4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
12 #include <linux/dccp.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/skbuff.h>
18 #include <linux/netdevice.h>
20 #include <linux/if_arp.h>
21 #include <linux/init.h>
22 #include <linux/random.h>
23 #include <linux/slab.h>
24 #include <net/checksum.h>
26 #include <net/inet_sock.h>
30 #include <asm/ioctls.h>
31 #include <linux/spinlock.h>
32 #include <linux/timer.h>
33 #include <linux/delay.h>
34 #include <linux/poll.h>
40 DEFINE_SNMP_STAT(struct dccp_mib
, dccp_statistics
) __read_mostly
;
42 EXPORT_SYMBOL_GPL(dccp_statistics
);
44 struct percpu_counter dccp_orphan_count
;
45 EXPORT_SYMBOL_GPL(dccp_orphan_count
);
47 struct inet_hashinfo dccp_hashinfo
;
48 EXPORT_SYMBOL_GPL(dccp_hashinfo
);
50 /* the maximum queue length for tx in packets. 0 is no limit */
51 int sysctl_dccp_tx_qlen __read_mostly
= 5;
53 #ifdef CONFIG_IP_DCCP_DEBUG
54 static const char *dccp_state_name(const int state
)
56 static const char *const dccp_state_names
[] = {
58 [DCCP_REQUESTING
] = "REQUESTING",
59 [DCCP_PARTOPEN
] = "PARTOPEN",
60 [DCCP_LISTEN
] = "LISTEN",
61 [DCCP_RESPOND
] = "RESPOND",
62 [DCCP_CLOSING
] = "CLOSING",
63 [DCCP_ACTIVE_CLOSEREQ
] = "CLOSEREQ",
64 [DCCP_PASSIVE_CLOSE
] = "PASSIVE_CLOSE",
65 [DCCP_PASSIVE_CLOSEREQ
] = "PASSIVE_CLOSEREQ",
66 [DCCP_TIME_WAIT
] = "TIME_WAIT",
67 [DCCP_CLOSED
] = "CLOSED",
70 if (state
>= DCCP_MAX_STATES
)
71 return "INVALID STATE!";
73 return dccp_state_names
[state
];
77 void dccp_set_state(struct sock
*sk
, const int state
)
79 const int oldstate
= sk
->sk_state
;
81 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk
), sk
,
82 dccp_state_name(oldstate
), dccp_state_name(state
));
83 WARN_ON(state
== oldstate
);
87 if (oldstate
!= DCCP_OPEN
)
88 DCCP_INC_STATS(DCCP_MIB_CURRESTAB
);
89 /* Client retransmits all Confirm options until entering OPEN */
90 if (oldstate
== DCCP_PARTOPEN
)
91 dccp_feat_list_purge(&dccp_sk(sk
)->dccps_featneg
);
95 if (oldstate
== DCCP_OPEN
|| oldstate
== DCCP_ACTIVE_CLOSEREQ
||
96 oldstate
== DCCP_CLOSING
)
97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS
);
99 sk
->sk_prot
->unhash(sk
);
100 if (inet_csk(sk
)->icsk_bind_hash
!= NULL
&&
101 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
105 if (oldstate
== DCCP_OPEN
)
106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB
);
109 /* Change state AFTER socket is unhashed to avoid closed
110 * socket sitting in hash tables.
112 sk
->sk_state
= state
;
115 EXPORT_SYMBOL_GPL(dccp_set_state
);
117 static void dccp_finish_passive_close(struct sock
*sk
)
119 switch (sk
->sk_state
) {
120 case DCCP_PASSIVE_CLOSE
:
121 /* Node (client or server) has received Close packet. */
122 dccp_send_reset(sk
, DCCP_RESET_CODE_CLOSED
);
123 dccp_set_state(sk
, DCCP_CLOSED
);
125 case DCCP_PASSIVE_CLOSEREQ
:
127 * Client received CloseReq. We set the `active' flag so that
128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
130 dccp_send_close(sk
, 1);
131 dccp_set_state(sk
, DCCP_CLOSING
);
135 void dccp_done(struct sock
*sk
)
137 dccp_set_state(sk
, DCCP_CLOSED
);
138 dccp_clear_xmit_timers(sk
);
140 sk
->sk_shutdown
= SHUTDOWN_MASK
;
142 if (!sock_flag(sk
, SOCK_DEAD
))
143 sk
->sk_state_change(sk
);
145 inet_csk_destroy_sock(sk
);
148 EXPORT_SYMBOL_GPL(dccp_done
);
150 const char *dccp_packet_name(const int type
)
152 static const char *const dccp_packet_names
[] = {
153 [DCCP_PKT_REQUEST
] = "REQUEST",
154 [DCCP_PKT_RESPONSE
] = "RESPONSE",
155 [DCCP_PKT_DATA
] = "DATA",
156 [DCCP_PKT_ACK
] = "ACK",
157 [DCCP_PKT_DATAACK
] = "DATAACK",
158 [DCCP_PKT_CLOSEREQ
] = "CLOSEREQ",
159 [DCCP_PKT_CLOSE
] = "CLOSE",
160 [DCCP_PKT_RESET
] = "RESET",
161 [DCCP_PKT_SYNC
] = "SYNC",
162 [DCCP_PKT_SYNCACK
] = "SYNCACK",
165 if (type
>= DCCP_NR_PKT_TYPES
)
168 return dccp_packet_names
[type
];
171 EXPORT_SYMBOL_GPL(dccp_packet_name
);
173 int dccp_init_sock(struct sock
*sk
, const __u8 ctl_sock_initialized
)
175 struct dccp_sock
*dp
= dccp_sk(sk
);
176 struct inet_connection_sock
*icsk
= inet_csk(sk
);
178 icsk
->icsk_rto
= DCCP_TIMEOUT_INIT
;
179 icsk
->icsk_syn_retries
= sysctl_dccp_request_retries
;
180 sk
->sk_state
= DCCP_CLOSED
;
181 sk
->sk_write_space
= dccp_write_space
;
182 icsk
->icsk_sync_mss
= dccp_sync_mss
;
183 dp
->dccps_mss_cache
= 536;
184 dp
->dccps_rate_last
= jiffies
;
185 dp
->dccps_role
= DCCP_ROLE_UNDEFINED
;
186 dp
->dccps_service
= DCCP_SERVICE_CODE_IS_ABSENT
;
187 dp
->dccps_l_ack_ratio
= dp
->dccps_r_ack_ratio
= 1;
189 dccp_init_xmit_timers(sk
);
191 INIT_LIST_HEAD(&dp
->dccps_featneg
);
192 /* control socket doesn't need feat nego */
193 if (likely(ctl_sock_initialized
))
194 return dccp_feat_init(sk
);
198 EXPORT_SYMBOL_GPL(dccp_init_sock
);
200 void dccp_destroy_sock(struct sock
*sk
)
202 struct dccp_sock
*dp
= dccp_sk(sk
);
205 * DCCP doesn't use sk_write_queue, just sk_send_head
206 * for retransmissions
208 if (sk
->sk_send_head
!= NULL
) {
209 kfree_skb(sk
->sk_send_head
);
210 sk
->sk_send_head
= NULL
;
213 /* Clean up a referenced DCCP bind bucket. */
214 if (inet_csk(sk
)->icsk_bind_hash
!= NULL
)
217 kfree(dp
->dccps_service_list
);
218 dp
->dccps_service_list
= NULL
;
220 if (dp
->dccps_hc_rx_ackvec
!= NULL
) {
221 dccp_ackvec_free(dp
->dccps_hc_rx_ackvec
);
222 dp
->dccps_hc_rx_ackvec
= NULL
;
224 ccid_hc_rx_delete(dp
->dccps_hc_rx_ccid
, sk
);
225 ccid_hc_tx_delete(dp
->dccps_hc_tx_ccid
, sk
);
226 dp
->dccps_hc_rx_ccid
= dp
->dccps_hc_tx_ccid
= NULL
;
228 /* clean up feature negotiation state */
229 dccp_feat_list_purge(&dp
->dccps_featneg
);
232 EXPORT_SYMBOL_GPL(dccp_destroy_sock
);
234 static inline int dccp_listen_start(struct sock
*sk
, int backlog
)
236 struct dccp_sock
*dp
= dccp_sk(sk
);
238 dp
->dccps_role
= DCCP_ROLE_LISTEN
;
239 /* do not start to listen if feature negotiation setup fails */
240 if (dccp_feat_finalise_settings(dp
))
242 return inet_csk_listen_start(sk
, backlog
);
245 static inline int dccp_need_reset(int state
)
247 return state
!= DCCP_CLOSED
&& state
!= DCCP_LISTEN
&&
248 state
!= DCCP_REQUESTING
;
251 int dccp_disconnect(struct sock
*sk
, int flags
)
253 struct inet_connection_sock
*icsk
= inet_csk(sk
);
254 struct inet_sock
*inet
= inet_sk(sk
);
256 const int old_state
= sk
->sk_state
;
258 if (old_state
!= DCCP_CLOSED
)
259 dccp_set_state(sk
, DCCP_CLOSED
);
262 * This corresponds to the ABORT function of RFC793, sec. 3.8
263 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
265 if (old_state
== DCCP_LISTEN
) {
266 inet_csk_listen_stop(sk
);
267 } else if (dccp_need_reset(old_state
)) {
268 dccp_send_reset(sk
, DCCP_RESET_CODE_ABORTED
);
269 sk
->sk_err
= ECONNRESET
;
270 } else if (old_state
== DCCP_REQUESTING
)
271 sk
->sk_err
= ECONNRESET
;
273 dccp_clear_xmit_timers(sk
);
275 __skb_queue_purge(&sk
->sk_receive_queue
);
276 __skb_queue_purge(&sk
->sk_write_queue
);
277 if (sk
->sk_send_head
!= NULL
) {
278 __kfree_skb(sk
->sk_send_head
);
279 sk
->sk_send_head
= NULL
;
282 inet
->inet_dport
= 0;
284 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
285 inet_reset_saddr(sk
);
288 sock_reset_flag(sk
, SOCK_DONE
);
290 icsk
->icsk_backoff
= 0;
291 inet_csk_delack_init(sk
);
294 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
296 sk
->sk_error_report(sk
);
300 EXPORT_SYMBOL_GPL(dccp_disconnect
);
303 * Wait for a DCCP event.
305 * Note that we don't need to lock the socket, as the upper poll layers
306 * take care of normal races (between the test and the event) and we don't
307 * go look at any of the socket buffers directly.
309 unsigned int dccp_poll(struct file
*file
, struct socket
*sock
,
313 struct sock
*sk
= sock
->sk
;
315 sock_poll_wait(file
, sk_sleep(sk
), wait
);
316 if (sk
->sk_state
== DCCP_LISTEN
)
317 return inet_csk_listen_poll(sk
);
319 /* Socket is not locked. We are protected from async events
320 by poll logic and correct handling of state changes
321 made by another threads is impossible in any case.
328 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== DCCP_CLOSED
)
330 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
331 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
334 if ((1 << sk
->sk_state
) & ~(DCCPF_REQUESTING
| DCCPF_RESPOND
)) {
335 if (atomic_read(&sk
->sk_rmem_alloc
) > 0)
336 mask
|= POLLIN
| POLLRDNORM
;
338 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
339 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
)) {
340 mask
|= POLLOUT
| POLLWRNORM
;
341 } else { /* send SIGIO later */
342 set_bit(SOCK_ASYNC_NOSPACE
,
343 &sk
->sk_socket
->flags
);
344 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
346 /* Race breaker. If space is freed after
347 * wspace test but before the flags are set,
348 * IO signal will be lost.
350 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
))
351 mask
|= POLLOUT
| POLLWRNORM
;
358 EXPORT_SYMBOL_GPL(dccp_poll
);
360 int dccp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
366 if (sk
->sk_state
== DCCP_LISTEN
)
372 unsigned long amount
= 0;
374 skb
= skb_peek(&sk
->sk_receive_queue
);
377 * We will only return the amount of this packet since
378 * that is all that will be read.
382 rc
= put_user(amount
, (int __user
*)arg
);
394 EXPORT_SYMBOL_GPL(dccp_ioctl
);
396 static int dccp_setsockopt_service(struct sock
*sk
, const __be32 service
,
397 char __user
*optval
, unsigned int optlen
)
399 struct dccp_sock
*dp
= dccp_sk(sk
);
400 struct dccp_service_list
*sl
= NULL
;
402 if (service
== DCCP_SERVICE_INVALID_VALUE
||
403 optlen
> DCCP_SERVICE_LIST_MAX_LEN
* sizeof(u32
))
406 if (optlen
> sizeof(service
)) {
407 sl
= kmalloc(optlen
, GFP_KERNEL
);
411 sl
->dccpsl_nr
= optlen
/ sizeof(u32
) - 1;
412 if (copy_from_user(sl
->dccpsl_list
,
413 optval
+ sizeof(service
),
414 optlen
- sizeof(service
)) ||
415 dccp_list_has_service(sl
, DCCP_SERVICE_INVALID_VALUE
)) {
422 dp
->dccps_service
= service
;
424 kfree(dp
->dccps_service_list
);
426 dp
->dccps_service_list
= sl
;
431 static int dccp_setsockopt_cscov(struct sock
*sk
, int cscov
, bool rx
)
436 if (cscov
< 0 || cscov
> 15)
439 * Populate a list of permissible values, in the range cscov...15. This
440 * is necessary since feature negotiation of single values only works if
441 * both sides incidentally choose the same value. Since the list starts
442 * lowest-value first, negotiation will pick the smallest shared value.
448 list
= kmalloc(len
, GFP_KERNEL
);
452 for (i
= 0; i
< len
; i
++)
455 rc
= dccp_feat_register_sp(sk
, DCCPF_MIN_CSUM_COVER
, rx
, list
, len
);
459 dccp_sk(sk
)->dccps_pcrlen
= cscov
;
461 dccp_sk(sk
)->dccps_pcslen
= cscov
;
467 static int dccp_setsockopt_ccid(struct sock
*sk
, int type
,
468 char __user
*optval
, unsigned int optlen
)
473 if (optlen
< 1 || optlen
> DCCP_FEAT_MAX_SP_VALS
)
476 val
= memdup_user(optval
, optlen
);
481 if (type
== DCCP_SOCKOPT_TX_CCID
|| type
== DCCP_SOCKOPT_CCID
)
482 rc
= dccp_feat_register_sp(sk
, DCCPF_CCID
, 1, val
, optlen
);
484 if (!rc
&& (type
== DCCP_SOCKOPT_RX_CCID
|| type
== DCCP_SOCKOPT_CCID
))
485 rc
= dccp_feat_register_sp(sk
, DCCPF_CCID
, 0, val
, optlen
);
492 static int do_dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
493 char __user
*optval
, unsigned int optlen
)
495 struct dccp_sock
*dp
= dccp_sk(sk
);
499 case DCCP_SOCKOPT_PACKET_SIZE
:
500 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
502 case DCCP_SOCKOPT_CHANGE_L
:
503 case DCCP_SOCKOPT_CHANGE_R
:
504 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
506 case DCCP_SOCKOPT_CCID
:
507 case DCCP_SOCKOPT_RX_CCID
:
508 case DCCP_SOCKOPT_TX_CCID
:
509 return dccp_setsockopt_ccid(sk
, optname
, optval
, optlen
);
512 if (optlen
< (int)sizeof(int))
515 if (get_user(val
, (int __user
*)optval
))
518 if (optname
== DCCP_SOCKOPT_SERVICE
)
519 return dccp_setsockopt_service(sk
, val
, optval
, optlen
);
523 case DCCP_SOCKOPT_SERVER_TIMEWAIT
:
524 if (dp
->dccps_role
!= DCCP_ROLE_SERVER
)
527 dp
->dccps_server_timewait
= (val
!= 0);
529 case DCCP_SOCKOPT_SEND_CSCOV
:
530 err
= dccp_setsockopt_cscov(sk
, val
, false);
532 case DCCP_SOCKOPT_RECV_CSCOV
:
533 err
= dccp_setsockopt_cscov(sk
, val
, true);
544 int dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
545 char __user
*optval
, unsigned int optlen
)
547 if (level
!= SOL_DCCP
)
548 return inet_csk(sk
)->icsk_af_ops
->setsockopt(sk
, level
,
551 return do_dccp_setsockopt(sk
, level
, optname
, optval
, optlen
);
554 EXPORT_SYMBOL_GPL(dccp_setsockopt
);
557 int compat_dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
558 char __user
*optval
, unsigned int optlen
)
560 if (level
!= SOL_DCCP
)
561 return inet_csk_compat_setsockopt(sk
, level
, optname
,
563 return do_dccp_setsockopt(sk
, level
, optname
, optval
, optlen
);
566 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt
);
569 static int dccp_getsockopt_service(struct sock
*sk
, int len
,
570 __be32 __user
*optval
,
573 const struct dccp_sock
*dp
= dccp_sk(sk
);
574 const struct dccp_service_list
*sl
;
575 int err
= -ENOENT
, slen
= 0, total_len
= sizeof(u32
);
578 if ((sl
= dp
->dccps_service_list
) != NULL
) {
579 slen
= sl
->dccpsl_nr
* sizeof(u32
);
588 if (put_user(total_len
, optlen
) ||
589 put_user(dp
->dccps_service
, optval
) ||
590 (sl
!= NULL
&& copy_to_user(optval
+ 1, sl
->dccpsl_list
, slen
)))
597 static int do_dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
598 char __user
*optval
, int __user
*optlen
)
600 struct dccp_sock
*dp
;
603 if (get_user(len
, optlen
))
606 if (len
< (int)sizeof(int))
612 case DCCP_SOCKOPT_PACKET_SIZE
:
613 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
615 case DCCP_SOCKOPT_SERVICE
:
616 return dccp_getsockopt_service(sk
, len
,
617 (__be32 __user
*)optval
, optlen
);
618 case DCCP_SOCKOPT_GET_CUR_MPS
:
619 val
= dp
->dccps_mss_cache
;
621 case DCCP_SOCKOPT_AVAILABLE_CCIDS
:
622 return ccid_getsockopt_builtin_ccids(sk
, len
, optval
, optlen
);
623 case DCCP_SOCKOPT_TX_CCID
:
624 val
= ccid_get_current_tx_ccid(dp
);
628 case DCCP_SOCKOPT_RX_CCID
:
629 val
= ccid_get_current_rx_ccid(dp
);
633 case DCCP_SOCKOPT_SERVER_TIMEWAIT
:
634 val
= dp
->dccps_server_timewait
;
636 case DCCP_SOCKOPT_SEND_CSCOV
:
637 val
= dp
->dccps_pcslen
;
639 case DCCP_SOCKOPT_RECV_CSCOV
:
640 val
= dp
->dccps_pcrlen
;
643 return ccid_hc_rx_getsockopt(dp
->dccps_hc_rx_ccid
, sk
, optname
,
644 len
, (u32 __user
*)optval
, optlen
);
646 return ccid_hc_tx_getsockopt(dp
->dccps_hc_tx_ccid
, sk
, optname
,
647 len
, (u32 __user
*)optval
, optlen
);
653 if (put_user(len
, optlen
) || copy_to_user(optval
, &val
, len
))
659 int dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
660 char __user
*optval
, int __user
*optlen
)
662 if (level
!= SOL_DCCP
)
663 return inet_csk(sk
)->icsk_af_ops
->getsockopt(sk
, level
,
666 return do_dccp_getsockopt(sk
, level
, optname
, optval
, optlen
);
669 EXPORT_SYMBOL_GPL(dccp_getsockopt
);
672 int compat_dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
673 char __user
*optval
, int __user
*optlen
)
675 if (level
!= SOL_DCCP
)
676 return inet_csk_compat_getsockopt(sk
, level
, optname
,
678 return do_dccp_getsockopt(sk
, level
, optname
, optval
, optlen
);
681 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt
);
684 int dccp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
687 const struct dccp_sock
*dp
= dccp_sk(sk
);
688 const int flags
= msg
->msg_flags
;
689 const int noblock
= flags
& MSG_DONTWAIT
;
694 if (len
> dp
->dccps_mss_cache
)
699 if (sysctl_dccp_tx_qlen
&&
700 (sk
->sk_write_queue
.qlen
>= sysctl_dccp_tx_qlen
)) {
705 timeo
= sock_sndtimeo(sk
, noblock
);
708 * We have to use sk_stream_wait_connect here to set sk_write_pending,
709 * so that the trick in dccp_rcv_request_sent_state_process.
711 /* Wait for a connection to finish. */
712 if ((1 << sk
->sk_state
) & ~(DCCPF_OPEN
| DCCPF_PARTOPEN
))
713 if ((rc
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
716 size
= sk
->sk_prot
->max_header
+ len
;
718 skb
= sock_alloc_send_skb(sk
, size
, noblock
, &rc
);
723 skb_reserve(skb
, sk
->sk_prot
->max_header
);
724 rc
= memcpy_fromiovec(skb_put(skb
, len
), msg
->msg_iov
, len
);
728 skb_queue_tail(&sk
->sk_write_queue
, skb
);
730 * The xmit_timer is set if the TX CCID is rate-based and will expire
731 * when congestion control permits to release further packets into the
732 * network. Window-based CCIDs do not use this timer.
734 if (!timer_pending(&dp
->dccps_xmit_timer
))
744 EXPORT_SYMBOL_GPL(dccp_sendmsg
);
746 int dccp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
747 size_t len
, int nonblock
, int flags
, int *addr_len
)
749 const struct dccp_hdr
*dh
;
754 if (sk
->sk_state
== DCCP_LISTEN
) {
759 timeo
= sock_rcvtimeo(sk
, nonblock
);
762 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
765 goto verify_sock_status
;
769 switch (dh
->dccph_type
) {
771 case DCCP_PKT_DATAACK
:
775 case DCCP_PKT_CLOSEREQ
:
776 if (!(flags
& MSG_PEEK
))
777 dccp_finish_passive_close(sk
);
780 dccp_pr_debug("found fin (%s) ok!\n",
781 dccp_packet_name(dh
->dccph_type
));
785 dccp_pr_debug("packet_type=%s\n",
786 dccp_packet_name(dh
->dccph_type
));
787 sk_eat_skb(sk
, skb
, 0);
790 if (sock_flag(sk
, SOCK_DONE
)) {
796 len
= sock_error(sk
);
800 if (sk
->sk_shutdown
& RCV_SHUTDOWN
) {
805 if (sk
->sk_state
== DCCP_CLOSED
) {
806 if (!sock_flag(sk
, SOCK_DONE
)) {
807 /* This occurs when user tries to read
808 * from never connected socket.
822 if (signal_pending(current
)) {
823 len
= sock_intr_errno(timeo
);
827 sk_wait_data(sk
, &timeo
);
832 else if (len
< skb
->len
)
833 msg
->msg_flags
|= MSG_TRUNC
;
835 if (skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, len
)) {
836 /* Exception. Bailout! */
840 if (flags
& MSG_TRUNC
)
843 if (!(flags
& MSG_PEEK
))
844 sk_eat_skb(sk
, skb
, 0);
852 EXPORT_SYMBOL_GPL(dccp_recvmsg
);
854 int inet_dccp_listen(struct socket
*sock
, int backlog
)
856 struct sock
*sk
= sock
->sk
;
857 unsigned char old_state
;
863 if (sock
->state
!= SS_UNCONNECTED
|| sock
->type
!= SOCK_DCCP
)
866 old_state
= sk
->sk_state
;
867 if (!((1 << old_state
) & (DCCPF_CLOSED
| DCCPF_LISTEN
)))
870 /* Really, if the socket is already in listen state
871 * we can only allow the backlog to be adjusted.
873 if (old_state
!= DCCP_LISTEN
) {
875 * FIXME: here it probably should be sk->sk_prot->listen_start
876 * see tcp_listen_start
878 err
= dccp_listen_start(sk
, backlog
);
882 sk
->sk_max_ack_backlog
= backlog
;
890 EXPORT_SYMBOL_GPL(inet_dccp_listen
);
892 static void dccp_terminate_connection(struct sock
*sk
)
894 u8 next_state
= DCCP_CLOSED
;
896 switch (sk
->sk_state
) {
897 case DCCP_PASSIVE_CLOSE
:
898 case DCCP_PASSIVE_CLOSEREQ
:
899 dccp_finish_passive_close(sk
);
902 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk
);
903 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_DACK
);
906 dccp_send_close(sk
, 1);
908 if (dccp_sk(sk
)->dccps_role
== DCCP_ROLE_SERVER
&&
909 !dccp_sk(sk
)->dccps_server_timewait
)
910 next_state
= DCCP_ACTIVE_CLOSEREQ
;
912 next_state
= DCCP_CLOSING
;
915 dccp_set_state(sk
, next_state
);
919 void dccp_close(struct sock
*sk
, long timeout
)
921 struct dccp_sock
*dp
= dccp_sk(sk
);
923 u32 data_was_unread
= 0;
928 sk
->sk_shutdown
= SHUTDOWN_MASK
;
930 if (sk
->sk_state
== DCCP_LISTEN
) {
931 dccp_set_state(sk
, DCCP_CLOSED
);
934 inet_csk_listen_stop(sk
);
936 goto adjudge_to_death
;
939 sk_stop_timer(sk
, &dp
->dccps_xmit_timer
);
942 * We need to flush the recv. buffs. We do this only on the
943 * descriptor close, not protocol-sourced closes, because the
944 *reader process may not have drained the data yet!
946 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
947 data_was_unread
+= skb
->len
;
951 if (data_was_unread
) {
952 /* Unread data was tossed, send an appropriate Reset Code */
953 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread
);
954 dccp_send_reset(sk
, DCCP_RESET_CODE_ABORTED
);
955 dccp_set_state(sk
, DCCP_CLOSED
);
956 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
957 /* Check zero linger _after_ checking for unread data. */
958 sk
->sk_prot
->disconnect(sk
, 0);
959 } else if (sk
->sk_state
!= DCCP_CLOSED
) {
961 * Normal connection termination. May need to wait if there are
962 * still packets in the TX queue that are delayed by the CCID.
964 dccp_flush_write_queue(sk
, &timeout
);
965 dccp_terminate_connection(sk
);
969 * Flush write queue. This may be necessary in several cases:
970 * - we have been closed by the peer but still have application data;
971 * - abortive termination (unread data or zero linger time),
972 * - normal termination but queue could not be flushed within time limit
974 __skb_queue_purge(&sk
->sk_write_queue
);
976 sk_stream_wait_close(sk
, timeout
);
979 state
= sk
->sk_state
;
984 * It is the last release_sock in its life. It will remove backlog.
988 * Now socket is owned by kernel and we acquire BH lock
989 * to finish close. No need to check for user refs.
993 WARN_ON(sock_owned_by_user(sk
));
995 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
997 /* Have we already been destroyed by a softirq or backlog? */
998 if (state
!= DCCP_CLOSED
&& sk
->sk_state
== DCCP_CLOSED
)
1001 if (sk
->sk_state
== DCCP_CLOSED
)
1002 inet_csk_destroy_sock(sk
);
1004 /* Otherwise, socket is reprieved until protocol close. */
1012 EXPORT_SYMBOL_GPL(dccp_close
);
1014 void dccp_shutdown(struct sock
*sk
, int how
)
1016 dccp_pr_debug("called shutdown(%x)\n", how
);
1019 EXPORT_SYMBOL_GPL(dccp_shutdown
);
1021 static inline int dccp_mib_init(void)
1023 return snmp_mib_init((void __percpu
**)dccp_statistics
,
1024 sizeof(struct dccp_mib
),
1025 __alignof__(struct dccp_mib
));
1028 static inline void dccp_mib_exit(void)
1030 snmp_mib_free((void __percpu
**)dccp_statistics
);
1033 static int thash_entries
;
1034 module_param(thash_entries
, int, 0444);
1035 MODULE_PARM_DESC(thash_entries
, "Number of ehash buckets");
1037 #ifdef CONFIG_IP_DCCP_DEBUG
1039 module_param(dccp_debug
, bool, 0644);
1040 MODULE_PARM_DESC(dccp_debug
, "Enable debug messages");
1042 EXPORT_SYMBOL_GPL(dccp_debug
);
1045 static int __init
dccp_init(void)
1048 int ehash_order
, bhash_order
, i
;
1051 BUILD_BUG_ON(sizeof(struct dccp_skb_cb
) >
1052 FIELD_SIZEOF(struct sk_buff
, cb
));
1053 rc
= percpu_counter_init(&dccp_orphan_count
, 0);
1057 inet_hashinfo_init(&dccp_hashinfo
);
1058 dccp_hashinfo
.bind_bucket_cachep
=
1059 kmem_cache_create("dccp_bind_bucket",
1060 sizeof(struct inet_bind_bucket
), 0,
1061 SLAB_HWCACHE_ALIGN
, NULL
);
1062 if (!dccp_hashinfo
.bind_bucket_cachep
)
1063 goto out_free_percpu
;
1066 * Size and allocate the main established and bind bucket
1069 * The methodology is similar to that of the buffer cache.
1071 if (totalram_pages
>= (128 * 1024))
1072 goal
= totalram_pages
>> (21 - PAGE_SHIFT
);
1074 goal
= totalram_pages
>> (23 - PAGE_SHIFT
);
1077 goal
= (thash_entries
*
1078 sizeof(struct inet_ehash_bucket
)) >> PAGE_SHIFT
;
1079 for (ehash_order
= 0; (1UL << ehash_order
) < goal
; ehash_order
++)
1082 unsigned long hash_size
= (1UL << ehash_order
) * PAGE_SIZE
/
1083 sizeof(struct inet_ehash_bucket
);
1085 while (hash_size
& (hash_size
- 1))
1087 dccp_hashinfo
.ehash_mask
= hash_size
- 1;
1088 dccp_hashinfo
.ehash
= (struct inet_ehash_bucket
*)
1089 __get_free_pages(GFP_ATOMIC
|__GFP_NOWARN
, ehash_order
);
1090 } while (!dccp_hashinfo
.ehash
&& --ehash_order
> 0);
1092 if (!dccp_hashinfo
.ehash
) {
1093 DCCP_CRIT("Failed to allocate DCCP established hash table");
1094 goto out_free_bind_bucket_cachep
;
1097 for (i
= 0; i
<= dccp_hashinfo
.ehash_mask
; i
++) {
1098 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo
.ehash
[i
].chain
, i
);
1099 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo
.ehash
[i
].twchain
, i
);
1102 if (inet_ehash_locks_alloc(&dccp_hashinfo
))
1103 goto out_free_dccp_ehash
;
1105 bhash_order
= ehash_order
;
1108 dccp_hashinfo
.bhash_size
= (1UL << bhash_order
) * PAGE_SIZE
/
1109 sizeof(struct inet_bind_hashbucket
);
1110 if ((dccp_hashinfo
.bhash_size
> (64 * 1024)) &&
1113 dccp_hashinfo
.bhash
= (struct inet_bind_hashbucket
*)
1114 __get_free_pages(GFP_ATOMIC
|__GFP_NOWARN
, bhash_order
);
1115 } while (!dccp_hashinfo
.bhash
&& --bhash_order
>= 0);
1117 if (!dccp_hashinfo
.bhash
) {
1118 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1119 goto out_free_dccp_locks
;
1122 for (i
= 0; i
< dccp_hashinfo
.bhash_size
; i
++) {
1123 spin_lock_init(&dccp_hashinfo
.bhash
[i
].lock
);
1124 INIT_HLIST_HEAD(&dccp_hashinfo
.bhash
[i
].chain
);
1127 rc
= dccp_mib_init();
1129 goto out_free_dccp_bhash
;
1131 rc
= dccp_ackvec_init();
1133 goto out_free_dccp_mib
;
1135 rc
= dccp_sysctl_init();
1137 goto out_ackvec_exit
;
1139 rc
= ccid_initialize_builtins();
1141 goto out_sysctl_exit
;
1143 dccp_timestamping_init();
1153 out_free_dccp_bhash
:
1154 free_pages((unsigned long)dccp_hashinfo
.bhash
, bhash_order
);
1155 out_free_dccp_locks
:
1156 inet_ehash_locks_free(&dccp_hashinfo
);
1157 out_free_dccp_ehash
:
1158 free_pages((unsigned long)dccp_hashinfo
.ehash
, ehash_order
);
1159 out_free_bind_bucket_cachep
:
1160 kmem_cache_destroy(dccp_hashinfo
.bind_bucket_cachep
);
1162 percpu_counter_destroy(&dccp_orphan_count
);
1164 dccp_hashinfo
.bhash
= NULL
;
1165 dccp_hashinfo
.ehash
= NULL
;
1166 dccp_hashinfo
.bind_bucket_cachep
= NULL
;
1170 static void __exit
dccp_fini(void)
1172 ccid_cleanup_builtins();
1174 free_pages((unsigned long)dccp_hashinfo
.bhash
,
1175 get_order(dccp_hashinfo
.bhash_size
*
1176 sizeof(struct inet_bind_hashbucket
)));
1177 free_pages((unsigned long)dccp_hashinfo
.ehash
,
1178 get_order((dccp_hashinfo
.ehash_mask
+ 1) *
1179 sizeof(struct inet_ehash_bucket
)));
1180 inet_ehash_locks_free(&dccp_hashinfo
);
1181 kmem_cache_destroy(dccp_hashinfo
.bind_bucket_cachep
);
1184 percpu_counter_destroy(&dccp_orphan_count
);
1187 module_init(dccp_init
);
1188 module_exit(dccp_fini
);
1190 MODULE_LICENSE("GPL");
1191 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1192 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");