xref: /xnu-10002.1.13/bsd/net/necp.h (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1 /*
2  * Copyright (c) 2013-2022 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 #ifndef _NET_NECP_H_
30 #define _NET_NECP_H_
31 
32 #include <net/net_kev.h>
33 #ifdef PRIVATE
34 
35 #include <netinet/in.h>
36 #include <netinet/in_stat.h>
37 #include <sys/socket.h>
38 #include <net/if.h>
39 
40 #if SKYWALK
41 #include <skywalk/os_nexus_private.h>
42 #else /* !SKYWALK */
43 typedef uint16_t nexus_port_t;
44 #endif /* !SKYWALK */
45 
46 /*
47  * Name registered by the NECP
48  */
49 #define NECP_CONTROL_NAME "com.apple.net.necp_control"
50 
51 #define NECP_TLV_LENGTH_UINT32  1
52 
53 struct necp_packet_header {
54 	u_int8_t            packet_type;
55 	u_int8_t                flags;
56 	u_int32_t           message_id;
57 };
58 
59 typedef struct {
60 	uid_t               uid;
61 	uuid_t              effective_uuid;
62 	uid_t               persona_id;
63 } necp_application_id_t;
64 
65 /*
66  * Control message commands
67  */
68 #define NECP_PACKET_TYPE_POLICY_ADD                             1
69 #define NECP_PACKET_TYPE_POLICY_GET                             2
70 #define NECP_PACKET_TYPE_POLICY_DELETE                  3
71 #define NECP_PACKET_TYPE_POLICY_APPLY_ALL               4
72 #define NECP_PACKET_TYPE_POLICY_LIST_ALL                5
73 #define NECP_PACKET_TYPE_POLICY_DELETE_ALL              6
74 #define NECP_PACKET_TYPE_SET_SESSION_PRIORITY   7
75 #define NECP_PACKET_TYPE_LOCK_SESSION_TO_PROC   8
76 #define NECP_PACKET_TYPE_REGISTER_SERVICE               9
77 #define NECP_PACKET_TYPE_UNREGISTER_SERVICE             10
78 #define NECP_PACKET_TYPE_POLICY_DUMP_ALL                11
79 
80 /*
81  * Session actions
82  */
83 #define NECP_SESSION_ACTION_POLICY_ADD                          1       // In: Policy TLVs				Out: necp_policy_id
84 #define NECP_SESSION_ACTION_POLICY_GET                          2       // In: necp_policy_id			Out: Policy TLVs
85 #define NECP_SESSION_ACTION_POLICY_DELETE                       3       // In: necp_policy_id			Out: None
86 #define NECP_SESSION_ACTION_POLICY_APPLY_ALL            4       // In: None						Out: None
87 #define NECP_SESSION_ACTION_POLICY_LIST_ALL                     5       // In: None						Out: TLVs of IDs
88 #define NECP_SESSION_ACTION_POLICY_DELETE_ALL           6       // In: None						Out: None
89 #define NECP_SESSION_ACTION_SET_SESSION_PRIORITY        7       // In: necp_session_priority	Out: None
90 #define NECP_SESSION_ACTION_LOCK_SESSION_TO_PROC        8       // In: None						Out: None
91 #define NECP_SESSION_ACTION_REGISTER_SERVICE            9       // In: uuid_t					Out: None
92 #define NECP_SESSION_ACTION_UNREGISTER_SERVICE          10      // In: uuid_t					Out: None
93 #define NECP_SESSION_ACTION_POLICY_DUMP_ALL                     11      // In: None						Out: uint32_t bytes length, then Policy TLVs
94 #define NECP_SESSION_ACTION_ADD_DOMAIN_FILTER           12      // In: struct net_bloom_filter  Out: uint32_t, ID
95 #define NECP_SESSION_ACTION_REMOVE_DOMAIN_FILTER        13      // In: uint32_t, ID             Out: None
96 #define NECP_SESSION_ACTION_REMOVE_ALL_DOMAIN_FILTERS   14      // In: None                     Out: None
97 
98 /*
99  * Control message flags
100  */
101 #define NECP_PACKET_FLAGS_RESPONSE                              0x01    // Used for acks, errors, and query responses
102 
103 /*
104  * Control message TLV types
105  */
106 #define NECP_TLV_NIL                                                    0
107 #define NECP_TLV_ERROR                                                  1       // u_int32_t
108 #define NECP_TLV_POLICY_ORDER                                   2       // u_int32_t
109 #define NECP_TLV_POLICY_CONDITION                               3
110 #define NECP_TLV_POLICY_RESULT                                  4
111 #define NECP_TLV_POLICY_ID                                              5       // u_int32_t
112 #define NECP_TLV_SESSION_PRIORITY                               6       // u_int32_t
113 #define NECP_TLV_ATTRIBUTE_DOMAIN                               7       // char[]
114 #define NECP_TLV_ATTRIBUTE_ACCOUNT                              8       // char[]
115 #define NECP_TLV_SERVICE_UUID                                   9       // uuid_t
116 #define NECP_TLV_ROUTE_RULE                                             10
117 #define NECP_TLV_ATTRIBUTE_DOMAIN_OWNER                        11       // char[]
118 #define NECP_TLV_ATTRIBUTE_TRACKER_DOMAIN                      12       // char[]
119 #define NECP_TLV_ATTRIBUTE_DOMAIN_CONTEXT                      13       // char[]
120 
121 /*
122  * Control message TLV sent only by the kernel to userspace
123  */
124 #define NECP_TLV_POLICY_OWNER                                   100     // char []
125 #define NECP_TLV_POLICY_DUMP                                    101
126 #define NECP_TLV_POLICY_RESULT_STRING                   102     // char []
127 #define NECP_TLV_POLICY_SESSION_ORDER                   103     // u_int32_t
128 
129 /*
130  * Condition flags
131  */
132 #define NECP_POLICY_CONDITION_FLAGS_NEGATIVE    0x01 // Negative
133 #define NECP_POLICY_CONDITION_FLAGS_EXACT       0x02 // For conditions that would otherwise have more inclusive matching, require an exact match
134 
135 /*
136  * Conditions
137  * Used for setting policies as well as passing parameters to necp_match_policy.
138  */
139 #define NECP_POLICY_CONDITION_DEFAULT                   0       // N/A, not valid with any other conditions
140 // Socket/Application conditions
141 #define NECP_POLICY_CONDITION_APPLICATION               1       // uuid_t, uses effective UUID when possible
142 #define NECP_POLICY_CONDITION_REAL_APPLICATION  2       // uuid_t, never uses effective UUID. Only valid with NECP_POLICY_CONDITION_APPLICATION
143 #define NECP_POLICY_CONDITION_DOMAIN                    3       // String, such as apple.com
144 #define NECP_POLICY_CONDITION_ACCOUNT                   4       // String
145 #define NECP_POLICY_CONDITION_ENTITLEMENT               5       // String
146 #define NECP_POLICY_CONDITION_PID                               6       // pid_t
147 #define NECP_POLICY_CONDITION_UID                               7       // uid_t
148 #define NECP_POLICY_CONDITION_ALL_INTERFACES    8       // N/A
149 #define NECP_POLICY_CONDITION_BOUND_INTERFACE   9       // String
150 #define NECP_POLICY_CONDITION_TRAFFIC_CLASS             10      // necp_policy_condition_tc_range
151 // Socket/IP conditions
152 #define NECP_POLICY_CONDITION_IP_PROTOCOL               11      // u_int16_t
153 #define NECP_POLICY_CONDITION_LOCAL_ADDR                12      // necp_policy_condition_addr
154 #define NECP_POLICY_CONDITION_REMOTE_ADDR               13      // necp_policy_condition_addr
155 #define NECP_POLICY_CONDITION_LOCAL_ADDR_RANGE  14      // necp_policy_condition_addr_range
156 #define NECP_POLICY_CONDITION_REMOTE_ADDR_RANGE 15      // necp_policy_condition_addr_range
157 #define NECP_POLICY_CONDITION_AGENT_TYPE                16      // struct necp_policy_condition_agent_type
158 #define NECP_POLICY_CONDITION_HAS_CLIENT                17      // N/A
159 #define NECP_POLICY_CONDITION_LOCAL_NETWORKS            18      // Matches all local networks
160 // Socket-only conditions
161 #define NECP_POLICY_CONDITION_FLOW_IP_PROTOCOL          19      // u_int16_t
162 #define NECP_POLICY_CONDITION_FLOW_LOCAL_ADDR           20      // necp_policy_condition_addr
163 #define NECP_POLICY_CONDITION_FLOW_REMOTE_ADDR          21      // necp_policy_condition_addr
164 #define NECP_POLICY_CONDITION_FLOW_LOCAL_ADDR_RANGE     22      // necp_policy_condition_addr_range
165 #define NECP_POLICY_CONDITION_FLOW_REMOTE_ADDR_RANGE    23      // necp_policy_condition_addr_range
166 #define NECP_POLICY_CONDITION_FLOW_IS_LOOPBACK          31      // N/A
167 // Socket/Application conditions, continued
168 #define NECP_POLICY_CONDITION_CLIENT_FLAGS              24      // u_int32_t, values from NECP_CLIENT_PARAMETER_FLAG_*
169 #define NECP_POLICY_CONDITION_FLOW_LOCAL_ADDR_EMPTY     25      // N/A
170 #define NECP_POLICY_CONDITION_FLOW_REMOTE_ADDR_EMPTY    26      // N/A
171 #define NECP_POLICY_CONDITION_PLATFORM_BINARY           27      // N/A
172 #define NECP_POLICY_CONDITION_SDK_VERSION               28      // struct necp_policy_condition_sdk_version
173 #define NECP_POLICY_CONDITION_SIGNING_IDENTIFIER        29      // String
174 #define NECP_POLICY_CONDITION_PACKET_FILTER_TAGS        30      // u_int16_t
175 #define NECP_POLICY_CONDITION_DELEGATE_IS_PLATFORM_BINARY      32      // N/A
176 #define NECP_POLICY_CONDITION_DOMAIN_OWNER              33      // String, owner of domain (for example, "Google Inc")
177 #define NECP_POLICY_CONDITION_DOMAIN_CONTEXT            34      // String, eTLD+1 leading to networking activities to the domain
178 #define NECP_POLICY_CONDITION_TRACKER_DOMAIN            35      // String, tracker domain
179 #define NECP_POLICY_CONDITION_ATTRIBUTED_BUNDLE_IDENTIFIER 36   // String, app to which traffic is attributed to
180 #define NECP_POLICY_CONDITION_SCHEME_PORT               37      // u_int16_t, the port associated with the scheme for a connection
181 #define NECP_POLICY_CONDITION_DOMAIN_FILTER             38      // struct net_bloom_filter
182 #define NECP_POLICY_CONDITION_SYSTEM_SIGNED_RESULT      39      // N/A
183 #define NECP_POLICY_CONDITION_REAL_UID                  40      // uid_t
184 #define NECP_POLICY_CONDITION_APPLICATION_ID            41      // necp_application_id_t
185 #define NECP_POLICY_CONDITION_URL                       42      // String, URL
186 
187 /*
188  * Policy Packet tags
189  */
190 #define NECP_POLICY_CONDITION_PACKET_FILTER_TAG_STACK_DROP         0x01
191 #define NECP_POLICY_CONDITION_PACKET_FILTER_TAG_MAX                NECP_POLICY_CONDITION_PACKET_FILTER_TAG_STACK_DROP
192 
193 /*
194  * Results
195  */
196 #define NECP_POLICY_RESULT_PASS                                 1       // N/A
197 #define NECP_POLICY_RESULT_SKIP                                 2       // u_int32_t, policy order to skip to. 0 to skip all session policies.
198 #define NECP_POLICY_RESULT_DROP                                 3       // N/A
199 #define NECP_POLICY_RESULT_SOCKET_DIVERT                4       // u_int32_t, flow divert control unit
200 #define NECP_POLICY_RESULT_SOCKET_FILTER                5       // u_int32_t, filter control unit
201 #define NECP_POLICY_RESULT_IP_TUNNEL                    6       // String, interface name
202 #define NECP_POLICY_RESULT_IP_FILTER                    7       // ?
203 #define NECP_POLICY_RESULT_TRIGGER                              8       // Deprecated
204 #define NECP_POLICY_RESULT_TRIGGER_IF_NEEDED    9       // Deprecated
205 #define NECP_POLICY_RESULT_TRIGGER_SCOPED               10      // Deprecated
206 #define NECP_POLICY_RESULT_NO_TRIGGER_SCOPED    11      // Deprecated
207 #define NECP_POLICY_RESULT_SOCKET_SCOPED                12      // String, interface name
208 #define NECP_POLICY_RESULT_ROUTE_RULES                  13      // N/A, must have route rules defined
209 #define NECP_POLICY_RESULT_USE_NETAGENT                 14      // netagent uuid_t
210 #define NECP_POLICY_RESULT_NETAGENT_SCOPED              15      // netagent uuid_t
211 #define NECP_POLICY_RESULT_SCOPED_DIRECT                16      // N/A, scopes to primary physical interface
212 #define NECP_POLICY_RESULT_ALLOW_UNENTITLED             17      // N/A
213 #define NECP_POLICY_RESULT_REMOVE_NETAGENT              18      // netagent uuid_t
214 
215 #define NECP_POLICY_RESULT_MAX                          NECP_POLICY_RESULT_REMOVE_NETAGENT
216 
217 /*
218  * PASS Result Flags
219  */
220 #define NECP_POLICY_PASS_NO_SKIP_IPSEC                  0x01
221 #define NECP_POLICY_PASS_PF_TAG                         0x02
222 
223 /*
224  * DROP Result Flags
225  */
226 #define NECP_POLICY_DROP_FLAG_LOCAL_NETWORK             0x01
227 
228 /*
229  * Route Rules
230  * Detailed parameters for NECP_POLICY_RESULT_ROUTE_RULES.
231  */
232 #define NECP_ROUTE_RULE_NONE                                    0       // N/A
233 #define NECP_ROUTE_RULE_DENY_INTERFACE                  1       // String, or empty to match all
234 #define NECP_ROUTE_RULE_ALLOW_INTERFACE                 2       // String, or empty to match all
235 #define NECP_ROUTE_RULE_QOS_MARKING                             3       // String, or empty to match all
236 #define NECP_ROUTE_RULE_DENY_LQM_ABORT                  4       // String, or empty to match all
237 #define NECP_ROUTE_RULE_USE_NETAGENT                    5       // UUID, followed by string or empty
238 #define NECP_ROUTE_RULE_REMOVE_NETAGENT                 6       // UUID, followed by string or empty
239 #define NECP_ROUTE_RULE_DIVERT_SOCKET                   7       // u_int32_t control unit, followed by string or empty
240 #define NECP_ROUTE_RULE_DENY_INTERFACE_WITH_TYPE        8       // u_int32_t effective type, followed by string or empty
241 
242 #define NECP_ROUTE_RULE_FLAG_CELLULAR                   0x01
243 #define NECP_ROUTE_RULE_FLAG_WIFI                       0x02
244 #define NECP_ROUTE_RULE_FLAG_WIRED                      0x04
245 #define NECP_ROUTE_RULE_FLAG_EXPENSIVE                  0x08
246 #define NECP_ROUTE_RULE_FLAG_CONSTRAINED                0x10
247 #define NECP_ROUTE_RULE_FLAG_COMPANION                  0x20
248 
249 #define NECP_ROUTE_RULE_FLAG_NETAGENT                   0x80 // Last bit, reserved to mark that this applies only when an agent UUID is present
250 
251 #define NECP_ROUTE_RULES_SUPPORT_NETAGENT_EXCEPTIONS    1
252 
253 /*
254  * Error types
255  */
256 #define NECP_ERROR_INTERNAL                                             0
257 #define NECP_ERROR_UNKNOWN_PACKET_TYPE                  1
258 #define NECP_ERROR_INVALID_TLV                                  2
259 #define NECP_ERROR_POLICY_RESULT_INVALID                3
260 #define NECP_ERROR_POLICY_CONDITIONS_INVALID    4
261 #define NECP_ERROR_POLICY_ID_NOT_FOUND                  5
262 #define NECP_ERROR_INVALID_PROCESS                              6
263 #define NECP_ERROR_ROUTE_RULES_INVALID                  7
264 
265 // Modifiers
266 #define NECP_MASK_USERSPACE_ONLY        0x80000000      // on filter_control_unit value
267 #define NECP_MASK_PRESERVE_CONNECTIONS  0x20000000      // on filter_control_unit value
268 
269 struct necp_policy_condition_tc_range {
270 	u_int32_t start_tc;
271 	u_int32_t end_tc;
272 } __attribute__((__packed__));
273 
274 struct necp_policy_condition_addr {
275 	u_int8_t                prefix;
276 	union {
277 #if !__has_ptrcheck
278 		struct sockaddr                 sa;
279 #endif
280 		struct __sockaddr_header        sah;
281 		struct sockaddr_in              sin;
282 		struct sockaddr_in6             sin6;
283 	} address __attribute__((__packed__));
284 } __attribute__((__packed__));
285 
286 struct necp_policy_condition_addr_range {
287 	union {
288 #if !__has_ptrcheck
289 		struct sockaddr                 sa;
290 #endif
291 		struct __sockaddr_header        sah;
292 		struct sockaddr_in              sin;
293 		struct sockaddr_in6             sin6;
294 	} start_address __attribute__((__packed__));
295 	union {
296 #if !__has_ptrcheck
297 		struct sockaddr                 sa;
298 #endif
299 		struct __sockaddr_header        sah;
300 		struct sockaddr_in              sin;
301 		struct sockaddr_in6             sin6;
302 	} end_address __attribute__((__packed__));
303 } __attribute__((__packed__));
304 
305 struct necp_policy_condition_agent_type {
306 	char agent_domain[32];
307 	char agent_type[32];
308 } __attribute__((__packed__));
309 
310 struct necp_policy_condition_sdk_version {
311 	uint32_t platform; // e.g., PLATFORM_IOS
312 	uint32_t min_version; // Encoded as XXXX.YY.ZZ
313 	uint32_t version; // Encoded as XXXX.YY.ZZ
314 } __attribute__((__packed__));
315 
316 #define NECP_SESSION_PRIORITY_UNKNOWN                   0
317 #define NECP_SESSION_PRIORITY_CONTROL                   1
318 #define NECP_SESSION_PRIORITY_CONTROL_1                 2
319 #define NECP_SESSION_PRIORITY_PRIVILEGED_TUNNEL         3
320 #define NECP_SESSION_PRIORITY_HIGH                      4
321 #define NECP_SESSION_PRIORITY_HIGH_1                    5
322 #define NECP_SESSION_PRIORITY_HIGH_2                    6
323 #define NECP_SESSION_PRIORITY_HIGH_3                    7
324 #define NECP_SESSION_PRIORITY_HIGH_4                    8
325 #define NECP_SESSION_PRIORITY_HIGH_RESTRICTED           9
326 #define NECP_SESSION_PRIORITY_DEFAULT                   10
327 #define NECP_SESSION_PRIORITY_LOW                       11
328 #define NECP_SESSION_NUM_PRIORITIES                             NECP_SESSION_PRIORITY_LOW
329 
330 typedef u_int32_t necp_policy_id;
331 typedef u_int32_t necp_policy_order;
332 typedef u_int32_t necp_session_priority;
333 
334 typedef u_int32_t necp_kernel_policy_result;
335 typedef u_int32_t necp_kernel_policy_filter;
336 
337 typedef union {
338 	u_int                                           tunnel_interface_index;
339 	u_int                                           scoped_interface_index;
340 	u_int32_t                                       flow_divert_control_unit;
341 	u_int32_t                                       filter_control_unit;
342 	u_int32_t                                       pass_flags;
343 	u_int32_t                                       drop_flags;
344 } necp_kernel_policy_routing_result_parameter;
345 
346 #define NECP_SERVICE_FLAGS_REGISTERED                   0x01
347 #define NECP_MAX_NETAGENTS                                              16
348 
349 #define NECP_AGENT_USE_FLAG_SCOPE                               0x01
350 #define NECP_AGENT_USE_FLAG_REMOVE                              0x02
351 
352 #define NECP_TFO_COOKIE_LEN_MAX      16
353 struct necp_aggregate_result {
354 	necp_kernel_policy_result                       routing_result;
355 	necp_kernel_policy_routing_result_parameter     routing_result_parameter;
356 	necp_kernel_policy_filter                       filter_control_unit;
357 	u_int32_t                                       flow_divert_aggregate_unit;
358 	necp_kernel_policy_result                       service_action;
359 	uuid_t                                                          service_uuid;
360 	u_int32_t                                                       service_flags;
361 	u_int32_t                                                       service_data;
362 	u_int                                                           routed_interface_index;
363 	u_int32_t                                                       policy_id;
364 	uuid_t                                                          netagents[NECP_MAX_NETAGENTS];
365 	u_int32_t                                                       netagent_use_flags[NECP_MAX_NETAGENTS];
366 	struct ipv6_prefix                                              nat64_prefixes[NAT64_MAX_NUM_PREFIXES];
367 	u_int8_t                                                        mss_recommended;
368 };
369 
370 /*
371  * Statistics.  It would be nice if the definitions in ntstat.h could be used,
372  * but they get entangled with #defines for v4 etc in pfvar.h and it may be better practice
373  * to have separate definitions here.
374  */
375 struct necp_stat_counts {
376 	/*	Counters	*/
377 	u_int64_t       necp_stat_rxpackets             __attribute__((aligned(8)));
378 	u_int64_t       necp_stat_rxbytes               __attribute__((aligned(8)));
379 	u_int64_t       necp_stat_txpackets             __attribute__((aligned(8)));
380 	u_int64_t       necp_stat_txbytes               __attribute__((aligned(8)));
381 
382 	u_int32_t       necp_stat_rxduplicatebytes;
383 	u_int32_t       necp_stat_rxoutoforderbytes;
384 	u_int32_t       necp_stat_txretransmit;
385 
386 	u_int32_t       necp_stat_connectattempts;
387 	u_int32_t       necp_stat_connectsuccesses;
388 
389 	u_int32_t       necp_stat_min_rtt;
390 	u_int32_t       necp_stat_avg_rtt;
391 	u_int32_t       necp_stat_var_rtt;
392 
393 #define NECP_STAT_ROUTE_FLAGS   1
394 	u_int32_t       necp_stat_route_flags;
395 };
396 
397 // Note, some metadata is implicit in the necp client itself:
398 // From the process itself : pid, upid, uuid, proc name.
399 // From the necp client parameters: local and remote addresses, euuid, traffic class, ifindex
400 //
401 // The following may well be supplied via future necp client parameters,
402 // but they are here so they don't get forgotten.
403 struct necp_basic_metadata {
404 	u_int32_t       rcvbufsize;
405 	u_int32_t       rcvbufused;
406 };
407 
408 struct necp_connection_probe_status {
409 	unsigned int    probe_activated : 1;
410 	unsigned int    write_probe_failed : 1;
411 	unsigned int    read_probe_failed : 1;
412 	unsigned int    conn_probe_failed : 1;
413 };
414 
415 struct necp_extra_tcp_metadata {
416 	struct necp_connection_probe_status probestatus;
417 
418 	u_int32_t       sndbufsize;
419 	u_int32_t       sndbufused;
420 	u_int32_t       txunacked;
421 	u_int32_t       txwindow;
422 	u_int32_t       txcwindow;
423 	u_int32_t       flags;                  // use SOF_*
424 	u_int32_t       flags1;                 // use SOF1_*
425 	u_int32_t       traffic_mgt_flags;
426 	u_int32_t       cc_alg_index;
427 	u_int32_t       state;
428 };
429 
430 struct necp_stats_hdr {
431 	u_int32_t                                       necp_stats_type __attribute__((aligned(8)));
432 	u_int32_t                                       necp_stats_ver;
433 	u_int64_t                                       __necp_stats_reserved; // Pad the field for future use
434 };
435 
436 #define NECP_CLIENT_STATISTICS_TYPE_TCP                         1       // Identifies use of necp_tcp_stats
437 #define NECP_CLIENT_STATISTICS_TYPE_UDP                         2       // Identifies use of necp_udp_stats
438 #define NECP_CLIENT_STATISTICS_TYPE_QUIC                        3       // Identifies use of necp_quic_stats
439 
440 #define NECP_CLIENT_STATISTICS_TYPE_TCP_VER_1           1       // Currently supported version for TCP
441 #define NECP_CLIENT_STATISTICS_TYPE_UDP_VER_1           1       // Currently supported version for UDP
442 #define NECP_CLIENT_STATISTICS_TYPE_QUIC_VER_1          1       // Currently supported version for QUIC
443 
444 #define NECP_CLIENT_STATISTICS_TYPE_TCP_CURRENT_VER             NECP_CLIENT_STATISTICS_TYPE_TCP_VER_1
445 #define NECP_CLIENT_STATISTICS_TYPE_UDP_CURRENT_VER             NECP_CLIENT_STATISTICS_TYPE_UDP_VER_1
446 #define NECP_CLIENT_STATISTICS_TYPE_QUIC_CURRENT_VER            NECP_CLIENT_STATISTICS_TYPE_QUIC_VER_1
447 
448 #define NECP_CLIENT_STATISTICS_EVENT_INIT                       0x00000000              // Register the flow
449 #define NECP_CLIENT_STATISTICS_EVENT_TIME_WAIT          0x00000001              // The flow is effectively finished but waiting on timer
450 
451 struct necp_tcp_stats {
452 	struct necp_stats_hdr                   necp_tcp_hdr;
453 	struct necp_stat_counts                 necp_tcp_counts;
454 	struct necp_basic_metadata              necp_tcp_basic;
455 	struct necp_extra_tcp_metadata  necp_tcp_extra;
456 };
457 
458 struct necp_udp_stats {
459 	struct necp_stats_hdr           necp_udp_hdr;
460 	struct necp_stat_counts         necp_udp_counts;
461 	struct necp_basic_metadata      necp_udp_basic;
462 };
463 
464 
465 /*
466  * The following reflects the special case for QUIC.
467  * It is a streaming protocol built on top of UDP.
468  * Therefore QUIC stats are defined as basic UDP stats
469  * with some extra meta data.
470  * TODO: For now the extra metadata is an exact replica
471  * of the metadata for TCP. However keeping that separate allows
472  * the structures to diverge later as new stats are added.
473  */
474 #define QUIC_STATELESS_RESET_TOKEN_SIZE               16
475 #define NECP_QUIC_HAS_PROBE_STATUS 1
476 struct necp_extra_quic_metadata {
477 	u_int32_t       sndbufsize;
478 	u_int32_t       sndbufused;
479 	u_int32_t       txunacked;
480 	u_int32_t       txwindow;
481 	u_int32_t       txcwindow;
482 	u_int32_t       traffic_mgt_flags;
483 	u_int32_t       cc_alg_index;
484 	u_int32_t       state;
485 	u_int8_t        ssr_token[QUIC_STATELESS_RESET_TOKEN_SIZE];
486 	struct necp_connection_probe_status probestatus;
487 };
488 
489 #define necp_quic_hdr           necp_quic_udp_stats.necp_udp_hdr
490 #define necp_quic_counts        necp_quic_udp_stats.necp_udp_counts
491 #define necp_quic_basic         necp_quic_udp_stats.necp_udp_basic
492 struct necp_quic_stats {
493 	struct necp_udp_stats           necp_quic_udp_stats;
494 	struct necp_extra_quic_metadata necp_quic_extra;
495 };
496 
497 typedef struct necp_all_stats {
498 	union {
499 		struct necp_tcp_stats   tcp_stats;
500 		struct necp_udp_stats   udp_stats;
501 		struct necp_quic_stats  quic_stats;
502 	} all_stats_u;
503 } necp_all_stats;
504 
505 // Memory for statistics is requested via a necp_stats_bufreq
506 //
507 struct necp_stats_bufreq {
508 	u_int32_t                                       necp_stats_bufreq_id __attribute__((aligned(8)));
509 	u_int32_t                                       necp_stats_bufreq_type;         //  NECP_CLIENT_STATISTICS_TYPE_*
510 	u_int32_t                                       necp_stats_bufreq_ver;          //  NECP_CLIENT_STATISTICS_TYPE_*_VER
511 	u_int32_t                                       necp_stats_bufreq_size;
512 	union {
513 		void                                    *necp_stats_bufreq_addr;
514 		mach_vm_address_t               necp_stats_bufreq_uaddr;
515 	};
516 };
517 
518 #define NECP_CLIENT_STATISTICS_BUFREQ_ID                                0xbf    // Distinguishes from statistics actions taking a necp_all_stats struct
519 
520 // There is a limit to the number of statistics structures that may be allocated per process, subject to change
521 //
522 #define NECP_MAX_PER_PROCESS_CLIENT_STATISTICS_STRUCTS  512
523 
524 #define NECP_TCP_ECN_HEURISTICS_SYN_RST 1
525 typedef struct necp_tcp_ecn_cache {
526 	u_int8_t                necp_tcp_ecn_heuristics_success:1;
527 	u_int8_t                necp_tcp_ecn_heuristics_loss:1;
528 	u_int8_t                necp_tcp_ecn_heuristics_drop_rst:1;
529 	u_int8_t                necp_tcp_ecn_heuristics_drop_rxmt:1;
530 	u_int8_t                necp_tcp_ecn_heuristics_aggressive:1;
531 	u_int8_t                necp_tcp_ecn_heuristics_syn_rst:1;
532 } necp_tcp_ecn_cache;
533 
534 #define NECP_TCP_TFO_HEURISTICS_RST 1
535 typedef struct necp_tcp_tfo_cache {
536 	u_int8_t                necp_tcp_tfo_cookie[NECP_TFO_COOKIE_LEN_MAX];
537 	u_int8_t                necp_tcp_tfo_cookie_len;
538 	u_int8_t                necp_tcp_tfo_heuristics_success:1; // TFO succeeded with data in the SYN
539 	u_int8_t                necp_tcp_tfo_heuristics_loss:1; // TFO SYN-loss with data
540 	u_int8_t                necp_tcp_tfo_heuristics_middlebox:1; // TFO middlebox detected
541 	u_int8_t                necp_tcp_tfo_heuristics_success_req:1; // TFO succeeded with the TFO-option in the SYN
542 	u_int8_t                necp_tcp_tfo_heuristics_loss_req:1; // TFO SYN-loss with the TFO-option
543 	u_int8_t                necp_tcp_tfo_heuristics_rst_data:1; // Recevied RST upon SYN with data in the SYN
544 	u_int8_t                necp_tcp_tfo_heuristics_rst_req:1; // Received RST upon SYN with the TFO-option
545 } necp_tcp_tfo_cache;
546 
547 #define NECP_CLIENT_CACHE_TYPE_ECN                 1       // Identifies use of necp_tcp_ecn_cache
548 #define NECP_CLIENT_CACHE_TYPE_TFO                 2       // Identifies use of necp_tcp_tfo_cache
549 
550 #define NECP_CLIENT_CACHE_TYPE_ECN_VER_1           1       // Currently supported version for ECN
551 #define NECP_CLIENT_CACHE_TYPE_TFO_VER_1           1       // Currently supported version for TFO
552 
553 typedef struct necp_cache_buffer {
554 	u_int8_t                necp_cache_buf_type;    //  NECP_CLIENT_CACHE_TYPE_*
555 	u_int8_t                necp_cache_buf_ver;     //  NECP_CLIENT_CACHE_TYPE_*_VER
556 	u_int32_t               necp_cache_buf_size;
557 	mach_vm_address_t       necp_cache_buf_addr;
558 } necp_cache_buffer;
559 
560 /*
561  * NECP Client definitions
562  */
563 #define NECP_MAX_CLIENT_PARAMETERS_SIZE                                 1024
564 #define NECP_MAX_CLIENT_RESULT_SIZE                                     512 // Legacy
565 #define NECP_BASE_CLIENT_RESULT_SIZE                                    1024
566 #define NECP_CLIENT_FLOW_RESULT_SIZE                                    512
567 
568 #define NECP_OPEN_FLAG_OBSERVER                                                 0x01 // Observers can query clients they don't own
569 #define NECP_OPEN_FLAG_BACKGROUND                                               0x02 // Mark this fd as backgrounded
570 #define NECP_OPEN_FLAG_PUSH_OBSERVER                                    0x04 // When used with the OBSERVER flag, allows updates to be pushed. Adding clients is not allowed in this mode.
571 
572 #define NECP_FD_SUPPORTS_GUARD                                                  1
573 
574 #define NECP_CLIENT_ACTION_ADD                                                  1 // Register a new client. Input: parameters in buffer; Output: client_id
575 #define NECP_CLIENT_ACTION_REMOVE                                               2 // Unregister a client. Input: client_id, optional struct ifnet_stats_per_flow
576 #define NECP_CLIENT_ACTION_COPY_PARAMETERS                              3 // Copy client parameters. Input: client_id; Output: parameters in buffer
577 #define NECP_CLIENT_ACTION_COPY_RESULT                                  4 // Copy client result. Input: client_id; Output: result in buffer
578 #define NECP_CLIENT_ACTION_COPY_LIST                                    5 // Copy all client IDs. Output: struct necp_client_list in buffer
579 #define NECP_CLIENT_ACTION_REQUEST_NEXUS_INSTANCE               6 // Request a nexus instance from a nexus provider, optional struct necp_stats_bufreq
580 #define NECP_CLIENT_ACTION_AGENT                                                7 // Interact with agent. Input: client_id, agent parameters
581 #define NECP_CLIENT_ACTION_COPY_AGENT                                   8 // Copy agent content. Input: agent UUID; Output: struct netagent
582 #define NECP_CLIENT_ACTION_COPY_INTERFACE                               9 // Copy interface details. Input: ifindex cast to UUID; Output: struct necp_interface_details
583 #define NECP_CLIENT_ACTION_SET_STATISTICS                               10 // Deprecated
584 #define NECP_CLIENT_ACTION_COPY_ROUTE_STATISTICS                11 // Get route statistics. Input: client_id; Output: struct necp_stat_counts
585 #define NECP_CLIENT_ACTION_AGENT_USE                                    12 // Return the use count and increment the use count. Input/Output: struct necp_agent_use_parameters
586 #define NECP_CLIENT_ACTION_MAP_SYSCTLS                                  13 // Get the read-only sysctls memory location. Output: mach_vm_address_t
587 #define NECP_CLIENT_ACTION_UPDATE_CACHE                                 14 // Update heuristics and cache
588 #define NECP_CLIENT_ACTION_COPY_CLIENT_UPDATE                   15 // Fetch an updated client for push-mode observer. Output: Client id, struct necp_client_observer_update in buffer
589 #define NECP_CLIENT_ACTION_COPY_UPDATED_RESULT                  16 // Copy client result only if changed. Input: client_id; Output: result in buffer
590 #define NECP_CLIENT_ACTION_ADD_FLOW                                             17 // Add a flow. Input: client_id; Output: struct necp_client_add_flow
591 #define NECP_CLIENT_ACTION_REMOVE_FLOW                                  18 // Remove a flow. Input: flow_id, optional struct ifnet_stats_per_flow
592 #define NECP_CLIENT_ACTION_CLAIM                                       19 // Claim a client that has been added for this unique PID. Input: client_id
593 #define NECP_CLIENT_ACTION_SIGN                                       20 // Sign a query answer. Input: struct necp_client_signable; Output: struct necp_client_signature
594 #define NECP_CLIENT_ACTION_GET_INTERFACE_ADDRESS                       21 // Get the best interface local address for given remote address. Input: ifindex, remote sockaddr; Output: matching local sockaddr
595 #define NECP_CLIENT_ACTION_ACQUIRE_AGENT_TOKEN                         22 // Get a one-time use token from an agent. Input: agent UUID; Output: token buffer
596 #define NECP_CLIENT_ACTION_VALIDATE                                    23 // Validate a query answer. Input: struct necp_client_validatable; Output: None
597 
598 #define NECP_CLIENT_PARAMETER_APPLICATION                               NECP_POLICY_CONDITION_APPLICATION               // Requires entitlement
599 #define NECP_CLIENT_PARAMETER_REAL_APPLICATION                  NECP_POLICY_CONDITION_REAL_APPLICATION  // Requires entitlement
600 #define NECP_CLIENT_PARAMETER_DOMAIN                                    NECP_POLICY_CONDITION_DOMAIN
601 #define NECP_CLIENT_PARAMETER_DOMAIN_OWNER                              NECP_POLICY_CONDITION_DOMAIN_OWNER
602 #define NECP_CLIENT_PARAMETER_DOMAIN_CONTEXT                            NECP_POLICY_CONDITION_DOMAIN_CONTEXT
603 #define NECP_CLIENT_PARAMETER_TRACKER_DOMAIN                            NECP_POLICY_CONDITION_TRACKER_DOMAIN
604 #define NECP_CLIENT_PARAMETER_URL                                       NECP_POLICY_CONDITION_URL
605 #define NECP_CLIENT_PARAMETER_ATTRIBUTED_BUNDLE_IDENTIFIER              NECP_POLICY_CONDITION_ATTRIBUTED_BUNDLE_IDENTIFIER
606 #define NECP_CLIENT_PARAMETER_ACCOUNT                                   NECP_POLICY_CONDITION_ACCOUNT
607 #define NECP_CLIENT_PARAMETER_PID                                               NECP_POLICY_CONDITION_PID                               // Requires entitlement
608 #define NECP_CLIENT_PARAMETER_UID                                               NECP_POLICY_CONDITION_UID                               // Requires entitlement
609 #define NECP_CLIENT_PARAMETER_BOUND_INTERFACE                   NECP_POLICY_CONDITION_BOUND_INTERFACE
610 #define NECP_CLIENT_PARAMETER_TRAFFIC_CLASS                             NECP_POLICY_CONDITION_TRAFFIC_CLASS
611 #define NECP_CLIENT_PARAMETER_IP_PROTOCOL                               NECP_POLICY_CONDITION_IP_PROTOCOL
612 #define NECP_CLIENT_PARAMETER_LOCAL_ADDRESS                             NECP_POLICY_CONDITION_LOCAL_ADDR
613 #define NECP_CLIENT_PARAMETER_REMOTE_ADDRESS                    NECP_POLICY_CONDITION_REMOTE_ADDR
614 #define NECP_CLIENT_PARAMETER_SCHEME_PORT                                               NECP_POLICY_CONDITION_SCHEME_PORT
615 #define NECP_CLIENT_PARAMETER_APPLICATION_ID                            NECP_POLICY_CONDITION_APPLICATION_ID
616 #define NECP_CLIENT_PARAMETER_NEXUS_KEY                                 102
617 
618 // "Prohibit" will never choose an interface with that property
619 #define NECP_CLIENT_PARAMETER_PROHIBIT_INTERFACE                100             // String, interface name
620 #define NECP_CLIENT_PARAMETER_PROHIBIT_IF_TYPE                  101             // u_int8_t, see ifru_functional_type in <net/if.h>
621 #define NECP_CLIENT_PARAMETER_PROHIBIT_AGENT                    102             // uuid_t, network agent UUID
622 #define NECP_CLIENT_PARAMETER_PROHIBIT_AGENT_TYPE               103             // struct necp_client_parameter_netagent_type
623 
624 // "Require" will choose an interface with that property, or none if not found
625 #define NECP_CLIENT_PARAMETER_REQUIRE_IF_TYPE                   111             // u_int8_t, see ifru_functional_type in <net/if.h>
626 #define NECP_CLIENT_PARAMETER_REQUIRE_AGENT                             112             // uuid_t, network agent UUID
627 #define NECP_CLIENT_PARAMETER_REQUIRE_AGENT_TYPE                113             // struct necp_client_parameter_netagent_type
628 
629 // "Prefer" will choose an interface with an agent, or best otherwise if not found
630 #define NECP_CLIENT_PARAMETER_PREFER_AGENT                              122             // uuid_t, network agent UUID
631 #define NECP_CLIENT_PARAMETER_PREFER_AGENT_TYPE                 123             // struct necp_client_parameter_netagent_type
632 
633 // "Avoid" will choose an interface without an agent, or best otherwise if unavoidable
634 #define NECP_CLIENT_PARAMETER_AVOID_AGENT                               124             // uuid_t, network agent UUID
635 #define NECP_CLIENT_PARAMETER_AVOID_AGENT_TYPE                  125             // struct necp_client_parameter_netagent_type
636 
637 // Use actions with NECP_CLIENT_ACTION_AGENT
638 #define NECP_CLIENT_PARAMETER_TRIGGER_AGENT                             130             // uuid_t, network agent UUID
639 #define NECP_CLIENT_PARAMETER_ASSERT_AGENT                              131             // uuid_t, network agent UUID
640 #define NECP_CLIENT_PARAMETER_UNASSERT_AGENT                    132             // uuid_t, network agent UUID
641 #define NECP_CLIENT_PARAMETER_AGENT_ADD_GROUP_MEMBERS                    133             // struct necp_client_group_action
642 #define NECP_CLIENT_PARAMETER_AGENT_REMOVE_GROUP_MEMBERS                    134             // struct necp_client_group_action
643 #define NECP_CLIENT_PARAMETER_REPORT_AGENT_ERROR                    135             // int32_t
644 
645 #define NECP_CLIENT_PARAMETER_FALLBACK_MODE                     140             // u_int8_t, see SO_FALLBACK_MODE_* values
646 
647 #define NECP_CLIENT_PARAMETER_PARENT_ID                                                 150 // uuid_t, client UUID
648 
649 #define NECP_CLIENT_PARAMETER_LOCAL_ENDPOINT                    200             // struct necp_client_endpoint
650 #define NECP_CLIENT_PARAMETER_REMOTE_ENDPOINT                   201             // struct necp_client_endpoint
651 #define NECP_CLIENT_PARAMETER_BROWSE_DESCRIPTOR                  202             // struct necp_client_endpoint
652 #define NECP_CLIENT_PARAMETER_RESOLVER_TAG                      203                             // struct necp_client_validatable
653 #define NECP_CLIENT_PARAMETER_ADVERTISE_DESCRIPTOR                  204             // struct necp_client_endpoint
654 #define NECP_CLIENT_PARAMETER_GROUP_DESCRIPTOR                  205             // struct necp_client_group
655 
656 #define NECP_CLIENT_PARAMETER_DELEGATED_UPID                              210 // u_int64_t, requires entitlement
657 
658 #define NECP_CLIENT_PARAMETER_ETHERTYPE                              220 // u_int16_t, ethertype
659 #define NECP_CLIENT_PARAMETER_TRANSPORT_PROTOCOL                        221 // u_int8_t, IPPROTO_
660 
661 #define NECP_CLIENT_PARAMETER_LOCAL_ADDRESS_PREFERENCE                        230 // u_int8_t, NECP_CLIENT_PARAMETER_LOCAL_ADDRESS_PREFERENCE_
662 
663 #define NECP_CLIENT_PARAMETER_LOCAL_ADDRESS_PREFERENCE_DEFAULT                    0
664 #define NECP_CLIENT_PARAMETER_LOCAL_ADDRESS_PREFERENCE_TEMPORARY                    1
665 #define NECP_CLIENT_PARAMETER_LOCAL_ADDRESS_PREFERENCE_STABLE                    2
666 
667 #define NECP_CLIENT_PARAMETER_FLAGS                                             250             // u_int32_t, see NECP_CLIENT_PAREMETER_FLAG_* values
668 #define NECP_CLIENT_PARAMETER_FLOW_DEMUX_PATTERN                                251 // struct necp_demux_pattern
669 
670 #define NECP_CLIENT_PARAMETER_FLAG_MULTIPATH                    0x0001  // Get multipath interface results
671 #define NECP_CLIENT_PARAMETER_FLAG_BROWSE                               0x0002  // Agent assertions on nexuses are requests to browse
672 #define NECP_CLIENT_PARAMETER_FLAG_PROHIBIT_EXPENSIVE   0x0004  // Prohibit expensive interfaces
673 #define NECP_CLIENT_PARAMETER_FLAG_LISTENER                             0x0008  // Client is interested in listening for inbound connections
674 #define NECP_CLIENT_PARAMETER_FLAG_DISCRETIONARY                0x0010  // Client's traffic is discretionary, and eligible for early defuncting
675 #define NECP_CLIENT_PARAMETER_FLAG_ECN_ENABLE                   0x0020  // Client is requesting to enable ECN
676 #define NECP_CLIENT_PARAMETER_FLAG_ECN_DISABLE                  0x0040  // Client is requesting to disable ECN
677 #define NECP_CLIENT_PARAMETER_FLAG_TFO_ENABLE                   0x0080  // Client is requesting to enable TFO
678 #define NECP_CLIENT_PARAMETER_FLAG_ONLY_PRIMARY_REQUIRES_TYPE   0x0100    // Interpret NECP_CLIENT_PARAMETER_REQUIRE_IF_TYPE only for primary interface, and allow exceptions for multipath or listeners
679 #define NECP_CLIENT_PARAMETER_FLAG_CUSTOM_ETHER                 0x0200  // Client expects to open a custom ethernet channel
680 #define NECP_CLIENT_PARAMETER_FLAG_CUSTOM_IP                    0x0400  // Client expects to open a custom IP protocol channel
681 #define NECP_CLIENT_PARAMETER_FLAG_INTERPOSE                    0x0800  // Client expects to open an interpose filter channel
682 #define NECP_CLIENT_PARAMETER_FLAG_PROHIBIT_CONSTRAINED       0x1000  // Prohibit constrained interfaces
683 #define NECP_CLIENT_PARAMETER_FLAG_FALLBACK_TRAFFIC           0x2000  // Fallback traffic
684 #define NECP_CLIENT_PARAMETER_FLAG_INBOUND                    0x4000  // Flow is inbound (passive)
685 #define NECP_CLIENT_PARAMETER_FLAG_SYSTEM_PROXY               0x8000  // Flow is a system proxy
686 #define NECP_CLIENT_PARAMETER_FLAG_KNOWN_TRACKER              0x10000  // Flow is contacting a known tracker
687 #define NECP_CLIENT_PARAMETER_FLAG_UNSAFE_SOCKET_ACCESS       0x20000  // Client allows direct access to sockets
688 #define NECP_CLIENT_PARAMETER_FLAG_NON_APP_INITIATED          0x40000  // Networking activities not initiated by application
689 #define NECP_CLIENT_PARAMETER_FLAG_THIRD_PARTY_WEB_CONTENT    0x80000  // Third-party web content, not main load
690 #define NECP_CLIENT_PARAMETER_FLAG_SILENT                    0x100000  // Private browsing - do not log/track
691 #define NECP_CLIENT_PARAMETER_FLAG_APPROVED_APP_DOMAIN       0x200000  // Approved associated app domain; domain is "owned" by app
692 #define NECP_CLIENT_PARAMETER_FLAG_NO_WAKE_FROM_SLEEP        0x400000  // Don't wake from sleep on traffic for this client
693 #define NECP_CLIENT_PARAMETER_FLAG_REUSE_LOCAL               0x800000  // Request support for local address/port reuse
694 #define NECP_CLIENT_PARAMETER_FLAG_ENHANCED_PRIVACY         0x1000000  // Attempt protocol upgrade or proxy usage for more privacy
695 #define NECP_CLIENT_PARAMETER_FLAG_WEB_SEARCH_CONTENT       0x2000000  // Web search traffic
696 
697 #define NECP_CLIENT_RESULT_CLIENT_ID                                    1               // uuid_t
698 #define NECP_CLIENT_RESULT_POLICY_RESULT                                2               // u_int32_t
699 #define NECP_CLIENT_RESULT_POLICY_RESULT_PARAMETER              3               // u_int32_t
700 #define NECP_CLIENT_RESULT_FILTER_CONTROL_UNIT                  4               // u_int32_t
701 #define NECP_CLIENT_RESULT_INTERFACE_INDEX                              5               // u_int32_t
702 #define NECP_CLIENT_RESULT_NETAGENT                                             6               // struct necp_client_result_netagent
703 #define NECP_CLIENT_RESULT_FLAGS                                                7               // u_int32_t, see NECP_CLIENT_RESULT_FLAG_* values
704 #define NECP_CLIENT_RESULT_INTERFACE                                    8               // struct necp_client_result_interface
705 #define NECP_CLIENT_RESULT_INTERFACE_OPTION                             9               // struct necp_client_interface_option
706 #define NECP_CLIENT_RESULT_EFFECTIVE_MTU                                10              // u_int32_t
707 #define NECP_CLIENT_RESULT_FLOW                                                 11              // TLV array of a single flow's state
708 #define NECP_CLIENT_RESULT_PROTO_CTL_EVENT                              12
709 #define NECP_CLIENT_RESULT_TFO_COOKIE                                   13              // NECP_TFO_COOKIE_LEN_MAX
710 #define NECP_CLIENT_RESULT_TFO_FLAGS                                    14              // u_int8_t
711 #define NECP_CLIENT_RESULT_RECOMMENDED_MSS                              15              // u_int8_t
712 #define NECP_CLIENT_RESULT_FLOW_ID                                              16              // uuid_t
713 #define NECP_CLIENT_RESULT_INTERFACE_TIME_DELTA                 17              // u_int32_t, seconds since interface up/down
714 #define NECP_CLIENT_RESULT_REASON                                               18              // u_int32_t, see NECP_CLIENT_RESULT_REASON_* values
715 #define NECP_CLIENT_RESULT_FLOW_DIVERT_AGGREGATE_UNIT                   19              // u_int32_t
716 #define NECP_CLIENT_RESULT_REQUEST_IN_PROCESS_FLOW_DIVERT               20              // Empty
717 
718 #define NECP_CLIENT_RESULT_NEXUS_INSTANCE                               100             // uuid_t
719 #define NECP_CLIENT_RESULT_NEXUS_PORT                                   101             // nexus_port_t
720 #define NECP_CLIENT_RESULT_NEXUS_KEY                                    102             // uuid_t
721 #define NECP_CLIENT_RESULT_NEXUS_PORT_FLOW_INDEX                103             // u_int32_t
722 #define NECP_CLIENT_RESULT_NEXUS_FLOW_STATS                             104             // struct sk_stats_flow *
723 
724 #define NECP_CLIENT_RESULT_LOCAL_ENDPOINT                               200             // struct necp_client_endpoint
725 #define NECP_CLIENT_RESULT_REMOTE_ENDPOINT                              201             // struct necp_client_endpoint
726 #define NECP_CLIENT_RESULT_DISCOVERED_ENDPOINT                  202             // struct necp_client_endpoint, result of browse
727 #define NECP_CLIENT_RESULT_RESOLVED_ENDPOINT                  203             // struct necp_client_endpoint, result of resolve
728 #define NECP_CLIENT_RESULT_LOCAL_ETHER_ADDR                                     204                     // struct ether_addr
729 #define NECP_CLIENT_RESULT_REMOTE_ETHER_ADDR                                    205                     // struct ether_addr
730 #define NECP_CLIENT_RESULT_EFFECTIVE_TRAFFIC_CLASS              210             // u_int32_t
731 #define NECP_CLIENT_RESULT_TRAFFIC_MGMT_BG                              211             // u_int32_t, 1: background, 0: not background
732 #define NECP_CLIENT_RESULT_GATEWAY                                      212             // struct necp_client_endpoint
733 #define NECP_CLIENT_RESULT_GROUP_MEMBER                                      213             // struct necp_client_endpoint
734 #define NECP_CLIENT_RESULT_NAT64                                        214             // struct ipv6_prefix[NAT64_MAX_NUM_PREFIXES]
735 #define NECP_CLIENT_RESULT_ESTIMATED_THROUGHPUT                         215             // struct necp_client_result_estimated_throughput
736 #define NECP_CLIENT_RESULT_AGENT_ERROR                                  216             // struct necp_client_result_agent_error
737 
738 #define NECP_CLIENT_RESULT_FLAG_IS_LOCAL                                0x0001  // Routes to this device
739 #define NECP_CLIENT_RESULT_FLAG_IS_DIRECT                               0x0002  // Routes to directly accessible peer
740 #define NECP_CLIENT_RESULT_FLAG_HAS_IPV4                                0x0004  // Supports IPv4
741 #define NECP_CLIENT_RESULT_FLAG_HAS_IPV6                                0x0008  // Supports IPv6
742 #define NECP_CLIENT_RESULT_FLAG_DEFUNCT                                 0x0010  // Defunct
743 #define NECP_CLIENT_RESULT_FLAG_SATISFIED                               0x0020  // Satisfied path
744 #define NECP_CLIENT_RESULT_FLAG_FLOW_ASSIGNED                   0x0040  // Assigned, the flow is active
745 #define NECP_CLIENT_RESULT_FLAG_FLOW_VIABLE                             0x0080  // Viable, the flow has a valid route
746 #define NECP_CLIENT_RESULT_FLAG_PROBE_CONNECTIVITY              0x0100  // Flow should probe connectivity
747 #define NECP_CLIENT_RESULT_FLAG_ECN_ENABLED                             0x0200  // ECN should be used
748 #define NECP_CLIENT_RESULT_FLAG_FAST_OPEN_BLOCKED               0x0400  // Fast open should not be used
749 #define NECP_CLIENT_RESULT_FLAG_LINK_QUALITY_ABORT              0x0800  // Link quality is very bad, recommend close connections
750 #define NECP_CLIENT_RESULT_FLAG_ALLOW_QOS_MARKING               0x1000  // QoS marking is allowed
751 #define NECP_CLIENT_RESULT_FLAG_HAS_NAT64                       0x2000  // Has NAT64 prefix
752 #define NECP_CLIENT_RESULT_FLAG_INTERFACE_LOW_POWER             0x4000  // Interface is in low-power mode
753 #define NECP_CLIENT_RESULT_FLAG_SPECIFIC_LISTENER               0x8000  // Listener should not listen on all interfaces
754 #define NECP_CLIENT_RESULT_FLAG_KEXT_FILTER_PRESENT             0x10000 // Kernel extension filter present
755 #define NECP_CLIENT_RESULT_FLAG_PF_RULES_PRESENT                0x20000 // Firewall rules present
756 #define NECP_CLIENT_RESULT_FLAG_ALF_PRESENT                     0x40000 // Application Firewall enabled
757 #define NECP_CLIENT_RESULT_FLAG_PARENTAL_CONTROLS_PRESENT       0x80000 // Parental Controls present
758 #define NECP_CLIENT_RESULT_FLAG_IS_GLOBAL_INTERNET              0x100000 // Routes to global Internet
759 
760 
761 #define NECP_CLIENT_RESULT_FLAG_FORCE_UPDATE (NECP_CLIENT_RESULT_FLAG_HAS_IPV4 | NECP_CLIENT_RESULT_FLAG_HAS_IPV6 | NECP_CLIENT_RESULT_FLAG_HAS_NAT64 | NECP_CLIENT_RESULT_FLAG_INTERFACE_LOW_POWER)
762 
763 #define NECP_CLIENT_RESULT_FAST_OPEN_SND_PROBE                  0x01    // DEPRECATED - Fast open send probe
764 #define NECP_CLIENT_RESULT_FAST_OPEN_RCV_PROBE                  0x02    // DEPRECATED - Fast open receive probe
765 
766 #define NECP_CLIENT_RESULT_RECOMMENDED_MSS_NONE                 0x01
767 #define NECP_CLIENT_RESULT_RECOMMENDED_MSS_LOW                  0x02
768 #define NECP_CLIENT_RESULT_RECOMMENDED_MSS_MEDIUM               0x04
769 
770 #define NECP_CLIENT_RESULT_REASON_EXPENSIVE_PROHIBITED          1  // Expensive networks were prohibited
771 #define NECP_CLIENT_RESULT_REASON_CONSTRAINED_PROHIBITED                2  // Constrained networks were prohibited
772 #define NECP_CLIENT_RESULT_REASON_CELLULAR_DENIED                3  // Denied by a cellular route rule
773 #define NECP_CLIENT_RESULT_REASON_WIFI_DENIED                4  // Denied by a wifi route rule
774 #define NECP_CLIENT_RESULT_REASON_LOCAL_NETWORK_PROHIBITED       5  // Local network access prohibited
775 
776 struct necp_interface_signature {
777 	u_int8_t signature[IFNET_SIGNATURELEN];
778 	u_int8_t signature_len;
779 };
780 
781 struct necp_interface_details {
782 	char name[IFXNAMSIZ];
783 	u_int32_t index;
784 	u_int32_t generation;
785 	u_int32_t functional_type;
786 	u_int32_t delegate_index;
787 	u_int32_t flags; // see NECP_INTERFACE_FLAG_*
788 	u_int32_t mtu;
789 	struct necp_interface_signature ipv4_signature;
790 	struct necp_interface_signature ipv6_signature;
791 	u_int32_t ipv4_netmask;
792 	u_int32_t ipv4_broadcast;
793 	/*
794 	 * This serves as a temporary header guard to protect libnetcore builds
795 	 * until the xnu changes are available in the build.
796 	 * XXX: Should be removed in a future build.
797 	 */
798 #define NECP_INTERFACE_SUPPORTS_TSO    1
799 	u_int32_t tso_max_segment_size_v4;
800 	u_int32_t tso_max_segment_size_v6;
801 #define NECP_INTERFACE_SUPPORTS_HWCSUM   1
802 	u_int32_t hwcsum_flags;
803 	u_int8_t  radio_type;
804 	u_int8_t  radio_channel;
805 };
806 
807 #define NECP_INTERFACE_FLAG_EXPENSIVE                                   0x0001
808 #define NECP_INTERFACE_FLAG_TXSTART                                     0X0002
809 #define NECP_INTERFACE_FLAG_NOACKPRI                                    0x0004
810 #define NECP_INTERFACE_FLAG_3CARRIERAGG                                 0x0008
811 #define NECP_INTERFACE_FLAG_IS_LOW_POWER                                0x0010
812 #define NECP_INTERFACE_FLAG_MPK_LOG                                     0x0020 // Multi-layer Packet Logging
813 #define NECP_INTERFACE_FLAG_CONSTRAINED                                 0x0040
814 #define NECP_INTERFACE_FLAG_HAS_NETMASK                                 0x0080
815 #define NECP_INTERFACE_FLAG_HAS_BROADCAST                               0x0100
816 #define NECP_INTERFACE_FLAG_SUPPORTS_MULTICAST                          0x0200
817 #define NECP_INTERFACE_FLAG_HAS_DNS                                     0x0400
818 #define NECP_INTERFACE_FLAG_HAS_NAT64                                   0x0800
819 #define NECP_INTERFACE_FLAG_IPV4_ROUTABLE                               0x1000
820 #define NECP_INTERFACE_FLAG_IPV6_ROUTABLE                               0x2000
821 
822 struct necp_client_parameter_netagent_type {
823 	char netagent_domain[32];
824 	char netagent_type[32];
825 };
826 
827 struct necp_client_result_netagent {
828 	u_int32_t generation;
829 	uuid_t netagent_uuid;
830 };
831 
832 struct necp_client_result_interface {
833 	u_int32_t generation;
834 	u_int32_t index;
835 };
836 
837 struct necp_client_result_estimated_throughput {
838 	u_int8_t up;
839 	u_int8_t down;
840 };
841 
842 struct necp_client_result_agent_error {
843 	u_int32_t code;
844 	u_int8_t domain;
845 };
846 
847 #define NECP_USES_INTERFACE_OPTIONS_FOR_BROWSE 1
848 
849 struct necp_client_interface_option {
850 	u_int32_t interface_index;
851 	u_int32_t interface_generation;
852 	uuid_t nexus_agent;
853 };
854 
855 #define NECP_CLIENT_ENDPOINT_TYPE_APPLICATION_SERVICE 6
856 
857 struct necp_client_endpoint {
858 	union {
859 		struct sockaddr sa;
860 		struct sockaddr_in sin;
861 		struct sockaddr_in6 sin6;
862 		struct {
863 			u_int8_t endpoint_length;
864 			u_int8_t endpoint_family; // Use AF_UNSPEC to target a name
865 			u_int16_t endpoint_port;
866 			u_int32_t endpoint_type; // Client-specific type
867 			char endpoint_data[0]; // Type-specific endpoint value
868 		} endpoint;
869 	} u;
870 };
871 
872 struct necp_client_group {
873 	u_int32_t group_type;
874 	uuid_t group_id;
875 };
876 
877 struct necp_client_list {
878 	u_int32_t client_count;
879 	uuid_t clients[0];
880 };
881 
882 struct kev_necp_policies_changed_data {
883 	u_int32_t               changed_count;  // Defaults to 0.
884 };
885 
886 #define NECP_CLIENT_FLOW_FLAGS_ALLOW_NEXUS                      0x01    // Request a nexus instance upon adding a flow
887 #define NECP_CLIENT_FLOW_FLAGS_USE_CLIENT_ID            0x02    // Register the client ID rather than the flow registration ID with network agents
888 #define NECP_CLIENT_FLOW_FLAGS_BROWSE                      0x04    // Create request with a browse agent
889 #define NECP_CLIENT_FLOW_FLAGS_RESOLVE                      0x08    // Create request with a resolution agent
890 #define NECP_CLIENT_FLOW_FLAGS_OVERRIDE_ADDRESS                      0x10    // Flow has a different remote address than the parent flow
891 #define NECP_CLIENT_FLOW_FLAGS_OVERRIDE_IP_PROTOCOL           0x20    // Flow has a different IP protocol than the parent flow
892 
893 struct necp_client_flow_stats {
894 	u_int32_t stats_type; // NECP_CLIENT_STATISTICS_TYPE_*
895 	u_int32_t stats_version; // NECP_CLIENT_STATISTICS_TYPE_*_VER
896 	u_int32_t stats_size;
897 	mach_vm_address_t stats_addr;
898 };
899 
900 struct necp_client_add_flow {
901 	uuid_t agent_uuid;
902 	uuid_t registration_id;
903 	u_int16_t flags; // NECP_CLIENT_FLOW_FLAGS_*
904 	u_int16_t stats_request_count;
905 	struct necp_client_flow_stats stats_requests[0];
906 	// sockaddr for override endpoint
907 	// uint8 for override ip protocol
908 } __attribute__((__packed__));
909 
910 struct necp_agent_use_parameters {
911 	uuid_t agent_uuid;
912 	uint64_t out_use_count;
913 };
914 
915 struct necp_client_group_action {
916 	uuid_t agent_uuid;
917 	u_int16_t group_member_count;
918 	struct necp_client_endpoint group_members[0];
919 } __attribute__((__packed__));
920 
921 struct necp_client_flow_protoctl_event {
922 	uint32_t        protoctl_event_code;
923 	uint32_t        protoctl_event_val;
924 	/* TCP seq number is in host byte order */
925 	uint32_t        protoctl_event_tcp_seq_num;
926 };
927 
928 #define NECP_CLIENT_UPDATE_TYPE_PARAMETERS              1       // Parameters, for a new client
929 #define NECP_CLIENT_UPDATE_TYPE_RESULT                  2       // Result, for a udpated client
930 #define NECP_CLIENT_UPDATE_TYPE_REMOVE                  3       // Empty, for a removed client
931 
932 struct necp_client_observer_update {
933 	u_int32_t update_type;  // NECP_CLIENT_UPDATE_TYPE_*
934 	u_int8_t tlv_buffer[0]; // Parameters or result as TLVs, based on type
935 };
936 
937 // These sign types are tied to specific clients.
938 // The client_id UUID is then the NECP client UUID that generated the query.
939 #define NECP_CLIENT_SIGN_TYPE_RESOLVER_ANSWER                   1       // struct necp_client_host_resolver_answer
940 #define NECP_CLIENT_SIGN_TYPE_BROWSE_RESULT                     2       // struct necp_client_browse_result
941 #define NECP_CLIENT_SIGN_TYPE_SERVICE_RESOLVER_ANSWER           3       // struct necp_client_service_resolver_answer
942 
943 // These sign types are valid for system-wide use.
944 // The client_id UUID is a unique per-query UUID.
945 // These should be generated only on behalf of trusted or entitled processes.
946 #define NECP_CLIENT_SIGN_TYPE_SYSTEM_RESOLVER_ANSWER            4       // struct necp_client_host_resolver_answer
947 #define NECP_CLIENT_SIGN_TYPE_SYSTEM_BROWSE_RESULT              5       // struct necp_client_browse_result
948 #define NECP_CLIENT_SIGN_TYPE_SYSTEM_SERVICE_RESOLVER_ANSWER    6       // struct necp_client_service_resolver_answer
949 
950 struct necp_client_signature {
951 	u_int8_t signed_tag[32];
952 } __attribute__((__packed__));
953 
954 //
955 struct necp_client_signable {
956 	uuid_t client_id; // Interpretation depends on sign_type
957 	u_int32_t sign_type;
958 	u_int8_t signable_data[0];
959 } __attribute__((__packed__));
960 
961 struct necp_client_resolver_answer {
962 	uuid_t client_id;
963 	u_int32_t sign_type;
964 	union sockaddr_in_4_6 address_answer; // Can include port
965 	u_int32_t hostname_length;
966 	char hostname[0];
967 } __attribute__((__packed__));
968 
969 struct necp_client_host_resolver_answer {
970 	struct necp_client_signable header;
971 	u_int32_t metadata_hash; // Extra metadata that can be signed along with the answer, such as a network signature.
972 	union sockaddr_in_4_6 address_answer; // Can include port
973 	u_int32_t hostname_length;
974 	char hostname[0];
975 } __attribute__((__packed__));
976 
977 struct necp_client_browse_result {
978 	struct necp_client_signable header;
979 	u_int32_t metadata_hash; // Extra metadata that can be signed along with the service, which may include a TXT record or a network signature
980 	u_int16_t service_length;
981 	char service[0];
982 } __attribute__((__packed__));
983 
984 struct necp_client_service_resolver_answer {
985 	struct necp_client_signable header;
986 	u_int32_t metadata_hash; // Extra metadata that can be signed along with the service, which may include a TXT record or a network signature
987 	u_int16_t service_length;
988 	u_int16_t port;
989 	u_int16_t hostname_length;
990 	char service[0];
991 	char hostname[0];
992 } __attribute__((__packed__));
993 
994 struct necp_client_validatable {
995 	struct necp_client_signature signature;
996 	struct necp_client_signable signable;
997 } __attribute__((__packed__));
998 
999 #define NECP_CLIENT_ACTION_SIGN_MAX_STRING_LENGTH 1024
1000 
1001 #define NECP_CLIENT_ACTION_SIGN_TAG_LENGTH 32
1002 
1003 #define NECP_CLIENT_ACTION_SIGN_DEFAULT_DATA_LENGTH 128
1004 #define NECP_CLIENT_ACTION_SIGN_MAX_TOTAL_LENGTH 4096
1005 
1006 #define NECP_FILTER_UNIT_NO_FILTER              UINT32_MAX // Reserved filter unit value that prohibits all filters and socket filters
1007 
1008 /*
1009  * The sysctl "net.necp.necp_drop_dest_level" controls the global drop rule policy for
1010  * a set of destinations addresses at the given level -- the drop rule is the last one
1011  * to be evaluated at this level.
1012  */
1013 #define MAX_NECP_DROP_DEST_LEVEL_ADDRS 8
1014 
1015 struct necp_drop_dest_entry {
1016 	u_int32_t                           level;          // priority level
1017 	u_int32_t                           order;          // session order (read only via sysctl)
1018 	struct necp_policy_condition_addr   cond_addr;
1019 };
1020 
1021 struct necp_drop_dest_policy {
1022 	u_int32_t entry_count;
1023 	struct necp_drop_dest_entry entries[MAX_NECP_DROP_DEST_LEVEL_ADDRS];
1024 };
1025 
1026 
1027 #define NECP_DEMUX_MAX_LEN  32
1028 struct necp_demux_pattern {
1029 	uint16_t offset;
1030 	uint16_t len;
1031 	uint8_t mask[NECP_DEMUX_MAX_LEN];
1032 	uint8_t value[NECP_DEMUX_MAX_LEN];
1033 };
1034 
1035 #ifdef BSD_KERNEL_PRIVATE
1036 #include <stdbool.h>
1037 #include <sys/socketvar.h>
1038 #include <sys/kern_control.h>
1039 #include <netinet/ip_var.h>
1040 #include <netinet6/ip6_var.h>
1041 #include <net/if_var.h>
1042 #include <sys/syslog.h>
1043 #include <net/network_agent.h>
1044 #include <net/ethernet.h>
1045 #include <os/log.h>
1046 #if SKYWALK
1047 #include <skywalk/namespace/netns.h>
1048 #endif /* SKYWALK */
1049 
1050 
1051 SYSCTL_DECL(_net_necp);
1052 
1053 extern os_log_t necp_log_handle;
1054 extern os_log_t necp_data_trace_log_handle;
1055 
1056 #define NECPLOG(level, format, ...) do {                                                                                        \
1057 	if (level == LOG_ERR) {                                                          \
1058 	    os_log_error(necp_log_handle, "%s: " format "\n", __FUNCTION__, __VA_ARGS__); \
1059 	} else {                                                                         \
1060 	    os_log(necp_log_handle, "%s: " format "\n", __FUNCTION__, __VA_ARGS__);       \
1061 	}                                                                                \
1062 } while (0)
1063 
1064 #define NECPLOG0(level, msg) do {                                                                                       \
1065 	if (level == LOG_ERR) {                                                          \
1066 	    os_log_error(necp_log_handle, "%s: %s\n", __FUNCTION__, msg);                 \
1067 	} else {                                                                         \
1068 	    os_log(necp_log_handle, "%s: %s\n", __FUNCTION__, msg);                       \
1069 	}                                                                                \
1070 } while (0)
1071 
1072 #define NECPDATATRACELOG(level, format, ...) do {                                                                                        \
1073     if (level == LOG_ERR) {                                                          \
1074 	os_log_error(necp_data_trace_log_handle, "%s: " format "\n", __FUNCTION__, __VA_ARGS__); \
1075     } else {                                                                         \
1076 	os_log(necp_data_trace_log_handle, "%s: " format "\n", __FUNCTION__, __VA_ARGS__);       \
1077     }                                                                                \
1078 } while (0)
1079 
1080 enum necp_fd_type_t {
1081 	necp_fd_type_invalid = 0,
1082 	necp_fd_type_session = 1,
1083 	necp_fd_type_client = 2,
1084 };
1085 
1086 union necp_sockaddr_union {
1087 #if !__has_ptrcheck
1088 	struct sockaddr                 sa;
1089 #endif
1090 	struct __sockaddr_header        sah;
1091 	struct sockaddr_in              sin;
1092 	struct sockaddr_in6             sin6;
1093 };
1094 
1095 /*
1096  * kstats
1097  * The ustats and kstats region are mirrored. So when we allocate with
1098  * skmem_cache from kstats region, we also get an ustats object. To tie them
1099  * together, kstats has an extra *necp_stats_ustats pointer pointing to the
1100  * ustats object
1101  */
1102 struct necp_all_kstats {
1103 	struct necp_all_stats           necp_stats_comm;        /* kernel private stats snapshot */
1104 	struct necp_all_stats           *necp_stats_ustats;     /* points to user-visible stats (in shared ustats region) */
1105 };
1106 
1107 extern void necp_client_init(void);
1108 extern int necp_application_find_policy_match_internal(proc_t proc, u_int8_t *parameters, u_int32_t parameters_size,
1109     struct necp_aggregate_result *returned_result,
1110     u_int32_t *flags, u_int32_t *reason, u_int required_interface_index,
1111     const union necp_sockaddr_union *override_local_addr,
1112     const union necp_sockaddr_union *override_remote_addr,
1113     struct necp_client_endpoint *returned_v4_gateway,
1114     struct necp_client_endpoint *returned_v6_gateway,
1115     struct rtentry **returned_route, bool ignore_address,
1116     bool has_client,
1117     uuid_t *returned_override_euuid);
1118 /*
1119  * TLV utilities
1120  *
1121  * Note that these functions (other than necp_buffer_find_tlv) do not check the length of the entire buffer,
1122  * so the caller must be sure that the entire TLV is within bounds.
1123  */
1124 struct necp_tlv_header {
1125 	u_int8_t type;
1126 	u_int32_t length;
1127 } __attribute__((__packed__));
1128 
1129 extern u_int8_t *necp_buffer_write_tlv(u_int8_t *cursor, u_int8_t type, u_int32_t length, const void *value,
1130     u_int8_t *buffer, u_int32_t buffer_length);
1131 extern u_int8_t *necp_buffer_write_tlv_if_different(u_int8_t *cursor, u_int8_t type,
1132     u_int32_t length, const void *value, bool *updated,
1133     u_int8_t *buffer, u_int32_t buffer_length);
1134 extern u_int8_t necp_buffer_get_tlv_type(u_int8_t *buffer, int tlv_offset);
1135 extern u_int32_t necp_buffer_get_tlv_length(u_int8_t *buffer, int tlv_offset);
1136 extern u_int8_t *necp_buffer_get_tlv_value(u_int8_t *buffer, int tlv_offset, u_int32_t *value_size);
1137 extern int necp_buffer_find_tlv(u_int8_t *buffer, u_int32_t buffer_length, int offset, u_int8_t type, int *err, int next);
1138 
1139 #define NECPCTL_DROP_ALL_LEVEL                          1       /* Drop all packets if no policy matches above this level */
1140 #define NECPCTL_DEBUG                                           2       /* Log all kernel policy matches */
1141 #define NECPCTL_PASS_LOOPBACK                           3       /* Pass all loopback traffic */
1142 #define NECPCTL_PASS_KEEPALIVES                         4       /* Pass all kernel-generated keepalive traffic */
1143 #define NECPCTL_SOCKET_POLICY_COUNT                     5       /* Count of all socket-level policies */
1144 #define NECPCTL_SOCKET_NON_APP_POLICY_COUNT     6       /* Count of non-per-app socket-level policies */
1145 #define NECPCTL_IP_POLICY_COUNT                         7       /* Count of all ip-level policies */
1146 #define NECPCTL_SESSION_COUNT                           8       /* Count of NECP sessions */
1147 #define NECPCTL_CLIENT_FD_COUNT                         9       /* Count of NECP client fds */
1148 #define NECPCTL_CLIENT_COUNT                            10      /* Count of NECP clients */
1149 #define NECPCTL_ARENA_COUNT                                     11      /* Count of NECP arenas (stats, etc) */
1150 #define NECPCTL_NEXUS_FLOW_COUNT                        12      /* Count of NECP nexus flows */
1151 #define NECPCTL_SOCKET_FLOW_COUNT                       13      /* Count of NECP socket flows */
1152 #define NECPCTL_IF_FLOW_COUNT                           14      /* Count of NECP socket flows */
1153 #define NECPCTL_OBSERVER_FD_COUNT                       15      /* Count of NECP observer fds */
1154 #define NECPCTL_OBSERVER_MESSAGE_LIMIT          16      /* Number of of NECP observer messages allowed to be queued */
1155 #define NECPCTL_SYSCTL_ARENA_COUNT                      17      /* Count of sysctl arenas */
1156 #define NECPCTL_DROP_UNENTITLED_LEVEL                   18      /* Drop unentitled process traffic above this level */
1157 #define NECPCTL_PASS_INTERPOSE                          19      /* Pass interpose */
1158 #define NECPCTL_RESTRICT_MULTICAST                      20      /* Restrict multicast access */
1159 #define NECPCTL_DEDUP_POLICIES                          21      /* Dedup overlapping policies */
1160 #define NECPCTL_CLIENT_TRACING_LEVEL                    22      /* Client tracing level */
1161 #define NECPCTL_CLIENT_TRACING_PID                      23      /* Apply client tracing only to specified pid */
1162 #define NECPCTL_DROP_MANAGEMENT_LEVEL                   24      /* Drop management traffic at this level */
1163 
1164 #define NECP_LOOPBACK_PASS_ALL         1  // Pass all loopback traffic
1165 #define NECP_LOOPBACK_PASS_WITH_FILTER 2  // Pass all loopback traffic, but activate content filter and/or flow divert if applicable
1166 
1167 #define NECPCTL_NAMES {                                 \
1168 	{ 0, 0 },                                                       \
1169 	{ "drop_all_level", CTLTYPE_INT },      \
1170 	{ "debug", CTLTYPE_INT },                       \
1171 	{ "pass_loopback", CTLTYPE_INT },       \
1172     { "pass_keepalives", CTLTYPE_INT },     \
1173     { "pass_interpose", CTLTYPE_INT },      \
1174 }
1175 
1176 typedef u_int32_t necp_kernel_policy_id;
1177 #define NECP_KERNEL_POLICY_ID_NONE                      0
1178 #define NECP_KERNEL_POLICY_ID_NO_MATCH          1
1179 #define NECP_KERNEL_POLICY_ID_FIRST_VALID_SOCKET        2
1180 #define NECP_KERNEL_POLICY_ID_FIRST_VALID_IP            UINT16_MAX
1181 
1182 typedef u_int32_t necp_app_id;
1183 
1184 #define NECP_KERNEL_POLICY_RESULT_NONE                                  0
1185 #define NECP_KERNEL_POLICY_RESULT_PASS                                  NECP_POLICY_RESULT_PASS
1186 #define NECP_KERNEL_POLICY_RESULT_SKIP                                  NECP_POLICY_RESULT_SKIP
1187 #define NECP_KERNEL_POLICY_RESULT_DROP                                  NECP_POLICY_RESULT_DROP
1188 #define NECP_KERNEL_POLICY_RESULT_SOCKET_DIVERT                 NECP_POLICY_RESULT_SOCKET_DIVERT
1189 #define NECP_KERNEL_POLICY_RESULT_SOCKET_FILTER                 NECP_POLICY_RESULT_SOCKET_FILTER
1190 #define NECP_KERNEL_POLICY_RESULT_IP_TUNNEL                             NECP_POLICY_RESULT_IP_TUNNEL
1191 #define NECP_KERNEL_POLICY_RESULT_IP_FILTER                             NECP_POLICY_RESULT_IP_FILTER
1192 #define NECP_KERNEL_POLICY_RESULT_SOCKET_SCOPED                 NECP_POLICY_RESULT_SOCKET_SCOPED
1193 #define NECP_KERNEL_POLICY_RESULT_ROUTE_RULES                   NECP_POLICY_RESULT_ROUTE_RULES
1194 #define NECP_KERNEL_POLICY_RESULT_USE_NETAGENT                  NECP_POLICY_RESULT_USE_NETAGENT
1195 #define NECP_KERNEL_POLICY_RESULT_NETAGENT_SCOPED               NECP_POLICY_RESULT_NETAGENT_SCOPED
1196 #define NECP_KERNEL_POLICY_RESULT_SCOPED_DIRECT                 NECP_POLICY_RESULT_SCOPED_DIRECT
1197 #define NECP_KERNEL_POLICY_RESULT_ALLOW_UNENTITLED              NECP_POLICY_RESULT_ALLOW_UNENTITLED
1198 #define NECP_KERNEL_POLICY_RESULT_REMOVE_NETAGENT               NECP_POLICY_RESULT_REMOVE_NETAGENT
1199 
1200 #define NECP_KERNEL_POLICY_PASS_NO_SKIP_IPSEC                   NECP_POLICY_PASS_NO_SKIP_IPSEC
1201 #define NECP_KERNEL_POLICY_PASS_PF_TAG                          NECP_POLICY_PASS_PF_TAG
1202 
1203 #define NECP_KERNEL_POLICY_DROP_FLAG_LOCAL_NETWORK              NECP_POLICY_DROP_FLAG_LOCAL_NETWORK
1204 
1205 typedef struct {
1206 	u_int32_t identifier;
1207 	u_int32_t data;
1208 } necp_kernel_policy_service;
1209 
1210 typedef union {
1211 	u_int                                           tunnel_interface_index;
1212 	u_int                                           scoped_interface_index;
1213 	u_int32_t                                       flow_divert_control_unit;
1214 	u_int32_t                                       filter_control_unit;
1215 	u_int32_t                                       skip_policy_order;
1216 	u_int32_t                                       route_rule_id;
1217 	u_int32_t                                       netagent_id;
1218 	u_int32_t                                       pass_flags;
1219 	u_int32_t                                       drop_flags;
1220 	necp_kernel_policy_service      service;
1221 } necp_kernel_policy_result_parameter;
1222 
1223 enum necp_boolean_state {
1224 	necp_boolean_state_unknown = 0,
1225 	necp_boolean_state_false = 1,
1226 	necp_boolean_state_true = 2,
1227 };
1228 
1229 struct necp_kernel_socket_policy {
1230 	LIST_ENTRY(necp_kernel_socket_policy)   chain;
1231 	necp_kernel_policy_id           id;
1232 	necp_policy_order                       order;
1233 	u_int32_t                                       session_order;
1234 	int                                                     session_pid;
1235 
1236 	u_int64_t                                       condition_mask;
1237 	u_int64_t                                       condition_negated_mask;
1238 	u_int32_t                                       cond_client_flags;
1239 	necp_kernel_policy_id           cond_policy_id;
1240 	u_int32_t                                       cond_app_id;                                    // Locally assigned ID value stored
1241 	u_int32_t                                       cond_real_app_id;                               // Locally assigned ID value stored
1242 	char                                            *cond_custom_entitlement;               // String
1243 	u_int32_t                                       cond_account_id;                                // Locally assigned ID value stored
1244 	char                                            *cond_domain;                                   // String
1245 	u_int8_t                                        cond_domain_dot_count;                  // Number of dots in cond_domain
1246 	u_int32_t                                       cond_domain_filter;
1247 	pid_t                                           cond_pid;
1248 	uid_t                                           cond_uid;
1249 	uid_t                                           cond_real_uid;
1250 	ifnet_t                                         cond_bound_interface;                   // Matches specific binding only
1251 	struct necp_policy_condition_tc_range cond_traffic_class;       // Matches traffic class in range
1252 	u_int16_t                                       cond_protocol;                                  // Matches IP protcol number
1253 	union necp_sockaddr_union       cond_local_start;                               // Matches local IP address (or start)
1254 	union necp_sockaddr_union       cond_local_end;                                 // Matches IP address range
1255 	u_int8_t                                        cond_local_prefix;                              // Defines subnet
1256 	union necp_sockaddr_union       cond_remote_start;                              // Matches remote IP address (or start)
1257 	union necp_sockaddr_union       cond_remote_end;                                // Matches IP address range
1258 	u_int8_t                                        cond_remote_prefix;                             // Defines subnet
1259 	struct necp_policy_condition_agent_type cond_agent_type;
1260 	struct necp_policy_condition_sdk_version cond_sdk_version;
1261 	char                                            *cond_signing_identifier;   // String
1262 	char                                            *cond_url;// String
1263 	u_int16_t                                       cond_packet_filter_tags;
1264 	u_int16_t                                       cond_scheme_port;
1265 	int32_t                                         cond_pid_version;
1266 
1267 	necp_kernel_policy_result       result;
1268 	necp_kernel_policy_result_parameter     result_parameter;
1269 };
1270 
1271 struct necp_kernel_ip_output_policy {
1272 	LIST_ENTRY(necp_kernel_ip_output_policy)        chain;
1273 	necp_kernel_policy_id           id;
1274 	necp_policy_order                       suborder;
1275 	necp_policy_order                       order;
1276 	u_int32_t                                       session_order;
1277 	int                                                     session_pid;
1278 
1279 	u_int64_t                                       condition_mask;
1280 	u_int64_t                                       condition_negated_mask;
1281 	necp_kernel_policy_id           cond_policy_id;
1282 	ifnet_t                                         cond_bound_interface;                   // Matches specific binding only
1283 	u_int16_t                                       cond_protocol;                                  // Matches IP protcol number
1284 	union necp_sockaddr_union       cond_local_start;                               // Matches local IP address (or start)
1285 	union necp_sockaddr_union       cond_local_end;                                 // Matches IP address range
1286 	u_int8_t                                        cond_local_prefix;                              // Defines subnet
1287 	union necp_sockaddr_union       cond_remote_start;                              // Matches remote IP address (or start)
1288 	union necp_sockaddr_union       cond_remote_end;                                // Matches IP address range
1289 	u_int8_t                                        cond_remote_prefix;                             // Defines subnet
1290 	u_int32_t                                       cond_last_interface_index;
1291 	u_int16_t                       cond_packet_filter_tags;
1292 	u_int16_t                       cond_scheme_port;
1293 
1294 	necp_kernel_policy_result       result;
1295 	necp_kernel_policy_result_parameter     result_parameter;
1296 };
1297 
1298 #define MAX_KERNEL_SOCKET_POLICIES                      1
1299 #define MAX_KERNEL_IP_OUTPUT_POLICIES           4
1300 struct necp_session_policy {
1301 	LIST_ENTRY(necp_session_policy) chain;
1302 	bool                            applied;                        // Applied into the kernel table
1303 	bool                            pending_deletion;       // Waiting to be removed from kernel table
1304 	bool                            pending_update;         // Policy has been modified since creation/last application
1305 	necp_policy_id          local_id;
1306 	necp_policy_order       order;
1307 	u_int8_t                        *result;
1308 	u_int32_t                       result_size;
1309 	u_int8_t                        *conditions; // Array of conditions, each with a u_int32_t length at start
1310 	u_int32_t                       conditions_size;
1311 	u_int8_t                        *route_rules; // Array of route rules, each with a u_int32_t length at start
1312 	u_int32_t                       route_rules_size;
1313 
1314 	uuid_t                          applied_app_uuid;
1315 	uuid_t                          applied_real_app_uuid;
1316 	char                            *applied_account;
1317 	u_int32_t                       applied_account_size;
1318 
1319 	uuid_t                          applied_result_uuid;
1320 
1321 	u_int32_t                       applied_route_rules_id;
1322 
1323 	necp_kernel_policy_id   kernel_socket_policies[MAX_KERNEL_SOCKET_POLICIES];
1324 	necp_kernel_policy_id   kernel_ip_output_policies[MAX_KERNEL_IP_OUTPUT_POLICIES];
1325 };
1326 
1327 struct necp_aggregate_socket_result {
1328 	necp_kernel_policy_result                       result;
1329 	necp_kernel_policy_result_parameter     result_parameter;
1330 	necp_kernel_policy_filter                       filter_control_unit;
1331 	u_int32_t                                       flow_divert_aggregate_unit;
1332 	u_int32_t                                                       route_rule_id;
1333 	int32_t                                         qos_marking_gencount;
1334 };
1335 
1336 struct necp_inpcb_result {
1337 	u_int32_t                                       app_id;
1338 	necp_kernel_policy_id                           policy_id;
1339 	necp_kernel_policy_id                           skip_policy_id;
1340 	int32_t                                         policy_gencount;
1341 	u_int32_t                                       flowhash;
1342 	u_int32_t                                       network_denied_notifies;// Notification count
1343 	struct necp_aggregate_socket_result             results;
1344 };
1345 
1346 extern void necp_init(void);
1347 
1348 struct inp_necp_attributes;
1349 extern errno_t necp_set_socket_attributes(struct inp_necp_attributes *attributes, struct sockopt *sopt);
1350 extern errno_t necp_get_socket_attributes(struct inp_necp_attributes *attributes, struct sockopt *sopt);
1351 extern errno_t necp_set_socket_domain_attributes(struct socket *so, const char *domain, const char *domain_owner);
1352 extern int necp_set_socket_resolver_signature(struct inpcb *inp, struct sockopt *sopt);
1353 extern int necp_get_socket_resolver_signature(struct inpcb *inp, struct sockopt *sopt);
1354 extern bool necp_socket_has_resolver_signature(struct inpcb *inp);
1355 extern bool necp_socket_resolver_signature_matches_address(struct inpcb *inp, union necp_sockaddr_union *address);
1356 extern void necp_inpcb_remove_cb(struct inpcb *inp);
1357 extern void necp_inpcb_dispose(struct inpcb *inp);
1358 
1359 extern u_int32_t necp_socket_get_content_filter_control_unit(struct socket *so);
1360 
1361 extern bool necp_socket_should_use_flow_divert(struct inpcb *inp);
1362 extern u_int32_t necp_socket_get_flow_divert_control_unit(struct inpcb *inp, uint32_t *aggregate_unit);
1363 
1364 extern bool necp_socket_should_rescope(struct inpcb *inp);
1365 extern u_int necp_socket_get_rescope_if_index(struct inpcb *inp);
1366 extern u_int32_t necp_socket_get_effective_mtu(struct inpcb *inp, u_int32_t current_mtu);
1367 
1368 extern bool necp_socket_is_allowed_to_recv_on_interface(struct inpcb *inp, ifnet_t interface);
1369 
1370 extern bool necp_socket_is_allowed_to_send_recv(struct inpcb *inp, ifnet_t input_interface, u_int16_t pf_tag,
1371     necp_kernel_policy_id *return_policy_id,
1372     u_int32_t *return_route_rule_id,
1373     necp_kernel_policy_id *return_skip_policy_id, u_int32_t *return_pass_flags);
1374 extern bool necp_socket_is_allowed_to_send_recv_v4(struct inpcb *inp, u_int16_t local_port,
1375     u_int16_t remote_port, struct in_addr *local_addr,
1376     struct in_addr *remote_addr, ifnet_t input_interface, u_int16_t pf_tag,
1377     necp_kernel_policy_id *return_policy_id, u_int32_t *return_route_rule_id,
1378     necp_kernel_policy_id *return_skip_policy_id, u_int32_t *return_pass_flags);
1379 extern bool necp_socket_is_allowed_to_send_recv_v6(struct inpcb *inp, u_int16_t local_port,
1380     u_int16_t remote_port, struct in6_addr *local_addr,
1381     struct in6_addr *remote_addr, ifnet_t input_interface, u_int16_t pf_tag,
1382     necp_kernel_policy_id *return_policy_id, u_int32_t *return_route_rule_id,
1383     necp_kernel_policy_id *return_skip_policy_id, u_int32_t *return_pass_flags);
1384 extern void necp_socket_update_qos_marking(struct inpcb *inp, struct rtentry *route, u_int32_t route_rule_id);
1385 extern bool necp_lookup_current_qos_marking(int32_t *qos_marking_gencount, struct rtentry *route, struct ifnet *interface, u_int32_t route_rule_id, bool old_qos_marking);
1386 extern int necp_mark_packet_from_socket(struct mbuf *packet, struct inpcb *inp, necp_kernel_policy_id policy_id,
1387     u_int32_t route_rule_id, necp_kernel_policy_id skip_policy_id, u_int32_t pass_flags);
1388 extern necp_kernel_policy_id necp_get_policy_id_from_packet(struct mbuf *packet);
1389 extern necp_kernel_policy_id necp_get_skip_policy_id_from_packet(struct mbuf *packet);
1390 extern u_int16_t necp_get_packet_filter_tags_from_packet(struct mbuf *packet);
1391 extern bool necp_packet_should_skip_filters(struct mbuf *packet);
1392 extern u_int32_t necp_get_last_interface_index_from_packet(struct mbuf *packet);
1393 extern u_int32_t necp_get_route_rule_id_from_packet(struct mbuf *packet);
1394 extern int necp_get_app_uuid_from_packet(struct mbuf *packet,
1395     uuid_t app_uuid);
1396 
1397 extern necp_kernel_policy_id necp_socket_find_policy_match(struct inpcb *inp, struct sockaddr *override_local_addr,
1398     struct sockaddr *override_remote_addr, u_int32_t override_bound_interface);
1399 extern necp_kernel_policy_id necp_ip_output_find_policy_match(struct mbuf *packet, int flags, struct ip_out_args *ipoa,
1400     struct rtentry *rt,
1401     necp_kernel_policy_result *result,
1402     necp_kernel_policy_result_parameter *result_parameter);
1403 extern necp_kernel_policy_id necp_ip6_output_find_policy_match(struct mbuf *packet, int flags, struct ip6_out_args *ip6oa,
1404     struct rtentry *rt,
1405     necp_kernel_policy_result *result,
1406     necp_kernel_policy_result_parameter *result_parameter);
1407 
1408 extern int necp_mark_packet_from_ip(struct mbuf *packet, necp_kernel_policy_id policy_id);
1409 extern int necp_mark_packet_from_interface(struct mbuf *packet, ifnet_t interface);
1410 
1411 extern ifnet_t necp_get_ifnet_from_result_parameter(necp_kernel_policy_result_parameter *result_parameter);
1412 extern bool necp_packet_can_rebind_to_ifnet(struct mbuf *packet, struct ifnet *interface, struct route *new_route, int family);
1413 
1414 extern bool necp_packet_is_allowed_over_interface(struct mbuf *packet, struct ifnet *interface);
1415 
1416 extern int necp_mark_packet_as_keepalive(struct mbuf *packet, bool is_keepalive);
1417 extern bool necp_get_is_keepalive_from_packet(struct mbuf *packet);
1418 
1419 extern int necp_sign_resolver_answer(uuid_t client_id, u_int32_t sign_type,
1420     u_int8_t *data, size_t data_length,
1421     u_int8_t *tag, size_t *out_tag_length);
1422 
1423 extern bool necp_validate_resolver_answer(uuid_t client_id, u_int32_t sign_type,
1424     u_int8_t *data, size_t data_length,
1425     u_int8_t *tag, size_t tag_length);
1426 
1427 extern void necp_update_all_clients(void); // Handle general re-evaluate event
1428 extern void necp_update_all_clients_immediately_if_needed(bool should_update_immediately); // Handle general re-evaluate event
1429 
1430 extern void necp_force_update_client(uuid_t client_id, uuid_t remove_netagent_uuid, u_int32_t agent_generation); // Cause a single client to get an update event
1431 
1432 extern bool necp_set_client_as_background(proc_t proc, struct fileproc *fp, bool background); // Set all clients for an fp as background or not
1433 
1434 struct necp_fd_data;
1435 extern void necp_fd_memstatus(proc_t proc, uint32_t status, struct necp_fd_data *client_fd); // Purge memory of clients for the process
1436 extern void necp_fd_defunct(proc_t proc, struct necp_fd_data *client_fd); // Set all clients for an process as defunct
1437 
1438 extern void necp_client_request_in_process_flow_divert(pid_t pid);
1439 
1440 extern int necp_client_register_socket_flow(pid_t pid, uuid_t client_id, struct inpcb *inp);
1441 
1442 extern int necp_client_register_socket_listener(pid_t pid, uuid_t client_id, struct inpcb *inp);
1443 
1444 #if SKYWALK
1445 extern int necp_client_get_netns_flow_info(uuid_t client_id, struct ns_flow_info *flow_info);
1446 #endif /* SKYWALK */
1447 
1448 extern int necp_client_assert_bb_radio_manager(uuid_t client_id, bool assert);
1449 
1450 extern int necp_client_assign_from_socket(pid_t pid, uuid_t client_id, struct inpcb *inp);
1451 
1452 extern int necp_assign_client_result(uuid_t netagent_uuid, uuid_t client_id,
1453     u_int8_t *assigned_results, size_t assigned_results_length);
1454 extern int necp_assign_client_group_members(uuid_t netagent_uuid, uuid_t client_id,
1455     u_int8_t *assigned_group_members, size_t assigned_group_members_length);
1456 
1457 struct skmem_obj_info;  // forward declaration
1458 extern int necp_stats_ctor(struct skmem_obj_info *oi, struct skmem_obj_info *oim, void *arg, uint32_t skmflag);
1459 extern int necp_stats_dtor(void *addr, void *arg);
1460 
1461 /* value to denote invalid flow advisory index */
1462 struct netagent_session;
1463 extern int
1464 necp_update_flow_protoctl_event(uuid_t netagent_uuid, uuid_t client_id,
1465     uint32_t protoctl_event_code, uint32_t protoctl_event_val,
1466     uint32_t protoctl_event_tcp_seq_num);
1467 
1468 #define NECP_FLOWADV_IDX_INVALID        UINT32_MAX
1469 extern void *necp_create_nexus_assign_message(uuid_t nexus_instance, nexus_port_t nexus_port, void *key, uint32_t key_length,
1470     struct necp_client_endpoint *local_endpoint, struct necp_client_endpoint *remote_endpoint,
1471     struct ether_addr *local_ether_addr,
1472     u_int32_t flow_adv_index, void *flow_stats, size_t *message_length);
1473 
1474 
1475 #define NECP_MAX_DEMUX_PATTERNS 4
1476 struct necp_client_nexus_parameters {
1477 	pid_t pid;
1478 	pid_t epid;
1479 	uuid_t euuid;
1480 #if SKYWALK
1481 	netns_token port_reservation;
1482 #else /* !SKYWALK */
1483 	void *reserved;
1484 #endif /* !SKYWALK */
1485 	union necp_sockaddr_union local_addr;
1486 	union necp_sockaddr_union remote_addr;
1487 	u_int8_t ip_protocol;
1488 	u_int8_t transport_protocol;
1489 	u_int16_t ethertype;
1490 	u_int32_t traffic_class;
1491 	necp_policy_id policy_id;
1492 	unsigned is_listener:1;
1493 	unsigned is_interpose:1;
1494 	unsigned is_custom_ether:1;
1495 	unsigned allow_qos_marking:1;
1496 	unsigned override_address_selection:1;
1497 	unsigned use_stable_address:1; // Used if override_address_selection is set
1498 	unsigned no_wake_from_sleep:1;
1499 	unsigned is_demuxable_parent:1;
1500 	unsigned reuse_port:1;
1501 
1502 	uuid_t parent_flow_uuid;
1503 	struct necp_demux_pattern demux_patterns[NECP_MAX_DEMUX_PATTERNS];
1504 	uint8_t demux_pattern_count;
1505 };
1506 
1507 struct necp_client_group_members {
1508 	size_t group_members_length;
1509 	u_int8_t *group_members;
1510 };
1511 
1512 struct necp_client_error_parameters {
1513 	int32_t error;
1514 	bool force_report;
1515 };
1516 
1517 struct necp_client_agent_parameters {
1518 	union {
1519 		struct necp_client_nexus_parameters nexus_request;
1520 		u_int8_t close_token[QUIC_STATELESS_RESET_TOKEN_SIZE];
1521 		struct necp_client_group_members group_members;
1522 		struct necp_client_error_parameters error;
1523 	} u;
1524 };
1525 
1526 #define NECP_CLIENT_CBACTION_NONVIABLE  1
1527 #define NECP_CLIENT_CBACTION_VIABLE     2
1528 #define NECP_CLIENT_CBACTION_INITIAL    3
1529 
1530 struct necp_client_add_flow_default {
1531 	uuid_t agent_uuid;
1532 	uuid_t registration_id;
1533 	u_int16_t flags; // NECP_CLIENT_FLOW_FLAGS_*
1534 	u_int16_t stats_request_count;
1535 	struct necp_client_flow_stats stats_requests[1];
1536 } __attribute__((__packed__));
1537 
1538 typedef void (*necp_client_flow_cb)(void *handle, int action, uint32_t interface_index, uint32_t necp_flags, bool *viable);
1539 
1540 #if SKYWALK
1541 struct skmem_arena_mmap_info;
1542 
1543 extern pid_t necp_client_get_proc_pid_from_arena_info(struct skmem_arena_mmap_info *arena_info);
1544 
1545 extern void necp_client_early_close(uuid_t client_id); // Cause a single client to close stats, etc
1546 
1547 #endif /* SKYWALK */
1548 
1549 #endif /* BSD_KERNEL_PRIVATE */
1550 
1551 #ifdef KERNEL
1552 #ifdef KERNEL_PRIVATE
1553 struct nstat_domain_info;
1554 extern void necp_copy_inp_domain_info(struct inpcb *, struct socket *, struct nstat_domain_info *);
1555 extern void necp_with_inp_domain_name(struct socket *so, void *ctx, void (*with_func)(char *domain_name, void *ctx));
1556 extern bool net_domain_contains_hostname(char *hostname_string, char *domain_string);
1557 #endif /* KERNEL_PRIVATE */
1558 #endif /* KERNEL */
1559 
1560 #ifndef KERNEL
1561 
1562 extern int necp_match_policy(const uint8_t *parameters, size_t parameters_size, struct necp_aggregate_result *returned_result);
1563 
1564 extern int necp_open(int flags);
1565 
1566 extern int necp_client_action(int necp_fd, uint32_t action, uuid_t client_id,
1567     size_t client_id_len, uint8_t *buffer, size_t buffer_size);
1568 
1569 extern int necp_session_open(int flags);
1570 
1571 extern int necp_session_action(int necp_fd, uint32_t action,
1572     uint8_t *in_buffer, size_t in_buffer_length,
1573     uint8_t *out_buffer, size_t out_buffer_length);
1574 
1575 #endif /* !KERNEL */
1576 
1577 #endif /* PRIVATE */
1578 
1579 #endif
1580