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-rw-r--r--net/netfilter/xt_multiport.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/net/netfilter/xt_multiport.c b/net/netfilter/xt_multiport.c
new file mode 100644
index 0000000..d06bb2d
--- /dev/null
+++ b/net/netfilter/xt_multiport.c
@@ -0,0 +1,248 @@
+/* Kernel module to match one of a list of TCP/UDP(-Lite)/SCTP/DCCP 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/xt_multiport.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: multiple port matching for TCP, UDP, UDP-Lite, SCTP and DCCP");
+MODULE_ALIAS("ipt_multiport");
+MODULE_ALIAS("ip6t_multiport");
+
+#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 bool
+ports_match_v0(const u_int16_t *portlist, enum xt_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 != XT_MULTIPORT_DESTINATION && portlist[i] == src)
+ return true;
+
+ if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst)
+ return true;
+ }
+
+ return false;
+}
+
+/* Returns 1 if the port is matched by the test, 0 otherwise. */
+static inline bool
+ports_match_v1(const struct xt_multiport_v1 *minfo,
+ u_int16_t src, u_int16_t dst)
+{
+ unsigned int i;
+ u_int16_t s, e;
+
+ for (i = 0; i < minfo->count; i++) {
+ s = minfo->ports[i];
+
+ if (minfo->pflags[i]) {
+ /* range port matching */
+ e = minfo->ports[++i];
+ duprintf("src or dst matches with %d-%d?\n", s, e);
+
+ if (minfo->flags == XT_MULTIPORT_SOURCE
+ && src >= s && src <= e)
+ return true ^ minfo->invert;
+ if (minfo->flags == XT_MULTIPORT_DESTINATION
+ && dst >= s && dst <= e)
+ return true ^ minfo->invert;
+ if (minfo->flags == XT_MULTIPORT_EITHER
+ && ((dst >= s && dst <= e)
+ || (src >= s && src <= e)))
+ return true ^ minfo->invert;
+ } else {
+ /* exact port matching */
+ duprintf("src or dst matches with %d?\n", s);
+
+ if (minfo->flags == XT_MULTIPORT_SOURCE
+ && src == s)
+ return true ^ minfo->invert;
+ if (minfo->flags == XT_MULTIPORT_DESTINATION
+ && dst == s)
+ return true ^ minfo->invert;
+ if (minfo->flags == XT_MULTIPORT_EITHER
+ && (src == s || dst == s))
+ return true ^ minfo->invert;
+ }
+ }
+
+ return minfo->invert;
+}
+
+static bool
+multiport_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+ const __be16 *pptr;
+ __be16 _ports[2];
+ const struct xt_multiport *multiinfo = par->matchinfo;
+
+ if (par->fragoff != 0)
+ return false;
+
+ pptr = skb_header_pointer(skb, par->thoff, sizeof(_ports), _ports);
+ if (pptr == NULL) {
+ /* We've been asked to examine this packet, and we
+ * can't. Hence, no choice but to drop.
+ */
+ duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
+ *par->hotdrop = true;
+ return false;
+ }
+
+ return ports_match_v0(multiinfo->ports, multiinfo->flags,
+ multiinfo->count, ntohs(pptr[0]), ntohs(pptr[1]));
+}
+
+static bool
+multiport_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+ const __be16 *pptr;
+ __be16 _ports[2];
+ const struct xt_multiport_v1 *multiinfo = par->matchinfo;
+
+ if (par->fragoff != 0)
+ return false;
+
+ pptr = skb_header_pointer(skb, par->thoff, sizeof(_ports), _ports);
+ if (pptr == NULL) {
+ /* We've been asked to examine this packet, and we
+ * can't. Hence, no choice but to drop.
+ */
+ duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
+ *par->hotdrop = true;
+ return false;
+ }
+
+ return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
+}
+
+static inline bool
+check(u_int16_t proto,
+ u_int8_t ip_invflags,
+ u_int8_t match_flags,
+ u_int8_t count)
+{
+ /* Must specify supported protocol, no unknown flags or bad count */
+ return (proto == IPPROTO_TCP || proto == IPPROTO_UDP
+ || proto == IPPROTO_UDPLITE
+ || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP)
+ && !(ip_invflags & XT_INV_PROTO)
+ && (match_flags == XT_MULTIPORT_SOURCE
+ || match_flags == XT_MULTIPORT_DESTINATION
+ || match_flags == XT_MULTIPORT_EITHER)
+ && count <= XT_MULTI_PORTS;
+}
+
+static bool multiport_mt_check_v0(const struct xt_mtchk_param *par)
+{
+ const struct ipt_ip *ip = par->entryinfo;
+ const struct xt_multiport *multiinfo = par->matchinfo;
+
+ return check(ip->proto, ip->invflags, multiinfo->flags,
+ multiinfo->count);
+}
+
+static bool multiport_mt_check(const struct xt_mtchk_param *par)
+{
+ const struct ipt_ip *ip = par->entryinfo;
+ const struct xt_multiport_v1 *multiinfo = par->matchinfo;
+
+ return check(ip->proto, ip->invflags, multiinfo->flags,
+ multiinfo->count);
+}
+
+static bool multiport_mt6_check_v0(const struct xt_mtchk_param *par)
+{
+ const struct ip6t_ip6 *ip = par->entryinfo;
+ const struct xt_multiport *multiinfo = par->matchinfo;
+
+ return check(ip->proto, ip->invflags, multiinfo->flags,
+ multiinfo->count);
+}
+
+static bool multiport_mt6_check(const struct xt_mtchk_param *par)
+{
+ const struct ip6t_ip6 *ip = par->entryinfo;
+ const struct xt_multiport_v1 *multiinfo = par->matchinfo;
+
+ return check(ip->proto, ip->invflags, multiinfo->flags,
+ multiinfo->count);
+}
+
+static struct xt_match multiport_mt_reg[] __read_mostly = {
+ {
+ .name = "multiport",
+ .family = NFPROTO_IPV4,
+ .revision = 0,
+ .checkentry = multiport_mt_check_v0,
+ .match = multiport_mt_v0,
+ .matchsize = sizeof(struct xt_multiport),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "multiport",
+ .family = NFPROTO_IPV4,
+ .revision = 1,
+ .checkentry = multiport_mt_check,
+ .match = multiport_mt,
+ .matchsize = sizeof(struct xt_multiport_v1),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "multiport",
+ .family = NFPROTO_IPV6,
+ .revision = 0,
+ .checkentry = multiport_mt6_check_v0,
+ .match = multiport_mt_v0,
+ .matchsize = sizeof(struct xt_multiport),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "multiport",
+ .family = NFPROTO_IPV6,
+ .revision = 1,
+ .checkentry = multiport_mt6_check,
+ .match = multiport_mt,
+ .matchsize = sizeof(struct xt_multiport_v1),
+ .me = THIS_MODULE,
+ },
+};
+
+static int __init multiport_mt_init(void)
+{
+ return xt_register_matches(multiport_mt_reg,
+ ARRAY_SIZE(multiport_mt_reg));
+}
+
+static void __exit multiport_mt_exit(void)
+{
+ xt_unregister_matches(multiport_mt_reg, ARRAY_SIZE(multiport_mt_reg));
+}
+
+module_init(multiport_mt_init);
+module_exit(multiport_mt_exit);
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