lib/libc/net/ethers.c

   1 /*      $NetBSD: ethers.c,v 1.20 2002/09/16 19:25:33 tron Exp $ */
   2
   3 /*
   4  * ethers(3N) a la Sun.
   5  *
   6  * Written by Roland McGrath <roland@frob.com> 10/14/93.
   7  * Public domain.
   8  */
   9
  10 #include <sys/cdefs.h>
  11 #if defined(LIBC_SCCS) && !defined(lint)
  12 __RCSID("$NetBSD: ethers.c,v 1.20 2002/09/16 19:25:33 tron Exp $");
  13 #endif /* LIBC_SCCS and not lint */
  14
  15 #include "namespace.h"
  16 #include <sys/param.h>
  17 #include <sys/socket.h>
  18
  19 #include <net/if.h>
  20 #include <net/if_ether.h>
  21 #include <netinet/in.h>
  22
  23 #include <assert.h>
  24 #include <errno.h>
  25 #include <paths.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #ifdef YP
  31 #include <rpcsvc/ypclnt.h>
  32 #endif
  33
  34 #ifdef __weak_alias
  35 __weak_alias(ether_aton,_ether_aton)
  36 __weak_alias(ether_hostton,_ether_hostton)
  37 __weak_alias(ether_line,_ether_line)
  38 __weak_alias(ether_ntoa,_ether_ntoa)
  39 __weak_alias(ether_ntohost,_ether_ntohost)
  40 #endif
  41
  42 #ifndef _PATH_ETHERS
  43 #define _PATH_ETHERS "/etc/ethers"
  44 #endif
  45
  46 char *
  47 ether_ntoa(e)
  48         const struct ether_addr *e;
  49 {
  50         static char a[18];
  51
  52         _DIAGASSERT(e != NULL);
  53
  54         (void) snprintf(a, sizeof a, "%02x:%02x:%02x:%02x:%02x:%02x",
  55             e->ether_addr_octet[0], e->ether_addr_octet[1],
  56             e->ether_addr_octet[2], e->ether_addr_octet[3],
  57             e->ether_addr_octet[4], e->ether_addr_octet[5]);
  58         return a;
  59 }
  60
  61 struct ether_addr *
  62 ether_aton(s)
  63         const char *s;
  64 {
  65         static struct ether_addr n;
  66         u_int i[6];
  67
  68         _DIAGASSERT(s != NULL);
  69
  70         if (sscanf(s, " %x:%x:%x:%x:%x:%x ", &i[0], &i[1],
  71             &i[2], &i[3], &i[4], &i[5]) == 6) {
  72                 n.ether_addr_octet[0] = (u_char)i[0];
  73                 n.ether_addr_octet[1] = (u_char)i[1];
  74                 n.ether_addr_octet[2] = (u_char)i[2];
  75                 n.ether_addr_octet[3] = (u_char)i[3];
  76                 n.ether_addr_octet[4] = (u_char)i[4];
  77                 n.ether_addr_octet[5] = (u_char)i[5];
  78                 return &n;
  79         }
  80         return NULL;
  81 }
  82
  83 int
  84 ether_ntohost(hostname, e)
  85         char *hostname;
  86         const struct ether_addr *e;
  87 {
  88         FILE *f;
  89         char *p;
  90         size_t len;
  91         struct ether_addr try;
  92 #ifdef YP
  93         char trybuf[sizeof "xx:xx:xx:xx:xx:xx"];
  94         int trylen;
  95 #endif
  96
  97         _DIAGASSERT(hostname != NULL);
  98         _DIAGASSERT(e != NULL);
  99
 100 #ifdef YP
 101         trylen = snprintf(trybuf, sizeof trybuf, "%x:%x:%x:%x:%x:%x",
 102             e->ether_addr_octet[0], e->ether_addr_octet[1],
 103             e->ether_addr_octet[2], e->ether_addr_octet[3],
 104             e->ether_addr_octet[4], e->ether_addr_octet[5]);
 105 #endif
 106
 107         f = fopen(_PATH_ETHERS, "r");
 108         if (f == NULL)
 109                 return -1;
 110         while ((p = fgetln(f, &len)) != NULL) {
 111                 if (p[len - 1] != '\n')
 112                         continue;               /* skip lines w/o \n */
 113                 p[--len] = '\0';
 114 #ifdef YP
 115                 /* A + in the file means try YP now.  */
 116                 if (len == 1 && *p == '+') {
 117                         char *ypbuf, *ypdom;
 118                         int ypbuflen;
 119
 120                         if (yp_get_default_domain(&ypdom))
 121                                 continue;
 122                         if (yp_match(ypdom, "ethers.byaddr", trybuf,
 123                             trylen, &ypbuf, &ypbuflen))
 124                                 continue;
 125                         if (ether_line(ypbuf, &try, hostname) == 0) {
 126                                 free(ypbuf);
 127                                 (void)fclose(f);
 128                                 return 0;
 129                         }
 130                         free(ypbuf);
 131                         continue;
 132                 }
 133 #endif
 134                 if (ether_line(p, &try, hostname) == 0 &&
 135                     memcmp(&try, e, sizeof try) == 0) {
 136                         (void)fclose(f);
 137                         return 0;
 138                 }
 139         }
 140         (void)fclose(f);
 141         errno = ENOENT;
 142         return -1;
 143 }
 144
 145 int
 146 ether_hostton(hostname, e)
 147         const char *hostname;
 148         struct ether_addr *e;
 149 {
 150         FILE *f;
 151         char *p;
 152         size_t len;
 153         char try[MAXHOSTNAMELEN + 1];
 154 #ifdef YP
 155         int hostlen = strlen(hostname);
 156 #endif
 157
 158         _DIAGASSERT(hostname != NULL);
 159         _DIAGASSERT(e != NULL);
 160
 161         f = fopen(_PATH_ETHERS, "r");
 162         if (f==NULL)
 163                 return -1;
 164
 165         while ((p = fgetln(f, &len)) != NULL) {
 166                 if (p[len - 1] != '\n')
 167                         continue;               /* skip lines w/o \n */
 168                 p[--len] = '\0';
 169 #ifdef YP
 170                 /* A + in the file means try YP now.  */
 171                 if (len == 1 && *p == '+') {
 172                         char *ypbuf, *ypdom;
 173                         int ypbuflen;
 174
 175                         if (yp_get_default_domain(&ypdom))
 176                                 continue;
 177                         if (yp_match(ypdom, "ethers.byname", hostname, hostlen,
 178                             &ypbuf, &ypbuflen))
 179                                 continue;
 180                         if (ether_line(ypbuf, e, try) == 0) {
 181                                 free(ypbuf);
 182                                 (void)fclose(f);
 183                                 return 0;
 184                         }
 185                         free(ypbuf);
 186                         continue;
 187                 }
 188 #endif
 189                 if (ether_line(p, e, try) == 0 && strcmp(hostname, try) == 0) {
 190                         (void)fclose(f);
 191                         return 0;
 192                 }
 193         }
 194         (void)fclose(f);
 195         errno = ENOENT;
 196         return -1;
 197 }
 198
 199 int
 200 ether_line(l, e, hostname)
 201         const char *l;
 202         struct ether_addr *e;
 203         char *hostname;
 204 {
 205         u_int i[6];
 206
 207 #define S2(arg) #arg
 208 #define S1(arg) S2(arg)
 209         static const char fmt[] = " %x:%x:%x:%x:%x:%x"
 210             " %" S1(MAXHOSTNAMELEN) "s\n";
 211 #undef S2
 212 #undef S1
 213
 214         _DIAGASSERT(l != NULL);
 215         _DIAGASSERT(e != NULL);
 216         _DIAGASSERT(hostname != NULL);
 217
 218         if (sscanf(l, fmt,
 219             &i[0], &i[1], &i[2], &i[3], &i[4], &i[5], hostname) == 7) {
 220                 e->ether_addr_octet[0] = (u_char)i[0];
 221                 e->ether_addr_octet[1] = (u_char)i[1];
 222                 e->ether_addr_octet[2] = (u_char)i[2];
 223                 e->ether_addr_octet[3] = (u_char)i[3];
 224                 e->ether_addr_octet[4] = (u_char)i[4];
 225                 e->ether_addr_octet[5] = (u_char)i[5];
 226                 return 0;
 227         }
 228         errno = EINVAL;
 229         return -1;
 230 }