1 | /* |
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2 | * Copyright (c) 1995 |
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3 | * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * 1. Redistributions of source code must retain the above copyright |
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9 | * notice, this list of conditions and the following disclaimer. |
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10 | * 2. Redistributions in binary form must reproduce the above copyright |
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11 | * notice, this list of conditions and the following disclaimer in the |
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12 | * documentation and/or other materials provided with the distribution. |
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13 | * 3. All advertising materials mentioning features or use of this software |
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14 | * must display the following acknowledgement: |
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15 | * This product includes software developed by Bill Paul. |
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16 | * 4. Neither the name of the author nor the names of any co-contributors |
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17 | * may be used to endorse or promote products derived from this software |
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18 | * without specific prior written permission. |
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19 | * |
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20 | * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND |
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21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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30 | * SUCH DAMAGE. |
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31 | * |
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32 | * ethernet address conversion and lookup routines |
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33 | * |
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34 | * Written by Bill Paul <wpaul@ctr.columbia.edu> |
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35 | * Center for Telecommunications Research |
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36 | * Columbia University, New York City |
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37 | * |
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38 | * $Id$ |
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39 | */ |
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40 | |
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41 | |
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42 | #include <stdio.h> |
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43 | #include <paths.h> |
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44 | #include <sys/types.h> |
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45 | #include <string.h> |
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46 | #include <stdlib.h> |
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47 | #include <sys/param.h> |
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48 | #include <sys/socket.h> |
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49 | #include <net/ethernet.h> |
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50 | #ifdef YP |
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51 | #include <rpc/rpc.h> |
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52 | #include <rpcsvc/yp_prot.h> |
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53 | #include <rpcsvc/ypclnt.h> |
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54 | #endif |
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55 | |
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56 | #ifndef _PATH_ETHERS |
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57 | #define _PATH_ETHERS "/etc/ethers" |
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58 | #endif |
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59 | |
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60 | /* |
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61 | * Parse a string of text containing an ethernet address and hostname |
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62 | * and separate it into its component parts. |
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63 | */ |
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64 | int ether_line(l, e, hostname) |
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65 | char *l; |
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66 | struct ether_addr *e; |
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67 | char *hostname; |
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68 | { |
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69 | int i, o[6]; |
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70 | |
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71 | i = sscanf(l, "%x:%x:%x:%x:%x:%x %s", &o[0], &o[1], &o[2], |
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72 | &o[3], &o[4], &o[5], |
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73 | hostname); |
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74 | if (i != 7) |
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75 | return (i); |
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76 | |
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77 | for (i=0; i<6; i++) |
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78 | e->octet[i] = o[i]; |
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79 | return (0); |
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80 | } |
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81 | |
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82 | /* |
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83 | * Convert an ASCII representation of an ethernet address to |
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84 | * binary form. |
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85 | */ |
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86 | struct ether_addr *ether_aton(a) |
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87 | char *a; |
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88 | { |
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89 | int i; |
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90 | static struct ether_addr o; |
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91 | unsigned int o0, o1, o2, o3, o4, o5; |
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92 | |
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93 | i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o0, &o1, &o2, &o3, &o4, &o5); |
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94 | |
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95 | if (i != 6) |
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96 | return (NULL); |
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97 | |
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98 | o.octet[0]=o0; |
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99 | o.octet[1]=o1; |
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100 | o.octet[2]=o2; |
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101 | o.octet[3]=o3; |
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102 | o.octet[4]=o4; |
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103 | o.octet[5]=o5; |
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104 | |
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105 | return ((struct ether_addr *)&o); |
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106 | } |
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107 | |
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108 | /* |
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109 | * Convert a binary representation of an ethernet address to |
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110 | * an ASCII string. |
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111 | */ |
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112 | char *ether_ntoa(n) |
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113 | struct ether_addr *n; |
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114 | { |
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115 | int i; |
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116 | static char a[18]; |
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117 | |
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118 | i = sprintf(a,"%x:%x:%x:%x:%x:%x",n->octet[0],n->octet[1],n->octet[2], |
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119 | n->octet[3],n->octet[4],n->octet[5]); |
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120 | if (i < 11) |
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121 | return (NULL); |
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122 | return ((char *)&a); |
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123 | } |
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124 | |
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125 | /* |
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126 | * Map an ethernet address to a hostname. Use either /etc/ethers or |
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127 | * NIS/YP. |
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128 | */ |
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129 | |
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130 | int ether_ntohost(hostname, e) |
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131 | char *hostname; |
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132 | struct ether_addr *e; |
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133 | { |
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134 | FILE *fp; |
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135 | char buf[BUFSIZ + 2]; |
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136 | struct ether_addr local_ether; |
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137 | char local_host[MAXHOSTNAMELEN]; |
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138 | #ifdef YP |
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139 | char *result; |
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140 | int resultlen; |
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141 | char *ether_a; |
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142 | char *yp_domain; |
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143 | #endif |
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144 | if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) |
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145 | return (1); |
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146 | |
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147 | while (fgets(buf,BUFSIZ,fp)) { |
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148 | if (buf[0] == '#') |
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149 | continue; |
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150 | #ifdef YP |
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151 | if (buf[0] == '+') { |
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152 | if (yp_get_default_domain(&yp_domain)) |
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153 | continue; |
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154 | ether_a = ether_ntoa(e); |
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155 | if (yp_match(yp_domain, "ethers.byaddr", ether_a, |
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156 | strlen(ether_a), &result, &resultlen)) { |
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157 | continue; |
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158 | } |
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159 | strncpy(buf, result, resultlen); |
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160 | buf[resultlen] = '\0'; |
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161 | free(result); |
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162 | } |
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163 | #endif |
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164 | if (!ether_line(buf, &local_ether, local_host)) { |
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165 | if (!bcmp((char *)&local_ether.octet[0], |
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166 | (char *)&e->octet[0], 6)) { |
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167 | /* We have a match */ |
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168 | strcpy(hostname, local_host); |
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169 | fclose(fp); |
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170 | return(0); |
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171 | } |
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172 | } |
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173 | } |
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174 | fclose(fp); |
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175 | return (1); |
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176 | } |
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177 | |
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178 | /* |
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179 | * Map a hostname to an ethernet address using /etc/ethers or |
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180 | * NIS/YP. |
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181 | */ |
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182 | int ether_hostton(hostname, e) |
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183 | char *hostname; |
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184 | struct ether_addr *e; |
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185 | { |
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186 | FILE *fp; |
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187 | char buf[BUFSIZ + 2]; |
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188 | struct ether_addr local_ether; |
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189 | char local_host[MAXHOSTNAMELEN]; |
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190 | #ifdef YP |
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191 | char *result; |
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192 | int resultlen; |
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193 | char *yp_domain; |
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194 | #endif |
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195 | if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) |
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196 | return (1); |
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197 | |
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198 | while (fgets(buf,BUFSIZ,fp)) { |
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199 | if (buf[0] == '#') |
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200 | continue; |
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201 | #ifdef YP |
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202 | if (buf[0] == '+') { |
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203 | if (yp_get_default_domain(&yp_domain)) |
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204 | continue; |
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205 | if (yp_match(yp_domain, "ethers.byname", hostname, |
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206 | strlen(hostname), &result, &resultlen)) { |
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207 | continue; |
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208 | } |
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209 | strncpy(buf, result, resultlen); |
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210 | buf[resultlen] = '\0'; |
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211 | free(result); |
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212 | } |
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213 | #endif |
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214 | if (!ether_line(buf, &local_ether, local_host)) { |
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215 | if (!strcmp(hostname, local_host)) { |
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216 | /* We have a match */ |
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217 | bcopy((char *)&local_ether.octet[0], |
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218 | (char *)&e->octet[0], 6); |
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219 | fclose(fp); |
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220 | return(0); |
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221 | } |
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222 | } |
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223 | } |
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224 | fclose(fp); |
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225 | return (1); |
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226 | } |
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