1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/9p/trans_fd.c 4 * 5 * Fd transport layer. Includes deprecated socket layer. 6 * 7 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com> 8 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> 9 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> 10 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/in.h> 16 #include <linux/module.h> 17 #include <linux/net.h> 18 #include <linux/ipv6.h> 19 #include <linux/kthread.h> 20 #include <linux/errno.h> 21 #include <linux/kernel.h> 22 #include <linux/un.h> 23 #include <linux/uaccess.h> 24 #include <linux/inet.h> 25 #include <linux/idr.h> 26 #include <linux/file.h> 27 #include <linux/parser.h> 28 #include <linux/slab.h> 29 #include <linux/seq_file.h> 30 #include <net/9p/9p.h> 31 #include <net/9p/client.h> 32 #include <net/9p/transport.h> 33 34 #include <linux/syscalls.h> /* killme */ 35 36 #define P9_PORT 564 37 #define MAX_SOCK_BUF (64*1024) 38 #define MAXPOLLWADDR 2 39 40 static struct p9_trans_module p9_tcp_trans; 41 static struct p9_trans_module p9_fd_trans; 42 43 /** 44 * struct p9_fd_opts - per-transport options 45 * @rfd: file descriptor for reading (trans=fd) 46 * @wfd: file descriptor for writing (trans=fd) 47 * @port: port to connect to (trans=tcp) 48 * 49 */ 50 51 struct p9_fd_opts { 52 int rfd; 53 int wfd; 54 u16 port; 55 bool privport; 56 }; 57 58 /* 59 * Option Parsing (code inspired by NFS code) 60 * - a little lazy - parse all fd-transport options 61 */ 62 63 enum { 64 /* Options that take integer arguments */ 65 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err, 66 /* Options that take no arguments */ 67 Opt_privport, 68 }; 69 70 static const match_table_t tokens = { 71 {Opt_port, "port=%u"}, 72 {Opt_rfdno, "rfdno=%u"}, 73 {Opt_wfdno, "wfdno=%u"}, 74 {Opt_privport, "privport"}, 75 {Opt_err, NULL}, 76 }; 77 78 enum { 79 Rworksched = 1, /* read work scheduled or running */ 80 Rpending = 2, /* can read */ 81 Wworksched = 4, /* write work scheduled or running */ 82 Wpending = 8, /* can write */ 83 }; 84 85 struct p9_poll_wait { 86 struct p9_conn *conn; 87 wait_queue_entry_t wait; 88 wait_queue_head_t *wait_addr; 89 }; 90 91 /** 92 * struct p9_conn - fd mux connection state information 93 * @mux_list: list link for mux to manage multiple connections (?) 94 * @client: reference to client instance for this connection 95 * @err: error state 96 * @req_list: accounting for requests which have been sent 97 * @unsent_req_list: accounting for requests that haven't been sent 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 m->rreq = NULL; 347 err = -EIO; 348 goto error; 349 } 350 m->rc.sdata = m->rreq->rc.sdata; 351 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 352 m->rc.capacity = m->rc.size; 353 } 354 355 /* packet is read in 356 * not an else because some packets (like clunk) have no payload 357 */ 358 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) { 359 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 360 m->rreq->rc.size = m->rc.offset; 361 spin_lock(&m->client->lock); 362 if (m->rreq->status == REQ_STATUS_SENT) { 363 list_del(&m->rreq->req_list); 364 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD); 365 } else if (m->rreq->status == REQ_STATUS_FLSHD) { 366 /* Ignore replies associated with a cancelled request. */ 367 p9_debug(P9_DEBUG_TRANS, 368 "Ignore replies associated with a cancelled request\n"); 369 } else { 370 spin_unlock(&m->client->lock); 371 p9_debug(P9_DEBUG_ERROR, 372 "Request tag %d errored out while we were reading the reply\n", 373 m->rc.tag); 374 err = -EIO; 375 goto error; 376 } 377 spin_unlock(&m->client->lock); 378 m->rc.sdata = NULL; 379 m->rc.offset = 0; 380 m->rc.capacity = 0; 381 p9_req_put(m->rreq); 382 m->rreq = NULL; 383 } 384 385 end_clear: 386 clear_bit(Rworksched, &m->wsched); 387 388 if (!list_empty(&m->req_list)) { 389 if (test_and_clear_bit(Rpending, &m->wsched)) 390 n = EPOLLIN; 391 else 392 n = p9_fd_poll(m->client, NULL, NULL); 393 394 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 395 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 396 schedule_work(&m->rq); 397 } 398 } 399 400 return; 401 error: 402 p9_conn_cancel(m, err); 403 clear_bit(Rworksched, &m->wsched); 404 } 405 406 /** 407 * p9_fd_write - write to a socket 408 * @client: client instance 409 * @v: buffer to send data from 410 * @len: size of send buffer 411 * 412 */ 413 414 static int p9_fd_write(struct p9_client *client, void *v, int len) 415 { 416 ssize_t ret; 417 struct p9_trans_fd *ts = NULL; 418 419 if (client && client->status != Disconnected) 420 ts = client->trans; 421 422 if (!ts) 423 return -EREMOTEIO; 424 425 if (!(ts->wr->f_flags & O_NONBLOCK)) 426 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 427 428 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 429 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 430 client->status = Disconnected; 431 return ret; 432 } 433 434 /** 435 * p9_write_work - called when a transport can send some data 436 * @work: container for work to be done 437 * 438 */ 439 440 static void p9_write_work(struct work_struct *work) 441 { 442 __poll_t n; 443 int err; 444 struct p9_conn *m; 445 struct p9_req_t *req; 446 447 m = container_of(work, struct p9_conn, wq); 448 449 if (m->err < 0) { 450 clear_bit(Wworksched, &m->wsched); 451 return; 452 } 453 454 if (!m->wsize) { 455 spin_lock(&m->client->lock); 456 if (list_empty(&m->unsent_req_list)) { 457 clear_bit(Wworksched, &m->wsched); 458 spin_unlock(&m->client->lock); 459 return; 460 } 461 462 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 463 req_list); 464 req->status = REQ_STATUS_SENT; 465 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 466 list_move_tail(&req->req_list, &m->req_list); 467 468 m->wbuf = req->tc.sdata; 469 m->wsize = req->tc.size; 470 m->wpos = 0; 471 p9_req_get(req); 472 m->wreq = req; 473 spin_unlock(&m->client->lock); 474 } 475 476 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 477 m, m->wpos, m->wsize); 478 clear_bit(Wpending, &m->wsched); 479 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 480 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 481 if (err == -EAGAIN) 482 goto end_clear; 483 484 485 if (err < 0) 486 goto error; 487 else if (err == 0) { 488 err = -EREMOTEIO; 489 goto error; 490 } 491 492 m->wpos += err; 493 if (m->wpos == m->wsize) { 494 m->wpos = m->wsize = 0; 495 p9_req_put(m->wreq); 496 m->wreq = NULL; 497 } 498 499 end_clear: 500 clear_bit(Wworksched, &m->wsched); 501 502 if (m->wsize || !list_empty(&m->unsent_req_list)) { 503 if (test_and_clear_bit(Wpending, &m->wsched)) 504 n = EPOLLOUT; 505 else 506 n = p9_fd_poll(m->client, NULL, NULL); 507 508 if ((n & EPOLLOUT) && 509 !test_and_set_bit(Wworksched, &m->wsched)) { 510 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 511 schedule_work(&m->wq); 512 } 513 } 514 515 return; 516 517 error: 518 p9_conn_cancel(m, err); 519 clear_bit(Wworksched, &m->wsched); 520 } 521 522 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 523 { 524 struct p9_poll_wait *pwait = 525 container_of(wait, struct p9_poll_wait, wait); 526 struct p9_conn *m = pwait->conn; 527 unsigned long flags; 528 529 spin_lock_irqsave(&p9_poll_lock, flags); 530 if (list_empty(&m->poll_pending_link)) 531 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 532 spin_unlock_irqrestore(&p9_poll_lock, flags); 533 534 schedule_work(&p9_poll_work); 535 return 1; 536 } 537 538 /** 539 * p9_pollwait - add poll task to the wait queue 540 * @filp: file pointer being polled 541 * @wait_address: wait_q to block on 542 * @p: poll state 543 * 544 * called by files poll operation to add v9fs-poll task to files wait queue 545 */ 546 547 static void 548 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 549 { 550 struct p9_conn *m = container_of(p, struct p9_conn, pt); 551 struct p9_poll_wait *pwait = NULL; 552 int i; 553 554 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 555 if (m->poll_wait[i].wait_addr == NULL) { 556 pwait = &m->poll_wait[i]; 557 break; 558 } 559 } 560 561 if (!pwait) { 562 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 563 return; 564 } 565 566 pwait->conn = m; 567 pwait->wait_addr = wait_address; 568 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 569 add_wait_queue(wait_address, &pwait->wait); 570 } 571 572 /** 573 * p9_conn_create - initialize the per-session mux data 574 * @client: client instance 575 * 576 * Note: Creates the polling task if this is the first session. 577 */ 578 579 static void p9_conn_create(struct p9_client *client) 580 { 581 __poll_t n; 582 struct p9_trans_fd *ts = client->trans; 583 struct p9_conn *m = &ts->conn; 584 585 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 586 587 INIT_LIST_HEAD(&m->mux_list); 588 m->client = client; 589 590 INIT_LIST_HEAD(&m->req_list); 591 INIT_LIST_HEAD(&m->unsent_req_list); 592 INIT_WORK(&m->rq, p9_read_work); 593 INIT_WORK(&m->wq, p9_write_work); 594 INIT_LIST_HEAD(&m->poll_pending_link); 595 init_poll_funcptr(&m->pt, p9_pollwait); 596 597 n = p9_fd_poll(client, &m->pt, NULL); 598 if (n & EPOLLIN) { 599 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 600 set_bit(Rpending, &m->wsched); 601 } 602 603 if (n & EPOLLOUT) { 604 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 605 set_bit(Wpending, &m->wsched); 606 } 607 } 608 609 /** 610 * p9_poll_mux - polls a mux and schedules read or write works if necessary 611 * @m: connection to poll 612 * 613 */ 614 615 static void p9_poll_mux(struct p9_conn *m) 616 { 617 __poll_t n; 618 int err = -ECONNRESET; 619 620 if (m->err < 0) 621 return; 622 623 n = p9_fd_poll(m->client, NULL, &err); 624 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { 625 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 626 p9_conn_cancel(m, err); 627 } 628 629 if (n & EPOLLIN) { 630 set_bit(Rpending, &m->wsched); 631 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 632 if (!test_and_set_bit(Rworksched, &m->wsched)) { 633 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 634 schedule_work(&m->rq); 635 } 636 } 637 638 if (n & EPOLLOUT) { 639 set_bit(Wpending, &m->wsched); 640 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 641 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 642 !test_and_set_bit(Wworksched, &m->wsched)) { 643 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 644 schedule_work(&m->wq); 645 } 646 } 647 } 648 649 /** 650 * p9_fd_request - send 9P request 651 * The function can sleep until the request is scheduled for sending. 652 * The function can be interrupted. Return from the function is not 653 * a guarantee that the request is sent successfully. 654 * 655 * @client: client instance 656 * @req: request to be sent 657 * 658 */ 659 660 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 661 { 662 __poll_t n; 663 struct p9_trans_fd *ts = client->trans; 664 struct p9_conn *m = &ts->conn; 665 666 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 667 m, current, &req->tc, req->tc.id); 668 if (m->err < 0) 669 return m->err; 670 671 spin_lock(&client->lock); 672 req->status = REQ_STATUS_UNSENT; 673 list_add_tail(&req->req_list, &m->unsent_req_list); 674 spin_unlock(&client->lock); 675 676 if (test_and_clear_bit(Wpending, &m->wsched)) 677 n = EPOLLOUT; 678 else 679 n = p9_fd_poll(m->client, NULL, NULL); 680 681 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 682 schedule_work(&m->wq); 683 684 return 0; 685 } 686 687 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 688 { 689 int ret = 1; 690 691 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 692 693 spin_lock(&client->lock); 694 695 if (req->status == REQ_STATUS_UNSENT) { 696 list_del(&req->req_list); 697 req->status = REQ_STATUS_FLSHD; 698 p9_req_put(req); 699 ret = 0; 700 } 701 spin_unlock(&client->lock); 702 703 return ret; 704 } 705 706 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 707 { 708 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 709 710 spin_lock(&client->lock); 711 /* Ignore cancelled request if message has been received 712 * before lock. 713 */ 714 if (req->status == REQ_STATUS_RCVD) { 715 spin_unlock(&client->lock); 716 return 0; 717 } 718 719 /* we haven't received a response for oldreq, 720 * remove it from the list. 721 */ 722 list_del(&req->req_list); 723 req->status = REQ_STATUS_FLSHD; 724 spin_unlock(&client->lock); 725 p9_req_put(req); 726 727 return 0; 728 } 729 730 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 731 { 732 if (clnt->trans_mod == &p9_tcp_trans) { 733 if (clnt->trans_opts.tcp.port != P9_PORT) 734 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 735 } else if (clnt->trans_mod == &p9_fd_trans) { 736 if (clnt->trans_opts.fd.rfd != ~0) 737 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 738 if (clnt->trans_opts.fd.wfd != ~0) 739 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 740 } 741 return 0; 742 } 743 744 /** 745 * parse_opts - parse mount options into p9_fd_opts structure 746 * @params: options string passed from mount 747 * @opts: fd transport-specific structure to parse options into 748 * 749 * Returns 0 upon success, -ERRNO upon failure 750 */ 751 752 static int parse_opts(char *params, struct p9_fd_opts *opts) 753 { 754 char *p; 755 substring_t args[MAX_OPT_ARGS]; 756 int option; 757 char *options, *tmp_options; 758 759 opts->port = P9_PORT; 760 opts->rfd = ~0; 761 opts->wfd = ~0; 762 opts->privport = false; 763 764 if (!params) 765 return 0; 766 767 tmp_options = kstrdup(params, GFP_KERNEL); 768 if (!tmp_options) { 769 p9_debug(P9_DEBUG_ERROR, 770 "failed to allocate copy of option string\n"); 771 return -ENOMEM; 772 } 773 options = tmp_options; 774 775 while ((p = strsep(&options, ",")) != NULL) { 776 int token; 777 int r; 778 if (!*p) 779 continue; 780 token = match_token(p, tokens, args); 781 if ((token != Opt_err) && (token != Opt_privport)) { 782 r = match_int(&args[0], &option); 783 if (r < 0) { 784 p9_debug(P9_DEBUG_ERROR, 785 "integer field, but no integer?\n"); 786 continue; 787 } 788 } 789 switch (token) { 790 case Opt_port: 791 opts->port = option; 792 break; 793 case Opt_rfdno: 794 opts->rfd = option; 795 break; 796 case Opt_wfdno: 797 opts->wfd = option; 798 break; 799 case Opt_privport: 800 opts->privport = true; 801 break; 802 default: 803 continue; 804 } 805 } 806 807 kfree(tmp_options); 808 return 0; 809 } 810 811 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 812 { 813 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 814 GFP_KERNEL); 815 if (!ts) 816 return -ENOMEM; 817 818 ts->rd = fget(rfd); 819 if (!ts->rd) 820 goto out_free_ts; 821 if (!(ts->rd->f_mode & FMODE_READ)) 822 goto out_put_rd; 823 ts->wr = fget(wfd); 824 if (!ts->wr) 825 goto out_put_rd; 826 if (!(ts->wr->f_mode & FMODE_WRITE)) 827 goto out_put_wr; 828 829 client->trans = ts; 830 client->status = Connected; 831 832 return 0; 833 834 out_put_wr: 835 fput(ts->wr); 836 out_put_rd: 837 fput(ts->rd); 838 out_free_ts: 839 kfree(ts); 840 return -EIO; 841 } 842 843 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 844 { 845 struct p9_trans_fd *p; 846 struct file *file; 847 848 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 849 if (!p) 850 return -ENOMEM; 851 852 csocket->sk->sk_allocation = GFP_NOIO; 853 file = sock_alloc_file(csocket, 0, NULL); 854 if (IS_ERR(file)) { 855 pr_err("%s (%d): failed to map fd\n", 856 __func__, task_pid_nr(current)); 857 kfree(p); 858 return PTR_ERR(file); 859 } 860 861 get_file(file); 862 p->wr = p->rd = file; 863 client->trans = p; 864 client->status = Connected; 865 866 p->rd->f_flags |= O_NONBLOCK; 867 868 p9_conn_create(client); 869 return 0; 870 } 871 872 /** 873 * p9_mux_destroy - cancels all pending requests of mux 874 * @m: mux to destroy 875 * 876 */ 877 878 static void p9_conn_destroy(struct p9_conn *m) 879 { 880 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 881 m, m->mux_list.prev, m->mux_list.next); 882 883 p9_mux_poll_stop(m); 884 cancel_work_sync(&m->rq); 885 if (m->rreq) { 886 p9_req_put(m->rreq); 887 m->rreq = NULL; 888 } 889 cancel_work_sync(&m->wq); 890 if (m->wreq) { 891 p9_req_put(m->wreq); 892 m->wreq = NULL; 893 } 894 895 p9_conn_cancel(m, -ECONNRESET); 896 897 m->client = NULL; 898 } 899 900 /** 901 * p9_fd_close - shutdown file descriptor transport 902 * @client: client instance 903 * 904 */ 905 906 static void p9_fd_close(struct p9_client *client) 907 { 908 struct p9_trans_fd *ts; 909 910 if (!client) 911 return; 912 913 ts = client->trans; 914 if (!ts) 915 return; 916 917 client->status = Disconnected; 918 919 p9_conn_destroy(&ts->conn); 920 921 if (ts->rd) 922 fput(ts->rd); 923 if (ts->wr) 924 fput(ts->wr); 925 926 kfree(ts); 927 } 928 929 /* 930 * stolen from NFS - maybe should be made a generic function? 931 */ 932 static inline int valid_ipaddr4(const char *buf) 933 { 934 int rc, count, in[4]; 935 936 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 937 if (rc != 4) 938 return -EINVAL; 939 for (count = 0; count < 4; count++) { 940 if (in[count] > 255) 941 return -EINVAL; 942 } 943 return 0; 944 } 945 946 static int p9_bind_privport(struct socket *sock) 947 { 948 struct sockaddr_in cl; 949 int port, err = -EINVAL; 950 951 memset(&cl, 0, sizeof(cl)); 952 cl.sin_family = AF_INET; 953 cl.sin_addr.s_addr = htonl(INADDR_ANY); 954 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 955 cl.sin_port = htons((ushort)port); 956 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 957 if (err != -EADDRINUSE) 958 break; 959 } 960 return err; 961 } 962 963 964 static int 965 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 966 { 967 int err; 968 struct socket *csocket; 969 struct sockaddr_in sin_server; 970 struct p9_fd_opts opts; 971 972 err = parse_opts(args, &opts); 973 if (err < 0) 974 return err; 975 976 if (addr == NULL || valid_ipaddr4(addr) < 0) 977 return -EINVAL; 978 979 csocket = NULL; 980 981 client->trans_opts.tcp.port = opts.port; 982 client->trans_opts.tcp.privport = opts.privport; 983 sin_server.sin_family = AF_INET; 984 sin_server.sin_addr.s_addr = in_aton(addr); 985 sin_server.sin_port = htons(opts.port); 986 err = __sock_create(current->nsproxy->net_ns, PF_INET, 987 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 988 if (err) { 989 pr_err("%s (%d): problem creating socket\n", 990 __func__, task_pid_nr(current)); 991 return err; 992 } 993 994 if (opts.privport) { 995 err = p9_bind_privport(csocket); 996 if (err < 0) { 997 pr_err("%s (%d): problem binding to privport\n", 998 __func__, task_pid_nr(current)); 999 sock_release(csocket); 1000 return err; 1001 } 1002 } 1003 1004 err = csocket->ops->connect(csocket, 1005 (struct sockaddr *)&sin_server, 1006 sizeof(struct sockaddr_in), 0); 1007 if (err < 0) { 1008 pr_err("%s (%d): problem connecting socket to %s\n", 1009 __func__, task_pid_nr(current), addr); 1010 sock_release(csocket); 1011 return err; 1012 } 1013 1014 return p9_socket_open(client, csocket); 1015 } 1016 1017 static int 1018 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 1019 { 1020 int err; 1021 struct socket *csocket; 1022 struct sockaddr_un sun_server; 1023 1024 csocket = NULL; 1025 1026 if (addr == NULL) 1027 return -EINVAL; 1028 1029 if (strlen(addr) >= UNIX_PATH_MAX) { 1030 pr_err("%s (%d): address too long: %s\n", 1031 __func__, task_pid_nr(current), addr); 1032 return -ENAMETOOLONG; 1033 } 1034 1035 sun_server.sun_family = PF_UNIX; 1036 strcpy(sun_server.sun_path, addr); 1037 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1038 SOCK_STREAM, 0, &csocket, 1); 1039 if (err < 0) { 1040 pr_err("%s (%d): problem creating socket\n", 1041 __func__, task_pid_nr(current)); 1042 1043 return err; 1044 } 1045 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1046 sizeof(struct sockaddr_un) - 1, 0); 1047 if (err < 0) { 1048 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1049 __func__, task_pid_nr(current), addr, err); 1050 sock_release(csocket); 1051 return err; 1052 } 1053 1054 return p9_socket_open(client, csocket); 1055 } 1056 1057 static int 1058 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1059 { 1060 int err; 1061 struct p9_fd_opts opts; 1062 1063 parse_opts(args, &opts); 1064 client->trans_opts.fd.rfd = opts.rfd; 1065 client->trans_opts.fd.wfd = opts.wfd; 1066 1067 if (opts.rfd == ~0 || opts.wfd == ~0) { 1068 pr_err("Insufficient options for proto=fd\n"); 1069 return -ENOPROTOOPT; 1070 } 1071 1072 err = p9_fd_open(client, opts.rfd, opts.wfd); 1073 if (err < 0) 1074 return err; 1075 1076 p9_conn_create(client); 1077 1078 return 0; 1079 } 1080 1081 static struct p9_trans_module p9_tcp_trans = { 1082 .name = "tcp", 1083 .maxsize = MAX_SOCK_BUF, 1084 .def = 0, 1085 .create = p9_fd_create_tcp, 1086 .close = p9_fd_close, 1087 .request = p9_fd_request, 1088 .cancel = p9_fd_cancel, 1089 .cancelled = p9_fd_cancelled, 1090 .show_options = p9_fd_show_options, 1091 .owner = THIS_MODULE, 1092 }; 1093 1094 static struct p9_trans_module p9_unix_trans = { 1095 .name = "unix", 1096 .maxsize = MAX_SOCK_BUF, 1097 .def = 0, 1098 .create = p9_fd_create_unix, 1099 .close = p9_fd_close, 1100 .request = p9_fd_request, 1101 .cancel = p9_fd_cancel, 1102 .cancelled = p9_fd_cancelled, 1103 .show_options = p9_fd_show_options, 1104 .owner = THIS_MODULE, 1105 }; 1106 1107 static struct p9_trans_module p9_fd_trans = { 1108 .name = "fd", 1109 .maxsize = MAX_SOCK_BUF, 1110 .def = 0, 1111 .create = p9_fd_create, 1112 .close = p9_fd_close, 1113 .request = p9_fd_request, 1114 .cancel = p9_fd_cancel, 1115 .cancelled = p9_fd_cancelled, 1116 .show_options = p9_fd_show_options, 1117 .owner = THIS_MODULE, 1118 }; 1119 1120 /** 1121 * p9_poll_workfn - poll worker thread 1122 * @work: work queue 1123 * 1124 * polls all v9fs transports for new events and queues the appropriate 1125 * work to the work queue 1126 * 1127 */ 1128 1129 static void p9_poll_workfn(struct work_struct *work) 1130 { 1131 unsigned long flags; 1132 1133 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1134 1135 spin_lock_irqsave(&p9_poll_lock, flags); 1136 while (!list_empty(&p9_poll_pending_list)) { 1137 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1138 struct p9_conn, 1139 poll_pending_link); 1140 list_del_init(&conn->poll_pending_link); 1141 spin_unlock_irqrestore(&p9_poll_lock, flags); 1142 1143 p9_poll_mux(conn); 1144 1145 spin_lock_irqsave(&p9_poll_lock, flags); 1146 } 1147 spin_unlock_irqrestore(&p9_poll_lock, flags); 1148 1149 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1150 } 1151 1152 int p9_trans_fd_init(void) 1153 { 1154 v9fs_register_trans(&p9_tcp_trans); 1155 v9fs_register_trans(&p9_unix_trans); 1156 v9fs_register_trans(&p9_fd_trans); 1157 1158 return 0; 1159 } 1160 1161 void p9_trans_fd_exit(void) 1162 { 1163 flush_work(&p9_poll_work); 1164 v9fs_unregister_trans(&p9_tcp_trans); 1165 v9fs_unregister_trans(&p9_unix_trans); 1166 v9fs_unregister_trans(&p9_fd_trans); 1167 } 1168