1 /*
2  * Copyright (c) 2021 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 #define IOKIT_ENABLE_SHARED_PTR
30 #include <kern/debug.h>
31 #include <libkern/coreanalytics/coreanalytics.h>
32 #include <libkern/coreanalytics/coreanalytics_shim.h>
33 #include <libkern/c++/OSBoolean.h>
34 #include <libkern/c++/OSDictionary.h>
35 #include <libkern/c++/OSNumber.h>
36 #include <libkern/c++/OSMetaClass.h>
37 #include <libkern/c++/OSString.h>
38 #include <os/atomic.h>
39 #include <os/log.h>
40 #include <sys/errno.h>
41 
42 /* Pulled from CoreAnalyticsHub.h in CoreAnalytics project */
43 static const char *kCoreAnalyticsMatchingClassName = "CoreAnalyticsHub";
44 
45 core_analytics_hub_functions_t *core_analytics_hub_functions = NULL;
46 
47 core_analytics_family_service_t *
48 core_analytics_family_match()
49 {
50 	OSSharedPtr<OSDictionary> dict = IOService::serviceMatching(kCoreAnalyticsMatchingClassName);
51 	OSSharedPtr<IOService> service = nullptr;
52 	if (dict) {
53 		service = IOService::waitForMatchingService(dict.get());
54 	} else {
55 		os_log_with_startup_serial(OS_LOG_DEFAULT, "No service matching %s", kCoreAnalyticsMatchingClassName);
56 	}
57 	if (service) {
58 		return service.detach();
59 	} else {
60 		os_log_with_startup_serial(OS_LOG_DEFAULT, "Unable to match CoreAnalyticsHub");
61 		return nullptr;
62 	}
63 }
64 
65 void
66 core_analytics_family_release(core_analytics_family_service_t *service)
67 {
68 	service->release();
69 }
70 
71 typedef struct core_analytics_serialized_event_s {
72 	OSSharedPtr<OSString> case_event_name;
73 	OSSharedPtr<OSDictionary> case_event;
74 } core_analytics_serialized_event_t;
75 
76 /*
77  * Stringifying CA_BOOL is different in C vs. C++ b/c the underlying
78  * bool typename is different (_Bool vs bool).
79  * We want to support both since the event may have been defined in C or C++ code.
80  */
81 extern const char *core_analytics_ca_bool_c_stringified;
82 const char *core_analytics_ca_bool_cpp_stringified = _CA_STRINGIFY_EXPAND(CA_BOOL);
83 
84 static OSSharedPtr<OSObject>
85 serialize_event_field(const char **field_spec, ptrdiff_t *event, OSSharedPtr<const OSSymbol> *key)
86 {
87 	OSSharedPtr<OSObject> field = nullptr;
88 	ptrdiff_t field_value = (ptrdiff_t) *event;
89 	uint64_t number_value;
90 	const char *str_value;
91 	size_t str_len = 0;
92 	bool bool_value;
93 
94 	if (strcmp(*field_spec, _CA_STRINGIFY_EXPAND(CA_INT)) == 0) {
95 		number_value = *(const uint64_t *)field_value;
96 		field = OSNumber::withNumber(number_value, sizeof(uint64_t) * 8);
97 		*event += sizeof(const uint64_t);
98 	} else if (strcmp(*field_spec, core_analytics_ca_bool_cpp_stringified) == 0 ||
99 	    strcmp(*field_spec, core_analytics_ca_bool_c_stringified) == 0) {
100 		bool_value = *(const bool *)field_value;
101 		field = OSBoolean::withBoolean(bool_value);
102 		*event += sizeof(const bool);
103 	} else if ((str_len = core_analytics_field_is_string(*field_spec)) != 0) {
104 		str_value = (const char *) field_value;
105 		assert(strlen(str_value) < str_len);
106 		if (strlen(str_value) < str_len) {
107 			field = OSString::withCString(str_value);
108 		} else {
109 			field = nullptr;
110 		}
111 		*event += str_len;
112 	} else {
113 		panic("Unknown CoreAnalytics event type: %s.", *field_spec);
114 	}
115 	*field_spec += strlen(*field_spec) + 1;
116 
117 	*key = OSSymbol::withCString(*field_spec);
118 	assert(*key != nullptr);
119 	if (!*key) {
120 		return nullptr;
121 	}
122 	*field_spec += strlen(*field_spec) + 1;
123 	return field;
124 }
125 
126 static int
127 core_analytics_serialize_event(const char *event_spec,
128     const ca_event_t event,
129     core_analytics_serialized_event_t *serialized_event)
130 {
131 	serialized_event->case_event_name = nullptr;
132 	serialized_event->case_event = nullptr;
133 	OSSharedPtr<OSDictionary> dict = nullptr;
134 	bool success;
135 	OSSharedPtr<OSString> name = OSString::withCStringNoCopy(event_spec);
136 	if (!name) {
137 		return ENOMEM;
138 	}
139 	dict = OSDictionary::withCapacity(1);
140 	if (!dict) {
141 		return ENOMEM;
142 	}
143 	const char *spec_curr = event_spec + strlen(event_spec) + 1;
144 	ptrdiff_t event_curr = (ptrdiff_t) event->data;
145 	while (strlen(spec_curr) != 0) {
146 		OSSharedPtr<const OSSymbol> key = NULL;
147 		OSSharedPtr<OSObject> object = serialize_event_field(&spec_curr, &event_curr, &key);
148 		if (!object) {
149 			return ENOMEM;
150 		}
151 		success = dict->setObject(key, object);
152 		if (!success) {
153 			return ENOMEM;
154 		}
155 	}
156 
157 	serialized_event->case_event_name = name;
158 	serialized_event->case_event = dict;
159 	return 0;
160 }
161 
162 int
163 core_analytics_send_event_lazy(
164 	core_analytics_family_service_t *core_analytics_hub,
165 	const char *event_spec, const ca_event_t event)
166 {
167 	int ret = 0;
168 	bool success;
169 	static constexpr size_t kMaxRetries = 5;
170 	static constexpr uint64_t kDelayBetweenRetries = 1000; // microseconds
171 	core_analytics_serialized_event_t serialized;
172 	if (!core_analytics_hub_functions) {
173 		return EAGAIN;
174 	}
175 
176 	ret = core_analytics_serialize_event(event_spec, event, &serialized);
177 	if (ret != 0) {
178 		return ret;
179 	}
180 	for (size_t i = 0; i < kMaxRetries; i++) {
181 		success = core_analytics_hub_functions->analytics_send_event_lazy(core_analytics_hub, serialized.case_event_name.get(), serialized.case_event.get());
182 		if (success) {
183 			break;
184 		} else {
185 			if (i != kMaxRetries - 1) {
186 				delay(kDelayBetweenRetries);
187 			} else {
188 				ret = EAGAIN;
189 				break;
190 			}
191 		}
192 	}
193 	return ret;
194 }
195 
196 void
197 core_analytics_hub_register(core_analytics_hub_functions_t *fns)
198 {
199 	if (fns->version != CORE_ANALYTICS_FUNCTIONS_TABLE_VERSION) {
200 		panic("CoreAnalyticsHub is out of sync with xnu. CoreAnalyticsHub table version: %d. xnu table version: %d", fns->version, CORE_ANALYTICS_FUNCTIONS_TABLE_VERSION);
201 	}
202 	core_analytics_hub_functions = fns;
203 	os_log_with_startup_serial(OS_LOG_DEFAULT, "Registered CoreAnalyticsHub functions with xnu.");
204 }
205