/* $OpenBSD: ethers.c,v 1.11 2000/08/22 19:04:41 deraadt Exp $ */ /* * Copyright (c) 1998 Todd C. Miller * 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. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``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 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. */ /* * ethers(3) a la Sun. * Originally Written by Roland McGrath 10/14/93. * Substantially modified by Todd C. Miller */ #if defined(LIBC_SCCS) && !defined(lint) static char rcsid[] = "$OpenBSD: ethers.c,v 1.11 2000/08/22 19:04:41 deraadt Exp $"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #ifdef YP #include #endif #ifndef _PATH_ETHERS #define _PATH_ETHERS "/etc/ethers" #endif static char * _ether_aton __P((char *, struct ether_addr *)); char * ether_ntoa(e) struct ether_addr *e; { static char a[] = "xx:xx:xx:xx:xx:xx"; if (e->ether_addr_octet[0] > 0xFF || e->ether_addr_octet[1] > 0xFF || e->ether_addr_octet[2] > 0xFF || e->ether_addr_octet[3] > 0xFF || e->ether_addr_octet[4] > 0xFF || e->ether_addr_octet[5] > 0xFF) { errno = EINVAL; return (NULL); } (void)sprintf(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(s, e) char *s; struct ether_addr *e; { int i; long l; char *pp; while (isspace(*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(*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(s) char *s; { static struct ether_addr n; return (_ether_aton(s, &n) ? &n : NULL); } int ether_ntohost(hostname, e) 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 if (e->ether_addr_octet[0] > 0xFF || e->ether_addr_octet[1] > 0xFF || e->ether_addr_octet[2] > 0xFF || e->ether_addr_octet[3] > 0xFF || e->ether_addr_octet[4] > 0xFF || e->ether_addr_octet[5] > 0xFF) { errno = EINVAL; return (-1); } #ifdef YP sprintf(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, "r"); 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(hostname, e) char *hostname; struct ether_addr *e; { FILE *f; char buf[BUFSIZ+1], *p; char try[MAXHOSTNAMELEN]; size_t len; #ifdef YP int hostlen = strlen(hostname); #endif f = fopen(_PATH_ETHERS, "r"); 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(line, e, hostname) 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(*p)) p++; if (*p == '\0') goto bad; n = strcspn(p, " \t\n"); if (n >= MAXHOSTNAMELEN) goto bad; (void)strncpy(hostname, p, n); hostname[n] = '\0'; return (0); bad: errno = EINVAL; return (-1); }