/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */

/*

 * Copyright (c) 1994, 1995, 1996, 1997, 1998

 *	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 Computer Systems

 *	Engineering Group at Lawrence Berkeley Laboratory.

 * 4. Neither the name of the University nor of the Laboratory 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.

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <net/if.h>

#include <ctype.h>

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <ifaddrs.h>

#include "pcap-int.h"

#ifdef HAVE_OS_PROTO_H

#include "os-proto.h"

#endif

/*

 * We don't do this on Solaris 11 and later, as it appears there aren't

 * any AF_PACKET addresses on interfaces, so we don't need this, and

 * we end up including both the OS's <net/bpf.h> and our <pcap/bpf.h>,

 * and their definitions of some data structures collide.

 */

#if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET)

# ifdef HAVE_NETPACKET_PACKET_H

/* Linux distributions with newer glibc */

#  include <netpacket/packet.h>

# else /* HAVE_NETPACKET_PACKET_H */

/* LynxOS, Linux distributions with older glibc */

# ifdef __Lynx__

/* LynxOS */

#  include <netpacket/if_packet.h>

# else /* __Lynx__ */

/* Linux */

#  include <linux/types.h>

#  include <linux/if_packet.h>

# endif /* __Lynx__ */

# endif /* HAVE_NETPACKET_PACKET_H */

#endif /* (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET) */

/*

 * This is fun.

 *

 * In older BSD systems, socket addresses were fixed-length, and

 * "sizeof (struct sockaddr)" gave the size of the structure.

 * All addresses fit within a "struct sockaddr".

 *

 * In newer BSD systems, the socket address is variable-length, and

 * there's an "sa_len" field giving the length of the structure;

 * this allows socket addresses to be longer than 2 bytes of family

 * and 14 bytes of data.

 *

 * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553

 * variant of the old BSD scheme (with "struct sockaddr_storage" rather

 * than "struct sockaddr"), and some use the new BSD scheme.

 *

 * Some versions of GNU libc use neither scheme, but has an "SA_LEN()"

 * macro that determines the size based on the address family.  Other

 * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553

 * but not in the final version).  On the latter systems, we explicitly

 * check the AF_ type to determine the length; we assume that on

 * all those systems we have "struct sockaddr_storage".

 */

#ifndef SA_LEN

#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN

#define SA_LEN(addr)	((addr)->sa_len)

#else /* HAVE_STRUCT_SOCKADDR_SA_LEN */

#ifdef HAVE_STRUCT_SOCKADDR_STORAGE

static size_t

get_sa_len(struct sockaddr *addr)

{

	switch (addr->sa_family) {

#ifdef AF_INET

	case AF_INET:

		return (sizeof (struct sockaddr_in));

#endif

#ifdef AF_INET6

	case AF_INET6:

		return (sizeof (struct sockaddr_in6));

#endif

#if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET)

	case AF_PACKET:

		return (sizeof (struct sockaddr_ll));

#endif

	default:

		return (sizeof (struct sockaddr));

	}

}

#define SA_LEN(addr)	(get_sa_len(addr))

#else /* HAVE_STRUCT_SOCKADDR_STORAGE */

#define SA_LEN(addr)	(sizeof (struct sockaddr))

#endif /* HAVE_STRUCT_SOCKADDR_STORAGE */

#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */

#endif /* SA_LEN */

/*

 * Get a list of all interfaces that are up and that we can open.

 * Returns -1 on error, 0 otherwise.

 * The list, as returned through "alldevsp", may be null if no interfaces

 * could be opened.

 */

int

pcap_findalldevs_interfaces(pcap_if_list_t *devlistp, char *errbuf,

    int (*check_usable)(const char *), get_if_flags_func get_flags_func)

{

	struct ifaddrs *ifap, *ifa;

	struct sockaddr *addr, *netmask, *broadaddr, *dstaddr;

	size_t addr_size, broadaddr_size, dstaddr_size;

	int ret = 0;

	char *p, *q;

	/*

	 * Get the list of interface addresses.

	 *

	 * Note: this won't return information about interfaces

	 * with no addresses, so, if a platform has interfaces

	 * with no interfaces on which traffic can be captured,

	 * we must check for those interfaces as well (see, for

	 * example, what's done on Linux).

	 *

	 * LAN interfaces will probably have link-layer

	 * addresses; I don't know whether all implementations

	 * of "getifaddrs()" now, or in the future, will return

	 * those.

	 */

	if (getifaddrs(&ifap) != 0) {

		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,

		    errno, "getifaddrs");

		return (-1);

	}

	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {

		/*

		 * If this entry has a colon followed by a number at

		 * the end, we assume it's a logical interface.  Those

		 * are just the way you assign multiple IP addresses to

		 * a real interface on Linux, so an entry for a logical

		 * interface should be treated like the entry for the

		 * real interface; we do that by stripping off the ":"

		 * and the number.

		 *

		 * XXX - should we do this only on Linux?

		 */

		p = strchr(ifa->ifa_name, ':');

		if (p != NULL) {

			/*

			 * We have a ":"; is it followed by a number?

			 */

			q = p + 1;

			while (isdigit((unsigned char)*q))

				q++;

			if (*q == '\0') {

				/*

				 * All digits after the ":" until the end.

				 * Strip off the ":" and everything after

				 * it.

				 */

			       *p = '\0';

			}

		}

		/*

		 * Can we capture on this device?

		 */

		if (!(*check_usable)(ifa->ifa_name)) {

			/*

			 * No.

			 */

			continue;

		}

		/*

		 * "ifa_addr" was apparently null on at least one

		 * interface on some system.  Therefore, we supply

		 * the address and netmask only if "ifa_addr" is

		 * non-null (if there's no address, there's obviously

		 * no netmask).

		 */

		if (ifa->ifa_addr != NULL) {

			addr = ifa->ifa_addr;

			addr_size = SA_LEN(addr);

			netmask = ifa->ifa_netmask;

		} else {

			addr = NULL;

			addr_size = 0;

			netmask = NULL;

		}

		/*

		 * Note that, on some platforms, ifa_broadaddr and

		 * ifa_dstaddr could be the same field (true on at

		 * least some versions of *BSD and macOS), so we

		 * can't just check whether the broadcast address

		 * is null and add it if so and check whether the

		 * destination address is null and add it if so.

		 *

		 * Therefore, we must also check the IFF_BROADCAST

		 * flag, and only add a broadcast address if it's

		 * set, and check the IFF_POINTTOPOINT flag, and

		 * only add a destination address if it's set (as

		 * per man page recommendations on some of those

		 * platforms).

		 */

		if (ifa->ifa_flags & IFF_BROADCAST &&

		    ifa->ifa_broadaddr != NULL) {

			broadaddr = ifa->ifa_broadaddr;

			broadaddr_size = SA_LEN(broadaddr);

		} else {

			broadaddr = NULL;

			broadaddr_size = 0;

		}

		if (ifa->ifa_flags & IFF_POINTOPOINT &&

		    ifa->ifa_dstaddr != NULL) {

			dstaddr = ifa->ifa_dstaddr;

			dstaddr_size = SA_LEN(ifa->ifa_dstaddr);

		} else {

			dstaddr = NULL;

			dstaddr_size = 0;

		}

		/*

		 * Add information for this address to the list.

		 */

		if (add_addr_to_if(devlistp, ifa->ifa_name, ifa->ifa_flags,

		    get_flags_func,

		    addr, addr_size, netmask, addr_size,

		    broadaddr, broadaddr_size, dstaddr, dstaddr_size,

		    errbuf) < 0) {

			ret = -1;

			break;

		}

	}

	freeifaddrs(ifap);

	return (ret);

}