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1#ifndef _DCCP_H
2#define _DCCP_H
3/*
4 * net/dccp/dccp.h
5 *
6 * An implementation of the DCCP protocol
1bc09869 7 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
e6bccd35 8 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
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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/dccp.h>
9823b7b5 16#include <linux/ktime.h>
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17#include <net/snmp.h>
18#include <net/sock.h>
19#include <net/tcp.h>
ae31c339 20#include "ackvec.h"
7c657876 21
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22/*
23 * DCCP - specific warning and debugging macros.
24 */
25#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
c9eaf173 26 __FUNCTION__, ##a)
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27#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
28 __FILE__, __LINE__, __FUNCTION__)
29#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
30#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
31 DCCP_BUG("\"%s\" holds (exception!)", \
32 __stringify(cond)); \
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33 } while (0)
34
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35#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
36 printk(fmt, ##args); \
c9eaf173 37 } while(0)
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38#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
39 "%s: " fmt, __FUNCTION__, ##a)
40
725ba8ee 41#ifdef CONFIG_IP_DCCP_DEBUG
7c657876 42extern int dccp_debug;
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43#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
44#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
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45#else
46#define dccp_pr_debug(format, a...)
47#define dccp_pr_debug_cat(format, a...)
48#endif
49
50extern struct inet_hashinfo dccp_hashinfo;
51
52extern atomic_t dccp_orphan_count;
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53
54extern void dccp_time_wait(struct sock *sk, int state, int timeo);
55
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56/*
57 * Set safe upper bounds for header and option length. Since Data Offset is 8
58 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
59 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
60 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
61 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
62 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
63 */
64#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
65#define DCCP_MAX_PACKET_HDR 28
66#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
67#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
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68
69#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
70 * state, about 60 seconds */
71
0e64e94e 72/* RFC 1122, 4.2.3.1 initial RTO value */
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73#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
74
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75#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
76
77/* bounds for sampled RTT values from packet exchanges (in usec) */
78#define DCCP_SANE_RTT_MIN 100
79#define DCCP_SANE_RTT_MAX (4 * USEC_PER_SEC)
80
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81/* Maximal interval between probes for local resources. */
82#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
83
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84/* sysctl variables for DCCP */
85extern int sysctl_dccp_request_retries;
86extern int sysctl_dccp_retries1;
87extern int sysctl_dccp_retries2;
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88extern int sysctl_dccp_feat_sequence_window;
89extern int sysctl_dccp_feat_rx_ccid;
90extern int sysctl_dccp_feat_tx_ccid;
91extern int sysctl_dccp_feat_ack_ratio;
92extern int sysctl_dccp_feat_send_ack_vector;
93extern int sysctl_dccp_feat_send_ndp_count;
b1308dc0 94extern int sysctl_dccp_tx_qlen;
2e2e9e92 95
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96/*
97 * 48-bit sequence number arithmetic (signed and unsigned)
98 */
99#define INT48_MIN 0x800000000000LL /* 2^47 */
100#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
101#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
102#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
103#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
104#define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
105#define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
106
107static inline void dccp_set_seqno(u64 *seqno, u64 value)
108{
109 *seqno = value & UINT48_MAX;
110}
111
112static inline void dccp_inc_seqno(u64 *seqno)
113{
114 *seqno = ADD48(*seqno, 1);
115}
116
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117/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
118static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
6b811d43 119{
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120 u64 delta = SUB48(seqno2, seqno1);
121
122 return TO_SIGNED48(delta);
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123}
124
7c657876 125/* is seq1 < seq2 ? */
a10cedd4 126static inline int before48(const u64 seq1, const u64 seq2)
7c657876 127{
d52de17b 128 return (s64)((seq2 << 16) - (seq1 << 16)) > 0;
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129}
130
131/* is seq1 > seq2 ? */
d52de17b 132#define after48(seq1, seq2) before48(seq2, seq1)
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133
134/* is seq2 <= seq1 <= seq3 ? */
a10cedd4 135static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
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136{
137 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
138}
139
140static inline u64 max48(const u64 seq1, const u64 seq2)
141{
142 return after48(seq1, seq2) ? seq1 : seq2;
143}
144
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145/* is seq1 next seqno after seq2 */
146static inline int follows48(const u64 seq1, const u64 seq2)
147{
b16be51b 148 return dccp_delta_seqno(seq2, seq1) == 1;
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149}
150
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151enum {
152 DCCP_MIB_NUM = 0,
153 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
154 DCCP_MIB_ESTABRESETS, /* EstabResets */
155 DCCP_MIB_CURRESTAB, /* CurrEstab */
c9eaf173 156 DCCP_MIB_OUTSEGS, /* OutSegs */
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157 DCCP_MIB_OUTRSTS,
158 DCCP_MIB_ABORTONTIMEOUT,
159 DCCP_MIB_TIMEOUTS,
160 DCCP_MIB_ABORTFAILED,
161 DCCP_MIB_PASSIVEOPENS,
162 DCCP_MIB_ATTEMPTFAILS,
163 DCCP_MIB_OUTDATAGRAMS,
164 DCCP_MIB_INERRS,
165 DCCP_MIB_OPTMANDATORYERROR,
166 DCCP_MIB_INVALIDOPT,
167 __DCCP_MIB_MAX
168};
169
170#define DCCP_MIB_MAX __DCCP_MIB_MAX
171struct dccp_mib {
172 unsigned long mibs[DCCP_MIB_MAX];
173} __SNMP_MIB_ALIGN__;
174
175DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
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176#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
177#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
178#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
179#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
180#define DCCP_ADD_STATS_BH(field, val) \
181 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
182#define DCCP_ADD_STATS_USER(field, val) \
183 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
7c657876 184
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185/*
186 * Checksumming routines
187 */
e961811f 188static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb)
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189{
190 const struct dccp_hdr* dh = dccp_hdr(skb);
191
192 if (dh->dccph_cscov == 0)
193 return skb->len;
194 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
195}
196
197static inline void dccp_csum_outgoing(struct sk_buff *skb)
198{
e961811f 199 unsigned int cov = dccp_csum_coverage(skb);
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200
201 if (cov >= skb->len)
202 dccp_hdr(skb)->dccph_cscov = 0;
203
204 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
205}
206
207extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
208
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209extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
210
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211extern void dccp_send_ack(struct sock *sk);
212extern void dccp_send_delayed_ack(struct sock *sk);
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213extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
214
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215extern void dccp_send_sync(struct sock *sk, const u64 seq,
216 const enum dccp_pkt_type pkt_type);
7c657876 217
97e5848d 218extern void dccp_write_xmit(struct sock *sk, int block);
c530cfb1 219extern void dccp_write_space(struct sock *sk);
27258ee5 220
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221extern void dccp_init_xmit_timers(struct sock *sk);
222static inline void dccp_clear_xmit_timers(struct sock *sk)
223{
224 inet_csk_clear_xmit_timers(sk);
225}
226
227extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
228
229extern const char *dccp_packet_name(const int type);
230extern const char *dccp_state_name(const int state);
231
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232extern void dccp_set_state(struct sock *sk, const int state);
233extern void dccp_done(struct sock *sk);
7c657876 234
cf557926 235extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
7c657876 236
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237extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
238
239extern struct sock *dccp_create_openreq_child(struct sock *sk,
240 const struct request_sock *req,
241 const struct sk_buff *skb);
242
243extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
244
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245extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
246 struct sk_buff *skb,
247 struct request_sock *req,
248 struct dst_entry *dst);
249extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
250 struct request_sock *req,
251 struct request_sock **prev);
252
253extern int dccp_child_process(struct sock *parent, struct sock *child,
254 struct sk_buff *skb);
255extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
256 struct dccp_hdr *dh, unsigned len);
257extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
258 const struct dccp_hdr *dh, const unsigned len);
259
72478873 260extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
3e0fadc5 261extern int dccp_destroy_sock(struct sock *sk);
f21e68ca 262
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263extern void dccp_close(struct sock *sk, long timeout);
264extern struct sk_buff *dccp_make_response(struct sock *sk,
265 struct dst_entry *dst,
266 struct request_sock *req);
267
268extern int dccp_connect(struct sock *sk);
269extern int dccp_disconnect(struct sock *sk, int flags);
c985ed70 270extern void dccp_hash(struct sock *sk);
f21e68ca 271extern void dccp_unhash(struct sock *sk);
7c657876 272extern int dccp_getsockopt(struct sock *sk, int level, int optname,
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273 char __user *optval, int __user *optlen);
274extern int dccp_setsockopt(struct sock *sk, int level, int optname,
275 char __user *optval, int optlen);
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276#ifdef CONFIG_COMPAT
277extern int compat_dccp_getsockopt(struct sock *sk,
278 int level, int optname,
279 char __user *optval, int __user *optlen);
280extern int compat_dccp_setsockopt(struct sock *sk,
281 int level, int optname,
282 char __user *optval, int optlen);
283#endif
7c657876 284extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
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285extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
286 struct msghdr *msg, size_t size);
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287extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
288 struct msghdr *msg, size_t len, int nonblock,
289 int flags, int *addr_len);
7c657876 290extern void dccp_shutdown(struct sock *sk, int how);
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291extern int inet_dccp_listen(struct socket *sock, int backlog);
292extern unsigned int dccp_poll(struct file *file, struct socket *sock,
293 poll_table *wait);
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294extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
295 int addr_len);
7c657876 296
017487d7 297extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
7ad07e7c 298extern void dccp_send_close(struct sock *sk, const int active);
f21e68ca 299extern int dccp_invalid_packet(struct sk_buff *skb);
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300extern u32 dccp_sample_rtt(struct sock *sk, ktime_t t_recv,
301 ktime_t *t_history);
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302
303static inline int dccp_bad_service_code(const struct sock *sk,
60fe62e7 304 const __be32 service)
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305{
306 const struct dccp_sock *dp = dccp_sk(sk);
307
308 if (dp->dccps_service == service)
309 return 0;
310 return !dccp_list_has_service(dp->dccps_service_list, service);
311}
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312
313struct dccp_skb_cb {
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314 __u8 dccpd_type:4;
315 __u8 dccpd_ccval:4;
316 __u8 dccpd_reset_code;
317 __u16 dccpd_opt_len;
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318 __u64 dccpd_seq;
319 __u64 dccpd_ack_seq;
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320};
321
322#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
323
324static inline int dccp_non_data_packet(const struct sk_buff *skb)
325{
326 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
327
328 return type == DCCP_PKT_ACK ||
329 type == DCCP_PKT_CLOSE ||
330 type == DCCP_PKT_CLOSEREQ ||
331 type == DCCP_PKT_RESET ||
332 type == DCCP_PKT_SYNC ||
333 type == DCCP_PKT_SYNCACK;
334}
335
336static inline int dccp_packet_without_ack(const struct sk_buff *skb)
337{
338 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
339
340 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
341}
342
6b811d43 343#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
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344
345static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
346{
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347 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
348 sizeof(*dh));
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349 dh->dccph_seq2 = 0;
350 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
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351 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
352}
353
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354static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
355 const u64 gsr)
7c657876 356{
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357 dhack->dccph_reserved1 = 0;
358 dhack->dccph_ack_nr_high = htons(gsr >> 32);
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359 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
360}
361
362static inline void dccp_update_gsr(struct sock *sk, u64 seq)
363{
364 struct dccp_sock *dp = dccp_sk(sk);
a4bf3902 365 const struct dccp_minisock *dmsk = dccp_msk(sk);
7c657876 366
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367 dp->dccps_gsr = seq;
368 dccp_set_seqno(&dp->dccps_swl,
a4bf3902 369 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
7c657876 370 dccp_set_seqno(&dp->dccps_swh,
a4bf3902 371 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
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372}
373
374static inline void dccp_update_gss(struct sock *sk, u64 seq)
375{
376 struct dccp_sock *dp = dccp_sk(sk);
7c657876 377
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378 dp->dccps_awh = dp->dccps_gss = seq;
379 dccp_set_seqno(&dp->dccps_awl,
7690af3f 380 (dp->dccps_gss -
a4bf3902 381 dccp_msk(sk)->dccpms_sequence_window + 1));
7c657876 382}
c9eaf173 383
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384static inline int dccp_ack_pending(const struct sock *sk)
385{
386 const struct dccp_sock *dp = dccp_sk(sk);
387 return dp->dccps_timestamp_echo != 0 ||
388#ifdef CONFIG_IP_DCCP_ACKVEC
a4bf3902 389 (dccp_msk(sk)->dccpms_send_ack_vector &&
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390 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
391#endif
392 inet_csk_ack_scheduled(sk);
393}
7c657876 394
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395extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
396extern int dccp_insert_option_elapsed_time(struct sock *sk,
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397 struct sk_buff *skb,
398 u32 elapsed_time);
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399extern u32 dccp_timestamp(void);
400extern void dccp_timestamping_init(void);
2d0817d1 401extern int dccp_insert_option_timestamp(struct sock *sk,
d4b81ff7 402 struct sk_buff *skb);
2d0817d1 403extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
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404 unsigned char option,
405 const void *value, unsigned char len);
406
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407#ifdef CONFIG_SYSCTL
408extern int dccp_sysctl_init(void);
409extern void dccp_sysctl_exit(void);
410#else
411static inline int dccp_sysctl_init(void)
412{
413 return 0;
414}
415
416static inline void dccp_sysctl_exit(void)
417{
418}
419#endif
420
7c657876 421#endif /* _DCCP_H */