Root/net/rds/af_rds.c

1/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/module.h>
34#include <linux/errno.h>
35#include <linux/kernel.h>
36#include <linux/gfp.h>
37#include <linux/in.h>
38#include <linux/poll.h>
39#include <net/sock.h>
40
41#include "rds.h"
42#include "rdma.h"
43
44/* this is just used for stats gathering :/ */
45static DEFINE_SPINLOCK(rds_sock_lock);
46static unsigned long rds_sock_count;
47static LIST_HEAD(rds_sock_list);
48DECLARE_WAIT_QUEUE_HEAD(rds_poll_waitq);
49
50/*
51 * This is called as the final descriptor referencing this socket is closed.
52 * We have to unbind the socket so that another socket can be bound to the
53 * address it was using.
54 *
55 * We have to be careful about racing with the incoming path. sock_orphan()
56 * sets SOCK_DEAD and we use that as an indicator to the rx path that new
57 * messages shouldn't be queued.
58 */
59static int rds_release(struct socket *sock)
60{
61    struct sock *sk = sock->sk;
62    struct rds_sock *rs;
63    unsigned long flags;
64
65    if (sk == NULL)
66        goto out;
67
68    rs = rds_sk_to_rs(sk);
69
70    sock_orphan(sk);
71    /* Note - rds_clear_recv_queue grabs rs_recv_lock, so
72     * that ensures the recv path has completed messing
73     * with the socket. */
74    rds_clear_recv_queue(rs);
75    rds_cong_remove_socket(rs);
76    rds_remove_bound(rs);
77    rds_send_drop_to(rs, NULL);
78    rds_rdma_drop_keys(rs);
79    rds_notify_queue_get(rs, NULL);
80
81    spin_lock_irqsave(&rds_sock_lock, flags);
82    list_del_init(&rs->rs_item);
83    rds_sock_count--;
84    spin_unlock_irqrestore(&rds_sock_lock, flags);
85
86    sock->sk = NULL;
87    sock_put(sk);
88out:
89    return 0;
90}
91
92/*
93 * Careful not to race with rds_release -> sock_orphan which clears sk_sleep.
94 * _bh() isn't OK here, we're called from interrupt handlers. It's probably OK
95 * to wake the waitqueue after sk_sleep is clear as we hold a sock ref, but
96 * this seems more conservative.
97 * NB - normally, one would use sk_callback_lock for this, but we can
98 * get here from interrupts, whereas the network code grabs sk_callback_lock
99 * with _lock_bh only - so relying on sk_callback_lock introduces livelocks.
100 */
101void rds_wake_sk_sleep(struct rds_sock *rs)
102{
103    unsigned long flags;
104
105    read_lock_irqsave(&rs->rs_recv_lock, flags);
106    __rds_wake_sk_sleep(rds_rs_to_sk(rs));
107    read_unlock_irqrestore(&rs->rs_recv_lock, flags);
108}
109
110static int rds_getname(struct socket *sock, struct sockaddr *uaddr,
111               int *uaddr_len, int peer)
112{
113    struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
114    struct rds_sock *rs = rds_sk_to_rs(sock->sk);
115
116    memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
117
118    /* racey, don't care */
119    if (peer) {
120        if (!rs->rs_conn_addr)
121            return -ENOTCONN;
122
123        sin->sin_port = rs->rs_conn_port;
124        sin->sin_addr.s_addr = rs->rs_conn_addr;
125    } else {
126        sin->sin_port = rs->rs_bound_port;
127        sin->sin_addr.s_addr = rs->rs_bound_addr;
128    }
129
130    sin->sin_family = AF_INET;
131
132    *uaddr_len = sizeof(*sin);
133    return 0;
134}
135
136/*
137 * RDS' poll is without a doubt the least intuitive part of the interface,
138 * as POLLIN and POLLOUT do not behave entirely as you would expect from
139 * a network protocol.
140 *
141 * POLLIN is asserted if
142 * - there is data on the receive queue.
143 * - to signal that a previously congested destination may have become
144 * uncongested
145 * - A notification has been queued to the socket (this can be a congestion
146 * update, or a RDMA completion).
147 *
148 * POLLOUT is asserted if there is room on the send queue. This does not mean
149 * however, that the next sendmsg() call will succeed. If the application tries
150 * to send to a congested destination, the system call may still fail (and
151 * return ENOBUFS).
152 */
153static unsigned int rds_poll(struct file *file, struct socket *sock,
154                 poll_table *wait)
155{
156    struct sock *sk = sock->sk;
157    struct rds_sock *rs = rds_sk_to_rs(sk);
158    unsigned int mask = 0;
159    unsigned long flags;
160
161    poll_wait(file, sk->sk_sleep, wait);
162
163    poll_wait(file, &rds_poll_waitq, wait);
164
165    read_lock_irqsave(&rs->rs_recv_lock, flags);
166    if (!rs->rs_cong_monitor) {
167        /* When a congestion map was updated, we signal POLLIN for
168         * "historical" reasons. Applications can also poll for
169         * WRBAND instead. */
170        if (rds_cong_updated_since(&rs->rs_cong_track))
171            mask |= (POLLIN | POLLRDNORM | POLLWRBAND);
172    } else {
173        spin_lock(&rs->rs_lock);
174        if (rs->rs_cong_notify)
175            mask |= (POLLIN | POLLRDNORM);
176        spin_unlock(&rs->rs_lock);
177    }
178    if (!list_empty(&rs->rs_recv_queue) ||
179        !list_empty(&rs->rs_notify_queue))
180        mask |= (POLLIN | POLLRDNORM);
181    if (rs->rs_snd_bytes < rds_sk_sndbuf(rs))
182        mask |= (POLLOUT | POLLWRNORM);
183    read_unlock_irqrestore(&rs->rs_recv_lock, flags);
184
185    return mask;
186}
187
188static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
189{
190    return -ENOIOCTLCMD;
191}
192
193static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
194                  int len)
195{
196    struct sockaddr_in sin;
197    int ret = 0;
198
199    /* racing with another thread binding seems ok here */
200    if (rs->rs_bound_addr == 0) {
201        ret = -ENOTCONN; /* XXX not a great errno */
202        goto out;
203    }
204
205    if (len < sizeof(struct sockaddr_in)) {
206        ret = -EINVAL;
207        goto out;
208    }
209
210    if (copy_from_user(&sin, optval, sizeof(sin))) {
211        ret = -EFAULT;
212        goto out;
213    }
214
215    rds_send_drop_to(rs, &sin);
216out:
217    return ret;
218}
219
220static int rds_set_bool_option(unsigned char *optvar, char __user *optval,
221                   int optlen)
222{
223    int value;
224
225    if (optlen < sizeof(int))
226        return -EINVAL;
227    if (get_user(value, (int __user *) optval))
228        return -EFAULT;
229    *optvar = !!value;
230    return 0;
231}
232
233static int rds_cong_monitor(struct rds_sock *rs, char __user *optval,
234                int optlen)
235{
236    int ret;
237
238    ret = rds_set_bool_option(&rs->rs_cong_monitor, optval, optlen);
239    if (ret == 0) {
240        if (rs->rs_cong_monitor) {
241            rds_cong_add_socket(rs);
242        } else {
243            rds_cong_remove_socket(rs);
244            rs->rs_cong_mask = 0;
245            rs->rs_cong_notify = 0;
246        }
247    }
248    return ret;
249}
250
251static int rds_setsockopt(struct socket *sock, int level, int optname,
252              char __user *optval, unsigned int optlen)
253{
254    struct rds_sock *rs = rds_sk_to_rs(sock->sk);
255    int ret;
256
257    if (level != SOL_RDS) {
258        ret = -ENOPROTOOPT;
259        goto out;
260    }
261
262    switch (optname) {
263    case RDS_CANCEL_SENT_TO:
264        ret = rds_cancel_sent_to(rs, optval, optlen);
265        break;
266    case RDS_GET_MR:
267        ret = rds_get_mr(rs, optval, optlen);
268        break;
269    case RDS_GET_MR_FOR_DEST:
270        ret = rds_get_mr_for_dest(rs, optval, optlen);
271        break;
272    case RDS_FREE_MR:
273        ret = rds_free_mr(rs, optval, optlen);
274        break;
275    case RDS_RECVERR:
276        ret = rds_set_bool_option(&rs->rs_recverr, optval, optlen);
277        break;
278    case RDS_CONG_MONITOR:
279        ret = rds_cong_monitor(rs, optval, optlen);
280        break;
281    default:
282        ret = -ENOPROTOOPT;
283    }
284out:
285    return ret;
286}
287
288static int rds_getsockopt(struct socket *sock, int level, int optname,
289              char __user *optval, int __user *optlen)
290{
291    struct rds_sock *rs = rds_sk_to_rs(sock->sk);
292    int ret = -ENOPROTOOPT, len;
293
294    if (level != SOL_RDS)
295        goto out;
296
297    if (get_user(len, optlen)) {
298        ret = -EFAULT;
299        goto out;
300    }
301
302    switch (optname) {
303    case RDS_INFO_FIRST ... RDS_INFO_LAST:
304        ret = rds_info_getsockopt(sock, optname, optval,
305                      optlen);
306        break;
307
308    case RDS_RECVERR:
309        if (len < sizeof(int))
310            ret = -EINVAL;
311        else
312        if (put_user(rs->rs_recverr, (int __user *) optval) ||
313            put_user(sizeof(int), optlen))
314            ret = -EFAULT;
315        else
316            ret = 0;
317        break;
318    default:
319        break;
320    }
321
322out:
323    return ret;
324
325}
326
327static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
328               int addr_len, int flags)
329{
330    struct sock *sk = sock->sk;
331    struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
332    struct rds_sock *rs = rds_sk_to_rs(sk);
333    int ret = 0;
334
335    lock_sock(sk);
336
337    if (addr_len != sizeof(struct sockaddr_in)) {
338        ret = -EINVAL;
339        goto out;
340    }
341
342    if (sin->sin_family != AF_INET) {
343        ret = -EAFNOSUPPORT;
344        goto out;
345    }
346
347    if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
348        ret = -EDESTADDRREQ;
349        goto out;
350    }
351
352    rs->rs_conn_addr = sin->sin_addr.s_addr;
353    rs->rs_conn_port = sin->sin_port;
354
355out:
356    release_sock(sk);
357    return ret;
358}
359
360static struct proto rds_proto = {
361    .name = "RDS",
362    .owner = THIS_MODULE,
363    .obj_size = sizeof(struct rds_sock),
364};
365
366static const struct proto_ops rds_proto_ops = {
367    .family = AF_RDS,
368    .owner = THIS_MODULE,
369    .release = rds_release,
370    .bind = rds_bind,
371    .connect = rds_connect,
372    .socketpair = sock_no_socketpair,
373    .accept = sock_no_accept,
374    .getname = rds_getname,
375    .poll = rds_poll,
376    .ioctl = rds_ioctl,
377    .listen = sock_no_listen,
378    .shutdown = sock_no_shutdown,
379    .setsockopt = rds_setsockopt,
380    .getsockopt = rds_getsockopt,
381    .sendmsg = rds_sendmsg,
382    .recvmsg = rds_recvmsg,
383    .mmap = sock_no_mmap,
384    .sendpage = sock_no_sendpage,
385};
386
387static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
388{
389    unsigned long flags;
390    struct rds_sock *rs;
391
392    sock_init_data(sock, sk);
393    sock->ops = &rds_proto_ops;
394    sk->sk_protocol = protocol;
395
396    rs = rds_sk_to_rs(sk);
397    spin_lock_init(&rs->rs_lock);
398    rwlock_init(&rs->rs_recv_lock);
399    INIT_LIST_HEAD(&rs->rs_send_queue);
400    INIT_LIST_HEAD(&rs->rs_recv_queue);
401    INIT_LIST_HEAD(&rs->rs_notify_queue);
402    INIT_LIST_HEAD(&rs->rs_cong_list);
403    spin_lock_init(&rs->rs_rdma_lock);
404    rs->rs_rdma_keys = RB_ROOT;
405
406    spin_lock_irqsave(&rds_sock_lock, flags);
407    list_add_tail(&rs->rs_item, &rds_sock_list);
408    rds_sock_count++;
409    spin_unlock_irqrestore(&rds_sock_lock, flags);
410
411    return 0;
412}
413
414static int rds_create(struct net *net, struct socket *sock, int protocol,
415              int kern)
416{
417    struct sock *sk;
418
419    if (sock->type != SOCK_SEQPACKET || protocol)
420        return -ESOCKTNOSUPPORT;
421
422    sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto);
423    if (!sk)
424        return -ENOMEM;
425
426    return __rds_create(sock, sk, protocol);
427}
428
429void rds_sock_addref(struct rds_sock *rs)
430{
431    sock_hold(rds_rs_to_sk(rs));
432}
433
434void rds_sock_put(struct rds_sock *rs)
435{
436    sock_put(rds_rs_to_sk(rs));
437}
438
439static const struct net_proto_family rds_family_ops = {
440    .family = AF_RDS,
441    .create = rds_create,
442    .owner = THIS_MODULE,
443};
444
445static void rds_sock_inc_info(struct socket *sock, unsigned int len,
446                  struct rds_info_iterator *iter,
447                  struct rds_info_lengths *lens)
448{
449    struct rds_sock *rs;
450    struct sock *sk;
451    struct rds_incoming *inc;
452    unsigned long flags;
453    unsigned int total = 0;
454
455    len /= sizeof(struct rds_info_message);
456
457    spin_lock_irqsave(&rds_sock_lock, flags);
458
459    list_for_each_entry(rs, &rds_sock_list, rs_item) {
460        sk = rds_rs_to_sk(rs);
461        read_lock(&rs->rs_recv_lock);
462
463        /* XXX too lazy to maintain counts.. */
464        list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
465            total++;
466            if (total <= len)
467                rds_inc_info_copy(inc, iter, inc->i_saddr,
468                          rs->rs_bound_addr, 1);
469        }
470
471        read_unlock(&rs->rs_recv_lock);
472    }
473
474    spin_unlock_irqrestore(&rds_sock_lock, flags);
475
476    lens->nr = total;
477    lens->each = sizeof(struct rds_info_message);
478}
479
480static void rds_sock_info(struct socket *sock, unsigned int len,
481              struct rds_info_iterator *iter,
482              struct rds_info_lengths *lens)
483{
484    struct rds_info_socket sinfo;
485    struct rds_sock *rs;
486    unsigned long flags;
487
488    len /= sizeof(struct rds_info_socket);
489
490    spin_lock_irqsave(&rds_sock_lock, flags);
491
492    if (len < rds_sock_count)
493        goto out;
494
495    list_for_each_entry(rs, &rds_sock_list, rs_item) {
496        sinfo.sndbuf = rds_sk_sndbuf(rs);
497        sinfo.rcvbuf = rds_sk_rcvbuf(rs);
498        sinfo.bound_addr = rs->rs_bound_addr;
499        sinfo.connected_addr = rs->rs_conn_addr;
500        sinfo.bound_port = rs->rs_bound_port;
501        sinfo.connected_port = rs->rs_conn_port;
502        sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));
503
504        rds_info_copy(iter, &sinfo, sizeof(sinfo));
505    }
506
507out:
508    lens->nr = rds_sock_count;
509    lens->each = sizeof(struct rds_info_socket);
510
511    spin_unlock_irqrestore(&rds_sock_lock, flags);
512}
513
514static void __exit rds_exit(void)
515{
516    sock_unregister(rds_family_ops.family);
517    proto_unregister(&rds_proto);
518    rds_conn_exit();
519    rds_cong_exit();
520    rds_sysctl_exit();
521    rds_threads_exit();
522    rds_stats_exit();
523    rds_page_exit();
524    rds_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);
525    rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
526}
527module_exit(rds_exit);
528
529static int __init rds_init(void)
530{
531    int ret;
532
533    ret = rds_conn_init();
534    if (ret)
535        goto out;
536    ret = rds_threads_init();
537    if (ret)
538        goto out_conn;
539    ret = rds_sysctl_init();
540    if (ret)
541        goto out_threads;
542    ret = rds_stats_init();
543    if (ret)
544        goto out_sysctl;
545    ret = proto_register(&rds_proto, 1);
546    if (ret)
547        goto out_stats;
548    ret = sock_register(&rds_family_ops);
549    if (ret)
550        goto out_proto;
551
552    rds_info_register_func(RDS_INFO_SOCKETS, rds_sock_info);
553    rds_info_register_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
554
555    goto out;
556
557out_proto:
558    proto_unregister(&rds_proto);
559out_stats:
560    rds_stats_exit();
561out_sysctl:
562    rds_sysctl_exit();
563out_threads:
564    rds_threads_exit();
565out_conn:
566    rds_conn_exit();
567    rds_cong_exit();
568    rds_page_exit();
569out:
570    return ret;
571}
572module_init(rds_init);
573
574#define DRV_VERSION "4.0"
575#define DRV_RELDATE "Feb 12, 2009"
576
577MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
578MODULE_DESCRIPTION("RDS: Reliable Datagram Sockets"
579           " v" DRV_VERSION " (" DRV_RELDATE ")");
580MODULE_VERSION(DRV_VERSION);
581MODULE_LICENSE("Dual BSD/GPL");
582MODULE_ALIAS_NETPROTO(PF_RDS);
583

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