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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) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.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/dccp.h>
16#include <net/snmp.h>
17#include <net/sock.h>
18#include <net/tcp.h>
19#include "ackvec.h"
20
21/*
22 * DCCP - specific warning and debugging macros.
23 */
24#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
25 __FUNCTION__, ##a)
26#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
27 __FILE__, __LINE__, __FUNCTION__)
28#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
29#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
30 DCCP_BUG("\"%s\" holds (exception!)", \
31 __stringify(cond)); \
32 } while (0)
33
34#ifdef MODULE
35#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
36 printk(fmt, ##args); \
37 } while(0)
38#else
39#define DCCP_PRINTK(enable, fmt, args...) printk(fmt, ##args)
40#endif
41#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
42 "%s: " fmt, __FUNCTION__, ##a)
43
44#ifdef CONFIG_IP_DCCP_DEBUG
45extern int dccp_debug;
46#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
47#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
48#else
49#define dccp_pr_debug(format, a...)
50#define dccp_pr_debug_cat(format, a...)
51#endif
52
53extern struct inet_hashinfo dccp_hashinfo;
54
55extern atomic_t dccp_orphan_count;
56
57extern void dccp_time_wait(struct sock *sk, int state, int timeo);
58
59/*
60 * Set safe upper bounds for header and option length. Since Data Offset is 8
61 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
62 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
63 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
64 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
65 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
66 */
67#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
68#define DCCP_MAX_PACKET_HDR 28
69#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
70#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
71
72#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
73 * state, about 60 seconds */
74
75/* RFC 1122, 4.2.3.1 initial RTO value */
76#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
77
78/* Maximal interval between probes for local resources. */
79#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
80
81#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
82
83/* sysctl variables for DCCP */
84extern int sysctl_dccp_request_retries;
85extern int sysctl_dccp_retries1;
86extern int sysctl_dccp_retries2;
87extern int sysctl_dccp_feat_sequence_window;
88extern int sysctl_dccp_feat_rx_ccid;
89extern int sysctl_dccp_feat_tx_ccid;
90extern int sysctl_dccp_feat_ack_ratio;
91extern int sysctl_dccp_feat_send_ack_vector;
92extern int sysctl_dccp_feat_send_ndp_count;
93extern int sysctl_dccp_tx_qlen;
94
95/* is seq1 < seq2 ? */
96static inline int before48(const u64 seq1, const u64 seq2)
97{
98 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
99}
100
101/* is seq1 > seq2 ? */
102static inline int after48(const u64 seq1, const u64 seq2)
103{
104 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
105}
106
107/* is seq2 <= seq1 <= seq3 ? */
108static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
109{
110 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
111}
112
113static inline u64 max48(const u64 seq1, const u64 seq2)
114{
115 return after48(seq1, seq2) ? seq1 : seq2;
116}
117
118/* is seq1 next seqno after seq2 */
119static inline int follows48(const u64 seq1, const u64 seq2)
120{
121 int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
122
123 return diff==1;
124}
125
126enum {
127 DCCP_MIB_NUM = 0,
128 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
129 DCCP_MIB_ESTABRESETS, /* EstabResets */
130 DCCP_MIB_CURRESTAB, /* CurrEstab */
131 DCCP_MIB_OUTSEGS, /* OutSegs */
132 DCCP_MIB_OUTRSTS,
133 DCCP_MIB_ABORTONTIMEOUT,
134 DCCP_MIB_TIMEOUTS,
135 DCCP_MIB_ABORTFAILED,
136 DCCP_MIB_PASSIVEOPENS,
137 DCCP_MIB_ATTEMPTFAILS,
138 DCCP_MIB_OUTDATAGRAMS,
139 DCCP_MIB_INERRS,
140 DCCP_MIB_OPTMANDATORYERROR,
141 DCCP_MIB_INVALIDOPT,
142 __DCCP_MIB_MAX
143};
144
145#define DCCP_MIB_MAX __DCCP_MIB_MAX
146struct dccp_mib {
147 unsigned long mibs[DCCP_MIB_MAX];
148} __SNMP_MIB_ALIGN__;
149
150DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
151#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
152#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
153#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
154#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
155#define DCCP_ADD_STATS_BH(field, val) \
156 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
157#define DCCP_ADD_STATS_USER(field, val) \
158 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
159
160/*
161 * Checksumming routines
162 */
163static inline int dccp_csum_coverage(const struct sk_buff *skb)
164{
165 const struct dccp_hdr* dh = dccp_hdr(skb);
166
167 if (dh->dccph_cscov == 0)
168 return skb->len;
169 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
170}
171
172static inline void dccp_csum_outgoing(struct sk_buff *skb)
173{
174 int cov = dccp_csum_coverage(skb);
175
176 if (cov >= skb->len)
177 dccp_hdr(skb)->dccph_cscov = 0;
178
179 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
180}
181
182extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
183
184extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
185
186extern void dccp_send_ack(struct sock *sk);
187extern void dccp_send_delayed_ack(struct sock *sk);
188extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
189
190extern void dccp_send_sync(struct sock *sk, const u64 seq,
191 const enum dccp_pkt_type pkt_type);
192
193extern void dccp_write_xmit(struct sock *sk, int block);
194extern void dccp_write_space(struct sock *sk);
195
196extern void dccp_init_xmit_timers(struct sock *sk);
197static inline void dccp_clear_xmit_timers(struct sock *sk)
198{
199 inet_csk_clear_xmit_timers(sk);
200}
201
202extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
203
204extern const char *dccp_packet_name(const int type);
205extern const char *dccp_state_name(const int state);
206
207extern void dccp_set_state(struct sock *sk, const int state);
208extern void dccp_done(struct sock *sk);
209
210extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
211
212extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
213
214extern struct sock *dccp_create_openreq_child(struct sock *sk,
215 const struct request_sock *req,
216 const struct sk_buff *skb);
217
218extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
219
220extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
221 struct sk_buff *skb,
222 struct request_sock *req,
223 struct dst_entry *dst);
224extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
225 struct request_sock *req,
226 struct request_sock **prev);
227
228extern int dccp_child_process(struct sock *parent, struct sock *child,
229 struct sk_buff *skb);
230extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
231 struct dccp_hdr *dh, unsigned len);
232extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
233 const struct dccp_hdr *dh, const unsigned len);
234
235extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
236extern int dccp_destroy_sock(struct sock *sk);
237
238extern void dccp_close(struct sock *sk, long timeout);
239extern struct sk_buff *dccp_make_response(struct sock *sk,
240 struct dst_entry *dst,
241 struct request_sock *req);
242
243extern int dccp_connect(struct sock *sk);
244extern int dccp_disconnect(struct sock *sk, int flags);
245extern void dccp_hash(struct sock *sk);
246extern void dccp_unhash(struct sock *sk);
247extern int dccp_getsockopt(struct sock *sk, int level, int optname,
248 char __user *optval, int __user *optlen);
249extern int dccp_setsockopt(struct sock *sk, int level, int optname,
250 char __user *optval, int optlen);
251#ifdef CONFIG_COMPAT
252extern int compat_dccp_getsockopt(struct sock *sk,
253 int level, int optname,
254 char __user *optval, int __user *optlen);
255extern int compat_dccp_setsockopt(struct sock *sk,
256 int level, int optname,
257 char __user *optval, int optlen);
258#endif
259extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
260extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
261 struct msghdr *msg, size_t size);
262extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
263 struct msghdr *msg, size_t len, int nonblock,
264 int flags, int *addr_len);
265extern void dccp_shutdown(struct sock *sk, int how);
266extern int inet_dccp_listen(struct socket *sock, int backlog);
267extern unsigned int dccp_poll(struct file *file, struct socket *sock,
268 poll_table *wait);
269extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
270 int addr_len);
271
272extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
273extern void dccp_send_close(struct sock *sk, const int active);
274extern int dccp_invalid_packet(struct sk_buff *skb);
275
276static inline int dccp_bad_service_code(const struct sock *sk,
277 const __be32 service)
278{
279 const struct dccp_sock *dp = dccp_sk(sk);
280
281 if (dp->dccps_service == service)
282 return 0;
283 return !dccp_list_has_service(dp->dccps_service_list, service);
284}
285
286struct dccp_skb_cb {
287 __u8 dccpd_type:4;
288 __u8 dccpd_ccval:4;
289 __u8 dccpd_reset_code;
290 __u16 dccpd_opt_len;
291 __u64 dccpd_seq;
292 __u64 dccpd_ack_seq;
293};
294
295#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
296
297static inline int dccp_non_data_packet(const struct sk_buff *skb)
298{
299 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
300
301 return type == DCCP_PKT_ACK ||
302 type == DCCP_PKT_CLOSE ||
303 type == DCCP_PKT_CLOSEREQ ||
304 type == DCCP_PKT_RESET ||
305 type == DCCP_PKT_SYNC ||
306 type == DCCP_PKT_SYNCACK;
307}
308
309static inline int dccp_packet_without_ack(const struct sk_buff *skb)
310{
311 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
312
313 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
314}
315
316#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
317#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
318
319static inline void dccp_set_seqno(u64 *seqno, u64 value)
320{
321 if (value > DCCP_MAX_SEQNO)
322 value -= DCCP_MAX_SEQNO + 1;
323 *seqno = value;
324}
325
326static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
327{
328 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
329}
330
331static inline void dccp_inc_seqno(u64 *seqno)
332{
333 if (++*seqno > DCCP_MAX_SEQNO)
334 *seqno = 0;
335}
336
337static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
338{
339 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
340 sizeof(*dh));
341 dh->dccph_seq2 = 0;
342 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
343 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
344}
345
346static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
347 const u64 gsr)
348{
349 dhack->dccph_reserved1 = 0;
350 dhack->dccph_ack_nr_high = htons(gsr >> 32);
351 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
352}
353
354static inline void dccp_update_gsr(struct sock *sk, u64 seq)
355{
356 struct dccp_sock *dp = dccp_sk(sk);
357 const struct dccp_minisock *dmsk = dccp_msk(sk);
358
359 dp->dccps_gsr = seq;
360 dccp_set_seqno(&dp->dccps_swl,
361 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
362 dccp_set_seqno(&dp->dccps_swh,
363 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
364}
365
366static inline void dccp_update_gss(struct sock *sk, u64 seq)
367{
368 struct dccp_sock *dp = dccp_sk(sk);
369
370 dp->dccps_awh = dp->dccps_gss = seq;
371 dccp_set_seqno(&dp->dccps_awl,
372 (dp->dccps_gss -
373 dccp_msk(sk)->dccpms_sequence_window + 1));
374}
375
376static inline int dccp_ack_pending(const struct sock *sk)
377{
378 const struct dccp_sock *dp = dccp_sk(sk);
379 return dp->dccps_timestamp_echo != 0 ||
380#ifdef CONFIG_IP_DCCP_ACKVEC
381 (dccp_msk(sk)->dccpms_send_ack_vector &&
382 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
383#endif
384 inet_csk_ack_scheduled(sk);
385}
386
387extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
388extern int dccp_insert_option_elapsed_time(struct sock *sk,
389 struct sk_buff *skb,
390 u32 elapsed_time);
391extern int dccp_insert_option_timestamp(struct sock *sk,
392 struct sk_buff *skb);
393extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
394 unsigned char option,
395 const void *value, unsigned char len);
396
397extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
398
399static inline suseconds_t timeval_usecs(const struct timeval *tv)
400{
401 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
402}
403
404static inline suseconds_t timeval_delta(const struct timeval *large,
405 const struct timeval *small)
406{
407 time_t secs = large->tv_sec - small->tv_sec;
408 suseconds_t usecs = large->tv_usec - small->tv_usec;
409
410 if (usecs < 0) {
411 secs--;
412 usecs += USEC_PER_SEC;
413 }
414 return secs * USEC_PER_SEC + usecs;
415}
416
417static inline void timeval_add_usecs(struct timeval *tv,
418 const suseconds_t usecs)
419{
420 tv->tv_usec += usecs;
421 while (tv->tv_usec >= USEC_PER_SEC) {
422 tv->tv_sec++;
423 tv->tv_usec -= USEC_PER_SEC;
424 }
425}
426
427static inline void timeval_sub_usecs(struct timeval *tv,
428 const suseconds_t usecs)
429{
430 tv->tv_usec -= usecs;
431 while (tv->tv_usec < 0) {
432 tv->tv_sec--;
433 tv->tv_usec += USEC_PER_SEC;
434 }
435 DCCP_BUG_ON(tv->tv_sec < 0);
436}
437
438#ifdef CONFIG_SYSCTL
439extern int dccp_sysctl_init(void);
440extern void dccp_sysctl_exit(void);
441#else
442static inline int dccp_sysctl_init(void)
443{
444 return 0;
445}
446
447static inline void dccp_sysctl_exit(void)
448{
449}
450#endif
451
452#endif /* _DCCP_H */