[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
new file mode 100644
index 0000000..ffdebc9
--- /dev/null
+++ b/net/netfilter/xt_conntrack.c
@@ -0,0 +1,238 @@
+/* Kernel module to match connection tracking information.
+ * Superset of Rusty's minimalistic state match.
+ *
+ * (C) 2001 Marc Boucher (marc@mbsi.ca).
+ *
+ * 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/skbuff.h>
+
+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
+#else
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_conntrack.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
+MODULE_DESCRIPTION("iptables connection tracking match module");
+MODULE_ALIAS("ipt_conntrack");
+
+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
+
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_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))
+
+ if (ct == &ip_conntrack_untracked)
+ statebit = XT_CONNTRACK_STATE_UNTRACKED;
+ else if (ct)
+ statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
+ else
+ statebit = XT_CONNTRACK_STATE_INVALID;
+
+ if(sinfo->flags & XT_CONNTRACK_STATE) {
+ if (ct) {
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
+ statebit |= XT_CONNTRACK_STATE_SNAT;
+
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
+ statebit |= XT_CONNTRACK_STATE_DNAT;
+ }
+
+ if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_PROTO) {
+ if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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, XT_CONNTRACK_ORIGSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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, XT_CONNTRACK_ORIGDST))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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, XT_CONNTRACK_REPLSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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, XT_CONNTRACK_REPLDST))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_STATUS) {
+ if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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), XT_CONNTRACK_EXPIRES))
+ return 0;
+ }
+
+ return 1;
+}
+
+#else /* CONFIG_IP_NF_CONNTRACK */
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_conntrack_info *sinfo = matchinfo;
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ unsigned int statebit;
+
+ ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
+
+#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
+
+ if (ct == &nf_conntrack_untracked)
+ statebit = XT_CONNTRACK_STATE_UNTRACKED;
+ else if (ct)
+ statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
+ else
+ statebit = XT_CONNTRACK_STATE_INVALID;
+
+ if(sinfo->flags & XT_CONNTRACK_STATE) {
+ if (ct) {
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
+ statebit |= XT_CONNTRACK_STATE_SNAT;
+
+ if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
+ statebit |= XT_CONNTRACK_STATE_DNAT;
+ }
+
+ if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_PROTO) {
+ if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, XT_CONNTRACK_ORIGSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, XT_CONNTRACK_ORIGDST))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, XT_CONNTRACK_REPLSRC))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_REPLDST) {
+ if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, XT_CONNTRACK_REPLDST))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_CONNTRACK_STATUS) {
+ if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
+ return 0;
+ }
+
+ if(sinfo->flags & XT_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), XT_CONNTRACK_EXPIRES))
+ return 0;
+ }
+
+ return 1;
+}
+
+#endif /* CONFIG_NF_IP_CONNTRACK */
+
+static int check(const char *tablename,
+ const void *ip,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ if (matchsize != XT_ALIGN(sizeof(struct xt_conntrack_info)))
+ return 0;
+
+ return 1;
+}
+
+static struct xt_match conntrack_match = {
+ .name = "conntrack",
+ .match = &match,
+ .checkentry = &check,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ int ret;
+ need_conntrack();
+ ret = xt_register_match(AF_INET, &conntrack_match);
+
+ return ret;
+}
+
+static void __exit fini(void)
+{
+ xt_unregister_match(AF_INET, &conntrack_match);
+}
+
+module_init(init);
+module_exit(fini);