blob: 5769edb56f55af8bcad0b05df40da761cfecfee5 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001/* Shared library add-on to iptables to add ESP support. */
2#include <stdio.h>
3#include <netdb.h>
4#include <string.h>
5#include <stdlib.h>
6#include <getopt.h>
7#include <errno.h>
8#include <limits.h>
9
10#include <xtables.h>
11#include <linux/netfilter/xt_esp.h>
12
13static void esp_help(void)
14{
15 printf(
16"esp match options:\n"
17"[!] --espspi spi[:spi]\n"
18" match spi (range)\n");
19}
20
21static const struct option esp_opts[] = {
22 { "espspi", 1, NULL, '1' },
23 { .name = NULL }
24};
25
26static u_int32_t
27parse_esp_spi(const char *spistr)
28{
29 unsigned long int spi;
30 char* ep;
31
32 spi = strtoul(spistr,&ep,0) ;
33
34 if ( spistr == ep ) {
35 xtables_error(PARAMETER_PROBLEM,
36 "ESP no valid digits in spi `%s'", spistr);
37 }
38 if ( spi == ULONG_MAX && errno == ERANGE ) {
39 xtables_error(PARAMETER_PROBLEM,
40 "spi `%s' specified too big: would overflow", spistr);
41 }
42 if ( *spistr != '\0' && *ep != '\0' ) {
43 xtables_error(PARAMETER_PROBLEM,
44 "ESP error parsing spi `%s'", spistr);
45 }
46 return spi;
47}
48
49static void
50parse_esp_spis(const char *spistring, u_int32_t *spis)
51{
52 char *buffer;
53 char *cp;
54
55 buffer = strdup(spistring);
56 if ((cp = strchr(buffer, ':')) == NULL)
57 spis[0] = spis[1] = parse_esp_spi(buffer);
58 else {
59 *cp = '\0';
60 cp++;
61
62 spis[0] = buffer[0] ? parse_esp_spi(buffer) : 0;
63 spis[1] = cp[0] ? parse_esp_spi(cp) : 0xFFFFFFFF;
64 if (spis[0] > spis[1])
65 xtables_error(PARAMETER_PROBLEM,
66 "Invalid ESP spi range: %s", spistring);
67 }
68 free(buffer);
69}
70
71static void esp_init(struct xt_entry_match *m)
72{
73 struct xt_esp *espinfo = (struct xt_esp *)m->data;
74
75 espinfo->spis[1] = 0xFFFFFFFF;
76}
77
78#define ESP_SPI 0x01
79
80static int
81esp_parse(int c, char **argv, int invert, unsigned int *flags,
82 const void *entry, struct xt_entry_match **match)
83{
84 struct xt_esp *espinfo = (struct xt_esp *)(*match)->data;
85
86 switch (c) {
87 case '1':
88 if (*flags & ESP_SPI)
89 xtables_error(PARAMETER_PROBLEM,
90 "Only one `--espspi' allowed");
91 xtables_check_inverse(optarg, &invert, &optind, 0);
92 parse_esp_spis(argv[optind-1], espinfo->spis);
93 if (invert)
94 espinfo->invflags |= XT_ESP_INV_SPI;
95 *flags |= ESP_SPI;
96 break;
97 default:
98 return 0;
99 }
100
101 return 1;
102}
103
104static void
105print_spis(const char *name, u_int32_t min, u_int32_t max,
106 int invert)
107{
108 const char *inv = invert ? "!" : "";
109
110 if (min != 0 || max != 0xFFFFFFFF || invert) {
111 if (min == max)
112 printf("%s:%s%u ", name, inv, min);
113 else
114 printf("%ss:%s%u:%u ", name, inv, min, max);
115 }
116}
117
118static void
119esp_print(const void *ip, const struct xt_entry_match *match, int numeric)
120{
121 const struct xt_esp *esp = (struct xt_esp *)match->data;
122
123 printf("esp ");
124 print_spis("spi", esp->spis[0], esp->spis[1],
125 esp->invflags & XT_ESP_INV_SPI);
126 if (esp->invflags & ~XT_ESP_INV_MASK)
127 printf("Unknown invflags: 0x%X ",
128 esp->invflags & ~XT_ESP_INV_MASK);
129}
130
131static void esp_save(const void *ip, const struct xt_entry_match *match)
132{
133 const struct xt_esp *espinfo = (struct xt_esp *)match->data;
134
135 if (!(espinfo->spis[0] == 0
136 && espinfo->spis[1] == 0xFFFFFFFF)) {
137 printf("%s--espspi ",
138 (espinfo->invflags & XT_ESP_INV_SPI) ? "! " : "");
139 if (espinfo->spis[0]
140 != espinfo->spis[1])
141 printf("%u:%u ",
142 espinfo->spis[0],
143 espinfo->spis[1]);
144 else
145 printf("%u ",
146 espinfo->spis[0]);
147 }
148
149}
150
151static struct xtables_match esp_match = {
152 .family = NFPROTO_IPV4,
153 .name = "esp",
154 .version = XTABLES_VERSION,
155 .size = XT_ALIGN(sizeof(struct xt_esp)),
156 .userspacesize = XT_ALIGN(sizeof(struct xt_esp)),
157 .help = esp_help,
158 .init = esp_init,
159 .parse = esp_parse,
160 .print = esp_print,
161 .save = esp_save,
162 .extra_opts = esp_opts,
163};
164
165static struct xtables_match esp_match6 = {
166 .family = NFPROTO_IPV6,
167 .name = "esp",
168 .version = XTABLES_VERSION,
169 .size = XT_ALIGN(sizeof(struct xt_esp)),
170 .userspacesize = XT_ALIGN(sizeof(struct xt_esp)),
171 .help = esp_help,
172 .init = esp_init,
173 .parse = esp_parse,
174 .print = esp_print,
175 .save = esp_save,
176 .extra_opts = esp_opts,
177};
178
179void
180_init(void)
181{
182 xtables_register_match(&esp_match);
183 xtables_register_match(&esp_match6);
184}