Git init

1 files changed, 217 insertions, 0 deletions

diff --git a/extensions/libipt_SAME.c b/extensions/libipt_SAME.c
new file mode 100644
index 0000000..ed02ef9
--- /dev/null
+++ b/extensions/libipt_SAME.c
@@ -0,0 +1,217 @@
+/* Shared library add-on to iptables to add simple non load-balancing SNAT support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <xtables.h>
+#include <net/netfilter/nf_nat.h>
+/* For 64bit kernel / 32bit userspace */
+#include <linux/netfilter_ipv4/ipt_SAME.h>
+
+static void SAME_help(void)
+{
+	printf(
+"SAME target options:\n"
+" --to <ipaddr>-<ipaddr>\n"
+"				Addresses to map source to.\n"
+"				 May be specified more than\n"
+"				  once for multiple ranges.\n"
+" --nodst\n"
+"				Don't use destination-ip in\n"
+"				           source selection\n"
+" --random\n"
+"				Randomize source port\n");
+}
+
+static const struct option SAME_opts[] = {
+	{ "to", 1, NULL, '1' },
+	{ "nodst", 0, NULL, '2'},
+	{ "random", 0, NULL, '3' },
+	{ .name = NULL }
+};
+
+static void SAME_init(struct xt_entry_target *t)
+{
+	struct ipt_same_info *mr = (struct ipt_same_info *)t->data;
+
+	/* Set default to 0 */
+	mr->rangesize = 0;
+	mr->info = 0;
+	mr->ipnum = 0;
+	
+}
+
+/* Parses range of IPs */
+static void
+parse_to(char *arg, struct nf_nat_range *range)
+{
+	char *dash;
+	const struct in_addr *ip;
+
+	range->flags |= IP_NAT_RANGE_MAP_IPS;
+	dash = strchr(arg, '-');
+
+	if (dash)
+		*dash = '\0';
+
+	ip = xtables_numeric_to_ipaddr(arg);
+	if (!ip)
+		xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
+			   arg);
+	range->min_ip = ip->s_addr;
+
+	if (dash) {
+		ip = xtables_numeric_to_ipaddr(dash+1);
+		if (!ip)
+			xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
+				   dash+1);
+	}
+	range->max_ip = ip->s_addr;
+	if (dash)
+		if (range->min_ip > range->max_ip)
+			xtables_error(PARAMETER_PROBLEM, "Bad IP range \"%s-%s\"\n",
+				   arg, dash+1);
+}
+
+#define IPT_SAME_OPT_TO			0x01
+#define IPT_SAME_OPT_NODST		0x02
+#define IPT_SAME_OPT_RANDOM		0x04
+
+static int SAME_parse(int c, char **argv, int invert, unsigned int *flags,
+                      const void *entry, struct xt_entry_target **target)
+{
+	struct ipt_same_info *mr
+		= (struct ipt_same_info *)(*target)->data;
+	unsigned int count;
+
+	switch (c) {
+	case '1':
+		if (mr->rangesize == IPT_SAME_MAX_RANGE)
+			xtables_error(PARAMETER_PROBLEM,
+				   "Too many ranges specified, maximum "
+				   "is %i ranges.\n",
+				   IPT_SAME_MAX_RANGE);
+		if (xtables_check_inverse(optarg, &invert, NULL, 0, argv))
+			xtables_error(PARAMETER_PROBLEM,
+				   "Unexpected `!' after --to");
+
+		parse_to(optarg, &mr->range[mr->rangesize]);
+		/* WTF do we need this for? */
+		if (*flags & IPT_SAME_OPT_RANDOM)
+			mr->range[mr->rangesize].flags 
+				|= IP_NAT_RANGE_PROTO_RANDOM;
+		mr->rangesize++;
+		*flags |= IPT_SAME_OPT_TO;
+		break;
+		
+	case '2':
+		if (*flags & IPT_SAME_OPT_NODST)
+			xtables_error(PARAMETER_PROBLEM,
+				   "Can't specify --nodst twice");
+		
+		mr->info |= IPT_SAME_NODST;
+		*flags |= IPT_SAME_OPT_NODST;
+		break;
+
+	case '3':	
+		*flags |= IPT_SAME_OPT_RANDOM;
+		for (count=0; count < mr->rangesize; count++)
+			mr->range[count].flags |= IP_NAT_RANGE_PROTO_RANDOM;
+		break;
+
+	default:
+		return 0;
+	}
+	
+	return 1;
+}
+
+static void SAME_check(unsigned int flags)
+{
+	if (!(flags & IPT_SAME_OPT_TO))
+		xtables_error(PARAMETER_PROBLEM,
+			   "SAME needs --to");
+}
+
+static void SAME_print(const void *ip, const struct xt_entry_target *target,
+                       int numeric)
+{
+	unsigned int count;
+	const struct ipt_same_info *mr = (const void *)target->data;
+	int random_selection = 0;
+	
+	printf("same:");
+	
+	for (count = 0; count < mr->rangesize; count++) {
+		const struct nf_nat_range *r = &mr->range[count];
+		struct in_addr a;
+
+		a.s_addr = r->min_ip;
+
+		printf("%s", xtables_ipaddr_to_numeric(&a));
+		a.s_addr = r->max_ip;
+		
+		if (r->min_ip == r->max_ip)
+			printf(" ");
+		else
+			printf("-%s ", xtables_ipaddr_to_numeric(&a));
+		if (r->flags & IP_NAT_RANGE_PROTO_RANDOM) 
+			random_selection = 1;
+	}
+	
+	if (mr->info & IPT_SAME_NODST)
+		printf("nodst ");
+
+	if (random_selection)
+		printf("random ");
+}
+
+static void SAME_save(const void *ip, const struct xt_entry_target *target)
+{
+	unsigned int count;
+	const struct ipt_same_info *mr = (const void *)target->data;
+	int random_selection = 0;
+
+	for (count = 0; count < mr->rangesize; count++) {
+		const struct nf_nat_range *r = &mr->range[count];
+		struct in_addr a;
+
+		a.s_addr = r->min_ip;
+		printf("--to %s", xtables_ipaddr_to_numeric(&a));
+		a.s_addr = r->max_ip;
+
+		if (r->min_ip == r->max_ip)
+			printf(" ");
+		else
+			printf("-%s ", xtables_ipaddr_to_numeric(&a));
+		if (r->flags & IP_NAT_RANGE_PROTO_RANDOM) 
+			random_selection = 1;
+	}
+	
+	if (mr->info & IPT_SAME_NODST)
+		printf("--nodst ");
+
+	if (random_selection)
+		printf("--random ");
+}
+
+static struct xtables_target same_tg_reg = {
+	.name		= "SAME",
+	.version	= XTABLES_VERSION,
+	.family		= NFPROTO_IPV4,
+	.size		= XT_ALIGN(sizeof(struct ipt_same_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct ipt_same_info)),
+	.help		= SAME_help,
+	.init		= SAME_init,
+	.parse		= SAME_parse,
+	.final_check	= SAME_check,
+	.print		= SAME_print,
+	.save		= SAME_save,
+	.extra_opts	= SAME_opts,
+};
+
+void _init(void)
+{
+	xtables_register_target(&same_tg_reg);
+}