summaryrefslogtreecommitdiff
path: root/net/dccp/dccp.h
blob: 148e8a65a10c09e6c5f1aaaa4a6835e8fccfe6f7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
#ifndef _DCCP_H
#define _DCCP_H
/*
 *  net/dccp/dccp.h
 *
 *  An implementation of the DCCP protocol
 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 */

#include <linux/config.h>
#include <linux/dccp.h>
#include <net/snmp.h>
#include <net/sock.h>
#include <net/tcp.h>

#ifdef CONFIG_IP_DCCP_DEBUG
extern int dccp_debug;

#define dccp_pr_debug(format, a...) \
	do { if (dccp_debug) \
		printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
	} while (0)
#define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
					     printk(format, ##a); } while (0)
#else
#define dccp_pr_debug(format, a...)
#define dccp_pr_debug_cat(format, a...)
#endif

extern struct inet_hashinfo dccp_hashinfo;

extern atomic_t dccp_orphan_count;
extern int dccp_tw_count;
extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);

extern void dccp_time_wait(struct sock *sk, int state, int timeo);

/* FIXME: Right size this */
#define DCCP_MAX_OPT_LEN 128

#define DCCP_MAX_PACKET_HDR 32

#define MAX_DCCP_HEADER  (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)

#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
				     * state, about 60 seconds */

/* draft-ietf-dccp-spec-11.txt initial RTO value */
#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))

/* Maximal interval between probes for local resources.  */
#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))

#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */

extern struct proto dccp_v4_prot;

/* is seq1 < seq2 ? */
static inline const  int before48(const u64 seq1, const u64 seq2)
{
	return (const s64)((seq1 << 16) - (seq2 << 16)) < 0;
}

/* is seq1 > seq2 ? */
static inline const  int after48(const u64 seq1, const u64 seq2)
{
	return (const s64)((seq2 << 16) - (seq1 << 16)) < 0;
}

/* is seq2 <= seq1 <= seq3 ? */
static inline const int between48(const u64 seq1, const u64 seq2,
				  const u64 seq3)
{
	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
}

static inline u64 max48(const u64 seq1, const u64 seq2)
{
	return after48(seq1, seq2) ? seq1 : seq2;
}

enum {
	DCCP_MIB_NUM = 0,
	DCCP_MIB_ACTIVEOPENS,			/* ActiveOpens */
	DCCP_MIB_ESTABRESETS,			/* EstabResets */
	DCCP_MIB_CURRESTAB,			/* CurrEstab */
	DCCP_MIB_OUTSEGS,			/* OutSegs */ 
	DCCP_MIB_OUTRSTS,
	DCCP_MIB_ABORTONTIMEOUT,
	DCCP_MIB_TIMEOUTS,
	DCCP_MIB_ABORTFAILED,
	DCCP_MIB_PASSIVEOPENS,
	DCCP_MIB_ATTEMPTFAILS,
	DCCP_MIB_OUTDATAGRAMS,
	DCCP_MIB_INERRS,
	DCCP_MIB_OPTMANDATORYERROR,
	DCCP_MIB_INVALIDOPT,
	__DCCP_MIB_MAX
};

#define DCCP_MIB_MAX	__DCCP_MIB_MAX
struct dccp_mib {
	unsigned long	mibs[DCCP_MIB_MAX];
} __SNMP_MIB_ALIGN__;

DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
#define DCCP_INC_STATS(field)	    SNMP_INC_STATS(dccp_statistics, field)
#define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
#define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
#define DCCP_DEC_STATS(field)	    SNMP_DEC_STATS(dccp_statistics, field)
#define DCCP_ADD_STATS_BH(field, val) \
			SNMP_ADD_STATS_BH(dccp_statistics, field, val)
#define DCCP_ADD_STATS_USER(field, val)	\
			SNMP_ADD_STATS_USER(dccp_statistics, field, val)

extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);

extern int dccp_send_response(struct sock *sk);
extern void dccp_send_ack(struct sock *sk);
extern void dccp_send_delayed_ack(struct sock *sk);
extern void dccp_send_sync(struct sock *sk, u64 seq);

extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
			   const int len);

extern void dccp_init_xmit_timers(struct sock *sk);
static inline void dccp_clear_xmit_timers(struct sock *sk)
{
	inet_csk_clear_xmit_timers(sk);
}

extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);

extern const char *dccp_packet_name(const int type);
extern const char *dccp_state_name(const int state);

static inline void dccp_set_state(struct sock *sk, const int state)
{
	const int oldstate = sk->sk_state;

	dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
		      dccp_role(sk), sk,
		      dccp_state_name(oldstate), dccp_state_name(state));
	WARN_ON(state == oldstate);

	switch (state) {
	case DCCP_OPEN:
		if (oldstate != DCCP_OPEN)
			DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
		break;

	case DCCP_CLOSED:
		if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
			DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash != NULL &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
			inet_put_port(&dccp_hashinfo, sk);
		/* fall through */
	default:
		if (oldstate == DCCP_OPEN)
			DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
	sk->sk_state = state;
}

static inline void dccp_done(struct sock *sk)
{
	dccp_set_state(sk, DCCP_CLOSED);
	dccp_clear_xmit_timers(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_state_change(sk);
	else
		inet_csk_destroy_sock(sk);
}

static inline void dccp_openreq_init(struct request_sock *req,
				     struct dccp_sock *dp,
				     struct sk_buff *skb)
{
	/*
	 * FIXME: fill in the other req fields from the DCCP options
	 * received
	 */
	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
	inet_rsk(req)->acked	= 0;
	req->rcv_wnd = 0;
}

extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);

extern struct sock *dccp_create_openreq_child(struct sock *sk,
					      const struct request_sock *req,
					      const struct sk_buff *skb);

extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);

extern void dccp_v4_err(struct sk_buff *skb, u32);

extern int dccp_v4_rcv(struct sk_buff *skb);

extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
					      struct sk_buff *skb,
					      struct request_sock *req,
					      struct dst_entry *dst);
extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
				   struct request_sock *req,
				   struct request_sock **prev);

extern int dccp_child_process(struct sock *parent, struct sock *child,
			      struct sk_buff *skb);
extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
				  struct dccp_hdr *dh, unsigned len);
extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
				const struct dccp_hdr *dh, const unsigned len);

extern void		dccp_close(struct sock *sk, long timeout);
extern struct sk_buff	*dccp_make_response(struct sock *sk,
					    struct dst_entry *dst,
					    struct request_sock *req);
extern struct sk_buff	*dccp_make_reset(struct sock *sk,
					 struct dst_entry *dst,
					 enum dccp_reset_codes code);

extern int	   dccp_connect(struct sock *sk);
extern int	   dccp_disconnect(struct sock *sk, int flags);
extern int	   dccp_getsockopt(struct sock *sk, int level, int optname,
				   char __user *optval, int __user *optlen);
extern int	   dccp_setsockopt(struct sock *sk, int level, int optname,
				   char __user *optval, int optlen);
extern int	   dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
extern int	   dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
				struct msghdr *msg, size_t size);
extern int	   dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
				struct msghdr *msg, size_t len, int nonblock,
				int flags, int *addr_len);
extern void	   dccp_shutdown(struct sock *sk, int how);

extern int	   dccp_v4_checksum(const struct sk_buff *skb,
				    const u32 saddr, const u32 daddr);

extern int	   dccp_v4_send_reset(struct sock *sk,
				      enum dccp_reset_codes code);
extern void	   dccp_send_close(struct sock *sk);

struct dccp_skb_cb {
	__u8 dccpd_type;
	__u8 dccpd_reset_code;
	__u8 dccpd_service;
	__u8 dccpd_ccval;
	__u64 dccpd_seq;
	__u64 dccpd_ack_seq;
	int  dccpd_opt_len;
};

#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))

static inline int dccp_non_data_packet(const struct sk_buff *skb)
{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_ACK	 ||
	       type == DCCP_PKT_CLOSE	 ||
	       type == DCCP_PKT_CLOSEREQ ||
	       type == DCCP_PKT_RESET	 ||
	       type == DCCP_PKT_SYNC	 ||
	       type == DCCP_PKT_SYNCACK;
}

static inline int dccp_packet_without_ack(const struct sk_buff *skb)
{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
}

#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)

static inline void dccp_set_seqno(u64 *seqno, u64 value)
{
	if (value > DCCP_MAX_SEQNO)
		value -= DCCP_MAX_SEQNO + 1;
	*seqno = value;
}

static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
{
	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
}

static inline void dccp_inc_seqno(u64 *seqno)
{
	if (++*seqno > DCCP_MAX_SEQNO)
		*seqno = 0;
}

static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
{
	struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
							   sizeof(*dh));

#if defined(__LITTLE_ENDIAN_BITFIELD)
	dh->dccph_seq	   = htonl((gss >> 32)) >> 8;
#elif defined(__BIG_ENDIAN_BITFIELD)
	dh->dccph_seq	   = htonl((gss >> 32));
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
}

static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
				    const u64 gsr)
{
#if defined(__LITTLE_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
#elif defined(__BIG_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32));
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
}

static inline void dccp_update_gsr(struct sock *sk, u64 seq)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 tmp_gsr;

	dccp_set_seqno(&tmp_gsr,
		       (dp->dccps_gsr + 1 -
		        (dp->dccps_options.dccpo_sequence_window / 4)));
	dp->dccps_gsr = seq;
	dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
	dccp_set_seqno(&dp->dccps_swh,
		       (dp->dccps_gsr +
			(3 * dp->dccps_options.dccpo_sequence_window) / 4));
}

static inline void dccp_update_gss(struct sock *sk, u64 seq)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 tmp_gss;

	dccp_set_seqno(&tmp_gss,
		       (dp->dccps_gss -
			dp->dccps_options.dccpo_sequence_window + 1));
	dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
	dp->dccps_awh = dp->dccps_gss = seq;
}

extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
extern void dccp_insert_option_elapsed_time(struct sock *sk,
					    struct sk_buff *skb,
					    u32 elapsed_time);
extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
			       unsigned char option,
			       const void *value, unsigned char len);

extern struct socket *dccp_ctl_socket;

#define DCCP_ACKPKTS_STATE_RECEIVED	0
#define DCCP_ACKPKTS_STATE_ECN_MARKED	(1 << 6)
#define DCCP_ACKPKTS_STATE_NOT_RECEIVED	(3 << 6)

#define DCCP_ACKPKTS_STATE_MASK		0xC0 /* 11000000 */
#define DCCP_ACKPKTS_LEN_MASK		0x3F /* 00111111 */

/** struct dccp_ackpkts - acknowledgeable packets
 *
 * This data structure is the one defined in the DCCP draft
 * Appendix A.
 *
 * @dccpap_buf_head - circular buffer head
 * @dccpap_buf_tail - circular buffer tail
 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
 * 		       buffer (i.e. %dccpap_buf_head)
 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
 * 		       by the buffer with State 0
 *
 * Additionally, the HC-Receiver must keep some information about the
 * Ack Vectors it has recently sent. For each packet sent carrying an
 * Ack Vector, it remembers four variables:
 *
 * @dccpap_ack_seqno - the Sequence Number used for the packet
 * 		       (HC-Receiver seqno)
 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
 * 		       (HC-Sender seqno)
 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
 *
 * @dccpap_buf_len - circular buffer length
 * @dccpap_buf - circular buffer of acknowledgeable packets
 */
struct dccp_ackpkts {
	unsigned int		dccpap_buf_head;
	unsigned int		dccpap_buf_tail;
	u64			dccpap_buf_ackno;
	u64			dccpap_ack_seqno;
	u64			dccpap_ack_ackno;
	unsigned int		dccpap_ack_ptr;
	unsigned int		dccpap_buf_vector_len;
	unsigned int		dccpap_ack_vector_len;
	unsigned int		dccpap_buf_len;
	unsigned long           dccpap_time;
	u8			dccpap_buf_nonce;
	u8			dccpap_ack_nonce;
	u8			dccpap_buf[0];
};

extern struct dccp_ackpkts *
		dccp_ackpkts_alloc(unsigned int len,
				  const unsigned int __nocast priority);
extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
					 struct sock *sk, u64 ackno);

#ifdef CONFIG_IP_DCCP_DEBUG
extern void dccp_ackvector_print(const u64 ackno,
				 const unsigned char *vector, int len);
extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
#else
static inline void dccp_ackvector_print(const u64 ackno,
					const unsigned char *vector,
					int len) { }
static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
#endif

#endif /* _DCCP_H */