Root/net/tipc/socket.c

1/*
2 * net/tipc/socket.c: TIPC socket API
3 *
4 * Copyright (c) 2001-2007, Ericsson AB
5 * Copyright (c) 2004-2008, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <linux/module.h>
38#include <linux/types.h>
39#include <linux/net.h>
40#include <linux/socket.h>
41#include <linux/errno.h>
42#include <linux/mm.h>
43#include <linux/slab.h>
44#include <linux/poll.h>
45#include <linux/fcntl.h>
46#include <asm/string.h>
47#include <asm/atomic.h>
48#include <net/sock.h>
49
50#include <linux/tipc.h>
51#include <linux/tipc_config.h>
52#include <net/tipc/tipc_msg.h>
53#include <net/tipc/tipc_port.h>
54
55#include "core.h"
56
57#define SS_LISTENING -1 /* socket is listening */
58#define SS_READY -2 /* socket is connectionless */
59
60#define OVERLOAD_LIMIT_BASE 5000
61#define CONN_TIMEOUT_DEFAULT 8000 /* default connect timeout = 8s */
62
63struct tipc_sock {
64    struct sock sk;
65    struct tipc_port *p;
66    struct tipc_portid peer_name;
67};
68
69#define tipc_sk(sk) ((struct tipc_sock *)(sk))
70#define tipc_sk_port(sk) ((struct tipc_port *)(tipc_sk(sk)->p))
71
72static int backlog_rcv(struct sock *sk, struct sk_buff *skb);
73static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
74static void wakeupdispatch(struct tipc_port *tport);
75
76static const struct proto_ops packet_ops;
77static const struct proto_ops stream_ops;
78static const struct proto_ops msg_ops;
79
80static struct proto tipc_proto;
81
82static int sockets_enabled = 0;
83
84static atomic_t tipc_queue_size = ATOMIC_INIT(0);
85
86/*
87 * Revised TIPC socket locking policy:
88 *
89 * Most socket operations take the standard socket lock when they start
90 * and hold it until they finish (or until they need to sleep). Acquiring
91 * this lock grants the owner exclusive access to the fields of the socket
92 * data structures, with the exception of the backlog queue. A few socket
93 * operations can be done without taking the socket lock because they only
94 * read socket information that never changes during the life of the socket.
95 *
96 * Socket operations may acquire the lock for the associated TIPC port if they
97 * need to perform an operation on the port. If any routine needs to acquire
98 * both the socket lock and the port lock it must take the socket lock first
99 * to avoid the risk of deadlock.
100 *
101 * The dispatcher handling incoming messages cannot grab the socket lock in
102 * the standard fashion, since invoked it runs at the BH level and cannot block.
103 * Instead, it checks to see if the socket lock is currently owned by someone,
104 * and either handles the message itself or adds it to the socket's backlog
105 * queue; in the latter case the queued message is processed once the process
106 * owning the socket lock releases it.
107 *
108 * NOTE: Releasing the socket lock while an operation is sleeping overcomes
109 * the problem of a blocked socket operation preventing any other operations
110 * from occurring. However, applications must be careful if they have
111 * multiple threads trying to send (or receive) on the same socket, as these
112 * operations might interfere with each other. For example, doing a connect
113 * and a receive at the same time might allow the receive to consume the
114 * ACK message meant for the connect. While additional work could be done
115 * to try and overcome this, it doesn't seem to be worthwhile at the present.
116 *
117 * NOTE: Releasing the socket lock while an operation is sleeping also ensures
118 * that another operation that must be performed in a non-blocking manner is
119 * not delayed for very long because the lock has already been taken.
120 *
121 * NOTE: This code assumes that certain fields of a port/socket pair are
122 * constant over its lifetime; such fields can be examined without taking
123 * the socket lock and/or port lock, and do not need to be re-read even
124 * after resuming processing after waiting. These fields include:
125 * - socket type
126 * - pointer to socket sk structure (aka tipc_sock structure)
127 * - pointer to port structure
128 * - port reference
129 */
130
131/**
132 * advance_rx_queue - discard first buffer in socket receive queue
133 *
134 * Caller must hold socket lock
135 */
136
137static void advance_rx_queue(struct sock *sk)
138{
139    buf_discard(__skb_dequeue(&sk->sk_receive_queue));
140    atomic_dec(&tipc_queue_size);
141}
142
143/**
144 * discard_rx_queue - discard all buffers in socket receive queue
145 *
146 * Caller must hold socket lock
147 */
148
149static void discard_rx_queue(struct sock *sk)
150{
151    struct sk_buff *buf;
152
153    while ((buf = __skb_dequeue(&sk->sk_receive_queue))) {
154        atomic_dec(&tipc_queue_size);
155        buf_discard(buf);
156    }
157}
158
159/**
160 * reject_rx_queue - reject all buffers in socket receive queue
161 *
162 * Caller must hold socket lock
163 */
164
165static void reject_rx_queue(struct sock *sk)
166{
167    struct sk_buff *buf;
168
169    while ((buf = __skb_dequeue(&sk->sk_receive_queue))) {
170        tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
171        atomic_dec(&tipc_queue_size);
172    }
173}
174
175/**
176 * tipc_create - create a TIPC socket
177 * @net: network namespace (must be default network)
178 * @sock: pre-allocated socket structure
179 * @protocol: protocol indicator (must be 0)
180 *
181 * This routine creates additional data structures used by the TIPC socket,
182 * initializes them, and links them together.
183 *
184 * Returns 0 on success, errno otherwise
185 */
186
187static int tipc_create(struct net *net, struct socket *sock, int protocol)
188{
189    const struct proto_ops *ops;
190    socket_state state;
191    struct sock *sk;
192    struct tipc_port *tp_ptr;
193
194    /* Validate arguments */
195
196    if (net != &init_net)
197        return -EAFNOSUPPORT;
198
199    if (unlikely(protocol != 0))
200        return -EPROTONOSUPPORT;
201
202    switch (sock->type) {
203    case SOCK_STREAM:
204        ops = &stream_ops;
205        state = SS_UNCONNECTED;
206        break;
207    case SOCK_SEQPACKET:
208        ops = &packet_ops;
209        state = SS_UNCONNECTED;
210        break;
211    case SOCK_DGRAM:
212    case SOCK_RDM:
213        ops = &msg_ops;
214        state = SS_READY;
215        break;
216    default:
217        return -EPROTOTYPE;
218    }
219
220    /* Allocate socket's protocol area */
221
222    sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto);
223    if (sk == NULL)
224        return -ENOMEM;
225
226    /* Allocate TIPC port for socket to use */
227
228    tp_ptr = tipc_createport_raw(sk, &dispatch, &wakeupdispatch,
229                     TIPC_LOW_IMPORTANCE);
230    if (unlikely(!tp_ptr)) {
231        sk_free(sk);
232        return -ENOMEM;
233    }
234
235    /* Finish initializing socket data structures */
236
237    sock->ops = ops;
238    sock->state = state;
239
240    sock_init_data(sock, sk);
241    sk->sk_rcvtimeo = msecs_to_jiffies(CONN_TIMEOUT_DEFAULT);
242    sk->sk_backlog_rcv = backlog_rcv;
243    tipc_sk(sk)->p = tp_ptr;
244
245    spin_unlock_bh(tp_ptr->lock);
246
247    if (sock->state == SS_READY) {
248        tipc_set_portunreturnable(tp_ptr->ref, 1);
249        if (sock->type == SOCK_DGRAM)
250            tipc_set_portunreliable(tp_ptr->ref, 1);
251    }
252
253    atomic_inc(&tipc_user_count);
254    return 0;
255}
256
257/**
258 * release - destroy a TIPC socket
259 * @sock: socket to destroy
260 *
261 * This routine cleans up any messages that are still queued on the socket.
262 * For DGRAM and RDM socket types, all queued messages are rejected.
263 * For SEQPACKET and STREAM socket types, the first message is rejected
264 * and any others are discarded. (If the first message on a STREAM socket
265 * is partially-read, it is discarded and the next one is rejected instead.)
266 *
267 * NOTE: Rejected messages are not necessarily returned to the sender! They
268 * are returned or discarded according to the "destination droppable" setting
269 * specified for the message by the sender.
270 *
271 * Returns 0 on success, errno otherwise
272 */
273
274static int release(struct socket *sock)
275{
276    struct sock *sk = sock->sk;
277    struct tipc_port *tport;
278    struct sk_buff *buf;
279    int res;
280
281    /*
282     * Exit if socket isn't fully initialized (occurs when a failed accept()
283     * releases a pre-allocated child socket that was never used)
284     */
285
286    if (sk == NULL)
287        return 0;
288
289    tport = tipc_sk_port(sk);
290    lock_sock(sk);
291
292    /*
293     * Reject all unreceived messages, except on an active connection
294     * (which disconnects locally & sends a 'FIN+' to peer)
295     */
296
297    while (sock->state != SS_DISCONNECTING) {
298        buf = __skb_dequeue(&sk->sk_receive_queue);
299        if (buf == NULL)
300            break;
301        atomic_dec(&tipc_queue_size);
302        if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf)))
303            buf_discard(buf);
304        else {
305            if ((sock->state == SS_CONNECTING) ||
306                (sock->state == SS_CONNECTED)) {
307                sock->state = SS_DISCONNECTING;
308                tipc_disconnect(tport->ref);
309            }
310            tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
311        }
312    }
313
314    /*
315     * Delete TIPC port; this ensures no more messages are queued
316     * (also disconnects an active connection & sends a 'FIN-' to peer)
317     */
318
319    res = tipc_deleteport(tport->ref);
320
321    /* Discard any remaining (connection-based) messages in receive queue */
322
323    discard_rx_queue(sk);
324
325    /* Reject any messages that accumulated in backlog queue */
326
327    sock->state = SS_DISCONNECTING;
328    release_sock(sk);
329
330    sock_put(sk);
331    sock->sk = NULL;
332
333    atomic_dec(&tipc_user_count);
334    return res;
335}
336
337/**
338 * bind - associate or disassocate TIPC name(s) with a socket
339 * @sock: socket structure
340 * @uaddr: socket address describing name(s) and desired operation
341 * @uaddr_len: size of socket address data structure
342 *
343 * Name and name sequence binding is indicated using a positive scope value;
344 * a negative scope value unbinds the specified name. Specifying no name
345 * (i.e. a socket address length of 0) unbinds all names from the socket.
346 *
347 * Returns 0 on success, errno otherwise
348 *
349 * NOTE: This routine doesn't need to take the socket lock since it doesn't
350 * access any non-constant socket information.
351 */
352
353static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
354{
355    struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
356    u32 portref = tipc_sk_port(sock->sk)->ref;
357
358    if (unlikely(!uaddr_len))
359        return tipc_withdraw(portref, 0, NULL);
360
361    if (uaddr_len < sizeof(struct sockaddr_tipc))
362        return -EINVAL;
363    if (addr->family != AF_TIPC)
364        return -EAFNOSUPPORT;
365
366    if (addr->addrtype == TIPC_ADDR_NAME)
367        addr->addr.nameseq.upper = addr->addr.nameseq.lower;
368    else if (addr->addrtype != TIPC_ADDR_NAMESEQ)
369        return -EAFNOSUPPORT;
370
371    return (addr->scope > 0) ?
372        tipc_publish(portref, addr->scope, &addr->addr.nameseq) :
373        tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq);
374}
375
376/**
377 * get_name - get port ID of socket or peer socket
378 * @sock: socket structure
379 * @uaddr: area for returned socket address
380 * @uaddr_len: area for returned length of socket address
381 * @peer: 0 = own ID, 1 = current peer ID, 2 = current/former peer ID
382 *
383 * Returns 0 on success, errno otherwise
384 *
385 * NOTE: This routine doesn't need to take the socket lock since it only
386 * accesses socket information that is unchanging (or which changes in
387 * a completely predictable manner).
388 */
389
390static int get_name(struct socket *sock, struct sockaddr *uaddr,
391            int *uaddr_len, int peer)
392{
393    struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
394    struct tipc_sock *tsock = tipc_sk(sock->sk);
395
396    if (peer) {
397        if ((sock->state != SS_CONNECTED) &&
398            ((peer != 2) || (sock->state != SS_DISCONNECTING)))
399            return -ENOTCONN;
400        addr->addr.id.ref = tsock->peer_name.ref;
401        addr->addr.id.node = tsock->peer_name.node;
402    } else {
403        tipc_ownidentity(tsock->p->ref, &addr->addr.id);
404    }
405
406    *uaddr_len = sizeof(*addr);
407    addr->addrtype = TIPC_ADDR_ID;
408    addr->family = AF_TIPC;
409    addr->scope = 0;
410    addr->addr.name.domain = 0;
411
412    return 0;
413}
414
415/**
416 * poll - read and possibly block on pollmask
417 * @file: file structure associated with the socket
418 * @sock: socket for which to calculate the poll bits
419 * @wait: ???
420 *
421 * Returns pollmask value
422 *
423 * COMMENTARY:
424 * It appears that the usual socket locking mechanisms are not useful here
425 * since the pollmask info is potentially out-of-date the moment this routine
426 * exits. TCP and other protocols seem to rely on higher level poll routines
427 * to handle any preventable race conditions, so TIPC will do the same ...
428 *
429 * TIPC sets the returned events as follows:
430 * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
431 * or if a connection-oriented socket is does not have an active connection
432 * (i.e. a read operation will not block).
433 * b) POLLOUT is set except when a socket's connection has been terminated
434 * (i.e. a write operation will not block).
435 * c) POLLHUP is set when a socket's connection has been terminated.
436 *
437 * IMPORTANT: The fact that a read or write operation will not block does NOT
438 * imply that the operation will succeed!
439 */
440
441static unsigned int poll(struct file *file, struct socket *sock,
442             poll_table *wait)
443{
444    struct sock *sk = sock->sk;
445    u32 mask;
446
447    poll_wait(file, sk->sk_sleep, wait);
448
449    if (!skb_queue_empty(&sk->sk_receive_queue) ||
450        (sock->state == SS_UNCONNECTED) ||
451        (sock->state == SS_DISCONNECTING))
452        mask = (POLLRDNORM | POLLIN);
453    else
454        mask = 0;
455
456    if (sock->state == SS_DISCONNECTING)
457        mask |= POLLHUP;
458    else
459        mask |= POLLOUT;
460
461    return mask;
462}
463
464/**
465 * dest_name_check - verify user is permitted to send to specified port name
466 * @dest: destination address
467 * @m: descriptor for message to be sent
468 *
469 * Prevents restricted configuration commands from being issued by
470 * unauthorized users.
471 *
472 * Returns 0 if permission is granted, otherwise errno
473 */
474
475static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m)
476{
477    struct tipc_cfg_msg_hdr hdr;
478
479    if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES))
480        return 0;
481    if (likely(dest->addr.name.name.type == TIPC_TOP_SRV))
482        return 0;
483    if (likely(dest->addr.name.name.type != TIPC_CFG_SRV))
484        return -EACCES;
485
486    if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr)))
487        return -EFAULT;
488    if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN)))
489        return -EACCES;
490
491    return 0;
492}
493
494/**
495 * send_msg - send message in connectionless manner
496 * @iocb: if NULL, indicates that socket lock is already held
497 * @sock: socket structure
498 * @m: message to send
499 * @total_len: length of message
500 *
501 * Message must have an destination specified explicitly.
502 * Used for SOCK_RDM and SOCK_DGRAM messages,
503 * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections.
504 * (Note: 'SYN+' is prohibited on SOCK_STREAM.)
505 *
506 * Returns the number of bytes sent on success, or errno otherwise
507 */
508
509static int send_msg(struct kiocb *iocb, struct socket *sock,
510            struct msghdr *m, size_t total_len)
511{
512    struct sock *sk = sock->sk;
513    struct tipc_port *tport = tipc_sk_port(sk);
514    struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
515    int needs_conn;
516    int res = -EINVAL;
517
518    if (unlikely(!dest))
519        return -EDESTADDRREQ;
520    if (unlikely((m->msg_namelen < sizeof(*dest)) ||
521             (dest->family != AF_TIPC)))
522        return -EINVAL;
523
524    if (iocb)
525        lock_sock(sk);
526
527    needs_conn = (sock->state != SS_READY);
528    if (unlikely(needs_conn)) {
529        if (sock->state == SS_LISTENING) {
530            res = -EPIPE;
531            goto exit;
532        }
533        if (sock->state != SS_UNCONNECTED) {
534            res = -EISCONN;
535            goto exit;
536        }
537        if ((tport->published) ||
538            ((sock->type == SOCK_STREAM) && (total_len != 0))) {
539            res = -EOPNOTSUPP;
540            goto exit;
541        }
542        if (dest->addrtype == TIPC_ADDR_NAME) {
543            tport->conn_type = dest->addr.name.name.type;
544            tport->conn_instance = dest->addr.name.name.instance;
545        }
546
547        /* Abort any pending connection attempts (very unlikely) */
548
549        reject_rx_queue(sk);
550    }
551
552    do {
553        if (dest->addrtype == TIPC_ADDR_NAME) {
554            if ((res = dest_name_check(dest, m)))
555                break;
556            res = tipc_send2name(tport->ref,
557                         &dest->addr.name.name,
558                         dest->addr.name.domain,
559                         m->msg_iovlen,
560                         m->msg_iov);
561        }
562        else if (dest->addrtype == TIPC_ADDR_ID) {
563            res = tipc_send2port(tport->ref,
564                         &dest->addr.id,
565                         m->msg_iovlen,
566                         m->msg_iov);
567        }
568        else if (dest->addrtype == TIPC_ADDR_MCAST) {
569            if (needs_conn) {
570                res = -EOPNOTSUPP;
571                break;
572            }
573            if ((res = dest_name_check(dest, m)))
574                break;
575            res = tipc_multicast(tport->ref,
576                         &dest->addr.nameseq,
577                         0,
578                         m->msg_iovlen,
579                         m->msg_iov);
580        }
581        if (likely(res != -ELINKCONG)) {
582            if (needs_conn && (res >= 0)) {
583                sock->state = SS_CONNECTING;
584            }
585            break;
586        }
587        if (m->msg_flags & MSG_DONTWAIT) {
588            res = -EWOULDBLOCK;
589            break;
590        }
591        release_sock(sk);
592        res = wait_event_interruptible(*sk->sk_sleep,
593                           !tport->congested);
594        lock_sock(sk);
595        if (res)
596            break;
597    } while (1);
598
599exit:
600    if (iocb)
601        release_sock(sk);
602    return res;
603}
604
605/**
606 * send_packet - send a connection-oriented message
607 * @iocb: if NULL, indicates that socket lock is already held
608 * @sock: socket structure
609 * @m: message to send
610 * @total_len: length of message
611 *
612 * Used for SOCK_SEQPACKET messages and SOCK_STREAM data.
613 *
614 * Returns the number of bytes sent on success, or errno otherwise
615 */
616
617static int send_packet(struct kiocb *iocb, struct socket *sock,
618               struct msghdr *m, size_t total_len)
619{
620    struct sock *sk = sock->sk;
621    struct tipc_port *tport = tipc_sk_port(sk);
622    struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
623    int res;
624
625    /* Handle implied connection establishment */
626
627    if (unlikely(dest))
628        return send_msg(iocb, sock, m, total_len);
629
630    if (iocb)
631        lock_sock(sk);
632
633    do {
634        if (unlikely(sock->state != SS_CONNECTED)) {
635            if (sock->state == SS_DISCONNECTING)
636                res = -EPIPE;
637            else
638                res = -ENOTCONN;
639            break;
640        }
641
642        res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov);
643        if (likely(res != -ELINKCONG)) {
644            break;
645        }
646        if (m->msg_flags & MSG_DONTWAIT) {
647            res = -EWOULDBLOCK;
648            break;
649        }
650        release_sock(sk);
651        res = wait_event_interruptible(*sk->sk_sleep,
652            (!tport->congested || !tport->connected));
653        lock_sock(sk);
654        if (res)
655            break;
656    } while (1);
657
658    if (iocb)
659        release_sock(sk);
660    return res;
661}
662
663/**
664 * send_stream - send stream-oriented data
665 * @iocb: (unused)
666 * @sock: socket structure
667 * @m: data to send
668 * @total_len: total length of data to be sent
669 *
670 * Used for SOCK_STREAM data.
671 *
672 * Returns the number of bytes sent on success (or partial success),
673 * or errno if no data sent
674 */
675
676static int send_stream(struct kiocb *iocb, struct socket *sock,
677               struct msghdr *m, size_t total_len)
678{
679    struct sock *sk = sock->sk;
680    struct tipc_port *tport = tipc_sk_port(sk);
681    struct msghdr my_msg;
682    struct iovec my_iov;
683    struct iovec *curr_iov;
684    int curr_iovlen;
685    char __user *curr_start;
686    u32 hdr_size;
687    int curr_left;
688    int bytes_to_send;
689    int bytes_sent;
690    int res;
691
692    lock_sock(sk);
693
694    /* Handle special cases where there is no connection */
695
696    if (unlikely(sock->state != SS_CONNECTED)) {
697        if (sock->state == SS_UNCONNECTED) {
698            res = send_packet(NULL, sock, m, total_len);
699            goto exit;
700        } else if (sock->state == SS_DISCONNECTING) {
701            res = -EPIPE;
702            goto exit;
703        } else {
704            res = -ENOTCONN;
705            goto exit;
706        }
707    }
708
709    if (unlikely(m->msg_name)) {
710        res = -EISCONN;
711        goto exit;
712    }
713
714    /*
715     * Send each iovec entry using one or more messages
716     *
717     * Note: This algorithm is good for the most likely case
718     * (i.e. one large iovec entry), but could be improved to pass sets
719     * of small iovec entries into send_packet().
720     */
721
722    curr_iov = m->msg_iov;
723    curr_iovlen = m->msg_iovlen;
724    my_msg.msg_iov = &my_iov;
725    my_msg.msg_iovlen = 1;
726    my_msg.msg_flags = m->msg_flags;
727    my_msg.msg_name = NULL;
728    bytes_sent = 0;
729
730    hdr_size = msg_hdr_sz(&tport->phdr);
731
732    while (curr_iovlen--) {
733        curr_start = curr_iov->iov_base;
734        curr_left = curr_iov->iov_len;
735
736        while (curr_left) {
737            bytes_to_send = tport->max_pkt - hdr_size;
738            if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE)
739                bytes_to_send = TIPC_MAX_USER_MSG_SIZE;
740            if (curr_left < bytes_to_send)
741                bytes_to_send = curr_left;
742            my_iov.iov_base = curr_start;
743            my_iov.iov_len = bytes_to_send;
744            if ((res = send_packet(NULL, sock, &my_msg, 0)) < 0) {
745                if (bytes_sent)
746                    res = bytes_sent;
747                goto exit;
748            }
749            curr_left -= bytes_to_send;
750            curr_start += bytes_to_send;
751            bytes_sent += bytes_to_send;
752        }
753
754        curr_iov++;
755    }
756    res = bytes_sent;
757exit:
758    release_sock(sk);
759    return res;
760}
761
762/**
763 * auto_connect - complete connection setup to a remote port
764 * @sock: socket structure
765 * @msg: peer's response message
766 *
767 * Returns 0 on success, errno otherwise
768 */
769
770static int auto_connect(struct socket *sock, struct tipc_msg *msg)
771{
772    struct tipc_sock *tsock = tipc_sk(sock->sk);
773
774    if (msg_errcode(msg)) {
775        sock->state = SS_DISCONNECTING;
776        return -ECONNREFUSED;
777    }
778
779    tsock->peer_name.ref = msg_origport(msg);
780    tsock->peer_name.node = msg_orignode(msg);
781    tipc_connect2port(tsock->p->ref, &tsock->peer_name);
782    tipc_set_portimportance(tsock->p->ref, msg_importance(msg));
783    sock->state = SS_CONNECTED;
784    return 0;
785}
786
787/**
788 * set_orig_addr - capture sender's address for received message
789 * @m: descriptor for message info
790 * @msg: received message header
791 *
792 * Note: Address is not captured if not requested by receiver.
793 */
794
795static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
796{
797    struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
798
799    if (addr) {
800        addr->family = AF_TIPC;
801        addr->addrtype = TIPC_ADDR_ID;
802        addr->addr.id.ref = msg_origport(msg);
803        addr->addr.id.node = msg_orignode(msg);
804        addr->addr.name.domain = 0; /* could leave uninitialized */
805        addr->scope = 0; /* could leave uninitialized */
806        m->msg_namelen = sizeof(struct sockaddr_tipc);
807    }
808}
809
810/**
811 * anc_data_recv - optionally capture ancillary data for received message
812 * @m: descriptor for message info
813 * @msg: received message header
814 * @tport: TIPC port associated with message
815 *
816 * Note: Ancillary data is not captured if not requested by receiver.
817 *
818 * Returns 0 if successful, otherwise errno
819 */
820
821static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
822                struct tipc_port *tport)
823{
824    u32 anc_data[3];
825    u32 err;
826    u32 dest_type;
827    int has_name;
828    int res;
829
830    if (likely(m->msg_controllen == 0))
831        return 0;
832
833    /* Optionally capture errored message object(s) */
834
835    err = msg ? msg_errcode(msg) : 0;
836    if (unlikely(err)) {
837        anc_data[0] = err;
838        anc_data[1] = msg_data_sz(msg);
839        if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data)))
840            return res;
841        if (anc_data[1] &&
842            (res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
843                    msg_data(msg))))
844            return res;
845    }
846
847    /* Optionally capture message destination object */
848
849    dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
850    switch (dest_type) {
851    case TIPC_NAMED_MSG:
852        has_name = 1;
853        anc_data[0] = msg_nametype(msg);
854        anc_data[1] = msg_namelower(msg);
855        anc_data[2] = msg_namelower(msg);
856        break;
857    case TIPC_MCAST_MSG:
858        has_name = 1;
859        anc_data[0] = msg_nametype(msg);
860        anc_data[1] = msg_namelower(msg);
861        anc_data[2] = msg_nameupper(msg);
862        break;
863    case TIPC_CONN_MSG:
864        has_name = (tport->conn_type != 0);
865        anc_data[0] = tport->conn_type;
866        anc_data[1] = tport->conn_instance;
867        anc_data[2] = tport->conn_instance;
868        break;
869    default:
870        has_name = 0;
871    }
872    if (has_name &&
873        (res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data)))
874        return res;
875
876    return 0;
877}
878
879/**
880 * recv_msg - receive packet-oriented message
881 * @iocb: (unused)
882 * @m: descriptor for message info
883 * @buf_len: total size of user buffer area
884 * @flags: receive flags
885 *
886 * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
887 * If the complete message doesn't fit in user area, truncate it.
888 *
889 * Returns size of returned message data, errno otherwise
890 */
891
892static int recv_msg(struct kiocb *iocb, struct socket *sock,
893            struct msghdr *m, size_t buf_len, int flags)
894{
895    struct sock *sk = sock->sk;
896    struct tipc_port *tport = tipc_sk_port(sk);
897    struct sk_buff *buf;
898    struct tipc_msg *msg;
899    unsigned int sz;
900    u32 err;
901    int res;
902
903    /* Catch invalid receive requests */
904
905    if (m->msg_iovlen != 1)
906        return -EOPNOTSUPP; /* Don't do multiple iovec entries yet */
907
908    if (unlikely(!buf_len))
909        return -EINVAL;
910
911    lock_sock(sk);
912
913    if (unlikely(sock->state == SS_UNCONNECTED)) {
914        res = -ENOTCONN;
915        goto exit;
916    }
917
918restart:
919
920    /* Look for a message in receive queue; wait if necessary */
921
922    while (skb_queue_empty(&sk->sk_receive_queue)) {
923        if (sock->state == SS_DISCONNECTING) {
924            res = -ENOTCONN;
925            goto exit;
926        }
927        if (flags & MSG_DONTWAIT) {
928            res = -EWOULDBLOCK;
929            goto exit;
930        }
931        release_sock(sk);
932        res = wait_event_interruptible(*sk->sk_sleep,
933            (!skb_queue_empty(&sk->sk_receive_queue) ||
934             (sock->state == SS_DISCONNECTING)));
935        lock_sock(sk);
936        if (res)
937            goto exit;
938    }
939
940    /* Look at first message in receive queue */
941
942    buf = skb_peek(&sk->sk_receive_queue);
943    msg = buf_msg(buf);
944    sz = msg_data_sz(msg);
945    err = msg_errcode(msg);
946
947    /* Complete connection setup for an implied connect */
948
949    if (unlikely(sock->state == SS_CONNECTING)) {
950        res = auto_connect(sock, msg);
951        if (res)
952            goto exit;
953    }
954
955    /* Discard an empty non-errored message & try again */
956
957    if ((!sz) && (!err)) {
958        advance_rx_queue(sk);
959        goto restart;
960    }
961
962    /* Capture sender's address (optional) */
963
964    set_orig_addr(m, msg);
965
966    /* Capture ancillary data (optional) */
967
968    res = anc_data_recv(m, msg, tport);
969    if (res)
970        goto exit;
971
972    /* Capture message data (if valid) & compute return value (always) */
973
974    if (!err) {
975        if (unlikely(buf_len < sz)) {
976            sz = buf_len;
977            m->msg_flags |= MSG_TRUNC;
978        }
979        if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg),
980                      sz))) {
981            res = -EFAULT;
982            goto exit;
983        }
984        res = sz;
985    } else {
986        if ((sock->state == SS_READY) ||
987            ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
988            res = 0;
989        else
990            res = -ECONNRESET;
991    }
992
993    /* Consume received message (optional) */
994
995    if (likely(!(flags & MSG_PEEK))) {
996        if ((sock->state != SS_READY) &&
997            (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
998            tipc_acknowledge(tport->ref, tport->conn_unacked);
999        advance_rx_queue(sk);
1000    }
1001exit:
1002    release_sock(sk);
1003    return res;
1004}
1005
1006/**
1007 * recv_stream - receive stream-oriented data
1008 * @iocb: (unused)
1009 * @m: descriptor for message info
1010 * @buf_len: total size of user buffer area
1011 * @flags: receive flags
1012 *
1013 * Used for SOCK_STREAM messages only. If not enough data is available
1014 * will optionally wait for more; never truncates data.
1015 *
1016 * Returns size of returned message data, errno otherwise
1017 */
1018
1019static int recv_stream(struct kiocb *iocb, struct socket *sock,
1020               struct msghdr *m, size_t buf_len, int flags)
1021{
1022    struct sock *sk = sock->sk;
1023    struct tipc_port *tport = tipc_sk_port(sk);
1024    struct sk_buff *buf;
1025    struct tipc_msg *msg;
1026    unsigned int sz;
1027    int sz_to_copy;
1028    int sz_copied = 0;
1029    int needed;
1030    char __user *crs = m->msg_iov->iov_base;
1031    unsigned char *buf_crs;
1032    u32 err;
1033    int res = 0;
1034
1035    /* Catch invalid receive attempts */
1036
1037    if (m->msg_iovlen != 1)
1038        return -EOPNOTSUPP; /* Don't do multiple iovec entries yet */
1039
1040    if (unlikely(!buf_len))
1041        return -EINVAL;
1042
1043    lock_sock(sk);
1044
1045    if (unlikely((sock->state == SS_UNCONNECTED) ||
1046             (sock->state == SS_CONNECTING))) {
1047        res = -ENOTCONN;
1048        goto exit;
1049    }
1050
1051restart:
1052
1053    /* Look for a message in receive queue; wait if necessary */
1054
1055    while (skb_queue_empty(&sk->sk_receive_queue)) {
1056        if (sock->state == SS_DISCONNECTING) {
1057            res = -ENOTCONN;
1058            goto exit;
1059        }
1060        if (flags & MSG_DONTWAIT) {
1061            res = -EWOULDBLOCK;
1062            goto exit;
1063        }
1064        release_sock(sk);
1065        res = wait_event_interruptible(*sk->sk_sleep,
1066            (!skb_queue_empty(&sk->sk_receive_queue) ||
1067             (sock->state == SS_DISCONNECTING)));
1068        lock_sock(sk);
1069        if (res)
1070            goto exit;
1071    }
1072
1073    /* Look at first message in receive queue */
1074
1075    buf = skb_peek(&sk->sk_receive_queue);
1076    msg = buf_msg(buf);
1077    sz = msg_data_sz(msg);
1078    err = msg_errcode(msg);
1079
1080    /* Discard an empty non-errored message & try again */
1081
1082    if ((!sz) && (!err)) {
1083        advance_rx_queue(sk);
1084        goto restart;
1085    }
1086
1087    /* Optionally capture sender's address & ancillary data of first msg */
1088
1089    if (sz_copied == 0) {
1090        set_orig_addr(m, msg);
1091        res = anc_data_recv(m, msg, tport);
1092        if (res)
1093            goto exit;
1094    }
1095
1096    /* Capture message data (if valid) & compute return value (always) */
1097
1098    if (!err) {
1099        buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
1100        sz = (unsigned char *)msg + msg_size(msg) - buf_crs;
1101
1102        needed = (buf_len - sz_copied);
1103        sz_to_copy = (sz <= needed) ? sz : needed;
1104        if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
1105            res = -EFAULT;
1106            goto exit;
1107        }
1108        sz_copied += sz_to_copy;
1109
1110        if (sz_to_copy < sz) {
1111            if (!(flags & MSG_PEEK))
1112                TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
1113            goto exit;
1114        }
1115
1116        crs += sz_to_copy;
1117    } else {
1118        if (sz_copied != 0)
1119            goto exit; /* can't add error msg to valid data */
1120
1121        if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
1122            res = 0;
1123        else
1124            res = -ECONNRESET;
1125    }
1126
1127    /* Consume received message (optional) */
1128
1129    if (likely(!(flags & MSG_PEEK))) {
1130        if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
1131            tipc_acknowledge(tport->ref, tport->conn_unacked);
1132        advance_rx_queue(sk);
1133    }
1134
1135    /* Loop around if more data is required */
1136
1137    if ((sz_copied < buf_len) /* didn't get all requested data */
1138        && (!skb_queue_empty(&sk->sk_receive_queue) ||
1139        (flags & MSG_WAITALL))
1140                     /* ... and more is ready or required */
1141        && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */
1142        && (!err) /* ... and haven't reached a FIN */
1143        )
1144        goto restart;
1145
1146exit:
1147    release_sock(sk);
1148    return sz_copied ? sz_copied : res;
1149}
1150
1151/**
1152 * rx_queue_full - determine if receive queue can accept another message
1153 * @msg: message to be added to queue
1154 * @queue_size: current size of queue
1155 * @base: nominal maximum size of queue
1156 *
1157 * Returns 1 if queue is unable to accept message, 0 otherwise
1158 */
1159
1160static int rx_queue_full(struct tipc_msg *msg, u32 queue_size, u32 base)
1161{
1162    u32 threshold;
1163    u32 imp = msg_importance(msg);
1164
1165    if (imp == TIPC_LOW_IMPORTANCE)
1166        threshold = base;
1167    else if (imp == TIPC_MEDIUM_IMPORTANCE)
1168        threshold = base * 2;
1169    else if (imp == TIPC_HIGH_IMPORTANCE)
1170        threshold = base * 100;
1171    else
1172        return 0;
1173
1174    if (msg_connected(msg))
1175        threshold *= 4;
1176
1177    return (queue_size >= threshold);
1178}
1179
1180/**
1181 * filter_rcv - validate incoming message
1182 * @sk: socket
1183 * @buf: message
1184 *
1185 * Enqueues message on receive queue if acceptable; optionally handles
1186 * disconnect indication for a connected socket.
1187 *
1188 * Called with socket lock already taken; port lock may also be taken.
1189 *
1190 * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1191 */
1192
1193static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
1194{
1195    struct socket *sock = sk->sk_socket;
1196    struct tipc_msg *msg = buf_msg(buf);
1197    u32 recv_q_len;
1198
1199    /* Reject message if it is wrong sort of message for socket */
1200
1201    /*
1202     * WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD?
1203     * "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY
1204     * BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC
1205     */
1206
1207    if (sock->state == SS_READY) {
1208        if (msg_connected(msg)) {
1209            msg_dbg(msg, "dispatch filter 1\n");
1210            return TIPC_ERR_NO_PORT;
1211        }
1212    } else {
1213        if (msg_mcast(msg)) {
1214            msg_dbg(msg, "dispatch filter 2\n");
1215            return TIPC_ERR_NO_PORT;
1216        }
1217        if (sock->state == SS_CONNECTED) {
1218            if (!msg_connected(msg)) {
1219                msg_dbg(msg, "dispatch filter 3\n");
1220                return TIPC_ERR_NO_PORT;
1221            }
1222        }
1223        else if (sock->state == SS_CONNECTING) {
1224            if (!msg_connected(msg) && (msg_errcode(msg) == 0)) {
1225                msg_dbg(msg, "dispatch filter 4\n");
1226                return TIPC_ERR_NO_PORT;
1227            }
1228        }
1229        else if (sock->state == SS_LISTENING) {
1230            if (msg_connected(msg) || msg_errcode(msg)) {
1231                msg_dbg(msg, "dispatch filter 5\n");
1232                return TIPC_ERR_NO_PORT;
1233            }
1234        }
1235        else if (sock->state == SS_DISCONNECTING) {
1236            msg_dbg(msg, "dispatch filter 6\n");
1237            return TIPC_ERR_NO_PORT;
1238        }
1239        else /* (sock->state == SS_UNCONNECTED) */ {
1240            if (msg_connected(msg) || msg_errcode(msg)) {
1241                msg_dbg(msg, "dispatch filter 7\n");
1242                return TIPC_ERR_NO_PORT;
1243            }
1244        }
1245    }
1246
1247    /* Reject message if there isn't room to queue it */
1248
1249    recv_q_len = (u32)atomic_read(&tipc_queue_size);
1250    if (unlikely(recv_q_len >= OVERLOAD_LIMIT_BASE)) {
1251        if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE))
1252            return TIPC_ERR_OVERLOAD;
1253    }
1254    recv_q_len = skb_queue_len(&sk->sk_receive_queue);
1255    if (unlikely(recv_q_len >= (OVERLOAD_LIMIT_BASE / 2))) {
1256        if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE / 2))
1257            return TIPC_ERR_OVERLOAD;
1258    }
1259
1260    /* Enqueue message (finally!) */
1261
1262    msg_dbg(msg, "<DISP<: ");
1263    TIPC_SKB_CB(buf)->handle = msg_data(msg);
1264    atomic_inc(&tipc_queue_size);
1265    __skb_queue_tail(&sk->sk_receive_queue, buf);
1266
1267    /* Initiate connection termination for an incoming 'FIN' */
1268
1269    if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
1270        sock->state = SS_DISCONNECTING;
1271        tipc_disconnect_port(tipc_sk_port(sk));
1272    }
1273
1274    if (waitqueue_active(sk->sk_sleep))
1275        wake_up_interruptible(sk->sk_sleep);
1276    return TIPC_OK;
1277}
1278
1279/**
1280 * backlog_rcv - handle incoming message from backlog queue
1281 * @sk: socket
1282 * @buf: message
1283 *
1284 * Caller must hold socket lock, but not port lock.
1285 *
1286 * Returns 0
1287 */
1288
1289static int backlog_rcv(struct sock *sk, struct sk_buff *buf)
1290{
1291    u32 res;
1292
1293    res = filter_rcv(sk, buf);
1294    if (res)
1295        tipc_reject_msg(buf, res);
1296    return 0;
1297}
1298
1299/**
1300 * dispatch - handle incoming message
1301 * @tport: TIPC port that received message
1302 * @buf: message
1303 *
1304 * Called with port lock already taken.
1305 *
1306 * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1307 */
1308
1309static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
1310{
1311    struct sock *sk = (struct sock *)tport->usr_handle;
1312    u32 res;
1313
1314    /*
1315     * Process message if socket is unlocked; otherwise add to backlog queue
1316     *
1317     * This code is based on sk_receive_skb(), but must be distinct from it
1318     * since a TIPC-specific filter/reject mechanism is utilized
1319     */
1320
1321    bh_lock_sock(sk);
1322    if (!sock_owned_by_user(sk)) {
1323        res = filter_rcv(sk, buf);
1324    } else {
1325        sk_add_backlog(sk, buf);
1326        res = TIPC_OK;
1327    }
1328    bh_unlock_sock(sk);
1329
1330    return res;
1331}
1332
1333/**
1334 * wakeupdispatch - wake up port after congestion
1335 * @tport: port to wakeup
1336 *
1337 * Called with port lock already taken.
1338 */
1339
1340static void wakeupdispatch(struct tipc_port *tport)
1341{
1342    struct sock *sk = (struct sock *)tport->usr_handle;
1343
1344    if (waitqueue_active(sk->sk_sleep))
1345        wake_up_interruptible(sk->sk_sleep);
1346}
1347
1348/**
1349 * connect - establish a connection to another TIPC port
1350 * @sock: socket structure
1351 * @dest: socket address for destination port
1352 * @destlen: size of socket address data structure
1353 * @flags: file-related flags associated with socket
1354 *
1355 * Returns 0 on success, errno otherwise
1356 */
1357
1358static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
1359           int flags)
1360{
1361    struct sock *sk = sock->sk;
1362    struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
1363    struct msghdr m = {NULL,};
1364    struct sk_buff *buf;
1365    struct tipc_msg *msg;
1366    int res;
1367
1368    lock_sock(sk);
1369
1370    /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */
1371
1372    if (sock->state == SS_READY) {
1373        res = -EOPNOTSUPP;
1374        goto exit;
1375    }
1376
1377    /* For now, TIPC does not support the non-blocking form of connect() */
1378
1379    if (flags & O_NONBLOCK) {
1380        res = -EWOULDBLOCK;
1381        goto exit;
1382    }
1383
1384    /* Issue Posix-compliant error code if socket is in the wrong state */
1385
1386    if (sock->state == SS_LISTENING) {
1387        res = -EOPNOTSUPP;
1388        goto exit;
1389    }
1390    if (sock->state == SS_CONNECTING) {
1391        res = -EALREADY;
1392        goto exit;
1393    }
1394    if (sock->state != SS_UNCONNECTED) {
1395        res = -EISCONN;
1396        goto exit;
1397    }
1398
1399    /*
1400     * Reject connection attempt using multicast address
1401     *
1402     * Note: send_msg() validates the rest of the address fields,
1403     * so there's no need to do it here
1404     */
1405
1406    if (dst->addrtype == TIPC_ADDR_MCAST) {
1407        res = -EINVAL;
1408        goto exit;
1409    }
1410
1411    /* Reject any messages already in receive queue (very unlikely) */
1412
1413    reject_rx_queue(sk);
1414
1415    /* Send a 'SYN-' to destination */
1416
1417    m.msg_name = dest;
1418    m.msg_namelen = destlen;
1419    res = send_msg(NULL, sock, &m, 0);
1420    if (res < 0) {
1421        goto exit;
1422    }
1423
1424    /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */
1425
1426    release_sock(sk);
1427    res = wait_event_interruptible_timeout(*sk->sk_sleep,
1428            (!skb_queue_empty(&sk->sk_receive_queue) ||
1429            (sock->state != SS_CONNECTING)),
1430            sk->sk_rcvtimeo);
1431    lock_sock(sk);
1432
1433    if (res > 0) {
1434        buf = skb_peek(&sk->sk_receive_queue);
1435        if (buf != NULL) {
1436            msg = buf_msg(buf);
1437            res = auto_connect(sock, msg);
1438            if (!res) {
1439                if (!msg_data_sz(msg))
1440                    advance_rx_queue(sk);
1441            }
1442        } else {
1443            if (sock->state == SS_CONNECTED) {
1444                res = -EISCONN;
1445            } else {
1446                res = -ECONNREFUSED;
1447            }
1448        }
1449    } else {
1450        if (res == 0)
1451            res = -ETIMEDOUT;
1452        else
1453            ; /* leave "res" unchanged */
1454        sock->state = SS_DISCONNECTING;
1455    }
1456
1457exit:
1458    release_sock(sk);
1459    return res;
1460}
1461
1462/**
1463 * listen - allow socket to listen for incoming connections
1464 * @sock: socket structure
1465 * @len: (unused)
1466 *
1467 * Returns 0 on success, errno otherwise
1468 */
1469
1470static int listen(struct socket *sock, int len)
1471{
1472    struct sock *sk = sock->sk;
1473    int res;
1474
1475    lock_sock(sk);
1476
1477    if (sock->state == SS_READY)
1478        res = -EOPNOTSUPP;
1479    else if (sock->state != SS_UNCONNECTED)
1480        res = -EINVAL;
1481    else {
1482        sock->state = SS_LISTENING;
1483        res = 0;
1484    }
1485
1486    release_sock(sk);
1487    return res;
1488}
1489
1490/**
1491 * accept - wait for connection request
1492 * @sock: listening socket
1493 * @newsock: new socket that is to be connected
1494 * @flags: file-related flags associated with socket
1495 *
1496 * Returns 0 on success, errno otherwise
1497 */
1498
1499static int accept(struct socket *sock, struct socket *new_sock, int flags)
1500{
1501    struct sock *sk = sock->sk;
1502    struct sk_buff *buf;
1503    int res;
1504
1505    lock_sock(sk);
1506
1507    if (sock->state == SS_READY) {
1508        res = -EOPNOTSUPP;
1509        goto exit;
1510    }
1511    if (sock->state != SS_LISTENING) {
1512        res = -EINVAL;
1513        goto exit;
1514    }
1515
1516    while (skb_queue_empty(&sk->sk_receive_queue)) {
1517        if (flags & O_NONBLOCK) {
1518            res = -EWOULDBLOCK;
1519            goto exit;
1520        }
1521        release_sock(sk);
1522        res = wait_event_interruptible(*sk->sk_sleep,
1523                (!skb_queue_empty(&sk->sk_receive_queue)));
1524        lock_sock(sk);
1525        if (res)
1526            goto exit;
1527    }
1528
1529    buf = skb_peek(&sk->sk_receive_queue);
1530
1531    res = tipc_create(sock_net(sock->sk), new_sock, 0);
1532    if (!res) {
1533        struct sock *new_sk = new_sock->sk;
1534        struct tipc_sock *new_tsock = tipc_sk(new_sk);
1535        struct tipc_port *new_tport = new_tsock->p;
1536        u32 new_ref = new_tport->ref;
1537        struct tipc_msg *msg = buf_msg(buf);
1538
1539        lock_sock(new_sk);
1540
1541        /*
1542         * Reject any stray messages received by new socket
1543         * before the socket lock was taken (very, very unlikely)
1544         */
1545
1546        reject_rx_queue(new_sk);
1547
1548        /* Connect new socket to it's peer */
1549
1550        new_tsock->peer_name.ref = msg_origport(msg);
1551        new_tsock->peer_name.node = msg_orignode(msg);
1552        tipc_connect2port(new_ref, &new_tsock->peer_name);
1553        new_sock->state = SS_CONNECTED;
1554
1555        tipc_set_portimportance(new_ref, msg_importance(msg));
1556        if (msg_named(msg)) {
1557            new_tport->conn_type = msg_nametype(msg);
1558            new_tport->conn_instance = msg_nameinst(msg);
1559        }
1560
1561        /*
1562         * Respond to 'SYN-' by discarding it & returning 'ACK'-.
1563         * Respond to 'SYN+' by queuing it on new socket.
1564         */
1565
1566        msg_dbg(msg,"<ACC<: ");
1567        if (!msg_data_sz(msg)) {
1568            struct msghdr m = {NULL,};
1569
1570            advance_rx_queue(sk);
1571            send_packet(NULL, new_sock, &m, 0);
1572        } else {
1573            __skb_dequeue(&sk->sk_receive_queue);
1574            __skb_queue_head(&new_sk->sk_receive_queue, buf);
1575        }
1576        release_sock(new_sk);
1577    }
1578exit:
1579    release_sock(sk);
1580    return res;
1581}
1582
1583/**
1584 * shutdown - shutdown socket connection
1585 * @sock: socket structure
1586 * @how: direction to close (must be SHUT_RDWR)
1587 *
1588 * Terminates connection (if necessary), then purges socket's receive queue.
1589 *
1590 * Returns 0 on success, errno otherwise
1591 */
1592
1593static int shutdown(struct socket *sock, int how)
1594{
1595    struct sock *sk = sock->sk;
1596    struct tipc_port *tport = tipc_sk_port(sk);
1597    struct sk_buff *buf;
1598    int res;
1599
1600    if (how != SHUT_RDWR)
1601        return -EINVAL;
1602
1603    lock_sock(sk);
1604
1605    switch (sock->state) {
1606    case SS_CONNECTING:
1607    case SS_CONNECTED:
1608
1609        /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
1610restart:
1611        buf = __skb_dequeue(&sk->sk_receive_queue);
1612        if (buf) {
1613            atomic_dec(&tipc_queue_size);
1614            if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) {
1615                buf_discard(buf);
1616                goto restart;
1617            }
1618            tipc_disconnect(tport->ref);
1619            tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
1620        } else {
1621            tipc_shutdown(tport->ref);
1622        }
1623
1624        sock->state = SS_DISCONNECTING;
1625
1626        /* fall through */
1627
1628    case SS_DISCONNECTING:
1629
1630        /* Discard any unreceived messages; wake up sleeping tasks */
1631
1632        discard_rx_queue(sk);
1633        if (waitqueue_active(sk->sk_sleep))
1634            wake_up_interruptible(sk->sk_sleep);
1635        res = 0;
1636        break;
1637
1638    default:
1639        res = -ENOTCONN;
1640    }
1641
1642    release_sock(sk);
1643    return res;
1644}
1645
1646/**
1647 * setsockopt - set socket option
1648 * @sock: socket structure
1649 * @lvl: option level
1650 * @opt: option identifier
1651 * @ov: pointer to new option value
1652 * @ol: length of option value
1653 *
1654 * For stream sockets only, accepts and ignores all IPPROTO_TCP options
1655 * (to ease compatibility).
1656 *
1657 * Returns 0 on success, errno otherwise
1658 */
1659
1660static int setsockopt(struct socket *sock,
1661              int lvl, int opt, char __user *ov, unsigned int ol)
1662{
1663    struct sock *sk = sock->sk;
1664    struct tipc_port *tport = tipc_sk_port(sk);
1665    u32 value;
1666    int res;
1667
1668    if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1669        return 0;
1670    if (lvl != SOL_TIPC)
1671        return -ENOPROTOOPT;
1672    if (ol < sizeof(value))
1673        return -EINVAL;
1674    if ((res = get_user(value, (u32 __user *)ov)))
1675        return res;
1676
1677    lock_sock(sk);
1678
1679    switch (opt) {
1680    case TIPC_IMPORTANCE:
1681        res = tipc_set_portimportance(tport->ref, value);
1682        break;
1683    case TIPC_SRC_DROPPABLE:
1684        if (sock->type != SOCK_STREAM)
1685            res = tipc_set_portunreliable(tport->ref, value);
1686        else
1687            res = -ENOPROTOOPT;
1688        break;
1689    case TIPC_DEST_DROPPABLE:
1690        res = tipc_set_portunreturnable(tport->ref, value);
1691        break;
1692    case TIPC_CONN_TIMEOUT:
1693        sk->sk_rcvtimeo = msecs_to_jiffies(value);
1694        /* no need to set "res", since already 0 at this point */
1695        break;
1696    default:
1697        res = -EINVAL;
1698    }
1699
1700    release_sock(sk);
1701
1702    return res;
1703}
1704
1705/**
1706 * getsockopt - get socket option
1707 * @sock: socket structure
1708 * @lvl: option level
1709 * @opt: option identifier
1710 * @ov: receptacle for option value
1711 * @ol: receptacle for length of option value
1712 *
1713 * For stream sockets only, returns 0 length result for all IPPROTO_TCP options
1714 * (to ease compatibility).
1715 *
1716 * Returns 0 on success, errno otherwise
1717 */
1718
1719static int getsockopt(struct socket *sock,
1720              int lvl, int opt, char __user *ov, int __user *ol)
1721{
1722    struct sock *sk = sock->sk;
1723    struct tipc_port *tport = tipc_sk_port(sk);
1724    int len;
1725    u32 value;
1726    int res;
1727
1728    if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1729        return put_user(0, ol);
1730    if (lvl != SOL_TIPC)
1731        return -ENOPROTOOPT;
1732    if ((res = get_user(len, ol)))
1733        return res;
1734
1735    lock_sock(sk);
1736
1737    switch (opt) {
1738    case TIPC_IMPORTANCE:
1739        res = tipc_portimportance(tport->ref, &value);
1740        break;
1741    case TIPC_SRC_DROPPABLE:
1742        res = tipc_portunreliable(tport->ref, &value);
1743        break;
1744    case TIPC_DEST_DROPPABLE:
1745        res = tipc_portunreturnable(tport->ref, &value);
1746        break;
1747    case TIPC_CONN_TIMEOUT:
1748        value = jiffies_to_msecs(sk->sk_rcvtimeo);
1749        /* no need to set "res", since already 0 at this point */
1750        break;
1751     case TIPC_NODE_RECVQ_DEPTH:
1752        value = (u32)atomic_read(&tipc_queue_size);
1753        break;
1754     case TIPC_SOCK_RECVQ_DEPTH:
1755        value = skb_queue_len(&sk->sk_receive_queue);
1756        break;
1757    default:
1758        res = -EINVAL;
1759    }
1760
1761    release_sock(sk);
1762
1763    if (res) {
1764        /* "get" failed */
1765    }
1766    else if (len < sizeof(value)) {
1767        res = -EINVAL;
1768    }
1769    else if (copy_to_user(ov, &value, sizeof(value))) {
1770        res = -EFAULT;
1771    }
1772    else {
1773        res = put_user(sizeof(value), ol);
1774    }
1775
1776    return res;
1777}
1778
1779/**
1780 * Protocol switches for the various types of TIPC sockets
1781 */
1782
1783static const struct proto_ops msg_ops = {
1784    .owner = THIS_MODULE,
1785    .family = AF_TIPC,
1786    .release = release,
1787    .bind = bind,
1788    .connect = connect,
1789    .socketpair = sock_no_socketpair,
1790    .accept = accept,
1791    .getname = get_name,
1792    .poll = poll,
1793    .ioctl = sock_no_ioctl,
1794    .listen = listen,
1795    .shutdown = shutdown,
1796    .setsockopt = setsockopt,
1797    .getsockopt = getsockopt,
1798    .sendmsg = send_msg,
1799    .recvmsg = recv_msg,
1800    .mmap = sock_no_mmap,
1801    .sendpage = sock_no_sendpage
1802};
1803
1804static const struct proto_ops packet_ops = {
1805    .owner = THIS_MODULE,
1806    .family = AF_TIPC,
1807    .release = release,
1808    .bind = bind,
1809    .connect = connect,
1810    .socketpair = sock_no_socketpair,
1811    .accept = accept,
1812    .getname = get_name,
1813    .poll = poll,
1814    .ioctl = sock_no_ioctl,
1815    .listen = listen,
1816    .shutdown = shutdown,
1817    .setsockopt = setsockopt,
1818    .getsockopt = getsockopt,
1819    .sendmsg = send_packet,
1820    .recvmsg = recv_msg,
1821    .mmap = sock_no_mmap,
1822    .sendpage = sock_no_sendpage
1823};
1824
1825static const struct proto_ops stream_ops = {
1826    .owner = THIS_MODULE,
1827    .family = AF_TIPC,
1828    .release = release,
1829    .bind = bind,
1830    .connect = connect,
1831    .socketpair = sock_no_socketpair,
1832    .accept = accept,
1833    .getname = get_name,
1834    .poll = poll,
1835    .ioctl = sock_no_ioctl,
1836    .listen = listen,
1837    .shutdown = shutdown,
1838    .setsockopt = setsockopt,
1839    .getsockopt = getsockopt,
1840    .sendmsg = send_stream,
1841    .recvmsg = recv_stream,
1842    .mmap = sock_no_mmap,
1843    .sendpage = sock_no_sendpage
1844};
1845
1846static const struct net_proto_family tipc_family_ops = {
1847    .owner = THIS_MODULE,
1848    .family = AF_TIPC,
1849    .create = tipc_create
1850};
1851
1852static struct proto tipc_proto = {
1853    .name = "TIPC",
1854    .owner = THIS_MODULE,
1855    .obj_size = sizeof(struct tipc_sock)
1856};
1857
1858/**
1859 * tipc_socket_init - initialize TIPC socket interface
1860 *
1861 * Returns 0 on success, errno otherwise
1862 */
1863int tipc_socket_init(void)
1864{
1865    int res;
1866
1867    res = proto_register(&tipc_proto, 1);
1868    if (res) {
1869        err("Failed to register TIPC protocol type\n");
1870        goto out;
1871    }
1872
1873    res = sock_register(&tipc_family_ops);
1874    if (res) {
1875        err("Failed to register TIPC socket type\n");
1876        proto_unregister(&tipc_proto);
1877        goto out;
1878    }
1879
1880    sockets_enabled = 1;
1881 out:
1882    return res;
1883}
1884
1885/**
1886 * tipc_socket_stop - stop TIPC socket interface
1887 */
1888
1889void tipc_socket_stop(void)
1890{
1891    if (!sockets_enabled)
1892        return;
1893
1894    sockets_enabled = 0;
1895    sock_unregister(tipc_family_ops.family);
1896    proto_unregister(&tipc_proto);
1897}
1898
1899

Archive Download this file



interactive