1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Fd transport layer. Includes deprecated socket layer. 4 * 5 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com> 6 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> 7 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> 8 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com> 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/in.h> 14 #include <linux/module.h> 15 #include <linux/net.h> 16 #include <linux/ipv6.h> 17 #include <linux/kthread.h> 18 #include <linux/errno.h> 19 #include <linux/kernel.h> 20 #include <linux/un.h> 21 #include <linux/uaccess.h> 22 #include <linux/inet.h> 23 #include <linux/idr.h> 24 #include <linux/file.h> 25 #include <linux/parser.h> 26 #include <linux/slab.h> 27 #include <linux/seq_file.h> 28 #include <net/9p/9p.h> 29 #include <net/9p/client.h> 30 #include <net/9p/transport.h> 31 32 #include <linux/syscalls.h> /* killme */ 33 34 #define P9_PORT 564 35 #define MAX_SOCK_BUF (1024*1024) 36 #define MAXPOLLWADDR 2 37 38 static struct p9_trans_module p9_tcp_trans; 39 static struct p9_trans_module p9_fd_trans; 40 41 /** 42 * struct p9_fd_opts - per-transport options 43 * @rfd: file descriptor for reading (trans=fd) 44 * @wfd: file descriptor for writing (trans=fd) 45 * @port: port to connect to (trans=tcp) 46 * @privport: port is privileged 47 */ 48 49 struct p9_fd_opts { 50 int rfd; 51 int wfd; 52 u16 port; 53 bool privport; 54 }; 55 56 /* 57 * Option Parsing (code inspired by NFS code) 58 * - a little lazy - parse all fd-transport options 59 */ 60 61 enum { 62 /* Options that take integer arguments */ 63 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err, 64 /* Options that take no arguments */ 65 Opt_privport, 66 }; 67 68 static const match_table_t tokens = { 69 {Opt_port, "port=%u"}, 70 {Opt_rfdno, "rfdno=%u"}, 71 {Opt_wfdno, "wfdno=%u"}, 72 {Opt_privport, "privport"}, 73 {Opt_err, NULL}, 74 }; 75 76 enum { 77 Rworksched = 1, /* read work scheduled or running */ 78 Rpending = 2, /* can read */ 79 Wworksched = 4, /* write work scheduled or running */ 80 Wpending = 8, /* can write */ 81 }; 82 83 struct p9_poll_wait { 84 struct p9_conn *conn; 85 wait_queue_entry_t wait; 86 wait_queue_head_t *wait_addr; 87 }; 88 89 /** 90 * struct p9_conn - fd mux connection state information 91 * @mux_list: list link for mux to manage multiple connections (?) 92 * @client: reference to client instance for this connection 93 * @err: error state 94 * @req_list: accounting for requests which have been sent 95 * @unsent_req_list: accounting for requests that haven't been sent 96 * @rreq: read request 97 * @wreq: write request 98 * @req: current request being processed (if any) 99 * @tmp_buf: temporary buffer to read in header 100 * @rc: temporary fcall for reading current frame 101 * @wpos: write position for current frame 102 * @wsize: amount of data to write for current frame 103 * @wbuf: current write buffer 104 * @poll_pending_link: pending links to be polled per conn 105 * @poll_wait: array of wait_q's for various worker threads 106 * @pt: poll state 107 * @rq: current read work 108 * @wq: current write work 109 * @wsched: ???? 110 * 111 */ 112 113 struct p9_conn { 114 struct list_head mux_list; 115 struct p9_client *client; 116 int err; 117 struct list_head req_list; 118 struct list_head unsent_req_list; 119 struct p9_req_t *rreq; 120 struct p9_req_t *wreq; 121 char tmp_buf[7]; 122 struct p9_fcall rc; 123 int wpos; 124 int wsize; 125 char *wbuf; 126 struct list_head poll_pending_link; 127 struct p9_poll_wait poll_wait[MAXPOLLWADDR]; 128 poll_table pt; 129 struct work_struct rq; 130 struct work_struct wq; 131 unsigned long wsched; 132 }; 133 134 /** 135 * struct p9_trans_fd - transport state 136 * @rd: reference to file to read from 137 * @wr: reference of file to write to 138 * @conn: connection state reference 139 * 140 */ 141 142 struct p9_trans_fd { 143 struct file *rd; 144 struct file *wr; 145 struct p9_conn conn; 146 }; 147 148 static void p9_poll_workfn(struct work_struct *work); 149 150 static DEFINE_SPINLOCK(p9_poll_lock); 151 static LIST_HEAD(p9_poll_pending_list); 152 static DECLARE_WORK(p9_poll_work, p9_poll_workfn); 153 154 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT; 155 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT; 156 157 static void p9_mux_poll_stop(struct p9_conn *m) 158 { 159 unsigned long flags; 160 int i; 161 162 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 163 struct p9_poll_wait *pwait = &m->poll_wait[i]; 164 165 if (pwait->wait_addr) { 166 remove_wait_queue(pwait->wait_addr, &pwait->wait); 167 pwait->wait_addr = NULL; 168 } 169 } 170 171 spin_lock_irqsave(&p9_poll_lock, flags); 172 list_del_init(&m->poll_pending_link); 173 spin_unlock_irqrestore(&p9_poll_lock, flags); 174 175 flush_work(&p9_poll_work); 176 } 177 178 /** 179 * p9_conn_cancel - cancel all pending requests with error 180 * @m: mux data 181 * @err: error code 182 * 183 */ 184 185 static void p9_conn_cancel(struct p9_conn *m, int err) 186 { 187 struct p9_req_t *req, *rtmp; 188 LIST_HEAD(cancel_list); 189 190 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err); 191 192 spin_lock(&m->client->lock); 193 194 if (m->err) { 195 spin_unlock(&m->client->lock); 196 return; 197 } 198 199 m->err = err; 200 201 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { 202 list_move(&req->req_list, &cancel_list); 203 } 204 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { 205 list_move(&req->req_list, &cancel_list); 206 } 207 208 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { 209 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); 210 list_del(&req->req_list); 211 if (!req->t_err) 212 req->t_err = err; 213 p9_client_cb(m->client, req, REQ_STATUS_ERROR); 214 } 215 spin_unlock(&m->client->lock); 216 } 217 218 static __poll_t 219 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err) 220 { 221 __poll_t ret; 222 struct p9_trans_fd *ts = NULL; 223 224 if (client && client->status == Connected) 225 ts = client->trans; 226 227 if (!ts) { 228 if (err) 229 *err = -EREMOTEIO; 230 return EPOLLERR; 231 } 232 233 ret = vfs_poll(ts->rd, pt); 234 if (ts->rd != ts->wr) 235 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN); 236 return ret; 237 } 238 239 /** 240 * p9_fd_read- read from a fd 241 * @client: client instance 242 * @v: buffer to receive data into 243 * @len: size of receive buffer 244 * 245 */ 246 247 static int p9_fd_read(struct p9_client *client, void *v, int len) 248 { 249 int ret; 250 struct p9_trans_fd *ts = NULL; 251 loff_t pos; 252 253 if (client && client->status != Disconnected) 254 ts = client->trans; 255 256 if (!ts) 257 return -EREMOTEIO; 258 259 if (!(ts->rd->f_flags & O_NONBLOCK)) 260 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 261 262 pos = ts->rd->f_pos; 263 ret = kernel_read(ts->rd, v, len, &pos); 264 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 265 client->status = Disconnected; 266 return ret; 267 } 268 269 /** 270 * p9_read_work - called when there is some data to be read from a transport 271 * @work: container of work to be done 272 * 273 */ 274 275 static void p9_read_work(struct work_struct *work) 276 { 277 __poll_t n; 278 int err; 279 struct p9_conn *m; 280 281 m = container_of(work, struct p9_conn, rq); 282 283 if (m->err < 0) 284 return; 285 286 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 287 288 if (!m->rc.sdata) { 289 m->rc.sdata = m->tmp_buf; 290 m->rc.offset = 0; 291 m->rc.capacity = 7; /* start by reading header */ 292 } 293 294 clear_bit(Rpending, &m->wsched); 295 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 296 m, m->rc.offset, m->rc.capacity, 297 m->rc.capacity - m->rc.offset); 298 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 299 m->rc.capacity - m->rc.offset); 300 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 301 if (err == -EAGAIN) 302 goto end_clear; 303 304 if (err <= 0) 305 goto error; 306 307 m->rc.offset += err; 308 309 /* header read in */ 310 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) { 311 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 312 313 /* Header size */ 314 m->rc.size = 7; 315 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0); 316 if (err) { 317 p9_debug(P9_DEBUG_ERROR, 318 "error parsing header: %d\n", err); 319 goto error; 320 } 321 322 if (m->rc.size >= m->client->msize) { 323 p9_debug(P9_DEBUG_ERROR, 324 "requested packet size too big: %d\n", 325 m->rc.size); 326 err = -EIO; 327 goto error; 328 } 329 330 p9_debug(P9_DEBUG_TRANS, 331 "mux %p pkt: size: %d bytes tag: %d\n", 332 m, m->rc.size, m->rc.tag); 333 334 m->rreq = p9_tag_lookup(m->client, m->rc.tag); 335 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) { 336 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 337 m->rc.tag); 338 err = -EIO; 339 goto error; 340 } 341 342 if (!m->rreq->rc.sdata) { 343 p9_debug(P9_DEBUG_ERROR, 344 "No recv fcall for tag %d (req %p), disconnecting!\n", 345 m->rc.tag, m->rreq); 346 p9_req_put(m->client, m->rreq); 347 m->rreq = NULL; 348 err = -EIO; 349 goto error; 350 } 351 m->rc.sdata = m->rreq->rc.sdata; 352 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 353 m->rc.capacity = m->rc.size; 354 } 355 356 /* packet is read in 357 * not an else because some packets (like clunk) have no payload 358 */ 359 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) { 360 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 361 m->rreq->rc.size = m->rc.offset; 362 spin_lock(&m->client->lock); 363 if (m->rreq->status == REQ_STATUS_SENT) { 364 list_del(&m->rreq->req_list); 365 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD); 366 } else if (m->rreq->status == REQ_STATUS_FLSHD) { 367 /* Ignore replies associated with a cancelled request. */ 368 p9_debug(P9_DEBUG_TRANS, 369 "Ignore replies associated with a cancelled request\n"); 370 } else { 371 spin_unlock(&m->client->lock); 372 p9_debug(P9_DEBUG_ERROR, 373 "Request tag %d errored out while we were reading the reply\n", 374 m->rc.tag); 375 err = -EIO; 376 goto error; 377 } 378 spin_unlock(&m->client->lock); 379 m->rc.sdata = NULL; 380 m->rc.offset = 0; 381 m->rc.capacity = 0; 382 p9_req_put(m->client, m->rreq); 383 m->rreq = NULL; 384 } 385 386 end_clear: 387 clear_bit(Rworksched, &m->wsched); 388 389 if (!list_empty(&m->req_list)) { 390 if (test_and_clear_bit(Rpending, &m->wsched)) 391 n = EPOLLIN; 392 else 393 n = p9_fd_poll(m->client, NULL, NULL); 394 395 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 396 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 397 schedule_work(&m->rq); 398 } 399 } 400 401 return; 402 error: 403 p9_conn_cancel(m, err); 404 clear_bit(Rworksched, &m->wsched); 405 } 406 407 /** 408 * p9_fd_write - write to a socket 409 * @client: client instance 410 * @v: buffer to send data from 411 * @len: size of send buffer 412 * 413 */ 414 415 static int p9_fd_write(struct p9_client *client, void *v, int len) 416 { 417 ssize_t ret; 418 struct p9_trans_fd *ts = NULL; 419 420 if (client && client->status != Disconnected) 421 ts = client->trans; 422 423 if (!ts) 424 return -EREMOTEIO; 425 426 if (!(ts->wr->f_flags & O_NONBLOCK)) 427 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 428 429 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 430 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 431 client->status = Disconnected; 432 return ret; 433 } 434 435 /** 436 * p9_write_work - called when a transport can send some data 437 * @work: container for work to be done 438 * 439 */ 440 441 static void p9_write_work(struct work_struct *work) 442 { 443 __poll_t n; 444 int err; 445 struct p9_conn *m; 446 struct p9_req_t *req; 447 448 m = container_of(work, struct p9_conn, wq); 449 450 if (m->err < 0) { 451 clear_bit(Wworksched, &m->wsched); 452 return; 453 } 454 455 if (!m->wsize) { 456 spin_lock(&m->client->lock); 457 if (list_empty(&m->unsent_req_list)) { 458 clear_bit(Wworksched, &m->wsched); 459 spin_unlock(&m->client->lock); 460 return; 461 } 462 463 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 464 req_list); 465 req->status = REQ_STATUS_SENT; 466 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 467 list_move_tail(&req->req_list, &m->req_list); 468 469 m->wbuf = req->tc.sdata; 470 m->wsize = req->tc.size; 471 m->wpos = 0; 472 p9_req_get(req); 473 m->wreq = req; 474 spin_unlock(&m->client->lock); 475 } 476 477 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 478 m, m->wpos, m->wsize); 479 clear_bit(Wpending, &m->wsched); 480 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 481 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 482 if (err == -EAGAIN) 483 goto end_clear; 484 485 486 if (err < 0) 487 goto error; 488 else if (err == 0) { 489 err = -EREMOTEIO; 490 goto error; 491 } 492 493 m->wpos += err; 494 if (m->wpos == m->wsize) { 495 m->wpos = m->wsize = 0; 496 p9_req_put(m->client, m->wreq); 497 m->wreq = NULL; 498 } 499 500 end_clear: 501 clear_bit(Wworksched, &m->wsched); 502 503 if (m->wsize || !list_empty(&m->unsent_req_list)) { 504 if (test_and_clear_bit(Wpending, &m->wsched)) 505 n = EPOLLOUT; 506 else 507 n = p9_fd_poll(m->client, NULL, NULL); 508 509 if ((n & EPOLLOUT) && 510 !test_and_set_bit(Wworksched, &m->wsched)) { 511 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 512 schedule_work(&m->wq); 513 } 514 } 515 516 return; 517 518 error: 519 p9_conn_cancel(m, err); 520 clear_bit(Wworksched, &m->wsched); 521 } 522 523 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 524 { 525 struct p9_poll_wait *pwait = 526 container_of(wait, struct p9_poll_wait, wait); 527 struct p9_conn *m = pwait->conn; 528 unsigned long flags; 529 530 spin_lock_irqsave(&p9_poll_lock, flags); 531 if (list_empty(&m->poll_pending_link)) 532 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 533 spin_unlock_irqrestore(&p9_poll_lock, flags); 534 535 schedule_work(&p9_poll_work); 536 return 1; 537 } 538 539 /** 540 * p9_pollwait - add poll task to the wait queue 541 * @filp: file pointer being polled 542 * @wait_address: wait_q to block on 543 * @p: poll state 544 * 545 * called by files poll operation to add v9fs-poll task to files wait queue 546 */ 547 548 static void 549 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 550 { 551 struct p9_conn *m = container_of(p, struct p9_conn, pt); 552 struct p9_poll_wait *pwait = NULL; 553 int i; 554 555 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 556 if (m->poll_wait[i].wait_addr == NULL) { 557 pwait = &m->poll_wait[i]; 558 break; 559 } 560 } 561 562 if (!pwait) { 563 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 564 return; 565 } 566 567 pwait->conn = m; 568 pwait->wait_addr = wait_address; 569 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 570 add_wait_queue(wait_address, &pwait->wait); 571 } 572 573 /** 574 * p9_conn_create - initialize the per-session mux data 575 * @client: client instance 576 * 577 * Note: Creates the polling task if this is the first session. 578 */ 579 580 static void p9_conn_create(struct p9_client *client) 581 { 582 __poll_t n; 583 struct p9_trans_fd *ts = client->trans; 584 struct p9_conn *m = &ts->conn; 585 586 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 587 588 INIT_LIST_HEAD(&m->mux_list); 589 m->client = client; 590 591 INIT_LIST_HEAD(&m->req_list); 592 INIT_LIST_HEAD(&m->unsent_req_list); 593 INIT_WORK(&m->rq, p9_read_work); 594 INIT_WORK(&m->wq, p9_write_work); 595 INIT_LIST_HEAD(&m->poll_pending_link); 596 init_poll_funcptr(&m->pt, p9_pollwait); 597 598 n = p9_fd_poll(client, &m->pt, NULL); 599 if (n & EPOLLIN) { 600 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 601 set_bit(Rpending, &m->wsched); 602 } 603 604 if (n & EPOLLOUT) { 605 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 606 set_bit(Wpending, &m->wsched); 607 } 608 } 609 610 /** 611 * p9_poll_mux - polls a mux and schedules read or write works if necessary 612 * @m: connection to poll 613 * 614 */ 615 616 static void p9_poll_mux(struct p9_conn *m) 617 { 618 __poll_t n; 619 int err = -ECONNRESET; 620 621 if (m->err < 0) 622 return; 623 624 n = p9_fd_poll(m->client, NULL, &err); 625 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { 626 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 627 p9_conn_cancel(m, err); 628 } 629 630 if (n & EPOLLIN) { 631 set_bit(Rpending, &m->wsched); 632 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 633 if (!test_and_set_bit(Rworksched, &m->wsched)) { 634 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 635 schedule_work(&m->rq); 636 } 637 } 638 639 if (n & EPOLLOUT) { 640 set_bit(Wpending, &m->wsched); 641 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 642 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 643 !test_and_set_bit(Wworksched, &m->wsched)) { 644 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 645 schedule_work(&m->wq); 646 } 647 } 648 } 649 650 /** 651 * p9_fd_request - send 9P request 652 * The function can sleep until the request is scheduled for sending. 653 * The function can be interrupted. Return from the function is not 654 * a guarantee that the request is sent successfully. 655 * 656 * @client: client instance 657 * @req: request to be sent 658 * 659 */ 660 661 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 662 { 663 __poll_t n; 664 struct p9_trans_fd *ts = client->trans; 665 struct p9_conn *m = &ts->conn; 666 667 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 668 m, current, &req->tc, req->tc.id); 669 if (m->err < 0) 670 return m->err; 671 672 spin_lock(&client->lock); 673 req->status = REQ_STATUS_UNSENT; 674 list_add_tail(&req->req_list, &m->unsent_req_list); 675 spin_unlock(&client->lock); 676 677 if (test_and_clear_bit(Wpending, &m->wsched)) 678 n = EPOLLOUT; 679 else 680 n = p9_fd_poll(m->client, NULL, NULL); 681 682 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 683 schedule_work(&m->wq); 684 685 return 0; 686 } 687 688 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 689 { 690 int ret = 1; 691 692 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 693 694 spin_lock(&client->lock); 695 696 if (req->status == REQ_STATUS_UNSENT) { 697 list_del(&req->req_list); 698 req->status = REQ_STATUS_FLSHD; 699 p9_req_put(client, req); 700 ret = 0; 701 } 702 spin_unlock(&client->lock); 703 704 return ret; 705 } 706 707 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 708 { 709 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 710 711 spin_lock(&client->lock); 712 /* Ignore cancelled request if message has been received 713 * before lock. 714 */ 715 if (req->status == REQ_STATUS_RCVD) { 716 spin_unlock(&client->lock); 717 return 0; 718 } 719 720 /* we haven't received a response for oldreq, 721 * remove it from the list. 722 */ 723 list_del(&req->req_list); 724 req->status = REQ_STATUS_FLSHD; 725 spin_unlock(&client->lock); 726 p9_req_put(client, req); 727 728 return 0; 729 } 730 731 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 732 { 733 if (clnt->trans_mod == &p9_tcp_trans) { 734 if (clnt->trans_opts.tcp.port != P9_PORT) 735 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 736 } else if (clnt->trans_mod == &p9_fd_trans) { 737 if (clnt->trans_opts.fd.rfd != ~0) 738 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 739 if (clnt->trans_opts.fd.wfd != ~0) 740 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 741 } 742 return 0; 743 } 744 745 /** 746 * parse_opts - parse mount options into p9_fd_opts structure 747 * @params: options string passed from mount 748 * @opts: fd transport-specific structure to parse options into 749 * 750 * Returns 0 upon success, -ERRNO upon failure 751 */ 752 753 static int parse_opts(char *params, struct p9_fd_opts *opts) 754 { 755 char *p; 756 substring_t args[MAX_OPT_ARGS]; 757 int option; 758 char *options, *tmp_options; 759 760 opts->port = P9_PORT; 761 opts->rfd = ~0; 762 opts->wfd = ~0; 763 opts->privport = false; 764 765 if (!params) 766 return 0; 767 768 tmp_options = kstrdup(params, GFP_KERNEL); 769 if (!tmp_options) { 770 p9_debug(P9_DEBUG_ERROR, 771 "failed to allocate copy of option string\n"); 772 return -ENOMEM; 773 } 774 options = tmp_options; 775 776 while ((p = strsep(&options, ",")) != NULL) { 777 int token; 778 int r; 779 if (!*p) 780 continue; 781 token = match_token(p, tokens, args); 782 if ((token != Opt_err) && (token != Opt_privport)) { 783 r = match_int(&args[0], &option); 784 if (r < 0) { 785 p9_debug(P9_DEBUG_ERROR, 786 "integer field, but no integer?\n"); 787 continue; 788 } 789 } 790 switch (token) { 791 case Opt_port: 792 opts->port = option; 793 break; 794 case Opt_rfdno: 795 opts->rfd = option; 796 break; 797 case Opt_wfdno: 798 opts->wfd = option; 799 break; 800 case Opt_privport: 801 opts->privport = true; 802 break; 803 default: 804 continue; 805 } 806 } 807 808 kfree(tmp_options); 809 return 0; 810 } 811 812 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 813 { 814 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 815 GFP_KERNEL); 816 if (!ts) 817 return -ENOMEM; 818 819 ts->rd = fget(rfd); 820 if (!ts->rd) 821 goto out_free_ts; 822 if (!(ts->rd->f_mode & FMODE_READ)) 823 goto out_put_rd; 824 ts->wr = fget(wfd); 825 if (!ts->wr) 826 goto out_put_rd; 827 if (!(ts->wr->f_mode & FMODE_WRITE)) 828 goto out_put_wr; 829 830 client->trans = ts; 831 client->status = Connected; 832 833 return 0; 834 835 out_put_wr: 836 fput(ts->wr); 837 out_put_rd: 838 fput(ts->rd); 839 out_free_ts: 840 kfree(ts); 841 return -EIO; 842 } 843 844 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 845 { 846 struct p9_trans_fd *p; 847 struct file *file; 848 849 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 850 if (!p) 851 return -ENOMEM; 852 853 csocket->sk->sk_allocation = GFP_NOIO; 854 file = sock_alloc_file(csocket, 0, NULL); 855 if (IS_ERR(file)) { 856 pr_err("%s (%d): failed to map fd\n", 857 __func__, task_pid_nr(current)); 858 kfree(p); 859 return PTR_ERR(file); 860 } 861 862 get_file(file); 863 p->wr = p->rd = file; 864 client->trans = p; 865 client->status = Connected; 866 867 p->rd->f_flags |= O_NONBLOCK; 868 869 p9_conn_create(client); 870 return 0; 871 } 872 873 /** 874 * p9_conn_destroy - cancels all pending requests of mux 875 * @m: mux to destroy 876 * 877 */ 878 879 static void p9_conn_destroy(struct p9_conn *m) 880 { 881 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 882 m, m->mux_list.prev, m->mux_list.next); 883 884 p9_mux_poll_stop(m); 885 cancel_work_sync(&m->rq); 886 if (m->rreq) { 887 p9_req_put(m->client, m->rreq); 888 m->rreq = NULL; 889 } 890 cancel_work_sync(&m->wq); 891 if (m->wreq) { 892 p9_req_put(m->client, m->wreq); 893 m->wreq = NULL; 894 } 895 896 p9_conn_cancel(m, -ECONNRESET); 897 898 m->client = NULL; 899 } 900 901 /** 902 * p9_fd_close - shutdown file descriptor transport 903 * @client: client instance 904 * 905 */ 906 907 static void p9_fd_close(struct p9_client *client) 908 { 909 struct p9_trans_fd *ts; 910 911 if (!client) 912 return; 913 914 ts = client->trans; 915 if (!ts) 916 return; 917 918 client->status = Disconnected; 919 920 p9_conn_destroy(&ts->conn); 921 922 if (ts->rd) 923 fput(ts->rd); 924 if (ts->wr) 925 fput(ts->wr); 926 927 kfree(ts); 928 } 929 930 /* 931 * stolen from NFS - maybe should be made a generic function? 932 */ 933 static inline int valid_ipaddr4(const char *buf) 934 { 935 int rc, count, in[4]; 936 937 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 938 if (rc != 4) 939 return -EINVAL; 940 for (count = 0; count < 4; count++) { 941 if (in[count] > 255) 942 return -EINVAL; 943 } 944 return 0; 945 } 946 947 static int p9_bind_privport(struct socket *sock) 948 { 949 struct sockaddr_in cl; 950 int port, err = -EINVAL; 951 952 memset(&cl, 0, sizeof(cl)); 953 cl.sin_family = AF_INET; 954 cl.sin_addr.s_addr = htonl(INADDR_ANY); 955 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 956 cl.sin_port = htons((ushort)port); 957 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 958 if (err != -EADDRINUSE) 959 break; 960 } 961 return err; 962 } 963 964 965 static int 966 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 967 { 968 int err; 969 struct socket *csocket; 970 struct sockaddr_in sin_server; 971 struct p9_fd_opts opts; 972 973 err = parse_opts(args, &opts); 974 if (err < 0) 975 return err; 976 977 if (addr == NULL || valid_ipaddr4(addr) < 0) 978 return -EINVAL; 979 980 csocket = NULL; 981 982 client->trans_opts.tcp.port = opts.port; 983 client->trans_opts.tcp.privport = opts.privport; 984 sin_server.sin_family = AF_INET; 985 sin_server.sin_addr.s_addr = in_aton(addr); 986 sin_server.sin_port = htons(opts.port); 987 err = __sock_create(current->nsproxy->net_ns, PF_INET, 988 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 989 if (err) { 990 pr_err("%s (%d): problem creating socket\n", 991 __func__, task_pid_nr(current)); 992 return err; 993 } 994 995 if (opts.privport) { 996 err = p9_bind_privport(csocket); 997 if (err < 0) { 998 pr_err("%s (%d): problem binding to privport\n", 999 __func__, task_pid_nr(current)); 1000 sock_release(csocket); 1001 return err; 1002 } 1003 } 1004 1005 err = csocket->ops->connect(csocket, 1006 (struct sockaddr *)&sin_server, 1007 sizeof(struct sockaddr_in), 0); 1008 if (err < 0) { 1009 pr_err("%s (%d): problem connecting socket to %s\n", 1010 __func__, task_pid_nr(current), addr); 1011 sock_release(csocket); 1012 return err; 1013 } 1014 1015 return p9_socket_open(client, csocket); 1016 } 1017 1018 static int 1019 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 1020 { 1021 int err; 1022 struct socket *csocket; 1023 struct sockaddr_un sun_server; 1024 1025 csocket = NULL; 1026 1027 if (!addr || !strlen(addr)) 1028 return -EINVAL; 1029 1030 if (strlen(addr) >= UNIX_PATH_MAX) { 1031 pr_err("%s (%d): address too long: %s\n", 1032 __func__, task_pid_nr(current), addr); 1033 return -ENAMETOOLONG; 1034 } 1035 1036 sun_server.sun_family = PF_UNIX; 1037 strcpy(sun_server.sun_path, addr); 1038 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1039 SOCK_STREAM, 0, &csocket, 1); 1040 if (err < 0) { 1041 pr_err("%s (%d): problem creating socket\n", 1042 __func__, task_pid_nr(current)); 1043 1044 return err; 1045 } 1046 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1047 sizeof(struct sockaddr_un) - 1, 0); 1048 if (err < 0) { 1049 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1050 __func__, task_pid_nr(current), addr, err); 1051 sock_release(csocket); 1052 return err; 1053 } 1054 1055 return p9_socket_open(client, csocket); 1056 } 1057 1058 static int 1059 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1060 { 1061 int err; 1062 struct p9_fd_opts opts; 1063 1064 parse_opts(args, &opts); 1065 client->trans_opts.fd.rfd = opts.rfd; 1066 client->trans_opts.fd.wfd = opts.wfd; 1067 1068 if (opts.rfd == ~0 || opts.wfd == ~0) { 1069 pr_err("Insufficient options for proto=fd\n"); 1070 return -ENOPROTOOPT; 1071 } 1072 1073 err = p9_fd_open(client, opts.rfd, opts.wfd); 1074 if (err < 0) 1075 return err; 1076 1077 p9_conn_create(client); 1078 1079 return 0; 1080 } 1081 1082 static struct p9_trans_module p9_tcp_trans = { 1083 .name = "tcp", 1084 .maxsize = MAX_SOCK_BUF, 1085 .def = 0, 1086 .create = p9_fd_create_tcp, 1087 .close = p9_fd_close, 1088 .request = p9_fd_request, 1089 .cancel = p9_fd_cancel, 1090 .cancelled = p9_fd_cancelled, 1091 .show_options = p9_fd_show_options, 1092 .owner = THIS_MODULE, 1093 }; 1094 MODULE_ALIAS_9P("tcp"); 1095 1096 static struct p9_trans_module p9_unix_trans = { 1097 .name = "unix", 1098 .maxsize = MAX_SOCK_BUF, 1099 .def = 0, 1100 .create = p9_fd_create_unix, 1101 .close = p9_fd_close, 1102 .request = p9_fd_request, 1103 .cancel = p9_fd_cancel, 1104 .cancelled = p9_fd_cancelled, 1105 .show_options = p9_fd_show_options, 1106 .owner = THIS_MODULE, 1107 }; 1108 MODULE_ALIAS_9P("unix"); 1109 1110 static struct p9_trans_module p9_fd_trans = { 1111 .name = "fd", 1112 .maxsize = MAX_SOCK_BUF, 1113 .def = 0, 1114 .create = p9_fd_create, 1115 .close = p9_fd_close, 1116 .request = p9_fd_request, 1117 .cancel = p9_fd_cancel, 1118 .cancelled = p9_fd_cancelled, 1119 .show_options = p9_fd_show_options, 1120 .owner = THIS_MODULE, 1121 }; 1122 MODULE_ALIAS_9P("fd"); 1123 1124 /** 1125 * p9_poll_workfn - poll worker thread 1126 * @work: work queue 1127 * 1128 * polls all v9fs transports for new events and queues the appropriate 1129 * work to the work queue 1130 * 1131 */ 1132 1133 static void p9_poll_workfn(struct work_struct *work) 1134 { 1135 unsigned long flags; 1136 1137 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1138 1139 spin_lock_irqsave(&p9_poll_lock, flags); 1140 while (!list_empty(&p9_poll_pending_list)) { 1141 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1142 struct p9_conn, 1143 poll_pending_link); 1144 list_del_init(&conn->poll_pending_link); 1145 spin_unlock_irqrestore(&p9_poll_lock, flags); 1146 1147 p9_poll_mux(conn); 1148 1149 spin_lock_irqsave(&p9_poll_lock, flags); 1150 } 1151 spin_unlock_irqrestore(&p9_poll_lock, flags); 1152 1153 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1154 } 1155 1156 static int __init p9_trans_fd_init(void) 1157 { 1158 v9fs_register_trans(&p9_tcp_trans); 1159 v9fs_register_trans(&p9_unix_trans); 1160 v9fs_register_trans(&p9_fd_trans); 1161 1162 return 0; 1163 } 1164 1165 static void __exit p9_trans_fd_exit(void) 1166 { 1167 flush_work(&p9_poll_work); 1168 v9fs_unregister_trans(&p9_tcp_trans); 1169 v9fs_unregister_trans(&p9_unix_trans); 1170 v9fs_unregister_trans(&p9_fd_trans); 1171 } 1172 1173 module_init(p9_trans_fd_init); 1174 module_exit(p9_trans_fd_exit); 1175 1176 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); 1177 MODULE_DESCRIPTION("Filedescriptor Transport for 9P"); 1178 MODULE_LICENSE("GPL"); 1179