6 * An implementation of the DCCP protocol
7 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/config.h>
15 #include <linux/dccp.h>
20 #ifdef CONFIG_IP_DCCP_DEBUG
21 extern int dccp_debug
;
23 #define dccp_pr_debug(format, a...) \
24 do { if (dccp_debug) \
25 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
27 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
28 printk(format, ##a); } while (0)
30 #define dccp_pr_debug(format, a...)
31 #define dccp_pr_debug_cat(format, a...)
34 extern struct inet_hashinfo dccp_hashinfo
;
36 extern atomic_t dccp_orphan_count
;
37 extern int dccp_tw_count
;
38 extern void dccp_tw_deschedule(struct inet_timewait_sock
*tw
);
40 extern void dccp_time_wait(struct sock
*sk
, int state
, int timeo
);
42 /* FIXME: Right size this */
43 #define DCCP_MAX_OPT_LEN 128
45 #define DCCP_MAX_PACKET_HDR 32
47 #define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
49 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
50 * state, about 60 seconds */
52 /* draft-ietf-dccp-spec-11.txt initial RTO value */
53 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
55 /* Maximal interval between probes for local resources. */
56 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
58 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
60 extern struct proto dccp_v4_prot
;
62 /* is seq1 < seq2 ? */
63 static inline const int before48(const u64 seq1
, const u64 seq2
)
65 return (const s64
)((seq1
<< 16) - (seq2
<< 16)) < 0;
68 /* is seq1 > seq2 ? */
69 static inline const int after48(const u64 seq1
, const u64 seq2
)
71 return (const s64
)((seq2
<< 16) - (seq1
<< 16)) < 0;
74 /* is seq2 <= seq1 <= seq3 ? */
75 static inline const int between48(const u64 seq1
, const u64 seq2
,
78 return (seq3
<< 16) - (seq2
<< 16) >= (seq1
<< 16) - (seq2
<< 16);
81 static inline u64
max48(const u64 seq1
, const u64 seq2
)
83 return after48(seq1
, seq2
) ? seq1
: seq2
;
88 DCCP_MIB_ACTIVEOPENS
, /* ActiveOpens */
89 DCCP_MIB_ESTABRESETS
, /* EstabResets */
90 DCCP_MIB_CURRESTAB
, /* CurrEstab */
91 DCCP_MIB_OUTSEGS
, /* OutSegs */
93 DCCP_MIB_ABORTONTIMEOUT
,
96 DCCP_MIB_PASSIVEOPENS
,
97 DCCP_MIB_ATTEMPTFAILS
,
98 DCCP_MIB_OUTDATAGRAMS
,
100 DCCP_MIB_OPTMANDATORYERROR
,
105 #define DCCP_MIB_MAX __DCCP_MIB_MAX
107 unsigned long mibs
[DCCP_MIB_MAX
];
108 } __SNMP_MIB_ALIGN__
;
110 DECLARE_SNMP_STAT(struct dccp_mib
, dccp_statistics
);
111 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
112 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
113 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
114 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
115 #define DCCP_ADD_STATS_BH(field, val) \
116 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
117 #define DCCP_ADD_STATS_USER(field, val) \
118 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
120 extern int dccp_transmit_skb(struct sock
*sk
, struct sk_buff
*skb
);
121 extern int dccp_retransmit_skb(struct sock
*sk
, struct sk_buff
*skb
);
123 extern int dccp_send_response(struct sock
*sk
);
124 extern void dccp_send_ack(struct sock
*sk
);
125 extern void dccp_send_delayed_ack(struct sock
*sk
);
126 extern void dccp_send_sync(struct sock
*sk
, u64 seq
);
128 extern int dccp_write_xmit(struct sock
*sk
, struct sk_buff
*skb
,
131 extern void dccp_init_xmit_timers(struct sock
*sk
);
132 static inline void dccp_clear_xmit_timers(struct sock
*sk
)
134 inet_csk_clear_xmit_timers(sk
);
137 extern unsigned int dccp_sync_mss(struct sock
*sk
, u32 pmtu
);
139 extern const char *dccp_packet_name(const int type
);
140 extern const char *dccp_state_name(const int state
);
142 static inline void dccp_set_state(struct sock
*sk
, const int state
)
144 const int oldstate
= sk
->sk_state
;
146 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
148 dccp_state_name(oldstate
), dccp_state_name(state
));
149 WARN_ON(state
== oldstate
);
153 if (oldstate
!= DCCP_OPEN
)
154 DCCP_INC_STATS(DCCP_MIB_CURRESTAB
);
158 if (oldstate
== DCCP_CLOSING
|| oldstate
== DCCP_OPEN
)
159 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS
);
161 sk
->sk_prot
->unhash(sk
);
162 if (inet_csk(sk
)->icsk_bind_hash
!= NULL
&&
163 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
164 inet_put_port(&dccp_hashinfo
, sk
);
167 if (oldstate
== DCCP_OPEN
)
168 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB
);
171 /* Change state AFTER socket is unhashed to avoid closed
172 * socket sitting in hash tables.
174 sk
->sk_state
= state
;
177 static inline void dccp_done(struct sock
*sk
)
179 dccp_set_state(sk
, DCCP_CLOSED
);
180 dccp_clear_xmit_timers(sk
);
182 sk
->sk_shutdown
= SHUTDOWN_MASK
;
184 if (!sock_flag(sk
, SOCK_DEAD
))
185 sk
->sk_state_change(sk
);
187 inet_csk_destroy_sock(sk
);
190 static inline void dccp_openreq_init(struct request_sock
*req
,
191 struct dccp_sock
*dp
,
195 * FIXME: fill in the other req fields from the DCCP options
198 inet_rsk(req
)->rmt_port
= dccp_hdr(skb
)->dccph_sport
;
199 inet_rsk(req
)->acked
= 0;
203 extern int dccp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
);
205 extern struct sock
*dccp_create_openreq_child(struct sock
*sk
,
206 const struct request_sock
*req
,
207 const struct sk_buff
*skb
);
209 extern int dccp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
);
211 extern void dccp_v4_err(struct sk_buff
*skb
, u32
);
213 extern int dccp_v4_rcv(struct sk_buff
*skb
);
215 extern struct sock
*dccp_v4_request_recv_sock(struct sock
*sk
,
217 struct request_sock
*req
,
218 struct dst_entry
*dst
);
219 extern struct sock
*dccp_check_req(struct sock
*sk
, struct sk_buff
*skb
,
220 struct request_sock
*req
,
221 struct request_sock
**prev
);
223 extern int dccp_child_process(struct sock
*parent
, struct sock
*child
,
224 struct sk_buff
*skb
);
225 extern int dccp_rcv_state_process(struct sock
*sk
, struct sk_buff
*skb
,
226 struct dccp_hdr
*dh
, unsigned len
);
227 extern int dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
228 const struct dccp_hdr
*dh
, const unsigned len
);
230 extern void dccp_close(struct sock
*sk
, long timeout
);
231 extern struct sk_buff
*dccp_make_response(struct sock
*sk
,
232 struct dst_entry
*dst
,
233 struct request_sock
*req
);
234 extern struct sk_buff
*dccp_make_reset(struct sock
*sk
,
235 struct dst_entry
*dst
,
236 enum dccp_reset_codes code
);
238 extern int dccp_connect(struct sock
*sk
);
239 extern int dccp_disconnect(struct sock
*sk
, int flags
);
240 extern int dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
241 char __user
*optval
, int __user
*optlen
);
242 extern int dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
243 char __user
*optval
, int optlen
);
244 extern int dccp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
);
245 extern int dccp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
,
246 struct msghdr
*msg
, size_t size
);
247 extern int dccp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
,
248 struct msghdr
*msg
, size_t len
, int nonblock
,
249 int flags
, int *addr_len
);
250 extern void dccp_shutdown(struct sock
*sk
, int how
);
252 extern int dccp_v4_checksum(const struct sk_buff
*skb
,
253 const u32 saddr
, const u32 daddr
);
255 extern int dccp_v4_send_reset(struct sock
*sk
,
256 enum dccp_reset_codes code
);
257 extern void dccp_send_close(struct sock
*sk
);
261 __u8 dccpd_reset_code
;
269 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
271 static inline int dccp_non_data_packet(const struct sk_buff
*skb
)
273 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
275 return type
== DCCP_PKT_ACK
||
276 type
== DCCP_PKT_CLOSE
||
277 type
== DCCP_PKT_CLOSEREQ
||
278 type
== DCCP_PKT_RESET
||
279 type
== DCCP_PKT_SYNC
||
280 type
== DCCP_PKT_SYNCACK
;
283 static inline int dccp_packet_without_ack(const struct sk_buff
*skb
)
285 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
287 return type
== DCCP_PKT_DATA
|| type
== DCCP_PKT_REQUEST
;
290 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
291 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
293 static inline void dccp_set_seqno(u64
*seqno
, u64 value
)
295 if (value
> DCCP_MAX_SEQNO
)
296 value
-= DCCP_MAX_SEQNO
+ 1;
300 static inline u64
dccp_delta_seqno(u64 seqno1
, u64 seqno2
)
302 return ((seqno2
<< 16) - (seqno1
<< 16)) >> 16;
305 static inline void dccp_inc_seqno(u64
*seqno
)
307 if (++*seqno
> DCCP_MAX_SEQNO
)
311 static inline void dccp_hdr_set_seq(struct dccp_hdr
*dh
, const u64 gss
)
313 struct dccp_hdr_ext
*dhx
= (struct dccp_hdr_ext
*)((void *)dh
+
316 #if defined(__LITTLE_ENDIAN_BITFIELD)
317 dh
->dccph_seq
= htonl((gss
>> 32)) >> 8;
318 #elif defined(__BIG_ENDIAN_BITFIELD)
319 dh
->dccph_seq
= htonl((gss
>> 32));
321 #error "Adjust your <asm/byteorder.h> defines"
323 dhx
->dccph_seq_low
= htonl(gss
& 0xffffffff);
326 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits
*dhack
,
329 #if defined(__LITTLE_ENDIAN_BITFIELD)
330 dhack
->dccph_ack_nr_high
= htonl((gsr
>> 32)) >> 8;
331 #elif defined(__BIG_ENDIAN_BITFIELD)
332 dhack
->dccph_ack_nr_high
= htonl((gsr
>> 32));
334 #error "Adjust your <asm/byteorder.h> defines"
336 dhack
->dccph_ack_nr_low
= htonl(gsr
& 0xffffffff);
339 static inline void dccp_update_gsr(struct sock
*sk
, u64 seq
)
341 struct dccp_sock
*dp
= dccp_sk(sk
);
344 dccp_set_seqno(&tmp_gsr
,
346 (dp
->dccps_options
.dccpo_sequence_window
/ 4)));
348 dccp_set_seqno(&dp
->dccps_swl
, max48(tmp_gsr
, dp
->dccps_isr
));
349 dccp_set_seqno(&dp
->dccps_swh
,
351 (3 * dp
->dccps_options
.dccpo_sequence_window
) / 4));
354 static inline void dccp_update_gss(struct sock
*sk
, u64 seq
)
356 struct dccp_sock
*dp
= dccp_sk(sk
);
359 dccp_set_seqno(&tmp_gss
,
361 dp
->dccps_options
.dccpo_sequence_window
+ 1));
362 dp
->dccps_awl
= max48(tmp_gss
, dp
->dccps_iss
);
363 dp
->dccps_awh
= dp
->dccps_gss
= seq
;
366 extern void dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
);
367 extern void dccp_insert_option_elapsed_time(struct sock
*sk
,
370 extern void dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
371 unsigned char option
,
372 const void *value
, unsigned char len
);
374 extern struct socket
*dccp_ctl_socket
;
376 #define DCCP_ACKPKTS_STATE_RECEIVED 0
377 #define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
378 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
380 #define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
381 #define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
383 /** struct dccp_ackpkts - acknowledgeable packets
385 * This data structure is the one defined in the DCCP draft
388 * @dccpap_buf_head - circular buffer head
389 * @dccpap_buf_tail - circular buffer tail
390 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
391 * buffer (i.e. %dccpap_buf_head)
392 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
393 * by the buffer with State 0
395 * Additionally, the HC-Receiver must keep some information about the
396 * Ack Vectors it has recently sent. For each packet sent carrying an
397 * Ack Vector, it remembers four variables:
399 * @dccpap_ack_seqno - the Sequence Number used for the packet
400 * (HC-Receiver seqno)
401 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
402 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
404 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
406 * @dccpap_buf_len - circular buffer length
407 * @dccpap_buf - circular buffer of acknowledgeable packets
409 struct dccp_ackpkts
{
410 unsigned int dccpap_buf_head
;
411 unsigned int dccpap_buf_tail
;
412 u64 dccpap_buf_ackno
;
413 u64 dccpap_ack_seqno
;
414 u64 dccpap_ack_ackno
;
415 unsigned int dccpap_ack_ptr
;
416 unsigned int dccpap_buf_vector_len
;
417 unsigned int dccpap_ack_vector_len
;
418 unsigned int dccpap_buf_len
;
419 unsigned long dccpap_time
;
425 extern struct dccp_ackpkts
*
426 dccp_ackpkts_alloc(unsigned int len
,
427 const unsigned int __nocast priority
);
428 extern void dccp_ackpkts_free(struct dccp_ackpkts
*ap
);
429 extern int dccp_ackpkts_add(struct dccp_ackpkts
*ap
, u64 ackno
, u8 state
);
430 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts
*ap
,
431 struct sock
*sk
, u64 ackno
);
433 #ifdef CONFIG_IP_DCCP_DEBUG
434 extern void dccp_ackvector_print(const u64 ackno
,
435 const unsigned char *vector
, int len
);
436 extern void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
);
438 static inline void dccp_ackvector_print(const u64 ackno
,
439 const unsigned char *vector
,
441 static inline void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
) { }