1 /* ebt_nat
2 *
3 * Authors:
4 * Bart De Schuymer <bdschuym@pandora.be>
5 *
6 * June, 2002
7 */
8
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <getopt.h>
13 #include <netinet/ether.h>
14 #include <xtables.h>
15 #include <linux/netfilter_bridge/ebt_nat.h>
16 #include "iptables/nft.h"
17 #include "iptables/nft-bridge.h"
18
19 #define NAT_D '1'
20 #define NAT_D_TARGET '2'
21 static const struct option brdnat_opts[] =
22 {
23 { "to-destination", required_argument, 0, NAT_D },
24 { "to-dst" , required_argument, 0, NAT_D },
25 { "dnat-target" , required_argument, 0, NAT_D_TARGET },
26 { 0 }
27 };
28
brdnat_print_help(void)29 static void brdnat_print_help(void)
30 {
31 printf(
32 "dnat options:\n"
33 " --to-dst address : MAC address to map destination to\n"
34 " --dnat-target target : ACCEPT, DROP, RETURN or CONTINUE\n");
35 }
36
brdnat_init(struct xt_entry_target * target)37 static void brdnat_init(struct xt_entry_target *target)
38 {
39 struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
40
41 natinfo->target = EBT_ACCEPT;
42 }
43
44 #define OPT_DNAT 0x01
45 #define OPT_DNAT_TARGET 0x02
brdnat_parse(int c,char ** argv,int invert,unsigned int * flags,const void * entry,struct xt_entry_target ** target)46 static int brdnat_parse(int c, char **argv, int invert, unsigned int *flags,
47 const void *entry, struct xt_entry_target **target)
48 {
49 struct ebt_nat_info *natinfo = (struct ebt_nat_info *)(*target)->data;
50 struct ether_addr *addr;
51
52 switch (c) {
53 case NAT_D:
54 EBT_CHECK_OPTION(flags, OPT_DNAT);
55 if (!(addr = ether_aton(optarg)))
56 xtables_error(PARAMETER_PROBLEM, "Problem with specified --to-destination mac");
57 memcpy(natinfo->mac, addr, ETH_ALEN);
58 break;
59 case NAT_D_TARGET:
60 EBT_CHECK_OPTION(flags, OPT_DNAT_TARGET);
61 if (ebt_fill_target(optarg, (unsigned int *)&natinfo->target))
62 xtables_error(PARAMETER_PROBLEM, "Illegal --dnat-target target");
63 break;
64 default:
65 return 0;
66 }
67 return 1;
68 }
69
brdnat_final_check(unsigned int flags)70 static void brdnat_final_check(unsigned int flags)
71 {
72 if (!flags)
73 xtables_error(PARAMETER_PROBLEM,
74 "You must specify proper arguments");
75 }
76
brdnat_print(const void * ip,const struct xt_entry_target * target,int numeric)77 static void brdnat_print(const void *ip, const struct xt_entry_target *target, int numeric)
78 {
79 struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
80
81 printf("--to-dst ");
82 xtables_print_mac(natinfo->mac);
83 printf(" --dnat-target %s", ebt_target_name(natinfo->target));
84 }
85
brdnat_verdict(int verdict)86 static const char* brdnat_verdict(int verdict)
87 {
88 switch (verdict) {
89 case EBT_ACCEPT: return "accept";
90 case EBT_DROP: return "drop";
91 case EBT_CONTINUE: return "continue";
92 case EBT_RETURN: return "return";
93 }
94
95 return "";
96 }
97
brdnat_xlate(struct xt_xlate * xl,const struct xt_xlate_tg_params * params)98 static int brdnat_xlate(struct xt_xlate *xl,
99 const struct xt_xlate_tg_params *params)
100 {
101 const struct ebt_nat_info *natinfo = (const void*)params->target->data;
102
103 xt_xlate_add(xl, "ether daddr set %s %s ",
104 ether_ntoa((struct ether_addr *)natinfo->mac),
105 brdnat_verdict(natinfo->target));
106
107 return 1;
108 }
109
110 static struct xtables_target brdnat_target =
111 {
112 .name = "dnat",
113 .version = XTABLES_VERSION,
114 .family = NFPROTO_BRIDGE,
115 .size = XT_ALIGN(sizeof(struct ebt_nat_info)),
116 .userspacesize = XT_ALIGN(sizeof(struct ebt_nat_info)),
117 .help = brdnat_print_help,
118 .init = brdnat_init,
119 .parse = brdnat_parse,
120 .final_check = brdnat_final_check,
121 .print = brdnat_print,
122 .xlate = brdnat_xlate,
123 .extra_opts = brdnat_opts,
124 };
125
_init(void)126 void _init(void)
127 {
128 xtables_register_target(&brdnat_target);
129 }
130