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>
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.
15 #include <linux/dccp.h>
22 * DCCP - specific warning and debugging macros.
24 #define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
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!)", \
35 #define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
36 printk(fmt, ##args); \
39 #define DCCP_PRINTK(enable, fmt, args...) printk(fmt, ##args)
41 #define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
42 "%s: " fmt, __FUNCTION__, ##a)
44 #ifdef CONFIG_IP_DCCP_DEBUG
45 extern 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)
49 #define dccp_pr_debug(format, a...)
50 #define dccp_pr_debug_cat(format, a...)
53 extern struct inet_hashinfo dccp_hashinfo
;
55 extern atomic_t dccp_orphan_count
;
57 extern void dccp_time_wait(struct sock
*sk
, int state
, int timeo
);
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
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)
72 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
73 * state, about 60 seconds */
75 /* RFC 1122, 4.2.3.1 initial RTO value */
76 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
78 /* Maximal interval between probes for local resources. */
79 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
81 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
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
;
95 /* is seq1 < seq2 ? */
96 static inline int before48(const u64 seq1
, const u64 seq2
)
98 return (s64
)((seq1
<< 16) - (seq2
<< 16)) < 0;
101 /* is seq1 > seq2 ? */
102 static inline int after48(const u64 seq1
, const u64 seq2
)
104 return (s64
)((seq2
<< 16) - (seq1
<< 16)) < 0;
107 /* is seq2 <= seq1 <= seq3 ? */
108 static inline int between48(const u64 seq1
, const u64 seq2
, const u64 seq3
)
110 return (seq3
<< 16) - (seq2
<< 16) >= (seq1
<< 16) - (seq2
<< 16);
113 static inline u64
max48(const u64 seq1
, const u64 seq2
)
115 return after48(seq1
, seq2
) ? seq1
: seq2
;
118 /* is seq1 next seqno after seq2 */
119 static inline int follows48(const u64 seq1
, const u64 seq2
)
121 int diff
= (seq1
& 0xFFFF) - (seq2
& 0xFFFF);
128 DCCP_MIB_ACTIVEOPENS
, /* ActiveOpens */
129 DCCP_MIB_ESTABRESETS
, /* EstabResets */
130 DCCP_MIB_CURRESTAB
, /* CurrEstab */
131 DCCP_MIB_OUTSEGS
, /* OutSegs */
133 DCCP_MIB_ABORTONTIMEOUT
,
135 DCCP_MIB_ABORTFAILED
,
136 DCCP_MIB_PASSIVEOPENS
,
137 DCCP_MIB_ATTEMPTFAILS
,
138 DCCP_MIB_OUTDATAGRAMS
,
140 DCCP_MIB_OPTMANDATORYERROR
,
145 #define DCCP_MIB_MAX __DCCP_MIB_MAX
147 unsigned long mibs
[DCCP_MIB_MAX
];
148 } __SNMP_MIB_ALIGN__
;
150 DECLARE_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)
161 * Checksumming routines
163 static inline int dccp_csum_coverage(const struct sk_buff
*skb
)
165 const struct dccp_hdr
* dh
= dccp_hdr(skb
);
167 if (dh
->dccph_cscov
== 0)
169 return (dh
->dccph_doff
+ dh
->dccph_cscov
- 1) * sizeof(u32
);
172 static inline void dccp_csum_outgoing(struct sk_buff
*skb
)
174 int cov
= dccp_csum_coverage(skb
);
177 dccp_hdr(skb
)->dccph_cscov
= 0;
179 skb
->csum
= skb_checksum(skb
, 0, (cov
> skb
->len
)? skb
->len
: cov
, 0);
182 extern void dccp_v4_send_check(struct sock
*sk
, int len
, struct sk_buff
*skb
);
184 extern int dccp_retransmit_skb(struct sock
*sk
, struct sk_buff
*skb
);
186 extern void dccp_send_ack(struct sock
*sk
);
187 extern void dccp_send_delayed_ack(struct sock
*sk
);
188 extern void dccp_reqsk_send_ack(struct sk_buff
*sk
, struct request_sock
*rsk
);
190 extern void dccp_send_sync(struct sock
*sk
, const u64 seq
,
191 const enum dccp_pkt_type pkt_type
);
193 extern void dccp_write_xmit(struct sock
*sk
, int block
);
194 extern void dccp_write_space(struct sock
*sk
);
196 extern void dccp_init_xmit_timers(struct sock
*sk
);
197 static inline void dccp_clear_xmit_timers(struct sock
*sk
)
199 inet_csk_clear_xmit_timers(sk
);
202 extern unsigned int dccp_sync_mss(struct sock
*sk
, u32 pmtu
);
204 extern const char *dccp_packet_name(const int type
);
205 extern const char *dccp_state_name(const int state
);
207 extern void dccp_set_state(struct sock
*sk
, const int state
);
208 extern void dccp_done(struct sock
*sk
);
210 extern void dccp_reqsk_init(struct request_sock
*req
, struct sk_buff
*skb
);
212 extern int dccp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
);
214 extern struct sock
*dccp_create_openreq_child(struct sock
*sk
,
215 const struct request_sock
*req
,
216 const struct sk_buff
*skb
);
218 extern int dccp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
);
220 extern struct sock
*dccp_v4_request_recv_sock(struct sock
*sk
,
222 struct request_sock
*req
,
223 struct dst_entry
*dst
);
224 extern struct sock
*dccp_check_req(struct sock
*sk
, struct sk_buff
*skb
,
225 struct request_sock
*req
,
226 struct request_sock
**prev
);
228 extern int dccp_child_process(struct sock
*parent
, struct sock
*child
,
229 struct sk_buff
*skb
);
230 extern int dccp_rcv_state_process(struct sock
*sk
, struct sk_buff
*skb
,
231 struct dccp_hdr
*dh
, unsigned len
);
232 extern int dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
233 const struct dccp_hdr
*dh
, const unsigned len
);
235 extern int dccp_init_sock(struct sock
*sk
, const __u8 ctl_sock_initialized
);
236 extern int dccp_destroy_sock(struct sock
*sk
);
238 extern void dccp_close(struct sock
*sk
, long timeout
);
239 extern struct sk_buff
*dccp_make_response(struct sock
*sk
,
240 struct dst_entry
*dst
,
241 struct request_sock
*req
);
243 extern int dccp_connect(struct sock
*sk
);
244 extern int dccp_disconnect(struct sock
*sk
, int flags
);
245 extern void dccp_hash(struct sock
*sk
);
246 extern void dccp_unhash(struct sock
*sk
);
247 extern int dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
248 char __user
*optval
, int __user
*optlen
);
249 extern int dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
250 char __user
*optval
, int optlen
);
252 extern int compat_dccp_getsockopt(struct sock
*sk
,
253 int level
, int optname
,
254 char __user
*optval
, int __user
*optlen
);
255 extern int compat_dccp_setsockopt(struct sock
*sk
,
256 int level
, int optname
,
257 char __user
*optval
, int optlen
);
259 extern int dccp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
);
260 extern int dccp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
,
261 struct msghdr
*msg
, size_t size
);
262 extern int dccp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
,
263 struct msghdr
*msg
, size_t len
, int nonblock
,
264 int flags
, int *addr_len
);
265 extern void dccp_shutdown(struct sock
*sk
, int how
);
266 extern int inet_dccp_listen(struct socket
*sock
, int backlog
);
267 extern unsigned int dccp_poll(struct file
*file
, struct socket
*sock
,
269 extern int dccp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
,
272 extern int dccp_send_reset(struct sock
*sk
, enum dccp_reset_codes code
);
273 extern void dccp_send_close(struct sock
*sk
, const int active
);
274 extern int dccp_invalid_packet(struct sk_buff
*skb
);
276 static inline int dccp_bad_service_code(const struct sock
*sk
,
277 const __be32 service
)
279 const struct dccp_sock
*dp
= dccp_sk(sk
);
281 if (dp
->dccps_service
== service
)
283 return !dccp_list_has_service(dp
->dccps_service_list
, service
);
289 __u8 dccpd_reset_code
;
295 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
297 static inline int dccp_non_data_packet(const struct sk_buff
*skb
)
299 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
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
;
309 static inline int dccp_packet_without_ack(const struct sk_buff
*skb
)
311 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
313 return type
== DCCP_PKT_DATA
|| type
== DCCP_PKT_REQUEST
;
316 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
317 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
319 static inline void dccp_set_seqno(u64
*seqno
, u64 value
)
321 if (value
> DCCP_MAX_SEQNO
)
322 value
-= DCCP_MAX_SEQNO
+ 1;
326 static inline u64
dccp_delta_seqno(u64 seqno1
, u64 seqno2
)
328 return ((seqno2
<< 16) - (seqno1
<< 16)) >> 16;
331 static inline void dccp_inc_seqno(u64
*seqno
)
333 if (++*seqno
> DCCP_MAX_SEQNO
)
337 static inline void dccp_hdr_set_seq(struct dccp_hdr
*dh
, const u64 gss
)
339 struct dccp_hdr_ext
*dhx
= (struct dccp_hdr_ext
*)((void *)dh
+
342 dh
->dccph_seq
= htons((gss
>> 32) & 0xfffff);
343 dhx
->dccph_seq_low
= htonl(gss
& 0xffffffff);
346 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits
*dhack
,
349 dhack
->dccph_reserved1
= 0;
350 dhack
->dccph_ack_nr_high
= htons(gsr
>> 32);
351 dhack
->dccph_ack_nr_low
= htonl(gsr
& 0xffffffff);
354 static inline void dccp_update_gsr(struct sock
*sk
, u64 seq
)
356 struct dccp_sock
*dp
= dccp_sk(sk
);
357 const struct dccp_minisock
*dmsk
= dccp_msk(sk
);
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);
366 static inline void dccp_update_gss(struct sock
*sk
, u64 seq
)
368 struct dccp_sock
*dp
= dccp_sk(sk
);
370 dp
->dccps_awh
= dp
->dccps_gss
= seq
;
371 dccp_set_seqno(&dp
->dccps_awl
,
373 dccp_msk(sk
)->dccpms_sequence_window
+ 1));
376 static inline int dccp_ack_pending(const struct sock
*sk
)
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
)) ||
384 inet_csk_ack_scheduled(sk
);
387 extern int dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
);
388 extern int dccp_insert_option_elapsed_time(struct sock
*sk
,
391 extern int dccp_insert_option_timestamp(struct sock
*sk
,
392 struct sk_buff
*skb
);
393 extern int dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
394 unsigned char option
,
395 const void *value
, unsigned char len
);
397 extern void dccp_timestamp(const struct sock
*sk
, struct timeval
*tv
);
399 static inline suseconds_t
timeval_usecs(const struct timeval
*tv
)
401 return tv
->tv_sec
* USEC_PER_SEC
+ tv
->tv_usec
;
404 static inline suseconds_t
timeval_delta(const struct timeval
*large
,
405 const struct timeval
*small
)
407 time_t secs
= large
->tv_sec
- small
->tv_sec
;
408 suseconds_t usecs
= large
->tv_usec
- small
->tv_usec
;
412 usecs
+= USEC_PER_SEC
;
414 return secs
* USEC_PER_SEC
+ usecs
;
417 static inline void timeval_add_usecs(struct timeval
*tv
,
418 const suseconds_t usecs
)
420 tv
->tv_usec
+= usecs
;
421 while (tv
->tv_usec
>= USEC_PER_SEC
) {
423 tv
->tv_usec
-= USEC_PER_SEC
;
427 static inline void timeval_sub_usecs(struct timeval
*tv
,
428 const suseconds_t usecs
)
430 tv
->tv_usec
-= usecs
;
431 while (tv
->tv_usec
< 0) {
433 tv
->tv_usec
+= USEC_PER_SEC
;
435 DCCP_BUG_ON(tv
->tv_sec
< 0);
439 extern int dccp_sysctl_init(void);
440 extern void dccp_sysctl_exit(void);
442 static inline int dccp_sysctl_init(void)
447 static inline void dccp_sysctl_exit(void)