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 loff_t pos; 276 277 if (client && client->status != Disconnected) 278 ts = client->trans; 279 280 if (!ts) 281 return -EREMOTEIO; 282 283 if (!(ts->rd->f_flags & O_NONBLOCK)) 284 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 285 286 pos = ts->rd->f_pos; 287 ret = kernel_read(ts->rd, v, len, &pos); 288 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 289 client->status = Disconnected; 290 return ret; 291 } 292 293 /** 294 * p9_read_work - called when there is some data to be read from a transport 295 * @work: container of work to be done 296 * 297 */ 298 299 static void p9_read_work(struct work_struct *work) 300 { 301 int n, err; 302 struct p9_conn *m; 303 int status = REQ_STATUS_ERROR; 304 305 m = container_of(work, struct p9_conn, rq); 306 307 if (m->err < 0) 308 return; 309 310 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 311 312 if (!m->rc.sdata) { 313 m->rc.sdata = m->tmp_buf; 314 m->rc.offset = 0; 315 m->rc.capacity = 7; /* start by reading header */ 316 } 317 318 clear_bit(Rpending, &m->wsched); 319 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 320 m, m->rc.offset, m->rc.capacity, 321 m->rc.capacity - m->rc.offset); 322 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 323 m->rc.capacity - m->rc.offset); 324 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 325 if (err == -EAGAIN) 326 goto end_clear; 327 328 if (err <= 0) 329 goto error; 330 331 m->rc.offset += err; 332 333 /* header read in */ 334 if ((!m->req) && (m->rc.offset == m->rc.capacity)) { 335 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 336 337 err = p9_parse_header(&m->rc, NULL, NULL, NULL, 0); 338 if (err) { 339 p9_debug(P9_DEBUG_ERROR, 340 "error parsing header: %d\n", err); 341 goto error; 342 } 343 344 if (m->rc.size >= m->client->msize) { 345 p9_debug(P9_DEBUG_ERROR, 346 "requested packet size too big: %d\n", 347 m->rc.size); 348 err = -EIO; 349 goto error; 350 } 351 352 p9_debug(P9_DEBUG_TRANS, 353 "mux %p pkt: size: %d bytes tag: %d\n", 354 m, m->rc.size, m->rc.tag); 355 356 m->req = p9_tag_lookup(m->client, m->rc.tag); 357 if (!m->req || (m->req->status != REQ_STATUS_SENT)) { 358 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 359 m->rc.tag); 360 err = -EIO; 361 goto error; 362 } 363 364 if (m->req->rc == NULL) { 365 p9_debug(P9_DEBUG_ERROR, 366 "No recv fcall for tag %d (req %p), disconnecting!\n", 367 m->rc.tag, m->req); 368 m->req = NULL; 369 err = -EIO; 370 goto error; 371 } 372 m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall); 373 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 374 m->rc.capacity = m->rc.size; 375 } 376 377 /* packet is read in 378 * not an else because some packets (like clunk) have no payload 379 */ 380 if ((m->req) && (m->rc.offset == m->rc.capacity)) { 381 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 382 spin_lock(&m->client->lock); 383 if (m->req->status != REQ_STATUS_ERROR) 384 status = REQ_STATUS_RCVD; 385 list_del(&m->req->req_list); 386 spin_unlock(&m->client->lock); 387 p9_client_cb(m->client, m->req, status); 388 m->rc.sdata = NULL; 389 m->rc.offset = 0; 390 m->rc.capacity = 0; 391 m->req = NULL; 392 } 393 394 end_clear: 395 clear_bit(Rworksched, &m->wsched); 396 397 if (!list_empty(&m->req_list)) { 398 if (test_and_clear_bit(Rpending, &m->wsched)) 399 n = POLLIN; 400 else 401 n = p9_fd_poll(m->client, NULL); 402 403 if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 404 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 405 schedule_work(&m->rq); 406 } 407 } 408 409 return; 410 error: 411 p9_conn_cancel(m, err); 412 clear_bit(Rworksched, &m->wsched); 413 } 414 415 /** 416 * p9_fd_write - write to a socket 417 * @client: client instance 418 * @v: buffer to send data from 419 * @len: size of send buffer 420 * 421 */ 422 423 static int p9_fd_write(struct p9_client *client, void *v, int len) 424 { 425 ssize_t ret; 426 struct p9_trans_fd *ts = NULL; 427 428 if (client && client->status != Disconnected) 429 ts = client->trans; 430 431 if (!ts) 432 return -EREMOTEIO; 433 434 if (!(ts->wr->f_flags & O_NONBLOCK)) 435 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 436 437 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 438 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 439 client->status = Disconnected; 440 return ret; 441 } 442 443 /** 444 * p9_write_work - called when a transport can send some data 445 * @work: container for work to be done 446 * 447 */ 448 449 static void p9_write_work(struct work_struct *work) 450 { 451 int n, err; 452 struct p9_conn *m; 453 struct p9_req_t *req; 454 455 m = container_of(work, struct p9_conn, wq); 456 457 if (m->err < 0) { 458 clear_bit(Wworksched, &m->wsched); 459 return; 460 } 461 462 if (!m->wsize) { 463 spin_lock(&m->client->lock); 464 if (list_empty(&m->unsent_req_list)) { 465 clear_bit(Wworksched, &m->wsched); 466 spin_unlock(&m->client->lock); 467 return; 468 } 469 470 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 471 req_list); 472 req->status = REQ_STATUS_SENT; 473 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 474 list_move_tail(&req->req_list, &m->req_list); 475 476 m->wbuf = req->tc->sdata; 477 m->wsize = req->tc->size; 478 m->wpos = 0; 479 spin_unlock(&m->client->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; 501 502 end_clear: 503 clear_bit(Wworksched, &m->wsched); 504 505 if (m->wsize || !list_empty(&m->unsent_req_list)) { 506 if (test_and_clear_bit(Wpending, &m->wsched)) 507 n = POLLOUT; 508 else 509 n = p9_fd_poll(m->client, NULL); 510 511 if ((n & POLLOUT) && 512 !test_and_set_bit(Wworksched, &m->wsched)) { 513 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 514 schedule_work(&m->wq); 515 } 516 } 517 518 return; 519 520 error: 521 p9_conn_cancel(m, err); 522 clear_bit(Wworksched, &m->wsched); 523 } 524 525 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 526 { 527 struct p9_poll_wait *pwait = 528 container_of(wait, struct p9_poll_wait, wait); 529 struct p9_conn *m = pwait->conn; 530 unsigned long flags; 531 532 spin_lock_irqsave(&p9_poll_lock, flags); 533 if (list_empty(&m->poll_pending_link)) 534 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 535 spin_unlock_irqrestore(&p9_poll_lock, flags); 536 537 schedule_work(&p9_poll_work); 538 return 1; 539 } 540 541 /** 542 * p9_pollwait - add poll task to the wait queue 543 * @filp: file pointer being polled 544 * @wait_address: wait_q to block on 545 * @p: poll state 546 * 547 * called by files poll operation to add v9fs-poll task to files wait queue 548 */ 549 550 static void 551 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 552 { 553 struct p9_conn *m = container_of(p, struct p9_conn, pt); 554 struct p9_poll_wait *pwait = NULL; 555 int i; 556 557 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 558 if (m->poll_wait[i].wait_addr == NULL) { 559 pwait = &m->poll_wait[i]; 560 break; 561 } 562 } 563 564 if (!pwait) { 565 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 566 return; 567 } 568 569 pwait->conn = m; 570 pwait->wait_addr = wait_address; 571 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 572 add_wait_queue(wait_address, &pwait->wait); 573 } 574 575 /** 576 * p9_conn_create - initialize the per-session mux data 577 * @client: client instance 578 * 579 * Note: Creates the polling task if this is the first session. 580 */ 581 582 static void p9_conn_create(struct p9_client *client) 583 { 584 int n; 585 struct p9_trans_fd *ts = client->trans; 586 struct p9_conn *m = &ts->conn; 587 588 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 589 590 INIT_LIST_HEAD(&m->mux_list); 591 m->client = client; 592 593 INIT_LIST_HEAD(&m->req_list); 594 INIT_LIST_HEAD(&m->unsent_req_list); 595 INIT_WORK(&m->rq, p9_read_work); 596 INIT_WORK(&m->wq, p9_write_work); 597 INIT_LIST_HEAD(&m->poll_pending_link); 598 init_poll_funcptr(&m->pt, p9_pollwait); 599 600 n = p9_fd_poll(client, &m->pt); 601 if (n & POLLIN) { 602 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 603 set_bit(Rpending, &m->wsched); 604 } 605 606 if (n & POLLOUT) { 607 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 608 set_bit(Wpending, &m->wsched); 609 } 610 } 611 612 /** 613 * p9_poll_mux - polls a mux and schedules read or write works if necessary 614 * @m: connection to poll 615 * 616 */ 617 618 static void p9_poll_mux(struct p9_conn *m) 619 { 620 int n; 621 622 if (m->err < 0) 623 return; 624 625 n = p9_fd_poll(m->client, NULL); 626 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) { 627 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 628 if (n >= 0) 629 n = -ECONNRESET; 630 p9_conn_cancel(m, n); 631 } 632 633 if (n & POLLIN) { 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 & POLLOUT) { 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 int 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 = POLLOUT; 682 else 683 n = p9_fd_poll(m->client, NULL); 684 685 if (n & POLLOUT && !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 ret = 0; 703 } 704 spin_unlock(&client->lock); 705 706 return ret; 707 } 708 709 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 710 { 711 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 712 713 /* we haven't received a response for oldreq, 714 * remove it from the list. 715 */ 716 spin_lock(&client->lock); 717 list_del(&req->req_list); 718 spin_unlock(&client->lock); 719 720 return 0; 721 } 722 723 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 724 { 725 if (clnt->trans_mod == &p9_tcp_trans) { 726 if (clnt->trans_opts.tcp.port != P9_PORT) 727 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 728 } else if (clnt->trans_mod == &p9_fd_trans) { 729 if (clnt->trans_opts.fd.rfd != ~0) 730 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 731 if (clnt->trans_opts.fd.wfd != ~0) 732 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 733 } 734 return 0; 735 } 736 737 /** 738 * parse_opts - parse mount options into p9_fd_opts structure 739 * @params: options string passed from mount 740 * @opts: fd transport-specific structure to parse options into 741 * 742 * Returns 0 upon success, -ERRNO upon failure 743 */ 744 745 static int parse_opts(char *params, struct p9_fd_opts *opts) 746 { 747 char *p; 748 substring_t args[MAX_OPT_ARGS]; 749 int option; 750 char *options, *tmp_options; 751 752 opts->port = P9_PORT; 753 opts->rfd = ~0; 754 opts->wfd = ~0; 755 opts->privport = false; 756 757 if (!params) 758 return 0; 759 760 tmp_options = kstrdup(params, GFP_KERNEL); 761 if (!tmp_options) { 762 p9_debug(P9_DEBUG_ERROR, 763 "failed to allocate copy of option string\n"); 764 return -ENOMEM; 765 } 766 options = tmp_options; 767 768 while ((p = strsep(&options, ",")) != NULL) { 769 int token; 770 int r; 771 if (!*p) 772 continue; 773 token = match_token(p, tokens, args); 774 if ((token != Opt_err) && (token != Opt_privport)) { 775 r = match_int(&args[0], &option); 776 if (r < 0) { 777 p9_debug(P9_DEBUG_ERROR, 778 "integer field, but no integer?\n"); 779 continue; 780 } 781 } 782 switch (token) { 783 case Opt_port: 784 opts->port = option; 785 break; 786 case Opt_rfdno: 787 opts->rfd = option; 788 break; 789 case Opt_wfdno: 790 opts->wfd = option; 791 break; 792 case Opt_privport: 793 opts->privport = true; 794 break; 795 default: 796 continue; 797 } 798 } 799 800 kfree(tmp_options); 801 return 0; 802 } 803 804 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 805 { 806 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 807 GFP_KERNEL); 808 if (!ts) 809 return -ENOMEM; 810 811 ts->rd = fget(rfd); 812 ts->wr = fget(wfd); 813 if (!ts->rd || !ts->wr) { 814 if (ts->rd) 815 fput(ts->rd); 816 if (ts->wr) 817 fput(ts->wr); 818 kfree(ts); 819 return -EIO; 820 } 821 822 client->trans = ts; 823 client->status = Connected; 824 825 return 0; 826 } 827 828 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 829 { 830 struct p9_trans_fd *p; 831 struct file *file; 832 833 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 834 if (!p) 835 return -ENOMEM; 836 837 csocket->sk->sk_allocation = GFP_NOIO; 838 file = sock_alloc_file(csocket, 0, NULL); 839 if (IS_ERR(file)) { 840 pr_err("%s (%d): failed to map fd\n", 841 __func__, task_pid_nr(current)); 842 sock_release(csocket); 843 kfree(p); 844 return PTR_ERR(file); 845 } 846 847 get_file(file); 848 p->wr = p->rd = file; 849 client->trans = p; 850 client->status = Connected; 851 852 p->rd->f_flags |= O_NONBLOCK; 853 854 p9_conn_create(client); 855 return 0; 856 } 857 858 /** 859 * p9_mux_destroy - cancels all pending requests of mux 860 * @m: mux to destroy 861 * 862 */ 863 864 static void p9_conn_destroy(struct p9_conn *m) 865 { 866 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 867 m, m->mux_list.prev, m->mux_list.next); 868 869 p9_mux_poll_stop(m); 870 cancel_work_sync(&m->rq); 871 cancel_work_sync(&m->wq); 872 873 p9_conn_cancel(m, -ECONNRESET); 874 875 m->client = NULL; 876 } 877 878 /** 879 * p9_fd_close - shutdown file descriptor transport 880 * @client: client instance 881 * 882 */ 883 884 static void p9_fd_close(struct p9_client *client) 885 { 886 struct p9_trans_fd *ts; 887 888 if (!client) 889 return; 890 891 ts = client->trans; 892 if (!ts) 893 return; 894 895 client->status = Disconnected; 896 897 p9_conn_destroy(&ts->conn); 898 899 if (ts->rd) 900 fput(ts->rd); 901 if (ts->wr) 902 fput(ts->wr); 903 904 kfree(ts); 905 } 906 907 /* 908 * stolen from NFS - maybe should be made a generic function? 909 */ 910 static inline int valid_ipaddr4(const char *buf) 911 { 912 int rc, count, in[4]; 913 914 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 915 if (rc != 4) 916 return -EINVAL; 917 for (count = 0; count < 4; count++) { 918 if (in[count] > 255) 919 return -EINVAL; 920 } 921 return 0; 922 } 923 924 static int p9_bind_privport(struct socket *sock) 925 { 926 struct sockaddr_in cl; 927 int port, err = -EINVAL; 928 929 memset(&cl, 0, sizeof(cl)); 930 cl.sin_family = AF_INET; 931 cl.sin_addr.s_addr = INADDR_ANY; 932 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 933 cl.sin_port = htons((ushort)port); 934 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 935 if (err != -EADDRINUSE) 936 break; 937 } 938 return err; 939 } 940 941 942 static int 943 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 944 { 945 int err; 946 struct socket *csocket; 947 struct sockaddr_in sin_server; 948 struct p9_fd_opts opts; 949 950 err = parse_opts(args, &opts); 951 if (err < 0) 952 return err; 953 954 if (valid_ipaddr4(addr) < 0) 955 return -EINVAL; 956 957 csocket = NULL; 958 959 client->trans_opts.tcp.port = opts.port; 960 client->trans_opts.tcp.privport = opts.privport; 961 sin_server.sin_family = AF_INET; 962 sin_server.sin_addr.s_addr = in_aton(addr); 963 sin_server.sin_port = htons(opts.port); 964 err = __sock_create(current->nsproxy->net_ns, PF_INET, 965 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 966 if (err) { 967 pr_err("%s (%d): problem creating socket\n", 968 __func__, task_pid_nr(current)); 969 return err; 970 } 971 972 if (opts.privport) { 973 err = p9_bind_privport(csocket); 974 if (err < 0) { 975 pr_err("%s (%d): problem binding to privport\n", 976 __func__, task_pid_nr(current)); 977 sock_release(csocket); 978 return err; 979 } 980 } 981 982 err = csocket->ops->connect(csocket, 983 (struct sockaddr *)&sin_server, 984 sizeof(struct sockaddr_in), 0); 985 if (err < 0) { 986 pr_err("%s (%d): problem connecting socket to %s\n", 987 __func__, task_pid_nr(current), addr); 988 sock_release(csocket); 989 return err; 990 } 991 992 return p9_socket_open(client, csocket); 993 } 994 995 static int 996 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 997 { 998 int err; 999 struct socket *csocket; 1000 struct sockaddr_un sun_server; 1001 1002 csocket = NULL; 1003 1004 if (strlen(addr) >= UNIX_PATH_MAX) { 1005 pr_err("%s (%d): address too long: %s\n", 1006 __func__, task_pid_nr(current), addr); 1007 return -ENAMETOOLONG; 1008 } 1009 1010 sun_server.sun_family = PF_UNIX; 1011 strcpy(sun_server.sun_path, addr); 1012 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1013 SOCK_STREAM, 0, &csocket, 1); 1014 if (err < 0) { 1015 pr_err("%s (%d): problem creating socket\n", 1016 __func__, task_pid_nr(current)); 1017 1018 return err; 1019 } 1020 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1021 sizeof(struct sockaddr_un) - 1, 0); 1022 if (err < 0) { 1023 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1024 __func__, task_pid_nr(current), addr, err); 1025 sock_release(csocket); 1026 return err; 1027 } 1028 1029 return p9_socket_open(client, csocket); 1030 } 1031 1032 static int 1033 p9_fd_create(struct p9_client *client, const char *addr, char *args) 1034 { 1035 int err; 1036 struct p9_fd_opts opts; 1037 1038 parse_opts(args, &opts); 1039 client->trans_opts.fd.rfd = opts.rfd; 1040 client->trans_opts.fd.wfd = opts.wfd; 1041 1042 if (opts.rfd == ~0 || opts.wfd == ~0) { 1043 pr_err("Insufficient options for proto=fd\n"); 1044 return -ENOPROTOOPT; 1045 } 1046 1047 err = p9_fd_open(client, opts.rfd, opts.wfd); 1048 if (err < 0) 1049 return err; 1050 1051 p9_conn_create(client); 1052 1053 return 0; 1054 } 1055 1056 static struct p9_trans_module p9_tcp_trans = { 1057 .name = "tcp", 1058 .maxsize = MAX_SOCK_BUF, 1059 .def = 0, 1060 .create = p9_fd_create_tcp, 1061 .close = p9_fd_close, 1062 .request = p9_fd_request, 1063 .cancel = p9_fd_cancel, 1064 .cancelled = p9_fd_cancelled, 1065 .show_options = p9_fd_show_options, 1066 .owner = THIS_MODULE, 1067 }; 1068 1069 static struct p9_trans_module p9_unix_trans = { 1070 .name = "unix", 1071 .maxsize = MAX_SOCK_BUF, 1072 .def = 0, 1073 .create = p9_fd_create_unix, 1074 .close = p9_fd_close, 1075 .request = p9_fd_request, 1076 .cancel = p9_fd_cancel, 1077 .cancelled = p9_fd_cancelled, 1078 .show_options = p9_fd_show_options, 1079 .owner = THIS_MODULE, 1080 }; 1081 1082 static struct p9_trans_module p9_fd_trans = { 1083 .name = "fd", 1084 .maxsize = MAX_SOCK_BUF, 1085 .def = 0, 1086 .create = p9_fd_create, 1087 .close = p9_fd_close, 1088 .request = p9_fd_request, 1089 .cancel = p9_fd_cancel, 1090 .cancelled = p9_fd_cancelled, 1091 .show_options = p9_fd_show_options, 1092 .owner = THIS_MODULE, 1093 }; 1094 1095 /** 1096 * p9_poll_proc - poll worker thread 1097 * @a: thread state and arguments 1098 * 1099 * polls all v9fs transports for new events and queues the appropriate 1100 * work to the work queue 1101 * 1102 */ 1103 1104 static void p9_poll_workfn(struct work_struct *work) 1105 { 1106 unsigned long flags; 1107 1108 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1109 1110 spin_lock_irqsave(&p9_poll_lock, flags); 1111 while (!list_empty(&p9_poll_pending_list)) { 1112 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1113 struct p9_conn, 1114 poll_pending_link); 1115 list_del_init(&conn->poll_pending_link); 1116 spin_unlock_irqrestore(&p9_poll_lock, flags); 1117 1118 p9_poll_mux(conn); 1119 1120 spin_lock_irqsave(&p9_poll_lock, flags); 1121 } 1122 spin_unlock_irqrestore(&p9_poll_lock, flags); 1123 1124 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1125 } 1126 1127 int p9_trans_fd_init(void) 1128 { 1129 v9fs_register_trans(&p9_tcp_trans); 1130 v9fs_register_trans(&p9_unix_trans); 1131 v9fs_register_trans(&p9_fd_trans); 1132 1133 return 0; 1134 } 1135 1136 void p9_trans_fd_exit(void) 1137 { 1138 flush_work(&p9_poll_work); 1139 v9fs_unregister_trans(&p9_tcp_trans); 1140 v9fs_unregister_trans(&p9_unix_trans); 1141 v9fs_unregister_trans(&p9_fd_trans); 1142 } 1143