src/src/lookups/nisplus.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* Copyright (c) The Exim Maintainers 2020 */
   7 /* See the file NOTICE for conditions of use and distribution. */
   8
   9 #include "../exim.h"
  10 #include "lf_functions.h"
  11
  12 #include <rpcsvc/nis.h>
  13
  14
  15 /*************************************************
  16 *              Open entry point                  *
  17 *************************************************/
  18
  19 /* See local README for interface description. */
  20
  21 static void *
  22 nisplus_open(const uschar * filename, uschar ** errmsg)
  23 {
  24 return (void *)(1);    /* Just return something non-null */
  25 }
  26
  27
  28
  29 /*************************************************
  30 *               Find entry point                 *
  31 *************************************************/
  32
  33 /* See local README for interface description. The format of queries for a
  34 NIS+ search is
  35
  36   [field=value,...],table-name
  37 or
  38   [field=value,...],table-name:result-field-name
  39
  40 in other words, a normal NIS+ "indexed name", with an optional result field
  41 name tagged on the end after a colon. If there is no result-field name, the
  42 yield is the concatenation of all the fields, preceded by their names and an
  43 equals sign. */
  44
  45 static int
  46 nisplus_find(void * handle, const uschar * filename, const uschar * query,
  47   int length, uschar ** result, uschar ** errmsg, uint * do_cache,
  48   const uschar * opts)
  49 {
  50 int error_error = FAIL;
  51 const uschar * field_name = NULL;
  52 nis_result *nrt = NULL;
  53 nis_result *nre = NULL;
  54 nis_object *tno, *eno;
  55 struct entry_obj *eo;
  56 struct table_obj *ta;
  57 const uschar * p = query + length;
  58 gstring * yield = NULL;
  59
  60 do_cache = do_cache;   /* Placate picky compilers */
  61
  62 /* Search backwards for a colon to see if a result field name
  63 has been given. */
  64
  65 while (p > query && p[-1] != ':') p--;
  66
  67 if (p > query)          /* get the query without the result-field */
  68   {
  69   uint len = p-1 - query;
  70   field_name = p;
  71   query = string_copyn(query, len);
  72   p = query + len;
  73   }
  74 else
  75   p = query + length;
  76
  77 /* Now search backwards to find the comma that starts the
  78 table name. */
  79
  80 while (p > query && p[-1] != ',') p--;
  81 if (p <= query)
  82   {
  83   *errmsg = US"NIS+ query malformed";
  84   error_error = DEFER;
  85   goto NISPLUS_EXIT;
  86   }
  87
  88 /* Look up the data for the table, in order to get the field names,
  89 check that we got back a table, and set up pointers so the field
  90 names can be scanned. */
  91
  92 nrt = nis_lookup(CS p, EXPAND_NAME | NO_CACHE);
  93 if (nrt->status != NIS_SUCCESS)
  94   {
  95   *errmsg = string_sprintf("NIS+ error accessing %s table: %s", p,
  96     nis_sperrno(nrt->status));
  97   if (nrt->status != NIS_NOTFOUND && nrt->status != NIS_NOSUCHTABLE)
  98     error_error = DEFER;
  99   goto NISPLUS_EXIT;
 100   }
 101 tno = nrt->objects.objects_val;
 102 if (tno->zo_data.zo_type != TABLE_OBJ)
 103   {
 104   *errmsg = string_sprintf("NIS+ error: %s is not a table", p);
 105   goto NISPLUS_EXIT;
 106   }
 107 ta = &tno->zo_data.objdata_u.ta_data;
 108
 109 /* Now look up the entry in the table, check that we got precisely one
 110 object and that it is a table entry. */
 111
 112 nre = nis_list(CS query, EXPAND_NAME, NULL, NULL);
 113 if (nre->status != NIS_SUCCESS)
 114   {
 115   *errmsg = string_sprintf("NIS+ error accessing entry %s: %s",
 116     query, nis_sperrno(nre->status));
 117   goto NISPLUS_EXIT;
 118   }
 119 if (nre->objects.objects_len > 1)
 120   {
 121   *errmsg = string_sprintf("NIS+ returned more than one object for %s",
 122     query);
 123   goto NISPLUS_EXIT;
 124   }
 125 else if (nre->objects.objects_len < 1)
 126   {
 127   *errmsg = string_sprintf("NIS+ returned no data for %s", query);
 128   goto NISPLUS_EXIT;
 129   }
 130 eno = nre->objects.objects_val;
 131 if (eno->zo_data.zo_type != ENTRY_OBJ)
 132   {
 133   *errmsg = string_sprintf("NIS+ error: %s is not an entry", query);
 134   goto NISPLUS_EXIT;
 135   }
 136
 137 /* Scan the columns in the entry and in the table. If a result field
 138 was given, look for that field; otherwise concatenate all the fields
 139 with their names. */
 140
 141 eo = &(eno->zo_data.objdata_u.en_data);
 142 for (int i = 0; i < eo->en_cols.en_cols_len; i++)
 143   {
 144   table_col *tc = ta->ta_cols.ta_cols_val + i;
 145   entry_col *ec = eo->en_cols.en_cols_val + i;
 146   int len = ec->ec_value.ec_value_len;
 147   uschar *value = US ec->ec_value.ec_value_val;
 148
 149   /* The value may be NULL for a zero-length field. Turn this into an
 150   empty string for consistency. Remove trailing whitespace and zero
 151   bytes. */
 152
 153   if (!value) value = US"";
 154   else
 155     while (len > 0 && (value[len-1] == 0 || isspace(value[len-1])))
 156       len--;
 157
 158   /* Concatenate all fields if no specific one selected */
 159
 160   if (!field_name)
 161     {
 162     yield = string_cat (yield, US tc->tc_name);
 163     yield = string_catn(yield, US"=", 1);
 164
 165     /* Quote the value if it contains spaces or is empty */
 166
 167     if (value[0] == 0 || Ustrchr(value, ' ') != NULL)
 168       {
 169       yield = string_catn(yield, US"\"", 1);
 170       for (int j = 0; j < len; j++)
 171         {
 172         if (value[j] == '\"' || value[j] == '\\')
 173           yield = string_catn(yield, US"\\", 1);
 174         yield = string_catn(yield, value+j, 1);
 175         }
 176       yield = string_catn(yield, US"\"", 1);
 177       }
 178     else
 179       yield = string_catn(yield, value, len);
 180
 181     yield = string_catn(yield, US" ", 1);
 182     }
 183
 184   /* When the specified field is found, grab its data and finish */
 185
 186   else if (Ustrcmp(field_name, tc->tc_name) == 0)
 187     {
 188     yield = string_catn(yield, value, len);
 189     goto NISPLUS_EXIT;
 190     }
 191   }
 192
 193 /* Error if a field name was specified and we didn't find it; if no
 194 field name, ensure the concatenated data is zero-terminated. */
 195
 196 if (field_name)
 197   *errmsg = string_sprintf("NIS+ field %s not found for %s", field_name,
 198     query);
 199 else
 200   gstring_release_unused(yield);
 201
 202 /* Free result store before finishing. */
 203
 204 NISPLUS_EXIT:
 205 if (nrt) nis_freeresult(nrt);
 206 if (nre) nis_freeresult(nre);
 207
 208 if (yield)
 209   {
 210   *result = string_from_gstring(yield);
 211   return OK;
 212   }
 213
 214 return error_error;      /* FAIL or DEFER */
 215 }
 216
 217
 218
 219 /*************************************************
 220 *               Quote entry point                *
 221 *************************************************/
 222
 223 /* The only quoting that is necessary for NIS+ is to double any doublequote
 224 characters. No options are recognized.
 225
 226 Arguments:
 227   s          the string to be quoted
 228   opt        additional option text or NULL if none
 229
 230 Returns:     the processed string or NULL for a bad option
 231 */
 232
 233 static uschar *
 234 nisplus_quote(uschar *s, uschar *opt)
 235 {
 236 int count = 0;
 237 uschar *quoted;
 238 uschar *t = s;
 239
 240 if (opt != NULL) return NULL;    /* No options recognized */
 241
 242 while (*t != 0) if (*t++ == '\"') count++;
 243 if (count == 0) return s;
 244
 245 t = quoted = store_get(Ustrlen(s) + count + 1, is_tainted(s));
 246
 247 while (*s != 0)
 248   {
 249   *t++ = *s;
 250   if (*s++ == '\"') *t++ = '\"';
 251   }
 252
 253 *t = 0;
 254 return quoted;
 255 }
 256
 257
 258 /*************************************************
 259 *         Version reporting entry point          *
 260 *************************************************/
 261
 262 /* See local README for interface description. */
 263
 264 #include "../version.h"
 265
 266 void
 267 nisplus_version_report(FILE *f)
 268 {
 269 #ifdef DYNLOOKUP
 270 fprintf(f, "Library version: NIS+: Exim version %s\n", EXIM_VERSION_STR);
 271 #endif
 272 }
 273
 274
 275 static lookup_info _lookup_info = {
 276   .name = US"nisplus",                  /* lookup name */
 277   .type = lookup_querystyle,            /* query-style lookup */
 278   .open = nisplus_open,                 /* open function */
 279   .check = NULL,                        /* check function */
 280   .find = nisplus_find,                 /* find function */
 281   .close = NULL,                        /* no close function */
 282   .tidy = NULL,                         /* no tidy function */
 283   .quote = nisplus_quote,               /* quoting function */
 284   .version_report = nisplus_version_report         /* version reporting */
 285 };
 286
 287 #ifdef DYNLOOKUP
 288 #define nisplus_lookup_module_info _lookup_module_info
 289 #endif
 290
 291 static lookup_info *_lookup_list[] = { &_lookup_info };
 292 lookup_module_info nisplus_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 293
 294 /* End of lookups/nisplus.c */