net/dccp/ccid.h

   1 #ifndef _CCID_H
   2 #define _CCID_H
   3 /*
   4  *  net/dccp/ccid.h
   5  *
   6  *  An implementation of the DCCP protocol
   7  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   8  *
   9  *  CCID infrastructure
  10  *
  11  *      This program is free software; you can redistribute it and/or modify it
  12  *      under the terms of the GNU General Public License version 2 as
  13  *      published by the Free Software Foundation.
  14  */
  15
  16 #include <net/sock.h>
  17 #include <linux/compiler.h>
  18 #include <linux/dccp.h>
  19 #include <linux/list.h>
  20 #include <linux/module.h>
  21
  22 #define CCID_MAX 255
  23
  24 struct tcp_info;
  25
  26 /**
  27  *  struct ccid_operations  -  Interface to Congestion-Control Infrastructure
  28  *
  29  *  @ccid_id: numerical CCID ID (up to %CCID_MAX, cf. table 5 in RFC 4340, 10.)
  30  *  @ccid_ccmps: the CCMPS including network/transport headers (0 when disabled)
  31  *  @ccid_name: alphabetical identifier string for @ccid_id
  32  *  @ccid_owner: module which implements/owns this CCID
  33  *  @ccid_hc_{r,t}x_slab: memory pool for the receiver/sender half-connection
  34  *  @ccid_hc_{r,t}x_obj_size: size of the receiver/sender half-connection socket
  35  *
  36  *  @ccid_hc_{r,t}x_init: CCID-specific initialisation routine (before startup)
  37  *  @ccid_hc_{r,t}x_exit: CCID-specific cleanup routine (before destruction)
  38  *  @ccid_hc_rx_packet_recv: implements the HC-receiver side
  39  *  @ccid_hc_{r,t}x_parse_options: parsing routine for CCID/HC-specific options
  40  *  @ccid_hc_{r,t}x_insert_options: insert routine for CCID/HC-specific options
  41  *  @ccid_hc_tx_packet_recv: implements feedback processing for the HC-sender
  42  *  @ccid_hc_tx_send_packet: implements the sending part of the HC-sender
  43  *  @ccid_hc_tx_packet_sent: does accounting for packets in flight by HC-sender
  44  *  @ccid_hc_{r,t}x_get_info: INET_DIAG information for HC-receiver/sender
  45  *  @ccid_hc_{r,t}x_getsockopt: socket options specific to HC-receiver/sender
  46  */
  47 struct ccid_operations {
  48         unsigned char           ccid_id;
  49         __u32                   ccid_ccmps;
  50         const char              *ccid_name;
  51         struct module           *ccid_owner;
  52         struct kmem_cache       *ccid_hc_rx_slab,
  53                                 *ccid_hc_tx_slab;
  54         __u32                   ccid_hc_rx_obj_size,
  55                                 ccid_hc_tx_obj_size;
  56         /* Interface Routines */
  57         int             (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk);
  58         int             (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk);
  59         void            (*ccid_hc_rx_exit)(struct sock *sk);
  60         void            (*ccid_hc_tx_exit)(struct sock *sk);
  61         void            (*ccid_hc_rx_packet_recv)(struct sock *sk,
  62                                                   struct sk_buff *skb);
  63         int             (*ccid_hc_rx_parse_options)(struct sock *sk, u8 pkt,
  64                                                     u8 opt, u8 *val, u8 len);
  65         int             (*ccid_hc_rx_insert_options)(struct sock *sk,
  66                                                      struct sk_buff *skb);
  67         void            (*ccid_hc_tx_packet_recv)(struct sock *sk,
  68                                                   struct sk_buff *skb);
  69         int             (*ccid_hc_tx_parse_options)(struct sock *sk, u8 pkt,
  70                                                     u8 opt, u8 *val, u8 len);
  71         int             (*ccid_hc_tx_send_packet)(struct sock *sk,
  72                                                   struct sk_buff *skb);
  73         void            (*ccid_hc_tx_packet_sent)(struct sock *sk,
  74                                                   int more, unsigned int len);
  75         void            (*ccid_hc_rx_get_info)(struct sock *sk,
  76                                                struct tcp_info *info);
  77         void            (*ccid_hc_tx_get_info)(struct sock *sk,
  78                                                struct tcp_info *info);
  79         int             (*ccid_hc_rx_getsockopt)(struct sock *sk,
  80                                                  const int optname, int len,
  81                                                  u32 __user *optval,
  82                                                  int __user *optlen);
  83         int             (*ccid_hc_tx_getsockopt)(struct sock *sk,
  84                                                  const int optname, int len,
  85                                                  u32 __user *optval,
  86                                                  int __user *optlen);
  87 };
  88
  89 extern int ccid_register(struct ccid_operations *ccid_ops);
  90 extern int ccid_unregister(struct ccid_operations *ccid_ops);
  91
  92 struct ccid {
  93         struct ccid_operations *ccid_ops;
  94         char                   ccid_priv[0];
  95 };
  96
  97 static inline void *ccid_priv(const struct ccid *ccid)
  98 {
  99         return (void *)ccid->ccid_priv;
 100 }
 101
 102 extern bool ccid_support_check(u8 const *ccid_array, u8 array_len);
 103 extern int  ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len);
 104 extern int  ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
 105                                           char __user *, int __user *);
 106
 107 extern int    ccid_request_modules(u8 const *ccid_array, u8 array_len);
 108 extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx,
 109                              gfp_t gfp);
 110
 111 static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp)
 112 {
 113         struct ccid *ccid = dp->dccps_hc_rx_ccid;
 114
 115         if (ccid == NULL || ccid->ccid_ops == NULL)
 116                 return -1;
 117         return ccid->ccid_ops->ccid_id;
 118 }
 119
 120 static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp)
 121 {
 122         struct ccid *ccid = dp->dccps_hc_tx_ccid;
 123
 124         if (ccid == NULL || ccid->ccid_ops == NULL)
 125                 return -1;
 126         return ccid->ccid_ops->ccid_id;
 127 }
 128
 129 extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk);
 130 extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk);
 131
 132 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
 133                                          struct sk_buff *skb)
 134 {
 135         int rc = 0;
 136         if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
 137                 rc = ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb);
 138         return rc;
 139 }
 140
 141 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
 142                                           int more, unsigned int len)
 143 {
 144         if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
 145                 ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, more, len);
 146 }
 147
 148 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
 149                                           struct sk_buff *skb)
 150 {
 151         if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
 152                 ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
 153 }
 154
 155 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
 156                                           struct sk_buff *skb)
 157 {
 158         if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
 159                 ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
 160 }
 161
 162 /**
 163  * ccid_hc_tx_parse_options  -  Parse CCID-specific options sent by the receiver
 164  * @pkt: type of packet that @opt appears on (RFC 4340, 5.1)
 165  * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3)
 166  * @val: value of @opt
 167  * @len: length of @val in bytes
 168  */
 169 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
 170                                            u8 pkt, u8 opt, u8 *val, u8 len)
 171 {
 172         if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL)
 173                 return 0;
 174         return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len);
 175 }
 176
 177 /**
 178  * ccid_hc_rx_parse_options  -  Parse CCID-specific options sent by the sender
 179  * Arguments are analogous to ccid_hc_tx_parse_options()
 180  */
 181 static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
 182                                            u8 pkt, u8 opt, u8 *val, u8 len)
 183 {
 184         if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL)
 185                 return 0;
 186         return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len);
 187 }
 188
 189 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
 190                                             struct sk_buff *skb)
 191 {
 192         if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
 193                 return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
 194         return 0;
 195 }
 196
 197 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
 198                                        struct tcp_info *info)
 199 {
 200         if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
 201                 ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
 202 }
 203
 204 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
 205                                        struct tcp_info *info)
 206 {
 207         if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
 208                 ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
 209 }
 210
 211 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
 212                                         const int optname, int len,
 213                                         u32 __user *optval, int __user *optlen)
 214 {
 215         int rc = -ENOPROTOOPT;
 216         if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
 217                 rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
 218                                                  optval, optlen);
 219         return rc;
 220 }
 221
 222 static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
 223                                         const int optname, int len,
 224                                         u32 __user *optval, int __user *optlen)
 225 {
 226         int rc = -ENOPROTOOPT;
 227         if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
 228                 rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,
 229                                                  optval, optlen);
 230         return rc;
 231 }
 232 #endif /* _CCID_H */