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/* $OpenBSD: ethers.c,v 1.23 2015/01/16 16:48:51 deraadt Exp $ */
/*
* Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* ethers(3) a la Sun.
* Originally Written by Roland McGrath <roland@frob.com> 10/14/93.
* Substantially modified by Todd C. Miller <Todd.Miller@courtesan.com>
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <paths.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#ifdef YP
#include <rpcsvc/ypclnt.h>
#endif
#ifndef _PATH_ETHERS
#define _PATH_ETHERS "/etc/ethers"
#endif
static char * _ether_aton(const char *, struct ether_addr *);
char *
ether_ntoa(struct ether_addr *e)
{
static char a[] = "xx:xx:xx:xx:xx:xx";
(void)snprintf(a, sizeof a, "%02x:%02x:%02x:%02x:%02x:%02x",
e->ether_addr_octet[0], e->ether_addr_octet[1],
e->ether_addr_octet[2], e->ether_addr_octet[3],
e->ether_addr_octet[4], e->ether_addr_octet[5]);
return (a);
}
static char *
_ether_aton(const char *s, struct ether_addr *e)
{
int i;
long l;
char *pp;
while (isspace((unsigned char)*s))
s++;
/* expect 6 hex octets separated by ':' or space/NUL if last octet */
for (i = 0; i < 6; i++) {
l = strtol(s, &pp, 16);
if (pp == s || l > 0xFF || l < 0)
return (NULL);
if (!(*pp == ':' ||
(i == 5 && (isspace((unsigned char)*pp) ||
*pp == '\0'))))
return (NULL);
e->ether_addr_octet[i] = (u_char)l;
s = pp + 1;
}
/* return character after the octets ala strtol(3) */
return (pp);
}
struct ether_addr *
ether_aton(const char *s)
{
static struct ether_addr n;
return (_ether_aton(s, &n) ? &n : NULL);
}
int
ether_ntohost(char *hostname, struct ether_addr *e)
{
FILE *f;
char buf[BUFSIZ+1], *p;
size_t len;
struct ether_addr try;
#ifdef YP
char trybuf[sizeof("xx:xx:xx:xx:xx:xx")];
int trylen;
#endif
#ifdef YP
snprintf(trybuf, sizeof trybuf, "%x:%x:%x:%x:%x:%x",
e->ether_addr_octet[0], e->ether_addr_octet[1],
e->ether_addr_octet[2], e->ether_addr_octet[3],
e->ether_addr_octet[4], e->ether_addr_octet[5]);
trylen = strlen(trybuf);
#endif
f = fopen(_PATH_ETHERS, "re");
if (f == NULL)
return (-1);
while ((p = fgetln(f, &len)) != NULL) {
if (p[len-1] == '\n')
len--;
if (len > sizeof(buf) - 2)
continue;
(void)memcpy(buf, p, len);
buf[len] = '\n'; /* code assumes newlines later on */
buf[len+1] = '\0';
#ifdef YP
/* A + in the file means try YP now. */
if (!strncmp(buf, "+\n", sizeof(buf))) {
char *ypbuf, *ypdom;
int ypbuflen;
if (yp_get_default_domain(&ypdom))
continue;
if (yp_match(ypdom, "ethers.byaddr", trybuf,
trylen, &ypbuf, &ypbuflen))
continue;
if (ether_line(ypbuf, &try, hostname) == 0) {
free(ypbuf);
(void)fclose(f);
return (0);
}
free(ypbuf);
continue;
}
#endif
if (ether_line(buf, &try, hostname) == 0 &&
memcmp((void *)&try, (void *)e, sizeof(try)) == 0) {
(void)fclose(f);
return (0);
}
}
(void)fclose(f);
errno = ENOENT;
return (-1);
}
int
ether_hostton(const char *hostname, struct ether_addr *e)
{
FILE *f;
char buf[BUFSIZ+1], *p;
char try[HOST_NAME_MAX+1];
size_t len;
#ifdef YP
int hostlen = strlen(hostname);
#endif
f = fopen(_PATH_ETHERS, "re");
if (f==NULL)
return (-1);
while ((p = fgetln(f, &len)) != NULL) {
if (p[len-1] == '\n')
len--;
if (len > sizeof(buf) - 2)
continue;
memcpy(buf, p, len);
buf[len] = '\n'; /* code assumes newlines later on */
buf[len+1] = '\0';
#ifdef YP
/* A + in the file means try YP now. */
if (!strncmp(buf, "+\n", sizeof(buf))) {
char *ypbuf, *ypdom;
int ypbuflen;
if (yp_get_default_domain(&ypdom))
continue;
if (yp_match(ypdom, "ethers.byname", hostname, hostlen,
&ypbuf, &ypbuflen))
continue;
if (ether_line(ypbuf, e, try) == 0) {
free(ypbuf);
(void)fclose(f);
return (0);
}
free(ypbuf);
continue;
}
#endif
if (ether_line(buf, e, try) == 0 && strcmp(hostname, try) == 0) {
(void)fclose(f);
return (0);
}
}
(void)fclose(f);
errno = ENOENT;
return (-1);
}
int
ether_line(const char *line, struct ether_addr *e, char *hostname)
{
char *p;
size_t n;
/* Parse "xx:xx:xx:xx:xx:xx" */
if ((p = _ether_aton(line, e)) == NULL || (*p != ' ' && *p != '\t'))
goto bad;
/* Now get the hostname */
while (isspace((unsigned char)*p))
p++;
if (*p == '\0')
goto bad;
n = strcspn(p, " \t\n");
if (n >= HOST_NAME_MAX+1)
goto bad;
strlcpy(hostname, p, n + 1);
return (0);
bad:
errno = EINVAL;
return (-1);
}
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