src/src/lookups/json.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) Jeremy Harris 2019 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #include "../exim.h"
   9 #include "lf_functions.h"
  10 #include <jansson.h>
  11
  12
  13
  14 /*************************************************
  15 *              Open entry point                  *
  16 *************************************************/
  17
  18 /* See local README for interface description */
  19
  20 static void *
  21 json_open(uschar *filename, uschar **errmsg)
  22 {
  23 FILE *f = Ufopen(filename, "rb");
  24 if (f == NULL)
  25   {
  26   int save_errno = errno;
  27   *errmsg = string_open_failed(errno, "%s for json search", filename);
  28   errno = save_errno;
  29   return NULL;
  30   }
  31 return f;
  32 }
  33
  34
  35
  36 /*************************************************
  37 *             Check entry point                  *
  38 *************************************************/
  39
  40 static BOOL
  41 json_check(void *handle, uschar *filename, int modemask, uid_t *owners,
  42   gid_t *owngroups, uschar **errmsg)
  43 {
  44 return lf_check_file(fileno((FILE *)handle), filename, S_IFREG, modemask,
  45   owners, owngroups, "json", errmsg) == 0;
  46 }
  47
  48
  49
  50 /*************************************************
  51 *         Find entry point for lsearch           *
  52 *************************************************/
  53
  54 /* See local README for interface description */
  55
  56 static int
  57 json_find(void *handle, uschar *filename, const uschar *keystring, int length,
  58   uschar **result, uschar **errmsg, uint *do_cache)
  59 {
  60 FILE * f = handle;
  61 json_t * j, * j0;
  62 json_error_t jerr;
  63 uschar * key;
  64 int sep = 0;
  65
  66 length = length;        /* Keep picky compilers happy */
  67 do_cache = do_cache;    /* Keep picky compilers happy */
  68
  69 rewind(f);
  70 if (!(j = json_loadf(f, 0, &jerr)))
  71   {
  72   *errmsg = string_sprintf("json error on open: %.*s\n",
  73        JSON_ERROR_TEXT_LENGTH, jerr.text);
  74   return FAIL;
  75   }
  76 j0 = j;
  77
  78 for (int k = 1;  (key = string_nextinlist(&keystring, &sep, NULL, 0)); k++)
  79   {
  80   BOOL numeric = TRUE;
  81   for (uschar * s = key; *s; s++) if (!isdigit(*s)) { numeric = FALSE; break; }
  82
  83   if (!(j = numeric
  84         ? json_array_get(j, (size_t) strtoul(CS key, NULL, 10))
  85         : json_object_get(j, CCS key)
  86      ) )
  87     {
  88     DEBUG(D_lookup) debug_printf("%s, for key %d: '%s'\n",
  89       numeric
  90       ? US"bad index, or not json array"
  91       : US"no such key, or not json object",
  92       k, key);
  93     json_decref(j0);
  94     return FAIL;
  95     }
  96   }
  97
  98 switch (json_typeof(j))
  99   {
 100   case JSON_STRING:
 101     *result = string_copyn(CUS json_string_value(j), json_string_length(j));
 102     break;
 103   case JSON_INTEGER:
 104     *result = string_sprintf("%" JSON_INTEGER_FORMAT, json_integer_value(j));
 105     break;
 106   case JSON_REAL:
 107     *result = string_sprintf("%f", json_real_value(j));
 108     break;
 109   case JSON_TRUE:       *result = US"true";     break;
 110   case JSON_FALSE:      *result = US"false";    break;
 111   case JSON_NULL:       *result = NULL;         break;
 112   default:              *result = US json_dumps(j, 0); break;
 113   }
 114 json_decref(j0);
 115 return OK;
 116 }
 117
 118
 119
 120 /*************************************************
 121 *              Close entry point                 *
 122 *************************************************/
 123
 124 /* See local README for interface description */
 125
 126 static void
 127 json_close(void *handle)
 128 {
 129 (void)fclose((FILE *)handle);
 130 }
 131
 132
 133
 134 /*************************************************
 135 *         Version reporting entry point          *
 136 *************************************************/
 137
 138 /* See local README for interface description. */
 139
 140 #include "../version.h"
 141
 142 void
 143 json_version_report(FILE *f)
 144 {
 145 fprintf(f, "Library version: json: Jansonn version %s\n", JANSSON_VERSION);
 146 }
 147
 148
 149 static lookup_info json_lookup_info = {
 150   US"json",                      /* lookup name */
 151   lookup_absfile,                /* uses absolute file name */
 152   json_open,                  /* open function */
 153   json_check,                 /* check function */
 154   json_find,                  /* find function */
 155   json_close,                 /* close function */
 156   NULL,                          /* no tidy function */
 157   NULL,                          /* no quoting function */
 158   json_version_report         /* version reporting */
 159 };
 160
 161
 162 #ifdef DYNLOOKUP
 163 #define json_lookup_module_info _lookup_module_info
 164 #endif
 165
 166 static lookup_info *_lookup_list[] = { &json_lookup_info };
 167 lookup_module_info json_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 168
 169 /* End of lookups/json.c */