1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
4   * Copyright (c) 2017, Linaro Ltd.
5   */
6  #ifndef __QMI_HELPERS_H__
7  #define __QMI_HELPERS_H__
8  
9  #include <linux/completion.h>
10  #include <linux/idr.h>
11  #include <linux/list.h>
12  #include <linux/qrtr.h>
13  #include <linux/types.h>
14  #include <linux/workqueue.h>
15  
16  struct socket;
17  
18  /**
19   * struct qmi_header - wireformat header of QMI messages
20   * @type:	type of message
21   * @txn_id:	transaction id
22   * @msg_id:	message id
23   * @msg_len:	length of message payload following header
24   */
25  struct qmi_header {
26  	u8 type;
27  	u16 txn_id;
28  	u16 msg_id;
29  	u16 msg_len;
30  } __packed;
31  
32  #define QMI_REQUEST	0
33  #define QMI_RESPONSE	2
34  #define QMI_INDICATION	4
35  
36  #define QMI_COMMON_TLV_TYPE 0
37  
38  enum qmi_elem_type {
39  	QMI_EOTI,
40  	QMI_OPT_FLAG,
41  	QMI_DATA_LEN,
42  	QMI_UNSIGNED_1_BYTE,
43  	QMI_UNSIGNED_2_BYTE,
44  	QMI_UNSIGNED_4_BYTE,
45  	QMI_UNSIGNED_8_BYTE,
46  	QMI_SIGNED_2_BYTE_ENUM,
47  	QMI_SIGNED_4_BYTE_ENUM,
48  	QMI_STRUCT,
49  	QMI_STRING,
50  };
51  
52  enum qmi_array_type {
53  	NO_ARRAY,
54  	STATIC_ARRAY,
55  	VAR_LEN_ARRAY,
56  };
57  
58  /**
59   * struct qmi_elem_info - describes how to encode a single QMI element
60   * @data_type:	Data type of this element.
61   * @elem_len:	Array length of this element, if an array.
62   * @elem_size:	Size of a single instance of this data type.
63   * @array_type:	Array type of this element.
64   * @tlv_type:	QMI message specific type to identify which element
65   *		is present in an incoming message.
66   * @offset:	Specifies the offset of the first instance of this
67   *		element in the data structure.
68   * @ei_array:	Null-terminated array of @qmi_elem_info to describe nested
69   *		structures.
70   */
71  struct qmi_elem_info {
72  	enum qmi_elem_type data_type;
73  	u32 elem_len;
74  	u32 elem_size;
75  	enum qmi_array_type array_type;
76  	u8 tlv_type;
77  	u32 offset;
78  	const struct qmi_elem_info *ei_array;
79  };
80  
81  #define QMI_RESULT_SUCCESS_V01			0
82  #define QMI_RESULT_FAILURE_V01			1
83  
84  #define QMI_ERR_NONE_V01			0
85  #define QMI_ERR_MALFORMED_MSG_V01		1
86  #define QMI_ERR_NO_MEMORY_V01			2
87  #define QMI_ERR_INTERNAL_V01			3
88  #define QMI_ERR_CLIENT_IDS_EXHAUSTED_V01	5
89  #define QMI_ERR_INVALID_ID_V01			41
90  #define QMI_ERR_ENCODING_V01			58
91  #define QMI_ERR_DISABLED_V01                    69
92  #define QMI_ERR_INCOMPATIBLE_STATE_V01		90
93  #define QMI_ERR_NOT_SUPPORTED_V01		94
94  
95  /**
96   * struct qmi_response_type_v01 - common response header (decoded)
97   * @result:	result of the transaction
98   * @error:	error value, when @result is QMI_RESULT_FAILURE_V01
99   */
100  struct qmi_response_type_v01 {
101  	u16 result;
102  	u16 error;
103  };
104  
105  extern const struct qmi_elem_info qmi_response_type_v01_ei[];
106  
107  /**
108   * struct qmi_service - context to track lookup-results
109   * @service:	service type
110   * @version:	version of the @service
111   * @instance:	instance id of the @service
112   * @node:	node of the service
113   * @port:	port of the service
114   * @priv:	handle for client's use
115   * @list_node:	list_head for house keeping
116   */
117  struct qmi_service {
118  	unsigned int service;
119  	unsigned int version;
120  	unsigned int instance;
121  
122  	unsigned int node;
123  	unsigned int port;
124  
125  	void *priv;
126  	struct list_head list_node;
127  };
128  
129  struct qmi_handle;
130  
131  /**
132   * struct qmi_ops - callbacks for qmi_handle
133   * @new_server:		inform client of a new_server lookup-result, returning
134   *                      successfully from this call causes the library to call
135   *                      @del_server as the service is removed from the
136   *                      lookup-result. @priv of the qmi_service can be used by
137   *                      the client
138   * @del_server:		inform client of a del_server lookup-result
139   * @net_reset:		inform client that the name service was restarted and
140   *                      that and any state needs to be released
141   * @msg_handler:	invoked for incoming messages, allows a client to
142   *                      override the usual QMI message handler
143   * @bye:                inform a client that all clients from a node are gone
144   * @del_client:         inform a client that a particular client is gone
145   */
146  struct qmi_ops {
147  	int (*new_server)(struct qmi_handle *qmi, struct qmi_service *svc);
148  	void (*del_server)(struct qmi_handle *qmi, struct qmi_service *svc);
149  	void (*net_reset)(struct qmi_handle *qmi);
150  	void (*msg_handler)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
151  			    const void *data, size_t count);
152  	void (*bye)(struct qmi_handle *qmi, unsigned int node);
153  	void (*del_client)(struct qmi_handle *qmi,
154  			   unsigned int node, unsigned int port);
155  };
156  
157  /**
158   * struct qmi_txn - transaction context
159   * @qmi:	QMI handle this transaction is associated with
160   * @id:		transaction id
161   * @lock:	for synchronization between handler and waiter of messages
162   * @completion:	completion object as the transaction receives a response
163   * @result:	result code for the completed transaction
164   * @ei:		description of the QMI encoded response (optional)
165   * @dest:	destination buffer to decode message into (optional)
166   */
167  struct qmi_txn {
168  	struct qmi_handle *qmi;
169  
170  	u16 id;
171  
172  	struct mutex lock;
173  	struct completion completion;
174  	int result;
175  
176  	const struct qmi_elem_info *ei;
177  	void *dest;
178  };
179  
180  /**
181   * struct qmi_msg_handler - description of QMI message handler
182   * @type:	type of message
183   * @msg_id:	message id
184   * @ei:		description of the QMI encoded message
185   * @decoded_size:	size of the decoded object
186   * @fn:		function to invoke as the message is decoded
187   */
188  struct qmi_msg_handler {
189  	unsigned int type;
190  	unsigned int msg_id;
191  
192  	const struct qmi_elem_info *ei;
193  
194  	size_t decoded_size;
195  	void (*fn)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
196  		   struct qmi_txn *txn, const void *decoded);
197  };
198  
199  /**
200   * struct qmi_handle - QMI context
201   * @sock:	socket handle
202   * @sock_lock:	synchronization of @sock modifications
203   * @sq:		sockaddr of @sock
204   * @work:	work for handling incoming messages
205   * @wq:		workqueue to post @work on
206   * @recv_buf:	scratch buffer for handling incoming messages
207   * @recv_buf_size:	size of @recv_buf
208   * @lookups:		list of registered lookup requests
209   * @lookup_results:	list of lookup-results advertised to the client
210   * @services:		list of registered services (by this client)
211   * @ops:	reference to callbacks
212   * @txns:	outstanding transactions
213   * @txn_lock:	lock for modifications of @txns
214   * @handlers:	list of handlers for incoming messages
215   */
216  struct qmi_handle {
217  	struct socket *sock;
218  	struct mutex sock_lock;
219  
220  	struct sockaddr_qrtr sq;
221  
222  	struct work_struct work;
223  	struct workqueue_struct *wq;
224  
225  	void *recv_buf;
226  	size_t recv_buf_size;
227  
228  	struct list_head lookups;
229  	struct list_head lookup_results;
230  	struct list_head services;
231  
232  	struct qmi_ops ops;
233  
234  	struct idr txns;
235  	struct mutex txn_lock;
236  
237  	const struct qmi_msg_handler *handlers;
238  };
239  
240  int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
241  		   unsigned int version, unsigned int instance);
242  int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
243  		   unsigned int version, unsigned int instance);
244  
245  int qmi_handle_init(struct qmi_handle *qmi, size_t max_msg_len,
246  		    const struct qmi_ops *ops,
247  		    const struct qmi_msg_handler *handlers);
248  void qmi_handle_release(struct qmi_handle *qmi);
249  
250  ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
251  			 struct qmi_txn *txn, int msg_id, size_t len,
252  			 const struct qmi_elem_info *ei, const void *c_struct);
253  ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
254  			  struct qmi_txn *txn, int msg_id, size_t len,
255  			  const struct qmi_elem_info *ei, const void *c_struct);
256  ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
257  			    int msg_id, size_t len, const struct qmi_elem_info *ei,
258  			    const void *c_struct);
259  
260  void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
261  			 unsigned int txn_id, const struct qmi_elem_info *ei,
262  			 const void *c_struct);
263  
264  int qmi_decode_message(const void *buf, size_t len,
265  		       const struct qmi_elem_info *ei, void *c_struct);
266  
267  int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
268  		 const struct qmi_elem_info *ei, void *c_struct);
269  int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout);
270  void qmi_txn_cancel(struct qmi_txn *txn);
271  
272  #endif
273