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
48 int
cap_random_buf(cap_channel_t * chan,void * buf,size_t nbytes)49 cap_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
90 static int
random_command(const char * cmd,const nvlist_t * limits __unused,nvlist_t * nvlin,nvlist_t * nvlout)91 random_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
117 CREATE_SERVICE("system.random", NULL, random_command, 0);
118