contrib/vhost-user-scsi/vhost-user-scsi.c

   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
  24 enum {
  25     VHOST_USER_SCSI_MAX_QUEUES = 8,
  26 };
  27
  28 typedef struct VusIscsiLun {
  29     struct iscsi_context *iscsi_ctx;
  30     int iscsi_lun;
  31 } VusIscsiLun;
  32
  33 typedef struct VusDev {
  34     VugDev parent;
  35
  36     VusIscsiLun lun;
  37     GMainLoop *loop;
  38 } VusDev;
  39
  40 /** libiscsi integration **/
  41
  42 typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq;
  43 typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp;
  44
  45 static 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
  80 out:
  81     if (iscsi_url) {
  82         iscsi_destroy_url(iscsi_url);
  83     }
  84     return ret;
  85
  86 fail:
  87     (void)iscsi_destroy_context(iscsi_ctx);
  88     ret = -1;
  89     goto out;
  90 }
  91
  92 static 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
 109 static 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
 124 static 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
 214 static 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
 230 static 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
 294 static 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
 309 static const VuDevIface vus_iface = {
 310     .queue_set_started = vus_queue_set_started,
 311 };
 312
 313 /** misc helpers **/
 314
 315 static 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
 346 fail:
 347     (void)close(sock);
 348
 349     return -1;
 350 }
 351
 352 /** vhost-user-scsi **/
 353
 354 int 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
 407 out:
 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
 424 err:
 425     err = EXIT_FAILURE;
 426     goto out;
 427
 428 help:
 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 }