linux/net/9p/trans_fd.c
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   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 <net/9p/9p.h>
  45#include <net/9p/client.h>
  46#include <net/9p/transport.h>
  47
  48#include <linux/syscalls.h> /* killme */
  49
  50#define P9_PORT 564
  51#define MAX_SOCK_BUF (64*1024)
  52#define MAXPOLLWADDR    2
  53
  54/**
  55 * struct p9_fd_opts - per-transport options
  56 * @rfd: file descriptor for reading (trans=fd)
  57 * @wfd: file descriptor for writing (trans=fd)
  58 * @port: port to connect to (trans=tcp)
  59 *
  60 */
  61
  62struct p9_fd_opts {
  63        int rfd;
  64        int wfd;
  65        u16 port;
  66};
  67
  68/**
  69 * struct p9_trans_fd - transport state
  70 * @rd: reference to file to read from
  71 * @wr: reference of file to write to
  72 * @conn: connection state reference
  73 *
  74 */
  75
  76struct p9_trans_fd {
  77        struct file *rd;
  78        struct file *wr;
  79        struct p9_conn *conn;
  80};
  81
  82/*
  83  * Option Parsing (code inspired by NFS code)
  84  *  - a little lazy - parse all fd-transport options
  85  */
  86
  87enum {
  88        /* Options that take integer arguments */
  89        Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  90};
  91
  92static const match_table_t tokens = {
  93        {Opt_port, "port=%u"},
  94        {Opt_rfdno, "rfdno=%u"},
  95        {Opt_wfdno, "wfdno=%u"},
  96        {Opt_err, NULL},
  97};
  98
  99enum {
 100        Rworksched = 1,         /* read work scheduled or running */
 101        Rpending = 2,           /* can read */
 102        Wworksched = 4,         /* write work scheduled or running */
 103        Wpending = 8,           /* can write */
 104};
 105
 106struct p9_poll_wait {
 107        struct p9_conn *conn;
 108        wait_queue_t wait;
 109        wait_queue_head_t *wait_addr;
 110};
 111
 112/**
 113 * struct p9_conn - fd mux connection state information
 114 * @mux_list: list link for mux to manage multiple connections (?)
 115 * @client: reference to client instance for this connection
 116 * @err: error state
 117 * @req_list: accounting for requests which have been sent
 118 * @unsent_req_list: accounting for requests that haven't been sent
 119 * @req: current request being processed (if any)
 120 * @tmp_buf: temporary buffer to read in header
 121 * @rsize: amount to read for current frame
 122 * @rpos: read position in current frame
 123 * @rbuf: current read buffer
 124 * @wpos: write position for current frame
 125 * @wsize: amount of data to write for current frame
 126 * @wbuf: current write buffer
 127 * @poll_pending_link: pending links to be polled per conn
 128 * @poll_wait: array of wait_q's for various worker threads
 129 * @pt: poll state
 130 * @rq: current read work
 131 * @wq: current write work
 132 * @wsched: ????
 133 *
 134 */
 135
 136struct p9_conn {
 137        struct list_head mux_list;
 138        struct p9_client *client;
 139        int err;
 140        struct list_head req_list;
 141        struct list_head unsent_req_list;
 142        struct p9_req_t *req;
 143        char tmp_buf[7];
 144        int rsize;
 145        int rpos;
 146        char *rbuf;
 147        int wpos;
 148        int wsize;
 149        char *wbuf;
 150        struct list_head poll_pending_link;
 151        struct p9_poll_wait poll_wait[MAXPOLLWADDR];
 152        poll_table pt;
 153        struct work_struct rq;
 154        struct work_struct wq;
 155        unsigned long wsched;
 156};
 157
 158static void p9_poll_workfn(struct work_struct *work);
 159
 160static DEFINE_SPINLOCK(p9_poll_lock);
 161static LIST_HEAD(p9_poll_pending_list);
 162static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
 163
 164static void p9_mux_poll_stop(struct p9_conn *m)
 165{
 166        unsigned long flags;
 167        int i;
 168
 169        for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 170                struct p9_poll_wait *pwait = &m->poll_wait[i];
 171
 172                if (pwait->wait_addr) {
 173                        remove_wait_queue(pwait->wait_addr, &pwait->wait);
 174                        pwait->wait_addr = NULL;
 175                }
 176        }
 177
 178        spin_lock_irqsave(&p9_poll_lock, flags);
 179        list_del_init(&m->poll_pending_link);
 180        spin_unlock_irqrestore(&p9_poll_lock, flags);
 181}
 182
 183/**
 184 * p9_conn_cancel - cancel all pending requests with error
 185 * @m: mux data
 186 * @err: error code
 187 *
 188 */
 189
 190static void p9_conn_cancel(struct p9_conn *m, int err)
 191{
 192        struct p9_req_t *req, *rtmp;
 193        unsigned long flags;
 194        LIST_HEAD(cancel_list);
 195
 196        p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 197
 198        spin_lock_irqsave(&m->client->lock, flags);
 199
 200        if (m->err) {
 201                spin_unlock_irqrestore(&m->client->lock, flags);
 202                return;
 203        }
 204
 205        m->err = err;
 206
 207        list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
 208                req->status = REQ_STATUS_ERROR;
 209                if (!req->t_err)
 210                        req->t_err = err;
 211                list_move(&req->req_list, &cancel_list);
 212        }
 213        list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
 214                req->status = REQ_STATUS_ERROR;
 215                if (!req->t_err)
 216                        req->t_err = err;
 217                list_move(&req->req_list, &cancel_list);
 218        }
 219        spin_unlock_irqrestore(&m->client->lock, flags);
 220
 221        list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 222                p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
 223                list_del(&req->req_list);
 224                p9_client_cb(m->client, req);
 225        }
 226}
 227
 228static int
 229p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
 230{
 231        int ret, n;
 232        struct p9_trans_fd *ts = NULL;
 233
 234        if (client && client->status == Connected)
 235                ts = client->trans;
 236
 237        if (!ts)
 238                return -EREMOTEIO;
 239
 240        if (!ts->rd->f_op || !ts->rd->f_op->poll)
 241                return -EIO;
 242
 243        if (!ts->wr->f_op || !ts->wr->f_op->poll)
 244                return -EIO;
 245
 246        ret = ts->rd->f_op->poll(ts->rd, pt);
 247        if (ret < 0)
 248                return ret;
 249
 250        if (ts->rd != ts->wr) {
 251                n = ts->wr->f_op->poll(ts->wr, pt);
 252                if (n < 0)
 253                        return n;
 254                ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 255        }
 256
 257        return ret;
 258}
 259
 260/**
 261 * p9_fd_read- read from a fd
 262 * @client: client instance
 263 * @v: buffer to receive data into
 264 * @len: size of receive buffer
 265 *
 266 */
 267
 268static int p9_fd_read(struct p9_client *client, void *v, int len)
 269{
 270        int ret;
 271        struct p9_trans_fd *ts = NULL;
 272
 273        if (client && client->status != Disconnected)
 274                ts = client->trans;
 275
 276        if (!ts)
 277                return -EREMOTEIO;
 278
 279        if (!(ts->rd->f_flags & O_NONBLOCK))
 280                p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
 281
 282        ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
 283        if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 284                client->status = Disconnected;
 285        return ret;
 286}
 287
 288/**
 289 * p9_read_work - called when there is some data to be read from a transport
 290 * @work: container of work to be done
 291 *
 292 */
 293
 294static void p9_read_work(struct work_struct *work)
 295{
 296        int n, err;
 297        struct p9_conn *m;
 298
 299        m = container_of(work, struct p9_conn, rq);
 300
 301        if (m->err < 0)
 302                return;
 303
 304        p9_debug(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
 305
 306        if (!m->rbuf) {
 307                m->rbuf = m->tmp_buf;
 308                m->rpos = 0;
 309                m->rsize = 7; /* start by reading header */
 310        }
 311
 312        clear_bit(Rpending, &m->wsched);
 313        p9_debug(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n",
 314                 m, m->rpos, m->rsize, m->rsize-m->rpos);
 315        err = p9_fd_read(m->client, m->rbuf + m->rpos,
 316                                                m->rsize - m->rpos);
 317        p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
 318        if (err == -EAGAIN) {
 319                goto end_clear;
 320        }
 321
 322        if (err <= 0)
 323                goto error;
 324
 325        m->rpos += err;
 326
 327        if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
 328                u16 tag;
 329                p9_debug(P9_DEBUG_TRANS, "got new header\n");
 330
 331                n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
 332                if (n >= m->client->msize) {
 333                        p9_debug(P9_DEBUG_ERROR,
 334                                 "requested packet size too big: %d\n", n);
 335                        err = -EIO;
 336                        goto error;
 337                }
 338
 339                tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
 340                p9_debug(P9_DEBUG_TRANS,
 341                         "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
 342
 343                m->req = p9_tag_lookup(m->client, tag);
 344                if (!m->req || (m->req->status != REQ_STATUS_SENT &&
 345                                        m->req->status != REQ_STATUS_FLSH)) {
 346                        p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
 347                                 tag);
 348                        err = -EIO;
 349                        goto error;
 350                }
 351
 352                if (m->req->rc == NULL) {
 353                        m->req->rc = kmalloc(sizeof(struct p9_fcall) +
 354                                                m->client->msize, GFP_NOFS);
 355                        if (!m->req->rc) {
 356                                m->req = NULL;
 357                                err = -ENOMEM;
 358                                goto error;
 359                        }
 360                }
 361                m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
 362                memcpy(m->rbuf, m->tmp_buf, m->rsize);
 363                m->rsize = n;
 364        }
 365
 366        /* not an else because some packets (like clunk) have no payload */
 367        if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
 368                p9_debug(P9_DEBUG_TRANS, "got new packet\n");
 369                spin_lock(&m->client->lock);
 370                if (m->req->status != REQ_STATUS_ERROR)
 371                        m->req->status = REQ_STATUS_RCVD;
 372                list_del(&m->req->req_list);
 373                spin_unlock(&m->client->lock);
 374                p9_client_cb(m->client, m->req);
 375                m->rbuf = NULL;
 376                m->rpos = 0;
 377                m->rsize = 0;
 378                m->req = NULL;
 379        }
 380
 381end_clear:
 382        clear_bit(Rworksched, &m->wsched);
 383
 384        if (!list_empty(&m->req_list)) {
 385                if (test_and_clear_bit(Rpending, &m->wsched))
 386                        n = POLLIN;
 387                else
 388                        n = p9_fd_poll(m->client, NULL);
 389
 390                if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
 391                        p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
 392                        schedule_work(&m->rq);
 393                }
 394        }
 395
 396        return;
 397error:
 398        p9_conn_cancel(m, err);
 399        clear_bit(Rworksched, &m->wsched);
 400}
 401
 402/**
 403 * p9_fd_write - write to a socket
 404 * @client: client instance
 405 * @v: buffer to send data from
 406 * @len: size of send buffer
 407 *
 408 */
 409
 410static int p9_fd_write(struct p9_client *client, void *v, int len)
 411{
 412        int ret;
 413        mm_segment_t oldfs;
 414        struct p9_trans_fd *ts = NULL;
 415
 416        if (client && client->status != Disconnected)
 417                ts = client->trans;
 418
 419        if (!ts)
 420                return -EREMOTEIO;
 421
 422        if (!(ts->wr->f_flags & O_NONBLOCK))
 423                p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
 424
 425        oldfs = get_fs();
 426        set_fs(get_ds());
 427        /* The cast to a user pointer is valid due to the set_fs() */
 428        ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
 429        set_fs(oldfs);
 430
 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
 442static void p9_write_work(struct work_struct *work)
 443{
 444        int n, err;
 445        struct p9_conn *m;
 446        struct p9_req_t *req;
 447
 448        m = container_of(work, struct p9_conn, wq);
 449
 450        if (m->err < 0) {
 451                clear_bit(Wworksched, &m->wsched);
 452                return;
 453        }
 454
 455        if (!m->wsize) {
 456                spin_lock(&m->client->lock);
 457                if (list_empty(&m->unsent_req_list)) {
 458                        clear_bit(Wworksched, &m->wsched);
 459                        spin_unlock(&m->client->lock);
 460                        return;
 461                }
 462
 463                req = list_entry(m->unsent_req_list.next, struct p9_req_t,
 464                               req_list);
 465                req->status = REQ_STATUS_SENT;
 466                p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
 467                list_move_tail(&req->req_list, &m->req_list);
 468
 469                m->wbuf = req->tc->sdata;
 470                m->wsize = req->tc->size;
 471                m->wpos = 0;
 472                spin_unlock(&m->client->lock);
 473        }
 474
 475        p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
 476                 m, m->wpos, m->wsize);
 477        clear_bit(Wpending, &m->wsched);
 478        err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
 479        p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
 480        if (err == -EAGAIN)
 481                goto end_clear;
 482
 483
 484        if (err < 0)
 485                goto error;
 486        else if (err == 0) {
 487                err = -EREMOTEIO;
 488                goto error;
 489        }
 490
 491        m->wpos += err;
 492        if (m->wpos == m->wsize)
 493                m->wpos = m->wsize = 0;
 494
 495end_clear:
 496        clear_bit(Wworksched, &m->wsched);
 497
 498        if (m->wsize || !list_empty(&m->unsent_req_list)) {
 499                if (test_and_clear_bit(Wpending, &m->wsched))
 500                        n = POLLOUT;
 501                else
 502                        n = p9_fd_poll(m->client, NULL);
 503
 504                if ((n & POLLOUT) &&
 505                   !test_and_set_bit(Wworksched, &m->wsched)) {
 506                        p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
 507                        schedule_work(&m->wq);
 508                }
 509        }
 510
 511        return;
 512
 513error:
 514        p9_conn_cancel(m, err);
 515        clear_bit(Wworksched, &m->wsched);
 516}
 517
 518static int p9_pollwake(wait_queue_t *wait, unsigned int mode, int sync, void *key)
 519{
 520        struct p9_poll_wait *pwait =
 521                container_of(wait, struct p9_poll_wait, wait);
 522        struct p9_conn *m = pwait->conn;
 523        unsigned long flags;
 524
 525        spin_lock_irqsave(&p9_poll_lock, flags);
 526        if (list_empty(&m->poll_pending_link))
 527                list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
 528        spin_unlock_irqrestore(&p9_poll_lock, flags);
 529
 530        schedule_work(&p9_poll_work);
 531        return 1;
 532}
 533
 534/**
 535 * p9_pollwait - add poll task to the wait queue
 536 * @filp: file pointer being polled
 537 * @wait_address: wait_q to block on
 538 * @p: poll state
 539 *
 540 * called by files poll operation to add v9fs-poll task to files wait queue
 541 */
 542
 543static void
 544p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 545{
 546        struct p9_conn *m = container_of(p, struct p9_conn, pt);
 547        struct p9_poll_wait *pwait = NULL;
 548        int i;
 549
 550        for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 551                if (m->poll_wait[i].wait_addr == NULL) {
 552                        pwait = &m->poll_wait[i];
 553                        break;
 554                }
 555        }
 556
 557        if (!pwait) {
 558                p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
 559                return;
 560        }
 561
 562        pwait->conn = m;
 563        pwait->wait_addr = wait_address;
 564        init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
 565        add_wait_queue(wait_address, &pwait->wait);
 566}
 567
 568/**
 569 * p9_conn_create - allocate and initialize the per-session mux data
 570 * @client: client instance
 571 *
 572 * Note: Creates the polling task if this is the first session.
 573 */
 574
 575static struct p9_conn *p9_conn_create(struct p9_client *client)
 576{
 577        int n;
 578        struct p9_conn *m;
 579
 580        p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
 581        m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
 582        if (!m)
 583                return ERR_PTR(-ENOMEM);
 584
 585        INIT_LIST_HEAD(&m->mux_list);
 586        m->client = client;
 587
 588        INIT_LIST_HEAD(&m->req_list);
 589        INIT_LIST_HEAD(&m->unsent_req_list);
 590        INIT_WORK(&m->rq, p9_read_work);
 591        INIT_WORK(&m->wq, p9_write_work);
 592        INIT_LIST_HEAD(&m->poll_pending_link);
 593        init_poll_funcptr(&m->pt, p9_pollwait);
 594
 595        n = p9_fd_poll(client, &m->pt);
 596        if (n & POLLIN) {
 597                p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 598                set_bit(Rpending, &m->wsched);
 599        }
 600
 601        if (n & POLLOUT) {
 602                p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 603                set_bit(Wpending, &m->wsched);
 604        }
 605
 606        return m;
 607}
 608
 609/**
 610 * p9_poll_mux - polls a mux and schedules read or write works if necessary
 611 * @m: connection to poll
 612 *
 613 */
 614
 615static void p9_poll_mux(struct p9_conn *m)
 616{
 617        int n;
 618
 619        if (m->err < 0)
 620                return;
 621
 622        n = p9_fd_poll(m->client, NULL);
 623        if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
 624                p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
 625                if (n >= 0)
 626                        n = -ECONNRESET;
 627                p9_conn_cancel(m, n);
 628        }
 629
 630        if (n & POLLIN) {
 631                set_bit(Rpending, &m->wsched);
 632                p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 633                if (!test_and_set_bit(Rworksched, &m->wsched)) {
 634                        p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
 635                        schedule_work(&m->rq);
 636                }
 637        }
 638
 639        if (n & POLLOUT) {
 640                set_bit(Wpending, &m->wsched);
 641                p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 642                if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
 643                    !test_and_set_bit(Wworksched, &m->wsched)) {
 644                        p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
 645                        schedule_work(&m->wq);
 646                }
 647        }
 648}
 649
 650/**
 651 * p9_fd_request - send 9P request
 652 * The function can sleep until the request is scheduled for sending.
 653 * The function can be interrupted. Return from the function is not
 654 * a guarantee that the request is sent successfully.
 655 *
 656 * @client: client instance
 657 * @req: request to be sent
 658 *
 659 */
 660
 661static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
 662{
 663        int n;
 664        struct p9_trans_fd *ts = client->trans;
 665        struct p9_conn *m = ts->conn;
 666
 667        p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
 668                 m, current, req->tc, req->tc->id);
 669        if (m->err < 0)
 670                return m->err;
 671
 672        spin_lock(&client->lock);
 673        req->status = REQ_STATUS_UNSENT;
 674        list_add_tail(&req->req_list, &m->unsent_req_list);
 675        spin_unlock(&client->lock);
 676
 677        if (test_and_clear_bit(Wpending, &m->wsched))
 678                n = POLLOUT;
 679        else
 680                n = p9_fd_poll(m->client, NULL);
 681
 682        if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 683                schedule_work(&m->wq);
 684
 685        return 0;
 686}
 687
 688static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 689{
 690        int ret = 1;
 691
 692        p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 693
 694        spin_lock(&client->lock);
 695
 696        if (req->status == REQ_STATUS_UNSENT) {
 697                list_del(&req->req_list);
 698                req->status = REQ_STATUS_FLSHD;
 699                ret = 0;
 700        } else if (req->status == REQ_STATUS_SENT)
 701                req->status = REQ_STATUS_FLSH;
 702
 703        spin_unlock(&client->lock);
 704
 705        return ret;
 706}
 707
 708/**
 709 * parse_opts - parse mount options into p9_fd_opts structure
 710 * @params: options string passed from mount
 711 * @opts: fd transport-specific structure to parse options into
 712 *
 713 * Returns 0 upon success, -ERRNO upon failure
 714 */
 715
 716static int parse_opts(char *params, struct p9_fd_opts *opts)
 717{
 718        char *p;
 719        substring_t args[MAX_OPT_ARGS];
 720        int option;
 721        char *options, *tmp_options;
 722
 723        opts->port = P9_PORT;
 724        opts->rfd = ~0;
 725        opts->wfd = ~0;
 726
 727        if (!params)
 728                return 0;
 729
 730        tmp_options = kstrdup(params, GFP_KERNEL);
 731        if (!tmp_options) {
 732                p9_debug(P9_DEBUG_ERROR,
 733                         "failed to allocate copy of option string\n");
 734                return -ENOMEM;
 735        }
 736        options = tmp_options;
 737
 738        while ((p = strsep(&options, ",")) != NULL) {
 739                int token;
 740                int r;
 741                if (!*p)
 742                        continue;
 743                token = match_token(p, tokens, args);
 744                if (token != Opt_err) {
 745                        r = match_int(&args[0], &option);
 746                        if (r < 0) {
 747                                p9_debug(P9_DEBUG_ERROR,
 748                                         "integer field, but no integer?\n");
 749                                continue;
 750                        }
 751                }
 752                switch (token) {
 753                case Opt_port:
 754                        opts->port = option;
 755                        break;
 756                case Opt_rfdno:
 757                        opts->rfd = option;
 758                        break;
 759                case Opt_wfdno:
 760                        opts->wfd = option;
 761                        break;
 762                default:
 763                        continue;
 764                }
 765        }
 766
 767        kfree(tmp_options);
 768        return 0;
 769}
 770
 771static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 772{
 773        struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
 774                                           GFP_KERNEL);
 775        if (!ts)
 776                return -ENOMEM;
 777
 778        ts->rd = fget(rfd);
 779        ts->wr = fget(wfd);
 780        if (!ts->rd || !ts->wr) {
 781                if (ts->rd)
 782                        fput(ts->rd);
 783                if (ts->wr)
 784                        fput(ts->wr);
 785                kfree(ts);
 786                return -EIO;
 787        }
 788
 789        client->trans = ts;
 790        client->status = Connected;
 791
 792        return 0;
 793}
 794
 795static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 796{
 797        struct p9_trans_fd *p;
 798        struct file *file;
 799        int ret;
 800
 801        p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
 802        if (!p)
 803                return -ENOMEM;
 804
 805        csocket->sk->sk_allocation = GFP_NOIO;
 806        file = sock_alloc_file(csocket, 0, NULL);
 807        if (IS_ERR(file)) {
 808                pr_err("%s (%d): failed to map fd\n",
 809                       __func__, task_pid_nr(current));
 810                sock_release(csocket);
 811                kfree(p);
 812                return PTR_ERR(file);
 813        }
 814
 815        get_file(file);
 816        p->wr = p->rd = file;
 817        client->trans = p;
 818        client->status = Connected;
 819
 820        p->rd->f_flags |= O_NONBLOCK;
 821
 822        p->conn = p9_conn_create(client);
 823        if (IS_ERR(p->conn)) {
 824                ret = PTR_ERR(p->conn);
 825                p->conn = NULL;
 826                kfree(p);
 827                sockfd_put(csocket);
 828                sockfd_put(csocket);
 829                return ret;
 830        }
 831        return 0;
 832}
 833
 834/**
 835 * p9_mux_destroy - cancels all pending requests and frees mux resources
 836 * @m: mux to destroy
 837 *
 838 */
 839
 840static void p9_conn_destroy(struct p9_conn *m)
 841{
 842        p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
 843                 m, m->mux_list.prev, m->mux_list.next);
 844
 845        p9_mux_poll_stop(m);
 846        cancel_work_sync(&m->rq);
 847        cancel_work_sync(&m->wq);
 848
 849        p9_conn_cancel(m, -ECONNRESET);
 850
 851        m->client = NULL;
 852        kfree(m);
 853}
 854
 855/**
 856 * p9_fd_close - shutdown file descriptor transport
 857 * @client: client instance
 858 *
 859 */
 860
 861static void p9_fd_close(struct p9_client *client)
 862{
 863        struct p9_trans_fd *ts;
 864
 865        if (!client)
 866                return;
 867
 868        ts = client->trans;
 869        if (!ts)
 870                return;
 871
 872        client->status = Disconnected;
 873
 874        p9_conn_destroy(ts->conn);
 875
 876        if (ts->rd)
 877                fput(ts->rd);
 878        if (ts->wr)
 879                fput(ts->wr);
 880
 881        kfree(ts);
 882}
 883
 884/*
 885 * stolen from NFS - maybe should be made a generic function?
 886 */
 887static inline int valid_ipaddr4(const char *buf)
 888{
 889        int rc, count, in[4];
 890
 891        rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
 892        if (rc != 4)
 893                return -EINVAL;
 894        for (count = 0; count < 4; count++) {
 895                if (in[count] > 255)
 896                        return -EINVAL;
 897        }
 898        return 0;
 899}
 900
 901static int
 902p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
 903{
 904        int err;
 905        struct socket *csocket;
 906        struct sockaddr_in sin_server;
 907        struct p9_fd_opts opts;
 908
 909        err = parse_opts(args, &opts);
 910        if (err < 0)
 911                return err;
 912
 913        if (valid_ipaddr4(addr) < 0)
 914                return -EINVAL;
 915
 916        csocket = NULL;
 917
 918        sin_server.sin_family = AF_INET;
 919        sin_server.sin_addr.s_addr = in_aton(addr);
 920        sin_server.sin_port = htons(opts.port);
 921        err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_INET,
 922                            SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
 923        if (err) {
 924                pr_err("%s (%d): problem creating socket\n",
 925                       __func__, task_pid_nr(current));
 926                return err;
 927        }
 928
 929        err = csocket->ops->connect(csocket,
 930                                    (struct sockaddr *)&sin_server,
 931                                    sizeof(struct sockaddr_in), 0);
 932        if (err < 0) {
 933                pr_err("%s (%d): problem connecting socket to %s\n",
 934                       __func__, task_pid_nr(current), addr);
 935                sock_release(csocket);
 936                return err;
 937        }
 938
 939        return p9_socket_open(client, csocket);
 940}
 941
 942static int
 943p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
 944{
 945        int err;
 946        struct socket *csocket;
 947        struct sockaddr_un sun_server;
 948
 949        csocket = NULL;
 950
 951        if (strlen(addr) >= UNIX_PATH_MAX) {
 952                pr_err("%s (%d): address too long: %s\n",
 953                       __func__, task_pid_nr(current), addr);
 954                return -ENAMETOOLONG;
 955        }
 956
 957        sun_server.sun_family = PF_UNIX;
 958        strcpy(sun_server.sun_path, addr);
 959        err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_UNIX,
 960                            SOCK_STREAM, 0, &csocket, 1);
 961        if (err < 0) {
 962                pr_err("%s (%d): problem creating socket\n",
 963                       __func__, task_pid_nr(current));
 964
 965                return err;
 966        }
 967        err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 968                        sizeof(struct sockaddr_un) - 1, 0);
 969        if (err < 0) {
 970                pr_err("%s (%d): problem connecting socket: %s: %d\n",
 971                       __func__, task_pid_nr(current), addr, err);
 972                sock_release(csocket);
 973                return err;
 974        }
 975
 976        return p9_socket_open(client, csocket);
 977}
 978
 979static int
 980p9_fd_create(struct p9_client *client, const char *addr, char *args)
 981{
 982        int err;
 983        struct p9_fd_opts opts;
 984        struct p9_trans_fd *p;
 985
 986        parse_opts(args, &opts);
 987
 988        if (opts.rfd == ~0 || opts.wfd == ~0) {
 989                pr_err("Insufficient options for proto=fd\n");
 990                return -ENOPROTOOPT;
 991        }
 992
 993        err = p9_fd_open(client, opts.rfd, opts.wfd);
 994        if (err < 0)
 995                return err;
 996
 997        p = (struct p9_trans_fd *) client->trans;
 998        p->conn = p9_conn_create(client);
 999        if (IS_ERR(p->conn)) {
1000                err = PTR_ERR(p->conn);
1001                p->conn = NULL;
1002                fput(p->rd);
1003                fput(p->wr);
1004                return err;
1005        }
1006
1007        return 0;
1008}
1009
1010static struct p9_trans_module p9_tcp_trans = {
1011        .name = "tcp",
1012        .maxsize = MAX_SOCK_BUF,
1013        .def = 1,
1014        .create = p9_fd_create_tcp,
1015        .close = p9_fd_close,
1016        .request = p9_fd_request,
1017        .cancel = p9_fd_cancel,
1018        .owner = THIS_MODULE,
1019};
1020
1021static struct p9_trans_module p9_unix_trans = {
1022        .name = "unix",
1023        .maxsize = MAX_SOCK_BUF,
1024        .def = 0,
1025        .create = p9_fd_create_unix,
1026        .close = p9_fd_close,
1027        .request = p9_fd_request,
1028        .cancel = p9_fd_cancel,
1029        .owner = THIS_MODULE,
1030};
1031
1032static struct p9_trans_module p9_fd_trans = {
1033        .name = "fd",
1034        .maxsize = MAX_SOCK_BUF,
1035        .def = 0,
1036        .create = p9_fd_create,
1037        .close = p9_fd_close,
1038        .request = p9_fd_request,
1039        .cancel = p9_fd_cancel,
1040        .owner = THIS_MODULE,
1041};
1042
1043/**
1044 * p9_poll_proc - poll worker thread
1045 * @a: thread state and arguments
1046 *
1047 * polls all v9fs transports for new events and queues the appropriate
1048 * work to the work queue
1049 *
1050 */
1051
1052static void p9_poll_workfn(struct work_struct *work)
1053{
1054        unsigned long flags;
1055
1056        p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1057
1058        spin_lock_irqsave(&p9_poll_lock, flags);
1059        while (!list_empty(&p9_poll_pending_list)) {
1060                struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1061                                                        struct p9_conn,
1062                                                        poll_pending_link);
1063                list_del_init(&conn->poll_pending_link);
1064                spin_unlock_irqrestore(&p9_poll_lock, flags);
1065
1066                p9_poll_mux(conn);
1067
1068                spin_lock_irqsave(&p9_poll_lock, flags);
1069        }
1070        spin_unlock_irqrestore(&p9_poll_lock, flags);
1071
1072        p9_debug(P9_DEBUG_TRANS, "finish\n");
1073}
1074
1075int p9_trans_fd_init(void)
1076{
1077        v9fs_register_trans(&p9_tcp_trans);
1078        v9fs_register_trans(&p9_unix_trans);
1079        v9fs_register_trans(&p9_fd_trans);
1080
1081        return 0;
1082}
1083
1084void p9_trans_fd_exit(void)
1085{
1086        flush_work(&p9_poll_work);
1087        v9fs_unregister_trans(&p9_tcp_trans);
1088        v9fs_unregister_trans(&p9_unix_trans);
1089        v9fs_unregister_trans(&p9_fd_trans);
1090}
1091
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