1 | /*- |
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2 | * Copyright (c) 1985, 1988, 1993 |
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3 | * The Regents of the University of California. 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 the University of |
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16 | * California, Berkeley and its contributors. |
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17 | * 4. Neither the name of the University nor the names of its contributors |
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18 | * may be used to endorse or promote products derived from this software |
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19 | * without specific prior written permission. |
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20 | * |
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21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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31 | * SUCH DAMAGE. |
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32 | * - |
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33 | * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
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34 | * |
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35 | * Permission to use, copy, modify, and distribute this software for any |
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36 | * purpose with or without fee is hereby granted, provided that the above |
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37 | * copyright notice and this permission notice appear in all copies, and that |
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38 | * the name of Digital Equipment Corporation not be used in advertising or |
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39 | * publicity pertaining to distribution of the document or software without |
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40 | * specific, written prior permission. |
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41 | * |
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42 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
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43 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
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44 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
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45 | * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
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46 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
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47 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
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48 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
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49 | * SOFTWARE. |
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50 | * - |
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51 | * --Copyright-- |
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52 | */ |
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53 | /* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro |
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54 | * Dep. Matematica Universidade de Coimbra, Portugal, Europe |
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55 | * |
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56 | * Permission to use, copy, modify, and distribute this software for any |
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57 | * purpose with or without fee is hereby granted, provided that the above |
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58 | * copyright notice and this permission notice appear in all copies. |
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59 | */ |
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60 | |
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61 | #if defined(LIBC_SCCS) && !defined(lint) |
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62 | static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; |
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63 | static char rcsid[] = "$Id$"; |
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64 | #endif /* LIBC_SCCS and not lint */ |
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65 | |
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66 | #include <sys/param.h> |
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67 | #include <sys/socket.h> |
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68 | #include <netinet/in.h> |
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69 | #include <arpa/inet.h> |
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70 | #include <arpa/nameser.h> |
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71 | |
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72 | #include <stdio.h> |
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73 | #include <netdb.h> |
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74 | #include <resolv.h> |
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75 | #include <ctype.h> |
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76 | #include <errno.h> |
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77 | #include <string.h> |
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78 | #include <unistd.h> |
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79 | #include <syslog.h> |
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80 | |
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81 | #include "res_config.h" |
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82 | |
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83 | extern int h_errno; |
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84 | |
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85 | #define BYADDR 0 |
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86 | #define BYNAME 1 |
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87 | #define MAXALIASES 35 |
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88 | |
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89 | #if PACKETSZ > 1024 |
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90 | #define MAXPACKET PACKETSZ |
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91 | #else |
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92 | #define MAXPACKET 1024 |
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93 | #endif |
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94 | |
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95 | typedef union { |
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96 | HEADER hdr; |
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97 | u_char buf[MAXPACKET]; |
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98 | } querybuf; |
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99 | |
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100 | typedef union { |
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101 | long al; |
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102 | char ac; |
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103 | } align; |
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104 | |
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105 | static struct netent * |
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106 | getnetanswer(answer, anslen, net_i) |
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107 | querybuf *answer; |
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108 | int anslen; |
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109 | int net_i; |
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110 | { |
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111 | |
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112 | register HEADER *hp; |
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113 | register u_char *cp; |
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114 | register int n; |
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115 | u_char *eom; |
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116 | int type, class, buflen, ancount, qdcount, haveanswer, i, nchar; |
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117 | char aux1[MAXHOSTNAMELEN], aux2[MAXHOSTNAMELEN], ans[MAXHOSTNAMELEN]; |
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118 | char *in, *st, *pauxt, *bp, **ap; |
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119 | char *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0; |
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120 | static struct netent net_entry; |
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121 | static char *net_aliases[MAXALIASES], netbuf[PACKETSZ]; |
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122 | |
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123 | /* |
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124 | * find first satisfactory answer |
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125 | * |
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126 | * answer --> +------------+ ( MESSAGE ) |
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127 | * | Header | |
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128 | * +------------+ |
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129 | * | Question | the question for the name server |
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130 | * +------------+ |
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131 | * | Answer | RRs answering the question |
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132 | * +------------+ |
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133 | * | Authority | RRs pointing toward an authority |
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134 | * | Additional | RRs holding additional information |
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135 | * +------------+ |
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136 | */ |
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137 | eom = answer->buf + anslen; |
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138 | hp = &answer->hdr; |
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139 | ancount = ntohs(hp->ancount); /* #/records in the answer section */ |
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140 | qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ |
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141 | bp = netbuf; |
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142 | buflen = sizeof(netbuf); |
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143 | cp = answer->buf + HFIXEDSZ; |
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144 | if (!qdcount) { |
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145 | if (hp->aa) |
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146 | h_errno = HOST_NOT_FOUND; |
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147 | else |
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148 | h_errno = TRY_AGAIN; |
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149 | return (NULL); |
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150 | } |
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151 | while (qdcount-- > 0) |
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152 | cp += __dn_skipname(cp, eom) + QFIXEDSZ; |
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153 | ap = net_aliases; |
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154 | *ap = NULL; |
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155 | net_entry.n_aliases = net_aliases; |
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156 | haveanswer = 0; |
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157 | while (--ancount >= 0 && cp < eom) { |
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158 | n = dn_expand(answer->buf, eom, cp, bp, buflen); |
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159 | if ((n < 0) || !res_dnok(bp)) |
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160 | break; |
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161 | cp += n; |
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162 | ans[0] = '\0'; |
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163 | (void)strncpy(&ans[0], bp, sizeof(ans) - 1); |
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164 | ans[sizeof(ans) - 1] = '\0'; |
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165 | GETSHORT(type, cp); |
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166 | GETSHORT(class, cp); |
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167 | cp += INT32SZ; /* TTL */ |
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168 | GETSHORT(n, cp); |
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169 | if (class == C_IN && type == T_PTR) { |
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170 | n = dn_expand(answer->buf, eom, cp, bp, buflen); |
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171 | if ((n < 0) || !res_hnok(bp)) { |
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172 | cp += n; |
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173 | return (NULL); |
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174 | } |
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175 | cp += n; |
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176 | *ap++ = bp; |
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177 | bp += strlen(bp) + 1; |
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178 | net_entry.n_addrtype = |
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179 | (class == C_IN) ? AF_INET : AF_UNSPEC; |
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180 | haveanswer++; |
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181 | } |
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182 | } |
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183 | if (haveanswer) { |
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184 | *ap = NULL; |
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185 | switch (net_i) { |
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186 | case BYADDR: |
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187 | net_entry.n_name = *net_entry.n_aliases; |
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188 | net_entry.n_net = 0L; |
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189 | break; |
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190 | case BYNAME: |
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191 | in = *net_entry.n_aliases; |
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192 | net_entry.n_name = &ans[0]; |
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193 | aux2[0] = '\0'; |
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194 | for (i = 0; i < 4; i++) { |
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195 | for (st = in, nchar = 0; |
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196 | *st != '.'; |
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197 | st++, nchar++) |
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198 | ; |
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199 | if (nchar != 1 || *in != '0' || flag) { |
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200 | flag = 1; |
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201 | (void)strncpy(paux1, |
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202 | (i==0) ? in : in-1, |
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203 | (i==0) ?nchar : nchar+1); |
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204 | paux1[(i==0) ? nchar : nchar+1] = '\0'; |
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205 | pauxt = paux2; |
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206 | paux2 = strcat(paux1, paux2); |
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207 | paux1 = pauxt; |
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208 | } |
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209 | in = ++st; |
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210 | } |
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211 | net_entry.n_net = inet_network(paux2); |
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212 | break; |
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213 | } |
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214 | net_entry.n_aliases++; |
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215 | return (&net_entry); |
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216 | } |
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217 | h_errno = TRY_AGAIN; |
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218 | return (NULL); |
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219 | } |
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220 | |
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221 | struct netent * |
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222 | _getnetbydnsaddr(net, net_type) |
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223 | register unsigned long net; |
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224 | register int net_type; |
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225 | { |
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226 | unsigned int netbr[4]; |
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227 | int nn, anslen; |
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228 | querybuf buf; |
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229 | char qbuf[MAXDNAME]; |
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230 | unsigned long net2; |
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231 | struct netent *net_entry; |
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232 | |
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233 | if (net_type != AF_INET) |
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234 | return (NULL); |
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235 | |
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236 | for (nn = 4, net2 = net; net2; net2 >>= 8) |
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237 | netbr[--nn] = net2 & 0xff; |
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238 | switch (nn) { |
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239 | case 3: /* Class A */ |
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240 | sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]); |
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241 | break; |
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242 | case 2: /* Class B */ |
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243 | sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); |
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244 | break; |
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245 | case 1: /* Class C */ |
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246 | sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], |
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247 | netbr[1]); |
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248 | break; |
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249 | case 0: /* Class D - E */ |
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250 | sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], |
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251 | netbr[1], netbr[0]); |
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252 | break; |
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253 | } |
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254 | anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf)); |
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255 | if (anslen < 0) { |
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256 | #ifdef DEBUG |
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257 | if (_res.options & RES_DEBUG) |
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258 | printf("res_query failed\n"); |
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259 | #endif |
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260 | return (NULL); |
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261 | } |
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262 | net_entry = getnetanswer(&buf, anslen, BYADDR); |
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263 | if (net_entry) { |
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264 | unsigned u_net = net; /* maybe net should be unsigned ? */ |
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265 | |
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266 | /* Strip trailing zeros */ |
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267 | while ((u_net & 0xff) == 0 && u_net != 0) |
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268 | u_net >>= 8; |
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269 | net_entry->n_net = u_net; |
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270 | return (net_entry); |
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271 | } |
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272 | return (NULL); |
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273 | } |
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274 | |
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275 | struct netent * |
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276 | _getnetbydnsname(net) |
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277 | register const char *net; |
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278 | { |
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279 | int anslen; |
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280 | querybuf buf; |
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281 | char qbuf[MAXDNAME]; |
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282 | |
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283 | if ((_res.options & RES_INIT) == 0 && res_init() == -1) { |
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284 | h_errno = NETDB_INTERNAL; |
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285 | return (NULL); |
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286 | } |
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287 | strncpy(qbuf, net, sizeof(qbuf) - 1); |
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288 | qbuf[sizeof(qbuf) - 1] = '\0'; |
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289 | anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf)); |
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290 | if (anslen < 0) { |
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291 | #ifdef DEBUG |
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292 | if (_res.options & RES_DEBUG) |
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293 | printf("res_query failed\n"); |
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294 | #endif |
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295 | return (NULL); |
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296 | } |
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297 | return getnetanswer(&buf, anslen, BYNAME); |
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298 | } |
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299 | |
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300 | void |
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301 | _setnetdnsent(stayopen) |
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302 | int stayopen; |
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303 | { |
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304 | if (stayopen) |
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305 | _res.options |= RES_STAYOPEN | RES_USEVC; |
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306 | } |
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307 | |
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308 | void |
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309 | _endnetdnsent() |
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310 | { |
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311 | _res.options &= ~(RES_STAYOPEN | RES_USEVC); |
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312 | res_close(); |
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313 | } |
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