1 /*
2  *  Copyright (c) 2016, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * @file
31  * @brief
32  *  This file defines the OpenThread IPv6 API.
33  */
34 
35 #ifndef OPENTHREAD_IP6_H_
36 #define OPENTHREAD_IP6_H_
37 
38 #include <openthread/message.h>
39 #include <openthread/platform/radio.h>
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 /**
46  * @addtogroup api-ip6
47  *
48  * @brief
49  *   This module includes functions that control IPv6 communication.
50  *
51  * @{
52  *
53  */
54 
55 #define OT_IP6_PREFIX_SIZE 8                             ///< Size of an IPv6 prefix (bytes)
56 #define OT_IP6_PREFIX_BITSIZE (OT_IP6_PREFIX_SIZE * 8)   ///< Size of an IPv6 prefix (bits)
57 #define OT_IP6_IID_SIZE 8                                ///< Size of an IPv6 Interface Identifier (bytes)
58 #define OT_IP6_ADDRESS_SIZE 16                           ///< Size of an IPv6 address (bytes)
59 #define OT_IP6_ADDRESS_BITSIZE (OT_IP6_ADDRESS_SIZE * 8) ///< Size of an IPv6 address (bits)
60 #define OT_IP6_HEADER_SIZE 40                            ///< Size of an IPv6 header (bytes)
61 #define OT_IP6_HEADER_PROTO_OFFSET 6                     ///< Offset of the proto field in the IPv6 header (bytes)
62 
63 /**
64  * @struct otIp6InterfaceIdentifier
65  *
66  * Represents the Interface Identifier of an IPv6 address.
67  *
68  */
69 OT_TOOL_PACKED_BEGIN
70 struct otIp6InterfaceIdentifier
71 {
72     union OT_TOOL_PACKED_FIELD
73     {
74         uint8_t  m8[OT_IP6_IID_SIZE];                     ///< 8-bit fields
75         uint16_t m16[OT_IP6_IID_SIZE / sizeof(uint16_t)]; ///< 16-bit fields
76         uint32_t m32[OT_IP6_IID_SIZE / sizeof(uint32_t)]; ///< 32-bit fields
77     } mFields;                                            ///< The Interface Identifier accessor fields
78 } OT_TOOL_PACKED_END;
79 
80 /**
81  * Represents the Interface Identifier of an IPv6 address.
82  *
83  */
84 typedef struct otIp6InterfaceIdentifier otIp6InterfaceIdentifier;
85 
86 /**
87  * @struct otIp6NetworkPrefix
88  *
89  * Represents the Network Prefix of an IPv6 address (most significant 64 bits of the address).
90  *
91  */
92 OT_TOOL_PACKED_BEGIN
93 struct otIp6NetworkPrefix
94 {
95     uint8_t m8[OT_IP6_PREFIX_SIZE]; ///< The Network Prefix.
96 } OT_TOOL_PACKED_END;
97 
98 /**
99  * Represents the Network Prefix of an IPv6 address (most significant 64 bits of the address).
100  *
101  */
102 typedef struct otIp6NetworkPrefix otIp6NetworkPrefix;
103 
104 /**
105  * @struct otIp6AddressComponents
106  *
107  * Represents the components of an IPv6 address.
108  *
109  */
110 OT_TOOL_PACKED_BEGIN
111 struct otIp6AddressComponents
112 {
113     otIp6NetworkPrefix       mNetworkPrefix; ///< The Network Prefix (most significant 64 bits of the address)
114     otIp6InterfaceIdentifier mIid;           ///< The Interface Identifier (least significant 64 bits of the address)
115 } OT_TOOL_PACKED_END;
116 
117 /**
118  * Represents the components of an IPv6 address.
119  *
120  */
121 typedef struct otIp6AddressComponents otIp6AddressComponents;
122 
123 /**
124  * @struct otIp6Address
125  *
126  * Represents an IPv6 address.
127  *
128  */
129 OT_TOOL_PACKED_BEGIN
130 struct otIp6Address
131 {
132     union OT_TOOL_PACKED_FIELD
133     {
134         uint8_t                m8[OT_IP6_ADDRESS_SIZE];                     ///< 8-bit fields
135         uint16_t               m16[OT_IP6_ADDRESS_SIZE / sizeof(uint16_t)]; ///< 16-bit fields
136         uint32_t               m32[OT_IP6_ADDRESS_SIZE / sizeof(uint32_t)]; ///< 32-bit fields
137         otIp6AddressComponents mComponents;                                 ///< IPv6 address components
138     } mFields;                                                              ///< IPv6 accessor fields
139 } OT_TOOL_PACKED_END;
140 
141 /**
142  * Represents an IPv6 address.
143  *
144  */
145 typedef struct otIp6Address otIp6Address;
146 
147 /**
148  * @struct otIp6Prefix
149  *
150  * Represents an IPv6 prefix.
151  *
152  */
153 OT_TOOL_PACKED_BEGIN
154 struct otIp6Prefix
155 {
156     otIp6Address mPrefix; ///< The IPv6 prefix.
157     uint8_t      mLength; ///< The IPv6 prefix length (in bits).
158 } OT_TOOL_PACKED_END;
159 
160 /**
161  * Represents an IPv6 prefix.
162  *
163  */
164 typedef struct otIp6Prefix otIp6Prefix;
165 
166 /**
167  * IPv6 Address origins
168  *
169  */
170 enum
171 {
172     OT_ADDRESS_ORIGIN_THREAD = 0, ///< Thread assigned address (ALOC, RLOC, MLEID, etc)
173     OT_ADDRESS_ORIGIN_SLAAC  = 1, ///< SLAAC assigned address
174     OT_ADDRESS_ORIGIN_DHCPV6 = 2, ///< DHCPv6 assigned address
175     OT_ADDRESS_ORIGIN_MANUAL = 3, ///< Manually assigned address
176 };
177 
178 /**
179  * Represents an IPv6 network interface unicast address.
180  *
181  */
182 typedef struct otNetifAddress
183 {
184     otIp6Address mAddress;                ///< The IPv6 unicast address.
185     uint8_t      mPrefixLength;           ///< The Prefix length (in bits).
186     uint8_t      mAddressOrigin;          ///< The IPv6 address origin.
187     bool         mPreferred : 1;          ///< TRUE if the address is preferred, FALSE otherwise.
188     bool         mValid : 1;              ///< TRUE if the address is valid, FALSE otherwise.
189     bool         mScopeOverrideValid : 1; ///< TRUE if the mScopeOverride value is valid, FALSE otherwise.
190     unsigned int mScopeOverride : 4;      ///< The IPv6 scope of this address.
191     bool         mRloc : 1;               ///< TRUE if the address is an RLOC, FALSE otherwise.
192     bool         mMeshLocal : 1;          ///< TRUE if the address is mesh-local, FALSE otherwise.
193     bool         mSrpRegistered : 1;      ///< Used by OT core only (indicates whether registered by SRP Client).
194     const struct otNetifAddress *mNext;   ///< A pointer to the next network interface address.
195 } otNetifAddress;
196 
197 /**
198  * Represents an IPv6 network interface multicast address.
199  *
200  */
201 typedef struct otNetifMulticastAddress
202 {
203     otIp6Address                          mAddress; ///< The IPv6 multicast address.
204     const struct otNetifMulticastAddress *mNext;    ///< A pointer to the next network interface multicast address.
205 } otNetifMulticastAddress;
206 
207 /**
208  * Represents an IPv6 socket address.
209  *
210  */
211 typedef struct otSockAddr
212 {
213     otIp6Address mAddress; ///< An IPv6 address.
214     uint16_t     mPort;    ///< A transport-layer port.
215 } otSockAddr;
216 
217 /**
218  * ECN statuses, represented as in the IP header.
219  *
220  */
221 enum
222 {
223     OT_ECN_NOT_CAPABLE = 0x0, ///< Non-ECT
224     OT_ECN_CAPABLE_0   = 0x2, ///< ECT(0)
225     OT_ECN_CAPABLE_1   = 0x1, ///< ECT(1)
226     OT_ECN_MARKED      = 0x3, ///< Congestion encountered (CE)
227 };
228 
229 /**
230  * Represents the local and peer IPv6 socket addresses.
231  *
232  */
233 typedef struct otMessageInfo
234 {
235     otIp6Address mSockAddr; ///< The local IPv6 address.
236     otIp6Address mPeerAddr; ///< The peer IPv6 address.
237     uint16_t     mSockPort; ///< The local transport-layer port.
238     uint16_t     mPeerPort; ///< The peer transport-layer port.
239     uint8_t      mHopLimit; ///< The IPv6 Hop Limit value. Only applies if `mAllowZeroHopLimit` is FALSE.
240                             ///< If `0`, IPv6 Hop Limit is default value `OPENTHREAD_CONFIG_IP6_HOP_LIMIT_DEFAULT`.
241                             ///< Otherwise, specifies the IPv6 Hop Limit.
242     uint8_t mEcn : 2;       ///< The ECN status of the packet, represented as in the IPv6 header.
243     bool    mIsHostInterface : 1;   ///< TRUE if packets sent/received via host interface, FALSE otherwise.
244     bool    mAllowZeroHopLimit : 1; ///< TRUE to allow IPv6 Hop Limit 0 in `mHopLimit`, FALSE otherwise.
245     bool    mMulticastLoop : 1;     ///< TRUE to allow looping back multicast, FALSE otherwise.
246 } otMessageInfo;
247 
248 /**
249  * Internet Protocol Numbers.
250  *
251  */
252 enum
253 {
254     OT_IP6_PROTO_HOP_OPTS = 0,  ///< IPv6 Hop-by-Hop Option
255     OT_IP6_PROTO_TCP      = 6,  ///< Transmission Control Protocol
256     OT_IP6_PROTO_UDP      = 17, ///< User Datagram
257     OT_IP6_PROTO_IP6      = 41, ///< IPv6 encapsulation
258     OT_IP6_PROTO_ROUTING  = 43, ///< Routing Header for IPv6
259     OT_IP6_PROTO_FRAGMENT = 44, ///< Fragment Header for IPv6
260     OT_IP6_PROTO_ICMP6    = 58, ///< ICMP for IPv6
261     OT_IP6_PROTO_NONE     = 59, ///< No Next Header for IPv6
262     OT_IP6_PROTO_DST_OPTS = 60, ///< Destination Options for IPv6
263 };
264 
265 /**
266  * Brings the IPv6 interface up or down.
267  *
268  * Call this to enable or disable IPv6 communication.
269  *
270  * @param[in] aInstance A pointer to an OpenThread instance.
271  * @param[in] aEnabled  TRUE to enable IPv6, FALSE otherwise.
272  *
273  * @retval OT_ERROR_NONE            Successfully brought the IPv6 interface up/down.
274  * @retval OT_ERROR_INVALID_STATE   IPv6 interface is not available since device is operating in raw-link mode
275  *                                  (applicable only when `OPENTHREAD_CONFIG_LINK_RAW_ENABLE` feature is enabled).
276  *
277  */
278 otError otIp6SetEnabled(otInstance *aInstance, bool aEnabled);
279 
280 /**
281  * Indicates whether or not the IPv6 interface is up.
282  *
283  * @param[in] aInstance A pointer to an OpenThread instance.
284  *
285  * @retval TRUE   The IPv6 interface is enabled.
286  * @retval FALSE  The IPv6 interface is disabled.
287  *
288  */
289 bool otIp6IsEnabled(otInstance *aInstance);
290 
291 /**
292  * Adds a Network Interface Address to the Thread interface.
293  *
294  * The passed-in instance @p aAddress is copied by the Thread interface. The Thread interface only
295  * supports a fixed number of externally added unicast addresses. See `OPENTHREAD_CONFIG_IP6_MAX_EXT_UCAST_ADDRS`.
296  *
297  * @param[in]  aInstance A pointer to an OpenThread instance.
298  * @param[in]  aAddress  A pointer to a Network Interface Address.
299  *
300  * @retval OT_ERROR_NONE          Successfully added (or updated) the Network Interface Address.
301  * @retval OT_ERROR_INVALID_ARGS  The IP Address indicated by @p aAddress is an internal address.
302  * @retval OT_ERROR_NO_BUFS       The Network Interface is already storing the maximum allowed external addresses.
303  *
304  */
305 otError otIp6AddUnicastAddress(otInstance *aInstance, const otNetifAddress *aAddress);
306 
307 /**
308  * Removes a Network Interface Address from the Thread interface.
309  *
310  * @param[in]  aInstance A pointer to an OpenThread instance.
311  * @param[in]  aAddress  A pointer to an IP Address.
312  *
313  * @retval OT_ERROR_NONE          Successfully removed the Network Interface Address.
314  * @retval OT_ERROR_INVALID_ARGS  The IP Address indicated by @p aAddress is an internal address.
315  * @retval OT_ERROR_NOT_FOUND     The IP Address indicated by @p aAddress was not found.
316  *
317  */
318 otError otIp6RemoveUnicastAddress(otInstance *aInstance, const otIp6Address *aAddress);
319 
320 /**
321  * Gets the list of IPv6 addresses assigned to the Thread interface.
322  *
323  * @param[in]  aInstance A pointer to an OpenThread instance.
324  *
325  * @returns A pointer to the first Network Interface Address.
326  *
327  */
328 const otNetifAddress *otIp6GetUnicastAddresses(otInstance *aInstance);
329 
330 /**
331  * Indicates whether or not a unicast IPv6 address is assigned to the Thread interface.
332  *
333  * @param[in]  aInstance A pointer to an OpenThread instance.
334  * @param[in]  aAddress  A pointer to the unicast address.
335  *
336  * @retval TRUE   If @p aAddress is assigned to the Thread interface.
337  * @retval FALSE  If @p aAddress is not assigned to the Thread interface.
338  *
339  */
340 bool otIp6HasUnicastAddress(otInstance *aInstance, const otIp6Address *aAddress);
341 
342 /**
343  * Subscribes the Thread interface to a Network Interface Multicast Address.
344  *
345  * The passed in instance @p aAddress will be copied by the Thread interface. The Thread interface only
346  * supports a fixed number of externally added multicast addresses. See `OPENTHREAD_CONFIG_IP6_MAX_EXT_MCAST_ADDRS`.
347  *
348  * @param[in]  aInstance A pointer to an OpenThread instance.
349  * @param[in]  aAddress  A pointer to an IP Address.
350  *
351  * @retval OT_ERROR_NONE           Successfully subscribed to the Network Interface Multicast Address.
352  * @retval OT_ERROR_ALREADY        The multicast address is already subscribed.
353  * @retval OT_ERROR_INVALID_ARGS   The IP Address indicated by @p aAddress is an invalid multicast address.
354  * @retval OT_ERROR_REJECTED       The IP Address indicated by @p aAddress is an internal multicast address.
355  * @retval OT_ERROR_NO_BUFS        The Network Interface is already storing the maximum allowed external multicast
356  *                                 addresses.
357  *
358  */
359 otError otIp6SubscribeMulticastAddress(otInstance *aInstance, const otIp6Address *aAddress);
360 
361 /**
362  * Unsubscribes the Thread interface to a Network Interface Multicast Address.
363  *
364  * @param[in]  aInstance A pointer to an OpenThread instance.
365  * @param[in]  aAddress  A pointer to an IP Address.
366  *
367  * @retval OT_ERROR_NONE          Successfully unsubscribed to the Network Interface Multicast Address.
368  * @retval OT_ERROR_REJECTED      The IP Address indicated by @p aAddress is an internal address.
369  * @retval OT_ERROR_NOT_FOUND     The IP Address indicated by @p aAddress was not found.
370  *
371  */
372 otError otIp6UnsubscribeMulticastAddress(otInstance *aInstance, const otIp6Address *aAddress);
373 
374 /**
375  * Gets the list of IPv6 multicast addresses subscribed to the Thread interface.
376  *
377  * @param[in]  aInstance A pointer to an OpenThread instance.
378  *
379  * @returns A pointer to the first Network Interface Multicast Address.
380  *
381  */
382 const otNetifMulticastAddress *otIp6GetMulticastAddresses(otInstance *aInstance);
383 
384 /**
385  * Checks if multicast promiscuous mode is enabled on the Thread interface.
386  *
387  * @param[in]  aInstance A pointer to an OpenThread instance.
388  *
389  * @sa otIp6SetMulticastPromiscuousEnabled
390  *
391  */
392 bool otIp6IsMulticastPromiscuousEnabled(otInstance *aInstance);
393 
394 /**
395  * Enables or disables multicast promiscuous mode on the Thread interface.
396  *
397  * @param[in]  aInstance  A pointer to an OpenThread instance.
398  * @param[in]  aEnabled   TRUE to enable Multicast Promiscuous mode, FALSE otherwise.
399  *
400  * @sa otIp6IsMulticastPromiscuousEnabled
401  *
402  */
403 void otIp6SetMulticastPromiscuousEnabled(otInstance *aInstance, bool aEnabled);
404 
405 /**
406  * Allocate a new message buffer for sending an IPv6 message.
407  *
408  * @note If @p aSettings is 'NULL', the link layer security is enabled and the message priority is set to
409  * OT_MESSAGE_PRIORITY_NORMAL by default.
410  *
411  * @param[in]  aInstance  A pointer to an OpenThread instance.
412  * @param[in]  aSettings  A pointer to the message settings or NULL to set default settings.
413  *
414  * @returns A pointer to the message buffer or NULL if no message buffers are available or parameters are invalid.
415  *
416  * @sa otMessageFree
417  *
418  */
419 otMessage *otIp6NewMessage(otInstance *aInstance, const otMessageSettings *aSettings);
420 
421 /**
422  * Allocate a new message buffer and write the IPv6 datagram to the message buffer for sending an IPv6 message.
423  *
424  * @note If @p aSettings is NULL, the link layer security is enabled and the message priority is obtained from IPv6
425  *       message itself.
426  *       If @p aSettings is not NULL, the @p aSetting->mPriority is ignored and obtained from IPv6 message itself.
427  *
428  * @param[in]  aInstance    A pointer to an OpenThread instance.
429  * @param[in]  aData        A pointer to the IPv6 datagram buffer.
430  * @param[in]  aDataLength  The size of the IPv6 datagram buffer pointed by @p aData.
431  * @param[in]  aSettings    A pointer to the message settings or NULL to set default settings.
432  *
433  * @returns A pointer to the message or NULL if malformed IPv6 header or insufficient message buffers are available.
434  *
435  * @sa otMessageFree
436  *
437  */
438 otMessage *otIp6NewMessageFromBuffer(otInstance              *aInstance,
439                                      const uint8_t           *aData,
440                                      uint16_t                 aDataLength,
441                                      const otMessageSettings *aSettings);
442 
443 /**
444  * Pointer is called when an IPv6 datagram is received.
445  *
446  * @param[in]  aMessage  A pointer to the message buffer containing the received IPv6 datagram. This function transfers
447  *                       the ownership of the @p aMessage to the receiver of the callback. The message should be
448  *                       freed by the receiver of the callback after it is processed (see otMessageFree()).
449  * @param[in]  aContext  A pointer to application-specific context.
450  *
451  */
452 typedef void (*otIp6ReceiveCallback)(otMessage *aMessage, void *aContext);
453 
454 /**
455  * Registers a callback to provide received IPv6 datagrams.
456  *
457  * By default, this callback does not pass Thread control traffic.  See otIp6SetReceiveFilterEnabled() to
458  * change the Thread control traffic filter setting.
459  *
460  * @param[in]  aInstance         A pointer to an OpenThread instance.
461  * @param[in]  aCallback         A pointer to a function that is called when an IPv6 datagram is received or
462  *                               NULL to disable the callback.
463  * @param[in]  aCallbackContext  A pointer to application-specific context.
464  *
465  * @sa otIp6IsReceiveFilterEnabled
466  * @sa otIp6SetReceiveFilterEnabled
467  *
468  */
469 void otIp6SetReceiveCallback(otInstance *aInstance, otIp6ReceiveCallback aCallback, void *aCallbackContext);
470 
471 /**
472  * Represents IPv6 address information.
473  *
474  */
475 typedef struct otIp6AddressInfo
476 {
477     const otIp6Address *mAddress;       ///< A pointer to the IPv6 address.
478     uint8_t             mPrefixLength;  ///< The prefix length of mAddress if it is a unicast address.
479     uint8_t             mScope : 4;     ///< The scope of this address.
480     bool                mPreferred : 1; ///< Whether this is a preferred address.
481     bool                mMeshLocal : 1; ///< Whether this is a mesh-local unicast/anycast address.
482 } otIp6AddressInfo;
483 
484 /**
485  * Pointer is called when an internal IPv6 address is added or removed.
486  *
487  * @param[in]   aAddressInfo        A pointer to the IPv6 address information.
488  * @param[in]   aIsAdded            TRUE if the @p aAddress was added, FALSE if @p aAddress was removed.
489  * @param[in]   aContext            A pointer to application-specific context.
490  *
491  */
492 typedef void (*otIp6AddressCallback)(const otIp6AddressInfo *aAddressInfo, bool aIsAdded, void *aContext);
493 
494 /**
495  * Registers a callback to notify internal IPv6 address changes.
496  *
497  * @param[in]   aInstance           A pointer to an OpenThread instance.
498  * @param[in]   aCallback           A pointer to a function that is called when an internal IPv6 address is added or
499  *                                  removed. NULL to disable the callback.
500  * @param[in]   aCallbackContext    A pointer to application-specific context.
501  *
502  */
503 void otIp6SetAddressCallback(otInstance *aInstance, otIp6AddressCallback aCallback, void *aCallbackContext);
504 
505 /**
506  * Indicates whether or not Thread control traffic is filtered out when delivering IPv6 datagrams
507  * via the callback specified in otIp6SetReceiveCallback().
508  *
509  * @param[in]  aInstance A pointer to an OpenThread instance.
510  *
511  * @returns  TRUE if Thread control traffic is filtered out, FALSE otherwise.
512  *
513  * @sa otIp6SetReceiveCallback
514  * @sa otIp6SetReceiveFilterEnabled
515  *
516  */
517 bool otIp6IsReceiveFilterEnabled(otInstance *aInstance);
518 
519 /**
520  * Sets whether or not Thread control traffic is filtered out when delivering IPv6 datagrams
521  * via the callback specified in otIp6SetReceiveCallback().
522  *
523  * @param[in]  aInstance A pointer to an OpenThread instance.
524  * @param[in]  aEnabled  TRUE if Thread control traffic is filtered out, FALSE otherwise.
525  *
526  * @sa otIp6SetReceiveCallback
527  * @sa otIsReceiveIp6FilterEnabled
528  *
529  */
530 void otIp6SetReceiveFilterEnabled(otInstance *aInstance, bool aEnabled);
531 
532 /**
533  * Sends an IPv6 datagram via the Thread interface.
534  *
535  * The caller transfers ownership of @p aMessage when making this call. OpenThread will free @p aMessage when
536  * processing is complete, including when a value other than `OT_ERROR_NONE` is returned.
537  *
538  * @param[in]  aInstance A pointer to an OpenThread instance.
539  * @param[in]  aMessage  A pointer to the message buffer containing the IPv6 datagram.
540  *
541  * @retval OT_ERROR_NONE                    Successfully processed the message.
542  * @retval OT_ERROR_DROP                    Message was well-formed but not fully processed due to packet processing
543  * rules.
544  * @retval OT_ERROR_NO_BUFS                 Could not allocate necessary message buffers when processing the datagram.
545  * @retval OT_ERROR_NO_ROUTE                No route to host.
546  * @retval OT_ERROR_INVALID_SOURCE_ADDRESS  Source address is invalid, e.g. an anycast address or a multicast address.
547  * @retval OT_ERROR_PARSE                   Encountered a malformed header when processing the message.
548  * @retval OT_ERROR_INVALID_ARGS            The message's metadata is invalid, e.g. the message uses
549  *                                          `OT_MESSAGE_ORIGIN_THREAD_NETIF` as the origin.
550  *
551  */
552 otError otIp6Send(otInstance *aInstance, otMessage *aMessage);
553 
554 /**
555  * Adds a port to the allowed unsecured port list.
556  *
557  * @param[in]  aInstance A pointer to an OpenThread instance.
558  * @param[in]  aPort     The port value.
559  *
560  * @retval OT_ERROR_NONE         The port was successfully added to the allowed unsecure port list.
561  * @retval OT_ERROR_INVALID_ARGS The port is invalid (value 0 is reserved for internal use).
562  * @retval OT_ERROR_NO_BUFS      The unsecure port list is full.
563  *
564  */
565 otError otIp6AddUnsecurePort(otInstance *aInstance, uint16_t aPort);
566 
567 /**
568  * Removes a port from the allowed unsecure port list.
569  *
570  * @note This function removes @p aPort by overwriting @p aPort with the element after @p aPort in the internal port
571  *       list. Be careful when calling otIp6GetUnsecurePorts() followed by otIp6RemoveUnsecurePort() to remove unsecure
572  *       ports.
573  *
574  * @param[in]  aInstance A pointer to an OpenThread instance.
575  * @param[in]  aPort     The port value.
576  *
577  * @retval OT_ERROR_NONE         The port was successfully removed from the allowed unsecure port list.
578  * @retval OT_ERROR_INVALID_ARGS The port is invalid (value 0 is reserved for internal use).
579  * @retval OT_ERROR_NOT_FOUND    The port was not found in the unsecure port list.
580  *
581  */
582 otError otIp6RemoveUnsecurePort(otInstance *aInstance, uint16_t aPort);
583 
584 /**
585  * Removes all ports from the allowed unsecure port list.
586  *
587  * @param[in]  aInstance A pointer to an OpenThread instance.
588  *
589  */
590 void otIp6RemoveAllUnsecurePorts(otInstance *aInstance);
591 
592 /**
593  * Returns a pointer to the unsecure port list.
594  *
595  * @note Port value 0 is used to indicate an invalid entry.
596  *
597  * @param[in]   aInstance    A pointer to an OpenThread instance.
598  * @param[out]  aNumEntries  The number of entries in the list.
599  *
600  * @returns A pointer to the unsecure port list.
601  *
602  */
603 const uint16_t *otIp6GetUnsecurePorts(otInstance *aInstance, uint8_t *aNumEntries);
604 
605 /**
606  * Test if two IPv6 addresses are the same.
607  *
608  * @param[in]  aFirst   A pointer to the first IPv6 address to compare.
609  * @param[in]  aSecond  A pointer to the second IPv6 address to compare.
610  *
611  * @retval TRUE   The two IPv6 addresses are the same.
612  * @retval FALSE  The two IPv6 addresses are not the same.
613  *
614  */
615 bool otIp6IsAddressEqual(const otIp6Address *aFirst, const otIp6Address *aSecond);
616 
617 /**
618  * Test if two IPv6 prefixes are the same.
619  *
620  * @param[in]  aFirst   A pointer to the first IPv6 prefix to compare.
621  * @param[in]  aSecond  A pointer to the second IPv6 prefix to compare.
622  *
623  * @retval TRUE   The two IPv6 prefixes are the same.
624  * @retval FALSE  The two IPv6 prefixes are not the same.
625  *
626  */
627 bool otIp6ArePrefixesEqual(const otIp6Prefix *aFirst, const otIp6Prefix *aSecond);
628 
629 /**
630  * Converts a human-readable IPv6 address string into a binary representation.
631  *
632  * @param[in]   aString   A pointer to a NULL-terminated string.
633  * @param[out]  aAddress  A pointer to an IPv6 address.
634  *
635  * @retval OT_ERROR_NONE   Successfully parsed @p aString and updated @p aAddress.
636  * @retval OT_ERROR_PARSE  Failed to parse @p aString as an IPv6 address.
637  *
638  */
639 otError otIp6AddressFromString(const char *aString, otIp6Address *aAddress);
640 
641 /**
642  * Converts a human-readable IPv6 prefix string into a binary representation.
643  *
644  * The @p aString parameter should be a string in the format "<address>/<plen>", where `<address>` is an IPv6
645  * address and `<plen>` is a prefix length.
646  *
647  * @param[in]   aString  A pointer to a NULL-terminated string.
648  * @param[out]  aPrefix  A pointer to an IPv6 prefix.
649  *
650  * @retval OT_ERROR_NONE   Successfully parsed the string as an IPv6 prefix and updated @p aPrefix.
651  * @retval OT_ERROR_PARSE  Failed to parse @p aString as an IPv6 prefix.
652  *
653  */
654 otError otIp6PrefixFromString(const char *aString, otIp6Prefix *aPrefix);
655 
656 #define OT_IP6_ADDRESS_STRING_SIZE 40 ///< Recommended size for string representation of an IPv6 address.
657 
658 /**
659  * Converts a given IPv6 address to a human-readable string.
660  *
661  * The IPv6 address string is formatted as 16 hex values separated by ':' (i.e., "%x:%x:%x:...:%x").
662  *
663  * If the resulting string does not fit in @p aBuffer (within its @p aSize characters), the string will be truncated
664  * but the outputted string is always null-terminated.
665  *
666  * @param[in]  aAddress  A pointer to an IPv6 address (MUST NOT be NULL).
667  * @param[out] aBuffer   A pointer to a char array to output the string (MUST NOT be NULL).
668  * @param[in]  aSize     The size of @p aBuffer (in bytes). Recommended to use `OT_IP6_ADDRESS_STRING_SIZE`.
669  *
670  */
671 void otIp6AddressToString(const otIp6Address *aAddress, char *aBuffer, uint16_t aSize);
672 
673 #define OT_IP6_SOCK_ADDR_STRING_SIZE 48 ///< Recommended size for string representation of an IPv6 socket address.
674 
675 /**
676  * Converts a given IPv6 socket address to a human-readable string.
677  *
678  * The IPv6 socket address string is formatted as [`address`]:`port` where `address` is shown
679  * as 16 hex values separated by `:` and `port` is the port number in decimal format,
680  * for example "[%x:%x:...:%x]:%u".
681  *
682  * If the resulting string does not fit in @p aBuffer (within its @p aSize characters), the string will be truncated
683  * but the outputted string is always null-terminated.
684  *
685  * @param[in]  aSockAddr A pointer to an IPv6 socket address (MUST NOT be NULL).
686  * @param[out] aBuffer   A pointer to a char array to output the string (MUST NOT be NULL).
687  * @param[in]  aSize     The size of @p aBuffer (in bytes). Recommended to use `OT_IP6_SOCK_ADDR_STRING_SIZE`.
688  *
689  */
690 void otIp6SockAddrToString(const otSockAddr *aSockAddr, char *aBuffer, uint16_t aSize);
691 
692 #define OT_IP6_PREFIX_STRING_SIZE 45 ///< Recommended size for string representation of an IPv6 prefix.
693 
694 /**
695  * Converts a given IPv6 prefix to a human-readable string.
696  *
697  * The IPv6 address string is formatted as "%x:%x:%x:...[::]/plen".
698  *
699  * If the resulting string does not fit in @p aBuffer (within its @p aSize characters), the string will be truncated
700  * but the outputted string is always null-terminated.
701  *
702  * @param[in]  aPrefix   A pointer to an IPv6 prefix (MUST NOT be NULL).
703  * @param[out] aBuffer   A pointer to a char array to output the string (MUST NOT be NULL).
704  * @param[in]  aSize     The size of @p aBuffer (in bytes). Recommended to use `OT_IP6_PREFIX_STRING_SIZE`.
705  *
706  */
707 void otIp6PrefixToString(const otIp6Prefix *aPrefix, char *aBuffer, uint16_t aSize);
708 
709 /**
710  * Returns the prefix match length (bits) for two IPv6 addresses.
711  *
712  * @param[in]  aFirst   A pointer to the first IPv6 address.
713  * @param[in]  aSecond  A pointer to the second IPv6 address.
714  *
715  * @returns  The prefix match length in bits.
716  *
717  */
718 uint8_t otIp6PrefixMatch(const otIp6Address *aFirst, const otIp6Address *aSecond);
719 
720 /**
721  * Gets a prefix with @p aLength from @p aAddress.
722  *
723  * @param[in]  aAddress   A pointer to an IPv6 address.
724  * @param[in]  aLength    The length of prefix in bits.
725  * @param[out] aPrefix    A pointer to output the IPv6 prefix.
726  *
727  */
728 void otIp6GetPrefix(const otIp6Address *aAddress, uint8_t aLength, otIp6Prefix *aPrefix);
729 
730 /**
731  * Indicates whether or not a given IPv6 address is the Unspecified Address.
732  *
733  * @param[in]  aAddress   A pointer to an IPv6 address.
734  *
735  * @retval TRUE   If the IPv6 address is the Unspecified Address.
736  * @retval FALSE  If the IPv6 address is not the Unspecified Address.
737  *
738  */
739 bool otIp6IsAddressUnspecified(const otIp6Address *aAddress);
740 
741 /**
742  * Perform OpenThread source address selection.
743  *
744  * @param[in]      aInstance     A pointer to an OpenThread instance.
745  * @param[in,out]  aMessageInfo  A pointer to the message information.
746  *
747  * @retval  OT_ERROR_NONE       Found a source address and is filled into mSockAddr of @p aMessageInfo.
748  * @retval  OT_ERROR_NOT_FOUND  No source address was found and @p aMessageInfo is unchanged.
749  *
750  */
751 otError otIp6SelectSourceAddress(otInstance *aInstance, otMessageInfo *aMessageInfo);
752 
753 /**
754  * Indicates whether the SLAAC module is enabled or not.
755  *
756  * `OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE` build-time feature must be enabled.
757  *
758  * @retval TRUE    SLAAC module is enabled.
759  * @retval FALSE   SLAAC module is disabled.
760  *
761  */
762 bool otIp6IsSlaacEnabled(otInstance *aInstance);
763 
764 /**
765  * Enables/disables the SLAAC module.
766  *
767  * `OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE` build-time feature must be enabled.
768  *
769  * When SLAAC module is enabled, SLAAC addresses (based on on-mesh prefixes in Network Data) are added to the interface.
770  * When SLAAC module is disabled any previously added SLAAC address is removed.
771  *
772  * @param[in] aInstance A pointer to an OpenThread instance.
773  * @param[in] aEnabled  TRUE to enable, FALSE to disable.
774  *
775  */
776 void otIp6SetSlaacEnabled(otInstance *aInstance, bool aEnabled);
777 
778 /**
779  * Pointer allows user to filter prefixes and not allow an SLAAC address based on a prefix to be added.
780  *
781  * `otIp6SetSlaacPrefixFilter()` can be used to set the filter handler. The filter handler is invoked by SLAAC module
782  * when it is about to add a SLAAC address based on a prefix. Its boolean return value determines whether the address
783  * is filtered (not added) or not.
784  *
785  * @param[in] aInstance   A pointer to an OpenThread instance.
786  * @param[in] aPrefix     A pointer to prefix for which SLAAC address is about to be added.
787  *
788  * @retval TRUE    Indicates that the SLAAC address based on the prefix should be filtered and NOT added.
789  * @retval FALSE   Indicates that the SLAAC address based on the prefix should be added.
790  *
791  */
792 typedef bool (*otIp6SlaacPrefixFilter)(otInstance *aInstance, const otIp6Prefix *aPrefix);
793 
794 /**
795  * Sets the SLAAC module filter handler.
796  *
797  * `OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE` build-time feature must be enabled.
798  *
799  * The filter handler is called by SLAAC module when it is about to add a SLAAC address based on a prefix to decide
800  * whether the address should be added or not.
801  *
802  * A NULL filter handler disables filtering and allows all SLAAC addresses to be added.
803  *
804  * If this function is not called, the default filter used by SLAAC module will be NULL (filtering is disabled).
805  *
806  * @param[in] aInstance    A pointer to an OpenThread instance.
807  * @param[in] aFilter      A pointer to SLAAC prefix filter handler, or NULL to disable filtering.
808  *
809  */
810 void otIp6SetSlaacPrefixFilter(otInstance *aInstance, otIp6SlaacPrefixFilter aFilter);
811 
812 /**
813  * Pointer is called with results of `otIp6RegisterMulticastListeners`.
814  *
815  * @param[in]  aContext  A pointer to the user context.
816  * @param[in]  aError    OT_ERROR_NONE when successfully sent MLR.req and received MLR.rsp,
817  *                       OT_ERROR_RESPONSE_TIMEOUT when failed to receive MLR.rsp,
818  *                       OT_ERROR_PARSE when failed to parse MLR.rsp.
819  * @param[in]  aMlrStatus         The Multicast Listener Registration status when @p aError is OT_ERROR_NONE.
820  * @param[in]  aFailedAddresses   A pointer to the failed IPv6 addresses when @p aError is OT_ERROR_NONE.
821  * @param[in]  aFailedAddressNum  The number of failed IPv6 addresses when @p aError is OT_ERROR_NONE.
822  *
823  * @sa otIp6RegisterMulticastListeners
824  *
825  */
826 typedef void (*otIp6RegisterMulticastListenersCallback)(void               *aContext,
827                                                         otError             aError,
828                                                         uint8_t             aMlrStatus,
829                                                         const otIp6Address *aFailedAddresses,
830                                                         uint8_t             aFailedAddressNum);
831 
832 #define OT_IP6_MAX_MLR_ADDRESSES 15 ///< Max number of IPv6 addresses supported by Multicast Listener Registration.
833 
834 /**
835  * Registers Multicast Listeners to Primary Backbone Router.
836  *
837  * `OPENTHREAD_CONFIG_TMF_PROXY_MLR_ENABLE` and `OPENTHREAD_CONFIG_COMMISSIONER_ENABLE`
838  * must be enabled.
839  *
840  * @param[in]  aInstance    A pointer to an OpenThread instance.
841  * @param[in]  aAddresses   A Multicast Address Array to register.
842  * @param[in]  aAddressNum  The number of Multicast Address to register (0 if @p aAddresses is NULL).
843  * @param[in]  aTimeout     A pointer to the timeout value (in seconds) to be included in MLR.req. A timeout value of 0
844  *                          removes the corresponding Multicast Listener. If NULL, MLR.req would have no Timeout Tlv by
845  *                          default.
846  * @param[in]  aCallback    A pointer to the callback function.
847  * @param[in]  aContext     A pointer to the user context.
848  *
849  * @retval OT_ERROR_NONE           Successfully sent MLR.req. The @p aCallback will be called iff this method
850  *                                 returns OT_ERROR_NONE.
851  * @retval OT_ERROR_BUSY           If a previous registration was ongoing.
852  * @retval OT_ERROR_INVALID_ARGS   If one or more arguments are invalid.
853  * @retval OT_ERROR_INVALID_STATE  If the device was not in a valid state to send MLR.req (e.g. Commissioner not
854  *                                 started, Primary Backbone Router not found).
855  * @retval OT_ERROR_NO_BUFS        If insufficient message buffers available.
856  *
857  * @sa otIp6RegisterMulticastListenersCallback
858  *
859  */
860 otError otIp6RegisterMulticastListeners(otInstance                             *aInstance,
861                                         const otIp6Address                     *aAddresses,
862                                         uint8_t                                 aAddressNum,
863                                         const uint32_t                         *aTimeout,
864                                         otIp6RegisterMulticastListenersCallback aCallback,
865                                         void                                   *aContext);
866 
867 /**
868  * Sets the Mesh Local IID (for test purpose).
869  *
870  * Requires `OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE`.
871  *
872  * @param[in]   aInstance   A pointer to an OpenThread instance.
873  * @param[in]   aIid        A pointer to the Mesh Local IID to set.
874  *
875  * @retval  OT_ERROR_NONE           Successfully set the Mesh Local IID.
876  * @retval  OT_ERROR_INVALID_STATE  Thread protocols are enabled.
877  *
878  */
879 otError otIp6SetMeshLocalIid(otInstance *aInstance, const otIp6InterfaceIdentifier *aIid);
880 
881 /**
882  * Converts a given IP protocol number to a human-readable string.
883  *
884  * @param[in] aIpProto   An IP protocol number (`OT_IP6_PROTO_*` enumeration).
885  *
886  * @returns A string representing @p aIpProto.
887  *
888  */
889 const char *otIp6ProtoToString(uint8_t aIpProto);
890 
891 /**
892  * Represents the counters for packets and bytes.
893  *
894  */
895 typedef struct otPacketsAndBytes
896 {
897     uint64_t mPackets; ///< The number of packets.
898     uint64_t mBytes;   ///< The number of bytes.
899 } otPacketsAndBytes;
900 
901 /**
902  * Represents the counters of packets forwarded via Border Routing.
903  *
904  */
905 typedef struct otBorderRoutingCounters
906 {
907     otPacketsAndBytes mInboundUnicast;    ///< The counters for inbound unicast.
908     otPacketsAndBytes mInboundMulticast;  ///< The counters for inbound multicast.
909     otPacketsAndBytes mOutboundUnicast;   ///< The counters for outbound unicast.
910     otPacketsAndBytes mOutboundMulticast; ///< The counters for outbound multicast.
911     otPacketsAndBytes mInboundInternet;   ///< The counters for inbound Internet when DHCPv6 PD enabled.
912     otPacketsAndBytes mOutboundInternet;  ///< The counters for outbound Internet when DHCPv6 PD enabled.
913     uint32_t          mRaRx;              ///< The number of received RA packets.
914     uint32_t          mRaTxSuccess;       ///< The number of RA packets successfully transmitted.
915     uint32_t          mRaTxFailure;       ///< The number of RA packets failed to transmit.
916     uint32_t          mRsRx;              ///< The number of received RS packets.
917     uint32_t          mRsTxSuccess;       ///< The number of RS packets successfully transmitted.
918     uint32_t          mRsTxFailure;       ///< The number of RS packets failed to transmit.
919 } otBorderRoutingCounters;
920 
921 /**
922  * Gets the Border Routing counters.
923  *
924  * `OPENTHREAD_CONFIG_IP6_BR_COUNTERS_ENABLE` build-time feature must be enabled.
925  *
926  * @param[in]  aInstance  A pointer to an OpenThread instance.
927  *
928  * @returns A pointer to the Border Routing counters.
929  *
930  */
931 const otBorderRoutingCounters *otIp6GetBorderRoutingCounters(otInstance *aInstance);
932 
933 /**
934  * Resets the Border Routing counters.
935  *
936  * @param[in]  aInstance  A pointer to an OpenThread instance.
937  *
938  */
939 void otIp6ResetBorderRoutingCounters(otInstance *aInstance);
940 
941 /**
942  * @}
943  *
944  */
945 
946 #ifdef __cplusplus
947 } // extern "C"
948 #endif
949 
950 #endif // OPENTHREAD_IP6_H_
951