add pablo's conntrack tool

2 files changed, 958 insertions, 0 deletions

diff --git a/src/conntrack.c b/src/conntrack.c
new file mode 100644
index 0000000..dfb3849
--- /dev/null
+++ b/src/conntrack.c
@@ -0,0 +1,472 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *
+ *      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; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ *      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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Note:
+ *	Yes, portions of this code has been stolen from iptables ;)
+ *	Special thanks to the the Netfilter Core Team.
+ *	Thanks to Javier de Miguel Rodriguez <jmiguel at talika.eii.us.es>
+ *	for introducing me to advanced firewalling stuff.
+ *
+ *						--pablo 13/04/2005
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include "libctnetlink.h"
+#include "libnfnetlink.h"
+#include "linux_list.h"
+#include "libct_proto.h"
+
+#define PROGNAME "conntrack"
+#define VERSION "0.12"
+
+#if 0
+#define DEBUGP printf
+#else
+#define DEBUGP
+#endif
+
+enum action {
+	CT_LIST_BIT 	= 0,
+	CT_LIST 	= (1 << CT_LIST_BIT),
+	
+	CT_CREATE_BIT	= 1,
+	CT_CREATE	= (1 << CT_CREATE_BIT),
+	
+	CT_DELETE_BIT	= 2,
+	CT_DELETE	= (1 << CT_DELETE_BIT),
+	
+	CT_GET_BIT	= 3,
+	CT_GET		= (1 << CT_GET_BIT),
+
+	CT_FLUSH_BIT	= 4,
+	CT_FLUSH	= (1 << CT_FLUSH_BIT),
+
+	CT_EVENT_BIT	= 5,
+	CT_EVENT	= (1 << CT_EVENT_BIT)
+};
+#define NUMBER_OF_CMD   6
+
+enum options {
+	CT_OPT_ORIG_SRC_BIT	= 0,
+	CT_OPT_ORIG_SRC 	= (1 << CT_OPT_ORIG_SRC_BIT),
+	
+	CT_OPT_ORIG_DST_BIT	= 1,
+	CT_OPT_ORIG_DST		= (1 << CT_OPT_ORIG_DST_BIT),
+
+	CT_OPT_ORIG		= (CT_OPT_ORIG_SRC | CT_OPT_ORIG_DST),
+	
+	CT_OPT_REPL_SRC_BIT	= 2,
+	CT_OPT_REPL_SRC		= (1 << CT_OPT_REPL_SRC_BIT),
+	
+	CT_OPT_REPL_DST_BIT	= 3,
+	CT_OPT_REPL_DST		= (1 << CT_OPT_REPL_DST_BIT),
+
+	CT_OPT_REPL		= (CT_OPT_REPL_SRC | CT_OPT_REPL_DST),
+
+	CT_OPT_PROTO_BIT	= 4,
+	CT_OPT_PROTO		= (1 << CT_OPT_PROTO_BIT),
+
+	CT_OPT_ID_BIT		= 5,
+	CT_OPT_ID		= (1 << CT_OPT_ID_BIT),
+
+	CT_OPT_TIMEOUT_BIT	= 6,
+	CT_OPT_TIMEOUT		= (1 << CT_OPT_TIMEOUT_BIT),
+
+	CT_OPT_STATUS_BIT	= 7,
+	CT_OPT_STATUS		= (1 << CT_OPT_STATUS_BIT),
+};
+#define NUMBER_OF_OPT   8
+
+static const char optflags[NUMBER_OF_OPT]
+= { 's', 'd', 'r', 'q', 'p', 'i', 't', 'u'};
+
+static struct option original_opts[] = {
+	{"dump", 1, 0, 'L'},
+	{"create", 1, 0, 'I'},
+	{"delete", 1, 0, 'D'},
+	{"get", 1, 0, 'G'},
+	{"flush", 1, 0, 'F'},
+	{"event", 1, 0, 'E'},
+	{"orig-src", 1, 0, 's'},
+	{"orig-dst", 1, 0, 'd'},
+	{"reply-src", 1, 0, 'r'},
+	{"reply-dst", 1, 0, 'q'},
+	{"protonum", 1, 0, 'p'},
+	{"timeout", 1, 0, 't'},
+	{"id", 1, 0, 'i'},
+	{"status", 1, 0, 'u'},
+	{0, 0, 0, 0}
+};
+
+#define OPTION_OFFSET 256
+
+static struct option *opts = original_opts;
+static unsigned int global_option_offset = 0;
+
+/* Table of legal combinations of commands and options.  If any of the
+ * given commands make an option legal, that option is legal (applies to
+ * CMD_LIST and CMD_ZERO only).
+ * Key:
+ *  +  compulsory
+ *  x  illegal
+ *     optional
+ */
+
+static char commands_v_options[NUMBER_OF_CMD][NUMBER_OF_OPT] =
+/* Well, it's better than "Re: Linux vs FreeBSD" */
+{
+          /*   -s  -d  -r  -q  -p  -i  -t  -u*/
+/*LIST*/      {'x','x','x','x','x','x','x','x'},
+/*CREATE*/    {'+','+','+','+','+','x','+','+'},
+/*DELETE*/    {' ',' ',' ',' ',' ','+','x','x'},
+/*GET*/       {' ',' ',' ',' ','+','+','x','x'},
+/*FLUSH*/     {'x','x','x','x','x','x','x','x'},
+/*EVENT*/     {'x','x','x','x','x','x','x','x'}
+};
+
+LIST_HEAD(proto_list);
+
+char *proto2str[] = {
+	[IPPROTO_TCP] = "tcp",
+        [IPPROTO_UDP] = "udp",
+        [IPPROTO_ICMP] = "icmp",
+        [IPPROTO_SCTP] = "sctp"
+};
+
+enum exittype {
+        OTHER_PROBLEM = 1,
+        PARAMETER_PROBLEM,
+        VERSION_PROBLEM
+};
+
+void
+exit_tryhelp(int status)
+{
+	fprintf(stderr, "Try `%s -h' or '%s --help' for more information.\n",
+			PROGNAME, PROGNAME);
+	exit(status);
+}
+
+static void
+exit_error(enum exittype status, char *msg, ...)
+{
+	va_list args;
+
+	/* On error paths, make sure that we don't leak the memory
+	 * reserved during options merging */
+	if (opts != original_opts) {
+		free(opts);
+		opts = original_opts;
+		global_option_offset = 0;
+	}
+	va_start(args, msg);
+	fprintf(stderr, "%s v%s: ", PROGNAME, VERSION);
+	vfprintf(stderr, msg, args);
+	va_end(args);
+	fprintf(stderr, "\n");
+	if (status == PARAMETER_PROBLEM)
+		exit_tryhelp(status);
+	exit(status);
+}
+
+static void
+generic_opt_check(int command, int options)
+{
+	int i, j, legal = 0;
+
+	/* Check that commands are valid with options.  Complicated by the
+	 * fact that if an option is legal with *any* command given, it is
+	 * legal overall (ie. -z and -l).
+	 */
+	for (i = 0; i < NUMBER_OF_OPT; i++) {
+		legal = 0; /* -1 => illegal, 1 => legal, 0 => undecided. */
+
+		for (j = 0; j < NUMBER_OF_CMD; j++) {
+			if (!(command & (1<<j)))
+				continue;
+
+			if (!(options & (1<<i))) {
+				if (commands_v_options[j][i] == '+') 
+					exit_error(PARAMETER_PROBLEM, 
+						   "You need to supply the "
+						   "`-%c' option for this "
+						   "command\n", optflags[i]);
+			} else {
+				if (commands_v_options[j][i] != 'x')
+					legal = 1;
+				else if (legal == 0)
+					legal = -1;
+			}
+		}
+		if (legal == -1)
+			exit_error(PARAMETER_PROBLEM, "Illegal option `-%c'"
+				   "with this command\n", optflags[i]);
+	}
+}
+
+static struct option *
+merge_options(struct option *oldopts, const struct option *newopts,
+	      unsigned int *option_offset)
+{
+	unsigned int num_old, num_new, i;
+	struct option *merge;
+
+	for (num_old = 0; oldopts[num_old].name; num_old++);
+	for (num_new = 0; newopts[num_new].name; num_new++);
+
+	global_option_offset += OPTION_OFFSET;
+	*option_offset = global_option_offset;
+
+	merge = malloc(sizeof(struct option) * (num_new + num_old + 1));
+	memcpy(merge, oldopts, num_old * sizeof(struct option));
+	for (i = 0; i < num_new; i++) {
+		merge[num_old + i] = newopts[i];
+		merge[num_old + i].val += *option_offset;
+	}
+	memset(merge + num_old + num_new, 0, sizeof(struct option));
+
+	return merge;
+}
+
+void not_implemented_yet()
+{
+	exit_error(OTHER_PROBLEM, "Sorry, not implemented yet :(\n");
+}
+
+unsigned int check_type()
+{
+	unsigned int type = 0;
+
+	if (!optarg)
+		exit_error(PARAMETER_PROBLEM, "must specified `conntrack' or "
+			   "`expect'\n");
+	
+	if (strncmp("conntrack", optarg, 9) == 0)
+		type = 0;
+	else if (strncmp("expect", optarg, 6) == 0)
+		type = 1;
+	else {
+		exit_error(PARAMETER_PROBLEM, "unknown type `%s'\n", optarg);
+	}
+
+	return type;
+}
+
+void usage(char *prog) {
+printf("Tool to manipulate conntrack and expectations. Version %s\n", VERSION);
+printf("Usage: %s [commands] [options]\n", prog);
+printf("\n");
+printf("Commands:\n");
+printf("-L table	    	List conntrack or expectation table\n");
+printf("-G table [options]  	Get conntrack or expectation\n");
+printf("-D table [options]	Delete conntrack or expectation\n");
+printf("-I table [options]	Create a conntrack or expectation\n");
+printf("-E table	    	Show events\n");
+printf("-F table	     	Flush table\n");
+printf("\n");
+printf("Options:\n");
+printf("--orig-src	     	Source address from original direction\n");
+printf("--orig-dst	     	Destination address from original direction\n");
+printf("--reply-src		Source addres from reply direction\n");
+printf("--reply-dst		Destination address from reply direction\n");
+printf("-p 			Layer 4 Protocol\n");
+printf("-t			Timeout\n");
+printf("-i			Conntrack ID\n");
+printf("-u			Status\n");
+}
+
+int main(int argc, char *argv[])
+{
+	char c;
+	unsigned int command = 0, options = 0;
+	struct ip_conntrack_tuple orig, reply, *o = NULL, *r = NULL;
+	struct ctproto_handler *h = NULL;
+	union ip_conntrack_proto proto;
+	unsigned long timeout = 0;
+	unsigned int status = 0;
+	unsigned long id = 0;
+	unsigned int type = 0;
+	
+	memset(&proto, 0, sizeof(union ip_conntrack_proto));
+	memset(&orig, 0, sizeof(struct ip_conntrack_tuple));
+	memset(&reply, 0, sizeof(struct ip_conntrack_tuple));
+	orig.dst.dir = IP_CT_DIR_ORIGINAL;
+	reply.dst.dir = IP_CT_DIR_REPLY;
+	
+	while ((c = getopt_long(argc, argv, 
+			"L:I:D:G:E:s:d:r:q:p:i:t:u:", opts, NULL)) != -1) {
+	switch(c) {
+		case 'L':
+			command |= CT_LIST;
+			type = check_type();
+			break;
+		case 'I':
+			command |= CT_CREATE;
+			type = check_type();
+			break;
+		case 'D':
+			command |= CT_DELETE;
+			type = check_type();
+			break;
+		case 'G':
+			command |= CT_GET;
+			type = check_type();
+			break;
+		case 'F':
+			command |= CT_FLUSH;
+			type = check_type();
+			break;
+		case 'E':
+			command |= CT_EVENT;
+			type = check_type();
+			break;
+		case 's':
+			options |= CT_OPT_ORIG_SRC;
+			if (optarg)
+				orig.src.ip = inet_addr(optarg);
+			break;
+		case 'd':
+			options |= CT_OPT_ORIG_DST;
+			if (optarg)
+				orig.dst.ip = inet_addr(optarg);
+			break;
+		case 'r':
+			options |= CT_OPT_REPL_SRC;
+			if (optarg)
+				reply.src.ip = inet_addr(optarg);
+			break;
+		case 'q':
+			options |= CT_OPT_REPL_DST;
+			if (optarg)
+				reply.dst.ip = inet_addr(optarg);
+			break;
+		case 'p':
+			options |= CT_OPT_PROTO;
+			h = findproto(optarg);
+			if (!h)
+				exit_error(PARAMETER_PROBLEM, "proto needed\n");
+			orig.dst.protonum = h->protonum;
+			reply.dst.protonum = h->protonum;
+			opts = merge_options(opts, h->opts, 
+					     &h->option_offset);
+			break;
+		case 'i':
+			options |= CT_OPT_ID;
+			id = atoi(optarg);
+			break;
+		case 't':
+			options |= CT_OPT_TIMEOUT;
+			if (optarg)
+				timeout = atol(optarg);
+			break;
+		case 'u': {
+		 	/* FIXME: NAT stuff, later... */
+			if (!optarg)
+				continue;
+
+			options |= CT_OPT_STATUS;
+			/* Just insert confirmed conntracks */
+			status |= IPS_CONFIRMED;
+			if (strncmp("SEEN_REPLY", optarg, strlen("SEEN_REPLY")) == 0)
+				status |= IPS_SEEN_REPLY;
+			else if (strncmp("ASSURED", optarg, strlen("ASSURED")) == 0)
+				status |= IPS_ASSURED;
+			else
+				exit_error(PARAMETER_PROBLEM, "Invalid status"
+					   "flag: %s\n", optarg);
+			break;
+		}
+		default:
+			if (h && !h->parse(c - h->option_offset, argv, 
+					   &orig, &reply))
+				exit_error(PARAMETER_PROBLEM, "parse error\n");
+
+			/* Unknown argument... */
+			if (!h) {
+				usage(argv[0]);
+				exit_error(PARAMETER_PROBLEM, "Missing "
+					   "arguments...\n");
+			}
+			break;
+		}
+	}
+
+	generic_opt_check(command, options);
+
+	switch(command) {
+		case CT_LIST:
+			printf("list\n");
+			if (type == 0)
+				dump_conntrack_table();
+			else
+				dump_expect_list();
+			break;
+		case CT_CREATE:
+			printf("create\n");
+			if (type == 0)
+				create_conntrack(&orig, &reply, timeout, 
+						 &proto, status);
+			else
+				not_implemented_yet();
+			break;
+		case CT_DELETE:
+			printf("delete\n");
+			if (type == 0) {
+				if (options & CT_OPT_ORIG)
+					delete_conntrack(&orig, CTA_ORIG, id);
+				else if (options & CT_OPT_REPL)
+					delete_conntrack(&reply, CTA_RPLY, id);
+			} else
+				not_implemented_yet();
+			break;
+		case CT_GET:
+			printf("get\n");
+			if (type == 0) {
+				if (options & CT_OPT_ORIG)
+					get_conntrack(&orig, CTA_ORIG, id);
+				else if (options & CT_OPT_REPL)
+					get_conntrack(&reply, CTA_RPLY, id);
+			} else
+				not_implemented_yet();
+			break;
+		case CT_FLUSH:
+			not_implemented_yet();
+			break;
+		case CT_EVENT:
+			printf("event\n");
+			if (type == 0)
+				event_conntrack();
+			else
+				/* and surely it won't ever... */
+				not_implemented_yet();
+		default:
+			usage(argv[0]);
+			break;
+	}
+
+	if (opts != original_opts) {
+		free(opts);
+		opts = original_opts;
+		global_option_offset = 0;
+	}
+}
diff --git a/src/libct.c b/src/libct.c
new file mode 100644
index 0000000..3828c0c
--- /dev/null
+++ b/src/libct.c
@@ -0,0 +1,486 @@
+#include <stdio.h>
+#include <getopt.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include "libctnetlink.h"
+#include "libnfnetlink.h"
+#include "linux_list.h"
+#include "libct_proto.h"
+
+#if 0
+#define DEBUGP printf
+#else
+#define DEBUGP
+#endif
+
+extern struct list_head proto_list;
+extern char *proto2str[];
+
+/* Built-in generic proto handler */
+
+/* FIXME: This should die... */
+static int parse(char c, char *argv[], 
+	   struct ip_conntrack_tuple *orig,
+	   struct ip_conntrack_tuple *reply) {
+	return 0;
+}
+/* FIXME: die die too... */
+static void print(struct ip_conntrack_tuple *t) {}
+
+static struct ctproto_handler generic_handler = {
+	.name 		= "generic",
+	.protonum	= 0,
+	.parse		= parse,
+	.print		= print,
+	.opts		= NULL
+};
+
+static int handler(struct sockaddr_nl *sock, struct nlmsghdr *nlh, void *arg)
+{
+	struct nfgenmsg *nfmsg;
+	struct nfattr *nfa;
+	int min_len = 0;
+	struct ctproto_handler *h = NULL;
+
+	DEBUGP("netlink header\n");
+	DEBUGP("len: %d type: %d flags: %d seq: %d pid: %d\n", 
+		nlh->nlmsg_len, nlh->nlmsg_type, nlh->nlmsg_flags, 
+		nlh->nlmsg_seq, nlh->nlmsg_pid);
+
+	nfmsg = NLMSG_DATA(nlh);
+	DEBUGP("nfmsg->nfgen_family: %d\n", nfmsg->nfgen_family);
+
+	min_len = sizeof(struct nfgenmsg);
+	if (nlh->nlmsg_len < min_len)
+		return -EINVAL;
+
+	DEBUGP("size:%d\n", nlh->nlmsg_len);
+
+	while (nlh->nlmsg_len > min_len) {
+		struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
+		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
+
+		struct ip_conntrack_tuple *orig, *reply;
+		unsigned long *status, *timeout;
+		struct cta_proto *proto;
+		unsigned long *id;
+
+		while (NFA_OK(attr, attrlen)) {
+			switch(attr->nfa_type) {
+			case CTA_ORIG:
+				orig = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ", 
+						NIPQUAD(orig->src.ip), 
+						NIPQUAD(orig->dst.ip));
+				h = findproto(proto2str[orig->dst.protonum]);
+				if (h)
+					h->print(orig);
+				break;
+			case CTA_RPLY:
+				reply = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
+						NIPQUAD(reply->src.ip), 
+						NIPQUAD(reply->dst.ip));
+				h = findproto(proto2str[reply->dst.protonum]);
+				if (h)
+					h->print(reply);	
+				break;
+			case CTA_STATUS:
+				status = NFA_DATA(attr);
+				printf("status:%u ", *status);
+				break;
+			case CTA_PROTOINFO:
+				proto = NFA_DATA(attr);
+				if (proto2str[proto->num_proto])
+					printf("%s %d", proto2str[proto->num_proto], proto->num_proto);
+				else
+					printf("unknown %d ", proto->num_proto);
+				break;
+			case CTA_TIMEOUT:
+				timeout = NFA_DATA(attr);
+				printf("timeout:%lu ", *timeout);
+				break;
+/*			case CTA_ID:
+				id = NFA_DATA(attr);
+				printf(" id:%lu ", *id);
+				break;*/
+			}
+			DEBUGP("nfa->nfa_type: %d\n", attr->nfa_type);
+			DEBUGP("nfa->nfa_len: %d\n", attr->nfa_len);
+			attr = NFA_NEXT(attr, attrlen);
+		}
+		min_len += nlh->nlmsg_len;
+		nlh = (struct nlmsghdr *) attr;
+		printf("\n");
+	}
+	DEBUGP("exit from handler\n");
+
+	return 0;
+}
+
+/* FIXME: use event messages better */
+static char *typemsg2str[] = {
+	"NEW",
+	"GET", 
+	"DESTROY"
+};
+
+static int event_handler(struct sockaddr_nl *sock, struct nlmsghdr *nlh, 
+			 void *arg)
+{
+	struct nfgenmsg *nfmsg;
+	struct nfattr *nfa;
+	int min_len = 0;
+	struct ctproto_handler *h = NULL;
+	int type = NFNL_MSG_TYPE(nlh->nlmsg_type);
+
+	DEBUGP("netlink header\n");
+	DEBUGP("len: %d type: %d flags: %d seq: %d pid: %d\n", 
+		nlh->nlmsg_len, nlh->nlmsg_type, nlh->nlmsg_flags, 
+		nlh->nlmsg_seq, nlh->nlmsg_pid);
+
+	nfmsg = NLMSG_DATA(nlh);
+	DEBUGP("nfmsg->nfgen_family: %d\n", nfmsg->nfgen_family);
+
+	min_len = sizeof(struct nfgenmsg);
+	if (nlh->nlmsg_len < min_len)
+		return -EINVAL;
+
+	DEBUGP("size:%d\n", nlh->nlmsg_len);
+
+	printf("type: [%s] ", typemsg2str[type]);
+
+	while (nlh->nlmsg_len > min_len) {
+		struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
+		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
+
+		struct ip_conntrack_tuple *orig, *reply;
+		unsigned long *status, *timeout;
+		struct cta_proto *proto;
+		unsigned long *id;
+
+		while (NFA_OK(attr, attrlen)) {
+			switch(attr->nfa_type) {
+			case CTA_ORIG:
+				orig = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ", 
+						NIPQUAD(orig->src.ip), 
+						NIPQUAD(orig->dst.ip));
+				h = findproto(proto2str[orig->dst.protonum]);
+				if (h)
+					h->print(orig);
+				break;
+			case CTA_RPLY:
+				reply = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
+						NIPQUAD(reply->src.ip), 
+						NIPQUAD(reply->dst.ip));
+				h = findproto(proto2str[reply->dst.protonum]);
+				if (h)
+					h->print(reply);	
+				break;
+			case CTA_STATUS:
+				status = NFA_DATA(attr);
+				printf("status:%u ", *status);
+				break;
+			case CTA_PROTOINFO:
+				proto = NFA_DATA(attr);
+				if (proto2str[proto->num_proto])
+					printf("%s %d", proto2str[proto->num_proto], proto->num_proto);
+				else
+					printf("unknown %d ", proto->num_proto);
+				break;
+			case CTA_TIMEOUT:
+				timeout = NFA_DATA(attr);
+				printf("timeout:%lu ", *timeout);
+				break;
+/*			case CTA_ID:
+				id = NFA_DATA(attr);
+				printf(" id:%lu ", *id);
+				break;*/
+			}
+			DEBUGP("nfa->nfa_type: %d\n", attr->nfa_type);
+			DEBUGP("nfa->nfa_len: %d\n", attr->nfa_len);
+			attr = NFA_NEXT(attr, attrlen);
+		}
+		min_len += nlh->nlmsg_len;
+		nlh = (struct nlmsghdr *) attr;
+		printf("\n");
+	}
+	DEBUGP("exit from handler\n");
+
+	return 0;
+}
+
+static int expect_handler(struct sockaddr_nl *sock, struct nlmsghdr *nlh, void *arg)
+{
+	struct nfgenmsg *nfmsg;
+	struct nfattr *nfa;
+	int min_len = 0;
+	struct ctproto_handler *h = NULL;
+
+	DEBUGP("netlink header\n");
+	DEBUGP("len: %d type: %d flags: %d seq: %d pid: %d\n", 
+		nlh->nlmsg_len, nlh->nlmsg_type, nlh->nlmsg_flags, 
+		nlh->nlmsg_seq, nlh->nlmsg_pid);
+
+	nfmsg = NLMSG_DATA(nlh);
+	DEBUGP("nfmsg->nfgen_family: %d\n", nfmsg->nfgen_family);
+
+	min_len = sizeof(struct nfgenmsg);
+	if (nlh->nlmsg_len < min_len)
+		return -EINVAL;
+
+	DEBUGP("size:%d\n", nlh->nlmsg_len);
+
+	while (nlh->nlmsg_len > min_len) {
+		struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
+		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
+
+		struct ip_conntrack_tuple *exp, *mask;
+		unsigned long *timeout;
+
+		while (NFA_OK(attr, attrlen)) {
+			switch(attr->nfa_type) {
+			case CTA_EXP_TUPLE:
+				exp = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ", 
+						NIPQUAD(exp->src.ip), 
+						NIPQUAD(exp->dst.ip));
+				h = findproto(proto2str[exp->dst.protonum]);
+				if (h)
+					h->print(exp);
+				break;
+			case CTA_EXP_MASK:
+				mask = NFA_DATA(attr);
+				printf("src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
+						NIPQUAD(mask->src.ip), 
+						NIPQUAD(mask->dst.ip));
+				h = findproto(proto2str[mask->dst.protonum]);
+				if (h)
+					h->print(mask);	
+				break;
+			case CTA_EXP_TIMEOUT:
+				timeout = NFA_DATA(attr);
+				printf("timeout:%lu ", *timeout);
+				break;
+			}
+			DEBUGP("nfa->nfa_type: %d\n", attr->nfa_type);
+			DEBUGP("nfa->nfa_len: %d\n", attr->nfa_len);
+			attr = NFA_NEXT(attr, attrlen);
+		}
+		min_len += nlh->nlmsg_len;
+		nlh = (struct nlmsghdr *) attr;
+		printf("\n");
+	}
+	DEBUGP("exit from handler\n");
+
+	return 0;
+}
+
+void create_conntrack(struct ip_conntrack_tuple *orig,
+		      struct ip_conntrack_tuple *reply,
+		      unsigned long timeout,
+		      union ip_conntrack_proto *proto,
+		      unsigned int status)
+{
+	struct cta_proto cta;
+	struct nfattr *cda[CTA_MAX];
+	struct ctnl_handle cth;
+	
+	cta.num_proto = orig->dst.protonum;
+	memcpy(&cta.proto, proto, sizeof(*proto));
+	if (ctnl_open(&cth, 0) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	/* FIXME: please unify returns values... */
+	if (ctnl_new_conntrack(&cth, orig, reply, timeout, proto, status) < 0) {
+		printf("error new conntrack\n");
+		exit(0);
+	}
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2");
+		exit(0);
+	}
+}
+
+void delete_conntrack(struct ip_conntrack_tuple *tuple,
+		      enum ctattr_type_t t,
+		      unsigned long id)
+{
+	struct nfattr *cda[CTA_MAX];
+	struct ctnl_handle cth;
+
+	if (ctnl_open(&cth, 0) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	/* FIXME: please unify returns values... */
+	if (ctnl_del_conntrack(&cth, tuple, t, id) < 0) {
+		printf("error del conntrack\n");
+		exit(0);
+	}
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2");
+		exit(0);
+	}
+}
+
+/* get_conntrack_handler */
+void get_conntrack(struct ip_conntrack_tuple *tuple, 
+		   enum ctattr_type_t t,
+		   unsigned long id)
+{
+	struct nfattr *cda[CTA_MAX];
+	struct ctnl_handle cth;
+	struct ctnl_msg_handler h = {
+		.type = 0,
+		.handler = handler
+	};
+
+	if (ctnl_open(&cth, 0) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	ctnl_register_handler(&cth, &h);
+
+	/* FIXME!!!! get_conntrack_handler returns -100 */
+	if (ctnl_get_conntrack(&cth, tuple, t, id) != -100) {
+		printf("error get conntrack\n");
+		exit(0);
+	}
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2");
+		exit(0);
+	}
+}
+
+void dump_conntrack_table()
+{
+	struct ctnl_handle cth;
+	struct ctnl_msg_handler h = {
+		.type = 0, /* Hm... really? */
+		.handler = handler
+	};
+	
+	if (ctnl_open(&cth, 0) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	ctnl_register_handler(&cth, &h);
+
+	if (ctnl_list_conntrack(&cth, AF_INET) != -100) {
+		printf("error list\n");
+		exit(0);
+	}
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2\n");
+		exit(0);
+	}
+}
+
+void event_conntrack()
+{
+	struct ctnl_handle cth;
+	struct ctnl_msg_handler hnew = {
+		.type = 0, /* new */
+		.handler = event_handler
+	};
+	struct ctnl_msg_handler hdestroy = {
+		.type = 2, /* destroy */
+		.handler = event_handler
+	};
+	
+	if (ctnl_open(&cth, NFGRP_IPV4_CT_TCP) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	ctnl_register_handler(&cth, &hnew);
+	ctnl_register_handler(&cth, &hdestroy);
+	ctnl_event_conntrack(&cth, AF_INET);
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2\n");
+		exit(0);
+	}
+}
+
+struct ctproto_handler *findproto(char *name)
+{
+	void *h = NULL;
+	struct list_head *i;
+	struct ctproto_handler *cur = NULL, *handler = NULL;
+
+	list_for_each(i, &proto_list) {
+		cur = (struct ctproto_handler *) i;
+		if (strcmp(cur->name, name) == 0) {
+			handler = cur;
+			break;
+		}
+	}
+
+	if (!handler) {
+		char path[sizeof("extensions/libct_proto_.so")
+			 + strlen(name)];
+                sprintf(path, "extensions/libct_proto_%s.so", name);
+		if (dlopen(path, RTLD_NOW))
+			handler = findproto(name);
+/*		else
+			fprintf (stderr, "%s\n", dlerror());*/
+	}
+
+	if (!handler)
+		handler = &generic_handler;
+
+	return handler;
+}
+
+void register_proto(struct ctproto_handler *h)
+{
+	list_add(&h->head, &proto_list);
+}
+
+void unregister_proto(struct ctproto_handler *h)
+{
+	list_del(&h->head);
+}
+
+void dump_expect_list()
+{
+	struct ctnl_handle cth;
+	struct ctnl_msg_handler h = {
+		.type = 0, /* Hm... really? */
+		.handler = expect_handler
+	};
+	
+	if (ctnl_open(&cth, 0) < 0) {
+		printf("error\n");
+		exit(0);
+	}
+
+	ctnl_register_handler(&cth, &h);
+
+	if (ctnl_list_expect(&cth, AF_INET) != -100) {
+		printf("error list\n");
+		exit(0);
+	}
+
+	if (ctnl_close(&cth) < 0) {
+		printf("error2\n");
+		exit(0);
+	}
+}
+