1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 #ifndef _CCID_H 3 #define _CCID_H 4 /* 5 * net/dccp/ccid.h 6 * 7 * An implementation of the DCCP protocol 8 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 9 * 10 * CCID infrastructure 11 */ 12 13 #include <net/sock.h> 14 #include <linux/compiler.h> 15 #include <linux/dccp.h> 16 #include <linux/list.h> 17 #include <linux/module.h> 18 19 /* maximum value for a CCID (RFC 4340, 19.5) */ 20 #define CCID_MAX 255 21 #define CCID_SLAB_NAME_LENGTH 32 22 23 struct tcp_info; 24 25 /** 26 * struct ccid_operations - Interface to Congestion-Control Infrastructure 27 * 28 * @ccid_id: numerical CCID ID (up to %CCID_MAX, cf. table 5 in RFC 4340, 10.) 29 * @ccid_ccmps: the CCMPS including network/transport headers (0 when disabled) 30 * @ccid_name: alphabetical identifier string for @ccid_id 31 * @ccid_hc_{r,t}x_slab: memory pool for the receiver/sender half-connection 32 * @ccid_hc_{r,t}x_obj_size: size of the receiver/sender half-connection socket 33 * 34 * @ccid_hc_{r,t}x_init: CCID-specific initialisation routine (before startup) 35 * @ccid_hc_{r,t}x_exit: CCID-specific cleanup routine (before destruction) 36 * @ccid_hc_rx_packet_recv: implements the HC-receiver side 37 * @ccid_hc_{r,t}x_parse_options: parsing routine for CCID/HC-specific options 38 * @ccid_hc_{r,t}x_insert_options: insert routine for CCID/HC-specific options 39 * @ccid_hc_tx_packet_recv: implements feedback processing for the HC-sender 40 * @ccid_hc_tx_send_packet: implements the sending part of the HC-sender 41 * @ccid_hc_tx_packet_sent: does accounting for packets in flight by HC-sender 42 * @ccid_hc_{r,t}x_get_info: INET_DIAG information for HC-receiver/sender 43 * @ccid_hc_{r,t}x_getsockopt: socket options specific to HC-receiver/sender 44 */ 45 struct ccid_operations { 46 unsigned char ccid_id; 47 __u32 ccid_ccmps; 48 const char *ccid_name; 49 struct kmem_cache *ccid_hc_rx_slab, 50 *ccid_hc_tx_slab; 51 char ccid_hc_rx_slab_name[CCID_SLAB_NAME_LENGTH]; 52 char ccid_hc_tx_slab_name[CCID_SLAB_NAME_LENGTH]; 53 __u32 ccid_hc_rx_obj_size, 54 ccid_hc_tx_obj_size; 55 /* Interface Routines */ 56 int (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk); 57 int (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk); 58 void (*ccid_hc_rx_exit)(struct sock *sk); 59 void (*ccid_hc_tx_exit)(struct sock *sk); 60 void (*ccid_hc_rx_packet_recv)(struct sock *sk, 61 struct sk_buff *skb); 62 int (*ccid_hc_rx_parse_options)(struct sock *sk, u8 pkt, 63 u8 opt, u8 *val, u8 len); 64 int (*ccid_hc_rx_insert_options)(struct sock *sk, 65 struct sk_buff *skb); 66 void (*ccid_hc_tx_packet_recv)(struct sock *sk, 67 struct sk_buff *skb); 68 int (*ccid_hc_tx_parse_options)(struct sock *sk, u8 pkt, 69 u8 opt, u8 *val, u8 len); 70 int (*ccid_hc_tx_send_packet)(struct sock *sk, 71 struct sk_buff *skb); 72 void (*ccid_hc_tx_packet_sent)(struct sock *sk, 73 unsigned int len); 74 void (*ccid_hc_rx_get_info)(struct sock *sk, 75 struct tcp_info *info); 76 void (*ccid_hc_tx_get_info)(struct sock *sk, 77 struct tcp_info *info); 78 int (*ccid_hc_rx_getsockopt)(struct sock *sk, 79 const int optname, int len, 80 u32 __user *optval, 81 int __user *optlen); 82 int (*ccid_hc_tx_getsockopt)(struct sock *sk, 83 const int optname, int len, 84 u32 __user *optval, 85 int __user *optlen); 86 }; 87 88 extern struct ccid_operations ccid2_ops; 89 #ifdef CONFIG_IP_DCCP_CCID3 90 extern struct ccid_operations ccid3_ops; 91 #endif 92 93 int ccid_initialize_builtins(void); 94 void ccid_cleanup_builtins(void); 95 96 struct ccid { 97 struct ccid_operations *ccid_ops; 98 char ccid_priv[]; 99 }; 100 101 static inline void *ccid_priv(const struct ccid *ccid) 102 { 103 return (void *)ccid->ccid_priv; 104 } 105 106 bool ccid_support_check(u8 const *ccid_array, u8 array_len); 107 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len); 108 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, 109 char __user *, int __user *); 110 111 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx); 112 113 static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp) 114 { 115 struct ccid *ccid = dp->dccps_hc_rx_ccid; 116 117 if (ccid == NULL || ccid->ccid_ops == NULL) 118 return -1; 119 return ccid->ccid_ops->ccid_id; 120 } 121 122 static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp) 123 { 124 struct ccid *ccid = dp->dccps_hc_tx_ccid; 125 126 if (ccid == NULL || ccid->ccid_ops == NULL) 127 return -1; 128 return ccid->ccid_ops->ccid_id; 129 } 130 131 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk); 132 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk); 133 134 /* 135 * Congestion control of queued data packets via CCID decision. 136 * 137 * The TX CCID performs its congestion-control by indicating whether and when a 138 * queued packet may be sent, using the return code of ccid_hc_tx_send_packet(). 139 * The following modes are supported via the symbolic constants below: 140 * - timer-based pacing (CCID returns a delay value in milliseconds); 141 * - autonomous dequeueing (CCID internally schedules dccps_xmitlet). 142 */ 143 144 enum ccid_dequeueing_decision { 145 CCID_PACKET_SEND_AT_ONCE = 0x00000, /* "green light": no delay */ 146 CCID_PACKET_DELAY_MAX = 0x0FFFF, /* maximum delay in msecs */ 147 CCID_PACKET_DELAY = 0x10000, /* CCID msec-delay mode */ 148 CCID_PACKET_WILL_DEQUEUE_LATER = 0x20000, /* CCID autonomous mode */ 149 CCID_PACKET_ERR = 0xF0000, /* error condition */ 150 }; 151 152 static inline int ccid_packet_dequeue_eval(const int return_code) 153 { 154 if (return_code < 0) 155 return CCID_PACKET_ERR; 156 if (return_code == 0) 157 return CCID_PACKET_SEND_AT_ONCE; 158 if (return_code <= CCID_PACKET_DELAY_MAX) 159 return CCID_PACKET_DELAY; 160 return return_code; 161 } 162 163 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk, 164 struct sk_buff *skb) 165 { 166 if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL) 167 return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb); 168 return CCID_PACKET_SEND_AT_ONCE; 169 } 170 171 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk, 172 unsigned int len) 173 { 174 if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL) 175 ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len); 176 } 177 178 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk, 179 struct sk_buff *skb) 180 { 181 if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL) 182 ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb); 183 } 184 185 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk, 186 struct sk_buff *skb) 187 { 188 if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL) 189 ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb); 190 } 191 192 /** 193 * ccid_hc_tx_parse_options - Parse CCID-specific options sent by the receiver 194 * @pkt: type of packet that @opt appears on (RFC 4340, 5.1) 195 * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3) 196 * @val: value of @opt 197 * @len: length of @val in bytes 198 */ 199 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk, 200 u8 pkt, u8 opt, u8 *val, u8 len) 201 { 202 if (!ccid || !ccid->ccid_ops->ccid_hc_tx_parse_options) 203 return 0; 204 return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len); 205 } 206 207 /** 208 * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender 209 * Arguments are analogous to ccid_hc_tx_parse_options() 210 */ 211 static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk, 212 u8 pkt, u8 opt, u8 *val, u8 len) 213 { 214 if (!ccid || !ccid->ccid_ops->ccid_hc_rx_parse_options) 215 return 0; 216 return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len); 217 } 218 219 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk, 220 struct sk_buff *skb) 221 { 222 if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL) 223 return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb); 224 return 0; 225 } 226 227 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk, 228 struct tcp_info *info) 229 { 230 if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL) 231 ccid->ccid_ops->ccid_hc_rx_get_info(sk, info); 232 } 233 234 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk, 235 struct tcp_info *info) 236 { 237 if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL) 238 ccid->ccid_ops->ccid_hc_tx_get_info(sk, info); 239 } 240 241 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk, 242 const int optname, int len, 243 u32 __user *optval, int __user *optlen) 244 { 245 int rc = -ENOPROTOOPT; 246 if (ccid != NULL && ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL) 247 rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len, 248 optval, optlen); 249 return rc; 250 } 251 252 static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk, 253 const int optname, int len, 254 u32 __user *optval, int __user *optlen) 255 { 256 int rc = -ENOPROTOOPT; 257 if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL) 258 rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len, 259 optval, optlen); 260 return rc; 261 } 262 #endif /* _CCID_H */ 263