(in);
464	return 0;
465}
466