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13#include "qemu/osdep.h"
14#include <iscsi/iscsi.h>
15#define inline __attribute__((gnu_inline))
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
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:
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
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
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
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
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}
437
