1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2013 The FreeBSD Foundation
5 * All rights reserved.
6 *
7 * This software was developed by Pawel Jakub Dawidek under sponsorship from
8 * the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include <sys/nv.h>
36
37 #include <assert.h>
38 #include <errno.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42
43 #include <libcasper.h>
44 #include <libcasper_service.h>
45
46 #include "cap_random.h"
47
48 #define MAXSIZE (1024 * 1024)
49
50 int
cap_random_buf(cap_channel_t * chan,void * buf,size_t nbytes)51 cap_random_buf(cap_channel_t *chan, void *buf, size_t nbytes)
52 {
53 nvlist_t *nvl;
54 const void *randbuf;
55 uint8_t *ptr;
56 size_t left, randbufsize;
57
58 left = nbytes;
59 ptr = buf;
60
61 while (left > 0) {
62 nvl = nvlist_create(0);
63 nvlist_add_string(nvl, "cmd", "generate");
64 nvlist_add_number(nvl, "size",
65 (uint64_t)(left > MAXSIZE ? MAXSIZE : left));
66 nvl = cap_xfer_nvlist(chan, nvl);
67 if (nvl == NULL)
68 return (-1);
69 if (nvlist_get_number(nvl, "error") != 0) {
70 errno = (int)nvlist_get_number(nvl, "error");
71 nvlist_destroy(nvl);
72 return (-1);
73 }
74
75 randbuf = nvlist_get_binary(nvl, "data", &randbufsize);
76 memcpy(ptr, randbuf, randbufsize);
77
78 nvlist_destroy(nvl);
79
80 ptr += randbufsize;
81 assert(left >= randbufsize);
82 left -= randbufsize;
83 }
84
85 return (0);
86 }
87
88 /*
89 * Service functions.
90 */
91
92 static int
random_command(const char * cmd,const nvlist_t * limits __unused,nvlist_t * nvlin,nvlist_t * nvlout)93 random_command(const char *cmd, const nvlist_t *limits __unused,
94 nvlist_t *nvlin, nvlist_t *nvlout)
95 {
96 void *data;
97 size_t size;
98
99 if (strcmp(cmd, "generate") != 0)
100 return (EINVAL);
101 if (!nvlist_exists_number(nvlin, "size"))
102 return (EINVAL);
103
104 size = (size_t)nvlist_get_number(nvlin, "size");
105 if (size == 0 || size > MAXSIZE)
106 return (EINVAL);
107
108 data = malloc(size);
109 if (data == NULL)
110 return (ENOMEM);
111
112 arc4random_buf(data, size);
113
114 nvlist_move_binary(nvlout, "data", data, size);
115
116 return (0);
117 }
118
119 CREATE_SERVICE("system.random", NULL, random_command, 0);
120