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Linux 2.6.22-rc3
[linux-2.6/next.git] / net / dccp / dccp.h
blobd8ad27bfe01a1d16bf50f17b92589be6988993ee
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 #define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
35 printk(fmt, ##args); \
36 } while(0)
37 #define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
38 "%s: " fmt, __FUNCTION__, ##a)
39
40 #ifdef CONFIG_IP_DCCP_DEBUG
41 extern int dccp_debug;
42 #define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
43 #define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
44 #else
45 #define dccp_pr_debug(format, a...)
46 #define dccp_pr_debug_cat(format, a...)
47 #endif
48
49 extern struct inet_hashinfo dccp_hashinfo;
50
51 extern atomic_t dccp_orphan_count;
52
53 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
54
55 /*
56 * Set safe upper bounds for header and option length. Since Data Offset is 8
57 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
58 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
59 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
60 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
61 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
62 */
63 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
64 #define DCCP_MAX_PACKET_HDR 28
65 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
66 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
67
68 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
69 * state, about 60 seconds */
70
71 /* RFC 1122, 4.2.3.1 initial RTO value */
72 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
73
74 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
75
76 /* bounds for sampled RTT values from packet exchanges (in usec) */
77 #define DCCP_SANE_RTT_MIN 100
78 #define DCCP_SANE_RTT_MAX (4 * USEC_PER_SEC)
79
80 /* Maximal interval between probes for local resources. */
81 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
82
83 /* sysctl variables for DCCP */
84 extern int sysctl_dccp_request_retries;
85 extern int sysctl_dccp_retries1;
86 extern int sysctl_dccp_retries2;
87 extern int sysctl_dccp_feat_sequence_window;
88 extern int sysctl_dccp_feat_rx_ccid;
89 extern int sysctl_dccp_feat_tx_ccid;
90 extern int sysctl_dccp_feat_ack_ratio;
91 extern int sysctl_dccp_feat_send_ack_vector;
92 extern int sysctl_dccp_feat_send_ndp_count;
93 extern int sysctl_dccp_tx_qlen;
94
95 /*
96 * 48-bit sequence number arithmetic (signed and unsigned)
97 */
98 #define INT48_MIN 0x800000000000LL /* 2^47 */
99 #define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
100 #define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
101 #define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
102 #define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
103 #define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
104 #define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
105
106 static inline void dccp_set_seqno(u64 *seqno, u64 value)
107 {
108 *seqno = value & UINT48_MAX;
109 }
110
111 static inline void dccp_inc_seqno(u64 *seqno)
112 {
113 *seqno = ADD48(*seqno, 1);
114 }
115
116 /* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
117 static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
118 {
119 u64 delta = SUB48(seqno2, seqno1);
120
121 return TO_SIGNED48(delta);
122 }
123
124 /* is seq1 < seq2 ? */
125 static inline int before48(const u64 seq1, const u64 seq2)
126 {
127 return (s64)((seq2 << 16) - (seq1 << 16)) > 0;
128 }
129
130 /* is seq1 > seq2 ? */
131 #define after48(seq1, seq2) before48(seq2, seq1)
132
133 /* is seq2 <= seq1 <= seq3 ? */
134 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
135 {
136 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
137 }
138
139 static inline u64 max48(const u64 seq1, const u64 seq2)
140 {
141 return after48(seq1, seq2) ? seq1 : seq2;
142 }
143
144 /* is seq1 next seqno after seq2 */
145 static inline int follows48(const u64 seq1, const u64 seq2)
146 {
147 return dccp_delta_seqno(seq2, seq1) == 1;
148 }
149
150 enum {
151 DCCP_MIB_NUM = 0,
152 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
153 DCCP_MIB_ESTABRESETS, /* EstabResets */
154 DCCP_MIB_CURRESTAB, /* CurrEstab */
155 DCCP_MIB_OUTSEGS, /* OutSegs */
156 DCCP_MIB_OUTRSTS,
157 DCCP_MIB_ABORTONTIMEOUT,
158 DCCP_MIB_TIMEOUTS,
159 DCCP_MIB_ABORTFAILED,
160 DCCP_MIB_PASSIVEOPENS,
161 DCCP_MIB_ATTEMPTFAILS,
162 DCCP_MIB_OUTDATAGRAMS,
163 DCCP_MIB_INERRS,
164 DCCP_MIB_OPTMANDATORYERROR,
165 DCCP_MIB_INVALIDOPT,
166 __DCCP_MIB_MAX
167 };
168
169 #define DCCP_MIB_MAX __DCCP_MIB_MAX
170 struct dccp_mib {
171 unsigned long mibs[DCCP_MIB_MAX];
172 } __SNMP_MIB_ALIGN__;
173
174 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
175 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
176 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
177 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
178 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
179 #define DCCP_ADD_STATS_BH(field, val) \
180 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
181 #define DCCP_ADD_STATS_USER(field, val) \
182 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
183
184 /*
185 * Checksumming routines
186 */
187 static inline int dccp_csum_coverage(const struct sk_buff *skb)
188 {
189 const struct dccp_hdr* dh = dccp_hdr(skb);
190
191 if (dh->dccph_cscov == 0)
192 return skb->len;
193 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
194 }
195
196 static inline void dccp_csum_outgoing(struct sk_buff *skb)
197 {
198 int cov = dccp_csum_coverage(skb);
199
200 if (cov >= skb->len)
201 dccp_hdr(skb)->dccph_cscov = 0;
202
203 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
204 }
205
206 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
207
208 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
209
210 extern void dccp_send_ack(struct sock *sk);
211 extern void dccp_send_delayed_ack(struct sock *sk);
212 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
213
214 extern void dccp_send_sync(struct sock *sk, const u64 seq,
215 const enum dccp_pkt_type pkt_type);
216
217 extern void dccp_write_xmit(struct sock *sk, int block);
218 extern void dccp_write_space(struct sock *sk);
219
220 extern void dccp_init_xmit_timers(struct sock *sk);
221 static inline void dccp_clear_xmit_timers(struct sock *sk)
222 {
223 inet_csk_clear_xmit_timers(sk);
224 }
225
226 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
227
228 extern const char *dccp_packet_name(const int type);
229 extern const char *dccp_state_name(const int state);
230
231 extern void dccp_set_state(struct sock *sk, const int state);
232 extern void dccp_done(struct sock *sk);
233
234 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
235
236 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
237
238 extern struct sock *dccp_create_openreq_child(struct sock *sk,
239 const struct request_sock *req,
240 const struct sk_buff *skb);
241
242 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
243
244 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
245 struct sk_buff *skb,
246 struct request_sock *req,
247 struct dst_entry *dst);
248 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
249 struct request_sock *req,
250 struct request_sock **prev);
251
252 extern int dccp_child_process(struct sock *parent, struct sock *child,
253 struct sk_buff *skb);
254 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
255 struct dccp_hdr *dh, unsigned len);
256 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
257 const struct dccp_hdr *dh, const unsigned len);
258
259 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
260 extern int dccp_destroy_sock(struct sock *sk);
261
262 extern void dccp_close(struct sock *sk, long timeout);
263 extern struct sk_buff *dccp_make_response(struct sock *sk,
264 struct dst_entry *dst,
265 struct request_sock *req);
266
267 extern int dccp_connect(struct sock *sk);
268 extern int dccp_disconnect(struct sock *sk, int flags);
269 extern void dccp_hash(struct sock *sk);
270 extern void dccp_unhash(struct sock *sk);
271 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
272 char __user *optval, int __user *optlen);
273 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
274 char __user *optval, int optlen);
275 #ifdef CONFIG_COMPAT
276 extern int compat_dccp_getsockopt(struct sock *sk,
277 int level, int optname,
278 char __user *optval, int __user *optlen);
279 extern int compat_dccp_setsockopt(struct sock *sk,
280 int level, int optname,
281 char __user *optval, int optlen);
282 #endif
283 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
284 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
285 struct msghdr *msg, size_t size);
286 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
287 struct msghdr *msg, size_t len, int nonblock,
288 int flags, int *addr_len);
289 extern void dccp_shutdown(struct sock *sk, int how);
290 extern int inet_dccp_listen(struct socket *sock, int backlog);
291 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
292 poll_table *wait);
293 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
294 int addr_len);
295
296 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
297 extern void dccp_send_close(struct sock *sk, const int active);
298 extern int dccp_invalid_packet(struct sk_buff *skb);
299 extern u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv,
300 struct timeval *t_history);
301
302 static inline int dccp_bad_service_code(const struct sock *sk,
303 const __be32 service)
304 {
305 const struct dccp_sock *dp = dccp_sk(sk);
306
307 if (dp->dccps_service == service)
308 return 0;
309 return !dccp_list_has_service(dp->dccps_service_list, service);
310 }
311
312 struct dccp_skb_cb {
313 __u8 dccpd_type:4;
314 __u8 dccpd_ccval:4;
315 __u8 dccpd_reset_code;
316 __u16 dccpd_opt_len;
317 __u64 dccpd_seq;
318 __u64 dccpd_ack_seq;
319 };
320
321 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
322
323 static inline int dccp_non_data_packet(const struct sk_buff *skb)
324 {
325 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
326
327 return type == DCCP_PKT_ACK ||
328 type == DCCP_PKT_CLOSE ||
329 type == DCCP_PKT_CLOSEREQ ||
330 type == DCCP_PKT_RESET ||
331 type == DCCP_PKT_SYNC ||
332 type == DCCP_PKT_SYNCACK;
333 }
334
335 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
336 {
337 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
338
339 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
340 }
341
342 #define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
343
344 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
345 {
346 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
347 sizeof(*dh));
348 dh->dccph_seq2 = 0;
349 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
350 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
351 }
352
353 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
354 const u64 gsr)
355 {
356 dhack->dccph_reserved1 = 0;
357 dhack->dccph_ack_nr_high = htons(gsr >> 32);
358 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
359 }
360
361 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
362 {
363 struct dccp_sock *dp = dccp_sk(sk);
364 const struct dccp_minisock *dmsk = dccp_msk(sk);
365
366 dp->dccps_gsr = seq;
367 dccp_set_seqno(&dp->dccps_swl,
368 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
369 dccp_set_seqno(&dp->dccps_swh,
370 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
371 }
372
373 static inline void dccp_update_gss(struct sock *sk, u64 seq)
374 {
375 struct dccp_sock *dp = dccp_sk(sk);
376
377 dp->dccps_awh = dp->dccps_gss = seq;
378 dccp_set_seqno(&dp->dccps_awl,
379 (dp->dccps_gss -
380 dccp_msk(sk)->dccpms_sequence_window + 1));
381 }
382
383 static inline int dccp_ack_pending(const struct sock *sk)
384 {
385 const struct dccp_sock *dp = dccp_sk(sk);
386 return dp->dccps_timestamp_echo != 0 ||
387 #ifdef CONFIG_IP_DCCP_ACKVEC
388 (dccp_msk(sk)->dccpms_send_ack_vector &&
389 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
390 #endif
391 inet_csk_ack_scheduled(sk);
392 }
393
394 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
395 extern int dccp_insert_option_elapsed_time(struct sock *sk,
396 struct sk_buff *skb,
397 u32 elapsed_time);
398 extern int dccp_insert_option_timestamp(struct sock *sk,
399 struct sk_buff *skb);
400 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
401 unsigned char option,
402 const void *value, unsigned char len);
403
404 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
405
406 static inline suseconds_t timeval_usecs(const struct timeval *tv)
407 {
408 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
409 }
410
411 static inline suseconds_t timeval_delta(const struct timeval *large,
412 const struct timeval *small)
413 {
414 time_t secs = large->tv_sec - small->tv_sec;
415 suseconds_t usecs = large->tv_usec - small->tv_usec;
416
417 if (usecs < 0) {
418 secs--;
419 usecs += USEC_PER_SEC;
420 }
421 return secs * USEC_PER_SEC + usecs;
422 }
423
424 static inline void timeval_add_usecs(struct timeval *tv,
425 const suseconds_t usecs)
426 {
427 tv->tv_usec += usecs;
428 while (tv->tv_usec >= USEC_PER_SEC) {
429 tv->tv_sec++;
430 tv->tv_usec -= USEC_PER_SEC;
431 }
432 }
433
434 static inline void timeval_sub_usecs(struct timeval *tv,
435 const suseconds_t usecs)
436 {
437 tv->tv_usec -= usecs;
438 while (tv->tv_usec < 0) {
439 tv->tv_sec--;
440 tv->tv_usec += USEC_PER_SEC;
441 }
442 DCCP_BUG_ON(tv->tv_sec < 0);
443 }
444
445 #ifdef CONFIG_SYSCTL
446 extern int dccp_sysctl_init(void);
447 extern void dccp_sysctl_exit(void);
448 #else
449 static inline int dccp_sysctl_init(void)
450 {
451 return 0;
452 }
453
454 static inline void dccp_sysctl_exit(void)
455 {
456 }
457 #endif
458
459 #endif /* _DCCP_H */
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