Add IPv6 support to pkttype match

1 files changed, 184 insertions, 0 deletions

diff --git a/extensions/libxt_pkttype.c b/extensions/libxt_pkttype.c
new file mode 100644
index 0000000..9654226
--- /dev/null
+++ b/extensions/libxt_pkttype.c
@@ -0,0 +1,184 @@
+/* 
+ * Shared library add-on to iptables to match 
+ * packets by their type (BROADCAST, UNICAST, MULTICAST). 
+ *
+ * Michal Ludvig <michal@logix.cz>
+ */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#if defined(__GLIBC__) && __GLIBC__ == 2
+#include <net/ethernet.h>
+#else
+#include <linux/if_ether.h>
+#endif
+#include <xtables.h>
+#include <linux/if_packet.h>
+#include <linux/netfilter/xt_pkttype.h>
+
+#define	PKTTYPE_VERSION	"0.1"
+
+struct pkttypes {
+	const char *name;
+	unsigned char pkttype;
+	unsigned char printhelp;
+	const char *help;
+};
+
+static const struct pkttypes supported_types[] = {
+	{"unicast", PACKET_HOST, 1, "to us"},
+	{"broadcast", PACKET_BROADCAST, 1, "to all"},
+	{"multicast", PACKET_MULTICAST, 1, "to group"},
+/*
+	{"otherhost", PACKET_OTHERHOST, 1, "to someone else"},
+	{"outgoing", PACKET_OUTGOING, 1, "outgoing of any type"},
+*/
+	/* aliases */
+	{"bcast", PACKET_BROADCAST, 0, NULL},
+	{"mcast", PACKET_MULTICAST, 0, NULL},
+	{"host", PACKET_HOST, 0, NULL}
+};
+
+static void print_types()
+{
+	unsigned int	i;
+	
+	printf("Valid packet types:\n");
+	for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
+	{
+		if(supported_types[i].printhelp == 1)
+			printf("\t%-14s\t\t%s\n", supported_types[i].name, supported_types[i].help);
+	}
+	printf("\n");
+}
+
+/* Function which prints out usage message. */
+static void help(void)
+{
+	printf(
+"pkt_type v%s options:\n"
+"  --pkt-type [!] packettype\tmatch packet type\n"
+"\n", PKTTYPE_VERSION);
+	print_types();
+}
+
+static struct option opts[] = {
+	{"pkt-type", 1, 0, '1'},
+	{0}
+};
+
+static void parse_pkttype(const char *pkttype, struct xt_pkttype_info *info)
+{
+	unsigned int	i;
+	
+	for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
+	{
+		if(strcasecmp(pkttype, supported_types[i].name)==0)
+		{
+			info->pkttype=supported_types[i].pkttype;
+			return;
+		}
+	}
+	
+	exit_error(PARAMETER_PROBLEM, "Bad packet type '%s'", pkttype);
+}
+
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+      const void *entry,
+      unsigned int *nfcache,
+      struct xt_entry_match **match)
+{
+	struct xt_pkttype_info *info = (struct xt_pkttype_info *)(*match)->data;
+	
+	switch(c)
+	{
+		case '1':
+			check_inverse(optarg, &invert, &optind, 0);
+			parse_pkttype(argv[optind-1], info);
+			if(invert)
+				info->invert=1;
+			*flags=1;
+			break;
+
+		default: 
+			return 0;
+	}
+
+	return 1;
+}
+
+static void final_check(unsigned int flags)
+{
+	if (!flags)
+		exit_error(PARAMETER_PROBLEM, "You must specify `--pkt-type'");
+}
+
+static void print_pkttype(struct xt_pkttype_info *info)
+{
+	unsigned int	i;
+	
+	for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
+	{
+		if(supported_types[i].pkttype==info->pkttype)
+		{
+			printf("%s ", supported_types[i].name);
+			return;
+		}
+	}
+
+	printf("%d ", info->pkttype);	/* in case we didn't find an entry in named-packtes */
+}
+
+static void print(const void *ip, const struct xt_entry_match *match, int numeric)
+{
+	struct xt_pkttype_info *info = (struct xt_pkttype_info *)match->data;
+	
+	printf("PKTTYPE %s= ", info->invert?"!":"");
+	print_pkttype(info);
+}
+
+static void save(const void *ip, const struct xt_entry_match *match)
+{
+	struct xt_pkttype_info *info = (struct xt_pkttype_info *)match->data;
+	
+	printf("--pkt-type %s", info->invert?"! ":"");
+	print_pkttype(info);
+}
+
+static struct xtables_match pkttype = {
+	.next		= NULL,
+	.family		= AF_INET,
+	.name		= "pkttype",
+	.version	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_pkttype_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_pkttype_info)),
+	.help		= &help,
+	.parse		= &parse, 
+	.final_check	= &final_check, 
+	.print		= &print,
+	.save		= &save, 
+	.extra_opts	= opts
+};
+
+static struct xtables_match pkttype6 = {
+	.next		= NULL,
+	.family		= AF_INET6,
+	.name		= "pkttype",
+	.version	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_pkttype_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_pkttype_info)),
+	.help		= &help,
+	.parse		= &parse, 
+	.final_check	= &final_check, 
+	.print		= &print,
+	.save		= &save, 
+	.extra_opts	= opts
+};
+
+void _init(void)
+{
+	xtables_register_match(&pkttype);
+	xtables_register_match(&pkttype6);
+}