net/9p/trans

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This source file includes following definitions.
p9_mux_poll_stop
p9_conn_cancel
p9_fd_poll
p9_fd_read
p9_read_work
p9_fd_write
p9_write_work
p9_pollwake
p9_pollwait
p9_conn_create
p9_poll_mux
p9_fd_request
p9_fd_cancel
p9_fd_cancelled
p9_fd_show_options
parse_opts
p9_fd_open
p9_socket_open
p9_conn_destroy
p9_fd_close
valid_ipaddr4
p9_bind_privport
p9_fd_create_tcp
p9_fd_create_unix
p9_fd_create
p9_poll_workfn
p9_trans_fd_init
p9_trans_fd_exit
   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  *
  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  * @req: current request being processed (if any)
  99  * @tmp_buf: temporary buffer to read in header
 100  * @rc: temporary fcall for reading current frame
 101  * @wpos: write position for current frame
 102  * @wsize: amount of data to write for current frame
 103  * @wbuf: current write buffer
 104  * @poll_pending_link: pending links to be polled per conn
 105  * @poll_wait: array of wait_q's for various worker threads
 106  * @pt: poll state
 107  * @rq: current read work
 108  * @wq: current write work
 109  * @wsched: ????
 110  *
 111  */
 112 
 113 struct p9_conn {
 114         struct list_head mux_list;
 115         struct p9_client *client;
 116         int err;
 117         struct list_head req_list;
 118         struct list_head unsent_req_list;
 119         struct p9_req_t *rreq;
 120         struct p9_req_t *wreq;
 121         char tmp_buf[7];
 122         struct p9_fcall rc;
 123         int wpos;
 124         int wsize;
 125         char *wbuf;
 126         struct list_head poll_pending_link;
 127         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
 128         poll_table pt;
 129         struct work_struct rq;
 130         struct work_struct wq;
 131         unsigned long wsched;
 132 };
 133 
 134 /**
 135  * struct p9_trans_fd - transport state
 136  * @rd: reference to file to read from
 137  * @wr: reference of file to write to
 138  * @conn: connection state reference
 139  *
 140  */
 141 
 142 struct p9_trans_fd {
 143         struct file *rd;
 144         struct file *wr;
 145         struct p9_conn conn;
 146 };
 147 
 148 static void p9_poll_workfn(struct work_struct *work);
 149 
 150 static DEFINE_SPINLOCK(p9_poll_lock);
 151 static LIST_HEAD(p9_poll_pending_list);
 152 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
 153 
 154 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
 155 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
 156 
 157 static void p9_mux_poll_stop(struct p9_conn *m)
 158 {
 159         unsigned long flags;
 160         int i;
 161 
 162         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 163                 struct p9_poll_wait *pwait = &m->poll_wait[i];
 164 
 165                 if (pwait->wait_addr) {
 166                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
 167                         pwait->wait_addr = NULL;
 168                 }
 169         }
 170 
 171         spin_lock_irqsave(&p9_poll_lock, flags);
 172         list_del_init(&m->poll_pending_link);
 173         spin_unlock_irqrestore(&p9_poll_lock, flags);
 174 
 175         flush_work(&p9_poll_work);
 176 }
 177 
 178 /**
 179  * p9_conn_cancel - cancel all pending requests with error
 180  * @m: mux data
 181  * @err: error code
 182  *
 183  */
 184 
 185 static void p9_conn_cancel(struct p9_conn *m, int err)
 186 {
 187         struct p9_req_t *req, *rtmp;
 188         LIST_HEAD(cancel_list);
 189 
 190         p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 191 
 192         spin_lock(&m->client->lock);
 193 
 194         if (m->err) {
 195                 spin_unlock(&m->client->lock);
 196                 return;
 197         }
 198 
 199         m->err = err;
 200 
 201         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
 202                 list_move(&req->req_list, &cancel_list);
 203         }
 204         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
 205                 list_move(&req->req_list, &cancel_list);
 206         }
 207 
 208         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 209                 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
 210                 list_del(&req->req_list);
 211                 if (!req->t_err)
 212                         req->t_err = err;
 213                 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
 214         }
 215         spin_unlock(&m->client->lock);
 216 }
 217 
 218 static __poll_t
 219 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
 220 {
 221         __poll_t ret;
 222         struct p9_trans_fd *ts = NULL;
 223 
 224         if (client && client->status == Connected)
 225                 ts = client->trans;
 226 
 227         if (!ts) {
 228                 if (err)
 229                         *err = -EREMOTEIO;
 230                 return EPOLLERR;
 231         }
 232 
 233         ret = vfs_poll(ts->rd, pt);
 234         if (ts->rd != ts->wr)
 235                 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
 236         return ret;
 237 }
 238 
 239 /**
 240  * p9_fd_read- read from a fd
 241  * @client: client instance
 242  * @v: buffer to receive data into
 243  * @len: size of receive buffer
 244  *
 245  */
 246 
 247 static int p9_fd_read(struct p9_client *client, void *v, int len)
 248 {
 249         int ret;
 250         struct p9_trans_fd *ts = NULL;
 251         loff_t pos;
 252 
 253         if (client && client->status != Disconnected)
 254                 ts = client->trans;
 255 
 256         if (!ts)
 257                 return -EREMOTEIO;
 258 
 259         if (!(ts->rd->f_flags & O_NONBLOCK))
 260                 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
 261 
 262         pos = ts->rd->f_pos;
 263         ret = kernel_read(ts->rd, v, len, &pos);
 264         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 265                 client->status = Disconnected;
 266         return ret;
 267 }
 268 
 269 /**
 270  * p9_read_work - called when there is some data to be read from a transport
 271  * @work: container of work to be done
 272  *
 273  */
 274 
 275 static void p9_read_work(struct work_struct *work)
 276 {
 277         __poll_t n;
 278         int err;
 279         struct p9_conn *m;
 280 
 281         m = container_of(work, struct p9_conn, rq);
 282 
 283         if (m->err < 0)
 284                 return;
 285 
 286         p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
 287 
 288         if (!m->rc.sdata) {
 289                 m->rc.sdata = m->tmp_buf;
 290                 m->rc.offset = 0;
 291                 m->rc.capacity = 7; /* start by reading header */
 292         }
 293 
 294         clear_bit(Rpending, &m->wsched);
 295         p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
 296                  m, m->rc.offset, m->rc.capacity,
 297                  m->rc.capacity - m->rc.offset);
 298         err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
 299                          m->rc.capacity - m->rc.offset);
 300         p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
 301         if (err == -EAGAIN)
 302                 goto end_clear;
 303 
 304         if (err <= 0)
 305                 goto error;
 306 
 307         m->rc.offset += err;
 308 
 309         /* header read in */
 310         if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
 311                 p9_debug(P9_DEBUG_TRANS, "got new header\n");
 312 
 313                 /* Header size */
 314                 m->rc.size = 7;
 315                 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
 316                 if (err) {
 317                         p9_debug(P9_DEBUG_ERROR,
 318                                  "error parsing header: %d\n", err);
 319                         goto error;
 320                 }
 321 
 322                 if (m->rc.size >= m->client->msize) {
 323                         p9_debug(P9_DEBUG_ERROR,
 324                                  "requested packet size too big: %d\n",
 325                                  m->rc.size);
 326                         err = -EIO;
 327                         goto error;
 328                 }
 329 
 330                 p9_debug(P9_DEBUG_TRANS,
 331                          "mux %p pkt: size: %d bytes tag: %d\n",
 332                          m, m->rc.size, m->rc.tag);
 333 
 334                 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
 335                 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
 336                         p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
 337                                  m->rc.tag);
 338                         err = -EIO;
 339                         goto error;
 340                 }
 341 
 342                 if (!m->rreq->rc.sdata) {
 343                         p9_debug(P9_DEBUG_ERROR,
 344                                  "No recv fcall for tag %d (req %p), disconnecting!\n",
 345                                  m->rc.tag, m->rreq);
 346                         m->rreq = NULL;
 347                         err = -EIO;
 348                         goto error;
 349                 }
 350                 m->rc.sdata = m->rreq->rc.sdata;
 351                 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
 352                 m->rc.capacity = m->rc.size;
 353         }
 354 
 355         /* packet is read in
 356          * not an else because some packets (like clunk) have no payload
 357          */
 358         if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
 359                 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
 360                 m->rreq->rc.size = m->rc.offset;
 361                 spin_lock(&m->client->lock);
 362                 if (m->rreq->status == REQ_STATUS_SENT) {
 363                         list_del(&m->rreq->req_list);
 364                         p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
 365                 } else {
 366                         spin_unlock(&m->client->lock);
 367                         p9_debug(P9_DEBUG_ERROR,
 368                                  "Request tag %d errored out while we were reading the reply\n",
 369                                  m->rc.tag);
 370                         err = -EIO;
 371                         goto error;
 372                 }
 373                 spin_unlock(&m->client->lock);
 374                 m->rc.sdata = NULL;
 375                 m->rc.offset = 0;
 376                 m->rc.capacity = 0;
 377                 p9_req_put(m->rreq);
 378                 m->rreq = NULL;
 379         }
 380 
 381 end_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 = EPOLLIN;
 387                 else
 388                         n = p9_fd_poll(m->client, NULL, NULL);
 389 
 390                 if ((n & EPOLLIN) && !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;
 397 error:
 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 
 410 static int p9_fd_write(struct p9_client *client, void *v, int len)
 411 {
 412         ssize_t ret;
 413         struct p9_trans_fd *ts = NULL;
 414 
 415         if (client && client->status != Disconnected)
 416                 ts = client->trans;
 417 
 418         if (!ts)
 419                 return -EREMOTEIO;
 420 
 421         if (!(ts->wr->f_flags & O_NONBLOCK))
 422                 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
 423 
 424         ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
 425         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 426                 client->status = Disconnected;
 427         return ret;
 428 }
 429 
 430 /**
 431  * p9_write_work - called when a transport can send some data
 432  * @work: container for work to be done
 433  *
 434  */
 435 
 436 static void p9_write_work(struct work_struct *work)
 437 {
 438         __poll_t n;
 439         int err;
 440         struct p9_conn *m;
 441         struct p9_req_t *req;
 442 
 443         m = container_of(work, struct p9_conn, wq);
 444 
 445         if (m->err < 0) {
 446                 clear_bit(Wworksched, &m->wsched);
 447                 return;
 448         }
 449 
 450         if (!m->wsize) {
 451                 spin_lock(&m->client->lock);
 452                 if (list_empty(&m->unsent_req_list)) {
 453                         clear_bit(Wworksched, &m->wsched);
 454                         spin_unlock(&m->client->lock);
 455                         return;
 456                 }
 457 
 458                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
 459                                req_list);
 460                 req->status = REQ_STATUS_SENT;
 461                 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
 462                 list_move_tail(&req->req_list, &m->req_list);
 463 
 464                 m->wbuf = req->tc.sdata;
 465                 m->wsize = req->tc.size;
 466                 m->wpos = 0;
 467                 p9_req_get(req);
 468                 m->wreq = req;
 469                 spin_unlock(&m->client->lock);
 470         }
 471 
 472         p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
 473                  m, m->wpos, m->wsize);
 474         clear_bit(Wpending, &m->wsched);
 475         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
 476         p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
 477         if (err == -EAGAIN)
 478                 goto end_clear;
 479 
 480 
 481         if (err < 0)
 482                 goto error;
 483         else if (err == 0) {
 484                 err = -EREMOTEIO;
 485                 goto error;
 486         }
 487 
 488         m->wpos += err;
 489         if (m->wpos == m->wsize) {
 490                 m->wpos = m->wsize = 0;
 491                 p9_req_put(m->wreq);
 492                 m->wreq = NULL;
 493         }
 494 
 495 end_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 = EPOLLOUT;
 501                 else
 502                         n = p9_fd_poll(m->client, NULL, NULL);
 503 
 504                 if ((n & EPOLLOUT) &&
 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 
 513 error:
 514         p9_conn_cancel(m, err);
 515         clear_bit(Wworksched, &m->wsched);
 516 }
 517 
 518 static int p9_pollwake(wait_queue_entry_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 
 543 static void
 544 p9_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 - 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 
 575 static void p9_conn_create(struct p9_client *client)
 576 {
 577         __poll_t n;
 578         struct p9_trans_fd *ts = client->trans;
 579         struct p9_conn *m = &ts->conn;
 580 
 581         p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
 582 
 583         INIT_LIST_HEAD(&m->mux_list);
 584         m->client = client;
 585 
 586         INIT_LIST_HEAD(&m->req_list);
 587         INIT_LIST_HEAD(&m->unsent_req_list);
 588         INIT_WORK(&m->rq, p9_read_work);
 589         INIT_WORK(&m->wq, p9_write_work);
 590         INIT_LIST_HEAD(&m->poll_pending_link);
 591         init_poll_funcptr(&m->pt, p9_pollwait);
 592 
 593         n = p9_fd_poll(client, &m->pt, NULL);
 594         if (n & EPOLLIN) {
 595                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 596                 set_bit(Rpending, &m->wsched);
 597         }
 598 
 599         if (n & EPOLLOUT) {
 600                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 601                 set_bit(Wpending, &m->wsched);
 602         }
 603 }
 604 
 605 /**
 606  * p9_poll_mux - polls a mux and schedules read or write works if necessary
 607  * @m: connection to poll
 608  *
 609  */
 610 
 611 static void p9_poll_mux(struct p9_conn *m)
 612 {
 613         __poll_t n;
 614         int err = -ECONNRESET;
 615 
 616         if (m->err < 0)
 617                 return;
 618 
 619         n = p9_fd_poll(m->client, NULL, &err);
 620         if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
 621                 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
 622                 p9_conn_cancel(m, err);
 623         }
 624 
 625         if (n & EPOLLIN) {
 626                 set_bit(Rpending, &m->wsched);
 627                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
 628                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
 629                         p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
 630                         schedule_work(&m->rq);
 631                 }
 632         }
 633 
 634         if (n & EPOLLOUT) {
 635                 set_bit(Wpending, &m->wsched);
 636                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
 637                 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
 638                     !test_and_set_bit(Wworksched, &m->wsched)) {
 639                         p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
 640                         schedule_work(&m->wq);
 641                 }
 642         }
 643 }
 644 
 645 /**
 646  * p9_fd_request - send 9P request
 647  * The function can sleep until the request is scheduled for sending.
 648  * The function can be interrupted. Return from the function is not
 649  * a guarantee that the request is sent successfully.
 650  *
 651  * @client: client instance
 652  * @req: request to be sent
 653  *
 654  */
 655 
 656 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
 657 {
 658         __poll_t n;
 659         struct p9_trans_fd *ts = client->trans;
 660         struct p9_conn *m = &ts->conn;
 661 
 662         p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
 663                  m, current, &req->tc, req->tc.id);
 664         if (m->err < 0)
 665                 return m->err;
 666 
 667         spin_lock(&client->lock);
 668         req->status = REQ_STATUS_UNSENT;
 669         list_add_tail(&req->req_list, &m->unsent_req_list);
 670         spin_unlock(&client->lock);
 671 
 672         if (test_and_clear_bit(Wpending, &m->wsched))
 673                 n = EPOLLOUT;
 674         else
 675                 n = p9_fd_poll(m->client, NULL, NULL);
 676 
 677         if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 678                 schedule_work(&m->wq);
 679 
 680         return 0;
 681 }
 682 
 683 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 684 {
 685         int ret = 1;
 686 
 687         p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 688 
 689         spin_lock(&client->lock);
 690 
 691         if (req->status == REQ_STATUS_UNSENT) {
 692                 list_del(&req->req_list);
 693                 req->status = REQ_STATUS_FLSHD;
 694                 p9_req_put(req);
 695                 ret = 0;
 696         }
 697         spin_unlock(&client->lock);
 698 
 699         return ret;
 700 }
 701 
 702 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
 703 {
 704         p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 705 
 706         /* we haven't received a response for oldreq,
 707          * remove it from the list.
 708          */
 709         spin_lock(&client->lock);
 710         list_del(&req->req_list);
 711         spin_unlock(&client->lock);
 712         p9_req_put(req);
 713 
 714         return 0;
 715 }
 716 
 717 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
 718 {
 719         if (clnt->trans_mod == &p9_tcp_trans) {
 720                 if (clnt->trans_opts.tcp.port != P9_PORT)
 721                         seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
 722         } else if (clnt->trans_mod == &p9_fd_trans) {
 723                 if (clnt->trans_opts.fd.rfd != ~0)
 724                         seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
 725                 if (clnt->trans_opts.fd.wfd != ~0)
 726                         seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
 727         }
 728         return 0;
 729 }
 730 
 731 /**
 732  * parse_opts - parse mount options into p9_fd_opts structure
 733  * @params: options string passed from mount
 734  * @opts: fd transport-specific structure to parse options into
 735  *
 736  * Returns 0 upon success, -ERRNO upon failure
 737  */
 738 
 739 static int parse_opts(char *params, struct p9_fd_opts *opts)
 740 {
 741         char *p;
 742         substring_t args[MAX_OPT_ARGS];
 743         int option;
 744         char *options, *tmp_options;
 745 
 746         opts->port = P9_PORT;
 747         opts->rfd = ~0;
 748         opts->wfd = ~0;
 749         opts->privport = false;
 750 
 751         if (!params)
 752                 return 0;
 753 
 754         tmp_options = kstrdup(params, GFP_KERNEL);
 755         if (!tmp_options) {
 756                 p9_debug(P9_DEBUG_ERROR,
 757                          "failed to allocate copy of option string\n");
 758                 return -ENOMEM;
 759         }
 760         options = tmp_options;
 761 
 762         while ((p = strsep(&options, ",")) != NULL) {
 763                 int token;
 764                 int r;
 765                 if (!*p)
 766                         continue;
 767                 token = match_token(p, tokens, args);
 768                 if ((token != Opt_err) && (token != Opt_privport)) {
 769                         r = match_int(&args[0], &option);
 770                         if (r < 0) {
 771                                 p9_debug(P9_DEBUG_ERROR,
 772                                          "integer field, but no integer?\n");
 773                                 continue;
 774                         }
 775                 }
 776                 switch (token) {
 777                 case Opt_port:
 778                         opts->port = option;
 779                         break;
 780                 case Opt_rfdno:
 781                         opts->rfd = option;
 782                         break;
 783                 case Opt_wfdno:
 784                         opts->wfd = option;
 785                         break;
 786                 case Opt_privport:
 787                         opts->privport = true;
 788                         break;
 789                 default:
 790                         continue;
 791                 }
 792         }
 793 
 794         kfree(tmp_options);
 795         return 0;
 796 }
 797 
 798 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 799 {
 800         struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
 801                                            GFP_KERNEL);
 802         if (!ts)
 803                 return -ENOMEM;
 804 
 805         ts->rd = fget(rfd);
 806         ts->wr = fget(wfd);
 807         if (!ts->rd || !ts->wr) {
 808                 if (ts->rd)
 809                         fput(ts->rd);
 810                 if (ts->wr)
 811                         fput(ts->wr);
 812                 kfree(ts);
 813                 return -EIO;
 814         }
 815 
 816         client->trans = ts;
 817         client->status = Connected;
 818 
 819         return 0;
 820 }
 821 
 822 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 823 {
 824         struct p9_trans_fd *p;
 825         struct file *file;
 826 
 827         p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
 828         if (!p)
 829                 return -ENOMEM;
 830 
 831         csocket->sk->sk_allocation = GFP_NOIO;
 832         file = sock_alloc_file(csocket, 0, NULL);
 833         if (IS_ERR(file)) {
 834                 pr_err("%s (%d): failed to map fd\n",
 835                        __func__, task_pid_nr(current));
 836                 kfree(p);
 837                 return PTR_ERR(file);
 838         }
 839 
 840         get_file(file);
 841         p->wr = p->rd = file;
 842         client->trans = p;
 843         client->status = Connected;
 844 
 845         p->rd->f_flags |= O_NONBLOCK;
 846 
 847         p9_conn_create(client);
 848         return 0;
 849 }
 850 
 851 /**
 852  * p9_mux_destroy - cancels all pending requests of mux
 853  * @m: mux to destroy
 854  *
 855  */
 856 
 857 static void p9_conn_destroy(struct p9_conn *m)
 858 {
 859         p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
 860                  m, m->mux_list.prev, m->mux_list.next);
 861 
 862         p9_mux_poll_stop(m);
 863         cancel_work_sync(&m->rq);
 864         if (m->rreq) {
 865                 p9_req_put(m->rreq);
 866                 m->rreq = NULL;
 867         }
 868         cancel_work_sync(&m->wq);
 869         if (m->wreq) {
 870                 p9_req_put(m->wreq);
 871                 m->wreq = NULL;
 872         }
 873 
 874         p9_conn_cancel(m, -ECONNRESET);
 875 
 876         m->client = NULL;
 877 }
 878 
 879 /**
 880  * p9_fd_close - shutdown file descriptor transport
 881  * @client: client instance
 882  *
 883  */
 884 
 885 static void p9_fd_close(struct p9_client *client)
 886 {
 887         struct p9_trans_fd *ts;
 888 
 889         if (!client)
 890                 return;
 891 
 892         ts = client->trans;
 893         if (!ts)
 894                 return;
 895 
 896         client->status = Disconnected;
 897 
 898         p9_conn_destroy(&ts->conn);
 899 
 900         if (ts->rd)
 901                 fput(ts->rd);
 902         if (ts->wr)
 903                 fput(ts->wr);
 904 
 905         kfree(ts);
 906 }
 907 
 908 /*
 909  * stolen from NFS - maybe should be made a generic function?
 910  */
 911 static inline int valid_ipaddr4(const char *buf)
 912 {
 913         int rc, count, in[4];
 914 
 915         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
 916         if (rc != 4)
 917                 return -EINVAL;
 918         for (count = 0; count < 4; count++) {
 919                 if (in[count] > 255)
 920                         return -EINVAL;
 921         }
 922         return 0;
 923 }
 924 
 925 static int p9_bind_privport(struct socket *sock)
 926 {
 927         struct sockaddr_in cl;
 928         int port, err = -EINVAL;
 929 
 930         memset(&cl, 0, sizeof(cl));
 931         cl.sin_family = AF_INET;
 932         cl.sin_addr.s_addr = INADDR_ANY;
 933         for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
 934                 cl.sin_port = htons((ushort)port);
 935                 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
 936                 if (err != -EADDRINUSE)
 937                         break;
 938         }
 939         return err;
 940 }
 941 
 942 
 943 static int
 944 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
 945 {
 946         int err;
 947         struct socket *csocket;
 948         struct sockaddr_in sin_server;
 949         struct p9_fd_opts opts;
 950 
 951         err = parse_opts(args, &opts);
 952         if (err < 0)
 953                 return err;
 954 
 955         if (addr == NULL || valid_ipaddr4(addr) < 0)
 956                 return -EINVAL;
 957 
 958         csocket = NULL;
 959 
 960         client->trans_opts.tcp.port = opts.port;
 961         client->trans_opts.tcp.privport = opts.privport;
 962         sin_server.sin_family = AF_INET;
 963         sin_server.sin_addr.s_addr = in_aton(addr);
 964         sin_server.sin_port = htons(opts.port);
 965         err = __sock_create(current->nsproxy->net_ns, PF_INET,
 966                             SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
 967         if (err) {
 968                 pr_err("%s (%d): problem creating socket\n",
 969                        __func__, task_pid_nr(current));
 970                 return err;
 971         }
 972 
 973         if (opts.privport) {
 974                 err = p9_bind_privport(csocket);
 975                 if (err < 0) {
 976                         pr_err("%s (%d): problem binding to privport\n",
 977                                __func__, task_pid_nr(current));
 978                         sock_release(csocket);
 979                         return err;
 980                 }
 981         }
 982 
 983         err = csocket->ops->connect(csocket,
 984                                     (struct sockaddr *)&sin_server,
 985                                     sizeof(struct sockaddr_in), 0);
 986         if (err < 0) {
 987                 pr_err("%s (%d): problem connecting socket to %s\n",
 988                        __func__, task_pid_nr(current), addr);
 989                 sock_release(csocket);
 990                 return err;
 991         }
 992 
 993         return p9_socket_open(client, csocket);
 994 }
 995 
 996 static int
 997 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
 998 {
 999         int err;
1000         struct socket *csocket;
1001         struct sockaddr_un sun_server;
1002 
1003         csocket = NULL;
1004 
1005         if (addr == NULL)
1006                 return -EINVAL;
1007 
1008         if (strlen(addr) >= UNIX_PATH_MAX) {
1009                 pr_err("%s (%d): address too long: %s\n",
1010                        __func__, task_pid_nr(current), addr);
1011                 return -ENAMETOOLONG;
1012         }
1013 
1014         sun_server.sun_family = PF_UNIX;
1015         strcpy(sun_server.sun_path, addr);
1016         err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1017                             SOCK_STREAM, 0, &csocket, 1);
1018         if (err < 0) {
1019                 pr_err("%s (%d): problem creating socket\n",
1020                        __func__, task_pid_nr(current));
1021 
1022                 return err;
1023         }
1024         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1025                         sizeof(struct sockaddr_un) - 1, 0);
1026         if (err < 0) {
1027                 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1028                        __func__, task_pid_nr(current), addr, err);
1029                 sock_release(csocket);
1030                 return err;
1031         }
1032 
1033         return p9_socket_open(client, csocket);
1034 }
1035 
1036 static int
1037 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1038 {
1039         int err;
1040         struct p9_fd_opts opts;
1041 
1042         parse_opts(args, &opts);
1043         client->trans_opts.fd.rfd = opts.rfd;
1044         client->trans_opts.fd.wfd = opts.wfd;
1045 
1046         if (opts.rfd == ~0 || opts.wfd == ~0) {
1047                 pr_err("Insufficient options for proto=fd\n");
1048                 return -ENOPROTOOPT;
1049         }
1050 
1051         err = p9_fd_open(client, opts.rfd, opts.wfd);
1052         if (err < 0)
1053                 return err;
1054 
1055         p9_conn_create(client);
1056 
1057         return 0;
1058 }
1059 
1060 static struct p9_trans_module p9_tcp_trans = {
1061         .name = "tcp",
1062         .maxsize = MAX_SOCK_BUF,
1063         .def = 0,
1064         .create = p9_fd_create_tcp,
1065         .close = p9_fd_close,
1066         .request = p9_fd_request,
1067         .cancel = p9_fd_cancel,
1068         .cancelled = p9_fd_cancelled,
1069         .show_options = p9_fd_show_options,
1070         .owner = THIS_MODULE,
1071 };
1072 
1073 static struct p9_trans_module p9_unix_trans = {
1074         .name = "unix",
1075         .maxsize = MAX_SOCK_BUF,
1076         .def = 0,
1077         .create = p9_fd_create_unix,
1078         .close = p9_fd_close,
1079         .request = p9_fd_request,
1080         .cancel = p9_fd_cancel,
1081         .cancelled = p9_fd_cancelled,
1082         .show_options = p9_fd_show_options,
1083         .owner = THIS_MODULE,
1084 };
1085 
1086 static struct p9_trans_module p9_fd_trans = {
1087         .name = "fd",
1088         .maxsize = MAX_SOCK_BUF,
1089         .def = 0,
1090         .create = p9_fd_create,
1091         .close = p9_fd_close,
1092         .request = p9_fd_request,
1093         .cancel = p9_fd_cancel,
1094         .cancelled = p9_fd_cancelled,
1095         .show_options = p9_fd_show_options,
1096         .owner = THIS_MODULE,
1097 };
1098 
1099 /**
1100  * p9_poll_workfn - poll worker thread
1101  * @work: work queue
1102  *
1103  * polls all v9fs transports for new events and queues the appropriate
1104  * work to the work queue
1105  *
1106  */
1107 
1108 static void p9_poll_workfn(struct work_struct *work)
1109 {
1110         unsigned long flags;
1111 
1112         p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1113 
1114         spin_lock_irqsave(&p9_poll_lock, flags);
1115         while (!list_empty(&p9_poll_pending_list)) {
1116                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1117                                                         struct p9_conn,
1118                                                         poll_pending_link);
1119                 list_del_init(&conn->poll_pending_link);
1120                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1121 
1122                 p9_poll_mux(conn);
1123 
1124                 spin_lock_irqsave(&p9_poll_lock, flags);
1125         }
1126         spin_unlock_irqrestore(&p9_poll_lock, flags);
1127 
1128         p9_debug(P9_DEBUG_TRANS, "finish\n");
1129 }
1130 
1131 int p9_trans_fd_init(void)
1132 {
1133         v9fs_register_trans(&p9_tcp_trans);
1134         v9fs_register_trans(&p9_unix_trans);
1135         v9fs_register_trans(&p9_fd_trans);
1136 
1137         return 0;
1138 }
1139 
1140 void p9_trans_fd_exit(void)
1141 {
1142         flush_work(&p9_poll_work);
1143         v9fs_unregister_trans(&p9_tcp_trans);
1144         v9fs_unregister_trans(&p9_unix_trans);
1145         v9fs_unregister_trans(&p9_fd_trans);
1146 }
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root/net/9p/trans_fd.c

DEFINITIONS
