6 * An implementation of the DCCP protocol
7 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/dccp.h>
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) printk(format, ##a); } while (0)
30 #define dccp_pr_debug(format, a...)
31 #define dccp_pr_debug_cat(format, a...)
34 extern struct inet_hashinfo dccp_hashinfo;
36 extern atomic_t dccp_orphan_count;
37 extern int dccp_tw_count;
38 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
40 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
42 /* FIXME: Right size this */
43 #define DCCP_MAX_OPT_LEN 128
45 #define DCCP_MAX_PACKET_HDR 32
47 #define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
49 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
50 * state, about 60 seconds */
52 /* draft-ietf-dccp-spec-11.txt initial RTO value */
53 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
55 /* Maximal interval between probes for local resources. */
56 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
58 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
60 extern struct proto dccp_v4_prot;
62 /* is seq1 < seq2 ? */
63 static inline const int before48(const u64 seq1, const u64 seq2)
65 return (const s64)((seq1 << 16) - (seq2 << 16)) < 0;
68 /* is seq1 > seq2 ? */
69 static inline const int after48(const u64 seq1, const u64 seq2)
71 return (const s64)((seq2 << 16) - (seq1 << 16)) < 0;
74 /* is seq2 <= seq1 <= seq3 ? */
75 static inline const int between48(const u64 seq1, const u64 seq2, const u64 seq3)
77 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
80 static inline u64 max48(const u64 seq1, const u64 seq2)
82 return after48(seq1, seq2) ? seq1 : seq2;
87 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
88 DCCP_MIB_ESTABRESETS, /* EstabResets */
89 DCCP_MIB_CURRESTAB, /* CurrEstab */
90 DCCP_MIB_OUTSEGS, /* OutSegs */
92 DCCP_MIB_ABORTONTIMEOUT,
95 DCCP_MIB_PASSIVEOPENS,
96 DCCP_MIB_ATTEMPTFAILS,
97 DCCP_MIB_OUTDATAGRAMS,
99 DCCP_MIB_OPTMANDATORYERROR,
104 #define DCCP_MIB_MAX __DCCP_MIB_MAX
106 unsigned long mibs[DCCP_MIB_MAX];
107 } __SNMP_MIB_ALIGN__;
109 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
110 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
111 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
112 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
113 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
114 #define DCCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(dccp_statistics, field, val)
115 #define DCCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(dccp_statistics, field, val)
117 extern int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
118 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
120 extern int dccp_send_response(struct sock *sk);
121 extern void dccp_send_ack(struct sock *sk);
122 extern void dccp_send_delayed_ack(struct sock *sk);
123 extern void dccp_send_sync(struct sock *sk, u64 seq);
125 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
128 extern void dccp_init_xmit_timers(struct sock *sk);
129 static inline void dccp_clear_xmit_timers(struct sock *sk)
131 inet_csk_clear_xmit_timers(sk);
134 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
136 extern const char *dccp_packet_name(const int type);
137 extern const char *dccp_state_name(const int state);
139 static inline void dccp_set_state(struct sock *sk, const int state)
141 const int oldstate = sk->sk_state;
143 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
145 dccp_state_name(oldstate), dccp_state_name(state));
146 WARN_ON(state == oldstate);
150 if (oldstate != DCCP_OPEN)
151 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
155 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
156 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
158 sk->sk_prot->unhash(sk);
159 if (inet_csk(sk)->icsk_bind_hash != NULL &&
160 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
161 inet_put_port(&dccp_hashinfo, sk);
164 if (oldstate == DCCP_OPEN)
165 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
168 /* Change state AFTER socket is unhashed to avoid closed
169 * socket sitting in hash tables.
171 sk->sk_state = state;
174 static inline void dccp_done(struct sock *sk)
176 dccp_set_state(sk, DCCP_CLOSED);
177 dccp_clear_xmit_timers(sk);
179 sk->sk_shutdown = SHUTDOWN_MASK;
181 if (!sock_flag(sk, SOCK_DEAD))
182 sk->sk_state_change(sk);
184 inet_csk_destroy_sock(sk);
187 static inline void dccp_openreq_init(struct request_sock *req,
188 struct dccp_sock *dp,
192 * FIXME: fill in the other req fields from the DCCP options
195 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
196 inet_rsk(req)->acked = 0;
200 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
202 extern struct sock *dccp_create_openreq_child(struct sock *sk,
203 const struct request_sock *req,
204 const struct sk_buff *skb);
206 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
208 extern void dccp_v4_err(struct sk_buff *skb, u32);
210 extern int dccp_v4_rcv(struct sk_buff *skb);
212 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
214 struct request_sock *req,
215 struct dst_entry *dst);
216 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
217 struct request_sock *req,
218 struct request_sock **prev);
220 extern int dccp_child_process(struct sock *parent, struct sock *child,
221 struct sk_buff *skb);
222 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
223 struct dccp_hdr *dh, unsigned len);
224 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
225 const struct dccp_hdr *dh, const unsigned len);
227 extern void dccp_close(struct sock *sk, long timeout);
228 extern struct sk_buff *dccp_make_response(struct sock *sk,
229 struct dst_entry *dst,
230 struct request_sock *req);
232 extern int dccp_connect(struct sock *sk);
233 extern int dccp_disconnect(struct sock *sk, int flags);
234 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
235 char *optval, int *optlen);
236 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
237 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
239 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
240 struct msghdr *msg, size_t len, int nonblock,
241 int flags, int *addr_len);
242 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
243 char *optval, int optlen);
244 extern void dccp_shutdown(struct sock *sk, int how);
246 extern int dccp_v4_checksum(const struct sk_buff *skb,
247 const u32 saddr, const u32 daddr);
249 extern int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code);
250 extern void dccp_send_close(struct sock *sk);
254 __u8 dccpd_reset_code;
262 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
264 static inline int dccp_non_data_packet(const struct sk_buff *skb)
266 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
268 return type == DCCP_PKT_ACK ||
269 type == DCCP_PKT_CLOSE ||
270 type == DCCP_PKT_CLOSEREQ ||
271 type == DCCP_PKT_RESET ||
272 type == DCCP_PKT_SYNC ||
273 type == DCCP_PKT_SYNCACK;
276 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
278 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
280 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
283 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
284 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
286 static inline void dccp_set_seqno(u64 *seqno, u64 value)
288 if (value > DCCP_MAX_SEQNO)
289 value -= DCCP_MAX_SEQNO + 1;
293 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
295 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
298 static inline void dccp_inc_seqno(u64 *seqno)
300 if (++*seqno > DCCP_MAX_SEQNO)
304 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
306 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh + sizeof(*dh));
308 #if defined(__LITTLE_ENDIAN_BITFIELD)
309 dh->dccph_seq = htonl((gss >> 32)) >> 8;
310 #elif defined(__BIG_ENDIAN_BITFIELD)
311 dh->dccph_seq = htonl((gss >> 32));
313 #error "Adjust your <asm/byteorder.h> defines"
315 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
318 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, const u64 gsr)
320 #if defined(__LITTLE_ENDIAN_BITFIELD)
321 dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
322 #elif defined(__BIG_ENDIAN_BITFIELD)
323 dhack->dccph_ack_nr_high = htonl((gsr >> 32));
325 #error "Adjust your <asm/byteorder.h> defines"
327 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
330 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
332 struct dccp_sock *dp = dccp_sk(sk);
335 dccp_set_seqno(&tmp_gsr, dp->dccps_gsr + 1 - (dp->dccps_options.dccpo_sequence_window / 4));
337 dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
338 dccp_set_seqno(&dp->dccps_swh,
339 dp->dccps_gsr + (3 * dp->dccps_options.dccpo_sequence_window) / 4);
342 static inline void dccp_update_gss(struct sock *sk, u64 seq)
344 struct dccp_sock *dp = dccp_sk(sk);
347 dccp_set_seqno(&tmp_gss, dp->dccps_gss - dp->dccps_options.dccpo_sequence_window + 1);
348 dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
349 dp->dccps_awh = dp->dccps_gss = seq;
352 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
353 extern void dccp_insert_option_elapsed_time(struct sock *sk,
356 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
357 unsigned char option,
358 const void *value, unsigned char len);
360 extern struct socket *dccp_ctl_socket;
362 #define DCCP_ACKPKTS_STATE_RECEIVED 0
363 #define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
364 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
366 #define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
367 #define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
369 /** struct dccp_ackpkts - acknowledgeable packets
371 * This data structure is the one defined in the DCCP draft
374 * @dccpap_buf_head - circular buffer head
375 * @dccpap_buf_tail - circular buffer tail
376 * @dccpap_buf_ackno - ack # of the most recent packet acknoldgeable in the buffer (i.e. %dccpap_buf_head)
377 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked by the buffer with State 0
379 * Additionally, the HC-Receiver must keep some information about the
380 * Ack Vectors it has recently sent. For each packet sent carrying an
381 * Ack Vector, it remembers four variables:
383 * @dccpap_ack_seqno - the Sequence Number used for the packet (HC-Receiver seqno)
384 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
385 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet (HC-Sender seqno)
386 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
388 * @dccpap_buf_len - circular buffer length
389 * @dccpap_buf - circular buffer of acknowledgeable packets
391 struct dccp_ackpkts {
392 unsigned int dccpap_buf_head;
393 unsigned int dccpap_buf_tail;
394 u64 dccpap_buf_ackno;
395 u64 dccpap_ack_seqno;
396 u64 dccpap_ack_ackno;
397 unsigned int dccpap_ack_ptr;
398 unsigned int dccpap_buf_vector_len;
399 unsigned int dccpap_ack_vector_len;
400 unsigned int dccpap_buf_len;
401 unsigned long dccpap_time;
407 extern struct dccp_ackpkts *dccp_ackpkts_alloc(unsigned int len, int priority);
408 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
409 extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
410 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
411 struct sock *sk, u64 ackno);
414 extern void dccp_ackvector_print(const u64 ackno,
415 const unsigned char *vector, int len);
416 extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
418 static inline void dccp_ackvector_print(const u64 ackno,
419 const unsigned char *vector,
421 static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }