/*
 * intf-win32.c
 *
 * Copyright (c) 2002 Dug Song <dugsong@monkey.org>
 *
 * $Id: intf-win32.c,v 1.24 2005/02/15 06:37:06 dugsong Exp $
 */

#ifdef _WIN32
#include "dnet_winconfig.h"
#else
#include "config.h"
#endif

#include <winsock2.h>
#include <windows.h>
#include <iphlpapi.h>

#include <dnet.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "pcap.h"

struct ifcombo {
	DWORD		*idx;
	int		 cnt;
	int		 max;
};

#define MIB_IF_TYPE_MAX		MAX_IF_TYPE	/* XXX - ipifcons.h */

struct intf_handle {
	struct ifcombo	 ifcombo[MIB_IF_TYPE_MAX];
	MIB_IFTABLE	*iftable;
	MIB_IPADDRTABLE	*iptable;
};

static char *
_ifcombo_name(int type)
{
	/* Unknown interface types get the prefix "net". */
	char *name = "net";
	
	if (type == MIB_IF_TYPE_ETHERNET || type == IF_TYPE_IEEE80211) {
		/* INTF_TYPE_IEEE80211 is used for wireless devices on
		   Windows Vista. */
		name = "eth";
	} else if (type == MIB_IF_TYPE_TOKENRING) {
		name = "tr";
	} else if (type == MIB_IF_TYPE_FDDI) {
		name = "fddi";
	} else if (type == MIB_IF_TYPE_PPP) {
		name = "ppp";
	} else if (type == MIB_IF_TYPE_LOOPBACK) {
		name = "lo";
	} else if (type == MIB_IF_TYPE_SLIP) {
		name = "sl";
	}
	return (name);
}

/* Return a canonical internal interface type number for the given
 * device string. */
static int
_ifcombo_type(const char *device)
{
	/* Unknown device names (like "net") get mapped to INTF_TYPE_OTHER. */
	int type = INTF_TYPE_OTHER;
	
	if (strncmp(device, "eth", 3) == 0) {
		type = INTF_TYPE_ETH;
	} else if (strncmp(device, "tr", 2) == 0) {
		type = INTF_TYPE_TOKENRING;
	} else if (strncmp(device, "fd", 2) == 0) {
		type = INTF_TYPE_FDDI;
	} else if (strncmp(device, "ppp", 3) == 0) {
		type = INTF_TYPE_PPP;
	} else if (strncmp(device, "lo", 2) == 0) {
		type = INTF_TYPE_LOOPBACK;
	} else if (strncmp(device, "sl", 2) == 0) {
		type = INTF_TYPE_SLIP;
	}
	return (type);
}

/* Map an MIB_IFROW.dwType interface type into an internal interface
   type. The internal types are never exposed to users of this library;
   they exist only for the sake of ordering interface types within an
   intf_handle, which has an array of ifcombo structures ordered by
   type. Entries in an intf_handle must not be stored or accessed by a
   raw MIB_IFROW.dwType number because they will not be able to be found
   by a device name such as "net0" if the device name does not map
   exactly to the dwType. */
static int
_if_type_canonicalize(int type)
{
	return _ifcombo_type(_ifcombo_name(type));
}

static void
_ifcombo_add(struct ifcombo *ifc, DWORD idx)
{
	if (ifc->cnt == ifc->max) {
		if (ifc->idx) {
			ifc->max *= 2;
			ifc->idx = realloc(ifc->idx,
			    sizeof(ifc->idx[0]) * ifc->max);
		} else {
			ifc->max = 8;
			ifc->idx = malloc(sizeof(ifc->idx[0]) * ifc->max);
		}
	}
	ifc->idx[ifc->cnt++] = idx;
}

static void
_ifrow_to_entry(intf_t *intf, MIB_IFROW *ifrow, struct intf_entry *entry)
{
	struct addr *ap, *lap;
	int i;
	int type;
	
	/* The total length of the entry may be passed in inside entry.
	   Remember it and clear the entry. */
	u_int intf_len = entry->intf_len;
	memset(entry, 0, sizeof(*entry));
	/* Restore the length. */
	entry->intf_len = intf_len;

	type = _if_type_canonicalize(ifrow->dwType);
	for (i = 0; i < intf->ifcombo[type].cnt; i++) {
		if (intf->ifcombo[type].idx[i] == ifrow->dwIndex)
			break;
	}
	/* XXX - type matches MIB-II ifType. */
	snprintf(entry->intf_name, sizeof(entry->intf_name), "%s%lu",
	    _ifcombo_name(type), i);
	entry->intf_type = (uint16_t)type;
	
	/* Get interface flags. */
	entry->intf_flags = 0;
	if (ifrow->dwAdminStatus == MIB_IF_ADMIN_STATUS_UP && 
	    (ifrow->dwOperStatus == MIB_IF_OPER_STATUS_OPERATIONAL || 
	     ifrow->dwOperStatus == MIB_IF_OPER_STATUS_CONNECTED))
		entry->intf_flags |= INTF_FLAG_UP;
	if (ifrow->dwType == MIB_IF_TYPE_LOOPBACK)
		entry->intf_flags |= INTF_FLAG_LOOPBACK;
	else
		entry->intf_flags |= INTF_FLAG_MULTICAST;
	
	/* Get interface MTU. */
	entry->intf_mtu = ifrow->dwMtu;
	
	/* Get hardware address. */
	if (ifrow->dwPhysAddrLen == ETH_ADDR_LEN) {
		entry->intf_link_addr.addr_type = ADDR_TYPE_ETH;
		entry->intf_link_addr.addr_bits = ETH_ADDR_BITS;
		memcpy(&entry->intf_link_addr.addr_eth, ifrow->bPhysAddr,
		    ETH_ADDR_LEN);
	}
	/* Get addresses. */
	ap = entry->intf_alias_addrs;
	lap = ap + ((entry->intf_len - sizeof(*entry)) /
	    sizeof(entry->intf_alias_addrs[0]));
	for (i = 0; i < (int)intf->iptable->dwNumEntries; i++) {
		if (intf->iptable->table[i].dwIndex == ifrow->dwIndex &&
		    intf->iptable->table[i].dwAddr != 0) {
			if (entry->intf_addr.addr_type == ADDR_TYPE_NONE) {
				/* Set primary address if unset. */
				entry->intf_addr.addr_type = ADDR_TYPE_IP;
				entry->intf_addr.addr_ip =
				    intf->iptable->table[i].dwAddr;
				addr_mtob(&intf->iptable->table[i].dwMask,
				    IP_ADDR_LEN, &entry->intf_addr.addr_bits);
			} else if (ap < lap) {
				/* Set aliases. */
				ap->addr_type = ADDR_TYPE_IP;
				ap->addr_ip = intf->iptable->table[i].dwAddr;
				addr_mtob(&intf->iptable->table[i].dwMask,
				    IP_ADDR_LEN, &ap->addr_bits);
				ap++, entry->intf_alias_num++;
			}
		}
	}
	entry->intf_len = (unsigned int) ((u_char *)ap - (u_char *)entry);
}

static int
_refresh_tables(intf_t *intf)
{
	MIB_IFROW *ifrow;
	ULONG len;
	u_int i, ret;

	/* Get interface table. */
	for (len = sizeof(intf->iftable[0]); ; ) {
		if (intf->iftable)
			free(intf->iftable);
		intf->iftable = malloc(len);
		ret = GetIfTable(intf->iftable, &len, FALSE);
		if (ret == NO_ERROR)
			break;
		else if (ret != ERROR_INSUFFICIENT_BUFFER)
			return (-1);
	}
	/* Get IP address table. */
	for (len = sizeof(intf->iptable[0]); ; ) {
		if (intf->iptable)
			free(intf->iptable);
		intf->iptable = malloc(len);
		ret = GetIpAddrTable(intf->iptable, &len, FALSE);
		if (ret == NO_ERROR)
			break;
		else if (ret != ERROR_INSUFFICIENT_BUFFER)
			return (-1);
	}
	/*
	 * Map "unfriendly" win32 interface indices to ours.
	 * XXX - like IP_ADAPTER_INFO ComboIndex
	 */
	for (i = 0; i < intf->iftable->dwNumEntries; i++) {
		int type;
		ifrow = &intf->iftable->table[i];
		type = _if_type_canonicalize(ifrow->dwType);
		if (type < MIB_IF_TYPE_MAX) {
			_ifcombo_add(&intf->ifcombo[type],
			    ifrow->dwIndex);
		} else
			return (-1);
	}
	return (0);
}

static int
_find_ifindex(intf_t *intf, const char *device)
{
	char *p = (char *)device;
	int n, type = _ifcombo_type(device);
	
	while (isalpha(*p)) p++;
	n = atoi(p);

	return (intf->ifcombo[type].idx[n]);
}

intf_t *
intf_open(void)
{
	return (calloc(1, sizeof(intf_t)));
}

int
intf_get(intf_t *intf, struct intf_entry *entry)
{
	MIB_IFROW ifrow;
	
	if (_refresh_tables(intf) < 0)
		return (-1);
	
	ifrow.dwIndex = _find_ifindex(intf, entry->intf_name);
	
	if (GetIfEntry(&ifrow) != NO_ERROR)
		return (-1);

	_ifrow_to_entry(intf, &ifrow, entry);
	
	return (0);
}

/* XXX - gross hack required by eth-win32:eth_open() */
const char *
intf_get_desc(intf_t *intf, const char *name)
{
	static char desc[MAXLEN_IFDESCR + 1];
	MIB_IFROW ifrow;
	
	if (_refresh_tables(intf) < 0)
		return (NULL);
	
	ifrow.dwIndex = _find_ifindex(intf, name);
	
	if (GetIfEntry(&ifrow) != NO_ERROR)
		return (NULL);

	
	return (desc);
}

/* Converts a dnet interface name (ifname) to its pcap equivalent, which is stored in
pcapdev (up to a length of pcapdevlen).  Returns 0 and fills in pcapdev if successful. */
int intf_get_pcap_devname(const char *ifname, char *pcapdev, int pcapdevlen) {
	int i;
	intf_t *intf;
	struct intf_entry ie;
	pcap_if_t *pcapdevs;
	pcap_if_t *pdev;
	char pname[128];
	struct sockaddr_in devip;
	pcap_addr_t *pa;

	if ((intf = intf_open()) == NULL)
		return -1;
	
	pname[0] = '\0';
	memset(&ie, 0, sizeof(ie));
	strlcpy(ie.intf_name, ifname, sizeof(ie.intf_name));
	if (intf_get(intf, &ie) != 0) {
		intf_close(intf);
		return -1;
	}
	intf_close(intf);
	
	/* Find the first IPv4 address for ie */
	if (ie.intf_addr.addr_type == ADDR_TYPE_IP) {
		addr_ntos(&ie.intf_addr, (struct sockaddr *) &devip);
	} else {
		for(i=0; i < (int) ie.intf_alias_num; i++) {
			if (ie.intf_alias_addrs[i].addr_type == ADDR_TYPE_IP) {
				addr_ntos(&ie.intf_alias_addrs[i], (struct sockaddr *) &devip);
				break;
			}
		}
		if (i == ie.intf_alias_num)
			return -1; // Failed to find IPv4 address, which is currently a requirement
	}

	/* Next we must find the pcap device name corresponding to the device.
	   The device description used to be compared with those from PacketGetAdapterNames(), but
	   that was unrelaible because dnet and pcap sometimes give different descriptions.  For example, 
	   dnet gave me "AMD PCNET Family PCI Ethernet Adapter - Packet Scheduler Miniport" for one of my 
	   adapters (in vmware), while pcap described it as "VMware Accelerated AMD PCNet Adapter (Microsoft's
	   Packet Scheduler)". Plus,  Packet* functions aren't really supported for external use by the 
	   WinPcap folks.  So I have rewritten this to compare interface addresses (which has its own 
	   problems -- what if you want to listen an an interface with no IP address set?) --Fyodor */
	if (pcap_findalldevs(&pcapdevs, NULL) == -1)
		return -1;

	for(pdev=pcapdevs; pdev && !pname[0]; pdev = pdev->next) {
		for (pa=pdev->addresses; pa && !pname[0]; pa = pa->next) {
			if (pa->addr->sa_family != AF_INET)
				continue;
			if (((struct sockaddr_in *)pa->addr)->sin_addr.s_addr == devip.sin_addr.s_addr) {
				strlcpy(pname, pdev->name, sizeof(pname)); /* Found it -- Yay! */
			break;
	}
		}
	}

	pcap_freealldevs(pcapdevs);
	if (pname[0]) {
		strlcpy(pcapdev, pname, pcapdevlen);
		return 0;
	}
	return -1;
}


int
intf_get_src(intf_t *intf, struct intf_entry *entry, struct addr *src)
{
	MIB_IFROW ifrow;
	MIB_IPADDRROW *iprow;
	int i;

	if (src->addr_type != ADDR_TYPE_IP) {
		errno = EINVAL;
		return (-1);
	}
	if (_refresh_tables(intf) < 0)
		return (-1);
	
	for (i = 0; i < (int)intf->iptable->dwNumEntries; i++) {
		iprow = &intf->iptable->table[i];
		if (iprow->dwAddr == src->addr_ip) {
			ifrow.dwIndex = iprow->dwIndex;
			if (GetIfEntry(&ifrow) != NO_ERROR)
				return (-1);
			_ifrow_to_entry(intf, &ifrow, entry);
			return (0);
		}
	}
	errno = ENXIO;
	return (-1);
}

int
intf_get_dst(intf_t *intf, struct intf_entry *entry, struct addr *dst)
{
	MIB_IFROW ifrow;
	
	if (dst->addr_type != ADDR_TYPE_IP) {
		errno = EINVAL;
		return (-1);
	}
	if (GetBestInterface(dst->addr_ip, &ifrow.dwIndex) != NO_ERROR)
		return (-1);

	if (GetIfEntry(&ifrow) != NO_ERROR)
		return (-1);
	
	if (_refresh_tables(intf) < 0)
		return (-1);
	
	_ifrow_to_entry(intf, &ifrow, entry);
	
	return (0);
}

int
intf_set(intf_t *intf, const struct intf_entry *entry)
{
	/*
	 * XXX - could set interface up/down via SetIfEntry(),
	 * but what about the rest of the configuration? :-(
	 * {Add,Delete}IPAddress for 2000/XP only
	 */
#if 0
	/* Set interface address. XXX - 2000/XP only? */
	if (entry->intf_addr.addr_type == ADDR_TYPE_IP) {
		ULONG ctx = 0, inst = 0;
		UINT ip, mask;

		memcpy(&ip, &entry->intf_addr.addr_ip, IP_ADDR_LEN);
		addr_btom(entry->intf_addr.addr_bits, &mask, IP_ADDR_LEN);
		
		if (AddIPAddress(ip, mask,
			_find_ifindex(intf, entry->intf_name),
			&ctx, &inst) != NO_ERROR) {
			return (-1);
		}
		return (0);
	}
#endif
	errno = ENOSYS;
	SetLastError(ERROR_NOT_SUPPORTED);
	return (-1);
}

int
intf_loop(intf_t *intf, intf_handler callback, void *arg)
{
	struct intf_entry *entry;
	u_char ebuf[1024];
	int i, ret = 0;

	if (_refresh_tables(intf) < 0)
		return (-1);
	
	entry = (struct intf_entry *)ebuf;
	
	for (i = 0; i < (int)intf->iftable->dwNumEntries; i++) {
		entry->intf_len = sizeof(ebuf);
		_ifrow_to_entry(intf, &intf->iftable->table[i], entry);
		if ((ret = (*callback)(entry, arg)) != 0)
			break;
	}
	return (ret);
}

intf_t *
intf_close(intf_t *intf)
{
	int i;

	if (intf != NULL) {
		for (i = 0; i < MIB_IF_TYPE_MAX; i++) {
			if (intf->ifcombo[i].idx)
				free(intf->ifcombo[i].idx);
		}
		if (intf->iftable)
			free(intf->iftable);
		if (intf->iptable)
			free(intf->iptable);
		free(intf);
	}
	return (NULL);
}