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 /* maximum value for a CCID (RFC 4340, 19.5) */ 23 #define CCID_MAX 255 24 #define CCID_SLAB_NAME_LENGTH 32 25 26 struct tcp_info; 27 28 /** 29 * struct ccid_operations - Interface to Congestion-Control Infrastructure 30 * 31 * @ccid_id: numerical CCID ID (up to %CCID_MAX, cf. table 5 in RFC 4340, 10.) 32 * @ccid_ccmps: the CCMPS including network/transport headers (0 when disabled) 33 * @ccid_name: alphabetical identifier string for @ccid_id 34 * @ccid_hc_{r,t}x_slab: memory pool for the receiver/sender half-connection 35 * @ccid_hc_{r,t}x_obj_size: size of the receiver/sender half-connection socket 36 * 37 * @ccid_hc_{r,t}x_init: CCID-specific initialisation routine (before startup) 38 * @ccid_hc_{r,t}x_exit: CCID-specific cleanup routine (before destruction) 39 * @ccid_hc_rx_packet_recv: implements the HC-receiver side 40 * @ccid_hc_{r,t}x_parse_options: parsing routine for CCID/HC-specific options 41 * @ccid_hc_{r,t}x_insert_options: insert routine for CCID/HC-specific options 42 * @ccid_hc_tx_packet_recv: implements feedback processing for the HC-sender 43 * @ccid_hc_tx_send_packet: implements the sending part of the HC-sender 44 * @ccid_hc_tx_packet_sent: does accounting for packets in flight by HC-sender 45 * @ccid_hc_{r,t}x_get_info: INET_DIAG information for HC-receiver/sender 46 * @ccid_hc_{r,t}x_getsockopt: socket options specific to HC-receiver/sender 47 */ 48 struct ccid_operations { 49 unsigned char ccid_id; 50 __u32 ccid_ccmps; 51 const char *ccid_name; 52 struct kmem_cache *ccid_hc_rx_slab, 53 *ccid_hc_tx_slab; 54 char ccid_hc_rx_slab_name[CCID_SLAB_NAME_LENGTH]; 55 char ccid_hc_tx_slab_name[CCID_SLAB_NAME_LENGTH]; 56 __u32 ccid_hc_rx_obj_size, 57 ccid_hc_tx_obj_size; 58 /* Interface Routines */ 59 int (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk); 60 int (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk); 61 void (*ccid_hc_rx_exit)(struct sock *sk); 62 void (*ccid_hc_tx_exit)(struct sock *sk); 63 void (*ccid_hc_rx_packet_recv)(struct sock *sk, 64 struct sk_buff *skb); 65 int (*ccid_hc_rx_parse_options)(struct sock *sk, u8 pkt, 66 u8 opt, u8 *val, u8 len); 67 int (*ccid_hc_rx_insert_options)(struct sock *sk, 68 struct sk_buff *skb); 69 void (*ccid_hc_tx_packet_recv)(struct sock *sk, 70 struct sk_buff *skb); 71 int (*ccid_hc_tx_parse_options)(struct sock *sk, u8 pkt, 72 u8 opt, u8 *val, u8 len); 73 int (*ccid_hc_tx_send_packet)(struct sock *sk, 74 struct sk_buff *skb); 75 void (*ccid_hc_tx_packet_sent)(struct sock *sk, 76 unsigned int len); 77 void (*ccid_hc_rx_get_info)(struct sock *sk, 78 struct tcp_info *info); 79 void (*ccid_hc_tx_get_info)(struct sock *sk, 80 struct tcp_info *info); 81 int (*ccid_hc_rx_getsockopt)(struct sock *sk, 82 const int optname, int len, 83 u32 __user *optval, 84 int __user *optlen); 85 int (*ccid_hc_tx_getsockopt)(struct sock *sk, 86 const int optname, int len, 87 u32 __user *optval, 88 int __user *optlen); 89 }; 90 91 extern struct ccid_operations ccid2_ops; 92 #ifdef CONFIG_IP_DCCP_CCID3 93 extern struct ccid_operations ccid3_ops; 94 #endif 95 96 int ccid_initialize_builtins(void); 97 void ccid_cleanup_builtins(void); 98 99 struct ccid { 100 struct ccid_operations *ccid_ops; 101 char ccid_priv[0]; 102 }; 103 104 static inline void *ccid_priv(const struct ccid *ccid) 105 { 106 return (void *)ccid->ccid_priv; 107 } 108 109 bool ccid_support_check(u8 const *ccid_array, u8 array_len); 110 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len); 111 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, 112 char __user *, int __user *); 113 114 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx); 115 116 static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp) 117 { 118 struct ccid *ccid = dp->dccps_hc_rx_ccid; 119 120 if (ccid == NULL || ccid->ccid_ops == NULL) 121 return -1; 122 return ccid->ccid_ops->ccid_id; 123 } 124 125 static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp) 126 { 127 struct ccid *ccid = dp->dccps_hc_tx_ccid; 128 129 if (ccid == NULL || ccid->ccid_ops == NULL) 130 return -1; 131 return ccid->ccid_ops->ccid_id; 132 } 133 134 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk); 135 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk); 136 137 /* 138 * Congestion control of queued data packets via CCID decision. 139 * 140 * The TX CCID performs its congestion-control by indicating whether and when a 141 * queued packet may be sent, using the return code of ccid_hc_tx_send_packet(). 142 * The following modes are supported via the symbolic constants below: 143 * - timer-based pacing (CCID returns a delay value in milliseconds); 144 * - autonomous dequeueing (CCID internally schedules dccps_xmitlet). 145 */ 146 147 enum ccid_dequeueing_decision { 148 CCID_PACKET_SEND_AT_ONCE = 0x00000, /* "green light": no delay */ 149 CCID_PACKET_DELAY_MAX = 0x0FFFF, /* maximum delay in msecs */ 150 CCID_PACKET_DELAY = 0x10000, /* CCID msec-delay mode */ 151 CCID_PACKET_WILL_DEQUEUE_LATER = 0x20000, /* CCID autonomous mode */ 152 CCID_PACKET_ERR = 0xF0000, /* error condition */ 153 }; 154 155 static inline int ccid_packet_dequeue_eval(const int return_code) 156 { 157 if (return_code < 0) 158 return CCID_PACKET_ERR; 159 if (return_code == 0) 160 return CCID_PACKET_SEND_AT_ONCE; 161 if (return_code <= CCID_PACKET_DELAY_MAX) 162 return CCID_PACKET_DELAY; 163 return return_code; 164 } 165 166 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk, 167 struct sk_buff *skb) 168 { 169 if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL) 170 return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb); 171 return CCID_PACKET_SEND_AT_ONCE; 172 } 173 174 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk, 175 unsigned int len) 176 { 177 if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL) 178 ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len); 179 } 180 181 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk, 182 struct sk_buff *skb) 183 { 184 if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL) 185 ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb); 186 } 187 188 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk, 189 struct sk_buff *skb) 190 { 191 if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL) 192 ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb); 193 } 194 195 /** 196 * ccid_hc_tx_parse_options - Parse CCID-specific options sent by the receiver 197 * @pkt: type of packet that @opt appears on (RFC 4340, 5.1) 198 * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3) 199 * @val: value of @opt 200 * @len: length of @val in bytes 201 */ 202 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk, 203 u8 pkt, u8 opt, u8 *val, u8 len) 204 { 205 if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL) 206 return 0; 207 return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len); 208 } 209 210 /** 211 * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender 212 * Arguments are analogous to ccid_hc_tx_parse_options() 213 */ 214 static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk, 215 u8 pkt, u8 opt, u8 *val, u8 len) 216 { 217 if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL) 218 return 0; 219 return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len); 220 } 221 222 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk, 223 struct sk_buff *skb) 224 { 225 if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL) 226 return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb); 227 return 0; 228 } 229 230 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk, 231 struct tcp_info *info) 232 { 233 if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL) 234 ccid->ccid_ops->ccid_hc_rx_get_info(sk, info); 235 } 236 237 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk, 238 struct tcp_info *info) 239 { 240 if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL) 241 ccid->ccid_ops->ccid_hc_tx_get_info(sk, info); 242 } 243 244 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk, 245 const int optname, int len, 246 u32 __user *optval, int __user *optlen) 247 { 248 int rc = -ENOPROTOOPT; 249 if (ccid != NULL && ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL) 250 rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len, 251 optval, optlen); 252 return rc; 253 } 254 255 static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk, 256 const int optname, int len, 257 u32 __user *optval, int __user *optlen) 258 { 259 int rc = -ENOPROTOOPT; 260 if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL) 261 rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len, 262 optval, optlen); 263 return rc; 264 } 265 #endif /* _CCID_H */ 266