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