/* * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009 * The President and Fellows of Harvard College. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include "autoconf.h" /* * Machine-independent generic randomness device. * * Remembers something that's a random source, and provides random() * and randmax() to the rest of the kernel. * * The kernel config mechanism can be used to explicitly choose which * of the available random sources to use, if more than one is * available. */ static struct random_softc *the_random = NULL; /* * VFS device functions. * open: allow reading only. */ static int randeachopen(struct device *dev, int openflags) { (void)dev; if (openflags != O_RDONLY) { return EIO; } return 0; } /* * VFS I/O function. Hand off to implementation. */ static int randio(struct device *dev, struct uio *uio) { struct random_softc *rs = dev->d_data; if (uio->uio_rw != UIO_READ) { return EIO; } return rs->rs_read(rs->rs_devdata, uio); } /* * VFS ioctl function. */ static int randioctl(struct device *dev, int op, userptr_t data) { /* * We don't support any ioctls. */ (void)dev; (void)op; (void)data; return EIOCTL; } static const struct device_ops random_devops = { .devop_eachopen = randeachopen, .devop_io = randio, .devop_ioctl = randioctl, }; /* * Config function. */ int config_random(struct random_softc *rs, int unit) { int result; /* We use only the first random device. */ if (unit!=0) { return ENODEV; } KASSERT(the_random==NULL); the_random = rs; rs->rs_dev.d_ops = &random_devops; rs->rs_dev.d_blocks = 0; rs->rs_dev.d_blocksize = 1; rs->rs_dev.d_data = rs; /* Add the VFS device structure to the VFS device list. */ result = vfs_adddev("random", &rs->rs_dev, 0); if (result) { return result; } return 0; } /* * Random number functions exported to the rest of the kernel. */ uint32_t random(void) { if (the_random==NULL) { panic("No random device\n"); } return the_random->rs_random(the_random->rs_devdata); } uint32_t randmax(void) { if (the_random==NULL) { panic("No random device\n"); } return the_random->rs_randmax(the_random->rs_devdata); }