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 /* is seq1 < seq2 ? */
66 static inline int before48(const u64 seq1, const u64 seq2)
68 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
71 /* is seq1 > seq2 ? */
72 static inline int after48(const u64 seq1, const u64 seq2)
74 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
77 /* is seq2 <= seq1 <= seq3 ? */
78 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
80 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
83 static inline u64 max48(const u64 seq1, const u64 seq2)
85 return after48(seq1, seq2) ? seq1 : seq2;
88 /* is seq1 next seqno after seq2 */
89 static inline int follows48(const u64 seq1, const u64 seq2)
91 int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
98 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
99 DCCP_MIB_ESTABRESETS, /* EstabResets */
100 DCCP_MIB_CURRESTAB, /* CurrEstab */
101 DCCP_MIB_OUTSEGS, /* OutSegs */
103 DCCP_MIB_ABORTONTIMEOUT,
105 DCCP_MIB_ABORTFAILED,
106 DCCP_MIB_PASSIVEOPENS,
107 DCCP_MIB_ATTEMPTFAILS,
108 DCCP_MIB_OUTDATAGRAMS,
110 DCCP_MIB_OPTMANDATORYERROR,
115 #define DCCP_MIB_MAX __DCCP_MIB_MAX
117 unsigned long mibs[DCCP_MIB_MAX];
118 } __SNMP_MIB_ALIGN__;
120 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
121 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
122 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
123 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
124 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
125 #define DCCP_ADD_STATS_BH(field, val) \
126 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
127 #define DCCP_ADD_STATS_USER(field, val) \
128 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
130 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
132 extern void dccp_send_ack(struct sock *sk);
133 extern void dccp_send_delayed_ack(struct sock *sk);
134 extern void dccp_send_sync(struct sock *sk, const u64 seq,
135 const enum dccp_pkt_type pkt_type);
137 extern void dccp_write_xmit(struct sock *sk, int block);
138 extern void dccp_write_space(struct sock *sk);
140 extern void dccp_init_xmit_timers(struct sock *sk);
141 static inline void dccp_clear_xmit_timers(struct sock *sk)
143 inet_csk_clear_xmit_timers(sk);
146 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
148 extern const char *dccp_packet_name(const int type);
149 extern const char *dccp_state_name(const int state);
151 extern void dccp_set_state(struct sock *sk, const int state);
152 extern void dccp_done(struct sock *sk);
154 static inline void dccp_openreq_init(struct request_sock *req,
155 struct dccp_sock *dp,
159 * FIXME: fill in the other req fields from the DCCP options
162 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
163 inet_rsk(req)->acked = 0;
167 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
169 extern struct sock *dccp_create_openreq_child(struct sock *sk,
170 const struct request_sock *req,
171 const struct sk_buff *skb);
173 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
175 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
177 struct request_sock *req,
178 struct dst_entry *dst);
179 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
180 struct request_sock *req,
181 struct request_sock **prev);
183 extern int dccp_child_process(struct sock *parent, struct sock *child,
184 struct sk_buff *skb);
185 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
186 struct dccp_hdr *dh, unsigned len);
187 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
188 const struct dccp_hdr *dh, const unsigned len);
190 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
191 extern int dccp_destroy_sock(struct sock *sk);
193 extern void dccp_close(struct sock *sk, long timeout);
194 extern struct sk_buff *dccp_make_response(struct sock *sk,
195 struct dst_entry *dst,
196 struct request_sock *req);
198 extern int dccp_connect(struct sock *sk);
199 extern int dccp_disconnect(struct sock *sk, int flags);
200 extern void dccp_hash(struct sock *sk);
201 extern void dccp_unhash(struct sock *sk);
202 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
203 char __user *optval, int __user *optlen);
204 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
205 char __user *optval, int optlen);
207 extern int compat_dccp_getsockopt(struct sock *sk,
208 int level, int optname,
209 char __user *optval, int __user *optlen);
210 extern int compat_dccp_setsockopt(struct sock *sk,
211 int level, int optname,
212 char __user *optval, int optlen);
214 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
215 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
216 struct msghdr *msg, size_t size);
217 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
218 struct msghdr *msg, size_t len, int nonblock,
219 int flags, int *addr_len);
220 extern void dccp_shutdown(struct sock *sk, int how);
221 extern int inet_dccp_listen(struct socket *sock, int backlog);
222 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
224 extern void dccp_v4_send_check(struct sock *sk, int len,
225 struct sk_buff *skb);
226 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
229 extern int dccp_v4_checksum(const struct sk_buff *skb,
230 const __be32 saddr, const __be32 daddr);
232 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
233 extern void dccp_send_close(struct sock *sk, const int active);
234 extern int dccp_invalid_packet(struct sk_buff *skb);
236 static inline int dccp_bad_service_code(const struct sock *sk,
237 const __be32 service)
239 const struct dccp_sock *dp = dccp_sk(sk);
241 if (dp->dccps_service == service)
243 return !dccp_list_has_service(dp->dccps_service_list, service);
249 __u8 dccpd_reset_code;
255 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
257 static inline int dccp_non_data_packet(const struct sk_buff *skb)
259 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
261 return type == DCCP_PKT_ACK ||
262 type == DCCP_PKT_CLOSE ||
263 type == DCCP_PKT_CLOSEREQ ||
264 type == DCCP_PKT_RESET ||
265 type == DCCP_PKT_SYNC ||
266 type == DCCP_PKT_SYNCACK;
269 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
271 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
273 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
276 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
277 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
279 static inline void dccp_set_seqno(u64 *seqno, u64 value)
281 if (value > DCCP_MAX_SEQNO)
282 value -= DCCP_MAX_SEQNO + 1;
286 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
288 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
291 static inline void dccp_inc_seqno(u64 *seqno)
293 if (++*seqno > DCCP_MAX_SEQNO)
297 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
299 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
302 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
303 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
306 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
309 dhack->dccph_reserved1 = 0;
310 dhack->dccph_ack_nr_high = htons(gsr >> 32);
311 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
314 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
316 struct dccp_sock *dp = dccp_sk(sk);
317 const struct dccp_minisock *dmsk = dccp_msk(sk);
320 dccp_set_seqno(&dp->dccps_swl,
321 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
322 dccp_set_seqno(&dp->dccps_swh,
323 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
326 static inline void dccp_update_gss(struct sock *sk, u64 seq)
328 struct dccp_sock *dp = dccp_sk(sk);
330 dp->dccps_awh = dp->dccps_gss = seq;
331 dccp_set_seqno(&dp->dccps_awl,
333 dccp_msk(sk)->dccpms_sequence_window + 1));
336 static inline int dccp_ack_pending(const struct sock *sk)
338 const struct dccp_sock *dp = dccp_sk(sk);
339 return dp->dccps_timestamp_echo != 0 ||
340 #ifdef CONFIG_IP_DCCP_ACKVEC
341 (dccp_msk(sk)->dccpms_send_ack_vector &&
342 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
344 inet_csk_ack_scheduled(sk);
347 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
348 extern int dccp_insert_option_elapsed_time(struct sock *sk,
351 extern int dccp_insert_option_timestamp(struct sock *sk,
352 struct sk_buff *skb);
353 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
354 unsigned char option,
355 const void *value, unsigned char len);
357 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
359 static inline suseconds_t timeval_usecs(const struct timeval *tv)
361 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
364 static inline suseconds_t timeval_delta(const struct timeval *large,
365 const struct timeval *small)
367 time_t secs = large->tv_sec - small->tv_sec;
368 suseconds_t usecs = large->tv_usec - small->tv_usec;
372 usecs += USEC_PER_SEC;
374 return secs * USEC_PER_SEC + usecs;
377 static inline void timeval_add_usecs(struct timeval *tv,
378 const suseconds_t usecs)
380 tv->tv_usec += usecs;
381 while (tv->tv_usec >= USEC_PER_SEC) {
383 tv->tv_usec -= USEC_PER_SEC;
387 static inline void timeval_sub_usecs(struct timeval *tv,
388 const suseconds_t usecs)
390 tv->tv_usec -= usecs;
391 while (tv->tv_usec < 0) {
393 tv->tv_usec += USEC_PER_SEC;
398 extern int dccp_sysctl_init(void);
399 extern void dccp_sysctl_exit(void);
401 static inline int dccp_sysctl_init(void)
406 static inline void dccp_sysctl_exit(void)