1/*- 2 * Copyright (c) 2013 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Pawel Jakub Dawidek under sponsorship from 6 * the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#include <sys/cdefs.h> 31__FBSDID("$FreeBSD$"); 32 33#include <sys/nv.h> 34 35#include <assert.h> 36#include <errno.h> 37#include <stdio.h> 38#include <stdlib.h> 39#include <string.h> 40 41#include <libcasper.h> 42#include <libcasper_service.h> 43 44#include "cap_random.h" 45 46#define MAXSIZE (1024 * 1024) 47 48int 49cap_random_buf(cap_channel_t *chan, void *buf, size_t nbytes) 50{ 51 nvlist_t *nvl; 52 const void *randbuf; 53 uint8_t *ptr; 54 size_t left, randbufsize; 55 56 left = nbytes; 57 ptr = buf; 58 59 while (left > 0) { 60 nvl = nvlist_create(0); 61 nvlist_add_string(nvl, "cmd", "generate"); 62 nvlist_add_number(nvl, "size", 63 (uint64_t)(left > MAXSIZE ? MAXSIZE : left)); 64 nvl = cap_xfer_nvlist(chan, nvl, 0); 65 if (nvl == NULL) 66 return (-1); 67 if (nvlist_get_number(nvl, "error") != 0) { 68 errno = (int)nvlist_get_number(nvl, "error"); 69 nvlist_destroy(nvl); 70 return (-1); 71 } 72 73 randbuf = nvlist_get_binary(nvl, "data", &randbufsize); 74 memcpy(ptr, randbuf, randbufsize); 75 76 nvlist_destroy(nvl); 77 78 ptr += randbufsize; 79 assert(left >= randbufsize); 80 left -= randbufsize; 81 } 82 83 return (0); 84} 85 86/* 87 * Service functions. 88 */ 89 90static int 91random_command(const char *cmd, const nvlist_t *limits __unused, 92 nvlist_t *nvlin, nvlist_t *nvlout) 93{ 94 void *data; 95 size_t size; 96 97 if (strcmp(cmd, "generate") != 0) 98 return (EINVAL); 99 if (!nvlist_exists_number(nvlin, "size")) 100 return (EINVAL); 101 102 size = (size_t)nvlist_get_number(nvlin, "size"); 103 if (size == 0 || size > MAXSIZE) 104 return (EINVAL); 105 106 data = malloc(size); 107 if (data == NULL) 108 return (ENOMEM); 109 110 arc4random_buf(data, size); 111 112 nvlist_move_binary(nvlout, "data", data, size); 113 114 return (0); 115} 116 117CREATE_SERVICE("system.random", NULL, random_command, 0); 118