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Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001#ifndef _DCCP_H
2#define _DCCP_H
3/*
4 * net/dccp/dccp.h
5 *
6 * An implementation of the DCCP protocol
Ian McDonald1bc09862005-08-20 00:23:43 -03007 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
Ian McDonalde6bccd32006-08-26 19:01:30 -07008 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07009 *
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.
13 */
14
15#include <linux/dccp.h>
Arnaldo Carvalho de Melo9823b7b2007-08-19 17:16:35 -070016#include <linux/ktime.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070017#include <net/snmp.h>
18#include <net/sock.h>
19#include <net/tcp.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070020#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070021
Gerrit Renker59348b12006-11-20 18:39:23 -020022/*
23 * DCCP - specific warning and debugging macros.
24 */
25#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
Harvey Harrison0dc47872008-03-05 20:47:47 -080026 __func__, ##a)
Gerrit Renker59348b12006-11-20 18:39:23 -020027#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
Harvey Harrison0dc47872008-03-05 20:47:47 -080028 __FILE__, __LINE__, __func__)
Gerrit Renker59348b12006-11-20 18:39:23 -020029#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
30#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
31 DCCP_BUG("\"%s\" holds (exception!)", \
32 __stringify(cond)); \
Gerrit Renker3c695262006-11-15 21:27:47 -020033 } while (0)
34
Gerrit Renker84116712006-11-20 18:26:03 -020035#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
36 printk(fmt, ##args); \
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +090037 } while(0)
Gerrit Renker84116712006-11-20 18:26:03 -020038#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
Harvey Harrison0dc47872008-03-05 20:47:47 -080039 "%s: " fmt, __func__, ##a)
Gerrit Renker84116712006-11-20 18:26:03 -020040
Arnaldo Carvalho de Melo725ba8e2005-08-13 20:35:39 -030041#ifdef CONFIG_IP_DCCP_DEBUG
Rusty Russelleb939922011-12-19 14:08:01 +000042extern bool dccp_debug;
Gerrit Renker84116712006-11-20 18:26:03 -020043#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
44#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
Gerrit Renkerf3f3abb2009-01-16 23:36:33 +000045#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070046#else
47#define dccp_pr_debug(format, a...)
48#define dccp_pr_debug_cat(format, a...)
Gerrit Renkerf3f3abb2009-01-16 23:36:33 +000049#define dccp_debug(format, a...)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070050#endif
51
52extern struct inet_hashinfo dccp_hashinfo;
53
Eric Dumazetdd24c002008-11-25 21:17:14 -080054extern struct percpu_counter dccp_orphan_count;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070055
Joe Perchesa402a5a2013-10-18 13:48:23 -070056void dccp_time_wait(struct sock *sk, int state, int timeo);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070057
Gerrit Renker60361be2006-11-10 02:13:56 -020058/*
59 * Set safe upper bounds for header and option length. Since Data Offset is 8
60 * bits (RFC 4340, sec. 5.1), the total header length can never be more than
61 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
62 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
63 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
64 * Hence a safe upper bound for the maximum option length is 1020-28 = 992
65 */
Gerrit Renker86739fb2009-02-27 22:38:29 +000066#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(uint32_t))
Gerrit Renker60361be2006-11-10 02:13:56 -020067#define DCCP_MAX_PACKET_HDR 28
68#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
69#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070070
Gerrit Renker86739fb2009-02-27 22:38:29 +000071/* Upper bound for initial feature-negotiation overhead (padded to 32 bits) */
72#define DCCP_FEATNEG_OVERHEAD (32 * sizeof(uint32_t))
73
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070074#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
75 * state, about 60 seconds */
76
Gerrit Renker0e64e942006-10-24 16:17:51 -070077/* RFC 1122, 4.2.3.1 initial RTO value */
Eric Dumazet95c96172012-04-15 05:58:06 +000078#define DCCP_TIMEOUT_INIT ((unsigned int)(3 * HZ))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070079
Gerrit Renker28be5442007-12-13 12:16:23 -020080/*
81 * The maximum back-off value for retransmissions. This is needed for
82 * - retransmitting client-Requests (sec. 8.1.1),
83 * - retransmitting Close/CloseReq when closing (sec. 8.3),
84 * - feature-negotiation retransmission (sec. 6.6.3),
85 * - Acks in client-PARTOPEN state (sec. 8.1.5).
86 */
Eric Dumazet95c96172012-04-15 05:58:06 +000087#define DCCP_RTO_MAX ((unsigned int)(64 * HZ))
Gerrit Renker4712a792007-03-20 15:23:18 -030088
Gerrit Renker954c2db2007-12-12 14:06:14 -020089/*
90 * RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4
91 */
Gerrit Renker4712a792007-03-20 15:23:18 -030092#define DCCP_SANE_RTT_MIN 100
Gerrit Renker954c2db2007-12-12 14:06:14 -020093#define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5)
94#define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC)
Gerrit Renker4712a792007-03-20 15:23:18 -030095
Gerrit Renker2e2e9e92006-11-13 13:23:52 -020096/* sysctl variables for DCCP */
97extern int sysctl_dccp_request_retries;
98extern int sysctl_dccp_retries1;
99extern int sysctl_dccp_retries2;
Ian McDonaldb1308dc2006-11-20 18:30:17 -0200100extern int sysctl_dccp_tx_qlen;
Gerrit Renkera94f0f92007-09-26 11:31:49 -0300101extern int sysctl_dccp_sync_ratelimit;
Gerrit Renker2e2e9e92006-11-13 13:23:52 -0200102
Gerrit Renker6b811d42007-03-20 12:26:51 -0300103/*
104 * 48-bit sequence number arithmetic (signed and unsigned)
105 */
106#define INT48_MIN 0x800000000000LL /* 2^47 */
107#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
108#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
109#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
110#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
111#define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
112#define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
113
114static inline void dccp_set_seqno(u64 *seqno, u64 value)
115{
116 *seqno = value & UINT48_MAX;
117}
118
119static inline void dccp_inc_seqno(u64 *seqno)
120{
121 *seqno = ADD48(*seqno, 1);
122}
123
Gerrit Renker0aec51c2007-03-20 12:45:59 -0300124/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
125static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
Gerrit Renker6b811d42007-03-20 12:26:51 -0300126{
Gerrit Renker0aec51c2007-03-20 12:45:59 -0300127 u64 delta = SUB48(seqno2, seqno1);
128
129 return TO_SIGNED48(delta);
Gerrit Renker6b811d42007-03-20 12:26:51 -0300130}
131
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700132/* is seq1 < seq2 ? */
Patrick McHardya10cedd2005-08-14 21:05:53 -0300133static inline int before48(const u64 seq1, const u64 seq2)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700134{
Gerrit Renkerd52de172007-03-20 13:00:26 -0300135 return (s64)((seq2 << 16) - (seq1 << 16)) > 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700136}
137
138/* is seq1 > seq2 ? */
Gerrit Renkerd52de172007-03-20 13:00:26 -0300139#define after48(seq1, seq2) before48(seq2, seq1)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700140
141/* is seq2 <= seq1 <= seq3 ? */
Patrick McHardya10cedd2005-08-14 21:05:53 -0300142static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700143{
144 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
145}
146
147static inline u64 max48(const u64 seq1, const u64 seq2)
148{
149 return after48(seq1, seq2) ? seq1 : seq2;
150}
151
Gerrit Renker2013c7e2008-07-13 11:51:40 +0100152/**
Ivo Caladod196c9a2010-10-11 20:40:04 +0200153 * dccp_loss_count - Approximate the number of lost data packets in a burst loss
154 * @s1: last known sequence number before the loss ('hole')
155 * @s2: first sequence number seen after the 'hole'
Gerrit Renker2013c7e2008-07-13 11:51:40 +0100156 * @ndp: NDP count on packet with sequence number @s2
Gerrit Renker2013c7e2008-07-13 11:51:40 +0100157 */
Ivo Caladod196c9a2010-10-11 20:40:04 +0200158static inline u64 dccp_loss_count(const u64 s1, const u64 s2, const u64 ndp)
Gerrit Renker2013c7e2008-07-13 11:51:40 +0100159{
160 s64 delta = dccp_delta_seqno(s1, s2);
161
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700162 WARN_ON(delta < 0);
Ivo Caladod196c9a2010-10-11 20:40:04 +0200163 delta -= ndp + 1;
164
165 return delta > 0 ? delta : 0;
166}
167
168/**
169 * dccp_loss_free - Evaluate condition for data loss from RFC 4340, 7.7.1
170 */
171static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp)
172{
173 return dccp_loss_count(s1, s2, ndp) == 0;
Gerrit Renker2013c7e2008-07-13 11:51:40 +0100174}
175
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700176enum {
177 DCCP_MIB_NUM = 0,
178 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
179 DCCP_MIB_ESTABRESETS, /* EstabResets */
180 DCCP_MIB_CURRESTAB, /* CurrEstab */
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900181 DCCP_MIB_OUTSEGS, /* OutSegs */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700182 DCCP_MIB_OUTRSTS,
183 DCCP_MIB_ABORTONTIMEOUT,
184 DCCP_MIB_TIMEOUTS,
185 DCCP_MIB_ABORTFAILED,
186 DCCP_MIB_PASSIVEOPENS,
187 DCCP_MIB_ATTEMPTFAILS,
188 DCCP_MIB_OUTDATAGRAMS,
189 DCCP_MIB_INERRS,
190 DCCP_MIB_OPTMANDATORYERROR,
191 DCCP_MIB_INVALIDOPT,
192 __DCCP_MIB_MAX
193};
194
195#define DCCP_MIB_MAX __DCCP_MIB_MAX
196struct dccp_mib {
197 unsigned long mibs[DCCP_MIB_MAX];
Eric Dumazetec733b152010-03-18 20:36:06 +0000198};
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700199
200DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300201#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
202#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300203#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700204
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200205/*
206 * Checksumming routines
207 */
Ian McDonalde9618112007-05-28 16:32:26 -0300208static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb)
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200209{
210 const struct dccp_hdr* dh = dccp_hdr(skb);
211
212 if (dh->dccph_cscov == 0)
213 return skb->len;
214 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
215}
216
217static inline void dccp_csum_outgoing(struct sk_buff *skb)
218{
Ian McDonalde9618112007-05-28 16:32:26 -0300219 unsigned int cov = dccp_csum_coverage(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200220
221 if (cov >= skb->len)
222 dccp_hdr(skb)->dccph_cscov = 0;
223
224 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
225}
226
Joe Perchesa402a5a2013-10-18 13:48:23 -0700227void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200228
Joe Perchesa402a5a2013-10-18 13:48:23 -0700229int dccp_retransmit_skb(struct sock *sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700230
Joe Perchesa402a5a2013-10-18 13:48:23 -0700231void dccp_send_ack(struct sock *sk);
232void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
233 struct request_sock *rsk);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200234
Joe Perchesa402a5a2013-10-18 13:48:23 -0700235void dccp_send_sync(struct sock *sk, const u64 seq,
236 const enum dccp_pkt_type pkt_type);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700237
Tomasz Grobelny871a2c12010-12-04 13:38:01 +0100238/*
239 * TX Packet Dequeueing Interface
240 */
Joe Perchesa402a5a2013-10-18 13:48:23 -0700241void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb);
242bool dccp_qpolicy_full(struct sock *sk);
243void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb);
244struct sk_buff *dccp_qpolicy_top(struct sock *sk);
245struct sk_buff *dccp_qpolicy_pop(struct sock *sk);
246bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param);
Tomasz Grobelny871a2c12010-12-04 13:38:01 +0100247
248/*
249 * TX Packet Output and TX Timers
250 */
Joe Perchesa402a5a2013-10-18 13:48:23 -0700251void dccp_write_xmit(struct sock *sk);
252void dccp_write_space(struct sock *sk);
253void dccp_flush_write_queue(struct sock *sk, long *time_budget);
Arnaldo Carvalho de Melo27258ee2005-08-09 20:30:56 -0700254
Joe Perchesa402a5a2013-10-18 13:48:23 -0700255void dccp_init_xmit_timers(struct sock *sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700256static inline void dccp_clear_xmit_timers(struct sock *sk)
257{
258 inet_csk_clear_xmit_timers(sk);
259}
260
Joe Perchesa402a5a2013-10-18 13:48:23 -0700261unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700262
Joe Perchesa402a5a2013-10-18 13:48:23 -0700263const char *dccp_packet_name(const int type);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700264
Joe Perchesa402a5a2013-10-18 13:48:23 -0700265void dccp_set_state(struct sock *sk, const int state);
266void dccp_done(struct sock *sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700267
Joe Perchesa402a5a2013-10-18 13:48:23 -0700268int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp,
269 struct sk_buff const *skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700270
Joe Perchesa402a5a2013-10-18 13:48:23 -0700271int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700272
Joe Perchesa402a5a2013-10-18 13:48:23 -0700273struct sock *dccp_create_openreq_child(struct sock *sk,
274 const struct request_sock *req,
275 const struct sk_buff *skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700276
Joe Perchesa402a5a2013-10-18 13:48:23 -0700277int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700278
Joe Perchesa402a5a2013-10-18 13:48:23 -0700279struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
280 struct request_sock *req,
281 struct dst_entry *dst);
282struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
283 struct request_sock *req,
284 struct request_sock **prev);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700285
Joe Perchesa402a5a2013-10-18 13:48:23 -0700286int dccp_child_process(struct sock *parent, struct sock *child,
287 struct sk_buff *skb);
288int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
289 struct dccp_hdr *dh, unsigned int len);
290int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
291 const struct dccp_hdr *dh, const unsigned int len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700292
Joe Perchesa402a5a2013-10-18 13:48:23 -0700293int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
294void dccp_destroy_sock(struct sock *sk);
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800295
Joe Perchesa402a5a2013-10-18 13:48:23 -0700296void dccp_close(struct sock *sk, long timeout);
297struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
298 struct request_sock *req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700299
Joe Perchesa402a5a2013-10-18 13:48:23 -0700300int dccp_connect(struct sock *sk);
301int dccp_disconnect(struct sock *sk, int flags);
302int dccp_getsockopt(struct sock *sk, int level, int optname,
303 char __user *optval, int __user *optlen);
304int dccp_setsockopt(struct sock *sk, int level, int optname,
305 char __user *optval, unsigned int optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800306#ifdef CONFIG_COMPAT
Joe Perchesa402a5a2013-10-18 13:48:23 -0700307int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
308 char __user *optval, int __user *optlen);
309int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
310 char __user *optval, unsigned int optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800311#endif
Joe Perchesa402a5a2013-10-18 13:48:23 -0700312int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
313int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
314 size_t size);
315int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
316 struct msghdr *msg, size_t len, int nonblock, int flags,
317 int *addr_len);
318void dccp_shutdown(struct sock *sk, int how);
319int inet_dccp_listen(struct socket *sock, int backlog);
320unsigned int dccp_poll(struct file *file, struct socket *sock,
321 poll_table *wait);
322int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700323
Joe Perchesa402a5a2013-10-18 13:48:23 -0700324struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *skb);
325int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
326void dccp_send_close(struct sock *sk, const int active);
327int dccp_invalid_packet(struct sk_buff *skb);
328u32 dccp_sample_rtt(struct sock *sk, long delta);
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800329
330static inline int dccp_bad_service_code(const struct sock *sk,
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800331 const __be32 service)
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800332{
333 const struct dccp_sock *dp = dccp_sk(sk);
334
335 if (dp->dccps_service == service)
336 return 0;
337 return !dccp_list_has_service(dp->dccps_service_list, service);
338}
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700339
Gerrit Renker0430ee32007-09-26 11:27:56 -0300340/**
341 * dccp_skb_cb - DCCP per-packet control information
342 * @dccpd_type: one of %dccp_pkt_type (or unknown)
343 * @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1
344 * @dccpd_reset_code: one of %dccp_reset_codes
345 * @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code)
346 * @dccpd_opt_len: total length of all options (5.8) in the packet
347 * @dccpd_seq: sequence number
348 * @dccpd_ack_seq: acknowledgment number subheader field value
Ben Hutchings2c530402012-07-10 10:55:09 +0000349 *
Gerrit Renker0430ee32007-09-26 11:27:56 -0300350 * This is used for transmission as well as for reception.
351 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700352struct dccp_skb_cb {
Patrick McHardy028b0272008-04-12 18:35:41 -0700353 union {
354 struct inet_skb_parm h4;
Eric Dumazetdfd56b82011-12-10 09:48:31 +0000355#if IS_ENABLED(CONFIG_IPV6)
Patrick McHardy028b0272008-04-12 18:35:41 -0700356 struct inet6_skb_parm h6;
357#endif
358 } header;
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700359 __u8 dccpd_type:4;
360 __u8 dccpd_ccval:4;
Gerrit Renker0430ee32007-09-26 11:27:56 -0300361 __u8 dccpd_reset_code,
362 dccpd_reset_data[3];
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700363 __u16 dccpd_opt_len;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700364 __u64 dccpd_seq;
365 __u64 dccpd_ack_seq;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700366};
367
368#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
369
Gerrit Renker2180c412007-12-06 12:27:15 -0200370/* RFC 4340, sec. 7.7 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700371static inline int dccp_non_data_packet(const struct sk_buff *skb)
372{
373 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
374
375 return type == DCCP_PKT_ACK ||
376 type == DCCP_PKT_CLOSE ||
377 type == DCCP_PKT_CLOSEREQ ||
378 type == DCCP_PKT_RESET ||
379 type == DCCP_PKT_SYNC ||
380 type == DCCP_PKT_SYNCACK;
381}
382
Gerrit Renker2180c412007-12-06 12:27:15 -0200383/* RFC 4340, sec. 7.7 */
384static inline int dccp_data_packet(const struct sk_buff *skb)
385{
386 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
387
388 return type == DCCP_PKT_DATA ||
389 type == DCCP_PKT_DATAACK ||
390 type == DCCP_PKT_REQUEST ||
391 type == DCCP_PKT_RESPONSE;
392}
393
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700394static inline int dccp_packet_without_ack(const struct sk_buff *skb)
395{
396 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
397
398 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
399}
400
Gerrit Renker6b811d42007-03-20 12:26:51 -0300401#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700402
403static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
404{
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300405 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
406 sizeof(*dh));
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800407 dh->dccph_seq2 = 0;
408 dh->dccph_seq = htons((gss >> 32) & 0xfffff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700409 dhx->dccph_seq_low = htonl(gss & 0xffffffff);
410}
411
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300412static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
413 const u64 gsr)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700414{
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800415 dhack->dccph_reserved1 = 0;
416 dhack->dccph_ack_nr_high = htons(gsr >> 32);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700417 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
418}
419
420static inline void dccp_update_gsr(struct sock *sk, u64 seq)
421{
422 struct dccp_sock *dp = dccp_sk(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700423
Samuel Jero763dadd2010-12-30 12:15:41 +0100424 if (after48(seq, dp->dccps_gsr))
425 dp->dccps_gsr = seq;
Gerrit Renker792b4872009-01-16 23:36:31 +0000426 /* Sequence validity window depends on remote Sequence Window (7.5.1) */
427 dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4);
Gerrit Renker0b53d462010-10-11 20:35:40 +0200428 /*
429 * Adjust SWL so that it is not below ISR. In contrast to RFC 4340,
430 * 7.5.1 we perform this check beyond the initial handshake: W/W' are
431 * always > 32, so for the first W/W' packets in the lifetime of a
432 * connection we always have to adjust SWL.
433 * A second reason why we are doing this is that the window depends on
434 * the feature-remote value of Sequence Window: nothing stops the peer
435 * from updating this value while we are busy adjusting SWL for the
436 * first W packets (we would have to count from scratch again then).
437 * Therefore it is safer to always make sure that the Sequence Window
438 * is not artificially extended by a peer who grows SWL downwards by
439 * continually updating the feature-remote Sequence-Window.
440 * If sequence numbers wrap it is bad luck. But that will take a while
441 * (48 bit), and this measure prevents Sequence-number attacks.
442 */
443 if (before48(dp->dccps_swl, dp->dccps_isr))
444 dp->dccps_swl = dp->dccps_isr;
Gerrit Renker792b4872009-01-16 23:36:31 +0000445 dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700446}
447
448static inline void dccp_update_gss(struct sock *sk, u64 seq)
449{
450 struct dccp_sock *dp = dccp_sk(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700451
Gerrit Renker792b4872009-01-16 23:36:31 +0000452 dp->dccps_gss = seq;
453 /* Ack validity window depends on local Sequence Window value (7.5.1) */
454 dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win);
Gerrit Renker0b53d462010-10-11 20:35:40 +0200455 /* Adjust AWL so that it is not below ISS - see comment above for SWL */
456 if (before48(dp->dccps_awl, dp->dccps_iss))
457 dp->dccps_awl = dp->dccps_iss;
Gerrit Renker792b4872009-01-16 23:36:31 +0000458 dp->dccps_awh = dp->dccps_gss;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700459}
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900460
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100461static inline int dccp_ackvec_pending(const struct sock *sk)
462{
463 return dccp_sk(sk)->dccps_hc_rx_ackvec != NULL &&
464 !dccp_ackvec_is_empty(dccp_sk(sk)->dccps_hc_rx_ackvec);
465}
466
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700467static inline int dccp_ack_pending(const struct sock *sk)
468{
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100469 return dccp_ackvec_pending(sk) || inet_csk_ack_scheduled(sk);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700470}
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700471
Joe Perchesa402a5a2013-10-18 13:48:23 -0700472int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val);
473int dccp_feat_finalise_settings(struct dccp_sock *dp);
474int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq);
475int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*,
476 struct sk_buff *skb);
477int dccp_feat_activate_values(struct sock *sk, struct list_head *fn);
478void dccp_feat_list_purge(struct list_head *fn_list);
Gerrit Renker61e64732008-11-04 23:54:04 -0800479
Joe Perchesa402a5a2013-10-18 13:48:23 -0700480int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
481int dccp_insert_options_rsk(struct dccp_request_sock *, struct sk_buff *);
Joe Perchesa402a5a2013-10-18 13:48:23 -0700482u32 dccp_timestamp(void);
483void dccp_timestamping_init(void);
484int dccp_insert_option(struct sk_buff *skb, unsigned char option,
485 const void *value, unsigned char len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700486
Arnaldo Carvalho de Meloe55d9122006-03-20 19:25:02 -0800487#ifdef CONFIG_SYSCTL
Joe Perchesa402a5a2013-10-18 13:48:23 -0700488int dccp_sysctl_init(void);
489void dccp_sysctl_exit(void);
Arnaldo Carvalho de Meloe55d9122006-03-20 19:25:02 -0800490#else
491static inline int dccp_sysctl_init(void)
492{
493 return 0;
494}
495
496static inline void dccp_sysctl_exit(void)
497{
498}
499#endif
500
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700501#endif /* _DCCP_H */