freebsd-dev/usr.sbin/bhyve/pci_virtio_rnd.c
Marcelo Araujo abfa3c39e7 Use capsicum_helpers(3) that allow us to simplify the code and its functions
will return success when the kernel is built without support of
the capability mode.

It is important to note, that I'm taking a more conservative approach
with these changes and it will be done in small steps.

Reviewed by:	jhb
MFC after:	6 weeks
Differential Revision:	https://reviews.freebsd.org/D18744
2019-01-16 00:39:23 +00:00

210 lines
5.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2014 Nahanni Systems Inc.
* 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 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 AUTHOR 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.
*/
/*
* virtio entropy device emulation.
* Randomness is sourced from /dev/random which does not block
* once it has been seeded at bootup.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#ifndef WITHOUT_CAPSICUM
#include <sys/capsicum.h>
#endif
#include <sys/linker_set.h>
#include <sys/uio.h>
#ifndef WITHOUT_CAPSICUM
#include <capsicum_helpers.h>
#endif
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <pthread.h>
#include <sysexits.h>
#include "bhyverun.h"
#include "pci_emul.h"
#include "virtio.h"
#define VTRND_RINGSZ 64
static int pci_vtrnd_debug;
#define DPRINTF(params) if (pci_vtrnd_debug) printf params
#define WPRINTF(params) printf params
/*
* Per-device softc
*/
struct pci_vtrnd_softc {
struct virtio_softc vrsc_vs;
struct vqueue_info vrsc_vq;
pthread_mutex_t vrsc_mtx;
uint64_t vrsc_cfg;
int vrsc_fd;
};
static void pci_vtrnd_reset(void *);
static void pci_vtrnd_notify(void *, struct vqueue_info *);
static struct virtio_consts vtrnd_vi_consts = {
"vtrnd", /* our name */
1, /* we support 1 virtqueue */
0, /* config reg size */
pci_vtrnd_reset, /* reset */
pci_vtrnd_notify, /* device-wide qnotify */
NULL, /* read virtio config */
NULL, /* write virtio config */
NULL, /* apply negotiated features */
0, /* our capabilities */
};
static void
pci_vtrnd_reset(void *vsc)
{
struct pci_vtrnd_softc *sc;
sc = vsc;
DPRINTF(("vtrnd: device reset requested !\n"));
vi_reset_dev(&sc->vrsc_vs);
}
static void
pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
{
struct iovec iov;
struct pci_vtrnd_softc *sc;
int len;
uint16_t idx;
sc = vsc;
if (sc->vrsc_fd < 0) {
vq_endchains(vq, 0);
return;
}
while (vq_has_descs(vq)) {
vq_getchain(vq, &idx, &iov, 1, NULL);
len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len);
DPRINTF(("vtrnd: vtrnd_notify(): %d\r\n", len));
/* Catastrophe if unable to read from /dev/random */
assert(len > 0);
/*
* Release this chain and handle more
*/
vq_relchain(vq, idx, len);
}
vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
}
static int
pci_vtrnd_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
struct pci_vtrnd_softc *sc;
int fd;
int len;
uint8_t v;
#ifndef WITHOUT_CAPSICUM
cap_rights_t rights;
#endif
/*
* Should always be able to open /dev/random.
*/
fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
assert(fd >= 0);
#ifndef WITHOUT_CAPSICUM
cap_rights_init(&rights, CAP_READ);
if (caph_rights_limit(fd, &rights) == -1)
errx(EX_OSERR, "Unable to apply rights for sandbox");
#endif
/*
* Check that device is seeded and non-blocking.
*/
len = read(fd, &v, sizeof(v));
if (len <= 0) {
WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len));
close(fd);
return (1);
}
sc = calloc(1, sizeof(struct pci_vtrnd_softc));
vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq);
sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx;
sc->vrsc_vq.vq_qsize = VTRND_RINGSZ;
/* keep /dev/random opened while emulating */
sc->vrsc_fd = fd;
/* initialize config space */
pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_RANDOM);
pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_CRYPTO);
pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_ENTROPY);
pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix()))
return (1);
vi_set_io_bar(&sc->vrsc_vs, 0);
return (0);
}
struct pci_devemu pci_de_vrnd = {
.pe_emu = "virtio-rnd",
.pe_init = pci_vtrnd_init,
.pe_barwrite = vi_pci_write,
.pe_barread = vi_pci_read
};
PCI_EMUL_SET(pci_de_vrnd);