xref: /linux/net/dccp/dccp.h (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/dccp.h>
16 #include <net/snmp.h>
17 #include <net/sock.h>
18 #include <net/tcp.h>
19 #include "ackvec.h"
20 
21 #ifdef CONFIG_IP_DCCP_DEBUG
22 extern 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 
35 extern struct inet_hashinfo dccp_hashinfo;
36 
37 extern atomic_t dccp_orphan_count;
38 extern int dccp_tw_count;
39 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
40 
41 extern 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 
61 /* is seq1 < seq2 ? */
62 static inline int before48(const u64 seq1, const u64 seq2)
63 {
64 	return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
65 }
66 
67 /* is seq1 > seq2 ? */
68 static inline int after48(const u64 seq1, const u64 seq2)
69 {
70 	return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
71 }
72 
73 /* is seq2 <= seq1 <= seq3 ? */
74 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
75 {
76 	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
77 }
78 
79 static inline u64 max48(const u64 seq1, const u64 seq2)
80 {
81 	return after48(seq1, seq2) ? seq1 : seq2;
82 }
83 
84 enum {
85 	DCCP_MIB_NUM = 0,
86 	DCCP_MIB_ACTIVEOPENS,			/* ActiveOpens */
87 	DCCP_MIB_ESTABRESETS,			/* EstabResets */
88 	DCCP_MIB_CURRESTAB,			/* CurrEstab */
89 	DCCP_MIB_OUTSEGS,			/* OutSegs */
90 	DCCP_MIB_OUTRSTS,
91 	DCCP_MIB_ABORTONTIMEOUT,
92 	DCCP_MIB_TIMEOUTS,
93 	DCCP_MIB_ABORTFAILED,
94 	DCCP_MIB_PASSIVEOPENS,
95 	DCCP_MIB_ATTEMPTFAILS,
96 	DCCP_MIB_OUTDATAGRAMS,
97 	DCCP_MIB_INERRS,
98 	DCCP_MIB_OPTMANDATORYERROR,
99 	DCCP_MIB_INVALIDOPT,
100 	__DCCP_MIB_MAX
101 };
102 
103 #define DCCP_MIB_MAX	__DCCP_MIB_MAX
104 struct dccp_mib {
105 	unsigned long	mibs[DCCP_MIB_MAX];
106 } __SNMP_MIB_ALIGN__;
107 
108 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
109 #define DCCP_INC_STATS(field)	    SNMP_INC_STATS(dccp_statistics, field)
110 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
111 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
112 #define DCCP_DEC_STATS(field)	    SNMP_DEC_STATS(dccp_statistics, field)
113 #define DCCP_ADD_STATS_BH(field, val) \
114 			SNMP_ADD_STATS_BH(dccp_statistics, field, val)
115 #define DCCP_ADD_STATS_USER(field, val)	\
116 			SNMP_ADD_STATS_USER(dccp_statistics, field, val)
117 
118 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
119 
120 extern void dccp_send_ack(struct sock *sk);
121 extern void dccp_send_delayed_ack(struct sock *sk);
122 extern void dccp_send_sync(struct sock *sk, const u64 seq,
123 			   const enum dccp_pkt_type pkt_type);
124 
125 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo);
126 extern void dccp_write_space(struct sock *sk);
127 
128 extern void dccp_init_xmit_timers(struct sock *sk);
129 static inline void dccp_clear_xmit_timers(struct sock *sk)
130 {
131 	inet_csk_clear_xmit_timers(sk);
132 }
133 
134 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
135 
136 extern const char *dccp_packet_name(const int type);
137 extern const char *dccp_state_name(const int state);
138 
139 extern void dccp_set_state(struct sock *sk, const int state);
140 extern void dccp_done(struct sock *sk);
141 
142 static inline void dccp_openreq_init(struct request_sock *req,
143 				     struct dccp_sock *dp,
144 				     struct sk_buff *skb)
145 {
146 	/*
147 	 * FIXME: fill in the other req fields from the DCCP options
148 	 * received
149 	 */
150 	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
151 	inet_rsk(req)->acked	= 0;
152 	req->rcv_wnd = 0;
153 }
154 
155 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
156 
157 extern struct sock *dccp_create_openreq_child(struct sock *sk,
158 					      const struct request_sock *req,
159 					      const struct sk_buff *skb);
160 
161 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
162 
163 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
164 					      struct sk_buff *skb,
165 					      struct request_sock *req,
166 					      struct dst_entry *dst);
167 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
168 				   struct request_sock *req,
169 				   struct request_sock **prev);
170 
171 extern int dccp_child_process(struct sock *parent, struct sock *child,
172 			      struct sk_buff *skb);
173 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
174 				  struct dccp_hdr *dh, unsigned len);
175 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
176 				const struct dccp_hdr *dh, const unsigned len);
177 
178 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
179 extern int dccp_destroy_sock(struct sock *sk);
180 
181 extern void		dccp_close(struct sock *sk, long timeout);
182 extern struct sk_buff	*dccp_make_response(struct sock *sk,
183 					    struct dst_entry *dst,
184 					    struct request_sock *req);
185 
186 extern int	   dccp_connect(struct sock *sk);
187 extern int	   dccp_disconnect(struct sock *sk, int flags);
188 extern void	   dccp_hash(struct sock *sk);
189 extern void	   dccp_unhash(struct sock *sk);
190 extern int	   dccp_getsockopt(struct sock *sk, int level, int optname,
191 				   char __user *optval, int __user *optlen);
192 extern int	   dccp_setsockopt(struct sock *sk, int level, int optname,
193 				   char __user *optval, int optlen);
194 #ifdef CONFIG_COMPAT
195 extern int	   compat_dccp_getsockopt(struct sock *sk,
196 				int level, int optname,
197 				char __user *optval, int __user *optlen);
198 extern int	   compat_dccp_setsockopt(struct sock *sk,
199 				int level, int optname,
200 				char __user *optval, int optlen);
201 #endif
202 extern int	   dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
203 extern int	   dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
204 				struct msghdr *msg, size_t size);
205 extern int	   dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
206 				struct msghdr *msg, size_t len, int nonblock,
207 				int flags, int *addr_len);
208 extern void	   dccp_shutdown(struct sock *sk, int how);
209 extern int	   inet_dccp_listen(struct socket *sock, int backlog);
210 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
211 			     poll_table *wait);
212 extern void	   dccp_v4_send_check(struct sock *sk, int len,
213 				      struct sk_buff *skb);
214 extern int	   dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
215 				   int addr_len);
216 
217 extern int	   dccp_v4_checksum(const struct sk_buff *skb,
218 				    const __be32 saddr, const __be32 daddr);
219 
220 extern int	   dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
221 extern void	   dccp_send_close(struct sock *sk, const int active);
222 extern int	   dccp_invalid_packet(struct sk_buff *skb);
223 
224 static inline int dccp_bad_service_code(const struct sock *sk,
225 					const __be32 service)
226 {
227 	const struct dccp_sock *dp = dccp_sk(sk);
228 
229 	if (dp->dccps_service == service)
230 		return 0;
231 	return !dccp_list_has_service(dp->dccps_service_list, service);
232 }
233 
234 struct dccp_skb_cb {
235 	__u8  dccpd_type:4;
236 	__u8  dccpd_ccval:4;
237 	__u8  dccpd_reset_code;
238 	__u16 dccpd_opt_len;
239 	__u64 dccpd_seq;
240 	__u64 dccpd_ack_seq;
241 };
242 
243 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
244 
245 static inline int dccp_non_data_packet(const struct sk_buff *skb)
246 {
247 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
248 
249 	return type == DCCP_PKT_ACK	 ||
250 	       type == DCCP_PKT_CLOSE	 ||
251 	       type == DCCP_PKT_CLOSEREQ ||
252 	       type == DCCP_PKT_RESET	 ||
253 	       type == DCCP_PKT_SYNC	 ||
254 	       type == DCCP_PKT_SYNCACK;
255 }
256 
257 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
258 {
259 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
260 
261 	return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
262 }
263 
264 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
265 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
266 
267 static inline void dccp_set_seqno(u64 *seqno, u64 value)
268 {
269 	if (value > DCCP_MAX_SEQNO)
270 		value -= DCCP_MAX_SEQNO + 1;
271 	*seqno = value;
272 }
273 
274 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
275 {
276 	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
277 }
278 
279 static inline void dccp_inc_seqno(u64 *seqno)
280 {
281 	if (++*seqno > DCCP_MAX_SEQNO)
282 		*seqno = 0;
283 }
284 
285 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
286 {
287 	struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
288 							   sizeof(*dh));
289 	dh->dccph_seq2 = 0;
290 	dh->dccph_seq = htons((gss >> 32) & 0xfffff);
291 	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
292 }
293 
294 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
295 				    const u64 gsr)
296 {
297 	dhack->dccph_reserved1 = 0;
298 	dhack->dccph_ack_nr_high = htons(gsr >> 32);
299 	dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
300 }
301 
302 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
303 {
304 	struct dccp_sock *dp = dccp_sk(sk);
305 	const struct dccp_minisock *dmsk = dccp_msk(sk);
306 
307 	dp->dccps_gsr = seq;
308 	dccp_set_seqno(&dp->dccps_swl,
309 		       dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
310 	dccp_set_seqno(&dp->dccps_swh,
311 		       dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
312 }
313 
314 static inline void dccp_update_gss(struct sock *sk, u64 seq)
315 {
316 	struct dccp_sock *dp = dccp_sk(sk);
317 
318 	dp->dccps_awh = dp->dccps_gss = seq;
319 	dccp_set_seqno(&dp->dccps_awl,
320 		       (dp->dccps_gss -
321 			dccp_msk(sk)->dccpms_sequence_window + 1));
322 }
323 
324 static inline int dccp_ack_pending(const struct sock *sk)
325 {
326 	const struct dccp_sock *dp = dccp_sk(sk);
327 	return dp->dccps_timestamp_echo != 0 ||
328 #ifdef CONFIG_IP_DCCP_ACKVEC
329 	       (dccp_msk(sk)->dccpms_send_ack_vector &&
330 		dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
331 #endif
332 	       inet_csk_ack_scheduled(sk);
333 }
334 
335 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
336 extern int dccp_insert_option_elapsed_time(struct sock *sk,
337 					    struct sk_buff *skb,
338 					    u32 elapsed_time);
339 extern int dccp_insert_option_timestamp(struct sock *sk,
340 					 struct sk_buff *skb);
341 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
342 			       unsigned char option,
343 			       const void *value, unsigned char len);
344 
345 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
346 
347 static inline suseconds_t timeval_usecs(const struct timeval *tv)
348 {
349 	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
350 }
351 
352 static inline suseconds_t timeval_delta(const struct timeval *large,
353 					const struct timeval *small)
354 {
355 	time_t	    secs  = large->tv_sec  - small->tv_sec;
356 	suseconds_t usecs = large->tv_usec - small->tv_usec;
357 
358 	if (usecs < 0) {
359 		secs--;
360 		usecs += USEC_PER_SEC;
361 	}
362 	return secs * USEC_PER_SEC + usecs;
363 }
364 
365 static inline void timeval_add_usecs(struct timeval *tv,
366 				     const suseconds_t usecs)
367 {
368 	tv->tv_usec += usecs;
369 	while (tv->tv_usec >= USEC_PER_SEC) {
370 		tv->tv_sec++;
371 		tv->tv_usec -= USEC_PER_SEC;
372 	}
373 }
374 
375 static inline void timeval_sub_usecs(struct timeval *tv,
376 				     const suseconds_t usecs)
377 {
378 	tv->tv_usec -= usecs;
379 	while (tv->tv_usec < 0) {
380 		tv->tv_sec--;
381 		tv->tv_usec += USEC_PER_SEC;
382 	}
383 }
384 
385 #ifdef CONFIG_SYSCTL
386 extern int dccp_sysctl_init(void);
387 extern void dccp_sysctl_exit(void);
388 #else
389 static inline int dccp_sysctl_init(void)
390 {
391 	return 0;
392 }
393 
394 static inline void dccp_sysctl_exit(void)
395 {
396 }
397 #endif
398 
399 #endif /* _DCCP_H */
400