1 /*
2  *  Copyright (c) 2021, 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  *   This file implements the infrastructure interface for posix.
32  */
33 
34 #include "openthread-posix-config.h"
35 
36 #include <net/if.h>
37 #include <openthread/nat64.h>
38 #include <openthread/openthread-system.h>
39 
40 #include "core/common/non_copyable.hpp"
41 #include "posix/platform/mainloop.hpp"
42 
43 #if OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
44 
45 namespace ot {
46 namespace Posix {
47 
48 /**
49  * Manages infrastructure network interface.
50  *
51  */
52 class InfraNetif : public Mainloop::Source, private NonCopyable
53 {
54 public:
55     /**
56      * Updates the fd_set and timeout for mainloop.
57      *
58      * @param[in,out]   aContext    A reference to the mainloop context.
59      *
60      */
61     void Update(otSysMainloopContext &aContext) override;
62 
63     /**
64      * Performs infrastructure network interface processing.
65      *
66      * @param[in]   aContext   A reference to the mainloop context.
67      *
68      */
69     void Process(const otSysMainloopContext &aContext) override;
70 
71     /**
72      * Initializes the infrastructure network interface.
73      *
74      * @note This method is called before OpenThread instance is created.
75      *
76      * @param[in]  aIfName      A pointer to infrastructure network interface name.
77      *
78      */
79     void Init(const char *aIfName);
80 
81     /**
82      * Sets up the infrastructure network interface.
83      *
84      * @note This method is called after OpenThread instance is created.
85      *
86      */
87     void SetUp(void);
88 
89     /**
90      * Tears down the infrastructure network interface.
91      *
92      * @note This method is called before OpenThread instance is destructed.
93      *
94      */
95     void TearDown(void);
96 
97     /**
98      * Deinitializes the infrastructure network interface.
99      *
100      * @note This method is called after OpenThread instance is destructed.
101      *
102      */
103     void Deinit(void);
104 
105     /**
106      * Checks whether the infrastructure network interface is running.
107      *
108      */
109     bool IsRunning(void) const;
110 
111     /**
112      * Returns the ifr_flags of the infrastructure network interface.
113      *
114      * @returns The ifr_flags of the infrastructure network interface.
115      *
116      */
117     uint32_t GetFlags(void) const;
118 
119     /**
120      * This functions counts the number of addresses on the infrastructure network interface.
121      *
122      * @param[out] aAddressCounters  The counters of addresses on infrastructure network interface.
123      *
124      */
125     void CountAddresses(otSysInfraNetIfAddressCounters &aAddressCounters) const;
126 
127     /**
128      * Sends an ICMPv6 Neighbor Discovery message on given infrastructure interface.
129      *
130      * See RFC 4861: https://tools.ietf.org/html/rfc4861.
131      *
132      * @param[in]  aInfraIfIndex  The index of the infrastructure interface this message is sent to.
133      * @param[in]  aDestAddress   The destination address this message is sent to.
134      * @param[in]  aBuffer        The ICMPv6 message buffer. The ICMPv6 checksum is left zero and the
135      *                            platform should do the checksum calculate.
136      * @param[in]  aBufferLength  The length of the message buffer.
137      *
138      * @note  Per RFC 4861, the implementation should send the message with IPv6 link-local source address
139      *        of interface @p aInfraIfIndex and IP Hop Limit 255.
140      *
141      * @retval OT_ERROR_NONE    Successfully sent the ICMPv6 message.
142      * @retval OT_ERROR_FAILED  Failed to send the ICMPv6 message.
143      *
144      */
145     otError SendIcmp6Nd(uint32_t            aInfraIfIndex,
146                         const otIp6Address &aDestAddress,
147                         const uint8_t      *aBuffer,
148                         uint16_t            aBufferLength);
149 
150     /**
151      * Sends an asynchronous address lookup for the well-known host name "ipv4only.arpa"
152      * to discover the NAT64 prefix.
153      *
154      * @param[in]  aInfraIfIndex  The index of the infrastructure interface the address look-up is sent to.
155      *
156      * @retval  OT_ERROR_NONE    Successfully request address look-up.
157      * @retval  OT_ERROR_FAILED  Failed to request address look-up.
158      *
159      */
160     otError DiscoverNat64Prefix(uint32_t aInfraIfIndex);
161 
162     /**
163      * Gets the infrastructure network interface name.
164      *
165      * @returns The infrastructure network interface name, or `nullptr` if not specified.
166      *
167      */
GetNetifName(void) const168     const char *GetNetifName(void) const { return (mInfraIfIndex != 0) ? mInfraIfName : nullptr; }
169 
170     /**
171      * Gets the infrastructure network interface singleton.
172      *
173      * @returns The singleton object.
174      *
175      */
176     static InfraNetif &Get(void);
177 
178 private:
179     static const char         kWellKnownIpv4OnlyName[];   // "ipv4only.arpa"
180     static const otIp4Address kWellKnownIpv4OnlyAddress1; // 192.0.0.170
181     static const otIp4Address kWellKnownIpv4OnlyAddress2; // 192.0.0.171
182     static const uint8_t      kValidNat64PrefixLength[];
183 
184     char     mInfraIfName[IFNAMSIZ];
185     uint32_t mInfraIfIndex       = 0;
186     int      mInfraIfIcmp6Socket = -1;
187     int      mNetLinkSocket      = -1;
188 
189     void        ReceiveNetLinkMessage(void);
190     void        ReceiveIcmp6Message(void);
191     bool        HasLinkLocalAddress(void) const;
192     static void DiscoverNat64PrefixDone(union sigval sv);
193 };
194 
195 } // namespace Posix
196 } // namespace ot
197 #endif // OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
198