patch-2.4.20 linux-2.4.20/net/ipv4/netfilter/ipt_ecn.c
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- Lines: 119
- Date:
Thu Nov 28 15:53:15 2002
- Orig file:
linux-2.4.19/net/ipv4/netfilter/ipt_ecn.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/net/ipv4/netfilter/ipt_ecn.c linux-2.4.20/net/ipv4/netfilter/ipt_ecn.c
@@ -0,0 +1,118 @@
+/* IP tables module for matching the value of the IPv4 and TCP ECN bits
+ *
+ * ipt_ecn.c,v 1.3 2002/05/29 15:09:00 laforge Exp
+ *
+ * (C) 2002 by Harald Welte <laforge@gnumonks.org>
+ *
+ * This software is distributed under the terms GNU GPL v2
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ecn.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("IP tables ECN matching module");
+MODULE_LICENSE("GPL");
+
+static inline int match_ip(const struct sk_buff *skb,
+ const struct iphdr *iph,
+ const struct ipt_ecn_info *einfo)
+{
+ return ((iph->tos&IPT_ECN_IP_MASK) == einfo->ip_ect);
+}
+
+static inline int match_tcp(const struct sk_buff *skb,
+ const struct iphdr *iph,
+ const struct ipt_ecn_info *einfo)
+{
+ struct tcphdr *tcph = (void *)iph + iph->ihl*4;
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
+ if (tcph->ece == 1)
+ return 0;
+ } else {
+ if (tcph->ece == 0)
+ return 0;
+ }
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
+ if (tcph->cwr == 1)
+ return 0;
+ } else {
+ if (tcph->cwr == 0)
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+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 ipt_ecn_info *info = matchinfo;
+ const struct iphdr *iph = skb->nh.iph;
+
+ if (info->operation & IPT_ECN_OP_MATCH_IP)
+ if (!match_ip(skb, iph, info))
+ return 0;
+
+ if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
+ if (iph->protocol != IPPROTO_TCP)
+ return 0;
+ if (!match_tcp(skb, iph, info))
+ return 0;
+ }
+
+ return 1;
+}
+
+static int checkentry(const char *tablename, const struct ipt_ip *ip,
+ void *matchinfo, unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ const struct ipt_ecn_info *info = matchinfo;
+
+ if (matchsize != IPT_ALIGN(sizeof(struct ipt_ecn_info)))
+ return 0;
+
+ if (info->operation & IPT_ECN_OP_MATCH_MASK)
+ return 0;
+
+ if (info->invert & IPT_ECN_OP_MATCH_MASK)
+ return 0;
+
+ if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)
+ && ip->proto != IPPROTO_TCP) {
+ printk(KERN_WARNING "ipt_ecn: can't match TCP bits in rule for"
+ " non-tcp packets\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct ipt_match ecn_match = { { NULL, NULL }, "ecn", &match,
+ &checkentry, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+ return ipt_register_match(&ecn_match);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_match(&ecn_match);
+}
+
+module_init(init);
+module_exit(fini);
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