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 __poll_t 232 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err) 233 { 234 __poll_t ret; 235 struct p9_trans_fd *ts = NULL; 236 237 if (client && client->status == Connected) 238 ts = client->trans; 239 240 if (!ts) { 241 if (err) 242 *err = -EREMOTEIO; 243 return EPOLLERR; 244 } 245 246 ret = vfs_poll(ts->rd, pt); 247 if (ts->rd != ts->wr) 248 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN); 249 return ret; 250 } 251 252 /** 253 * p9_fd_read- read from a fd 254 * @client: client instance 255 * @v: buffer to receive data into 256 * @len: size of receive buffer 257 * 258 */ 259 260 static int p9_fd_read(struct p9_client *client, void *v, int len) 261 { 262 int ret; 263 struct p9_trans_fd *ts = NULL; 264 loff_t pos; 265 266 if (client && client->status != Disconnected) 267 ts = client->trans; 268 269 if (!ts) 270 return -EREMOTEIO; 271 272 if (!(ts->rd->f_flags & O_NONBLOCK)) 273 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); 274 275 pos = ts->rd->f_pos; 276 ret = kernel_read(ts->rd, v, len, &pos); 277 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 278 client->status = Disconnected; 279 return ret; 280 } 281 282 /** 283 * p9_read_work - called when there is some data to be read from a transport 284 * @work: container of work to be done 285 * 286 */ 287 288 static void p9_read_work(struct work_struct *work) 289 { 290 __poll_t n; 291 int err; 292 struct p9_conn *m; 293 int status = REQ_STATUS_ERROR; 294 295 m = container_of(work, struct p9_conn, rq); 296 297 if (m->err < 0) 298 return; 299 300 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); 301 302 if (!m->rc.sdata) { 303 m->rc.sdata = m->tmp_buf; 304 m->rc.offset = 0; 305 m->rc.capacity = 7; /* start by reading header */ 306 } 307 308 clear_bit(Rpending, &m->wsched); 309 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", 310 m, m->rc.offset, m->rc.capacity, 311 m->rc.capacity - m->rc.offset); 312 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, 313 m->rc.capacity - m->rc.offset); 314 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); 315 if (err == -EAGAIN) 316 goto end_clear; 317 318 if (err <= 0) 319 goto error; 320 321 m->rc.offset += err; 322 323 /* header read in */ 324 if ((!m->req) && (m->rc.offset == m->rc.capacity)) { 325 p9_debug(P9_DEBUG_TRANS, "got new header\n"); 326 327 err = p9_parse_header(&m->rc, NULL, NULL, NULL, 0); 328 if (err) { 329 p9_debug(P9_DEBUG_ERROR, 330 "error parsing header: %d\n", err); 331 goto error; 332 } 333 334 if (m->rc.size >= m->client->msize) { 335 p9_debug(P9_DEBUG_ERROR, 336 "requested packet size too big: %d\n", 337 m->rc.size); 338 err = -EIO; 339 goto error; 340 } 341 342 p9_debug(P9_DEBUG_TRANS, 343 "mux %p pkt: size: %d bytes tag: %d\n", 344 m, m->rc.size, m->rc.tag); 345 346 m->req = p9_tag_lookup(m->client, m->rc.tag); 347 if (!m->req || (m->req->status != REQ_STATUS_SENT)) { 348 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", 349 m->rc.tag); 350 err = -EIO; 351 goto error; 352 } 353 354 if (m->req->rc == NULL) { 355 p9_debug(P9_DEBUG_ERROR, 356 "No recv fcall for tag %d (req %p), disconnecting!\n", 357 m->rc.tag, m->req); 358 m->req = NULL; 359 err = -EIO; 360 goto error; 361 } 362 m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall); 363 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); 364 m->rc.capacity = m->rc.size; 365 } 366 367 /* packet is read in 368 * not an else because some packets (like clunk) have no payload 369 */ 370 if ((m->req) && (m->rc.offset == m->rc.capacity)) { 371 p9_debug(P9_DEBUG_TRANS, "got new packet\n"); 372 spin_lock(&m->client->lock); 373 if (m->req->status != REQ_STATUS_ERROR) 374 status = REQ_STATUS_RCVD; 375 list_del(&m->req->req_list); 376 spin_unlock(&m->client->lock); 377 p9_client_cb(m->client, m->req, status); 378 m->rc.sdata = NULL; 379 m->rc.offset = 0; 380 m->rc.capacity = 0; 381 m->req = NULL; 382 } 383 384 end_clear: 385 clear_bit(Rworksched, &m->wsched); 386 387 if (!list_empty(&m->req_list)) { 388 if (test_and_clear_bit(Rpending, &m->wsched)) 389 n = EPOLLIN; 390 else 391 n = p9_fd_poll(m->client, NULL, NULL); 392 393 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { 394 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 395 schedule_work(&m->rq); 396 } 397 } 398 399 return; 400 error: 401 p9_conn_cancel(m, err); 402 clear_bit(Rworksched, &m->wsched); 403 } 404 405 /** 406 * p9_fd_write - write to a socket 407 * @client: client instance 408 * @v: buffer to send data from 409 * @len: size of send buffer 410 * 411 */ 412 413 static int p9_fd_write(struct p9_client *client, void *v, int len) 414 { 415 ssize_t ret; 416 struct p9_trans_fd *ts = NULL; 417 418 if (client && client->status != Disconnected) 419 ts = client->trans; 420 421 if (!ts) 422 return -EREMOTEIO; 423 424 if (!(ts->wr->f_flags & O_NONBLOCK)) 425 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); 426 427 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); 428 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) 429 client->status = Disconnected; 430 return ret; 431 } 432 433 /** 434 * p9_write_work - called when a transport can send some data 435 * @work: container for work to be done 436 * 437 */ 438 439 static void p9_write_work(struct work_struct *work) 440 { 441 __poll_t n; 442 int err; 443 struct p9_conn *m; 444 struct p9_req_t *req; 445 446 m = container_of(work, struct p9_conn, wq); 447 448 if (m->err < 0) { 449 clear_bit(Wworksched, &m->wsched); 450 return; 451 } 452 453 if (!m->wsize) { 454 spin_lock(&m->client->lock); 455 if (list_empty(&m->unsent_req_list)) { 456 clear_bit(Wworksched, &m->wsched); 457 spin_unlock(&m->client->lock); 458 return; 459 } 460 461 req = list_entry(m->unsent_req_list.next, struct p9_req_t, 462 req_list); 463 req->status = REQ_STATUS_SENT; 464 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); 465 list_move_tail(&req->req_list, &m->req_list); 466 467 m->wbuf = req->tc->sdata; 468 m->wsize = req->tc->size; 469 m->wpos = 0; 470 spin_unlock(&m->client->lock); 471 } 472 473 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", 474 m, m->wpos, m->wsize); 475 clear_bit(Wpending, &m->wsched); 476 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); 477 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); 478 if (err == -EAGAIN) 479 goto end_clear; 480 481 482 if (err < 0) 483 goto error; 484 else if (err == 0) { 485 err = -EREMOTEIO; 486 goto error; 487 } 488 489 m->wpos += err; 490 if (m->wpos == m->wsize) 491 m->wpos = m->wsize = 0; 492 493 end_clear: 494 clear_bit(Wworksched, &m->wsched); 495 496 if (m->wsize || !list_empty(&m->unsent_req_list)) { 497 if (test_and_clear_bit(Wpending, &m->wsched)) 498 n = EPOLLOUT; 499 else 500 n = p9_fd_poll(m->client, NULL, NULL); 501 502 if ((n & EPOLLOUT) && 503 !test_and_set_bit(Wworksched, &m->wsched)) { 504 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 505 schedule_work(&m->wq); 506 } 507 } 508 509 return; 510 511 error: 512 p9_conn_cancel(m, err); 513 clear_bit(Wworksched, &m->wsched); 514 } 515 516 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) 517 { 518 struct p9_poll_wait *pwait = 519 container_of(wait, struct p9_poll_wait, wait); 520 struct p9_conn *m = pwait->conn; 521 unsigned long flags; 522 523 spin_lock_irqsave(&p9_poll_lock, flags); 524 if (list_empty(&m->poll_pending_link)) 525 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); 526 spin_unlock_irqrestore(&p9_poll_lock, flags); 527 528 schedule_work(&p9_poll_work); 529 return 1; 530 } 531 532 /** 533 * p9_pollwait - add poll task to the wait queue 534 * @filp: file pointer being polled 535 * @wait_address: wait_q to block on 536 * @p: poll state 537 * 538 * called by files poll operation to add v9fs-poll task to files wait queue 539 */ 540 541 static void 542 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) 543 { 544 struct p9_conn *m = container_of(p, struct p9_conn, pt); 545 struct p9_poll_wait *pwait = NULL; 546 int i; 547 548 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { 549 if (m->poll_wait[i].wait_addr == NULL) { 550 pwait = &m->poll_wait[i]; 551 break; 552 } 553 } 554 555 if (!pwait) { 556 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); 557 return; 558 } 559 560 pwait->conn = m; 561 pwait->wait_addr = wait_address; 562 init_waitqueue_func_entry(&pwait->wait, p9_pollwake); 563 add_wait_queue(wait_address, &pwait->wait); 564 } 565 566 /** 567 * p9_conn_create - initialize the per-session mux data 568 * @client: client instance 569 * 570 * Note: Creates the polling task if this is the first session. 571 */ 572 573 static void p9_conn_create(struct p9_client *client) 574 { 575 __poll_t n; 576 struct p9_trans_fd *ts = client->trans; 577 struct p9_conn *m = &ts->conn; 578 579 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); 580 581 INIT_LIST_HEAD(&m->mux_list); 582 m->client = client; 583 584 INIT_LIST_HEAD(&m->req_list); 585 INIT_LIST_HEAD(&m->unsent_req_list); 586 INIT_WORK(&m->rq, p9_read_work); 587 INIT_WORK(&m->wq, p9_write_work); 588 INIT_LIST_HEAD(&m->poll_pending_link); 589 init_poll_funcptr(&m->pt, p9_pollwait); 590 591 n = p9_fd_poll(client, &m->pt, NULL); 592 if (n & EPOLLIN) { 593 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 594 set_bit(Rpending, &m->wsched); 595 } 596 597 if (n & EPOLLOUT) { 598 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 599 set_bit(Wpending, &m->wsched); 600 } 601 } 602 603 /** 604 * p9_poll_mux - polls a mux and schedules read or write works if necessary 605 * @m: connection to poll 606 * 607 */ 608 609 static void p9_poll_mux(struct p9_conn *m) 610 { 611 __poll_t n; 612 int err = -ECONNRESET; 613 614 if (m->err < 0) 615 return; 616 617 n = p9_fd_poll(m->client, NULL, &err); 618 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { 619 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); 620 p9_conn_cancel(m, err); 621 } 622 623 if (n & EPOLLIN) { 624 set_bit(Rpending, &m->wsched); 625 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); 626 if (!test_and_set_bit(Rworksched, &m->wsched)) { 627 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); 628 schedule_work(&m->rq); 629 } 630 } 631 632 if (n & EPOLLOUT) { 633 set_bit(Wpending, &m->wsched); 634 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); 635 if ((m->wsize || !list_empty(&m->unsent_req_list)) && 636 !test_and_set_bit(Wworksched, &m->wsched)) { 637 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); 638 schedule_work(&m->wq); 639 } 640 } 641 } 642 643 /** 644 * p9_fd_request - send 9P request 645 * The function can sleep until the request is scheduled for sending. 646 * The function can be interrupted. Return from the function is not 647 * a guarantee that the request is sent successfully. 648 * 649 * @client: client instance 650 * @req: request to be sent 651 * 652 */ 653 654 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) 655 { 656 __poll_t n; 657 struct p9_trans_fd *ts = client->trans; 658 struct p9_conn *m = &ts->conn; 659 660 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", 661 m, current, req->tc, req->tc->id); 662 if (m->err < 0) 663 return m->err; 664 665 spin_lock(&client->lock); 666 req->status = REQ_STATUS_UNSENT; 667 list_add_tail(&req->req_list, &m->unsent_req_list); 668 spin_unlock(&client->lock); 669 670 if (test_and_clear_bit(Wpending, &m->wsched)) 671 n = EPOLLOUT; 672 else 673 n = p9_fd_poll(m->client, NULL, NULL); 674 675 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) 676 schedule_work(&m->wq); 677 678 return 0; 679 } 680 681 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) 682 { 683 int ret = 1; 684 685 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 686 687 spin_lock(&client->lock); 688 689 if (req->status == REQ_STATUS_UNSENT) { 690 list_del(&req->req_list); 691 req->status = REQ_STATUS_FLSHD; 692 ret = 0; 693 } 694 spin_unlock(&client->lock); 695 696 return ret; 697 } 698 699 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) 700 { 701 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); 702 703 /* we haven't received a response for oldreq, 704 * remove it from the list. 705 */ 706 spin_lock(&client->lock); 707 list_del(&req->req_list); 708 spin_unlock(&client->lock); 709 710 return 0; 711 } 712 713 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) 714 { 715 if (clnt->trans_mod == &p9_tcp_trans) { 716 if (clnt->trans_opts.tcp.port != P9_PORT) 717 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); 718 } else if (clnt->trans_mod == &p9_fd_trans) { 719 if (clnt->trans_opts.fd.rfd != ~0) 720 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); 721 if (clnt->trans_opts.fd.wfd != ~0) 722 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); 723 } 724 return 0; 725 } 726 727 /** 728 * parse_opts - parse mount options into p9_fd_opts structure 729 * @params: options string passed from mount 730 * @opts: fd transport-specific structure to parse options into 731 * 732 * Returns 0 upon success, -ERRNO upon failure 733 */ 734 735 static int parse_opts(char *params, struct p9_fd_opts *opts) 736 { 737 char *p; 738 substring_t args[MAX_OPT_ARGS]; 739 int option; 740 char *options, *tmp_options; 741 742 opts->port = P9_PORT; 743 opts->rfd = ~0; 744 opts->wfd = ~0; 745 opts->privport = false; 746 747 if (!params) 748 return 0; 749 750 tmp_options = kstrdup(params, GFP_KERNEL); 751 if (!tmp_options) { 752 p9_debug(P9_DEBUG_ERROR, 753 "failed to allocate copy of option string\n"); 754 return -ENOMEM; 755 } 756 options = tmp_options; 757 758 while ((p = strsep(&options, ",")) != NULL) { 759 int token; 760 int r; 761 if (!*p) 762 continue; 763 token = match_token(p, tokens, args); 764 if ((token != Opt_err) && (token != Opt_privport)) { 765 r = match_int(&args[0], &option); 766 if (r < 0) { 767 p9_debug(P9_DEBUG_ERROR, 768 "integer field, but no integer?\n"); 769 continue; 770 } 771 } 772 switch (token) { 773 case Opt_port: 774 opts->port = option; 775 break; 776 case Opt_rfdno: 777 opts->rfd = option; 778 break; 779 case Opt_wfdno: 780 opts->wfd = option; 781 break; 782 case Opt_privport: 783 opts->privport = true; 784 break; 785 default: 786 continue; 787 } 788 } 789 790 kfree(tmp_options); 791 return 0; 792 } 793 794 static int p9_fd_open(struct p9_client *client, int rfd, int wfd) 795 { 796 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd), 797 GFP_KERNEL); 798 if (!ts) 799 return -ENOMEM; 800 801 ts->rd = fget(rfd); 802 ts->wr = fget(wfd); 803 if (!ts->rd || !ts->wr) { 804 if (ts->rd) 805 fput(ts->rd); 806 if (ts->wr) 807 fput(ts->wr); 808 kfree(ts); 809 return -EIO; 810 } 811 812 client->trans = ts; 813 client->status = Connected; 814 815 return 0; 816 } 817 818 static int p9_socket_open(struct p9_client *client, struct socket *csocket) 819 { 820 struct p9_trans_fd *p; 821 struct file *file; 822 823 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL); 824 if (!p) 825 return -ENOMEM; 826 827 csocket->sk->sk_allocation = GFP_NOIO; 828 file = sock_alloc_file(csocket, 0, NULL); 829 if (IS_ERR(file)) { 830 pr_err("%s (%d): failed to map fd\n", 831 __func__, task_pid_nr(current)); 832 kfree(p); 833 return PTR_ERR(file); 834 } 835 836 get_file(file); 837 p->wr = p->rd = file; 838 client->trans = p; 839 client->status = Connected; 840 841 p->rd->f_flags |= O_NONBLOCK; 842 843 p9_conn_create(client); 844 return 0; 845 } 846 847 /** 848 * p9_mux_destroy - cancels all pending requests of mux 849 * @m: mux to destroy 850 * 851 */ 852 853 static void p9_conn_destroy(struct p9_conn *m) 854 { 855 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", 856 m, m->mux_list.prev, m->mux_list.next); 857 858 p9_mux_poll_stop(m); 859 cancel_work_sync(&m->rq); 860 cancel_work_sync(&m->wq); 861 862 p9_conn_cancel(m, -ECONNRESET); 863 864 m->client = NULL; 865 } 866 867 /** 868 * p9_fd_close - shutdown file descriptor transport 869 * @client: client instance 870 * 871 */ 872 873 static void p9_fd_close(struct p9_client *client) 874 { 875 struct p9_trans_fd *ts; 876 877 if (!client) 878 return; 879 880 ts = client->trans; 881 if (!ts) 882 return; 883 884 client->status = Disconnected; 885 886 p9_conn_destroy(&ts->conn); 887 888 if (ts->rd) 889 fput(ts->rd); 890 if (ts->wr) 891 fput(ts->wr); 892 893 kfree(ts); 894 } 895 896 /* 897 * stolen from NFS - maybe should be made a generic function? 898 */ 899 static inline int valid_ipaddr4(const char *buf) 900 { 901 int rc, count, in[4]; 902 903 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); 904 if (rc != 4) 905 return -EINVAL; 906 for (count = 0; count < 4; count++) { 907 if (in[count] > 255) 908 return -EINVAL; 909 } 910 return 0; 911 } 912 913 static int p9_bind_privport(struct socket *sock) 914 { 915 struct sockaddr_in cl; 916 int port, err = -EINVAL; 917 918 memset(&cl, 0, sizeof(cl)); 919 cl.sin_family = AF_INET; 920 cl.sin_addr.s_addr = INADDR_ANY; 921 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { 922 cl.sin_port = htons((ushort)port); 923 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl)); 924 if (err != -EADDRINUSE) 925 break; 926 } 927 return err; 928 } 929 930 931 static int 932 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args) 933 { 934 int err; 935 struct socket *csocket; 936 struct sockaddr_in sin_server; 937 struct p9_fd_opts opts; 938 939 err = parse_opts(args, &opts); 940 if (err < 0) 941 return err; 942 943 if (valid_ipaddr4(addr) < 0) 944 return -EINVAL; 945 946 csocket = NULL; 947 948 client->trans_opts.tcp.port = opts.port; 949 client->trans_opts.tcp.privport = opts.privport; 950 sin_server.sin_family = AF_INET; 951 sin_server.sin_addr.s_addr = in_aton(addr); 952 sin_server.sin_port = htons(opts.port); 953 err = __sock_create(current->nsproxy->net_ns, PF_INET, 954 SOCK_STREAM, IPPROTO_TCP, &csocket, 1); 955 if (err) { 956 pr_err("%s (%d): problem creating socket\n", 957 __func__, task_pid_nr(current)); 958 return err; 959 } 960 961 if (opts.privport) { 962 err = p9_bind_privport(csocket); 963 if (err < 0) { 964 pr_err("%s (%d): problem binding to privport\n", 965 __func__, task_pid_nr(current)); 966 sock_release(csocket); 967 return err; 968 } 969 } 970 971 err = csocket->ops->connect(csocket, 972 (struct sockaddr *)&sin_server, 973 sizeof(struct sockaddr_in), 0); 974 if (err < 0) { 975 pr_err("%s (%d): problem connecting socket to %s\n", 976 __func__, task_pid_nr(current), addr); 977 sock_release(csocket); 978 return err; 979 } 980 981 return p9_socket_open(client, csocket); 982 } 983 984 static int 985 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) 986 { 987 int err; 988 struct socket *csocket; 989 struct sockaddr_un sun_server; 990 991 csocket = NULL; 992 993 if (strlen(addr) >= UNIX_PATH_MAX) { 994 pr_err("%s (%d): address too long: %s\n", 995 __func__, task_pid_nr(current), addr); 996 return -ENAMETOOLONG; 997 } 998 999 sun_server.sun_family = PF_UNIX; 1000 strcpy(sun_server.sun_path, addr); 1001 err = __sock_create(current->nsproxy->net_ns, PF_UNIX, 1002 SOCK_STREAM, 0, &csocket, 1); 1003 if (err < 0) { 1004 pr_err("%s (%d): problem creating socket\n", 1005 __func__, task_pid_nr(current)); 1006 1007 return err; 1008 } 1009 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server, 1010 sizeof(struct sockaddr_un) - 1, 0); 1011 if (err < 0) { 1012 pr_err("%s (%d): problem connecting socket: %s: %d\n", 1013 __func__, task_pid_nr(current), addr, err); 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(struct p9_client *client, const char *addr, char *args) 1023 { 1024 int err; 1025 struct p9_fd_opts opts; 1026 1027 parse_opts(args, &opts); 1028 client->trans_opts.fd.rfd = opts.rfd; 1029 client->trans_opts.fd.wfd = opts.wfd; 1030 1031 if (opts.rfd == ~0 || opts.wfd == ~0) { 1032 pr_err("Insufficient options for proto=fd\n"); 1033 return -ENOPROTOOPT; 1034 } 1035 1036 err = p9_fd_open(client, opts.rfd, opts.wfd); 1037 if (err < 0) 1038 return err; 1039 1040 p9_conn_create(client); 1041 1042 return 0; 1043 } 1044 1045 static struct p9_trans_module p9_tcp_trans = { 1046 .name = "tcp", 1047 .maxsize = MAX_SOCK_BUF, 1048 .def = 0, 1049 .create = p9_fd_create_tcp, 1050 .close = p9_fd_close, 1051 .request = p9_fd_request, 1052 .cancel = p9_fd_cancel, 1053 .cancelled = p9_fd_cancelled, 1054 .show_options = p9_fd_show_options, 1055 .owner = THIS_MODULE, 1056 }; 1057 1058 static struct p9_trans_module p9_unix_trans = { 1059 .name = "unix", 1060 .maxsize = MAX_SOCK_BUF, 1061 .def = 0, 1062 .create = p9_fd_create_unix, 1063 .close = p9_fd_close, 1064 .request = p9_fd_request, 1065 .cancel = p9_fd_cancel, 1066 .cancelled = p9_fd_cancelled, 1067 .show_options = p9_fd_show_options, 1068 .owner = THIS_MODULE, 1069 }; 1070 1071 static struct p9_trans_module p9_fd_trans = { 1072 .name = "fd", 1073 .maxsize = MAX_SOCK_BUF, 1074 .def = 0, 1075 .create = p9_fd_create, 1076 .close = p9_fd_close, 1077 .request = p9_fd_request, 1078 .cancel = p9_fd_cancel, 1079 .cancelled = p9_fd_cancelled, 1080 .show_options = p9_fd_show_options, 1081 .owner = THIS_MODULE, 1082 }; 1083 1084 /** 1085 * p9_poll_workfn - poll worker thread 1086 * @work: work queue 1087 * 1088 * polls all v9fs transports for new events and queues the appropriate 1089 * work to the work queue 1090 * 1091 */ 1092 1093 static void p9_poll_workfn(struct work_struct *work) 1094 { 1095 unsigned long flags; 1096 1097 p9_debug(P9_DEBUG_TRANS, "start %p\n", current); 1098 1099 spin_lock_irqsave(&p9_poll_lock, flags); 1100 while (!list_empty(&p9_poll_pending_list)) { 1101 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, 1102 struct p9_conn, 1103 poll_pending_link); 1104 list_del_init(&conn->poll_pending_link); 1105 spin_unlock_irqrestore(&p9_poll_lock, flags); 1106 1107 p9_poll_mux(conn); 1108 1109 spin_lock_irqsave(&p9_poll_lock, flags); 1110 } 1111 spin_unlock_irqrestore(&p9_poll_lock, flags); 1112 1113 p9_debug(P9_DEBUG_TRANS, "finish\n"); 1114 } 1115 1116 int p9_trans_fd_init(void) 1117 { 1118 v9fs_register_trans(&p9_tcp_trans); 1119 v9fs_register_trans(&p9_unix_trans); 1120 v9fs_register_trans(&p9_fd_trans); 1121 1122 return 0; 1123 } 1124 1125 void p9_trans_fd_exit(void) 1126 { 1127 flush_work(&p9_poll_work); 1128 v9fs_unregister_trans(&p9_tcp_trans); 1129 v9fs_unregister_trans(&p9_unix_trans); 1130 v9fs_unregister_trans(&p9_fd_trans); 1131 } 1132