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
skip_spis_match(uint32_t min,uint32_t max,bool inv)42 static bool skip_spis_match(uint32_t min, uint32_t max, bool inv)
43 {
44 return min == 0 && max == UINT32_MAX && !inv;
45 }
46
47 static void
print_spis(const char * name,uint32_t min,uint32_t max,int invert)48 print_spis(const char *name, uint32_t min, uint32_t max,
49 int invert)
50 {
51 const char *inv = invert ? "!" : "";
52
53 if (!skip_spis_match(min, max, invert)) {
54 if (min == max)
55 printf(" %s:%s%u", name, inv, min);
56 else
57 printf(" %ss:%s%u:%u", name, inv, min, max);
58 }
59 }
60
61 static void
esp_print(const void * ip,const struct xt_entry_match * match,int numeric)62 esp_print(const void *ip, const struct xt_entry_match *match, int numeric)
63 {
64 const struct xt_esp *esp = (struct xt_esp *)match->data;
65
66 printf(" esp");
67 print_spis("spi", esp->spis[0], esp->spis[1],
68 esp->invflags & XT_ESP_INV_SPI);
69 if (esp->invflags & ~XT_ESP_INV_MASK)
70 printf(" Unknown invflags: 0x%X",
71 esp->invflags & ~XT_ESP_INV_MASK);
72 }
73
esp_save(const void * ip,const struct xt_entry_match * match)74 static void esp_save(const void *ip, const struct xt_entry_match *match)
75 {
76 const struct xt_esp *espinfo = (struct xt_esp *)match->data;
77 bool inv_spi = espinfo->invflags & XT_ESP_INV_SPI;
78
79 if (!skip_spis_match(espinfo->spis[0], espinfo->spis[1], inv_spi)) {
80 printf("%s --espspi ", inv_spi ? " !" : "");
81 if (espinfo->spis[0]
82 != espinfo->spis[1])
83 printf("%u:%u",
84 espinfo->spis[0],
85 espinfo->spis[1]);
86 else
87 printf("%u",
88 espinfo->spis[0]);
89 }
90
91 }
92
esp_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)93 static int esp_xlate(struct xt_xlate *xl,
94 const struct xt_xlate_mt_params *params)
95 {
96 const struct xt_esp *espinfo = (struct xt_esp *)params->match->data;
97 bool inv_spi = espinfo->invflags & XT_ESP_INV_SPI;
98
99 if (!skip_spis_match(espinfo->spis[0], espinfo->spis[1], inv_spi)) {
100 xt_xlate_add(xl, "esp spi%s", inv_spi ? " !=" : "");
101 if (espinfo->spis[0] != espinfo->spis[1])
102 xt_xlate_add(xl, " %u-%u", espinfo->spis[0],
103 espinfo->spis[1]);
104 else
105 xt_xlate_add(xl, " %u", espinfo->spis[0]);
106 } else if (afinfo->family == NFPROTO_IPV4) {
107 xt_xlate_add(xl, "meta l4proto esp");
108 } else if (afinfo->family == NFPROTO_IPV6) {
109 xt_xlate_add(xl, "exthdr esp exists");
110 } else {
111 return 0;
112 }
113
114 return 1;
115 }
116
117 static struct xtables_match esp_match = {
118 .family = NFPROTO_UNSPEC,
119 .name = "esp",
120 .version = XTABLES_VERSION,
121 .size = XT_ALIGN(sizeof(struct xt_esp)),
122 .userspacesize = XT_ALIGN(sizeof(struct xt_esp)),
123 .help = esp_help,
124 .init = esp_init,
125 .print = esp_print,
126 .save = esp_save,
127 .x6_parse = esp_parse,
128 .x6_options = esp_opts,
129 .xlate = esp_xlate,
130 };
131
132 void
_init(void)133 _init(void)
134 {
135 xtables_register_match(&esp_match);
136 }
137