net/9p/trans_fd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/fs/9p/trans_fd.c
   4  *
   5  * Fd transport layer.  Includes deprecated socket layer.
   6  *
   7  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
   8  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   9  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  10  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/in.h>
  16 #include <linux/module.h>
  17 #include <linux/net.h>
  18 #include <linux/ipv6.h>
  19 #include <linux/kthread.h>
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/un.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/inet.h>
  25 #include <linux/idr.h>
  26 #include <linux/file.h>
  27 #include <linux/parser.h>
  28 #include <linux/slab.h>
  29 #include <linux/seq_file.h>
  30 #include <net/9p/9p.h>
  31 #include <net/9p/client.h>
  32 #include <net/9p/transport.h>
  33
  34 #include <linux/syscalls.h> /* killme */
  35
  36 #define P9_PORT 564
  37 #define MAX_SOCK_BUF (64*1024)
  38 #define MAXPOLLWADDR    2
  39
  40 static struct p9_trans_module p9_tcp_trans;
  41 static struct p9_trans_module p9_fd_trans;
  42
  43 /**
  44  * struct p9_fd_opts - per-transport options
  45  * @rfd: file descriptor for reading (trans=fd)
  46  * @wfd: file descriptor for writing (trans=fd)
  47  * @port: port to connect to (trans=tcp)
  48  * @privport: port is privileged
  49  */
  50
  51 struct p9_fd_opts {
  52         int rfd;
  53         int wfd;
  54         u16 port;
  55         bool privport;
  56 };
  57
  58 /*
  59   * Option Parsing (code inspired by NFS code)
  60   *  - a little lazy - parse all fd-transport options
  61   */
  62
  63 enum {
  64         /* Options that take integer arguments */
  65         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  66         /* Options that take no arguments */
  67         Opt_privport,
  68 };
  69
  70 static const match_table_t tokens = {
  71         {Opt_port, "port=%u"},
  72         {Opt_rfdno, "rfdno=%u"},
  73         {Opt_wfdno, "wfdno=%u"},
  74         {Opt_privport, "privport"},
  75         {Opt_err, NULL},
  76 };
  77
  78 enum {
  79         Rworksched = 1,         /* read work scheduled or running */
  80         Rpending = 2,           /* can read */
  81         Wworksched = 4,         /* write work scheduled or running */
  82         Wpending = 8,           /* can write */
  83 };
  84
  85 struct p9_poll_wait {
  86         struct p9_conn *conn;
  87         wait_queue_entry_t wait;
  88         wait_queue_head_t *wait_addr;
  89 };
  90
  91 /**
  92  * struct p9_conn - fd mux connection state information
  93  * @mux_list: list link for mux to manage multiple connections (?)
  94  * @client: reference to client instance for this connection
  95  * @err: error state
  96  * @req_list: accounting for requests which have been sent
  97  * @unsent_req_list: accounting for requests that haven't been sent
  98  * @rreq: read request
  99  * @wreq: write request
 100  * @req: current request being processed (if any)
 101  * @tmp_buf: temporary buffer to read in header
 102  * @rc: temporary fcall for reading current frame
 103  * @wpos: write position for current frame
 104  * @wsize: amount of data to write for current frame
 105  * @wbuf: current write buffer
 106  * @poll_pending_link: pending links to be polled per conn
 107  * @poll_wait: array of wait_q's for various worker threads
 108  * @pt: poll state
 109  * @rq: current read work
 110  * @wq: current write work
 111  * @wsched: ????
 112  *
 113  */
 114
 115 struct p9_conn {
 116         struct list_head mux_list;
 117         struct p9_client *client;
 118         int err;
 119         struct list_head req_list;
 120         struct list_head unsent_req_list;
 121         struct p9_req_t *rreq;
 122         struct p9_req_t *wreq;
 123         char tmp_buf[7];
 124         struct p9_fcall rc;
 125         int wpos;
 126         int wsize;
 127         char *wbuf;
 128         struct list_head poll_pending_link;
 129         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
 130         poll_table pt;
 131         struct work_struct rq;
 132         struct work_struct wq;
 133         unsigned long wsched;
 134 };
 135
 136 /**
 137  * struct p9_trans_fd - transport state
 138  * @rd: reference to file to read from
 139  * @wr: reference of file to write to
 140  * @conn: connection state reference
 141  *
 142  */
 143
 144 struct p9_trans_fd {
 145         struct file *rd;
 146         struct file *wr;
 147         struct p9_conn conn;
 148 };
 149
 150 static void p9_poll_workfn(struct work_struct *work);
 151
 152 static DEFINE_SPINLOCK(p9_poll_lock);
 153 static LIST_HEAD(p9_poll_pending_list);
 154 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
 155
 156 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
 157 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
 158
 159 static void p9_mux_poll_stop(struct p9_conn *m)
 160 {
 161         unsigned long flags;
 162         int i;
 163
 164         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 165                 struct p9_poll_wait *pwait = &m->poll_wait[i];
 166
 167                 if (pwait->wait_addr) {
 168                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
 169                         pwait->wait_addr = NULL;
 170                 }
 171         }
 172
 173         spin_lock_irqsave(&p9_poll_lock, flags);
 174         list_del_init(&m->poll_pending_link);
 175         spin_unlock_irqrestore(&p9_poll_lock, flags);
 176
 177         flush_work(&p9_poll_work);
 178 }
 179
 180 /**
 181  * p9_conn_cancel - cancel all pending requests with error
 182  * @m: mux data
 183  * @err: error code
 184  *
 185  */
 186
 187 static void p9_conn_cancel(struct p9_conn *m, int err)
 188 {
 189         struct p9_req_t *req, *rtmp;
 190         LIST_HEAD(cancel_list);
 191
 192         p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 193
 194         spin_lock(&m->client->lock);
 195
 196         if (m->err) {
 197                 spin_unlock(&m->client->lock);
 198                 return;
 199         }
 200
 201         m->err = err;
 202
 203         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
 204                 list_move(&req->req_list, &cancel_list);
 205         }
 206         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
 207                 list_move(&req->req_list, &cancel_list);
 208         }
 209
 210         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 211                 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
 212                 list_del(&req->req_list);
 213                 if (!req->t_err)
 214                         req->t_err = err;
 215                 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
 216         }
 217         spin_unlock(&m->client->lock);
 218 }
 219
 220 static __poll_t
 221 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
 222 {
 223         __poll_t ret;
 224         struct p9_trans_fd *ts = NULL;
 225
 226         if (client && client->status == Connected)
 227                 ts = client->trans;
 228
 229         if (!ts) {
 230                 if (err)
 231                         *err = -EREMOTEIO;
 232                 return EPOLLERR;
 233         }
 234
 235         ret = vfs_poll(ts->rd, pt);
 236         if (ts->rd != ts->wr)
 237                 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
 238         return ret;
 239 }
 240
 241 /**
 242  * p9_fd_read- read from a fd
 243  * @client: client instance
 244  * @v: buffer to receive data into
 245  * @len: size of receive buffer
 246  *
 247  */
 248
 249 static int p9_fd_read(struct p9_client *client, void *v, int len)
 250 {
 251         int ret;
 252         struct p9_trans_fd *ts = NULL;
 253         loff_t pos;
 254
 255         if (client && client->status != Disconnected)
 256                 ts = client->trans;
 257
 258         if (!ts)
 259                 return -EREMOTEIO;
 260
 261         if (!(ts->rd->f_flags & O_NONBLOCK))
 262                 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
 263
 264         pos = ts->rd->f_pos;
 265         ret = kernel_read(ts->rd, v, len, &pos);
 266         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 267                 client->status = Disconnected;
 268         return ret;
 269 }
 270
 271 /**
 272  * p9_read_work - called when there is some data to be read from a transport
 273  * @work: container of work to be done
 274  *
 275  */
 276
 277 static void p9_read_work(struct work_struct *work)
 278 {
 279         __poll_t n;
 280         int err;
 281         struct p9_conn *m;
 282
 283         m = container_of(work, struct p9_conn, rq);
 284
 285         if (m->err < 0)
 286                 return;
 287
 288         p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
 289
 290         if (!m->rc.sdata) {
 291                 m->rc.sdata = m->tmp_buf;
 292                 m->rc.offset = 0;
 293                 m->rc.capacity = 7; /* start by reading header */
 294         }
 295
 296         clear_bit(Rpending, &m->wsched);
 297         p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
 298                  m, m->rc.offset, m->rc.capacity,
 299                  m->rc.capacity - m->rc.offset);
 300         err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
 301                          m->rc.capacity - m->rc.offset);
 302         p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
 303         if (err == -EAGAIN)
 304                 goto end_clear;
 305
 306         if (err <= 0)
 307                 goto error;
 308
 309         m->rc.offset += err;
 310
 311         /* header read in */
 312         if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
 313                 p9_debug(P9_DEBUG_TRANS, "got new header\n");
 314
 315                 /* Header size */
 316                 m->rc.size = 7;
 317                 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
 318                 if (err) {
 319                         p9_debug(P9_DEBUG_ERROR,
 320                                  "error parsing header: %d\n", err);
 321                         goto error;
 322                 }
 323
 324                 if (m->rc.size >= m->client->msize) {
 325                         p9_debug(P9_DEBUG_ERROR,
 326                                  "requested packet size too big: %d\n",
 327                                  m->rc.size);
 328                         err = -EIO;
 329                         goto error;
 330                 }
 331
 332                 p9_debug(P9_DEBUG_TRANS,
 333                          "mux %p pkt: size: %d bytes tag: %d\n",
 334                          m, m->rc.size, m->rc.tag);
 335
 336                 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
 337                 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
 338                         p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
 339                                  m->rc.tag);
 340                         err = -EIO;
 341                         goto error;
 342                 }
 343
 344                 if (!m->rreq->rc.sdata) {
 345                         p9_debug(P9_DEBUG_ERROR,
 346                                  "No recv fcall for tag %d (req %p), disconnecting!\n",
 347                                  m->rc.tag, m->rreq);
 348                         m->rreq = NULL;
 349                         err = -EIO;
 350                         goto error;
 351                 }
 352                 m->rc.sdata = m->rreq->rc.sdata;
 353                 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
 354                 m->rc.capacity = m->rc.size;
 355         }
 356
 357         /* packet is read in
 358          * not an else because some packets (like clunk) have no payload
 359          */
 360         if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
 361                 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
 362                 m->rreq->rc.size = m->rc.offset;
 363                 spin_lock(&m->client->lock);
 364                 if (m->rreq->status == REQ_STATUS_SENT) {
 365                         list_del(&m->rreq->req_list);
 366                         p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
 367                 } else if (m->rreq->status == REQ_STATUS_FLSHD) {
 368                         /* Ignore replies associated with a cancelled request. */
 369                         p9_debug(P9_DEBUG_TRANS,
 370                                  "Ignore replies associated with a cancelled request\n");
 371                 } else {
 372                         spin_unlock(&m->client->lock);
 373                         p9_debug(P9_DEBUG_ERROR,
 374                                  "Request tag %d errored out while we were reading the reply\n",
 375                                  m->rc.tag);
 376                         err = -EIO;
 377                         goto error;
 378                 }
 379                 spin_unlock(&m->client->lock);
 380                 m->rc.sdata = NULL;
 381                 m->rc.offset = 0;
 382                 m->rc.capacity = 0;
 383                 p9_req_put(m->rreq);
 384                 m->rreq = NULL;
 385         }
 386
 387 end_clear:
 388         clear_bit(Rworksched, &m->wsched);
 389
 390         if (!list_empty(&m->req_list)) {
 391                 if (test_and_clear_bit(Rpending, &m->wsched))
 392                         n = EPOLLIN;
 393                 else
 394                         n = p9_fd_poll(m->client, NULL, NULL);
 395
 396                 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
 397                         p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
 398                         schedule_work(&m->rq);
 399                 }
 400         }
 401
 402         return;
 403 error:
 404         p9_conn_cancel(m, err);
 405         clear_bit(Rworksched, &m->wsched);
 406 }
 407
 408 /**
 409  * p9_fd_write - write to a socket
 410  * @client: client instance
 411  * @v: buffer to send data from
 412  * @len: size of send buffer
 413  *
 414  */
 415
 416 static int p9_fd_write(struct p9_client *client, void *v, int len)
 417 {
 418         ssize_t ret;
 419         struct p9_trans_fd *ts = NULL;
 420
 421         if (client && client->status != Disconnected)
 422                 ts = client->trans;
 423
 424         if (!ts)
 425                 return -EREMOTEIO;
 426
 427         if (!(ts->wr->f_flags & O_NONBLOCK))
 428                 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
 429
 430         ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
 431         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 432                 client->status = Disconnected;
 433         return ret;
 434 }
 435
 436 /**
 437  * p9_write_work - called when a transport can send some data
 438  * @work: container for work to be done
 439  *
 440  */
 441
 442 static void p9_write_work(struct work_struct *work)
 443 {
 444         __poll_t n;
 445         int err;
 446         struct p9_conn *m;
 447         struct p9_req_t *req;
 448
 449         m = container_of(work, struct p9_conn, wq);
 450
 451         if (m->err < 0) {
 452                 clear_bit(Wworksched, &m->wsched);
 453                 return;
 454         }
 455
 456         if (!m->wsize) {
 457                 spin_lock(&m->client->lock);
 458                 if (list_empty(&m->unsent_req_list)) {
 459                         clear_bit(Wworksched, &m->wsched);
 460                         spin_unlock(&m->client->lock);
 461                         return;
 462                 }
 463
 464                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
 465                                req_list);
 466                 req->status = REQ_STATUS_SENT;
 467                 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
 468                 list_move_tail(&req->req_list, &m->req_list);
 469
 470                 m->wbuf = req->tc.sdata;
 471                 m->wsize = req->tc.size;
 472                 m->wpos = 0;
 473                 p9_req_get(req);
 474                 m->wreq = req;
 475                 spin_unlock(&m->client->lock);
 476         }
 477
 478         p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
 479                  m, m->wpos, m->wsize);
 480         clear_bit(Wpending, &m->wsched);
 481         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
 482         p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
 483         if (err == -EAGAIN)
 484                 goto end_clear;
 485
 486
 487         if (err < 0)
 488                 goto error;
 489         else if (err == 0) {
 490                 err = -EREMOTEIO;
 491                 goto error;
 492         }
 493
 494         m->wpos += err;
 495         if (m->wpos == m->wsize) {
 496                 m->wpos = m->wsize = 0;
 497                 p9_req_put(m->wreq);
 498                 m->wreq = NULL;
 499         }
 500
 501 end_clear:
 502         clear_bit(Wworksched, &m->wsched);
 503
 504         if (m->wsize || !list_empty(&m->unsent_req_list)) {
 505                 if (test_and_clear_bit(Wpending, &m->wsched))
 506                         n = EPOLLOUT;
 507                 else
 508                         n = p9_fd_poll(m->client, NULL, NULL);
 509
 510                 if ((n & EPOLLOUT) &&
 511                    !test_and_set_bit(Wworksched, &m->wsched)) {
 512                         p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
 513                         schedule_work(&m->wq);
 514                 }
 515         }
 516
 517         return;
 518
 519 error:
 520         p9_conn_cancel(m, err);
 521         clear_bit(Wworksched, &m->wsched);
 522 }
 523
 524 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
 525 {
 526         struct p9_poll_wait *pwait =
 527                 container_of(wait, struct p9_poll_wait, wait);
 528         struct p9_conn *m = pwait->conn;
 529         unsigned long flags;
 530
 531         spin_lock_irqsave(&p9_poll_lock, flags);
 532         if (list_empty(&m->poll_pending_link))
 533                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
 534         spin_unlock_irqrestore(&p9_poll_lock, flags);
 535
 536         schedule_work(&p9_poll_work);
 537         return 1;
 538 }
 539
 540 /**
 541  * p9_pollwait - add poll task to the wait queue
 542  * @filp: file pointer being polled
 543  * @wait_address: wait_q to block on
 544  * @p: poll state
 545  *
 546  * called by files poll operation to add v9fs-poll task to files wait queue
 547  */
 548
 549 static void
 550 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 551 {
 552         struct p9_conn *m = container_of(p, struct p9_conn, pt);
 553         struct p9_poll_wait *pwait = NULL;
 554         int i;
 555
 556         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 557                 if (m->poll_wait[i].wait_addr == NULL) {
 558                         pwait = &m->poll_wait[i];
 559                         break;
 560                 }
 561         }
 562
 563         if (!pwait) {
 564                 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
 565                 return;
 566         }
 567
 568         pwait->conn = m;
 569         pwait->wait_addr = wait_address;
 570         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
 571         add_wait_queue(wait_address, &pwait->wait);
 572 }
 573
 574 /**
 575  * p9_conn_create - initialize the per-session mux data
 576  * @client: client instance
 577  *
 578  * Note: Creates the polling task if this is the first session.
 579  */
 580
 581 static void p9_conn_create(struct p9_client *client)
 582 {
 583         __poll_t n;
 584         struct p9_trans_fd *ts = client->trans;
 585         struct p9_conn *m = &ts->conn;
 586
 587         p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
 588
 589         INIT_LIST_HEAD(&m->mux_list);
 590         m->client = client;
 591
 592         INIT_LIST_HEAD(&m->req_list);
 593         INIT_LIST_HEAD(&m->unsent_req_list);
 594         INIT_WORK(&m->rq, p9_read_work);
 595         INIT_WORK(&m->wq, p9_write_work);
 596         INIT_LIST_HEAD(&m->poll_pending_link);
 597         init_poll_funcptr(&m->pt, p9_pollwait);
 598
 599         n = p9_fd_poll(client, &m->pt, NULL);
 600         if (n & EPOLLIN) {
 601                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 602                 set_bit(Rpending, &m->wsched);
 603         }
 604
 605         if (n & EPOLLOUT) {
 606                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 607                 set_bit(Wpending, &m->wsched);
 608         }
 609 }
 610
 611 /**
 612  * p9_poll_mux - polls a mux and schedules read or write works if necessary
 613  * @m: connection to poll
 614  *
 615  */
 616
 617 static void p9_poll_mux(struct p9_conn *m)
 618 {
 619         __poll_t n;
 620         int err = -ECONNRESET;
 621
 622         if (m->err < 0)
 623                 return;
 624
 625         n = p9_fd_poll(m->client, NULL, &err);
 626         if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
 627                 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
 628                 p9_conn_cancel(m, err);
 629         }
 630
 631         if (n & EPOLLIN) {
 632                 set_bit(Rpending, &m->wsched);
 633                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 634                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
 635                         p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
 636                         schedule_work(&m->rq);
 637                 }
 638         }
 639
 640         if (n & EPOLLOUT) {
 641                 set_bit(Wpending, &m->wsched);
 642                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 643                 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
 644                     !test_and_set_bit(Wworksched, &m->wsched)) {
 645                         p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
 646                         schedule_work(&m->wq);
 647                 }
 648         }
 649 }
 650
 651 /**
 652  * p9_fd_request - send 9P request
 653  * The function can sleep until the request is scheduled for sending.
 654  * The function can be interrupted. Return from the function is not
 655  * a guarantee that the request is sent successfully.
 656  *
 657  * @client: client instance
 658  * @req: request to be sent
 659  *
 660  */
 661
 662 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
 663 {
 664         __poll_t n;
 665         struct p9_trans_fd *ts = client->trans;
 666         struct p9_conn *m = &ts->conn;
 667
 668         p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
 669                  m, current, &req->tc, req->tc.id);
 670         if (m->err < 0)
 671                 return m->err;
 672
 673         spin_lock(&client->lock);
 674         req->status = REQ_STATUS_UNSENT;
 675         list_add_tail(&req->req_list, &m->unsent_req_list);
 676         spin_unlock(&client->lock);
 677
 678         if (test_and_clear_bit(Wpending, &m->wsched))
 679                 n = EPOLLOUT;
 680         else
 681                 n = p9_fd_poll(m->client, NULL, NULL);
 682
 683         if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 684                 schedule_work(&m->wq);
 685
 686         return 0;
 687 }
 688
 689 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 690 {
 691         int ret = 1;
 692
 693         p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 694
 695         spin_lock(&client->lock);
 696
 697         if (req->status == REQ_STATUS_UNSENT) {
 698                 list_del(&req->req_list);
 699                 req->status = REQ_STATUS_FLSHD;
 700                 p9_req_put(req);
 701                 ret = 0;
 702         }
 703         spin_unlock(&client->lock);
 704
 705         return ret;
 706 }
 707
 708 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
 709 {
 710         p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 711
 712         spin_lock(&client->lock);
 713         /* Ignore cancelled request if message has been received
 714          * before lock.
 715          */
 716         if (req->status == REQ_STATUS_RCVD) {
 717                 spin_unlock(&client->lock);
 718                 return 0;
 719         }
 720
 721         /* we haven't received a response for oldreq,
 722          * remove it from the list.
 723          */
 724         list_del(&req->req_list);
 725         req->status = REQ_STATUS_FLSHD;
 726         spin_unlock(&client->lock);
 727         p9_req_put(req);
 728
 729         return 0;
 730 }
 731
 732 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
 733 {
 734         if (clnt->trans_mod == &p9_tcp_trans) {
 735                 if (clnt->trans_opts.tcp.port != P9_PORT)
 736                         seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
 737         } else if (clnt->trans_mod == &p9_fd_trans) {
 738                 if (clnt->trans_opts.fd.rfd != ~0)
 739                         seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
 740                 if (clnt->trans_opts.fd.wfd != ~0)
 741                         seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
 742         }
 743         return 0;
 744 }
 745
 746 /**
 747  * parse_opts - parse mount options into p9_fd_opts structure
 748  * @params: options string passed from mount
 749  * @opts: fd transport-specific structure to parse options into
 750  *
 751  * Returns 0 upon success, -ERRNO upon failure
 752  */
 753
 754 static int parse_opts(char *params, struct p9_fd_opts *opts)
 755 {
 756         char *p;
 757         substring_t args[MAX_OPT_ARGS];
 758         int option;
 759         char *options, *tmp_options;
 760
 761         opts->port = P9_PORT;
 762         opts->rfd = ~0;
 763         opts->wfd = ~0;
 764         opts->privport = false;
 765
 766         if (!params)
 767                 return 0;
 768
 769         tmp_options = kstrdup(params, GFP_KERNEL);
 770         if (!tmp_options) {
 771                 p9_debug(P9_DEBUG_ERROR,
 772                          "failed to allocate copy of option string\n");
 773                 return -ENOMEM;
 774         }
 775         options = tmp_options;
 776
 777         while ((p = strsep(&options, ",")) != NULL) {
 778                 int token;
 779                 int r;
 780                 if (!*p)
 781                         continue;
 782                 token = match_token(p, tokens, args);
 783                 if ((token != Opt_err) && (token != Opt_privport)) {
 784                         r = match_int(&args[0], &option);
 785                         if (r < 0) {
 786                                 p9_debug(P9_DEBUG_ERROR,
 787                                          "integer field, but no integer?\n");
 788                                 continue;
 789                         }
 790                 }
 791                 switch (token) {
 792                 case Opt_port:
 793                         opts->port = option;
 794                         break;
 795                 case Opt_rfdno:
 796                         opts->rfd = option;
 797                         break;
 798                 case Opt_wfdno:
 799                         opts->wfd = option;
 800                         break;
 801                 case Opt_privport:
 802                         opts->privport = true;
 803                         break;
 804                 default:
 805                         continue;
 806                 }
 807         }
 808
 809         kfree(tmp_options);
 810         return 0;
 811 }
 812
 813 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 814 {
 815         struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
 816                                            GFP_KERNEL);
 817         if (!ts)
 818                 return -ENOMEM;
 819
 820         ts->rd = fget(rfd);
 821         if (!ts->rd)
 822                 goto out_free_ts;
 823         if (!(ts->rd->f_mode & FMODE_READ))
 824                 goto out_put_rd;
 825         ts->wr = fget(wfd);
 826         if (!ts->wr)
 827                 goto out_put_rd;
 828         if (!(ts->wr->f_mode & FMODE_WRITE))
 829                 goto out_put_wr;
 830
 831         client->trans = ts;
 832         client->status = Connected;
 833
 834         return 0;
 835
 836 out_put_wr:
 837         fput(ts->wr);
 838 out_put_rd:
 839         fput(ts->rd);
 840 out_free_ts:
 841         kfree(ts);
 842         return -EIO;
 843 }
 844
 845 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 846 {
 847         struct p9_trans_fd *p;
 848         struct file *file;
 849
 850         p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
 851         if (!p)
 852                 return -ENOMEM;
 853
 854         csocket->sk->sk_allocation = GFP_NOIO;
 855         file = sock_alloc_file(csocket, 0, NULL);
 856         if (IS_ERR(file)) {
 857                 pr_err("%s (%d): failed to map fd\n",
 858                        __func__, task_pid_nr(current));
 859                 kfree(p);
 860                 return PTR_ERR(file);
 861         }
 862
 863         get_file(file);
 864         p->wr = p->rd = file;
 865         client->trans = p;
 866         client->status = Connected;
 867
 868         p->rd->f_flags |= O_NONBLOCK;
 869
 870         p9_conn_create(client);
 871         return 0;
 872 }
 873
 874 /**
 875  * p9_mux_destroy - cancels all pending requests of mux
 876  * @m: mux to destroy
 877  *
 878  */
 879
 880 static void p9_conn_destroy(struct p9_conn *m)
 881 {
 882         p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
 883                  m, m->mux_list.prev, m->mux_list.next);
 884
 885         p9_mux_poll_stop(m);
 886         cancel_work_sync(&m->rq);
 887         if (m->rreq) {
 888                 p9_req_put(m->rreq);
 889                 m->rreq = NULL;
 890         }
 891         cancel_work_sync(&m->wq);
 892         if (m->wreq) {
 893                 p9_req_put(m->wreq);
 894                 m->wreq = NULL;
 895         }
 896
 897         p9_conn_cancel(m, -ECONNRESET);
 898
 899         m->client = NULL;
 900 }
 901
 902 /**
 903  * p9_fd_close - shutdown file descriptor transport
 904  * @client: client instance
 905  *
 906  */
 907
 908 static void p9_fd_close(struct p9_client *client)
 909 {
 910         struct p9_trans_fd *ts;
 911
 912         if (!client)
 913                 return;
 914
 915         ts = client->trans;
 916         if (!ts)
 917                 return;
 918
 919         client->status = Disconnected;
 920
 921         p9_conn_destroy(&ts->conn);
 922
 923         if (ts->rd)
 924                 fput(ts->rd);
 925         if (ts->wr)
 926                 fput(ts->wr);
 927
 928         kfree(ts);
 929 }
 930
 931 /*
 932  * stolen from NFS - maybe should be made a generic function?
 933  */
 934 static inline int valid_ipaddr4(const char *buf)
 935 {
 936         int rc, count, in[4];
 937
 938         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
 939         if (rc != 4)
 940                 return -EINVAL;
 941         for (count = 0; count < 4; count++) {
 942                 if (in[count] > 255)
 943                         return -EINVAL;
 944         }
 945         return 0;
 946 }
 947
 948 static int p9_bind_privport(struct socket *sock)
 949 {
 950         struct sockaddr_in cl;
 951         int port, err = -EINVAL;
 952
 953         memset(&cl, 0, sizeof(cl));
 954         cl.sin_family = AF_INET;
 955         cl.sin_addr.s_addr = htonl(INADDR_ANY);
 956         for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
 957                 cl.sin_port = htons((ushort)port);
 958                 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
 959                 if (err != -EADDRINUSE)
 960                         break;
 961         }
 962         return err;
 963 }
 964
 965
 966 static int
 967 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
 968 {
 969         int err;
 970         struct socket *csocket;
 971         struct sockaddr_in sin_server;
 972         struct p9_fd_opts opts;
 973
 974         err = parse_opts(args, &opts);
 975         if (err < 0)
 976                 return err;
 977
 978         if (addr == NULL || valid_ipaddr4(addr) < 0)
 979                 return -EINVAL;
 980
 981         csocket = NULL;
 982
 983         client->trans_opts.tcp.port = opts.port;
 984         client->trans_opts.tcp.privport = opts.privport;
 985         sin_server.sin_family = AF_INET;
 986         sin_server.sin_addr.s_addr = in_aton(addr);
 987         sin_server.sin_port = htons(opts.port);
 988         err = __sock_create(current->nsproxy->net_ns, PF_INET,
 989                             SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
 990         if (err) {
 991                 pr_err("%s (%d): problem creating socket\n",
 992                        __func__, task_pid_nr(current));
 993                 return err;
 994         }
 995
 996         if (opts.privport) {
 997                 err = p9_bind_privport(csocket);
 998                 if (err < 0) {
 999                         pr_err("%s (%d): problem binding to privport\n",
1000                                __func__, task_pid_nr(current));
1001                         sock_release(csocket);
1002                         return err;
1003                 }
1004         }
1005
1006         err = csocket->ops->connect(csocket,
1007                                     (struct sockaddr *)&sin_server,
1008                                     sizeof(struct sockaddr_in), 0);
1009         if (err < 0) {
1010                 pr_err("%s (%d): problem connecting socket to %s\n",
1011                        __func__, task_pid_nr(current), addr);
1012                 sock_release(csocket);
1013                 return err;
1014         }
1015
1016         return p9_socket_open(client, csocket);
1017 }
1018
1019 static int
1020 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1021 {
1022         int err;
1023         struct socket *csocket;
1024         struct sockaddr_un sun_server;
1025
1026         csocket = NULL;
1027
1028         if (!addr || !strlen(addr))
1029                 return -EINVAL;
1030
1031         if (strlen(addr) >= UNIX_PATH_MAX) {
1032                 pr_err("%s (%d): address too long: %s\n",
1033                        __func__, task_pid_nr(current), addr);
1034                 return -ENAMETOOLONG;
1035         }
1036
1037         sun_server.sun_family = PF_UNIX;
1038         strcpy(sun_server.sun_path, addr);
1039         err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1040                             SOCK_STREAM, 0, &csocket, 1);
1041         if (err < 0) {
1042                 pr_err("%s (%d): problem creating socket\n",
1043                        __func__, task_pid_nr(current));
1044
1045                 return err;
1046         }
1047         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1048                         sizeof(struct sockaddr_un) - 1, 0);
1049         if (err < 0) {
1050                 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1051                        __func__, task_pid_nr(current), addr, err);
1052                 sock_release(csocket);
1053                 return err;
1054         }
1055
1056         return p9_socket_open(client, csocket);
1057 }
1058
1059 static int
1060 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1061 {
1062         int err;
1063         struct p9_fd_opts opts;
1064
1065         parse_opts(args, &opts);
1066         client->trans_opts.fd.rfd = opts.rfd;
1067         client->trans_opts.fd.wfd = opts.wfd;
1068
1069         if (opts.rfd == ~0 || opts.wfd == ~0) {
1070                 pr_err("Insufficient options for proto=fd\n");
1071                 return -ENOPROTOOPT;
1072         }
1073
1074         err = p9_fd_open(client, opts.rfd, opts.wfd);
1075         if (err < 0)
1076                 return err;
1077
1078         p9_conn_create(client);
1079
1080         return 0;
1081 }
1082
1083 static struct p9_trans_module p9_tcp_trans = {
1084         .name = "tcp",
1085         .maxsize = MAX_SOCK_BUF,
1086         .def = 0,
1087         .create = p9_fd_create_tcp,
1088         .close = p9_fd_close,
1089         .request = p9_fd_request,
1090         .cancel = p9_fd_cancel,
1091         .cancelled = p9_fd_cancelled,
1092         .show_options = p9_fd_show_options,
1093         .owner = THIS_MODULE,
1094 };
1095
1096 static struct p9_trans_module p9_unix_trans = {
1097         .name = "unix",
1098         .maxsize = MAX_SOCK_BUF,
1099         .def = 0,
1100         .create = p9_fd_create_unix,
1101         .close = p9_fd_close,
1102         .request = p9_fd_request,
1103         .cancel = p9_fd_cancel,
1104         .cancelled = p9_fd_cancelled,
1105         .show_options = p9_fd_show_options,
1106         .owner = THIS_MODULE,
1107 };
1108
1109 static struct p9_trans_module p9_fd_trans = {
1110         .name = "fd",
1111         .maxsize = MAX_SOCK_BUF,
1112         .def = 0,
1113         .create = p9_fd_create,
1114         .close = p9_fd_close,
1115         .request = p9_fd_request,
1116         .cancel = p9_fd_cancel,
1117         .cancelled = p9_fd_cancelled,
1118         .show_options = p9_fd_show_options,
1119         .owner = THIS_MODULE,
1120 };
1121
1122 /**
1123  * p9_poll_workfn - poll worker thread
1124  * @work: work queue
1125  *
1126  * polls all v9fs transports for new events and queues the appropriate
1127  * work to the work queue
1128  *
1129  */
1130
1131 static void p9_poll_workfn(struct work_struct *work)
1132 {
1133         unsigned long flags;
1134
1135         p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1136
1137         spin_lock_irqsave(&p9_poll_lock, flags);
1138         while (!list_empty(&p9_poll_pending_list)) {
1139                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1140                                                         struct p9_conn,
1141                                                         poll_pending_link);
1142                 list_del_init(&conn->poll_pending_link);
1143                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1144
1145                 p9_poll_mux(conn);
1146
1147                 spin_lock_irqsave(&p9_poll_lock, flags);
1148         }
1149         spin_unlock_irqrestore(&p9_poll_lock, flags);
1150
1151         p9_debug(P9_DEBUG_TRANS, "finish\n");
1152 }
1153
1154 int p9_trans_fd_init(void)
1155 {
1156         v9fs_register_trans(&p9_tcp_trans);
1157         v9fs_register_trans(&p9_unix_trans);
1158         v9fs_register_trans(&p9_fd_trans);
1159
1160         return 0;
1161 }
1162
1163 void p9_trans_fd_exit(void)
1164 {
1165         flush_work(&p9_poll_work);
1166         v9fs_unregister_trans(&p9_tcp_trans);
1167         v9fs_unregister_trans(&p9_unix_trans);
1168         v9fs_unregister_trans(&p9_fd_trans);
1169 }