/* vi: set sw=4 ts=4: */
/*
 * stolen from net-tools-1.59 and stripped down for busybox by
 *			Erik Andersen <andersen@codepoet.org>
 *
 * Heavily modified by Manuel Novoa III       Mar 12, 2001
 *
 * Added print_bytes_scaled function to reduce code size.
 * Added some (potentially) missing defines.
 * Improved display support for -a and for a named interface.
 *
 * -----------------------------------------------------------
 *
 * ifconfig   This file contains an implementation of the command
 *              that either displays or sets the characteristics of
 *              one or more of the system's networking interfaces.
 *
 *
 * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
 *              and others.  Copyright 1993 MicroWalt Corporation
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 *
 * Patched to support 'add' and 'del' keywords for INET(4) addresses
 * by Mrs. Brisby <mrs.brisby@nimh.org>
 *
 * {1.34} - 19980630 - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *                     - gettext instead of catgets for i18n
 *          10/1998  - Andi Kleen. Use interface list primitives.
 *	    20001008 - Bernd Eckenfels, Patch from RH for setting mtu
 *			(default AF was wrong)
 */

#include <net/if.h>
#include <net/if_arp.h>
#include "inet_common.h"
#include "libbb.h"

#if ENABLE_FEATURE_IPV6
# define HAVE_AFINET6 1
#else
# undef HAVE_AFINET6
#endif

#define _PATH_PROCNET_DEV               "/proc/net/dev"
#define _PATH_PROCNET_IFINET6           "/proc/net/if_inet6"

#ifdef HAVE_AFINET6

#ifndef _LINUX_IN6_H
/*
 *    This is in linux/include/net/ipv6.h.
 */

struct in6_ifreq {
	struct in6_addr ifr6_addr;
	uint32_t ifr6_prefixlen;
	unsigned int ifr6_ifindex;
};

#endif

#endif /* HAVE_AFINET6 */

/* Defines for glibc2.0 users. */
#ifndef SIOCSIFTXQLEN
#define SIOCSIFTXQLEN      0x8943
#define SIOCGIFTXQLEN      0x8942
#endif

/* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
#ifndef ifr_qlen
#define ifr_qlen        ifr_ifru.ifru_mtu
#endif

#ifndef HAVE_TXQUEUELEN
#define HAVE_TXQUEUELEN 1
#endif

#ifndef IFF_DYNAMIC
#define IFF_DYNAMIC     0x8000	/* dialup device with changing addresses */
#endif

/* Display an Internet socket address. */
static const char *INET_sprint(struct sockaddr *sap, int numeric)
{
	static char buff[128];

	if (sap->sa_family == 0xFFFF || sap->sa_family == 0)
		return "[NONE SET]";

	if (INET_rresolve(buff, sizeof(buff), (struct sockaddr_in *) sap,
					  numeric, 0xffffff00) != 0)
		return NULL;

	return buff;
}

#ifdef UNUSED_AND_BUGGY
static int INET_getsock(char *bufp, struct sockaddr *sap)
{
	char *sp = bufp, *bp;
	unsigned int i;
	unsigned val;
	struct sockaddr_in *sock_in;

	sock_in = (struct sockaddr_in *) sap;
	sock_in->sin_family = AF_INET;
	sock_in->sin_port = 0;

	val = 0;
	bp = (char *) &val;
	for (i = 0; i < sizeof(sock_in->sin_addr.s_addr); i++) {
		*sp = toupper(*sp);

		if ((unsigned)(*sp - 'A') <= 5)
			bp[i] |= (int) (*sp - ('A' - 10));
		else if (isdigit(*sp))
			bp[i] |= (int) (*sp - '0');
		else
			return -1;

		bp[i] <<= 4;
		sp++;
		*sp = toupper(*sp);

		if ((unsigned)(*sp - 'A') <= 5)
			bp[i] |= (int) (*sp - ('A' - 10));
		else if (isdigit(*sp))
			bp[i] |= (int) (*sp - '0');
		else
			return -1;

		sp++;
	}
	sock_in->sin_addr.s_addr = htonl(val);

	return (sp - bufp);
}
#endif

static int INET_input(/*int type,*/ const char *bufp, struct sockaddr *sap)
{
	return INET_resolve(bufp, (struct sockaddr_in *) sap, 0);
/*
	switch (type) {
	case 1:
		return (INET_getsock(bufp, sap));
	case 256:
		return (INET_resolve(bufp, (struct sockaddr_in *) sap, 1));
	default:
		return (INET_resolve(bufp, (struct sockaddr_in *) sap, 0));
	}
*/
}

static const struct aftype inet_aftype = {
	.name =		"inet",
	.title =	"DARPA Internet",
	.af =		AF_INET,
	.alen =		4,
	.sprint =	INET_sprint,
	.input =	INET_input,
};

#ifdef HAVE_AFINET6

/* Display an Internet socket address. */
/* dirty! struct sockaddr usually doesn't suffer for inet6 addresses, fst. */
static const char *INET6_sprint(struct sockaddr *sap, int numeric)
{
	static char buff[128];

	if (sap->sa_family == 0xFFFF || sap->sa_family == 0)
		return "[NONE SET]";
	if (INET6_rresolve(buff, sizeof(buff), (struct sockaddr_in6 *) sap, numeric))
		return "[UNKNOWN]";
	return buff;
}

#ifdef UNUSED
static int INET6_getsock(char *bufp, struct sockaddr *sap)
{
	struct sockaddr_in6 *sin6;

	sin6 = (struct sockaddr_in6 *) sap;
	sin6->sin6_family = AF_INET6;
	sin6->sin6_port = 0;

	if (inet_pton(AF_INET6, bufp, sin6->sin6_addr.s6_addr) <= 0)
		return -1;

	return 16;			/* ?;) */
}
#endif

static int INET6_input(/*int type,*/ const char *bufp, struct sockaddr *sap)
{
	return INET6_resolve(bufp, (struct sockaddr_in6 *) sap);
/*
	switch (type) {
	case 1:
		return (INET6_getsock(bufp, sap));
	default:
		return (INET6_resolve(bufp, (struct sockaddr_in6 *) sap));
	}
*/
}

static const struct aftype inet6_aftype = {
	.name =		"inet6",
	.title =	"IPv6",
	.af =		AF_INET6,
	.alen =		sizeof(struct in6_addr),
	.sprint =	INET6_sprint,
	.input =	INET6_input,
};

#endif /* HAVE_AFINET6 */

/* Display an UNSPEC address. */
static char *UNSPEC_print(unsigned char *ptr)
{
	static char buff[sizeof(struct sockaddr) * 3 + 1];
	char *pos;
	unsigned int i;

	pos = buff;
	for (i = 0; i < sizeof(struct sockaddr); i++) {
		/* careful -- not every libc's sprintf returns # bytes written */
		sprintf(pos, "%02X-", (*ptr++ & 0377));
		pos += 3;
	}
	/* Erase trailing "-".  Works as long as sizeof(struct sockaddr) != 0 */
	*--pos = '\0';
	return buff;
}

/* Display an UNSPEC socket address. */
static const char *UNSPEC_sprint(struct sockaddr *sap, int numeric)
{
	if (sap->sa_family == 0xFFFF || sap->sa_family == 0)
		return "[NONE SET]";
	return UNSPEC_print((unsigned char *)sap->sa_data);
}

static const struct aftype unspec_aftype = {
	.name   = "unspec",
	.title  = "UNSPEC",
	.af     = AF_UNSPEC,
	.alen    = 0,
	.print  = UNSPEC_print,
	.sprint = UNSPEC_sprint,
};

static const struct aftype *const aftypes[] = {
	&inet_aftype,
#ifdef HAVE_AFINET6
	&inet6_aftype,
#endif
	&unspec_aftype,
	NULL
};

/* Check our protocol family table for this family. */
const struct aftype *get_aftype(const char *name)
{
	const struct aftype *const *afp;

	afp = aftypes;
	while (*afp != NULL) {
		if (!strcmp((*afp)->name, name))
			return (*afp);
		afp++;
	}
	return NULL;
}

/* Check our protocol family table for this family. */
static const struct aftype *get_afntype(int af)
{
	const struct aftype *const *afp;

	afp = aftypes;
	while (*afp != NULL) {
		if ((*afp)->af == af)
			return *afp;
		afp++;
	}
	return NULL;
}

struct user_net_device_stats {
	unsigned long long rx_packets;	/* total packets received       */
	unsigned long long tx_packets;	/* total packets transmitted    */
	unsigned long long rx_bytes;	/* total bytes received         */
	unsigned long long tx_bytes;	/* total bytes transmitted      */
	unsigned long rx_errors;	/* bad packets received         */
	unsigned long tx_errors;	/* packet transmit problems     */
	unsigned long rx_dropped;	/* no space in linux buffers    */
	unsigned long tx_dropped;	/* no space available in linux  */
	unsigned long rx_multicast;	/* multicast packets received   */
	unsigned long rx_compressed;
	unsigned long tx_compressed;
	unsigned long collisions;

	/* detailed rx_errors: */
	unsigned long rx_length_errors;
	unsigned long rx_over_errors;	/* receiver ring buff overflow  */
	unsigned long rx_crc_errors;	/* recved pkt with crc error    */
	unsigned long rx_frame_errors;	/* recv'd frame alignment error */
	unsigned long rx_fifo_errors;	/* recv'r fifo overrun          */
	unsigned long rx_missed_errors;	/* receiver missed packet     */
	/* detailed tx_errors */
	unsigned long tx_aborted_errors;
	unsigned long tx_carrier_errors;
	unsigned long tx_fifo_errors;
	unsigned long tx_heartbeat_errors;
	unsigned long tx_window_errors;
};

struct interface {
	struct interface *next, *prev;
	char name[IFNAMSIZ];	/* interface name        */
	short type;			/* if type               */
	short flags;		/* various flags         */
	int metric;			/* routing metric        */
	int mtu;			/* MTU value             */
	int tx_queue_len;	/* transmit queue length */
	struct ifmap map;	/* hardware setup        */
	struct sockaddr addr;	/* IP address            */
	struct sockaddr dstaddr;	/* P-P IP address        */
	struct sockaddr broadaddr;	/* IP broadcast address  */
	struct sockaddr netmask;	/* IP network mask       */
	int has_ip;
	char hwaddr[32];	/* HW address            */
	int statistics_valid;
	struct user_net_device_stats stats;	/* statistics            */
	int keepalive;		/* keepalive value for SLIP */
	int outfill;		/* outfill value for SLIP */
};


int interface_opt_a;	/* show all interfaces          */

static struct interface *int_list, *int_last;


#if 0
/* like strcmp(), but knows about numbers */
except that the freshly added calls to xatoul() brf on ethernet aliases with
uClibc with e.g.: ife->name='lo'  name='eth0:1'
static int nstrcmp(const char *a, const char *b)
{
	const char *a_ptr = a;
	const char *b_ptr = b;

	while (*a == *b) {
		if (*a == '\0') {
			return 0;
		}
		if (!isdigit(*a) && isdigit(*(a+1))) {
			a_ptr = a+1;
			b_ptr = b+1;
		}
		a++;
		b++;
	}

	if (isdigit(*a) && isdigit(*b)) {
		return xatoul(a_ptr) > xatoul(b_ptr) ? 1 : -1;
	}
	return *a - *b;
}
#endif

static struct interface *add_interface(char *name)
{
	struct interface *ife, **nextp, *new;

	for (ife = int_last; ife; ife = ife->prev) {
		int n = /*n*/strcmp(ife->name, name);

		if (n == 0)
			return ife;
		if (n < 0)
			break;
	}

	new = xzalloc(sizeof(*new));
	safe_strncpy(new->name, name, IFNAMSIZ);
	nextp = ife ? &ife->next : &int_list;
	new->prev = ife;
	new->next = *nextp;
	if (new->next)
		new->next->prev = new;
	else
		int_last = new;
	*nextp = new;
	return new;
}

static char *get_name(char *name, char *p)
{
	/* Extract <name> from nul-terminated p where p matches
	   <name>: after leading whitespace.
	   If match is not made, set name empty and return unchanged p */
	int namestart=0, nameend=0;
	while (isspace(p[namestart]))
		namestart++;
	nameend=namestart;
	while (p[nameend] && p[nameend]!=':' && !isspace(p[nameend]))
		nameend++;
	if (p[nameend]==':') {
		if ((nameend-namestart)<IFNAMSIZ) {
			memcpy(name,&p[namestart],nameend-namestart);
			name[nameend-namestart]='\0';
			p=&p[nameend];
		} else {
			/* Interface name too large */
			name[0]='\0';
		}
	} else {
		/* trailing ':' not found - return empty */
		name[0]='\0';
	}
	return p + 1;
}

/* If scanf supports size qualifiers for %n conversions, then we can
 * use a modified fmt that simply stores the position in the fields
 * having no associated fields in the proc string.  Of course, we need
 * to zero them again when we're done.  But that is smaller than the
 * old approach of multiple scanf occurrences with large numbers of
 * args. */

/* static const char *const ss_fmt[] = { */
/*	"%lln%llu%lu%lu%lu%lu%ln%ln%lln%llu%lu%lu%lu%lu%lu", */
/*	"%llu%llu%lu%lu%lu%lu%ln%ln%llu%llu%lu%lu%lu%lu%lu", */
/*	"%llu%llu%lu%lu%lu%lu%lu%lu%llu%llu%lu%lu%lu%lu%lu%lu" */
/* }; */

	/* Lie about the size of the int pointed to for %n. */
#if INT_MAX == LONG_MAX
static const char *const ss_fmt[] = {
	"%n%llu%u%u%u%u%n%n%n%llu%u%u%u%u%u",
	"%llu%llu%u%u%u%u%n%n%llu%llu%u%u%u%u%u",
	"%llu%llu%u%u%u%u%u%u%llu%llu%u%u%u%u%u%u"
};
#else
static const char *const ss_fmt[] = {
	"%n%llu%lu%lu%lu%lu%n%n%n%llu%lu%lu%lu%lu%lu",
	"%llu%llu%lu%lu%lu%lu%n%n%llu%llu%lu%lu%lu%lu%lu",
	"%llu%llu%lu%lu%lu%lu%lu%lu%llu%llu%lu%lu%lu%lu%lu%lu"
};

#endif

static void get_dev_fields(char *bp, struct interface *ife, int procnetdev_vsn)
{
	memset(&ife->stats, 0, sizeof(struct user_net_device_stats));

	sscanf(bp, ss_fmt[procnetdev_vsn],
		   &ife->stats.rx_bytes, /* missing for 0 */
		   &ife->stats.rx_packets,
		   &ife->stats.rx_errors,
		   &ife->stats.rx_dropped,
		   &ife->stats.rx_fifo_errors,
		   &ife->stats.rx_frame_errors,
		   &ife->stats.rx_compressed, /* missing for <= 1 */
		   &ife->stats.rx_multicast, /* missing for <= 1 */
		   &ife->stats.tx_bytes, /* missing for 0 */
		   &ife->stats.tx_packets,
		   &ife->stats.tx_errors,
		   &ife->stats.tx_dropped,
		   &ife->stats.tx_fifo_errors,
		   &ife->stats.collisions,
		   &ife->stats.tx_carrier_errors,
		   &ife->stats.tx_compressed /* missing for <= 1 */
		   );

	if (procnetdev_vsn <= 1) {
		if (procnetdev_vsn == 0) {
			ife->stats.rx_bytes = 0;
			ife->stats.tx_bytes = 0;
		}
		ife->stats.rx_multicast = 0;
		ife->stats.rx_compressed = 0;
		ife->stats.tx_compressed = 0;
	}
}

static inline int procnetdev_version(char *buf)
{
	if (strstr(buf, "compressed"))
		return 2;
	if (strstr(buf, "bytes"))
		return 1;
	return 0;
}

static int if_readconf(void)
{
	int numreqs = 30;
	struct ifconf ifc;
	struct ifreq *ifr;
	int n, err = -1;
	int skfd;

	ifc.ifc_buf = NULL;

	/* SIOCGIFCONF currently seems to only work properly on AF_INET sockets
	   (as of 2.1.128) */
	skfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (skfd < 0) {
		bb_perror_msg("error: no inet socket available");
		return -1;
	}

	for (;;) {
		ifc.ifc_len = sizeof(struct ifreq) * numreqs;
		ifc.ifc_buf = xrealloc(ifc.ifc_buf, ifc.ifc_len);

		if (ioctl(skfd, SIOCGIFCONF, &ifc) < 0) {
			perror("SIOCGIFCONF");
			goto out;
		}
		if (ifc.ifc_len == sizeof(struct ifreq) * numreqs) {
			/* assume it overflowed and try again */
			numreqs += 10;
			continue;
		}
		break;
	}

	ifr = ifc.ifc_req;
	for (n = 0; n < ifc.ifc_len; n += sizeof(struct ifreq)) {
		add_interface(ifr->ifr_name);
		ifr++;
	}
	err = 0;

 out:
	close(skfd);
	free(ifc.ifc_buf);
	return err;
}

static int if_readlist_proc(char *target)
{
	static int proc_read;
	FILE *fh;
	char buf[512];
	struct interface *ife;
	int err, procnetdev_vsn;

	if (proc_read)
		return 0;
	if (!target)
		proc_read = 1;

	fh = fopen(_PATH_PROCNET_DEV, "r");
	if (!fh) {
		bb_perror_msg("warning: cannot open %s, limiting output", _PATH_PROCNET_DEV);
		return if_readconf();
	}
	fgets(buf, sizeof buf, fh);	/* eat line */
	fgets(buf, sizeof buf, fh);

	procnetdev_vsn = procnetdev_version(buf);

	err = 0;
	while (fgets(buf, sizeof buf, fh)) {
		char *s, name[128];

		s = get_name(name, buf);
		ife = add_interface(name);
		get_dev_fields(s, ife, procnetdev_vsn);
		ife->statistics_valid = 1;
		if (target && !strcmp(target, name))
			break;
	}
	if (ferror(fh)) {
		perror(_PATH_PROCNET_DEV);
		err = -1;
		proc_read = 0;
	}
	fclose(fh);
	return err;
}

static int if_readlist(void)
{
	int err = if_readlist_proc(NULL);
	/* Needed in order to get ethN:M aliases */
	if (!err)
		err = if_readconf();
	return err;
}

static int for_all_interfaces(int (*doit) (struct interface *, void *),
							  void *cookie)
{
	struct interface *ife;

	if (!int_list && (if_readlist() < 0))
		return -1;
	for (ife = int_list; ife; ife = ife->next) {
		int err = doit(ife, cookie);

		if (err)
			return err;
	}
	return 0;
}

/* Fetch the interface configuration from the kernel. */
static int if_fetch(struct interface *ife)
{
	struct ifreq ifr;
	char *ifname = ife->name;
	int skfd;

	skfd = xsocket(AF_INET, SOCK_DGRAM, 0);

	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0) {
		close(skfd);
		return -1;
	}
	ife->flags = ifr.ifr_flags;

	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	memset(ife->hwaddr, 0, 32);
	if (ioctl(skfd, SIOCGIFHWADDR, &ifr) >= 0)
		memcpy(ife->hwaddr, ifr.ifr_hwaddr.sa_data, 8);

	ife->type = ifr.ifr_hwaddr.sa_family;

	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	ife->metric = 0;
	if (ioctl(skfd, SIOCGIFMETRIC, &ifr) >= 0)
		ife->metric = ifr.ifr_metric;

	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	ife->mtu = 0;
	if (ioctl(skfd, SIOCGIFMTU, &ifr) >= 0)
		ife->mtu = ifr.ifr_mtu;

	memset(&ife->map, 0, sizeof(struct ifmap));
#ifdef SIOCGIFMAP
	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	if (ioctl(skfd, SIOCGIFMAP, &ifr) == 0)
		ife->map = ifr.ifr_map;
#endif

#ifdef HAVE_TXQUEUELEN
	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	ife->tx_queue_len = -1;	/* unknown value */
	if (ioctl(skfd, SIOCGIFTXQLEN, &ifr) >= 0)
		ife->tx_queue_len = ifr.ifr_qlen;
#else
	ife->tx_queue_len = -1;	/* unknown value */
#endif

	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	ifr.ifr_addr.sa_family = AF_INET;
	memset(&ife->addr, 0, sizeof(struct sockaddr));
	if (ioctl(skfd, SIOCGIFADDR, &ifr) == 0) {
		ife->has_ip = 1;
		ife->addr = ifr.ifr_addr;
		strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
		memset(&ife->dstaddr, 0, sizeof(struct sockaddr));
		if (ioctl(skfd, SIOCGIFDSTADDR, &ifr) >= 0)
			ife->dstaddr = ifr.ifr_dstaddr;

		strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
		memset(&ife->broadaddr, 0, sizeof(struct sockaddr));
		if (ioctl(skfd, SIOCGIFBRDADDR, &ifr) >= 0)
			ife->broadaddr = ifr.ifr_broadaddr;

		strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
		memset(&ife->netmask, 0, sizeof(struct sockaddr));
		if (ioctl(skfd, SIOCGIFNETMASK, &ifr) >= 0)
			ife->netmask = ifr.ifr_netmask;
	}

	close(skfd);
	return 0;
}


static int do_if_fetch(struct interface *ife)
{
	if (if_fetch(ife) < 0) {
		const char *errmsg;

		if (errno == ENODEV) {
			/* Give better error message for this case. */
			errmsg = "Device not found";
		} else {
			errmsg = strerror(errno);
		}
		bb_error_msg("%s: error fetching interface information: %s",
				ife->name, errmsg);
		return -1;
	}
	return 0;
}

static const struct hwtype unspec_hwtype = {
	.name =		"unspec",
	.title =	"UNSPEC",
	.type =		-1,
	.print =	UNSPEC_print
};

static const struct hwtype loop_hwtype = {
	.name =		"loop",
	.title =	"Local Loopback",
	.type =		ARPHRD_LOOPBACK
};

#include <net/if_arp.h>

#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined(_NEWLIB_VERSION)
#include <net/ethernet.h>
#else
#include <linux/if_ether.h>
#endif

/* Display an Ethernet address in readable format. */
static char *pr_ether(unsigned char *ptr)
{
	static char buff[64];

	snprintf(buff, sizeof(buff), "%02X:%02X:%02X:%02X:%02X:%02X",
			 (ptr[0] & 0377), (ptr[1] & 0377), (ptr[2] & 0377),
			 (ptr[3] & 0377), (ptr[4] & 0377), (ptr[5] & 0377)
		);
	return buff;
}

static int in_ether(const char *bufp, struct sockaddr *sap);

static struct hwtype ether_hwtype = {
	.name =		"ether",
	.title =	"Ethernet",
	.type =		ARPHRD_ETHER,
	.alen =		ETH_ALEN,
	.print =	pr_ether,
	.input =	in_ether
};

static unsigned hexchar2int(char c)
{
	if (isdigit(c))
		return c - '0';
	c &= ~0x20; /* a -> A */
	if ((unsigned)(c - 'A') <= 5)
		return c - ('A' - 10);
	return ~0U;
}

/* Input an Ethernet address and convert to binary. */
static int in_ether(const char *bufp, struct sockaddr *sap)
{
	unsigned char *ptr;
	char c;
	int i;
	unsigned val;

	sap->sa_family = ether_hwtype.type;
	ptr = (unsigned char*) sap->sa_data;

	i = 0;
	while ((*bufp != '\0') && (i < ETH_ALEN)) {
		val = hexchar2int(*bufp++) * 0x10;
		if (val > 0xff) {
			errno = EINVAL;
			return -1;
		}
		c = *bufp;
		if (c == ':' || c == 0)
			val >>= 4;
		else {
			val |= hexchar2int(c);
			if (val > 0xff) {
				errno = EINVAL;
				return -1;
			}
		}
		if (c != 0)
			bufp++;
		*ptr++ = (unsigned char) val;
		i++;

		/* We might get a semicolon here - not required. */
		if (*bufp == ':') {
			bufp++;
		}
	}
	return 0;
}

#include <net/if_arp.h>

static const struct hwtype ppp_hwtype = {
	.name =		"ppp",
	.title =	"Point-to-Point Protocol",
	.type =		ARPHRD_PPP
};

#if ENABLE_FEATURE_IPV6
static const struct hwtype sit_hwtype = {
	.name =			"sit",
	.title =		"IPv6-in-IPv4",
	.type =			ARPHRD_SIT,
	.print =		UNSPEC_print,
	.suppress_null_addr =	1
} ;
#endif

static const struct hwtype *const hwtypes[] = {
	&loop_hwtype,
	&ether_hwtype,
	&ppp_hwtype,
	&unspec_hwtype,
#if ENABLE_FEATURE_IPV6
	&sit_hwtype,
#endif
	NULL
};

#ifdef IFF_PORTSEL
static const char *const if_port_text[] = {
	/* Keep in step with <linux/netdevice.h> */
	"unknown",
	"10base2",
	"10baseT",
	"AUI",
	"100baseT",
	"100baseTX",
	"100baseFX",
	NULL
};
#endif

/* Check our hardware type table for this type. */
const struct hwtype *get_hwtype(const char *name)
{
	const struct hwtype *const *hwp;

	hwp = hwtypes;
	while (*hwp != NULL) {
		if (!strcmp((*hwp)->name, name))
			return (*hwp);
		hwp++;
	}
	return NULL;
}

/* Check our hardware type table for this type. */
const struct hwtype *get_hwntype(int type)
{
	const struct hwtype *const *hwp;

	hwp = hwtypes;
	while (*hwp != NULL) {
		if ((*hwp)->type == type)
			return *hwp;
		hwp++;
	}
	return NULL;
}

/* return 1 if address is all zeros */
static int hw_null_address(const struct hwtype *hw, void *ap)
{
	unsigned int i;
	unsigned char *address = (unsigned char *) ap;

	for (i = 0; i < hw->alen; i++)
		if (address[i])
			return 0;
	return 1;
}

static const char TRext[] = "\0\0\0Ki\0Mi\0Gi\0Ti";

static void print_bytes_scaled(unsigned long long ull, const char *end)
{
	unsigned long long int_part;
	const char *ext;
	unsigned int frac_part;
	int i;

	frac_part = 0;
	ext = TRext;
	int_part = ull;
	i = 4;
	do {
		if (int_part >= 1024) {
			frac_part = ((((unsigned int) int_part) & (1024-1)) * 10) / 1024;
			int_part /= 1024;
			ext += 3;	/* KiB, MiB, GiB, TiB */
		}
		--i;
	} while (i);

	printf("X bytes:%llu (%llu.%u %sB)%s", ull, int_part, frac_part, ext, end);
}

static const char *const ife_print_flags_strs[] = {
	"UP ",
	"BROADCAST ",
	"DEBUG ",
	"LOOPBACK ",
	"POINTOPOINT ",
	"NOTRAILERS ",
	"RUNNING ",
	"NOARP ",
	"PROMISC ",
	"ALLMULTI ",
	"SLAVE ",
	"MASTER ",
	"MULTICAST ",
#ifdef HAVE_DYNAMIC
	"DYNAMIC "
#endif
};

static const unsigned short ife_print_flags_mask[] = {
	IFF_UP,
	IFF_BROADCAST,
	IFF_DEBUG,
	IFF_LOOPBACK,
	IFF_POINTOPOINT,
	IFF_NOTRAILERS,
	IFF_RUNNING,
	IFF_NOARP,
	IFF_PROMISC,
	IFF_ALLMULTI,
	IFF_SLAVE,
	IFF_MASTER,
	IFF_MULTICAST,
#ifdef HAVE_DYNAMIC
	IFF_DYNAMIC
#endif
	0
};

static void ife_print(struct interface *ptr)
{
	const struct aftype *ap;
	const struct hwtype *hw;
	int hf;
	int can_compress = 0;

#ifdef HAVE_AFINET6
	FILE *f;
	char addr6[40], devname[20];
	struct sockaddr_in6 sap;
	int plen, scope, dad_status, if_idx;
	char addr6p[8][5];
#endif

	ap = get_afntype(ptr->addr.sa_family);
	if (ap == NULL)
		ap = get_afntype(0);

	hf = ptr->type;

	if (hf == ARPHRD_CSLIP || hf == ARPHRD_CSLIP6)
		can_compress = 1;

	hw = get_hwntype(hf);
	if (hw == NULL)
		hw = get_hwntype(-1);

	printf("%-9.9s Link encap:%s  ", ptr->name, hw->title);
	/* For some hardware types (eg Ash, ATM) we don't print the
	   hardware address if it's null.  */
	if (hw->print != NULL && (!(hw_null_address(hw, ptr->hwaddr) &&
								hw->suppress_null_addr)))
		printf("HWaddr %s  ", hw->print((unsigned char *)ptr->hwaddr));
#ifdef IFF_PORTSEL
	if (ptr->flags & IFF_PORTSEL) {
		printf("Media:%s", if_port_text[ptr->map.port] /* [0] */);
		if (ptr->flags & IFF_AUTOMEDIA)
			printf("(auto)");
	}
#endif
	puts("");

	if (ptr->has_ip) {
		printf("          %s addr:%s ", ap->name,
			   ap->sprint(&ptr->addr, 1));
		if (ptr->flags & IFF_POINTOPOINT) {
			printf(" P-t-P:%s ", ap->sprint(&ptr->dstaddr, 1));
		}
		if (ptr->flags & IFF_BROADCAST) {
			printf(" Bcast:%s ", ap->sprint(&ptr->broadaddr, 1));
		}
		printf(" Mask:%s\n", ap->sprint(&ptr->netmask, 1));
	}

#ifdef HAVE_AFINET6

#define IPV6_ADDR_ANY           0x0000U

#define IPV6_ADDR_UNICAST       0x0001U
#define IPV6_ADDR_MULTICAST     0x0002U
#define IPV6_ADDR_ANYCAST       0x0004U

#define IPV6_ADDR_LOOPBACK      0x0010U
#define IPV6_ADDR_LINKLOCAL     0x0020U
#define IPV6_ADDR_SITELOCAL     0x0040U

#define IPV6_ADDR_COMPATv4      0x0080U

#define IPV6_ADDR_SCOPE_MASK    0x00f0U

#define IPV6_ADDR_MAPPED        0x1000U
#define IPV6_ADDR_RESERVED      0x2000U	/* reserved address space */

	f = fopen(_PATH_PROCNET_IFINET6, "r");
	if (f != NULL) {
		while (fscanf
			   (f, "%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %20s\n",
				addr6p[0], addr6p[1], addr6p[2], addr6p[3], addr6p[4],
				addr6p[5], addr6p[6], addr6p[7], &if_idx, &plen, &scope,
				&dad_status, devname) != EOF
		) {
			if (!strcmp(devname, ptr->name)) {
				sprintf(addr6, "%s:%s:%s:%s:%s:%s:%s:%s",
						addr6p[0], addr6p[1], addr6p[2], addr6p[3],
						addr6p[4], addr6p[5], addr6p[6], addr6p[7]);
				inet_pton(AF_INET6, addr6,
						  (struct sockaddr *) &sap.sin6_addr);
				sap.sin6_family = AF_INET6;
				printf("          inet6 addr: %s/%d",
					   inet6_aftype.sprint((struct sockaddr *) &sap, 1),
					   plen);
				printf(" Scope:");
				switch (scope & IPV6_ADDR_SCOPE_MASK) {
				case 0:
					printf("Global");
					break;
				case IPV6_ADDR_LINKLOCAL:
					printf("Link");
					break;
				case IPV6_ADDR_SITELOCAL:
					printf("Site");
					break;
				case IPV6_ADDR_COMPATv4:
					printf("Compat");
					break;
				case IPV6_ADDR_LOOPBACK:
					printf("Host");
					break;
				default:
					printf("Unknown");
				}
				puts("");
			}
		}
		fclose(f);
	}
#endif

	printf("          ");
	/* DONT FORGET TO ADD THE FLAGS IN ife_print_short, too */

	if (ptr->flags == 0) {
		printf("[NO FLAGS] ");
	} else {
		int i = 0;
		do {
			if (ptr->flags & ife_print_flags_mask[i]) {
				printf(ife_print_flags_strs[i]);
			}
		} while (ife_print_flags_mask[++i]);
	}

	/* DONT FORGET TO ADD THE FLAGS IN ife_print_short */
	printf(" MTU:%d  Metric:%d", ptr->mtu, ptr->metric ? ptr->metric : 1);
#ifdef SIOCSKEEPALIVE
	if (ptr->outfill || ptr->keepalive)
		printf("  Outfill:%d  Keepalive:%d", ptr->outfill, ptr->keepalive);
#endif
	puts("");

	/* If needed, display the interface statistics. */

	if (ptr->statistics_valid) {
		/* XXX: statistics are currently only printed for the primary address,
		 *      not for the aliases, although strictly speaking they're shared
		 *      by all addresses.
		 */
		printf("          ");

		printf("RX packets:%llu errors:%lu dropped:%lu overruns:%lu frame:%lu\n",
			   ptr->stats.rx_packets, ptr->stats.rx_errors,
			   ptr->stats.rx_dropped, ptr->stats.rx_fifo_errors,
			   ptr->stats.rx_frame_errors);
		if (can_compress)
			printf("             compressed:%lu\n",
				   ptr->stats.rx_compressed);
		printf("          ");
		printf("TX packets:%llu errors:%lu dropped:%lu overruns:%lu carrier:%lu\n",
			   ptr->stats.tx_packets, ptr->stats.tx_errors,
			   ptr->stats.tx_dropped, ptr->stats.tx_fifo_errors,
			   ptr->stats.tx_carrier_errors);
		printf("          collisions:%lu ", ptr->stats.collisions);
		if (can_compress)
			printf("compressed:%lu ", ptr->stats.tx_compressed);
		if (ptr->tx_queue_len != -1)
			printf("txqueuelen:%d ", ptr->tx_queue_len);
		printf("\n          R");
		print_bytes_scaled(ptr->stats.rx_bytes, "  T");
		print_bytes_scaled(ptr->stats.tx_bytes, "\n");

	}

	if ((ptr->map.irq || ptr->map.mem_start || ptr->map.dma ||
		 ptr->map.base_addr)) {
		printf("          ");
		if (ptr->map.irq)
			printf("Interrupt:%d ", ptr->map.irq);
		if (ptr->map.base_addr >= 0x100)	/* Only print devices using it for
											   I/O maps */
			printf("Base address:0x%lx ",
				   (unsigned long) ptr->map.base_addr);
		if (ptr->map.mem_start) {
			printf("Memory:%lx-%lx ", ptr->map.mem_start,
				   ptr->map.mem_end);
		}
		if (ptr->map.dma)
			printf("DMA chan:%x ", ptr->map.dma);
		puts("");
	}
	puts("");
}


static int do_if_print(struct interface *ife, void *cookie)
{
	int *opt_a = (int *) cookie;
	int res;

	res = do_if_fetch(ife);
	if (res >= 0) {
		if ((ife->flags & IFF_UP) || *opt_a)
			ife_print(ife);
	}
	return res;
}

static struct interface *lookup_interface(char *name)
{
	struct interface *ife = NULL;

	if (if_readlist_proc(name) < 0)
		return NULL;
	ife = add_interface(name);
	return ife;
}

/* for ipv4 add/del modes */
static int if_print(char *ifname)
{
	int res;

	if (!ifname) {
		res = for_all_interfaces(do_if_print, &interface_opt_a);
	} else {
		struct interface *ife;

		ife = lookup_interface(ifname);
		res = do_if_fetch(ife);
		if (res >= 0)
			ife_print(ife);
	}
	return res;
}

int display_interfaces(char *ifname)
{
	int status;

	status = if_print(ifname);

	return (status < 0); /* status < 0 == 1 -- error */
}