mdw@git.distorted.org.uk Git - secnet/blob - random.c

   1 /*
   2  * This file is part of secnet.
   3  * See README for full list of copyright holders.
   4  *
   5  * secnet is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * secnet is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * version 3 along with secnet; if not, see
  17  * https://www.gnu.org/licenses/gpl.html.
  18  */
  19
  20 #include "secnet.h"
  21 #include <stdio.h>
  22 #include <fcntl.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <unistd.h>
  26 #include <assert.h>
  27
  28 struct rgen_data {
  29     closure_t cl;
  30     struct random_if ops;
  31     struct cloc loc;
  32     int fd;
  33 };
  34
  35 static random_fn random_generate;
  36 static void random_generate(void *data, int32_t bytes, uint8_t *buff)
  37 {
  38     struct rgen_data *st=data;
  39     int r;
  40
  41     r= read(st->fd,buff,bytes);
  42
  43     assert(r == bytes);
  44     /* This is totally crap error checking, but callers of
  45      * this function do not check the return value and dealing
  46      * with failure of this everywhere would be very inconvenient.
  47      */
  48 }
  49
  50 static list_t *random_apply(closure_t *self, struct cloc loc,
  51                             dict_t *context, list_t *args)
  52 {
  53     struct rgen_data *st;
  54     item_t *arg1, *arg2;
  55     string_t filename=NULL;
  56
  57     NEW(st);
  58
  59     st->cl.description="randomsource";
  60     st->cl.type=CL_RANDOMSRC;
  61     st->cl.apply=NULL;
  62     st->cl.interface=&st->ops;
  63     st->ops.st=st;
  64     st->ops.blocking=False;
  65     st->ops.generate=random_generate;
  66     st->loc=loc;
  67
  68     arg1=list_elem(args,0);
  69     arg2=list_elem(args,1);
  70
  71     if (!arg1) {
  72         cfgfatal(loc,"randomsource","requires a filename\n");
  73     }
  74     if (arg1->type != t_string) {
  75         cfgfatal(arg1->loc,"randomsource",
  76                  "filename (arg1) must be a string\n");
  77     }
  78     filename=arg1->data.string;
  79
  80     if (arg2) {
  81         if (arg2->type != t_bool) {
  82             cfgfatal(arg2->loc,"randomsource",
  83                      "blocking parameter (arg2) must be bool\n");
  84         }
  85         st->ops.blocking=arg2->data.bool;
  86     }
  87
  88     if (!filename) {
  89         cfgfatal(loc,"randomsource","requires a filename\n");
  90     }
  91     st->fd=open(filename,O_RDONLY);
  92     if (st->fd<0) {
  93         fatal_perror("randomsource (%s:%d): cannot open %s",arg1->loc.file,
  94                      arg1->loc.line,filename);
  95     }
  96     return new_closure(&st->cl);
  97 }
  98
  99 void random_module(dict_t *d)
 100 {
 101     add_closure(d,"randomfile",random_apply);
 102 }