pdns/cdb.cc

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30
  31 #include "cdb.hh"
  32
  33 CDB::CDB(const string &cdbfile)
  34 {
  35   d_fd = open(cdbfile.c_str(), O_RDONLY);
  36   if (d_fd < 0)
  37   {
  38     throw std::runtime_error("Failed to open cdb database file '"+cdbfile+"'. Error: " + stringerror());
  39   }
  40
  41   memset(&d_cdbf,0,sizeof(struct cdb_find));
  42   int cdbinit = cdb_init(&d_cdb, d_fd);
  43   if (cdbinit < 0)
  44   {
  45     close(d_fd);
  46     d_fd = -1;
  47     throw std::runtime_error("Failed to initialize cdb structure. ErrorNt: '" + std::to_string(cdbinit) + "'");
  48   }
  49 }
  50
  51 CDB::~CDB() {
  52   cdb_free(&d_cdb);
  53   close(d_fd);
  54 }
  55
  56 int CDB::searchKey(const string &key) {
  57   d_searchType = SearchKey;
  58
  59   // A 'bug' in tinycdb (the lib used for reading the CDB files) means we have to copy the key because the cdb_find struct
  60   // keeps a pointer to it.
  61   d_key = key;
  62   return cdb_findinit(&d_cdbf, &d_cdb, d_key.c_str(), d_key.size());
  63 }
  64
  65 bool CDB::searchSuffix(const string &key) {
  66   d_searchType = SearchSuffix;
  67
  68   //See CDB::searchKey()
  69   d_key = key;
  70
  71   // We are ok with a search on things, but we do want to know if a record with that key exists.........
  72   bool hasDomain = (cdb_find(&d_cdb, d_key.c_str(), d_key.size()) == 1);
  73   if (hasDomain) {
  74     cdb_seqinit(&d_seqPtr, &d_cdb);
  75   }
  76
  77   return hasDomain;
  78 }
  79
  80 void CDB::searchAll() {
  81   d_searchType = SearchAll;
  82   cdb_seqinit(&d_seqPtr, &d_cdb);
  83 }
  84
  85 bool CDB::moveToNext() {
  86   int hasNext = 0;
  87   if (d_searchType == SearchKey) {
  88     hasNext = cdb_findnext(&d_cdbf);
  89   } else {
  90     hasNext = cdb_seqnext(&d_seqPtr, &d_cdb);
  91   }
  92   return (hasNext > 0);
  93 }
  94
  95 bool CDB::readNext(pair<string, string> &value) {
  96   while (moveToNext()) {
  97     unsigned int pos;
  98     unsigned int len;
  99
 100     pos = cdb_keypos(&d_cdb);
 101     len = cdb_keylen(&d_cdb);
 102
 103     std::string key;
 104     key.resize(len);
 105     cdb_read(&d_cdb, &key[0], len, pos);
 106
 107     if (d_searchType == SearchSuffix) {
 108       char *p = strstr(const_cast<char*>(key.c_str()), d_key.c_str());
 109       if (p == nullptr) {
 110         continue;
 111       }
 112     }
 113
 114     pos = cdb_datapos(&d_cdb);
 115     len = cdb_datalen(&d_cdb);
 116     std::string val;
 117     val.resize(len);
 118     cdb_read(&d_cdb, &val[0], len, pos);
 119
 120     value = make_pair(std::move(key), std::move(val));
 121     return true;
 122   }
 123
 124   // We're done searching, so we can clean up d_key
 125   if (d_searchType != SearchAll) {
 126     d_key.clear();
 127   }
 128
 129   return false;
 130 }
 131
 132 vector<string> CDB::findall(string &key)
 133 {
 134   vector<string> ret;
 135   struct cdb_find cdbf;
 136
 137   cdb_findinit(&cdbf, &d_cdb, key.c_str(), key.size());
 138   int x=0;
 139   while(cdb_findnext(&cdbf) > 0) {
 140     x++;
 141     unsigned int vpos = cdb_datapos(&d_cdb);
 142     unsigned int vlen = cdb_datalen(&d_cdb);
 143     std::string val;
 144     val.resize(vlen);
 145     cdb_read(&d_cdb, &val[0], vlen, vpos);
 146     ret.push_back(std::move(val));
 147   }
 148
 149   return ret;
 150 }