6 * An implementation of the DCCP protocol
7 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
17 #include <linux/compiler.h>
18 #include <linux/dccp.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
27 * struct ccid_operations - Interface to Congestion-Control Infrastructure
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
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
47 struct ccid_operations {
48 unsigned char ccid_id;
50 const char *ccid_name;
51 struct module *ccid_owner;
52 struct kmem_cache *ccid_hc_rx_slab,
54 __u32 ccid_hc_rx_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,
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,
67 void (*ccid_hc_tx_packet_recv)(struct sock *sk,
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,
73 void (*ccid_hc_tx_packet_sent)(struct sock *sk,
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,
83 int (*ccid_hc_tx_getsockopt)(struct sock *sk,
84 const int optname, int len,
89 extern int ccid_register(struct ccid_operations *ccid_ops);
90 extern int ccid_unregister(struct ccid_operations *ccid_ops);
93 struct ccid_operations *ccid_ops;
97 static inline void *ccid_priv(const struct ccid *ccid)
99 return (void *)ccid->ccid_priv;
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 *);
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,
111 static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp)
113 struct ccid *ccid = dp->dccps_hc_rx_ccid;
115 if (ccid == NULL || ccid->ccid_ops == NULL)
117 return ccid->ccid_ops->ccid_id;
120 static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp)
122 struct ccid *ccid = dp->dccps_hc_tx_ccid;
124 if (ccid == NULL || ccid->ccid_ops == NULL)
126 return ccid->ccid_ops->ccid_id;
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);
133 * Congestion control of queued data packets via CCID decision.
135 * The TX CCID performs its congestion-control by indicating whether and when a
136 * queued packet may be sent, using the return code of ccid_hc_tx_send_packet().
137 * The following modes are supported via the symbolic constants below:
138 * - timer-based pacing (CCID returns a delay value in milliseconds);
139 * - autonomous dequeueing (CCID internally schedules dccps_xmitlet).
142 enum ccid_dequeueing_decision {
143 CCID_PACKET_SEND_AT_ONCE = 0x00000, /* "green light": no delay */
144 CCID_PACKET_DELAY_MAX = 0x0FFFF, /* maximum delay in msecs */
145 CCID_PACKET_DELAY = 0x10000, /* CCID msec-delay mode */
146 CCID_PACKET_WILL_DEQUEUE_LATER = 0x20000, /* CCID autonomous mode */
147 CCID_PACKET_ERR = 0xF0000, /* error condition */
150 static inline int ccid_packet_dequeue_eval(const int return_code)
153 return CCID_PACKET_ERR;
154 if (return_code == 0)
155 return CCID_PACKET_SEND_AT_ONCE;
156 if (return_code <= CCID_PACKET_DELAY_MAX)
157 return CCID_PACKET_DELAY;
161 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
164 if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
165 return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb);
166 return CCID_PACKET_SEND_AT_ONCE;
169 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
172 if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
173 ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len);
176 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
179 if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
180 ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
183 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
186 if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
187 ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
191 * ccid_hc_tx_parse_options - Parse CCID-specific options sent by the receiver
192 * @pkt: type of packet that @opt appears on (RFC 4340, 5.1)
193 * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3)
194 * @val: value of @opt
195 * @len: length of @val in bytes
197 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
198 u8 pkt, u8 opt, u8 *val, u8 len)
200 if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL)
202 return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len);
206 * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender
207 * Arguments are analogous to ccid_hc_tx_parse_options()
209 static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
210 u8 pkt, u8 opt, u8 *val, u8 len)
212 if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL)
214 return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len);
217 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
220 if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
221 return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
225 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
226 struct tcp_info *info)
228 if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
229 ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
232 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
233 struct tcp_info *info)
235 if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
236 ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
239 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
240 const int optname, int len,
241 u32 __user *optval, int __user *optlen)
243 int rc = -ENOPROTOOPT;
244 if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
245 rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
250 static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
251 const int optname, int len,
252 u32 __user *optval, int __user *optlen)
254 int rc = -ENOPROTOOPT;
255 if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
256 rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,