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git.proxmox.com Git - ovs.git/blob - lib/entropy.c
1 /* Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
24 #include "socket-util.h"
27 VLOG_DEFINE_THIS_MODULE(entropy
);
29 static const char urandom
[] = "/dev/urandom";
31 /* Initializes 'buffer' with 'n' bytes of high-quality random numbers. Returns
32 * 0 if successful, otherwise a positive errno value or EOF on error. */
34 get_entropy(void *buffer
, size_t n
)
40 fd
= open(urandom
, O_RDONLY
);
42 VLOG_ERR("%s: open failed (%s)", urandom
, strerror(errno
));
43 return errno
? errno
: EINVAL
;
46 error
= read_fully(fd
, buffer
, n
, &bytes_read
);
50 VLOG_ERR("%s: read error (%s)", urandom
, ovs_retval_to_string(error
));
55 /* Initializes 'buffer' with 'n' bytes of high-quality random numbers. Exits
56 * if an error occurs. */
58 get_entropy_or_die(void *buffer
, size_t n
)
60 int error
= get_entropy(buffer
, n
);
62 VLOG_FATAL("%s: read error (%s)",
63 urandom
, ovs_retval_to_string(error
));