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1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H
18 #define ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H
19 
20 #include <hardware/hardware.h>
21 #include <hardware/hw_auth_token.h>
22 
23 #define FINGERPRINT_MODULE_API_VERSION_1_0 HARDWARE_MODULE_API_VERSION(1, 0)
24 #define FINGERPRINT_MODULE_API_VERSION_2_0 HARDWARE_MODULE_API_VERSION(2, 0)
25 #define FINGERPRINT_MODULE_API_VERSION_2_1 HARDWARE_MODULE_API_VERSION(2, 1)
26 #define FINGERPRINT_MODULE_API_VERSION_3_0 HARDWARE_MODULE_API_VERSION(3, 0)
27 #define FINGERPRINT_HARDWARE_MODULE_ID "fingerprint"
28 
29 typedef enum fingerprint_msg_type {
30     FINGERPRINT_ERROR = -1,
31     FINGERPRINT_ACQUIRED = 1,
32     FINGERPRINT_TEMPLATE_ENROLLING = 3,
33     FINGERPRINT_TEMPLATE_REMOVED = 4,
34     FINGERPRINT_AUTHENTICATED = 5,
35     FINGERPRINT_TEMPLATE_ENUMERATING = 6,
36 } fingerprint_msg_type_t;
37 
38 /*
39  * Fingerprint errors are meant to tell the framework to terminate the current operation and ask
40  * for the user to correct the situation. These will almost always result in messaging and user
41  * interaction to correct the problem.
42  *
43  * For example, FINGERPRINT_ERROR_CANCELED should follow any acquisition message that results in
44  * a situation where the current operation can't continue without user interaction. For example,
45  * if the sensor is dirty during enrollment and no further enrollment progress can be made,
46  * send FINGERPRINT_ACQUIRED_IMAGER_DIRTY followed by FINGERPRINT_ERROR_CANCELED.
47  */
48 typedef enum fingerprint_error {
49     FINGERPRINT_ERROR_HW_UNAVAILABLE = 1, /* The hardware has an error that can't be resolved. */
50     FINGERPRINT_ERROR_UNABLE_TO_PROCESS = 2, /* Bad data; operation can't continue */
51     FINGERPRINT_ERROR_TIMEOUT = 3, /* The operation has timed out waiting for user input. */
52     FINGERPRINT_ERROR_NO_SPACE = 4, /* No space available to store a template */
53     FINGERPRINT_ERROR_CANCELED = 5, /* The current operation can't proceed. See above. */
54     FINGERPRINT_ERROR_UNABLE_TO_REMOVE = 6, /* fingerprint with given id can't be removed */
55     FINGERPRINT_ERROR_LOCKOUT = 7, /* the fingerprint hardware is in lockout due to too many attempts */
56     FINGERPRINT_ERROR_VENDOR_BASE = 1000 /* vendor-specific error messages start here */
57 } fingerprint_error_t;
58 
59 /*
60  * Fingerprint acquisition info is meant as feedback for the current operation.  Anything but
61  * FINGERPRINT_ACQUIRED_GOOD will be shown to the user as feedback on how to take action on the
62  * current operation. For example, FINGERPRINT_ACQUIRED_IMAGER_DIRTY can be used to tell the user
63  * to clean the sensor.  If this will cause the current operation to fail, an additional
64  * FINGERPRINT_ERROR_CANCELED can be sent to stop the operation in progress (e.g. enrollment).
65  * In general, these messages will result in a "Try again" message.
66  */
67 typedef enum fingerprint_acquired_info {
68     FINGERPRINT_ACQUIRED_GOOD = 0,
69     FINGERPRINT_ACQUIRED_PARTIAL = 1, /* sensor needs more data, i.e. longer swipe. */
70     FINGERPRINT_ACQUIRED_INSUFFICIENT = 2, /* image doesn't contain enough detail for recognition*/
71     FINGERPRINT_ACQUIRED_IMAGER_DIRTY = 3, /* sensor needs to be cleaned */
72     FINGERPRINT_ACQUIRED_TOO_SLOW = 4, /* mostly swipe-type sensors; not enough data collected */
73     FINGERPRINT_ACQUIRED_TOO_FAST = 5, /* for swipe and area sensors; tell user to slow down*/
74     FINGERPRINT_ACQUIRED_DETECTED = 6, /* when the finger is first detected. Used to optimize wakeup.
75                                           Should be followed by one of the above messages */
76     FINGERPRINT_ACQUIRED_VENDOR_BASE = 1000 /* vendor-specific acquisition messages start here */
77 } fingerprint_acquired_info_t;
78 
79 typedef struct fingerprint_finger_id {
80     uint32_t gid;
81     uint32_t fid;
82 } fingerprint_finger_id_t;
83 
84 typedef struct fingerprint_enroll {
85     fingerprint_finger_id_t finger;
86     /* samples_remaining goes from N (no data collected, but N scans needed)
87      * to 0 (no more data is needed to build a template). */
88     uint32_t samples_remaining;
89     uint64_t msg; /* Vendor specific message. Used for user guidance */
90 } fingerprint_enroll_t;
91 
92 typedef struct fingerprint_iterator {
93     fingerprint_finger_id_t finger;
94     uint32_t remaining_templates;
95 } fingerprint_iterator_t;
96 
97 typedef fingerprint_iterator_t fingerprint_enumerated_t;
98 typedef fingerprint_iterator_t fingerprint_removed_t;
99 
100 typedef struct fingerprint_acquired {
101     fingerprint_acquired_info_t acquired_info; /* information about the image */
102 } fingerprint_acquired_t;
103 
104 typedef struct fingerprint_authenticated {
105     fingerprint_finger_id_t finger;
106     hw_auth_token_t hat;
107 } fingerprint_authenticated_t;
108 
109 typedef struct fingerprint_msg {
110     fingerprint_msg_type_t type;
111     union {
112         fingerprint_error_t error;
113         fingerprint_enroll_t enroll;
114         fingerprint_enumerated_t enumerated;
115         fingerprint_removed_t removed;
116         fingerprint_acquired_t acquired;
117         fingerprint_authenticated_t authenticated;
118     } data;
119 } fingerprint_msg_t;
120 
121 /* Callback function type */
122 typedef void (*fingerprint_notify_t)(const fingerprint_msg_t *msg);
123 
124 /* Synchronous operation */
125 typedef struct fingerprint_device {
126     /**
127      * Common methods of the fingerprint device. This *must* be the first member
128      * of fingerprint_device as users of this structure will cast a hw_device_t
129      * to fingerprint_device pointer in contexts where it's known
130      * the hw_device_t references a fingerprint_device.
131      */
132     struct hw_device_t common;
133 
134     /*
135      * Client provided callback function to receive notifications.
136      * Do not set by hand, use the function above instead.
137      */
138     fingerprint_notify_t notify;
139 
140     /*
141      * Set notification callback:
142      * Registers a user function that would receive notifications from the HAL
143      * The call will block if the HAL state machine is in busy state until HAL
144      * leaves the busy state.
145      *
146      * Function return: 0 if callback function is successfuly registered
147      *                  or a negative number in case of error, generally from the errno.h set.
148      */
149     int (*set_notify)(struct fingerprint_device *dev, fingerprint_notify_t notify);
150 
151     /*
152      * Fingerprint pre-enroll enroll request:
153      * Generates a unique token to upper layers to indicate the start of an enrollment transaction.
154      * This token will be wrapped by security for verification and passed to enroll() for
155      * verification before enrollment will be allowed. This is to ensure adding a new fingerprint
156      * template was preceded by some kind of credential confirmation (e.g. device password).
157      *
158      * Function return: 0 if function failed
159      *                  otherwise, a uint64_t of token
160      */
161     uint64_t (*pre_enroll)(struct fingerprint_device *dev);
162 
163     /*
164      * Fingerprint enroll request:
165      * Switches the HAL state machine to collect and store a new fingerprint
166      * template. Switches back as soon as enroll is complete
167      * (fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENROLLING &&
168      *  fingerprint_msg.data.enroll.samples_remaining == 0)
169      * or after timeout_sec seconds.
170      * The fingerprint template will be assigned to the group gid. User has a choice
171      * to supply the gid or set it to 0 in which case a unique group id will be generated.
172      *
173      * Function return: 0 if enrollment process can be successfully started
174      *                  or a negative number in case of error, generally from the errno.h set.
175      *                  A notify() function may be called indicating the error condition.
176      */
177     int (*enroll)(struct fingerprint_device *dev, const hw_auth_token_t *hat,
178                     uint32_t gid, uint32_t timeout_sec);
179 
180     /*
181      * Finishes the enroll operation and invalidates the pre_enroll() generated challenge.
182      * This will be called at the end of a multi-finger enrollment session to indicate
183      * that no more fingers will be added.
184      *
185      * Function return: 0 if the request is accepted
186      *                  or a negative number in case of error, generally from the errno.h set.
187      */
188     int (*post_enroll)(struct fingerprint_device *dev);
189 
190     /*
191      * get_authenticator_id:
192      * Returns a token associated with the current fingerprint set. This value will
193      * change whenever a new fingerprint is enrolled, thus creating a new fingerprint
194      * set.
195      *
196      * Function return: current authenticator id or 0 if function failed.
197      */
198     uint64_t (*get_authenticator_id)(struct fingerprint_device *dev);
199 
200     /*
201      * Cancel pending enroll or authenticate, sending FINGERPRINT_ERROR_CANCELED
202      * to all running clients. Switches the HAL state machine back to the idle state.
203      * Unlike enroll_done() doesn't invalidate the pre_enroll() challenge.
204      *
205      * Function return: 0 if cancel request is accepted
206      *                  or a negative number in case of error, generally from the errno.h set.
207      */
208     int (*cancel)(struct fingerprint_device *dev);
209 
210     /*
211      * Enumerate all the fingerprint templates found in the directory set by
212      * set_active_group()
213      * For each template found a notify() will be called with:
214      * fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENUMERATED
215      * fingerprint_msg.data.enumerated.finger indicating a template id
216      * fingerprint_msg.data.enumerated.remaining_templates indicating how many more
217      * enumeration messages to expect.
218      * Note: If there are no fingerprints, then this should return 0 and the first fingerprint
219      *                  enumerated should have fingerid=0 and remaining=0
220      * Function return: 0 if enumerate request is accepted
221      *                  or a negative number in case of error, generally from the errno.h set.
222      */
223     int (*enumerate)(struct fingerprint_device *dev);
224 
225     /*
226      * Fingerprint remove request:
227      * Deletes a fingerprint template.
228      * Works only within the path set by set_active_group().
229      * The fid parameter can be used as a widcard:
230      *   * fid == 0 -- delete all the templates in the group.
231      *   * fid != 0 -- delete this specific template from the group.
232      * For each template found a notify() will be called with:
233      * fingerprint_msg.type == FINGERPRINT_TEMPLATE_REMOVED
234      * fingerprint_msg.data.removed.finger indicating a template id deleted
235      * fingerprint_msg.data.removed.remaining_templates indicating how many more
236      * templates will be deleted by this operation.
237      *
238      * Function return: 0 if fingerprint template(s) can be successfully deleted
239      *                  or a negative number in case of error, generally from the errno.h set.
240      */
241     int (*remove)(struct fingerprint_device *dev, uint32_t gid, uint32_t fid);
242 
243     /*
244      * Restricts the HAL operation to a set of fingerprints belonging to a
245      * group provided.
246      * The caller must provide a path to a storage location within the user's
247      * data directory.
248      *
249      * Function return: 0 on success
250      *                  or a negative number in case of error, generally from the errno.h set.
251      */
252     int (*set_active_group)(struct fingerprint_device *dev, uint32_t gid,
253                             const char *store_path);
254 
255     /*
256      * Authenticates an operation identifed by operation_id
257      *
258      * Function return: 0 on success
259      *                  or a negative number in case of error, generally from the errno.h set.
260      */
261     int (*authenticate)(struct fingerprint_device *dev, uint64_t operation_id, uint32_t gid);
262 
263     /* Reserved for backward binary compatibility */
264     void *reserved[4];
265 } fingerprint_device_t;
266 
267 typedef struct fingerprint_module {
268     /**
269      * Common methods of the fingerprint module. This *must* be the first member
270      * of fingerprint_module as users of this structure will cast a hw_module_t
271      * to fingerprint_module pointer in contexts where it's known
272      * the hw_module_t references a fingerprint_module.
273      */
274     struct hw_module_t common;
275 } fingerprint_module_t;
276 
277 #endif  /* ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H */
278