summaryrefslogtreecommitdiff
path: root/net/ipv6/netfilter/ip6t_multiport.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv6/netfilter/ip6t_multiport.c')
-rw-r--r--net/ipv6/netfilter/ip6t_multiport.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6t_multiport.c b/net/ipv6/netfilter/ip6t_multiport.c
new file mode 100644
index 00000000000..6e3246153fa
--- /dev/null
+++ b/net/ipv6/netfilter/ip6t_multiport.c
@@ -0,0 +1,125 @@
+/* Kernel module to match one of a list of TCP/UDP ports: ports are in
+ the same place so we can treat them as equal. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/udp.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+
+#include <linux/netfilter_ipv6/ip6t_multiport.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("ip6tables match for multiple ports");
+
+#if 0
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+/* Returns 1 if the port is matched by the test, 0 otherwise. */
+static inline int
+ports_match(const u_int16_t *portlist, enum ip6t_multiport_flags flags,
+ u_int8_t count, u_int16_t src, u_int16_t dst)
+{
+ unsigned int i;
+ for (i=0; i<count; i++) {
+ if (flags != IP6T_MULTIPORT_DESTINATION
+ && portlist[i] == src)
+ return 1;
+
+ if (flags != IP6T_MULTIPORT_SOURCE
+ && portlist[i] == dst)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ u16 _ports[2], *pptr;
+ const struct ip6t_multiport *multiinfo = matchinfo;
+
+ /* Must not be a fragment. */
+ if (offset)
+ return 0;
+
+ /* Must be big enough to read ports (both UDP and TCP have
+ them at the start). */
+ pptr = skb_header_pointer(skb, protoff, sizeof(_ports), &_ports[0]);
+ if (pptr == NULL) {
+ /* We've been asked to examine this packet, and we
+ * can't. Hence, no choice but to drop.
+ */
+ duprintf("ip6t_multiport:"
+ " Dropping evil offset=0 tinygram.\n");
+ *hotdrop = 1;
+ return 0;
+ }
+
+ return ports_match(multiinfo->ports,
+ multiinfo->flags, multiinfo->count,
+ ntohs(pptr[0]), ntohs(pptr[1]));
+}
+
+/* Called when user tries to insert an entry of this type. */
+static int
+checkentry(const char *tablename,
+ const struct ip6t_ip6 *ip,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ const struct ip6t_multiport *multiinfo = matchinfo;
+
+ if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_multiport)))
+ return 0;
+
+ /* Must specify proto == TCP/UDP, no unknown flags or bad count */
+ return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP)
+ && !(ip->invflags & IP6T_INV_PROTO)
+ && matchsize == IP6T_ALIGN(sizeof(struct ip6t_multiport))
+ && (multiinfo->flags == IP6T_MULTIPORT_SOURCE
+ || multiinfo->flags == IP6T_MULTIPORT_DESTINATION
+ || multiinfo->flags == IP6T_MULTIPORT_EITHER)
+ && multiinfo->count <= IP6T_MULTI_PORTS;
+}
+
+static struct ip6t_match multiport_match = {
+ .name = "multiport",
+ .match = &match,
+ .checkentry = &checkentry,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ return ip6t_register_match(&multiport_match);
+}
+
+static void __exit fini(void)
+{
+ ip6t_unregister_match(&multiport_match);
+}
+
+module_init(init);
+module_exit(fini);