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Linux kernel mirror (for testing)
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linux
1#ifndef _DCCP_H
2#define _DCCP_H
3/*
4 * net/dccp/dccp.h
5 *
6 * An implementation of the DCCP protocol
7 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
8 * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/config.h>
16#include <linux/dccp.h>
17#include <net/snmp.h>
18#include <net/sock.h>
19#include <net/tcp.h>
20
21#ifdef CONFIG_IP_DCCP_DEBUG
22extern int dccp_debug;
23
24#define dccp_pr_debug(format, a...) \
25 do { if (dccp_debug) \
26 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
27 } while (0)
28#define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
29 printk(format, ##a); } while (0)
30#else
31#define dccp_pr_debug(format, a...)
32#define dccp_pr_debug_cat(format, a...)
33#endif
34
35extern struct inet_hashinfo dccp_hashinfo;
36
37extern atomic_t dccp_orphan_count;
38extern int dccp_tw_count;
39extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
40
41extern void dccp_time_wait(struct sock *sk, int state, int timeo);
42
43/* FIXME: Right size this */
44#define DCCP_MAX_OPT_LEN 128
45
46#define DCCP_MAX_PACKET_HDR 32
47
48#define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
49
50#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
51 * state, about 60 seconds */
52
53/* draft-ietf-dccp-spec-11.txt initial RTO value */
54#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
55
56/* Maximal interval between probes for local resources. */
57#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
58
59#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
60
61extern struct proto dccp_v4_prot;
62
63/* is seq1 < seq2 ? */
64static inline int before48(const u64 seq1, const u64 seq2)
65{
66 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
67}
68
69/* is seq1 > seq2 ? */
70static inline int after48(const u64 seq1, const u64 seq2)
71{
72 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
73}
74
75/* is seq2 <= seq1 <= seq3 ? */
76static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
77{
78 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
79}
80
81static inline u64 max48(const u64 seq1, const u64 seq2)
82{
83 return after48(seq1, seq2) ? seq1 : seq2;
84}
85
86enum {
87 DCCP_MIB_NUM = 0,
88 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
89 DCCP_MIB_ESTABRESETS, /* EstabResets */
90 DCCP_MIB_CURRESTAB, /* CurrEstab */
91 DCCP_MIB_OUTSEGS, /* OutSegs */
92 DCCP_MIB_OUTRSTS,
93 DCCP_MIB_ABORTONTIMEOUT,
94 DCCP_MIB_TIMEOUTS,
95 DCCP_MIB_ABORTFAILED,
96 DCCP_MIB_PASSIVEOPENS,
97 DCCP_MIB_ATTEMPTFAILS,
98 DCCP_MIB_OUTDATAGRAMS,
99 DCCP_MIB_INERRS,
100 DCCP_MIB_OPTMANDATORYERROR,
101 DCCP_MIB_INVALIDOPT,
102 __DCCP_MIB_MAX
103};
104
105#define DCCP_MIB_MAX __DCCP_MIB_MAX
106struct dccp_mib {
107 unsigned long mibs[DCCP_MIB_MAX];
108} __SNMP_MIB_ALIGN__;
109
110DECLARE_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)
119
120extern int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
121extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
122
123extern int dccp_send_response(struct sock *sk);
124extern void dccp_send_ack(struct sock *sk);
125extern void dccp_send_delayed_ack(struct sock *sk);
126extern void dccp_send_sync(struct sock *sk, const u64 seq,
127 const enum dccp_pkt_type pkt_type);
128
129extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo);
130extern void dccp_write_space(struct sock *sk);
131
132extern void dccp_init_xmit_timers(struct sock *sk);
133static inline void dccp_clear_xmit_timers(struct sock *sk)
134{
135 inet_csk_clear_xmit_timers(sk);
136}
137
138extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
139
140extern const char *dccp_packet_name(const int type);
141extern const char *dccp_state_name(const int state);
142
143static inline void dccp_set_state(struct sock *sk, const int state)
144{
145 const int oldstate = sk->sk_state;
146
147 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
148 dccp_role(sk), sk,
149 dccp_state_name(oldstate), dccp_state_name(state));
150 WARN_ON(state == oldstate);
151
152 switch (state) {
153 case DCCP_OPEN:
154 if (oldstate != DCCP_OPEN)
155 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
156 break;
157
158 case DCCP_CLOSED:
159 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
160 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
161
162 sk->sk_prot->unhash(sk);
163 if (inet_csk(sk)->icsk_bind_hash != NULL &&
164 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
165 inet_put_port(&dccp_hashinfo, sk);
166 /* fall through */
167 default:
168 if (oldstate == DCCP_OPEN)
169 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
170 }
171
172 /* Change state AFTER socket is unhashed to avoid closed
173 * socket sitting in hash tables.
174 */
175 sk->sk_state = state;
176}
177
178static inline void dccp_done(struct sock *sk)
179{
180 dccp_set_state(sk, DCCP_CLOSED);
181 dccp_clear_xmit_timers(sk);
182
183 sk->sk_shutdown = SHUTDOWN_MASK;
184
185 if (!sock_flag(sk, SOCK_DEAD))
186 sk->sk_state_change(sk);
187 else
188 inet_csk_destroy_sock(sk);
189}
190
191static inline void dccp_openreq_init(struct request_sock *req,
192 struct dccp_sock *dp,
193 struct sk_buff *skb)
194{
195 /*
196 * FIXME: fill in the other req fields from the DCCP options
197 * received
198 */
199 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
200 inet_rsk(req)->acked = 0;
201 req->rcv_wnd = 0;
202}
203
204extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
205
206extern struct sock *dccp_create_openreq_child(struct sock *sk,
207 const struct request_sock *req,
208 const struct sk_buff *skb);
209
210extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
211
212extern void dccp_v4_err(struct sk_buff *skb, u32);
213
214extern int dccp_v4_rcv(struct sk_buff *skb);
215
216extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
217 struct sk_buff *skb,
218 struct request_sock *req,
219 struct dst_entry *dst);
220extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
221 struct request_sock *req,
222 struct request_sock **prev);
223
224extern int dccp_child_process(struct sock *parent, struct sock *child,
225 struct sk_buff *skb);
226extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
227 struct dccp_hdr *dh, unsigned len);
228extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
229 const struct dccp_hdr *dh, const unsigned len);
230
231extern void dccp_close(struct sock *sk, long timeout);
232extern struct sk_buff *dccp_make_response(struct sock *sk,
233 struct dst_entry *dst,
234 struct request_sock *req);
235extern struct sk_buff *dccp_make_reset(struct sock *sk,
236 struct dst_entry *dst,
237 enum dccp_reset_codes code);
238
239extern int dccp_connect(struct sock *sk);
240extern int dccp_disconnect(struct sock *sk, int flags);
241extern int dccp_getsockopt(struct sock *sk, int level, int optname,
242 char __user *optval, int __user *optlen);
243extern int dccp_setsockopt(struct sock *sk, int level, int optname,
244 char __user *optval, int optlen);
245extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
246extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
247 struct msghdr *msg, size_t size);
248extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
249 struct msghdr *msg, size_t len, int nonblock,
250 int flags, int *addr_len);
251extern void dccp_shutdown(struct sock *sk, int how);
252
253extern int dccp_v4_checksum(const struct sk_buff *skb,
254 const u32 saddr, const u32 daddr);
255
256extern int dccp_v4_send_reset(struct sock *sk,
257 enum dccp_reset_codes code);
258extern void dccp_send_close(struct sock *sk, const int active);
259
260struct dccp_skb_cb {
261 __u8 dccpd_type;
262 __u8 dccpd_reset_code;
263 __u8 dccpd_service;
264 __u8 dccpd_ccval;
265 __u64 dccpd_seq;
266 __u64 dccpd_ack_seq;
267 int dccpd_opt_len;
268};
269
270#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
271
272static inline int dccp_non_data_packet(const struct sk_buff *skb)
273{
274 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
275
276 return type == DCCP_PKT_ACK ||
277 type == DCCP_PKT_CLOSE ||
278 type == DCCP_PKT_CLOSEREQ ||
279 type == DCCP_PKT_RESET ||
280 type == DCCP_PKT_SYNC ||
281 type == DCCP_PKT_SYNCACK;
282}
283
284static inline int dccp_packet_without_ack(const struct sk_buff *skb)
285{
286 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
287
288 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
289}
290
291#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
292#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
293
294static inline void dccp_set_seqno(u64 *seqno, u64 value)
295{
296 if (value > DCCP_MAX_SEQNO)
297 value -= DCCP_MAX_SEQNO + 1;
298 *seqno = value;
299}
300
301static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
302{
303 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
304}
305
306static inline void dccp_inc_seqno(u64 *seqno)
307{
308 if (++*seqno > DCCP_MAX_SEQNO)
309 *seqno = 0;
310}
311
312static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
313{
314 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
315 sizeof(*dh));
316
317#if defined(__LITTLE_ENDIAN_BITFIELD)
318 dh->dccph_seq = htonl((gss >> 32)) >> 8;
319#elif defined(__BIG_ENDIAN_BITFIELD)
320 dh->dccph_seq = htonl((gss >> 32));
321#else
322#error "Adjust your <asm/byteorder.h> defines"
323#endif
324 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
325}
326
327static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
328 const u64 gsr)
329{
330#if defined(__LITTLE_ENDIAN_BITFIELD)
331 dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
332#elif defined(__BIG_ENDIAN_BITFIELD)
333 dhack->dccph_ack_nr_high = htonl((gsr >> 32));
334#else
335#error "Adjust your <asm/byteorder.h> defines"
336#endif
337 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
338}
339
340static inline void dccp_update_gsr(struct sock *sk, u64 seq)
341{
342 struct dccp_sock *dp = dccp_sk(sk);
343
344 dp->dccps_gsr = seq;
345 dccp_set_seqno(&dp->dccps_swl,
346 (dp->dccps_gsr + 1 -
347 (dp->dccps_options.dccpo_sequence_window / 4)));
348 dccp_set_seqno(&dp->dccps_swh,
349 (dp->dccps_gsr +
350 (3 * dp->dccps_options.dccpo_sequence_window) / 4));
351}
352
353static inline void dccp_update_gss(struct sock *sk, u64 seq)
354{
355 struct dccp_sock *dp = dccp_sk(sk);
356
357 dp->dccps_awh = dp->dccps_gss = seq;
358 dccp_set_seqno(&dp->dccps_awl,
359 (dp->dccps_gss -
360 dp->dccps_options.dccpo_sequence_window + 1));
361}
362
363extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
364extern void dccp_insert_option_elapsed_time(struct sock *sk,
365 struct sk_buff *skb,
366 u32 elapsed_time);
367extern void dccp_insert_option_timestamp(struct sock *sk,
368 struct sk_buff *skb);
369extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
370 unsigned char option,
371 const void *value, unsigned char len);
372
373extern struct socket *dccp_ctl_socket;
374
375#define DCCP_ACKPKTS_STATE_RECEIVED 0
376#define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
377#define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
378
379#define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
380#define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
381
382/** struct dccp_ackpkts - acknowledgeable packets
383 *
384 * This data structure is the one defined in the DCCP draft
385 * Appendix A.
386 *
387 * @dccpap_buf_head - circular buffer head
388 * @dccpap_buf_tail - circular buffer tail
389 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
390 * buffer (i.e. %dccpap_buf_head)
391 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
392 * by the buffer with State 0
393 *
394 * Additionally, the HC-Receiver must keep some information about the
395 * Ack Vectors it has recently sent. For each packet sent carrying an
396 * Ack Vector, it remembers four variables:
397 *
398 * @dccpap_ack_seqno - the Sequence Number used for the packet
399 * (HC-Receiver seqno)
400 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
401 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
402 * (HC-Sender seqno)
403 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
404 *
405 * @dccpap_buf_len - circular buffer length
406 * @dccpap_time - the time in usecs
407 * @dccpap_buf - circular buffer of acknowledgeable packets
408 */
409struct 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 struct timeval dccpap_time;
420 u8 dccpap_buf_nonce;
421 u8 dccpap_ack_nonce;
422 u8 dccpap_buf[0];
423};
424
425extern struct dccp_ackpkts *
426 dccp_ackpkts_alloc(unsigned int len,
427 const unsigned int __nocast priority);
428extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
429extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
430 u64 ackno, u8 state);
431extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
432 struct sock *sk, u64 ackno);
433
434extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
435
436static inline suseconds_t timeval_usecs(const struct timeval *tv)
437{
438 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
439}
440
441static inline suseconds_t timeval_delta(const struct timeval *large,
442 const struct timeval *small)
443{
444 time_t secs = large->tv_sec - small->tv_sec;
445 suseconds_t usecs = large->tv_usec - small->tv_usec;
446
447 if (usecs < 0) {
448 secs--;
449 usecs += USEC_PER_SEC;
450 }
451 return secs * USEC_PER_SEC + usecs;
452}
453
454static inline void timeval_add_usecs(struct timeval *tv,
455 const suseconds_t usecs)
456{
457 tv->tv_usec += usecs;
458 while (tv->tv_usec >= USEC_PER_SEC) {
459 tv->tv_sec++;
460 tv->tv_usec -= USEC_PER_SEC;
461 }
462}
463
464static inline void timeval_sub_usecs(struct timeval *tv,
465 const suseconds_t usecs)
466{
467 tv->tv_usec -= usecs;
468 while (tv->tv_usec < 0) {
469 tv->tv_sec--;
470 tv->tv_usec += USEC_PER_SEC;
471 }
472}
473
474#ifdef CONFIG_IP_DCCP_DEBUG
475extern void dccp_ackvector_print(const u64 ackno,
476 const unsigned char *vector, int len);
477extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
478#else
479static inline void dccp_ackvector_print(const u64 ackno,
480 const unsigned char *vector,
481 int len) { }
482static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
483#endif
484
485#endif /* _DCCP_H */