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/config.h>
15 #include <linux/dccp.h>
20 #ifdef CONFIG_IP_DCCP_DEBUG
21 extern int dccp_debug;
23 #define dccp_pr_debug(format, a...) \
24 do { if (dccp_debug) \
25 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
27 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
28 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 int before48(const u64 seq1, const u64 seq2)
65 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
68 /* is seq1 > seq2 ? */
69 static inline int after48(const u64 seq1, const u64 seq2)
71 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
74 /* is seq2 <= seq1 <= seq3 ? */
75 static inline 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) \
115 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
116 #define DCCP_ADD_STATS_USER(field, val) \
117 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
119 extern int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
120 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
122 extern int dccp_send_response(struct sock *sk);
123 extern void dccp_send_ack(struct sock *sk);
124 extern void dccp_send_delayed_ack(struct sock *sk);
125 extern void dccp_send_sync(struct sock *sk, u64 seq);
127 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
130 extern void dccp_init_xmit_timers(struct sock *sk);
131 static inline void dccp_clear_xmit_timers(struct sock *sk)
133 inet_csk_clear_xmit_timers(sk);
136 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
138 extern const char *dccp_packet_name(const int type);
139 extern const char *dccp_state_name(const int state);
141 static inline void dccp_set_state(struct sock *sk, const int state)
143 const int oldstate = sk->sk_state;
145 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
147 dccp_state_name(oldstate), dccp_state_name(state));
148 WARN_ON(state == oldstate);
152 if (oldstate != DCCP_OPEN)
153 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
157 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
158 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
160 sk->sk_prot->unhash(sk);
161 if (inet_csk(sk)->icsk_bind_hash != NULL &&
162 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
163 inet_put_port(&dccp_hashinfo, sk);
166 if (oldstate == DCCP_OPEN)
167 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
170 /* Change state AFTER socket is unhashed to avoid closed
171 * socket sitting in hash tables.
173 sk->sk_state = state;
176 static inline void dccp_done(struct sock *sk)
178 dccp_set_state(sk, DCCP_CLOSED);
179 dccp_clear_xmit_timers(sk);
181 sk->sk_shutdown = SHUTDOWN_MASK;
183 if (!sock_flag(sk, SOCK_DEAD))
184 sk->sk_state_change(sk);
186 inet_csk_destroy_sock(sk);
189 static inline void dccp_openreq_init(struct request_sock *req,
190 struct dccp_sock *dp,
194 * FIXME: fill in the other req fields from the DCCP options
197 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
198 inet_rsk(req)->acked = 0;
202 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
204 extern struct sock *dccp_create_openreq_child(struct sock *sk,
205 const struct request_sock *req,
206 const struct sk_buff *skb);
208 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
210 extern void dccp_v4_err(struct sk_buff *skb, u32);
212 extern int dccp_v4_rcv(struct sk_buff *skb);
214 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
216 struct request_sock *req,
217 struct dst_entry *dst);
218 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
219 struct request_sock *req,
220 struct request_sock **prev);
222 extern int dccp_child_process(struct sock *parent, struct sock *child,
223 struct sk_buff *skb);
224 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
225 struct dccp_hdr *dh, unsigned len);
226 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
227 const struct dccp_hdr *dh, const unsigned len);
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);
233 extern struct sk_buff *dccp_make_reset(struct sock *sk,
234 struct dst_entry *dst,
235 enum dccp_reset_codes code);
237 extern int dccp_connect(struct sock *sk);
238 extern int dccp_disconnect(struct sock *sk, int flags);
239 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
240 char __user *optval, int __user *optlen);
241 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
242 char __user *optval, int optlen);
243 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
244 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
245 struct msghdr *msg, size_t size);
246 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
247 struct msghdr *msg, size_t len, int nonblock,
248 int flags, int *addr_len);
249 extern void dccp_shutdown(struct sock *sk, int how);
251 extern int dccp_v4_checksum(const struct sk_buff *skb,
252 const u32 saddr, const u32 daddr);
254 extern int dccp_v4_send_reset(struct sock *sk,
255 enum dccp_reset_codes code);
256 extern void dccp_send_close(struct sock *sk);
260 __u8 dccpd_reset_code;
268 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
270 static inline int dccp_non_data_packet(const struct sk_buff *skb)
272 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
274 return type == DCCP_PKT_ACK ||
275 type == DCCP_PKT_CLOSE ||
276 type == DCCP_PKT_CLOSEREQ ||
277 type == DCCP_PKT_RESET ||
278 type == DCCP_PKT_SYNC ||
279 type == DCCP_PKT_SYNCACK;
282 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
284 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
286 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
289 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
290 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
292 static inline void dccp_set_seqno(u64 *seqno, u64 value)
294 if (value > DCCP_MAX_SEQNO)
295 value -= DCCP_MAX_SEQNO + 1;
299 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
301 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
304 static inline void dccp_inc_seqno(u64 *seqno)
306 if (++*seqno > DCCP_MAX_SEQNO)
310 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
312 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
315 #if defined(__LITTLE_ENDIAN_BITFIELD)
316 dh->dccph_seq = htonl((gss >> 32)) >> 8;
317 #elif defined(__BIG_ENDIAN_BITFIELD)
318 dh->dccph_seq = htonl((gss >> 32));
320 #error "Adjust your <asm/byteorder.h> defines"
322 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
325 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
328 #if defined(__LITTLE_ENDIAN_BITFIELD)
329 dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
330 #elif defined(__BIG_ENDIAN_BITFIELD)
331 dhack->dccph_ack_nr_high = htonl((gsr >> 32));
333 #error "Adjust your <asm/byteorder.h> defines"
335 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
338 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
340 struct dccp_sock *dp = dccp_sk(sk);
343 dccp_set_seqno(&tmp_gsr,
345 (dp->dccps_options.dccpo_sequence_window / 4)));
347 dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
348 dccp_set_seqno(&dp->dccps_swh,
350 (3 * dp->dccps_options.dccpo_sequence_window) / 4));
353 static inline void dccp_update_gss(struct sock *sk, u64 seq)
355 struct dccp_sock *dp = dccp_sk(sk);
358 dccp_set_seqno(&tmp_gss,
360 dp->dccps_options.dccpo_sequence_window + 1));
361 dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
362 dp->dccps_awh = dp->dccps_gss = seq;
365 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
366 extern void dccp_insert_option_elapsed_time(struct sock *sk,
369 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
370 unsigned char option,
371 const void *value, unsigned char len);
373 extern struct socket *dccp_ctl_socket;
375 #define DCCP_ACKPKTS_STATE_RECEIVED 0
376 #define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
377 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
379 #define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
380 #define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
382 /** struct dccp_ackpkts - acknowledgeable packets
384 * This data structure is the one defined in the DCCP draft
387 * @dccpap_buf_head - circular buffer head
388 * @dccpap_buf_tail - circular buffer tail
389 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
390 * buffer (i.e. %dccpap_buf_head)
391 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
392 * by the buffer with State 0
394 * Additionally, the HC-Receiver must keep some information about the
395 * Ack Vectors it has recently sent. For each packet sent carrying an
396 * Ack Vector, it remembers four variables:
398 * @dccpap_ack_seqno - the Sequence Number used for the packet
399 * (HC-Receiver seqno)
400 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
401 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
403 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
405 * @dccpap_buf_len - circular buffer length
406 * @dccpap_buf - circular buffer of acknowledgeable packets
408 struct dccp_ackpkts {
409 unsigned int dccpap_buf_head;
410 unsigned int dccpap_buf_tail;
411 u64 dccpap_buf_ackno;
412 u64 dccpap_ack_seqno;
413 u64 dccpap_ack_ackno;
414 unsigned int dccpap_ack_ptr;
415 unsigned int dccpap_buf_vector_len;
416 unsigned int dccpap_ack_vector_len;
417 unsigned int dccpap_buf_len;
418 unsigned long dccpap_time;
424 extern struct dccp_ackpkts *
425 dccp_ackpkts_alloc(unsigned int len,
426 const unsigned int __nocast priority);
427 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
428 extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
429 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
430 struct sock *sk, u64 ackno);
432 #ifdef CONFIG_IP_DCCP_DEBUG
433 extern void dccp_ackvector_print(const u64 ackno,
434 const unsigned char *vector, int len);
435 extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
437 static inline void dccp_ackvector_print(const u64 ackno,
438 const unsigned char *vector,
440 static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }