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1 /* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2  * Use of this source code is governed by a BSD-style license that can be
3  * found in the LICENSE file.
4  */
5 
6 /*
7  * A remote client to the server.
8  */
9 #ifndef CRAS_RCLIENT_H_
10 #define CRAS_RCLIENT_H_
11 
12 #include "cras_types.h"
13 
14 struct cras_client_message;
15 struct cras_message;
16 struct cras_server_message;
17 
18 /* An attached client.
19  *  id - The id of the client.
20  *  fd - Connection for client communication.
21  *  ops - cras_rclient_ops for the cras_rclient.
22  *  supported_directions - Bit mask for supported stream directions.
23  */
24 struct cras_rclient {
25 	struct cras_observer_client *observer;
26 	size_t id;
27 	int fd;
28 	const struct cras_rclient_ops *ops;
29 	int supported_directions;
30 };
31 
32 /* Operations for cras_rclient.
33  * handle_message_from_client - Entry point for handling a message from the
34  * corresponded client.
35  * send_message_to_client - Method for sending message to the corresponded
36  * client.
37  * destroy - Method to destroy and free the cras_rclient.
38  */
39 struct cras_rclient_ops {
40 	int (*handle_message_from_client)(struct cras_rclient *,
41 					  const struct cras_server_message *,
42 					  int *fds, unsigned int num_fds);
43 	int (*send_message_to_client)(const struct cras_rclient *,
44 				      const struct cras_client_message *,
45 				      int *fds, unsigned int num_fds);
46 	void (*destroy)(struct cras_rclient *);
47 };
48 
49 /* Creates an rclient structure.
50  * Args:
51  *    fd - The file descriptor used for communication with the client.
52  *    id - Unique identifier for this client.
53  *    conn_type - Client connection type.
54  * Returns:
55  *    A pointer to the newly created rclient on success, NULL on failure.
56  */
57 struct cras_rclient *cras_rclient_create(int fd, size_t id,
58 					 enum CRAS_CONNECTION_TYPE conn_type);
59 
60 /* Destroys an rclient created with "cras_rclient_create".
61  * Args:
62  *    client - The client to destroy.
63  */
64 void cras_rclient_destroy(struct cras_rclient *client);
65 
66 /* Handles a received buffer from the client.
67  * Args:
68  *    client - The client that received this message.
69  *    buf - The raw byte buffer the client sent. It should contain a valid
70  *      cras_server_message.
71  *    buf_len - The length of |buf|.
72  *    fds - Array of valid file descriptors sent by the remote client.
73  *    num_fds - Length of |fds|.
74  * Returns:
75  *    0 on success, otherwise a negative error code.
76  */
77 int cras_rclient_buffer_from_client(struct cras_rclient *client,
78 				    const uint8_t *buf, size_t buf_len,
79 				    int *fds, int num_fds);
80 
81 /* Sends a message to the client.
82  * Args:
83  *    client - The client to send the message to.
84  *    msg - The message to send.
85  *    fds - Array of file descriptors or null
86  *    num_fds - Number of entries in the fds array.
87  * Returns:
88  *    number of bytes written on success, otherwise a negative error code.
89  */
90 int cras_rclient_send_message(const struct cras_rclient *client,
91 			      const struct cras_client_message *msg, int *fds,
92 			      unsigned int num_fds);
93 
94 #endif /* CRAS_RCLIENT_H_ */
95