1 /* 2 * linux/fs/9p/trans_fd.c 3 * 4 * Fd transport layer. Includes deprecated socket layer. 5 * 6 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com> 7 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> 8 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> 9 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 13 * as published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to: 22 * Free Software Foundation 23 * 51 Franklin Street, Fifth Floor 24 * Boston, MA 02111-1301 USA 25 * 26 */ 27 28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 29 30 #include <linux/in.h> 31 #include <linux/module.h> 32 #include <linux/net.h> 33 #include <linux/ipv6.h> 34 #include <linux/kthread.h> 35 #include <linux/errno.h> 36 #include <linux/kernel.h> 37 #include <linux/un.h> 38 #include <linux/uaccess.h> 39 #include <linux/inet.h> 40 #include <linux/idr.h> 41 #include <linux/file.h> 42 #include <linux/parser.h> 43 #include <linux/slab.h> 44 #include <linux/seq_file.h> 45 #include <net/9p/9p.h> 46 #include <net/9p/client.h> 47 #include <net/9p/transport.h> 48 49 #include <linux/syscalls.h> /* killme */ 50 51 #define P9_PORT 564 52 #define MAX_SOCK_BUF (64*1024) 53 #define MAXPOLLWADDR 2 54 55 static struct p9_trans_module p9_tcp_trans; 56 static struct p9_trans_module p9_fd_trans; 57 58 /** 59 * struct p9_fd_opts - per-transport options 60 * @rfd: file descriptor for reading (trans=fd) 61 * @wfd: file descriptor for writing (trans=fd) 62 * @port: port to connect to (trans=tcp) 63 * 64 */ 65 66 struct p9_fd_opts { 67 int rfd; 68 int wfd; 69 u16 port; 70 bool privport; 71 }; 72 73 /* 74 * Option Parsing (code inspired by NFS code) 75 * - a little lazy - parse all fd-transport options 76 */ 77 78 enum { 79 /* Options that take integer arguments */ 80 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err, 81 /* Options that take no arguments */ 82 Opt_privport, 83 }; 84 85 static const match_table_t tokens = { 86 {Opt_port, "port=%u"}, 87 {Opt_rfdno, "rfdno=%u"}, 88 {Opt_wfdno, "wfdno=%u"}, 89 {Opt_privport, "privport"}, 90 {Opt_err, NULL}, 91 }; 92 93 enum { 94 Rworksched = 1, /* read work scheduled or running */ 95 Rpending = 2, /* can read */ 96 Wworksched = 4, /* write work scheduled or running */ 97 Wpending = 8, /* can write */ 98 }; 99 100 struct p9_poll_wait { 101 struct p9_conn *conn; 102 wait_queue_entry_t wait; 103 wait_queue_head_t *wait_addr; 104 }; 105 106 /** 107 * struct p9_conn - fd mux connection state information 108 * @mux_list: list link for mux to manage multiple connections (?) 109 * @client: reference to client instance for this connection 110 * @err: error state 111 * @req_list: accounting for requests which have been sent 112 * @unsent_req_list: accounting for requests that haven't been sent 113 * @req: current request being processed (if any) 114 * @tmp_buf: temporary buffer to read in header 115 * @rc: temporary fcall for reading current frame 116 * @wpos: write position for current frame 117 * @wsize: amount of data to write for current frame 118 * @wbuf: current write buffer 119 * @poll_pending_link: pending links to be polled per conn 120 * @poll_wait: array of wait_q's for various worker threads 121 * @pt: poll state 122 * @rq: current read work 123 * @wq: current write work 124 * @wsched: ???? 125 * 126 */ 127 128 struct p9_conn { 129 struct list_head mux_list; 130 struct p9_client *client; 131 int err; 132 struct list_head req_list; 133 struct list_head unsent_req_list; 134 struct p9_req_t *req; 135 char tmp_buf[7]; 136 struct p9_fcall rc; 137 int wpos; 138 int wsize; 139 char *wbuf; 140 struct list_head poll_pending_link; 141 struct p9_poll_wait poll_wait[MAXPOLLWADDR]; 142 poll_table pt; 143 struct work_struct rq; 144 struct work_struct wq; 145 unsigned long wsched; 146 }; 147 148 /** 149 * struct p9_trans_fd - transport state 150 * @rd: reference to file to read from 151 * @wr: reference of file to write to 152 * @conn: connection state reference 153 * 154 */ 155 156 struct p9_trans_fd { 157 struct file *rd; 158 struct file *wr; 159 struct p9_conn conn; 160 }; 161 162 static void p9_poll_workfn(struct work_struct *work); 163 164 static DEFINE_SPINLOCK(p9_poll_lock); 165 static LIST_HEAD(p9_poll_pending_list); 166 static DECLARE_WORK(p9_poll_work, p9_poll_workfn); 167 168 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT; 169 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT; 170 171 static void p9_mux_poll_stop(struct p9_conn *m) 172 { 173 unsigned long flags; 174 int i; 175 176 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 177 struct p9_poll_wait *pwait = &m->poll_wait[i]; 178 179 if (pwait->wait_addr) { 180 remove_wait_queue(pwait->wait_addr, &pwait->wait); 181 pwait->wait_addr = NULL; 182 } 183 } 184 185 spin_lock_irqsave(&p9_poll_lock, flags); 186 list_del_init(&m->poll_pending_link); 187 spin_unlock_irqrestore(&p9_poll_lock, flags); 188 } 189 190 /** 191 * p9_conn_cancel - cancel all pending requests with error 192 * @m: mux data 193 * @err: error code 194 * 195 */ 196 197 static void p9_conn_cancel(struct p9_conn *m, int err) 198 { 199 struct p9_req_t *req, *rtmp; 200 unsigned long flags; 201 LIST_HEAD(cancel_list); 202 203 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err); 204 205 spin_lock_irqsave(&m->client->lock, flags); 206 207 if (m->err) { 208 spin_unlock_irqrestore(&m->client->lock, flags); 209 return; 210 } 211 212 m->err = err; 213 214 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { 215 list_move(&req->req_list, &cancel_list); 216 } 217 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { 218 list_move(&req->req_list, &cancel_list); 219 } 220 spin_unlock_irqrestore(&m->client->lock, flags); 221 222 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { 223 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); 224 list_del(&req->req_list); 225 if (!req->t_err) 226 req->t_err = err; 227 p9_client_cb(m->client, req, REQ_STATUS_ERROR); 228 } 229 } 230 231 static int 232 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt) 233 { 234 int ret, n; 235 struct p9_trans_fd *ts = NULL; 236 237 if (client && client->status == Connected) 238 ts = client->trans; 239 240 if (!ts) 241 return -EREMOTEIO; 242 243 if (!ts->rd->f_op->poll) 244 return -EIO; 245 246 if (!ts->wr->f_op->poll) 247 return -EIO; 248 249 ret = ts->rd->f_op->poll(ts->rd, pt); 250 if (ret < 0) 251 return ret; 252 253 if (ts->rd != ts->wr) { 254 n = ts->wr->f_op->poll(ts->wr, pt); 255 if (n < 0) 256 return n; 257 ret = (ret & ~POLLOUT) | (n & ~POLLIN); 258 } 259 260 return ret; 261 } 262 263 /** 264 * p9_fd_read- read from a fd 265 * @client: client instance 266 * @v: buffer to receive data into 267 * @len: size of receive buffer 268 * 269 */ 270 271 static int p9_fd_read(struct p9_client *client, void *v, int len) 272 { 273 int ret; 274 struct p9_trans_fd *ts = NULL; 275 276 if (client && client->status != Disconnected) 277 ts = client->trans; 278 279 if (!ts) 280 return -EREMOTEIO; 281 282 if (!(ts->rd->f_flags & O_NONBLOCK)) 283 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 284 285 ret = kernel_read(ts->rd, ts->rd->f_pos, v, len); 286 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 287 client->status = Disconnected; 288 return ret; 289 } 290 291 /** 292 * p9_read_work - called when there is some data to be read from a transport 293 * @work: container of work to be done 294 * 295 */ 296 297 static void p9_read_work(struct work_struct *work) 298 { 299 int n, err; 300 struct p9_conn *m; 301 int status = REQ_STATUS_ERROR; 302 303 m = container_of(work, struct p9_conn, rq); 304 305 if (m->err < 0) 306 return; 307 308 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 309 310 if (!m->rc.sdata) { 311 m->rc.sdata = m->tmp_buf; 312 m->rc.offset = 0; 313 m->rc.capacity = 7; /* start by reading header */ 314 } 315 316 clear_bit(Rpending, &m->wsched); 317 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 318 m, m->rc.offset, m->rc.capacity, 319 m->rc.capacity - m->rc.offset); 320 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 321 m->rc.capacity - m->rc.offset); 322 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 323 if (err == -EAGAIN) 324 goto end_clear; 325 326 if (err <= 0) 327 goto error; 328 329 m->rc.offset += err; 330 331 /* header read in */ 332 if ((!m->req) && (m->rc.offset == m->rc.capacity)) { 333 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 334 335 err = p9_parse_header(&m->rc, NULL, NULL, NULL, 0); 336 if (err) { 337 p9_debug(P9_DEBUG_ERROR, 338 "error parsing header: %d\n", err); 339 goto error; 340 } 341 342 if (m->rc.size >= m->client->msize) { 343 p9_debug(P9_DEBUG_ERROR, 344 "requested packet size too big: %d\n", 345 m->rc.size); 346 err = -EIO; 347 goto error; 348 } 349 350 p9_debug(P9_DEBUG_TRANS, 351 "mux %p pkt: size: %d bytes tag: %d\n", 352 m, m->rc.size, m->rc.tag); 353 354 m->req = p9_tag_lookup(m->client, m->rc.tag); 355 if (!m->req || (m->req->status != REQ_STATUS_SENT)) { 356 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 357 m->rc.tag); 358 err = -EIO; 359 goto error; 360 } 361 362 if (m->req->rc == NULL) { 363 p9_debug(P9_DEBUG_ERROR, 364 "No recv fcall for tag %d (req %p), disconnecting!\n", 365 m->rc.tag, m->req); 366 m->req = NULL; 367 err = -EIO; 368 goto error; 369 } 370 m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall); 371 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 372 m->rc.capacity = m->rc.size; 373 } 374 375 /* packet is read in 376 * not an else because some packets (like clunk) have no payload 377 */ 378 if ((m->req) && (m->rc.offset == m->rc.capacity)) { 379 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 380 spin_lock(&m->client->lock); 381 if (m->req->status != REQ_STATUS_ERROR) 382 status = REQ_STATUS_RCVD; 383 list_del(&m->req->req_list); 384 spin_unlock(&m->client->lock); 385 p9_client_cb(m->client, m->req, status); 386 m->rc.sdata = NULL; 387 m->rc.offset = 0; 388 m->rc.capacity = 0; 389 m->req = NULL; 390 } 391 392 end_clear: 393 clear_bit(Rworksched, &m->wsched); 394 395 if (!list_empty(&m->req_list)) { 396 if (test_and_clear_bit(Rpending, &m->wsched)) 397 n = POLLIN; 398 else 399 n = p9_fd_poll(m->client, NULL); 400 401 if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 402 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 403 schedule_work(&m->rq); 404 } 405 } 406 407 return; 408 error: 409 p9_conn_cancel(m, err); 410 clear_bit(Rworksched, &m->wsched); 411 } 412 413 /** 414 * p9_fd_write - write to a socket 415 * @client: client instance 416 * @v: buffer to send data from 417 * @len: size of send buffer 418 * 419 */ 420 421 static int p9_fd_write(struct p9_client *client, void *v, int len) 422 { 423 int ret; 424 mm_segment_t oldfs; 425 struct p9_trans_fd *ts = NULL; 426 427 if (client && client->status != Disconnected) 428 ts = client->trans; 429 430 if (!ts) 431 return -EREMOTEIO; 432 433 if (!(ts->wr->f_flags & O_NONBLOCK)) 434 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 435 436 oldfs = get_fs(); 437 set_fs(get_ds()); 438 /* The cast to a user pointer is valid due to the set_fs() */ 439 ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos); 440 set_fs(oldfs); 441 442 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 443 client->status = Disconnected; 444 return ret; 445 } 446 447 /** 448 * p9_write_work - called when a transport can send some data 449 * @work: container for work to be done 450 * 451 */ 452 453 static void p9_write_work(struct work_struct *work) 454 { 455 int n, err; 456 struct p9_conn *m; 457 struct p9_req_t *req; 458 459 m = container_of(work, struct p9_conn, wq); 460 461 if (m->err < 0) { 462 clear_bit(Wworksched, &m->wsched); 463 return; 464 } 465 466 if (!m->wsize) { 467 spin_lock(&m->client->lock); 468 if (list_empty(&m->unsent_req_list)) { 469 clear_bit(Wworksched, &m->wsched); 470 spin_unlock(&m->client->lock); 471 return; 472 } 473 474 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 475 req_list); 476 req->status = REQ_STATUS_SENT; 477 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 478 list_move_tail(&req->req_list, &m->req_list); 479 480 m->wbuf = req->tc->sdata; 481 m->wsize = req->tc->size; 482 m->wpos = 0; 483 spin_unlock(&m->client->lock); 484 } 485 486 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 487 m, m->wpos, m->wsize); 488 clear_bit(Wpending, &m->wsched); 489 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 490 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 491 if (err == -EAGAIN) 492 goto end_clear; 493 494 495 if (err < 0) 496 goto error; 497 else if (err == 0) { 498 err = -EREMOTEIO; 499 goto error; 500 } 501 502 m->wpos += err; 503 if (m->wpos == m->wsize) 504 m->wpos = m->wsize = 0; 505 506 end_clear: 507 clear_bit(Wworksched, &m->wsched); 508 509 if (m->wsize || !list_empty(&m->unsent_req_list)) { 510 if (test_and_clear_bit(Wpending, &m->wsched)) 511 n = POLLOUT; 512 else 513 n = p9_fd_poll(m->client, NULL); 514 515 if ((n & POLLOUT) && 516 !test_and_set_bit(Wworksched, &m->wsched)) { 517 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 518 schedule_work(&m->wq); 519 } 520 } 521 522 return; 523 524 error: 525 p9_conn_cancel(m, err); 526 clear_bit(Wworksched, &m->wsched); 527 } 528 529 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 530 { 531 struct p9_poll_wait *pwait = 532 container_of(wait, struct p9_poll_wait, wait); 533 struct p9_conn *m = pwait->conn; 534 unsigned long flags; 535 536 spin_lock_irqsave(&p9_poll_lock, flags); 537 if (list_empty(&m->poll_pending_link)) 538 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 539 spin_unlock_irqrestore(&p9_poll_lock, flags); 540 541 schedule_work(&p9_poll_work); 542 return 1; 543 } 544 545 /** 546 * p9_pollwait - add poll task to the wait queue 547 * @filp: file pointer being polled 548 * @wait_address: wait_q to block on 549 * @p: poll state 550 * 551 * called by files poll operation to add v9fs-poll task to files wait queue 552 */ 553 554 static void 555 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 556 { 557 struct p9_conn *m = container_of(p, struct p9_conn, pt); 558 struct p9_poll_wait *pwait = NULL; 559 int i; 560 561 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 562 if (m->poll_wait[i].wait_addr == NULL) { 563 pwait = &m->poll_wait[i]; 564 break; 565 } 566 } 567 568 if (!pwait) { 569 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 570 return; 571 } 572 573 pwait->conn = m; 574 pwait->wait_addr = wait_address; 575 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 576 add_wait_queue(wait_address, &pwait->wait); 577 } 578 579 /** 580 * p9_conn_create - initialize the per-session mux data 581 * @client: client instance 582 * 583 * Note: Creates the polling task if this is the first session. 584 */ 585 586 static void p9_conn_create(struct p9_client *client) 587 { 588 int n; 589 struct p9_trans_fd *ts = client->trans; 590 struct p9_conn *m = &ts->conn; 591 592 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 593 594 INIT_LIST_HEAD(&m->mux_list); 595 m->client = client; 596 597 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); 605 if (n & POLLIN) { 606 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 607 set_bit(Rpending, &m->wsched); 608 } 609 610 if (n & POLLOUT) { 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 int n; 625 626 if (m->err < 0) 627 return; 628 629 n = p9_fd_poll(m->client, NULL); 630 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) { 631 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 632 if (n >= 0) 633 n = -ECONNRESET; 634 p9_conn_cancel(m, n); 635 } 636 637 if (n & POLLIN) { 638 set_bit(Rpending, &m->wsched); 639 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 640 if (!test_and_set_bit(Rworksched, &m->wsched)) { 641 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 642 schedule_work(&m->rq); 643 } 644 } 645 646 if (n & POLLOUT) { 647 set_bit(Wpending, &m->wsched); 648 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 649 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 650 !test_and_set_bit(Wworksched, &m->wsched)) { 651 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 652 schedule_work(&m->wq); 653 } 654 } 655 } 656 657 /** 658 * p9_fd_request - send 9P request 659 * The function can sleep until the request is scheduled for sending. 660 * The function can be interrupted. Return from the function is not 661 * a guarantee that the request is sent successfully. 662 * 663 * @client: client instance 664 * @req: request to be sent 665 * 666 */ 667 668 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 669 { 670 int n; 671 struct p9_trans_fd *ts = client->trans; 672 struct p9_conn *m = &ts->conn; 673 674 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 675 m, current, req->tc, req->tc->id); 676 if (m->err < 0) 677 return m->err; 678 679 spin_lock(&client->lock); 680 req->status = REQ_STATUS_UNSENT; 681 list_add_tail(&req->req_list, &m->unsent_req_list); 682 spin_unlock(&client->lock); 683 684 if (test_and_clear_bit(Wpending, &m->wsched)) 685 n = POLLOUT; 686 else 687 n = p9_fd_poll(m->client, NULL); 688 689 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 690 schedule_work(&m->wq); 691 692 return 0; 693 } 694 695 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 696 { 697 int ret = 1; 698 699 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 700 701 spin_lock(&client->lock); 702 703 if (req->status == REQ_STATUS_UNSENT) { 704 list_del(&req->req_list); 705 req->status = REQ_STATUS_FLSHD; 706 ret = 0; 707 } 708 spin_unlock(&client->lock); 709 710 return ret; 711 } 712 713 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 714 { 715 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 716 717 /* we haven't received a response for oldreq, 718 * remove it from the list. 719 */ 720 spin_lock(&client->lock); 721 list_del(&req->req_list); 722 spin_unlock(&client->lock); 723 724 return 0; 725 } 726 727 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 728 { 729 if (clnt->trans_mod == &p9_tcp_trans) { 730 if (clnt->trans_opts.tcp.port != P9_PORT) 731 seq_printf(m, "port=%u", clnt->trans_opts.tcp.port); 732 } else if (clnt->trans_mod == &p9_fd_trans) { 733 if (clnt->trans_opts.fd.rfd != ~0) 734 seq_printf(m, "rfd=%u", clnt->trans_opts.fd.rfd); 735 if (clnt->trans_opts.fd.wfd != ~0) 736 seq_printf(m, "wfd=%u", clnt->trans_opts.fd.wfd); 737 } 738 return 0; 739 } 740 741 /** 742 * parse_opts - parse mount options into p9_fd_opts structure 743 * @params: options string passed from mount 744 * @opts: fd transport-specific structure to parse options into 745 * 746 * Returns 0 upon success, -ERRNO upon failure 747 */ 748 749 static int parse_opts(char *params, struct p9_fd_opts *opts) 750 { 751 char *p; 752 substring_t args[MAX_OPT_ARGS]; 753 int option; 754 char *options, *tmp_options; 755 756 opts->port = P9_PORT; 757 opts->rfd = ~0; 758 opts->wfd = ~0; 759 opts->privport = false; 760 761 if (!params) 762 return 0; 763 764 tmp_options = kstrdup(params, GFP_KERNEL); 765 if (!tmp_options) { 766 p9_debug(P9_DEBUG_ERROR, 767 "failed to allocate copy of option string\n"); 768 return -ENOMEM; 769 } 770 options = tmp_options; 771 772 while ((p = strsep(&options, ",")) != NULL) { 773 int token; 774 int r; 775 if (!*p) 776 continue; 777 token = match_token(p, tokens, args); 778 if ((token != Opt_err) && (token != Opt_privport)) { 779 r = match_int(&args[0], &option); 780 if (r < 0) { 781 p9_debug(P9_DEBUG_ERROR, 782 "integer field, but no integer?\n"); 783 continue; 784 } 785 } 786 switch (token) { 787 case Opt_port: 788 opts->port = option; 789 break; 790 case Opt_rfdno: 791 opts->rfd = option; 792 break; 793 case Opt_wfdno: 794 opts->wfd = option; 795 break; 796 case Opt_privport: 797 opts->privport = true; 798 break; 799 default: 800 continue; 801 } 802 } 803 804 kfree(tmp_options); 805 return 0; 806 } 807 808 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 809 { 810 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 811 GFP_KERNEL); 812 if (!ts) 813 return -ENOMEM; 814 815 ts->rd = fget(rfd); 816 ts->wr = fget(wfd); 817 if (!ts->rd || !ts->wr) { 818 if (ts->rd) 819 fput(ts->rd); 820 if (ts->wr) 821 fput(ts->wr); 822 kfree(ts); 823 return -EIO; 824 } 825 826 client->trans = ts; 827 client->status = Connected; 828 829 return 0; 830 } 831 832 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 833 { 834 struct p9_trans_fd *p; 835 struct file *file; 836 837 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 838 if (!p) 839 return -ENOMEM; 840 841 csocket->sk->sk_allocation = GFP_NOIO; 842 file = sock_alloc_file(csocket, 0, NULL); 843 if (IS_ERR(file)) { 844 pr_err("%s (%d): failed to map fd\n", 845 __func__, task_pid_nr(current)); 846 sock_release(csocket); 847 kfree(p); 848 return PTR_ERR(file); 849 } 850 851 get_file(file); 852 p->wr = p->rd = file; 853 client->trans = p; 854 client->status = Connected; 855 856 p->rd->f_flags |= O_NONBLOCK; 857 858 p9_conn_create(client); 859 return 0; 860 } 861 862 /** 863 * p9_mux_destroy - cancels all pending requests of mux 864 * @m: mux to destroy 865 * 866 */ 867 868 static void p9_conn_destroy(struct p9_conn *m) 869 { 870 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 871 m, m->mux_list.prev, m->mux_list.next); 872 873 p9_mux_poll_stop(m); 874 cancel_work_sync(&m->rq); 875 cancel_work_sync(&m->wq); 876 877 p9_conn_cancel(m, -ECONNRESET); 878 879 m->client = NULL; 880 } 881 882 /** 883 * p9_fd_close - shutdown file descriptor transport 884 * @client: client instance 885 * 886 */ 887 888 static void p9_fd_close(struct p9_client *client) 889 { 890 struct p9_trans_fd *ts; 891 892 if (!client) 893 return; 894 895 ts = client->trans; 896 if (!ts) 897 return; 898 899 client->status = Disconnected; 900 901 p9_conn_destroy(&ts->conn); 902 903 if (ts->rd) 904 fput(ts->rd); 905 if (ts->wr) 906 fput(ts->wr); 907 908 kfree(ts); 909 } 910 911 /* 912 * stolen from NFS - maybe should be made a generic function? 913 */ 914 static inline int valid_ipaddr4(const char *buf) 915 { 916 int rc, count, in[4]; 917 918 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 919 if (rc != 4) 920 return -EINVAL; 921 for (count = 0; count < 4; count++) { 922 if (in[count] > 255) 923 return -EINVAL; 924 } 925 return 0; 926 } 927 928 static int p9_bind_privport(struct socket *sock) 929 { 930 struct sockaddr_in cl; 931 int port, err = -EINVAL; 932 933 memset(&cl, 0, sizeof(cl)); 934 cl.sin_family = AF_INET; 935 cl.sin_addr.s_addr = INADDR_ANY; 936 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 937 cl.sin_port = htons((ushort)port); 938 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 939 if (err != -EADDRINUSE) 940 break; 941 } 942 return err; 943 } 944 945 946 static int 947 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 948 { 949 int err; 950 struct socket *csocket; 951 struct sockaddr_in sin_server; 952 struct p9_fd_opts opts; 953 954 err = parse_opts(args, &opts); 955 if (err < 0) 956 return err; 957 958 if (valid_ipaddr4(addr) < 0) 959 return -EINVAL; 960 961 csocket = NULL; 962 963 client->trans_opts.tcp.port = opts.port; 964 client->trans_opts.tcp.privport = opts.privport; 965 sin_server.sin_family = AF_INET; 966 sin_server.sin_addr.s_addr = in_aton(addr); 967 sin_server.sin_port = htons(opts.port); 968 err = __sock_create(current->nsproxy->net_ns, PF_INET, 969 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 970 if (err) { 971 pr_err("%s (%d): problem creating socket\n", 972 __func__, task_pid_nr(current)); 973 return err; 974 } 975 976 if (opts.privport) { 977 err = p9_bind_privport(csocket); 978 if (err < 0) { 979 pr_err("%s (%d): problem binding to privport\n", 980 __func__, task_pid_nr(current)); 981 sock_release(csocket); 982 return err; 983 } 984 } 985 986 err = csocket->ops->connect(csocket, 987 (struct sockaddr *)&sin_server, 988 sizeof(struct sockaddr_in), 0); 989 if (err < 0) { 990 pr_err("%s (%d): problem connecting socket to %s\n", 991 __func__, task_pid_nr(current), addr); 992 sock_release(csocket); 993 return err; 994 } 995 996 return p9_socket_open(client, csocket); 997 } 998 999 static int 1000 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 1001 { 1002 int err; 1003 struct socket *csocket; 1004 struct sockaddr_un sun_server; 1005 1006 csocket = NULL; 1007 1008 if (strlen(addr) >= UNIX_PATH_MAX) { 1009 pr_err("%s (%d): address too long: %s\n", 1010 __func__, task_pid_nr(current), addr); 1011 return -ENAMETOOLONG; 1012 } 1013 1014 sun_server.sun_family = PF_UNIX; 1015 strcpy(sun_server.sun_path, addr); 1016 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1017 SOCK_STREAM, 0, &csocket, 1); 1018 if (err < 0) { 1019 pr_err("%s (%d): problem creating socket\n", 1020 __func__, task_pid_nr(current)); 1021 1022 return err; 1023 } 1024 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1025 sizeof(struct sockaddr_un) - 1, 0); 1026 if (err < 0) { 1027 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1028 __func__, task_pid_nr(current), addr, err); 1029 sock_release(csocket); 1030 return err; 1031 } 1032 1033 return p9_socket_open(client, csocket); 1034 } 1035 1036 static int 1037 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1038 { 1039 int err; 1040 struct p9_fd_opts opts; 1041 1042 parse_opts(args, &opts); 1043 client->trans_opts.fd.rfd = opts.rfd; 1044 client->trans_opts.fd.wfd = opts.wfd; 1045 1046 if (opts.rfd == ~0 || opts.wfd == ~0) { 1047 pr_err("Insufficient options for proto=fd\n"); 1048 return -ENOPROTOOPT; 1049 } 1050 1051 err = p9_fd_open(client, opts.rfd, opts.wfd); 1052 if (err < 0) 1053 return err; 1054 1055 p9_conn_create(client); 1056 1057 return 0; 1058 } 1059 1060 static struct p9_trans_module p9_tcp_trans = { 1061 .name = "tcp", 1062 .maxsize = MAX_SOCK_BUF, 1063 .def = 0, 1064 .create = p9_fd_create_tcp, 1065 .close = p9_fd_close, 1066 .request = p9_fd_request, 1067 .cancel = p9_fd_cancel, 1068 .cancelled = p9_fd_cancelled, 1069 .show_options = p9_fd_show_options, 1070 .owner = THIS_MODULE, 1071 }; 1072 1073 static struct p9_trans_module p9_unix_trans = { 1074 .name = "unix", 1075 .maxsize = MAX_SOCK_BUF, 1076 .def = 0, 1077 .create = p9_fd_create_unix, 1078 .close = p9_fd_close, 1079 .request = p9_fd_request, 1080 .cancel = p9_fd_cancel, 1081 .cancelled = p9_fd_cancelled, 1082 .show_options = p9_fd_show_options, 1083 .owner = THIS_MODULE, 1084 }; 1085 1086 static struct p9_trans_module p9_fd_trans = { 1087 .name = "fd", 1088 .maxsize = MAX_SOCK_BUF, 1089 .def = 0, 1090 .create = p9_fd_create, 1091 .close = p9_fd_close, 1092 .request = p9_fd_request, 1093 .cancel = p9_fd_cancel, 1094 .cancelled = p9_fd_cancelled, 1095 .show_options = p9_fd_show_options, 1096 .owner = THIS_MODULE, 1097 }; 1098 1099 /** 1100 * p9_poll_proc - poll worker thread 1101 * @a: thread state and arguments 1102 * 1103 * polls all v9fs transports for new events and queues the appropriate 1104 * work to the work queue 1105 * 1106 */ 1107 1108 static void p9_poll_workfn(struct work_struct *work) 1109 { 1110 unsigned long flags; 1111 1112 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1113 1114 spin_lock_irqsave(&p9_poll_lock, flags); 1115 while (!list_empty(&p9_poll_pending_list)) { 1116 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1117 struct p9_conn, 1118 poll_pending_link); 1119 list_del_init(&conn->poll_pending_link); 1120 spin_unlock_irqrestore(&p9_poll_lock, flags); 1121 1122 p9_poll_mux(conn); 1123 1124 spin_lock_irqsave(&p9_poll_lock, flags); 1125 } 1126 spin_unlock_irqrestore(&p9_poll_lock, flags); 1127 1128 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1129 } 1130 1131 int p9_trans_fd_init(void) 1132 { 1133 v9fs_register_trans(&p9_tcp_trans); 1134 v9fs_register_trans(&p9_unix_trans); 1135 v9fs_register_trans(&p9_fd_trans); 1136 1137 return 0; 1138 } 1139 1140 void p9_trans_fd_exit(void) 1141 { 1142 flush_work(&p9_poll_work); 1143 v9fs_unregister_trans(&p9_tcp_trans); 1144 v9fs_unregister_trans(&p9_unix_trans); 1145 v9fs_unregister_trans(&p9_fd_trans); 1146 } 1147