1 | #include "port_before.h" |
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2 | |
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3 | /* |
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4 | * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
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5 | * Copyright (c) 1996,1999 by Internet Software Consortium. |
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6 | * |
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7 | * Permission to use, copy, modify, and distribute this software for any |
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8 | * purpose with or without fee is hereby granted, provided that the above |
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9 | * copyright notice and this permission notice appear in all copies. |
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10 | * |
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11 | * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES |
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12 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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13 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR |
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14 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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15 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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16 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
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17 | * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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18 | */ |
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19 | |
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20 | #ifndef lint |
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21 | static const char rcsid[] = "$Id: ns_parse.c,v 1.5.18.4 2007/08/27 03:34:24 marka Exp $"; |
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22 | #endif |
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23 | |
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24 | /* Import. */ |
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25 | |
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26 | #include "port_before.h" |
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27 | |
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28 | #include <sys/types.h> |
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29 | |
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30 | #include <netinet/in.h> |
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31 | #include <arpa/nameser.h> |
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32 | |
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33 | #include <errno.h> |
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34 | #include <resolv.h> |
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35 | #include <string.h> |
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36 | |
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37 | #include "port_after.h" |
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38 | |
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39 | /* Forward. */ |
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40 | |
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41 | static void setsection(ns_msg *msg, ns_sect sect); |
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42 | |
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43 | /* Macros. */ |
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44 | |
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45 | #if !defined(SOLARIS2) || defined(__COVERITY__) |
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46 | #define RETERR(err) do { errno = (err); return (-1); } while (0) |
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47 | #else |
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48 | #define RETERR(err) \ |
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49 | do { errno = (err); if (errno == errno) return (-1); } while (0) |
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50 | #endif |
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51 | |
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52 | /* Public. */ |
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53 | |
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54 | /* These need to be in the same order as the nres.h:ns_flag enum. */ |
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55 | struct _ns_flagdata _ns_flagdata[16] = { |
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56 | { 0x8000, 15 }, /*%< qr. */ |
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57 | { 0x7800, 11 }, /*%< opcode. */ |
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58 | { 0x0400, 10 }, /*%< aa. */ |
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59 | { 0x0200, 9 }, /*%< tc. */ |
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60 | { 0x0100, 8 }, /*%< rd. */ |
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61 | { 0x0080, 7 }, /*%< ra. */ |
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62 | { 0x0040, 6 }, /*%< z. */ |
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63 | { 0x0020, 5 }, /*%< ad. */ |
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64 | { 0x0010, 4 }, /*%< cd. */ |
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65 | { 0x000f, 0 }, /*%< rcode. */ |
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66 | { 0x0000, 0 }, /*%< expansion (1/6). */ |
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67 | { 0x0000, 0 }, /*%< expansion (2/6). */ |
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68 | { 0x0000, 0 }, /*%< expansion (3/6). */ |
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69 | { 0x0000, 0 }, /*%< expansion (4/6). */ |
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70 | { 0x0000, 0 }, /*%< expansion (5/6). */ |
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71 | { 0x0000, 0 }, /*%< expansion (6/6). */ |
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72 | }; |
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73 | |
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74 | int ns_msg_getflag(ns_msg handle, int flag) { |
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75 | return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); |
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76 | } |
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77 | |
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78 | int |
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79 | ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { |
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80 | const u_char *optr = ptr; |
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81 | |
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82 | for ((void)NULL; count > 0; count--) { |
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83 | int b, rdlength; |
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84 | |
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85 | b = dn_skipname(ptr, eom); |
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86 | if (b < 0) |
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87 | RETERR(EMSGSIZE); |
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88 | ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; |
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89 | if (section != ns_s_qd) { |
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90 | if (ptr + NS_INT32SZ + NS_INT16SZ > eom) |
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91 | RETERR(EMSGSIZE); |
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92 | ptr += NS_INT32SZ/*TTL*/; |
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93 | NS_GET16(rdlength, ptr); |
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94 | ptr += rdlength/*RData*/; |
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95 | } |
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96 | } |
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97 | if (ptr > eom) |
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98 | RETERR(EMSGSIZE); |
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99 | return (ptr - optr); |
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100 | } |
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101 | |
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102 | int |
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103 | ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { |
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104 | const u_char *eom = msg + msglen; |
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105 | int i; |
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106 | |
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107 | memset(handle, 0x5e, sizeof *handle); |
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108 | handle->_msg = msg; |
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109 | handle->_eom = eom; |
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110 | if (msg + NS_INT16SZ > eom) |
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111 | RETERR(EMSGSIZE); |
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112 | NS_GET16(handle->_id, msg); |
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113 | if (msg + NS_INT16SZ > eom) |
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114 | RETERR(EMSGSIZE); |
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115 | NS_GET16(handle->_flags, msg); |
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116 | for (i = 0; i < ns_s_max; i++) { |
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117 | if (msg + NS_INT16SZ > eom) |
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118 | RETERR(EMSGSIZE); |
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119 | NS_GET16(handle->_counts[i], msg); |
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120 | } |
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121 | for (i = 0; i < ns_s_max; i++) |
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122 | if (handle->_counts[i] == 0) |
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123 | handle->_sections[i] = NULL; |
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124 | else { |
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125 | int b = ns_skiprr(msg, eom, (ns_sect)i, |
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126 | handle->_counts[i]); |
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127 | |
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128 | if (b < 0) |
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129 | return (-1); |
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130 | handle->_sections[i] = msg; |
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131 | msg += b; |
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132 | } |
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133 | if (msg != eom) |
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134 | RETERR(EMSGSIZE); |
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135 | setsection(handle, ns_s_max); |
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136 | return (0); |
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137 | } |
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138 | |
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139 | int |
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140 | ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { |
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141 | int b; |
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142 | int tmp; |
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143 | |
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144 | /* Make section right. */ |
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145 | tmp = section; |
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146 | if (tmp < 0 || section >= ns_s_max) |
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147 | RETERR(ENODEV); |
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148 | if (section != handle->_sect) |
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149 | setsection(handle, section); |
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150 | |
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151 | /* Make rrnum right. */ |
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152 | if (rrnum == -1) |
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153 | rrnum = handle->_rrnum; |
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154 | if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) |
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155 | RETERR(ENODEV); |
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156 | if (rrnum < handle->_rrnum) |
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157 | setsection(handle, section); |
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158 | if (rrnum > handle->_rrnum) { |
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159 | b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, |
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160 | rrnum - handle->_rrnum); |
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161 | |
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162 | if (b < 0) |
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163 | return (-1); |
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164 | handle->_msg_ptr += b; |
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165 | handle->_rrnum = rrnum; |
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166 | } |
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167 | |
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168 | /* Do the parse. */ |
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169 | b = dn_expand(handle->_msg, handle->_eom, |
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170 | handle->_msg_ptr, rr->name, NS_MAXDNAME); |
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171 | if (b < 0) |
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172 | return (-1); |
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173 | handle->_msg_ptr += b; |
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174 | if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) |
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175 | RETERR(EMSGSIZE); |
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176 | NS_GET16(rr->type, handle->_msg_ptr); |
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177 | NS_GET16(rr->rr_class, handle->_msg_ptr); |
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178 | if (section == ns_s_qd) { |
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179 | rr->ttl = 0; |
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180 | rr->rdlength = 0; |
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181 | rr->rdata = NULL; |
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182 | } else { |
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183 | if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) |
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184 | RETERR(EMSGSIZE); |
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185 | NS_GET32(rr->ttl, handle->_msg_ptr); |
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186 | NS_GET16(rr->rdlength, handle->_msg_ptr); |
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187 | if (handle->_msg_ptr + rr->rdlength > handle->_eom) |
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188 | RETERR(EMSGSIZE); |
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189 | rr->rdata = handle->_msg_ptr; |
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190 | handle->_msg_ptr += rr->rdlength; |
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191 | } |
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192 | if (++handle->_rrnum > handle->_counts[(int)section]) |
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193 | setsection(handle, (ns_sect)((int)section + 1)); |
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194 | |
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195 | /* All done. */ |
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196 | return (0); |
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197 | } |
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198 | |
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199 | /* Private. */ |
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200 | |
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201 | static void |
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202 | setsection(ns_msg *msg, ns_sect sect) { |
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203 | msg->_sect = sect; |
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204 | if (sect == ns_s_max) { |
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205 | msg->_rrnum = -1; |
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206 | msg->_msg_ptr = NULL; |
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207 | } else { |
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208 | msg->_rrnum = 0; |
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209 | msg->_msg_ptr = msg->_sections[(int)sect]; |
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210 | } |
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211 | } |
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212 | |
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213 | /*! \file */ |
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