--- /dev/null
+/* Shared library add-on to iptables to add customized REJECT support.
+ *
+ * (C) 2000 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_REJECT.h>
+#include <linux/version.h>
+
+/* If we are compiling against a kernel that does not support
+ * IPT_ICMP_ADMIN_PROHIBITED, we are emulating it.
+ * The result will be a plain DROP of the packet instead of
+ * reject. -- Maciej Soltysiak <solt@dns.toxicfilms.tv>
+ */
+#ifndef IPT_ICMP_ADMIN_PROHIBITED
+#define IPT_ICMP_ADMIN_PROHIBITED IPT_TCP_RESET + 1
+#endif
+
+struct reject_names {
+ const char *name;
+ const char *alias;
+ enum ipt_reject_with with;
+ const char *desc;
+};
+
+static const struct reject_names reject_table[] = {
+ {"icmp-net-unreachable", "net-unreach",
+ IPT_ICMP_NET_UNREACHABLE, "ICMP network unreachable"},
+ {"icmp-host-unreachable", "host-unreach",
+ IPT_ICMP_HOST_UNREACHABLE, "ICMP host unreachable"},
+ {"icmp-proto-unreachable", "proto-unreach",
+ IPT_ICMP_PROT_UNREACHABLE, "ICMP protocol unreachable"},
+ {"icmp-port-unreachable", "port-unreach",
+ IPT_ICMP_PORT_UNREACHABLE, "ICMP port unreachable (default)"},
+#if 0
+ {"echo-reply", "echoreply",
+ IPT_ICMP_ECHOREPLY, "for ICMP echo only: faked ICMP echo reply"},
+#endif
+ {"icmp-net-prohibited", "net-prohib",
+ IPT_ICMP_NET_PROHIBITED, "ICMP network prohibited"},
+ {"icmp-host-prohibited", "host-prohib",
+ IPT_ICMP_HOST_PROHIBITED, "ICMP host prohibited"},
+ {"tcp-reset", "tcp-rst",
+ IPT_TCP_RESET, "TCP RST packet"},
+ {"icmp-admin-prohibited", "admin-prohib",
+ IPT_ICMP_ADMIN_PROHIBITED, "ICMP administratively prohibited (*)"}
+};
+
+static void
+print_reject_types(void)
+{
+ unsigned int i;
+
+ printf("Valid reject types:\n");
+
+ for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++) {
+ printf(" %-25s\t%s\n", reject_table[i].name, reject_table[i].desc);
+ printf(" %-25s\talias\n", reject_table[i].alias);
+ }
+ printf("\n");
+}
+
+/* Saves the union ipt_targinfo in parsable form to stdout. */
+
+/* Function which prints out usage message. */
+static void REJECT_help(void)
+{
+ printf(
+"REJECT target options:\n"
+"--reject-with type drop input packet and send back\n"
+" a reply packet according to type:\n");
+
+ print_reject_types();
+
+ printf("(*) See man page or read the INCOMPATIBILITES file for compatibility issues.\n");
+}
+
+static const struct option REJECT_opts[] = {
+ { "reject-with", 1, NULL, '1' },
+ { .name = NULL }
+};
+
+/* Allocate and initialize the target. */
+static void REJECT_init(struct xt_entry_target *t)
+{
+ struct ipt_reject_info *reject = (struct ipt_reject_info *)t->data;
+
+ /* default */
+ reject->with = IPT_ICMP_PORT_UNREACHABLE;
+
+}
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int REJECT_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ struct ipt_reject_info *reject = (struct ipt_reject_info *)(*target)->data;
+ unsigned int limit = sizeof(reject_table)/sizeof(struct reject_names);
+ unsigned int i;
+
+ switch(c) {
+ case '1':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --reject-with");
+ for (i = 0; i < limit; i++) {
+ if ((strncasecmp(reject_table[i].name, optarg, strlen(optarg)) == 0)
+ || (strncasecmp(reject_table[i].alias, optarg, strlen(optarg)) == 0)) {
+ reject->with = reject_table[i].with;
+ return 1;
+ }
+ }
+ /* This due to be dropped late in 2.4 pre-release cycle --RR */
+ if (strncasecmp("echo-reply", optarg, strlen(optarg)) == 0
+ || strncasecmp("echoreply", optarg, strlen(optarg)) == 0)
+ fprintf(stderr, "--reject-with echo-reply no longer"
+ " supported\n");
+ exit_error(PARAMETER_PROBLEM, "unknown reject type `%s'",optarg);
+ default:
+ /* Fall through */
+ break;
+ }
+ return 0;
+}
+
+/* Prints out ipt_reject_info. */
+static void REJECT_print(const void *ip, const struct xt_entry_target *target,
+ int numeric)
+{
+ const struct ipt_reject_info *reject
+ = (const struct ipt_reject_info *)target->data;
+ unsigned int i;
+
+ for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++) {
+ if (reject_table[i].with == reject->with)
+ break;
+ }
+ printf("reject-with %s ", reject_table[i].name);
+}
+
+/* Saves ipt_reject in parsable form to stdout. */
+static void REJECT_save(const void *ip, const struct xt_entry_target *target)
+{
+ const struct ipt_reject_info *reject
+ = (const struct ipt_reject_info *)target->data;
+ unsigned int i;
+
+ for (i = 0; i < sizeof(reject_table)/sizeof(struct reject_names); i++)
+ if (reject_table[i].with == reject->with)
+ break;
+
+ printf("--reject-with %s ", reject_table[i].name);
+}
+
+static struct xtables_target reject_tg_reg = {
+ .name = "REJECT",
+ .version = XTABLES_VERSION,
+ .family = PF_INET,
+ .size = XT_ALIGN(sizeof(struct ipt_reject_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct ipt_reject_info)),
+ .help = REJECT_help,
+ .init = REJECT_init,
+ .parse = REJECT_parse,
+ .print = REJECT_print,
+ .save = REJECT_save,
+ .extra_opts = REJECT_opts,
+};
+
+void _init(void)
+{
+ xtables_register_target(&reject_tg_reg);
+}
git://git.onelab.eu / iptables.git / blobdiff