Exemple #1
0
int main(int argc, char **argv)
{
	struct args args = {
		/* Defaults. */
		.stack		= "ip",
		.add_rules	= 0,
		.ebtables	= "/sbin/ebtables",
		.sleep		= 10,
		.parents	= 0,
		.daemon		= 0,

		/* This parameter expects something like
		 * "experiment/stack/column/run".
		 */
		.file		= NULL,

		.count		= 0,
		.entries	= 0,
		.ifs		= NULL,
	};

	int i, sk, rcount;
	FILE *f;
	double start;
	struct ebt_counter *cnt;

	/* Read parameters. */
	argp_parse(&argp, argc, argv, 0, NULL, &args);

	/* Install ebtables(8) rules. */
	if (args.add_rules) {
		for (i = 0; i < args.count; i++)
			ebt_add_rule(args.ebtables, args.stack, args.ifs[i]);
	}

	/* Create parent paths of @args.file. */
	if (args.file && args.parents)
		assert(!close(mkdir_parents(args.file)));

	/* Test that only the expected ebtables(8) rules are in place.
	 * This is important to avoid silently wrong measurements.
	 */
	sk = ebt_socket();
	if (sk < 0)
		err(1, "Can't get a socket");
	rcount = ebt_rule_count(sk, args.stack);
	if (rcount != args.count)
		errx(1, "There is a mismatch between the number of ebtables(8) rules installed (= %i) and the number of monitored interfaces (= %i)",
		rcount, args.count);
	if (!rcount)
		errx(1, "There is no ebtables(8) rules to measure");

	/* Create sampling file. */
	if (args.file) {
		f = fopen(args.file, "w");
		if (!f)
			err(1, "Can't open file `%s'", args.file);
		ebt_add_header_to_file(sk, args.stack, f);
	} else {
		f = stdout;
	}

	/* Daemonize. */
	if (args.daemon && daemon(1, 1))
		err(1, "Can't daemonize");

	start = now();
	if (args.file) {
		ebt_write_sample_to_file(sk, args.stack, f);
		if (fflush(f))
			err(1, "Can't save content of file `%s'", args.file);
	} else {
		cnt = ebt_create_cnt(sk, args.stack);
		assert(cnt);
	}

	while (1) {
		double diff = now() - start;
		if (diff < args.sleep)
			nsleep(args.sleep - diff);
		else
			warnx("Option --sleep=%i is too little; not enough time to estimate rates. Consider increasing the period",
			args.sleep);

		start = now();
		if (args.file)
			ebt_write_sample_to_file(sk, args.stack, f);
		else
			ebt_write_rates_to_file(sk, args.stack, f, args.sleep,
				cnt);
		if (fflush(f))
			err(1, "Can't save content of file `%s'",
				args.file ? args.file : "STDOUT");
	}

	ebt_free_cnt(cnt);
	if (args.file)
		assert(!fclose(f));
	ebt_close(sk);
	end_args(&args);
	return 0;
}
Exemple #2
0
/* We use exec_style instead of #ifdef's because ebtables.so is a shared object. */
int do_command(int argc, char *argv[], struct ebt_u_replace *replace_)
{
	char *buffer;
	int c, i;
	int policy = 0;
	int rule_nr = 0;
	int rule_nr_end = 0;
	struct ebt_u_target *t;
	struct ebt_u_match *m;
	struct ebt_u_match_list *m_l;
	struct ebt_u_entries *entries;

	opterr = 0;

	replace = replace_;

	replace->flags = 0;
	replace->selected_chain = -1;
	replace->command = 'h';

	if (!new_entry) {
		new_entry = (struct ebt_u_entry *)malloc(sizeof(struct ebt_u_entry));
		if (!new_entry)
			ebt_print_memory();
	}
	/* Put some sane values in our new entry */
	ebt_initialize_entry(new_entry);
	new_entry->replace = replace;

	/* The scenario induced by this loop makes that:
	 * '-t' and '-M' (if specified) have to come
	 * before '-A' and the like */

	/* Getopt saves the day */
	while ((c = getopt_long(argc, argv,
	   "-A:D:I:N:E:X::L::F::P:Vhi:o:j:p:s:d:t:", ebt_options, NULL)) != -1) {
		switch (c) {

		case 'A': /* Add a rule */
		case 'D': /* Delete a rule */
		case 'P': /* Define policy */
		case 'I': /* Insert a rule */
		case 'N': /* Make a user defined chain */
		case 'E': /* Rename chain */
		case 'X': /* Delete chain */
			/* We allow -N chainname -P policy */
			if (replace->command == 'N' && c == 'P') {
				replace->command = c;
				optind--; /* No table specified */
				goto handle_P;
			}
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");

			replace->command = c;
			replace->flags |= OPT_COMMAND;
			ebt_get_kernel_table(replace);
			if (optarg && (optarg[0] == '-' || !strcmp(optarg, "!")))
				ebt_print_error2("No chain name specified");
			if (c == 'N') {
				if (ebt_get_chainnr(replace, optarg) != -1)
					ebt_print_error2("Chain %s already exists", optarg);
				else if (ebt_find_target(optarg))
					ebt_print_error2("Target with name %s exists", optarg);
				else if (strlen(optarg) >= EBT_CHAIN_MAXNAMELEN)
					ebt_print_error2("Chain name length can't exceed %d",
							EBT_CHAIN_MAXNAMELEN - 1);
				else if (strchr(optarg, ' ') != NULL)
					ebt_print_error2("Use of ' ' not allowed in chain names");
				ebt_new_chain(replace, optarg, EBT_ACCEPT);
				/* This is needed to get -N x -P y working */
				replace->selected_chain = ebt_get_chainnr(replace, optarg);
				break;
			} else if (c == 'X') {
				if (optind >= argc) {
					replace->selected_chain = -1;
					ebt_delete_chain(replace);
					break;
				}

				if (optind < argc - 1)
					ebt_print_error2("No extra options allowed with -X");

				if ((replace->selected_chain = ebt_get_chainnr(replace, argv[optind])) == -1)
					ebt_print_error2("Chain '%s' doesn't exist", argv[optind]);
				ebt_delete_chain(replace);
				optind++;
				break;
			}

			if ((replace->selected_chain = ebt_get_chainnr(replace, optarg)) == -1)
				ebt_print_error2("Chain '%s' doesn't exist", optarg);
			if (c == 'E') {
				if (optind >= argc)
					ebt_print_error2("No new chain name specified");
				else if (optind < argc - 1)
					ebt_print_error2("No extra options allowed with -E");
				else if (strlen(argv[optind]) >= EBT_CHAIN_MAXNAMELEN)
					ebt_print_error2("Chain name length can't exceed %d characters", EBT_CHAIN_MAXNAMELEN - 1);
				else if (ebt_get_chainnr(replace, argv[optind]) != -1)
					ebt_print_error2("Chain '%s' already exists", argv[optind]);
				else if (ebt_find_target(argv[optind]))
					ebt_print_error2("Target with name '%s' exists", argv[optind]);
				else if (strchr(argv[optind], ' ') != NULL)
					ebt_print_error2("Use of ' ' not allowed in chain names");
				ebt_rename_chain(replace, argv[optind]);
				optind++;
				break;
			} else if (c == 'D' && optind < argc && (argv[optind][0] != '-' || (argv[optind][1] >= '0' && argv[optind][1] <= '9'))) {
				if (optind != argc - 1)
					ebt_print_error2("No extra options allowed with -D start_nr[:end_nr]");
				if (parse_rule_range(argv[optind], &rule_nr, &rule_nr_end))
					ebt_print_error2("Problem with the specified rule number(s) '%s'", argv[optind]);
				optind++;
			} else if (c == 'I') {
				if (optind >= argc || (argv[optind][0] == '-' && (argv[optind][1] < '0' || argv[optind][1] > '9')))
					rule_nr = 1;
				else {
					rule_nr = strtol(argv[optind], &buffer, 10);
					if (*buffer != '\0')
						ebt_print_error2("Problem with the specified rule number '%s'", argv[optind]);
					optind++;
				}
			} else if (c == 'P') {
handle_P:
				if (optind >= argc)
					ebt_print_error2("No policy specified");
				for (i = 0; i < NUM_STANDARD_TARGETS; i++)
					if (!strcmp(argv[optind], ebt_standard_targets[i])) {
						policy = -i -1;
						if (policy == EBT_CONTINUE)
							ebt_print_error2("Wrong policy '%s'", argv[optind]);
						break;
					}
				if (i == NUM_STANDARD_TARGETS)
					ebt_print_error2("Unknown policy '%s'", argv[optind]);
				optind++;
			}
			break;
		case 'L': /* List */
		case 'F': /* Flush */
			if (replace->flags & OPT_COMMAND)
				ebt_print_error2("Multiple commands are not allowed");
			replace->command = c;
			replace->flags |= OPT_COMMAND;

			ebt_get_kernel_table(replace);
			i = -1;
			if (optind < argc && argv[optind][0] != '-') {
				if ((i = ebt_get_chainnr(replace, argv[optind])) == -1)
					ebt_print_error2("Chain '%s' doesn't exist", argv[optind]);
				optind++;
			}
			if (i != -1)
				replace->selected_chain = i;
			break;
		case 'V': /* Version */
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			replace->command = 'V';
			PRINT_VERSION;
			exit(0);
		case 'h': /* Help */
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			replace->command = 'h';

			/* All other arguments should be extension names */
			while (optind < argc) {
				struct ebt_u_match *m;

				if (!strcasecmp("list_extensions", argv[optind])) {
					ebt_list_extensions();
					exit(0);
				}
				if ((m = ebt_find_match(argv[optind])))
					ebt_add_match(new_entry, m);
				else {
					if (!(t = ebt_find_target(argv[optind])))
						ebt_print_error2("Extension '%s' not found", argv[optind]);
					if (replace->flags & OPT_JUMP)
						ebt_print_error2("Sorry, you can only see help for one target extension at a time");
					replace->flags |= OPT_JUMP;
					new_entry->t = (struct ebt_entry_target *)t;
				}
				optind++;
			}
			break;
		case 't': /* Table */
			if (OPT_COMMANDS)
				ebt_print_error2("Please put the -t option first");
			ebt_check_option2(&(replace->flags), OPT_TABLE);
			if (strlen(optarg) > EBT_TABLE_MAXNAMELEN - 1)
				ebt_print_error2("Table name length cannot exceed %d characters", EBT_TABLE_MAXNAMELEN - 1);
			strcpy(replace->name, optarg);
			break;
		case 'i': /* Input interface */
		case 2  : /* Logical input interface */
		case 'o': /* Output interface */
		case 3  : /* Logical output interface */
		case 'j': /* Target */
		case 'p': /* Net family protocol */
		case 's': /* Source mac */
		case 'd': /* Destination mac */
			if (!OPT_COMMANDS)
				ebt_print_error2("No command specified");
			if (replace->command != 'A' && replace->command != 'D' && replace->command != 'I')
				ebt_print_error2("Command and option do not match");
			if (c == 'i') {
				ebt_check_option2(&(replace->flags), OPT_IN);
				if (replace->selected_chain > 2 && replace->selected_chain < NF_BR_BROUTING)
					ebt_print_error2("Use -i only in INPUT, FORWARD, PREROUTING and BROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IIN;

				if (strlen(optarg) >= IFNAMSIZ)
big_iface_length:
					ebt_print_error2("Interface name length cannot exceed %d characters", IFNAMSIZ - 1);
				strcpy(new_entry->in, optarg);
				if (parse_iface(new_entry->in, "-i"))
					return -1;
				break;
			} else if (c == 2) {
				ebt_check_option2(&(replace->flags), OPT_LOGICALIN);
				if (replace->selected_chain > 2 && replace->selected_chain < NF_BR_BROUTING)
					ebt_print_error2("Use --logical-in only in INPUT, FORWARD, PREROUTING and BROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ILOGICALIN;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->logical_in, optarg);
				if (parse_iface(new_entry->logical_in, "--logical-in"))
					return -1;
				break;
			} else if (c == 'o') {
				ebt_check_option2(&(replace->flags), OPT_OUT);
				if (replace->selected_chain < 2 || replace->selected_chain == NF_BR_BROUTING)
					ebt_print_error2("Use -o only in OUTPUT, FORWARD and POSTROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IOUT;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->out, optarg);
				if (parse_iface(new_entry->out, "-o"))
					return -1;
				break;
			} else if (c == 3) {
				ebt_check_option2(&(replace->flags), OPT_LOGICALOUT);
				if (replace->selected_chain < 2 || replace->selected_chain == NF_BR_BROUTING)
					ebt_print_error2("Use --logical-out only in OUTPUT, FORWARD and POSTROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ILOGICALOUT;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->logical_out, optarg);
				if (parse_iface(new_entry->logical_out, "--logical-out"))
					return -1;
				break;
			} else if (c == 'j') {
				ebt_check_option2(&(replace->flags), OPT_JUMP);
				for (i = 0; i < NUM_STANDARD_TARGETS; i++)
					if (!strcmp(optarg, ebt_standard_targets[i])) {
						t = ebt_find_target(EBT_STANDARD_TARGET);
						((struct ebt_standard_target *) t->t)->verdict = -i - 1;
						break;
					}
				if (-i - 1 == EBT_RETURN && replace->selected_chain < NF_BR_NUMHOOKS) {
					ebt_print_error2("Return target only for user defined chains");
				} else if (i != NUM_STANDARD_TARGETS)
					break;

				if ((i = ebt_get_chainnr(replace, optarg)) != -1) {
					if (i < NF_BR_NUMHOOKS)
						ebt_print_error2("Don't jump to a standard chain");
					t = ebt_find_target(EBT_STANDARD_TARGET);
					((struct ebt_standard_target *) t->t)->verdict = i - NF_BR_NUMHOOKS;
					break;
				} else {
					/* Must be an extension then */
					struct ebt_u_target *t;

					t = ebt_find_target(optarg);
					/* -j standard not allowed either */
					if (!t || t == (struct ebt_u_target *)new_entry->t)
						ebt_print_error2("Illegal target name '%s'", optarg);
					new_entry->t = (struct ebt_entry_target *)t;
					ebt_find_target(EBT_STANDARD_TARGET)->used = 0;
					t->used = 1;
				}
				break;
			} else if (c == 's') {
				ebt_check_option2(&(replace->flags), OPT_SOURCE);
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ISOURCE;

				if (ebt_get_mac_and_mask(optarg, new_entry->sourcemac, new_entry->sourcemsk))
					ebt_print_error2("Problem with specified source mac '%s'", optarg);
				new_entry->bitmask |= EBT_SOURCEMAC;
				break;
			} else if (c == 'd') {
				ebt_check_option2(&(replace->flags), OPT_DEST);
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IDEST;

				if (ebt_get_mac_and_mask(optarg, new_entry->destmac, new_entry->destmsk))
					ebt_print_error2("Problem with specified destination mac '%s'", optarg);
				new_entry->bitmask |= EBT_DESTMAC;
				break;
			}
			ebt_check_option2(&(replace->flags), OPT_PROTOCOL);
			if (ebt_check_inverse2(optarg))
				new_entry->invflags |= EBT_IPROTO;

			new_entry->bitmask &= ~((unsigned int)EBT_NOPROTO);
			i = strtol(optarg, &buffer, 16);
			if (*buffer == '\0' && (i < 0 || i > 0xFFFF))
				ebt_print_error2("Problem with the specified protocol");
			if (*buffer != '\0') {
				const struct ethertypeent *ent;

				if (!strcasecmp(optarg, "LENGTH")) {
					new_entry->bitmask |= EBT_802_3;
					break;
				}
				ent = getethertypebyname(optarg);
				if (!ent)
					ebt_print_error2("Problem with the specified Ethernet protocol '%s'", optarg);
				new_entry->ethproto = ent->e_ethertype;
			} else
				new_entry->ethproto = i;

			if (new_entry->ethproto < 0x0600)
				ebt_print_error2("Sorry, protocols have values above or equal to 0x0600");
			break;
		case 1 :
			if (!strcmp(optarg, "!"))
				ebt_check_inverse2(optarg);
			else
				ebt_print_error2("Bad argument : '%s'", optarg);
			/* ebt_check_inverse() did optind++ */
			optind--;
			continue;
		default:
			/* Is it a target option? */
			t = (struct ebt_u_target *)new_entry->t;
			if ((t->parse(c - t->option_offset, argv, argc, new_entry, &t->flags, &t->t))) {
				goto check_extension;
			}

			/* Is it a match_option? */
			for (m = ebt_matches; m; m = m->next)
				if (m->parse(c - m->option_offset, argv, argc, new_entry, &m->flags, &m->m))
					break;

			if (m != NULL) {
				if (m->used == 0) {
					ebt_add_match(new_entry, m);
					m->used = 1;
				}
				goto check_extension;
			}

			if (c == '?')
				ebt_print_error2("Unknown argument: '%s'", argv[optind - 1], (char)optopt, (char)c);
			else {
				if (!strcmp(t->name, "standard"))
					ebt_print_error2("Unknown argument: don't forget the -t option");
				else
					ebt_print_error2("Target-specific option does not correspond with specified target");
			}
check_extension:
			if (replace->command != 'A' && replace->command != 'I' &&
			    replace->command != 'D')
				ebt_print_error2("Extensions only for -A, -I and -D");
		}
		ebt_invert = 0;
	}

	if (!(table = ebt_find_table(replace->name)))
		ebt_print_error2("Bad table name");

	if (replace->command == 'h') {
		print_help();
		exit(0);
	}

	/* Do the final checks */
	if (replace->command == 'A' || replace->command == 'I' ||
	   replace->command == 'D') {
		/* This will put the hook_mask right for the chains */
		ebt_check_for_loops(replace);
		entries = ebt_to_chain(replace);
		m_l = new_entry->m_list;
		t = (struct ebt_u_target *)new_entry->t;
		while (m_l) {
			m = (struct ebt_u_match *)(m_l->m);
			m->final_check(new_entry, m->m, replace->name,
			   entries->hook_mask, 0);
			m_l = m_l->next;
		}
		t->final_check(new_entry, t->t, replace->name,
		   entries->hook_mask, 0);
	}
	/* So, the extensions can work with the host endian.
	 * The kernel does not have to do this of course */
	new_entry->ethproto = htons(new_entry->ethproto);

	if (replace->command == 'P') {
		if (replace->selected_chain < NF_BR_NUMHOOKS && policy == EBT_RETURN)
			ebt_print_error2("Policy RETURN only allowed for user defined chains");
		ebt_change_policy(replace, policy);
	} else if (replace->command == 'L') {
		list_rules();
		exit(0);
	}
	if (replace->command == 'F') {
		ebt_flush_chains(replace);
	} else if (replace->command == 'A' || replace->command == 'I') {
		ebt_add_rule(replace, new_entry, rule_nr);
		if (rule_nr <= 0)
			rule_nr--;
		rule_nr_end = rule_nr;

		/* a jump to a udc requires checking for loops */
		if (!strcmp(new_entry->t->u.name, EBT_STANDARD_TARGET) &&
		((struct ebt_standard_target *)(new_entry->t))->verdict >= 0) {
			/* FIXME: this can be done faster */
			ebt_check_for_loops(replace);
		}

		/* Do the final_check(), for all entries.
		 * This is needed when adding a rule that has a chain target */
		i = -1;
		while (++i != replace->num_chains) {
			struct ebt_u_entry *e;

			entries = replace->chains[i];
			if (!entries) {
				if (i < NF_BR_NUMHOOKS)
					continue;
				else
					ebt_print_bug("whoops\n");
			}
			e = entries->entries->next;
			while (e != entries->entries) {
				/* Userspace extensions use host endian */
				e->ethproto = ntohs(e->ethproto);
				ebt_do_final_checks(replace, e, entries);
				e->ethproto = htons(e->ethproto);
				e = e->next;
			}
		}
		/* Don't reuse the added rule */
		new_entry = NULL;
	} else if (replace->command == 'D') {
		ebt_delete_rule(replace, new_entry, rule_nr, rule_nr_end);
	}
	/* Commands -N, -E, -X fall through */

	if (table->check)
		table->check(replace);

	ebt_deliver_table(replace);

	if (replace->nentries)
		ebt_deliver_counters(replace);

	return 0;
}
/* We use exec_style instead of #ifdef's because ebtables.so is a shared object. */
int do_command(int argc, char *argv[], int exec_style,
               struct ebt_u_replace *replace_)
{
	char *buffer;
	int c, i;
	int zerochain = -1; /* Needed for the -Z option (we can have -Z <this> -L <that>) */
	int chcounter; /* Needed for -C */
	int policy = 0;
	int rule_nr = 0;
	int rule_nr_end = 0;
	struct ebt_u_target *t;
	struct ebt_u_match *m;
	struct ebt_u_watcher *w;
	struct ebt_u_match_list *m_l;
	struct ebt_u_watcher_list *w_l;
	struct ebt_u_entries *entries;

	opterr = 0;
	ebt_modprobe = NULL;

	replace = replace_;

	/* The daemon doesn't use the environment variable */
	if (exec_style == EXEC_STYLE_PRG) {
		buffer = getenv(ATOMIC_ENV_VARIABLE);
		if (buffer) {
			replace->filename = malloc(strlen(buffer) + 1);
			if (!replace->filename)
				ebt_print_memory();
			strcpy(replace->filename, buffer);
			buffer = NULL;
		}
	}

	replace->flags &= OPT_KERNELDATA; /* ebtablesd needs OPT_KERNELDATA */
	replace->selected_chain = -1;
	replace->command = 'h';

	if (!new_entry) {
		new_entry = (struct ebt_u_entry *)malloc(sizeof(struct ebt_u_entry));
		if (!new_entry)
			ebt_print_memory();
	}
	/* Put some sane values in our new entry */
	ebt_initialize_entry(new_entry);
	new_entry->replace = replace;

	/* The scenario induced by this loop makes that:
	 * '-t'  ,'-M' and --atomic (if specified) have to come
	 * before '-A' and the like */

	/* Getopt saves the day */
	while ((c = getopt_long(argc, argv,
	   "-A:D:C:I:N:E:X::L::Z::F::P:Vhi:o:j:c:p:s:d:t:M:", ebt_options, NULL)) != -1) {
		switch (c) {

		case 'A': /* Add a rule */
		case 'D': /* Delete a rule */
		case 'C': /* Change counters */
		case 'P': /* Define policy */
		case 'I': /* Insert a rule */
		case 'N': /* Make a user defined chain */
		case 'E': /* Rename chain */
		case 'X': /* Delete chain */
			/* We allow -N chainname -P policy */
			if (replace->command == 'N' && c == 'P') {
				replace->command = c;
				optind--; /* No table specified */
				goto handle_P;
			}
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");

			replace->command = c;
			replace->flags |= OPT_COMMAND;
			if (!(replace->flags & OPT_KERNELDATA))
				ebt_get_kernel_table(replace, 0);
			if (optarg && (optarg[0] == '-' || !strcmp(optarg, "!")))
				ebt_print_error2("No chain name specified");
			if (c == 'N') {
				if (ebt_get_chainnr(replace, optarg) != -1)
					ebt_print_error2("Chain %s already exists", optarg);
				else if (ebt_find_target(optarg))
					ebt_print_error2("Target with name %s exists", optarg);
				else if (strlen(optarg) >= EBT_CHAIN_MAXNAMELEN)
					ebt_print_error2("Chain name length can't exceed %d",
							EBT_CHAIN_MAXNAMELEN - 1);
				else if (strchr(optarg, ' ') != NULL)
					ebt_print_error2("Use of ' ' not allowed in chain names");
				ebt_new_chain(replace, optarg, EBT_ACCEPT);
				/* This is needed to get -N x -P y working */
				replace->selected_chain = ebt_get_chainnr(replace, optarg);
				break;
			} else if (c == 'X') {
				if (optind >= argc) {
					replace->selected_chain = -1;
					ebt_delete_chain(replace);
					break;
				}

				if (optind < argc - 1)
					ebt_print_error2("No extra options allowed with -X");

				if ((replace->selected_chain = ebt_get_chainnr(replace, argv[optind])) == -1)
					ebt_print_error2("Chain '%s' doesn't exist", argv[optind]);
				ebt_delete_chain(replace);
				if (ebt_errormsg[0] != '\0')
					return -1;
				optind++;
				break;
			}

			if ((replace->selected_chain = ebt_get_chainnr(replace, optarg)) == -1)
				ebt_print_error2("Chain '%s' doesn't exist", optarg);
			if (c == 'E') {
				if (optind >= argc)
					ebt_print_error2("No new chain name specified");
				else if (optind < argc - 1)
					ebt_print_error2("No extra options allowed with -E");
				else if (strlen(argv[optind]) >= EBT_CHAIN_MAXNAMELEN)
					ebt_print_error2("Chain name length can't exceed %d characters", EBT_CHAIN_MAXNAMELEN - 1);
				else if (ebt_get_chainnr(replace, argv[optind]) != -1)
					ebt_print_error2("Chain '%s' already exists", argv[optind]);
				else if (ebt_find_target(argv[optind]))
					ebt_print_error2("Target with name '%s' exists", argv[optind]);
				else if (strchr(argv[optind], ' ') != NULL)
					ebt_print_error2("Use of ' ' not allowed in chain names");
				ebt_rename_chain(replace, argv[optind]);
				optind++;
				break;
			} else if (c == 'D' && optind < argc && (argv[optind][0] != '-' || (argv[optind][1] >= '0' && argv[optind][1] <= '9'))) {
				if (optind != argc - 1)
					ebt_print_error2("No extra options allowed with -D start_nr[:end_nr]");
				if (parse_rule_range(argv[optind], &rule_nr, &rule_nr_end))
					ebt_print_error2("Problem with the specified rule number(s) '%s'", argv[optind]);
				optind++;
			} else if (c == 'C') {
				if ((chcounter = parse_change_counters_rule(argc, argv, &rule_nr, &rule_nr_end, exec_style)) == -1)
					return -1;
			} else if (c == 'I') {
				if (optind >= argc || (argv[optind][0] == '-' && (argv[optind][1] < '0' || argv[optind][1] > '9')))
					rule_nr = 1;
				else {
					rule_nr = strtol(argv[optind], &buffer, 10);
					if (*buffer != '\0')
						ebt_print_error2("Problem with the specified rule number '%s'", argv[optind]);
					optind++;
				}
			} else if (c == 'P') {
handle_P:
				if (optind >= argc)
					ebt_print_error2("No policy specified");
				for (i = 0; i < NUM_STANDARD_TARGETS; i++)
					if (!strcmp(argv[optind], ebt_standard_targets[i])) {
						policy = -i -1;
						if (policy == EBT_CONTINUE)
							ebt_print_error2("Wrong policy '%s'", argv[optind]);
						break;
					}
				if (i == NUM_STANDARD_TARGETS)
					ebt_print_error2("Unknown policy '%s'", argv[optind]);
				optind++;
			}
			break;
		case 'L': /* List */
		case 'F': /* Flush */
		case 'Z': /* Zero counters */
			if (c == 'Z') {
				if ((replace->flags & OPT_ZERO) || (replace->flags & OPT_COMMAND && replace->command != 'L'))
print_zero:
					ebt_print_error2("Command -Z only allowed together with command -L");
				replace->flags |= OPT_ZERO;
			} else {
				if (replace->flags & OPT_COMMAND)
					ebt_print_error2("Multiple commands are not allowed");
				replace->command = c;
				replace->flags |= OPT_COMMAND;
				if (replace->flags & OPT_ZERO && c != 'L')
					goto print_zero;
			}

#ifdef SILENT_DAEMON
			if (c== 'L' && exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("-L not supported in daemon mode");
#endif

			if (!(replace->flags & OPT_KERNELDATA))
				ebt_get_kernel_table(replace, 0);
			i = -1;
			if (optind < argc && argv[optind][0] != '-') {
				if ((i = ebt_get_chainnr(replace, argv[optind])) == -1)
					ebt_print_error2("Chain '%s' doesn't exist", argv[optind]);
				optind++;
			}
			if (i != -1) {
				if (c == 'Z')
					zerochain = i;
				else
					replace->selected_chain = i;
			}
			break;
		case 'V': /* Version */
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			replace->command = 'V';
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2(PROGNAME" v"PROGVERSION" ("PROGDATE")\n");
			PRINT_VERSION;
			exit(0);
		case 'M': /* Modprobe */
			if (OPT_COMMANDS)
				ebt_print_error2("Please put the -M option earlier");
			free(ebt_modprobe);
			ebt_modprobe = optarg;
			break;
		case 'h': /* Help */
#ifdef SILENT_DAEMON
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("-h not supported in daemon mode");
#endif
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			replace->command = 'h';

			/* All other arguments should be extension names */
			while (optind < argc) {
				struct ebt_u_match *m;
				struct ebt_u_watcher *w;

				if (!strcasecmp("list_extensions", argv[optind])) {
					ebt_list_extensions();
					exit(0);
				}
				if ((m = ebt_find_match(argv[optind])))
					ebt_add_match(new_entry, m);
				else if ((w = ebt_find_watcher(argv[optind])))
					ebt_add_watcher(new_entry, w);
				else {
					if (!(t = ebt_find_target(argv[optind])))
						ebt_print_error2("Extension '%s' not found", argv[optind]);
					if (replace->flags & OPT_JUMP)
						ebt_print_error2("Sorry, you can only see help for one target extension at a time");
					replace->flags |= OPT_JUMP;
					new_entry->t = (struct ebt_entry_target *)t;
				}
				optind++;
			}
			break;
		case 't': /* Table */
			if (OPT_COMMANDS)
				ebt_print_error2("Please put the -t option first");
			ebt_check_option2(&(replace->flags), OPT_TABLE);
			if (strlen(optarg) > EBT_TABLE_MAXNAMELEN - 1)
				ebt_print_error2("Table name length cannot exceed %d characters", EBT_TABLE_MAXNAMELEN - 1);
			strcpy(replace->name, optarg);
			break;
		case 'i': /* Input interface */
		case 2  : /* Logical input interface */
		case 'o': /* Output interface */
		case 3  : /* Logical output interface */
		case 'j': /* Target */
		case 'p': /* Net family protocol */
		case 's': /* Source mac */
		case 'd': /* Destination mac */
		case 'c': /* Set counters */
			if (!OPT_COMMANDS)
				ebt_print_error2("No command specified");
			if (replace->command != 'A' && replace->command != 'D' && replace->command != 'I' && replace->command != 'C')
				ebt_print_error2("Command and option do not match");
			if (c == 'i') {
				ebt_check_option2(&(replace->flags), OPT_IN);
				if (replace->selected_chain > 2 && replace->selected_chain < NF_BR_BROUTING)
					ebt_print_error2("Use -i only in INPUT, FORWARD, PREROUTING and BROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IIN;

				if (strlen(optarg) >= IFNAMSIZ)
big_iface_length:
					ebt_print_error2("Interface name length cannot exceed %d characters", IFNAMSIZ - 1);
				strcpy(new_entry->in, optarg);
				if (parse_iface(new_entry->in, "-i"))
					return -1;
				break;
			} else if (c == 2) {
				ebt_check_option2(&(replace->flags), OPT_LOGICALIN);
				if (replace->selected_chain > 2 && replace->selected_chain < NF_BR_BROUTING)
					ebt_print_error2("Use --logical-in only in INPUT, FORWARD, PREROUTING and BROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ILOGICALIN;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->logical_in, optarg);
				if (parse_iface(new_entry->logical_in, "--logical-in"))
					return -1;
				break;
			} else if (c == 'o') {
				ebt_check_option2(&(replace->flags), OPT_OUT);
				if (replace->selected_chain < 2 )//|| replace->selected_chain == NF_BR_BROUTING)
					ebt_print_error2("Use -o only in OUTPUT, FORWARD and POSTROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IOUT;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->out, optarg);
				if (parse_iface(new_entry->out, "-o"))
					return -1;
				break;
			} else if (c == 3) {
				ebt_check_option2(&(replace->flags), OPT_LOGICALOUT);
				if (replace->selected_chain < 2 || replace->selected_chain == NF_BR_BROUTING)
					ebt_print_error2("Use --logical-out only in OUTPUT, FORWARD and POSTROUTING chains");
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ILOGICALOUT;

				if (strlen(optarg) >= IFNAMSIZ)
					goto big_iface_length;
				strcpy(new_entry->logical_out, optarg);
				if (parse_iface(new_entry->logical_out, "--logical-out"))
					return -1;    
				break;
			} else if (c == 'j') {
				ebt_check_option2(&(replace->flags), OPT_JUMP);
				for (i = 0; i < NUM_STANDARD_TARGETS; i++)
					if (!strcmp(optarg, ebt_standard_targets[i])) {
						t = ebt_find_target(EBT_STANDARD_TARGET);
						((struct ebt_standard_target *) t->t)->verdict = -i - 1;
						break;
					}
				if (-i - 1 == EBT_RETURN && replace->selected_chain < NF_BR_NUMHOOKS) {
					ebt_print_error2("Return target only for user defined chains");
				} else if (i != NUM_STANDARD_TARGETS)
					break;

				if ((i = ebt_get_chainnr(replace, optarg)) != -1) {
					if (i < NF_BR_NUMHOOKS)
						ebt_print_error2("Don't jump to a standard chain");
					t = ebt_find_target(EBT_STANDARD_TARGET);
					((struct ebt_standard_target *) t->t)->verdict = i - NF_BR_NUMHOOKS;
					break;
				} else {
					/* Must be an extension then */
					struct ebt_u_target *t;

					t = ebt_find_target(optarg);
					/* -j standard not allowed either */
					if (!t || t == (struct ebt_u_target *)new_entry->t)
						ebt_print_error2("Illegal target name '%s'", optarg);
					new_entry->t = (struct ebt_entry_target *)t;
					ebt_find_target(EBT_STANDARD_TARGET)->used = 0;
					t->used = 1;
				}
				break;
			} else if (c == 's') {
				ebt_check_option2(&(replace->flags), OPT_SOURCE);
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_ISOURCE;

				if (ebt_get_mac_and_mask(optarg, new_entry->sourcemac, new_entry->sourcemsk))
					ebt_print_error2("Problem with specified source mac '%s'", optarg);
				new_entry->bitmask |= EBT_SOURCEMAC;
				break;
			} else if (c == 'd') {
				ebt_check_option2(&(replace->flags), OPT_DEST);
				if (ebt_check_inverse2(optarg))
					new_entry->invflags |= EBT_IDEST;

				if (ebt_get_mac_and_mask(optarg, new_entry->destmac, new_entry->destmsk))
					ebt_print_error2("Problem with specified destination mac '%s'", optarg);
				new_entry->bitmask |= EBT_DESTMAC;
				break;
			} else if (c == 'c') {
				ebt_check_option2(&(replace->flags), OPT_COUNT);
				if (ebt_check_inverse2(optarg))
					ebt_print_error2("Unexpected '!' after -c");
				if (optind >= argc || optarg[0] == '-' || argv[optind][0] == '-')
					ebt_print_error2("Option -c needs 2 arguments");

				new_entry->cnt.pcnt = strtoull(optarg, &buffer, 10);
				if (*buffer != '\0')
					ebt_print_error2("Packet counter '%s' invalid", optarg);
				new_entry->cnt.bcnt = strtoull(argv[optind], &buffer, 10);
				if (*buffer != '\0')
					ebt_print_error2("Packet counter '%s' invalid", argv[optind]);
				optind++;
				break;
			}
			ebt_check_option2(&(replace->flags), OPT_PROTOCOL);
			if (ebt_check_inverse2(optarg))
				new_entry->invflags |= EBT_IPROTO;

			new_entry->bitmask &= ~((unsigned int)EBT_NOPROTO);
			i = strtol(optarg, &buffer, 16);
			if (*buffer == '\0' && (i < 0 || i > 0xFFFF))
				ebt_print_error2("Problem with the specified protocol");
			if (*buffer != '\0') {
				struct ethertypeent *ent;

				if (!strcasecmp(optarg, "LENGTH")) {
					new_entry->bitmask |= EBT_802_3;
					break;
				}
				ent = getethertypebyname(optarg);
				if (!ent)
					ebt_print_error2("Problem with the specified Ethernet protocol '%s', perhaps "_PATH_ETHERTYPES " is missing", optarg);
				new_entry->ethproto = ent->e_ethertype;
			} else
				new_entry->ethproto = i;

			if (new_entry->ethproto < 0x0600)
				ebt_print_error2("Sorry, protocols have values above or equal to 0x0600");
			break;
		case 4  : /* Lc */
#ifdef SILENT_DAEMON
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("--Lc is not supported in daemon mode");
#endif
			ebt_check_option2(&(replace->flags), LIST_C);
			if (replace->command != 'L')
				ebt_print_error("Use --Lc with -L");
			replace->flags |= LIST_C;
			break;
		case 5  : /* Ln */
#ifdef SILENT_DAEMON
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("--Ln is not supported in daemon mode");
#endif
			ebt_check_option2(&(replace->flags), LIST_N);
			if (replace->command != 'L')
				ebt_print_error2("Use --Ln with -L");
			if (replace->flags & LIST_X)
				ebt_print_error2("--Lx is not compatible with --Ln");
			replace->flags |= LIST_N;
			break;
		case 6  : /* Lx */
#ifdef SILENT_DAEMON
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("--Lx is not supported in daemon mode");
#endif
			ebt_check_option2(&(replace->flags), LIST_X);
			if (replace->command != 'L')
				ebt_print_error2("Use --Lx with -L");
			if (replace->flags & LIST_N)
				ebt_print_error2("--Lx is not compatible with --Ln");
			replace->flags |= LIST_X;
			break;
		case 12 : /* Lmac2 */
#ifdef SILENT_DAEMON
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error("--Lmac2 is not supported in daemon mode");
#endif
			ebt_check_option2(&(replace->flags), LIST_MAC2);
			if (replace->command != 'L')
				ebt_print_error2("Use --Lmac2 with -L");
			replace->flags |= LIST_MAC2;
			break;
		case 8 : /* atomic-commit */
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("--atomic-commit is not supported in daemon mode");
			replace->command = c;
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			replace->flags |= OPT_COMMAND;
			if (!replace->filename)
				ebt_print_error2("No atomic file specified");
			/* Get the information from the file */
			ebt_get_table(replace, 0);
			/* We don't want the kernel giving us its counters,
			 * they would overwrite the counters extracted from
			 * the file */
			replace->num_counters = 0;
			/* Make sure the table will be written to the kernel */
			free(replace->filename);
			replace->filename = NULL;
			break;
		case 7 : /* atomic-init */
		case 10: /* atomic-save */
		case 11: /* init-table */
			if (exec_style == EXEC_STYLE_DAEMON) {
				if (c == 7) {
					ebt_print_error2("--atomic-init is not supported in daemon mode");
				} else if (c == 10)
					ebt_print_error2("--atomic-save is not supported in daemon mode");
				ebt_print_error2("--init-table is not supported in daemon mode");
			}
			replace->command = c;
			if (OPT_COMMANDS)
				ebt_print_error2("Multiple commands are not allowed");
			if (c != 11 && !replace->filename)
				ebt_print_error2("No atomic file specified");
			replace->flags |= OPT_COMMAND;
			{
				char *tmp = replace->filename;

				/* Get the kernel table */
				replace->filename = NULL;
				ebt_get_kernel_table(replace, c == 10 ? 0 : 1);
				replace->filename = tmp;
			}
			break;
		case 9 : /* atomic */
			if (exec_style == EXEC_STYLE_DAEMON)
				ebt_print_error2("--atomic is not supported in daemon mode");
			if (OPT_COMMANDS)
				ebt_print_error2("--atomic has to come before the command");
			/* A possible memory leak here, but this is not
			 * executed in daemon mode */
			replace->filename = (char *)malloc(strlen(optarg) + 1);
			strcpy(replace->filename, optarg);
			break;
		case 13 : /* concurrent */
			signal(SIGINT, sighandler);
			signal(SIGTERM, sighandler);
			use_lockfd = 1;
			break;
		case 1 :
			if (!strcmp(optarg, "!"))
				ebt_check_inverse2(optarg);
			else
				ebt_print_error2("Bad argument : '%s'", optarg);
			/* ebt_check_inverse() did optind++ */
			optind--;
			continue;
		default:
			/* Is it a target option? */
			t = (struct ebt_u_target *)new_entry->t;
			if ((t->parse(c - t->option_offset, argv, argc, new_entry, &t->flags, &t->t))) {
				if (ebt_errormsg[0] != '\0')
					return -1;
				goto check_extension;
			}

			/* Is it a match_option? */
			for (m = ebt_matches; m; m = m->next)
				if (m->parse(c - m->option_offset, argv, argc, new_entry, &m->flags, &m->m))
					break;

			if (m != NULL) {
				if (ebt_errormsg[0] != '\0')
					return -1;
				if (m->used == 0) {
					ebt_add_match(new_entry, m);
					m->used = 1;
				}
				goto check_extension;
			}

			/* Is it a watcher option? */
			for (w = ebt_watchers; w; w = w->next)
				if (w->parse(c - w->option_offset, argv, argc, new_entry, &w->flags, &w->w))
					break;

			if (w == NULL && c == '?')
				ebt_print_error2("Unknown argument: '%s'", argv[optind - 1], (char)optopt, (char)c);
			else if (w == NULL) {
				if (!strcmp(t->name, "standard"))
					ebt_print_error2("Unknown argument: don't forget the -t option");
				else
					ebt_print_error2("Target-specific option does not correspond with specified target");
			}
			if (ebt_errormsg[0] != '\0')
				return -1;
			if (w->used == 0) {
				ebt_add_watcher(new_entry, w);
				w->used = 1;
			}
check_extension:
			if (replace->command != 'A' && replace->command != 'I' &&
			    replace->command != 'D' && replace->command != 'C')
				ebt_print_error2("Extensions only for -A, -I, -D and -C");
		}
		ebt_invert = 0;
	}

	/* Just in case we didn't catch an error */
	if (ebt_errormsg[0] != '\0')
		return -1;

	if (!(table = ebt_find_table(replace->name)))
		ebt_print_error2("Bad table name");

	if (replace->command == 'h' && !(replace->flags & OPT_ZERO)) {
		print_help();
		if (exec_style == EXEC_STYLE_PRG)
			exit(0);
	}

	/* Do the final checks */
	if (replace->command == 'A' || replace->command == 'I' ||
	   replace->command == 'D' || replace->command == 'C') {
		/* This will put the hook_mask right for the chains */
		ebt_check_for_loops(replace);
		if (ebt_errormsg[0] != '\0')
			return -1;
		entries = ebt_to_chain(replace);
		m_l = new_entry->m_list;
		w_l = new_entry->w_list;
		t = (struct ebt_u_target *)new_entry->t;
		while (m_l) {
			m = (struct ebt_u_match *)(m_l->m);
			m->final_check(new_entry, m->m, replace->name,
			   entries->hook_mask, 0);
			if (ebt_errormsg[0] != '\0')
				return -1;
			m_l = m_l->next;
		}
		while (w_l) {
			w = (struct ebt_u_watcher *)(w_l->w);
			w->final_check(new_entry, w->w, replace->name,
			   entries->hook_mask, 0);
			if (ebt_errormsg[0] != '\0')
				return -1;
			w_l = w_l->next;
		}
		t->final_check(new_entry, t->t, replace->name,
		   entries->hook_mask, 0);
		if (ebt_errormsg[0] != '\0')
			return -1;
	}
	/* So, the extensions can work with the host endian.
	 * The kernel does not have to do this of course */
	new_entry->ethproto = htons(new_entry->ethproto);

	if (replace->command == 'P') {
		if (replace->selected_chain < NF_BR_NUMHOOKS && policy == EBT_RETURN)
			ebt_print_error2("Policy RETURN only allowed for user defined chains");
		ebt_change_policy(replace, policy);
		if (ebt_errormsg[0] != '\0')
			return -1;
	} else if (replace->command == 'L') {
		list_rules();
		if (!(replace->flags & OPT_ZERO) && exec_style == EXEC_STYLE_PRG)
			exit(0);
	}
	if (replace->flags & OPT_ZERO) {
		replace->selected_chain = zerochain;
		ebt_zero_counters(replace);
	} else if (replace->command == 'F') {
		ebt_flush_chains(replace);
	} else if (replace->command == 'A' || replace->command == 'I') {
		ebt_add_rule(replace, new_entry, rule_nr);
		if (ebt_errormsg[0] != '\0')
			return -1;
		/* Makes undoing the add easier (jumps to delete_the_rule) */
		if (rule_nr <= 0)
			rule_nr--;
		rule_nr_end = rule_nr;

		/* a jump to a udc requires checking for loops */
		if (!strcmp(new_entry->t->u.name, EBT_STANDARD_TARGET) &&
		((struct ebt_standard_target *)(new_entry->t))->verdict >= 0) {
			/* FIXME: this can be done faster */
			ebt_check_for_loops(replace);
			if (ebt_errormsg[0] != '\0')
				goto delete_the_rule;
		}

		/* Do the final_check(), for all entries.
		 * This is needed when adding a rule that has a chain target */
		i = -1;
		while (++i != replace->num_chains) {
			struct ebt_u_entry *e;

			entries = replace->chains[i];
			if (!entries) {
				if (i < NF_BR_NUMHOOKS)
					continue;
				else
					ebt_print_bug("whoops\n");
			}
			e = entries->entries->next;
			while (e != entries->entries) {
				/* Userspace extensions use host endian */
				e->ethproto = ntohs(e->ethproto);
				ebt_do_final_checks(replace, e, entries);
				if (ebt_errormsg[0] != '\0')
					goto delete_the_rule;
				e->ethproto = htons(e->ethproto);
				e = e->next;
			}
		}
		/* Don't reuse the added rule */
		new_entry = NULL;
	} else if (replace->command == 'D') {
delete_the_rule:
		ebt_delete_rule(replace, new_entry, rule_nr, rule_nr_end);
		if (ebt_errormsg[0] != '\0')
			return -1;
	} else if (replace->command == 'C') {
		ebt_change_counters(replace, new_entry, rule_nr, rule_nr_end, &(new_entry->cnt_surplus), chcounter);
		if (ebt_errormsg[0] != '\0')
			return -1;
	}
	/* Commands -N, -E, -X, --atomic-commit, --atomic-commit, --atomic-save,
	 * --init-table fall through */

	if (ebt_errormsg[0] != '\0')
		return -1;
	if (table->check)
		table->check(replace);

	if (exec_style == EXEC_STYLE_PRG) {/* Implies ebt_errormsg[0] == '\0' */
		ebt_deliver_table(replace);

		if (replace->nentries)
			ebt_deliver_counters(replace);
	}
	return 0;
}