patch-2.3.99-pre2 linux/net/ipv4/netfilter/ipt_multiport.c
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- Lines: 103
- Date:
Fri Mar 17 10:56:20 2000
- Orig file:
v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_multiport.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_multiport.c linux/net/ipv4/netfilter/ipt_multiport.c
@@ -0,0 +1,102 @@
+/* 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. */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/udp.h>
+#include <linux/skbuff.h>
+
+#include <linux/netfilter_ipv4/ipt_multiport.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#if 0
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+EXPORT_NO_SYMBOLS;
+
+/* Returns 1 if the port is matched by the test, 0 otherwise. */
+static inline int
+ports_match(const u_int16_t *portlist, enum ipt_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 != IPT_MULTIPORT_DESTINATION
+ && portlist[i] == src)
+ return 1;
+
+ if (flags != IPT_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,
+ const void *hdr,
+ u_int16_t datalen,
+ int *hotdrop)
+{
+ const struct udphdr *udp = hdr;
+ const struct ipt_multiport *multiinfo = matchinfo;
+
+ /* Must be big enough to read ports. */
+ if (offset == 0 && datalen < sizeof(struct udphdr)) {
+ /* We've been asked to examine this packet, and we
+ can't. Hence, no choice but to drop. */
+ duprintf("ipt_multiport:"
+ " Dropping evil offset=0 tinygram.\n");
+ *hotdrop = 1;
+ return 0;
+ }
+
+ /* Must not be a fragment. */
+ return !offset
+ && ports_match(multiinfo->ports,
+ multiinfo->flags, multiinfo->count,
+ ntohs(udp->source), ntohs(udp->dest));
+}
+
+/* Called when user tries to insert an entry of this type. */
+static int
+checkentry(const char *tablename,
+ const struct ipt_ip *ip,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ const struct ipt_multiport *multiinfo = matchinfo;
+
+ /* Must specify proto == TCP/UDP, no unknown flags or bad count */
+ return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP)
+ && !(ip->flags & IPT_INV_PROTO)
+ && matchsize == IPT_ALIGN(sizeof(struct ipt_multiport))
+ && (multiinfo->flags == IPT_MULTIPORT_SOURCE
+ || multiinfo->flags == IPT_MULTIPORT_DESTINATION
+ || multiinfo->flags == IPT_MULTIPORT_EITHER)
+ && multiinfo->count <= IPT_MULTI_PORTS;
+}
+
+static struct ipt_match multiport_match
+= { { NULL, NULL }, "multiport", &match, &checkentry, THIS_MODULE };
+
+static int __init init(void)
+{
+ return ipt_register_match(&multiport_match);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_match(&multiport_match);
+}
+
+module_init(init);
+module_exit(fini);
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