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>
22 /* maximum value for a CCID (RFC 4340, 19.5) */
24 #define CCID_SLAB_NAME_LENGTH 32
29 * struct ccid_operations - Interface to Congestion-Control Infrastructure
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
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
48 struct ccid_operations {
49 unsigned char ccid_id;
51 const char *ccid_name;
52 struct kmem_cache *ccid_hc_rx_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,
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,
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,
69 void (*ccid_hc_tx_packet_recv)(struct sock *sk,
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,
75 void (*ccid_hc_tx_packet_sent)(struct sock *sk,
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,
85 int (*ccid_hc_tx_getsockopt)(struct sock *sk,
86 const int optname, int len,
91 extern struct ccid_operations ccid2_ops;
92 #ifdef CONFIG_IP_DCCP_CCID3
93 extern struct ccid_operations ccid3_ops;
96 extern int ccid_initialize_builtins(void);
97 extern void ccid_cleanup_builtins(void);
100 struct ccid_operations *ccid_ops;
104 static inline void *ccid_priv(const struct ccid *ccid)
106 return (void *)ccid->ccid_priv;
109 extern bool ccid_support_check(u8 const *ccid_array, u8 array_len);
110 extern int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len);
111 extern int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
112 char __user *, int __user *);
114 extern struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx);
116 static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp)
118 struct ccid *ccid = dp->dccps_hc_rx_ccid;
120 if (ccid == NULL || ccid->ccid_ops == NULL)
122 return ccid->ccid_ops->ccid_id;
125 static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp)
127 struct ccid *ccid = dp->dccps_hc_tx_ccid;
129 if (ccid == NULL || ccid->ccid_ops == NULL)
131 return ccid->ccid_ops->ccid_id;
134 extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk);
135 extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk);
138 * Congestion control of queued data packets via CCID decision.
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).
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 */
155 static inline int ccid_packet_dequeue_eval(const int return_code)
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;
166 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
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;
174 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
177 if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
178 ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len);
181 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
184 if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
185 ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
188 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
191 if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
192 ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
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
202 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
203 u8 pkt, u8 opt, u8 *val, u8 len)
205 if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL)
207 return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len);
211 * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender
212 * Arguments are analogous to ccid_hc_tx_parse_options()
214 static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
215 u8 pkt, u8 opt, u8 *val, u8 len)
217 if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL)
219 return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len);
222 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
225 if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
226 return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
230 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
231 struct tcp_info *info)
233 if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
234 ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
237 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
238 struct tcp_info *info)
240 if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
241 ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
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)
248 int rc = -ENOPROTOOPT;
249 if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
250 rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
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)
259 int rc = -ENOPROTOOPT;
260 if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
261 rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,