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 #include <glib.h>
  20
  21 #define VUS_ISCSI_INITIATOR "iqn.2016-11.com.nutanix:vhost-user-scsi"
  22
  23 typedef struct VusIscsiLun {
  24     struct iscsi_context *iscsi_ctx;
  25     int iscsi_lun;
  26 } VusIscsiLun;
  27
  28 typedef struct VusDev {
  29     VugDev parent;
  30
  31     VusIscsiLun lun;
  32     GMainLoop *loop;
  33 } VusDev;
  34
  35 /** libiscsi integration **/
  36
  37 typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq;
  38 typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp;
  39
  40 static int vus_iscsi_add_lun(VusIscsiLun *lun, char *iscsi_uri)
  41 {
  42     struct iscsi_url *iscsi_url;
  43     struct iscsi_context *iscsi_ctx;
  44     int ret = 0;
  45
  46     assert(lun);
  47     assert(iscsi_uri);
  48     assert(!lun->iscsi_ctx);
  49
  50     iscsi_ctx = iscsi_create_context(VUS_ISCSI_INITIATOR);
  51     if (!iscsi_ctx) {
  52         g_warning("Unable to create iSCSI context");
  53         return -1;
  54     }
  55
  56     iscsi_url = iscsi_parse_full_url(iscsi_ctx, iscsi_uri);
  57     if (!iscsi_url) {
  58         g_warning("Unable to parse iSCSI URL: %s", iscsi_get_error(iscsi_ctx));
  59         goto fail;
  60     }
  61
  62     iscsi_set_session_type(iscsi_ctx, ISCSI_SESSION_NORMAL);
  63     iscsi_set_header_digest(iscsi_ctx, ISCSI_HEADER_DIGEST_NONE_CRC32C);
  64     if (iscsi_full_connect_sync(iscsi_ctx, iscsi_url->portal, iscsi_url->lun)) {
  65         g_warning("Unable to login to iSCSI portal: %s",
  66                   iscsi_get_error(iscsi_ctx));
  67         goto fail;
  68     }
  69
  70     lun->iscsi_ctx = iscsi_ctx;
  71     lun->iscsi_lun = iscsi_url->lun;
  72
  73     g_debug("Context %p created for lun 0: %s", iscsi_ctx, iscsi_uri);
  74
  75 out:
  76     if (iscsi_url) {
  77         iscsi_destroy_url(iscsi_url);
  78     }
  79     return ret;
  80
  81 fail:
  82     (void)iscsi_destroy_context(iscsi_ctx);
  83     ret = -1;
  84     goto out;
  85 }
  86
  87 static struct scsi_task *scsi_task_new(int cdb_len, uint8_t *cdb, int dir,
  88                                        int xfer_len)
  89 {
  90     struct scsi_task *task;
  91
  92     assert(cdb_len > 0);
  93     assert(cdb);
  94
  95     task = g_new0(struct scsi_task, 1);
  96     memcpy(task->cdb, cdb, cdb_len);
  97     task->cdb_size = cdb_len;
  98     task->xfer_dir = dir;
  99     task->expxferlen = xfer_len;
 100
 101     return task;
 102 }
 103
 104 static int get_cdb_len(uint8_t *cdb)
 105 {
 106     assert(cdb);
 107
 108     switch (cdb[0] >> 5) {
 109     case 0: return 6;
 110     case 1: /* fall through */
 111     case 2: return 10;
 112     case 4: return 16;
 113     case 5: return 12;
 114     }
 115     g_warning("Unable to determine cdb len (0x%02hhX)", cdb[0] >> 5);
 116     return -1;
 117 }
 118
 119 static int handle_cmd_sync(struct iscsi_context *ctx,
 120                            VirtIOSCSICmdReq *req,
 121                            struct iovec *out, unsigned int out_len,
 122                            VirtIOSCSICmdResp *rsp,
 123                            struct iovec *in, unsigned int in_len)
 124 {
 125     struct scsi_task *task;
 126     uint32_t dir;
 127     uint32_t len;
 128     int cdb_len;
 129     int i;
 130
 131     assert(ctx);
 132     assert(req);
 133     assert(rsp);
 134
 135     if (!(!req->lun[1] && req->lun[2] == 0x40 && !req->lun[3])) {
 136         /* Ignore anything different than target=0, lun=0 */
 137         g_debug("Ignoring unconnected lun (0x%hhX, 0x%hhX)",
 138              req->lun[1], req->lun[3]);
 139         rsp->status = SCSI_STATUS_CHECK_CONDITION;
 140         memset(rsp->sense, 0, sizeof(rsp->sense));
 141         rsp->sense_len = 18;
 142         rsp->sense[0] = 0x70;
 143         rsp->sense[2] = SCSI_SENSE_ILLEGAL_REQUEST;
 144         rsp->sense[7] = 10;
 145         rsp->sense[12] = 0x24;
 146
 147         return 0;
 148     }
 149
 150     cdb_len = get_cdb_len(req->cdb);
 151     if (cdb_len == -1) {
 152         return -1;
 153     }
 154
 155     len = 0;
 156     if (!out_len && !in_len) {
 157         dir = SCSI_XFER_NONE;
 158     } else if (out_len) {
 159         dir = SCSI_XFER_WRITE;
 160         for (i = 0; i < out_len; i++) {
 161             len += out[i].iov_len;
 162         }
 163     } else {
 164         dir = SCSI_XFER_READ;
 165         for (i = 0; i < in_len; i++) {
 166             len += in[i].iov_len;
 167         }
 168     }
 169
 170     task = scsi_task_new(cdb_len, req->cdb, dir, len);
 171
 172     if (dir == SCSI_XFER_WRITE) {
 173         task->iovector_out.iov = (struct scsi_iovec *)out;
 174         task->iovector_out.niov = out_len;
 175     } else if (dir == SCSI_XFER_READ) {
 176         task->iovector_in.iov = (struct scsi_iovec *)in;
 177         task->iovector_in.niov = in_len;
 178     }
 179
 180     g_debug("Sending iscsi cmd (cdb_len=%d, dir=%d, task=%p)",
 181          cdb_len, dir, task);
 182     if (!iscsi_scsi_command_sync(ctx, 0, task, NULL)) {
 183         g_warning("Error serving SCSI command");
 184         g_free(task);
 185         return -1;
 186     }
 187
 188     memset(rsp, 0, sizeof(*rsp));
 189
 190     rsp->status = task->status;
 191     rsp->resid  = task->residual;
 192
 193     if (task->status == SCSI_STATUS_CHECK_CONDITION) {
 194         rsp->response = VIRTIO_SCSI_S_FAILURE;
 195         rsp->sense_len = task->datain.size - 2;
 196         memcpy(rsp->sense, &task->datain.data[2], rsp->sense_len);
 197     }
 198
 199     g_free(task);
 200
 201     g_debug("Filled in rsp: status=%hhX, resid=%u, response=%hhX, sense_len=%u",
 202          rsp->status, rsp->resid, rsp->response, rsp->sense_len);
 203
 204     return 0;
 205 }
 206
 207 /** libvhost-user callbacks **/
 208
 209 static void vus_panic_cb(VuDev *vu_dev, const char *buf)
 210 {
 211     VugDev *gdev;
 212     VusDev *vdev_scsi;
 213
 214     assert(vu_dev);
 215
 216     gdev = container_of(vu_dev, VugDev, parent);
 217     vdev_scsi = container_of(gdev, VusDev, parent);
 218     if (buf) {
 219         g_warning("vu_panic: %s", buf);
 220     }
 221
 222     g_main_loop_quit(vdev_scsi->loop);
 223 }
 224
 225 static void vus_proc_req(VuDev *vu_dev, int idx)
 226 {
 227     VugDev *gdev;
 228     VusDev *vdev_scsi;
 229     VuVirtq *vq;
 230
 231     assert(vu_dev);
 232
 233     gdev = container_of(vu_dev, VugDev, parent);
 234     vdev_scsi = container_of(gdev, VusDev, parent);
 235     if (idx < 0 || idx >= VHOST_MAX_NR_VIRTQUEUE) {
 236         g_warning("VQ Index out of range: %d", idx);
 237         vus_panic_cb(vu_dev, NULL);
 238         return;
 239     }
 240
 241     vq = vu_get_queue(vu_dev, idx);
 242     if (!vq) {
 243         g_warning("Error fetching VQ (dev=%p, idx=%d)", vu_dev, idx);
 244         vus_panic_cb(vu_dev, NULL);
 245         return;
 246     }
 247
 248     g_debug("Got kicked on vq[%d]@%p", idx, vq);
 249
 250     while (1) {
 251         VuVirtqElement *elem;
 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 }
 292
 293 static void vus_queue_set_started(VuDev *vu_dev, int idx, bool started)
 294 {
 295     VuVirtq *vq;
 296
 297     assert(vu_dev);
 298
 299     if (idx < 0 || idx >= VHOST_MAX_NR_VIRTQUEUE) {
 300         g_warning("VQ Index out of range: %d", idx);
 301         vus_panic_cb(vu_dev, NULL);
 302         return;
 303     }
 304
 305     vq = vu_get_queue(vu_dev, idx);
 306
 307     if (idx == 0 || idx == 1) {
 308         g_debug("queue %d unimplemented", idx);
 309     } else {
 310         vu_set_queue_handler(vu_dev, vq, started ? vus_proc_req : NULL);
 311     }
 312 }
 313
 314 static const VuDevIface vus_iface = {
 315     .queue_set_started = vus_queue_set_started,
 316 };
 317
 318 /** misc helpers **/
 319
 320 static int unix_sock_new(char *unix_fn)
 321 {
 322     int sock;
 323     struct sockaddr_un un;
 324     size_t len;
 325
 326     assert(unix_fn);
 327
 328     sock = socket(AF_UNIX, SOCK_STREAM, 0);
 329     if (sock <= 0) {
 330         perror("socket");
 331         return -1;
 332     }
 333
 334     un.sun_family = AF_UNIX;
 335     (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
 336     len = sizeof(un.sun_family) + strlen(un.sun_path);
 337
 338     (void)unlink(unix_fn);
 339     if (bind(sock, (struct sockaddr *)&un, len) < 0) {
 340         perror("bind");
 341         goto fail;
 342     }
 343
 344     if (listen(sock, 1) < 0) {
 345         perror("listen");
 346         goto fail;
 347     }
 348
 349     return sock;
 350
 351 fail:
 352     (void)close(sock);
 353
 354     return -1;
 355 }
 356
 357 /** vhost-user-scsi **/
 358
 359 int main(int argc, char **argv)
 360 {
 361     VusDev *vdev_scsi = NULL;
 362     char *unix_fn = NULL;
 363     char *iscsi_uri = NULL;
 364     int lsock = -1, csock = -1, opt, err = EXIT_SUCCESS;
 365
 366     while ((opt = getopt(argc, argv, "u:i:")) != -1) {
 367         switch (opt) {
 368         case 'h':
 369             goto help;
 370         case 'u':
 371             unix_fn = g_strdup(optarg);
 372             break;
 373         case 'i':
 374             iscsi_uri = g_strdup(optarg);
 375             break;
 376         default:
 377             goto help;
 378         }
 379     }
 380     if (!unix_fn || !iscsi_uri) {
 381         goto help;
 382     }
 383
 384     lsock = unix_sock_new(unix_fn);
 385     if (lsock < 0) {
 386         goto err;
 387     }
 388
 389     csock = accept(lsock, NULL, NULL);
 390     if (csock < 0) {
 391         perror("accept");
 392         goto err;
 393     }
 394
 395     vdev_scsi = g_new0(VusDev, 1);
 396     vdev_scsi->loop = g_main_loop_new(NULL, FALSE);
 397
 398     if (vus_iscsi_add_lun(&vdev_scsi->lun, iscsi_uri) != 0) {
 399         goto err;
 400     }
 401
 402     vug_init(&vdev_scsi->parent, csock, vus_panic_cb, &vus_iface);
 403
 404     g_main_loop_run(vdev_scsi->loop);
 405
 406     vug_deinit(&vdev_scsi->parent);
 407
 408 out:
 409     if (vdev_scsi) {
 410         g_main_loop_unref(vdev_scsi->loop);
 411         g_free(vdev_scsi);
 412         unlink(unix_fn);
 413     }
 414     if (csock >= 0) {
 415         close(csock);
 416     }
 417     if (lsock >= 0) {
 418         close(lsock);
 419     }
 420     g_free(unix_fn);
 421     g_free(iscsi_uri);
 422
 423     return err;
 424
 425 err:
 426     err = EXIT_FAILURE;
 427     goto out;
 428
 429 help:
 430     fprintf(stderr, "Usage: %s [ -u unix_sock_path -i iscsi_uri ] | [ -h ]\n",
 431             argv[0]);
 432     fprintf(stderr, "          -u path to unix socket\n");
 433     fprintf(stderr, "          -i iscsi uri for lun 0\n");
 434     fprintf(stderr, "          -h print help and quit\n");
 435
 436     goto err;
 437 }