/* * util/data/dname.h - domain name routines * * Copyright (c) 2007, NLnet Labs. All rights reserved. * * This software is open source. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the NLNET LABS nor the names of its contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * \file * * This file contains functions to deal with domain names (dnames). * * Some of the functions deal with domain names as a wireformat buffer, * with a length. */ #ifndef UTIL_DATA_DNAME_H #define UTIL_DATA_DNAME_H #include "util/storage/lruhash.h" struct sldns_buffer; /** max number of compression ptrs to follow */ #define MAX_COMPRESS_PTRS 256 /** * Determine length of dname in buffer, no compression ptrs allowed, * @param query: the ldns buffer, current position at start of dname. * at end, position is at end of the dname. * @return: 0 on parse failure, or length including ending 0 of dname. */ size_t query_dname_len(struct sldns_buffer* query); /** * Determine if dname in memory is correct. no compression ptrs allowed. * @param dname: where dname starts in memory. * @param len: dname is not allowed to exceed this length (i.e. of allocation). * @return length of dname if dname is ok, 0 on a parse error. */ size_t dname_valid(uint8_t* dname, size_t len); /** lowercase query dname */ void query_dname_tolower(uint8_t* dname); /** * lowercase pkt dname (follows compression pointers) * @param pkt: the packet, used to follow compression pointers. Position * is unchanged. * @param dname: start of dname in packet. */ void pkt_dname_tolower(struct sldns_buffer* pkt, uint8_t* dname); /** * Compare query dnames (uncompressed storage). The Dnames passed do not * have to be lowercased, comparison routine does this. * * This routine is special, in that the comparison that it does corresponds * with the canonical comparison needed when comparing dnames inside rdata * for RR types that need canonicalization. That means that the first byte * that is smaller (possibly after lowercasing) makes an RR smaller, or the * shortest name makes an RR smaller. * * This routine does not compute the canonical order needed for NSEC * processing. * * Dnames have to be valid format. * @param d1: dname to compare * @param d2: dname to compare * @return: -1, 0, or +1 depending on comparison results. * Sort order is first difference found. not the canonical ordering. */ int query_dname_compare(uint8_t* d1, uint8_t* d2); /** * Determine correct, compressed, dname present in packet. * Checks for parse errors. * @param pkt: packet to read from (from current start position). * @return: 0 on parse error. * At exit the position is right after the (compressed) dname. * Compression pointers are followed and checked for loops. * The uncompressed wireformat length is returned. */ size_t pkt_dname_len(struct sldns_buffer* pkt); /** * Compare dnames in packet (compressed). Dnames must be valid. * routine performs lowercasing, so the packet casing is preserved. * @param pkt: packet, used to resolve compression pointers. * @param d1: dname to compare * @param d2: dname to compare * @return: -1, 0, or +1 depending on comparison results. * Sort order is first difference found. not the canonical ordering. */ int dname_pkt_compare(struct sldns_buffer* pkt, uint8_t* d1, uint8_t* d2); /** * Hash dname, label by label, lowercasing, into hashvalue. * Dname in query format (not compressed). * @param dname: dname to hash. * @param h: initial hash value. * @return: result hash value. */ hashvalue_t dname_query_hash(uint8_t* dname, hashvalue_t h); /** * Hash dname, label by label, lowercasing, into hashvalue. * Dname in pkt format (compressed). * @param pkt: packet, for resolving compression pointers. * @param dname: dname to hash, pointer to the pkt buffer. * Must be valid format. No loops, etc. * @param h: initial hash value. * @return: result hash value. * Result is the same as dname_query_hash, even if compression is used. */ hashvalue_t dname_pkt_hash(struct sldns_buffer* pkt, uint8_t* dname, hashvalue_t h); /** * Copy over a valid dname and decompress it. * @param pkt: packet to resolve compression pointers. * @param to: buffer of size from pkt_len function to hold result. * @param dname: pointer into packet where dname starts. */ void dname_pkt_copy(struct sldns_buffer* pkt, uint8_t* to, uint8_t* dname); /** * Copy over a valid dname to a packet. * @param pkt: packet to copy to. * @param dname: dname to copy. * @return: 0 if not enough space in buffer. */ int dname_buffer_write(struct sldns_buffer* pkt, uint8_t* dname); /** * Count the number of labels in an uncompressed dname in memory. * @param dname: pointer to uncompressed dname. * @return: count of labels, including root label, "com." has 2 labels. */ int dname_count_labels(uint8_t* dname); /** * Count labels and dname length both, for uncompressed dname in memory. * @param dname: pointer to uncompressed dname. * @param size: length of dname, including root label. * @return: count of labels, including root label, "com." has 2 labels. */ int dname_count_size_labels(uint8_t* dname, size_t* size); /** * Compare dnames, sorted not canonical, but by label. * Such that zone contents follows zone apex. * @param d1: first dname. pointer to uncompressed wireformat. * @param labs1: number of labels in first dname. * @param d2: second dname. pointer to uncompressed wireformat. * @param labs2: number of labels in second dname. * @param mlabs: number of labels that matched exactly (the shared topdomain). * @return: 0 for equal, -1 smaller, or +1 d1 larger than d2. */ int dname_lab_cmp(uint8_t* d1, int labs1, uint8_t* d2, int labs2, int* mlabs); /** * See if domain name d1 is a strict subdomain of d2. * That is a subdomain, but not equal. * @param d1: domain name, uncompressed wireformat * @param labs1: number of labels in d1, including root label. * @param d2: domain name, uncompressed wireformat * @param labs2: number of labels in d2, including root label. * @return true if d1 is a subdomain of d2, but not equal to d2. */ int dname_strict_subdomain(uint8_t* d1, int labs1, uint8_t* d2, int labs2); /** * Like dname_strict_subdomain but counts labels * @param d1: domain name, uncompressed wireformat * @param d2: domain name, uncompressed wireformat * @return true if d1 is a subdomain of d2, but not equal to d2. */ int dname_strict_subdomain_c(uint8_t* d1, uint8_t* d2); /** * Counts labels. Tests is d1 is a subdomain of d2. * @param d1: domain name, uncompressed wireformat * @param d2: domain name, uncompressed wireformat * @return true if d1 is a subdomain of d2. */ int dname_subdomain_c(uint8_t* d1, uint8_t* d2); /** * Debug helper. Print wireformat dname to output. * @param out: like stdout or a file. * @param pkt: if not NULL, the packet for resolving compression ptrs. * @param dname: pointer to (start of) dname. */ void dname_print(FILE* out, struct sldns_buffer* pkt, uint8_t* dname); /** * Debug helper. Print dname to given string buffer (string buffer must * be at least 255 chars + 1 for the 0, in printable form. * This may lose information (? for nonprintable characters, or & if * the name is too long, # for a bad label length). * @param dname: uncompressed wireformat. * @param str: buffer of 255+1 length. */ void dname_str(uint8_t* dname, char* str); /** * Returns true if the uncompressed wireformat dname is the root "." * @param dname: the dname to check * @return true if ".", false if not. */ int dname_is_root(uint8_t* dname); /** * Snip off first label from a dname, returning the parent zone. * @param dname: from what to strip off. uncompressed wireformat. * @param len: length, adjusted to become less. * @return stripped off, or "." if input was ".". */ void dname_remove_label(uint8_t** dname, size_t* len); /** * Snip off first N labels from a dname, returning the parent zone. * @param dname: from what to strip off. uncompressed wireformat. * @param len: length, adjusted to become less. * @param n: number of labels to strip off (from the left). * if 0, nothing happens. * @return stripped off, or "." if input was ".". */ void dname_remove_labels(uint8_t** dname, size_t* len, int n); /** * Count labels for the RRSIG signature label field. * Like a normal labelcount, but "*" wildcard and "." root are not counted. * @param dname: valid uncompressed wireformat. * @return number of labels like in RRSIG; '*' and '.' are not counted. */ int dname_signame_label_count(uint8_t* dname); /** * Return true if the label is a wildcard, *.example.com. * @param dname: valid uncompressed wireformat. * @return true if wildcard, or false. */ int dname_is_wild(uint8_t* dname); /** * Compare dnames, Canonical in rfc4034 sense, but by label. * Such that zone contents follows zone apex. * * @param d1: first dname. pointer to uncompressed wireformat. * @param labs1: number of labels in first dname. * @param d2: second dname. pointer to uncompressed wireformat. * @param labs2: number of labels in second dname. * @param mlabs: number of labels that matched exactly (the shared topdomain). * @return: 0 for equal, -1 smaller, or +1 d1 larger than d2. */ int dname_canon_lab_cmp(uint8_t* d1, int labs1, uint8_t* d2, int labs2, int* mlabs); /** * Canonical dname compare. Takes care of counting labels. * Per rfc 4034 canonical order. * * @param d1: first dname. pointer to uncompressed wireformat. * @param d2: second dname. pointer to uncompressed wireformat. * @return: 0 for equal, -1 smaller, or +1 d1 larger than d2. */ int dname_canonical_compare(uint8_t* d1, uint8_t* d2); /** * Get the shared topdomain between two names. Root "." or longer. * @param d1: first dname. pointer to uncompressed wireformat. * @param d2: second dname. pointer to uncompressed wireformat. * @return pointer to shared topdomain. Ptr to a part of d1. */ uint8_t* dname_get_shared_topdomain(uint8_t* d1, uint8_t* d2); #endif /* UTIL_DATA_DNAME_H */