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