1 | #include <machine/rtems-bsd-user-space.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_name.c,v 1.11 2009/01/23 19:59:16 each Exp $"; |
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22 | #endif |
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23 | #include <sys/cdefs.h> |
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24 | __FBSDID("$FreeBSD$"); |
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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 <rtems/bsd/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 | #include <ctype.h> |
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37 | #include <stdlib.h> |
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38 | #include <limits.h> |
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39 | |
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40 | #include "port_after.h" |
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41 | |
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42 | #ifdef SPRINTF_CHAR |
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43 | # define SPRINTF(x) strlen(sprintf/**/x) |
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44 | #else |
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45 | # define SPRINTF(x) ((size_t)sprintf x) |
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46 | #endif |
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47 | |
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48 | #define NS_TYPE_ELT 0x40 /*%< EDNS0 extended label type */ |
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49 | #define DNS_LABELTYPE_BITSTRING 0x41 |
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50 | |
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51 | /* Data. */ |
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52 | |
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53 | static const char digits[] = "0123456789"; |
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54 | |
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55 | static const char digitvalue[256] = { |
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56 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/ |
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57 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/ |
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58 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/ |
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59 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/ |
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60 | -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/ |
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61 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/ |
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62 | -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/ |
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63 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/ |
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64 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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65 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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66 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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67 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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68 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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69 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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70 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
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71 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/ |
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72 | }; |
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73 | |
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74 | /* Forward. */ |
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75 | |
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76 | static int special(int); |
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77 | static int printable(int); |
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78 | static int dn_find(const u_char *, const u_char *, |
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79 | const u_char * const *, |
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80 | const u_char * const *); |
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81 | static int encode_bitsring(const char **, const char *, |
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82 | unsigned char **, unsigned char **, |
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83 | unsigned const char *); |
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84 | static int labellen(const u_char *); |
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85 | static int decode_bitstring(const unsigned char **, |
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86 | char *, const char *); |
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87 | |
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88 | /* Public. */ |
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89 | |
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90 | /*% |
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91 | * Convert an encoded domain name to printable ascii as per RFC1035. |
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92 | |
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93 | * return: |
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94 | *\li Number of bytes written to buffer, or -1 (with errno set) |
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95 | * |
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96 | * notes: |
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97 | *\li The root is returned as "." |
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98 | *\li All other domains are returned in non absolute form |
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99 | */ |
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100 | int |
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101 | ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) |
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102 | { |
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103 | const u_char *cp; |
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104 | char *dn, *eom; |
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105 | u_char c; |
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106 | u_int n; |
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107 | int l; |
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108 | |
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109 | cp = src; |
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110 | dn = dst; |
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111 | eom = dst + dstsiz; |
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112 | |
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113 | while ((n = *cp++) != 0) { |
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114 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
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115 | /* Some kind of compression pointer. */ |
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116 | errno = EMSGSIZE; |
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117 | return (-1); |
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118 | } |
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119 | if (dn != dst) { |
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120 | if (dn >= eom) { |
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121 | errno = EMSGSIZE; |
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122 | return (-1); |
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123 | } |
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124 | *dn++ = '.'; |
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125 | } |
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126 | if ((l = labellen(cp - 1)) < 0) { |
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127 | errno = EMSGSIZE; /*%< XXX */ |
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128 | return (-1); |
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129 | } |
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130 | if (dn + l >= eom) { |
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131 | errno = EMSGSIZE; |
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132 | return (-1); |
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133 | } |
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134 | if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) { |
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135 | int m; |
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136 | |
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137 | if (n != DNS_LABELTYPE_BITSTRING) { |
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138 | /* XXX: labellen should reject this case */ |
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139 | errno = EINVAL; |
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140 | return (-1); |
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141 | } |
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142 | if ((m = decode_bitstring(&cp, dn, eom)) < 0) |
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143 | { |
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144 | errno = EMSGSIZE; |
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145 | return (-1); |
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146 | } |
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147 | dn += m; |
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148 | continue; |
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149 | } |
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150 | for ((void)NULL; l > 0; l--) { |
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151 | c = *cp++; |
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152 | if (special(c)) { |
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153 | if (dn + 1 >= eom) { |
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154 | errno = EMSGSIZE; |
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155 | return (-1); |
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156 | } |
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157 | *dn++ = '\\'; |
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158 | *dn++ = (char)c; |
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159 | } else if (!printable(c)) { |
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160 | if (dn + 3 >= eom) { |
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161 | errno = EMSGSIZE; |
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162 | return (-1); |
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163 | } |
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164 | *dn++ = '\\'; |
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165 | *dn++ = digits[c / 100]; |
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166 | *dn++ = digits[(c % 100) / 10]; |
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167 | *dn++ = digits[c % 10]; |
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168 | } else { |
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169 | if (dn >= eom) { |
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170 | errno = EMSGSIZE; |
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171 | return (-1); |
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172 | } |
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173 | *dn++ = (char)c; |
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174 | } |
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175 | } |
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176 | } |
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177 | if (dn == dst) { |
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178 | if (dn >= eom) { |
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179 | errno = EMSGSIZE; |
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180 | return (-1); |
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181 | } |
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182 | *dn++ = '.'; |
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183 | } |
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184 | if (dn >= eom) { |
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185 | errno = EMSGSIZE; |
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186 | return (-1); |
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187 | } |
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188 | *dn++ = '\0'; |
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189 | return (dn - dst); |
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190 | } |
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191 | |
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192 | /*% |
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193 | * Convert a ascii string into an encoded domain name as per RFC1035. |
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194 | * |
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195 | * return: |
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196 | * |
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197 | *\li -1 if it fails |
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198 | *\li 1 if string was fully qualified |
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199 | *\li 0 is string was not fully qualified |
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200 | * |
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201 | * notes: |
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202 | *\li Enforces label and domain length limits. |
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203 | */ |
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204 | int |
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205 | ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { |
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206 | return (ns_name_pton2(src, dst, dstsiz, NULL)); |
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207 | } |
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208 | |
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209 | /* |
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210 | * ns_name_pton2(src, dst, dstsiz, *dstlen) |
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211 | * Convert a ascii string into an encoded domain name as per RFC1035. |
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212 | * return: |
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213 | * -1 if it fails |
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214 | * 1 if string was fully qualified |
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215 | * 0 is string was not fully qualified |
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216 | * side effects: |
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217 | * fills in *dstlen (if non-NULL) |
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218 | * notes: |
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219 | * Enforces label and domain length limits. |
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220 | */ |
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221 | int |
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222 | ns_name_pton2(const char *src, u_char *dst, size_t dstsiz, size_t *dstlen) { |
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223 | u_char *label, *bp, *eom; |
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224 | int c, n, escaped, e = 0; |
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225 | char *cp; |
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226 | |
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227 | escaped = 0; |
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228 | bp = dst; |
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229 | eom = dst + dstsiz; |
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230 | label = bp++; |
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231 | |
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232 | while ((c = *src++) != 0) { |
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233 | if (escaped) { |
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234 | if (c == '[') { /*%< start a bit string label */ |
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235 | if ((cp = strchr(src, ']')) == NULL) { |
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236 | errno = EINVAL; /*%< ??? */ |
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237 | return (-1); |
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238 | } |
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239 | if ((e = encode_bitsring(&src, cp + 2, |
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240 | &label, &bp, eom)) |
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241 | != 0) { |
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242 | errno = e; |
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243 | return (-1); |
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244 | } |
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245 | escaped = 0; |
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246 | label = bp++; |
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247 | if ((c = *src++) == 0) |
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248 | goto done; |
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249 | else if (c != '.') { |
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250 | errno = EINVAL; |
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251 | return (-1); |
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252 | } |
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253 | continue; |
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254 | } |
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255 | else if ((cp = strchr(digits, c)) != NULL) { |
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256 | n = (cp - digits) * 100; |
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257 | if ((c = *src++) == 0 || |
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258 | (cp = strchr(digits, c)) == NULL) { |
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259 | errno = EMSGSIZE; |
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260 | return (-1); |
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261 | } |
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262 | n += (cp - digits) * 10; |
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263 | if ((c = *src++) == 0 || |
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264 | (cp = strchr(digits, c)) == NULL) { |
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265 | errno = EMSGSIZE; |
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266 | return (-1); |
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267 | } |
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268 | n += (cp - digits); |
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269 | if (n > 255) { |
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270 | errno = EMSGSIZE; |
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271 | return (-1); |
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272 | } |
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273 | c = n; |
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274 | } |
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275 | escaped = 0; |
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276 | } else if (c == '\\') { |
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277 | escaped = 1; |
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278 | continue; |
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279 | } else if (c == '.') { |
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280 | c = (bp - label - 1); |
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281 | if ((c & NS_CMPRSFLGS) != 0) { /*%< Label too big. */ |
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282 | errno = EMSGSIZE; |
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283 | return (-1); |
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284 | } |
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285 | if (label >= eom) { |
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286 | errno = EMSGSIZE; |
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287 | return (-1); |
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288 | } |
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289 | *label = c; |
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290 | /* Fully qualified ? */ |
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291 | if (*src == '\0') { |
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292 | if (c != 0) { |
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293 | if (bp >= eom) { |
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294 | errno = EMSGSIZE; |
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295 | return (-1); |
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296 | } |
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297 | *bp++ = '\0'; |
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298 | } |
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299 | if ((bp - dst) > MAXCDNAME) { |
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300 | errno = EMSGSIZE; |
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301 | return (-1); |
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302 | } |
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303 | if (dstlen != NULL) |
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304 | *dstlen = (bp - dst); |
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305 | return (1); |
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306 | } |
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307 | if (c == 0 || *src == '.') { |
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308 | errno = EMSGSIZE; |
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309 | return (-1); |
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310 | } |
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311 | label = bp++; |
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312 | continue; |
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313 | } |
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314 | if (bp >= eom) { |
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315 | errno = EMSGSIZE; |
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316 | return (-1); |
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317 | } |
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318 | *bp++ = (u_char)c; |
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319 | } |
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320 | c = (bp - label - 1); |
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321 | if ((c & NS_CMPRSFLGS) != 0) { /*%< Label too big. */ |
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322 | errno = EMSGSIZE; |
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323 | return (-1); |
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324 | } |
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325 | done: |
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326 | if (label >= eom) { |
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327 | errno = EMSGSIZE; |
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328 | return (-1); |
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329 | } |
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330 | *label = c; |
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331 | if (c != 0) { |
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332 | if (bp >= eom) { |
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333 | errno = EMSGSIZE; |
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334 | return (-1); |
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335 | } |
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336 | *bp++ = 0; |
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337 | } |
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338 | if ((bp - dst) > MAXCDNAME) { /*%< src too big */ |
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339 | errno = EMSGSIZE; |
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340 | return (-1); |
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341 | } |
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342 | if (dstlen != NULL) |
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343 | *dstlen = (bp - dst); |
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344 | return (0); |
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345 | } |
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346 | |
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347 | /*% |
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348 | * Convert a network strings labels into all lowercase. |
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349 | * |
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350 | * return: |
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351 | *\li Number of bytes written to buffer, or -1 (with errno set) |
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352 | * |
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353 | * notes: |
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354 | *\li Enforces label and domain length limits. |
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355 | */ |
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356 | |
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357 | int |
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358 | ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) |
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359 | { |
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360 | const u_char *cp; |
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361 | u_char *dn, *eom; |
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362 | u_char c; |
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363 | u_int n; |
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364 | int l; |
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365 | |
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366 | cp = src; |
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367 | dn = dst; |
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368 | eom = dst + dstsiz; |
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369 | |
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370 | if (dn >= eom) { |
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371 | errno = EMSGSIZE; |
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372 | return (-1); |
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373 | } |
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374 | while ((n = *cp++) != 0) { |
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375 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
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376 | /* Some kind of compression pointer. */ |
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377 | errno = EMSGSIZE; |
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378 | return (-1); |
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379 | } |
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380 | *dn++ = n; |
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381 | if ((l = labellen(cp - 1)) < 0) { |
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382 | errno = EMSGSIZE; |
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383 | return (-1); |
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384 | } |
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385 | if (dn + l >= eom) { |
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386 | errno = EMSGSIZE; |
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387 | return (-1); |
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388 | } |
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389 | for ((void)NULL; l > 0; l--) { |
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390 | c = *cp++; |
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391 | if (isascii(c) && isupper(c)) |
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392 | *dn++ = tolower(c); |
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393 | else |
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394 | *dn++ = c; |
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395 | } |
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396 | } |
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397 | *dn++ = '\0'; |
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398 | return (dn - dst); |
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399 | } |
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400 | |
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401 | /*% |
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402 | * Unpack a domain name from a message, source may be compressed. |
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403 | * |
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404 | * return: |
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405 | *\li -1 if it fails, or consumed octets if it succeeds. |
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406 | */ |
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407 | int |
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408 | ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src, |
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409 | u_char *dst, size_t dstsiz) |
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410 | { |
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411 | return (ns_name_unpack2(msg, eom, src, dst, dstsiz, NULL)); |
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412 | } |
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413 | |
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414 | /* |
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415 | * ns_name_unpack2(msg, eom, src, dst, dstsiz, *dstlen) |
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416 | * Unpack a domain name from a message, source may be compressed. |
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417 | * return: |
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418 | * -1 if it fails, or consumed octets if it succeeds. |
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419 | * side effect: |
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420 | * fills in *dstlen (if non-NULL). |
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421 | */ |
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422 | int |
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423 | ns_name_unpack2(const u_char *msg, const u_char *eom, const u_char *src, |
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424 | u_char *dst, size_t dstsiz, size_t *dstlen) |
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425 | { |
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426 | const u_char *srcp, *dstlim; |
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427 | u_char *dstp; |
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428 | int n, len, checked, l; |
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429 | |
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430 | len = -1; |
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431 | checked = 0; |
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432 | dstp = dst; |
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433 | srcp = src; |
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434 | dstlim = dst + dstsiz; |
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435 | if (srcp < msg || srcp >= eom) { |
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436 | errno = EMSGSIZE; |
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437 | return (-1); |
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438 | } |
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439 | /* Fetch next label in domain name. */ |
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440 | while ((n = *srcp++) != 0) { |
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441 | /* Check for indirection. */ |
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442 | switch (n & NS_CMPRSFLGS) { |
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443 | case 0: |
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444 | case NS_TYPE_ELT: |
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445 | /* Limit checks. */ |
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446 | if ((l = labellen(srcp - 1)) < 0) { |
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447 | errno = EMSGSIZE; |
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448 | return (-1); |
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449 | } |
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450 | if (dstp + l + 1 >= dstlim || srcp + l >= eom) { |
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451 | errno = EMSGSIZE; |
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452 | return (-1); |
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453 | } |
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454 | checked += l + 1; |
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455 | *dstp++ = n; |
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456 | memcpy(dstp, srcp, l); |
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457 | dstp += l; |
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458 | srcp += l; |
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459 | break; |
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460 | |
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461 | case NS_CMPRSFLGS: |
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462 | if (srcp >= eom) { |
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463 | errno = EMSGSIZE; |
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464 | return (-1); |
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465 | } |
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466 | if (len < 0) |
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467 | len = srcp - src + 1; |
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468 | l = ((n & 0x3f) << 8) | (*srcp & 0xff); |
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469 | if (l >= eom - msg) { /*%< Out of range. */ |
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470 | errno = EMSGSIZE; |
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471 | return (-1); |
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472 | } |
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473 | srcp = msg + l; |
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474 | checked += 2; |
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475 | /* |
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476 | * Check for loops in the compressed name; |
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477 | * if we've looked at the whole message, |
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478 | * there must be a loop. |
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479 | */ |
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480 | if (checked >= eom - msg) { |
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481 | errno = EMSGSIZE; |
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482 | return (-1); |
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483 | } |
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484 | break; |
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485 | |
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486 | default: |
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487 | errno = EMSGSIZE; |
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488 | return (-1); /*%< flag error */ |
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489 | } |
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490 | } |
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491 | *dstp++ = 0; |
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492 | if (dstlen != NULL) |
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493 | *dstlen = dstp - dst; |
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494 | if (len < 0) |
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495 | len = srcp - src; |
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496 | return (len); |
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497 | } |
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498 | |
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499 | /*% |
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500 | * Pack domain name 'domain' into 'comp_dn'. |
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501 | * |
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502 | * return: |
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503 | *\li Size of the compressed name, or -1. |
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504 | * |
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505 | * notes: |
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506 | *\li 'dnptrs' is an array of pointers to previous compressed names. |
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507 | *\li dnptrs[0] is a pointer to the beginning of the message. The array |
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508 | * ends with NULL. |
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509 | *\li 'lastdnptr' is a pointer to the end of the array pointed to |
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510 | * by 'dnptrs'. |
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511 | * |
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512 | * Side effects: |
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513 | *\li The list of pointers in dnptrs is updated for labels inserted into |
---|
514 | * the message as we compress the name. If 'dnptr' is NULL, we don't |
---|
515 | * try to compress names. If 'lastdnptr' is NULL, we don't update the |
---|
516 | * list. |
---|
517 | */ |
---|
518 | int |
---|
519 | ns_name_pack(const u_char *src, u_char *dst, int dstsiz, |
---|
520 | const u_char **dnptrs, const u_char **lastdnptr) |
---|
521 | { |
---|
522 | u_char *dstp; |
---|
523 | const u_char **cpp, **lpp, *eob, *msg; |
---|
524 | const u_char *srcp; |
---|
525 | int n, l, first = 1; |
---|
526 | |
---|
527 | srcp = src; |
---|
528 | dstp = dst; |
---|
529 | eob = dstp + dstsiz; |
---|
530 | lpp = cpp = NULL; |
---|
531 | if (dnptrs != NULL) { |
---|
532 | if ((msg = *dnptrs++) != NULL) { |
---|
533 | for (cpp = dnptrs; *cpp != NULL; cpp++) |
---|
534 | (void)NULL; |
---|
535 | lpp = cpp; /*%< end of list to search */ |
---|
536 | } |
---|
537 | } else |
---|
538 | msg = NULL; |
---|
539 | |
---|
540 | /* make sure the domain we are about to add is legal */ |
---|
541 | l = 0; |
---|
542 | do { |
---|
543 | int l0; |
---|
544 | |
---|
545 | n = *srcp; |
---|
546 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
---|
547 | errno = EMSGSIZE; |
---|
548 | return (-1); |
---|
549 | } |
---|
550 | if ((l0 = labellen(srcp)) < 0) { |
---|
551 | errno = EINVAL; |
---|
552 | return (-1); |
---|
553 | } |
---|
554 | l += l0 + 1; |
---|
555 | if (l > MAXCDNAME) { |
---|
556 | errno = EMSGSIZE; |
---|
557 | return (-1); |
---|
558 | } |
---|
559 | srcp += l0 + 1; |
---|
560 | } while (n != 0); |
---|
561 | |
---|
562 | /* from here on we need to reset compression pointer array on error */ |
---|
563 | srcp = src; |
---|
564 | do { |
---|
565 | /* Look to see if we can use pointers. */ |
---|
566 | n = *srcp; |
---|
567 | if (n != 0 && msg != NULL) { |
---|
568 | l = dn_find(srcp, msg, (const u_char * const *)dnptrs, |
---|
569 | (const u_char * const *)lpp); |
---|
570 | if (l >= 0) { |
---|
571 | if (dstp + 1 >= eob) { |
---|
572 | goto cleanup; |
---|
573 | } |
---|
574 | *dstp++ = (l >> 8) | NS_CMPRSFLGS; |
---|
575 | *dstp++ = l % 256; |
---|
576 | return (dstp - dst); |
---|
577 | } |
---|
578 | /* Not found, save it. */ |
---|
579 | if (lastdnptr != NULL && cpp < lastdnptr - 1 && |
---|
580 | (dstp - msg) < 0x4000 && first) { |
---|
581 | *cpp++ = dstp; |
---|
582 | *cpp = NULL; |
---|
583 | first = 0; |
---|
584 | } |
---|
585 | } |
---|
586 | /* copy label to buffer */ |
---|
587 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
---|
588 | /* Should not happen. */ |
---|
589 | goto cleanup; |
---|
590 | } |
---|
591 | n = labellen(srcp); |
---|
592 | if (dstp + 1 + n >= eob) { |
---|
593 | goto cleanup; |
---|
594 | } |
---|
595 | memcpy(dstp, srcp, n + 1); |
---|
596 | srcp += n + 1; |
---|
597 | dstp += n + 1; |
---|
598 | } while (n != 0); |
---|
599 | |
---|
600 | if (dstp > eob) { |
---|
601 | cleanup: |
---|
602 | if (msg != NULL) |
---|
603 | *lpp = NULL; |
---|
604 | errno = EMSGSIZE; |
---|
605 | return (-1); |
---|
606 | } |
---|
607 | return (dstp - dst); |
---|
608 | } |
---|
609 | |
---|
610 | /*% |
---|
611 | * Expand compressed domain name to presentation format. |
---|
612 | * |
---|
613 | * return: |
---|
614 | *\li Number of bytes read out of `src', or -1 (with errno set). |
---|
615 | * |
---|
616 | * note: |
---|
617 | *\li Root domain returns as "." not "". |
---|
618 | */ |
---|
619 | int |
---|
620 | ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src, |
---|
621 | char *dst, size_t dstsiz) |
---|
622 | { |
---|
623 | u_char tmp[NS_MAXCDNAME]; |
---|
624 | int n; |
---|
625 | |
---|
626 | if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1) |
---|
627 | return (-1); |
---|
628 | if (ns_name_ntop(tmp, dst, dstsiz) == -1) |
---|
629 | return (-1); |
---|
630 | return (n); |
---|
631 | } |
---|
632 | |
---|
633 | /*% |
---|
634 | * Compress a domain name into wire format, using compression pointers. |
---|
635 | * |
---|
636 | * return: |
---|
637 | *\li Number of bytes consumed in `dst' or -1 (with errno set). |
---|
638 | * |
---|
639 | * notes: |
---|
640 | *\li 'dnptrs' is an array of pointers to previous compressed names. |
---|
641 | *\li dnptrs[0] is a pointer to the beginning of the message. |
---|
642 | *\li The list ends with NULL. 'lastdnptr' is a pointer to the end of the |
---|
643 | * array pointed to by 'dnptrs'. Side effect is to update the list of |
---|
644 | * pointers for labels inserted into the message as we compress the name. |
---|
645 | *\li If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr' |
---|
646 | * is NULL, we don't update the list. |
---|
647 | */ |
---|
648 | int |
---|
649 | ns_name_compress(const char *src, u_char *dst, size_t dstsiz, |
---|
650 | const u_char **dnptrs, const u_char **lastdnptr) |
---|
651 | { |
---|
652 | u_char tmp[NS_MAXCDNAME]; |
---|
653 | |
---|
654 | if (ns_name_pton(src, tmp, sizeof tmp) == -1) |
---|
655 | return (-1); |
---|
656 | return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr)); |
---|
657 | } |
---|
658 | |
---|
659 | /*% |
---|
660 | * Reset dnptrs so that there are no active references to pointers at or |
---|
661 | * after src. |
---|
662 | */ |
---|
663 | void |
---|
664 | ns_name_rollback(const u_char *src, const u_char **dnptrs, |
---|
665 | const u_char **lastdnptr) |
---|
666 | { |
---|
667 | while (dnptrs < lastdnptr && *dnptrs != NULL) { |
---|
668 | if (*dnptrs >= src) { |
---|
669 | *dnptrs = NULL; |
---|
670 | break; |
---|
671 | } |
---|
672 | dnptrs++; |
---|
673 | } |
---|
674 | } |
---|
675 | |
---|
676 | /*% |
---|
677 | * Advance *ptrptr to skip over the compressed name it points at. |
---|
678 | * |
---|
679 | * return: |
---|
680 | *\li 0 on success, -1 (with errno set) on failure. |
---|
681 | */ |
---|
682 | int |
---|
683 | ns_name_skip(const u_char **ptrptr, const u_char *eom) |
---|
684 | { |
---|
685 | const u_char *cp; |
---|
686 | u_int n; |
---|
687 | int l; |
---|
688 | |
---|
689 | cp = *ptrptr; |
---|
690 | while (cp < eom && (n = *cp++) != 0) { |
---|
691 | /* Check for indirection. */ |
---|
692 | switch (n & NS_CMPRSFLGS) { |
---|
693 | case 0: /*%< normal case, n == len */ |
---|
694 | cp += n; |
---|
695 | continue; |
---|
696 | case NS_TYPE_ELT: /*%< EDNS0 extended label */ |
---|
697 | if ((l = labellen(cp - 1)) < 0) { |
---|
698 | errno = EMSGSIZE; /*%< XXX */ |
---|
699 | return (-1); |
---|
700 | } |
---|
701 | cp += l; |
---|
702 | continue; |
---|
703 | case NS_CMPRSFLGS: /*%< indirection */ |
---|
704 | cp++; |
---|
705 | break; |
---|
706 | default: /*%< illegal type */ |
---|
707 | errno = EMSGSIZE; |
---|
708 | return (-1); |
---|
709 | } |
---|
710 | break; |
---|
711 | } |
---|
712 | if (cp > eom) { |
---|
713 | errno = EMSGSIZE; |
---|
714 | return (-1); |
---|
715 | } |
---|
716 | *ptrptr = cp; |
---|
717 | return (0); |
---|
718 | } |
---|
719 | |
---|
720 | /* Find the number of octets an nname takes up, including the root label. |
---|
721 | * (This is basically ns_name_skip() without compression-pointer support.) |
---|
722 | * ((NOTE: can only return zero if passed-in namesiz argument is zero.)) |
---|
723 | */ |
---|
724 | ssize_t |
---|
725 | ns_name_length(ns_nname_ct nname, size_t namesiz) { |
---|
726 | ns_nname_ct orig = nname; |
---|
727 | u_int n; |
---|
728 | |
---|
729 | while (namesiz-- > 0 && (n = *nname++) != 0) { |
---|
730 | if ((n & NS_CMPRSFLGS) != 0) { |
---|
731 | errno = EISDIR; |
---|
732 | return (-1); |
---|
733 | } |
---|
734 | if (n > namesiz) { |
---|
735 | errno = EMSGSIZE; |
---|
736 | return (-1); |
---|
737 | } |
---|
738 | nname += n; |
---|
739 | namesiz -= n; |
---|
740 | } |
---|
741 | return (nname - orig); |
---|
742 | } |
---|
743 | |
---|
744 | /* Compare two nname's for equality. Return -1 on error (setting errno). |
---|
745 | */ |
---|
746 | int |
---|
747 | ns_name_eq(ns_nname_ct a, size_t as, ns_nname_ct b, size_t bs) { |
---|
748 | ns_nname_ct ae = a + as, be = b + bs; |
---|
749 | int ac, bc; |
---|
750 | |
---|
751 | while (ac = *a, bc = *b, ac != 0 && bc != 0) { |
---|
752 | if ((ac & NS_CMPRSFLGS) != 0 || (bc & NS_CMPRSFLGS) != 0) { |
---|
753 | errno = EISDIR; |
---|
754 | return (-1); |
---|
755 | } |
---|
756 | if (a + ac >= ae || b + bc >= be) { |
---|
757 | errno = EMSGSIZE; |
---|
758 | return (-1); |
---|
759 | } |
---|
760 | if (ac != bc || strncasecmp((const char *) ++a, |
---|
761 | (const char *) ++b, ac) != 0) |
---|
762 | return (0); |
---|
763 | a += ac, b += bc; |
---|
764 | } |
---|
765 | return (ac == 0 && bc == 0); |
---|
766 | } |
---|
767 | |
---|
768 | /* Is domain "A" owned by (at or below) domain "B"? |
---|
769 | */ |
---|
770 | int |
---|
771 | ns_name_owned(ns_namemap_ct a, int an, ns_namemap_ct b, int bn) { |
---|
772 | /* If A is shorter, it cannot be owned by B. */ |
---|
773 | if (an < bn) |
---|
774 | return (0); |
---|
775 | |
---|
776 | /* If they are unequal before the length of the shorter, A cannot... */ |
---|
777 | while (bn > 0) { |
---|
778 | if (a->len != b->len || |
---|
779 | strncasecmp((const char *) a->base, |
---|
780 | (const char *) b->base, a->len) != 0) |
---|
781 | return (0); |
---|
782 | a++, an--; |
---|
783 | b++, bn--; |
---|
784 | } |
---|
785 | |
---|
786 | /* A might be longer or not, but either way, B owns it. */ |
---|
787 | return (1); |
---|
788 | } |
---|
789 | |
---|
790 | /* Build an array of <base,len> tuples from an nname, top-down order. |
---|
791 | * Return the number of tuples (labels) thus discovered. |
---|
792 | */ |
---|
793 | int |
---|
794 | ns_name_map(ns_nname_ct nname, size_t namelen, ns_namemap_t map, int mapsize) { |
---|
795 | u_int n; |
---|
796 | int l; |
---|
797 | |
---|
798 | n = *nname++; |
---|
799 | namelen--; |
---|
800 | |
---|
801 | /* Root zone? */ |
---|
802 | if (n == 0) { |
---|
803 | /* Extra data follows name? */ |
---|
804 | if (namelen > 0) { |
---|
805 | errno = EMSGSIZE; |
---|
806 | return (-1); |
---|
807 | } |
---|
808 | return (0); |
---|
809 | } |
---|
810 | |
---|
811 | /* Compression pointer? */ |
---|
812 | if ((n & NS_CMPRSFLGS) != 0) { |
---|
813 | errno = EISDIR; |
---|
814 | return (-1); |
---|
815 | } |
---|
816 | |
---|
817 | /* Label too long? */ |
---|
818 | if (n > namelen) { |
---|
819 | errno = EMSGSIZE; |
---|
820 | return (-1); |
---|
821 | } |
---|
822 | |
---|
823 | /* Recurse to get rest of name done first. */ |
---|
824 | l = ns_name_map(nname + n, namelen - n, map, mapsize); |
---|
825 | if (l < 0) |
---|
826 | return (-1); |
---|
827 | |
---|
828 | /* Too many labels? */ |
---|
829 | if (l >= mapsize) { |
---|
830 | errno = ENAMETOOLONG; |
---|
831 | return (-1); |
---|
832 | } |
---|
833 | |
---|
834 | /* We're on our way back up-stack, store current map data. */ |
---|
835 | map[l].base = nname; |
---|
836 | map[l].len = n; |
---|
837 | return (l + 1); |
---|
838 | } |
---|
839 | |
---|
840 | /* Count the labels in a domain name. Root counts, so COM. has two. This |
---|
841 | * is to make the result comparable to the result of ns_name_map(). |
---|
842 | */ |
---|
843 | int |
---|
844 | ns_name_labels(ns_nname_ct nname, size_t namesiz) { |
---|
845 | int ret = 0; |
---|
846 | u_int n; |
---|
847 | |
---|
848 | while (namesiz-- > 0 && (n = *nname++) != 0) { |
---|
849 | if ((n & NS_CMPRSFLGS) != 0) { |
---|
850 | errno = EISDIR; |
---|
851 | return (-1); |
---|
852 | } |
---|
853 | if (n > namesiz) { |
---|
854 | errno = EMSGSIZE; |
---|
855 | return (-1); |
---|
856 | } |
---|
857 | nname += n; |
---|
858 | namesiz -= n; |
---|
859 | ret++; |
---|
860 | } |
---|
861 | return (ret + 1); |
---|
862 | } |
---|
863 | |
---|
864 | /* Private. */ |
---|
865 | |
---|
866 | /*% |
---|
867 | * Thinking in noninternationalized USASCII (per the DNS spec), |
---|
868 | * is this characted special ("in need of quoting") ? |
---|
869 | * |
---|
870 | * return: |
---|
871 | *\li boolean. |
---|
872 | */ |
---|
873 | static int |
---|
874 | special(int ch) { |
---|
875 | switch (ch) { |
---|
876 | case 0x22: /*%< '"' */ |
---|
877 | case 0x2E: /*%< '.' */ |
---|
878 | case 0x3B: /*%< ';' */ |
---|
879 | case 0x5C: /*%< '\\' */ |
---|
880 | case 0x28: /*%< '(' */ |
---|
881 | case 0x29: /*%< ')' */ |
---|
882 | /* Special modifiers in zone files. */ |
---|
883 | case 0x40: /*%< '@' */ |
---|
884 | case 0x24: /*%< '$' */ |
---|
885 | return (1); |
---|
886 | default: |
---|
887 | return (0); |
---|
888 | } |
---|
889 | } |
---|
890 | |
---|
891 | /*% |
---|
892 | * Thinking in noninternationalized USASCII (per the DNS spec), |
---|
893 | * is this character visible and not a space when printed ? |
---|
894 | * |
---|
895 | * return: |
---|
896 | *\li boolean. |
---|
897 | */ |
---|
898 | static int |
---|
899 | printable(int ch) { |
---|
900 | return (ch > 0x20 && ch < 0x7f); |
---|
901 | } |
---|
902 | |
---|
903 | /*% |
---|
904 | * Thinking in noninternationalized USASCII (per the DNS spec), |
---|
905 | * convert this character to lower case if it's upper case. |
---|
906 | */ |
---|
907 | static int |
---|
908 | mklower(int ch) { |
---|
909 | if (ch >= 0x41 && ch <= 0x5A) |
---|
910 | return (ch + 0x20); |
---|
911 | return (ch); |
---|
912 | } |
---|
913 | |
---|
914 | /*% |
---|
915 | * Search for the counted-label name in an array of compressed names. |
---|
916 | * |
---|
917 | * return: |
---|
918 | *\li offset from msg if found, or -1. |
---|
919 | * |
---|
920 | * notes: |
---|
921 | *\li dnptrs is the pointer to the first name on the list, |
---|
922 | *\li not the pointer to the start of the message. |
---|
923 | */ |
---|
924 | static int |
---|
925 | dn_find(const u_char *domain, const u_char *msg, |
---|
926 | const u_char * const *dnptrs, |
---|
927 | const u_char * const *lastdnptr) |
---|
928 | { |
---|
929 | const u_char *dn, *cp, *sp; |
---|
930 | const u_char * const *cpp; |
---|
931 | u_int n; |
---|
932 | |
---|
933 | for (cpp = dnptrs; cpp < lastdnptr; cpp++) { |
---|
934 | sp = *cpp; |
---|
935 | /* |
---|
936 | * terminate search on: |
---|
937 | * root label |
---|
938 | * compression pointer |
---|
939 | * unusable offset |
---|
940 | */ |
---|
941 | while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 && |
---|
942 | (sp - msg) < 0x4000) { |
---|
943 | dn = domain; |
---|
944 | cp = sp; |
---|
945 | while ((n = *cp++) != 0) { |
---|
946 | /* |
---|
947 | * check for indirection |
---|
948 | */ |
---|
949 | switch (n & NS_CMPRSFLGS) { |
---|
950 | case 0: /*%< normal case, n == len */ |
---|
951 | n = labellen(cp - 1); /*%< XXX */ |
---|
952 | if (n != *dn++) |
---|
953 | goto next; |
---|
954 | |
---|
955 | for ((void)NULL; n > 0; n--) |
---|
956 | if (mklower(*dn++) != |
---|
957 | mklower(*cp++)) |
---|
958 | goto next; |
---|
959 | /* Is next root for both ? */ |
---|
960 | if (*dn == '\0' && *cp == '\0') |
---|
961 | return (sp - msg); |
---|
962 | if (*dn) |
---|
963 | continue; |
---|
964 | goto next; |
---|
965 | case NS_CMPRSFLGS: /*%< indirection */ |
---|
966 | cp = msg + (((n & 0x3f) << 8) | *cp); |
---|
967 | break; |
---|
968 | |
---|
969 | default: /*%< illegal type */ |
---|
970 | errno = EMSGSIZE; |
---|
971 | return (-1); |
---|
972 | } |
---|
973 | } |
---|
974 | next: ; |
---|
975 | sp += *sp + 1; |
---|
976 | } |
---|
977 | } |
---|
978 | errno = ENOENT; |
---|
979 | return (-1); |
---|
980 | } |
---|
981 | |
---|
982 | static int |
---|
983 | decode_bitstring(const unsigned char **cpp, char *dn, const char *eom) |
---|
984 | { |
---|
985 | const unsigned char *cp = *cpp; |
---|
986 | char *beg = dn, tc; |
---|
987 | int b, blen, plen, i; |
---|
988 | |
---|
989 | if ((blen = (*cp & 0xff)) == 0) |
---|
990 | blen = 256; |
---|
991 | plen = (blen + 3) / 4; |
---|
992 | plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1); |
---|
993 | if (dn + plen >= eom) |
---|
994 | return (-1); |
---|
995 | |
---|
996 | cp++; |
---|
997 | i = SPRINTF((dn, "\\[x")); |
---|
998 | if (i < 0) |
---|
999 | return (-1); |
---|
1000 | dn += i; |
---|
1001 | for (b = blen; b > 7; b -= 8, cp++) { |
---|
1002 | i = SPRINTF((dn, "%02x", *cp & 0xff)); |
---|
1003 | if (i < 0) |
---|
1004 | return (-1); |
---|
1005 | dn += i; |
---|
1006 | } |
---|
1007 | if (b > 4) { |
---|
1008 | tc = *cp++; |
---|
1009 | i = SPRINTF((dn, "%02x", tc & (0xff << (8 - b)))); |
---|
1010 | if (i < 0) |
---|
1011 | return (-1); |
---|
1012 | dn += i; |
---|
1013 | } else if (b > 0) { |
---|
1014 | tc = *cp++; |
---|
1015 | i = SPRINTF((dn, "%1x", |
---|
1016 | ((tc >> 4) & 0x0f) & (0x0f << (4 - b)))); |
---|
1017 | if (i < 0) |
---|
1018 | return (-1); |
---|
1019 | dn += i; |
---|
1020 | } |
---|
1021 | i = SPRINTF((dn, "/%d]", blen)); |
---|
1022 | if (i < 0) |
---|
1023 | return (-1); |
---|
1024 | dn += i; |
---|
1025 | |
---|
1026 | *cpp = cp; |
---|
1027 | return (dn - beg); |
---|
1028 | } |
---|
1029 | |
---|
1030 | static int |
---|
1031 | encode_bitsring(const char **bp, const char *end, unsigned char **labelp, |
---|
1032 | unsigned char ** dst, unsigned const char *eom) |
---|
1033 | { |
---|
1034 | int afterslash = 0; |
---|
1035 | const char *cp = *bp; |
---|
1036 | unsigned char *tp; |
---|
1037 | char c; |
---|
1038 | const char *beg_blen; |
---|
1039 | char *end_blen = NULL; |
---|
1040 | int value = 0, count = 0, tbcount = 0, blen = 0; |
---|
1041 | |
---|
1042 | beg_blen = end_blen = NULL; |
---|
1043 | |
---|
1044 | /* a bitstring must contain at least 2 characters */ |
---|
1045 | if (end - cp < 2) |
---|
1046 | return (EINVAL); |
---|
1047 | |
---|
1048 | /* XXX: currently, only hex strings are supported */ |
---|
1049 | if (*cp++ != 'x') |
---|
1050 | return (EINVAL); |
---|
1051 | if (!isxdigit((*cp) & 0xff)) /*%< reject '\[x/BLEN]' */ |
---|
1052 | return (EINVAL); |
---|
1053 | |
---|
1054 | for (tp = *dst + 1; cp < end && tp < eom; cp++) { |
---|
1055 | switch((c = *cp)) { |
---|
1056 | case ']': /*%< end of the bitstring */ |
---|
1057 | if (afterslash) { |
---|
1058 | if (beg_blen == NULL) |
---|
1059 | return (EINVAL); |
---|
1060 | blen = (int)strtol(beg_blen, &end_blen, 10); |
---|
1061 | if (*end_blen != ']') |
---|
1062 | return (EINVAL); |
---|
1063 | } |
---|
1064 | if (count) |
---|
1065 | *tp++ = ((value << 4) & 0xff); |
---|
1066 | cp++; /*%< skip ']' */ |
---|
1067 | goto done; |
---|
1068 | case '/': |
---|
1069 | afterslash = 1; |
---|
1070 | break; |
---|
1071 | default: |
---|
1072 | if (afterslash) { |
---|
1073 | if (!isdigit(c&0xff)) |
---|
1074 | return (EINVAL); |
---|
1075 | if (beg_blen == NULL) { |
---|
1076 | |
---|
1077 | if (c == '0') { |
---|
1078 | /* blen never begings with 0 */ |
---|
1079 | return (EINVAL); |
---|
1080 | } |
---|
1081 | beg_blen = cp; |
---|
1082 | } |
---|
1083 | } else { |
---|
1084 | if (!isxdigit(c&0xff)) |
---|
1085 | return (EINVAL); |
---|
1086 | value <<= 4; |
---|
1087 | value += digitvalue[(int)c]; |
---|
1088 | count += 4; |
---|
1089 | tbcount += 4; |
---|
1090 | if (tbcount > 256) |
---|
1091 | return (EINVAL); |
---|
1092 | if (count == 8) { |
---|
1093 | *tp++ = value; |
---|
1094 | count = 0; |
---|
1095 | } |
---|
1096 | } |
---|
1097 | break; |
---|
1098 | } |
---|
1099 | } |
---|
1100 | done: |
---|
1101 | if (cp >= end || tp >= eom) |
---|
1102 | return (EMSGSIZE); |
---|
1103 | |
---|
1104 | /* |
---|
1105 | * bit length validation: |
---|
1106 | * If a <length> is present, the number of digits in the <bit-data> |
---|
1107 | * MUST be just sufficient to contain the number of bits specified |
---|
1108 | * by the <length>. If there are insignificant bits in a final |
---|
1109 | * hexadecimal or octal digit, they MUST be zero. |
---|
1110 | * RFC2673, Section 3.2. |
---|
1111 | */ |
---|
1112 | if (blen > 0) { |
---|
1113 | int traillen; |
---|
1114 | |
---|
1115 | if (((blen + 3) & ~3) != tbcount) |
---|
1116 | return (EINVAL); |
---|
1117 | traillen = tbcount - blen; /*%< between 0 and 3 */ |
---|
1118 | if (((value << (8 - traillen)) & 0xff) != 0) |
---|
1119 | return (EINVAL); |
---|
1120 | } |
---|
1121 | else |
---|
1122 | blen = tbcount; |
---|
1123 | if (blen == 256) |
---|
1124 | blen = 0; |
---|
1125 | |
---|
1126 | /* encode the type and the significant bit fields */ |
---|
1127 | **labelp = DNS_LABELTYPE_BITSTRING; |
---|
1128 | **dst = blen; |
---|
1129 | |
---|
1130 | *bp = cp; |
---|
1131 | *dst = tp; |
---|
1132 | |
---|
1133 | return (0); |
---|
1134 | } |
---|
1135 | |
---|
1136 | static int |
---|
1137 | labellen(const u_char *lp) |
---|
1138 | { |
---|
1139 | int bitlen; |
---|
1140 | u_char l = *lp; |
---|
1141 | |
---|
1142 | if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
---|
1143 | /* should be avoided by the caller */ |
---|
1144 | return (-1); |
---|
1145 | } |
---|
1146 | |
---|
1147 | if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) { |
---|
1148 | if (l == DNS_LABELTYPE_BITSTRING) { |
---|
1149 | if ((bitlen = *(lp + 1)) == 0) |
---|
1150 | bitlen = 256; |
---|
1151 | return ((bitlen + 7 ) / 8 + 1); |
---|
1152 | } |
---|
1153 | return (-1); /*%< unknwon ELT */ |
---|
1154 | } |
---|
1155 | return (l); |
---|
1156 | } |
---|
1157 | |
---|
1158 | /*! \file */ |
---|