4.2BSD/usr/src/etc/ifconfig.c

#ifndef lint
static char sccsid[] = "@(#)ifconfig.c	4.5 (Berkeley) 11/2/83";
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

#include <netinet/in.h>
#include <net/if.h>

#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <netdb.h>

struct	ifreq ifr;
struct	sockaddr_in sin = { AF_INET };
char	name[30];
int	flags;
int	s;

int	setifflags(), setifaddr();

struct	cmd {
	char	*c_name;
	int	c_parameter;
	int	(*c_func)();
} cmds[] = {
	{ "up",		IFF_UP,		setifflags } ,
	{ "down",	-IFF_UP,	setifflags },
	{ "trailers",	-IFF_NOTRAILERS,setifflags },
	{ "-trailers",	IFF_NOTRAILERS,	setifflags },
	{ "arp",	-IFF_NOARP,	setifflags },
	{ "-arp",	IFF_NOARP,	setifflags },
	{ "debug",	IFF_DEBUG,	setifflags },
	{ "-debug",	-IFF_DEBUG,	setifflags },
#ifdef notdef
#define	EN_SWABIPS	0x100
	{ "swabips",	EN_SWABIPS,	setifflags },
	{ "-swabips",	-EN_SWABIPS,	setifflags },
#endif
	{ 0,		0,		setifaddr },
};

main(argc, argv)
	int argc;
	char *argv[];
{

	if (argc < 2) {
		fprintf(stderr, "usage: ifconfig interface %s %s %s\n",
		    "[ address ] [ up ] [ down ]",
		    "[ trailers | -trailers ]",
		    "[ arp | -arp ]");
		exit(1);
	}
	s = socket(AF_INET, SOCK_DGRAM, 0);
	if (s < 0) {
		perror("ifconfig: socket");
		exit(1);
	}
	argc--, argv++;
	strcpy(name, *argv);
	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
		Perror("ioctl (SIOCGIFFLAGS)");
		exit(1);
	}
	flags = ifr.ifr_flags;
	argc--, argv++;
	if (argc == 0) {
		status();
		exit(0);
	}
	while (argc > 0) {
		register struct cmd *p;

		for (p = cmds; p->c_name; p++)
			if (strcmp(*argv, p->c_name) == 0)
				break;
		if (p->c_func)
			(*p->c_func)(*argv, p->c_parameter);
		argc--, argv++;
	}
	exit(0);
}

/*ARGSUSED*/
setifaddr(addr, param)
	char *addr;
	int param;
{

	getaddr(addr, (struct sockaddr_in *)&ifr.ifr_addr);
	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	if (ioctl(s, SIOCSIFADDR, (caddr_t)&ifr) < 0)
		Perror("ioctl (SIOCSIFADDR)");
}

setifflags(vname, value)
	char *vname;
	int value;
{

	if (value < 0) {
		value = -value;
		flags &= ~value;
	} else
		flags |= value;
	ifr.ifr_flags = flags;
	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0)
		Perror(vname);
}

status()
{
	struct sockaddr_in *sin;

	strncpy(ifr.ifr_name, name, sizeof (ifr.ifr_name));
	if (ioctl(s, SIOCGIFADDR, (caddr_t)&ifr) < 0)
		Perror("ioctl (SIOCGIFADDR)");
	sin = (struct sockaddr_in *)&ifr.ifr_addr;
	printf("%s: %s ", name, inet_ntoa(sin->sin_addr));
#define	IFFBITS \
"\020\1UP\2BROADCAST\3DEBUG\4ROUTE\5POINTOPOINT\6NOTRAILERS\7RUNNING\10NOARP"
	printb("flags", flags, IFFBITS); putchar('\n');
}

Perror(cmd)
	char *cmd;
{
	extern int errno;

	fprintf(stderr, "ifconfig: ");
	switch (errno) {

	case ENXIO:
		fprintf(stderr, "%s: ", cmd);
		fprintf(stderr, "no such interface\n");
		break;

	case EPERM:
		fprintf(stderr, "%s: permission denied\n");
		break;

	default:
		perror(cmd);
	}
	exit(1);
}

struct	in_addr inet_makeaddr();

getaddr(s, sin)
	char *s;
	struct sockaddr_in *sin;
{
	struct hostent *hp;
	struct netent *np;
	int val;

	hp = gethostbyname(s);
	if (hp) {
		sin->sin_family = hp->h_addrtype;
		bcopy(hp->h_addr, (char *)&sin->sin_addr, hp->h_length);
		return;
	}
	np = getnetbyname(s);
	if (np) {
		sin->sin_family = np->n_addrtype;
		sin->sin_addr = inet_makeaddr(np->n_net, INADDR_ANY);
		return;
	}
	sin->sin_family = AF_INET;
	val = inet_addr(s);
	if (val != -1) {
		sin->sin_addr.s_addr = val;
		return;
	}
	val = inet_network(s);
	if (val != -1) {
		sin->sin_addr = inet_makeaddr(val, INADDR_ANY);
		return;
	}
	fprintf(stderr, "%s: bad value\n", s);
	exit(1);
}

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

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