This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / net / netfilter / xt_connbytes.c

diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c
new file mode 100644 (file)
index 0000000..1396fe2
--- /dev/null
+++ b/net/netfilter/xt_connbytes.c
@@ -0,0 +1,183 @@
+/* Kernel module to match connection tracking byte counter.
+ * GPL (C) 2002 Martin Devera (devik@cdi.cz).
+ *
+ * 2004-07-20 Harald Welte <laforge@netfilter.org>
+ *     - reimplemented to use per-connection accounting counters
+ *     - add functionality to match number of packets
+ *     - add functionality to match average packet size
+ *     - add support to match directions seperately
+ * 2005-10-16 Harald Welte <laforge@netfilter.org>
+ *     - Port to x_tables
+ *
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/netfilter/nf_conntrack_compat.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_connbytes.h>
+
+#include <asm/div64.h>
+#include <asm/bitops.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection");
+MODULE_ALIAS("ipt_connbytes");
+
+/* 64bit divisor, dividend and result. dynamic precision */
+static u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor)
+{
+       u_int32_t d = divisor;
+
+       if (divisor > 0xffffffffULL) {
+               unsigned int shift = fls(divisor >> 32);
+
+               d = divisor >> shift;
+               dividend >>= shift;
+       }
+
+       do_div(dividend, d);
+       return dividend;
+}
+
+static int
+match(const struct sk_buff *skb,
+      const struct net_device *in,
+      const struct net_device *out,
+      const struct xt_match *match,
+      const void *matchinfo,
+      int offset,
+      unsigned int protoff,
+      int *hotdrop)
+{
+       const struct xt_connbytes_info *sinfo = matchinfo;
+       u_int64_t what = 0;     /* initialize to make gcc happy */
+       const struct ip_conntrack_counter *counters;
+
+       if (!(counters = nf_ct_get_counters(skb)))
+               return 0; /* no match */
+
+       switch (sinfo->what) {
+       case XT_CONNBYTES_PKTS:
+               switch (sinfo->direction) {
+               case XT_CONNBYTES_DIR_ORIGINAL:
+                       what = counters[IP_CT_DIR_ORIGINAL].packets;
+                       break;
+               case XT_CONNBYTES_DIR_REPLY:
+                       what = counters[IP_CT_DIR_REPLY].packets;
+                       break;
+               case XT_CONNBYTES_DIR_BOTH:
+                       what = counters[IP_CT_DIR_ORIGINAL].packets;
+                       what += counters[IP_CT_DIR_REPLY].packets;
+                       break;
+               }
+               break;
+       case XT_CONNBYTES_BYTES:
+               switch (sinfo->direction) {
+               case XT_CONNBYTES_DIR_ORIGINAL:
+                       what = counters[IP_CT_DIR_ORIGINAL].bytes;
+                       break;
+               case XT_CONNBYTES_DIR_REPLY:
+                       what = counters[IP_CT_DIR_REPLY].bytes;
+                       break;
+               case XT_CONNBYTES_DIR_BOTH:
+                       what = counters[IP_CT_DIR_ORIGINAL].bytes;
+                       what += counters[IP_CT_DIR_REPLY].bytes;
+                       break;
+               }
+               break;
+       case XT_CONNBYTES_AVGPKT:
+               switch (sinfo->direction) {
+               case XT_CONNBYTES_DIR_ORIGINAL:
+                       what = div64_64(counters[IP_CT_DIR_ORIGINAL].bytes,
+                                       counters[IP_CT_DIR_ORIGINAL].packets);
+                       break;
+               case XT_CONNBYTES_DIR_REPLY:
+                       what = div64_64(counters[IP_CT_DIR_REPLY].bytes,
+                                       counters[IP_CT_DIR_REPLY].packets);
+                       break;
+               case XT_CONNBYTES_DIR_BOTH:
+                       {
+                               u_int64_t bytes;
+                               u_int64_t pkts;
+                               bytes = counters[IP_CT_DIR_ORIGINAL].bytes +
+                                       counters[IP_CT_DIR_REPLY].bytes;
+                               pkts = counters[IP_CT_DIR_ORIGINAL].packets+
+                                       counters[IP_CT_DIR_REPLY].packets;
+
+                               /* FIXME_THEORETICAL: what to do if sum
+                                * overflows ? */
+
+                               what = div64_64(bytes, pkts);
+                       }
+                       break;
+               }
+               break;
+       }
+
+       if (sinfo->count.to)
+               return (what <= sinfo->count.to && what >= sinfo->count.from);
+       else
+               return (what >= sinfo->count.from);
+}
+
+static int check(const char *tablename,
+                const void *ip,
+                const struct xt_match *match,
+                void *matchinfo,
+                unsigned int matchsize,
+                unsigned int hook_mask)
+{
+       const struct xt_connbytes_info *sinfo = matchinfo;
+
+       if (sinfo->what != XT_CONNBYTES_PKTS &&
+           sinfo->what != XT_CONNBYTES_BYTES &&
+           sinfo->what != XT_CONNBYTES_AVGPKT)
+               return 0;
+
+       if (sinfo->direction != XT_CONNBYTES_DIR_ORIGINAL &&
+           sinfo->direction != XT_CONNBYTES_DIR_REPLY &&
+           sinfo->direction != XT_CONNBYTES_DIR_BOTH)
+               return 0;
+
+       return 1;
+}
+
+static struct xt_match connbytes_match = {
+       .name           = "connbytes",
+       .match          = match,
+       .checkentry     = check,
+       .matchsize      = sizeof(struct xt_connbytes_info),
+       .family         = AF_INET,
+       .me             = THIS_MODULE
+};
+static struct xt_match connbytes6_match = {
+       .name           = "connbytes",
+       .match          = match,
+       .checkentry     = check,
+       .matchsize      = sizeof(struct xt_connbytes_info),
+       .family         = AF_INET6,
+       .me             = THIS_MODULE
+};
+
+static int __init xt_connbytes_init(void)
+{
+       int ret;
+       ret = xt_register_match(&connbytes_match);
+       if (ret)
+               return ret;
+
+       ret = xt_register_match(&connbytes6_match);
+       if (ret)
+               xt_unregister_match(&connbytes_match);
+       return ret;
+}
+
+static void __exit xt_connbytes_fini(void)
+{
+       xt_unregister_match(&connbytes_match);
+       xt_unregister_match(&connbytes6_match);
+}
+
+module_init(xt_connbytes_init);
+module_exit(xt_connbytes_fini);