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1 /* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
2  *                         Patrick Schaaf <bof@bof.de>
3  *                         Martin Josefsson <gandalf@wlug.westbo.se>
4  * Copyright (C) 2003-2004 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 /* Shared library add-on to iptables to add IP set matching. */
12 #include <stdio.h>
13 #include <netdb.h>
14 #include <string.h>
15 #include <stdlib.h>
16 #include <getopt.h>
17 #include <ctype.h>
18 #include <errno.h>
19 
20 #include <iptables.h>
21 #include <linux/netfilter_ipv4/ip_conntrack.h>
22 #include <linux/netfilter_ipv4/ipt_set.h>
23 #include "libipt_2set.h"
24 
25 /* Function which prints out usage message. */
help(void)26 static void help(void)
27 {
28 	printf("set v%s options:\n"
29 	       " [!] --set     name flags\n"
30 	       "		'name' is the set name from to match,\n"
31 	       "		'flags' are the comma separated list of\n"
32 	       "		'src' and 'dst'.\n"
33 	       "\n", IPTABLES_VERSION);
34 }
35 
36 static struct option opts[] = {
37 	{"set", 1, 0, '1'},
38 	{0}
39 };
40 
41 /* Initialize the match. */
init(struct ipt_entry_match * match,unsigned int * nfcache)42 static void init(struct ipt_entry_match *match, unsigned int *nfcache)
43 {
44 	struct ipt_set_info_match *info =
45 		(struct ipt_set_info_match *) match->data;
46 
47 
48 	memset(info, 0, sizeof(struct ipt_set_info_match));
49 
50 }
51 
52 /* Function which parses command options; returns true if it ate an option */
53 static int
parse(int c,char ** argv,int invert,unsigned int * flags,const struct ipt_entry * entry,unsigned int * nfcache,struct ipt_entry_match ** match)54 parse(int c, char **argv, int invert, unsigned int *flags,
55       const struct ipt_entry *entry,
56       unsigned int *nfcache, struct ipt_entry_match **match)
57 {
58 	struct ipt_set_info_match *myinfo =
59 		(struct ipt_set_info_match *) (*match)->data;
60 	struct ipt_set_info *info = &myinfo->match_set;
61 
62 	switch (c) {
63 	case '1':		/* --set <set> <flag>[,<flag> */
64 		if (info->flags[0])
65 			exit_error(PARAMETER_PROBLEM,
66 				   "--set can be specified only once");
67 
68 		check_inverse(optarg, &invert, &optind, 0);
69 		if (invert)
70 			info->flags[0] |= IPSET_MATCH_INV;
71 
72 		if (!argv[optind]
73 		    || argv[optind][0] == '-'
74 		    || argv[optind][0] == '!')
75 			exit_error(PARAMETER_PROBLEM,
76 				   "--set requires two args.");
77 
78 		if (strlen(argv[optind-1]) > IP_SET_MAXNAMELEN - 1)
79 			exit_error(PARAMETER_PROBLEM,
80 				   "setname `%s' too long, max %d characters.",
81 				   argv[optind-1], IP_SET_MAXNAMELEN - 1);
82 
83 		get_set_byname(argv[optind - 1], info);
84 		parse_bindings(argv[optind], info);
85 		DEBUGP("parse: set index %u\n", info->index);
86 		optind++;
87 
88 		*flags = 1;
89 		break;
90 
91 	default:
92 		return 0;
93 	}
94 
95 	return 1;
96 }
97 
98 /* Final check; must have specified --set. */
final_check(unsigned int flags)99 static void final_check(unsigned int flags)
100 {
101 	if (!flags)
102 		exit_error(PARAMETER_PROBLEM,
103 			   "You must specify `--set' with proper arguments");
104 	DEBUGP("final check OK\n");
105 }
106 
107 static void
print_match(const char * prefix,const struct ipt_set_info * info)108 print_match(const char *prefix, const struct ipt_set_info *info)
109 {
110 	int i;
111 	char setname[IP_SET_MAXNAMELEN];
112 
113 	get_set_byid(setname, info->index);
114 	printf("%s%s %s",
115 	       (info->flags[0] & IPSET_MATCH_INV) ? "! " : "",
116 	       prefix,
117 	       setname);
118 	for (i = 0; i < IP_SET_MAX_BINDINGS; i++) {
119 		if (!info->flags[i])
120 			break;
121 		printf("%s%s",
122 		       i == 0 ? " " : ",",
123 		       info->flags[i] & IPSET_SRC ? "src" : "dst");
124 	}
125 	printf(" ");
126 }
127 
128 /* Prints out the matchinfo. */
129 static void
print(const struct ipt_ip * ip,const struct ipt_entry_match * match,int numeric)130 print(const struct ipt_ip *ip,
131       const struct ipt_entry_match *match, int numeric)
132 {
133 	struct ipt_set_info_match *info =
134 		(struct ipt_set_info_match *) match->data;
135 
136 	print_match("set", &info->match_set);
137 }
138 
139 /* Saves the matchinfo in parsable form to stdout. */
save(const struct ipt_ip * ip,const struct ipt_entry_match * match)140 static void save(const struct ipt_ip *ip,
141 		 const struct ipt_entry_match *match)
142 {
143 	struct ipt_set_info_match *info =
144 		(struct ipt_set_info_match *) match->data;
145 
146 	print_match("--set", &info->match_set);
147 }
148 
149 static
150 struct iptables_match set = {
151 	.name		= "set",
152 	.version	= IPTABLES_VERSION,
153 	.size		= IPT_ALIGN(sizeof(struct ipt_set_info_match)),
154 	.userspacesize	= IPT_ALIGN(sizeof(struct ipt_set_info_match)),
155 	.help		= &help,
156 	.init		= &init,
157 	.parse		= &parse,
158 	.final_check	= &final_check,
159 	.print		= &print,
160 	.save		= &save,
161 	.extra_opts	= opts
162 };
163 
ipt_2set_init(void)164 void ipt_2set_init(void)
165 {
166 	register_match(&set);
167 }
168