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_lock: lock protecting req_list and requests statuses 95 * @req_list: accounting for requests which have been sent 96 * @unsent_req_list: accounting for requests that haven't been sent 97 * @rreq: read request 98 * @wreq: write request 99 * @req: current request being processed (if any) 100 * @tmp_buf: temporary buffer to read in header 101 * @rc: temporary fcall for reading current frame 102 * @wpos: write position for current frame 103 * @wsize: amount of data to write for current frame 104 * @wbuf: current write buffer 105 * @poll_pending_link: pending links to be polled per conn 106 * @poll_wait: array of wait_q's for various worker threads 107 * @pt: poll state 108 * @rq: current read work 109 * @wq: current write work 110 * @wsched: ???? 111 * 112 */ 113 114 struct p9_conn { 115 struct list_head mux_list; 116 struct p9_client *client; 117 int err; 118 spinlock_t req_lock; 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[P9_HDRSZ]; 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->req_lock); 195 196 if (m->err) { 197 spin_unlock(&m->req_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 req->status = REQ_STATUS_ERROR; 206 } 207 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { 208 list_move(&req->req_list, &cancel_list); 209 req->status = REQ_STATUS_ERROR; 210 } 211 212 spin_unlock(&m->req_lock); 213 214 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { 215 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); 216 list_del(&req->req_list); 217 if (!req->t_err) 218 req->t_err = err; 219 p9_client_cb(m->client, req, REQ_STATUS_ERROR); 220 } 221 } 222 223 static __poll_t 224 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err) 225 { 226 __poll_t ret; 227 struct p9_trans_fd *ts = NULL; 228 229 if (client && client->status == Connected) 230 ts = client->trans; 231 232 if (!ts) { 233 if (err) 234 *err = -EREMOTEIO; 235 return EPOLLERR; 236 } 237 238 ret = vfs_poll(ts->rd, pt); 239 if (ts->rd != ts->wr) 240 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN); 241 return ret; 242 } 243 244 /** 245 * p9_fd_read- read from a fd 246 * @client: client instance 247 * @v: buffer to receive data into 248 * @len: size of receive buffer 249 * 250 */ 251 252 static int p9_fd_read(struct p9_client *client, void *v, int len) 253 { 254 int ret; 255 struct p9_trans_fd *ts = NULL; 256 loff_t pos; 257 258 if (client && client->status != Disconnected) 259 ts = client->trans; 260 261 if (!ts) 262 return -EREMOTEIO; 263 264 if (!(ts->rd->f_flags & O_NONBLOCK)) 265 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 266 267 pos = ts->rd->f_pos; 268 ret = kernel_read(ts->rd, v, len, &pos); 269 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 270 client->status = Disconnected; 271 return ret; 272 } 273 274 /** 275 * p9_read_work - called when there is some data to be read from a transport 276 * @work: container of work to be done 277 * 278 */ 279 280 static void p9_read_work(struct work_struct *work) 281 { 282 __poll_t n; 283 int err; 284 struct p9_conn *m; 285 286 m = container_of(work, struct p9_conn, rq); 287 288 if (m->err < 0) 289 return; 290 291 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 292 293 if (!m->rc.sdata) { 294 m->rc.sdata = m->tmp_buf; 295 m->rc.offset = 0; 296 m->rc.capacity = P9_HDRSZ; /* start by reading header */ 297 } 298 299 clear_bit(Rpending, &m->wsched); 300 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 301 m, m->rc.offset, m->rc.capacity, 302 m->rc.capacity - m->rc.offset); 303 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 304 m->rc.capacity - m->rc.offset); 305 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 306 if (err == -EAGAIN) 307 goto end_clear; 308 309 if (err <= 0) 310 goto error; 311 312 m->rc.offset += err; 313 314 /* header read in */ 315 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) { 316 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 317 318 /* Header size */ 319 m->rc.size = P9_HDRSZ; 320 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0); 321 if (err) { 322 p9_debug(P9_DEBUG_ERROR, 323 "error parsing header: %d\n", err); 324 goto error; 325 } 326 327 p9_debug(P9_DEBUG_TRANS, 328 "mux %p pkt: size: %d bytes tag: %d\n", 329 m, m->rc.size, m->rc.tag); 330 331 m->rreq = p9_tag_lookup(m->client, m->rc.tag); 332 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) { 333 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 334 m->rc.tag); 335 err = -EIO; 336 goto error; 337 } 338 339 if (m->rc.size > m->rreq->rc.capacity) { 340 p9_debug(P9_DEBUG_ERROR, 341 "requested packet size too big: %d for tag %d with capacity %zd\n", 342 m->rc.size, m->rc.tag, m->rreq->rc.capacity); 343 err = -EIO; 344 goto error; 345 } 346 347 if (!m->rreq->rc.sdata) { 348 p9_debug(P9_DEBUG_ERROR, 349 "No recv fcall for tag %d (req %p), disconnecting!\n", 350 m->rc.tag, m->rreq); 351 p9_req_put(m->client, m->rreq); 352 m->rreq = NULL; 353 err = -EIO; 354 goto error; 355 } 356 m->rc.sdata = m->rreq->rc.sdata; 357 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 358 m->rc.capacity = m->rc.size; 359 } 360 361 /* packet is read in 362 * not an else because some packets (like clunk) have no payload 363 */ 364 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) { 365 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 366 m->rreq->rc.size = m->rc.offset; 367 spin_lock(&m->req_lock); 368 if (m->rreq->status == REQ_STATUS_SENT) { 369 list_del(&m->rreq->req_list); 370 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD); 371 } else if (m->rreq->status == REQ_STATUS_FLSHD) { 372 /* Ignore replies associated with a cancelled request. */ 373 p9_debug(P9_DEBUG_TRANS, 374 "Ignore replies associated with a cancelled request\n"); 375 } else { 376 spin_unlock(&m->req_lock); 377 p9_debug(P9_DEBUG_ERROR, 378 "Request tag %d errored out while we were reading the reply\n", 379 m->rc.tag); 380 err = -EIO; 381 goto error; 382 } 383 spin_unlock(&m->req_lock); 384 m->rc.sdata = NULL; 385 m->rc.offset = 0; 386 m->rc.capacity = 0; 387 p9_req_put(m->client, m->rreq); 388 m->rreq = NULL; 389 } 390 391 end_clear: 392 clear_bit(Rworksched, &m->wsched); 393 394 if (!list_empty(&m->req_list)) { 395 if (test_and_clear_bit(Rpending, &m->wsched)) 396 n = EPOLLIN; 397 else 398 n = p9_fd_poll(m->client, NULL, NULL); 399 400 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 401 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 402 schedule_work(&m->rq); 403 } 404 } 405 406 return; 407 error: 408 p9_conn_cancel(m, err); 409 clear_bit(Rworksched, &m->wsched); 410 } 411 412 /** 413 * p9_fd_write - write to a socket 414 * @client: client instance 415 * @v: buffer to send data from 416 * @len: size of send buffer 417 * 418 */ 419 420 static int p9_fd_write(struct p9_client *client, void *v, int len) 421 { 422 ssize_t ret; 423 struct p9_trans_fd *ts = NULL; 424 425 if (client && client->status != Disconnected) 426 ts = client->trans; 427 428 if (!ts) 429 return -EREMOTEIO; 430 431 if (!(ts->wr->f_flags & O_NONBLOCK)) 432 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 433 434 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 435 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 436 client->status = Disconnected; 437 return ret; 438 } 439 440 /** 441 * p9_write_work - called when a transport can send some data 442 * @work: container for work to be done 443 * 444 */ 445 446 static void p9_write_work(struct work_struct *work) 447 { 448 __poll_t n; 449 int err; 450 struct p9_conn *m; 451 struct p9_req_t *req; 452 453 m = container_of(work, struct p9_conn, wq); 454 455 if (m->err < 0) { 456 clear_bit(Wworksched, &m->wsched); 457 return; 458 } 459 460 if (!m->wsize) { 461 spin_lock(&m->req_lock); 462 if (list_empty(&m->unsent_req_list)) { 463 clear_bit(Wworksched, &m->wsched); 464 spin_unlock(&m->req_lock); 465 return; 466 } 467 468 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 469 req_list); 470 req->status = REQ_STATUS_SENT; 471 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 472 list_move_tail(&req->req_list, &m->req_list); 473 474 m->wbuf = req->tc.sdata; 475 m->wsize = req->tc.size; 476 m->wpos = 0; 477 p9_req_get(req); 478 m->wreq = req; 479 spin_unlock(&m->req_lock); 480 } 481 482 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 483 m, m->wpos, m->wsize); 484 clear_bit(Wpending, &m->wsched); 485 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 486 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 487 if (err == -EAGAIN) 488 goto end_clear; 489 490 491 if (err < 0) 492 goto error; 493 else if (err == 0) { 494 err = -EREMOTEIO; 495 goto error; 496 } 497 498 m->wpos += err; 499 if (m->wpos == m->wsize) { 500 m->wpos = m->wsize = 0; 501 p9_req_put(m->client, m->wreq); 502 m->wreq = NULL; 503 } 504 505 end_clear: 506 clear_bit(Wworksched, &m->wsched); 507 508 if (m->wsize || !list_empty(&m->unsent_req_list)) { 509 if (test_and_clear_bit(Wpending, &m->wsched)) 510 n = EPOLLOUT; 511 else 512 n = p9_fd_poll(m->client, NULL, NULL); 513 514 if ((n & EPOLLOUT) && 515 !test_and_set_bit(Wworksched, &m->wsched)) { 516 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 517 schedule_work(&m->wq); 518 } 519 } 520 521 return; 522 523 error: 524 p9_conn_cancel(m, err); 525 clear_bit(Wworksched, &m->wsched); 526 } 527 528 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 529 { 530 struct p9_poll_wait *pwait = 531 container_of(wait, struct p9_poll_wait, wait); 532 struct p9_conn *m = pwait->conn; 533 unsigned long flags; 534 535 spin_lock_irqsave(&p9_poll_lock, flags); 536 if (list_empty(&m->poll_pending_link)) 537 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 538 spin_unlock_irqrestore(&p9_poll_lock, flags); 539 540 schedule_work(&p9_poll_work); 541 return 1; 542 } 543 544 /** 545 * p9_pollwait - add poll task to the wait queue 546 * @filp: file pointer being polled 547 * @wait_address: wait_q to block on 548 * @p: poll state 549 * 550 * called by files poll operation to add v9fs-poll task to files wait queue 551 */ 552 553 static void 554 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 555 { 556 struct p9_conn *m = container_of(p, struct p9_conn, pt); 557 struct p9_poll_wait *pwait = NULL; 558 int i; 559 560 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 561 if (m->poll_wait[i].wait_addr == NULL) { 562 pwait = &m->poll_wait[i]; 563 break; 564 } 565 } 566 567 if (!pwait) { 568 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 569 return; 570 } 571 572 pwait->conn = m; 573 pwait->wait_addr = wait_address; 574 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 575 add_wait_queue(wait_address, &pwait->wait); 576 } 577 578 /** 579 * p9_conn_create - initialize the per-session mux data 580 * @client: client instance 581 * 582 * Note: Creates the polling task if this is the first session. 583 */ 584 585 static void p9_conn_create(struct p9_client *client) 586 { 587 __poll_t n; 588 struct p9_trans_fd *ts = client->trans; 589 struct p9_conn *m = &ts->conn; 590 591 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 592 593 INIT_LIST_HEAD(&m->mux_list); 594 m->client = client; 595 596 spin_lock_init(&m->req_lock); 597 INIT_LIST_HEAD(&m->req_list); 598 INIT_LIST_HEAD(&m->unsent_req_list); 599 INIT_WORK(&m->rq, p9_read_work); 600 INIT_WORK(&m->wq, p9_write_work); 601 INIT_LIST_HEAD(&m->poll_pending_link); 602 init_poll_funcptr(&m->pt, p9_pollwait); 603 604 n = p9_fd_poll(client, &m->pt, NULL); 605 if (n & EPOLLIN) { 606 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 607 set_bit(Rpending, &m->wsched); 608 } 609 610 if (n & EPOLLOUT) { 611 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 612 set_bit(Wpending, &m->wsched); 613 } 614 } 615 616 /** 617 * p9_poll_mux - polls a mux and schedules read or write works if necessary 618 * @m: connection to poll 619 * 620 */ 621 622 static void p9_poll_mux(struct p9_conn *m) 623 { 624 __poll_t n; 625 int err = -ECONNRESET; 626 627 if (m->err < 0) 628 return; 629 630 n = p9_fd_poll(m->client, NULL, &err); 631 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { 632 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 633 p9_conn_cancel(m, err); 634 } 635 636 if (n & EPOLLIN) { 637 set_bit(Rpending, &m->wsched); 638 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 639 if (!test_and_set_bit(Rworksched, &m->wsched)) { 640 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 641 schedule_work(&m->rq); 642 } 643 } 644 645 if (n & EPOLLOUT) { 646 set_bit(Wpending, &m->wsched); 647 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 648 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 649 !test_and_set_bit(Wworksched, &m->wsched)) { 650 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 651 schedule_work(&m->wq); 652 } 653 } 654 } 655 656 /** 657 * p9_fd_request - send 9P request 658 * The function can sleep until the request is scheduled for sending. 659 * The function can be interrupted. Return from the function is not 660 * a guarantee that the request is sent successfully. 661 * 662 * @client: client instance 663 * @req: request to be sent 664 * 665 */ 666 667 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 668 { 669 __poll_t n; 670 struct p9_trans_fd *ts = client->trans; 671 struct p9_conn *m = &ts->conn; 672 673 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 674 m, current, &req->tc, req->tc.id); 675 if (m->err < 0) 676 return m->err; 677 678 spin_lock(&m->req_lock); 679 req->status = REQ_STATUS_UNSENT; 680 list_add_tail(&req->req_list, &m->unsent_req_list); 681 spin_unlock(&m->req_lock); 682 683 if (test_and_clear_bit(Wpending, &m->wsched)) 684 n = EPOLLOUT; 685 else 686 n = p9_fd_poll(m->client, NULL, NULL); 687 688 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 689 schedule_work(&m->wq); 690 691 return 0; 692 } 693 694 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 695 { 696 struct p9_trans_fd *ts = client->trans; 697 struct p9_conn *m = &ts->conn; 698 int ret = 1; 699 700 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 701 702 spin_lock(&m->req_lock); 703 704 if (req->status == REQ_STATUS_UNSENT) { 705 list_del(&req->req_list); 706 req->status = REQ_STATUS_FLSHD; 707 p9_req_put(client, req); 708 ret = 0; 709 } 710 spin_unlock(&m->req_lock); 711 712 return ret; 713 } 714 715 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 716 { 717 struct p9_trans_fd *ts = client->trans; 718 struct p9_conn *m = &ts->conn; 719 720 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 721 722 spin_lock(&m->req_lock); 723 /* Ignore cancelled request if message has been received 724 * before lock. 725 */ 726 if (req->status == REQ_STATUS_RCVD) { 727 spin_unlock(&m->req_lock); 728 return 0; 729 } 730 731 /* we haven't received a response for oldreq, 732 * remove it from the list. 733 */ 734 list_del(&req->req_list); 735 req->status = REQ_STATUS_FLSHD; 736 spin_unlock(&m->req_lock); 737 738 p9_req_put(client, req); 739 740 return 0; 741 } 742 743 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 744 { 745 if (clnt->trans_mod == &p9_tcp_trans) { 746 if (clnt->trans_opts.tcp.port != P9_PORT) 747 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 748 } else if (clnt->trans_mod == &p9_fd_trans) { 749 if (clnt->trans_opts.fd.rfd != ~0) 750 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 751 if (clnt->trans_opts.fd.wfd != ~0) 752 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 753 } 754 return 0; 755 } 756 757 /** 758 * parse_opts - parse mount options into p9_fd_opts structure 759 * @params: options string passed from mount 760 * @opts: fd transport-specific structure to parse options into 761 * 762 * Returns 0 upon success, -ERRNO upon failure 763 */ 764 765 static int parse_opts(char *params, struct p9_fd_opts *opts) 766 { 767 char *p; 768 substring_t args[MAX_OPT_ARGS]; 769 int option; 770 char *options, *tmp_options; 771 772 opts->port = P9_PORT; 773 opts->rfd = ~0; 774 opts->wfd = ~0; 775 opts->privport = false; 776 777 if (!params) 778 return 0; 779 780 tmp_options = kstrdup(params, GFP_KERNEL); 781 if (!tmp_options) { 782 p9_debug(P9_DEBUG_ERROR, 783 "failed to allocate copy of option string\n"); 784 return -ENOMEM; 785 } 786 options = tmp_options; 787 788 while ((p = strsep(&options, ",")) != NULL) { 789 int token; 790 int r; 791 if (!*p) 792 continue; 793 token = match_token(p, tokens, args); 794 if ((token != Opt_err) && (token != Opt_privport)) { 795 r = match_int(&args[0], &option); 796 if (r < 0) { 797 p9_debug(P9_DEBUG_ERROR, 798 "integer field, but no integer?\n"); 799 continue; 800 } 801 } 802 switch (token) { 803 case Opt_port: 804 opts->port = option; 805 break; 806 case Opt_rfdno: 807 opts->rfd = option; 808 break; 809 case Opt_wfdno: 810 opts->wfd = option; 811 break; 812 case Opt_privport: 813 opts->privport = true; 814 break; 815 default: 816 continue; 817 } 818 } 819 820 kfree(tmp_options); 821 return 0; 822 } 823 824 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 825 { 826 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 827 GFP_KERNEL); 828 if (!ts) 829 return -ENOMEM; 830 831 ts->rd = fget(rfd); 832 if (!ts->rd) 833 goto out_free_ts; 834 if (!(ts->rd->f_mode & FMODE_READ)) 835 goto out_put_rd; 836 /* prevent workers from hanging on IO when fd is a pipe */ 837 ts->rd->f_flags |= O_NONBLOCK; 838 ts->wr = fget(wfd); 839 if (!ts->wr) 840 goto out_put_rd; 841 if (!(ts->wr->f_mode & FMODE_WRITE)) 842 goto out_put_wr; 843 ts->wr->f_flags |= O_NONBLOCK; 844 845 client->trans = ts; 846 client->status = Connected; 847 848 return 0; 849 850 out_put_wr: 851 fput(ts->wr); 852 out_put_rd: 853 fput(ts->rd); 854 out_free_ts: 855 kfree(ts); 856 return -EIO; 857 } 858 859 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 860 { 861 struct p9_trans_fd *p; 862 struct file *file; 863 864 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 865 if (!p) { 866 sock_release(csocket); 867 return -ENOMEM; 868 } 869 870 csocket->sk->sk_allocation = GFP_NOIO; 871 file = sock_alloc_file(csocket, 0, NULL); 872 if (IS_ERR(file)) { 873 pr_err("%s (%d): failed to map fd\n", 874 __func__, task_pid_nr(current)); 875 kfree(p); 876 return PTR_ERR(file); 877 } 878 879 get_file(file); 880 p->wr = p->rd = file; 881 client->trans = p; 882 client->status = Connected; 883 884 p->rd->f_flags |= O_NONBLOCK; 885 886 p9_conn_create(client); 887 return 0; 888 } 889 890 /** 891 * p9_conn_destroy - cancels all pending requests of mux 892 * @m: mux to destroy 893 * 894 */ 895 896 static void p9_conn_destroy(struct p9_conn *m) 897 { 898 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 899 m, m->mux_list.prev, m->mux_list.next); 900 901 p9_mux_poll_stop(m); 902 cancel_work_sync(&m->rq); 903 if (m->rreq) { 904 p9_req_put(m->client, m->rreq); 905 m->rreq = NULL; 906 } 907 cancel_work_sync(&m->wq); 908 if (m->wreq) { 909 p9_req_put(m->client, m->wreq); 910 m->wreq = NULL; 911 } 912 913 p9_conn_cancel(m, -ECONNRESET); 914 915 m->client = NULL; 916 } 917 918 /** 919 * p9_fd_close - shutdown file descriptor transport 920 * @client: client instance 921 * 922 */ 923 924 static void p9_fd_close(struct p9_client *client) 925 { 926 struct p9_trans_fd *ts; 927 928 if (!client) 929 return; 930 931 ts = client->trans; 932 if (!ts) 933 return; 934 935 client->status = Disconnected; 936 937 p9_conn_destroy(&ts->conn); 938 939 if (ts->rd) 940 fput(ts->rd); 941 if (ts->wr) 942 fput(ts->wr); 943 944 kfree(ts); 945 } 946 947 /* 948 * stolen from NFS - maybe should be made a generic function? 949 */ 950 static inline int valid_ipaddr4(const char *buf) 951 { 952 int rc, count, in[4]; 953 954 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 955 if (rc != 4) 956 return -EINVAL; 957 for (count = 0; count < 4; count++) { 958 if (in[count] > 255) 959 return -EINVAL; 960 } 961 return 0; 962 } 963 964 static int p9_bind_privport(struct socket *sock) 965 { 966 struct sockaddr_in cl; 967 int port, err = -EINVAL; 968 969 memset(&cl, 0, sizeof(cl)); 970 cl.sin_family = AF_INET; 971 cl.sin_addr.s_addr = htonl(INADDR_ANY); 972 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 973 cl.sin_port = htons((ushort)port); 974 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 975 if (err != -EADDRINUSE) 976 break; 977 } 978 return err; 979 } 980 981 982 static int 983 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 984 { 985 int err; 986 struct socket *csocket; 987 struct sockaddr_in sin_server; 988 struct p9_fd_opts opts; 989 990 err = parse_opts(args, &opts); 991 if (err < 0) 992 return err; 993 994 if (addr == NULL || valid_ipaddr4(addr) < 0) 995 return -EINVAL; 996 997 csocket = NULL; 998 999 client->trans_opts.tcp.port = opts.port; 1000 client->trans_opts.tcp.privport = opts.privport; 1001 sin_server.sin_family = AF_INET; 1002 sin_server.sin_addr.s_addr = in_aton(addr); 1003 sin_server.sin_port = htons(opts.port); 1004 err = __sock_create(current->nsproxy->net_ns, PF_INET, 1005 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 1006 if (err) { 1007 pr_err("%s (%d): problem creating socket\n", 1008 __func__, task_pid_nr(current)); 1009 return err; 1010 } 1011 1012 if (opts.privport) { 1013 err = p9_bind_privport(csocket); 1014 if (err < 0) { 1015 pr_err("%s (%d): problem binding to privport\n", 1016 __func__, task_pid_nr(current)); 1017 sock_release(csocket); 1018 return err; 1019 } 1020 } 1021 1022 err = csocket->ops->connect(csocket, 1023 (struct sockaddr *)&sin_server, 1024 sizeof(struct sockaddr_in), 0); 1025 if (err < 0) { 1026 pr_err("%s (%d): problem connecting socket to %s\n", 1027 __func__, task_pid_nr(current), addr); 1028 sock_release(csocket); 1029 return err; 1030 } 1031 1032 return p9_socket_open(client, csocket); 1033 } 1034 1035 static int 1036 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 1037 { 1038 int err; 1039 struct socket *csocket; 1040 struct sockaddr_un sun_server; 1041 1042 csocket = NULL; 1043 1044 if (!addr || !strlen(addr)) 1045 return -EINVAL; 1046 1047 if (strlen(addr) >= UNIX_PATH_MAX) { 1048 pr_err("%s (%d): address too long: %s\n", 1049 __func__, task_pid_nr(current), addr); 1050 return -ENAMETOOLONG; 1051 } 1052 1053 sun_server.sun_family = PF_UNIX; 1054 strcpy(sun_server.sun_path, addr); 1055 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1056 SOCK_STREAM, 0, &csocket, 1); 1057 if (err < 0) { 1058 pr_err("%s (%d): problem creating socket\n", 1059 __func__, task_pid_nr(current)); 1060 1061 return err; 1062 } 1063 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1064 sizeof(struct sockaddr_un) - 1, 0); 1065 if (err < 0) { 1066 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1067 __func__, task_pid_nr(current), addr, err); 1068 sock_release(csocket); 1069 return err; 1070 } 1071 1072 return p9_socket_open(client, csocket); 1073 } 1074 1075 static int 1076 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1077 { 1078 int err; 1079 struct p9_fd_opts opts; 1080 1081 err = parse_opts(args, &opts); 1082 if (err < 0) 1083 return err; 1084 client->trans_opts.fd.rfd = opts.rfd; 1085 client->trans_opts.fd.wfd = opts.wfd; 1086 1087 if (opts.rfd == ~0 || opts.wfd == ~0) { 1088 pr_err("Insufficient options for proto=fd\n"); 1089 return -ENOPROTOOPT; 1090 } 1091 1092 err = p9_fd_open(client, opts.rfd, opts.wfd); 1093 if (err < 0) 1094 return err; 1095 1096 p9_conn_create(client); 1097 1098 return 0; 1099 } 1100 1101 static struct p9_trans_module p9_tcp_trans = { 1102 .name = "tcp", 1103 .maxsize = MAX_SOCK_BUF, 1104 .pooled_rbuffers = false, 1105 .def = 0, 1106 .create = p9_fd_create_tcp, 1107 .close = p9_fd_close, 1108 .request = p9_fd_request, 1109 .cancel = p9_fd_cancel, 1110 .cancelled = p9_fd_cancelled, 1111 .show_options = p9_fd_show_options, 1112 .owner = THIS_MODULE, 1113 }; 1114 MODULE_ALIAS_9P("tcp"); 1115 1116 static struct p9_trans_module p9_unix_trans = { 1117 .name = "unix", 1118 .maxsize = MAX_SOCK_BUF, 1119 .def = 0, 1120 .create = p9_fd_create_unix, 1121 .close = p9_fd_close, 1122 .request = p9_fd_request, 1123 .cancel = p9_fd_cancel, 1124 .cancelled = p9_fd_cancelled, 1125 .show_options = p9_fd_show_options, 1126 .owner = THIS_MODULE, 1127 }; 1128 MODULE_ALIAS_9P("unix"); 1129 1130 static struct p9_trans_module p9_fd_trans = { 1131 .name = "fd", 1132 .maxsize = MAX_SOCK_BUF, 1133 .def = 0, 1134 .create = p9_fd_create, 1135 .close = p9_fd_close, 1136 .request = p9_fd_request, 1137 .cancel = p9_fd_cancel, 1138 .cancelled = p9_fd_cancelled, 1139 .show_options = p9_fd_show_options, 1140 .owner = THIS_MODULE, 1141 }; 1142 MODULE_ALIAS_9P("fd"); 1143 1144 /** 1145 * p9_poll_workfn - poll worker thread 1146 * @work: work queue 1147 * 1148 * polls all v9fs transports for new events and queues the appropriate 1149 * work to the work queue 1150 * 1151 */ 1152 1153 static void p9_poll_workfn(struct work_struct *work) 1154 { 1155 unsigned long flags; 1156 1157 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1158 1159 spin_lock_irqsave(&p9_poll_lock, flags); 1160 while (!list_empty(&p9_poll_pending_list)) { 1161 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1162 struct p9_conn, 1163 poll_pending_link); 1164 list_del_init(&conn->poll_pending_link); 1165 spin_unlock_irqrestore(&p9_poll_lock, flags); 1166 1167 p9_poll_mux(conn); 1168 1169 spin_lock_irqsave(&p9_poll_lock, flags); 1170 } 1171 spin_unlock_irqrestore(&p9_poll_lock, flags); 1172 1173 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1174 } 1175 1176 static int __init p9_trans_fd_init(void) 1177 { 1178 v9fs_register_trans(&p9_tcp_trans); 1179 v9fs_register_trans(&p9_unix_trans); 1180 v9fs_register_trans(&p9_fd_trans); 1181 1182 return 0; 1183 } 1184 1185 static void __exit p9_trans_fd_exit(void) 1186 { 1187 flush_work(&p9_poll_work); 1188 v9fs_unregister_trans(&p9_tcp_trans); 1189 v9fs_unregister_trans(&p9_unix_trans); 1190 v9fs_unregister_trans(&p9_fd_trans); 1191 } 1192 1193 module_init(p9_trans_fd_init); 1194 module_exit(p9_trans_fd_exit); 1195 1196 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); 1197 MODULE_DESCRIPTION("Filedescriptor Transport for 9P"); 1198 MODULE_LICENSE("GPL"); 1199