4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
  24  * Copyright (c) 2015, Joyent, Inc.
  25  */
  26 
  27 /*
  28  * This file implements the interfaces that the /dev/random
  29  * driver uses for read(2), write(2) and poll(2) on /dev/random or
  30  * /dev/urandom. It also implements the kernel API - random_add_entropy(),
  31  * random_add_pseudo_entropy(), random_get_pseudo_bytes()
  32  * and random_get_bytes().
  33  *
  34  * We periodically collect random bits from providers which are registered
  35  * with the Kernel Cryptographic Framework (kCF) as capable of random
  36  * number generation. The random bits are maintained in a cache and
  37  * it is used for high quality random numbers (/dev/random) requests.
  38  * We pick a provider and call its SPI routine, if the cache does not have
  39  * enough bytes to satisfy a request.
  40  *
  41  * /dev/urandom requests use a software-based generator algorithm that uses the
  42  * random bits in the cache as a seed. We create one pseudo-random generator
  43  * (for /dev/urandom) per possible CPU on the system, and use it,
  44  * kmem-magazine-style, to avoid cache line contention.

 905  *
 906  * &rnd_pollhead is passed in *phpp in order to indicate the calling thread
 907  * will block. When enough random bytes are available, later, the timeout
 908  * handler routine will issue the pollwakeup() calls.
 909  */
 910 void
 911 kcf_rnd_chpoll(short events, int anyyet, short *reventsp,
 912     struct pollhead **phpp)
 913 {
 914         *reventsp = events & POLLOUT;
 915 
 916         if (events & (POLLIN | POLLRDNORM)) {
 917                 /*
 918                  * Sampling of rnbyte_cnt is an atomic
 919                  * operation. Hence we do not need any locking.
 920                  */
 921                 if (rnbyte_cnt >= MINEXTRACTBYTES)
 922                         *reventsp |= (events & (POLLIN | POLLRDNORM));
 923         }
 924 
 925         if (*reventsp == 0 && !anyyet)
 926                 *phpp = &rnd_pollhead;
 927 }
 928 
 929 /*ARGSUSED*/
 930 static void
 931 rnd_handler(void *arg)
 932 {
 933         int len = 0;
 934 
 935         if (!rng_prov_found && rng_ok_to_log) {
 936                 cmn_err(CE_WARN, "No randomness provider enabled for "
 937                     "/dev/random. Use cryptoadm(1M) to enable a provider.");
 938                 rng_ok_to_log = B_FALSE;
 939         }
 940 
 941         if (num_waiters > 0)
 942                 /*
 943                  * Note: len has no relationship with how many bytes
 944                  * a poll thread needs.
 945                  */

   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
  24  * Copyright 2017 Joyent, Inc.
  25  */
  26 
  27 /*
  28  * This file implements the interfaces that the /dev/random
  29  * driver uses for read(2), write(2) and poll(2) on /dev/random or
  30  * /dev/urandom. It also implements the kernel API - random_add_entropy(),
  31  * random_add_pseudo_entropy(), random_get_pseudo_bytes()
  32  * and random_get_bytes().
  33  *
  34  * We periodically collect random bits from providers which are registered
  35  * with the Kernel Cryptographic Framework (kCF) as capable of random
  36  * number generation. The random bits are maintained in a cache and
  37  * it is used for high quality random numbers (/dev/random) requests.
  38  * We pick a provider and call its SPI routine, if the cache does not have
  39  * enough bytes to satisfy a request.
  40  *
  41  * /dev/urandom requests use a software-based generator algorithm that uses the
  42  * random bits in the cache as a seed. We create one pseudo-random generator
  43  * (for /dev/urandom) per possible CPU on the system, and use it,
  44  * kmem-magazine-style, to avoid cache line contention.

 905  *
 906  * &rnd_pollhead is passed in *phpp in order to indicate the calling thread
 907  * will block. When enough random bytes are available, later, the timeout
 908  * handler routine will issue the pollwakeup() calls.
 909  */
 910 void
 911 kcf_rnd_chpoll(short events, int anyyet, short *reventsp,
 912     struct pollhead **phpp)
 913 {
 914         *reventsp = events & POLLOUT;
 915 
 916         if (events & (POLLIN | POLLRDNORM)) {
 917                 /*
 918                  * Sampling of rnbyte_cnt is an atomic
 919                  * operation. Hence we do not need any locking.
 920                  */
 921                 if (rnbyte_cnt >= MINEXTRACTBYTES)
 922                         *reventsp |= (events & (POLLIN | POLLRDNORM));
 923         }
 924 
 925         if ((*reventsp == 0 && !anyyet) || (events & POLLET))
 926                 *phpp = &rnd_pollhead;
 927 }
 928 
 929 /*ARGSUSED*/
 930 static void
 931 rnd_handler(void *arg)
 932 {
 933         int len = 0;
 934 
 935         if (!rng_prov_found && rng_ok_to_log) {
 936                 cmn_err(CE_WARN, "No randomness provider enabled for "
 937                     "/dev/random. Use cryptoadm(1M) to enable a provider.");
 938                 rng_ok_to_log = B_FALSE;
 939         }
 940 
 941         if (num_waiters > 0)
 942                 /*
 943                  * Note: len has no relationship with how many bytes
 944                  * a poll thread needs.
 945                  */