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authormarc <marc>2000-03-20 06:03:29 +0000
committermarc <marc>2000-03-20 06:03:29 +0000
commit5c306289b8a78a060a12eba5cd86e0efc3533da0 (patch)
treecbaf2a4e3f8249de3967b959a214c27ff5fdee2a /extensions/libipt_REDIRECT.c
reorganized tree after kernel mergesvn_t_netfilter
Diffstat (limited to 'extensions/libipt_REDIRECT.c')
-rw-r--r--extensions/libipt_REDIRECT.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/extensions/libipt_REDIRECT.c b/extensions/libipt_REDIRECT.c
new file mode 100644
index 0000000..aaafaaf
--- /dev/null
+++ b/extensions/libipt_REDIRECT.c
@@ -0,0 +1,166 @@
+/* Shared library add-on to iptables to add redirect support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"REDIRECT v%s options:\n"
+" --to-ports <port>[-<port>]\n"
+" Port (range) to map to.\n\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+ { "to-ports", 1, 0, '1' },
+ { 0 }
+};
+
+/* Initialize the target. */
+static void
+init(struct ipt_entry_target *t, unsigned int *nfcache)
+{
+ struct ip_nat_multi_range *mr = (struct ip_nat_multi_range *)t->data;
+
+ /* Actually, it's 0, but it's ignored at the moment. */
+ mr->rangesize = 1;
+
+ /* Can't cache this */
+ *nfcache |= NFC_UNKNOWN;
+}
+
+/* Parses ports */
+static void
+parse_ports(const char *arg, struct ip_nat_multi_range *mr)
+{
+ const char *dash;
+ int port;
+
+ mr->range[0].flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+
+ port = atoi(arg);
+ if (port == 0 || port > 65535)
+ exit_error(PARAMETER_PROBLEM, "Port `%s' not valid\n", arg);
+
+ dash = strchr(arg, '-');
+ if (!dash) {
+ mr->range[0].min.tcp.port
+ = mr->range[0].max.tcp.port
+ = port;
+ } else {
+ int maxport;
+
+ maxport = atoi(dash + 1);
+ if (maxport == 0 || maxport > 65535)
+ exit_error(PARAMETER_PROBLEM,
+ "Port `%s' not valid\n", dash+1);
+ if (maxport < port)
+ /* People are stupid. */
+ exit_error(PARAMETER_PROBLEM,
+ "Port range `%s' funky\n", arg);
+ mr->range[0].min.tcp.port = port;
+ mr->range[0].max.tcp.port = maxport;
+ }
+}
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+ const struct ipt_entry *entry,
+ struct ipt_entry_target **target)
+{
+ struct ip_nat_multi_range *mr
+ = (struct ip_nat_multi_range *)(*target)->data;
+ int portok;
+
+ if (entry->ip.proto == IPPROTO_TCP
+ || entry->ip.proto == IPPROTO_UDP)
+ portok = 1;
+ else
+ portok = 0;
+
+ switch (c) {
+ case '1':
+ if (!portok)
+ exit_error(PARAMETER_PROBLEM,
+ "Need TCP or UDP with port specification");
+
+ if (check_inverse(optarg, &invert))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --to-ports");
+
+ parse_ports(optarg, mr);
+ return 1;
+
+ default:
+ return 0;
+ }
+}
+
+/* Final check; don't care. */
+static void final_check(unsigned int flags)
+{
+}
+
+/* Prints out the targinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_target *target,
+ int numeric)
+{
+ struct ip_nat_multi_range *mr
+ = (struct ip_nat_multi_range *)target->data;
+ struct ip_nat_range *r = &mr->range[0];
+
+ printf("REDIRECT ");
+ if (r->flags & IP_NAT_RANGE_PROTO_SPECIFIED) {
+ printf("%hu", r->min.tcp.port);
+ if (r->max.tcp.port != r->min.tcp.port)
+ printf("-%hu", r->max.tcp.port);
+ printf(" ");
+ }
+}
+
+/* Saves the union ipt_targinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
+{
+ struct ip_nat_multi_range *mr
+ = (struct ip_nat_multi_range *)target->data;
+ struct ip_nat_range *r = &mr->range[0];
+
+ if (r->flags & IP_NAT_RANGE_PROTO_SPECIFIED) {
+ printf("%hu", r->min.tcp.port);
+ if (r->max.tcp.port != r->min.tcp.port)
+ printf("-%hu", r->max.tcp.port);
+ printf(" ");
+ }
+}
+
+struct iptables_target redir
+= { NULL,
+ "REDIRECT",
+ NETFILTER_VERSION,
+ sizeof(struct ip_nat_multi_range),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_target(&redir);
+}