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 #define LDNS_DNAME_NORMALIZE tolower 46 47 /** 48 * concatenates two dnames together 49 * \param[in] rd1 the leftside 50 * \param[in] rd2 the rightside 51 * \return a new rdf with leftside/rightside 52 */ 53 ldns_rdf *ldns_dname_cat_clone(const ldns_rdf *rd1, const ldns_rdf *rd2); 54 55 /** 56 * concatenates rd2 after rd1 (rd2 is copied, rd1 is modified) 57 * \param[in] rd1 the leftside 58 * \param[in] rd2 the rightside 59 * \return LDNS_STATUS_OK on success 60 */ 61 ldns_status ldns_dname_cat(ldns_rdf *rd1, ldns_rdf *rd2); 62 63 /** 64 * Returns a clone of the given dname with the labels 65 * reversed 66 * \param[in] d the dname to reverse 67 * \return clone of the dname with the labels reversed. 68 */ 69 ldns_rdf *ldns_dname_reverse(const ldns_rdf *d); 70 71 /** 72 * Clones the given dname from the nth label on 73 * \param[in] d The dname to clone 74 * \param[in] n the label nr to clone from, if this is 0, the complete 75 * dname is cloned 76 * \return A newly allocated *rdf structure, containing the cloned dname, 77 * or NULL if either d was NULL, not a dname, or if n >= 78 * label_count 79 */ 80 ldns_rdf * 81 ldns_dname_clone_from(const ldns_rdf *d, uint16_t n); 82 83 /** 84 * chop one label off the left side of a dname. so 85 * wwww.nlnetlabs.nl, becomes nlnetlabs.nl 86 * This new name is a clone and must be freed with ldns_deep_free() 87 * \param[in] d the dname to chop 88 * \return the remaining dname 89 */ 90 ldns_rdf *ldns_dname_left_chop(const ldns_rdf *d); 91 92 /** 93 * count the number of labels inside a LDNS_RDF_DNAME type rdf. 94 * \param[in] *r the rdf 95 * \return the number of labels 96 */ 97 uint8_t ldns_dname_label_count(const ldns_rdf *r); 98 99 /** 100 * creates a new dname rdf from a string. 101 * \param[in] str string to use 102 * \return ldns_rdf* or NULL in case of an error 103 */ 104 ldns_rdf *ldns_dname_new_frm_str(const char *str); 105 106 /** 107 * Create a new dname rdf from a string 108 * \param[in] s the size of the new dname 109 * \param[in] *data pointer to the actual data 110 * \return ldns_rdf* 111 */ 112 ldns_rdf *ldns_dname_new(uint16_t s, void *data); 113 114 /** 115 * Create a new dname rdf from data (the data is copied) 116 * \param[in] size the size of the data 117 * \param[in] *data pointer to the actual data 118 * \return ldns_rdf* 119 */ 120 ldns_rdf *ldns_dname_new_frm_data(uint16_t size, const void *data); 121 122 /** 123 * Put a dname into canonical fmt - ie. lowercase it 124 * \param[in] rdf the dname to lowercase 125 * \return void 126 */ 127 void ldns_dname2canonical(const ldns_rdf *rdf); 128 129 /** 130 * test wether the name sub falls under parent (i.e. is a subdomain 131 * of parent). This function will return false if the given dnames are 132 * equal. 133 * \param[in] sub the name to test 134 * \param[in] parent the parent's name 135 * \return true if sub falls under parent, otherwise false 136 */ 137 bool ldns_dname_is_subdomain(const ldns_rdf *sub, const ldns_rdf *parent); 138 139 /** 140 * Compares the two dname rdf's according to the algorithm for ordering 141 * in RFC4034 Section 6. 142 * \param[in] dname1 First dname rdf to compare 143 * \param[in] dname2 Second dname rdf to compare 144 * \return -1 if dname1 comes before dname2, 1 if dname1 comes after dname2, and 0 if they are equal. 145 */ 146 int ldns_dname_compare(const ldns_rdf *dname1, const ldns_rdf *dname2); 147 148 /** 149 * Checks whether the dname matches the given wildcard 150 * \param[in] dname The dname to check 151 * \param[in] wildcard The wildcard to check with 152 * \return 1 If the wildcard matches, OR if 'wildcard' is not a wildcard and 153 * the names are *exactly* the same 154 * 0 If the wildcard does not match, or if it is not a wildcard and 155 * the names are not the same 156 */ 157 int ldns_dname_match_wildcard(const ldns_rdf *dname, const ldns_rdf *wildcard); 158 159 /** 160 * check if middle lays in the interval defined by prev and next 161 * prev <= middle < next. This is usefull for nsec checking 162 * \param[in] prev the previous dname 163 * \param[in] middle the dname to check 164 * \param[in] next the next dname 165 * return 0 on error or unknown, -1 when middle is in the interval, +1 when not 166 */ 167 int ldns_dname_interval(const ldns_rdf *prev, const ldns_rdf *middle, const ldns_rdf *next); 168 169 /** 170 * Checks whether the given dname string is absolute (i.e. ends with a '.') 171 * \param[in] *dname_str a string representing the dname 172 * \return true or false 173 */ 174 bool ldns_dname_str_absolute(const char *dname_str); 175 176 /** 177 * look inside the rdf and if it is an LDNS_RDF_TYPE_DNAME 178 * try and retrieve a specific label. The labels are numbered 179 * starting from 0 (left most). 180 * \param[in] rdf the rdf to look in 181 * \param[in] labelpos return the label with this number 182 * \return a ldns_rdf* with the label as name or NULL on error 183 */ 184 ldns_rdf * ldns_dname_label(const ldns_rdf *rdf, uint8_t labelpos); 185 186 #endif /* LDNS_DNAME_H */ 187