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) \
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;
38 extern int dccp_tw_count;
39 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
41 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
43 /* FIXME: Right size this */
44 #define DCCP_MAX_OPT_LEN 128
46 #define DCCP_MAX_PACKET_HDR 32
48 #define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
50 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
51 * state, about 60 seconds */
53 /* draft-ietf-dccp-spec-11.txt initial RTO value */
54 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
56 /* Maximal interval between probes for local resources. */
57 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
59 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
61 extern struct proto dccp_v4_prot;
63 /* is seq1 < seq2 ? */
64 static inline const int before48(const u64 seq1, const u64 seq2)
66 return (const s64)((seq1 << 16) - (seq2 << 16)) < 0;
69 /* is seq1 > seq2 ? */
70 static inline const int after48(const u64 seq1, const u64 seq2)
72 return (const s64)((seq2 << 16) - (seq1 << 16)) < 0;
75 /* is seq2 <= seq1 <= seq3 ? */
76 static inline const int between48(const u64 seq1, const u64 seq2,
79 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
82 static inline u64 max48(const u64 seq1, const u64 seq2)
84 return after48(seq1, seq2) ? seq1 : seq2;
89 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
90 DCCP_MIB_ESTABRESETS, /* EstabResets */
91 DCCP_MIB_CURRESTAB, /* CurrEstab */
92 DCCP_MIB_OUTSEGS, /* OutSegs */
94 DCCP_MIB_ABORTONTIMEOUT,
97 DCCP_MIB_PASSIVEOPENS,
98 DCCP_MIB_ATTEMPTFAILS,
99 DCCP_MIB_OUTDATAGRAMS,
101 DCCP_MIB_OPTMANDATORYERROR,
106 #define DCCP_MIB_MAX __DCCP_MIB_MAX
108 unsigned long mibs[DCCP_MIB_MAX];
109 } __SNMP_MIB_ALIGN__;
111 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
112 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
113 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
114 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
115 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
116 #define DCCP_ADD_STATS_BH(field, val) \
117 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
118 #define DCCP_ADD_STATS_USER(field, val) \
119 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
121 extern int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
122 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
124 extern int dccp_send_response(struct sock *sk);
125 extern void dccp_send_ack(struct sock *sk);
126 extern void dccp_send_delayed_ack(struct sock *sk);
127 extern void dccp_send_sync(struct sock *sk, u64 seq);
129 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
132 extern void dccp_init_xmit_timers(struct sock *sk);
133 static inline void dccp_clear_xmit_timers(struct sock *sk)
135 inet_csk_clear_xmit_timers(sk);
138 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
140 extern const char *dccp_packet_name(const int type);
141 extern const char *dccp_state_name(const int state);
143 static inline void dccp_set_state(struct sock *sk, const int state)
145 const int oldstate = sk->sk_state;
147 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
149 dccp_state_name(oldstate), dccp_state_name(state));
150 WARN_ON(state == oldstate);
154 if (oldstate != DCCP_OPEN)
155 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
159 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
160 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
162 sk->sk_prot->unhash(sk);
163 if (inet_csk(sk)->icsk_bind_hash != NULL &&
164 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
165 inet_put_port(&dccp_hashinfo, sk);
168 if (oldstate == DCCP_OPEN)
169 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
172 /* Change state AFTER socket is unhashed to avoid closed
173 * socket sitting in hash tables.
175 sk->sk_state = state;
178 static inline void dccp_done(struct sock *sk)
180 dccp_set_state(sk, DCCP_CLOSED);
181 dccp_clear_xmit_timers(sk);
183 sk->sk_shutdown = SHUTDOWN_MASK;
185 if (!sock_flag(sk, SOCK_DEAD))
186 sk->sk_state_change(sk);
188 inet_csk_destroy_sock(sk);
191 static inline void dccp_openreq_init(struct request_sock *req,
192 struct dccp_sock *dp,
196 * FIXME: fill in the other req fields from the DCCP options
199 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
200 inet_rsk(req)->acked = 0;
204 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
206 extern struct sock *dccp_create_openreq_child(struct sock *sk,
207 const struct request_sock *req,
208 const struct sk_buff *skb);
210 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
212 extern void dccp_v4_err(struct sk_buff *skb, u32);
214 extern int dccp_v4_rcv(struct sk_buff *skb);
216 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
218 struct request_sock *req,
219 struct dst_entry *dst);
220 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
221 struct request_sock *req,
222 struct request_sock **prev);
224 extern int dccp_child_process(struct sock *parent, struct sock *child,
225 struct sk_buff *skb);
226 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
227 struct dccp_hdr *dh, unsigned len);
228 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
229 const struct dccp_hdr *dh, const unsigned len);
231 extern void dccp_close(struct sock *sk, long timeout);
232 extern struct sk_buff *dccp_make_response(struct sock *sk,
233 struct dst_entry *dst,
234 struct request_sock *req);
236 extern int dccp_connect(struct sock *sk);
237 extern int dccp_disconnect(struct sock *sk, int flags);
238 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
239 char *optval, int *optlen);
240 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
241 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
242 struct msghdr *msg, size_t size);
243 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
244 struct msghdr *msg, size_t len, int nonblock,
245 int flags, int *addr_len);
246 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
247 char *optval, int optlen);
248 extern void dccp_shutdown(struct sock *sk, int how);
250 extern int dccp_v4_checksum(const struct sk_buff *skb,
251 const u32 saddr, const u32 daddr);
253 extern int dccp_v4_send_reset(struct sock *sk,
254 enum dccp_reset_codes code);
255 extern void dccp_send_close(struct sock *sk);
259 __u8 dccpd_reset_code;
267 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
269 static inline int dccp_non_data_packet(const struct sk_buff *skb)
271 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
273 return type == DCCP_PKT_ACK ||
274 type == DCCP_PKT_CLOSE ||
275 type == DCCP_PKT_CLOSEREQ ||
276 type == DCCP_PKT_RESET ||
277 type == DCCP_PKT_SYNC ||
278 type == DCCP_PKT_SYNCACK;
281 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
283 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
285 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
288 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
289 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
291 static inline void dccp_set_seqno(u64 *seqno, u64 value)
293 if (value > DCCP_MAX_SEQNO)
294 value -= DCCP_MAX_SEQNO + 1;
298 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
300 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
303 static inline void dccp_inc_seqno(u64 *seqno)
305 if (++*seqno > DCCP_MAX_SEQNO)
309 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
311 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
314 #if defined(__LITTLE_ENDIAN_BITFIELD)
315 dh->dccph_seq = htonl((gss >> 32)) >> 8;
316 #elif defined(__BIG_ENDIAN_BITFIELD)
317 dh->dccph_seq = htonl((gss >> 32));
319 #error "Adjust your <asm/byteorder.h> defines"
321 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
324 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
327 #if defined(__LITTLE_ENDIAN_BITFIELD)
328 dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
329 #elif defined(__BIG_ENDIAN_BITFIELD)
330 dhack->dccph_ack_nr_high = htonl((gsr >> 32));
332 #error "Adjust your <asm/byteorder.h> defines"
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);
342 dccp_set_seqno(&tmp_gsr,
344 (dp->dccps_options.dccpo_sequence_window / 4)));
346 dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
347 dccp_set_seqno(&dp->dccps_swh,
349 (3 * dp->dccps_options.dccpo_sequence_window) / 4));
352 static inline void dccp_update_gss(struct sock *sk, u64 seq)
354 struct dccp_sock *dp = dccp_sk(sk);
357 dccp_set_seqno(&tmp_gss,
359 dp->dccps_options.dccpo_sequence_window + 1));
360 dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
361 dp->dccps_awh = dp->dccps_gss = seq;
364 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
365 extern void dccp_insert_option_elapsed_time(struct sock *sk,
368 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
369 unsigned char option,
370 const void *value, unsigned char len);
372 extern struct socket *dccp_ctl_socket;
374 #define DCCP_ACKPKTS_STATE_RECEIVED 0
375 #define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
376 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
378 #define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
379 #define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
381 /** struct dccp_ackpkts - acknowledgeable packets
383 * This data structure is the one defined in the DCCP draft
386 * @dccpap_buf_head - circular buffer head
387 * @dccpap_buf_tail - circular buffer tail
388 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
389 * buffer (i.e. %dccpap_buf_head)
390 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
391 * by the buffer with State 0
393 * Additionally, the HC-Receiver must keep some information about the
394 * Ack Vectors it has recently sent. For each packet sent carrying an
395 * Ack Vector, it remembers four variables:
397 * @dccpap_ack_seqno - the Sequence Number used for the packet
398 * (HC-Receiver seqno)
399 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
400 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
402 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
404 * @dccpap_buf_len - circular buffer length
405 * @dccpap_buf - circular buffer of acknowledgeable packets
407 struct dccp_ackpkts {
408 unsigned int dccpap_buf_head;
409 unsigned int dccpap_buf_tail;
410 u64 dccpap_buf_ackno;
411 u64 dccpap_ack_seqno;
412 u64 dccpap_ack_ackno;
413 unsigned int dccpap_ack_ptr;
414 unsigned int dccpap_buf_vector_len;
415 unsigned int dccpap_ack_vector_len;
416 unsigned int dccpap_buf_len;
417 unsigned long dccpap_time;
423 extern struct dccp_ackpkts *dccp_ackpkts_alloc(unsigned int len, int priority);
424 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
425 extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
426 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
427 struct sock *sk, u64 ackno);
430 extern void dccp_ackvector_print(const u64 ackno,
431 const unsigned char *vector, int len);
432 extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
434 static inline void dccp_ackvector_print(const u64 ackno,
435 const unsigned char *vector,
437 static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }