1
2
3
4
5
6
7
8
9
10
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
22enum {
23 VHOST_USER_SCSI_MAX_QUEUES = 8,
24};
25
26typedef struct VusIscsiLun {
27 struct iscsi_context *iscsi_ctx;
28 int iscsi_lun;
29} VusIscsiLun;
30
31typedef struct VusDev {
32 VugDev parent;
33
34 VusIscsiLun lun;
35 GMainLoop *loop;
36} VusDev;
37
38
39
40typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq;
41typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp;
42
43static 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
78out:
79 if (iscsi_url) {
80 iscsi_destroy_url(iscsi_url);
81 }
82 return ret;
83
84fail:
85 (void)iscsi_destroy_context(iscsi_ctx);
86 ret = -1;
87 goto out;
88}
89
90static 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
107static 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:
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
122static 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
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
211
212static 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
228static 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
291static 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
306static const VuDevIface vus_iface = {
307 .queue_set_started = vus_queue_set_started,
308};
309
310
311
312static 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
343fail:
344 (void)close(sock);
345
346 return -1;
347}
348
349
350
351int 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
404out:
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
421err:
422 err = EXIT_FAILURE;
423 goto out;
424
425help:
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}
434
