patch-2.4.20 linux-2.4.20/net/ipv4/netfilter/ipt_conntrack.c
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- Lines: 124
- Date:
Thu Nov 28 15:53:15 2002
- Orig file:
linux-2.4.19/net/ipv4/netfilter/ipt_conntrack.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/net/ipv4/netfilter/ipt_conntrack.c linux-2.4.20/net/ipv4/netfilter/ipt_conntrack.c
@@ -0,0 +1,123 @@
+/* Kernel module to match connection tracking information.
+ * Superset of Rusty's minimalistic state match.
+ * GPL (C) 2001 Marc Boucher (marc@mbsi.ca).
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_conntrack.h>
+
+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_conntrack_info *sinfo = matchinfo;
+ struct ip_conntrack *ct;
+ enum ip_conntrack_info ctinfo;
+ unsigned int statebit;
+
+ ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
+
+#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
+
+ statebit = ct ? IPT_CONNTRACK_STATE_INVALID : IPT_CONNTRACK_STATE_BIT(ctinfo);
+ if(sinfo->flags & IPT_CONNTRACK_STATE) {
+ if (ct) {
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
+ statebit |= IPT_CONNTRACK_STATE_SNAT;
+
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
+ statebit |= IPT_CONNTRACK_STATE_DNAT;
+ }
+
+ if (FWINV((statebit & sinfo->statemask) == 0, IPT_CONNTRACK_STATE))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_PROTO) {
+ if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, IPT_CONNTRACK_PROTO))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, IPT_CONNTRACK_ORIGSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_ORIGDST) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, IPT_CONNTRACK_ORIGDST))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_REPLSRC) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, IPT_CONNTRACK_REPLSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_REPLDST) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, IPT_CONNTRACK_REPLDST))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_STATUS) {
+ if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, IPT_CONNTRACK_STATUS))
+ return 0;
+ }
+
+ if(sinfo->flags & IPT_CONNTRACK_EXPIRES) {
+ unsigned long expires;
+
+ if(!ct)
+ return 0;
+
+ expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
+
+ if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), IPT_CONNTRACK_EXPIRES))
+ return 0;
+ }
+
+ return 1;
+}
+
+static int check(const char *tablename,
+ const struct ipt_ip *ip,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ if (matchsize != IPT_ALIGN(sizeof(struct ipt_conntrack_info)))
+ return 0;
+
+ return 1;
+}
+
+static struct ipt_match conntrack_match
+= { { NULL, NULL }, "conntrack", &match, &check, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+ /* NULL if ip_conntrack not a module */
+ if (ip_conntrack_module)
+ __MOD_INC_USE_COUNT(ip_conntrack_module);
+ return ipt_register_match(&conntrack_match);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_match(&conntrack_match);
+ if (ip_conntrack_module)
+ __MOD_DEC_USE_COUNT(ip_conntrack_module);
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");
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