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 #ifdef CONFIG_IP_DCCP_DEBUG
22 extern int dccp_debug;
24 #define dccp_pr_debug(format, a...) \
25 do { if (dccp_debug) \
26 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
28 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
29 printk(format, ##a); } while (0)
31 #define dccp_pr_debug(format, a...)
32 #define dccp_pr_debug_cat(format, a...)
35 extern struct inet_hashinfo dccp_hashinfo;
37 extern atomic_t dccp_orphan_count;
39 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
42 * Set safe upper bounds for header and option length. Since Data Offset is 8
43 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
44 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
45 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
46 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
47 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
49 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
50 #define DCCP_MAX_PACKET_HDR 28
51 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
52 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
54 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
55 * state, about 60 seconds */
57 /* RFC 1122, 4.2.3.1 initial RTO value */
58 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
60 /* Maximal interval between probes for local resources. */
61 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
63 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
65 #define DCCP_XMIT_TIMEO 30000 /* Time/msecs for blocking transmit per packet */
67 /* sysctl variables for DCCP */
68 extern int sysctl_dccp_request_retries;
69 extern int sysctl_dccp_retries1;
70 extern int sysctl_dccp_retries2;
71 extern int dccp_feat_default_sequence_window;
72 extern int dccp_feat_default_rx_ccid;
73 extern int dccp_feat_default_tx_ccid;
74 extern int dccp_feat_default_ack_ratio;
75 extern int dccp_feat_default_send_ack_vector;
76 extern int dccp_feat_default_send_ndp_count;
78 /* is seq1 < seq2 ? */
79 static inline int before48(const u64 seq1, const u64 seq2)
81 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
84 /* is seq1 > seq2 ? */
85 static inline int after48(const u64 seq1, const u64 seq2)
87 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
90 /* is seq2 <= seq1 <= seq3 ? */
91 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
93 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
96 static inline u64 max48(const u64 seq1, const u64 seq2)
98 return after48(seq1, seq2) ? seq1 : seq2;
101 /* is seq1 next seqno after seq2 */
102 static inline int follows48(const u64 seq1, const u64 seq2)
104 int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
111 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
112 DCCP_MIB_ESTABRESETS, /* EstabResets */
113 DCCP_MIB_CURRESTAB, /* CurrEstab */
114 DCCP_MIB_OUTSEGS, /* OutSegs */
116 DCCP_MIB_ABORTONTIMEOUT,
118 DCCP_MIB_ABORTFAILED,
119 DCCP_MIB_PASSIVEOPENS,
120 DCCP_MIB_ATTEMPTFAILS,
121 DCCP_MIB_OUTDATAGRAMS,
123 DCCP_MIB_OPTMANDATORYERROR,
128 #define DCCP_MIB_MAX __DCCP_MIB_MAX
130 unsigned long mibs[DCCP_MIB_MAX];
131 } __SNMP_MIB_ALIGN__;
133 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
134 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
135 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
136 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
137 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
138 #define DCCP_ADD_STATS_BH(field, val) \
139 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
140 #define DCCP_ADD_STATS_USER(field, val) \
141 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
144 * Checksumming routines
146 static inline int dccp_csum_coverage(const struct sk_buff *skb)
148 const struct dccp_hdr* dh = dccp_hdr(skb);
150 if (dh->dccph_cscov == 0)
152 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
155 static inline void dccp_csum_outgoing(struct sk_buff *skb)
157 int cov = dccp_csum_coverage(skb);
160 dccp_hdr(skb)->dccph_cscov = 0;
162 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
165 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
167 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
169 extern void dccp_send_ack(struct sock *sk);
170 extern void dccp_send_delayed_ack(struct sock *sk);
171 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
173 extern void dccp_send_sync(struct sock *sk, const u64 seq,
174 const enum dccp_pkt_type pkt_type);
176 extern void dccp_write_xmit(struct sock *sk, int block);
177 extern void dccp_write_space(struct sock *sk);
179 extern void dccp_init_xmit_timers(struct sock *sk);
180 static inline void dccp_clear_xmit_timers(struct sock *sk)
182 inet_csk_clear_xmit_timers(sk);
185 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
187 extern const char *dccp_packet_name(const int type);
188 extern const char *dccp_state_name(const int state);
190 extern void dccp_set_state(struct sock *sk, const int state);
191 extern void dccp_done(struct sock *sk);
193 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
195 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
197 extern struct sock *dccp_create_openreq_child(struct sock *sk,
198 const struct request_sock *req,
199 const struct sk_buff *skb);
201 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
203 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
205 struct request_sock *req,
206 struct dst_entry *dst);
207 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
208 struct request_sock *req,
209 struct request_sock **prev);
211 extern int dccp_child_process(struct sock *parent, struct sock *child,
212 struct sk_buff *skb);
213 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
214 struct dccp_hdr *dh, unsigned len);
215 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
216 const struct dccp_hdr *dh, const unsigned len);
218 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
219 extern int dccp_destroy_sock(struct sock *sk);
221 extern void dccp_close(struct sock *sk, long timeout);
222 extern struct sk_buff *dccp_make_response(struct sock *sk,
223 struct dst_entry *dst,
224 struct request_sock *req);
226 extern int dccp_connect(struct sock *sk);
227 extern int dccp_disconnect(struct sock *sk, int flags);
228 extern void dccp_hash(struct sock *sk);
229 extern void dccp_unhash(struct sock *sk);
230 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
231 char __user *optval, int __user *optlen);
232 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
233 char __user *optval, int optlen);
235 extern int compat_dccp_getsockopt(struct sock *sk,
236 int level, int optname,
237 char __user *optval, int __user *optlen);
238 extern int compat_dccp_setsockopt(struct sock *sk,
239 int level, int optname,
240 char __user *optval, int optlen);
242 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
243 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
244 struct msghdr *msg, size_t size);
245 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
246 struct msghdr *msg, size_t len, int nonblock,
247 int flags, int *addr_len);
248 extern void dccp_shutdown(struct sock *sk, int how);
249 extern int inet_dccp_listen(struct socket *sock, int backlog);
250 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
252 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
255 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
256 extern void dccp_send_close(struct sock *sk, const int active);
257 extern int dccp_invalid_packet(struct sk_buff *skb);
259 static inline int dccp_bad_service_code(const struct sock *sk,
260 const __be32 service)
262 const struct dccp_sock *dp = dccp_sk(sk);
264 if (dp->dccps_service == service)
266 return !dccp_list_has_service(dp->dccps_service_list, service);
272 __u8 dccpd_reset_code;
278 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
280 static inline int dccp_non_data_packet(const struct sk_buff *skb)
282 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
284 return type == DCCP_PKT_ACK ||
285 type == DCCP_PKT_CLOSE ||
286 type == DCCP_PKT_CLOSEREQ ||
287 type == DCCP_PKT_RESET ||
288 type == DCCP_PKT_SYNC ||
289 type == DCCP_PKT_SYNCACK;
292 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
294 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
296 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
299 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
300 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
302 static inline void dccp_set_seqno(u64 *seqno, u64 value)
304 if (value > DCCP_MAX_SEQNO)
305 value -= DCCP_MAX_SEQNO + 1;
309 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
311 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
314 static inline void dccp_inc_seqno(u64 *seqno)
316 if (++*seqno > DCCP_MAX_SEQNO)
320 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
322 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
325 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
326 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
329 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
332 dhack->dccph_reserved1 = 0;
333 dhack->dccph_ack_nr_high = htons(gsr >> 32);
334 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
337 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
339 struct dccp_sock *dp = dccp_sk(sk);
340 const struct dccp_minisock *dmsk = dccp_msk(sk);
343 dccp_set_seqno(&dp->dccps_swl,
344 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
345 dccp_set_seqno(&dp->dccps_swh,
346 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
349 static inline void dccp_update_gss(struct sock *sk, u64 seq)
351 struct dccp_sock *dp = dccp_sk(sk);
353 dp->dccps_awh = dp->dccps_gss = seq;
354 dccp_set_seqno(&dp->dccps_awl,
356 dccp_msk(sk)->dccpms_sequence_window + 1));
359 static inline int dccp_ack_pending(const struct sock *sk)
361 const struct dccp_sock *dp = dccp_sk(sk);
362 return dp->dccps_timestamp_echo != 0 ||
363 #ifdef CONFIG_IP_DCCP_ACKVEC
364 (dccp_msk(sk)->dccpms_send_ack_vector &&
365 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
367 inet_csk_ack_scheduled(sk);
370 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
371 extern int dccp_insert_option_elapsed_time(struct sock *sk,
374 extern int dccp_insert_option_timestamp(struct sock *sk,
375 struct sk_buff *skb);
376 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
377 unsigned char option,
378 const void *value, unsigned char len);
380 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
382 static inline suseconds_t timeval_usecs(const struct timeval *tv)
384 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
387 static inline suseconds_t timeval_delta(const struct timeval *large,
388 const struct timeval *small)
390 time_t secs = large->tv_sec - small->tv_sec;
391 suseconds_t usecs = large->tv_usec - small->tv_usec;
395 usecs += USEC_PER_SEC;
397 return secs * USEC_PER_SEC + usecs;
400 static inline void timeval_add_usecs(struct timeval *tv,
401 const suseconds_t usecs)
403 tv->tv_usec += usecs;
404 while (tv->tv_usec >= USEC_PER_SEC) {
406 tv->tv_usec -= USEC_PER_SEC;
410 static inline void timeval_sub_usecs(struct timeval *tv,
411 const suseconds_t usecs)
413 tv->tv_usec -= usecs;
414 while (tv->tv_usec < 0) {
416 tv->tv_usec += USEC_PER_SEC;
421 extern int dccp_sysctl_init(void);
422 extern void dccp_sysctl_exit(void);
424 static inline int dccp_sysctl_init(void)
429 static inline void dccp_sysctl_exit(void)