sbin/ifconfig/ifconfig.c

/*
 * Copyright (c) 1983, 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.
 * 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.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1983, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)ifconfig.c	8.2 (Berkeley) 2/16/94";
#endif
static const char rcsid[] =
  "$FreeBSD: head/sbin/ifconfig/ifconfig.c 187253 2009-01-14 22:55:49Z sam $";
#endif /* not lint */

#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/module.h>
#include <sys/linker.h>

#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>

/* IP */
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <ifaddrs.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ifconfig.h"

/*
 * Since "struct ifreq" is composed of various union members, callers
 * should pay special attention to interprete the value.
 * (.e.g. little/big endian difference in the structure.)
 */
struct	ifreq ifr;

char	name[IFNAMSIZ];
int	setaddr;
int	setmask;
int	doalias;
int	clearaddr;
int	newaddr = 1;
int	verbose;
int	noload;

int	supmedia = 0;
int	printkeys = 0;		/* Print keying material for interfaces. */

static	int ifconfig(int argc, char *const *argv, int iscreate,
		const struct afswtch *afp);
static	void status(const struct afswtch *afp, const struct sockaddr_dl *sdl,
		struct ifaddrs *ifa);
static	void tunnel_status(int s);
static	void usage(void);

static struct afswtch *af_getbyname(const char *name);
static struct afswtch *af_getbyfamily(int af);
static void af_other_status(int);

static struct option *opts = NULL;

void
opt_register(struct option *p)
{
	p->next = opts;
	opts = p;
}

static void
usage(void)
{
	char options[1024];
	struct option *p;

	/* XXX not right but close enough for now */
	options[0] = '\0';
	for (p = opts; p != NULL; p = p->next) {
		strlcat(options, p->opt_usage, sizeof(options));
		strlcat(options, " ", sizeof(options));
	}

	fprintf(stderr,
	"usage: ifconfig %sinterface address_family [address [dest_address]]\n"
	"                [parameters]\n"
	"       ifconfig interface create\n"
	"       ifconfig -a %s[-d] [-m] [-u] [-v] [address_family]\n"
	"       ifconfig -l [-d] [-u] [address_family]\n"
	"       ifconfig %s[-d] [-m] [-u] [-v]\n",
		options, options, options);
	exit(1);
}

int
main(int argc, char *argv[])
{
	int c, all, namesonly, downonly, uponly;
	const struct afswtch *afp = NULL;
	int ifindex;
	struct ifaddrs *ifap, *ifa;
	struct ifreq paifr;
	const struct sockaddr_dl *sdl;
	char options[1024], *cp;
	const char *ifname;
	struct option *p;
	size_t iflen;

	all = downonly = uponly = namesonly = noload = verbose = 0;

	/* Parse leading line options */
	strlcpy(options, "adklmnuv", sizeof(options));
	for (p = opts; p != NULL; p = p->next)
		strlcat(options, p->opt, sizeof(options));
	while ((c = getopt(argc, argv, options)) != -1) {
		switch (c) {
		case 'a':	/* scan all interfaces */
			all++;
			break;
		case 'd':	/* restrict scan to "down" interfaces */
			downonly++;
			break;
		case 'k':
			printkeys++;
			break;
		case 'l':	/* scan interface names only */
			namesonly++;
			break;
		case 'm':	/* show media choices in status */
			supmedia = 1;
			break;
		case 'n':	/* suppress module loading */
			noload++;
			break;
		case 'u':	/* restrict scan to "up" interfaces */
			uponly++;
			break;
		case 'v':
			verbose++;
			break;
		default:
			for (p = opts; p != NULL; p = p->next)
				if (p->opt[0] == c) {
					p->cb(optarg);
					break;
				}
			if (p == NULL)
				usage();
			break;
		}
	}
	argc -= optind;
	argv += optind;

	/* -l cannot be used with -a or -m */
	if (namesonly && (all || supmedia))
		usage();

	/* nonsense.. */
	if (uponly && downonly)
		usage();

	/* no arguments is equivalent to '-a' */
	if (!namesonly && argc < 1)
		all = 1;

	/* -a and -l allow an address family arg to limit the output */
	if (all || namesonly) {
		if (argc > 1)
			usage();

		ifname = NULL;
		ifindex = 0;
		if (argc == 1) {
			afp = af_getbyname(*argv);
			if (afp == NULL)
				usage();
			if (afp->af_name != NULL)
				argc--, argv++;
			/* leave with afp non-zero */
		}
	} else {
		/* not listing, need an argument */
		if (argc < 1)
			usage();

		ifname = *argv;
		argc--, argv++;

		/* check and maybe load support for this interface */
		ifmaybeload(ifname);

		ifindex = if_nametoindex(ifname);
		if (ifindex == 0) {
			/*
			 * NOTE:  We must special-case the `create' command
			 * right here as we would otherwise fail when trying
			 * to find the interface.
			 */
			if (argc > 0 && (strcmp(argv[0], "create") == 0 ||
			    strcmp(argv[0], "plumb") == 0)) {
				iflen = strlcpy(name, ifname, sizeof(name));
				if (iflen >= sizeof(name))
					errx(1, "%s: cloning name too long",
					    ifname);
				ifconfig(argc, argv, 1, NULL);
				exit(0);
			}
			errx(1, "interface %s does not exist", ifname);
		}
	}

	/* Check for address family */
	if (argc > 0) {
		afp = af_getbyname(*argv);
		if (afp != NULL)
			argc--, argv++;
	}

	if (getifaddrs(&ifap) != 0)
		err(EXIT_FAILURE, "getifaddrs");
	cp = NULL;
	ifindex = 0;
	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
		memset(&paifr, 0, sizeof(paifr));
		strncpy(paifr.ifr_name, ifa->ifa_name, sizeof(paifr.ifr_name));
		if (sizeof(paifr.ifr_addr) >= ifa->ifa_addr->sa_len) {
			memcpy(&paifr.ifr_addr, ifa->ifa_addr,
			    ifa->ifa_addr->sa_len);
		}

		if (ifname != NULL && strcmp(ifname, ifa->ifa_name) != 0)
			continue;
		if (ifa->ifa_addr->sa_family == AF_LINK)
			sdl = (const struct sockaddr_dl *) ifa->ifa_addr;
		else
			sdl = NULL;
		if (cp != NULL && strcmp(cp, ifa->ifa_name) == 0)
			continue;
		iflen = strlcpy(name, ifa->ifa_name, sizeof(name));
		if (iflen >= sizeof(name)) {
			warnx("%s: interface name too long, skipping",
			    ifa->ifa_name);
			continue;
		}
		cp = ifa->ifa_name;

		if (downonly && (ifa->ifa_flags & IFF_UP) != 0)
			continue;
		if (uponly && (ifa->ifa_flags & IFF_UP) == 0)
			continue;
		ifindex++;
		/*
		 * Are we just listing the interfaces?
		 */
		if (namesonly) {
			if (ifindex > 1)
				printf(" ");
			fputs(name, stdout);
			continue;
		}

		if (argc > 0)
			ifconfig(argc, argv, 0, afp);
		else
			status(afp, sdl, ifa);
	}
	if (namesonly)
		printf("\n");
	freeifaddrs(ifap);

	exit(0);
}

static struct afswtch *afs = NULL;

void
af_register(struct afswtch *p)
{
	p->af_next = afs;
	afs = p;
}

static struct afswtch *
af_getbyname(const char *name)
{
	struct afswtch *afp;

	for (afp = afs; afp !=  NULL; afp = afp->af_next)
		if (strcmp(afp->af_name, name) == 0)
			return afp;
	return NULL;
}

static struct afswtch *
af_getbyfamily(int af)
{
	struct afswtch *afp;

	for (afp = afs; afp != NULL; afp = afp->af_next)
		if (afp->af_af == af)
			return afp;
	return NULL;
}

static void
af_other_status(int s)
{
	struct afswtch *afp;
	uint8_t afmask[howmany(AF_MAX, NBBY)];

	memset(afmask, 0, sizeof(afmask));
	for (afp = afs; afp != NULL; afp = afp->af_next) {
		if (afp->af_other_status == NULL)
			continue;
		if (afp->af_af != AF_UNSPEC && isset(afmask, afp->af_af))
			continue;
		afp->af_other_status(s);
		setbit(afmask, afp->af_af);
	}
}

static void
af_all_tunnel_status(int s)
{
	struct afswtch *afp;
	uint8_t afmask[howmany(AF_MAX, NBBY)];

	memset(afmask, 0, sizeof(afmask));
	for (afp = afs; afp != NULL; afp = afp->af_next) {
		if (afp->af_status_tunnel == NULL)
			continue;
		if (afp->af_af != AF_UNSPEC && isset(afmask, afp->af_af))
			continue;
		afp->af_status_tunnel(s);
		setbit(afmask, afp->af_af);
	}
}

static struct cmd *cmds = NULL;

void
cmd_register(struct cmd *p)
{
	p->c_next = cmds;
	cmds = p;
}

static const struct cmd *
cmd_lookup(const char *name, int iscreate)
{
#define	N(a)	(sizeof(a)/sizeof(a[0]))
	const struct cmd *p;

	for (p = cmds; p != NULL; p = p->c_next)
		if (strcmp(name, p->c_name) == 0) {
			if (iscreate) {
				if (p->c_iscloneop)
					return p;
			} else {
				if (!p->c_iscloneop)
					return p;
			}
		}
	return NULL;
#undef N
}

struct callback {
	callback_func *cb_func;
	void	*cb_arg;
	struct callback *cb_next;
};
static struct callback *callbacks = NULL;

void
callback_register(callback_func *func, void *arg)
{
	struct callback *cb;

	cb = malloc(sizeof(struct callback));
	if (cb == NULL)
		errx(1, "unable to allocate memory for callback");
	cb->cb_func = func;
	cb->cb_arg = arg;
	cb->cb_next = callbacks;
	callbacks = cb;
}

/* specially-handled commands */
static void setifaddr(const char *, int, int, const struct afswtch *);
static const struct cmd setifaddr_cmd = DEF_CMD("ifaddr", 0, setifaddr);

static void setifdstaddr(const char *, int, int, const struct afswtch *);
static const struct cmd setifdstaddr_cmd =
	DEF_CMD("ifdstaddr", 0, setifdstaddr);

static int
ifconfig(int argc, char *const *argv, int iscreate, const struct afswtch *afp)
{
	const struct afswtch *nafp;
	const struct cmd *p;
	struct callback *cb;
	int s;

	strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
top:
	if (afp == NULL)
		afp = af_getbyname("inet");
	ifr.ifr_addr.sa_family =
		afp->af_af == AF_LINK || afp->af_af == AF_UNSPEC ?
		AF_INET : afp->af_af;

	if ((s = socket(ifr.ifr_addr.sa_family, SOCK_DGRAM, 0)) < 0)
		err(1, "socket(family %u,SOCK_DGRAM", ifr.ifr_addr.sa_family);

	while (argc > 0) {
		p = cmd_lookup(*argv, iscreate);
		if (iscreate && p == NULL) {
			/*
			 * Push the clone create callback so the new
			 * device is created and can be used for any
			 * remaining arguments.
			 */
			cb = callbacks;
			if (cb == NULL)
				errx(1, "internal error, no callback");
			callbacks = cb->cb_next;
			cb->cb_func(s, cb->cb_arg);
			iscreate = 0;
			/*
			 * Handle any address family spec that
			 * immediately follows and potentially
			 * recreate the socket.
			 */
			nafp = af_getbyname(*argv);
			if (nafp != NULL) {
				argc--, argv++;
				if (nafp != afp) {
					close(s);
					afp = nafp;
					goto top;
				}
			}
			/*
			 * Look for a normal parameter.
			 */
			continue;
		}
		if (p == NULL) {
			/*
			 * Not a recognized command, choose between setting
			 * the interface address and the dst address.
			 */
			p = (setaddr ? &setifdstaddr_cmd : &setifaddr_cmd);
		}
		if (p->c_u.c_func || p->c_u.c_func2) {
			if (p->c_parameter == NEXTARG) {
				if (argv[1] == NULL)
					errx(1, "'%s' requires argument",
					    p->c_name);
				p->c_u.c_func(argv[1], 0, s, afp);
				argc--, argv++;
			} else if (p->c_parameter == OPTARG) {
				p->c_u.c_func(argv[1], 0, s, afp);
				if (argv[1] != NULL)
					argc--, argv++;
			} else if (p->c_parameter == NEXTARG2) {
				if (argc < 3)
					errx(1, "'%s' requires 2 arguments",
					    p->c_name);
				p->c_u.c_func2(argv[1], argv[2], s, afp);
				argc -= 2, argv += 2;
			} else
				p->c_u.c_func(*argv, p->c_parameter, s, afp);
		}
		argc--, argv++;
	}

	/*
	 * Do any post argument processing required by the address family.
	 */
	if (afp->af_postproc != NULL)
		afp->af_postproc(s, afp);
	/*
	 * Do deferred callbacks registered while processing
	 * command-line arguments.
	 */
	for (cb = callbacks; cb != NULL; cb = cb->cb_next)
		cb->cb_func(s, cb->cb_arg);
	/*
	 * Do deferred operations.
	 */
	if (clearaddr) {
		if (afp->af_ridreq == NULL || afp->af_difaddr == 0) {
			warnx("interface %s cannot change %s addresses!",
			      name, afp->af_name);
			clearaddr = 0;
		}
	}
	if (clearaddr) {
		int ret;
		strncpy(afp->af_ridreq, name, sizeof ifr.ifr_name);
		ret = ioctl(s, afp->af_difaddr, afp->af_ridreq);
		if (ret < 0) {
			if (errno == EADDRNOTAVAIL && (doalias >= 0)) {
				/* means no previous address for interface */
			} else
				Perror("ioctl (SIOCDIFADDR)");
		}
	}
	if (newaddr) {
		if (afp->af_addreq == NULL || afp->af_aifaddr == 0) {
			warnx("interface %s cannot change %s addresses!",
			      name, afp->af_name);
			newaddr = 0;
		}
	}
	if (newaddr && (setaddr || setmask)) {
		strncpy(afp->af_addreq, name, sizeof ifr.ifr_name);
		if (ioctl(s, afp->af_aifaddr, afp->af_addreq) < 0)
			Perror("ioctl (SIOCAIFADDR)");
	}

	close(s);
	return(0);
}

/*ARGSUSED*/
static void
setifaddr(const char *addr, int param, int s, const struct afswtch *afp)
{
	if (afp->af_getaddr == NULL)
		return;
	/*
	 * Delay the ioctl to set the interface addr until flags are all set.
	 * The address interpretation may depend on the flags,
	 * and the flags may change when the address is set.
	 */
	setaddr++;
	if (doalias == 0 && afp->af_af != AF_LINK)
		clearaddr = 1;
	afp->af_getaddr(addr, (doalias >= 0 ? ADDR : RIDADDR));
}

static void
settunnel(const char *src, const char *dst, int s, const struct afswtch *afp)
{
	struct addrinfo *srcres, *dstres;
	int ecode;

	if (afp->af_settunnel == NULL) {
		warn("address family %s does not support tunnel setup",
			afp->af_name);
		return;
	}

	if ((ecode = getaddrinfo(src, NULL, NULL, &srcres)) != 0)
		errx(1, "error in parsing address string: %s",
		    gai_strerror(ecode));

	if ((ecode = getaddrinfo(dst, NULL, NULL, &dstres)) != 0)
		errx(1, "error in parsing address string: %s",
		    gai_strerror(ecode));

	if (srcres->ai_addr->sa_family != dstres->ai_addr->sa_family)
		errx(1,
		    "source and destination address families do not match");

	afp->af_settunnel(s, srcres, dstres);

	freeaddrinfo(srcres);
	freeaddrinfo(dstres);
}

/* ARGSUSED */
static void
deletetunnel(const char *vname, int param, int s, const struct afswtch *afp)
{

	if (ioctl(s, SIOCDIFPHYADDR, &ifr) < 0)
		err(1, "SIOCDIFPHYADDR");
}

static void
setifnetmask(const char *addr, int dummy __unused, int s,
    const struct afswtch *afp)
{
	if (afp->af_getaddr != NULL) {
		setmask++;
		afp->af_getaddr(addr, MASK);
	}
}

static void
setifbroadaddr(const char *addr, int dummy __unused, int s,
    const struct afswtch *afp)
{
	if (afp->af_getaddr != NULL)
		afp->af_getaddr(addr, DSTADDR);
}

static void
setifipdst(const char *addr, int dummy __unused, int s,
    const struct afswtch *afp)
{
	const struct afswtch *inet;

	inet = af_getbyname("inet");
	if (inet == NULL)
		return;
	inet->af_getaddr(addr, DSTADDR);
	clearaddr = 0;
	newaddr = 0;
}

static void
notealias(const char *addr, int param, int s, const struct afswtch *afp)
{
#define rqtosa(x) (&(((struct ifreq *)(afp->x))->ifr_addr))
	if (setaddr && doalias == 0 && param < 0)
		if (afp->af_addreq != NULL && afp->af_ridreq != NULL)
			bcopy((caddr_t)rqtosa(af_addreq),
			      (caddr_t)rqtosa(af_ridreq),
			      rqtosa(af_addreq)->sa_len);
	doalias = param;
	if (param < 0) {
		clearaddr = 1;
		newaddr = 0;
	} else
		clearaddr = 0;
#undef rqtosa
}

/*ARGSUSED*/
static void
setifdstaddr(const char *addr, int param __unused, int s,
    const struct afswtch *afp)
{
	if (afp->af_getaddr != NULL)
		afp->af_getaddr(addr, DSTADDR);
}

/*
 * Note: doing an SIOCIGIFFLAGS scribbles on the union portion
 * of the ifreq structure, which may confuse other parts of ifconfig.
 * Make a private copy so we can avoid that.
 */
static void
setifflags(const char *vname, int value, int s, const struct afswtch *afp)
{
	struct ifreq		my_ifr;
	int flags;

	memset(&my_ifr, 0, sizeof(my_ifr));
	(void) strlcpy(my_ifr.ifr_name, name, sizeof(my_ifr.ifr_name));

 	if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&my_ifr) < 0) {
 		Perror("ioctl (SIOCGIFFLAGS)");
 		exit(1);
 	}
	flags = (my_ifr.ifr_flags & 0xffff) | (my_ifr.ifr_flagshigh << 16);

	if (value < 0) {
		value = -value;
		flags &= ~value;
	} else
		flags |= value;
	my_ifr.ifr_flags = flags & 0xffff;
	my_ifr.ifr_flagshigh = flags >> 16;
	if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&my_ifr) < 0)
		Perror(vname);
}

void
setifcap(const char *vname, int value, int s, const struct afswtch *afp)
{
	int flags;

 	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) < 0) {
 		Perror("ioctl (SIOCGIFCAP)");
 		exit(1);
 	}
	flags = ifr.ifr_curcap;
	if (value < 0) {
		value = -value;
		flags &= ~value;
	} else
		flags |= value;
	flags &= ifr.ifr_reqcap;
	ifr.ifr_reqcap = flags;
	if (ioctl(s, SIOCSIFCAP, (caddr_t)&ifr) < 0)
		Perror(vname);
}

static void
setifmetric(const char *val, int dummy __unused, int s,
    const struct afswtch *afp)
{
	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	ifr.ifr_metric = atoi(val);
	if (ioctl(s, SIOCSIFMETRIC, (caddr_t)&ifr) < 0)
		warn("ioctl (set metric)");
}

static void
setifmtu(const char *val, int dummy __unused, int s,
    const struct afswtch *afp)
{
	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	ifr.ifr_mtu = atoi(val);
	if (ioctl(s, SIOCSIFMTU, (caddr_t)&ifr) < 0)
		warn("ioctl (set mtu)");
}

static void
setifname(const char *val, int dummy __unused, int s,
    const struct afswtch *afp)
{
	char *newname;

	newname = strdup(val);
	if (newname == NULL) {
		warn("no memory to set ifname");
		return;
	}
	ifr.ifr_data = newname;
	if (ioctl(s, SIOCSIFNAME, (caddr_t)&ifr) < 0) {
		warn("ioctl (set name)");
		free(newname);
		return;
	}
	strlcpy(name, newname, sizeof(name));
	free(newname);
}

#define	IFFBITS \
"\020\1UP\2BROADCAST\3DEBUG\4LOOPBACK\5POINTOPOINT\6SMART\7RUNNING" \
"\10NOARP\11PROMISC\12ALLMULTI\13OACTIVE\14SIMPLEX\15LINK0\16LINK1\17LINK2" \
"\20MULTICAST\22PPROMISC\23MONITOR\24STATICARP\25NEEDSGIANT"

#define	IFCAPBITS \
"\020\1RXCSUM\2TXCSUM\3NETCONS\4VLAN_MTU\5VLAN_HWTAGGING\6JUMBO_MTU\7POLLING" \
"\10VLAN_HWCSUM\11TSO4\12TSO6\13LRO\14WOL_UCAST\15WOL_MCAST\16WOL_MAGIC" \
"\21VLAN_HWFILTER"

/*
 * Print the status of the interface.  If an address family was
 * specified, show only it; otherwise, show them all.
 */
static void
status(const struct afswtch *afp, const struct sockaddr_dl *sdl,
	struct ifaddrs *ifa)
{
	struct ifaddrs *ift;
	int allfamilies, s;
	struct ifstat ifs;

	if (afp == NULL) {
		allfamilies = 1;
		afp = af_getbyname("inet");
	} else
		allfamilies = 0;

	ifr.ifr_addr.sa_family = afp->af_af == AF_LINK ? AF_INET : afp->af_af;
	strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));

	s = socket(ifr.ifr_addr.sa_family, SOCK_DGRAM, 0);
	if (s < 0)
		err(1, "socket(family %u,SOCK_DGRAM)", ifr.ifr_addr.sa_family);

	printf("%s: ", name);
	printb("flags", ifa->ifa_flags, IFFBITS);
	if (ioctl(s, SIOCGIFMETRIC, &ifr) != -1)
		printf(" metric %d", ifr.ifr_metric);
	if (ioctl(s, SIOCGIFMTU, &ifr) != -1)
		printf(" mtu %d", ifr.ifr_mtu);
	putchar('\n');

	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) == 0) {
		if (ifr.ifr_curcap != 0) {
			printb("\toptions", ifr.ifr_curcap, IFCAPBITS);
			putchar('\n');
		}
		if (supmedia && ifr.ifr_reqcap != 0) {
			printb("\tcapabilities", ifr.ifr_reqcap, IFCAPBITS);
			putchar('\n');
		}
	}

	tunnel_status(s);

	for (ift = ifa; ift != NULL; ift = ift->ifa_next) {
		if (ift->ifa_addr == NULL)
			continue;
		if (strcmp(ifa->ifa_name, ift->ifa_name) != 0)
			continue;
		if (allfamilies) {
			const struct afswtch *p;
			p = af_getbyfamily(ift->ifa_addr->sa_family);
			if (p != NULL && p->af_status != NULL)
				p->af_status(s, ift);
		} else if (afp->af_af == ift->ifa_addr->sa_family)
			afp->af_status(s, ift);
	}
#if 0
	if (allfamilies || afp->af_af == AF_LINK) {
		const struct afswtch *lafp;

		/*
		 * Hack; the link level address is received separately
		 * from the routing information so any address is not
		 * handled above.  Cobble together an entry and invoke
		 * the status method specially.
		 */
		lafp = af_getbyname("lladdr");
		if (lafp != NULL) {
			info.rti_info[RTAX_IFA] = (struct sockaddr *)sdl;
			lafp->af_status(s, &info);
		}
	}
#endif
	if (allfamilies)
		af_other_status(s);
	else if (afp->af_other_status != NULL)
		afp->af_other_status(s);

	strncpy(ifs.ifs_name, name, sizeof ifs.ifs_name);
	if (ioctl(s, SIOCGIFSTATUS, &ifs) == 0)
		printf("%s", ifs.ascii);

	close(s);
	return;
}

static void
tunnel_status(int s)
{
	af_all_tunnel_status(s);
}

void
Perror(const char *cmd)
{
	switch (errno) {

	case ENXIO:
		errx(1, "%s: no such interface", cmd);
		break;

	case EPERM:
		errx(1, "%s: permission denied", cmd);
		break;

	default:
		err(1, "%s", cmd);
	}
}

/*
 * Print a value a la the %b format of the kernel's printf
 */
void
printb(const char *s, unsigned v, const char *bits)
{
	int i, any = 0;
	char c;

	if (bits && *bits == 8)
		printf("%s=%o", s, v);
	else
		printf("%s=%x", s, v);
	bits++;
	if (bits) {
		putchar('<');
		while ((i = *bits++) != '\0') {
			if (v & (1 << (i-1))) {
				if (any)
					putchar(',');
				any = 1;
				for (; (c = *bits) > 32; bits++)
					putchar(c);
			} else
				for (; *bits > 32; bits++)
					;
		}
		putchar('>');
	}
}

void
ifmaybeload(const char *name)
{
#define MOD_PREFIX_LEN		3	/* "if_" */
	struct module_stat mstat;
	int fileid, modid;
	char ifkind[IFNAMSIZ + MOD_PREFIX_LEN], ifname[IFNAMSIZ], *dp;
	const char *cp;

	/* loading suppressed by the user */
	if (noload)
		return;

	/* trim the interface number off the end */
	strlcpy(ifname, name, sizeof(ifname));
	for (dp = ifname; *dp != 0; dp++)
		if (isdigit(*dp)) {
			*dp = 0;
			break;
		}

	/* turn interface and unit into module name */
	strcpy(ifkind, "if_");
	strlcpy(ifkind + MOD_PREFIX_LEN, ifname,
	    sizeof(ifkind) - MOD_PREFIX_LEN);

	/* scan files in kernel */
	mstat.version = sizeof(struct module_stat);
	for (fileid = kldnext(0); fileid > 0; fileid = kldnext(fileid)) {
		/* scan modules in file */
		for (modid = kldfirstmod(fileid); modid > 0;
		     modid = modfnext(modid)) {
			if (modstat(modid, &mstat) < 0)
				continue;
			/* strip bus name if present */
			if ((cp = strchr(mstat.name, '/')) != NULL) {
				cp++;
			} else {
				cp = mstat.name;
			}
			/* already loaded? */
			if (strncmp(ifname, cp, strlen(ifname) + 1) == 0 ||
			    strncmp(ifkind, cp, strlen(ifkind) + 1) == 0)
				return;
		}
	}

	/* not present, we should try to load it */
	kldload(ifkind);
}

static struct cmd basic_cmds[] = {
	DEF_CMD("up",		IFF_UP,		setifflags),
	DEF_CMD("down",		-IFF_UP,	setifflags),
	DEF_CMD("arp",		-IFF_NOARP,	setifflags),
	DEF_CMD("-arp",		IFF_NOARP,	setifflags),
	DEF_CMD("debug",	IFF_DEBUG,	setifflags),
	DEF_CMD("-debug",	-IFF_DEBUG,	setifflags),
	DEF_CMD("promisc",	IFF_PPROMISC,	setifflags),
	DEF_CMD("-promisc",	-IFF_PPROMISC,	setifflags),
	DEF_CMD("add",		IFF_UP,		notealias),
	DEF_CMD("alias",	IFF_UP,		notealias),
	DEF_CMD("-alias",	-IFF_UP,	notealias),
	DEF_CMD("delete",	-IFF_UP,	notealias),
	DEF_CMD("remove",	-IFF_UP,	notealias),
#ifdef notdef
#define	EN_SWABIPS	0x1000
	DEF_CMD("swabips",	EN_SWABIPS,	setifflags),
	DEF_CMD("-swabips",	-EN_SWABIPS,	setifflags),
#endif
	DEF_CMD_ARG("netmask",			setifnetmask),
	DEF_CMD_ARG("metric",			setifmetric),
	DEF_CMD_ARG("broadcast",		setifbroadaddr),
	DEF_CMD_ARG("ipdst",			setifipdst),
	DEF_CMD_ARG2("tunnel",			settunnel),
	DEF_CMD("-tunnel", 0,			deletetunnel),
	DEF_CMD("deletetunnel", 0,		deletetunnel),
	DEF_CMD("link0",	IFF_LINK0,	setifflags),
	DEF_CMD("-link0",	-IFF_LINK0,	setifflags),
	DEF_CMD("link1",	IFF_LINK1,	setifflags),
	DEF_CMD("-link1",	-IFF_LINK1,	setifflags),
	DEF_CMD("link2",	IFF_LINK2,	setifflags),
	DEF_CMD("-link2",	-IFF_LINK2,	setifflags),
	DEF_CMD("monitor",	IFF_MONITOR,	setifflags),
	DEF_CMD("-monitor",	-IFF_MONITOR,	setifflags),
	DEF_CMD("staticarp",	IFF_STATICARP,	setifflags),
	DEF_CMD("-staticarp",	-IFF_STATICARP,	setifflags),
	DEF_CMD("rxcsum",	IFCAP_RXCSUM,	setifcap),
	DEF_CMD("-rxcsum",	-IFCAP_RXCSUM,	setifcap),
	DEF_CMD("txcsum",	IFCAP_TXCSUM,	setifcap),
	DEF_CMD("-txcsum",	-IFCAP_TXCSUM,	setifcap),
	DEF_CMD("netcons",	IFCAP_NETCONS,	setifcap),
	DEF_CMD("-netcons",	-IFCAP_NETCONS,	setifcap),
	DEF_CMD("polling",	IFCAP_POLLING,	setifcap),
	DEF_CMD("-polling",	-IFCAP_POLLING,	setifcap),
	DEF_CMD("tso",		IFCAP_TSO,	setifcap),
	DEF_CMD("-tso",		-IFCAP_TSO,	setifcap),
	DEF_CMD("lro",		IFCAP_LRO,	setifcap),
	DEF_CMD("-lro",		-IFCAP_LRO,	setifcap),
	DEF_CMD("wol",		IFCAP_WOL,	setifcap),
	DEF_CMD("-wol",		-IFCAP_WOL,	setifcap),
	DEF_CMD("wol_ucast",	IFCAP_WOL_UCAST,	setifcap),
	DEF_CMD("-wol_ucast",	-IFCAP_WOL_UCAST,	setifcap),
	DEF_CMD("wol_mcast",	IFCAP_WOL_MCAST,	setifcap),
	DEF_CMD("-wol_mcast",	-IFCAP_WOL_MCAST,	setifcap),
	DEF_CMD("wol_magic",	IFCAP_WOL_MAGIC,	setifcap),
	DEF_CMD("-wol_magic",	-IFCAP_WOL_MAGIC,	setifcap),
	DEF_CMD("normal",	-IFF_LINK0,	setifflags),
	DEF_CMD("compress",	IFF_LINK0,	setifflags),
	DEF_CMD("noicmp",	IFF_LINK1,	setifflags),
	DEF_CMD_ARG("mtu",			setifmtu),
	DEF_CMD_ARG("name",			setifname),
};

static __constructor void
ifconfig_ctor(void)
{
#define	N(a)	(sizeof(a) / sizeof(a[0]))
	int i;

	for (i = 0; i < N(basic_cmds);  i++)
		cmd_register(&basic_cmds[i]);
#undef N
}