1 /* 2 * dname.h 3 * 4 * dname definitions 5 * 6 * a Net::DNS like library for C 7 * 8 * (c) NLnet Labs, 2004-2006 9 * 10 * See the file LICENSE for the license 11 */ 12 13 /** 14 * \file dname.h 15 * 16 * dname contains function to read and manipulate domain names. 17 * 18 * Example domain names are "www.nlnetlabs.nl." and "." (the root) 19 * 20 * If a domain name ends with a dot ("."), it is called a Fully Qualified 21 * Domain Name (FQDN). In certain places (for instance when reading a zone 22 * file), an origin (which is just another domain name) non-FQDNs will be 23 * placed after the current. For instance, if i have a zone file where the 24 * origin has been set to "nl.", and my file contains the name 25 * "www.nlnetlabs", it will result in "www.nlnetlabs.nl.". Internally, dnames are 26 * always absolute (the dot is added when it is missing and there is no origin). 27 * 28 * An FQDN is also 29 * known as an absolute domain name, therefore the function to check this is 30 * called \ref ldns_dname_str_absolute 31 * 32 * Domain names are stored in \ref ldns_rdf structures, with the type 33 * \ref LDNS_RDF_TYPE_DNAME 34 * 35 * This module is *NOT* about the RR type called DNAME. 36 */ 37 38 39 #ifndef LDNS_DNAME_H 40 #define LDNS_DNAME_H 41 42 #include <ldns/common.h> 43 #include <ldns/rdata.h> 44 45 #ifdef __cplusplus 46 extern "C" { 47 #endif 48 49 #define LDNS_DNAME_NORMALIZE tolower 50 51 /** 52 * concatenates two dnames together 53 * \param[in] rd1 the leftside 54 * \param[in] rd2 the rightside 55 * \return a new rdf with leftside/rightside 56 */ 57 ldns_rdf *ldns_dname_cat_clone(const ldns_rdf *rd1, const ldns_rdf *rd2); 58 59 /** 60 * concatenates rd2 after rd1 (rd2 is copied, rd1 is modified) 61 * \param[in] rd1 the leftside 62 * \param[in] rd2 the rightside 63 * \return LDNS_STATUS_OK on success 64 */ 65 ldns_status ldns_dname_cat(ldns_rdf *rd1, const ldns_rdf *rd2); 66 67 /** 68 * Returns a clone of the given dname with the labels 69 * reversed 70 * \param[in] d the dname to reverse 71 * \return clone of the dname with the labels reversed. 72 */ 73 ldns_rdf *ldns_dname_reverse(const ldns_rdf *d); 74 75 /** 76 * Clones the given dname from the nth label on 77 * \param[in] d The dname to clone 78 * \param[in] n the label nr to clone from, if this is 0, the complete 79 * dname is cloned 80 * \return A newly allocated *rdf structure, containing the cloned dname, 81 * or NULL if either d was NULL, not a dname, or if n >= 82 * label_count 83 */ 84 ldns_rdf * 85 ldns_dname_clone_from(const ldns_rdf *d, uint16_t n); 86 87 /** 88 * chop one label off the left side of a dname. so 89 * wwww.nlnetlabs.nl, becomes nlnetlabs.nl 90 * This new name is a clone and must be freed with ldns_deep_free() 91 * \param[in] d the dname to chop 92 * \return the remaining dname 93 */ 94 ldns_rdf *ldns_dname_left_chop(const ldns_rdf *d); 95 96 /** 97 * count the number of labels inside a LDNS_RDF_DNAME type rdf. 98 * \param[in] *r the rdf 99 * \return the number of labels 100 */ 101 uint8_t ldns_dname_label_count(const ldns_rdf *r); 102 103 /** 104 * creates a new dname rdf from a string. 105 * \param[in] str string to use 106 * \return ldns_rdf* or NULL in case of an error 107 */ 108 ldns_rdf *ldns_dname_new_frm_str(const char *str); 109 110 /** 111 * Create a new dname rdf from a string. The data pointer 112 * is stored in the rdf, not a copy of the data 113 * \param[in] s the size of the new dname 114 * \param[in] *data pointer to the actual data 115 * 116 * \return ldns_rdf* 117 */ 118 ldns_rdf *ldns_dname_new(uint16_t s, void *data); 119 120 /** 121 * Create a new dname rdf from data (the data is copied) 122 * \param[in] size the size of the data 123 * \param[in] *data pointer to the actual data 124 * 125 * \return ldns_rdf* 126 */ 127 ldns_rdf *ldns_dname_new_frm_data(uint16_t size, const void *data); 128 129 /** 130 * Put a dname into canonical fmt - ie. lowercase it 131 * \param[in] rdf the dname to lowercase 132 * \return void 133 */ 134 void ldns_dname2canonical(const ldns_rdf *rdf); 135 136 /** 137 * test whether the name sub falls under parent (i.e. is a subdomain 138 * of parent). This function will return false if the given dnames are 139 * equal. 140 * \param[in] sub the name to test 141 * \param[in] parent the parent's name 142 * \return true if sub falls under parent, otherwise false 143 */ 144 bool ldns_dname_is_subdomain(const ldns_rdf *sub, const ldns_rdf *parent); 145 146 /** 147 * Compares the two dname rdf's according to the algorithm for ordering 148 * in RFC4034 Section 6. 149 * \param[in] dname1 First dname rdf to compare 150 * \param[in] dname2 Second dname rdf to compare 151 * \return -1 if dname1 comes before dname2, 1 if dname1 comes after dname2, and 0 if they are equal. 152 */ 153 int ldns_dname_compare(const ldns_rdf *dname1, const ldns_rdf *dname2); 154 int ldns_dname_compare_v(const void *, const void *); 155 156 /** 157 * Checks whether the dname matches the given wildcard 158 * \param[in] dname The dname to check 159 * \param[in] wildcard The wildcard to check with 160 * \return 1 If the wildcard matches, OR if 'wildcard' is not a wildcard and 161 * the names are *exactly* the same 162 * 0 If the wildcard does not match, or if it is not a wildcard and 163 * the names are not the same 164 */ 165 int ldns_dname_match_wildcard(const ldns_rdf *dname, const ldns_rdf *wildcard); 166 167 /** 168 * check if middle lays in the interval defined by prev and next 169 * prev <= middle < next. This is useful for nsec checking 170 * \param[in] prev the previous dname 171 * \param[in] middle the dname to check 172 * \param[in] next the next dname 173 * return 0 on error or unknown, -1 when middle is in the interval, +1 when not 174 */ 175 int ldns_dname_interval(const ldns_rdf *prev, const ldns_rdf *middle, const ldns_rdf *next); 176 177 /** 178 * Checks whether the given dname string is absolute (i.e. ends with a '.') 179 * \param[in] *dname_str a string representing the dname 180 * \return true or false 181 */ 182 bool ldns_dname_str_absolute(const char *dname_str); 183 184 /** 185 * Checks whether the given dname is absolute (i.e. ends with a '.') 186 * \param[in] *dname a rdf representing the dname 187 * \return true or false 188 */ 189 bool ldns_dname_absolute(const ldns_rdf *dname); 190 191 /** 192 * look inside the rdf and if it is an LDNS_RDF_TYPE_DNAME 193 * try and retrieve a specific label. The labels are numbered 194 * starting from 0 (left most). 195 * \param[in] rdf the rdf to look in 196 * \param[in] labelpos return the label with this number 197 * \return a ldns_rdf* with the label as name or NULL on error 198 */ 199 ldns_rdf * ldns_dname_label(const ldns_rdf *rdf, uint8_t labelpos); 200 201 /** 202 * Check if dname is a wildcard, starts with *. 203 * \param[in] dname: the rdf to look in 204 * \return true if a wildcard, false if not. 205 */ 206 int ldns_dname_is_wildcard(const ldns_rdf* dname); 207 208 #ifdef __cplusplus 209 } 210 #endif 211 212 #endif /* LDNS_DNAME_H */ 213