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