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1 files changed, 387 insertions, 0 deletions

diff --git a/extensions/libxt_iprange.c b/extensions/libxt_iprange.c
new file mode 100644
index 0000000..55a2f84
--- /dev/null
+++ b/extensions/libxt_iprange.c
@@ -0,0 +1,387 @@
+/* Shared library add-on to iptables to add IP range matching support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <netinet/in.h>
+#include <xtables.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/xt_iprange.h>
+
+struct ipt_iprange {
+	/* Inclusive: network order. */
+	__be32 min_ip, max_ip;
+};
+
+struct ipt_iprange_info {
+	struct ipt_iprange src;
+	struct ipt_iprange dst;
+
+	/* Flags from above */
+	u_int8_t flags;
+};
+
+enum {
+	F_SRCIP = 1 << 0,
+	F_DSTIP = 1 << 1,
+};
+
+static void iprange_mt_help(void)
+{
+	printf(
+"iprange match options:\n"
+"[!] --src-range ip[-ip]    Match source IP in the specified range\n"
+"[!] --dst-range ip[-ip]    Match destination IP in the specified range\n");
+}
+
+static const struct option iprange_mt_opts[] = {
+	{.name = "src-range", .has_arg = true, .val = '1'},
+	{.name = "dst-range", .has_arg = true, .val = '2'},
+	{ .name = NULL }
+};
+
+static void
+iprange_parse_spec(const char *from, const char *to, union nf_inet_addr *range,
+		   uint8_t family, const char *optname)
+{
+	const char *spec[2] = {from, to};
+	struct in6_addr *ia6;
+	struct in_addr *ia4;
+	unsigned int i;
+
+	memset(range, 0, sizeof(union nf_inet_addr) * 2);
+
+	if (family == NFPROTO_IPV6) {
+		for (i = 0; i < ARRAY_SIZE(spec); ++i) {
+			ia6 = xtables_numeric_to_ip6addr(spec[i]);
+			if (ia6 == NULL)
+				xtables_param_act(XTF_BAD_VALUE, "iprange",
+					optname, spec[i]);
+			range[i].in6 = *ia6;
+		}
+	} else {
+		for (i = 0; i < ARRAY_SIZE(spec); ++i) {
+			ia4 = xtables_numeric_to_ipaddr(spec[i]);
+			if (ia4 == NULL)
+				xtables_param_act(XTF_BAD_VALUE, "iprange",
+					optname, spec[i]);
+			range[i].in = *ia4;
+		}
+	}
+}
+
+static void iprange_parse_range(char *arg, union nf_inet_addr *range,
+				u_int8_t family, const char *optname)
+{
+	char *dash;
+
+	dash = strchr(arg, '-');
+	if (dash == NULL) {
+		iprange_parse_spec(arg, arg, range, family, optname);
+		return;
+	}
+
+	*dash = '\0';
+	iprange_parse_spec(arg, dash + 1, range, family, optname);
+	if (memcmp(&range[0], &range[1], sizeof(*range)) > 0)
+		fprintf(stderr, "xt_iprange: range %s-%s is reversed and "
+			"will never match\n", arg, dash + 1);
+}
+
+static int iprange_parse(int c, char **argv, int invert, unsigned int *flags,
+                         const void *entry, struct xt_entry_match **match)
+{
+	struct ipt_iprange_info *info = (struct ipt_iprange_info *)(*match)->data;
+	union nf_inet_addr range[2];
+
+	switch (c) {
+	case '1':
+		if (*flags & IPRANGE_SRC)
+			xtables_error(PARAMETER_PROBLEM,
+				   "iprange match: Only use --src-range ONCE!");
+		*flags |= IPRANGE_SRC;
+
+		info->flags |= IPRANGE_SRC;
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		if (invert)
+			info->flags |= IPRANGE_SRC_INV;
+		iprange_parse_range(optarg, range, NFPROTO_IPV4, "--src-range");
+		info->src.min_ip = range[0].ip;
+		info->src.max_ip = range[1].ip;
+		break;
+
+	case '2':
+		if (*flags & IPRANGE_DST)
+			xtables_error(PARAMETER_PROBLEM,
+				   "iprange match: Only use --dst-range ONCE!");
+		*flags |= IPRANGE_DST;
+
+		info->flags |= IPRANGE_DST;
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		if (invert)
+			info->flags |= IPRANGE_DST_INV;
+
+		iprange_parse_range(optarg, range, NFPROTO_IPV4, "--dst-range");
+		info->dst.min_ip = range[0].ip;
+		info->dst.max_ip = range[1].ip;
+		break;
+
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static int
+iprange_mt4_parse(int c, char **argv, int invert, unsigned int *flags,
+                  const void *entry, struct xt_entry_match **match)
+{
+	struct xt_iprange_mtinfo *info = (void *)(*match)->data;
+
+	switch (c) {
+	case '1': /* --src-range */
+		iprange_parse_range(optarg, &info->src_min, NFPROTO_IPV4,
+			"--src-range");
+		info->flags |= IPRANGE_SRC;
+		if (invert)
+			info->flags |= IPRANGE_SRC_INV;
+		*flags |= F_SRCIP;
+		return true;
+
+	case '2': /* --dst-range */
+		iprange_parse_range(optarg, &info->dst_min, NFPROTO_IPV4,
+			"--dst-range");
+		info->flags |= IPRANGE_DST;
+		if (invert)
+			info->flags |= IPRANGE_DST_INV;
+		*flags |= F_DSTIP;
+		return true;
+	}
+	return false;
+}
+
+static int
+iprange_mt6_parse(int c, char **argv, int invert, unsigned int *flags,
+                  const void *entry, struct xt_entry_match **match)
+{
+	struct xt_iprange_mtinfo *info = (void *)(*match)->data;
+
+	switch (c) {
+	case '1': /* --src-range */
+		iprange_parse_range(optarg, &info->src_min, NFPROTO_IPV6,
+			"--src-range");
+		info->flags |= IPRANGE_SRC;
+		if (invert)
+			info->flags |= IPRANGE_SRC_INV;
+		*flags |= F_SRCIP;
+		return true;
+
+	case '2': /* --dst-range */
+		iprange_parse_range(optarg, &info->dst_min, NFPROTO_IPV6,
+			"--dst-range");
+		info->flags |= IPRANGE_DST;
+		if (invert)
+			info->flags |= IPRANGE_DST_INV;
+		*flags |= F_DSTIP;
+		return true;
+	}
+	return false;
+}
+
+static void iprange_mt_check(unsigned int flags)
+{
+	if (flags == 0)
+		xtables_error(PARAMETER_PROBLEM,
+			   "iprange match: You must specify `--src-range' or `--dst-range'");
+}
+
+static void
+print_iprange(const struct ipt_iprange *range)
+{
+	const unsigned char *byte_min, *byte_max;
+
+	byte_min = (const unsigned char *)&range->min_ip;
+	byte_max = (const unsigned char *)&range->max_ip;
+	printf("%u.%u.%u.%u-%u.%u.%u.%u ",
+		byte_min[0], byte_min[1], byte_min[2], byte_min[3],
+		byte_max[0], byte_max[1], byte_max[2], byte_max[3]);
+}
+
+static void iprange_print(const void *ip, const struct xt_entry_match *match,
+                          int numeric)
+{
+	const struct ipt_iprange_info *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		printf("source IP range ");
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		print_iprange(&info->src);
+	}
+	if (info->flags & IPRANGE_DST) {
+		printf("destination IP range ");
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		print_iprange(&info->dst);
+	}
+}
+
+static void
+iprange_mt4_print(const void *ip, const struct xt_entry_match *match,
+                  int numeric)
+{
+	const struct xt_iprange_mtinfo *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		printf("source IP range ");
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		/*
+		 * ipaddr_to_numeric() uses a static buffer, so cannot
+		 * combine the printf() calls.
+		 */
+		printf("%s", xtables_ipaddr_to_numeric(&info->src_min.in));
+		printf("-%s ", xtables_ipaddr_to_numeric(&info->src_max.in));
+	}
+	if (info->flags & IPRANGE_DST) {
+		printf("destination IP range ");
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		printf("%s", xtables_ipaddr_to_numeric(&info->dst_min.in));
+		printf("-%s ", xtables_ipaddr_to_numeric(&info->dst_max.in));
+	}
+}
+
+static void
+iprange_mt6_print(const void *ip, const struct xt_entry_match *match,
+                  int numeric)
+{
+	const struct xt_iprange_mtinfo *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		printf("source IP range ");
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		/*
+		 * ipaddr_to_numeric() uses a static buffer, so cannot
+		 * combine the printf() calls.
+		 */
+		printf("%s", xtables_ip6addr_to_numeric(&info->src_min.in6));
+		printf("-%s ", xtables_ip6addr_to_numeric(&info->src_max.in6));
+	}
+	if (info->flags & IPRANGE_DST) {
+		printf("destination IP range ");
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		printf("%s", xtables_ip6addr_to_numeric(&info->dst_min.in6));
+		printf("-%s ", xtables_ip6addr_to_numeric(&info->dst_max.in6));
+	}
+}
+
+static void iprange_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct ipt_iprange_info *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		printf("--src-range ");
+		print_iprange(&info->src);
+		if (info->flags & IPRANGE_DST)
+			fputc(' ', stdout);
+	}
+	if (info->flags & IPRANGE_DST) {
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		printf("--dst-range ");
+		print_iprange(&info->dst);
+	}
+}
+
+static void iprange_mt4_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_iprange_mtinfo *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		printf("--src-range %s", xtables_ipaddr_to_numeric(&info->src_min.in));
+		printf("-%s ", xtables_ipaddr_to_numeric(&info->src_max.in));
+	}
+	if (info->flags & IPRANGE_DST) {
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		printf("--dst-range %s", xtables_ipaddr_to_numeric(&info->dst_min.in));
+		printf("-%s ", xtables_ipaddr_to_numeric(&info->dst_max.in));
+	}
+}
+
+static void iprange_mt6_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_iprange_mtinfo *info = (const void *)match->data;
+
+	if (info->flags & IPRANGE_SRC) {
+		if (info->flags & IPRANGE_SRC_INV)
+			printf("! ");
+		printf("--src-range %s", xtables_ip6addr_to_numeric(&info->src_min.in6));
+		printf("-%s ", xtables_ip6addr_to_numeric(&info->src_max.in6));
+	}
+	if (info->flags & IPRANGE_DST) {
+		if (info->flags & IPRANGE_DST_INV)
+			printf("! ");
+		printf("--dst-range %s", xtables_ip6addr_to_numeric(&info->dst_min.in6));
+		printf("-%s ", xtables_ip6addr_to_numeric(&info->dst_max.in6));
+	}
+}
+
+static struct xtables_match iprange_mt_reg[] = {
+	{
+		.version       = XTABLES_VERSION,
+		.name          = "iprange",
+		.revision      = 0,
+		.family        = NFPROTO_IPV4,
+		.size          = XT_ALIGN(sizeof(struct ipt_iprange_info)),
+		.userspacesize = XT_ALIGN(sizeof(struct ipt_iprange_info)),
+		.help          = iprange_mt_help,
+		.parse         = iprange_parse,
+		.final_check   = iprange_mt_check,
+		.print         = iprange_print,
+		.save          = iprange_save,
+		.extra_opts    = iprange_mt_opts,
+	},
+	{
+		.version       = XTABLES_VERSION,
+		.name          = "iprange",
+		.revision      = 1,
+		.family        = NFPROTO_IPV4,
+		.size          = XT_ALIGN(sizeof(struct xt_iprange_mtinfo)),
+		.userspacesize = XT_ALIGN(sizeof(struct xt_iprange_mtinfo)),
+		.help          = iprange_mt_help,
+		.parse         = iprange_mt4_parse,
+		.final_check   = iprange_mt_check,
+		.print         = iprange_mt4_print,
+		.save          = iprange_mt4_save,
+		.extra_opts    = iprange_mt_opts,
+	},
+	{
+		.version       = XTABLES_VERSION,
+		.name          = "iprange",
+		.revision      = 1,
+		.family        = NFPROTO_IPV6,
+		.size          = XT_ALIGN(sizeof(struct xt_iprange_mtinfo)),
+		.userspacesize = XT_ALIGN(sizeof(struct xt_iprange_mtinfo)),
+		.help          = iprange_mt_help,
+		.parse         = iprange_mt6_parse,
+		.final_check   = iprange_mt_check,
+		.print         = iprange_mt6_print,
+		.save          = iprange_mt6_save,
+		.extra_opts    = iprange_mt_opts,
+	},
+};
+
+void _init(void)
+{
+	xtables_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
+}