xref: /aosp_15_r20/external/iptables/extensions/libebt_dnat.c (revision a71a954618bbadd4a345637e5edcf36eec826889)
1*a71a9546SAutomerger Merge Worker /* ebt_nat
2*a71a9546SAutomerger Merge Worker  *
3*a71a9546SAutomerger Merge Worker  * Authors:
4*a71a9546SAutomerger Merge Worker  * Bart De Schuymer <[email protected]>
5*a71a9546SAutomerger Merge Worker  *
6*a71a9546SAutomerger Merge Worker  * June, 2002
7*a71a9546SAutomerger Merge Worker  */
8*a71a9546SAutomerger Merge Worker 
9*a71a9546SAutomerger Merge Worker #include <stdio.h>
10*a71a9546SAutomerger Merge Worker #include <stdlib.h>
11*a71a9546SAutomerger Merge Worker #include <string.h>
12*a71a9546SAutomerger Merge Worker #include <getopt.h>
13*a71a9546SAutomerger Merge Worker #include <netinet/ether.h>
14*a71a9546SAutomerger Merge Worker #include <xtables.h>
15*a71a9546SAutomerger Merge Worker #include <linux/netfilter_bridge/ebt_nat.h>
16*a71a9546SAutomerger Merge Worker #include "iptables/nft.h"
17*a71a9546SAutomerger Merge Worker #include "iptables/nft-bridge.h"
18*a71a9546SAutomerger Merge Worker 
19*a71a9546SAutomerger Merge Worker #define NAT_D '1'
20*a71a9546SAutomerger Merge Worker #define NAT_D_TARGET '2'
21*a71a9546SAutomerger Merge Worker static const struct option brdnat_opts[] =
22*a71a9546SAutomerger Merge Worker {
23*a71a9546SAutomerger Merge Worker 	{ "to-destination", required_argument, 0, NAT_D },
24*a71a9546SAutomerger Merge Worker 	{ "to-dst"        , required_argument, 0, NAT_D },
25*a71a9546SAutomerger Merge Worker 	{ "dnat-target"   , required_argument, 0, NAT_D_TARGET },
26*a71a9546SAutomerger Merge Worker 	{ 0 }
27*a71a9546SAutomerger Merge Worker };
28*a71a9546SAutomerger Merge Worker 
brdnat_print_help(void)29*a71a9546SAutomerger Merge Worker static void brdnat_print_help(void)
30*a71a9546SAutomerger Merge Worker {
31*a71a9546SAutomerger Merge Worker 	printf(
32*a71a9546SAutomerger Merge Worker 	"dnat options:\n"
33*a71a9546SAutomerger Merge Worker 	" --to-dst address       : MAC address to map destination to\n"
34*a71a9546SAutomerger Merge Worker 	" --dnat-target target   : ACCEPT, DROP, RETURN or CONTINUE\n");
35*a71a9546SAutomerger Merge Worker }
36*a71a9546SAutomerger Merge Worker 
brdnat_init(struct xt_entry_target * target)37*a71a9546SAutomerger Merge Worker static void brdnat_init(struct xt_entry_target *target)
38*a71a9546SAutomerger Merge Worker {
39*a71a9546SAutomerger Merge Worker 	struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
40*a71a9546SAutomerger Merge Worker 
41*a71a9546SAutomerger Merge Worker 	natinfo->target = EBT_ACCEPT;
42*a71a9546SAutomerger Merge Worker }
43*a71a9546SAutomerger Merge Worker 
44*a71a9546SAutomerger Merge Worker #define OPT_DNAT        0x01
45*a71a9546SAutomerger Merge Worker #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*a71a9546SAutomerger Merge Worker static int brdnat_parse(int c, char **argv, int invert, unsigned int *flags,
47*a71a9546SAutomerger Merge Worker 			 const void *entry, struct xt_entry_target **target)
48*a71a9546SAutomerger Merge Worker {
49*a71a9546SAutomerger Merge Worker 	struct ebt_nat_info *natinfo = (struct ebt_nat_info *)(*target)->data;
50*a71a9546SAutomerger Merge Worker 	struct ether_addr *addr;
51*a71a9546SAutomerger Merge Worker 
52*a71a9546SAutomerger Merge Worker 	switch (c) {
53*a71a9546SAutomerger Merge Worker 	case NAT_D:
54*a71a9546SAutomerger Merge Worker 		EBT_CHECK_OPTION(flags, OPT_DNAT);
55*a71a9546SAutomerger Merge Worker 		if (!(addr = ether_aton(optarg)))
56*a71a9546SAutomerger Merge Worker 			xtables_error(PARAMETER_PROBLEM, "Problem with specified --to-destination mac");
57*a71a9546SAutomerger Merge Worker 		memcpy(natinfo->mac, addr, ETH_ALEN);
58*a71a9546SAutomerger Merge Worker 		break;
59*a71a9546SAutomerger Merge Worker 	case NAT_D_TARGET:
60*a71a9546SAutomerger Merge Worker 		EBT_CHECK_OPTION(flags, OPT_DNAT_TARGET);
61*a71a9546SAutomerger Merge Worker 		if (ebt_fill_target(optarg, (unsigned int *)&natinfo->target))
62*a71a9546SAutomerger Merge Worker 			xtables_error(PARAMETER_PROBLEM, "Illegal --dnat-target target");
63*a71a9546SAutomerger Merge Worker 		break;
64*a71a9546SAutomerger Merge Worker 	default:
65*a71a9546SAutomerger Merge Worker 		return 0;
66*a71a9546SAutomerger Merge Worker 	}
67*a71a9546SAutomerger Merge Worker 	return 1;
68*a71a9546SAutomerger Merge Worker }
69*a71a9546SAutomerger Merge Worker 
brdnat_final_check(unsigned int flags)70*a71a9546SAutomerger Merge Worker static void brdnat_final_check(unsigned int flags)
71*a71a9546SAutomerger Merge Worker {
72*a71a9546SAutomerger Merge Worker 	if (!flags)
73*a71a9546SAutomerger Merge Worker 		xtables_error(PARAMETER_PROBLEM,
74*a71a9546SAutomerger Merge Worker 			      "You must specify proper arguments");
75*a71a9546SAutomerger Merge Worker }
76*a71a9546SAutomerger Merge Worker 
brdnat_print(const void * ip,const struct xt_entry_target * target,int numeric)77*a71a9546SAutomerger Merge Worker static void brdnat_print(const void *ip, const struct xt_entry_target *target, int numeric)
78*a71a9546SAutomerger Merge Worker {
79*a71a9546SAutomerger Merge Worker 	struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
80*a71a9546SAutomerger Merge Worker 
81*a71a9546SAutomerger Merge Worker 	printf("--to-dst ");
82*a71a9546SAutomerger Merge Worker 	xtables_print_mac(natinfo->mac);
83*a71a9546SAutomerger Merge Worker 	printf(" --dnat-target %s", ebt_target_name(natinfo->target));
84*a71a9546SAutomerger Merge Worker }
85*a71a9546SAutomerger Merge Worker 
brdnat_verdict(int verdict)86*a71a9546SAutomerger Merge Worker static const char* brdnat_verdict(int verdict)
87*a71a9546SAutomerger Merge Worker {
88*a71a9546SAutomerger Merge Worker 	switch (verdict) {
89*a71a9546SAutomerger Merge Worker 	case EBT_ACCEPT: return "accept";
90*a71a9546SAutomerger Merge Worker 	case EBT_DROP: return "drop";
91*a71a9546SAutomerger Merge Worker 	case EBT_CONTINUE: return "continue";
92*a71a9546SAutomerger Merge Worker 	case EBT_RETURN: return "return";
93*a71a9546SAutomerger Merge Worker 	}
94*a71a9546SAutomerger Merge Worker 
95*a71a9546SAutomerger Merge Worker 	return "";
96*a71a9546SAutomerger Merge Worker }
97*a71a9546SAutomerger Merge Worker 
brdnat_xlate(struct xt_xlate * xl,const struct xt_xlate_tg_params * params)98*a71a9546SAutomerger Merge Worker static int brdnat_xlate(struct xt_xlate *xl,
99*a71a9546SAutomerger Merge Worker 			 const struct xt_xlate_tg_params *params)
100*a71a9546SAutomerger Merge Worker {
101*a71a9546SAutomerger Merge Worker 	const struct ebt_nat_info *natinfo = (const void*)params->target->data;
102*a71a9546SAutomerger Merge Worker 
103*a71a9546SAutomerger Merge Worker 	xt_xlate_add(xl, "ether daddr set %s %s ",
104*a71a9546SAutomerger Merge Worker 		     ether_ntoa((struct ether_addr *)natinfo->mac),
105*a71a9546SAutomerger Merge Worker 		     brdnat_verdict(natinfo->target));
106*a71a9546SAutomerger Merge Worker 
107*a71a9546SAutomerger Merge Worker 	return 1;
108*a71a9546SAutomerger Merge Worker }
109*a71a9546SAutomerger Merge Worker 
110*a71a9546SAutomerger Merge Worker static struct xtables_target brdnat_target =
111*a71a9546SAutomerger Merge Worker {
112*a71a9546SAutomerger Merge Worker 	.name		= "dnat",
113*a71a9546SAutomerger Merge Worker 	.version	= XTABLES_VERSION,
114*a71a9546SAutomerger Merge Worker 	.family		= NFPROTO_BRIDGE,
115*a71a9546SAutomerger Merge Worker 	.size           = XT_ALIGN(sizeof(struct ebt_nat_info)),
116*a71a9546SAutomerger Merge Worker 	.userspacesize	= XT_ALIGN(sizeof(struct ebt_nat_info)),
117*a71a9546SAutomerger Merge Worker 	.help		= brdnat_print_help,
118*a71a9546SAutomerger Merge Worker 	.init		= brdnat_init,
119*a71a9546SAutomerger Merge Worker 	.parse		= brdnat_parse,
120*a71a9546SAutomerger Merge Worker 	.final_check	= brdnat_final_check,
121*a71a9546SAutomerger Merge Worker 	.print		= brdnat_print,
122*a71a9546SAutomerger Merge Worker 	.xlate		= brdnat_xlate,
123*a71a9546SAutomerger Merge Worker 	.extra_opts	= brdnat_opts,
124*a71a9546SAutomerger Merge Worker };
125*a71a9546SAutomerger Merge Worker 
_init(void)126*a71a9546SAutomerger Merge Worker void _init(void)
127*a71a9546SAutomerger Merge Worker {
128*a71a9546SAutomerger Merge Worker 	xtables_register_target(&brdnat_target);
129*a71a9546SAutomerger Merge Worker }
130