modules/tinydnsbackend/cdb.cc

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4 #include "cdb.hh"
   5 #include <cdb.h>
   6 #include "pdns/misc.hh"
   7 #include "pdns/iputils.hh"
   8 #include <utility>
   9
  10
  11 CDB::CDB(const string &cdbfile)
  12 {
  13   d_fd = open(cdbfile.c_str(), O_RDONLY);
  14   if (d_fd < 0)
  15   {
  16     L<<Logger::Error<<"Failed to open cdb database file '"<<cdbfile<<"'. Error: "<<stringerror()<<endl;
  17     throw new PDNSException("Failed to open cdb database file '"+cdbfile+"'. Error: " + stringerror());
  18   }
  19
  20   memset(&d_cdbf,0,sizeof(struct cdb_find));
  21   int cdbinit = cdb_init(&d_cdb, d_fd);
  22   if (cdbinit < 0)
  23   {
  24     L<<Logger::Error<<"Failed to initialize cdb structure. ErrorNr: '"<<cdbinit<<endl;
  25     throw new PDNSException("Failed to initialize cdb structure.");
  26   }
  27
  28   d_key = NULL;
  29   d_seqPtr = 0;
  30   d_searchType = SearchKey;
  31 }
  32
  33 CDB::~CDB() {
  34   cdb_free(&d_cdb);
  35   close(d_fd);
  36 }
  37
  38 int CDB::searchKey(const string &key) {
  39   d_searchType = SearchKey;
  40
  41   // A 'bug' in tinycdb (the lib used for reading the CDB files) means we have to copy the key because the cdb_find struct
  42   // keeps a pointer to it.
  43   d_key = strdup(key.c_str());
  44   return cdb_findinit(&d_cdbf, &d_cdb, d_key, key.size());
  45 }
  46
  47 bool CDB::searchSuffix(const string &key) {
  48   d_searchType = SearchSuffix;
  49
  50   //See CDB::searchKey()
  51   d_key = strdup(key.c_str());
  52
  53   // We are ok with a search on things, but we do want to know if a record with that key exists.........
  54   bool hasDomain = (cdb_find(&d_cdb, key.c_str(), key.size()) == 1);
  55   if (hasDomain) {
  56     cdb_seqinit(&d_seqPtr, &d_cdb);
  57   }
  58
  59   return hasDomain;
  60 }
  61
  62 void CDB::searchAll() {
  63   d_searchType = SearchAll;
  64   cdb_seqinit(&d_seqPtr, &d_cdb);
  65 }
  66
  67 bool CDB::moveToNext() {
  68   int hasNext = 0;
  69   if (d_searchType == SearchKey) {
  70     hasNext = cdb_findnext(&d_cdbf);
  71   } else {
  72     hasNext = cdb_seqnext(&d_seqPtr, &d_cdb);
  73   }
  74   return (hasNext > 0);
  75 }
  76
  77 bool CDB::readNext(pair<string, string> &value) {
  78   while (moveToNext()) {
  79     unsigned int pos;
  80     unsigned int len;
  81
  82     pos = cdb_keypos(&d_cdb);
  83     len = cdb_keylen(&d_cdb);
  84
  85     char *key = (char *)malloc(len);
  86     cdb_read(&d_cdb, key, len, pos);
  87
  88     if (d_searchType == SearchSuffix) {
  89       char *p = strstr(key, d_key);
  90       if (p == NULL) {
  91         free(key);
  92         continue;
  93       }
  94     }
  95     string skey(key, len);
  96     free(key);
  97
  98     pos = cdb_datapos(&d_cdb);
  99     len = cdb_datalen(&d_cdb);
 100     char *val = (char *)malloc(len);
 101     cdb_read(&d_cdb, val, len, pos);
 102     string sval(val, len);
 103     free(val);
 104
 105     value = make_pair(skey, sval);
 106     return true;
 107   }
 108   // We're done searching, so we can clean up d_key
 109   if (d_searchType != SearchAll) {
 110     free(d_key);
 111   }
 112   return false;
 113 }
 114
 115 vector<string> CDB::findall(string &key)
 116 {
 117   vector<string> ret;
 118   struct cdb_find cdbf;
 119
 120   cdb_findinit(&cdbf, &d_cdb, key.c_str(), key.size());
 121   int x=0;
 122   while(cdb_findnext(&cdbf) > 0) {
 123     x++;
 124     unsigned int vpos = cdb_datapos(&d_cdb);
 125     unsigned int vlen = cdb_datalen(&d_cdb);
 126     char *val = (char *)malloc(vlen);
 127     cdb_read(&d_cdb, val, vlen, vpos);
 128     string sval(val, vlen);
 129     ret.push_back(sval);
 130     free(val);
 131   }
 132   return ret;
 133 }