diff options
Diffstat (limited to 'cdb.cc')
| -rw-r--r-- | cdb.cc | 227 |
1 files changed, 227 insertions, 0 deletions
@@ -0,0 +1,227 @@ +/* + * This file is part of PowerDNS or dnsdist. + * Copyright -- PowerDNS.COM B.V. and its contributors + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * In addition, for the avoidance of any doubt, permission is granted to + * link this program with OpenSSL and to (re)distribute the binaries + * produced as the result of such linking. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> + +#include "cdb.hh" + +CDB::CDB(const string &cdbfile) +{ + d_fd = open(cdbfile.c_str(), O_RDONLY); + if (d_fd < 0) + { + throw std::runtime_error("Failed to open cdb database file '"+cdbfile+"': " + stringerror()); + } + + memset(&d_cdbf,0,sizeof(struct cdb_find)); + int cdbinit = cdb_init(&d_cdb, d_fd); + if (cdbinit < 0) + { + close(d_fd); + d_fd = -1; + throw std::runtime_error("Failed to initialize cdb structure for database '+cdbfile+': '" + std::to_string(cdbinit) + "'"); + } +} + +CDB::~CDB() { + cdb_free(&d_cdb); + close(d_fd); +} + +int CDB::searchKey(const string &key) { + d_searchType = SearchKey; + + // A 'bug' in tinycdb (the lib used for reading the CDB files) means we have to copy the key because the cdb_find struct + // keeps a pointer to it. + d_key = key; + return cdb_findinit(&d_cdbf, &d_cdb, d_key.c_str(), d_key.size()); +} + +bool CDB::searchSuffix(const string &key) { + d_searchType = SearchSuffix; + + //See CDB::searchKey() + d_key = key; + + // We are ok with a search on things, but we do want to know if a record with that key exists......... + bool hasDomain = (cdb_find(&d_cdb, d_key.c_str(), d_key.size()) == 1); + if (hasDomain) { + cdb_seqinit(&d_seqPtr, &d_cdb); + } + + return hasDomain; +} + +void CDB::searchAll() { + d_searchType = SearchAll; + cdb_seqinit(&d_seqPtr, &d_cdb); +} + +bool CDB::moveToNext() { + int hasNext = 0; + if (d_searchType == SearchKey) { + hasNext = cdb_findnext(&d_cdbf); + } else { + hasNext = cdb_seqnext(&d_seqPtr, &d_cdb); + } + return (hasNext > 0); +} + +bool CDB::readNext(pair<string, string> &value) { + while (moveToNext()) { + unsigned int pos; + unsigned int len; + + pos = cdb_keypos(&d_cdb); + len = cdb_keylen(&d_cdb); + + std::string key; + key.resize(len); + int ret = cdb_read(&d_cdb, &key[0], len, pos); + if (ret < 0) { + throw std::runtime_error("Error while reading key for key '" + key + "' from CDB database: " + std::to_string(ret)); + } + + if (d_searchType == SearchSuffix) { + char *p = strstr(const_cast<char*>(key.c_str()), d_key.c_str()); + if (p == nullptr) { + continue; + } + } + + pos = cdb_datapos(&d_cdb); + len = cdb_datalen(&d_cdb); + std::string val; + val.resize(len); + ret = cdb_read(&d_cdb, &val[0], len, pos); + if (ret < 0) { + throw std::runtime_error("Error while reading value for key '" + key + "' from CDB database: " + std::to_string(ret)); + } + + value = {std::move(key), std::move(val)}; + return true; + } + + // We're done searching, so we can clean up d_key + if (d_searchType != SearchAll) { + d_key.clear(); + } + + return false; +} + +vector<string> CDB::findall(string &key) +{ + vector<string> ret; + struct cdb_find cdbf; + + int res = cdb_findinit(&cdbf, &d_cdb, key.c_str(), key.size()); + if (res < 0) { + throw std::runtime_error("Error looking up key '" + key + "' from CDB database: " + std::to_string(res)); + } + + int x=0; + while(cdb_findnext(&cdbf) > 0) { + x++; + unsigned int vpos = cdb_datapos(&d_cdb); + unsigned int vlen = cdb_datalen(&d_cdb); + std::string val; + val.resize(vlen); + res = cdb_read(&d_cdb, &val[0], vlen, vpos); + if (res < 0) { + throw std::runtime_error("Error while reading value for key '" + key + "' from CDB database: " + std::to_string(res)); + } + ret.push_back(std::move(val)); + } + + return ret; +} + +bool CDB::keyExists(const string& key) +{ + int ret = cdb_find(&d_cdb, key.c_str(), key.size()); + if (ret < 0) { + throw std::runtime_error("Error while looking up key '" + key + "' from CDB database: " + std::to_string(ret)); + } + if (ret == 0) { + /* no such key */ + return false; + } + + return true; +} + +bool CDB::findOne(const string& key, string& value) +{ + if (!keyExists(key)) { + return false; + } + + unsigned int vpos = cdb_datapos(&d_cdb); + unsigned int vlen = cdb_datalen(&d_cdb); + value.resize(vlen); + int ret = cdb_read(&d_cdb, &value[0], vlen, vpos); + if (ret < 0) { + throw std::runtime_error("Error while reading value for key '" + key + "' from CDB database: " + std::to_string(ret)); + } + + return true; +} + +CDBWriter::CDBWriter(int fd): d_fd(fd) +{ + cdb_make_start(&d_cdbm, d_fd); +} + +CDBWriter::~CDBWriter() +{ + close(); +} + +void CDBWriter::close() +{ + if (d_fd >= 0) { + cdb_make_finish(&d_cdbm); + ::close(d_fd); + d_fd = -1; + } +} + +bool CDBWriter::addEntry(const std::string& key, const std::string& value) +{ + if (d_fd < 0) { + throw std::runtime_error("Can't add an entry to a closed CDB database"); + } + + int ret = cdb_make_add(&d_cdbm, key.c_str(), key.size(), value.c_str(), value.size()); + if (ret != 0) { + throw std::runtime_error("Error adding key '" + key + "' to CDB database: " + std::to_string(ret)); + } + + return true; +} |