xref: /openbmc/linux/net/dccp/ccid.h (revision 8402a31d)
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 
ccid_priv(const struct ccid * ccid)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 
ccid_get_current_rx_ccid(struct dccp_sock * dp)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 
ccid_get_current_tx_ccid(struct dccp_sock * dp)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 
ccid_packet_dequeue_eval(const int return_code)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 
ccid_hc_tx_send_packet(struct ccid * ccid,struct sock * sk,struct sk_buff * skb)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 
ccid_hc_tx_packet_sent(struct ccid * ccid,struct sock * sk,unsigned int len)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 
ccid_hc_rx_packet_recv(struct ccid * ccid,struct sock * sk,struct sk_buff * skb)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 
ccid_hc_tx_packet_recv(struct ccid * ccid,struct sock * sk,struct sk_buff * skb)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  */
ccid_hc_tx_parse_options(struct ccid * ccid,struct sock * sk,u8 pkt,u8 opt,u8 * val,u8 len)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  */
ccid_hc_rx_parse_options(struct ccid * ccid,struct sock * sk,u8 pkt,u8 opt,u8 * val,u8 len)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 
ccid_hc_rx_insert_options(struct ccid * ccid,struct sock * sk,struct sk_buff * skb)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 
ccid_hc_rx_get_info(struct ccid * ccid,struct sock * sk,struct tcp_info * info)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 
ccid_hc_tx_get_info(struct ccid * ccid,struct sock * sk,struct tcp_info * info)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 
ccid_hc_rx_getsockopt(struct ccid * ccid,struct sock * sk,const int optname,int len,u32 __user * optval,int __user * optlen)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 
ccid_hc_tx_getsockopt(struct ccid * ccid,struct sock * sk,const int optname,int len,u32 __user * optval,int __user * optlen)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