Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 1 | /* |
| 2 | * (c) 2017 Stefano Stabellini <stefano@aporeto.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | |
Stefano Stabellini | fb02987 | 2017-07-06 11:01:00 -0700 | [diff] [blame^] | 15 | #include <linux/inet.h> |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 16 | #include <linux/kthread.h> |
| 17 | #include <linux/list.h> |
| 18 | #include <linux/radix-tree.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/semaphore.h> |
| 21 | #include <linux/wait.h> |
Stefano Stabellini | fb02987 | 2017-07-06 11:01:00 -0700 | [diff] [blame^] | 22 | #include <net/sock.h> |
| 23 | #include <net/inet_common.h> |
| 24 | #include <net/inet_connection_sock.h> |
| 25 | #include <net/request_sock.h> |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 26 | |
| 27 | #include <xen/events.h> |
| 28 | #include <xen/grant_table.h> |
| 29 | #include <xen/xen.h> |
| 30 | #include <xen/xenbus.h> |
| 31 | #include <xen/interface/io/pvcalls.h> |
| 32 | |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 33 | #define PVCALLS_VERSIONS "1" |
| 34 | #define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER |
| 35 | |
Stefano Stabellini | 9be0733 | 2017-07-05 13:08:48 -0700 | [diff] [blame] | 36 | struct pvcalls_back_global { |
| 37 | struct list_head frontends; |
| 38 | struct semaphore frontends_lock; |
| 39 | } pvcalls_back_global; |
| 40 | |
Stefano Stabellini | d0e4d56 | 2017-07-06 10:59:29 -0700 | [diff] [blame] | 41 | /* |
| 42 | * Per-frontend data structure. It contains pointers to the command |
| 43 | * ring, its event channel, a list of active sockets and a tree of |
| 44 | * passive sockets. |
| 45 | */ |
| 46 | struct pvcalls_fedata { |
| 47 | struct list_head list; |
| 48 | struct xenbus_device *dev; |
| 49 | struct xen_pvcalls_sring *sring; |
| 50 | struct xen_pvcalls_back_ring ring; |
| 51 | int irq; |
| 52 | struct list_head socket_mappings; |
| 53 | struct radix_tree_root socketpass_mappings; |
| 54 | struct semaphore socket_lock; |
| 55 | }; |
| 56 | |
Stefano Stabellini | b1efa69 | 2017-07-06 11:00:00 -0700 | [diff] [blame] | 57 | static int pvcalls_back_socket(struct xenbus_device *dev, |
| 58 | struct xen_pvcalls_request *req) |
| 59 | { |
Stefano Stabellini | fb02987 | 2017-07-06 11:01:00 -0700 | [diff] [blame^] | 60 | struct pvcalls_fedata *fedata; |
| 61 | int ret; |
| 62 | struct xen_pvcalls_response *rsp; |
| 63 | |
| 64 | fedata = dev_get_drvdata(&dev->dev); |
| 65 | |
| 66 | if (req->u.socket.domain != AF_INET || |
| 67 | req->u.socket.type != SOCK_STREAM || |
| 68 | (req->u.socket.protocol != IPPROTO_IP && |
| 69 | req->u.socket.protocol != AF_INET)) |
| 70 | ret = -EAFNOSUPPORT; |
| 71 | else |
| 72 | ret = 0; |
| 73 | |
| 74 | /* leave the actual socket allocation for later */ |
| 75 | |
| 76 | rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| 77 | rsp->req_id = req->req_id; |
| 78 | rsp->cmd = req->cmd; |
| 79 | rsp->u.socket.id = req->u.socket.id; |
| 80 | rsp->ret = ret; |
| 81 | |
Stefano Stabellini | b1efa69 | 2017-07-06 11:00:00 -0700 | [diff] [blame] | 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | static int pvcalls_back_connect(struct xenbus_device *dev, |
| 86 | struct xen_pvcalls_request *req) |
| 87 | { |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static int pvcalls_back_release(struct xenbus_device *dev, |
| 92 | struct xen_pvcalls_request *req) |
| 93 | { |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | static int pvcalls_back_bind(struct xenbus_device *dev, |
| 98 | struct xen_pvcalls_request *req) |
| 99 | { |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | static int pvcalls_back_listen(struct xenbus_device *dev, |
| 104 | struct xen_pvcalls_request *req) |
| 105 | { |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int pvcalls_back_accept(struct xenbus_device *dev, |
| 110 | struct xen_pvcalls_request *req) |
| 111 | { |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | static int pvcalls_back_poll(struct xenbus_device *dev, |
| 116 | struct xen_pvcalls_request *req) |
| 117 | { |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | static int pvcalls_back_handle_cmd(struct xenbus_device *dev, |
| 122 | struct xen_pvcalls_request *req) |
| 123 | { |
| 124 | int ret = 0; |
| 125 | |
| 126 | switch (req->cmd) { |
| 127 | case PVCALLS_SOCKET: |
| 128 | ret = pvcalls_back_socket(dev, req); |
| 129 | break; |
| 130 | case PVCALLS_CONNECT: |
| 131 | ret = pvcalls_back_connect(dev, req); |
| 132 | break; |
| 133 | case PVCALLS_RELEASE: |
| 134 | ret = pvcalls_back_release(dev, req); |
| 135 | break; |
| 136 | case PVCALLS_BIND: |
| 137 | ret = pvcalls_back_bind(dev, req); |
| 138 | break; |
| 139 | case PVCALLS_LISTEN: |
| 140 | ret = pvcalls_back_listen(dev, req); |
| 141 | break; |
| 142 | case PVCALLS_ACCEPT: |
| 143 | ret = pvcalls_back_accept(dev, req); |
| 144 | break; |
| 145 | case PVCALLS_POLL: |
| 146 | ret = pvcalls_back_poll(dev, req); |
| 147 | break; |
| 148 | default: |
| 149 | { |
| 150 | struct pvcalls_fedata *fedata; |
| 151 | struct xen_pvcalls_response *rsp; |
| 152 | |
| 153 | fedata = dev_get_drvdata(&dev->dev); |
| 154 | rsp = RING_GET_RESPONSE( |
| 155 | &fedata->ring, fedata->ring.rsp_prod_pvt++); |
| 156 | rsp->req_id = req->req_id; |
| 157 | rsp->cmd = req->cmd; |
| 158 | rsp->ret = -ENOTSUPP; |
| 159 | break; |
| 160 | } |
| 161 | } |
| 162 | return ret; |
| 163 | } |
| 164 | |
| 165 | static void pvcalls_back_work(struct pvcalls_fedata *fedata) |
| 166 | { |
| 167 | int notify, notify_all = 0, more = 1; |
| 168 | struct xen_pvcalls_request req; |
| 169 | struct xenbus_device *dev = fedata->dev; |
| 170 | |
| 171 | while (more) { |
| 172 | while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) { |
| 173 | RING_COPY_REQUEST(&fedata->ring, |
| 174 | fedata->ring.req_cons++, |
| 175 | &req); |
| 176 | |
| 177 | if (!pvcalls_back_handle_cmd(dev, &req)) { |
| 178 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY( |
| 179 | &fedata->ring, notify); |
| 180 | notify_all += notify; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | if (notify_all) { |
| 185 | notify_remote_via_irq(fedata->irq); |
| 186 | notify_all = 0; |
| 187 | } |
| 188 | |
| 189 | RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more); |
| 190 | } |
| 191 | } |
| 192 | |
Stefano Stabellini | d0e4d56 | 2017-07-06 10:59:29 -0700 | [diff] [blame] | 193 | static irqreturn_t pvcalls_back_event(int irq, void *dev_id) |
| 194 | { |
Stefano Stabellini | b1efa69 | 2017-07-06 11:00:00 -0700 | [diff] [blame] | 195 | struct xenbus_device *dev = dev_id; |
| 196 | struct pvcalls_fedata *fedata = NULL; |
| 197 | |
| 198 | if (dev == NULL) |
| 199 | return IRQ_HANDLED; |
| 200 | |
| 201 | fedata = dev_get_drvdata(&dev->dev); |
| 202 | if (fedata == NULL) |
| 203 | return IRQ_HANDLED; |
| 204 | |
| 205 | pvcalls_back_work(fedata); |
Stefano Stabellini | d0e4d56 | 2017-07-06 10:59:29 -0700 | [diff] [blame] | 206 | return IRQ_HANDLED; |
| 207 | } |
| 208 | |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 209 | static int backend_connect(struct xenbus_device *dev) |
| 210 | { |
Stefano Stabellini | d0e4d56 | 2017-07-06 10:59:29 -0700 | [diff] [blame] | 211 | int err, evtchn; |
| 212 | grant_ref_t ring_ref; |
| 213 | struct pvcalls_fedata *fedata = NULL; |
| 214 | |
| 215 | fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL); |
| 216 | if (!fedata) |
| 217 | return -ENOMEM; |
| 218 | |
| 219 | fedata->irq = -1; |
| 220 | err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u", |
| 221 | &evtchn); |
| 222 | if (err != 1) { |
| 223 | err = -EINVAL; |
| 224 | xenbus_dev_fatal(dev, err, "reading %s/event-channel", |
| 225 | dev->otherend); |
| 226 | goto error; |
| 227 | } |
| 228 | |
| 229 | err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref); |
| 230 | if (err != 1) { |
| 231 | err = -EINVAL; |
| 232 | xenbus_dev_fatal(dev, err, "reading %s/ring-ref", |
| 233 | dev->otherend); |
| 234 | goto error; |
| 235 | } |
| 236 | |
| 237 | err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn); |
| 238 | if (err < 0) |
| 239 | goto error; |
| 240 | fedata->irq = err; |
| 241 | |
| 242 | err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event, |
| 243 | IRQF_ONESHOT, "pvcalls-back", dev); |
| 244 | if (err < 0) |
| 245 | goto error; |
| 246 | |
| 247 | err = xenbus_map_ring_valloc(dev, &ring_ref, 1, |
| 248 | (void **)&fedata->sring); |
| 249 | if (err < 0) |
| 250 | goto error; |
| 251 | |
| 252 | BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1); |
| 253 | fedata->dev = dev; |
| 254 | |
| 255 | INIT_LIST_HEAD(&fedata->socket_mappings); |
| 256 | INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL); |
| 257 | sema_init(&fedata->socket_lock, 1); |
| 258 | dev_set_drvdata(&dev->dev, fedata); |
| 259 | |
| 260 | down(&pvcalls_back_global.frontends_lock); |
| 261 | list_add_tail(&fedata->list, &pvcalls_back_global.frontends); |
| 262 | up(&pvcalls_back_global.frontends_lock); |
| 263 | |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 264 | return 0; |
Stefano Stabellini | d0e4d56 | 2017-07-06 10:59:29 -0700 | [diff] [blame] | 265 | |
| 266 | error: |
| 267 | if (fedata->irq >= 0) |
| 268 | unbind_from_irqhandler(fedata->irq, dev); |
| 269 | if (fedata->sring != NULL) |
| 270 | xenbus_unmap_ring_vfree(dev, fedata->sring); |
| 271 | kfree(fedata); |
| 272 | return err; |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 273 | } |
| 274 | |
| 275 | static int backend_disconnect(struct xenbus_device *dev) |
| 276 | { |
| 277 | return 0; |
| 278 | } |
| 279 | |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 280 | static int pvcalls_back_probe(struct xenbus_device *dev, |
| 281 | const struct xenbus_device_id *id) |
| 282 | { |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 283 | int err, abort; |
| 284 | struct xenbus_transaction xbt; |
| 285 | |
| 286 | again: |
| 287 | abort = 1; |
| 288 | |
| 289 | err = xenbus_transaction_start(&xbt); |
| 290 | if (err) { |
| 291 | pr_warn("%s cannot create xenstore transaction\n", __func__); |
| 292 | return err; |
| 293 | } |
| 294 | |
| 295 | err = xenbus_printf(xbt, dev->nodename, "versions", "%s", |
| 296 | PVCALLS_VERSIONS); |
| 297 | if (err) { |
| 298 | pr_warn("%s write out 'versions' failed\n", __func__); |
| 299 | goto abort; |
| 300 | } |
| 301 | |
| 302 | err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u", |
| 303 | MAX_RING_ORDER); |
| 304 | if (err) { |
| 305 | pr_warn("%s write out 'max-page-order' failed\n", __func__); |
| 306 | goto abort; |
| 307 | } |
| 308 | |
| 309 | err = xenbus_printf(xbt, dev->nodename, "function-calls", |
| 310 | XENBUS_FUNCTIONS_CALLS); |
| 311 | if (err) { |
| 312 | pr_warn("%s write out 'function-calls' failed\n", __func__); |
| 313 | goto abort; |
| 314 | } |
| 315 | |
| 316 | abort = 0; |
| 317 | abort: |
| 318 | err = xenbus_transaction_end(xbt, abort); |
| 319 | if (err) { |
| 320 | if (err == -EAGAIN && !abort) |
| 321 | goto again; |
| 322 | pr_warn("%s cannot complete xenstore transaction\n", __func__); |
| 323 | return err; |
| 324 | } |
| 325 | |
| 326 | if (abort) |
| 327 | return -EFAULT; |
| 328 | |
| 329 | xenbus_switch_state(dev, XenbusStateInitWait); |
| 330 | |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 331 | return 0; |
| 332 | } |
| 333 | |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 334 | static void set_backend_state(struct xenbus_device *dev, |
| 335 | enum xenbus_state state) |
| 336 | { |
| 337 | while (dev->state != state) { |
| 338 | switch (dev->state) { |
| 339 | case XenbusStateClosed: |
| 340 | switch (state) { |
| 341 | case XenbusStateInitWait: |
| 342 | case XenbusStateConnected: |
| 343 | xenbus_switch_state(dev, XenbusStateInitWait); |
| 344 | break; |
| 345 | case XenbusStateClosing: |
| 346 | xenbus_switch_state(dev, XenbusStateClosing); |
| 347 | break; |
| 348 | default: |
| 349 | __WARN(); |
| 350 | } |
| 351 | break; |
| 352 | case XenbusStateInitWait: |
| 353 | case XenbusStateInitialised: |
| 354 | switch (state) { |
| 355 | case XenbusStateConnected: |
| 356 | backend_connect(dev); |
| 357 | xenbus_switch_state(dev, XenbusStateConnected); |
| 358 | break; |
| 359 | case XenbusStateClosing: |
| 360 | case XenbusStateClosed: |
| 361 | xenbus_switch_state(dev, XenbusStateClosing); |
| 362 | break; |
| 363 | default: |
| 364 | __WARN(); |
| 365 | } |
| 366 | break; |
| 367 | case XenbusStateConnected: |
| 368 | switch (state) { |
| 369 | case XenbusStateInitWait: |
| 370 | case XenbusStateClosing: |
| 371 | case XenbusStateClosed: |
| 372 | down(&pvcalls_back_global.frontends_lock); |
| 373 | backend_disconnect(dev); |
| 374 | up(&pvcalls_back_global.frontends_lock); |
| 375 | xenbus_switch_state(dev, XenbusStateClosing); |
| 376 | break; |
| 377 | default: |
| 378 | __WARN(); |
| 379 | } |
| 380 | break; |
| 381 | case XenbusStateClosing: |
| 382 | switch (state) { |
| 383 | case XenbusStateInitWait: |
| 384 | case XenbusStateConnected: |
| 385 | case XenbusStateClosed: |
| 386 | xenbus_switch_state(dev, XenbusStateClosed); |
| 387 | break; |
| 388 | default: |
| 389 | __WARN(); |
| 390 | } |
| 391 | break; |
| 392 | default: |
| 393 | __WARN(); |
| 394 | } |
| 395 | } |
| 396 | } |
| 397 | |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 398 | static void pvcalls_back_changed(struct xenbus_device *dev, |
| 399 | enum xenbus_state frontend_state) |
| 400 | { |
Stefano Stabellini | 0a9c75c | 2017-07-06 10:59:17 -0700 | [diff] [blame] | 401 | switch (frontend_state) { |
| 402 | case XenbusStateInitialising: |
| 403 | set_backend_state(dev, XenbusStateInitWait); |
| 404 | break; |
| 405 | |
| 406 | case XenbusStateInitialised: |
| 407 | case XenbusStateConnected: |
| 408 | set_backend_state(dev, XenbusStateConnected); |
| 409 | break; |
| 410 | |
| 411 | case XenbusStateClosing: |
| 412 | set_backend_state(dev, XenbusStateClosing); |
| 413 | break; |
| 414 | |
| 415 | case XenbusStateClosed: |
| 416 | set_backend_state(dev, XenbusStateClosed); |
| 417 | if (xenbus_dev_is_online(dev)) |
| 418 | break; |
| 419 | device_unregister(&dev->dev); |
| 420 | break; |
| 421 | case XenbusStateUnknown: |
| 422 | set_backend_state(dev, XenbusStateClosed); |
| 423 | device_unregister(&dev->dev); |
| 424 | break; |
| 425 | |
| 426 | default: |
| 427 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", |
| 428 | frontend_state); |
| 429 | break; |
| 430 | } |
Stefano Stabellini | 72e59c3 | 2017-07-05 13:08:39 -0700 | [diff] [blame] | 431 | } |
| 432 | |
| 433 | static int pvcalls_back_remove(struct xenbus_device *dev) |
| 434 | { |
| 435 | return 0; |
| 436 | } |
| 437 | |
| 438 | static int pvcalls_back_uevent(struct xenbus_device *xdev, |
| 439 | struct kobj_uevent_env *env) |
| 440 | { |
| 441 | return 0; |
| 442 | } |
| 443 | |
| 444 | static const struct xenbus_device_id pvcalls_back_ids[] = { |
| 445 | { "pvcalls" }, |
| 446 | { "" } |
| 447 | }; |
| 448 | |
| 449 | static struct xenbus_driver pvcalls_back_driver = { |
| 450 | .ids = pvcalls_back_ids, |
| 451 | .probe = pvcalls_back_probe, |
| 452 | .remove = pvcalls_back_remove, |
| 453 | .uevent = pvcalls_back_uevent, |
| 454 | .otherend_changed = pvcalls_back_changed, |
| 455 | }; |
Stefano Stabellini | 9be0733 | 2017-07-05 13:08:48 -0700 | [diff] [blame] | 456 | |
| 457 | static int __init pvcalls_back_init(void) |
| 458 | { |
| 459 | int ret; |
| 460 | |
| 461 | if (!xen_domain()) |
| 462 | return -ENODEV; |
| 463 | |
| 464 | ret = xenbus_register_backend(&pvcalls_back_driver); |
| 465 | if (ret < 0) |
| 466 | return ret; |
| 467 | |
| 468 | sema_init(&pvcalls_back_global.frontends_lock, 1); |
| 469 | INIT_LIST_HEAD(&pvcalls_back_global.frontends); |
| 470 | return 0; |
| 471 | } |
| 472 | module_init(pvcalls_back_init); |