net/dccp/feat.h

   1 #ifndef _DCCP_FEAT_H
   2 #define _DCCP_FEAT_H
   3 /*
   4  *  net/dccp/feat.h
   5  *
   6  *  An implementation of the DCCP protocol
   7  *  Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
   8  *
   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.
  12  */
  13
  14 #include <linux/types.h>
  15 #include "dccp.h"
  16
  17 static inline int dccp_feat_is_valid_length(u8 type, u8 feature, u8 len)
  18 {
  19         /* sec. 6.1: Confirm has at least length 3,
  20          * sec. 6.2: Change  has at least length 4 */
  21         if (len < 3)
  22                 return 1;
  23         if (len < 4  && (type == DCCPO_CHANGE_L || type == DCCPO_CHANGE_R))
  24                 return 1;
  25         /* XXX: add per-feature length validation (sec. 6.6.8) */
  26         return 0;
  27 }
  28
  29 static inline int dccp_feat_is_reserved(const u8 feat)
  30 {
  31         return (feat > DCCPF_DATA_CHECKSUM &&
  32                 feat < DCCPF_MIN_CCID_SPECIFIC) ||
  33                 feat == DCCPF_RESERVED;
  34 }
  35
  36 /* feature negotiation knows only these four option types (RFC 4340, sec. 6) */
  37 static inline int dccp_feat_is_valid_type(const u8 optnum)
  38 {
  39         return optnum >= DCCPO_CHANGE_L && optnum <= DCCPO_CONFIRM_R;
  40
  41 }
  42
  43 #ifdef CONFIG_IP_DCCP_DEBUG
  44 extern const char *dccp_feat_typename(const u8 type);
  45 extern const char *dccp_feat_name(const u8 feat);
  46
  47 static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
  48 {
  49         dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type),
  50                                            dccp_feat_name(feat), feat, val);
  51 }
  52 #else
  53 #define dccp_feat_debug(type, feat, val)
  54 #endif /* CONFIG_IP_DCCP_DEBUG */
  55
  56 extern int  dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
  57                              u8 *val, u8 len, gfp_t gfp);
  58 extern int  dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
  59                                   u8 *val, u8 len);
  60 extern int  dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
  61                                    u8 *val, u8 len);
  62 extern void dccp_feat_clean(struct dccp_minisock *dmsk);
  63 extern int  dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
  64 extern int  dccp_feat_init(struct dccp_minisock *dmsk);
  65
  66 #endif /* _DCCP_FEAT_H */