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