/*-
 * Copyright (c) 2004-2009 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Copyright (c) 1990, 1994 Regents of The University of Michigan.
 * All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation, and that the name of The University
 * of Michigan not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior
 * permission. This software is supplied as is without expressed or
 * implied warranties of any kind.
 *
 * This product includes software developed by the University of
 * California, Berkeley and its contributors.
 *
 *	Research Systems Unix Group
 *	The University of Michigan
 *	c/o Wesley Craig
 *	535 W. William Street
 *	Ann Arbor, Michigan
 *	+1-313-764-2278
 *	netatalk@umich.edu
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>

#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/ddp_var.h>
#include <netatalk/ddp_pcb.h>
#include <netatalk/at_extern.h>

struct mtx		 ddp_list_mtx;
static struct ddpcb	*ddp_ports[ATPORT_LAST];
struct ddpcb		*ddpcb_list = NULL;

void
at_sockaddr(struct ddpcb *ddp, struct sockaddr **addr)
{

	/*
	 * Prevent modification of ddp during copy of addr.
	 */
	DDP_LOCK_ASSERT(ddp);
	*addr = sodupsockaddr((struct sockaddr *)&ddp->ddp_lsat, M_NOWAIT);
}

int 
at_pcbsetaddr(struct ddpcb *ddp, struct sockaddr *addr, struct thread *td)
{
	struct sockaddr_at lsat, *sat;
	struct at_ifaddr *aa;
	struct ddpcb *ddpp;

	/*
	 * We read and write both the ddp passed in, and also ddp_ports.
	 */
	DDP_LIST_XLOCK_ASSERT();
	DDP_LOCK_ASSERT(ddp);

	/*
	 * Shouldn't be bound.
	 */
	if (ddp->ddp_lsat.sat_port != ATADDR_ANYPORT)
		return (EINVAL);

	/*
	 * Validate passed address.
	 */
	aa = NULL;
	if (addr != NULL) {
		sat = (struct sockaddr_at *)addr;
		if (sat->sat_family != AF_APPLETALK)
			return (EAFNOSUPPORT);

		if (sat->sat_addr.s_node != ATADDR_ANYNODE ||
		    sat->sat_addr.s_net != ATADDR_ANYNET) {
			AT_IFADDR_RLOCK();
			TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
				if ((sat->sat_addr.s_net ==
				    AA_SAT(aa)->sat_addr.s_net) &&
				    (sat->sat_addr.s_node ==
				    AA_SAT(aa)->sat_addr.s_node))
					break;
			}
			AT_IFADDR_RUNLOCK();
			if (aa == NULL)
				return (EADDRNOTAVAIL);
		}

		if (sat->sat_port != ATADDR_ANYPORT) {
			if (sat->sat_port < ATPORT_FIRST ||
			    sat->sat_port >= ATPORT_LAST)
				return (EINVAL);
			if (sat->sat_port < ATPORT_RESERVED &&
			    priv_check(td, PRIV_NETATALK_RESERVEDPORT))
				return (EACCES);
		}
	} else {
		bzero((caddr_t)&lsat, sizeof(struct sockaddr_at));
		lsat.sat_len = sizeof(struct sockaddr_at);
		lsat.sat_addr.s_node = ATADDR_ANYNODE;
		lsat.sat_addr.s_net = ATADDR_ANYNET;
		lsat.sat_family = AF_APPLETALK;
		sat = &lsat;
	}

	if (sat->sat_addr.s_node == ATADDR_ANYNODE &&
	    sat->sat_addr.s_net == ATADDR_ANYNET) {
		AT_IFADDR_RLOCK();
		if (TAILQ_EMPTY(&at_ifaddrhead)) {
			AT_IFADDR_RUNLOCK();
			return (EADDRNOTAVAIL);
		}
		sat->sat_addr = AA_SAT(TAILQ_FIRST(&at_ifaddrhead))->sat_addr;
		AT_IFADDR_RUNLOCK();
	}
	ddp->ddp_lsat = *sat;

	/*
	 * Choose port.
	 */
	if (sat->sat_port == ATADDR_ANYPORT) {
		for (sat->sat_port = ATPORT_RESERVED;
		    sat->sat_port < ATPORT_LAST; sat->sat_port++) {
			if (ddp_ports[sat->sat_port - 1] == NULL)
				break;
		}
		if (sat->sat_port == ATPORT_LAST)
			return (EADDRNOTAVAIL);
		ddp->ddp_lsat.sat_port = sat->sat_port;
		ddp_ports[sat->sat_port - 1] = ddp;
	} else {
		for (ddpp = ddp_ports[sat->sat_port - 1]; ddpp;
		    ddpp = ddpp->ddp_pnext) {
			if (ddpp->ddp_lsat.sat_addr.s_net ==
			    sat->sat_addr.s_net &&
			    ddpp->ddp_lsat.sat_addr.s_node ==
			    sat->sat_addr.s_node)
				break;
		}
		if (ddpp != NULL)
			return (EADDRINUSE);
		ddp->ddp_pnext = ddp_ports[sat->sat_port - 1];
		ddp_ports[sat->sat_port - 1] = ddp;
		if (ddp->ddp_pnext != NULL)
			ddp->ddp_pnext->ddp_pprev = ddp;
	}

	return (0);
}

int
at_pcbconnect(struct ddpcb *ddp, struct sockaddr *addr, struct thread *td)
{
	struct sockaddr_at	*sat = (struct sockaddr_at *)addr;
	struct route	*ro;
	struct at_ifaddr	*aa = NULL;
	struct ifnet	*ifp;
	u_short		hintnet = 0, net;

	DDP_LIST_XLOCK_ASSERT();
	DDP_LOCK_ASSERT(ddp);

	if (sat->sat_family != AF_APPLETALK)
		return (EAFNOSUPPORT);

	/*
	 * Under phase 2, network 0 means "the network".  We take "the
	 * network" to mean the network the control block is bound to.  If
	 * the control block is not bound, there is an error.
	 */
	if (sat->sat_addr.s_net == ATADDR_ANYNET &&
	    sat->sat_addr.s_node != ATADDR_ANYNODE) {
		if (ddp->ddp_lsat.sat_port == ATADDR_ANYPORT)
			return (EADDRNOTAVAIL);
		hintnet = ddp->ddp_lsat.sat_addr.s_net;
	}

	ro = &ddp->ddp_route;
	/*
	 * If we've got an old route for this pcb, check that it is valid.
	 * If we've changed our address, we may have an old "good looking"
	 * route here.  Attempt to detect it.
	 */
	if (ro->ro_rt) {
		if (hintnet)
			net = hintnet;
		else
			net = sat->sat_addr.s_net;
		aa = NULL;
		AT_IFADDR_RLOCK();
		if ((ifp = ro->ro_rt->rt_ifp) != NULL) {
			TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
				if (aa->aa_ifp == ifp &&
				    ntohs(net) >= ntohs(aa->aa_firstnet) &&
				    ntohs(net) <= ntohs(aa->aa_lastnet))
					break;
			}
		}
		if (aa == NULL || (satosat(&ro->ro_dst)->sat_addr.s_net !=
		    (hintnet ? hintnet : sat->sat_addr.s_net) ||
		    satosat(&ro->ro_dst)->sat_addr.s_node !=
		    sat->sat_addr.s_node)) {
			RTFREE(ro->ro_rt);
			ro->ro_rt = NULL;
		}
		AT_IFADDR_RUNLOCK();
	}

	/*
	 * If we've got no route for this interface, try to find one.
	 */
	if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
		ro->ro_dst.sa_len = sizeof(struct sockaddr_at);
		ro->ro_dst.sa_family = AF_APPLETALK;
		if (hintnet)
			satosat(&ro->ro_dst)->sat_addr.s_net = hintnet;
		else
			satosat(&ro->ro_dst)->sat_addr.s_net =
			    sat->sat_addr.s_net;
		satosat(&ro->ro_dst)->sat_addr.s_node = sat->sat_addr.s_node;
		rtalloc(ro);
	}

	/*
	 * Make sure any route that we have has a valid interface.
	 */
	aa = NULL;
	if (ro->ro_rt && (ifp = ro->ro_rt->rt_ifp)) {
		AT_IFADDR_RLOCK();
		TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
			if (aa->aa_ifp == ifp)
				break;
		}
		AT_IFADDR_RUNLOCK();
	}
	if (aa == NULL)
		return (ENETUNREACH);

	ddp->ddp_fsat = *sat;
	if (ddp->ddp_lsat.sat_port == ATADDR_ANYPORT)
		return (at_pcbsetaddr(ddp, NULL, td));
	return (0);
}

void 
at_pcbdisconnect(struct ddpcb	*ddp)
{

	DDP_LOCK_ASSERT(ddp);

	ddp->ddp_fsat.sat_addr.s_net = ATADDR_ANYNET;
	ddp->ddp_fsat.sat_addr.s_node = ATADDR_ANYNODE;
	ddp->ddp_fsat.sat_port = ATADDR_ANYPORT;
}

int
at_pcballoc(struct socket *so)
{
	struct ddpcb *ddp;

	DDP_LIST_XLOCK_ASSERT();

	ddp = malloc(sizeof *ddp, M_PCB, M_NOWAIT | M_ZERO);
	if (ddp == NULL)
		return (ENOBUFS);
	DDP_LOCK_INIT(ddp);
	ddp->ddp_lsat.sat_port = ATADDR_ANYPORT;

	ddp->ddp_socket = so;
	so->so_pcb = (caddr_t)ddp;

	ddp->ddp_next = ddpcb_list;
	ddp->ddp_prev = NULL;
	ddp->ddp_pprev = NULL;
	ddp->ddp_pnext = NULL;
	if (ddpcb_list != NULL)
		ddpcb_list->ddp_prev = ddp;
	ddpcb_list = ddp;
	return(0);
}

void
at_pcbdetach(struct socket *so, struct ddpcb *ddp)
{

	/*
	 * We modify ddp, ddp_ports, and the global list.
	 */
	DDP_LIST_XLOCK_ASSERT();
	DDP_LOCK_ASSERT(ddp);
	KASSERT(so->so_pcb != NULL, ("at_pcbdetach: so_pcb == NULL"));

	so->so_pcb = NULL;

	/* Remove ddp from ddp_ports list. */
	if (ddp->ddp_lsat.sat_port != ATADDR_ANYPORT &&
	    ddp_ports[ddp->ddp_lsat.sat_port - 1] != NULL) {
		if (ddp->ddp_pprev != NULL)
			ddp->ddp_pprev->ddp_pnext = ddp->ddp_pnext;
		else
			ddp_ports[ddp->ddp_lsat.sat_port - 1] = ddp->ddp_pnext;
		if (ddp->ddp_pnext != NULL)
			ddp->ddp_pnext->ddp_pprev = ddp->ddp_pprev;
	}

	if (ddp->ddp_route.ro_rt)
		RTFREE(ddp->ddp_route.ro_rt);

	if (ddp->ddp_prev)
		ddp->ddp_prev->ddp_next = ddp->ddp_next;
	else
		ddpcb_list = ddp->ddp_next;
	if (ddp->ddp_next)
		ddp->ddp_next->ddp_prev = ddp->ddp_prev;
	DDP_UNLOCK(ddp);
	DDP_LOCK_DESTROY(ddp);
	free(ddp, M_PCB);
}

/*
 * For the moment, this just find the pcb with the correct local address.  In
 * the future, this will actually do some real searching, so we can use the
 * sender's address to do de-multiplexing on a single port to many sockets
 * (pcbs).
 */
struct ddpcb *
ddp_search(struct sockaddr_at *from, struct sockaddr_at *to,
    struct at_ifaddr *aa)
{
	struct ddpcb *ddp;

	DDP_LIST_SLOCK_ASSERT();

	/*
	 * Check for bad ports.
	 */
	if (to->sat_port < ATPORT_FIRST || to->sat_port >= ATPORT_LAST)
		return (NULL);

	/*
	 * Make sure the local address matches the sent address.  What about
	 * the interface?
	 */
	for (ddp = ddp_ports[to->sat_port - 1]; ddp; ddp = ddp->ddp_pnext) {
		DDP_LOCK(ddp);
		/* XXX should we handle 0.YY? */
		/* XXXX.YY to socket on destination interface */
		if (to->sat_addr.s_net == ddp->ddp_lsat.sat_addr.s_net &&
		    to->sat_addr.s_node == ddp->ddp_lsat.sat_addr.s_node) {
			DDP_UNLOCK(ddp);
			break;
		}

		/* 0.255 to socket on receiving interface */
		if (to->sat_addr.s_node == ATADDR_BCAST &&
		    (to->sat_addr.s_net == 0 ||
		    to->sat_addr.s_net == ddp->ddp_lsat.sat_addr.s_net) &&
		    ddp->ddp_lsat.sat_addr.s_net ==
		    AA_SAT(aa)->sat_addr.s_net) {
			DDP_UNLOCK(ddp);
			break;
		}

		/* XXXX.0 to socket on destination interface */
		if (to->sat_addr.s_net == aa->aa_firstnet &&
		    to->sat_addr.s_node == 0 &&
		    ntohs(ddp->ddp_lsat.sat_addr.s_net) >=
		    ntohs(aa->aa_firstnet) &&
		    ntohs(ddp->ddp_lsat.sat_addr.s_net) <=
		    ntohs(aa->aa_lastnet)) {
			DDP_UNLOCK(ddp);
			break;
		}
		DDP_UNLOCK(ddp);
	}
	return (ddp);
}