1/* 2 * ixfr.h -- generating IXFR responses. 3 * 4 * Copyright (c) 2021, NLnet Labs. All rights reserved. 5 * 6 * See LICENSE for the license. 7 * 8 */ 9 10#ifndef IXFR_H 11#define IXFR_H 12struct nsd; 13#include "query.h" 14#include "rbtree.h" 15struct ixfr_data; 16struct zone; 17struct buffer; 18struct region; 19 20/* default for number of ixfr versions in files */ 21#define IXFR_NUMBER_DEFAULT 5 /* number of versions */ 22/* default for IXFR storage */ 23#define IXFR_SIZE_DEFAULT 1048576 /* in bytes, 1M */ 24 25/* data structure that stores IXFR contents for a zone. */ 26struct zone_ixfr { 27 /* Items are of type ixfr_data. The key is old_serial. 28 * So it can be looked up on an incoming IXFR. They are sorted 29 * by old_serial, so the looked up and next are the versions needed. 30 * Tree of ixfr data for versions */ 31 struct rbtree* data; 32 /* total size stored at this time, in bytes, 33 * sum of sizes of the ixfr data elements */ 34 size_t total_size; 35 /* the oldest serial number in the tree, searchable by old_serial */ 36 uint32_t oldest_serial; 37 /* the newest serial number in the tree, that is searchable in the 38 * tree, so it is the old_serial of the newest data entry, that 39 * has an even newer new_serial of that entry */ 40 uint32_t newest_serial; 41}; 42 43/* Data structure that stores one IXFR. 44 * The RRs are stored in uncompressed wireformat, that means 45 * an uncompressed domain name, type, class, TTL, rdatalen, 46 * uncompressed rdata in wireformat. 47 * 48 * The data structure is formatted like this so that making an IXFR 49 * that moves across several versions can be done by collating the 50 * pieces precisely from the versions involved. In particular, for 51 * an IXFR from olddata to newdata, for a combined output: 52 * newdata.newsoa olddata.oldsoa olddata.del olddata.add 53 * newdata.del newdata.add 54 * in sequence should produce a valid, non-condensed, IXFR with multiple 55 * versions inside. 56 */ 57struct ixfr_data { 58 /* Node in the rbtree. Key is oldserial */ 59 struct rbnode node; 60 /* from what serial the IXFR starts from, the 'old' serial */ 61 uint32_t oldserial; 62 /* where to IXFR goes to, the 'new' serial */ 63 uint32_t newserial; 64 /* the new SOA record, with newserial */ 65 uint8_t* newsoa; 66 /* byte length of the uncompressed wireformat RR in newsoa */ 67 size_t newsoa_len; 68 /* the old SOA record, with oldserial */ 69 uint8_t* oldsoa; 70 /* byte length of the uncompressed wireformat RR in oldsoa*/ 71 size_t oldsoa_len; 72 /* the deleted RRs, ends with the newserial SOA record. 73 * if the ixfr is collated out multiple versions, then 74 * this deleted RRs section contains several add and del sections 75 * for the older versions, and ends with the last del section, 76 * and the SOA record with the newserial. 77 * That is everything except the final add section for newserial. */ 78 uint8_t* del; 79 /* byte length of the uncompressed wireformat RRs in del */ 80 size_t del_len; 81 /* the added RRs, ends with the newserial SOA record. */ 82 uint8_t* add; 83 /* byte length of the uncompressed wireformat RRs in add */ 84 size_t add_len; 85 /* log string (if not NULL) about where data is from */ 86 char* log_str; 87 /* the number of the ixfr.<num> file on disk. If 0, there is no 88 * file. If 1, it is file ixfr<nothingafterit>. */ 89 int file_num; 90}; 91 92/* process queries in IXFR state */ 93query_state_type query_ixfr(struct nsd *nsd, struct query *query); 94 95/* 96 * While an IXFR is processed, in incoming IXFR that is downloaded by NSD, 97 * this structure keeps track of how to store the data from it. That data 98 * can then be used to answer IXFR queries. 99 * 100 * The structure keeps track of allocation data for the IXFR records. 101 * If it is cancelled, that is flagged so storage stops. 102 */ 103struct ixfr_store { 104 /* the zone info, with options and zone ixfr reference */ 105 struct zone* zone; 106 /* are we cancelled, it is not an IXFR, no need to store information 107 * any more. */ 108 int cancelled; 109 /* data has been trimmed and newsoa added */ 110 int data_trimmed; 111 /* the ixfr data that we are storing into */ 112 struct ixfr_data* data; 113 /* capacity for the delrrs storage, size of ixfr del allocation */ 114 size_t del_capacity; 115 /* capacity for the addrrs storage, size of ixfr add allocation */ 116 size_t add_capacity; 117}; 118 119/* 120 * Start the storage of the IXFR data from this IXFR. 121 * If it returns NULL, the IXFR storage stops. On malloc failure, the 122 * storage is returned NULL, or cancelled if failures happen later on. 123 * 124 * When done, the finish routine links the data into the memory for the zone. 125 * If it turns out to not be used, use the cancel routine. Or the free 126 * routine if the ixfr_store itself needs to be deleted too, like on error. 127 * 128 * zone: the zone structure 129 * ixfr_store_mem: preallocated by caller, used to allocate the store struct. 130 * old_serial: the start serial of the IXFR. 131 * new_serial: the end serial of the IXFR. 132 * return NULL or a fresh ixfr_store structure for adding records to the 133 * IXFR with this serial number. The NULL is on error. 134 */ 135struct ixfr_store* ixfr_store_start(struct zone* zone, 136 struct ixfr_store* ixfr_store_mem); 137 138/* 139 * Cancel the ixfr store in progress. The pointer remains valid, no store done. 140 * ixfr_store: this is set to cancel. 141 */ 142void ixfr_store_cancel(struct ixfr_store* ixfr_store); 143 144/* 145 * Free ixfr store structure, it is no longer used. 146 * ixfr_store: deleted 147 */ 148void ixfr_store_free(struct ixfr_store* ixfr_store); 149 150/* 151 * Finish ixfr store processing. Links the data into the zone ixfr data. 152 * ixfr_store: Data is linked into the zone struct. The ixfr_store is freed. 153 * nsd: nsd structure for allocation region and global options. 154 * log_buf: log string for the update. 155 */ 156void ixfr_store_finish(struct ixfr_store* ixfr_store, struct nsd* nsd, 157 char* log_buf); 158 159/* finish just the data activities, trim up the storage and append newsoa */ 160void ixfr_store_finish_data(struct ixfr_store* ixfr_store); 161 162/* 163 * Add the new SOA record to the ixfr store. 164 * ixfr_store: stores ixfr data that is collected. 165 * ttl: the TTL of the SOA record 166 * packet: DNS packet that contains the SOA. position restored on function 167 * exit. 168 * rrlen: wire rdata length of the SOA. 169 */ 170void ixfr_store_add_newsoa(struct ixfr_store* ixfr_store, uint32_t ttl, 171 struct buffer* packet, size_t rrlen); 172 173/* 174 * Add the old SOA record to the ixfr store. 175 * ixfr_store: stores ixfr data that is collected. 176 * ttl: the TTL of the SOA record 177 * packet: DNS packet that contains the SOA. position restored on function 178 * exit. 179 * rrlen: wire rdata length of the SOA. 180 */ 181void ixfr_store_add_oldsoa(struct ixfr_store* ixfr_store, uint32_t ttl, 182 struct buffer* packet, size_t rrlen); 183 184void ixfr_store_delrr(struct ixfr_store* ixfr_store, const struct dname* dname, 185 uint16_t type, uint16_t klass, uint32_t ttl, struct buffer* packet, 186 uint16_t rrlen, struct region* temp_region); 187void ixfr_store_addrr(struct ixfr_store* ixfr_store, const struct dname* dname, 188 uint16_t type, uint16_t klass, uint32_t ttl, struct buffer* packet, 189 uint16_t rrlen, struct region* temp_region); 190int ixfr_store_addrr_rdatas(struct ixfr_store* ixfr_store, 191 const struct dname* dname, uint16_t type, uint16_t klass, 192 uint32_t ttl, rdata_atom_type* rdatas, ssize_t rdata_num); 193int ixfr_store_delrr_uncompressed(struct ixfr_store* ixfr_store, 194 uint8_t* dname, size_t dname_len, uint16_t type, uint16_t klass, 195 uint32_t ttl, uint8_t* rdata, size_t rdata_len); 196int ixfr_store_add_newsoa_rdatas(struct ixfr_store* ixfr_store, 197 const struct dname* dname, uint16_t type, uint16_t klass, 198 uint32_t ttl, rdata_atom_type* rdatas, ssize_t rdata_num); 199int ixfr_store_oldsoa_uncompressed(struct ixfr_store* ixfr_store, 200 uint8_t* dname, size_t dname_len, uint16_t type, uint16_t klass, 201 uint32_t ttl, uint8_t* rdata, size_t rdata_len); 202 203/* an AXFR has been received, the IXFRs do not connect in version number. 204 * Delete the unconnected IXFRs from memory */ 205void ixfr_store_delixfrs(struct zone* zone); 206 207/* return if the zone has ixfr storage enabled for it */ 208int zone_is_ixfr_enabled(struct zone* zone); 209 210/* create new zone_ixfr structure */ 211struct zone_ixfr* zone_ixfr_create(struct nsd* nsd); 212 213/* free the zone_ixfr */ 214void zone_ixfr_free(struct zone_ixfr* ixfr); 215 216/* make space to fit in the data */ 217void zone_ixfr_make_space(struct zone_ixfr* ixfr, struct zone* zone, 218 struct ixfr_data* data, struct ixfr_store* ixfr_store); 219 220/* remove ixfr data from the zone_ixfr */ 221void zone_ixfr_remove(struct zone_ixfr* ixfr, struct ixfr_data* data); 222 223/* add ixfr data to the zone_ixfr */ 224void zone_ixfr_add(struct zone_ixfr* ixfr, struct ixfr_data* data, int isnew); 225 226/* find serial number in ixfr list, or NULL if not found */ 227struct ixfr_data* zone_ixfr_find_serial(struct zone_ixfr* ixfr, 228 uint32_t qserial); 229 230/* size of the ixfr data */ 231size_t ixfr_data_size(struct ixfr_data* data); 232 233/* write ixfr contents to file for the zone */ 234void ixfr_write_to_file(struct zone* zone, const char* zfile); 235 236/* read ixfr contents from file for the zone */ 237void ixfr_read_from_file(struct nsd* nsd, struct zone* zone, const char* zfile); 238 239/* get the current serial from the zone */ 240uint32_t zone_get_current_serial(struct zone* zone); 241 242/* write the ixfr data to file */ 243int ixfr_write_file(struct zone* zone, struct ixfr_data* data, 244 const char* zfile, int file_num); 245 246/* see if ixfr file exists */ 247int ixfr_file_exists(const char* zfile, int file_num); 248 249/* rename the ixfr file */ 250int ixfr_rename_it(const char* zname, const char* zfile, int oldnum, 251 int oldtemp, int newnum, int newtemp); 252 253/* read the file header of an ixfr file and return serial numbers. */ 254int ixfr_read_file_header(const char* zname, const char* zfile, 255 int file_num, uint32_t* oldserial, uint32_t* newserial, 256 size_t* data_size, int enoent_is_err); 257 258/* unlink an ixfr file */ 259int ixfr_unlink_it(const char* zname, const char* zfile, int file_num, 260 int silent_enoent); 261 262/* delete the ixfr files that are too many */ 263void ixfr_delete_superfluous_files(struct zone* zone, const char* zfile, 264 int dest_num_files); 265 266#endif /* IXFR_H */ 267