[DCCP]: Initial implementation
[linux-3.10.git] / net / dccp / proto.c
1 /*
2  *  net/dccp/proto.c
3  *
4  *  An implementation of the DCCP protocol
5  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6  *
7  *      This program is free software; you can redistribute it and/or modify it
8  *      under the terms of the GNU General Public License version 2 as
9  *      published by the Free Software Foundation.
10  */
11
12 #include <linux/config.h>
13 #include <linux/dccp.h>
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/skbuff.h>
19 #include <linux/netdevice.h>
20 #include <linux/in.h>
21 #include <linux/if_arp.h>
22 #include <linux/init.h>
23 #include <linux/random.h>
24 #include <net/checksum.h>
25
26 #include <net/inet_common.h>
27 #include <net/ip.h>
28 #include <net/protocol.h>
29 #include <net/sock.h>
30 #include <net/xfrm.h>
31
32 #include <asm/semaphore.h>
33 #include <linux/spinlock.h>
34 #include <linux/timer.h>
35 #include <linux/delay.h>
36 #include <linux/poll.h>
37 #include <linux/dccp.h>
38
39 #include "ccid.h"
40 #include "dccp.h"
41
42 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics);
43
44 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
45
46 static struct net_protocol dccp_protocol = {
47         .handler        = dccp_v4_rcv,
48         .err_handler    = dccp_v4_err,
49 };
50
51 const char *dccp_packet_name(const int type)
52 {
53         static const char *dccp_packet_names[] = {
54                 [DCCP_PKT_REQUEST]  = "REQUEST",
55                 [DCCP_PKT_RESPONSE] = "RESPONSE",
56                 [DCCP_PKT_DATA]     = "DATA",
57                 [DCCP_PKT_ACK]      = "ACK",
58                 [DCCP_PKT_DATAACK]  = "DATAACK",
59                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
60                 [DCCP_PKT_CLOSE]    = "CLOSE",
61                 [DCCP_PKT_RESET]    = "RESET",
62                 [DCCP_PKT_SYNC]     = "SYNC",
63                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
64         };
65
66         if (type >= DCCP_NR_PKT_TYPES)
67                 return "INVALID";
68         else
69                 return dccp_packet_names[type];
70 }
71
72 EXPORT_SYMBOL_GPL(dccp_packet_name);
73
74 const char *dccp_state_name(const int state)
75 {
76         static char *dccp_state_names[] = {
77         [DCCP_OPEN]       = "OPEN",
78         [DCCP_REQUESTING] = "REQUESTING",
79         [DCCP_PARTOPEN]   = "PARTOPEN",
80         [DCCP_LISTEN]     = "LISTEN",
81         [DCCP_RESPOND]    = "RESPOND",
82         [DCCP_CLOSING]    = "CLOSING",
83         [DCCP_TIME_WAIT]  = "TIME_WAIT",
84         [DCCP_CLOSED]     = "CLOSED",
85         };
86
87         if (state >= DCCP_MAX_STATES)
88                 return "INVALID STATE!";
89         else
90                 return dccp_state_names[state];
91 }
92
93 EXPORT_SYMBOL_GPL(dccp_state_name);
94
95 static inline int dccp_listen_start(struct sock *sk)
96 {
97         dccp_sk(sk)->dccps_role = DCCP_ROLE_LISTEN;
98         return inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
99 }
100
101 int dccp_disconnect(struct sock *sk, int flags)
102 {
103         struct inet_connection_sock *icsk = inet_csk(sk);
104         struct inet_sock *inet = inet_sk(sk);
105         int err = 0;
106         const int old_state = sk->sk_state;
107
108         if (old_state != DCCP_CLOSED)
109                 dccp_set_state(sk, DCCP_CLOSED);
110
111         /* ABORT function of RFC793 */
112         if (old_state == DCCP_LISTEN) {
113                 inet_csk_listen_stop(sk);
114         /* FIXME: do the active reset thing */
115         } else if (old_state == DCCP_REQUESTING)
116                 sk->sk_err = ECONNRESET;
117
118         dccp_clear_xmit_timers(sk);
119         __skb_queue_purge(&sk->sk_receive_queue);
120         if (sk->sk_send_head != NULL) {
121                 __kfree_skb(sk->sk_send_head);
122                 sk->sk_send_head = NULL;
123         }
124
125         inet->dport = 0;
126
127         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
128                 inet_reset_saddr(sk);
129
130         sk->sk_shutdown = 0;
131         sock_reset_flag(sk, SOCK_DONE);
132
133         icsk->icsk_backoff = 0;
134         inet_csk_delack_init(sk);
135         __sk_dst_reset(sk);
136
137         BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
138
139         sk->sk_error_report(sk);
140         return err;
141 }
142
143 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
144 {
145         dccp_pr_debug("entry\n");
146         return -ENOIOCTLCMD;
147 }
148
149 int dccp_setsockopt(struct sock *sk, int level, int optname,
150                     char *optval, int optlen)
151 {
152         dccp_pr_debug("entry\n");
153
154         if (level != SOL_DCCP)
155                 return ip_setsockopt(sk, level, optname, optval, optlen);
156
157         return -EOPNOTSUPP;
158 }
159
160 int dccp_getsockopt(struct sock *sk, int level, int optname,
161                     char *optval, int *optlen)
162 {
163         dccp_pr_debug("entry\n");
164
165         if (level != SOL_DCCP)
166                 return ip_getsockopt(sk, level, optname, optval, optlen);
167
168         return -EOPNOTSUPP;
169 }
170
171 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
172                  size_t len)
173 {
174         const struct dccp_sock *dp = dccp_sk(sk);
175         const int flags = msg->msg_flags;
176         const int noblock = flags & MSG_DONTWAIT;
177         struct sk_buff *skb;
178         int rc, size;
179         long timeo;
180
181         if (len > dp->dccps_mss_cache)
182                 return -EMSGSIZE;
183
184         lock_sock(sk);
185
186         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
187
188         /*
189          * We have to use sk_stream_wait_connect here to set sk_write_pending,
190          * so that the trick in dccp_rcv_request_sent_state_process.
191          */
192         /* Wait for a connection to finish. */
193         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
194                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
195                         goto out_err;
196
197         size = sk->sk_prot->max_header + len;
198         release_sock(sk);
199         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
200         lock_sock(sk);
201
202         if (skb == NULL)
203                 goto out_release;
204
205         skb_reserve(skb, sk->sk_prot->max_header);
206         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
207         if (rc == 0) {
208                 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
209                 const struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
210                 long delay; 
211
212                 /*
213                  * XXX: This is just to match the Waikato tree CA interaction
214                  * points, after the CCID3 code is stable and I have a better
215                  * understanding of behaviour I'll change this to look more like
216                  * TCP.
217                  */
218                 while (1) {
219                         rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk,
220                                                     skb, len, &delay);
221                         if (rc == 0)
222                                 break;
223                         if (rc != -EAGAIN)
224                                 goto out_discard;
225                         if (delay > timeo)
226                                 goto out_discard;
227                         release_sock(sk);
228                         delay = schedule_timeout(delay);
229                         lock_sock(sk);
230                         timeo -= delay;
231                         if (signal_pending(current))
232                                 goto out_interrupted;
233                         rc = -EPIPE;
234                         if (!(sk->sk_state == DCCP_PARTOPEN || sk->sk_state == DCCP_OPEN))
235                                 goto out_discard;
236                 }
237
238                 if (sk->sk_state == DCCP_PARTOPEN) {
239                         /* See 8.1.5.  Handshake Completion */
240                         inet_csk_schedule_ack(sk);
241                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
242                         dcb->dccpd_type = DCCP_PKT_DATAACK;
243                         /* FIXME: we really should have a dccps_ack_pending or use icsk */
244                 } else if (inet_csk_ack_scheduled(sk) ||
245                            (dp->dccps_options.dccpo_send_ack_vector &&
246                             ap->dccpap_buf_ackno != DCCP_MAX_SEQNO + 1 &&
247                             ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1))
248                         dcb->dccpd_type = DCCP_PKT_DATAACK;
249                 else
250                         dcb->dccpd_type = DCCP_PKT_DATA;
251                 dccp_transmit_skb(sk, skb);
252                 ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
253         } else {
254 out_discard:
255                 kfree_skb(skb);
256         }
257 out_release:
258         release_sock(sk);
259         return rc ? : len;
260 out_err:
261         rc = sk_stream_error(sk, flags, rc);
262         goto out_release;
263 out_interrupted:
264         rc = sock_intr_errno(timeo);
265         goto out_discard;
266 }
267
268 EXPORT_SYMBOL(dccp_sendmsg);
269
270 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
271                  size_t len, int nonblock, int flags, int *addr_len)
272 {
273         const struct dccp_hdr *dh;
274         int copied = 0;
275         unsigned long used;
276         int err;
277         int target;             /* Read at least this many bytes */
278         long timeo;
279
280         lock_sock(sk);
281
282         err = -ENOTCONN;
283         if (sk->sk_state == DCCP_LISTEN)
284                 goto out;
285
286         timeo = sock_rcvtimeo(sk, nonblock);
287
288         /* Urgent data needs to be handled specially. */
289         if (flags & MSG_OOB)
290                 goto recv_urg;
291
292         /* FIXME */
293 #if 0
294         seq = &tp->copied_seq;
295         if (flags & MSG_PEEK) {
296                 peek_seq = tp->copied_seq;
297                 seq = &peek_seq;
298         }
299 #endif
300
301         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
302
303         do {
304                 struct sk_buff *skb;
305                 u32 offset;
306
307         /* FIXME */
308 #if 0
309                 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
310                 if (tp->urg_data && tp->urg_seq == *seq) {
311                         if (copied)
312                                 break;
313                         if (signal_pending(current)) {
314                                 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
315                                 break;
316                         }
317                 }
318 #endif
319
320                 /* Next get a buffer. */
321
322                 skb = skb_peek(&sk->sk_receive_queue);
323                 do {
324                         if (!skb)
325                                 break;
326
327                         offset = 0;
328                         dh = dccp_hdr(skb);
329
330                         if (dh->dccph_type == DCCP_PKT_DATA ||
331                             dh->dccph_type == DCCP_PKT_DATAACK)
332                                 goto found_ok_skb;
333
334                         if (dh->dccph_type == DCCP_PKT_RESET ||
335                             dh->dccph_type == DCCP_PKT_CLOSE) {
336                                 dccp_pr_debug("found fin ok!\n");
337                                 goto found_fin_ok;
338                         }
339                         dccp_pr_debug("packet_type=%s\n", dccp_packet_name(dh->dccph_type));
340                         BUG_TRAP(flags & MSG_PEEK);
341                         skb = skb->next;
342                 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
343
344                 /* Well, if we have backlog, try to process it now yet. */
345                 if (copied >= target && !sk->sk_backlog.tail)
346                         break;
347
348                 if (copied) {
349                         if (sk->sk_err ||
350                             sk->sk_state == DCCP_CLOSED ||
351                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
352                             !timeo ||
353                             signal_pending(current) ||
354                             (flags & MSG_PEEK))
355                                 break;
356                 } else {
357                         if (sock_flag(sk, SOCK_DONE))
358                                 break;
359
360                         if (sk->sk_err) {
361                                 copied = sock_error(sk);
362                                 break;
363                         }
364
365                         if (sk->sk_shutdown & RCV_SHUTDOWN)
366                                 break;
367
368                         if (sk->sk_state == DCCP_CLOSED) {
369                                 if (!sock_flag(sk, SOCK_DONE)) {
370                                         /* This occurs when user tries to read
371                                          * from never connected socket.
372                                          */
373                                         copied = -ENOTCONN;
374                                         break;
375                                 }
376                                 break;
377                         }
378
379                         if (!timeo) {
380                                 copied = -EAGAIN;
381                                 break;
382                         }
383
384                         if (signal_pending(current)) {
385                                 copied = sock_intr_errno(timeo);
386                                 break;
387                         }
388                 }
389
390                 /* FIXME: cleanup_rbuf(sk, copied); */
391
392                 if (copied >= target) {
393                         /* Do not sleep, just process backlog. */
394                         release_sock(sk);
395                         lock_sock(sk);
396                 } else
397                         sk_wait_data(sk, &timeo);
398
399                 continue;
400
401         found_ok_skb:
402                 /* Ok so how much can we use? */
403                 used = skb->len - offset;
404                 if (len < used)
405                         used = len;
406
407                 if (!(flags & MSG_TRUNC)) {
408                         err = skb_copy_datagram_iovec(skb, offset,
409                                                       msg->msg_iov, used);
410                         if (err) {
411                                 /* Exception. Bailout! */
412                                 if (!copied)
413                                         copied = -EFAULT;
414                                 break;
415                         }
416                 }
417
418                 copied += used;
419                 len -= used;
420
421                 /* FIXME: tcp_rcv_space_adjust(sk); */
422
423 //skip_copy:
424                 if (used + offset < skb->len)
425                         continue;
426
427                 if (!(flags & MSG_PEEK))
428                         sk_eat_skb(sk, skb);
429                 continue;
430         found_fin_ok:
431                 if (!(flags & MSG_PEEK))
432                         sk_eat_skb(sk, skb);
433                 break;
434                 
435         } while (len > 0);
436
437         /* According to UNIX98, msg_name/msg_namelen are ignored
438          * on connected socket. I was just happy when found this 8) --ANK
439          */
440
441         /* Clean up data we have read: This will do ACK frames. */
442         /* FIXME: cleanup_rbuf(sk, copied); */
443
444         release_sock(sk);
445         return copied;
446
447 out:
448         release_sock(sk);
449         return err;
450
451 recv_urg:
452         /* FIXME: err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); */
453         goto out;
454 }
455
456 static int inet_dccp_listen(struct socket *sock, int backlog)
457 {
458         struct sock *sk = sock->sk;
459         unsigned char old_state;
460         int err;
461
462         lock_sock(sk);
463
464         err = -EINVAL;
465         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
466                 goto out;
467
468         old_state = sk->sk_state;
469         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
470                 goto out;
471
472         /* Really, if the socket is already in listen state
473          * we can only allow the backlog to be adjusted.
474          */
475         if (old_state != DCCP_LISTEN) {
476                 /*
477                  * FIXME: here it probably should be sk->sk_prot->listen_start
478                  * see tcp_listen_start
479                  */
480                 err = dccp_listen_start(sk);
481                 if (err)
482                         goto out;
483         }
484         sk->sk_max_ack_backlog = backlog;
485         err = 0;
486
487 out:
488         release_sock(sk);
489         return err;
490 }
491
492 static const unsigned char dccp_new_state[] = {
493         /* current state:        new state:      action:        */
494         [0]                     = DCCP_CLOSED,
495         [DCCP_OPEN]             = DCCP_CLOSING | DCCP_ACTION_FIN,
496         [DCCP_REQUESTING]       = DCCP_CLOSED,
497         [DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
498         [DCCP_LISTEN]           = DCCP_CLOSED,
499         [DCCP_RESPOND]  = DCCP_CLOSED,
500         [DCCP_CLOSING]  = DCCP_CLOSED,
501         [DCCP_TIME_WAIT]        = DCCP_CLOSED,
502         [DCCP_CLOSED]   = DCCP_CLOSED,
503 };
504
505 static int dccp_close_state(struct sock *sk)
506 {
507         const int next = dccp_new_state[sk->sk_state];
508         const int ns = next & DCCP_STATE_MASK;
509
510         if (ns != sk->sk_state)
511                 dccp_set_state(sk, ns);
512
513         return next & DCCP_ACTION_FIN;
514 }
515
516 void dccp_close(struct sock *sk, long timeout)
517 {
518         struct sk_buff *skb;
519
520         lock_sock(sk);
521
522         sk->sk_shutdown = SHUTDOWN_MASK;
523
524         if (sk->sk_state == DCCP_LISTEN) {
525                 dccp_set_state(sk, DCCP_CLOSED);
526
527                 /* Special case. */
528                 inet_csk_listen_stop(sk);
529
530                 goto adjudge_to_death;
531         }
532
533         /*
534          * We need to flush the recv. buffs.  We do this only on the
535          * descriptor close, not protocol-sourced closes, because the
536           *reader process may not have drained the data yet!
537          */
538         /* FIXME: check for unread data */
539         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
540                 __kfree_skb(skb);
541         }
542
543         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
544                 /* Check zero linger _after_ checking for unread data. */
545                 sk->sk_prot->disconnect(sk, 0);
546         } else if (dccp_close_state(sk)) {
547                 dccp_send_close(sk);
548         }
549
550         sk_stream_wait_close(sk, timeout);
551
552 adjudge_to_death:
553         release_sock(sk);
554         /*
555          * Now socket is owned by kernel and we acquire BH lock
556          * to finish close. No need to check for user refs.
557          */
558         local_bh_disable();
559         bh_lock_sock(sk);
560         BUG_TRAP(!sock_owned_by_user(sk));
561
562         sock_hold(sk);
563         sock_orphan(sk);
564                                                 
565         if (sk->sk_state != DCCP_CLOSED)
566                 dccp_set_state(sk, DCCP_CLOSED);
567
568         atomic_inc(&dccp_orphan_count);
569         if (sk->sk_state == DCCP_CLOSED)
570                 inet_csk_destroy_sock(sk);
571
572         /* Otherwise, socket is reprieved until protocol close. */
573
574         bh_unlock_sock(sk);
575         local_bh_enable();
576         sock_put(sk);
577 }
578
579 void dccp_shutdown(struct sock *sk, int how)
580 {
581         dccp_pr_debug("entry\n");
582 }
583
584 struct proto_ops inet_dccp_ops = {
585         .family         = PF_INET,
586         .owner          = THIS_MODULE,
587         .release        = inet_release,
588         .bind           = inet_bind,
589         .connect        = inet_stream_connect,
590         .socketpair     = sock_no_socketpair,
591         .accept         = inet_accept,
592         .getname        = inet_getname,
593         .poll           = sock_no_poll,
594         .ioctl          = inet_ioctl,
595         .listen         = inet_dccp_listen, /* FIXME: work on inet_listen to rename it to sock_common_listen */
596         .shutdown       = inet_shutdown,
597         .setsockopt     = sock_common_setsockopt,
598         .getsockopt     = sock_common_getsockopt,
599         .sendmsg        = inet_sendmsg,
600         .recvmsg        = sock_common_recvmsg,
601         .mmap           = sock_no_mmap,
602         .sendpage       = sock_no_sendpage,
603 };
604
605 extern struct net_proto_family inet_family_ops;
606
607 static struct inet_protosw dccp_v4_protosw = {
608         .type           = SOCK_DCCP,
609         .protocol       = IPPROTO_DCCP,
610         .prot           = &dccp_v4_prot,
611         .ops            = &inet_dccp_ops,
612         .capability     = -1,
613         .no_check       = 0,
614         .flags          = 0,
615 };
616
617 /*
618  * This is the global socket data structure used for responding to
619  * the Out-of-the-blue (OOTB) packets. A control sock will be created
620  * for this socket at the initialization time.
621  */
622 struct socket *dccp_ctl_socket;
623
624 static char dccp_ctl_socket_err_msg[] __initdata =
625         KERN_ERR "DCCP: Failed to create the control socket.\n";
626
627 static int __init dccp_ctl_sock_init(void)
628 {
629         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
630                                   &dccp_ctl_socket);
631         if (rc < 0)
632                 printk(dccp_ctl_socket_err_msg);
633         else {
634                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
635                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
636
637                 /* Unhash it so that IP input processing does not even
638                  * see it, we do not wish this socket to see incoming
639                  * packets.
640                  */
641                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
642         }
643
644         return rc;
645 }
646
647 static void __exit dccp_ctl_sock_exit(void)
648 {
649         if (dccp_ctl_socket != NULL)
650                 sock_release(dccp_ctl_socket);
651 }
652
653 static int __init init_dccp_v4_mibs(void)
654 {
655         int rc = -ENOMEM;
656
657         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
658         if (dccp_statistics[0] == NULL)
659                 goto out;
660
661         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
662         if (dccp_statistics[1] == NULL)
663                 goto out_free_one;
664
665         rc = 0;
666 out:
667         return rc;
668 out_free_one:
669         free_percpu(dccp_statistics[0]);
670         dccp_statistics[0] = NULL;
671         goto out;
672
673 }
674
675 static int thash_entries;
676 module_param(thash_entries, int, 0444);
677 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
678
679 int dccp_debug;
680 module_param(dccp_debug, int, 0444);
681 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
682
683 static int __init dccp_init(void)
684 {
685         unsigned long goal;
686         int ehash_order, bhash_order, i;
687         int rc = proto_register(&dccp_v4_prot, 1);
688
689         if (rc)
690                 goto out;
691
692         dccp_hashinfo.bind_bucket_cachep = kmem_cache_create("dccp_bind_bucket",
693                                                sizeof(struct inet_bind_bucket),
694                                                0, SLAB_HWCACHE_ALIGN,
695                                                NULL, NULL);
696         if (!dccp_hashinfo.bind_bucket_cachep)
697                 goto out_proto_unregister;
698
699         /*
700          * Size and allocate the main established and bind bucket
701          * hash tables.
702          *
703          * The methodology is similar to that of the buffer cache.
704          */
705         if (num_physpages >= (128 * 1024))
706                 goal = num_physpages >> (21 - PAGE_SHIFT);
707         else
708                 goal = num_physpages >> (23 - PAGE_SHIFT);
709
710         if (thash_entries)
711                 goal = (thash_entries * sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
712         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
713                 ;
714         do {
715                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
716                                         sizeof(struct inet_ehash_bucket);
717                 dccp_hashinfo.ehash_size >>= 1;
718                 while (dccp_hashinfo.ehash_size & (dccp_hashinfo.ehash_size - 1))
719                         dccp_hashinfo.ehash_size--;
720                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
721                         __get_free_pages(GFP_ATOMIC, ehash_order);
722         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
723
724         if (!dccp_hashinfo.ehash) {
725                 printk(KERN_CRIT "Failed to allocate DCCP "
726                                  "established hash table\n");
727                 goto out_free_bind_bucket_cachep;
728         }
729
730         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
731                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
732                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
733         }
734
735         bhash_order = ehash_order;
736
737         do {
738                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
739                                         sizeof(struct inet_bind_hashbucket);
740                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && bhash_order > 0)
741                         continue;
742                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
743                         __get_free_pages(GFP_ATOMIC, bhash_order);
744         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
745
746         if (!dccp_hashinfo.bhash) {
747                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
748                 goto out_free_dccp_ehash;
749         }
750
751         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
752                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
753                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
754         }
755
756         if (init_dccp_v4_mibs())
757                 goto out_free_dccp_bhash;
758
759         rc = -EAGAIN;
760         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
761                 goto out_free_dccp_v4_mibs;
762
763         inet_register_protosw(&dccp_v4_protosw);
764
765         rc = dccp_ctl_sock_init();
766         if (rc)
767                 goto out_unregister_protosw;
768 out:
769         return rc;
770 out_unregister_protosw:
771         inet_unregister_protosw(&dccp_v4_protosw);
772         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
773 out_free_dccp_v4_mibs:
774         free_percpu(dccp_statistics[0]);
775         free_percpu(dccp_statistics[1]);
776         dccp_statistics[0] = dccp_statistics[1] = NULL;
777 out_free_dccp_bhash:
778         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
779         dccp_hashinfo.bhash = NULL;
780 out_free_dccp_ehash:
781         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
782         dccp_hashinfo.ehash = NULL;
783 out_free_bind_bucket_cachep:
784         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
785         dccp_hashinfo.bind_bucket_cachep = NULL;
786 out_proto_unregister:
787         proto_unregister(&dccp_v4_prot);
788         goto out;
789 }
790
791 static const char dccp_del_proto_err_msg[] __exitdata =
792         KERN_ERR "can't remove dccp net_protocol\n";
793
794 static void __exit dccp_fini(void)
795 {
796         dccp_ctl_sock_exit();
797
798         inet_unregister_protosw(&dccp_v4_protosw);
799
800         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
801                 printk(dccp_del_proto_err_msg);
802
803         /* Free the control endpoint.  */
804         sock_release(dccp_ctl_socket);
805
806         proto_unregister(&dccp_v4_prot);
807
808         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
809 }
810
811 module_init(dccp_init);
812 module_exit(dccp_fini);
813
814 /* __stringify doesn't likes enums, so use SOCK_DCCP (6) value directly  */
815 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-6");
816 MODULE_LICENSE("GPL");
817 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
818 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");