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>
21 #define DCCP_CRIT(fmt, a...) LIMIT_NETDEBUG(KERN_CRIT fmt " at %s:%d/%s()\n", \
22 ##a, __FILE__, __LINE__, __FUNCTION__)
23 #define DCCP_BUG(fmt, a...) do { DCCP_CRIT(fmt, ##a); dump_stack(); } while (0)
24 #define DCCP_BUG_ON(cond) do { if (unlikely((cond) == 0)) \
25 DCCP_BUG("BUG: condition \"%s\" fails",\
26 __stringify((cond))); \
29 #ifdef CONFIG_IP_DCCP_DEBUG
30 extern int dccp_debug
;
32 #define dccp_pr_debug(format, a...) \
33 do { if (dccp_debug) \
34 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
36 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
37 printk(format, ##a); } while (0)
39 #define dccp_pr_debug(format, a...)
40 #define dccp_pr_debug_cat(format, a...)
43 extern struct inet_hashinfo dccp_hashinfo
;
45 extern atomic_t dccp_orphan_count
;
47 extern void dccp_time_wait(struct sock
*sk
, int state
, int timeo
);
50 * Set safe upper bounds for header and option length. Since Data Offset is 8
51 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
52 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
53 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
54 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
55 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
57 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
58 #define DCCP_MAX_PACKET_HDR 28
59 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
60 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
62 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
63 * state, about 60 seconds */
65 /* RFC 1122, 4.2.3.1 initial RTO value */
66 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
68 /* Maximal interval between probes for local resources. */
69 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
71 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
73 #define DCCP_XMIT_TIMEO 30000 /* Time/msecs for blocking transmit per packet */
75 /* sysctl variables for DCCP */
76 extern int sysctl_dccp_request_retries
;
77 extern int sysctl_dccp_retries1
;
78 extern int sysctl_dccp_retries2
;
79 extern int sysctl_dccp_feat_sequence_window
;
80 extern int sysctl_dccp_feat_rx_ccid
;
81 extern int sysctl_dccp_feat_tx_ccid
;
82 extern int sysctl_dccp_feat_ack_ratio
;
83 extern int sysctl_dccp_feat_send_ack_vector
;
84 extern int sysctl_dccp_feat_send_ndp_count
;
86 /* is seq1 < seq2 ? */
87 static inline int before48(const u64 seq1
, const u64 seq2
)
89 return (s64
)((seq1
<< 16) - (seq2
<< 16)) < 0;
92 /* is seq1 > seq2 ? */
93 static inline int after48(const u64 seq1
, const u64 seq2
)
95 return (s64
)((seq2
<< 16) - (seq1
<< 16)) < 0;
98 /* is seq2 <= seq1 <= seq3 ? */
99 static inline int between48(const u64 seq1
, const u64 seq2
, const u64 seq3
)
101 return (seq3
<< 16) - (seq2
<< 16) >= (seq1
<< 16) - (seq2
<< 16);
104 static inline u64
max48(const u64 seq1
, const u64 seq2
)
106 return after48(seq1
, seq2
) ? seq1
: seq2
;
109 /* is seq1 next seqno after seq2 */
110 static inline int follows48(const u64 seq1
, const u64 seq2
)
112 int diff
= (seq1
& 0xFFFF) - (seq2
& 0xFFFF);
119 DCCP_MIB_ACTIVEOPENS
, /* ActiveOpens */
120 DCCP_MIB_ESTABRESETS
, /* EstabResets */
121 DCCP_MIB_CURRESTAB
, /* CurrEstab */
122 DCCP_MIB_OUTSEGS
, /* OutSegs */
124 DCCP_MIB_ABORTONTIMEOUT
,
126 DCCP_MIB_ABORTFAILED
,
127 DCCP_MIB_PASSIVEOPENS
,
128 DCCP_MIB_ATTEMPTFAILS
,
129 DCCP_MIB_OUTDATAGRAMS
,
131 DCCP_MIB_OPTMANDATORYERROR
,
136 #define DCCP_MIB_MAX __DCCP_MIB_MAX
138 unsigned long mibs
[DCCP_MIB_MAX
];
139 } __SNMP_MIB_ALIGN__
;
141 DECLARE_SNMP_STAT(struct dccp_mib
, dccp_statistics
);
142 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
143 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
144 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
145 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
146 #define DCCP_ADD_STATS_BH(field, val) \
147 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
148 #define DCCP_ADD_STATS_USER(field, val) \
149 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
152 * Checksumming routines
154 static inline int dccp_csum_coverage(const struct sk_buff
*skb
)
156 const struct dccp_hdr
* dh
= dccp_hdr(skb
);
158 if (dh
->dccph_cscov
== 0)
160 return (dh
->dccph_doff
+ dh
->dccph_cscov
- 1) * sizeof(u32
);
163 static inline void dccp_csum_outgoing(struct sk_buff
*skb
)
165 int cov
= dccp_csum_coverage(skb
);
168 dccp_hdr(skb
)->dccph_cscov
= 0;
170 skb
->csum
= skb_checksum(skb
, 0, (cov
> skb
->len
)? skb
->len
: cov
, 0);
173 extern void dccp_v4_send_check(struct sock
*sk
, int len
, struct sk_buff
*skb
);
175 extern int dccp_retransmit_skb(struct sock
*sk
, struct sk_buff
*skb
);
177 extern void dccp_send_ack(struct sock
*sk
);
178 extern void dccp_send_delayed_ack(struct sock
*sk
);
179 extern void dccp_reqsk_send_ack(struct sk_buff
*sk
, struct request_sock
*rsk
);
181 extern void dccp_send_sync(struct sock
*sk
, const u64 seq
,
182 const enum dccp_pkt_type pkt_type
);
184 extern void dccp_write_xmit(struct sock
*sk
, int block
);
185 extern void dccp_write_space(struct sock
*sk
);
187 extern void dccp_init_xmit_timers(struct sock
*sk
);
188 static inline void dccp_clear_xmit_timers(struct sock
*sk
)
190 inet_csk_clear_xmit_timers(sk
);
193 extern unsigned int dccp_sync_mss(struct sock
*sk
, u32 pmtu
);
195 extern const char *dccp_packet_name(const int type
);
196 extern const char *dccp_state_name(const int state
);
198 extern void dccp_set_state(struct sock
*sk
, const int state
);
199 extern void dccp_done(struct sock
*sk
);
201 extern void dccp_reqsk_init(struct request_sock
*req
, struct sk_buff
*skb
);
203 extern int dccp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
);
205 extern struct sock
*dccp_create_openreq_child(struct sock
*sk
,
206 const struct request_sock
*req
,
207 const struct sk_buff
*skb
);
209 extern int dccp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
);
211 extern struct sock
*dccp_v4_request_recv_sock(struct sock
*sk
,
213 struct request_sock
*req
,
214 struct dst_entry
*dst
);
215 extern struct sock
*dccp_check_req(struct sock
*sk
, struct sk_buff
*skb
,
216 struct request_sock
*req
,
217 struct request_sock
**prev
);
219 extern int dccp_child_process(struct sock
*parent
, struct sock
*child
,
220 struct sk_buff
*skb
);
221 extern int dccp_rcv_state_process(struct sock
*sk
, struct sk_buff
*skb
,
222 struct dccp_hdr
*dh
, unsigned len
);
223 extern int dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
224 const struct dccp_hdr
*dh
, const unsigned len
);
226 extern int dccp_init_sock(struct sock
*sk
, const __u8 ctl_sock_initialized
);
227 extern int dccp_destroy_sock(struct sock
*sk
);
229 extern void dccp_close(struct sock
*sk
, long timeout
);
230 extern struct sk_buff
*dccp_make_response(struct sock
*sk
,
231 struct dst_entry
*dst
,
232 struct request_sock
*req
);
234 extern int dccp_connect(struct sock
*sk
);
235 extern int dccp_disconnect(struct sock
*sk
, int flags
);
236 extern void dccp_hash(struct sock
*sk
);
237 extern void dccp_unhash(struct sock
*sk
);
238 extern int dccp_getsockopt(struct sock
*sk
, int level
, int optname
,
239 char __user
*optval
, int __user
*optlen
);
240 extern int dccp_setsockopt(struct sock
*sk
, int level
, int optname
,
241 char __user
*optval
, int optlen
);
243 extern int compat_dccp_getsockopt(struct sock
*sk
,
244 int level
, int optname
,
245 char __user
*optval
, int __user
*optlen
);
246 extern int compat_dccp_setsockopt(struct sock
*sk
,
247 int level
, int optname
,
248 char __user
*optval
, int optlen
);
250 extern int dccp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
);
251 extern int dccp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
,
252 struct msghdr
*msg
, size_t size
);
253 extern int dccp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
,
254 struct msghdr
*msg
, size_t len
, int nonblock
,
255 int flags
, int *addr_len
);
256 extern void dccp_shutdown(struct sock
*sk
, int how
);
257 extern int inet_dccp_listen(struct socket
*sock
, int backlog
);
258 extern unsigned int dccp_poll(struct file
*file
, struct socket
*sock
,
260 extern int dccp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
,
263 extern int dccp_send_reset(struct sock
*sk
, enum dccp_reset_codes code
);
264 extern void dccp_send_close(struct sock
*sk
, const int active
);
265 extern int dccp_invalid_packet(struct sk_buff
*skb
);
267 static inline int dccp_bad_service_code(const struct sock
*sk
,
268 const __be32 service
)
270 const struct dccp_sock
*dp
= dccp_sk(sk
);
272 if (dp
->dccps_service
== service
)
274 return !dccp_list_has_service(dp
->dccps_service_list
, service
);
280 __u8 dccpd_reset_code
;
286 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
288 static inline int dccp_non_data_packet(const struct sk_buff
*skb
)
290 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
292 return type
== DCCP_PKT_ACK
||
293 type
== DCCP_PKT_CLOSE
||
294 type
== DCCP_PKT_CLOSEREQ
||
295 type
== DCCP_PKT_RESET
||
296 type
== DCCP_PKT_SYNC
||
297 type
== DCCP_PKT_SYNCACK
;
300 static inline int dccp_packet_without_ack(const struct sk_buff
*skb
)
302 const __u8 type
= DCCP_SKB_CB(skb
)->dccpd_type
;
304 return type
== DCCP_PKT_DATA
|| type
== DCCP_PKT_REQUEST
;
307 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
308 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
310 static inline void dccp_set_seqno(u64
*seqno
, u64 value
)
312 if (value
> DCCP_MAX_SEQNO
)
313 value
-= DCCP_MAX_SEQNO
+ 1;
317 static inline u64
dccp_delta_seqno(u64 seqno1
, u64 seqno2
)
319 return ((seqno2
<< 16) - (seqno1
<< 16)) >> 16;
322 static inline void dccp_inc_seqno(u64
*seqno
)
324 if (++*seqno
> DCCP_MAX_SEQNO
)
328 static inline void dccp_hdr_set_seq(struct dccp_hdr
*dh
, const u64 gss
)
330 struct dccp_hdr_ext
*dhx
= (struct dccp_hdr_ext
*)((void *)dh
+
333 dh
->dccph_seq
= htons((gss
>> 32) & 0xfffff);
334 dhx
->dccph_seq_low
= htonl(gss
& 0xffffffff);
337 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits
*dhack
,
340 dhack
->dccph_reserved1
= 0;
341 dhack
->dccph_ack_nr_high
= htons(gsr
>> 32);
342 dhack
->dccph_ack_nr_low
= htonl(gsr
& 0xffffffff);
345 static inline void dccp_update_gsr(struct sock
*sk
, u64 seq
)
347 struct dccp_sock
*dp
= dccp_sk(sk
);
348 const struct dccp_minisock
*dmsk
= dccp_msk(sk
);
351 dccp_set_seqno(&dp
->dccps_swl
,
352 dp
->dccps_gsr
+ 1 - (dmsk
->dccpms_sequence_window
/ 4));
353 dccp_set_seqno(&dp
->dccps_swh
,
354 dp
->dccps_gsr
+ (3 * dmsk
->dccpms_sequence_window
) / 4);
357 static inline void dccp_update_gss(struct sock
*sk
, u64 seq
)
359 struct dccp_sock
*dp
= dccp_sk(sk
);
361 dp
->dccps_awh
= dp
->dccps_gss
= seq
;
362 dccp_set_seqno(&dp
->dccps_awl
,
364 dccp_msk(sk
)->dccpms_sequence_window
+ 1));
367 static inline int dccp_ack_pending(const struct sock
*sk
)
369 const struct dccp_sock
*dp
= dccp_sk(sk
);
370 return dp
->dccps_timestamp_echo
!= 0 ||
371 #ifdef CONFIG_IP_DCCP_ACKVEC
372 (dccp_msk(sk
)->dccpms_send_ack_vector
&&
373 dccp_ackvec_pending(dp
->dccps_hc_rx_ackvec
)) ||
375 inet_csk_ack_scheduled(sk
);
378 extern int dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
);
379 extern int dccp_insert_option_elapsed_time(struct sock
*sk
,
382 extern int dccp_insert_option_timestamp(struct sock
*sk
,
383 struct sk_buff
*skb
);
384 extern int dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
385 unsigned char option
,
386 const void *value
, unsigned char len
);
388 extern void dccp_timestamp(const struct sock
*sk
, struct timeval
*tv
);
390 static inline suseconds_t
timeval_usecs(const struct timeval
*tv
)
392 return tv
->tv_sec
* USEC_PER_SEC
+ tv
->tv_usec
;
395 static inline suseconds_t
timeval_delta(const struct timeval
*large
,
396 const struct timeval
*small
)
398 time_t secs
= large
->tv_sec
- small
->tv_sec
;
399 suseconds_t usecs
= large
->tv_usec
- small
->tv_usec
;
403 usecs
+= USEC_PER_SEC
;
405 return secs
* USEC_PER_SEC
+ usecs
;
408 static inline void timeval_add_usecs(struct timeval
*tv
,
409 const suseconds_t usecs
)
411 tv
->tv_usec
+= usecs
;
412 while (tv
->tv_usec
>= USEC_PER_SEC
) {
414 tv
->tv_usec
-= USEC_PER_SEC
;
418 static inline void timeval_sub_usecs(struct timeval
*tv
,
419 const suseconds_t usecs
)
421 tv
->tv_usec
-= usecs
;
422 while (tv
->tv_usec
< 0) {
424 tv
->tv_usec
+= USEC_PER_SEC
;
429 extern int dccp_sysctl_init(void);
430 extern void dccp_sysctl_exit(void);
432 static inline int dccp_sysctl_init(void)
437 static inline void dccp_sysctl_exit(void)