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Diffstat (limited to 'extensions/libip6t_icmp6.c')
-rw-r--r--extensions/libip6t_icmp6.c263
1 files changed, 263 insertions, 0 deletions
diff --git a/extensions/libip6t_icmp6.c b/extensions/libip6t_icmp6.c
new file mode 100644
index 0000000..fb321b3
--- /dev/null
+++ b/extensions/libip6t_icmp6.c
@@ -0,0 +1,263 @@
+/* Shared library add-on to ip6tables to add ICMP support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <xtables.h>
+#include <limits.h> /* INT_MAX in ip6_tables.h */
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+struct icmpv6_names {
+ const char *name;
+ u_int8_t type;
+ u_int8_t code_min, code_max;
+};
+
+static const struct icmpv6_names icmpv6_codes[] = {
+ { "destination-unreachable", 1, 0, 0xFF },
+ { "no-route", 1, 0, 0 },
+ { "communication-prohibited", 1, 1, 1 },
+ { "address-unreachable", 1, 3, 3 },
+ { "port-unreachable", 1, 4, 4 },
+
+ { "packet-too-big", 2, 0, 0xFF },
+
+ { "time-exceeded", 3, 0, 0xFF },
+ /* Alias */ { "ttl-exceeded", 3, 0, 0xFF },
+ { "ttl-zero-during-transit", 3, 0, 0 },
+ { "ttl-zero-during-reassembly", 3, 1, 1 },
+
+ { "parameter-problem", 4, 0, 0xFF },
+ { "bad-header", 4, 0, 0 },
+ { "unknown-header-type", 4, 1, 1 },
+ { "unknown-option", 4, 2, 2 },
+
+ { "echo-request", 128, 0, 0xFF },
+ /* Alias */ { "ping", 128, 0, 0xFF },
+
+ { "echo-reply", 129, 0, 0xFF },
+ /* Alias */ { "pong", 129, 0, 0xFF },
+
+ { "router-solicitation", 133, 0, 0xFF },
+
+ { "router-advertisement", 134, 0, 0xFF },
+
+ { "neighbour-solicitation", 135, 0, 0xFF },
+ /* Alias */ { "neighbor-solicitation", 135, 0, 0xFF },
+
+ { "neighbour-advertisement", 136, 0, 0xFF },
+ /* Alias */ { "neighbor-advertisement", 136, 0, 0xFF },
+
+ { "redirect", 137, 0, 0xFF },
+
+};
+
+static void
+print_icmpv6types(void)
+{
+ unsigned int i;
+ printf("Valid ICMPv6 Types:");
+
+ for (i = 0; i < ARRAY_SIZE(icmpv6_codes); ++i) {
+ if (i && icmpv6_codes[i].type == icmpv6_codes[i-1].type) {
+ if (icmpv6_codes[i].code_min == icmpv6_codes[i-1].code_min
+ && (icmpv6_codes[i].code_max
+ == icmpv6_codes[i-1].code_max))
+ printf(" (%s)", icmpv6_codes[i].name);
+ else
+ printf("\n %s", icmpv6_codes[i].name);
+ }
+ else
+ printf("\n%s", icmpv6_codes[i].name);
+ }
+ printf("\n");
+}
+
+static void icmp6_help(void)
+{
+ printf(
+"icmpv6 match options:\n"
+"[!] --icmpv6-type typename match icmpv6 type\n"
+" (or numeric type or type/code)\n");
+ print_icmpv6types();
+}
+
+static const struct option icmp6_opts[] = {
+ { "icmpv6-type", 1, NULL, '1' },
+ { .name = NULL }
+};
+
+static void
+parse_icmpv6(const char *icmpv6type, u_int8_t *type, u_int8_t code[])
+{
+ static const unsigned int limit = ARRAY_SIZE(icmpv6_codes);
+ unsigned int match = limit;
+ unsigned int i;
+
+ for (i = 0; i < limit; i++) {
+ if (strncasecmp(icmpv6_codes[i].name, icmpv6type, strlen(icmpv6type))
+ == 0) {
+ if (match != limit)
+ xtables_error(PARAMETER_PROBLEM,
+ "Ambiguous ICMPv6 type `%s':"
+ " `%s' or `%s'?",
+ icmpv6type,
+ icmpv6_codes[match].name,
+ icmpv6_codes[i].name);
+ match = i;
+ }
+ }
+
+ if (match != limit) {
+ *type = icmpv6_codes[match].type;
+ code[0] = icmpv6_codes[match].code_min;
+ code[1] = icmpv6_codes[match].code_max;
+ } else {
+ char *slash;
+ char buffer[strlen(icmpv6type) + 1];
+ unsigned int number;
+
+ strcpy(buffer, icmpv6type);
+ slash = strchr(buffer, '/');
+
+ if (slash)
+ *slash = '\0';
+
+ if (!xtables_strtoui(buffer, NULL, &number, 0, UINT8_MAX))
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid ICMPv6 type `%s'\n", buffer);
+ *type = number;
+ if (slash) {
+ if (!xtables_strtoui(slash+1, NULL, &number, 0, UINT8_MAX))
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid ICMPv6 code `%s'\n",
+ slash+1);
+ code[0] = code[1] = number;
+ } else {
+ code[0] = 0;
+ code[1] = 0xFF;
+ }
+ }
+}
+
+static void icmp6_init(struct xt_entry_match *m)
+{
+ struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data;
+
+ icmpv6info->code[1] = 0xFF;
+}
+
+static int icmp6_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_match **match)
+{
+ struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ if (*flags == 1)
+ xtables_error(PARAMETER_PROBLEM,
+ "icmpv6 match: only use --icmpv6-type once!");
+ xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+ parse_icmpv6(optarg, &icmpv6info->type,
+ icmpv6info->code);
+ if (invert)
+ icmpv6info->invflags |= IP6T_ICMP_INV;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+static void print_icmpv6type(u_int8_t type,
+ u_int8_t code_min, u_int8_t code_max,
+ int invert,
+ int numeric)
+{
+ if (!numeric) {
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(icmpv6_codes); ++i)
+ if (icmpv6_codes[i].type == type
+ && icmpv6_codes[i].code_min == code_min
+ && icmpv6_codes[i].code_max == code_max)
+ break;
+
+ if (i != ARRAY_SIZE(icmpv6_codes)) {
+ printf("%s%s ",
+ invert ? "!" : "",
+ icmpv6_codes[i].name);
+ return;
+ }
+ }
+
+ if (invert)
+ printf("!");
+
+ printf("type %u", type);
+ if (code_min == 0 && code_max == 0xFF)
+ printf(" ");
+ else if (code_min == code_max)
+ printf(" code %u ", code_min);
+ else
+ printf(" codes %u-%u ", code_min, code_max);
+}
+
+static void icmp6_print(const void *ip, const struct xt_entry_match *match,
+ int numeric)
+{
+ const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data;
+
+ printf("ipv6-icmp ");
+ print_icmpv6type(icmpv6->type, icmpv6->code[0], icmpv6->code[1],
+ icmpv6->invflags & IP6T_ICMP_INV,
+ numeric);
+
+ if (icmpv6->invflags & ~IP6T_ICMP_INV)
+ printf("Unknown invflags: 0x%X ",
+ icmpv6->invflags & ~IP6T_ICMP_INV);
+}
+
+static void icmp6_save(const void *ip, const struct xt_entry_match *match)
+{
+ const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data;
+
+ if (icmpv6->invflags & IP6T_ICMP_INV)
+ printf("! ");
+
+ printf("--icmpv6-type %u", icmpv6->type);
+ if (icmpv6->code[0] != 0 || icmpv6->code[1] != 0xFF)
+ printf("/%u", icmpv6->code[0]);
+ printf(" ");
+}
+
+static void icmp6_check(unsigned int flags)
+{
+ if (!flags)
+ xtables_error(PARAMETER_PROBLEM,
+ "icmpv6 match: You must specify `--icmpv6-type'");
+}
+
+static struct xtables_match icmp6_mt6_reg = {
+ .name = "icmp6",
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_IPV6,
+ .size = XT_ALIGN(sizeof(struct ip6t_icmp)),
+ .userspacesize = XT_ALIGN(sizeof(struct ip6t_icmp)),
+ .help = icmp6_help,
+ .init = icmp6_init,
+ .parse = icmp6_parse,
+ .final_check = icmp6_check,
+ .print = icmp6_print,
+ .save = icmp6_save,
+ .extra_opts = icmp6_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&icmp6_mt6_reg);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 11:08:29 +0000