[collectd] [PATCH] Added libiptc.

Sebastian Harl sh at tokkee.org
Thu May 1 12:48:02 CEST 2008


libiptc is not meant to be a public interface by upstream. Debian has thus
removed it from all packages. To be able to use it, we need to take care
of it ourselves.

The configure script now checks, if libiptc is available and uses the
shipped version as a fallback.

The following changes to the libiptc sources were required:
 * added copyright headers mentioning the "Netfilter Core Team" as author
 * changed libiptc/* includes to * only
 * made libiptc.c:standard_target_map() static

Signed-off-by: Sebastian Harl <sh at tokkee.org>
---
 .gitignore                       |    3 +
 configure.in                     |   52 +-
 src/Makefile.am                  |   11 +-
 src/iptables.c                   |    4 +-
 src/libiptc/Makefile.am          |   14 +
 src/libiptc/ipt_kernel_headers.h |   45 +
 src/libiptc/libip4tc.c           |  516 +++++++++
 src/libiptc/libip6tc.c           |  455 ++++++++
 src/libiptc/libip6tc.h           |  173 +++
 src/libiptc/libiptc.c            | 2296 ++++++++++++++++++++++++++++++++++++++
 src/libiptc/libiptc.h            |  185 +++
 src/libiptc/linux_list.h         |  741 ++++++++++++
 12 files changed, 4486 insertions(+), 9 deletions(-)
 create mode 100644 src/libiptc/Makefile.am
 create mode 100644 src/libiptc/ipt_kernel_headers.h
 create mode 100644 src/libiptc/libip4tc.c
 create mode 100644 src/libiptc/libip6tc.c
 create mode 100644 src/libiptc/libip6tc.h
 create mode 100644 src/libiptc/libiptc.c
 create mode 100644 src/libiptc/libiptc.h
 create mode 100644 src/libiptc/linux_list.h

diff --git a/.gitignore b/.gitignore
index 5eb8974..5d4fbca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,6 +48,9 @@ src/collectd*.1
 src/collectd*.5
 src/types.db.5
 src/config.h.in~
+src/libiptc/.libs
+src/libiptc/*.la
+src/libiptc/*.lo
 src/liboconfig/.libs
 src/liboconfig/*.la
 src/liboconfig/*.lo
diff --git a/configure.in b/configure.in
index e834ffd..cb83793 100644
--- a/configure.in
+++ b/configure.in
@@ -1598,6 +1598,16 @@ then
 	LDFLAGS=$SAVE_LDFLAGS
 fi
 
+if test "x$ac_system" = "xLinux"
+then
+	AC_ARG_VAR([KERNEL_DIR], [path to Linux kernel sources])
+	if test -z "$KERNEL_DIR"
+	then
+		KERNEL_DIR="/lib/modules/`uname -r`/source"
+	fi
+fi
+
+with_own_libiptc="no"
 AC_ARG_WITH(libiptc, [AS_HELP_STRING([--with-libiptc@<:@=PREFIX@:>@], [Path to libiptc.])],
 [
 	if test "x$withval" != "xno" && test "x$withval" != "xyes"
@@ -1622,22 +1632,45 @@ then
 	AC_CHECK_LIB(iptc, iptc_init,
 	[
 		AC_DEFINE(HAVE_LIBIPTC, 1, [Define to 1 if you have the iptc library (-liptc).])
-	], [with_libiptc="no (libiptc not found)"])
+	],
+	[
+		with_libiptc="yes"
+		with_own_libiptc="yes"
+	])
 fi
-if test "x$with_libiptc" = "xyes"
+if test "x$with_libiptc" = "xyes" -a "x$with_own_libiptc" != "xyes"
 then
 	AC_CHECK_HEADERS(libiptc/libiptc.h,
 	[
 		AC_DEFINE(HAVE_LIBIPTC_LIBIPTC_H, 1, [Define to 1 if you have the <libiptc/libiptc.h> header file.])
-	], [with_libiptc="no (libiptc/libiptc.h not found)"])
+	],
+	[
+		with_libiptc="yes"
+		with_own_libiptc="yes"
+	])
 fi
 if test "x$with_libiptc" = "xyes"
 then
-	collect_libiptc=1
-else
-	collect_libiptc=0
+	SAVE_CFLAGS=$CFLAGS
+	CFLAGS="$CFLAGS -I$KERNEL_DIR/include"
+
+	AC_CHECK_HEADERS(linux/netfilter_ipv4/ip_tables.h linux/netfilter_ipv6/ip6_tables.h, [],
+	[
+		with_libiptc="no (Linux iptables headers not found - check KERNEL_DIR)"
+		with_own_libiptc="no"
+	],
+	[
+#include "$srcdir/src/libiptc/ipt_kernel_headers.h"
+	])
+
+	CFLAGS=$SAVE_CFLAGS
 fi
 AM_CONDITIONAL(BUILD_WITH_LIBIPTC, test "x$with_libiptc" = "xyes")
+AM_CONDITIONAL(BUILD_WITH_OWN_LIBIPTC, test "x$with_own_libiptc" = "xyes")
+if test "x$with_own_libiptc" = "xyes"
+then
+	AC_DEFINE(OWN_LIBIPTC, 1, [Define to 1 if we use the shipped iptc library.])
+fi
 
 with_snmp_config="net-snmp-config"
 with_snmp_cflags=""
@@ -2514,7 +2547,7 @@ fi
 AC_SUBST(PERL_BINDINGS)
 AC_SUBST(PERL_BINDINGS_OPTIONS)
 
-AC_OUTPUT(Makefile src/Makefile src/collectd.conf src/liboconfig/Makefile src/liboping/Makefile bindings/Makefile)
+AC_OUTPUT(Makefile src/Makefile src/collectd.conf src/libiptc/Makefile src/liboconfig/Makefile src/liboping/Makefile bindings/Makefile)
 
 if test "x$with_rrdtool" = "xyes" -a "x$librrd_threadsafe" != "xyes"
 then
@@ -2526,6 +2559,11 @@ then
 	with_liboping="yes (shipped version)"
 fi
 
+if test "x$with_libiptc" = "xyes" -a "x$with_own_libiptc" = "xyes"
+then
+	with_libiptc="yes (shipped version)"
+fi
+
 if test "x$with_libperl" = "xyes"
 then
 	with_libperl="yes (version `$perl_interpreter -MConfig -e 'print $Config{version};'`)"
diff --git a/src/Makefile.am b/src/Makefile.am
index fe4af77..322f76c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,4 +1,7 @@
 SUBDIRS =
+if BUILD_WITH_OWN_LIBIPTC
+SUBDIRS += libiptc
+endif
 if BUILD_WITH_OWN_LIBOCONFIG
 SUBDIRS += liboconfig
 endif
@@ -272,7 +275,13 @@ endif # BUILD_PLUGIN_INTERFACE
 if BUILD_PLUGIN_IPTABLES
 pkglib_LTLIBRARIES += iptables.la
 iptables_la_SOURCES = iptables.c
-iptables_la_LDFLAGS = -module -avoid-version -liptc
+iptables_la_LDFLAGS = -module -avoid-version
+if BUILD_WITH_OWN_LIBIPTC
+iptables_la_LIBADD  = libiptc/libiptc.la
+iptables_la_DEPENDENCIES = libiptc/libiptc.la
+else
+iptables_la_LDFLAGS += -liptc
+endif
 collectd_LDADD += "-dlopen" iptables.la
 collectd_DEPENDENCIES += iptables.la
 endif
diff --git a/src/iptables.c b/src/iptables.c
index 576cd63..dc69f6b 100644
--- a/src/iptables.c
+++ b/src/iptables.c
@@ -25,7 +25,9 @@
 #include "plugin.h"
 #include "configfile.h"
 
-#if HAVE_LIBIPTC_LIBIPTC_H
+#if OWN_LIBIPTC
+# include "libiptc/libiptc.h"
+#else
 # include <libiptc/libiptc.h>
 #endif
 
diff --git a/src/libiptc/Makefile.am b/src/libiptc/Makefile.am
new file mode 100644
index 0000000..338aecb
--- /dev/null
+++ b/src/libiptc/Makefile.am
@@ -0,0 +1,14 @@
+AUTOMAKE_OPTIONS = foreign no-dependencies
+
+EXTRA_DIST = libiptc.c
+
+if COMPILER_IS_GCC
+AM_CFLAGS = -Wall -Werror
+endif
+
+noinst_LTLIBRARIES = libiptc.la
+
+libiptc_la_CFLAGS = -DIPTABLES_VERSION=\"1.4.0\" -I$(KERNEL_DIR)/include
+libiptc_la_SOURCES = libip4tc.c libip6tc.c \
+		ipt_kernel_headers.h libip6tc.h libiptc.h linux_list.h
+
diff --git a/src/libiptc/ipt_kernel_headers.h b/src/libiptc/ipt_kernel_headers.h
new file mode 100644
index 0000000..bf81f6e
--- /dev/null
+++ b/src/libiptc/ipt_kernel_headers.h
@@ -0,0 +1,45 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+/* This is the userspace/kernel interface for Generic IP Chains,
+   required for libc6. */
+#ifndef _FWCHAINS_KERNEL_HEADERS_H
+#define _FWCHAINS_KERNEL_HEADERS_H
+
+#include <limits.h>
+
+#if defined(__GLIBC__) && __GLIBC__ == 2
+#include <netinet/ip.h>
+#include <netinet/in.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <net/if.h>
+#include <sys/types.h>
+#else /* libc5 */
+#include <sys/socket.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/icmp.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/types.h>
+#include <linux/in6.h>
+#endif
+#endif
diff --git a/src/libiptc/libip4tc.c b/src/libiptc/libip4tc.c
new file mode 100644
index 0000000..66abb44
--- /dev/null
+++ b/src/libiptc/libip4tc.c
@@ -0,0 +1,516 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+/* Library which manipulates firewall rules.  Version 0.1. */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+   COPYING for details). */
+
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#ifdef DEBUG_CONNTRACK
+#define inline
+#endif
+
+#if !defined(__GLIBC__) || (__GLIBC__ < 2)
+typedef unsigned int socklen_t;
+#endif
+
+#include "libiptc.h"
+
+#define IP_VERSION	4
+#define IP_OFFSET	0x1FFF
+
+#define HOOK_PRE_ROUTING	NF_IP_PRE_ROUTING
+#define HOOK_LOCAL_IN		NF_IP_LOCAL_IN
+#define HOOK_FORWARD		NF_IP_FORWARD
+#define HOOK_LOCAL_OUT		NF_IP_LOCAL_OUT
+#define HOOK_POST_ROUTING	NF_IP_POST_ROUTING
+#ifdef NF_IP_DROPPING
+#define HOOK_DROPPING		NF_IP_DROPPING
+#endif
+
+#define STRUCT_ENTRY_TARGET	struct ipt_entry_target
+#define STRUCT_ENTRY		struct ipt_entry
+#define STRUCT_ENTRY_MATCH	struct ipt_entry_match
+#define STRUCT_GETINFO		struct ipt_getinfo
+#define STRUCT_GET_ENTRIES	struct ipt_get_entries
+#define STRUCT_COUNTERS		struct ipt_counters
+#define STRUCT_COUNTERS_INFO	struct ipt_counters_info
+#define STRUCT_STANDARD_TARGET	struct ipt_standard_target
+#define STRUCT_REPLACE		struct ipt_replace
+
+#define STRUCT_TC_HANDLE	struct iptc_handle
+#define TC_HANDLE_T		iptc_handle_t
+
+#define ENTRY_ITERATE		IPT_ENTRY_ITERATE
+#define TABLE_MAXNAMELEN	IPT_TABLE_MAXNAMELEN
+#define FUNCTION_MAXNAMELEN	IPT_FUNCTION_MAXNAMELEN
+
+#define GET_TARGET		ipt_get_target
+
+#define ERROR_TARGET		IPT_ERROR_TARGET
+#define NUMHOOKS		NF_IP_NUMHOOKS
+
+#define IPT_CHAINLABEL		ipt_chainlabel
+
+#define TC_DUMP_ENTRIES		dump_entries
+#define TC_IS_CHAIN		iptc_is_chain
+#define TC_FIRST_CHAIN		iptc_first_chain
+#define TC_NEXT_CHAIN		iptc_next_chain
+#define TC_FIRST_RULE		iptc_first_rule
+#define TC_NEXT_RULE		iptc_next_rule
+#define TC_GET_TARGET		iptc_get_target
+#define TC_BUILTIN		iptc_builtin
+#define TC_GET_POLICY		iptc_get_policy
+#define TC_INSERT_ENTRY		iptc_insert_entry
+#define TC_REPLACE_ENTRY	iptc_replace_entry
+#define TC_APPEND_ENTRY		iptc_append_entry
+#define TC_DELETE_ENTRY		iptc_delete_entry
+#define TC_DELETE_NUM_ENTRY	iptc_delete_num_entry
+#define TC_CHECK_PACKET		iptc_check_packet
+#define TC_FLUSH_ENTRIES	iptc_flush_entries
+#define TC_ZERO_ENTRIES		iptc_zero_entries
+#define TC_READ_COUNTER		iptc_read_counter
+#define TC_ZERO_COUNTER		iptc_zero_counter
+#define TC_SET_COUNTER		iptc_set_counter
+#define TC_CREATE_CHAIN		iptc_create_chain
+#define TC_GET_REFERENCES	iptc_get_references
+#define TC_DELETE_CHAIN		iptc_delete_chain
+#define TC_RENAME_CHAIN		iptc_rename_chain
+#define TC_SET_POLICY		iptc_set_policy
+#define TC_GET_RAW_SOCKET	iptc_get_raw_socket
+#define TC_INIT			iptc_init
+#define TC_FREE			iptc_free
+#define TC_COMMIT		iptc_commit
+#define TC_STRERROR		iptc_strerror
+#define TC_NUM_RULES		iptc_num_rules
+#define TC_GET_RULE		iptc_get_rule
+
+#define TC_AF			AF_INET
+#define TC_IPPROTO		IPPROTO_IP
+
+#define SO_SET_REPLACE		IPT_SO_SET_REPLACE
+#define SO_SET_ADD_COUNTERS	IPT_SO_SET_ADD_COUNTERS
+#define SO_GET_INFO		IPT_SO_GET_INFO
+#define SO_GET_ENTRIES		IPT_SO_GET_ENTRIES
+#define SO_GET_VERSION		IPT_SO_GET_VERSION
+
+#define STANDARD_TARGET		IPT_STANDARD_TARGET
+#define LABEL_RETURN		IPTC_LABEL_RETURN
+#define LABEL_ACCEPT		IPTC_LABEL_ACCEPT
+#define LABEL_DROP		IPTC_LABEL_DROP
+#define LABEL_QUEUE		IPTC_LABEL_QUEUE
+
+#define ALIGN			IPT_ALIGN
+#define RETURN			IPT_RETURN
+
+#include "libiptc.c"
+
+#define IP_PARTS_NATIVE(n)			\
+(unsigned int)((n)>>24)&0xFF,			\
+(unsigned int)((n)>>16)&0xFF,			\
+(unsigned int)((n)>>8)&0xFF,			\
+(unsigned int)((n)&0xFF)
+
+#define IP_PARTS(n) IP_PARTS_NATIVE(ntohl(n))
+
+int
+dump_entry(STRUCT_ENTRY *e, const TC_HANDLE_T handle)
+{
+	size_t i;
+	STRUCT_ENTRY_TARGET *t;
+
+	printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
+	       iptcb_entry2offset(handle, e));
+	printf("SRC IP: %u.%u.%u.%u/%u.%u.%u.%u\n",
+	       IP_PARTS(e->ip.src.s_addr),IP_PARTS(e->ip.smsk.s_addr));
+	printf("DST IP: %u.%u.%u.%u/%u.%u.%u.%u\n",
+	       IP_PARTS(e->ip.dst.s_addr),IP_PARTS(e->ip.dmsk.s_addr));
+	printf("Interface: `%s'/", e->ip.iniface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ip.iniface_mask[i] ? 'X' : '.');
+	printf("to `%s'/", e->ip.outiface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ip.outiface_mask[i] ? 'X' : '.');
+	printf("\nProtocol: %u\n", e->ip.proto);
+	printf("Flags: %02X\n", e->ip.flags);
+	printf("Invflags: %02X\n", e->ip.invflags);
+	printf("Counters: %llu packets, %llu bytes\n",
+	       (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
+	printf("Cache: %08X\n", e->nfcache);
+
+	IPT_MATCH_ITERATE(e, print_match);
+
+	t = GET_TARGET(e);
+	printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
+	if (strcmp(t->u.user.name, STANDARD_TARGET) == 0) {
+		int pos = *(int *)t->data;
+		if (pos < 0)
+			printf("verdict=%s\n",
+			       pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
+			       : pos == -NF_DROP-1 ? "NF_DROP"
+			       : pos == -NF_QUEUE-1 ? "NF_QUEUE"
+			       : pos == RETURN ? "RETURN"
+			       : "UNKNOWN");
+		else
+			printf("verdict=%u\n", pos);
+	} else if (strcmp(t->u.user.name, IPT_ERROR_TARGET) == 0)
+		printf("error=`%s'\n", t->data);
+
+	printf("\n");
+	return 0;
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b, unsigned char *matchmask)
+{
+	unsigned int i;
+	unsigned char *mptr;
+
+	/* Always compare head structures: ignore mask here. */
+	if (a->ip.src.s_addr != b->ip.src.s_addr
+	    || a->ip.dst.s_addr != b->ip.dst.s_addr
+	    || a->ip.smsk.s_addr != b->ip.smsk.s_addr
+	    || a->ip.dmsk.s_addr != b->ip.dmsk.s_addr
+	    || a->ip.proto != b->ip.proto
+	    || a->ip.flags != b->ip.flags
+	    || a->ip.invflags != b->ip.invflags)
+		return NULL;
+
+	for (i = 0; i < IFNAMSIZ; i++) {
+		if (a->ip.iniface_mask[i] != b->ip.iniface_mask[i])
+			return NULL;
+		if ((a->ip.iniface[i] & a->ip.iniface_mask[i])
+		    != (b->ip.iniface[i] & b->ip.iniface_mask[i]))
+			return NULL;
+		if (a->ip.outiface_mask[i] != b->ip.outiface_mask[i])
+			return NULL;
+		if ((a->ip.outiface[i] & a->ip.outiface_mask[i])
+		    != (b->ip.outiface[i] & b->ip.outiface_mask[i]))
+			return NULL;
+	}
+
+	if (a->target_offset != b->target_offset
+	    || a->next_offset != b->next_offset)
+		return NULL;
+
+	mptr = matchmask + sizeof(STRUCT_ENTRY);
+	if (IPT_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
+		return NULL;
+	mptr += IPT_ALIGN(sizeof(struct ipt_entry_target));
+
+	return mptr;
+}
+
+#if 0
+/***************************** DEBUGGING ********************************/
+static inline int
+unconditional(const struct ipt_ip *ip)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(*ip)/sizeof(u_int32_t); i++)
+		if (((u_int32_t *)ip)[i])
+			return 0;
+
+	return 1;
+}
+
+static inline int
+check_match(const STRUCT_ENTRY_MATCH *m, unsigned int *off)
+{
+	assert(m->u.match_size >= sizeof(STRUCT_ENTRY_MATCH));
+	assert(ALIGN(m->u.match_size) == m->u.match_size);
+
+	(*off) += m->u.match_size;
+	return 0;
+}
+
+static inline int
+check_entry(const STRUCT_ENTRY *e, unsigned int *i, unsigned int *off,
+	    unsigned int user_offset, int *was_return,
+	    TC_HANDLE_T h)
+{
+	unsigned int toff;
+	STRUCT_STANDARD_TARGET *t;
+
+	assert(e->target_offset >= sizeof(STRUCT_ENTRY));
+	assert(e->next_offset >= e->target_offset
+	       + sizeof(STRUCT_ENTRY_TARGET));
+	toff = sizeof(STRUCT_ENTRY);
+	IPT_MATCH_ITERATE(e, check_match, &toff);
+
+	assert(toff == e->target_offset);
+
+	t = (STRUCT_STANDARD_TARGET *)
+		GET_TARGET((STRUCT_ENTRY *)e);
+	/* next_offset will have to be multiple of entry alignment. */
+	assert(e->next_offset == ALIGN(e->next_offset));
+	assert(e->target_offset == ALIGN(e->target_offset));
+	assert(t->target.u.target_size == ALIGN(t->target.u.target_size));
+	assert(!TC_IS_CHAIN(t->target.u.user.name, h));
+
+	if (strcmp(t->target.u.user.name, STANDARD_TARGET) == 0) {
+		assert(t->target.u.target_size
+		       == ALIGN(sizeof(STRUCT_STANDARD_TARGET)));
+
+		assert(t->verdict == -NF_DROP-1
+		       || t->verdict == -NF_ACCEPT-1
+		       || t->verdict == RETURN
+		       || t->verdict < (int)h->entries->size);
+
+		if (t->verdict >= 0) {
+			STRUCT_ENTRY *te = get_entry(h, t->verdict);
+			int idx;
+
+			idx = iptcb_entry2index(h, te);
+			assert(strcmp(GET_TARGET(te)->u.user.name,
+				      IPT_ERROR_TARGET)
+			       != 0);
+			assert(te != e);
+
+			/* Prior node must be error node, or this node. */
+			assert(t->verdict == iptcb_entry2offset(h, e)+e->next_offset
+			       || strcmp(GET_TARGET(index2entry(h, idx-1))
+					 ->u.user.name, IPT_ERROR_TARGET)
+			       == 0);
+		}
+
+		if (t->verdict == RETURN
+		    && unconditional(&e->ip)
+		    && e->target_offset == sizeof(*e))
+			*was_return = 1;
+		else
+			*was_return = 0;
+	} else if (strcmp(t->target.u.user.name, IPT_ERROR_TARGET) == 0) {
+		assert(t->target.u.target_size
+		       == ALIGN(sizeof(struct ipt_error_target)));
+
+		/* If this is in user area, previous must have been return */
+		if (*off > user_offset)
+			assert(*was_return);
+
+		*was_return = 0;
+	}
+	else *was_return = 0;
+
+	if (*off == user_offset)
+		assert(strcmp(t->target.u.user.name, IPT_ERROR_TARGET) == 0);
+
+	(*off) += e->next_offset;
+	(*i)++;
+	return 0;
+}
+
+#ifdef IPTC_DEBUG
+/* Do every conceivable sanity check on the handle */
+static void
+do_check(TC_HANDLE_T h, unsigned int line)
+{
+	unsigned int i, n;
+	unsigned int user_offset; /* Offset of first user chain */
+	int was_return;
+
+	assert(h->changed == 0 || h->changed == 1);
+	if (strcmp(h->info.name, "filter") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP_LOCAL_IN
+			   | 1 << NF_IP_FORWARD
+			   | 1 << NF_IP_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP_LOCAL_IN] == 0);
+
+		n = get_chain_end(h, 0);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_FORWARD] == n);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+	} else if (strcmp(h->info.name, "nat") == 0) {
+		assert((h->info.valid_hooks
+		        == (1 << NF_IP_PRE_ROUTING
+			    | 1 << NF_IP_POST_ROUTING
+			    | 1 << NF_IP_LOCAL_OUT)) ||
+		       (h->info.valid_hooks
+			== (1 << NF_IP_PRE_ROUTING
+			    | 1 << NF_IP_LOCAL_IN
+			    | 1 << NF_IP_POST_ROUTING
+			    | 1 << NF_IP_LOCAL_OUT)));
+
+		assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_POST_ROUTING] == n);
+		n = get_chain_end(h, n);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP_LOCAL_IN)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP_LOCAL_IN] == n);
+			user_offset = h->info.hook_entry[NF_IP_LOCAL_IN];
+		}
+
+	} else if (strcmp(h->info.name, "mangle") == 0) {
+		/* This code is getting ugly because linux < 2.4.18-pre6 had
+		 * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
+		 * */
+		assert((h->info.valid_hooks
+			== (1 << NF_IP_PRE_ROUTING
+			    | 1 << NF_IP_LOCAL_OUT)) || 
+		       (h->info.valid_hooks
+			== (1 << NF_IP_PRE_ROUTING
+			    | 1 << NF_IP_LOCAL_IN
+			    | 1 << NF_IP_FORWARD
+			    | 1 << NF_IP_LOCAL_OUT
+			    | 1 << NF_IP_POST_ROUTING)));
+
+		/* Hooks should be first five */
+		assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		if (h->info.valid_hooks & (1 << NF_IP_LOCAL_IN)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP_LOCAL_IN] == n);
+			n = get_chain_end(h, n);
+		}
+
+		if (h->info.valid_hooks & (1 << NF_IP_FORWARD)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP_FORWARD] == n);
+			n = get_chain_end(h, n);
+		}
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP_POST_ROUTING)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP_POST_ROUTING] == n);
+			user_offset = h->info.hook_entry[NF_IP_POST_ROUTING];
+		}
+	} else if (strcmp(h->info.name, "raw") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP_PRE_ROUTING
+			   | 1 << NF_IP_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+#ifdef NF_IP_DROPPING
+	} else if (strcmp(h->info.name, "drop") == 0) {
+		assert(h->info.valid_hooks == (1 << NF_IP_DROPPING));
+
+		/* Hook should be first */
+		assert(h->info.hook_entry[NF_IP_DROPPING] == 0);
+		user_offset = 0;
+#endif
+	} else {
+		fprintf(stderr, "Unknown table `%s'\n", h->info.name);
+		abort();
+	}
+
+	/* User chain == end of last builtin + policy entry */
+	user_offset = get_chain_end(h, user_offset);
+	user_offset += get_entry(h, user_offset)->next_offset;
+
+	/* Overflows should be end of entry chains, and unconditional
+           policy nodes. */
+	for (i = 0; i < NUMHOOKS; i++) {
+		STRUCT_ENTRY *e;
+		STRUCT_STANDARD_TARGET *t;
+
+		if (!(h->info.valid_hooks & (1 << i)))
+			continue;
+		assert(h->info.underflow[i]
+		       == get_chain_end(h, h->info.hook_entry[i]));
+
+		e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
+		assert(unconditional(&e->ip));
+		assert(e->target_offset == sizeof(*e));
+		t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+		assert(t->target.u.target_size == ALIGN(sizeof(*t)));
+		assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
+
+		assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
+		assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
+
+		/* Hooks and underflows must be valid entries */
+		entry2index(h, get_entry(h, h->info.hook_entry[i]));
+		entry2index(h, get_entry(h, h->info.underflow[i]));
+	}
+
+	assert(h->info.size
+	       >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
+					 +sizeof(STRUCT_STANDARD_TARGET)));
+
+	assert(h->entries.size
+	       >= (h->new_number
+		   * (sizeof(STRUCT_ENTRY)
+		      + sizeof(STRUCT_STANDARD_TARGET))));
+	assert(strcmp(h->info.name, h->entries.name) == 0);
+
+	i = 0; n = 0;
+	was_return = 0;
+	/* Check all the entries. */
+	ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
+		      check_entry, &i, &n, user_offset, &was_return, h);
+
+	assert(i == h->new_number);
+	assert(n == h->entries.size);
+
+	/* Final entry must be error node */
+	assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
+		      ->u.user.name,
+		      ERROR_TARGET) == 0);
+}
+#endif /*IPTC_DEBUG*/
+
+#endif
diff --git a/src/libiptc/libip6tc.c b/src/libiptc/libip6tc.c
new file mode 100644
index 0000000..b30bb28
--- /dev/null
+++ b/src/libiptc/libip6tc.c
@@ -0,0 +1,455 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+/* Library which manipulates firewall rules.  Version 0.1. */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+   COPYING for details). */
+
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+
+#ifdef DEBUG_CONNTRACK
+#define inline
+#endif
+
+#if !defined(__GLIBC__) || (__GLIBC__ < 2)
+typedef unsigned int socklen_t;
+#endif
+
+#include "libip6tc.h"
+
+#define HOOK_PRE_ROUTING	NF_IP6_PRE_ROUTING
+#define HOOK_LOCAL_IN		NF_IP6_LOCAL_IN
+#define HOOK_FORWARD		NF_IP6_FORWARD
+#define HOOK_LOCAL_OUT		NF_IP6_LOCAL_OUT
+#define HOOK_POST_ROUTING	NF_IP6_POST_ROUTING
+
+#define STRUCT_ENTRY_TARGET	struct ip6t_entry_target
+#define STRUCT_ENTRY		struct ip6t_entry
+#define STRUCT_ENTRY_MATCH	struct ip6t_entry_match
+#define STRUCT_GETINFO		struct ip6t_getinfo
+#define STRUCT_GET_ENTRIES	struct ip6t_get_entries
+#define STRUCT_COUNTERS		struct ip6t_counters
+#define STRUCT_COUNTERS_INFO	struct ip6t_counters_info
+#define STRUCT_STANDARD_TARGET	struct ip6t_standard_target
+#define STRUCT_REPLACE		struct ip6t_replace
+
+#define STRUCT_TC_HANDLE	struct ip6tc_handle
+#define TC_HANDLE_T		ip6tc_handle_t
+
+#define ENTRY_ITERATE		IP6T_ENTRY_ITERATE
+#define TABLE_MAXNAMELEN	IP6T_TABLE_MAXNAMELEN
+#define FUNCTION_MAXNAMELEN	IP6T_FUNCTION_MAXNAMELEN
+
+#define GET_TARGET		ip6t_get_target
+
+#define ERROR_TARGET		IP6T_ERROR_TARGET
+#define NUMHOOKS		NF_IP6_NUMHOOKS
+
+#define IPT_CHAINLABEL		ip6t_chainlabel
+
+#define TC_DUMP_ENTRIES		dump_entries6
+#define TC_IS_CHAIN		ip6tc_is_chain
+#define TC_FIRST_CHAIN		ip6tc_first_chain
+#define TC_NEXT_CHAIN		ip6tc_next_chain
+#define TC_FIRST_RULE		ip6tc_first_rule
+#define TC_NEXT_RULE		ip6tc_next_rule
+#define TC_GET_TARGET		ip6tc_get_target
+#define TC_BUILTIN		ip6tc_builtin
+#define TC_GET_POLICY		ip6tc_get_policy
+#define TC_INSERT_ENTRY		ip6tc_insert_entry
+#define TC_REPLACE_ENTRY	ip6tc_replace_entry
+#define TC_APPEND_ENTRY		ip6tc_append_entry
+#define TC_DELETE_ENTRY		ip6tc_delete_entry
+#define TC_DELETE_NUM_ENTRY	ip6tc_delete_num_entry
+#define TC_CHECK_PACKET		ip6tc_check_packet
+#define TC_FLUSH_ENTRIES	ip6tc_flush_entries
+#define TC_ZERO_ENTRIES		ip6tc_zero_entries
+#define TC_ZERO_COUNTER		ip6tc_zero_counter
+#define TC_READ_COUNTER		ip6tc_read_counter
+#define TC_SET_COUNTER		ip6tc_set_counter
+#define TC_CREATE_CHAIN		ip6tc_create_chain
+#define TC_GET_REFERENCES	ip6tc_get_references
+#define TC_DELETE_CHAIN		ip6tc_delete_chain
+#define TC_RENAME_CHAIN		ip6tc_rename_chain
+#define TC_SET_POLICY		ip6tc_set_policy
+#define TC_GET_RAW_SOCKET	ip6tc_get_raw_socket
+#define TC_INIT			ip6tc_init
+#define TC_FREE			ip6tc_free
+#define TC_COMMIT		ip6tc_commit
+#define TC_STRERROR		ip6tc_strerror
+#define TC_NUM_RULES		ip6tc_num_rules
+#define TC_GET_RULE		ip6tc_get_rule
+
+#define TC_AF			AF_INET6
+#define TC_IPPROTO		IPPROTO_IPV6
+
+#define SO_SET_REPLACE		IP6T_SO_SET_REPLACE
+#define SO_SET_ADD_COUNTERS	IP6T_SO_SET_ADD_COUNTERS
+#define SO_GET_INFO		IP6T_SO_GET_INFO
+#define SO_GET_ENTRIES		IP6T_SO_GET_ENTRIES
+#define SO_GET_VERSION		IP6T_SO_GET_VERSION
+
+#define STANDARD_TARGET		IP6T_STANDARD_TARGET
+#define LABEL_RETURN		IP6TC_LABEL_RETURN
+#define LABEL_ACCEPT		IP6TC_LABEL_ACCEPT
+#define LABEL_DROP		IP6TC_LABEL_DROP
+#define LABEL_QUEUE		IP6TC_LABEL_QUEUE
+
+#define ALIGN			IP6T_ALIGN
+#define RETURN			IP6T_RETURN
+
+#include "libiptc.c"
+
+#define BIT6(a, l) \
+ ((ntohl(a->in6_u.u6_addr32[(l) / 32]) >> (31 - ((l) & 31))) & 1)
+
+int
+ipv6_prefix_length(const struct in6_addr *a)
+{
+	int l, i;
+	for (l = 0; l < 128; l++) {
+		if (BIT6(a, l) == 0)
+			break;
+	}
+	for (i = l + 1; i < 128; i++) {
+		if (BIT6(a, i) == 1)
+			return -1;
+	}
+	return l;
+}
+
+static int
+dump_entry(struct ip6t_entry *e, const ip6tc_handle_t handle)
+{
+	size_t i;
+	char buf[40];
+	int len;
+	struct ip6t_entry_target *t;
+	
+	printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
+	       iptcb_entry2offset(handle, e));
+	puts("SRC IP: ");
+	inet_ntop(AF_INET6, &e->ipv6.src, buf, sizeof buf);
+	puts(buf);
+	putchar('/');
+	len = ipv6_prefix_length(&e->ipv6.smsk);
+	if (len != -1)
+		printf("%d", len);
+	else {
+		inet_ntop(AF_INET6, &e->ipv6.smsk, buf, sizeof buf);
+		puts(buf);
+	}
+	putchar('\n');
+	
+	puts("DST IP: ");
+	inet_ntop(AF_INET6, &e->ipv6.dst, buf, sizeof buf);
+	puts(buf);
+	putchar('/');
+	len = ipv6_prefix_length(&e->ipv6.dmsk);
+	if (len != -1)
+		printf("%d", len);
+	else {
+		inet_ntop(AF_INET6, &e->ipv6.dmsk, buf, sizeof buf);
+		puts(buf);
+	}
+	putchar('\n');
+	
+	printf("Interface: `%s'/", e->ipv6.iniface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ipv6.iniface_mask[i] ? 'X' : '.');
+	printf("to `%s'/", e->ipv6.outiface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ipv6.outiface_mask[i] ? 'X' : '.');
+	printf("\nProtocol: %u\n", e->ipv6.proto);
+	if (e->ipv6.flags & IP6T_F_TOS)
+		printf("TOS: %u\n", e->ipv6.tos);
+	printf("Flags: %02X\n", e->ipv6.flags);
+	printf("Invflags: %02X\n", e->ipv6.invflags);
+	printf("Counters: %llu packets, %llu bytes\n",
+	       (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
+	printf("Cache: %08X\n", e->nfcache);
+	
+	IP6T_MATCH_ITERATE(e, print_match);
+
+	t = ip6t_get_target(e);
+	printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
+	if (strcmp(t->u.user.name, IP6T_STANDARD_TARGET) == 0) {
+		int pos = *(int *)t->data;
+		if (pos < 0)
+			printf("verdict=%s\n",
+			       pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
+			       : pos == -NF_DROP-1 ? "NF_DROP"
+			       : pos == IP6T_RETURN ? "RETURN"
+			       : "UNKNOWN");
+		else
+			printf("verdict=%u\n", pos);
+	} else if (strcmp(t->u.user.name, IP6T_ERROR_TARGET) == 0)
+		printf("error=`%s'\n", t->data);
+
+	printf("\n");
+	return 0;
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b,
+	unsigned char *matchmask)
+{
+	unsigned int i;
+	unsigned char *mptr;
+
+	/* Always compare head structures: ignore mask here. */
+	if (memcmp(&a->ipv6.src, &b->ipv6.src, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.dst, &b->ipv6.dst, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.smsk, &b->ipv6.smsk, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.dmsk, &b->ipv6.dmsk, sizeof(struct in6_addr))
+	    || a->ipv6.proto != b->ipv6.proto
+	    || a->ipv6.tos != b->ipv6.tos
+	    || a->ipv6.flags != b->ipv6.flags
+	    || a->ipv6.invflags != b->ipv6.invflags)
+		return NULL;
+
+	for (i = 0; i < IFNAMSIZ; i++) {
+		if (a->ipv6.iniface_mask[i] != b->ipv6.iniface_mask[i])
+			return NULL;
+		if ((a->ipv6.iniface[i] & a->ipv6.iniface_mask[i])
+		    != (b->ipv6.iniface[i] & b->ipv6.iniface_mask[i]))
+			return NULL;
+		if (a->ipv6.outiface_mask[i] != b->ipv6.outiface_mask[i])
+			return NULL;
+		if ((a->ipv6.outiface[i] & a->ipv6.outiface_mask[i])
+		    != (b->ipv6.outiface[i] & b->ipv6.outiface_mask[i]))
+			return NULL;
+	}
+
+	if (a->target_offset != b->target_offset
+	    || a->next_offset != b->next_offset)
+		return NULL;
+
+	mptr = matchmask + sizeof(STRUCT_ENTRY);
+	if (IP6T_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
+		return NULL;
+	mptr += IP6T_ALIGN(sizeof(struct ip6t_entry_target));
+
+	return mptr;
+}
+
+/* All zeroes == unconditional rule. */
+static inline int
+unconditional(const struct ip6t_ip6 *ipv6)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(*ipv6); i++)
+		if (((char *)ipv6)[i])
+			break;
+
+	return (i == sizeof(*ipv6));
+}
+
+#ifdef IPTC_DEBUG
+/* Do every conceivable sanity check on the handle */
+static void
+do_check(TC_HANDLE_T h, unsigned int line)
+{
+	unsigned int i, n;
+	unsigned int user_offset; /* Offset of first user chain */
+	int was_return;
+
+	assert(h->changed == 0 || h->changed == 1);
+	if (strcmp(h->info.name, "filter") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP6_LOCAL_IN
+			   | 1 << NF_IP6_FORWARD
+			   | 1 << NF_IP6_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == 0);
+
+		n = get_chain_end(h, 0);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+	} else if (strcmp(h->info.name, "nat") == 0) {
+		assert((h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)) ||
+		       (h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_IN
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)));
+
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+		n = get_chain_end(h, n);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+			user_offset = h->info.hook_entry[NF_IP6_LOCAL_IN];
+		}
+
+	} else if (strcmp(h->info.name, "mangle") == 0) {
+		/* This code is getting ugly because linux < 2.4.18-pre6 had
+		 * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
+		 * */
+		assert((h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_OUT)) ||
+		       (h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_IN
+			    | 1 << NF_IP6_FORWARD
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)));
+
+		/* Hooks should be first five */
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+			n = get_chain_end(h, n);
+		}
+
+		if (h->info.valid_hooks & (1 << NF_IP6_FORWARD)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+			n = get_chain_end(h, n);
+		}
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP6_POST_ROUTING)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+			user_offset = h->info.hook_entry[NF_IP6_POST_ROUTING];
+		}
+	} else if (strcmp(h->info.name, "raw") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP6_PRE_ROUTING
+			   | 1 << NF_IP6_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+	} else {
+                fprintf(stderr, "Unknown table `%s'\n", h->info.name);
+		abort();
+	}
+
+	/* User chain == end of last builtin + policy entry */
+	user_offset = get_chain_end(h, user_offset);
+	user_offset += get_entry(h, user_offset)->next_offset;
+
+	/* Overflows should be end of entry chains, and unconditional
+           policy nodes. */
+	for (i = 0; i < NUMHOOKS; i++) {
+		STRUCT_ENTRY *e;
+		STRUCT_STANDARD_TARGET *t;
+
+		if (!(h->info.valid_hooks & (1 << i)))
+			continue;
+		assert(h->info.underflow[i]
+		       == get_chain_end(h, h->info.hook_entry[i]));
+
+		e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
+		assert(unconditional(&e->ipv6));
+		assert(e->target_offset == sizeof(*e));
+		t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+		printf("target_size=%u, align=%u\n",
+			t->target.u.target_size, ALIGN(sizeof(*t)));
+		assert(t->target.u.target_size == ALIGN(sizeof(*t)));
+		assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
+
+		assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
+		assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
+
+		/* Hooks and underflows must be valid entries */
+		iptcb_entry2index(h, get_entry(h, h->info.hook_entry[i]));
+		iptcb_entry2index(h, get_entry(h, h->info.underflow[i]));
+	}
+
+	assert(h->info.size
+	       >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
+					 +sizeof(STRUCT_STANDARD_TARGET)));
+
+	assert(h->entries.size
+	       >= (h->new_number
+		   * (sizeof(STRUCT_ENTRY)
+		      + sizeof(STRUCT_STANDARD_TARGET))));
+	assert(strcmp(h->info.name, h->entries.name) == 0);
+
+	i = 0; n = 0;
+	was_return = 0;
+
+#if 0
+	/* Check all the entries. */
+	ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
+		      check_entry, &i, &n, user_offset, &was_return, h);
+
+	assert(i == h->new_number);
+	assert(n == h->entries.size);
+
+	/* Final entry must be error node */
+	assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
+		      ->u.user.name,
+		      ERROR_TARGET) == 0);
+#endif
+}
+#endif /*IPTC_DEBUG*/
diff --git a/src/libiptc/libip6tc.h b/src/libiptc/libip6tc.h
new file mode 100644
index 0000000..103267b
--- /dev/null
+++ b/src/libiptc/libip6tc.h
@@ -0,0 +1,173 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef _LIBIP6TC_H
+#define _LIBIP6TC_H
+/* Library which manipulates firewall rules. Version 0.2. */
+
+#include <linux/types.h>
+#include "ipt_kernel_headers.h"
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+#ifndef IP6T_MIN_ALIGN
+#define IP6T_MIN_ALIGN (__alignof__(struct ip6t_entry))
+#endif
+#define IP6T_ALIGN(s) (((s) + (IP6T_MIN_ALIGN-1)) & ~(IP6T_MIN_ALIGN-1))
+
+typedef char ip6t_chainlabel[32];
+
+#define IP6TC_LABEL_ACCEPT "ACCEPT"
+#define IP6TC_LABEL_DROP "DROP"
+#define IP6TC_LABEL_QUEUE   "QUEUE"
+#define IP6TC_LABEL_RETURN "RETURN"
+
+/* Transparent handle type. */
+typedef struct ip6tc_handle *ip6tc_handle_t;
+
+/* Does this chain exist? */
+int ip6tc_is_chain(const char *chain, const ip6tc_handle_t handle);
+
+/* Take a snapshot of the rules. Returns NULL on error. */
+ip6tc_handle_t ip6tc_init(const char *tablename);
+
+/* Cleanup after ip6tc_init(). */
+void ip6tc_free(ip6tc_handle_t *h);
+
+/* Iterator functions to run through the chains.  Returns NULL at end. */
+const char *ip6tc_first_chain(ip6tc_handle_t *handle);
+const char *ip6tc_next_chain(ip6tc_handle_t *handle);
+
+/* Get first rule in the given chain: NULL for empty chain. */
+const struct ip6t_entry *ip6tc_first_rule(const char *chain,
+					  ip6tc_handle_t *handle);
+
+/* Returns NULL when rules run out. */
+const struct ip6t_entry *ip6tc_next_rule(const struct ip6t_entry *prev,
+					 ip6tc_handle_t *handle);
+
+/* Returns a pointer to the target name of this position. */
+const char *ip6tc_get_target(const struct ip6t_entry *e,
+			     ip6tc_handle_t *handle);
+
+/* Is this a built-in chain? */
+int ip6tc_builtin(const char *chain, const ip6tc_handle_t handle);
+
+/* Get the policy of a given built-in chain */
+const char *ip6tc_get_policy(const char *chain,
+			     struct ip6t_counters *counters,
+			     ip6tc_handle_t *handle);
+
+/* These functions return TRUE for OK or 0 and set errno. If errno ==
+   0, it means there was a version error (ie. upgrade libiptc). */
+/* Rule numbers start at 1 for the first rule. */
+
+/* Insert the entry `fw' in chain `chain' into position `rulenum'. */
+int ip6tc_insert_entry(const ip6t_chainlabel chain,
+		       const struct ip6t_entry *e,
+		       unsigned int rulenum,
+		       ip6tc_handle_t *handle);
+
+/* Atomically replace rule `rulenum' in `chain' with `fw'. */
+int ip6tc_replace_entry(const ip6t_chainlabel chain,
+			const struct ip6t_entry *e,
+			unsigned int rulenum,
+			ip6tc_handle_t *handle);
+
+/* Append entry `fw' to chain `chain'. Equivalent to insert with
+   rulenum = length of chain. */
+int ip6tc_append_entry(const ip6t_chainlabel chain,
+		       const struct ip6t_entry *e,
+		       ip6tc_handle_t *handle);
+
+/* Delete the first rule in `chain' which matches `fw'. */
+int ip6tc_delete_entry(const ip6t_chainlabel chain,
+		       const struct ip6t_entry *origfw,
+		       unsigned char *matchmask,
+		       ip6tc_handle_t *handle);
+
+/* Delete the rule in position `rulenum' in `chain'. */
+int ip6tc_delete_num_entry(const ip6t_chainlabel chain,
+			   unsigned int rulenum,
+			   ip6tc_handle_t *handle);
+
+/* Check the packet `fw' on chain `chain'. Returns the verdict, or
+   NULL and sets errno. */
+const char *ip6tc_check_packet(const ip6t_chainlabel chain,
+			       struct ip6t_entry *,
+			       ip6tc_handle_t *handle);
+
+/* Flushes the entries in the given chain (ie. empties chain). */
+int ip6tc_flush_entries(const ip6t_chainlabel chain,
+			ip6tc_handle_t *handle);
+
+/* Zeroes the counters in a chain. */
+int ip6tc_zero_entries(const ip6t_chainlabel chain,
+		       ip6tc_handle_t *handle);
+
+/* Creates a new chain. */
+int ip6tc_create_chain(const ip6t_chainlabel chain,
+		       ip6tc_handle_t *handle);
+
+/* Deletes a chain. */
+int ip6tc_delete_chain(const ip6t_chainlabel chain,
+		       ip6tc_handle_t *handle);
+
+/* Renames a chain. */
+int ip6tc_rename_chain(const ip6t_chainlabel oldname,
+		       const ip6t_chainlabel newname,
+		       ip6tc_handle_t *handle);
+
+/* Sets the policy on a built-in chain. */
+int ip6tc_set_policy(const ip6t_chainlabel chain,
+		     const ip6t_chainlabel policy,
+		     struct ip6t_counters *counters,
+		     ip6tc_handle_t *handle);
+
+/* Get the number of references to this chain */
+int ip6tc_get_references(unsigned int *ref, const ip6t_chainlabel chain,
+			 ip6tc_handle_t *handle);
+
+/* read packet and byte counters for a specific rule */
+struct ip6t_counters *ip6tc_read_counter(const ip6t_chainlabel chain,
+					unsigned int rulenum,
+					ip6tc_handle_t *handle);
+
+/* zero packet and byte counters for a specific rule */
+int ip6tc_zero_counter(const ip6t_chainlabel chain,
+		       unsigned int rulenum,
+		       ip6tc_handle_t *handle);
+
+/* set packet and byte counters for a specific rule */
+int ip6tc_set_counter(const ip6t_chainlabel chain,
+		      unsigned int rulenum,
+		      struct ip6t_counters *counters,
+		      ip6tc_handle_t *handle);
+
+/* Makes the actual changes. */
+int ip6tc_commit(ip6tc_handle_t *handle);
+
+/* Get raw socket. */
+int ip6tc_get_raw_socket();
+
+/* Translates errno numbers into more human-readable form than strerror. */
+const char *ip6tc_strerror(int err);
+
+/* Return prefix length, or -1 if not contiguous */
+int ipv6_prefix_length(const struct in6_addr *a);
+
+#endif /* _LIBIP6TC_H */
diff --git a/src/libiptc/libiptc.c b/src/libiptc/libiptc.c
new file mode 100644
index 0000000..f8e88b2
--- /dev/null
+++ b/src/libiptc/libiptc.c
@@ -0,0 +1,2296 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+/* Library which manipulates firewall rules.  Version $Revision: 7138 $ */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C) 1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+ * COPYING for details). 
+ * (C) 2000-2004 by the Netfilter Core Team <coreteam at netfilter.org>
+ *
+ * 2003-Jun-20: Harald Welte <laforge at netfilter.org>:
+ *	- Reimplementation of chain cache to use offsets instead of entries
+ * 2003-Jun-23: Harald Welte <laforge at netfilter.org>:
+ * 	- performance optimization, sponsored by Astaro AG (http://www.astaro.com/)
+ * 	  don't rebuild the chain cache after every operation, instead fix it
+ * 	  up after a ruleset change.  
+ * 2004-Aug-18: Harald Welte <laforge at netfilter.org>:
+ * 	- futher performance work: total reimplementation of libiptc.
+ * 	- libiptc now has a real internal (linked-list) represntation of the
+ * 	  ruleset and a parser/compiler from/to this internal representation
+ * 	- again sponsored by Astaro AG (http://www.astaro.com/)
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "linux_list.h"
+
+//#define IPTC_DEBUG2 1
+
+#ifdef IPTC_DEBUG2
+#include <fcntl.h>
+#define DEBUGP(x, args...)	fprintf(stderr, "%s: " x, __FUNCTION__, ## args)
+#define DEBUGP_C(x, args...)	fprintf(stderr, x, ## args)
+#else
+#define DEBUGP(x, args...)
+#define DEBUGP_C(x, args...)
+#endif
+
+#ifndef IPT_LIB_DIR
+#define IPT_LIB_DIR "/usr/local/lib/iptables"
+#endif
+
+static int sockfd = -1;
+static int sockfd_use = 0;
+static void *iptc_fn = NULL;
+
+static const char *hooknames[] = {
+	[HOOK_PRE_ROUTING]	= "PREROUTING",
+	[HOOK_LOCAL_IN]		= "INPUT",
+	[HOOK_FORWARD]		= "FORWARD",
+	[HOOK_LOCAL_OUT]	= "OUTPUT",
+	[HOOK_POST_ROUTING]	= "POSTROUTING",
+#ifdef HOOK_DROPPING
+	[HOOK_DROPPING]		= "DROPPING"
+#endif
+};
+
+/* Convenience structures */
+struct ipt_error_target
+{
+	STRUCT_ENTRY_TARGET t;
+	char error[TABLE_MAXNAMELEN];
+};
+
+struct chain_head;
+struct rule_head;
+
+struct counter_map
+{
+	enum {
+		COUNTER_MAP_NOMAP,
+		COUNTER_MAP_NORMAL_MAP,
+		COUNTER_MAP_ZEROED,
+		COUNTER_MAP_SET
+	} maptype;
+	unsigned int mappos;
+};
+
+enum iptcc_rule_type {
+	IPTCC_R_STANDARD,		/* standard target (ACCEPT, ...) */
+	IPTCC_R_MODULE,			/* extension module (SNAT, ...) */
+	IPTCC_R_FALLTHROUGH,		/* fallthrough rule */
+	IPTCC_R_JUMP,			/* jump to other chain */
+};
+
+struct rule_head
+{
+	struct list_head list;
+	struct chain_head *chain;
+	struct counter_map counter_map;
+
+	unsigned int index;		/* index (needed for counter_map) */
+	unsigned int offset;		/* offset in rule blob */
+
+	enum iptcc_rule_type type;
+	struct chain_head *jump;	/* jump target, if IPTCC_R_JUMP */
+
+	unsigned int size;		/* size of entry data */
+	STRUCT_ENTRY entry[0];
+};
+
+struct chain_head
+{
+	struct list_head list;
+	char name[TABLE_MAXNAMELEN];
+	unsigned int hooknum;		/* hook number+1 if builtin */
+	unsigned int references;	/* how many jumps reference us */
+	int verdict;			/* verdict if builtin */
+
+	STRUCT_COUNTERS counters;	/* per-chain counters */
+	struct counter_map counter_map;
+
+	unsigned int num_rules;		/* number of rules in list */
+	struct list_head rules;		/* list of rules */
+
+	unsigned int index;		/* index (needed for jump resolval) */
+	unsigned int head_offset;	/* offset in rule blob */
+	unsigned int foot_index;	/* index (needed for counter_map) */
+	unsigned int foot_offset;	/* offset in rule blob */
+};
+
+STRUCT_TC_HANDLE
+{
+	int changed;			 /* Have changes been made? */
+
+	struct list_head chains;
+	
+	struct chain_head *chain_iterator_cur;
+	struct rule_head *rule_iterator_cur;
+
+	STRUCT_GETINFO info;
+	STRUCT_GET_ENTRIES *entries;
+};
+
+/* allocate a new chain head for the cache */
+static struct chain_head *iptcc_alloc_chain_head(const char *name, int hooknum)
+{
+	struct chain_head *c = malloc(sizeof(*c));
+	if (!c)
+		return NULL;
+	memset(c, 0, sizeof(*c));
+
+	strncpy(c->name, name, TABLE_MAXNAMELEN);
+	c->hooknum = hooknum;
+	INIT_LIST_HEAD(&c->rules);
+
+	return c;
+}
+
+/* allocate and initialize a new rule for the cache */
+static struct rule_head *iptcc_alloc_rule(struct chain_head *c, unsigned int size)
+{
+	struct rule_head *r = malloc(sizeof(*r)+size);
+	if (!r)
+		return NULL;
+	memset(r, 0, sizeof(*r));
+
+	r->chain = c;
+	r->size = size;
+
+	return r;
+}
+
+/* notify us that the ruleset has been modified by the user */
+static void
+set_changed(TC_HANDLE_T h)
+{
+	h->changed = 1;
+}
+
+#ifdef IPTC_DEBUG
+static void do_check(TC_HANDLE_T h, unsigned int line);
+#define CHECK(h) do { if (!getenv("IPTC_NO_CHECK")) do_check((h), __LINE__); } while(0)
+#else
+#define CHECK(h)
+#endif
+
+
+/**********************************************************************
+ * iptc blob utility functions (iptcb_*)
+ **********************************************************************/
+
+static inline int
+iptcb_get_number(const STRUCT_ENTRY *i,
+	   const STRUCT_ENTRY *seek,
+	   unsigned int *pos)
+{
+	if (i == seek)
+		return 1;
+	(*pos)++;
+	return 0;
+}
+
+static inline int
+iptcb_get_entry_n(STRUCT_ENTRY *i,
+	    unsigned int number,
+	    unsigned int *pos,
+	    STRUCT_ENTRY **pe)
+{
+	if (*pos == number) {
+		*pe = i;
+		return 1;
+	}
+	(*pos)++;
+	return 0;
+}
+
+static inline STRUCT_ENTRY *
+iptcb_get_entry(TC_HANDLE_T h, unsigned int offset)
+{
+	return (STRUCT_ENTRY *)((char *)h->entries->entrytable + offset);
+}
+
+static unsigned int
+iptcb_entry2index(const TC_HANDLE_T h, const STRUCT_ENTRY *seek)
+{
+	unsigned int pos = 0;
+
+	if (ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
+			  iptcb_get_number, seek, &pos) == 0) {
+		fprintf(stderr, "ERROR: offset %u not an entry!\n",
+			(unsigned int)((char *)seek - (char *)h->entries->entrytable));
+		abort();
+	}
+	return pos;
+}
+
+static inline STRUCT_ENTRY *
+iptcb_offset2entry(TC_HANDLE_T h, unsigned int offset)
+{
+	return (STRUCT_ENTRY *) ((void *)h->entries->entrytable+offset);
+}
+
+
+static inline unsigned long
+iptcb_entry2offset(const TC_HANDLE_T h, const STRUCT_ENTRY *e)
+{
+	return (void *)e - (void *)h->entries->entrytable;
+}
+
+static inline unsigned int
+iptcb_offset2index(const TC_HANDLE_T h, unsigned int offset)
+{
+	return iptcb_entry2index(h, iptcb_offset2entry(h, offset));
+}
+
+/* Returns 0 if not hook entry, else hooknumber + 1 */
+static inline unsigned int
+iptcb_ent_is_hook_entry(STRUCT_ENTRY *e, TC_HANDLE_T h)
+{
+	unsigned int i;
+
+	for (i = 0; i < NUMHOOKS; i++) {
+		if ((h->info.valid_hooks & (1 << i))
+		    && iptcb_get_entry(h, h->info.hook_entry[i]) == e)
+			return i+1;
+	}
+	return 0;
+}
+
+
+/**********************************************************************
+ * iptc cache utility functions (iptcc_*)
+ **********************************************************************/
+
+/* Is the given chain builtin (1) or user-defined (0) */
+static unsigned int iptcc_is_builtin(struct chain_head *c)
+{
+	return (c->hooknum ? 1 : 0);
+}
+
+/* Get a specific rule within a chain */
+static struct rule_head *iptcc_get_rule_num(struct chain_head *c,
+					    unsigned int rulenum)
+{
+	struct rule_head *r;
+	unsigned int num = 0;
+
+	list_for_each_entry(r, &c->rules, list) {
+		num++;
+		if (num == rulenum)
+			return r;
+	}
+	return NULL;
+}
+
+/* Get a specific rule within a chain backwards */
+static struct rule_head *iptcc_get_rule_num_reverse(struct chain_head *c,
+					    unsigned int rulenum)
+{
+	struct rule_head *r;
+	unsigned int num = 0;
+
+	list_for_each_entry_reverse(r, &c->rules, list) {
+		num++;
+		if (num == rulenum)
+			return r;
+	}
+	return NULL;
+}
+
+/* Returns chain head if found, otherwise NULL. */
+static struct chain_head *
+iptcc_find_chain_by_offset(TC_HANDLE_T handle, unsigned int offset)
+{
+	struct list_head *pos;
+
+	if (list_empty(&handle->chains))
+		return NULL;
+
+	list_for_each(pos, &handle->chains) {
+		struct chain_head *c = list_entry(pos, struct chain_head, list);
+		if (offset >= c->head_offset && offset <= c->foot_offset)
+			return c;
+	}
+
+	return NULL;
+}
+/* Returns chain head if found, otherwise NULL. */
+static struct chain_head *
+iptcc_find_label(const char *name, TC_HANDLE_T handle)
+{
+	struct list_head *pos;
+
+	if (list_empty(&handle->chains))
+		return NULL;
+
+	list_for_each(pos, &handle->chains) {
+		struct chain_head *c = list_entry(pos, struct chain_head, list);
+		if (!strcmp(c->name, name))
+			return c;
+	}
+
+	return NULL;
+}
+
+/* called when rule is to be removed from cache */
+static void iptcc_delete_rule(struct rule_head *r)
+{
+	DEBUGP("deleting rule %p (offset %u)\n", r, r->offset);
+	/* clean up reference count of called chain */
+	if (r->type == IPTCC_R_JUMP
+	    && r->jump)
+		r->jump->references--;
+
+	list_del(&r->list);
+	free(r);
+}
+
+
+/**********************************************************************
+ * RULESET PARSER (blob -> cache)
+ **********************************************************************/
+
+/* Delete policy rule of previous chain, since cache doesn't contain
+ * chain policy rules.
+ * WARNING: This function has ugly design and relies on a lot of context, only
+ * to be called from specific places within the parser */
+static int __iptcc_p_del_policy(TC_HANDLE_T h, unsigned int num)
+{
+	if (h->chain_iterator_cur) {
+		/* policy rule is last rule */
+		struct rule_head *pr = (struct rule_head *)
+			h->chain_iterator_cur->rules.prev;
+
+		/* save verdict */
+		h->chain_iterator_cur->verdict = 
+			*(int *)GET_TARGET(pr->entry)->data;
+
+		/* save counter and counter_map information */
+		h->chain_iterator_cur->counter_map.maptype = 
+						COUNTER_MAP_NORMAL_MAP;
+		h->chain_iterator_cur->counter_map.mappos = num-1;
+		memcpy(&h->chain_iterator_cur->counters, &pr->entry->counters, 
+			sizeof(h->chain_iterator_cur->counters));
+
+		/* foot_offset points to verdict rule */
+		h->chain_iterator_cur->foot_index = num;
+		h->chain_iterator_cur->foot_offset = pr->offset;
+
+		/* delete rule from cache */
+		iptcc_delete_rule(pr);
+		h->chain_iterator_cur->num_rules--;
+
+		return 1;
+	}
+	return 0;
+}
+
+/* alphabetically insert a chain into the list */
+static inline void iptc_insert_chain(TC_HANDLE_T h, struct chain_head *c)
+{
+	struct chain_head *tmp;
+
+	/* sort only user defined chains */
+	if (!c->hooknum) {
+		list_for_each_entry(tmp, &h->chains, list) {
+			if (!tmp->hooknum && strcmp(c->name, tmp->name) <= 0) {
+				list_add(&c->list, tmp->list.prev);
+				return;
+			}
+		}
+	}
+
+	/* survived till end of list: add at tail */
+	list_add_tail(&c->list, &h->chains);
+}
+
+/* Another ugly helper function split out of cache_add_entry to make it less
+ * spaghetti code */
+static void __iptcc_p_add_chain(TC_HANDLE_T h, struct chain_head *c,
+				unsigned int offset, unsigned int *num)
+{
+	struct list_head  *tail = h->chains.prev;
+	struct chain_head *ctail;
+
+	__iptcc_p_del_policy(h, *num);
+
+	c->head_offset = offset;
+	c->index = *num;
+
+	/* Chains from kernel are already sorted, as they are inserted
+	 * sorted. But there exists an issue when shifting to 1.4.0
+	 * from an older version, as old versions allow last created
+	 * chain to be unsorted.
+	 */
+	if (iptcc_is_builtin(c)) /* Only user defined chains are sorted*/
+		list_add_tail(&c->list, &h->chains);
+	else {
+		ctail = list_entry(tail, struct chain_head, list);
+		if (strcmp(c->name, ctail->name) > 0)
+			list_add_tail(&c->list, &h->chains);/* Already sorted*/
+		else
+			iptc_insert_chain(h, c);/* Was not sorted */
+	}
+
+	h->chain_iterator_cur = c;
+}
+
+/* main parser function: add an entry from the blob to the cache */
+static int cache_add_entry(STRUCT_ENTRY *e, 
+			   TC_HANDLE_T h, 
+			   STRUCT_ENTRY **prev,
+			   unsigned int *num)
+{
+	unsigned int builtin;
+	unsigned int offset = (char *)e - (char *)h->entries->entrytable;
+
+	DEBUGP("entering...");
+
+	/* Last entry ("policy rule"). End it.*/
+	if (iptcb_entry2offset(h,e) + e->next_offset == h->entries->size) {
+		/* This is the ERROR node at the end of the chain */
+		DEBUGP_C("%u:%u: end of table:\n", *num, offset);
+
+		__iptcc_p_del_policy(h, *num);
+
+		h->chain_iterator_cur = NULL;
+		goto out_inc;
+	}
+
+	/* We know this is the start of a new chain if it's an ERROR
+	 * target, or a hook entry point */
+
+	if (strcmp(GET_TARGET(e)->u.user.name, ERROR_TARGET) == 0) {
+		struct chain_head *c = 
+			iptcc_alloc_chain_head((const char *)GET_TARGET(e)->data, 0);
+		DEBUGP_C("%u:%u:new userdefined chain %s: %p\n", *num, offset, 
+			(char *)c->name, c);
+		if (!c) {
+			errno = -ENOMEM;
+			return -1;
+		}
+
+		__iptcc_p_add_chain(h, c, offset, num);
+
+	} else if ((builtin = iptcb_ent_is_hook_entry(e, h)) != 0) {
+		struct chain_head *c =
+			iptcc_alloc_chain_head((char *)hooknames[builtin-1], 
+						builtin);
+		DEBUGP_C("%u:%u new builtin chain: %p (rules=%p)\n", 
+			*num, offset, c, &c->rules);
+		if (!c) {
+			errno = -ENOMEM;
+			return -1;
+		}
+
+		c->hooknum = builtin;
+
+		__iptcc_p_add_chain(h, c, offset, num);
+
+		/* FIXME: this is ugly. */
+		goto new_rule;
+	} else {
+		/* has to be normal rule */
+		struct rule_head *r;
+new_rule:
+
+		if (!(r = iptcc_alloc_rule(h->chain_iterator_cur, 
+					   e->next_offset))) {
+			errno = ENOMEM;
+			return -1;
+		}
+		DEBUGP_C("%u:%u normal rule: %p: ", *num, offset, r);
+
+		r->index = *num;
+		r->offset = offset;
+		memcpy(r->entry, e, e->next_offset);
+		r->counter_map.maptype = COUNTER_MAP_NORMAL_MAP;
+		r->counter_map.mappos = r->index;
+
+		/* handling of jumps, etc. */
+		if (!strcmp(GET_TARGET(e)->u.user.name, STANDARD_TARGET)) {
+			STRUCT_STANDARD_TARGET *t;
+
+			t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+			if (t->target.u.target_size
+			    != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
+				errno = EINVAL;
+				return -1;
+			}
+
+			if (t->verdict < 0) {
+				DEBUGP_C("standard, verdict=%d\n", t->verdict);
+				r->type = IPTCC_R_STANDARD;
+			} else if (t->verdict == r->offset+e->next_offset) {
+				DEBUGP_C("fallthrough\n");
+				r->type = IPTCC_R_FALLTHROUGH;
+			} else {
+				DEBUGP_C("jump, target=%u\n", t->verdict);
+				r->type = IPTCC_R_JUMP;
+				/* Jump target fixup has to be deferred
+				 * until second pass, since we migh not
+				 * yet have parsed the target */
+			}
+		} else {
+			DEBUGP_C("module, target=%s\n", GET_TARGET(e)->u.user.name);
+			r->type = IPTCC_R_MODULE;
+		}
+
+		list_add_tail(&r->list, &h->chain_iterator_cur->rules);
+		h->chain_iterator_cur->num_rules++;
+	}
+out_inc:
+	(*num)++;
+	return 0;
+}
+
+
+/* parse an iptables blob into it's pieces */
+static int parse_table(TC_HANDLE_T h)
+{
+	STRUCT_ENTRY *prev;
+	unsigned int num = 0;
+	struct chain_head *c;
+
+	/* First pass: over ruleset blob */
+	ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
+			cache_add_entry, h, &prev, &num);
+
+	/* Second pass: fixup parsed data from first pass */
+	list_for_each_entry(c, &h->chains, list) {
+		struct rule_head *r;
+		list_for_each_entry(r, &c->rules, list) {
+			struct chain_head *c;
+			STRUCT_STANDARD_TARGET *t;
+
+			if (r->type != IPTCC_R_JUMP)
+				continue;
+
+			t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+			c = iptcc_find_chain_by_offset(h, t->verdict);
+			if (!c)
+				return -1;
+			r->jump = c;
+			c->references++;
+		}
+	}
+
+	/* FIXME: sort chains */
+
+	return 1;
+}
+
+
+/**********************************************************************
+ * RULESET COMPILATION (cache -> blob)
+ **********************************************************************/
+
+/* Convenience structures */
+struct iptcb_chain_start{
+	STRUCT_ENTRY e;
+	struct ipt_error_target name;
+};
+#define IPTCB_CHAIN_START_SIZE	(sizeof(STRUCT_ENTRY) +			\
+				 ALIGN(sizeof(struct ipt_error_target)))
+
+struct iptcb_chain_foot {
+	STRUCT_ENTRY e;
+	STRUCT_STANDARD_TARGET target;
+};
+#define IPTCB_CHAIN_FOOT_SIZE	(sizeof(STRUCT_ENTRY) +			\
+				 ALIGN(sizeof(STRUCT_STANDARD_TARGET)))
+
+struct iptcb_chain_error {
+	STRUCT_ENTRY entry;
+	struct ipt_error_target target;
+};
+#define IPTCB_CHAIN_ERROR_SIZE	(sizeof(STRUCT_ENTRY) +			\
+				 ALIGN(sizeof(struct ipt_error_target)))
+
+
+
+/* compile rule from cache into blob */
+static inline int iptcc_compile_rule (TC_HANDLE_T h, STRUCT_REPLACE *repl, struct rule_head *r)
+{
+	/* handle jumps */
+	if (r->type == IPTCC_R_JUMP) {
+		STRUCT_STANDARD_TARGET *t;
+		t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+		/* memset for memcmp convenience on delete/replace */
+		memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
+		strcpy(t->target.u.user.name, STANDARD_TARGET);
+		/* Jumps can only happen to builtin chains, so we
+		 * can safely assume that they always have a header */
+		t->verdict = r->jump->head_offset + IPTCB_CHAIN_START_SIZE;
+	} else if (r->type == IPTCC_R_FALLTHROUGH) {
+		STRUCT_STANDARD_TARGET *t;
+		t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+		t->verdict = r->offset + r->size;
+	}
+	
+	/* copy entry from cache to blob */
+	memcpy((char *)repl->entries+r->offset, r->entry, r->size);
+
+	return 1;
+}
+
+/* compile chain from cache into blob */
+static int iptcc_compile_chain(TC_HANDLE_T h, STRUCT_REPLACE *repl, struct chain_head *c)
+{
+	int ret;
+	struct rule_head *r;
+	struct iptcb_chain_start *head;
+	struct iptcb_chain_foot *foot;
+
+	/* only user-defined chains have heaer */
+	if (!iptcc_is_builtin(c)) {
+		/* put chain header in place */
+		head = (void *)repl->entries + c->head_offset;
+		head->e.target_offset = sizeof(STRUCT_ENTRY);
+		head->e.next_offset = IPTCB_CHAIN_START_SIZE;
+		strcpy(head->name.t.u.user.name, ERROR_TARGET);
+		head->name.t.u.target_size = 
+				ALIGN(sizeof(struct ipt_error_target));
+		strcpy(head->name.error, c->name);
+	} else {
+		repl->hook_entry[c->hooknum-1] = c->head_offset;	
+		repl->underflow[c->hooknum-1] = c->foot_offset;
+	}
+
+	/* iterate over rules */
+	list_for_each_entry(r, &c->rules, list) {
+		ret = iptcc_compile_rule(h, repl, r);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* put chain footer in place */
+	foot = (void *)repl->entries + c->foot_offset;
+	foot->e.target_offset = sizeof(STRUCT_ENTRY);
+	foot->e.next_offset = IPTCB_CHAIN_FOOT_SIZE;
+	strcpy(foot->target.target.u.user.name, STANDARD_TARGET);
+	foot->target.target.u.target_size =
+				ALIGN(sizeof(STRUCT_STANDARD_TARGET));
+	/* builtin targets have verdict, others return */
+	if (iptcc_is_builtin(c))
+		foot->target.verdict = c->verdict;
+	else
+		foot->target.verdict = RETURN;
+	/* set policy-counters */
+	memcpy(&foot->e.counters, &c->counters, sizeof(STRUCT_COUNTERS));
+
+	return 0;
+}
+
+/* calculate offset and number for every rule in the cache */
+static int iptcc_compile_chain_offsets(TC_HANDLE_T h, struct chain_head *c,
+				       unsigned int *offset, unsigned int *num)
+{
+	struct rule_head *r;
+
+	c->head_offset = *offset;
+	DEBUGP("%s: chain_head %u, offset=%u\n", c->name, *num, *offset);
+
+	if (!iptcc_is_builtin(c))  {
+		/* Chain has header */
+		*offset += sizeof(STRUCT_ENTRY) 
+			     + ALIGN(sizeof(struct ipt_error_target));
+		(*num)++;
+	}
+
+	list_for_each_entry(r, &c->rules, list) {
+		DEBUGP("rule %u, offset=%u, index=%u\n", *num, *offset, *num);
+		r->offset = *offset;
+		r->index = *num;
+		*offset += r->size;
+		(*num)++;
+	}
+
+	DEBUGP("%s; chain_foot %u, offset=%u, index=%u\n", c->name, *num, 
+		*offset, *num);
+	c->foot_offset = *offset;
+	c->foot_index = *num;
+	*offset += sizeof(STRUCT_ENTRY)
+		   + ALIGN(sizeof(STRUCT_STANDARD_TARGET));
+	(*num)++;
+
+	return 1;
+}
+
+/* put the pieces back together again */
+static int iptcc_compile_table_prep(TC_HANDLE_T h, unsigned int *size)
+{
+	struct chain_head *c;
+	unsigned int offset = 0, num = 0;
+	int ret = 0;
+
+	/* First pass: calculate offset for every rule */
+	list_for_each_entry(c, &h->chains, list) {
+		ret = iptcc_compile_chain_offsets(h, c, &offset, &num);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Append one error rule at end of chain */
+	num++;
+	offset += sizeof(STRUCT_ENTRY)
+		  + ALIGN(sizeof(struct ipt_error_target));
+
+	/* ruleset size is now in offset */
+	*size = offset;
+	return num;
+}
+
+static int iptcc_compile_table(TC_HANDLE_T h, STRUCT_REPLACE *repl)
+{
+	struct chain_head *c;
+	struct iptcb_chain_error *error;
+
+	/* Second pass: copy from cache to offsets, fill in jumps */
+	list_for_each_entry(c, &h->chains, list) {
+		int ret = iptcc_compile_chain(h, repl, c);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Append error rule at end of chain */
+	error = (void *)repl->entries + repl->size - IPTCB_CHAIN_ERROR_SIZE;
+	error->entry.target_offset = sizeof(STRUCT_ENTRY);
+	error->entry.next_offset = IPTCB_CHAIN_ERROR_SIZE;
+	error->target.t.u.user.target_size = 
+		ALIGN(sizeof(struct ipt_error_target));
+	strcpy((char *)&error->target.t.u.user.name, ERROR_TARGET);
+	strcpy((char *)&error->target.error, "ERROR");
+
+	return 1;
+}
+
+/**********************************************************************
+ * EXTERNAL API (operates on cache only)
+ **********************************************************************/
+
+/* Allocate handle of given size */
+static TC_HANDLE_T
+alloc_handle(const char *tablename, unsigned int size, unsigned int num_rules)
+{
+	size_t len;
+	TC_HANDLE_T h;
+
+	len = sizeof(STRUCT_TC_HANDLE) + size;
+
+	h = malloc(sizeof(STRUCT_TC_HANDLE));
+	if (!h) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	memset(h, 0, sizeof(*h));
+	INIT_LIST_HEAD(&h->chains);
+	strcpy(h->info.name, tablename);
+
+	h->entries = malloc(sizeof(STRUCT_GET_ENTRIES) + size);
+	if (!h->entries)
+		goto out_free_handle;
+
+	strcpy(h->entries->name, tablename);
+	h->entries->size = size;
+
+	return h;
+
+out_free_handle:
+	free(h);
+
+	return NULL;
+}
+
+
+TC_HANDLE_T
+TC_INIT(const char *tablename)
+{
+	TC_HANDLE_T h;
+	STRUCT_GETINFO info;
+	unsigned int tmp;
+	socklen_t s;
+
+	iptc_fn = TC_INIT;
+
+	if (strlen(tablename) >= TABLE_MAXNAMELEN) {
+		errno = EINVAL;
+		return NULL;
+	}
+	
+	if (sockfd_use == 0) {
+		sockfd = socket(TC_AF, SOCK_RAW, IPPROTO_RAW);
+		if (sockfd < 0)
+			return NULL;
+	}
+	sockfd_use++;
+
+	s = sizeof(info);
+
+	strcpy(info.name, tablename);
+	if (getsockopt(sockfd, TC_IPPROTO, SO_GET_INFO, &info, &s) < 0) {
+		if (--sockfd_use == 0) {
+			close(sockfd);
+			sockfd = -1;
+		}
+		return NULL;
+	}
+
+	DEBUGP("valid_hooks=0x%08x, num_entries=%u, size=%u\n",
+		info.valid_hooks, info.num_entries, info.size);
+
+	if ((h = alloc_handle(info.name, info.size, info.num_entries))
+	    == NULL) {
+		if (--sockfd_use == 0) {
+			close(sockfd);
+			sockfd = -1;
+		}
+		return NULL;
+	}
+
+	/* Initialize current state */
+	h->info = info;
+
+	h->entries->size = h->info.size;
+
+	tmp = sizeof(STRUCT_GET_ENTRIES) + h->info.size;
+
+	if (getsockopt(sockfd, TC_IPPROTO, SO_GET_ENTRIES, h->entries,
+		       &tmp) < 0)
+		goto error;
+
+#ifdef IPTC_DEBUG2
+	{
+		int fd = open("/tmp/libiptc-so_get_entries.blob", 
+				O_CREAT|O_WRONLY);
+		if (fd >= 0) {
+			write(fd, h->entries, tmp);
+			close(fd);
+		}
+	}
+#endif
+
+	if (parse_table(h) < 0)
+		goto error;
+
+	CHECK(h);
+	return h;
+error:
+	TC_FREE(&h);
+	return NULL;
+}
+
+void
+TC_FREE(TC_HANDLE_T *h)
+{
+	struct chain_head *c, *tmp;
+
+	iptc_fn = TC_FREE;
+	if (--sockfd_use == 0) {
+		close(sockfd);
+		sockfd = -1;
+	}
+
+	list_for_each_entry_safe(c, tmp, &(*h)->chains, list) {
+		struct rule_head *r, *rtmp;
+
+		list_for_each_entry_safe(r, rtmp, &c->rules, list) {
+			free(r);
+		}
+
+		free(c);
+	}
+
+	free((*h)->entries);
+	free(*h);
+
+	*h = NULL;
+}
+
+static inline int
+print_match(const STRUCT_ENTRY_MATCH *m)
+{
+	printf("Match name: `%s'\n", m->u.user.name);
+	return 0;
+}
+
+static int dump_entry(STRUCT_ENTRY *e, const TC_HANDLE_T handle);
+ 
+void
+TC_DUMP_ENTRIES(const TC_HANDLE_T handle)
+{
+	iptc_fn = TC_DUMP_ENTRIES;
+	CHECK(handle);
+
+	printf("libiptc v%s. %u bytes.\n",
+	       IPTABLES_VERSION, handle->entries->size);
+	printf("Table `%s'\n", handle->info.name);
+	printf("Hooks: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
+	       handle->info.hook_entry[HOOK_PRE_ROUTING],
+	       handle->info.hook_entry[HOOK_LOCAL_IN],
+	       handle->info.hook_entry[HOOK_FORWARD],
+	       handle->info.hook_entry[HOOK_LOCAL_OUT],
+	       handle->info.hook_entry[HOOK_POST_ROUTING]);
+	printf("Underflows: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
+	       handle->info.underflow[HOOK_PRE_ROUTING],
+	       handle->info.underflow[HOOK_LOCAL_IN],
+	       handle->info.underflow[HOOK_FORWARD],
+	       handle->info.underflow[HOOK_LOCAL_OUT],
+	       handle->info.underflow[HOOK_POST_ROUTING]);
+
+	ENTRY_ITERATE(handle->entries->entrytable, handle->entries->size,
+		      dump_entry, handle);
+}
+
+/* Does this chain exist? */
+int TC_IS_CHAIN(const char *chain, const TC_HANDLE_T handle)
+{
+	iptc_fn = TC_IS_CHAIN;
+	return iptcc_find_label(chain, handle) != NULL;
+}
+
+static void iptcc_chain_iterator_advance(TC_HANDLE_T handle)
+{
+	struct chain_head *c = handle->chain_iterator_cur;
+
+	if (c->list.next == &handle->chains)
+		handle->chain_iterator_cur = NULL;
+	else
+		handle->chain_iterator_cur = 
+			list_entry(c->list.next, struct chain_head, list);
+}
+
+/* Iterator functions to run through the chains. */
+const char *
+TC_FIRST_CHAIN(TC_HANDLE_T *handle)
+{
+	struct chain_head *c = list_entry((*handle)->chains.next,
+					  struct chain_head, list);
+
+	iptc_fn = TC_FIRST_CHAIN;
+
+
+	if (list_empty(&(*handle)->chains)) {
+		DEBUGP(": no chains\n");
+		return NULL;
+	}
+
+	(*handle)->chain_iterator_cur = c;
+	iptcc_chain_iterator_advance(*handle);
+
+	DEBUGP(": returning `%s'\n", c->name);
+	return c->name;
+}
+
+/* Iterator functions to run through the chains.  Returns NULL at end. */
+const char *
+TC_NEXT_CHAIN(TC_HANDLE_T *handle)
+{
+	struct chain_head *c = (*handle)->chain_iterator_cur;
+
+	iptc_fn = TC_NEXT_CHAIN;
+
+	if (!c) {
+		DEBUGP(": no more chains\n");
+		return NULL;
+	}
+
+	iptcc_chain_iterator_advance(*handle);
+	
+	DEBUGP(": returning `%s'\n", c->name);
+	return c->name;
+}
+
+/* Get first rule in the given chain: NULL for empty chain. */
+const STRUCT_ENTRY *
+TC_FIRST_RULE(const char *chain, TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+
+	iptc_fn = TC_FIRST_RULE;
+
+	DEBUGP("first rule(%s): ", chain);
+
+	c = iptcc_find_label(chain, *handle);
+	if (!c) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	/* Empty chain: single return/policy rule */
+	if (list_empty(&c->rules)) {
+		DEBUGP_C("no rules, returning NULL\n");
+		return NULL;
+	}
+
+	r = list_entry(c->rules.next, struct rule_head, list);
+	(*handle)->rule_iterator_cur = r;
+	DEBUGP_C("%p\n", r);
+
+	return r->entry;
+}
+
+/* Returns NULL when rules run out. */
+const STRUCT_ENTRY *
+TC_NEXT_RULE(const STRUCT_ENTRY *prev, TC_HANDLE_T *handle)
+{
+	struct rule_head *r;
+
+	iptc_fn = TC_NEXT_RULE;
+	DEBUGP("rule_iterator_cur=%p...", (*handle)->rule_iterator_cur);
+
+	if (!(*handle)->rule_iterator_cur) {
+		DEBUGP_C("returning NULL\n");
+		return NULL;
+	}
+	
+	r = list_entry((*handle)->rule_iterator_cur->list.next, 
+			struct rule_head, list);
+
+	iptc_fn = TC_NEXT_RULE;
+
+	DEBUGP_C("next=%p, head=%p...", &r->list, 
+		&(*handle)->rule_iterator_cur->chain->rules);
+
+	if (&r->list == &(*handle)->rule_iterator_cur->chain->rules) {
+		(*handle)->rule_iterator_cur = NULL;
+		DEBUGP_C("finished, returning NULL\n");
+		return NULL;
+	}
+
+	(*handle)->rule_iterator_cur = r;
+
+	/* NOTE: prev is without any influence ! */
+	DEBUGP_C("returning rule %p\n", r);
+	return r->entry;
+}
+
+/* How many rules in this chain? */
+unsigned int
+TC_NUM_RULES(const char *chain, TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	iptc_fn = TC_NUM_RULES;
+	CHECK(*handle);
+
+	c = iptcc_find_label(chain, *handle);
+	if (!c) {
+		errno = ENOENT;
+		return (unsigned int)-1;
+	}
+	
+	return c->num_rules;
+}
+
+const STRUCT_ENTRY *TC_GET_RULE(const char *chain,
+				unsigned int n,
+				TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+	
+	iptc_fn = TC_GET_RULE;
+
+	CHECK(*handle);
+
+	c = iptcc_find_label(chain, *handle);
+	if (!c) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	r = iptcc_get_rule_num(c, n);
+	if (!r)
+		return NULL;
+	return r->entry;
+}
+
+/* Returns a pointer to the target name of this position. */
+static const char *standard_target_map(int verdict)
+{
+	switch (verdict) {
+		case RETURN:
+			return LABEL_RETURN;
+			break;
+		case -NF_ACCEPT-1:
+			return LABEL_ACCEPT;
+			break;
+		case -NF_DROP-1:
+			return LABEL_DROP;
+			break;
+		case -NF_QUEUE-1:
+			return LABEL_QUEUE;
+			break;
+		default:
+			fprintf(stderr, "ERROR: %d not a valid target)\n",
+				verdict);
+			abort();
+			break;
+	}
+	/* not reached */
+	return NULL;
+}
+
+/* Returns a pointer to the target name of this position. */
+const char *TC_GET_TARGET(const STRUCT_ENTRY *ce,
+			  TC_HANDLE_T *handle)
+{
+	STRUCT_ENTRY *e = (STRUCT_ENTRY *)ce;
+	struct rule_head *r = container_of(e, struct rule_head, entry[0]);
+
+	iptc_fn = TC_GET_TARGET;
+
+	switch(r->type) {
+		int spos;
+		case IPTCC_R_FALLTHROUGH:
+			return "";
+			break;
+		case IPTCC_R_JUMP:
+			DEBUGP("r=%p, jump=%p, name=`%s'\n", r, r->jump, r->jump->name);
+			return r->jump->name;
+			break;
+		case IPTCC_R_STANDARD:
+			spos = *(int *)GET_TARGET(e)->data;
+			DEBUGP("r=%p, spos=%d'\n", r, spos);
+			return standard_target_map(spos);
+			break;
+		case IPTCC_R_MODULE:
+			return GET_TARGET(e)->u.user.name;
+			break;
+	}
+	return NULL;
+}
+/* Is this a built-in chain?  Actually returns hook + 1. */
+int
+TC_BUILTIN(const char *chain, const TC_HANDLE_T handle)
+{
+	struct chain_head *c;
+	
+	iptc_fn = TC_BUILTIN;
+
+	c = iptcc_find_label(chain, handle);
+	if (!c) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	return iptcc_is_builtin(c);
+}
+
+/* Get the policy of a given built-in chain */
+const char *
+TC_GET_POLICY(const char *chain,
+	      STRUCT_COUNTERS *counters,
+	      TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+
+	iptc_fn = TC_GET_POLICY;
+
+	DEBUGP("called for chain %s\n", chain);
+
+	c = iptcc_find_label(chain, *handle);
+	if (!c) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	if (!iptcc_is_builtin(c))
+		return NULL;
+
+	*counters = c->counters;
+
+	return standard_target_map(c->verdict);
+}
+
+static int
+iptcc_standard_map(struct rule_head *r, int verdict)
+{
+	STRUCT_ENTRY *e = r->entry;
+	STRUCT_STANDARD_TARGET *t;
+
+	t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+
+	if (t->target.u.target_size
+	    != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
+		errno = EINVAL;
+		return 0;
+	}
+	/* memset for memcmp convenience on delete/replace */
+	memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
+	strcpy(t->target.u.user.name, STANDARD_TARGET);
+	t->verdict = verdict;
+
+	r->type = IPTCC_R_STANDARD;
+
+	return 1;
+}
+
+static int
+iptcc_map_target(const TC_HANDLE_T handle,
+	   struct rule_head *r)
+{
+	STRUCT_ENTRY *e = r->entry;
+	STRUCT_ENTRY_TARGET *t = GET_TARGET(e);
+
+	/* Maybe it's empty (=> fall through) */
+	if (strcmp(t->u.user.name, "") == 0) {
+		r->type = IPTCC_R_FALLTHROUGH;
+		return 1;
+	}
+	/* Maybe it's a standard target name... */
+	else if (strcmp(t->u.user.name, LABEL_ACCEPT) == 0)
+		return iptcc_standard_map(r, -NF_ACCEPT - 1);
+	else if (strcmp(t->u.user.name, LABEL_DROP) == 0)
+		return iptcc_standard_map(r, -NF_DROP - 1);
+	else if (strcmp(t->u.user.name, LABEL_QUEUE) == 0)
+		return iptcc_standard_map(r, -NF_QUEUE - 1);
+	else if (strcmp(t->u.user.name, LABEL_RETURN) == 0)
+		return iptcc_standard_map(r, RETURN);
+	else if (TC_BUILTIN(t->u.user.name, handle)) {
+		/* Can't jump to builtins. */
+		errno = EINVAL;
+		return 0;
+	} else {
+		/* Maybe it's an existing chain name. */
+		struct chain_head *c;
+		DEBUGP("trying to find chain `%s': ", t->u.user.name);
+
+		c = iptcc_find_label(t->u.user.name, handle);
+		if (c) {
+			DEBUGP_C("found!\n");
+			r->type = IPTCC_R_JUMP;
+			r->jump = c;
+			c->references++;
+			return 1;
+		}
+		DEBUGP_C("not found :(\n");
+	}
+
+	/* Must be a module?  If not, kernel will reject... */
+	/* memset to all 0 for your memcmp convenience: don't clear version */
+	memset(t->u.user.name + strlen(t->u.user.name),
+	       0,
+	       FUNCTION_MAXNAMELEN - 1 - strlen(t->u.user.name));
+	r->type = IPTCC_R_MODULE;
+	set_changed(handle);
+	return 1;
+}
+
+/* Insert the entry `fw' in chain `chain' into position `rulenum'. */
+int
+TC_INSERT_ENTRY(const IPT_CHAINLABEL chain,
+		const STRUCT_ENTRY *e,
+		unsigned int rulenum,
+		TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+	struct list_head *prev;
+
+	iptc_fn = TC_INSERT_ENTRY;
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	/* first rulenum index = 0
+	   first c->num_rules index = 1 */
+	if (rulenum > c->num_rules) {
+		errno = E2BIG;
+		return 0;
+	}
+
+	/* If we are inserting at the end just take advantage of the
+	   double linked list, insert will happen before the entry
+	   prev points to. */
+	if (rulenum == c->num_rules) {
+		prev = &c->rules;
+	} else if (rulenum + 1 <= c->num_rules/2) {
+		r = iptcc_get_rule_num(c, rulenum + 1);
+		prev = &r->list;
+	} else {
+		r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+		prev = &r->list;
+	}
+
+	if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+		errno = ENOMEM;
+		return 0;
+	}
+
+	memcpy(r->entry, e, e->next_offset);
+	r->counter_map.maptype = COUNTER_MAP_SET;
+
+	if (!iptcc_map_target(*handle, r)) {
+		free(r);
+		return 0;
+	}
+
+	list_add_tail(&r->list, prev);
+	c->num_rules++;
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Atomically replace rule `rulenum' in `chain' with `fw'. */
+int
+TC_REPLACE_ENTRY(const IPT_CHAINLABEL chain,
+		 const STRUCT_ENTRY *e,
+		 unsigned int rulenum,
+		 TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r, *old;
+
+	iptc_fn = TC_REPLACE_ENTRY;
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (rulenum >= c->num_rules) {
+		errno = E2BIG;
+		return 0;
+	}
+
+	/* Take advantage of the double linked list if possible. */
+	if (rulenum + 1 <= c->num_rules/2) {
+		old = iptcc_get_rule_num(c, rulenum + 1);
+	} else {
+		old = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+	}
+
+	if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+		errno = ENOMEM;
+		return 0;
+	}
+
+	memcpy(r->entry, e, e->next_offset);
+	r->counter_map.maptype = COUNTER_MAP_SET;
+
+	if (!iptcc_map_target(*handle, r)) {
+		free(r);
+		return 0;
+	}
+
+	list_add(&r->list, &old->list);
+	iptcc_delete_rule(old);
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Append entry `fw' to chain `chain'.  Equivalent to insert with
+   rulenum = length of chain. */
+int
+TC_APPEND_ENTRY(const IPT_CHAINLABEL chain,
+		const STRUCT_ENTRY *e,
+		TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+
+	iptc_fn = TC_APPEND_ENTRY;
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		DEBUGP("unable to find chain `%s'\n", chain);
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+		DEBUGP("unable to allocate rule for chain `%s'\n", chain);
+		errno = ENOMEM;
+		return 0;
+	}
+
+	memcpy(r->entry, e, e->next_offset);
+	r->counter_map.maptype = COUNTER_MAP_SET;
+
+	if (!iptcc_map_target(*handle, r)) {
+		DEBUGP("unable to map target of rule for chain `%s'\n", chain);
+		free(r);
+		return 0;
+	}
+
+	list_add_tail(&r->list, &c->rules);
+	c->num_rules++;
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+static inline int
+match_different(const STRUCT_ENTRY_MATCH *a,
+		const unsigned char *a_elems,
+		const unsigned char *b_elems,
+		unsigned char **maskptr)
+{
+	const STRUCT_ENTRY_MATCH *b;
+	unsigned int i;
+
+	/* Offset of b is the same as a. */
+	b = (void *)b_elems + ((unsigned char *)a - a_elems);
+
+	if (a->u.match_size != b->u.match_size)
+		return 1;
+
+	if (strcmp(a->u.user.name, b->u.user.name) != 0)
+		return 1;
+
+	*maskptr += ALIGN(sizeof(*a));
+
+	for (i = 0; i < a->u.match_size - ALIGN(sizeof(*a)); i++)
+		if (((a->data[i] ^ b->data[i]) & (*maskptr)[i]) != 0)
+			return 1;
+	*maskptr += i;
+	return 0;
+}
+
+static inline int
+target_same(struct rule_head *a, struct rule_head *b,const unsigned char *mask)
+{
+	unsigned int i;
+	STRUCT_ENTRY_TARGET *ta, *tb;
+
+	if (a->type != b->type)
+		return 0;
+
+	ta = GET_TARGET(a->entry);
+	tb = GET_TARGET(b->entry);
+
+	switch (a->type) {
+	case IPTCC_R_FALLTHROUGH:
+		return 1;
+	case IPTCC_R_JUMP:
+		return a->jump == b->jump;
+	case IPTCC_R_STANDARD:
+		return ((STRUCT_STANDARD_TARGET *)ta)->verdict
+			== ((STRUCT_STANDARD_TARGET *)tb)->verdict;
+	case IPTCC_R_MODULE:
+		if (ta->u.target_size != tb->u.target_size)
+			return 0;
+		if (strcmp(ta->u.user.name, tb->u.user.name) != 0)
+			return 0;
+
+		for (i = 0; i < ta->u.target_size - sizeof(*ta); i++)
+			if (((ta->data[i] ^ tb->data[i]) & mask[i]) != 0)
+				return 0;
+		return 1;
+	default:
+		fprintf(stderr, "ERROR: bad type %i\n", a->type);
+		abort();
+	}
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a,
+	const STRUCT_ENTRY *b,
+	unsigned char *matchmask);
+
+/* Delete the first rule in `chain' which matches `fw'. */
+int
+TC_DELETE_ENTRY(const IPT_CHAINLABEL chain,
+		const STRUCT_ENTRY *origfw,
+		unsigned char *matchmask,
+		TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r, *i;
+
+	iptc_fn = TC_DELETE_ENTRY;
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	/* Create a rule_head from origfw. */
+	r = iptcc_alloc_rule(c, origfw->next_offset);
+	if (!r) {
+		errno = ENOMEM;
+		return 0;
+	}
+
+	memcpy(r->entry, origfw, origfw->next_offset);
+	r->counter_map.maptype = COUNTER_MAP_NOMAP;
+	if (!iptcc_map_target(*handle, r)) {
+		DEBUGP("unable to map target of rule for chain `%s'\n", chain);
+		free(r);
+		return 0;
+	} else {
+		/* iptcc_map_target increment target chain references
+		 * since this is a fake rule only used for matching
+		 * the chain references count is decremented again. 
+		 */
+		if (r->type == IPTCC_R_JUMP
+		    && r->jump)
+			r->jump->references--;
+	}
+
+	list_for_each_entry(i, &c->rules, list) {
+		unsigned char *mask;
+
+		mask = is_same(r->entry, i->entry, matchmask);
+		if (!mask)
+			continue;
+
+		if (!target_same(r, i, mask))
+			continue;
+
+		/* If we are about to delete the rule that is the
+		 * current iterator, move rule iterator back.  next
+		 * pointer will then point to real next node */
+		if (i == (*handle)->rule_iterator_cur) {
+			(*handle)->rule_iterator_cur = 
+				list_entry((*handle)->rule_iterator_cur->list.prev,
+					   struct rule_head, list);
+		}
+
+		c->num_rules--;
+		iptcc_delete_rule(i);
+
+		set_changed(*handle);
+		free(r);
+		return 1;
+	}
+
+	free(r);
+	errno = ENOENT;
+	return 0;
+}
+
+
+/* Delete the rule in position `rulenum' in `chain'. */
+int
+TC_DELETE_NUM_ENTRY(const IPT_CHAINLABEL chain,
+		    unsigned int rulenum,
+		    TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+
+	iptc_fn = TC_DELETE_NUM_ENTRY;
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (rulenum >= c->num_rules) {
+		errno = E2BIG;
+		return 0;
+	}
+
+	/* Take advantage of the double linked list if possible. */
+	if (rulenum + 1 <= c->num_rules/2) {
+		r = iptcc_get_rule_num(c, rulenum + 1);
+	} else {
+		r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+	}
+
+	/* If we are about to delete the rule that is the current
+	 * iterator, move rule iterator back.  next pointer will then
+	 * point to real next node */
+	if (r == (*handle)->rule_iterator_cur) {
+		(*handle)->rule_iterator_cur = 
+			list_entry((*handle)->rule_iterator_cur->list.prev,
+				   struct rule_head, list);
+	}
+
+	c->num_rules--;
+	iptcc_delete_rule(r);
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Check the packet `fw' on chain `chain'.  Returns the verdict, or
+   NULL and sets errno. */
+const char *
+TC_CHECK_PACKET(const IPT_CHAINLABEL chain,
+		STRUCT_ENTRY *entry,
+		TC_HANDLE_T *handle)
+{
+	iptc_fn = TC_CHECK_PACKET;
+	errno = ENOSYS;
+	return NULL;
+}
+
+/* Flushes the entries in the given chain (ie. empties chain). */
+int
+TC_FLUSH_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r, *tmp;
+
+	iptc_fn = TC_FLUSH_ENTRIES;
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	list_for_each_entry_safe(r, tmp, &c->rules, list) {
+		iptcc_delete_rule(r);
+	}
+
+	c->num_rules = 0;
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Zeroes the counters in a chain. */
+int
+TC_ZERO_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+
+	iptc_fn = TC_ZERO_ENTRIES;
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (c->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+		c->counter_map.maptype = COUNTER_MAP_ZEROED;
+
+	list_for_each_entry(r, &c->rules, list) {
+		if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+			r->counter_map.maptype = COUNTER_MAP_ZEROED;
+	}
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+STRUCT_COUNTERS *
+TC_READ_COUNTER(const IPT_CHAINLABEL chain,
+		unsigned int rulenum,
+		TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+
+	iptc_fn = TC_READ_COUNTER;
+	CHECK(*handle);
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	if (!(r = iptcc_get_rule_num(c, rulenum))) {
+		errno = E2BIG;
+		return NULL;
+	}
+
+	return &r->entry[0].counters;
+}
+
+int
+TC_ZERO_COUNTER(const IPT_CHAINLABEL chain,
+		unsigned int rulenum,
+		TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+	
+	iptc_fn = TC_ZERO_COUNTER;
+	CHECK(*handle);
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (!(r = iptcc_get_rule_num(c, rulenum))) {
+		errno = E2BIG;
+		return 0;
+	}
+
+	if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+		r->counter_map.maptype = COUNTER_MAP_ZEROED;
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+int 
+TC_SET_COUNTER(const IPT_CHAINLABEL chain,
+	       unsigned int rulenum,
+	       STRUCT_COUNTERS *counters,
+	       TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	struct rule_head *r;
+	STRUCT_ENTRY *e;
+
+	iptc_fn = TC_SET_COUNTER;
+	CHECK(*handle);
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (!(r = iptcc_get_rule_num(c, rulenum))) {
+		errno = E2BIG;
+		return 0;
+	}
+
+	e = r->entry;
+	r->counter_map.maptype = COUNTER_MAP_SET;
+
+	memcpy(&e->counters, counters, sizeof(STRUCT_COUNTERS));
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Creates a new chain. */
+/* To create a chain, create two rules: error node and unconditional
+ * return. */
+int
+TC_CREATE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+	static struct chain_head *c;
+
+	iptc_fn = TC_CREATE_CHAIN;
+
+	/* find_label doesn't cover built-in targets: DROP, ACCEPT,
+           QUEUE, RETURN. */
+	if (iptcc_find_label(chain, *handle)
+	    || strcmp(chain, LABEL_DROP) == 0
+	    || strcmp(chain, LABEL_ACCEPT) == 0
+	    || strcmp(chain, LABEL_QUEUE) == 0
+	    || strcmp(chain, LABEL_RETURN) == 0) {
+		DEBUGP("Chain `%s' already exists\n", chain);
+		errno = EEXIST;
+		return 0;
+	}
+
+	if (strlen(chain)+1 > sizeof(IPT_CHAINLABEL)) {
+		DEBUGP("Chain name `%s' too long\n", chain);
+		errno = EINVAL;
+		return 0;
+	}
+
+	c = iptcc_alloc_chain_head(chain, 0);
+	if (!c) {
+		DEBUGP("Cannot allocate memory for chain `%s'\n", chain);
+		errno = ENOMEM;
+		return 0;
+
+	}
+
+	DEBUGP("Creating chain `%s'\n", chain);
+	iptc_insert_chain(*handle, c); /* Insert sorted */
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Get the number of references to this chain. */
+int
+TC_GET_REFERENCES(unsigned int *ref, const IPT_CHAINLABEL chain,
+		  TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+
+	iptc_fn = TC_GET_REFERENCES;
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	*ref = c->references;
+
+	return 1;
+}
+
+/* Deletes a chain. */
+int
+TC_DELETE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+	unsigned int references;
+	struct chain_head *c;
+
+	iptc_fn = TC_DELETE_CHAIN;
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		DEBUGP("cannot find chain `%s'\n", chain);
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (TC_BUILTIN(chain, *handle)) {
+		DEBUGP("cannot remove builtin chain `%s'\n", chain);
+		errno = EINVAL;
+		return 0;
+	}
+
+	if (!TC_GET_REFERENCES(&references, chain, handle)) {
+		DEBUGP("cannot get references on chain `%s'\n", chain);
+		return 0;
+	}
+
+	if (references > 0) {
+		DEBUGP("chain `%s' still has references\n", chain);
+		errno = EMLINK;
+		return 0;
+	}
+
+	if (c->num_rules) {
+		DEBUGP("chain `%s' is not empty\n", chain);
+		errno = ENOTEMPTY;
+		return 0;
+	}
+
+	/* If we are about to delete the chain that is the current
+	 * iterator, move chain iterator firward. */
+	if (c == (*handle)->chain_iterator_cur)
+		iptcc_chain_iterator_advance(*handle);
+
+	list_del(&c->list);
+	free(c);
+
+	DEBUGP("chain `%s' deleted\n", chain);
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Renames a chain. */
+int TC_RENAME_CHAIN(const IPT_CHAINLABEL oldname,
+		    const IPT_CHAINLABEL newname,
+		    TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+	iptc_fn = TC_RENAME_CHAIN;
+
+	/* find_label doesn't cover built-in targets: DROP, ACCEPT,
+           QUEUE, RETURN. */
+	if (iptcc_find_label(newname, *handle)
+	    || strcmp(newname, LABEL_DROP) == 0
+	    || strcmp(newname, LABEL_ACCEPT) == 0
+	    || strcmp(newname, LABEL_QUEUE) == 0
+	    || strcmp(newname, LABEL_RETURN) == 0) {
+		errno = EEXIST;
+		return 0;
+	}
+
+	if (!(c = iptcc_find_label(oldname, *handle))
+	    || TC_BUILTIN(oldname, *handle)) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (strlen(newname)+1 > sizeof(IPT_CHAINLABEL)) {
+		errno = EINVAL;
+		return 0;
+	}
+
+	strncpy(c->name, newname, sizeof(IPT_CHAINLABEL));
+	
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Sets the policy on a built-in chain. */
+int
+TC_SET_POLICY(const IPT_CHAINLABEL chain,
+	      const IPT_CHAINLABEL policy,
+	      STRUCT_COUNTERS *counters,
+	      TC_HANDLE_T *handle)
+{
+	struct chain_head *c;
+
+	iptc_fn = TC_SET_POLICY;
+
+	if (!(c = iptcc_find_label(chain, *handle))) {
+		DEBUGP("cannot find chain `%s'\n", chain);
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (!iptcc_is_builtin(c)) {
+		DEBUGP("cannot set policy of userdefinedchain `%s'\n", chain);
+		errno = ENOENT;
+		return 0;
+	}
+
+	if (strcmp(policy, LABEL_ACCEPT) == 0)
+		c->verdict = -NF_ACCEPT - 1;
+	else if (strcmp(policy, LABEL_DROP) == 0)
+		c->verdict = -NF_DROP - 1;
+	else {
+		errno = EINVAL;
+		return 0;
+	}
+
+	if (counters) {
+		/* set byte and packet counters */
+		memcpy(&c->counters, counters, sizeof(STRUCT_COUNTERS));
+		c->counter_map.maptype = COUNTER_MAP_SET;
+	} else {
+		c->counter_map.maptype = COUNTER_MAP_NOMAP;
+	}
+
+	set_changed(*handle);
+
+	return 1;
+}
+
+/* Without this, on gcc 2.7.2.3, we get:
+   libiptc.c: In function `TC_COMMIT':
+   libiptc.c:833: fixed or forbidden register was spilled.
+   This may be due to a compiler bug or to impossible asm
+   statements or clauses.
+*/
+static void
+subtract_counters(STRUCT_COUNTERS *answer,
+		  const STRUCT_COUNTERS *a,
+		  const STRUCT_COUNTERS *b)
+{
+	answer->pcnt = a->pcnt - b->pcnt;
+	answer->bcnt = a->bcnt - b->bcnt;
+}
+
+
+static void counters_nomap(STRUCT_COUNTERS_INFO *newcounters,
+			   unsigned int index)
+{
+	newcounters->counters[index] = ((STRUCT_COUNTERS) { 0, 0});
+	DEBUGP_C("NOMAP => zero\n");
+}
+
+static void counters_normal_map(STRUCT_COUNTERS_INFO *newcounters,
+				STRUCT_REPLACE *repl,
+				unsigned int index,
+				unsigned int mappos)
+{
+	/* Original read: X.
+	 * Atomic read on replacement: X + Y.
+	 * Currently in kernel: Z.
+	 * Want in kernel: X + Y + Z.
+	 * => Add in X + Y
+	 * => Add in replacement read.
+	 */
+	newcounters->counters[index] = repl->counters[mappos];
+	DEBUGP_C("NORMAL_MAP => mappos %u \n", mappos);
+}
+
+static void counters_map_zeroed(STRUCT_COUNTERS_INFO *newcounters,
+				STRUCT_REPLACE *repl,
+				unsigned int index,
+				unsigned int mappos,
+				STRUCT_COUNTERS *counters)
+{
+	/* Original read: X.
+	 * Atomic read on replacement: X + Y.
+	 * Currently in kernel: Z.
+	 * Want in kernel: Y + Z.
+	 * => Add in Y.
+	 * => Add in (replacement read - original read).
+	 */
+	subtract_counters(&newcounters->counters[index],
+			  &repl->counters[mappos],
+			  counters);
+	DEBUGP_C("ZEROED => mappos %u\n", mappos);
+}
+
+static void counters_map_set(STRUCT_COUNTERS_INFO *newcounters,
+			     unsigned int index,
+			     STRUCT_COUNTERS *counters)
+{
+	/* Want to set counter (iptables-restore) */
+
+	memcpy(&newcounters->counters[index], counters,
+		sizeof(STRUCT_COUNTERS));
+
+	DEBUGP_C("SET\n");
+}
+
+
+int
+TC_COMMIT(TC_HANDLE_T *handle)
+{
+	/* Replace, then map back the counters. */
+	STRUCT_REPLACE *repl;
+	STRUCT_COUNTERS_INFO *newcounters;
+	struct chain_head *c;
+	int ret;
+	size_t counterlen;
+	int new_number;
+	unsigned int new_size;
+
+	iptc_fn = TC_COMMIT;
+	CHECK(*handle);
+
+	/* Don't commit if nothing changed. */
+	if (!(*handle)->changed)
+		goto finished;
+
+	new_number = iptcc_compile_table_prep(*handle, &new_size);
+	if (new_number < 0) {
+		errno = ENOMEM;
+		goto out_zero;
+	}
+
+	repl = malloc(sizeof(*repl) + new_size);
+	if (!repl) {
+		errno = ENOMEM;
+		goto out_zero;
+	}
+	memset(repl, 0, sizeof(*repl) + new_size);
+
+#if 0
+	TC_DUMP_ENTRIES(*handle);
+#endif
+
+	counterlen = sizeof(STRUCT_COUNTERS_INFO)
+			+ sizeof(STRUCT_COUNTERS) * new_number;
+
+	/* These are the old counters we will get from kernel */
+	repl->counters = malloc(sizeof(STRUCT_COUNTERS)
+				* (*handle)->info.num_entries);
+	if (!repl->counters) {
+		errno = ENOMEM;
+		goto out_free_repl;
+	}
+	/* These are the counters we're going to put back, later. */
+	newcounters = malloc(counterlen);
+	if (!newcounters) {
+		errno = ENOMEM;
+		goto out_free_repl_counters;
+	}
+	memset(newcounters, 0, counterlen);
+
+	strcpy(repl->name, (*handle)->info.name);
+	repl->num_entries = new_number;
+	repl->size = new_size;
+
+	repl->num_counters = (*handle)->info.num_entries;
+	repl->valid_hooks = (*handle)->info.valid_hooks;
+
+	DEBUGP("num_entries=%u, size=%u, num_counters=%u\n",
+		repl->num_entries, repl->size, repl->num_counters);
+
+	ret = iptcc_compile_table(*handle, repl);
+	if (ret < 0) {
+		errno = ret;
+		goto out_free_newcounters;
+	}
+
+
+#ifdef IPTC_DEBUG2
+	{
+		int fd = open("/tmp/libiptc-so_set_replace.blob", 
+				O_CREAT|O_WRONLY);
+		if (fd >= 0) {
+			write(fd, repl, sizeof(*repl) + repl->size);
+			close(fd);
+		}
+	}
+#endif
+
+	ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_REPLACE, repl,
+			 sizeof(*repl) + repl->size);
+	if (ret < 0)
+		goto out_free_newcounters;
+
+	/* Put counters back. */
+	strcpy(newcounters->name, (*handle)->info.name);
+	newcounters->num_counters = new_number;
+
+	list_for_each_entry(c, &(*handle)->chains, list) {
+		struct rule_head *r;
+
+		/* Builtin chains have their own counters */
+		if (iptcc_is_builtin(c)) {
+			DEBUGP("counter for chain-index %u: ", c->foot_index);
+			switch(c->counter_map.maptype) {
+			case COUNTER_MAP_NOMAP:
+				counters_nomap(newcounters, c->foot_index);
+				break;
+			case COUNTER_MAP_NORMAL_MAP:
+				counters_normal_map(newcounters, repl,
+						    c->foot_index, 
+						    c->counter_map.mappos);
+				break;
+			case COUNTER_MAP_ZEROED:
+				counters_map_zeroed(newcounters, repl,
+						    c->foot_index, 
+						    c->counter_map.mappos,
+						    &c->counters);
+				break;
+			case COUNTER_MAP_SET:
+				counters_map_set(newcounters, c->foot_index,
+						 &c->counters);
+				break;
+			}
+		}
+
+		list_for_each_entry(r, &c->rules, list) {
+			DEBUGP("counter for index %u: ", r->index);
+			switch (r->counter_map.maptype) {
+			case COUNTER_MAP_NOMAP:
+				counters_nomap(newcounters, r->index);
+				break;
+
+			case COUNTER_MAP_NORMAL_MAP:
+				counters_normal_map(newcounters, repl,
+						    r->index, 
+						    r->counter_map.mappos);
+				break;
+
+			case COUNTER_MAP_ZEROED:
+				counters_map_zeroed(newcounters, repl,
+						    r->index,
+						    r->counter_map.mappos,
+						    &r->entry->counters);
+				break;
+
+			case COUNTER_MAP_SET:
+				counters_map_set(newcounters, r->index,
+						 &r->entry->counters);
+				break;
+			}
+		}
+	}
+
+#ifdef IPTC_DEBUG2
+	{
+		int fd = open("/tmp/libiptc-so_set_add_counters.blob", 
+				O_CREAT|O_WRONLY);
+		if (fd >= 0) {
+			write(fd, newcounters, counterlen);
+			close(fd);
+		}
+	}
+#endif
+
+	ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_ADD_COUNTERS,
+			 newcounters, counterlen);
+	if (ret < 0)
+		goto out_free_newcounters;
+
+	free(repl->counters);
+	free(repl);
+	free(newcounters);
+
+finished:
+	TC_FREE(handle);
+	return 1;
+
+out_free_newcounters:
+	free(newcounters);
+out_free_repl_counters:
+	free(repl->counters);
+out_free_repl:
+	free(repl);
+out_zero:
+	return 0;
+}
+
+/* Get raw socket. */
+int
+TC_GET_RAW_SOCKET(void)
+{
+	return sockfd;
+}
+
+/* Translates errno numbers into more human-readable form than strerror. */
+const char *
+TC_STRERROR(int err)
+{
+	unsigned int i;
+	struct table_struct {
+		void *fn;
+		int err;
+		const char *message;
+	} table [] =
+	  { { TC_INIT, EPERM, "Permission denied (you must be root)" },
+	    { TC_INIT, EINVAL, "Module is wrong version" },
+	    { TC_INIT, ENOENT, 
+		    "Table does not exist (do you need to insmod?)" },
+	    { TC_DELETE_CHAIN, ENOTEMPTY, "Chain is not empty" },
+	    { TC_DELETE_CHAIN, EINVAL, "Can't delete built-in chain" },
+	    { TC_DELETE_CHAIN, EMLINK,
+	      "Can't delete chain with references left" },
+	    { TC_CREATE_CHAIN, EEXIST, "Chain already exists" },
+	    { TC_INSERT_ENTRY, E2BIG, "Index of insertion too big" },
+	    { TC_REPLACE_ENTRY, E2BIG, "Index of replacement too big" },
+	    { TC_DELETE_NUM_ENTRY, E2BIG, "Index of deletion too big" },
+	    { TC_READ_COUNTER, E2BIG, "Index of counter too big" },
+	    { TC_ZERO_COUNTER, E2BIG, "Index of counter too big" },
+	    { TC_INSERT_ENTRY, ELOOP, "Loop found in table" },
+	    { TC_INSERT_ENTRY, EINVAL, "Target problem" },
+	    /* EINVAL for CHECK probably means bad interface. */
+	    { TC_CHECK_PACKET, EINVAL,
+	      "Bad arguments (does that interface exist?)" },
+	    { TC_CHECK_PACKET, ENOSYS,
+	      "Checking will most likely never get implemented" },
+	    /* ENOENT for DELETE probably means no matching rule */
+	    { TC_DELETE_ENTRY, ENOENT,
+	      "Bad rule (does a matching rule exist in that chain?)" },
+	    { TC_SET_POLICY, ENOENT,
+	      "Bad built-in chain name" },
+	    { TC_SET_POLICY, EINVAL,
+	      "Bad policy name" },
+
+	    { NULL, 0, "Incompatible with this kernel" },
+	    { NULL, ENOPROTOOPT, "iptables who? (do you need to insmod?)" },
+	    { NULL, ENOSYS, "Will be implemented real soon.  I promise ;)" },
+	    { NULL, ENOMEM, "Memory allocation problem" },
+	    { NULL, ENOENT, "No chain/target/match by that name" },
+	  };
+
+	for (i = 0; i < sizeof(table)/sizeof(struct table_struct); i++) {
+		if ((!table[i].fn || table[i].fn == iptc_fn)
+		    && table[i].err == err)
+			return table[i].message;
+	}
+
+	return strerror(err);
+}
diff --git a/src/libiptc/libiptc.h b/src/libiptc/libiptc.h
new file mode 100644
index 0000000..d9f7423
--- /dev/null
+++ b/src/libiptc/libiptc.h
@@ -0,0 +1,185 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef _LIBIPTC_H
+#define _LIBIPTC_H
+/* Library which manipulates filtering rules. */
+
+#include <linux/types.h>
+#include "ipt_kernel_headers.h"
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef IPT_MIN_ALIGN
+/* ipt_entry has pointers and u_int64_t's in it, so if you align to
+   it, you'll also align to any crazy matches and targets someone
+   might write */
+#define IPT_MIN_ALIGN (__alignof__(struct ipt_entry))
+#endif
+
+#define IPT_ALIGN(s) (((s) + ((IPT_MIN_ALIGN)-1)) & ~((IPT_MIN_ALIGN)-1))
+
+typedef char ipt_chainlabel[32];
+
+#define IPTC_LABEL_ACCEPT  "ACCEPT"
+#define IPTC_LABEL_DROP    "DROP"
+#define IPTC_LABEL_QUEUE   "QUEUE"
+#define IPTC_LABEL_RETURN  "RETURN"
+
+/* Transparent handle type. */
+typedef struct iptc_handle *iptc_handle_t;
+
+/* Does this chain exist? */
+int iptc_is_chain(const char *chain, const iptc_handle_t handle);
+
+/* Take a snapshot of the rules.  Returns NULL on error. */
+iptc_handle_t iptc_init(const char *tablename);
+
+/* Cleanup after iptc_init(). */
+void iptc_free(iptc_handle_t *h);
+
+/* Iterator functions to run through the chains.  Returns NULL at end. */
+const char *iptc_first_chain(iptc_handle_t *handle);
+const char *iptc_next_chain(iptc_handle_t *handle);
+
+/* Get first rule in the given chain: NULL for empty chain. */
+const struct ipt_entry *iptc_first_rule(const char *chain,
+					iptc_handle_t *handle);
+
+/* Returns NULL when rules run out. */
+const struct ipt_entry *iptc_next_rule(const struct ipt_entry *prev,
+				       iptc_handle_t *handle);
+
+/* Returns a pointer to the target name of this entry. */
+const char *iptc_get_target(const struct ipt_entry *e,
+			    iptc_handle_t *handle);
+
+/* Is this a built-in chain? */
+int iptc_builtin(const char *chain, const iptc_handle_t handle);
+
+/* Get the policy of a given built-in chain */
+const char *iptc_get_policy(const char *chain,
+			    struct ipt_counters *counter,
+			    iptc_handle_t *handle);
+
+/* These functions return TRUE for OK or 0 and set errno.  If errno ==
+   0, it means there was a version error (ie. upgrade libiptc). */
+/* Rule numbers start at 1 for the first rule. */
+
+/* Insert the entry `e' in chain `chain' into position `rulenum'. */
+int iptc_insert_entry(const ipt_chainlabel chain,
+		      const struct ipt_entry *e,
+		      unsigned int rulenum,
+		      iptc_handle_t *handle);
+
+/* Atomically replace rule `rulenum' in `chain' with `e'. */
+int iptc_replace_entry(const ipt_chainlabel chain,
+		       const struct ipt_entry *e,
+		       unsigned int rulenum,
+		       iptc_handle_t *handle);
+
+/* Append entry `e' to chain `chain'.  Equivalent to insert with
+   rulenum = length of chain. */
+int iptc_append_entry(const ipt_chainlabel chain,
+		      const struct ipt_entry *e,
+		      iptc_handle_t *handle);
+
+/* Delete the first rule in `chain' which matches `e', subject to
+   matchmask (array of length == origfw) */
+int iptc_delete_entry(const ipt_chainlabel chain,
+		      const struct ipt_entry *origfw,
+		      unsigned char *matchmask,
+		      iptc_handle_t *handle);
+
+/* Delete the rule in position `rulenum' in `chain'. */
+int iptc_delete_num_entry(const ipt_chainlabel chain,
+			  unsigned int rulenum,
+			  iptc_handle_t *handle);
+
+/* Check the packet `e' on chain `chain'.  Returns the verdict, or
+   NULL and sets errno. */
+const char *iptc_check_packet(const ipt_chainlabel chain,
+			      struct ipt_entry *entry,
+			      iptc_handle_t *handle);
+
+/* Flushes the entries in the given chain (ie. empties chain). */
+int iptc_flush_entries(const ipt_chainlabel chain,
+		       iptc_handle_t *handle);
+
+/* Zeroes the counters in a chain. */
+int iptc_zero_entries(const ipt_chainlabel chain,
+		      iptc_handle_t *handle);
+
+/* Creates a new chain. */
+int iptc_create_chain(const ipt_chainlabel chain,
+		      iptc_handle_t *handle);
+
+/* Deletes a chain. */
+int iptc_delete_chain(const ipt_chainlabel chain,
+		      iptc_handle_t *handle);
+
+/* Renames a chain. */
+int iptc_rename_chain(const ipt_chainlabel oldname,
+		      const ipt_chainlabel newname,
+		      iptc_handle_t *handle);
+
+/* Sets the policy on a built-in chain. */
+int iptc_set_policy(const ipt_chainlabel chain,
+		    const ipt_chainlabel policy,
+		    struct ipt_counters *counters,
+		    iptc_handle_t *handle);
+
+/* Get the number of references to this chain */
+int iptc_get_references(unsigned int *ref,
+			const ipt_chainlabel chain,
+			iptc_handle_t *handle);
+
+/* read packet and byte counters for a specific rule */
+struct ipt_counters *iptc_read_counter(const ipt_chainlabel chain,
+				       unsigned int rulenum,
+				       iptc_handle_t *handle);
+
+/* zero packet and byte counters for a specific rule */
+int iptc_zero_counter(const ipt_chainlabel chain,
+		      unsigned int rulenum,
+		      iptc_handle_t *handle);
+
+/* set packet and byte counters for a specific rule */
+int iptc_set_counter(const ipt_chainlabel chain,
+		     unsigned int rulenum,
+		     struct ipt_counters *counters,
+		     iptc_handle_t *handle);
+
+/* Makes the actual changes. */
+int iptc_commit(iptc_handle_t *handle);
+
+/* Get raw socket. */
+int iptc_get_raw_socket();
+
+/* Translates errno numbers into more human-readable form than strerror. */
+const char *iptc_strerror(int err);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* _LIBIPTC_H */
diff --git a/src/libiptc/linux_list.h b/src/libiptc/linux_list.h
new file mode 100644
index 0000000..56d9a26
--- /dev/null
+++ b/src/libiptc/linux_list.h
@@ -0,0 +1,741 @@
+/**
+ * This file was imported from the iptables sources.
+ * Copyright (C) 1999-2008 Netfilter Core Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef _LINUX_LIST_H
+#define _LINUX_LIST_H
+
+#undef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ *
+ * @ptr:	the pointer to the member.
+ * @type:	the type of the container struct this is embedded in.
+ * @member:	the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({			\
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type,x) \
+({	type __dummy; \
+	typeof(x) __dummy2; \
+	(void)(&__dummy == &__dummy2); \
+	1; \
+})
+
+#define prefetch(x)		1
+
+/* empty define to make this work in userspace -HW */
+#define smp_wmb()
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x00100100)
+#define LIST_POISON2  ((void *) 0x00200200)
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+	struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next)
+{
+	next->prev = new;
+	new->next = next;
+	new->prev = prev;
+	prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head->prev, head);
+}
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add_rcu(struct list_head * new,
+		struct list_head * prev, struct list_head * next)
+{
+	new->next = next;
+	new->prev = prev;
+	smp_wmb();
+	next->prev = new;
+	prev->next = new;
+}
+
+/**
+ * list_add_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_rcu(struct list_head *new, struct list_head *head)
+{
+	__list_add_rcu(new, head, head->next);
+}
+
+/**
+ * list_add_tail_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_tail_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_tail_rcu(struct list_head *new,
+					struct list_head *head)
+{
+	__list_add_rcu(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head * prev, struct list_head * next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	entry->next = LIST_POISON1;
+	entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_rcu - deletes entry from list without re-initialization
+ * @entry: the element to delete from the list.
+ *
+ * Note: list_empty on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_del_rcu()
+ * or list_add_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ *
+ * Note that the caller is not permitted to immediately free
+ * the newly deleted entry.  Instead, either synchronize_kernel()
+ * or call_rcu() must be used to defer freeing until an RCU
+ * grace period has elapsed.
+ */
+static inline void list_del_rcu(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+				  struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(const struct list_head *head)
+{
+	return head->next == head;
+}
+
+/**
+ * list_empty_careful - tests whether a list is
+ * empty _and_ checks that no other CPU might be
+ * in the process of still modifying either member
+ *
+ * NOTE: using list_empty_careful() without synchronization
+ * can only be safe if the only activity that can happen
+ * to the list entry is list_del_init(). Eg. it cannot be used
+ * if another CPU could re-list_add() it.
+ *
+ * @head: the list to test.
+ */
+static inline int list_empty_careful(const struct list_head *head)
+{
+	struct list_head *next = head->next;
+	return (next == head) && (next == head->prev);
+}
+
+static inline void __list_splice(struct list_head *list,
+				 struct list_head *head)
+{
+	struct list_head *first = list->next;
+	struct list_head *last = list->prev;
+	struct list_head *at = head->next;
+
+	first->prev = head;
+	head->next = first;
+
+	last->next = at;
+	at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+	if (!list_empty(list))
+		__list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+				    struct list_head *head)
+{
+	if (!list_empty(list)) {
+		__list_splice(list, head);
+		INIT_LIST_HEAD(list);
+	}
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:	the &struct list_head pointer.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+	container_of(ptr, type, member)
+
+/**
+ * list_for_each	-	iterate over a list
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each(pos, head) \
+	for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+        	pos = pos->next, prefetch(pos->next))
+
+/**
+ * __list_for_each	-	iterate over a list
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ *
+ * This variant differs from list_for_each() in that it's the
+ * simplest possible list iteration code, no prefetching is done.
+ * Use this for code that knows the list to be very short (empty
+ * or 1 entry) most of the time.
+ */
+#define __list_for_each(pos, head) \
+	for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_prev	-	iterate over a list backwards
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+	for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
+        	pos = pos->prev, prefetch(pos->prev))
+
+/**
+ * list_for_each_safe	-	iterate over a list safe against removal of list entry
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @n:		another &struct list_head to use as temporary storage
+ * @head:	the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+	for (pos = (head)->next, n = pos->next; pos != (head); \
+		pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry	-	iterate over list of given type
+ * @pos:	the type * to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member)				\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+		     prefetch(pos->member.next);			\
+	     &pos->member != (head); 					\
+	     pos = list_entry(pos->member.next, typeof(*pos), member),	\
+		     prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_reverse - iterate backwards over list of given type.
+ * @pos:	the type * to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_reverse(pos, head, member)			\
+	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
+		     prefetch(pos->member.prev);			\
+	     &pos->member != (head); 					\
+	     pos = list_entry(pos->member.prev, typeof(*pos), member),	\
+		     prefetch(pos->member.prev))
+
+/**
+ * list_prepare_entry - prepare a pos entry for use as a start point in
+ *			list_for_each_entry_continue
+ * @pos:	the type * to use as a start point
+ * @head:	the head of the list
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_prepare_entry(pos, head, member) \
+	((pos) ? : list_entry(head, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_continue -	iterate over list of given type
+ *			continuing after existing point
+ * @pos:	the type * to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_continue(pos, head, member) 		\
+	for (pos = list_entry(pos->member.next, typeof(*pos), member),	\
+		     prefetch(pos->member.next);			\
+	     &pos->member != (head);					\
+	     pos = list_entry(pos->member.next, typeof(*pos), member),	\
+		     prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos:	the type * to use as a loop counter.
+ * @n:		another type * to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member)			\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+		n = list_entry(pos->member.next, typeof(*pos), member);	\
+	     &pos->member != (head); 					\
+	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+/**
+ * list_for_each_rcu	-	iterate over an rcu-protected list
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_rcu(pos, head) \
+	for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+        	pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))
+
+#define __list_for_each_rcu(pos, head) \
+	for (pos = (head)->next; pos != (head); \
+        	pos = pos->next, ({ smp_read_barrier_depends(); 0;}))
+
+/**
+ * list_for_each_safe_rcu	-	iterate over an rcu-protected list safe
+ *					against removal of list entry
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @n:		another &struct list_head to use as temporary storage
+ * @head:	the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_safe_rcu(pos, n, head) \
+	for (pos = (head)->next, n = pos->next; pos != (head); \
+		pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)
+
+/**
+ * list_for_each_entry_rcu	-	iterate over rcu list of given type
+ * @pos:	the type * to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_entry_rcu(pos, head, member)			\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+		     prefetch(pos->member.next);			\
+	     &pos->member != (head); 					\
+	     pos = list_entry(pos->member.next, typeof(*pos), member),	\
+		     ({ smp_read_barrier_depends(); 0;}),		\
+		     prefetch(pos->member.next))
+
+
+/**
+ * list_for_each_continue_rcu	-	iterate over an rcu-protected list
+ *			continuing after existing point.
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_continue_rcu(pos, head) \
+	for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
+        	(pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))
+
+/*
+ * Double linked lists with a single pointer list head.
+ * Mostly useful for hash tables where the two pointer list head is
+ * too wasteful.
+ * You lose the ability to access the tail in O(1).
+ */
+
+struct hlist_head {
+	struct hlist_node *first;
+};
+
+struct hlist_node {
+	struct hlist_node *next, **pprev;
+};
+
+#define HLIST_HEAD_INIT { .first = NULL }
+#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
+#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
+#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
+
+static inline int hlist_unhashed(const struct hlist_node *h)
+{
+	return !h->pprev;
+}
+
+static inline int hlist_empty(const struct hlist_head *h)
+{
+	return !h->first;
+}
+
+static inline void __hlist_del(struct hlist_node *n)
+{
+	struct hlist_node *next = n->next;
+	struct hlist_node **pprev = n->pprev;
+	*pprev = next;
+	if (next)
+		next->pprev = pprev;
+}
+
+static inline void hlist_del(struct hlist_node *n)
+{
+	__hlist_del(n);
+	n->next = LIST_POISON1;
+	n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: list_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry().
+ */
+static inline void hlist_del_rcu(struct hlist_node *n)
+{
+	__hlist_del(n);
+	n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_del_init(struct hlist_node *n)
+{
+	if (n->pprev)  {
+		__hlist_del(n);
+		INIT_HLIST_NODE(n);
+	}
+}
+
+#define hlist_del_rcu_init hlist_del_init
+
+static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
+{
+	struct hlist_node *first = h->first;
+	n->next = first;
+	if (first)
+		first->pprev = &n->next;
+	h->first = n;
+	n->pprev = &h->first;
+}
+
+
+/**
+ * hlist_add_head_rcu - adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry(), but only if smp_read_barrier_depends()
+ * is used to prevent memory-consistency problems on Alpha CPUs.
+ * Regardless of the type of CPU, the list-traversal primitive
+ * must be guarded by rcu_read_lock().
+ *
+ * OK, so why don't we have an hlist_for_each_entry_rcu()???
+ */
+static inline void hlist_add_head_rcu(struct hlist_node *n,
+					struct hlist_head *h)
+{
+	struct hlist_node *first = h->first;
+	n->next = first;
+	n->pprev = &h->first;
+	smp_wmb();
+	if (first)
+		first->pprev = &n->next;
+	h->first = n;
+}
+
+/* next must be != NULL */
+static inline void hlist_add_before(struct hlist_node *n,
+					struct hlist_node *next)
+{
+	n->pprev = next->pprev;
+	n->next = next;
+	next->pprev = &n->next;
+	*(n->pprev) = n;
+}
+
+static inline void hlist_add_after(struct hlist_node *n,
+					struct hlist_node *next)
+{
+	next->next = n->next;
+	n->next = next;
+	next->pprev = &n->next;
+
+	if(next->next)
+		next->next->pprev  = &next->next;
+}
+
+#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
+
+#define hlist_for_each(pos, head) \
+	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
+	     pos = pos->next)
+
+#define hlist_for_each_safe(pos, n, head) \
+	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
+	     pos = n)
+
+/**
+ * hlist_for_each_entry	- iterate over list of given type
+ * @tpos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry(tpos, pos, head, member)			 \
+	for (pos = (head)->first;					 \
+	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = pos->next)
+
+/**
+ * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
+ * @tpos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @member:	the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue(tpos, pos, member)		 \
+	for (pos = (pos)->next;						 \
+	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = pos->next)
+
+/**
+ * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
+ * @tpos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @member:	the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_from(tpos, pos, member)			 \
+	for (; pos && ({ prefetch(pos->next); 1;}) &&			 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = pos->next)
+
+/**
+ * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @n:		another &struct hlist_node to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
+	for (pos = (head)->first;					 \
+	     pos && ({ n = pos->next; 1; }) && 				 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define hlist_for_each_entry_rcu(tpos, pos, head, member)		 \
+	for (pos = (head)->first;					 \
+	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+
+#endif
-- 
1.5.5.1.79.g57cf

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