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
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