1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2014 Nahanni Systems Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * virtio entropy device emulation. 32 * Randomness is sourced from /dev/random which does not block 33 * once it has been seeded at bootup. 34 */ 35 36 #include <sys/param.h> 37 #ifndef WITHOUT_CAPSICUM 38 #include <sys/capsicum.h> 39 #endif 40 #include <sys/linker_set.h> 41 #include <sys/uio.h> 42 43 #ifndef WITHOUT_CAPSICUM 44 #include <capsicum_helpers.h> 45 #endif 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <assert.h> 54 #include <pthread.h> 55 #include <sysexits.h> 56 57 #include "bhyverun.h" 58 #include "debug.h" 59 #include "pci_emul.h" 60 #include "virtio.h" 61 62 #define VTRND_RINGSZ 64 63 64 65 static int pci_vtrnd_debug; 66 #define DPRINTF(params) if (pci_vtrnd_debug) PRINTLN params 67 #define WPRINTF(params) PRINTLN params 68 69 /* 70 * Per-device softc 71 */ 72 struct pci_vtrnd_softc { 73 struct virtio_softc vrsc_vs; 74 struct vqueue_info vrsc_vq; 75 pthread_mutex_t vrsc_mtx; 76 uint64_t vrsc_cfg; 77 int vrsc_fd; 78 }; 79 80 static void pci_vtrnd_reset(void *); 81 static void pci_vtrnd_notify(void *, struct vqueue_info *); 82 83 static struct virtio_consts vtrnd_vi_consts = { 84 .vc_name = "vtrnd", 85 .vc_nvq = 1, 86 .vc_cfgsize = 0, 87 .vc_reset = pci_vtrnd_reset, 88 .vc_qnotify = pci_vtrnd_notify, 89 .vc_hv_caps = 0, 90 }; 91 92 static void 93 pci_vtrnd_reset(void *vsc) 94 { 95 struct pci_vtrnd_softc *sc; 96 97 sc = vsc; 98 99 DPRINTF(("vtrnd: device reset requested !")); 100 vi_reset_dev(&sc->vrsc_vs); 101 } 102 103 104 static void 105 pci_vtrnd_notify(void *vsc, struct vqueue_info *vq) 106 { 107 struct iovec iov; 108 struct pci_vtrnd_softc *sc; 109 struct vi_req req; 110 int len, n; 111 112 sc = vsc; 113 114 if (sc->vrsc_fd < 0) { 115 vq_endchains(vq, 0); 116 return; 117 } 118 119 while (vq_has_descs(vq)) { 120 n = vq_getchain(vq, &iov, 1, &req); 121 assert(n == 1); 122 123 len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len); 124 125 DPRINTF(("vtrnd: vtrnd_notify(): %d", len)); 126 127 /* Catastrophe if unable to read from /dev/random */ 128 assert(len > 0); 129 130 /* 131 * Release this chain and handle more 132 */ 133 vq_relchain(vq, req.idx, len); 134 } 135 vq_endchains(vq, 1); /* Generate interrupt if appropriate. */ 136 } 137 138 139 static int 140 pci_vtrnd_init(struct pci_devinst *pi, nvlist_t *nvl __unused) 141 { 142 struct pci_vtrnd_softc *sc; 143 int fd; 144 int len; 145 uint8_t v; 146 #ifndef WITHOUT_CAPSICUM 147 cap_rights_t rights; 148 #endif 149 150 /* 151 * Should always be able to open /dev/random. 152 */ 153 fd = open("/dev/random", O_RDONLY | O_NONBLOCK); 154 155 assert(fd >= 0); 156 157 #ifndef WITHOUT_CAPSICUM 158 cap_rights_init(&rights, CAP_READ); 159 if (caph_rights_limit(fd, &rights) == -1) 160 errx(EX_OSERR, "Unable to apply rights for sandbox"); 161 #endif 162 163 /* 164 * Check that device is seeded and non-blocking. 165 */ 166 len = read(fd, &v, sizeof(v)); 167 if (len <= 0) { 168 WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len)); 169 close(fd); 170 return (1); 171 } 172 173 sc = calloc(1, sizeof(struct pci_vtrnd_softc)); 174 175 pthread_mutex_init(&sc->vrsc_mtx, NULL); 176 177 vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq); 178 sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx; 179 180 sc->vrsc_vq.vq_qsize = VTRND_RINGSZ; 181 182 /* keep /dev/random opened while emulating */ 183 sc->vrsc_fd = fd; 184 185 /* initialize config space */ 186 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_RANDOM); 187 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR); 188 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_CRYPTO); 189 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_ENTROPY); 190 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR); 191 192 if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix())) 193 return (1); 194 vi_set_io_bar(&sc->vrsc_vs, 0); 195 196 return (0); 197 } 198 199 200 static const struct pci_devemu pci_de_vrnd = { 201 .pe_emu = "virtio-rnd", 202 .pe_init = pci_vtrnd_init, 203 .pe_barwrite = vi_pci_write, 204 .pe_barread = vi_pci_read, 205 #ifdef BHYVE_SNAPSHOT 206 .pe_snapshot = vi_pci_snapshot, 207 #endif 208 }; 209 PCI_EMUL_SET(pci_de_vrnd); 210