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>
22 * DCCP - specific warning and debugging macros.
24 #define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
26 #define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
27 __FILE__, __LINE__, __FUNCTION__)
28 #define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
29 #define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
30 DCCP_BUG("\"%s\" holds (exception!)", \
35 #define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
36 printk(fmt, ##args); \
39 #define DCCP_PRINTK(enable, fmt, args...) printk(fmt, ##args)
41 #define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
42 "%s: " fmt, __FUNCTION__, ##a)
44 #ifdef CONFIG_IP_DCCP_DEBUG
45 extern int dccp_debug;
46 #define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
47 #define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
49 #define dccp_pr_debug(format, a...)
50 #define dccp_pr_debug_cat(format, a...)
53 extern struct inet_hashinfo dccp_hashinfo;
55 extern atomic_t dccp_orphan_count;
57 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
60 * Set safe upper bounds for header and option length. Since Data Offset is 8
61 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
62 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
63 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
64 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
65 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
67 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
68 #define DCCP_MAX_PACKET_HDR 28
69 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
70 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
72 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
73 * state, about 60 seconds */
75 /* RFC 1122, 4.2.3.1 initial RTO value */
76 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
78 /* Maximal interval between probes for local resources. */
79 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
81 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
83 /* sysctl variables for DCCP */
84 extern int sysctl_dccp_request_retries;
85 extern int sysctl_dccp_retries1;
86 extern int sysctl_dccp_retries2;
87 extern int sysctl_dccp_feat_sequence_window;
88 extern int sysctl_dccp_feat_rx_ccid;
89 extern int sysctl_dccp_feat_tx_ccid;
90 extern int sysctl_dccp_feat_ack_ratio;
91 extern int sysctl_dccp_feat_send_ack_vector;
92 extern int sysctl_dccp_feat_send_ndp_count;
93 extern int sysctl_dccp_tx_qlen;
96 * 48-bit sequence number arithmetic (signed and unsigned)
98 #define INT48_MIN 0x800000000000LL /* 2^47 */
99 #define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
100 #define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
101 #define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
102 #define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
103 #define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
104 #define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
106 static inline void dccp_set_seqno(u64 *seqno, u64 value)
108 *seqno = value & UINT48_MAX;
111 static inline void dccp_inc_seqno(u64 *seqno)
113 *seqno = ADD48(*seqno, 1);
116 /* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
117 static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
119 u64 delta = SUB48(seqno2, seqno1);
121 return TO_SIGNED48(delta);
124 /* is seq1 < seq2 ? */
125 static inline int before48(const u64 seq1, const u64 seq2)
127 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
130 /* is seq1 > seq2 ? */
131 static inline int after48(const u64 seq1, const u64 seq2)
133 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
136 /* is seq2 <= seq1 <= seq3 ? */
137 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
139 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
142 static inline u64 max48(const u64 seq1, const u64 seq2)
144 return after48(seq1, seq2) ? seq1 : seq2;
147 /* is seq1 next seqno after seq2 */
148 static inline int follows48(const u64 seq1, const u64 seq2)
150 int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
157 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
158 DCCP_MIB_ESTABRESETS, /* EstabResets */
159 DCCP_MIB_CURRESTAB, /* CurrEstab */
160 DCCP_MIB_OUTSEGS, /* OutSegs */
162 DCCP_MIB_ABORTONTIMEOUT,
164 DCCP_MIB_ABORTFAILED,
165 DCCP_MIB_PASSIVEOPENS,
166 DCCP_MIB_ATTEMPTFAILS,
167 DCCP_MIB_OUTDATAGRAMS,
169 DCCP_MIB_OPTMANDATORYERROR,
174 #define DCCP_MIB_MAX __DCCP_MIB_MAX
176 unsigned long mibs[DCCP_MIB_MAX];
177 } __SNMP_MIB_ALIGN__;
179 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
180 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
181 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
182 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
183 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
184 #define DCCP_ADD_STATS_BH(field, val) \
185 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
186 #define DCCP_ADD_STATS_USER(field, val) \
187 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
190 * Checksumming routines
192 static inline int dccp_csum_coverage(const struct sk_buff *skb)
194 const struct dccp_hdr* dh = dccp_hdr(skb);
196 if (dh->dccph_cscov == 0)
198 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
201 static inline void dccp_csum_outgoing(struct sk_buff *skb)
203 int cov = dccp_csum_coverage(skb);
206 dccp_hdr(skb)->dccph_cscov = 0;
208 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
211 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
213 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
215 extern void dccp_send_ack(struct sock *sk);
216 extern void dccp_send_delayed_ack(struct sock *sk);
217 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
219 extern void dccp_send_sync(struct sock *sk, const u64 seq,
220 const enum dccp_pkt_type pkt_type);
222 extern void dccp_write_xmit(struct sock *sk, int block);
223 extern void dccp_write_space(struct sock *sk);
225 extern void dccp_init_xmit_timers(struct sock *sk);
226 static inline void dccp_clear_xmit_timers(struct sock *sk)
228 inet_csk_clear_xmit_timers(sk);
231 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
233 extern const char *dccp_packet_name(const int type);
234 extern const char *dccp_state_name(const int state);
236 extern void dccp_set_state(struct sock *sk, const int state);
237 extern void dccp_done(struct sock *sk);
239 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
241 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
243 extern struct sock *dccp_create_openreq_child(struct sock *sk,
244 const struct request_sock *req,
245 const struct sk_buff *skb);
247 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
249 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
251 struct request_sock *req,
252 struct dst_entry *dst);
253 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
254 struct request_sock *req,
255 struct request_sock **prev);
257 extern int dccp_child_process(struct sock *parent, struct sock *child,
258 struct sk_buff *skb);
259 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
260 struct dccp_hdr *dh, unsigned len);
261 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
262 const struct dccp_hdr *dh, const unsigned len);
264 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
265 extern int dccp_destroy_sock(struct sock *sk);
267 extern void dccp_close(struct sock *sk, long timeout);
268 extern struct sk_buff *dccp_make_response(struct sock *sk,
269 struct dst_entry *dst,
270 struct request_sock *req);
272 extern int dccp_connect(struct sock *sk);
273 extern int dccp_disconnect(struct sock *sk, int flags);
274 extern void dccp_hash(struct sock *sk);
275 extern void dccp_unhash(struct sock *sk);
276 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
277 char __user *optval, int __user *optlen);
278 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
279 char __user *optval, int optlen);
281 extern int compat_dccp_getsockopt(struct sock *sk,
282 int level, int optname,
283 char __user *optval, int __user *optlen);
284 extern int compat_dccp_setsockopt(struct sock *sk,
285 int level, int optname,
286 char __user *optval, int optlen);
288 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
289 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
290 struct msghdr *msg, size_t size);
291 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
292 struct msghdr *msg, size_t len, int nonblock,
293 int flags, int *addr_len);
294 extern void dccp_shutdown(struct sock *sk, int how);
295 extern int inet_dccp_listen(struct socket *sock, int backlog);
296 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
298 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
301 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
302 extern void dccp_send_close(struct sock *sk, const int active);
303 extern int dccp_invalid_packet(struct sk_buff *skb);
305 static inline int dccp_bad_service_code(const struct sock *sk,
306 const __be32 service)
308 const struct dccp_sock *dp = dccp_sk(sk);
310 if (dp->dccps_service == service)
312 return !dccp_list_has_service(dp->dccps_service_list, service);
318 __u8 dccpd_reset_code;
324 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
326 static inline int dccp_non_data_packet(const struct sk_buff *skb)
328 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
330 return type == DCCP_PKT_ACK ||
331 type == DCCP_PKT_CLOSE ||
332 type == DCCP_PKT_CLOSEREQ ||
333 type == DCCP_PKT_RESET ||
334 type == DCCP_PKT_SYNC ||
335 type == DCCP_PKT_SYNCACK;
338 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
340 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
342 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
345 #define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
347 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
349 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
352 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
353 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
356 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
359 dhack->dccph_reserved1 = 0;
360 dhack->dccph_ack_nr_high = htons(gsr >> 32);
361 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
364 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
366 struct dccp_sock *dp = dccp_sk(sk);
367 const struct dccp_minisock *dmsk = dccp_msk(sk);
370 dccp_set_seqno(&dp->dccps_swl,
371 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
372 dccp_set_seqno(&dp->dccps_swh,
373 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
376 static inline void dccp_update_gss(struct sock *sk, u64 seq)
378 struct dccp_sock *dp = dccp_sk(sk);
380 dp->dccps_awh = dp->dccps_gss = seq;
381 dccp_set_seqno(&dp->dccps_awl,
383 dccp_msk(sk)->dccpms_sequence_window + 1));
386 static inline int dccp_ack_pending(const struct sock *sk)
388 const struct dccp_sock *dp = dccp_sk(sk);
389 return dp->dccps_timestamp_echo != 0 ||
390 #ifdef CONFIG_IP_DCCP_ACKVEC
391 (dccp_msk(sk)->dccpms_send_ack_vector &&
392 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
394 inet_csk_ack_scheduled(sk);
397 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
398 extern int dccp_insert_option_elapsed_time(struct sock *sk,
401 extern int dccp_insert_option_timestamp(struct sock *sk,
402 struct sk_buff *skb);
403 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
404 unsigned char option,
405 const void *value, unsigned char len);
407 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
409 static inline suseconds_t timeval_usecs(const struct timeval *tv)
411 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
414 static inline suseconds_t timeval_delta(const struct timeval *large,
415 const struct timeval *small)
417 time_t secs = large->tv_sec - small->tv_sec;
418 suseconds_t usecs = large->tv_usec - small->tv_usec;
422 usecs += USEC_PER_SEC;
424 return secs * USEC_PER_SEC + usecs;
427 static inline void timeval_add_usecs(struct timeval *tv,
428 const suseconds_t usecs)
430 tv->tv_usec += usecs;
431 while (tv->tv_usec >= USEC_PER_SEC) {
433 tv->tv_usec -= USEC_PER_SEC;
437 static inline void timeval_sub_usecs(struct timeval *tv,
438 const suseconds_t usecs)
440 tv->tv_usec -= usecs;
441 while (tv->tv_usec < 0) {
443 tv->tv_usec += USEC_PER_SEC;
445 DCCP_BUG_ON(tv->tv_sec < 0);
449 extern int dccp_sysctl_init(void);
450 extern void dccp_sysctl_exit(void);
452 static inline int dccp_sysctl_init(void)
457 static inline void dccp_sysctl_exit(void)