xref: /src/sbin/ifconfig/util.c

/*	$NetBSD: util.c,v 1.3 2008/05/07 18:17:42 dyoung Exp $	*/

/*-
 * Copyright (c)2008 David Young.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

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

#include <sys/socket.h>
#include <netinet/in.h>		/* XXX */

#include "util.h"

int
getsock(int naf)
{
	static int oaf = -1, s;

	if (oaf == naf || (oaf != -1 && naf == AF_UNSPEC))
		return s;

	if (oaf != -1)
		close(s);

	if (naf == AF_UNSPEC)
		naf = AF_INET;

	s = socket(naf, SOCK_DGRAM, 0);
	if (s == -1)
		oaf = -1;
	else
		oaf = naf;
	return s;
}

const char *
get_string(const char *val, const char *sep, u_int8_t *buf, int *lenp)
{
	int len;
	bool hexstr;
	u_int8_t *p;

	len = *lenp;
	p = buf;
	hexstr = (val[0] == '0' && tolower((u_char)val[1]) == 'x');
	if (hexstr)
		val += 2;
	for (;;) {
		if (*val == '\0')
			break;
		if (sep != NULL && strchr(sep, *val) != NULL) {
			val++;
			break;
		}
		if (hexstr) {
			if (!isxdigit((u_char)val[0]) ||
			    !isxdigit((u_char)val[1])) {
				warnx("bad hexadecimal digits");
				return NULL;
			}
		}
		if (p > buf + len) {
			if (hexstr)
				warnx("hexadecimal digits too long");
			else
				warnx("strings too long");
			return NULL;
		}
		if (hexstr) {
#define	tohex(x)	(isdigit(x) ? (x) - '0' : tolower(x) - 'a' + 10)
			*p++ = (tohex((u_char)val[0]) << 4) |
			    tohex((u_char)val[1]);
#undef tohex
			val += 2;
		} else
			*p++ = *val++;
	}
	len = p - buf;
	if (len < *lenp)
		memset(p, 0, *lenp - len);
	*lenp = len;
	return val;
}

void
print_string(const u_int8_t *buf, int len)
{
	int i;
	bool hasspc;

	i = 0;
	hasspc = false;
	if (len < 2 || buf[0] != '0' || tolower(buf[1]) != 'x') {
		for (; i < len; i++) {
			if (!isprint(buf[i]))
				break;
			if (isspace(buf[i]))
				hasspc = true;
		}
	}
	if (i == len) {
		if (hasspc || len == 0)
			printf("\"%.*s\"", len, buf);
		else
			printf("%.*s", len, buf);
	} else {
		printf("0x");
		for (i = 0; i < len; i++)
			printf("%02x", buf[i]);
	}
}

struct paddr_prefix *
prefixlen_to_mask(int af, int plen)
{
	union {
		struct sockaddr sa;
		struct sockaddr_in sin;
		struct sockaddr_in6 sin6;
	} u;
	struct paddr_prefix *pfx;
	size_t addrlen;
	uint8_t *addr;
	int nbit;

	memset(&u, 0, sizeof(u));

	switch (af) {
	case AF_INET:
		addrlen = sizeof(u.sin.sin_addr);
		addr = (uint8_t *)&u.sin.sin_addr;
		u.sa.sa_len = sizeof(u.sin);
		break;
	case AF_INET6:
		addrlen = sizeof(u.sin6.sin6_addr);
		addr = (uint8_t *)&u.sin6.sin6_addr;
		u.sa.sa_len = sizeof(u.sin6);
		break;
	default:
		errno = EINVAL;
		return NULL;
	}
	u.sa.sa_family = af;

	if (plen < 0 || plen > addrlen * NBBY) {
		errno = EINVAL;
		return NULL;
	}

	if (plen == 0)
		plen = addrlen * NBBY;

	memset(addr, 0xff, (plen + NBBY - 1) / NBBY);

	nbit = plen % NBBY;
	if (nbit != 0)
		addr[plen / NBBY] &= ~((uint8_t)0xff >> nbit);
	pfx = malloc(offsetof(struct paddr_prefix, pfx_addr) + u.sa.sa_len);
	if (pfx == NULL)
		return NULL;
	pfx->pfx_len = plen;
	memcpy(&pfx->pfx_addr, &u.sa, u.sa.sa_len);

	return pfx;
}