src/src/lookups/dsearch.c

   1 /* $Cambridge: exim/src/src/lookups/dsearch.c,v 1.5 2007/05/31 12:42:07 magnus Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2007 */
   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 #include "dsearch.h"
  18
  19
  20
  21 /*************************************************
  22 *              Open entry point                  *
  23 *************************************************/
  24
  25 /* See local README for interface description. We open the directory to test
  26 whether it exists and whether it is searchable. However, we don't need to keep
  27 it open, because the "search" can be done by a call to lstat() rather than
  28 actually scanning through the list of files. */
  29
  30 void *
  31 dsearch_open(uschar *dirname, uschar **errmsg)
  32 {
  33 DIR *dp = opendir(CS dirname);
  34 if (dp == NULL)
  35   {
  36   int save_errno = errno;
  37   *errmsg = string_open_failed(errno, "%s for directory search", dirname);
  38   errno = save_errno;
  39   return NULL;
  40   }
  41 closedir(dp);
  42 return (void *)(-1);
  43 }
  44
  45
  46 /*************************************************
  47 *             Check entry point                  *
  48 *************************************************/
  49
  50 /* The handle will always be (void *)(-1), but don't try casting it to an
  51 integer as this gives warnings on 64-bit systems. */
  52
  53 BOOL
  54 dsearch_check(void *handle, uschar *filename, int modemask, uid_t *owners,
  55   gid_t *owngroups, uschar **errmsg)
  56 {
  57 handle = handle;
  58 return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
  59   "dsearch", errmsg) == 0;
  60 }
  61
  62
  63 /*************************************************
  64 *              Find entry point                  *
  65 *************************************************/
  66
  67 /* See local README for interface description. We use lstat() instead of
  68 scanning the directory, as it is hopefully faster to let the OS do the scanning
  69 for us. */
  70
  71 int
  72 dsearch_find(void *handle, uschar *dirname, uschar *keystring, int length,
  73   uschar **result, uschar **errmsg, BOOL *do_cache)
  74 {
  75 struct stat statbuf;
  76 int save_errno;
  77 uschar filename[PATH_MAX];
  78
  79 handle = handle;  /* Keep picky compilers happy */
  80 length = length;
  81 do_cache = do_cache;
  82
  83 if (Ustrchr(keystring, '/') != 0)
  84   {
  85   *errmsg = string_sprintf("key for dsearch lookup contains a slash: %s",
  86     keystring);
  87   return DEFER;
  88   }
  89
  90 if (!string_format(filename, sizeof(filename), "%s/%s", dirname, keystring))
  91   {
  92   *errmsg = US"path name too long";
  93   return DEFER;
  94   }
  95
  96 if (Ulstat(filename, &statbuf) >= 0)
  97   {
  98   *result = string_copy(keystring);
  99   return OK;
 100   }
 101
 102 if (errno == ENOENT) return FAIL;
 103
 104 save_errno = errno;
 105 *errmsg = string_sprintf("%s: lstat failed", filename);
 106 errno = save_errno;
 107 return DEFER;
 108 }
 109
 110
 111 /*************************************************
 112 *              Close entry point                 *
 113 *************************************************/
 114
 115 /* See local README for interface description */
 116
 117 void
 118 dsearch_close(void *handle)
 119 {
 120 handle = handle;   /* Avoid compiler warning */
 121 }
 122
 123 /* End of lookups/dsearch.c */