diff options
Diffstat (limited to 'sys/dev/random/randomdev.c')
| -rw-r--r-- | sys/dev/random/randomdev.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/sys/dev/random/randomdev.c b/sys/dev/random/randomdev.c new file mode 100644 index 000000000000..99c4ea6260de --- /dev/null +++ b/sys/dev/random/randomdev.c @@ -0,0 +1,223 @@ +/*- + * Copyright (c) 2000-2004 Mark R V Murray + * All rights reserved. + * + * 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 + * in this position and unchanged. + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bus.h> +#include <sys/conf.h> +#include <sys/fcntl.h> +#include <sys/filio.h> +#include <sys/kernel.h> +#include <sys/kthread.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/module.h> +#include <sys/mutex.h> +#include <sys/poll.h> +#include <sys/priv.h> +#include <sys/proc.h> +#include <sys/selinfo.h> +#include <sys/uio.h> +#include <sys/unistd.h> + +#include <machine/bus.h> +#include <machine/cpu.h> + +#include <dev/random/randomdev.h> + +#define RANDOM_MINOR 0 + +static d_close_t random_close; +static d_read_t random_read; +static d_write_t random_write; +static d_ioctl_t random_ioctl; +static d_poll_t random_poll; + +static struct cdevsw random_cdevsw = { + .d_version = D_VERSION, + .d_close = random_close, + .d_read = random_read, + .d_write = random_write, + .d_ioctl = random_ioctl, + .d_poll = random_poll, + .d_name = "random", +}; + +struct random_systat random_systat; + +/* For use with make_dev(9)/destroy_dev(9). */ +static struct cdev *random_dev; + +/* Used to fake out unused random calls in random_systat */ +void +random_null_func(void) +{ +} + +/* ARGSUSED */ +static int +random_close(struct cdev *dev __unused, int flags, int fmt __unused, + struct thread *td) +{ + if ((flags & FWRITE) && (priv_check(td, PRIV_RANDOM_RESEED) == 0) + && (securelevel_gt(td->td_ucred, 0) == 0)) { + (*random_systat.reseed)(); + random_systat.seeded = 1; + arc4rand(NULL, 0, 1); /* Reseed arc4random as well. */ + } + + return (0); +} + +/* ARGSUSED */ +static int +random_read(struct cdev *dev __unused, struct uio *uio, int flag) +{ + int c, error = 0; + void *random_buf; + + /* Blocking logic */ + if (!random_systat.seeded) + error = (*random_systat.block)(flag); + + /* The actual read */ + if (!error) { + + random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); + + while (uio->uio_resid > 0 && !error) { + c = MIN(uio->uio_resid, PAGE_SIZE); + c = (*random_systat.read)(random_buf, c); + error = uiomove(random_buf, c, uio); + } + + free(random_buf, M_TEMP); + + } + + return (error); +} + +/* ARGSUSED */ +static int +random_write(struct cdev *dev __unused, struct uio *uio, int flag __unused) +{ + int c, error = 0; + void *random_buf; + + random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); + + while (uio->uio_resid > 0) { + c = MIN((int)uio->uio_resid, PAGE_SIZE); + error = uiomove(random_buf, c, uio); + if (error) + break; + (*random_systat.write)(random_buf, c); + } + + free(random_buf, M_TEMP); + + return (error); +} + +/* ARGSUSED */ +static int +random_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr __unused, + int flags __unused, struct thread *td __unused) +{ + int error = 0; + + switch (cmd) { + /* Really handled in upper layer */ + case FIOASYNC: + case FIONBIO: + break; + default: + error = ENOTTY; + } + return (error); +} + +/* ARGSUSED */ +static int +random_poll(struct cdev *dev __unused, int events, struct thread *td) +{ + int revents = 0; + + if (events & (POLLIN | POLLRDNORM)) { + if (random_systat.seeded) + revents = events & (POLLIN | POLLRDNORM); + else + revents = (*random_systat.poll) (events,td); + } + return (revents); +} + +/* ARGSUSED */ +static int +random_modevent(module_t mod __unused, int type, void *data __unused) +{ + int error = 0; + + switch (type) { + case MOD_LOAD: + random_ident_hardware(&random_systat); + (*random_systat.init)(); + + if (bootverbose) + printf("random: <entropy source, %s>\n", + random_systat.ident); + + random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, + UID_ROOT, GID_WHEEL, 0666, "random"); + make_dev_alias(random_dev, "urandom"); /* XXX Deprecated */ + + break; + + case MOD_UNLOAD: + (*random_systat.deinit)(); + + destroy_dev(random_dev); + + break; + + case MOD_SHUTDOWN: + break; + + default: + error = EOPNOTSUPP; + break; + + } + return (error); +} + +DEV_MODULE(random, random_modevent, NULL); +MODULE_VERSION(random, 1); |