/*	$OpenBSD: policy.c,v 1.11 2010/07/03 16:59:35 reyk Exp $	*/
/*	$vantronix: policy.c,v 1.29 2010/05/28 15:34:35 reyk Exp $	*/

/*
 * Copyright (c) 2010 Reyk Floeter <reyk@vantronix.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/tree.h>

#include <net/if.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <event.h>

#include "iked.h"
#include "ikev2.h"

static __inline int
	 policy_cmp(struct iked_policy *, struct iked_policy *);
static __inline int
	 sa_cmp(struct iked_sa *, struct iked_sa *);
static __inline int
	 user_cmp(struct iked_user *, struct iked_user *);

void
policy_init(struct iked *env)
{
	RB_INIT(&env->sc_policies);
	RB_INIT(&env->sc_users);
	RB_INIT(&env->sc_sas);
}

int
policy_lookup(struct iked *env, struct iked_message *msg)
{
	struct iked_policy	 pol;

	if (msg->msg_sa != NULL && msg->msg_sa->sa_policy != NULL) {
		/* Existing SA with policy */
		msg->msg_policy = msg->msg_sa->sa_policy;
		goto found;
	}

	bzero(&pol, sizeof(pol));
	memcpy(&pol.pol_peer, &msg->msg_peer, sizeof(pol.pol_peer));
	memcpy(&pol.pol_local, &msg->msg_local, sizeof(pol.pol_local));

	/* Try to find a matching policy for this message */
	if ((msg->msg_policy =
	    RB_FIND(iked_policies, &env->sc_policies, &pol)) != NULL)
		goto found;

	/* No matching policy found, try the default */
	if ((msg->msg_policy = env->sc_defaultcon) != NULL)
		goto found;

	/* No policy found */
	return (-1);

 found:
	return (0);
}

static __inline int
policy_cmp(struct iked_policy *a, struct iked_policy *b)
{
	int	 ret;

	if (b->pol_flags & IKED_POLICY_DEFAULT)
		return (-2);

	if ((ret = sockaddr_cmp((struct sockaddr *)&a->pol_peer,
	    (struct sockaddr *)&b->pol_peer, b->pol_peermask)) != 0)
		return (ret);
	if ((ret = sockaddr_cmp((struct sockaddr *)&a->pol_local,
	    (struct sockaddr *)&b->pol_local, b->pol_localmask)) != 0)
		return (ret);

	return (0);
}

void
policy_ref(struct iked *env, struct iked_policy *pol)
{
	pol->pol_refcnt++;
	pol->pol_flags |= IKED_POLICY_REFCNT;
}

void
policy_unref(struct iked *env, struct iked_policy *pol)
{
	if (pol == NULL || (pol->pol_flags & IKED_POLICY_REFCNT) == 0)
		return;
	if (--(pol->pol_refcnt) <= 0)
		config_free_policy(env, pol);
}

RB_GENERATE(iked_policies, iked_policy, pol_entry, policy_cmp);

void
sa_state(struct iked *env, struct iked_sa *sa, int state)
{
	const char		*a;
	const char		*b;

	a = print_map(sa->sa_state, ikev2_state_map);
	b = print_map(state, ikev2_state_map);

	if (state > sa->sa_state) {
		switch (state) {
		case IKEV2_STATE_ESTABLISHED:
		case IKEV2_STATE_CLOSED:
			log_info("%s: %s -> %s from %s to %s policy '%s'",
			    __func__, a, b,
			    print_host(&sa->sa_peer.addr, NULL, 0),
			    print_host(&sa->sa_local.addr, NULL, 0),
			    sa->sa_policy->pol_name);
			break;
		default:
			log_debug("%s: %s -> %s", __func__, a, b);
			break;
		}
	}

	sa->sa_state = state;
}

void
sa_stateflags(struct iked_sa *sa, u_int flags)
{
	u_int	require;

	if (sa->sa_state > IKEV2_STATE_SA_INIT)
		require = sa->sa_statevalid;
	else
		require = sa->sa_stateinit;

	log_debug("%s: 0x%02x -> 0x%02x %s (required 0x%02x %s)", __func__,
	    sa->sa_stateflags, sa->sa_stateflags | flags,
	    print_bits(sa->sa_stateflags | flags, IKED_REQ_BITS), require,
	    print_bits(require, IKED_REQ_BITS));

	sa->sa_stateflags |= flags;
}

int
sa_stateok(struct iked_sa *sa, int state)
{
	u_int	 require;

	if (sa->sa_state < state)
		return (0);

	if (state == IKEV2_STATE_SA_INIT)
		require = sa->sa_stateinit;
	else
		require = sa->sa_statevalid;

	if (state == IKEV2_STATE_SA_INIT ||
	    state == IKEV2_STATE_VALID ||
	    state == IKEV2_STATE_EAP) {
		log_debug("%s: %s flags 0x%02x, require 0x%02x %s", __func__,
		    print_map(state, ikev2_state_map),
		    (sa->sa_stateflags & require), require,
		    print_bits(require, IKED_REQ_BITS));

		if ((sa->sa_stateflags & require) != require)
			return (0);	/* not ready, ignore */
	}
	return (1);
}

struct iked_sa *
sa_new(struct iked *env, u_int64_t ispi, u_int64_t rspi,
    u_int initiator, struct iked_policy *pol)
{
	struct iked_sa	*sa;
	struct iked_id	*localid;
	u_int		 diff;

	if ((ispi == 0 && rspi == 0) ||
	    (sa = sa_lookup(env, ispi, rspi, initiator)) == NULL) {
		/* Create new SA */
		sa = config_new_sa(env, initiator);
	}
	if (sa == NULL) {
		log_debug("%s: failed to get sa", __func__);
		return (NULL);
	}
	if (sa->sa_policy == NULL)
		sa->sa_policy = pol;
	else
		pol = sa->sa_policy;

	sa->sa_statevalid = IKED_REQ_AUTH|IKED_REQ_SA;
	if (pol != NULL && pol->pol_auth.auth_eap) {
		sa->sa_statevalid |= IKED_REQ_CERT;
	} else if (pol != NULL && pol->pol_auth.auth_method !=
	    IKEV2_AUTH_SHARED_KEY_MIC) {
		sa->sa_statevalid |= IKED_REQ_VALID|IKED_REQ_CERT;
	}

	if (initiator) {
		localid = &sa->sa_iid;
		diff = IKED_REQ_VALID|IKED_REQ_SA;
		sa->sa_stateinit = sa->sa_statevalid & ~diff;
		sa->sa_statevalid = sa->sa_statevalid & diff;
	} else
		localid = &sa->sa_rid;

	if (!ibuf_length(localid->id_buf) &&
	    ikev2_policy2id(&pol->pol_localid, localid, 1) != 0) {
		log_debug("%s: failed to get local id", __func__);
		sa_free(env, sa);
		return (NULL);
	}

	if (sa->sa_hdr.sh_ispi == 0)
		sa->sa_hdr.sh_ispi = ispi;
	if (sa->sa_hdr.sh_rspi == 0)
		sa->sa_hdr.sh_rspi = rspi;

	/* Re-insert node into the tree */
	RB_INSERT(iked_sas, &env->sc_sas, sa);

	return (sa);
}

void
sa_free(struct iked *env, struct iked_sa *sa)
{
	log_debug("%s: ispi %s rspi %s", __func__,
	    print_spi(sa->sa_hdr.sh_ispi, 8),
	    print_spi(sa->sa_hdr.sh_rspi, 8));

	config_free_sa(env, sa);
}

int
sa_address(struct iked_sa *sa, struct iked_addr *addr,
    struct sockaddr_storage *peer)
{
	struct iked_policy	*pol = sa->sa_policy;

	if (pol == NULL) {
		log_debug("%s: invalid policy", __func__);
		return (-1);
	}

	bzero(addr, sizeof(*addr));
	addr->addr_af = peer->ss_family;
	addr->addr_port = htons(socket_getport(peer));
	memcpy(&addr->addr, peer, sizeof(*peer));
	if (socket_af((struct sockaddr *)&addr->addr, addr->addr_port) == -1) {
		log_debug("%s: invalid address", __func__);
		return (-1);
	}

	if (addr == &sa->sa_peer) {
		/* XXX Re-insert node into the tree */
		(void)RB_REMOVE(iked_sapeers, &pol->pol_sapeers, sa);
		RB_INSERT(iked_sapeers, &pol->pol_sapeers, sa);
	}

	return (0);
}

void
childsa_free(struct iked_childsa *sa)
{
	ibuf_release(sa->csa_encrkey);
	ibuf_release(sa->csa_integrkey);
	free(sa);
}

void
flow_free(struct iked_flow *flow)
{
	free(flow);
}

struct iked_sa *
sa_lookup(struct iked *env, u_int64_t ispi, u_int64_t rspi,
    u_int initiator)
{
	struct iked_sa	*sa, key;

	key.sa_hdr.sh_ispi = ispi;
	key.sa_hdr.sh_rspi = rspi;
	key.sa_hdr.sh_initiator = initiator;

	if ((sa = RB_FIND(iked_sas, &env->sc_sas, &key)) != NULL) {
		gettimeofday(&sa->sa_timeused, NULL);

		/* Validate if SPIr matches */
		if ((sa->sa_hdr.sh_rspi != 0) &&
		    (sa->sa_hdr.sh_rspi != rspi))
			return (NULL);
	}

	return (sa);
}

static __inline int
sa_cmp(struct iked_sa *a, struct iked_sa *b)
{
	if (a->sa_hdr.sh_initiator != b->sa_hdr.sh_initiator)
		return (-2);

	if (a->sa_hdr.sh_ispi > b->sa_hdr.sh_ispi)
		return (-1);
	if (a->sa_hdr.sh_ispi < b->sa_hdr.sh_ispi)
		return (1);

#if 0
	/* Responder SPI is not yet set in the local IKE SADB */
	if ((b->sa_type == IKED_SATYPE_LOCAL && b->sa_hdr.sh_rspi == 0) ||
	    (a->sa_type == IKED_SATYPE_LOCAL && a->sa_hdr.sh_rspi == 0))
		return (0);

	if (a->sa_hdr.sh_rspi > b->sa_hdr.sh_rspi)
		return (-1);
	if (a->sa_hdr.sh_rspi < b->sa_hdr.sh_rspi)
		return (1);
#endif

	return (0);
}

RB_GENERATE(iked_sas, iked_sa, sa_entry, sa_cmp);

struct iked_sa *
sa_peer_lookup(struct iked_policy *pol, struct sockaddr_storage *peer)
{
	struct iked_sa	 key;

	memcpy(&key.sa_peer.addr, peer, sizeof(*peer));
	return (RB_FIND(iked_sapeers, &pol->pol_sapeers, &key));
}

static __inline int
sa_peer_cmp(struct iked_sa *a, struct iked_sa *b)
{
	return (sockaddr_cmp((struct sockaddr *)&a->sa_peer.addr,
	    (struct sockaddr *)&b->sa_peer.addr, -1));
}

RB_GENERATE(iked_sapeers, iked_sa, sa_peer_entry, sa_peer_cmp);

struct iked_user *
user_lookup(struct iked *env, const char *user)
{
	struct iked_user	 key;

	if (strlcpy(key.usr_name, user,
	    sizeof(key.usr_name)) >= sizeof(key.usr_name))
		return (NULL);

	return (RB_FIND(iked_users, &env->sc_users, &key));
}

static __inline int
user_cmp(struct iked_user *a, struct iked_user *b)
{
	return (strcmp(a->usr_name, b->usr_name));
}

RB_GENERATE(iked_users, iked_user, usr_entry, user_cmp);