6 * An implementation of the DCCP protocol
7 * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
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/types.h>
18 FEAT_AT_RX
= 1, /* located at RX side of half-connection */
19 FEAT_AT_TX
= 2, /* located at TX side of half-connection */
20 FEAT_SP
= 4, /* server-priority reconciliation (6.3.1) */
21 FEAT_NN
= 8, /* non-negotiable reconciliation (6.3.2) */
22 FEAT_UNKNOWN
= 0xFF /* not understood or invalid feature */
25 enum dccp_feat_state
{
26 FEAT_DEFAULT
= 0, /* using default values from 6.4 */
27 FEAT_INITIALISING
, /* feature is being initialised */
28 FEAT_CHANGING
, /* Change sent but not confirmed yet */
29 FEAT_UNSTABLE
, /* local modification in state CHANGING */
30 FEAT_STABLE
/* both ends (think they) agree */
34 * dccp_feat_val - Container for SP or NN feature values
35 * @nn: single NN value
36 * @sp.vec: single SP value plus optional preference list
37 * @sp.len: length of @sp.vec in bytes
48 * struct feat_entry - Data structure to perform feature negotiation
49 * @feat_num: one of %dccp_feature_numbers
50 * @val: feature's current value (SP features may have preference list)
51 * @state: feature's current state
52 * @needs_mandatory: whether Mandatory options should be sent
53 * @needs_confirm: whether to send a Confirm instead of a Change
54 * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
55 * @is_local: feature location (1) or feature-remote (0)
56 * @node: list pointers, entries arranged in FIFO order
58 struct dccp_feat_entry
{
61 enum dccp_feat_state state
:8;
62 bool needs_mandatory
:1,
67 struct list_head node
;
70 static inline u8
dccp_feat_genopt(struct dccp_feat_entry
*entry
)
72 if (entry
->needs_confirm
)
73 return entry
->is_local
? DCCPO_CONFIRM_L
: DCCPO_CONFIRM_R
;
74 return entry
->is_local
? DCCPO_CHANGE_L
: DCCPO_CHANGE_R
;
77 #ifdef CONFIG_IP_DCCP_DEBUG
78 extern const char *dccp_feat_typename(const u8 type
);
79 extern const char *dccp_feat_name(const u8 feat
);
81 static inline void dccp_feat_debug(const u8 type
, const u8 feat
, const u8 val
)
83 dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type
),
84 dccp_feat_name(feat
), feat
, val
);
87 #define dccp_feat_debug(type, feat, val)
88 #endif /* CONFIG_IP_DCCP_DEBUG */
90 extern int dccp_feat_change(struct dccp_minisock
*dmsk
, u8 type
, u8 feature
,
91 u8
*val
, u8 len
, gfp_t gfp
);
92 extern int dccp_feat_change_recv(struct sock
*sk
, u8 type
, u8 feature
,
94 extern int dccp_feat_confirm_recv(struct sock
*sk
, u8 type
, u8 feature
,
96 extern void dccp_feat_clean(struct dccp_minisock
*dmsk
);
97 extern int dccp_feat_clone(struct sock
*oldsk
, struct sock
*newsk
);
98 extern int dccp_feat_init(struct dccp_minisock
*dmsk
);
100 #endif /* _DCCP_FEAT_H */