/*
* net/dccp/feat.h
*
- * Feature negotiation for the DCCP protocol (RFC 4340, section 6)
- * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
+ * An implementation of the DCCP protocol
* Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
+
#include <linux/types.h>
#include "dccp.h"
-/*
- * Known limit values
- */
-/* Ack Ratio takes 2-byte integer values (11.3) */
-#define DCCPF_ACK_RATIO_MAX 0xFFFF
-/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
-#define DCCPF_SEQ_WMIN 32
-#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull
-/* Maximum number of SP values that fit in a single (Confirm) option */
-#define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2)
-
-enum dccp_feat_type {
- FEAT_AT_RX = 1, /* located at RX side of half-connection */
- FEAT_AT_TX = 2, /* located at TX side of half-connection */
- FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */
- FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */
- FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */
-};
-
-enum dccp_feat_state {
- FEAT_DEFAULT = 0, /* using default values from 6.4 */
- FEAT_INITIALISING, /* feature is being initialised */
- FEAT_CHANGING, /* Change sent but not confirmed yet */
- FEAT_UNSTABLE, /* local modification in state CHANGING */
- FEAT_STABLE /* both ends (think they) agree */
-};
-
-/**
- * dccp_feat_val - Container for SP or NN feature values
- * @nn: single NN value
- * @sp.vec: single SP value plus optional preference list
- * @sp.len: length of @sp.vec in bytes
- */
-typedef union {
- u64 nn;
- struct {
- u8 *vec;
- u8 len;
- } sp;
-} dccp_feat_val;
-
-/**
- * struct feat_entry - Data structure to perform feature negotiation
- * @feat_num: one of %dccp_feature_numbers
- * @val: feature's current value (SP features may have preference list)
- * @state: feature's current state
- * @needs_mandatory: whether Mandatory options should be sent
- * @needs_confirm: whether to send a Confirm instead of a Change
- * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
- * @is_local: feature location (1) or feature-remote (0)
- * @node: list pointers, entries arranged in FIFO order
- */
-struct dccp_feat_entry {
- u8 feat_num;
- dccp_feat_val val;
- enum dccp_feat_state state:8;
- bool needs_mandatory:1,
- needs_confirm:1,
- empty_confirm:1,
- is_local:1;
-
- struct list_head node;
-};
-
-static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
-{
- if (entry->needs_confirm)
- return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R;
- return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
-}
-
-/**
- * struct ccid_dependency - Track changes resulting from choosing a CCID
- * @dependent_feat: one of %dccp_feature_numbers
- * @is_local: local (1) or remote (0) @dependent_feat
- * @is_mandatory: whether presence of @dependent_feat is mission-critical or not
- * @val: corresponding default value for @dependent_feat (u8 is sufficient here)
- */
-struct ccid_dependency {
- u8 dependent_feat;
- bool is_local:1,
- is_mandatory:1;
- u8 val;
-};
-
-/*
- * Sysctls to seed defaults for feature negotiation
- */
-extern unsigned long sysctl_dccp_sequence_window;
-extern int sysctl_dccp_rx_ccid;
-extern int sysctl_dccp_tx_ccid;
-
#ifdef CONFIG_IP_DCCP_DEBUG
extern const char *dccp_feat_typename(const u8 type);
extern const char *dccp_feat_name(const u8 feat);
#define dccp_feat_debug(type, feat, val)
#endif /* CONFIG_IP_DCCP_DEBUG */
-extern int dccp_feat_init(struct sock *sk);
-extern void dccp_feat_initialise_sysctls(void);
-extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
- u8 const *list, u8 len);
-extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
-extern int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *,
- u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
-extern int dccp_feat_clone_list(struct list_head const *, struct list_head *);
-
-/*
- * Encoding variable-length options and their maximum length.
- *
- * This affects NN options (SP options are all u8) and other variable-length
- * options (see table 3 in RFC 4340). The limit is currently given the Sequence
- * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other
- * options consume less than 6 bytes (timestamps are 4 bytes).
- * When updating this constant (e.g. due to new internet drafts / RFCs), make
- * sure that you also update all code which refers to it.
- */
-#define DCCP_OPTVAL_MAXLEN 6
-
-extern void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
-extern u64 dccp_decode_value_var(const u8 *bf, const u8 len);
+extern int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
+ u8 *val, u8 len, gfp_t gfp);
+extern int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
+ u8 *val, u8 len);
+extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
+ u8 *val, u8 len);
+extern void dccp_feat_clean(struct dccp_minisock *dmsk);
+extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
+extern int dccp_feat_init(struct dccp_minisock *dmsk);
-extern int dccp_insert_option_mandatory(struct sk_buff *skb);
-extern int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
- u8 *val, u8 len, bool repeat_first);
#endif /* _DCCP_FEAT_H */
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