cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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vhost-user-scsi.c (10592B)

      1/*
      2 * vhost-user-scsi sample application
      3 *
      4 * Copyright (c) 2016 Nutanix Inc. All rights reserved.
      5 *
      6 * Author:
      7 *  Felipe Franciosi <felipe@nutanix.com>
      8 *
      9 * This work is licensed under the terms of the GNU GPL, version 2 only.
     10 * See the COPYING file in the top-level directory.
     11 */
     12
     13#include "qemu/osdep.h"
     14#include <iscsi/iscsi.h>
     15#define inline __attribute__((gnu_inline))  /* required for libiscsi v1.9.0 */
     16#include <iscsi/scsi-lowlevel.h>
     17#undef inline
     18#include "libvhost-user-glib.h"
     19#include "standard-headers/linux/virtio_scsi.h"
     20
     21
     22#define VUS_ISCSI_INITIATOR "iqn.2016-11.com.nutanix:vhost-user-scsi"
     23
     24enum {
     25    VHOST_USER_SCSI_MAX_QUEUES = 8,
     26};
     27
     28typedef struct VusIscsiLun {
     29    struct iscsi_context *iscsi_ctx;
     30    int iscsi_lun;
     31} VusIscsiLun;
     32
     33typedef struct VusDev {
     34    VugDev parent;
     35
     36    VusIscsiLun lun;
     37    GMainLoop *loop;
     38} VusDev;
     39
     40/** libiscsi integration **/
     41
     42typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq;
     43typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp;
     44
     45static int vus_iscsi_add_lun(VusIscsiLun *lun, char *iscsi_uri)
     46{
     47    struct iscsi_url *iscsi_url;
     48    struct iscsi_context *iscsi_ctx;
     49    int ret = 0;
     50
     51    assert(lun);
     52    assert(iscsi_uri);
     53    assert(!lun->iscsi_ctx);
     54
     55    iscsi_ctx = iscsi_create_context(VUS_ISCSI_INITIATOR);
     56    if (!iscsi_ctx) {
     57        g_warning("Unable to create iSCSI context");
     58        return -1;
     59    }
     60
     61    iscsi_url = iscsi_parse_full_url(iscsi_ctx, iscsi_uri);
     62    if (!iscsi_url) {
     63        g_warning("Unable to parse iSCSI URL: %s", iscsi_get_error(iscsi_ctx));
     64        goto fail;
     65    }
     66
     67    iscsi_set_session_type(iscsi_ctx, ISCSI_SESSION_NORMAL);
     68    iscsi_set_header_digest(iscsi_ctx, ISCSI_HEADER_DIGEST_NONE_CRC32C);
     69    if (iscsi_full_connect_sync(iscsi_ctx, iscsi_url->portal, iscsi_url->lun)) {
     70        g_warning("Unable to login to iSCSI portal: %s",
     71                  iscsi_get_error(iscsi_ctx));
     72        goto fail;
     73    }
     74
     75    lun->iscsi_ctx = iscsi_ctx;
     76    lun->iscsi_lun = iscsi_url->lun;
     77
     78    g_debug("Context %p created for lun 0: %s", iscsi_ctx, iscsi_uri);
     79
     80out:
     81    if (iscsi_url) {
     82        iscsi_destroy_url(iscsi_url);
     83    }
     84    return ret;
     85
     86fail:
     87    (void)iscsi_destroy_context(iscsi_ctx);
     88    ret = -1;
     89    goto out;
     90}
     91
     92static struct scsi_task *scsi_task_new(int cdb_len, uint8_t *cdb, int dir,
     93                                       int xfer_len)
     94{
     95    struct scsi_task *task;
     96
     97    assert(cdb_len > 0);
     98    assert(cdb);
     99
    100    task = g_new0(struct scsi_task, 1);
    101    memcpy(task->cdb, cdb, cdb_len);
    102    task->cdb_size = cdb_len;
    103    task->xfer_dir = dir;
    104    task->expxferlen = xfer_len;
    105
    106    return task;
    107}
    108
    109static int get_cdb_len(uint8_t *cdb)
    110{
    111    assert(cdb);
    112
    113    switch (cdb[0] >> 5) {
    114    case 0: return 6;
    115    case 1: /* fall through */
    116    case 2: return 10;
    117    case 4: return 16;
    118    case 5: return 12;
    119    }
    120    g_warning("Unable to determine cdb len (0x%02hhX)", (uint8_t)(cdb[0] >> 5));
    121    return -1;
    122}
    123
    124static int handle_cmd_sync(struct iscsi_context *ctx,
    125                           VirtIOSCSICmdReq *req,
    126                           struct iovec *out, unsigned int out_len,
    127                           VirtIOSCSICmdResp *rsp,
    128                           struct iovec *in, unsigned int in_len)
    129{
    130    struct scsi_task *task;
    131    uint32_t dir;
    132    uint32_t len;
    133    int cdb_len;
    134    int i;
    135
    136    assert(ctx);
    137    assert(req);
    138    assert(rsp);
    139
    140    if (!(!req->lun[1] && req->lun[2] == 0x40 && !req->lun[3])) {
    141        /* Ignore anything different than target=0, lun=0 */
    142        g_debug("Ignoring unconnected lun (0x%hhX, 0x%hhX)",
    143             req->lun[1], req->lun[3]);
    144        rsp->status = SCSI_STATUS_CHECK_CONDITION;
    145        memset(rsp->sense, 0, sizeof(rsp->sense));
    146        rsp->sense_len = 18;
    147        rsp->sense[0] = 0x70;
    148        rsp->sense[2] = SCSI_SENSE_ILLEGAL_REQUEST;
    149        rsp->sense[7] = 10;
    150        rsp->sense[12] = 0x24;
    151
    152        return 0;
    153    }
    154
    155    cdb_len = get_cdb_len(req->cdb);
    156    if (cdb_len == -1) {
    157        return -1;
    158    }
    159
    160    len = 0;
    161    if (!out_len && !in_len) {
    162        dir = SCSI_XFER_NONE;
    163    } else if (out_len) {
    164        dir = SCSI_XFER_WRITE;
    165        for (i = 0; i < out_len; i++) {
    166            len += out[i].iov_len;
    167        }
    168    } else {
    169        dir = SCSI_XFER_READ;
    170        for (i = 0; i < in_len; i++) {
    171            len += in[i].iov_len;
    172        }
    173    }
    174
    175    task = scsi_task_new(cdb_len, req->cdb, dir, len);
    176
    177    if (dir == SCSI_XFER_WRITE) {
    178        task->iovector_out.iov = (struct scsi_iovec *)out;
    179        task->iovector_out.niov = out_len;
    180    } else if (dir == SCSI_XFER_READ) {
    181        task->iovector_in.iov = (struct scsi_iovec *)in;
    182        task->iovector_in.niov = in_len;
    183    }
    184
    185    g_debug("Sending iscsi cmd (cdb_len=%d, dir=%d, task=%p)",
    186         cdb_len, dir, task);
    187    if (!iscsi_scsi_command_sync(ctx, 0, task, NULL)) {
    188        g_warning("Error serving SCSI command");
    189        g_free(task);
    190        return -1;
    191    }
    192
    193    memset(rsp, 0, sizeof(*rsp));
    194
    195    rsp->status = task->status;
    196    rsp->resid  = task->residual;
    197
    198    if (task->status == SCSI_STATUS_CHECK_CONDITION) {
    199        rsp->response = VIRTIO_SCSI_S_FAILURE;
    200        rsp->sense_len = task->datain.size - 2;
    201        memcpy(rsp->sense, &task->datain.data[2], rsp->sense_len);
    202    }
    203
    204    g_free(task);
    205
    206    g_debug("Filled in rsp: status=%hhX, resid=%u, response=%hhX, sense_len=%u",
    207         rsp->status, rsp->resid, rsp->response, rsp->sense_len);
    208
    209    return 0;
    210}
    211
    212/** libvhost-user callbacks **/
    213
    214static void vus_panic_cb(VuDev *vu_dev, const char *buf)
    215{
    216    VugDev *gdev;
    217    VusDev *vdev_scsi;
    218
    219    assert(vu_dev);
    220
    221    gdev = container_of(vu_dev, VugDev, parent);
    222    vdev_scsi = container_of(gdev, VusDev, parent);
    223    if (buf) {
    224        g_warning("vu_panic: %s", buf);
    225    }
    226
    227    g_main_loop_quit(vdev_scsi->loop);
    228}
    229
    230static void vus_proc_req(VuDev *vu_dev, int idx)
    231{
    232    VugDev *gdev;
    233    VusDev *vdev_scsi;
    234    VuVirtq *vq;
    235    VuVirtqElement *elem = NULL;
    236
    237    assert(vu_dev);
    238
    239    gdev = container_of(vu_dev, VugDev, parent);
    240    vdev_scsi = container_of(gdev, VusDev, parent);
    241
    242    vq = vu_get_queue(vu_dev, idx);
    243    if (!vq) {
    244        g_warning("Error fetching VQ (dev=%p, idx=%d)", vu_dev, idx);
    245        vus_panic_cb(vu_dev, NULL);
    246        return;
    247    }
    248
    249    g_debug("Got kicked on vq[%d]@%p", idx, vq);
    250
    251    while (1) {
    252        VirtIOSCSICmdReq *req;
    253        VirtIOSCSICmdResp *rsp;
    254
    255        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement));
    256        if (!elem) {
    257            g_debug("No more elements pending on vq[%d]@%p", idx, vq);
    258            break;
    259        }
    260        g_debug("Popped elem@%p", elem);
    261
    262        assert(!(elem->out_num > 1 && elem->in_num > 1));
    263        assert(elem->out_num > 0 && elem->in_num > 0);
    264
    265        if (elem->out_sg[0].iov_len < sizeof(VirtIOSCSICmdReq)) {
    266            g_warning("Invalid virtio-scsi req header");
    267            vus_panic_cb(vu_dev, NULL);
    268            break;
    269        }
    270        req = (VirtIOSCSICmdReq *)elem->out_sg[0].iov_base;
    271
    272        if (elem->in_sg[0].iov_len < sizeof(VirtIOSCSICmdResp)) {
    273            g_warning("Invalid virtio-scsi rsp header");
    274            vus_panic_cb(vu_dev, NULL);
    275            break;
    276        }
    277        rsp = (VirtIOSCSICmdResp *)elem->in_sg[0].iov_base;
    278
    279        if (handle_cmd_sync(vdev_scsi->lun.iscsi_ctx,
    280                            req, &elem->out_sg[1], elem->out_num - 1,
    281                            rsp, &elem->in_sg[1], elem->in_num - 1) != 0) {
    282            vus_panic_cb(vu_dev, NULL);
    283            break;
    284        }
    285
    286        vu_queue_push(vu_dev, vq, elem, 0);
    287        vu_queue_notify(vu_dev, vq);
    288
    289        free(elem);
    290    }
    291    free(elem);
    292}
    293
    294static void vus_queue_set_started(VuDev *vu_dev, int idx, bool started)
    295{
    296    VuVirtq *vq;
    297
    298    assert(vu_dev);
    299
    300    vq = vu_get_queue(vu_dev, idx);
    301
    302    if (idx == 0 || idx == 1) {
    303        g_debug("queue %d unimplemented", idx);
    304    } else {
    305        vu_set_queue_handler(vu_dev, vq, started ? vus_proc_req : NULL);
    306    }
    307}
    308
    309static const VuDevIface vus_iface = {
    310    .queue_set_started = vus_queue_set_started,
    311};
    312
    313/** misc helpers **/
    314
    315static int unix_sock_new(char *unix_fn)
    316{
    317    int sock;
    318    struct sockaddr_un un;
    319    size_t len;
    320
    321    assert(unix_fn);
    322
    323    sock = socket(AF_UNIX, SOCK_STREAM, 0);
    324    if (sock < 0) {
    325        perror("socket");
    326        return -1;
    327    }
    328
    329    un.sun_family = AF_UNIX;
    330    (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
    331    len = sizeof(un.sun_family) + strlen(un.sun_path);
    332
    333    (void)unlink(unix_fn);
    334    if (bind(sock, (struct sockaddr *)&un, len) < 0) {
    335        perror("bind");
    336        goto fail;
    337    }
    338
    339    if (listen(sock, 1) < 0) {
    340        perror("listen");
    341        goto fail;
    342    }
    343
    344    return sock;
    345
    346fail:
    347    (void)close(sock);
    348
    349    return -1;
    350}
    351
    352/** vhost-user-scsi **/
    353
    354int main(int argc, char **argv)
    355{
    356    VusDev *vdev_scsi = NULL;
    357    char *unix_fn = NULL;
    358    char *iscsi_uri = NULL;
    359    int lsock = -1, csock = -1, opt, err = EXIT_SUCCESS;
    360
    361    while ((opt = getopt(argc, argv, "u:i:")) != -1) {
    362        switch (opt) {
    363        case 'h':
    364            goto help;
    365        case 'u':
    366            unix_fn = g_strdup(optarg);
    367            break;
    368        case 'i':
    369            iscsi_uri = g_strdup(optarg);
    370            break;
    371        default:
    372            goto help;
    373        }
    374    }
    375    if (!unix_fn || !iscsi_uri) {
    376        goto help;
    377    }
    378
    379    lsock = unix_sock_new(unix_fn);
    380    if (lsock < 0) {
    381        goto err;
    382    }
    383
    384    csock = accept(lsock, NULL, NULL);
    385    if (csock < 0) {
    386        perror("accept");
    387        goto err;
    388    }
    389
    390    vdev_scsi = g_new0(VusDev, 1);
    391    vdev_scsi->loop = g_main_loop_new(NULL, FALSE);
    392
    393    if (vus_iscsi_add_lun(&vdev_scsi->lun, iscsi_uri) != 0) {
    394        goto err;
    395    }
    396
    397    if (!vug_init(&vdev_scsi->parent, VHOST_USER_SCSI_MAX_QUEUES, csock,
    398                  vus_panic_cb, &vus_iface)) {
    399        g_printerr("Failed to initialize libvhost-user-glib\n");
    400        goto err;
    401    }
    402
    403    g_main_loop_run(vdev_scsi->loop);
    404
    405    vug_deinit(&vdev_scsi->parent);
    406
    407out:
    408    if (vdev_scsi) {
    409        g_main_loop_unref(vdev_scsi->loop);
    410        g_free(vdev_scsi);
    411        unlink(unix_fn);
    412    }
    413    if (csock >= 0) {
    414        close(csock);
    415    }
    416    if (lsock >= 0) {
    417        close(lsock);
    418    }
    419    g_free(unix_fn);
    420    g_free(iscsi_uri);
    421
    422    return err;
    423
    424err:
    425    err = EXIT_FAILURE;
    426    goto out;
    427
    428help:
    429    fprintf(stderr, "Usage: %s [ -u unix_sock_path -i iscsi_uri ] | [ -h ]\n",
    430            argv[0]);
    431    fprintf(stderr, "          -u path to unix socket\n");
    432    fprintf(stderr, "          -i iscsi uri for lun 0\n");
    433    fprintf(stderr, "          -h print help and quit\n");
    434
    435    goto err;
    436}