/*
 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1982, 1989, 1993
 *	The Regents of the University of California.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <kern/lock.h>

#include <net/if.h>
#include <net/route.h>
#include <net/if_llc.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/kpi_protocol.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_arp.h>

#include <sys/socketvar.h>

#include <net/dlil.h>

#if BRIDGE
#include <net/bridge.h>
#endif

/* #include "vlan.h" */
#if NVLAN > 0
#include <net/if_vlan_var.h>
#endif /* NVLAN > 0 */
#include <net/ether_if_module.h>
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif

/* Local function declerations */
extern void *kdp_get_interface(void);
extern void kdp_set_ip_and_mac_addresses(struct in_addr *ipaddr,
										 struct ether_addr *macaddr);

static __inline__ void
_ip_copy(struct in_addr * dst, const struct in_addr * src)
{
	*dst = *src;
	return;
}

static void
ether_inet_arp_input(
	struct mbuf *m)
{
	struct ether_arp *ea;
	struct sockaddr_dl	sender_hw;
	struct sockaddr_in	sender_ip;
	struct sockaddr_in	target_ip;
	
	if (mbuf_len(m) < sizeof(*ea) &&
		mbuf_pullup(&m, sizeof(*ea)) != 0)
		return;
	
	ea = mbuf_data(m);
	
	/* Verify this is an ethernet/ip arp and address lengths are correct */
	if (ntohs(ea->arp_hrd) != ARPHRD_ETHER ||
		ntohs(ea->arp_pro) != ETHERTYPE_IP ||
		ea->arp_pln != sizeof(struct in_addr) ||
		ea->arp_hln != ETHER_ADDR_LEN) {
		mbuf_free(m);
		return;
	}
	
	/* Verify the sender is not broadcast */
	if (bcmp(ea->arp_sha, etherbroadcastaddr, ETHER_ADDR_LEN) == 0) {
		mbuf_free(m);
		return;
	}
	
	bzero(&sender_ip, sizeof(sender_ip));
	sender_ip.sin_len = sizeof(sender_ip);
	sender_ip.sin_family = AF_INET;
	_ip_copy(&sender_ip.sin_addr, (const struct in_addr *)ea->arp_spa);
	target_ip = sender_ip;
	_ip_copy(&target_ip.sin_addr, (const struct in_addr *)ea->arp_tpa);
	
	bzero(&sender_hw, sizeof(sender_hw));
	sender_hw.sdl_len = sizeof(sender_hw);
	sender_hw.sdl_family = AF_LINK;
	sender_hw.sdl_type = IFT_ETHER;
	sender_hw.sdl_alen = ETHER_ADDR_LEN;
	bcopy(ea->arp_sha, LLADDR(&sender_hw), ETHER_ADDR_LEN);
	
	arp_ip_handle_input(mbuf_pkthdr_rcvif(m), ntohs(ea->arp_op), &sender_hw, &sender_ip, &target_ip);
	mbuf_free(m);
}

/*
 * Process a received Ethernet packet;
 * the packet is in the mbuf chain m without
 * the ether header, which is provided separately.
 */
static errno_t
ether_inet_input(
	__unused ifnet_t			ifp,
	__unused protocol_family_t	protocol_family,
	mbuf_t						m_list)
{
	mbuf_t	m;
	mbuf_t	*tailptr = &m_list;
	mbuf_t	nextpkt;
	
	/* Strip ARP and non-IP packets out of the list */
	for (m = m_list; m; m = nextpkt) {
    	struct ether_header *eh = mbuf_pkthdr_header(m);
    	
    	nextpkt = m->m_nextpkt;
		
    	if (eh->ether_type == htons(ETHERTYPE_IP)) {
    		/* put this packet in the list */
    		*tailptr = m;
    		tailptr = &m->m_nextpkt;
    	}
    	else {
    		/* Pass ARP packets to arp input */
			m->m_nextpkt = NULL;
    		if (eh->ether_type == htons(ETHERTYPE_ARP))
    			ether_inet_arp_input(m);
    		else
    			mbuf_freem(m);
    	}
	}
	
	*tailptr = NULL;
	
	/* Pass IP list to ip input */
	if (m_list != NULL && proto_input(PF_INET, m_list) != 0)
	{
		mbuf_freem_list(m_list);
	}
	
    return 0;
}

static errno_t
ether_inet_pre_output(
	ifnet_t						ifp,
	__unused protocol_family_t	protocol_family,
	mbuf_t						*m0,
	const struct sockaddr		*dst_netaddr,
	void*						route,
	char						*type,
	char						*edst)
{
    register struct mbuf *m = *m0;
    const struct ether_header *eh;
    errno_t	result = 0;


    if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) 
		return ENETDOWN;
	
    /*
     * Tell ether_frameout it's ok to loop packet unless negated below.
     */
    m->m_flags |= M_LOOP;

    switch (dst_netaddr->sa_family) {
    
		case AF_INET: {
				struct sockaddr_dl	ll_dest;
				result = arp_lookup_ip(ifp, (const struct sockaddr_in*)dst_netaddr,
									   &ll_dest, sizeof(ll_dest), (route_t)route, *m0);
				if (result == 0) {
					bcopy(LLADDR(&ll_dest), edst, ETHER_ADDR_LEN);
					*(u_int16_t*)type = htons(ETHERTYPE_IP);
				}
			}
			break;

		case pseudo_AF_HDRCMPLT:	
		case AF_UNSPEC:
			m->m_flags &= ~M_LOOP;
			eh = (const struct ether_header *)dst_netaddr->sa_data;
			(void)memcpy(edst, eh->ether_dhost, 6);
			*(u_short *)type = eh->ether_type;
			break;
	
		default:
			printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
				   dst_netaddr->sa_family);
	
			result = EAFNOSUPPORT;
    }

    return result;
}

static errno_t
ether_inet_resolve_multi(
	ifnet_t					ifp,
	const struct sockaddr	*proto_addr,
	struct sockaddr_dl		*out_ll,
	size_t					ll_len)
{
	static const size_t minsize = offsetof(struct sockaddr_dl, sdl_data[0]) + ETHER_ADDR_LEN;
	const struct sockaddr_in	*sin = (const struct sockaddr_in*)proto_addr;
	
	if (proto_addr->sa_family != AF_INET)
		return EAFNOSUPPORT;
	
	if (proto_addr->sa_len < sizeof(struct sockaddr_in))
		return EINVAL;

	if (ll_len < minsize)
		return EMSGSIZE;
	
	bzero(out_ll, minsize);
	out_ll->sdl_len = minsize;
	out_ll->sdl_family = AF_LINK;
	out_ll->sdl_index = ifp->if_index;
	out_ll->sdl_type = IFT_ETHER;
	out_ll->sdl_nlen = 0;
	out_ll->sdl_alen = ETHER_ADDR_LEN;
	out_ll->sdl_slen = 0;
	ETHER_MAP_IP_MULTICAST(&sin->sin_addr, LLADDR(out_ll));
	
	return 0;
}

static errno_t
ether_inet_prmod_ioctl(
    ifnet_t						ifp,
    __unused protocol_family_t	protocol_family,
    u_int32_t					command,
    void*						data)
{
    ifaddr_t ifa = data;
    struct ifreq *ifr = data;
    int error = 0;


    switch (command) {
    case SIOCSIFADDR:
    case SIOCAIFADDR:
	if ((ifnet_flags(ifp) & IFF_RUNNING) == 0) {
		ifnet_set_flags(ifp, IFF_UP, IFF_UP);
		ifnet_ioctl(ifp, 0, SIOCSIFFLAGS, NULL);
	}

	 switch (ifaddr_address_family(ifa)) {

	 case AF_INET:

	    inet_arp_init_ifaddr(ifp, ifa);
	    /*
	     * Register new IP and MAC addresses with the kernel
	     * debugger if the interface is the same as was registered
	     * by IOKernelDebugger. If no interface was registered,
	     * fall back and just match against en0 interface.
	     * Do this only for the first address of the interface
	     * and not for aliases.
	     */
	    if (command == SIOCSIFADDR &&
	        ((kdp_get_interface() != 0 &&
	        kdp_get_interface() == ifp->if_softc) ||
		(kdp_get_interface() == 0 && ifp->if_unit == 0)))
			kdp_set_ip_and_mac_addresses(&(IA_SIN(ifa)->sin_addr),
			    ifnet_lladdr(ifp));

	    break;

	default:
	    break;
	}

	break;

    case SIOCGIFADDR:
		ifnet_lladdr_copy_bytes(ifp, ifr->ifr_addr.sa_data, ETHER_ADDR_LEN);
		break;

    default:
		error = EOPNOTSUPP;
		break;
    }

    return (error);
}

static void
ether_inet_event(
	ifnet_t						ifp,
	__unused protocol_family_t	protocol,
	const struct kev_msg		*event)
{
	ifaddr_t	*addresses;
	
	if (event->vendor_code !=  KEV_VENDOR_APPLE ||
		event->kev_class != KEV_NETWORK_CLASS ||
		event->kev_subclass != KEV_DL_SUBCLASS ||
		event->event_code != KEV_DL_LINK_ADDRESS_CHANGED) {
		return;
	}
	
	if (ifnet_get_address_list_family(ifp, &addresses, AF_INET) == 0) {
		int i;
		
		for (i = 0; addresses[i] != NULL; i++) {
			inet_arp_init_ifaddr(ifp, addresses[i]);
		}
		
		ifnet_free_address_list(addresses);
	}
}

static errno_t
ether_inet_arp(
	ifnet_t								ifp,
	u_short								arpop,
	const struct sockaddr_dl*			sender_hw,
	const struct sockaddr*				sender_proto,
	const struct sockaddr_dl*			target_hw,
	const struct sockaddr*				target_proto)
{
	mbuf_t	m;
	errno_t	result;
	struct ether_header *eh;
	struct ether_arp *ea;
	const struct sockaddr_in* sender_ip = (const struct sockaddr_in*)sender_proto;
	const struct sockaddr_in* target_ip = (const struct sockaddr_in*)target_proto;
	char *datap;
	
	if (target_ip == NULL)
		return EINVAL;
	
	if ((sender_ip && sender_ip->sin_family != AF_INET) ||
	    target_ip->sin_family != AF_INET)
		return EAFNOSUPPORT;
	
	result = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_DATA, &m);
	if (result != 0)
		return result;
	
	mbuf_setlen(m, sizeof(*ea));
	mbuf_pkthdr_setlen(m, sizeof(*ea));
	
	/* Move the data pointer in the mbuf to the end, aligned to 4 bytes */
	datap = mbuf_datastart(m);
	datap += mbuf_trailingspace(m);
	datap -= (((u_long)datap) & 0x3);
	mbuf_setdata(m, datap, sizeof(*ea));
	ea = mbuf_data(m);
	
	/*
	 * Prepend the ethernet header, we will send the raw frame;
	 * callee frees the original mbuf when allocation fails.
	 */
	result = mbuf_prepend(&m, sizeof(*eh), MBUF_DONTWAIT);
	if (result != 0)
		return result;

	eh = mbuf_data(m);
	eh->ether_type = htons(ETHERTYPE_ARP);

#if CONFIG_MACF_NET
	mac_mbuf_label_associate_linklayer(ifp, m);
#endif
	
	/* Fill out the arp header */
	ea->arp_pro = htons(ETHERTYPE_IP);
	ea->arp_hln = sizeof(ea->arp_sha);
	ea->arp_pln = sizeof(ea->arp_spa);
	ea->arp_hrd = htons(ARPHRD_ETHER);
	ea->arp_op = htons(arpop);
	
	/* Sender Hardware */
	if (sender_hw != NULL) {
		bcopy(CONST_LLADDR(sender_hw), ea->arp_sha, sizeof(ea->arp_sha));
	}
	else {
		ifnet_lladdr_copy_bytes(ifp, ea->arp_sha, ETHER_ADDR_LEN);
	}
	ifnet_lladdr_copy_bytes(ifp, eh->ether_shost, sizeof(eh->ether_shost));
	
	/* Sender IP */
	if (sender_ip != NULL) {
		bcopy(&sender_ip->sin_addr, ea->arp_spa, sizeof(ea->arp_spa));
	}
	else {
		struct ifaddr *ifa;
		
		/* Look for an IP address to use as our source */
		ifnet_lock_shared(ifp);
		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
			if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET)
				break;
		}
		if (ifa) {
			bcopy(&((struct sockaddr_in*)ifa->ifa_addr)->sin_addr, ea->arp_spa,
				  sizeof(ea->arp_spa));
		}
		ifnet_lock_done(ifp);
		
		if (ifa == NULL) {
			mbuf_free(m);
			return ENXIO;
		}
	}
	
	/* Target Hardware */
	if (target_hw == 0) {
		bzero(ea->arp_tha, sizeof(ea->arp_tha));
		bcopy(etherbroadcastaddr, eh->ether_dhost, sizeof(eh->ether_dhost));
	}
	else {
		bcopy(CONST_LLADDR(target_hw), ea->arp_tha, sizeof(ea->arp_tha));
		bcopy(CONST_LLADDR(target_hw), eh->ether_dhost, sizeof(eh->ether_dhost));
	}
	
	/* Target IP */
	bcopy(&target_ip->sin_addr, ea->arp_tpa, sizeof(ea->arp_tpa));
	
	ifnet_output_raw(ifp, PF_INET, m);
	
	return 0;
}

errno_t
ether_attach_inet(
	struct ifnet	*ifp,
	__unused protocol_family_t proto_family)
{
	struct ifnet_attach_proto_param_v2 proto;
	struct ifnet_demux_desc demux[2];
	u_short en_native=htons(ETHERTYPE_IP);
	u_short arp_native=htons(ETHERTYPE_ARP);
	errno_t	error;
	
	bzero(&demux[0], sizeof(demux));
	demux[0].type = DLIL_DESC_ETYPE2;
	demux[0].data = &en_native;
	demux[0].datalen = sizeof(en_native);
	demux[1].type = DLIL_DESC_ETYPE2;
	demux[1].data = &arp_native;
	demux[1].datalen = sizeof(arp_native);

	bzero(&proto, sizeof(proto));
	proto.demux_list = demux;
	proto.demux_count = sizeof(demux) / sizeof(demux[0]);
	proto.input = ether_inet_input;
	proto.pre_output = ether_inet_pre_output;
	proto.ioctl = ether_inet_prmod_ioctl;
	proto.event = ether_inet_event;
	proto.resolve = ether_inet_resolve_multi;
	proto.send_arp = ether_inet_arp;
	
	error = ifnet_attach_protocol_v2(ifp, proto_family, &proto);
	if (error && error != EEXIST) {
		printf("WARNING: ether_attach_inet can't attach ip to %s%d\n",
			   ifp->if_name, ifp->if_unit);
	}
	return error;
}

void
ether_detach_inet(
	struct ifnet *ifp,
	protocol_family_t proto_family)
{
	(void)ifnet_detach_protocol(ifp, proto_family);
}