src/lookups/dbmdb.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #include "../exim.h"
   9 #include "lf_functions.h"
  10
  11
  12 /*************************************************
  13 *              Open entry point                  *
  14 *************************************************/
  15
  16 /* See local README for interface description */
  17
  18 static void *
  19 dbmdb_open(uschar *filename, uschar **errmsg)
  20 {
  21 EXIM_DB *yield = NULL;
  22 EXIM_DBOPEN(filename, O_RDONLY, 0, &yield);
  23 if (yield == NULL)
  24   {
  25   int save_errno = errno;
  26   *errmsg = string_open_failed(errno, "%s as a %s file", filename, EXIM_DBTYPE);
  27   errno = save_errno;
  28   }
  29 return yield;
  30 }
  31
  32
  33
  34 /*************************************************
  35 *             Check entry point                  *
  36 *************************************************/
  37
  38 /* This needs to know more about the underlying files than is good for it!
  39 We need to know what the real file names are in order to check the owners and
  40 modes. If USE_DB is set, we know it is Berkeley DB, which uses an unmodified
  41 file name. If USE_TDB or USE_GDBM is set, we know it is tdb or gdbm, which do
  42 the same. Otherwise, for safety, we have to check for x.db or x.dir and x.pag.
  43 */
  44
  45 static BOOL
  46 dbmdb_check(void *handle, uschar *filename, int modemask, uid_t *owners,
  47   gid_t *owngroups, uschar **errmsg)
  48 {
  49 int rc;
  50 handle = handle;    /* Keep picky compilers happy */
  51
  52 #if defined(USE_DB) || defined(USE_TDB) || defined(USE_GDBM)
  53 rc = lf_check_file(-1, filename, S_IFREG, modemask, owners, owngroups,
  54   "dbm", errmsg);
  55 #else
  56   {
  57   uschar filebuffer[256];
  58   (void)sprintf(CS filebuffer, "%.250s.db", filename);
  59   rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
  60     "dbm", errmsg);
  61   if (rc < 0)        /* stat() failed */
  62     {
  63     (void)sprintf(CS filebuffer, "%.250s.dir", filename);
  64     rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
  65       "dbm", errmsg);
  66     if (rc == 0)     /* x.dir was OK */
  67       {
  68       (void)sprintf(CS filebuffer, "%.250s.pag", filename);
  69       rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
  70         "dbm", errmsg);
  71       }
  72     }
  73   }
  74 #endif
  75
  76 return rc == 0;
  77 }
  78
  79
  80
  81 /*************************************************
  82 *              Find entry point                  *
  83 *************************************************/
  84
  85 /* See local README for interface description. This function adds 1 to
  86 the keylength in order to include the terminating zero. */
  87
  88 static int
  89 dbmdb_find(void *handle, uschar *filename, const uschar *keystring, int length,
  90   uschar **result, uschar **errmsg, uint *do_cache)
  91 {
  92 EXIM_DB *d = (EXIM_DB *)handle;
  93 EXIM_DATUM key, data;
  94
  95 filename = filename;    /* Keep picky compilers happy */
  96 errmsg = errmsg;
  97 do_cache = do_cache;
  98
  99 EXIM_DATUM_INIT(key);               /* Some DBM libraries require datums to */
 100 EXIM_DATUM_INIT(data);              /* be cleared before use. */
 101 EXIM_DATUM_DATA(key) = CS keystring;
 102 EXIM_DATUM_SIZE(key) = length + 1;
 103
 104 if (EXIM_DBGET(d, key, data))
 105   {
 106   *result = string_copyn(US EXIM_DATUM_DATA(data), EXIM_DATUM_SIZE(data));
 107   EXIM_DATUM_FREE(data);            /* Some DBM libraries need a free() call */
 108   return OK;
 109   }
 110 return FAIL;
 111 }
 112
 113
 114
 115 /*************************************************
 116 *      Find entry point - no zero on key         *
 117 *************************************************/
 118
 119 /* See local README for interface description */
 120
 121 int
 122 static dbmnz_find(void *handle, uschar *filename, const uschar *keystring, int length,
 123   uschar **result, uschar **errmsg, uint *do_cache)
 124 {
 125 return dbmdb_find(handle, filename, keystring, length-1, result, errmsg,
 126   do_cache);
 127 }
 128
 129
 130
 131 /*************************************************
 132 *     Find entry point - zero-joined list key    *
 133 *************************************************/
 134
 135 /*
 136  * The parameter passed as a key is a list in normal Exim list syntax.
 137  * The elements of that list are joined together on NUL, with no trailing
 138  * NUL, to form the key.
 139  */
 140
 141 static int
 142 dbmjz_find(void *handle, uschar *filename, const uschar *keystring, int length,
 143   uschar **result, uschar **errmsg, uint *do_cache)
 144 {
 145 uschar *key_item, *key_buffer, *key_p;
 146 const uschar *key_elems = keystring;
 147 int buflen, bufleft, key_item_len, sep = 0;
 148
 149 /* To a first approximation, the size of the lookup key needs to be about,
 150 or less than, the length of the delimited list passed in + 1. */
 151
 152 buflen = length + 3;
 153 key_buffer = store_get(buflen);
 154
 155 key_buffer[0] = '\0';
 156
 157 key_p = key_buffer;
 158 bufleft = buflen;
 159
 160 /* In all cases of an empty list item, we can set 1 and advance by 1 and then
 161 pick up the trailing NUL from the previous list item, EXCEPT when at the
 162 beginning of the output string, in which case we need to supply that NUL
 163 ourselves.  */
 164 while ((key_item = string_nextinlist(&key_elems, &sep, key_p, bufleft)) != NULL)
 165   {
 166   key_item_len = Ustrlen(key_item) + 1;
 167   if (key_item_len == 1)
 168     {
 169     key_p[0] = '\0';
 170     if (key_p == key_buffer)
 171       {
 172       key_p[1] = '\0';
 173       key_item_len += 1;
 174       }
 175     }
 176
 177   bufleft -= key_item_len;
 178   if (bufleft <= 0)
 179     {
 180     /* The string_nextinlist() will stop at buffer size, but we should always
 181     have at least 1 character extra, so some assumption has failed. */
 182     *errmsg = string_copy(US"Ran out of buffer space for joining elements");
 183     return DEFER;
 184     }
 185   key_p += key_item_len;
 186   }
 187
 188 if (key_p == key_buffer)
 189   {
 190   *errmsg = string_copy(US"empty list key");
 191   return FAIL;
 192   }
 193
 194 /* We do not pass in the final NULL; if needed, the list should include an
 195 empty element to put one in. Boundary: key length 1, is a NULL */
 196 key_item_len = key_p - key_buffer - 1;
 197
 198 DEBUG(D_lookup) debug_printf("NUL-joined key length: %d\n", key_item_len);
 199
 200 /* beware that dbmdb_find() adds 1 to length to get back terminating NUL, so
 201 because we've calculated the real length, we need to subtract one more here */
 202 return dbmdb_find(handle, filename,
 203     key_buffer, key_item_len - 1,
 204     result, errmsg, do_cache);
 205 }
 206
 207
 208
 209 /*************************************************
 210 *              Close entry point                 *
 211 *************************************************/
 212
 213 /* See local README for interface description */
 214
 215 void
 216 static dbmdb_close(void *handle)
 217 {
 218 EXIM_DBCLOSE((EXIM_DB *)handle);
 219 }
 220
 221
 222
 223 /*************************************************
 224 *         Version reporting entry point          *
 225 *************************************************/
 226
 227 /* See local README for interface description. */
 228
 229 #include "../version.h"
 230
 231 void
 232 dbm_version_report(FILE *f)
 233 {
 234 #ifdef DYNLOOKUP
 235 fprintf(f, "Library version: DBM: Exim version %s\n", EXIM_VERSION_STR);
 236 #endif
 237 }
 238
 239
 240 lookup_info dbm_lookup_info = {
 241   US"dbm",                       /* lookup name */
 242   lookup_absfile,                /* uses absolute file name */
 243   dbmdb_open,                    /* open function */
 244   dbmdb_check,                   /* check function */
 245   dbmdb_find,                    /* find function */
 246   dbmdb_close,                   /* close function */
 247   NULL,                          /* no tidy function */
 248   NULL,                          /* no quoting function */
 249   dbm_version_report             /* version reporting */
 250 };
 251
 252 lookup_info dbmz_lookup_info = {
 253   US"dbmnz",                     /* lookup name */
 254   lookup_absfile,                /* uses absolute file name */
 255   dbmdb_open,      /* sic */     /* open function */
 256   dbmdb_check,     /* sic */     /* check function */
 257   dbmnz_find,                    /* find function */
 258   dbmdb_close,     /* sic */     /* close function */
 259   NULL,                          /* no tidy function */
 260   NULL,                          /* no quoting function */
 261   NULL                           /* no version reporting (redundant) */
 262 };
 263
 264 lookup_info dbmjz_lookup_info = {
 265   US"dbmjz",                     /* lookup name */
 266   lookup_absfile,                /* uses absolute file name */
 267   dbmdb_open,      /* sic */     /* open function */
 268   dbmdb_check,     /* sic */     /* check function */
 269   dbmjz_find,                    /* find function */
 270   dbmdb_close,     /* sic */     /* close function */
 271   NULL,                          /* no tidy function */
 272   NULL,                          /* no quoting function */
 273   NULL                           /* no version reporting (redundant) */
 274 };
 275
 276 #ifdef DYNLOOKUP
 277 #define dbmdb_lookup_module_info _lookup_module_info
 278 #endif
 279
 280 static lookup_info *_lookup_list[] = { &dbm_lookup_info, &dbmz_lookup_info, &dbmjz_lookup_info };
 281 lookup_module_info dbmdb_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
 282
 283 /* End of lookups/dbmdb.c */