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-rw-r--r--net/dccp/feat.h144
1 files changed, 24 insertions, 120 deletions
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 2217066e22d7..e272222c7ace 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -3,134 +3,38 @@
3/* 3/*
4 * net/dccp/feat.h 4 * net/dccp/feat.h
5 * 5 *
6 * Feature negotiation for the DCCP protocol (RFC 4340, section 6) 6 * An implementation of the DCCP protocol
7 * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
8 * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> 7 * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
9 * 8 *
10 * This program is free software; you can redistribute it and/or modify it 9 * 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 10 * under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation. 11 * published by the Free Software Foundation.
13 */ 12 */
13
14#include <linux/types.h> 14#include <linux/types.h>
15#include "dccp.h" 15#include "dccp.h"
16 16
17/* 17#ifdef CONFIG_IP_DCCP_DEBUG
18 * Known limit values 18extern const char *dccp_feat_typename(const u8 type);
19 */ 19extern const char *dccp_feat_name(const u8 feat);
20/* Ack Ratio takes 2-byte integer values (11.3) */
21#define DCCPF_ACK_RATIO_MAX 0xFFFF
22/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
23#define DCCPF_SEQ_WMIN 32
24#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull
25/* Maximum number of SP values that fit in a single (Confirm) option */
26#define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2)
27
28enum dccp_feat_type {
29 FEAT_AT_RX = 1, /* located at RX side of half-connection */
30 FEAT_AT_TX = 2, /* located at TX side of half-connection */
31 FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */
32 FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */
33 FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */
34};
35
36enum dccp_feat_state {
37 FEAT_DEFAULT = 0, /* using default values from 6.4 */
38 FEAT_INITIALISING, /* feature is being initialised */
39 FEAT_CHANGING, /* Change sent but not confirmed yet */
40 FEAT_UNSTABLE, /* local modification in state CHANGING */
41 FEAT_STABLE /* both ends (think they) agree */
42};
43 20
44/** 21static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
45 * dccp_feat_val - Container for SP or NN feature values
46 * @nn: single NN value
47 * @sp.vec: single SP value plus optional preference list
48 * @sp.len: length of @sp.vec in bytes
49 */
50typedef union {
51 u64 nn;
52 struct {
53 u8 *vec;
54 u8 len;
55 } sp;
56} dccp_feat_val;
57
58/**
59 * struct feat_entry - Data structure to perform feature negotiation
60 * @feat_num: one of %dccp_feature_numbers
61 * @val: feature's current value (SP features may have preference list)
62 * @state: feature's current state
63 * @needs_mandatory: whether Mandatory options should be sent
64 * @needs_confirm: whether to send a Confirm instead of a Change
65 * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
66 * @is_local: feature location (1) or feature-remote (0)
67 * @node: list pointers, entries arranged in FIFO order
68 */
69struct dccp_feat_entry {
70 u8 feat_num;
71 dccp_feat_val val;
72 enum dccp_feat_state state:8;
73 bool needs_mandatory:1,
74 needs_confirm:1,
75 empty_confirm:1,
76 is_local:1;
77
78 struct list_head node;
79};
80
81static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
82{ 22{
83 if (entry->needs_confirm) 23 dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type),
84 return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R; 24 dccp_feat_name(feat), feat, val);
85 return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
86} 25}
26#else
27#define dccp_feat_debug(type, feat, val)
28#endif /* CONFIG_IP_DCCP_DEBUG */
29
30extern int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
31 u8 *val, u8 len, gfp_t gfp);
32extern int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
33 u8 *val, u8 len);
34extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
35 u8 *val, u8 len);
36extern void dccp_feat_clean(struct dccp_minisock *dmsk);
37extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
38extern int dccp_feat_init(struct dccp_minisock *dmsk);
87 39
88/**
89 * struct ccid_dependency - Track changes resulting from choosing a CCID
90 * @dependent_feat: one of %dccp_feature_numbers
91 * @is_local: local (1) or remote (0) @dependent_feat
92 * @is_mandatory: whether presence of @dependent_feat is mission-critical or not
93 * @val: corresponding default value for @dependent_feat (u8 is sufficient here)
94 */
95struct ccid_dependency {
96 u8 dependent_feat;
97 bool is_local:1,
98 is_mandatory:1;
99 u8 val;
100};
101
102/*
103 * Sysctls to seed defaults for feature negotiation
104 */
105extern unsigned long sysctl_dccp_sequence_window;
106extern int sysctl_dccp_rx_ccid;
107extern int sysctl_dccp_tx_ccid;
108
109extern int dccp_feat_init(struct sock *sk);
110extern void dccp_feat_initialise_sysctls(void);
111extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
112 u8 const *list, u8 len);
113extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
114extern int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *,
115 u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
116extern int dccp_feat_clone_list(struct list_head const *, struct list_head *);
117
118/*
119 * Encoding variable-length options and their maximum length.
120 *
121 * This affects NN options (SP options are all u8) and other variable-length
122 * options (see table 3 in RFC 4340). The limit is currently given the Sequence
123 * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other
124 * options consume less than 6 bytes (timestamps are 4 bytes).
125 * When updating this constant (e.g. due to new internet drafts / RFCs), make
126 * sure that you also update all code which refers to it.
127 */
128#define DCCP_OPTVAL_MAXLEN 6
129
130extern void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
131extern u64 dccp_decode_value_var(const u8 *bf, const u8 len);
132
133extern int dccp_insert_option_mandatory(struct sk_buff *skb);
134extern int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
135 u8 *val, u8 len, bool repeat_first);
136#endif /* _DCCP_FEAT_H */ 40#endif /* _DCCP_FEAT_H */
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