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 (1024*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 spin_unlock(&m->client->lock); 211 212 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { 213 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); 214 list_del(&req->req_list); 215 if (!req->t_err) 216 req->t_err = err; 217 p9_client_cb(m->client, req, REQ_STATUS_ERROR); 218 } 219 } 220 221 static __poll_t 222 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err) 223 { 224 __poll_t ret; 225 struct p9_trans_fd *ts = NULL; 226 227 if (client && client->status == Connected) 228 ts = client->trans; 229 230 if (!ts) { 231 if (err) 232 *err = -EREMOTEIO; 233 return EPOLLERR; 234 } 235 236 ret = vfs_poll(ts->rd, pt); 237 if (ts->rd != ts->wr) 238 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN); 239 return ret; 240 } 241 242 /** 243 * p9_fd_read- read from a fd 244 * @client: client instance 245 * @v: buffer to receive data into 246 * @len: size of receive buffer 247 * 248 */ 249 250 static int p9_fd_read(struct p9_client *client, void *v, int len) 251 { 252 int ret; 253 struct p9_trans_fd *ts = NULL; 254 loff_t pos; 255 256 if (client && client->status != Disconnected) 257 ts = client->trans; 258 259 if (!ts) 260 return -EREMOTEIO; 261 262 if (!(ts->rd->f_flags & O_NONBLOCK)) 263 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 264 265 pos = ts->rd->f_pos; 266 ret = kernel_read(ts->rd, v, len, &pos); 267 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 268 client->status = Disconnected; 269 return ret; 270 } 271 272 /** 273 * p9_read_work - called when there is some data to be read from a transport 274 * @work: container of work to be done 275 * 276 */ 277 278 static void p9_read_work(struct work_struct *work) 279 { 280 __poll_t n; 281 int err; 282 struct p9_conn *m; 283 284 m = container_of(work, struct p9_conn, rq); 285 286 if (m->err < 0) 287 return; 288 289 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 290 291 if (!m->rc.sdata) { 292 m->rc.sdata = m->tmp_buf; 293 m->rc.offset = 0; 294 m->rc.capacity = 7; /* start by reading header */ 295 } 296 297 clear_bit(Rpending, &m->wsched); 298 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 299 m, m->rc.offset, m->rc.capacity, 300 m->rc.capacity - m->rc.offset); 301 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 302 m->rc.capacity - m->rc.offset); 303 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 304 if (err == -EAGAIN) 305 goto end_clear; 306 307 if (err <= 0) 308 goto error; 309 310 m->rc.offset += err; 311 312 /* header read in */ 313 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) { 314 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 315 316 /* Header size */ 317 m->rc.size = 7; 318 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0); 319 if (err) { 320 p9_debug(P9_DEBUG_ERROR, 321 "error parsing header: %d\n", err); 322 goto error; 323 } 324 325 if (m->rc.size >= m->client->msize) { 326 p9_debug(P9_DEBUG_ERROR, 327 "requested packet size too big: %d\n", 328 m->rc.size); 329 err = -EIO; 330 goto error; 331 } 332 333 p9_debug(P9_DEBUG_TRANS, 334 "mux %p pkt: size: %d bytes tag: %d\n", 335 m, m->rc.size, m->rc.tag); 336 337 m->rreq = p9_tag_lookup(m->client, m->rc.tag); 338 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) { 339 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 340 m->rc.tag); 341 err = -EIO; 342 goto error; 343 } 344 345 if (!m->rreq->rc.sdata) { 346 p9_debug(P9_DEBUG_ERROR, 347 "No recv fcall for tag %d (req %p), disconnecting!\n", 348 m->rc.tag, m->rreq); 349 p9_req_put(m->client, m->rreq); 350 m->rreq = NULL; 351 err = -EIO; 352 goto error; 353 } 354 m->rc.sdata = m->rreq->rc.sdata; 355 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 356 m->rc.capacity = m->rc.size; 357 } 358 359 /* packet is read in 360 * not an else because some packets (like clunk) have no payload 361 */ 362 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) { 363 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 364 m->rreq->rc.size = m->rc.offset; 365 spin_lock(&m->client->lock); 366 if (m->rreq->status == REQ_STATUS_SENT) { 367 list_del(&m->rreq->req_list); 368 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD); 369 } else if (m->rreq->status == REQ_STATUS_FLSHD) { 370 /* Ignore replies associated with a cancelled request. */ 371 p9_debug(P9_DEBUG_TRANS, 372 "Ignore replies associated with a cancelled request\n"); 373 } else { 374 spin_unlock(&m->client->lock); 375 p9_debug(P9_DEBUG_ERROR, 376 "Request tag %d errored out while we were reading the reply\n", 377 m->rc.tag); 378 err = -EIO; 379 goto error; 380 } 381 spin_unlock(&m->client->lock); 382 m->rc.sdata = NULL; 383 m->rc.offset = 0; 384 m->rc.capacity = 0; 385 p9_req_put(m->client, m->rreq); 386 m->rreq = NULL; 387 } 388 389 end_clear: 390 clear_bit(Rworksched, &m->wsched); 391 392 if (!list_empty(&m->req_list)) { 393 if (test_and_clear_bit(Rpending, &m->wsched)) 394 n = EPOLLIN; 395 else 396 n = p9_fd_poll(m->client, NULL, NULL); 397 398 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 399 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 400 schedule_work(&m->rq); 401 } 402 } 403 404 return; 405 error: 406 p9_conn_cancel(m, err); 407 clear_bit(Rworksched, &m->wsched); 408 } 409 410 /** 411 * p9_fd_write - write to a socket 412 * @client: client instance 413 * @v: buffer to send data from 414 * @len: size of send buffer 415 * 416 */ 417 418 static int p9_fd_write(struct p9_client *client, void *v, int len) 419 { 420 ssize_t ret; 421 struct p9_trans_fd *ts = NULL; 422 423 if (client && client->status != Disconnected) 424 ts = client->trans; 425 426 if (!ts) 427 return -EREMOTEIO; 428 429 if (!(ts->wr->f_flags & O_NONBLOCK)) 430 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 431 432 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 433 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 434 client->status = Disconnected; 435 return ret; 436 } 437 438 /** 439 * p9_write_work - called when a transport can send some data 440 * @work: container for work to be done 441 * 442 */ 443 444 static void p9_write_work(struct work_struct *work) 445 { 446 __poll_t n; 447 int err; 448 struct p9_conn *m; 449 struct p9_req_t *req; 450 451 m = container_of(work, struct p9_conn, wq); 452 453 if (m->err < 0) { 454 clear_bit(Wworksched, &m->wsched); 455 return; 456 } 457 458 if (!m->wsize) { 459 spin_lock(&m->client->lock); 460 if (list_empty(&m->unsent_req_list)) { 461 clear_bit(Wworksched, &m->wsched); 462 spin_unlock(&m->client->lock); 463 return; 464 } 465 466 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 467 req_list); 468 req->status = REQ_STATUS_SENT; 469 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 470 list_move_tail(&req->req_list, &m->req_list); 471 472 m->wbuf = req->tc.sdata; 473 m->wsize = req->tc.size; 474 m->wpos = 0; 475 p9_req_get(req); 476 m->wreq = req; 477 spin_unlock(&m->client->lock); 478 } 479 480 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 481 m, m->wpos, m->wsize); 482 clear_bit(Wpending, &m->wsched); 483 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 484 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 485 if (err == -EAGAIN) 486 goto end_clear; 487 488 489 if (err < 0) 490 goto error; 491 else if (err == 0) { 492 err = -EREMOTEIO; 493 goto error; 494 } 495 496 m->wpos += err; 497 if (m->wpos == m->wsize) { 498 m->wpos = m->wsize = 0; 499 p9_req_put(m->client, m->wreq); 500 m->wreq = NULL; 501 } 502 503 end_clear: 504 clear_bit(Wworksched, &m->wsched); 505 506 if (m->wsize || !list_empty(&m->unsent_req_list)) { 507 if (test_and_clear_bit(Wpending, &m->wsched)) 508 n = EPOLLOUT; 509 else 510 n = p9_fd_poll(m->client, NULL, NULL); 511 512 if ((n & EPOLLOUT) && 513 !test_and_set_bit(Wworksched, &m->wsched)) { 514 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 515 schedule_work(&m->wq); 516 } 517 } 518 519 return; 520 521 error: 522 p9_conn_cancel(m, err); 523 clear_bit(Wworksched, &m->wsched); 524 } 525 526 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 527 { 528 struct p9_poll_wait *pwait = 529 container_of(wait, struct p9_poll_wait, wait); 530 struct p9_conn *m = pwait->conn; 531 unsigned long flags; 532 533 spin_lock_irqsave(&p9_poll_lock, flags); 534 if (list_empty(&m->poll_pending_link)) 535 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 536 spin_unlock_irqrestore(&p9_poll_lock, flags); 537 538 schedule_work(&p9_poll_work); 539 return 1; 540 } 541 542 /** 543 * p9_pollwait - add poll task to the wait queue 544 * @filp: file pointer being polled 545 * @wait_address: wait_q to block on 546 * @p: poll state 547 * 548 * called by files poll operation to add v9fs-poll task to files wait queue 549 */ 550 551 static void 552 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 553 { 554 struct p9_conn *m = container_of(p, struct p9_conn, pt); 555 struct p9_poll_wait *pwait = NULL; 556 int i; 557 558 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 559 if (m->poll_wait[i].wait_addr == NULL) { 560 pwait = &m->poll_wait[i]; 561 break; 562 } 563 } 564 565 if (!pwait) { 566 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 567 return; 568 } 569 570 pwait->conn = m; 571 pwait->wait_addr = wait_address; 572 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 573 add_wait_queue(wait_address, &pwait->wait); 574 } 575 576 /** 577 * p9_conn_create - initialize the per-session mux data 578 * @client: client instance 579 * 580 * Note: Creates the polling task if this is the first session. 581 */ 582 583 static void p9_conn_create(struct p9_client *client) 584 { 585 __poll_t n; 586 struct p9_trans_fd *ts = client->trans; 587 struct p9_conn *m = &ts->conn; 588 589 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 590 591 INIT_LIST_HEAD(&m->mux_list); 592 m->client = client; 593 594 INIT_LIST_HEAD(&m->req_list); 595 INIT_LIST_HEAD(&m->unsent_req_list); 596 INIT_WORK(&m->rq, p9_read_work); 597 INIT_WORK(&m->wq, p9_write_work); 598 INIT_LIST_HEAD(&m->poll_pending_link); 599 init_poll_funcptr(&m->pt, p9_pollwait); 600 601 n = p9_fd_poll(client, &m->pt, NULL); 602 if (n & EPOLLIN) { 603 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 604 set_bit(Rpending, &m->wsched); 605 } 606 607 if (n & EPOLLOUT) { 608 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 609 set_bit(Wpending, &m->wsched); 610 } 611 } 612 613 /** 614 * p9_poll_mux - polls a mux and schedules read or write works if necessary 615 * @m: connection to poll 616 * 617 */ 618 619 static void p9_poll_mux(struct p9_conn *m) 620 { 621 __poll_t n; 622 int err = -ECONNRESET; 623 624 if (m->err < 0) 625 return; 626 627 n = p9_fd_poll(m->client, NULL, &err); 628 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { 629 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 630 p9_conn_cancel(m, err); 631 } 632 633 if (n & EPOLLIN) { 634 set_bit(Rpending, &m->wsched); 635 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 636 if (!test_and_set_bit(Rworksched, &m->wsched)) { 637 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 638 schedule_work(&m->rq); 639 } 640 } 641 642 if (n & EPOLLOUT) { 643 set_bit(Wpending, &m->wsched); 644 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 645 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 646 !test_and_set_bit(Wworksched, &m->wsched)) { 647 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 648 schedule_work(&m->wq); 649 } 650 } 651 } 652 653 /** 654 * p9_fd_request - send 9P request 655 * The function can sleep until the request is scheduled for sending. 656 * The function can be interrupted. Return from the function is not 657 * a guarantee that the request is sent successfully. 658 * 659 * @client: client instance 660 * @req: request to be sent 661 * 662 */ 663 664 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 665 { 666 __poll_t n; 667 struct p9_trans_fd *ts = client->trans; 668 struct p9_conn *m = &ts->conn; 669 670 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 671 m, current, &req->tc, req->tc.id); 672 if (m->err < 0) 673 return m->err; 674 675 spin_lock(&client->lock); 676 req->status = REQ_STATUS_UNSENT; 677 list_add_tail(&req->req_list, &m->unsent_req_list); 678 spin_unlock(&client->lock); 679 680 if (test_and_clear_bit(Wpending, &m->wsched)) 681 n = EPOLLOUT; 682 else 683 n = p9_fd_poll(m->client, NULL, NULL); 684 685 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 686 schedule_work(&m->wq); 687 688 return 0; 689 } 690 691 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 692 { 693 int ret = 1; 694 695 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 696 697 spin_lock(&client->lock); 698 699 if (req->status == REQ_STATUS_UNSENT) { 700 list_del(&req->req_list); 701 req->status = REQ_STATUS_FLSHD; 702 p9_req_put(client, req); 703 ret = 0; 704 } 705 spin_unlock(&client->lock); 706 707 return ret; 708 } 709 710 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 711 { 712 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 713 714 spin_lock(&client->lock); 715 /* Ignore cancelled request if message has been received 716 * before lock. 717 */ 718 if (req->status == REQ_STATUS_RCVD) { 719 spin_unlock(&client->lock); 720 return 0; 721 } 722 723 /* we haven't received a response for oldreq, 724 * remove it from the list. 725 */ 726 list_del(&req->req_list); 727 req->status = REQ_STATUS_FLSHD; 728 spin_unlock(&client->lock); 729 p9_req_put(client, req); 730 731 return 0; 732 } 733 734 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 735 { 736 if (clnt->trans_mod == &p9_tcp_trans) { 737 if (clnt->trans_opts.tcp.port != P9_PORT) 738 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 739 } else if (clnt->trans_mod == &p9_fd_trans) { 740 if (clnt->trans_opts.fd.rfd != ~0) 741 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 742 if (clnt->trans_opts.fd.wfd != ~0) 743 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 744 } 745 return 0; 746 } 747 748 /** 749 * parse_opts - parse mount options into p9_fd_opts structure 750 * @params: options string passed from mount 751 * @opts: fd transport-specific structure to parse options into 752 * 753 * Returns 0 upon success, -ERRNO upon failure 754 */ 755 756 static int parse_opts(char *params, struct p9_fd_opts *opts) 757 { 758 char *p; 759 substring_t args[MAX_OPT_ARGS]; 760 int option; 761 char *options, *tmp_options; 762 763 opts->port = P9_PORT; 764 opts->rfd = ~0; 765 opts->wfd = ~0; 766 opts->privport = false; 767 768 if (!params) 769 return 0; 770 771 tmp_options = kstrdup(params, GFP_KERNEL); 772 if (!tmp_options) { 773 p9_debug(P9_DEBUG_ERROR, 774 "failed to allocate copy of option string\n"); 775 return -ENOMEM; 776 } 777 options = tmp_options; 778 779 while ((p = strsep(&options, ",")) != NULL) { 780 int token; 781 int r; 782 if (!*p) 783 continue; 784 token = match_token(p, tokens, args); 785 if ((token != Opt_err) && (token != Opt_privport)) { 786 r = match_int(&args[0], &option); 787 if (r < 0) { 788 p9_debug(P9_DEBUG_ERROR, 789 "integer field, but no integer?\n"); 790 continue; 791 } 792 } 793 switch (token) { 794 case Opt_port: 795 opts->port = option; 796 break; 797 case Opt_rfdno: 798 opts->rfd = option; 799 break; 800 case Opt_wfdno: 801 opts->wfd = option; 802 break; 803 case Opt_privport: 804 opts->privport = true; 805 break; 806 default: 807 continue; 808 } 809 } 810 811 kfree(tmp_options); 812 return 0; 813 } 814 815 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 816 { 817 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 818 GFP_KERNEL); 819 if (!ts) 820 return -ENOMEM; 821 822 ts->rd = fget(rfd); 823 if (!ts->rd) 824 goto out_free_ts; 825 if (!(ts->rd->f_mode & FMODE_READ)) 826 goto out_put_rd; 827 ts->wr = fget(wfd); 828 if (!ts->wr) 829 goto out_put_rd; 830 if (!(ts->wr->f_mode & FMODE_WRITE)) 831 goto out_put_wr; 832 833 client->trans = ts; 834 client->status = Connected; 835 836 return 0; 837 838 out_put_wr: 839 fput(ts->wr); 840 out_put_rd: 841 fput(ts->rd); 842 out_free_ts: 843 kfree(ts); 844 return -EIO; 845 } 846 847 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 848 { 849 struct p9_trans_fd *p; 850 struct file *file; 851 852 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 853 if (!p) 854 return -ENOMEM; 855 856 csocket->sk->sk_allocation = GFP_NOIO; 857 file = sock_alloc_file(csocket, 0, NULL); 858 if (IS_ERR(file)) { 859 pr_err("%s (%d): failed to map fd\n", 860 __func__, task_pid_nr(current)); 861 kfree(p); 862 return PTR_ERR(file); 863 } 864 865 get_file(file); 866 p->wr = p->rd = file; 867 client->trans = p; 868 client->status = Connected; 869 870 p->rd->f_flags |= O_NONBLOCK; 871 872 p9_conn_create(client); 873 return 0; 874 } 875 876 /** 877 * p9_conn_destroy - cancels all pending requests of mux 878 * @m: mux to destroy 879 * 880 */ 881 882 static void p9_conn_destroy(struct p9_conn *m) 883 { 884 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 885 m, m->mux_list.prev, m->mux_list.next); 886 887 p9_mux_poll_stop(m); 888 cancel_work_sync(&m->rq); 889 if (m->rreq) { 890 p9_req_put(m->client, m->rreq); 891 m->rreq = NULL; 892 } 893 cancel_work_sync(&m->wq); 894 if (m->wreq) { 895 p9_req_put(m->client, m->wreq); 896 m->wreq = NULL; 897 } 898 899 p9_conn_cancel(m, -ECONNRESET); 900 901 m->client = NULL; 902 } 903 904 /** 905 * p9_fd_close - shutdown file descriptor transport 906 * @client: client instance 907 * 908 */ 909 910 static void p9_fd_close(struct p9_client *client) 911 { 912 struct p9_trans_fd *ts; 913 914 if (!client) 915 return; 916 917 ts = client->trans; 918 if (!ts) 919 return; 920 921 client->status = Disconnected; 922 923 p9_conn_destroy(&ts->conn); 924 925 if (ts->rd) 926 fput(ts->rd); 927 if (ts->wr) 928 fput(ts->wr); 929 930 kfree(ts); 931 } 932 933 /* 934 * stolen from NFS - maybe should be made a generic function? 935 */ 936 static inline int valid_ipaddr4(const char *buf) 937 { 938 int rc, count, in[4]; 939 940 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 941 if (rc != 4) 942 return -EINVAL; 943 for (count = 0; count < 4; count++) { 944 if (in[count] > 255) 945 return -EINVAL; 946 } 947 return 0; 948 } 949 950 static int p9_bind_privport(struct socket *sock) 951 { 952 struct sockaddr_in cl; 953 int port, err = -EINVAL; 954 955 memset(&cl, 0, sizeof(cl)); 956 cl.sin_family = AF_INET; 957 cl.sin_addr.s_addr = htonl(INADDR_ANY); 958 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 959 cl.sin_port = htons((ushort)port); 960 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 961 if (err != -EADDRINUSE) 962 break; 963 } 964 return err; 965 } 966 967 968 static int 969 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 970 { 971 int err; 972 struct socket *csocket; 973 struct sockaddr_in sin_server; 974 struct p9_fd_opts opts; 975 976 err = parse_opts(args, &opts); 977 if (err < 0) 978 return err; 979 980 if (addr == NULL || valid_ipaddr4(addr) < 0) 981 return -EINVAL; 982 983 csocket = NULL; 984 985 client->trans_opts.tcp.port = opts.port; 986 client->trans_opts.tcp.privport = opts.privport; 987 sin_server.sin_family = AF_INET; 988 sin_server.sin_addr.s_addr = in_aton(addr); 989 sin_server.sin_port = htons(opts.port); 990 err = __sock_create(current->nsproxy->net_ns, PF_INET, 991 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 992 if (err) { 993 pr_err("%s (%d): problem creating socket\n", 994 __func__, task_pid_nr(current)); 995 return err; 996 } 997 998 if (opts.privport) { 999 err = p9_bind_privport(csocket); 1000 if (err < 0) { 1001 pr_err("%s (%d): problem binding to privport\n", 1002 __func__, task_pid_nr(current)); 1003 sock_release(csocket); 1004 return err; 1005 } 1006 } 1007 1008 err = csocket->ops->connect(csocket, 1009 (struct sockaddr *)&sin_server, 1010 sizeof(struct sockaddr_in), 0); 1011 if (err < 0) { 1012 pr_err("%s (%d): problem connecting socket to %s\n", 1013 __func__, task_pid_nr(current), addr); 1014 sock_release(csocket); 1015 return err; 1016 } 1017 1018 return p9_socket_open(client, csocket); 1019 } 1020 1021 static int 1022 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 1023 { 1024 int err; 1025 struct socket *csocket; 1026 struct sockaddr_un sun_server; 1027 1028 csocket = NULL; 1029 1030 if (!addr || !strlen(addr)) 1031 return -EINVAL; 1032 1033 if (strlen(addr) >= UNIX_PATH_MAX) { 1034 pr_err("%s (%d): address too long: %s\n", 1035 __func__, task_pid_nr(current), addr); 1036 return -ENAMETOOLONG; 1037 } 1038 1039 sun_server.sun_family = PF_UNIX; 1040 strcpy(sun_server.sun_path, addr); 1041 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1042 SOCK_STREAM, 0, &csocket, 1); 1043 if (err < 0) { 1044 pr_err("%s (%d): problem creating socket\n", 1045 __func__, task_pid_nr(current)); 1046 1047 return err; 1048 } 1049 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1050 sizeof(struct sockaddr_un) - 1, 0); 1051 if (err < 0) { 1052 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1053 __func__, task_pid_nr(current), addr, err); 1054 sock_release(csocket); 1055 return err; 1056 } 1057 1058 return p9_socket_open(client, csocket); 1059 } 1060 1061 static int 1062 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1063 { 1064 int err; 1065 struct p9_fd_opts opts; 1066 1067 parse_opts(args, &opts); 1068 client->trans_opts.fd.rfd = opts.rfd; 1069 client->trans_opts.fd.wfd = opts.wfd; 1070 1071 if (opts.rfd == ~0 || opts.wfd == ~0) { 1072 pr_err("Insufficient options for proto=fd\n"); 1073 return -ENOPROTOOPT; 1074 } 1075 1076 err = p9_fd_open(client, opts.rfd, opts.wfd); 1077 if (err < 0) 1078 return err; 1079 1080 p9_conn_create(client); 1081 1082 return 0; 1083 } 1084 1085 static struct p9_trans_module p9_tcp_trans = { 1086 .name = "tcp", 1087 .maxsize = MAX_SOCK_BUF, 1088 .def = 0, 1089 .create = p9_fd_create_tcp, 1090 .close = p9_fd_close, 1091 .request = p9_fd_request, 1092 .cancel = p9_fd_cancel, 1093 .cancelled = p9_fd_cancelled, 1094 .show_options = p9_fd_show_options, 1095 .owner = THIS_MODULE, 1096 }; 1097 1098 static struct p9_trans_module p9_unix_trans = { 1099 .name = "unix", 1100 .maxsize = MAX_SOCK_BUF, 1101 .def = 0, 1102 .create = p9_fd_create_unix, 1103 .close = p9_fd_close, 1104 .request = p9_fd_request, 1105 .cancel = p9_fd_cancel, 1106 .cancelled = p9_fd_cancelled, 1107 .show_options = p9_fd_show_options, 1108 .owner = THIS_MODULE, 1109 }; 1110 1111 static struct p9_trans_module p9_fd_trans = { 1112 .name = "fd", 1113 .maxsize = MAX_SOCK_BUF, 1114 .def = 0, 1115 .create = p9_fd_create, 1116 .close = p9_fd_close, 1117 .request = p9_fd_request, 1118 .cancel = p9_fd_cancel, 1119 .cancelled = p9_fd_cancelled, 1120 .show_options = p9_fd_show_options, 1121 .owner = THIS_MODULE, 1122 }; 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 int 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 void 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