src/src/lookups/dsearch.c

   1 /* $Cambridge: exim/src/src/lookups/dsearch.c,v 1.6 2009/11/16 19:50:38 nm4 Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2009 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10 /* The idea for this code came from Matthew Byng-Maddick, but his original has
  11 been heavily reworked a lot for Exim 4 (and it now uses stat() (more precisely:
  12 lstat()) rather than a directory scan). */
  13
  14
  15 #include "../exim.h"
  16 #include "lf_functions.h"
  17
  18
  19
  20 /*************************************************
  21 *              Open entry point                  *
  22 *************************************************/
  23
  24 /* See local README for interface description. We open the directory to test
  25 whether it exists and whether it is searchable. However, we don't need to keep
  26 it open, because the "search" can be done by a call to lstat() rather than
  27 actually scanning through the list of files. */
  28
  29 static void *
  30 dsearch_open(uschar *dirname, uschar **errmsg)
  31 {
  32 DIR *dp = opendir(CS dirname);
  33 if (dp == NULL)
  34   {
  35   int save_errno = errno;
  36   *errmsg = string_open_failed(errno, "%s for directory search", dirname);
  37   errno = save_errno;
  38   return NULL;
  39   }
  40 closedir(dp);
  41 return (void *)(-1);
  42 }
  43
  44
  45 /*************************************************
  46 *             Check entry point                  *
  47 *************************************************/
  48
  49 /* The handle will always be (void *)(-1), but don't try casting it to an
  50 integer as this gives warnings on 64-bit systems. */
  51
  52 BOOL
  53 static dsearch_check(void *handle, uschar *filename, int modemask, uid_t *owners,
  54   gid_t *owngroups, uschar **errmsg)
  55 {
  56 handle = handle;
  57 return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
  58   "dsearch", errmsg) == 0;
  59 }
  60
  61
  62 /*************************************************
  63 *              Find entry point                  *
  64 *************************************************/
  65
  66 /* See local README for interface description. We use lstat() instead of
  67 scanning the directory, as it is hopefully faster to let the OS do the scanning
  68 for us. */
  69
  70 int
  71 static dsearch_find(void *handle, uschar *dirname, uschar *keystring, int length,
  72   uschar **result, uschar **errmsg, BOOL *do_cache)
  73 {
  74 struct stat statbuf;
  75 int save_errno;
  76 uschar filename[PATH_MAX];
  77
  78 handle = handle;  /* Keep picky compilers happy */
  79 length = length;
  80 do_cache = do_cache;
  81
  82 if (Ustrchr(keystring, '/') != 0)
  83   {
  84   *errmsg = string_sprintf("key for dsearch lookup contains a slash: %s",
  85     keystring);
  86   return DEFER;
  87   }
  88
  89 if (!string_format(filename, sizeof(filename), "%s/%s", dirname, keystring))
  90   {
  91   *errmsg = US"path name too long";
  92   return DEFER;
  93   }
  94
  95 if (Ulstat(filename, &statbuf) >= 0)
  96   {
  97   *result = string_copy(keystring);
  98   return OK;
  99   }
 100
 101 if (errno == ENOENT) return FAIL;
 102
 103 save_errno = errno;
 104 *errmsg = string_sprintf("%s: lstat failed", filename);
 105 errno = save_errno;
 106 return DEFER;
 107 }
 108
 109
 110 /*************************************************
 111 *              Close entry point                 *
 112 *************************************************/
 113
 114 /* See local README for interface description */
 115
 116 void
 117 static dsearch_close(void *handle)
 118 {
 119 handle = handle;   /* Avoid compiler warning */
 120 }
 121
 122 static lookup_info _lookup_info = {
 123   US"dsearch",                   /* lookup name */
 124   lookup_absfile,                /* uses absolute file name */
 125   dsearch_open,                  /* open function */
 126   dsearch_check,                 /* check function */
 127   dsearch_find,                  /* find function */
 128   dsearch_close,                 /* close function */
 129   NULL,                          /* no tidy function */
 130   NULL                           /* no quoting function */
 131 };
 132
 133 #ifdef DYNLOOKUP
 134 #define dsearch_lookup_module_info _lookup_module_info
 135 #endif
 136
 137 static lookup_info *_lookup_list[] = { &_lookup_info };
 138 lookup_module_info dsearch_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 139
 140 /* End of lookups/dsearch.c */