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 #define DCCP_CRIT(fmt, a...) LIMIT_NETDEBUG(KERN_CRIT fmt " at %s:%d/%s()\n", \
22 ##a, __FILE__, __LINE__, __FUNCTION__)
23 #define DCCP_BUG(fmt, a...) do { DCCP_CRIT(fmt, ##a); dump_stack(); } while (0)
24 #define DCCP_BUG_ON(cond) do { if (unlikely((cond) == 0)) \
25 DCCP_BUG("BUG: condition \"%s\" fails",\
26 __stringify((cond))); \
30 #define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
31 printk(fmt, ##args); \
34 #define DCCP_PRINTK(enable, fmt, args...) printk(fmt, ##args)
36 #define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
37 "%s: " fmt, __FUNCTION__, ##a)
39 #ifdef CONFIG_IP_DCCP_DEBUG
40 extern int dccp_debug;
41 #define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
42 #define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
44 #define dccp_pr_debug(format, a...)
45 #define dccp_pr_debug_cat(format, a...)
48 extern struct inet_hashinfo dccp_hashinfo;
50 extern atomic_t dccp_orphan_count;
52 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
55 * Set safe upper bounds for header and option length. Since Data Offset is 8
56 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
57 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
58 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
59 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
60 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
62 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
63 #define DCCP_MAX_PACKET_HDR 28
64 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
65 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
67 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
68 * state, about 60 seconds */
70 /* RFC 1122, 4.2.3.1 initial RTO value */
71 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
73 /* Maximal interval between probes for local resources. */
74 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
76 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
78 #define DCCP_XMIT_TIMEO 30000 /* Time/msecs for blocking transmit per packet */
80 /* sysctl variables for DCCP */
81 extern int sysctl_dccp_request_retries;
82 extern int sysctl_dccp_retries1;
83 extern int sysctl_dccp_retries2;
84 extern int sysctl_dccp_feat_sequence_window;
85 extern int sysctl_dccp_feat_rx_ccid;
86 extern int sysctl_dccp_feat_tx_ccid;
87 extern int sysctl_dccp_feat_ack_ratio;
88 extern int sysctl_dccp_feat_send_ack_vector;
89 extern int sysctl_dccp_feat_send_ndp_count;
91 /* is seq1 < seq2 ? */
92 static inline int before48(const u64 seq1, const u64 seq2)
94 return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
97 /* is seq1 > seq2 ? */
98 static inline int after48(const u64 seq1, const u64 seq2)
100 return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
103 /* is seq2 <= seq1 <= seq3 ? */
104 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
106 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
109 static inline u64 max48(const u64 seq1, const u64 seq2)
111 return after48(seq1, seq2) ? seq1 : seq2;
114 /* is seq1 next seqno after seq2 */
115 static inline int follows48(const u64 seq1, const u64 seq2)
117 int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
124 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
125 DCCP_MIB_ESTABRESETS, /* EstabResets */
126 DCCP_MIB_CURRESTAB, /* CurrEstab */
127 DCCP_MIB_OUTSEGS, /* OutSegs */
129 DCCP_MIB_ABORTONTIMEOUT,
131 DCCP_MIB_ABORTFAILED,
132 DCCP_MIB_PASSIVEOPENS,
133 DCCP_MIB_ATTEMPTFAILS,
134 DCCP_MIB_OUTDATAGRAMS,
136 DCCP_MIB_OPTMANDATORYERROR,
141 #define DCCP_MIB_MAX __DCCP_MIB_MAX
143 unsigned long mibs[DCCP_MIB_MAX];
144 } __SNMP_MIB_ALIGN__;
146 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
147 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
148 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
149 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
150 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
151 #define DCCP_ADD_STATS_BH(field, val) \
152 SNMP_ADD_STATS_BH(dccp_statistics, field, val)
153 #define DCCP_ADD_STATS_USER(field, val) \
154 SNMP_ADD_STATS_USER(dccp_statistics, field, val)
157 * Checksumming routines
159 static inline int dccp_csum_coverage(const struct sk_buff *skb)
161 const struct dccp_hdr* dh = dccp_hdr(skb);
163 if (dh->dccph_cscov == 0)
165 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
168 static inline void dccp_csum_outgoing(struct sk_buff *skb)
170 int cov = dccp_csum_coverage(skb);
173 dccp_hdr(skb)->dccph_cscov = 0;
175 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
178 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
180 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
182 extern void dccp_send_ack(struct sock *sk);
183 extern void dccp_send_delayed_ack(struct sock *sk);
184 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
186 extern void dccp_send_sync(struct sock *sk, const u64 seq,
187 const enum dccp_pkt_type pkt_type);
189 extern void dccp_write_xmit(struct sock *sk, int block);
190 extern void dccp_write_space(struct sock *sk);
192 extern void dccp_init_xmit_timers(struct sock *sk);
193 static inline void dccp_clear_xmit_timers(struct sock *sk)
195 inet_csk_clear_xmit_timers(sk);
198 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
200 extern const char *dccp_packet_name(const int type);
201 extern const char *dccp_state_name(const int state);
203 extern void dccp_set_state(struct sock *sk, const int state);
204 extern void dccp_done(struct sock *sk);
206 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
208 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
210 extern struct sock *dccp_create_openreq_child(struct sock *sk,
211 const struct request_sock *req,
212 const struct sk_buff *skb);
214 extern int dccp_v4_do_rcv(struct sock *sk, 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 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
232 extern int dccp_destroy_sock(struct sock *sk);
234 extern void dccp_close(struct sock *sk, long timeout);
235 extern struct sk_buff *dccp_make_response(struct sock *sk,
236 struct dst_entry *dst,
237 struct request_sock *req);
239 extern int dccp_connect(struct sock *sk);
240 extern int dccp_disconnect(struct sock *sk, int flags);
241 extern void dccp_hash(struct sock *sk);
242 extern void dccp_unhash(struct sock *sk);
243 extern int dccp_getsockopt(struct sock *sk, int level, int optname,
244 char __user *optval, int __user *optlen);
245 extern int dccp_setsockopt(struct sock *sk, int level, int optname,
246 char __user *optval, int optlen);
248 extern int compat_dccp_getsockopt(struct sock *sk,
249 int level, int optname,
250 char __user *optval, int __user *optlen);
251 extern int compat_dccp_setsockopt(struct sock *sk,
252 int level, int optname,
253 char __user *optval, int optlen);
255 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
256 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
257 struct msghdr *msg, size_t size);
258 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
259 struct msghdr *msg, size_t len, int nonblock,
260 int flags, int *addr_len);
261 extern void dccp_shutdown(struct sock *sk, int how);
262 extern int inet_dccp_listen(struct socket *sock, int backlog);
263 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
265 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
268 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
269 extern void dccp_send_close(struct sock *sk, const int active);
270 extern int dccp_invalid_packet(struct sk_buff *skb);
272 static inline int dccp_bad_service_code(const struct sock *sk,
273 const __be32 service)
275 const struct dccp_sock *dp = dccp_sk(sk);
277 if (dp->dccps_service == service)
279 return !dccp_list_has_service(dp->dccps_service_list, service);
285 __u8 dccpd_reset_code;
291 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
293 static inline int dccp_non_data_packet(const struct sk_buff *skb)
295 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
297 return type == DCCP_PKT_ACK ||
298 type == DCCP_PKT_CLOSE ||
299 type == DCCP_PKT_CLOSEREQ ||
300 type == DCCP_PKT_RESET ||
301 type == DCCP_PKT_SYNC ||
302 type == DCCP_PKT_SYNCACK;
305 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
307 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
309 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
312 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
313 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
315 static inline void dccp_set_seqno(u64 *seqno, u64 value)
317 if (value > DCCP_MAX_SEQNO)
318 value -= DCCP_MAX_SEQNO + 1;
322 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
324 return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
327 static inline void dccp_inc_seqno(u64 *seqno)
329 if (++*seqno > DCCP_MAX_SEQNO)
333 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
335 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
338 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
339 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
342 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
345 dhack->dccph_reserved1 = 0;
346 dhack->dccph_ack_nr_high = htons(gsr >> 32);
347 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
350 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
352 struct dccp_sock *dp = dccp_sk(sk);
353 const struct dccp_minisock *dmsk = dccp_msk(sk);
356 dccp_set_seqno(&dp->dccps_swl,
357 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
358 dccp_set_seqno(&dp->dccps_swh,
359 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
362 static inline void dccp_update_gss(struct sock *sk, u64 seq)
364 struct dccp_sock *dp = dccp_sk(sk);
366 dp->dccps_awh = dp->dccps_gss = seq;
367 dccp_set_seqno(&dp->dccps_awl,
369 dccp_msk(sk)->dccpms_sequence_window + 1));
372 static inline int dccp_ack_pending(const struct sock *sk)
374 const struct dccp_sock *dp = dccp_sk(sk);
375 return dp->dccps_timestamp_echo != 0 ||
376 #ifdef CONFIG_IP_DCCP_ACKVEC
377 (dccp_msk(sk)->dccpms_send_ack_vector &&
378 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
380 inet_csk_ack_scheduled(sk);
383 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
384 extern int dccp_insert_option_elapsed_time(struct sock *sk,
387 extern int dccp_insert_option_timestamp(struct sock *sk,
388 struct sk_buff *skb);
389 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
390 unsigned char option,
391 const void *value, unsigned char len);
393 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
395 static inline suseconds_t timeval_usecs(const struct timeval *tv)
397 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
400 static inline suseconds_t timeval_delta(const struct timeval *large,
401 const struct timeval *small)
403 time_t secs = large->tv_sec - small->tv_sec;
404 suseconds_t usecs = large->tv_usec - small->tv_usec;
408 usecs += USEC_PER_SEC;
410 return secs * USEC_PER_SEC + usecs;
413 static inline void timeval_add_usecs(struct timeval *tv,
414 const suseconds_t usecs)
416 tv->tv_usec += usecs;
417 while (tv->tv_usec >= USEC_PER_SEC) {
419 tv->tv_usec -= USEC_PER_SEC;
423 static inline void timeval_sub_usecs(struct timeval *tv,
424 const suseconds_t usecs)
426 tv->tv_usec -= usecs;
427 while (tv->tv_usec < 0) {
429 tv->tv_usec += USEC_PER_SEC;
434 extern int dccp_sysctl_init(void);
435 extern void dccp_sysctl_exit(void);
437 static inline int dccp_sysctl_init(void)
442 static inline void dccp_sysctl_exit(void)