1 #include <stdio.h>
2 #include <xtables.h>
3 #include <linux/netfilter/xt_esp.h>
4 
5 enum {
6 	O_ESPSPI = 0,
7 };
8 
esp_help(void)9 static void esp_help(void)
10 {
11 	printf(
12 "esp match options:\n"
13 "[!] --espspi spi[:spi]\n"
14 "				match spi (range)\n");
15 }
16 
17 static const struct xt_option_entry esp_opts[] = {
18 	{.name = "espspi", .id = O_ESPSPI, .type = XTTYPE_UINT32RC,
19 	 .flags = XTOPT_INVERT | XTOPT_PUT,
20 	 XTOPT_POINTER(struct xt_esp, spis)},
21 	XTOPT_TABLEEND,
22 };
23 
esp_init(struct xt_entry_match * m)24 static void esp_init(struct xt_entry_match *m)
25 {
26 	struct xt_esp *espinfo = (void *)m->data;
27 
28 	espinfo->spis[1] = ~0U;
29 }
30 
esp_parse(struct xt_option_call * cb)31 static void esp_parse(struct xt_option_call *cb)
32 {
33 	struct xt_esp *espinfo = cb->data;
34 
35 	xtables_option_parse(cb);
36 	if (cb->nvals == 1)
37 		espinfo->spis[1] = espinfo->spis[0];
38 	if (cb->invert)
39 		espinfo->invflags |= XT_ESP_INV_SPI;
40 }
41 
42 static void
print_spis(const char * name,uint32_t min,uint32_t max,int invert)43 print_spis(const char *name, uint32_t min, uint32_t max,
44 	    int invert)
45 {
46 	const char *inv = invert ? "!" : "";
47 
48 	if (min != 0 || max != 0xFFFFFFFF || invert) {
49 		if (min == max)
50 			printf(" %s:%s%u", name, inv, min);
51 		else
52 			printf(" %ss:%s%u:%u", name, inv, min, max);
53 	}
54 }
55 
56 static void
esp_print(const void * ip,const struct xt_entry_match * match,int numeric)57 esp_print(const void *ip, const struct xt_entry_match *match, int numeric)
58 {
59 	const struct xt_esp *esp = (struct xt_esp *)match->data;
60 
61 	printf(" esp");
62 	print_spis("spi", esp->spis[0], esp->spis[1],
63 		    esp->invflags & XT_ESP_INV_SPI);
64 	if (esp->invflags & ~XT_ESP_INV_MASK)
65 		printf(" Unknown invflags: 0x%X",
66 		       esp->invflags & ~XT_ESP_INV_MASK);
67 }
68 
esp_save(const void * ip,const struct xt_entry_match * match)69 static void esp_save(const void *ip, const struct xt_entry_match *match)
70 {
71 	const struct xt_esp *espinfo = (struct xt_esp *)match->data;
72 
73 	if (!(espinfo->spis[0] == 0
74 	    && espinfo->spis[1] == 0xFFFFFFFF)) {
75 		printf("%s --espspi ",
76 			(espinfo->invflags & XT_ESP_INV_SPI) ? " !" : "");
77 		if (espinfo->spis[0]
78 		    != espinfo->spis[1])
79 			printf("%u:%u",
80 			       espinfo->spis[0],
81 			       espinfo->spis[1]);
82 		else
83 			printf("%u",
84 			       espinfo->spis[0]);
85 	}
86 
87 }
88 
esp_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)89 static int esp_xlate(struct xt_xlate *xl,
90 		     const struct xt_xlate_mt_params *params)
91 {
92 	const struct xt_esp *espinfo = (struct xt_esp *)params->match->data;
93 
94 	if (!(espinfo->spis[0] == 0 && espinfo->spis[1] == 0xFFFFFFFF)) {
95 		xt_xlate_add(xl, "esp spi%s",
96 			   (espinfo->invflags & XT_ESP_INV_SPI) ? " !=" : "");
97 		if (espinfo->spis[0] != espinfo->spis[1])
98 			xt_xlate_add(xl, " %u-%u", espinfo->spis[0],
99 				   espinfo->spis[1]);
100 		else
101 			xt_xlate_add(xl, " %u", espinfo->spis[0]);
102 	}
103 
104 	return 1;
105 }
106 
107 static struct xtables_match esp_match = {
108 	.family		= NFPROTO_UNSPEC,
109 	.name		= "esp",
110 	.version	= XTABLES_VERSION,
111 	.size		= XT_ALIGN(sizeof(struct xt_esp)),
112 	.userspacesize	= XT_ALIGN(sizeof(struct xt_esp)),
113 	.help		= esp_help,
114 	.init		= esp_init,
115 	.print		= esp_print,
116 	.save		= esp_save,
117 	.x6_parse	= esp_parse,
118 	.x6_options	= esp_opts,
119 	.xlate		= esp_xlate,
120 };
121 
122 void
_init(void)123 _init(void)
124 {
125 	xtables_register_match(&esp_match);
126 }
127