1 | /**
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2 | * @file
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3 | * MDNS responder implementation
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4 | *
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5 | * @defgroup mdns MDNS
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6 | * @ingroup apps
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7 | *
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8 | * RFC 6762 - Multicast DNS\n
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9 | * RFC 6763 - DNS-Based Service Discovery\n
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10 | *
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11 | * @verbinclude mdns.txt
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12 | *
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13 | * Things left to implement:
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14 | * -------------------------
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15 | *
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16 | * - Tiebreaking for simultaneous probing
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17 | * - Sending goodbye messages (zero ttl) - shutdown, DHCP lease about to expire, DHCP turned off...
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18 | * - Checking that source address of unicast requests are on the same network
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19 | * - Limiting multicast responses to 1 per second per resource record
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20 | * - Fragmenting replies if required
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21 | * - Handling multi-packet known answers
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22 | * - Individual known answer detection for all local IPv6 addresses
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23 | * - Dynamic size of outgoing packet
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24 | */
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25 |
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26 | /*
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27 | * Copyright (c) 2015 Verisure Innovation AB
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28 | * All rights reserved.
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29 | *
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30 | * Redistribution and use in source and binary forms, with or without modification,
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31 | * are permitted provided that the following conditions are met:
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32 | *
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33 | * 1. Redistributions of source code must retain the above copyright notice,
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34 | * this list of conditions and the following disclaimer.
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35 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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36 | * this list of conditions and the following disclaimer in the documentation
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37 | * and/or other materials provided with the distribution.
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38 | * 3. The name of the author may not be used to endorse or promote products
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39 | * derived from this software without specific prior written permission.
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40 | *
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41 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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42 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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43 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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44 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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45 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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46 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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47 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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48 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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49 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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50 | * OF SUCH DAMAGE.
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51 | *
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52 | * This file is part of the lwIP TCP/IP stack.
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53 | *
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54 | * Author: Erik Ekman <erik@kryo.se>
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55 | *
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56 | */
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57 |
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58 | #include "lwip/apps/mdns.h"
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59 | #include "lwip/apps/mdns_priv.h"
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60 | #include "lwip/netif.h"
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61 | #include "lwip/udp.h"
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62 | #include "lwip/ip_addr.h"
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63 | #include "lwip/mem.h"
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64 | #include "lwip/prot/dns.h"
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65 | #include "lwip/prot/iana.h"
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66 | #include "lwip/timeouts.h"
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67 |
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68 | #include <string.h>
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69 |
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70 | #if LWIP_MDNS_RESPONDER
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71 |
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72 | #if (LWIP_IPV4 && !LWIP_IGMP)
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73 | #error "If you want to use MDNS with IPv4, you have to define LWIP_IGMP=1 in your lwipopts.h"
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74 | #endif
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75 | #if (LWIP_IPV6 && !LWIP_IPV6_MLD)
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76 | #error "If you want to use MDNS with IPv6, you have to define LWIP_IPV6_MLD=1 in your lwipopts.h"
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77 | #endif
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78 | #if (!LWIP_UDP)
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79 | #error "If you want to use MDNS, you have to define LWIP_UDP=1 in your lwipopts.h"
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80 | #endif
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81 |
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82 | #if LWIP_IPV4
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83 | #include "lwip/igmp.h"
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84 | /* IPv4 multicast group 224.0.0.251 */
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85 | static const ip_addr_t v4group = DNS_MQUERY_IPV4_GROUP_INIT;
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86 | #endif
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87 |
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88 | #if LWIP_IPV6
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89 | #include "lwip/mld6.h"
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90 | /* IPv6 multicast group FF02::FB */
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91 | static const ip_addr_t v6group = DNS_MQUERY_IPV6_GROUP_INIT;
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92 | #endif
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93 |
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94 | #define MDNS_TTL 255
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95 |
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96 | /* Stored offsets to beginning of domain names
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97 | * Used for compression.
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98 | */
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99 | #define NUM_DOMAIN_OFFSETS 10
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100 | #define DOMAIN_JUMP_SIZE 2
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101 | #define DOMAIN_JUMP 0xc000
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102 |
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103 | static u8_t mdns_netif_client_id;
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104 | static struct udp_pcb *mdns_pcb;
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105 | #if MDNS_RESP_USENETIF_EXTCALLBACK
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106 | NETIF_DECLARE_EXT_CALLBACK(netif_callback)
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107 | #endif
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108 | static mdns_name_result_cb_t mdns_name_result_cb;
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109 |
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110 | #define NETIF_TO_HOST(netif) (struct mdns_host*)(netif_get_client_data(netif, mdns_netif_client_id))
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111 |
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112 | #define TOPDOMAIN_LOCAL "local"
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113 |
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114 | #define REVERSE_PTR_TOPDOMAIN "arpa"
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115 | #define REVERSE_PTR_V4_DOMAIN "in-addr"
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116 | #define REVERSE_PTR_V6_DOMAIN "ip6"
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117 |
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118 | #define SRV_PRIORITY 0
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119 | #define SRV_WEIGHT 0
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120 |
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121 | /* Payload size allocated for each outgoing UDP packet */
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122 | #define OUTPACKET_SIZE 500
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123 |
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124 | /* Lookup from hostname -> IPv4 */
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125 | #define REPLY_HOST_A 0x01
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126 | /* Lookup from IPv4/v6 -> hostname */
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127 | #define REPLY_HOST_PTR_V4 0x02
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128 | /* Lookup from hostname -> IPv6 */
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129 | #define REPLY_HOST_AAAA 0x04
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130 | /* Lookup from hostname -> IPv6 */
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131 | #define REPLY_HOST_PTR_V6 0x08
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132 |
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133 | /* Lookup for service types */
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134 | #define REPLY_SERVICE_TYPE_PTR 0x10
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135 | /* Lookup for instances of service */
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136 | #define REPLY_SERVICE_NAME_PTR 0x20
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137 | /* Lookup for location of service instance */
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138 | #define REPLY_SERVICE_SRV 0x40
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139 | /* Lookup for text info on service instance */
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140 | #define REPLY_SERVICE_TXT 0x80
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141 |
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142 | #define MDNS_PROBE_DELAY_MS 250
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143 | #define MDNS_PROBE_COUNT 3
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144 | #ifdef LWIP_RAND
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145 | /* first probe timeout SHOULD be random 0-250 ms*/
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146 | #define MDNS_INITIAL_PROBE_DELAY_MS (LWIP_RAND() % MDNS_PROBE_DELAY_MS)
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147 | #else
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148 | #define MDNS_INITIAL_PROBE_DELAY_MS MDNS_PROBE_DELAY_MS
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149 | #endif
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150 |
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151 | #define MDNS_PROBING_NOT_STARTED 0
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152 | #define MDNS_PROBING_ONGOING 1
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153 | #define MDNS_PROBING_COMPLETE 2
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154 |
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155 | static const char *dnssd_protos[] = {
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156 | "_udp", /* DNSSD_PROTO_UDP */
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157 | "_tcp", /* DNSSD_PROTO_TCP */
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158 | };
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159 |
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160 | /** Description of a service */
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161 | struct mdns_service {
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162 | /** TXT record to answer with */
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163 | struct mdns_domain txtdata;
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164 | /** Name of service, like 'myweb' */
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165 | char name[MDNS_LABEL_MAXLEN + 1];
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166 | /** Type of service, like '_http' */
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167 | char service[MDNS_LABEL_MAXLEN + 1];
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168 | /** Callback function and userdata
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169 | * to update txtdata buffer */
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170 | service_get_txt_fn_t txt_fn;
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171 | void *txt_userdata;
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172 | /** TTL in seconds of SRV/TXT replies */
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173 | u32_t dns_ttl;
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174 | /** Protocol, TCP or UDP */
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175 | u16_t proto;
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176 | /** Port of the service */
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177 | u16_t port;
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178 | };
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179 |
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180 | /** Description of a host/netif */
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181 | struct mdns_host {
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182 | /** Hostname */
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183 | char name[MDNS_LABEL_MAXLEN + 1];
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184 | /** Pointer to services */
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185 | struct mdns_service *services[MDNS_MAX_SERVICES];
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186 | /** TTL in seconds of A/AAAA/PTR replies */
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187 | u32_t dns_ttl;
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188 | /** Number of probes sent for the current name */
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189 | u8_t probes_sent;
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190 | /** State in probing sequence */
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191 | u8_t probing_state;
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192 | };
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193 |
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194 | /** Information about received packet */
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195 | struct mdns_packet {
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196 | /** Sender IP/port */
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197 | ip_addr_t source_addr;
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198 | u16_t source_port;
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199 | /** If packet was received unicast */
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200 | u16_t recv_unicast;
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201 | /** Netif that received the packet */
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202 | struct netif *netif;
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203 | /** Packet data */
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204 | struct pbuf *pbuf;
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205 | /** Current parsing offset in packet */
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206 | u16_t parse_offset;
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207 | /** Identifier. Used in legacy queries */
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208 | u16_t tx_id;
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209 | /** Number of questions in packet,
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210 | * read from packet header */
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211 | u16_t questions;
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212 | /** Number of unparsed questions */
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213 | u16_t questions_left;
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214 | /** Number of answers in packet,
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215 | * (sum of normal, authoritative and additional answers)
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216 | * read from packet header */
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217 | u16_t answers;
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218 | /** Number of unparsed answers */
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219 | u16_t answers_left;
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220 | };
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221 |
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222 | /** Information about outgoing packet */
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223 | struct mdns_outpacket {
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224 | /** Netif to send the packet on */
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225 | struct netif *netif;
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226 | /** Packet data */
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227 | struct pbuf *pbuf;
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228 | /** Current write offset in packet */
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229 | u16_t write_offset;
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230 | /** Identifier. Used in legacy queries */
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231 | u16_t tx_id;
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232 | /** Destination IP/port if sent unicast */
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233 | ip_addr_t dest_addr;
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234 | u16_t dest_port;
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235 | /** Number of questions written */
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236 | u16_t questions;
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237 | /** Number of normal answers written */
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238 | u16_t answers;
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239 | /** Number of authoritative answers written */
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240 | u16_t authoritative;
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241 | /** Number of additional answers written */
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242 | u16_t additional;
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243 | /** Offsets for written domain names in packet.
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244 | * Used for compression */
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245 | u16_t domain_offsets[NUM_DOMAIN_OFFSETS];
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246 | /** If all answers in packet should set cache_flush bit */
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247 | u8_t cache_flush;
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248 | /** If reply should be sent unicast */
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249 | u8_t unicast_reply;
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250 | /** If legacy query. (tx_id needed, and write
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251 | * question again in reply before answer) */
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252 | u8_t legacy_query;
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253 | /* Reply bitmask for host information */
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254 | u8_t host_replies;
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255 | /* Bitmask for which reverse IPv6 hosts to answer */
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256 | u8_t host_reverse_v6_replies;
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257 | /* Reply bitmask per service */
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258 | u8_t serv_replies[MDNS_MAX_SERVICES];
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259 | };
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260 |
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261 | /** Domain, type and class.
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262 | * Shared between questions and answers */
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263 | struct mdns_rr_info {
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264 | struct mdns_domain domain;
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265 | u16_t type;
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266 | u16_t klass;
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267 | };
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268 |
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269 | struct mdns_question {
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270 | struct mdns_rr_info info;
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271 | /** unicast reply requested */
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272 | u16_t unicast;
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273 | };
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274 |
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275 | struct mdns_answer {
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276 | struct mdns_rr_info info;
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277 | /** cache flush command bit */
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278 | u16_t cache_flush;
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279 | /* Validity time in seconds */
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280 | u32_t ttl;
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281 | /** Length of variable answer */
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282 | u16_t rd_length;
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283 | /** Offset of start of variable answer in packet */
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284 | u16_t rd_offset;
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285 | };
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286 |
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287 | static err_t mdns_send_outpacket(struct mdns_outpacket *outpkt, u8_t flags);
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288 | static void mdns_probe(void* arg);
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289 |
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290 | static err_t
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291 | mdns_domain_add_label_base(struct mdns_domain *domain, u8_t len)
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292 | {
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293 | if (len > MDNS_LABEL_MAXLEN) {
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294 | return ERR_VAL;
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295 | }
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296 | if (len > 0 && (1 + len + domain->length >= MDNS_DOMAIN_MAXLEN)) {
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297 | return ERR_VAL;
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298 | }
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299 | /* Allow only zero marker on last byte */
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300 | if (len == 0 && (1 + domain->length > MDNS_DOMAIN_MAXLEN)) {
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301 | return ERR_VAL;
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302 | }
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303 | domain->name[domain->length] = len;
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304 | domain->length++;
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305 | return ERR_OK;
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306 | }
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307 |
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308 | /**
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309 | * Add a label part to a domain
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310 | * @param domain The domain to add a label to
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311 | * @param label The label to add, like <hostname>, 'local', 'com' or ''
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312 | * @param len The length of the label
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313 | * @return ERR_OK on success, an err_t otherwise if label too long
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314 | */
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315 | err_t
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316 | mdns_domain_add_label(struct mdns_domain *domain, const char *label, u8_t len)
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317 | {
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318 | err_t err = mdns_domain_add_label_base(domain, len);
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319 | if (err != ERR_OK) {
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320 | return err;
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321 | }
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322 | if (len) {
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323 | MEMCPY(&domain->name[domain->length], label, len);
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324 | domain->length += len;
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325 | }
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326 | return ERR_OK;
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327 | }
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328 |
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329 | /**
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330 | * Add a label part to a domain (@see mdns_domain_add_label but copy directly from pbuf)
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331 | */
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332 | static err_t
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333 | mdns_domain_add_label_pbuf(struct mdns_domain *domain, const struct pbuf *p, u16_t offset, u8_t len)
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334 | {
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335 | err_t err = mdns_domain_add_label_base(domain, len);
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336 | if (err != ERR_OK) {
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337 | return err;
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338 | }
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339 | if (len) {
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340 | if (pbuf_copy_partial(p, &domain->name[domain->length], len, offset) != len) {
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341 | /* take back the ++ done before */
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342 | domain->length--;
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343 | return ERR_ARG;
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344 | }
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345 | domain->length += len;
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346 | }
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347 | return ERR_OK;
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348 | }
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349 |
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350 | /**
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351 | * Internal readname function with max 6 levels of recursion following jumps
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352 | * while decompressing name
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353 | */
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354 | static u16_t
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355 | mdns_readname_loop(struct pbuf *p, u16_t offset, struct mdns_domain *domain, unsigned depth)
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356 | {
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357 | u8_t c;
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358 |
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359 | do {
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360 | if (depth > 5) {
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361 | /* Too many jumps */
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362 | return MDNS_READNAME_ERROR;
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363 | }
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364 |
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365 | c = pbuf_get_at(p, offset);
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366 | offset++;
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367 |
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368 | /* is this a compressed label? */
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369 | if ((c & 0xc0) == 0xc0) {
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370 | u16_t jumpaddr;
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371 | if (offset >= p->tot_len) {
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372 | /* Make sure both jump bytes fit in the packet */
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373 | return MDNS_READNAME_ERROR;
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374 | }
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375 | jumpaddr = (((c & 0x3f) << 8) | (pbuf_get_at(p, offset) & 0xff));
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376 | offset++;
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377 | if (jumpaddr >= SIZEOF_DNS_HDR && jumpaddr < p->tot_len) {
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378 | u16_t res;
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379 | /* Recursive call, maximum depth will be checked */
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380 | res = mdns_readname_loop(p, jumpaddr, domain, depth + 1);
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381 | /* Dont return offset since new bytes were not read (jumped to somewhere in packet) */
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382 | if (res == MDNS_READNAME_ERROR) {
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383 | return res;
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384 | }
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385 | } else {
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386 | return MDNS_READNAME_ERROR;
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387 | }
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388 | break;
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389 | }
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390 |
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391 | /* normal label */
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392 | if (c <= MDNS_LABEL_MAXLEN) {
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393 | err_t res;
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394 |
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395 | if (c + domain->length >= MDNS_DOMAIN_MAXLEN) {
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396 | return MDNS_READNAME_ERROR;
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397 | }
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398 | res = mdns_domain_add_label_pbuf(domain, p, offset, c);
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399 | if (res != ERR_OK) {
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400 | return MDNS_READNAME_ERROR;
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401 | }
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402 | offset += c;
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403 | } else {
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404 | /* bad length byte */
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405 | return MDNS_READNAME_ERROR;
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406 | }
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407 | } while (c != 0);
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408 |
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409 | return offset;
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410 | }
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411 |
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412 | /**
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413 | * Read possibly compressed domain name from packet buffer
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414 | * @param p The packet
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415 | * @param offset start position of domain name in packet
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416 | * @param domain The domain name destination
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417 | * @return The new offset after the domain, or MDNS_READNAME_ERROR
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418 | * if reading failed
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419 | */
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420 | u16_t
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421 | mdns_readname(struct pbuf *p, u16_t offset, struct mdns_domain *domain)
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422 | {
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423 | memset(domain, 0, sizeof(struct mdns_domain));
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424 | return mdns_readname_loop(p, offset, domain, 0);
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425 | }
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426 |
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427 | /**
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428 | * Print domain name to debug output
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429 | * @param domain The domain name
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430 | */
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431 | static void
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432 | mdns_domain_debug_print(struct mdns_domain *domain)
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433 | {
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434 | u8_t *src = domain->name;
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435 | u8_t i;
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436 |
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437 | while (*src) {
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438 | u8_t label_len = *src;
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439 | src++;
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440 | for (i = 0; i < label_len; i++) {
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441 | LWIP_DEBUGF(MDNS_DEBUG, ("%c", src[i]));
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442 | }
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443 | src += label_len;
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444 | LWIP_DEBUGF(MDNS_DEBUG, ("."));
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445 | }
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446 | }
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447 |
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448 | /**
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449 | * Return 1 if contents of domains match (case-insensitive)
|
---|
450 | * @param a Domain name to compare 1
|
---|
451 | * @param b Domain name to compare 2
|
---|
452 | * @return 1 if domains are equal ignoring case, 0 otherwise
|
---|
453 | */
|
---|
454 | int
|
---|
455 | mdns_domain_eq(struct mdns_domain *a, struct mdns_domain *b)
|
---|
456 | {
|
---|
457 | u8_t *ptra, *ptrb;
|
---|
458 | u8_t len;
|
---|
459 | int res;
|
---|
460 |
|
---|
461 | if (a->length != b->length) {
|
---|
462 | return 0;
|
---|
463 | }
|
---|
464 |
|
---|
465 | ptra = a->name;
|
---|
466 | ptrb = b->name;
|
---|
467 | while (*ptra && *ptrb && ptra < &a->name[a->length]) {
|
---|
468 | if (*ptra != *ptrb) {
|
---|
469 | return 0;
|
---|
470 | }
|
---|
471 | len = *ptra;
|
---|
472 | ptra++;
|
---|
473 | ptrb++;
|
---|
474 | res = lwip_strnicmp((char *) ptra, (char *) ptrb, len);
|
---|
475 | if (res != 0) {
|
---|
476 | return 0;
|
---|
477 | }
|
---|
478 | ptra += len;
|
---|
479 | ptrb += len;
|
---|
480 | }
|
---|
481 | if (*ptra != *ptrb && ptra < &a->name[a->length]) {
|
---|
482 | return 0;
|
---|
483 | }
|
---|
484 | return 1;
|
---|
485 | }
|
---|
486 |
|
---|
487 | /**
|
---|
488 | * Call user supplied function to setup TXT data
|
---|
489 | * @param service The service to build TXT record for
|
---|
490 | */
|
---|
491 | static void
|
---|
492 | mdns_prepare_txtdata(struct mdns_service *service)
|
---|
493 | {
|
---|
494 | memset(&service->txtdata, 0, sizeof(struct mdns_domain));
|
---|
495 | if (service->txt_fn) {
|
---|
496 | service->txt_fn(service, service->txt_userdata);
|
---|
497 | }
|
---|
498 | }
|
---|
499 |
|
---|
500 | #if LWIP_IPV4
|
---|
501 | /**
|
---|
502 | * Build domain for reverse lookup of IPv4 address
|
---|
503 | * like 12.0.168.192.in-addr.arpa. for 192.168.0.12
|
---|
504 | * @param domain Where to write the domain name
|
---|
505 | * @param addr Pointer to an IPv4 address to encode
|
---|
506 | * @return ERR_OK if domain was written, an err_t otherwise
|
---|
507 | */
|
---|
508 | static err_t
|
---|
509 | mdns_build_reverse_v4_domain(struct mdns_domain *domain, const ip4_addr_t *addr)
|
---|
510 | {
|
---|
511 | int i;
|
---|
512 | err_t res;
|
---|
513 | const u8_t *ptr;
|
---|
514 |
|
---|
515 | LWIP_UNUSED_ARG(res);
|
---|
516 | if (!domain || !addr) {
|
---|
517 | return ERR_ARG;
|
---|
518 | }
|
---|
519 | memset(domain, 0, sizeof(struct mdns_domain));
|
---|
520 | ptr = (const u8_t *) addr;
|
---|
521 | for (i = sizeof(ip4_addr_t) - 1; i >= 0; i--) {
|
---|
522 | char buf[4];
|
---|
523 | u8_t val = ptr[i];
|
---|
524 |
|
---|
525 | lwip_itoa(buf, sizeof(buf), val);
|
---|
526 | res = mdns_domain_add_label(domain, buf, (u8_t)strlen(buf));
|
---|
527 | LWIP_ERROR("mdns_build_reverse_v4_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
528 | }
|
---|
529 | res = mdns_domain_add_label(domain, REVERSE_PTR_V4_DOMAIN, (u8_t)(sizeof(REVERSE_PTR_V4_DOMAIN) - 1));
|
---|
530 | LWIP_ERROR("mdns_build_reverse_v4_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
531 | res = mdns_domain_add_label(domain, REVERSE_PTR_TOPDOMAIN, (u8_t)(sizeof(REVERSE_PTR_TOPDOMAIN) - 1));
|
---|
532 | LWIP_ERROR("mdns_build_reverse_v4_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
533 | res = mdns_domain_add_label(domain, NULL, 0);
|
---|
534 | LWIP_ERROR("mdns_build_reverse_v4_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
535 |
|
---|
536 | return ERR_OK;
|
---|
537 | }
|
---|
538 | #endif
|
---|
539 |
|
---|
540 | #if LWIP_IPV6
|
---|
541 | /**
|
---|
542 | * Build domain for reverse lookup of IP address
|
---|
543 | * like b.a.9.8.7.6.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. for 2001:db8::567:89ab
|
---|
544 | * @param domain Where to write the domain name
|
---|
545 | * @param addr Pointer to an IPv6 address to encode
|
---|
546 | * @return ERR_OK if domain was written, an err_t otherwise
|
---|
547 | */
|
---|
548 | static err_t
|
---|
549 | mdns_build_reverse_v6_domain(struct mdns_domain *domain, const ip6_addr_t *addr)
|
---|
550 | {
|
---|
551 | int i;
|
---|
552 | err_t res;
|
---|
553 | const u8_t *ptr;
|
---|
554 | LWIP_UNUSED_ARG(res);
|
---|
555 | if (!domain || !addr) {
|
---|
556 | return ERR_ARG;
|
---|
557 | }
|
---|
558 | memset(domain, 0, sizeof(struct mdns_domain));
|
---|
559 | ptr = (const u8_t *) addr;
|
---|
560 | for (i = sizeof(ip6_addr_p_t) - 1; i >= 0; i--) {
|
---|
561 | char buf;
|
---|
562 | u8_t byte = ptr[i];
|
---|
563 | int j;
|
---|
564 | for (j = 0; j < 2; j++) {
|
---|
565 | if ((byte & 0x0F) < 0xA) {
|
---|
566 | buf = '0' + (byte & 0x0F);
|
---|
567 | } else {
|
---|
568 | buf = 'a' + (byte & 0x0F) - 0xA;
|
---|
569 | }
|
---|
570 | res = mdns_domain_add_label(domain, &buf, sizeof(buf));
|
---|
571 | LWIP_ERROR("mdns_build_reverse_v6_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
572 | byte >>= 4;
|
---|
573 | }
|
---|
574 | }
|
---|
575 | res = mdns_domain_add_label(domain, REVERSE_PTR_V6_DOMAIN, (u8_t)(sizeof(REVERSE_PTR_V6_DOMAIN) - 1));
|
---|
576 | LWIP_ERROR("mdns_build_reverse_v6_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
577 | res = mdns_domain_add_label(domain, REVERSE_PTR_TOPDOMAIN, (u8_t)(sizeof(REVERSE_PTR_TOPDOMAIN) - 1));
|
---|
578 | LWIP_ERROR("mdns_build_reverse_v6_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
579 | res = mdns_domain_add_label(domain, NULL, 0);
|
---|
580 | LWIP_ERROR("mdns_build_reverse_v6_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
581 |
|
---|
582 | return ERR_OK;
|
---|
583 | }
|
---|
584 | #endif
|
---|
585 |
|
---|
586 | /* Add .local. to domain */
|
---|
587 | static err_t
|
---|
588 | mdns_add_dotlocal(struct mdns_domain *domain)
|
---|
589 | {
|
---|
590 | err_t res = mdns_domain_add_label(domain, TOPDOMAIN_LOCAL, (u8_t)(sizeof(TOPDOMAIN_LOCAL) - 1));
|
---|
591 | LWIP_UNUSED_ARG(res);
|
---|
592 | LWIP_ERROR("mdns_add_dotlocal: Failed to add label", (res == ERR_OK), return res);
|
---|
593 | return mdns_domain_add_label(domain, NULL, 0);
|
---|
594 | }
|
---|
595 |
|
---|
596 | /**
|
---|
597 | * Build the <hostname>.local. domain name
|
---|
598 | * @param domain Where to write the domain name
|
---|
599 | * @param mdns TMDNS netif descriptor.
|
---|
600 | * @return ERR_OK if domain <hostname>.local. was written, an err_t otherwise
|
---|
601 | */
|
---|
602 | static err_t
|
---|
603 | mdns_build_host_domain(struct mdns_domain *domain, struct mdns_host *mdns)
|
---|
604 | {
|
---|
605 | err_t res;
|
---|
606 | LWIP_UNUSED_ARG(res);
|
---|
607 | memset(domain, 0, sizeof(struct mdns_domain));
|
---|
608 | LWIP_ERROR("mdns_build_host_domain: mdns != NULL", (mdns != NULL), return ERR_VAL);
|
---|
609 | res = mdns_domain_add_label(domain, mdns->name, (u8_t)strlen(mdns->name));
|
---|
610 | LWIP_ERROR("mdns_build_host_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
611 | return mdns_add_dotlocal(domain);
|
---|
612 | }
|
---|
613 |
|
---|
614 | /**
|
---|
615 | * Build the lookup-all-services special DNS-SD domain name
|
---|
616 | * @param domain Where to write the domain name
|
---|
617 | * @return ERR_OK if domain _services._dns-sd._udp.local. was written, an err_t otherwise
|
---|
618 | */
|
---|
619 | static err_t
|
---|
620 | mdns_build_dnssd_domain(struct mdns_domain *domain)
|
---|
621 | {
|
---|
622 | err_t res;
|
---|
623 | LWIP_UNUSED_ARG(res);
|
---|
624 | memset(domain, 0, sizeof(struct mdns_domain));
|
---|
625 | res = mdns_domain_add_label(domain, "_services", (u8_t)(sizeof("_services") - 1));
|
---|
626 | LWIP_ERROR("mdns_build_dnssd_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
627 | res = mdns_domain_add_label(domain, "_dns-sd", (u8_t)(sizeof("_dns-sd") - 1));
|
---|
628 | LWIP_ERROR("mdns_build_dnssd_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
629 | res = mdns_domain_add_label(domain, dnssd_protos[DNSSD_PROTO_UDP], (u8_t)strlen(dnssd_protos[DNSSD_PROTO_UDP]));
|
---|
630 | LWIP_ERROR("mdns_build_dnssd_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
631 | return mdns_add_dotlocal(domain);
|
---|
632 | }
|
---|
633 |
|
---|
634 | /**
|
---|
635 | * Build domain name for a service
|
---|
636 | * @param domain Where to write the domain name
|
---|
637 | * @param service The service struct, containing service name, type and protocol
|
---|
638 | * @param include_name Whether to include the service name in the domain
|
---|
639 | * @return ERR_OK if domain was written. If service name is included,
|
---|
640 | * <name>.<type>.<proto>.local. will be written, otherwise <type>.<proto>.local.
|
---|
641 | * An err_t is returned on error.
|
---|
642 | */
|
---|
643 | static err_t
|
---|
644 | mdns_build_service_domain(struct mdns_domain *domain, struct mdns_service *service, int include_name)
|
---|
645 | {
|
---|
646 | err_t res;
|
---|
647 | LWIP_UNUSED_ARG(res);
|
---|
648 | memset(domain, 0, sizeof(struct mdns_domain));
|
---|
649 | if (include_name) {
|
---|
650 | res = mdns_domain_add_label(domain, service->name, (u8_t)strlen(service->name));
|
---|
651 | LWIP_ERROR("mdns_build_service_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
652 | }
|
---|
653 | res = mdns_domain_add_label(domain, service->service, (u8_t)strlen(service->service));
|
---|
654 | LWIP_ERROR("mdns_build_service_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
655 | res = mdns_domain_add_label(domain, dnssd_protos[service->proto], (u8_t)strlen(dnssd_protos[service->proto]));
|
---|
656 | LWIP_ERROR("mdns_build_service_domain: Failed to add label", (res == ERR_OK), return res);
|
---|
657 | return mdns_add_dotlocal(domain);
|
---|
658 | }
|
---|
659 |
|
---|
660 | /**
|
---|
661 | * Check which replies we should send for a host/netif based on question
|
---|
662 | * @param netif The network interface that received the question
|
---|
663 | * @param rr Domain/type/class from a question
|
---|
664 | * @param reverse_v6_reply Bitmask of which IPv6 addresses to send reverse PTRs for
|
---|
665 | * if reply bit has REPLY_HOST_PTR_V6 set
|
---|
666 | * @return Bitmask of which replies to send
|
---|
667 | */
|
---|
668 | static int
|
---|
669 | check_host(struct netif *netif, struct mdns_rr_info *rr, u8_t *reverse_v6_reply)
|
---|
670 | {
|
---|
671 | err_t res;
|
---|
672 | int replies = 0;
|
---|
673 | struct mdns_domain mydomain;
|
---|
674 |
|
---|
675 | LWIP_UNUSED_ARG(reverse_v6_reply); /* if ipv6 is disabled */
|
---|
676 |
|
---|
677 | if (rr->klass != DNS_RRCLASS_IN && rr->klass != DNS_RRCLASS_ANY) {
|
---|
678 | /* Invalid class */
|
---|
679 | return replies;
|
---|
680 | }
|
---|
681 |
|
---|
682 | /* Handle PTR for our addresses */
|
---|
683 | if (rr->type == DNS_RRTYPE_PTR || rr->type == DNS_RRTYPE_ANY) {
|
---|
684 | #if LWIP_IPV6
|
---|
685 | int i;
|
---|
686 | for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
|
---|
687 | if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i))) {
|
---|
688 | res = mdns_build_reverse_v6_domain(&mydomain, netif_ip6_addr(netif, i));
|
---|
689 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain)) {
|
---|
690 | replies |= REPLY_HOST_PTR_V6;
|
---|
691 | /* Mark which addresses where requested */
|
---|
692 | if (reverse_v6_reply) {
|
---|
693 | *reverse_v6_reply |= (1 << i);
|
---|
694 | }
|
---|
695 | }
|
---|
696 | }
|
---|
697 | }
|
---|
698 | #endif
|
---|
699 | #if LWIP_IPV4
|
---|
700 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif))) {
|
---|
701 | res = mdns_build_reverse_v4_domain(&mydomain, netif_ip4_addr(netif));
|
---|
702 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain)) {
|
---|
703 | replies |= REPLY_HOST_PTR_V4;
|
---|
704 | }
|
---|
705 | }
|
---|
706 | #endif
|
---|
707 | }
|
---|
708 |
|
---|
709 | res = mdns_build_host_domain(&mydomain, NETIF_TO_HOST(netif));
|
---|
710 | /* Handle requests for our hostname */
|
---|
711 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain)) {
|
---|
712 | /* TODO return NSEC if unsupported protocol requested */
|
---|
713 | #if LWIP_IPV4
|
---|
714 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif))
|
---|
715 | && (rr->type == DNS_RRTYPE_A || rr->type == DNS_RRTYPE_ANY)) {
|
---|
716 | replies |= REPLY_HOST_A;
|
---|
717 | }
|
---|
718 | #endif
|
---|
719 | #if LWIP_IPV6
|
---|
720 | if (rr->type == DNS_RRTYPE_AAAA || rr->type == DNS_RRTYPE_ANY) {
|
---|
721 | replies |= REPLY_HOST_AAAA;
|
---|
722 | }
|
---|
723 | #endif
|
---|
724 | }
|
---|
725 |
|
---|
726 | return replies;
|
---|
727 | }
|
---|
728 |
|
---|
729 | /**
|
---|
730 | * Check which replies we should send for a service based on question
|
---|
731 | * @param service A registered MDNS service
|
---|
732 | * @param rr Domain/type/class from a question
|
---|
733 | * @return Bitmask of which replies to send
|
---|
734 | */
|
---|
735 | static int
|
---|
736 | check_service(struct mdns_service *service, struct mdns_rr_info *rr)
|
---|
737 | {
|
---|
738 | err_t res;
|
---|
739 | int replies = 0;
|
---|
740 | struct mdns_domain mydomain;
|
---|
741 |
|
---|
742 | if (rr->klass != DNS_RRCLASS_IN && rr->klass != DNS_RRCLASS_ANY) {
|
---|
743 | /* Invalid class */
|
---|
744 | return 0;
|
---|
745 | }
|
---|
746 |
|
---|
747 | res = mdns_build_dnssd_domain(&mydomain);
|
---|
748 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain) &&
|
---|
749 | (rr->type == DNS_RRTYPE_PTR || rr->type == DNS_RRTYPE_ANY)) {
|
---|
750 | /* Request for all service types */
|
---|
751 | replies |= REPLY_SERVICE_TYPE_PTR;
|
---|
752 | }
|
---|
753 |
|
---|
754 | res = mdns_build_service_domain(&mydomain, service, 0);
|
---|
755 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain) &&
|
---|
756 | (rr->type == DNS_RRTYPE_PTR || rr->type == DNS_RRTYPE_ANY)) {
|
---|
757 | /* Request for the instance of my service */
|
---|
758 | replies |= REPLY_SERVICE_NAME_PTR;
|
---|
759 | }
|
---|
760 |
|
---|
761 | res = mdns_build_service_domain(&mydomain, service, 1);
|
---|
762 | if (res == ERR_OK && mdns_domain_eq(&rr->domain, &mydomain)) {
|
---|
763 | /* Request for info about my service */
|
---|
764 | if (rr->type == DNS_RRTYPE_SRV || rr->type == DNS_RRTYPE_ANY) {
|
---|
765 | replies |= REPLY_SERVICE_SRV;
|
---|
766 | }
|
---|
767 | if (rr->type == DNS_RRTYPE_TXT || rr->type == DNS_RRTYPE_ANY) {
|
---|
768 | replies |= REPLY_SERVICE_TXT;
|
---|
769 | }
|
---|
770 | }
|
---|
771 |
|
---|
772 | return replies;
|
---|
773 | }
|
---|
774 |
|
---|
775 | /**
|
---|
776 | * Return bytes needed to write before jump for best result of compressing supplied domain
|
---|
777 | * against domain in outpacket starting at specified offset.
|
---|
778 | * If a match is found, offset is updated to where to jump to
|
---|
779 | * @param pbuf Pointer to pbuf with the partially constructed DNS packet
|
---|
780 | * @param offset Start position of a domain written earlier. If this location is suitable
|
---|
781 | * for compression, the pointer is updated to where in the domain to jump to.
|
---|
782 | * @param domain The domain to write
|
---|
783 | * @return Number of bytes to write of the new domain before writing a jump to the offset.
|
---|
784 | * If compression can not be done against this previous domain name, the full new
|
---|
785 | * domain length is returned.
|
---|
786 | */
|
---|
787 | u16_t
|
---|
788 | mdns_compress_domain(struct pbuf *pbuf, u16_t *offset, struct mdns_domain *domain)
|
---|
789 | {
|
---|
790 | struct mdns_domain target;
|
---|
791 | u16_t target_end;
|
---|
792 | u8_t target_len;
|
---|
793 | u8_t writelen = 0;
|
---|
794 | u8_t *ptr;
|
---|
795 | if (pbuf == NULL) {
|
---|
796 | return domain->length;
|
---|
797 | }
|
---|
798 | target_end = mdns_readname(pbuf, *offset, &target);
|
---|
799 | if (target_end == MDNS_READNAME_ERROR) {
|
---|
800 | return domain->length;
|
---|
801 | }
|
---|
802 | target_len = (u8_t)(target_end - *offset);
|
---|
803 | ptr = domain->name;
|
---|
804 | while (writelen < domain->length) {
|
---|
805 | u8_t domainlen = (u8_t)(domain->length - writelen);
|
---|
806 | u8_t labellen;
|
---|
807 | if (domainlen <= target.length && domainlen > DOMAIN_JUMP_SIZE) {
|
---|
808 | /* Compare domains if target is long enough, and we have enough left of the domain */
|
---|
809 | u8_t targetpos = (u8_t)(target.length - domainlen);
|
---|
810 | if ((targetpos + DOMAIN_JUMP_SIZE) >= target_len) {
|
---|
811 | /* We are checking at or beyond a jump in the original, stop looking */
|
---|
812 | break;
|
---|
813 | }
|
---|
814 | if (target.length >= domainlen &&
|
---|
815 | memcmp(&domain->name[writelen], &target.name[targetpos], domainlen) == 0) {
|
---|
816 | *offset += targetpos;
|
---|
817 | return writelen;
|
---|
818 | }
|
---|
819 | }
|
---|
820 | /* Skip to next label in domain */
|
---|
821 | labellen = *ptr;
|
---|
822 | writelen += 1 + labellen;
|
---|
823 | ptr += 1 + labellen;
|
---|
824 | }
|
---|
825 | /* Nothing found */
|
---|
826 | return domain->length;
|
---|
827 | }
|
---|
828 |
|
---|
829 | /**
|
---|
830 | * Write domain to outpacket. Compression will be attempted,
|
---|
831 | * unless domain->skip_compression is set.
|
---|
832 | * @param outpkt The outpacket to write to
|
---|
833 | * @param domain The domain name to write
|
---|
834 | * @return ERR_OK on success, an err_t otherwise
|
---|
835 | */
|
---|
836 | static err_t
|
---|
837 | mdns_write_domain(struct mdns_outpacket *outpkt, struct mdns_domain *domain)
|
---|
838 | {
|
---|
839 | int i;
|
---|
840 | err_t res;
|
---|
841 | u16_t writelen = domain->length;
|
---|
842 | u16_t jump_offset = 0;
|
---|
843 | u16_t jump;
|
---|
844 |
|
---|
845 | if (!domain->skip_compression) {
|
---|
846 | for (i = 0; i < NUM_DOMAIN_OFFSETS; i++) {
|
---|
847 | u16_t offset = outpkt->domain_offsets[i];
|
---|
848 | if (offset) {
|
---|
849 | u16_t len = mdns_compress_domain(outpkt->pbuf, &offset, domain);
|
---|
850 | if (len < writelen) {
|
---|
851 | writelen = len;
|
---|
852 | jump_offset = offset;
|
---|
853 | }
|
---|
854 | }
|
---|
855 | }
|
---|
856 | }
|
---|
857 |
|
---|
858 | if (writelen) {
|
---|
859 | /* Write uncompressed part of name */
|
---|
860 | res = pbuf_take_at(outpkt->pbuf, domain->name, writelen, outpkt->write_offset);
|
---|
861 | if (res != ERR_OK) {
|
---|
862 | return res;
|
---|
863 | }
|
---|
864 |
|
---|
865 | /* Store offset of this new domain */
|
---|
866 | for (i = 0; i < NUM_DOMAIN_OFFSETS; i++) {
|
---|
867 | if (outpkt->domain_offsets[i] == 0) {
|
---|
868 | outpkt->domain_offsets[i] = outpkt->write_offset;
|
---|
869 | break;
|
---|
870 | }
|
---|
871 | }
|
---|
872 |
|
---|
873 | outpkt->write_offset += writelen;
|
---|
874 | }
|
---|
875 | if (jump_offset) {
|
---|
876 | /* Write jump */
|
---|
877 | jump = lwip_htons(DOMAIN_JUMP | jump_offset);
|
---|
878 | res = pbuf_take_at(outpkt->pbuf, &jump, DOMAIN_JUMP_SIZE, outpkt->write_offset);
|
---|
879 | if (res != ERR_OK) {
|
---|
880 | return res;
|
---|
881 | }
|
---|
882 | outpkt->write_offset += DOMAIN_JUMP_SIZE;
|
---|
883 | }
|
---|
884 | return ERR_OK;
|
---|
885 | }
|
---|
886 |
|
---|
887 | /**
|
---|
888 | * Write a question to an outpacket
|
---|
889 | * A question contains domain, type and class. Since an answer also starts with these fields this function is also
|
---|
890 | * called from mdns_add_answer().
|
---|
891 | * @param outpkt The outpacket to write to
|
---|
892 | * @param domain The domain name the answer is for
|
---|
893 | * @param type The DNS type of the answer (like 'AAAA', 'SRV')
|
---|
894 | * @param klass The DNS type of the answer (like 'IN')
|
---|
895 | * @param unicast If highest bit in class should be set, to instruct the responder to
|
---|
896 | * reply with a unicast packet
|
---|
897 | * @return ERR_OK on success, an err_t otherwise
|
---|
898 | */
|
---|
899 | static err_t
|
---|
900 | mdns_add_question(struct mdns_outpacket *outpkt, struct mdns_domain *domain, u16_t type, u16_t klass, u16_t unicast)
|
---|
901 | {
|
---|
902 | u16_t question_len;
|
---|
903 | u16_t field16;
|
---|
904 | err_t res;
|
---|
905 |
|
---|
906 | if (!outpkt->pbuf) {
|
---|
907 | /* If no pbuf is active, allocate one */
|
---|
908 | outpkt->pbuf = pbuf_alloc(PBUF_TRANSPORT, OUTPACKET_SIZE, PBUF_RAM);
|
---|
909 | if (!outpkt->pbuf) {
|
---|
910 | return ERR_MEM;
|
---|
911 | }
|
---|
912 | outpkt->write_offset = SIZEOF_DNS_HDR;
|
---|
913 | }
|
---|
914 |
|
---|
915 | /* Worst case calculation. Domain string might be compressed */
|
---|
916 | question_len = domain->length + sizeof(type) + sizeof(klass);
|
---|
917 | if (outpkt->write_offset + question_len > outpkt->pbuf->tot_len) {
|
---|
918 | /* No space */
|
---|
919 | return ERR_MEM;
|
---|
920 | }
|
---|
921 |
|
---|
922 | /* Write name */
|
---|
923 | res = mdns_write_domain(outpkt, domain);
|
---|
924 | if (res != ERR_OK) {
|
---|
925 | return res;
|
---|
926 | }
|
---|
927 |
|
---|
928 | /* Write type */
|
---|
929 | field16 = lwip_htons(type);
|
---|
930 | res = pbuf_take_at(outpkt->pbuf, &field16, sizeof(field16), outpkt->write_offset);
|
---|
931 | if (res != ERR_OK) {
|
---|
932 | return res;
|
---|
933 | }
|
---|
934 | outpkt->write_offset += sizeof(field16);
|
---|
935 |
|
---|
936 | /* Write class */
|
---|
937 | if (unicast) {
|
---|
938 | klass |= 0x8000;
|
---|
939 | }
|
---|
940 | field16 = lwip_htons(klass);
|
---|
941 | res = pbuf_take_at(outpkt->pbuf, &field16, sizeof(field16), outpkt->write_offset);
|
---|
942 | if (res != ERR_OK) {
|
---|
943 | return res;
|
---|
944 | }
|
---|
945 | outpkt->write_offset += sizeof(field16);
|
---|
946 |
|
---|
947 | return ERR_OK;
|
---|
948 | }
|
---|
949 |
|
---|
950 | /**
|
---|
951 | * Write answer to reply packet.
|
---|
952 | * buf or answer_domain can be null. The rd_length written will be buf_length +
|
---|
953 | * size of (compressed) domain. Most uses will need either buf or answer_domain,
|
---|
954 | * special case is SRV that starts with 3 u16 and then a domain name.
|
---|
955 | * @param reply The outpacket to write to
|
---|
956 | * @param domain The domain name the answer is for
|
---|
957 | * @param type The DNS type of the answer (like 'AAAA', 'SRV')
|
---|
958 | * @param klass The DNS type of the answer (like 'IN')
|
---|
959 | * @param cache_flush If highest bit in class should be set, to instruct receiver that
|
---|
960 | * this reply replaces any earlier answer for this domain/type/class
|
---|
961 | * @param ttl Validity time in seconds to send out for IP address data in DNS replies
|
---|
962 | * @param buf Pointer to buffer of answer data
|
---|
963 | * @param buf_length Length of variable data
|
---|
964 | * @param answer_domain A domain to write after any buffer data as answer
|
---|
965 | * @return ERR_OK on success, an err_t otherwise
|
---|
966 | */
|
---|
967 | static err_t
|
---|
968 | mdns_add_answer(struct mdns_outpacket *reply, struct mdns_domain *domain, u16_t type, u16_t klass, u16_t cache_flush,
|
---|
969 | u32_t ttl, const u8_t *buf, size_t buf_length, struct mdns_domain *answer_domain)
|
---|
970 | {
|
---|
971 | u16_t answer_len;
|
---|
972 | u16_t field16;
|
---|
973 | u16_t rdlen_offset;
|
---|
974 | u16_t answer_offset;
|
---|
975 | u32_t field32;
|
---|
976 | err_t res;
|
---|
977 |
|
---|
978 | if (!reply->pbuf) {
|
---|
979 | /* If no pbuf is active, allocate one */
|
---|
980 | reply->pbuf = pbuf_alloc(PBUF_TRANSPORT, OUTPACKET_SIZE, PBUF_RAM);
|
---|
981 | if (!reply->pbuf) {
|
---|
982 | return ERR_MEM;
|
---|
983 | }
|
---|
984 | reply->write_offset = SIZEOF_DNS_HDR;
|
---|
985 | }
|
---|
986 |
|
---|
987 | /* Worst case calculation. Domain strings might be compressed */
|
---|
988 | answer_len = domain->length + sizeof(type) + sizeof(klass) + sizeof(ttl) + sizeof(field16)/*rd_length*/;
|
---|
989 | if (buf) {
|
---|
990 | answer_len += (u16_t)buf_length;
|
---|
991 | }
|
---|
992 | if (answer_domain) {
|
---|
993 | answer_len += answer_domain->length;
|
---|
994 | }
|
---|
995 | if (reply->write_offset + answer_len > reply->pbuf->tot_len) {
|
---|
996 | /* No space */
|
---|
997 | return ERR_MEM;
|
---|
998 | }
|
---|
999 |
|
---|
1000 | /* Answer starts with same data as question, then more fields */
|
---|
1001 | mdns_add_question(reply, domain, type, klass, cache_flush);
|
---|
1002 |
|
---|
1003 | /* Write TTL */
|
---|
1004 | field32 = lwip_htonl(ttl);
|
---|
1005 | res = pbuf_take_at(reply->pbuf, &field32, sizeof(field32), reply->write_offset);
|
---|
1006 | if (res != ERR_OK) {
|
---|
1007 | return res;
|
---|
1008 | }
|
---|
1009 | reply->write_offset += sizeof(field32);
|
---|
1010 |
|
---|
1011 | /* Store offsets and skip forward to the data */
|
---|
1012 | rdlen_offset = reply->write_offset;
|
---|
1013 | reply->write_offset += sizeof(field16);
|
---|
1014 | answer_offset = reply->write_offset;
|
---|
1015 |
|
---|
1016 | if (buf) {
|
---|
1017 | /* Write static data */
|
---|
1018 | res = pbuf_take_at(reply->pbuf, buf, (u16_t)buf_length, reply->write_offset);
|
---|
1019 | if (res != ERR_OK) {
|
---|
1020 | return res;
|
---|
1021 | }
|
---|
1022 | reply->write_offset += (u16_t)buf_length;
|
---|
1023 | }
|
---|
1024 |
|
---|
1025 | if (answer_domain) {
|
---|
1026 | /* Write name answer (compressed if possible) */
|
---|
1027 | res = mdns_write_domain(reply, answer_domain);
|
---|
1028 | if (res != ERR_OK) {
|
---|
1029 | return res;
|
---|
1030 | }
|
---|
1031 | }
|
---|
1032 |
|
---|
1033 | /* Write rd_length after when we know the answer size */
|
---|
1034 | field16 = lwip_htons(reply->write_offset - answer_offset);
|
---|
1035 | res = pbuf_take_at(reply->pbuf, &field16, sizeof(field16), rdlen_offset);
|
---|
1036 |
|
---|
1037 | return res;
|
---|
1038 | }
|
---|
1039 |
|
---|
1040 | /**
|
---|
1041 | * Helper function for mdns_read_question/mdns_read_answer
|
---|
1042 | * Reads a domain, type and class from the packet
|
---|
1043 | * @param pkt The MDNS packet to read from. The parse_offset field will be
|
---|
1044 | * incremented to point to the next unparsed byte.
|
---|
1045 | * @param info The struct to fill with domain, type and class
|
---|
1046 | * @return ERR_OK on success, an err_t otherwise
|
---|
1047 | */
|
---|
1048 | static err_t
|
---|
1049 | mdns_read_rr_info(struct mdns_packet *pkt, struct mdns_rr_info *info)
|
---|
1050 | {
|
---|
1051 | u16_t field16, copied;
|
---|
1052 | pkt->parse_offset = mdns_readname(pkt->pbuf, pkt->parse_offset, &info->domain);
|
---|
1053 | if (pkt->parse_offset == MDNS_READNAME_ERROR) {
|
---|
1054 | return ERR_VAL;
|
---|
1055 | }
|
---|
1056 |
|
---|
1057 | copied = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), pkt->parse_offset);
|
---|
1058 | if (copied != sizeof(field16)) {
|
---|
1059 | return ERR_VAL;
|
---|
1060 | }
|
---|
1061 | pkt->parse_offset += copied;
|
---|
1062 | info->type = lwip_ntohs(field16);
|
---|
1063 |
|
---|
1064 | copied = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), pkt->parse_offset);
|
---|
1065 | if (copied != sizeof(field16)) {
|
---|
1066 | return ERR_VAL;
|
---|
1067 | }
|
---|
1068 | pkt->parse_offset += copied;
|
---|
1069 | info->klass = lwip_ntohs(field16);
|
---|
1070 |
|
---|
1071 | return ERR_OK;
|
---|
1072 | }
|
---|
1073 |
|
---|
1074 | /**
|
---|
1075 | * Read a question from the packet.
|
---|
1076 | * All questions have to be read before the answers.
|
---|
1077 | * @param pkt The MDNS packet to read from. The questions_left field will be decremented
|
---|
1078 | * and the parse_offset will be updated.
|
---|
1079 | * @param question The struct to fill with question data
|
---|
1080 | * @return ERR_OK on success, an err_t otherwise
|
---|
1081 | */
|
---|
1082 | static err_t
|
---|
1083 | mdns_read_question(struct mdns_packet *pkt, struct mdns_question *question)
|
---|
1084 | {
|
---|
1085 | /* Safety check */
|
---|
1086 | if (pkt->pbuf->tot_len < pkt->parse_offset) {
|
---|
1087 | return ERR_VAL;
|
---|
1088 | }
|
---|
1089 |
|
---|
1090 | if (pkt->questions_left) {
|
---|
1091 | err_t res;
|
---|
1092 | pkt->questions_left--;
|
---|
1093 |
|
---|
1094 | memset(question, 0, sizeof(struct mdns_question));
|
---|
1095 | res = mdns_read_rr_info(pkt, &question->info);
|
---|
1096 | if (res != ERR_OK) {
|
---|
1097 | return res;
|
---|
1098 | }
|
---|
1099 |
|
---|
1100 | /* Extract unicast flag from class field */
|
---|
1101 | question->unicast = question->info.klass & 0x8000;
|
---|
1102 | question->info.klass &= 0x7FFF;
|
---|
1103 |
|
---|
1104 | return ERR_OK;
|
---|
1105 | }
|
---|
1106 | return ERR_VAL;
|
---|
1107 | }
|
---|
1108 |
|
---|
1109 | /**
|
---|
1110 | * Read an answer from the packet
|
---|
1111 | * The variable length reply is not copied, its pbuf offset and length is stored instead.
|
---|
1112 | * @param pkt The MDNS packet to read. The answers_left field will be decremented and
|
---|
1113 | * the parse_offset will be updated.
|
---|
1114 | * @param answer The struct to fill with answer data
|
---|
1115 | * @return ERR_OK on success, an err_t otherwise
|
---|
1116 | */
|
---|
1117 | static err_t
|
---|
1118 | mdns_read_answer(struct mdns_packet *pkt, struct mdns_answer *answer)
|
---|
1119 | {
|
---|
1120 | /* Read questions first */
|
---|
1121 | if (pkt->questions_left) {
|
---|
1122 | return ERR_VAL;
|
---|
1123 | }
|
---|
1124 |
|
---|
1125 | /* Safety check */
|
---|
1126 | if (pkt->pbuf->tot_len < pkt->parse_offset) {
|
---|
1127 | return ERR_VAL;
|
---|
1128 | }
|
---|
1129 |
|
---|
1130 | if (pkt->answers_left) {
|
---|
1131 | u16_t copied, field16;
|
---|
1132 | u32_t ttl;
|
---|
1133 | err_t res;
|
---|
1134 | pkt->answers_left--;
|
---|
1135 |
|
---|
1136 | memset(answer, 0, sizeof(struct mdns_answer));
|
---|
1137 | res = mdns_read_rr_info(pkt, &answer->info);
|
---|
1138 | if (res != ERR_OK) {
|
---|
1139 | return res;
|
---|
1140 | }
|
---|
1141 |
|
---|
1142 | /* Extract cache_flush flag from class field */
|
---|
1143 | answer->cache_flush = answer->info.klass & 0x8000;
|
---|
1144 | answer->info.klass &= 0x7FFF;
|
---|
1145 |
|
---|
1146 | copied = pbuf_copy_partial(pkt->pbuf, &ttl, sizeof(ttl), pkt->parse_offset);
|
---|
1147 | if (copied != sizeof(ttl)) {
|
---|
1148 | return ERR_VAL;
|
---|
1149 | }
|
---|
1150 | pkt->parse_offset += copied;
|
---|
1151 | answer->ttl = lwip_ntohl(ttl);
|
---|
1152 |
|
---|
1153 | copied = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), pkt->parse_offset);
|
---|
1154 | if (copied != sizeof(field16)) {
|
---|
1155 | return ERR_VAL;
|
---|
1156 | }
|
---|
1157 | pkt->parse_offset += copied;
|
---|
1158 | answer->rd_length = lwip_ntohs(field16);
|
---|
1159 |
|
---|
1160 | answer->rd_offset = pkt->parse_offset;
|
---|
1161 | pkt->parse_offset += answer->rd_length;
|
---|
1162 |
|
---|
1163 | return ERR_OK;
|
---|
1164 | }
|
---|
1165 | return ERR_VAL;
|
---|
1166 | }
|
---|
1167 |
|
---|
1168 | #if LWIP_IPV4
|
---|
1169 | /** Write an IPv4 address (A) RR to outpacket */
|
---|
1170 | static err_t
|
---|
1171 | mdns_add_a_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct netif *netif)
|
---|
1172 | {
|
---|
1173 | struct mdns_domain host;
|
---|
1174 | mdns_build_host_domain(&host, NETIF_TO_HOST(netif));
|
---|
1175 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with A record\n"));
|
---|
1176 | return mdns_add_answer(reply, &host, DNS_RRTYPE_A, DNS_RRCLASS_IN, cache_flush, (NETIF_TO_HOST(netif))->dns_ttl, (const u8_t *) netif_ip4_addr(netif), sizeof(ip4_addr_t), NULL);
|
---|
1177 | }
|
---|
1178 |
|
---|
1179 | /** Write a 4.3.2.1.in-addr.arpa -> hostname.local PTR RR to outpacket */
|
---|
1180 | static err_t
|
---|
1181 | mdns_add_hostv4_ptr_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct netif *netif)
|
---|
1182 | {
|
---|
1183 | struct mdns_domain host, revhost;
|
---|
1184 | mdns_build_host_domain(&host, NETIF_TO_HOST(netif));
|
---|
1185 | mdns_build_reverse_v4_domain(&revhost, netif_ip4_addr(netif));
|
---|
1186 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with v4 PTR record\n"));
|
---|
1187 | return mdns_add_answer(reply, &revhost, DNS_RRTYPE_PTR, DNS_RRCLASS_IN, cache_flush, (NETIF_TO_HOST(netif))->dns_ttl, NULL, 0, &host);
|
---|
1188 | }
|
---|
1189 | #endif
|
---|
1190 |
|
---|
1191 | #if LWIP_IPV6
|
---|
1192 | /** Write an IPv6 address (AAAA) RR to outpacket */
|
---|
1193 | static err_t
|
---|
1194 | mdns_add_aaaa_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct netif *netif, int addrindex)
|
---|
1195 | {
|
---|
1196 | struct mdns_domain host;
|
---|
1197 | mdns_build_host_domain(&host, NETIF_TO_HOST(netif));
|
---|
1198 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with AAAA record\n"));
|
---|
1199 | return mdns_add_answer(reply, &host, DNS_RRTYPE_AAAA, DNS_RRCLASS_IN, cache_flush, (NETIF_TO_HOST(netif))->dns_ttl, (const u8_t *) netif_ip6_addr(netif, addrindex), sizeof(ip6_addr_p_t), NULL);
|
---|
1200 | }
|
---|
1201 |
|
---|
1202 | /** Write a x.y.z.ip6.arpa -> hostname.local PTR RR to outpacket */
|
---|
1203 | static err_t
|
---|
1204 | mdns_add_hostv6_ptr_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct netif *netif, int addrindex)
|
---|
1205 | {
|
---|
1206 | struct mdns_domain host, revhost;
|
---|
1207 | mdns_build_host_domain(&host, NETIF_TO_HOST(netif));
|
---|
1208 | mdns_build_reverse_v6_domain(&revhost, netif_ip6_addr(netif, addrindex));
|
---|
1209 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with v6 PTR record\n"));
|
---|
1210 | return mdns_add_answer(reply, &revhost, DNS_RRTYPE_PTR, DNS_RRCLASS_IN, cache_flush, (NETIF_TO_HOST(netif))->dns_ttl, NULL, 0, &host);
|
---|
1211 | }
|
---|
1212 | #endif
|
---|
1213 |
|
---|
1214 | /** Write an all-services -> servicetype PTR RR to outpacket */
|
---|
1215 | static err_t
|
---|
1216 | mdns_add_servicetype_ptr_answer(struct mdns_outpacket *reply, struct mdns_service *service)
|
---|
1217 | {
|
---|
1218 | struct mdns_domain service_type, service_dnssd;
|
---|
1219 | mdns_build_service_domain(&service_type, service, 0);
|
---|
1220 | mdns_build_dnssd_domain(&service_dnssd);
|
---|
1221 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with service type PTR record\n"));
|
---|
1222 | return mdns_add_answer(reply, &service_dnssd, DNS_RRTYPE_PTR, DNS_RRCLASS_IN, 0, service->dns_ttl, NULL, 0, &service_type);
|
---|
1223 | }
|
---|
1224 |
|
---|
1225 | /** Write a servicetype -> servicename PTR RR to outpacket */
|
---|
1226 | static err_t
|
---|
1227 | mdns_add_servicename_ptr_answer(struct mdns_outpacket *reply, struct mdns_service *service)
|
---|
1228 | {
|
---|
1229 | struct mdns_domain service_type, service_instance;
|
---|
1230 | mdns_build_service_domain(&service_type, service, 0);
|
---|
1231 | mdns_build_service_domain(&service_instance, service, 1);
|
---|
1232 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with service name PTR record\n"));
|
---|
1233 | return mdns_add_answer(reply, &service_type, DNS_RRTYPE_PTR, DNS_RRCLASS_IN, 0, service->dns_ttl, NULL, 0, &service_instance);
|
---|
1234 | }
|
---|
1235 |
|
---|
1236 | /** Write a SRV RR to outpacket */
|
---|
1237 | static err_t
|
---|
1238 | mdns_add_srv_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct mdns_host *mdns, struct mdns_service *service)
|
---|
1239 | {
|
---|
1240 | struct mdns_domain service_instance, srvhost;
|
---|
1241 | u16_t srvdata[3];
|
---|
1242 | mdns_build_service_domain(&service_instance, service, 1);
|
---|
1243 | mdns_build_host_domain(&srvhost, mdns);
|
---|
1244 | if (reply->legacy_query) {
|
---|
1245 | /* RFC 6762 section 18.14:
|
---|
1246 | * In legacy unicast responses generated to answer legacy queries,
|
---|
1247 | * name compression MUST NOT be performed on SRV records.
|
---|
1248 | */
|
---|
1249 | srvhost.skip_compression = 1;
|
---|
1250 | }
|
---|
1251 | srvdata[0] = lwip_htons(SRV_PRIORITY);
|
---|
1252 | srvdata[1] = lwip_htons(SRV_WEIGHT);
|
---|
1253 | srvdata[2] = lwip_htons(service->port);
|
---|
1254 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with SRV record\n"));
|
---|
1255 | return mdns_add_answer(reply, &service_instance, DNS_RRTYPE_SRV, DNS_RRCLASS_IN, cache_flush, service->dns_ttl,
|
---|
1256 | (const u8_t *) &srvdata, sizeof(srvdata), &srvhost);
|
---|
1257 | }
|
---|
1258 |
|
---|
1259 | /** Write a TXT RR to outpacket */
|
---|
1260 | static err_t
|
---|
1261 | mdns_add_txt_answer(struct mdns_outpacket *reply, u16_t cache_flush, struct mdns_service *service)
|
---|
1262 | {
|
---|
1263 | struct mdns_domain service_instance;
|
---|
1264 | mdns_build_service_domain(&service_instance, service, 1);
|
---|
1265 | mdns_prepare_txtdata(service);
|
---|
1266 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Responding with TXT record\n"));
|
---|
1267 | return mdns_add_answer(reply, &service_instance, DNS_RRTYPE_TXT, DNS_RRCLASS_IN, cache_flush, service->dns_ttl,
|
---|
1268 | (u8_t *) &service->txtdata.name, service->txtdata.length, NULL);
|
---|
1269 | }
|
---|
1270 |
|
---|
1271 | /**
|
---|
1272 | * Setup outpacket as a reply to the incoming packet
|
---|
1273 | */
|
---|
1274 | static void
|
---|
1275 | mdns_init_outpacket(struct mdns_outpacket *out, struct mdns_packet *in)
|
---|
1276 | {
|
---|
1277 | memset(out, 0, sizeof(struct mdns_outpacket));
|
---|
1278 | out->cache_flush = 1;
|
---|
1279 | out->netif = in->netif;
|
---|
1280 |
|
---|
1281 | /* Copy source IP/port to use when responding unicast, or to choose
|
---|
1282 | * which pcb to use for multicast (IPv4/IPv6)
|
---|
1283 | */
|
---|
1284 | SMEMCPY(&out->dest_addr, &in->source_addr, sizeof(ip_addr_t));
|
---|
1285 | out->dest_port = in->source_port;
|
---|
1286 |
|
---|
1287 | if (in->source_port != LWIP_IANA_PORT_MDNS) {
|
---|
1288 | out->unicast_reply = 1;
|
---|
1289 | out->cache_flush = 0;
|
---|
1290 | if (in->questions == 1) {
|
---|
1291 | out->legacy_query = 1;
|
---|
1292 | out->tx_id = in->tx_id;
|
---|
1293 | }
|
---|
1294 | }
|
---|
1295 |
|
---|
1296 | if (in->recv_unicast) {
|
---|
1297 | out->unicast_reply = 1;
|
---|
1298 | }
|
---|
1299 | }
|
---|
1300 |
|
---|
1301 | /**
|
---|
1302 | * Send chosen answers as a reply
|
---|
1303 | *
|
---|
1304 | * Add all selected answers (first write will allocate pbuf)
|
---|
1305 | * Add additional answers based on the selected answers
|
---|
1306 | * Send the packet
|
---|
1307 | */
|
---|
1308 | static err_t
|
---|
1309 | mdns_send_outpacket(struct mdns_outpacket *outpkt, u8_t flags)
|
---|
1310 | {
|
---|
1311 | struct mdns_service *service;
|
---|
1312 | err_t res = ERR_ARG;
|
---|
1313 | int i;
|
---|
1314 | struct mdns_host *mdns = NETIF_TO_HOST(outpkt->netif);
|
---|
1315 | u16_t answers = 0;
|
---|
1316 |
|
---|
1317 | /* Write answers to host questions */
|
---|
1318 | #if LWIP_IPV4
|
---|
1319 | if (outpkt->host_replies & REPLY_HOST_A) {
|
---|
1320 | res = mdns_add_a_answer(outpkt, outpkt->cache_flush, outpkt->netif);
|
---|
1321 | if (res != ERR_OK) {
|
---|
1322 | goto cleanup;
|
---|
1323 | }
|
---|
1324 | answers++;
|
---|
1325 | }
|
---|
1326 | if (outpkt->host_replies & REPLY_HOST_PTR_V4) {
|
---|
1327 | res = mdns_add_hostv4_ptr_answer(outpkt, outpkt->cache_flush, outpkt->netif);
|
---|
1328 | if (res != ERR_OK) {
|
---|
1329 | goto cleanup;
|
---|
1330 | }
|
---|
1331 | answers++;
|
---|
1332 | }
|
---|
1333 | #endif
|
---|
1334 | #if LWIP_IPV6
|
---|
1335 | if (outpkt->host_replies & REPLY_HOST_AAAA) {
|
---|
1336 | int addrindex;
|
---|
1337 | for (addrindex = 0; addrindex < LWIP_IPV6_NUM_ADDRESSES; addrindex++) {
|
---|
1338 | if (ip6_addr_isvalid(netif_ip6_addr_state(outpkt->netif, addrindex))) {
|
---|
1339 | res = mdns_add_aaaa_answer(outpkt, outpkt->cache_flush, outpkt->netif, addrindex);
|
---|
1340 | if (res != ERR_OK) {
|
---|
1341 | goto cleanup;
|
---|
1342 | }
|
---|
1343 | answers++;
|
---|
1344 | }
|
---|
1345 | }
|
---|
1346 | }
|
---|
1347 | if (outpkt->host_replies & REPLY_HOST_PTR_V6) {
|
---|
1348 | u8_t rev_addrs = outpkt->host_reverse_v6_replies;
|
---|
1349 | int addrindex = 0;
|
---|
1350 | while (rev_addrs) {
|
---|
1351 | if (rev_addrs & 1) {
|
---|
1352 | res = mdns_add_hostv6_ptr_answer(outpkt, outpkt->cache_flush, outpkt->netif, addrindex);
|
---|
1353 | if (res != ERR_OK) {
|
---|
1354 | goto cleanup;
|
---|
1355 | }
|
---|
1356 | answers++;
|
---|
1357 | }
|
---|
1358 | addrindex++;
|
---|
1359 | rev_addrs >>= 1;
|
---|
1360 | }
|
---|
1361 | }
|
---|
1362 | #endif
|
---|
1363 |
|
---|
1364 | /* Write answers to service questions */
|
---|
1365 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1366 | service = mdns->services[i];
|
---|
1367 | if (!service) {
|
---|
1368 | continue;
|
---|
1369 | }
|
---|
1370 |
|
---|
1371 | if (outpkt->serv_replies[i] & REPLY_SERVICE_TYPE_PTR) {
|
---|
1372 | res = mdns_add_servicetype_ptr_answer(outpkt, service);
|
---|
1373 | if (res != ERR_OK) {
|
---|
1374 | goto cleanup;
|
---|
1375 | }
|
---|
1376 | answers++;
|
---|
1377 | }
|
---|
1378 |
|
---|
1379 | if (outpkt->serv_replies[i] & REPLY_SERVICE_NAME_PTR) {
|
---|
1380 | res = mdns_add_servicename_ptr_answer(outpkt, service);
|
---|
1381 | if (res != ERR_OK) {
|
---|
1382 | goto cleanup;
|
---|
1383 | }
|
---|
1384 | answers++;
|
---|
1385 | }
|
---|
1386 |
|
---|
1387 | if (outpkt->serv_replies[i] & REPLY_SERVICE_SRV) {
|
---|
1388 | res = mdns_add_srv_answer(outpkt, outpkt->cache_flush, mdns, service);
|
---|
1389 | if (res != ERR_OK) {
|
---|
1390 | goto cleanup;
|
---|
1391 | }
|
---|
1392 | answers++;
|
---|
1393 | }
|
---|
1394 |
|
---|
1395 | if (outpkt->serv_replies[i] & REPLY_SERVICE_TXT) {
|
---|
1396 | res = mdns_add_txt_answer(outpkt, outpkt->cache_flush, service);
|
---|
1397 | if (res != ERR_OK) {
|
---|
1398 | goto cleanup;
|
---|
1399 | }
|
---|
1400 | answers++;
|
---|
1401 | }
|
---|
1402 | }
|
---|
1403 |
|
---|
1404 | /* if this is a response, the data above is anwers, else this is a probe and the answers above goes into auth section */
|
---|
1405 | if (flags & DNS_FLAG1_RESPONSE) {
|
---|
1406 | outpkt->answers += answers;
|
---|
1407 | } else {
|
---|
1408 | outpkt->authoritative += answers;
|
---|
1409 | }
|
---|
1410 |
|
---|
1411 | /* All answers written, add additional RRs */
|
---|
1412 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1413 | service = mdns->services[i];
|
---|
1414 | if (!service) {
|
---|
1415 | continue;
|
---|
1416 | }
|
---|
1417 |
|
---|
1418 | if (outpkt->serv_replies[i] & REPLY_SERVICE_NAME_PTR) {
|
---|
1419 | /* Our service instance requested, include SRV & TXT
|
---|
1420 | * if they are already not requested. */
|
---|
1421 | if (!(outpkt->serv_replies[i] & REPLY_SERVICE_SRV)) {
|
---|
1422 | res = mdns_add_srv_answer(outpkt, outpkt->cache_flush, mdns, service);
|
---|
1423 | if (res != ERR_OK) {
|
---|
1424 | goto cleanup;
|
---|
1425 | }
|
---|
1426 | outpkt->additional++;
|
---|
1427 | }
|
---|
1428 |
|
---|
1429 | if (!(outpkt->serv_replies[i] & REPLY_SERVICE_TXT)) {
|
---|
1430 | res = mdns_add_txt_answer(outpkt, outpkt->cache_flush, service);
|
---|
1431 | if (res != ERR_OK) {
|
---|
1432 | goto cleanup;
|
---|
1433 | }
|
---|
1434 | outpkt->additional++;
|
---|
1435 | }
|
---|
1436 | }
|
---|
1437 |
|
---|
1438 | /* If service instance, SRV, record or an IP address is requested,
|
---|
1439 | * supply all addresses for the host
|
---|
1440 | */
|
---|
1441 | if ((outpkt->serv_replies[i] & (REPLY_SERVICE_NAME_PTR | REPLY_SERVICE_SRV)) ||
|
---|
1442 | (outpkt->host_replies & (REPLY_HOST_A | REPLY_HOST_AAAA))) {
|
---|
1443 | #if LWIP_IPV6
|
---|
1444 | if (!(outpkt->host_replies & REPLY_HOST_AAAA)) {
|
---|
1445 | int addrindex;
|
---|
1446 | for (addrindex = 0; addrindex < LWIP_IPV6_NUM_ADDRESSES; addrindex++) {
|
---|
1447 | if (ip6_addr_isvalid(netif_ip6_addr_state(outpkt->netif, addrindex))) {
|
---|
1448 | res = mdns_add_aaaa_answer(outpkt, outpkt->cache_flush, outpkt->netif, addrindex);
|
---|
1449 | if (res != ERR_OK) {
|
---|
1450 | goto cleanup;
|
---|
1451 | }
|
---|
1452 | outpkt->additional++;
|
---|
1453 | }
|
---|
1454 | }
|
---|
1455 | }
|
---|
1456 | #endif
|
---|
1457 | #if LWIP_IPV4
|
---|
1458 | if (!(outpkt->host_replies & REPLY_HOST_A) &&
|
---|
1459 | !ip4_addr_isany_val(*netif_ip4_addr(outpkt->netif))) {
|
---|
1460 | res = mdns_add_a_answer(outpkt, outpkt->cache_flush, outpkt->netif);
|
---|
1461 | if (res != ERR_OK) {
|
---|
1462 | goto cleanup;
|
---|
1463 | }
|
---|
1464 | outpkt->additional++;
|
---|
1465 | }
|
---|
1466 | #endif
|
---|
1467 | }
|
---|
1468 | }
|
---|
1469 |
|
---|
1470 | if (outpkt->pbuf) {
|
---|
1471 | const ip_addr_t *mcast_destaddr;
|
---|
1472 | struct dns_hdr hdr;
|
---|
1473 |
|
---|
1474 | /* Write header */
|
---|
1475 | memset(&hdr, 0, sizeof(hdr));
|
---|
1476 | hdr.flags1 = flags;
|
---|
1477 | hdr.numquestions = lwip_htons(outpkt->questions);
|
---|
1478 | hdr.numanswers = lwip_htons(outpkt->answers);
|
---|
1479 | hdr.numauthrr = lwip_htons(outpkt->authoritative);
|
---|
1480 | hdr.numextrarr = lwip_htons(outpkt->additional);
|
---|
1481 | hdr.id = lwip_htons(outpkt->tx_id);
|
---|
1482 | pbuf_take(outpkt->pbuf, &hdr, sizeof(hdr));
|
---|
1483 |
|
---|
1484 | /* Shrink packet */
|
---|
1485 | pbuf_realloc(outpkt->pbuf, outpkt->write_offset);
|
---|
1486 |
|
---|
1487 | if (IP_IS_V6_VAL(outpkt->dest_addr)) {
|
---|
1488 | #if LWIP_IPV6
|
---|
1489 | mcast_destaddr = &v6group;
|
---|
1490 | #endif
|
---|
1491 | } else {
|
---|
1492 | #if LWIP_IPV4
|
---|
1493 | mcast_destaddr = &v4group;
|
---|
1494 | #endif
|
---|
1495 | }
|
---|
1496 | /* Send created packet */
|
---|
1497 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Sending packet, len=%d, unicast=%d\n", outpkt->write_offset, outpkt->unicast_reply));
|
---|
1498 | if (outpkt->unicast_reply) {
|
---|
1499 | res = udp_sendto_if(mdns_pcb, outpkt->pbuf, &outpkt->dest_addr, outpkt->dest_port, outpkt->netif);
|
---|
1500 | } else {
|
---|
1501 | res = udp_sendto_if(mdns_pcb, outpkt->pbuf, mcast_destaddr, LWIP_IANA_PORT_MDNS, outpkt->netif);
|
---|
1502 | }
|
---|
1503 | }
|
---|
1504 |
|
---|
1505 | cleanup:
|
---|
1506 | if (outpkt->pbuf) {
|
---|
1507 | pbuf_free(outpkt->pbuf);
|
---|
1508 | outpkt->pbuf = NULL;
|
---|
1509 | }
|
---|
1510 | return res;
|
---|
1511 | }
|
---|
1512 |
|
---|
1513 | /**
|
---|
1514 | * Send unsolicited answer containing all our known data
|
---|
1515 | * @param netif The network interface to send on
|
---|
1516 | * @param destination The target address to send to (usually multicast address)
|
---|
1517 | */
|
---|
1518 | static void
|
---|
1519 | mdns_announce(struct netif *netif, const ip_addr_t *destination)
|
---|
1520 | {
|
---|
1521 | struct mdns_outpacket announce;
|
---|
1522 | int i;
|
---|
1523 | struct mdns_host *mdns = NETIF_TO_HOST(netif);
|
---|
1524 |
|
---|
1525 | memset(&announce, 0, sizeof(announce));
|
---|
1526 | announce.netif = netif;
|
---|
1527 | announce.cache_flush = 1;
|
---|
1528 | #if LWIP_IPV4
|
---|
1529 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif))) {
|
---|
1530 | announce.host_replies = REPLY_HOST_A | REPLY_HOST_PTR_V4;
|
---|
1531 | }
|
---|
1532 | #endif
|
---|
1533 | #if LWIP_IPV6
|
---|
1534 | for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
|
---|
1535 | if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i))) {
|
---|
1536 | announce.host_replies |= REPLY_HOST_AAAA | REPLY_HOST_PTR_V6;
|
---|
1537 | announce.host_reverse_v6_replies |= (1 << i);
|
---|
1538 | }
|
---|
1539 | }
|
---|
1540 | #endif
|
---|
1541 |
|
---|
1542 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1543 | struct mdns_service *serv = mdns->services[i];
|
---|
1544 | if (serv) {
|
---|
1545 | announce.serv_replies[i] = REPLY_SERVICE_TYPE_PTR | REPLY_SERVICE_NAME_PTR |
|
---|
1546 | REPLY_SERVICE_SRV | REPLY_SERVICE_TXT;
|
---|
1547 | }
|
---|
1548 | }
|
---|
1549 |
|
---|
1550 | announce.dest_port = LWIP_IANA_PORT_MDNS;
|
---|
1551 | SMEMCPY(&announce.dest_addr, destination, sizeof(announce.dest_addr));
|
---|
1552 | mdns_send_outpacket(&announce, DNS_FLAG1_RESPONSE | DNS_FLAG1_AUTHORATIVE);
|
---|
1553 | }
|
---|
1554 |
|
---|
1555 | /**
|
---|
1556 | * Handle question MDNS packet
|
---|
1557 | * 1. Parse all questions and set bits what answers to send
|
---|
1558 | * 2. Clear pending answers if known answers are supplied
|
---|
1559 | * 3. Put chosen answers in new packet and send as reply
|
---|
1560 | */
|
---|
1561 | static void
|
---|
1562 | mdns_handle_question(struct mdns_packet *pkt)
|
---|
1563 | {
|
---|
1564 | struct mdns_service *service;
|
---|
1565 | struct mdns_outpacket reply;
|
---|
1566 | int replies = 0;
|
---|
1567 | int i;
|
---|
1568 | err_t res;
|
---|
1569 | struct mdns_host *mdns = NETIF_TO_HOST(pkt->netif);
|
---|
1570 |
|
---|
1571 | if (mdns->probing_state != MDNS_PROBING_COMPLETE) {
|
---|
1572 | /* Don't answer questions until we've verified our domains via probing */
|
---|
1573 | /* @todo we should check incoming questions during probing for tiebreaking */
|
---|
1574 | return;
|
---|
1575 | }
|
---|
1576 |
|
---|
1577 | mdns_init_outpacket(&reply, pkt);
|
---|
1578 |
|
---|
1579 | while (pkt->questions_left) {
|
---|
1580 | struct mdns_question q;
|
---|
1581 |
|
---|
1582 | res = mdns_read_question(pkt, &q);
|
---|
1583 | if (res != ERR_OK) {
|
---|
1584 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Failed to parse question, skipping query packet\n"));
|
---|
1585 | return;
|
---|
1586 | }
|
---|
1587 |
|
---|
1588 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Query for domain "));
|
---|
1589 | mdns_domain_debug_print(&q.info.domain);
|
---|
1590 | LWIP_DEBUGF(MDNS_DEBUG, (" type %d class %d\n", q.info.type, q.info.klass));
|
---|
1591 |
|
---|
1592 | if (q.unicast) {
|
---|
1593 | /* Reply unicast if any question is unicast */
|
---|
1594 | reply.unicast_reply = 1;
|
---|
1595 | }
|
---|
1596 |
|
---|
1597 | reply.host_replies |= check_host(pkt->netif, &q.info, &reply.host_reverse_v6_replies);
|
---|
1598 | replies |= reply.host_replies;
|
---|
1599 |
|
---|
1600 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1601 | service = mdns->services[i];
|
---|
1602 | if (!service) {
|
---|
1603 | continue;
|
---|
1604 | }
|
---|
1605 | reply.serv_replies[i] |= check_service(service, &q.info);
|
---|
1606 | replies |= reply.serv_replies[i];
|
---|
1607 | }
|
---|
1608 |
|
---|
1609 | if (replies && reply.legacy_query) {
|
---|
1610 | /* Add question to reply packet (legacy packet only has 1 question) */
|
---|
1611 | res = mdns_add_question(&reply, &q.info.domain, q.info.type, q.info.klass, 0);
|
---|
1612 | reply.questions = 1;
|
---|
1613 | if (res != ERR_OK) {
|
---|
1614 | goto cleanup;
|
---|
1615 | }
|
---|
1616 | }
|
---|
1617 | }
|
---|
1618 |
|
---|
1619 | /* Handle known answers */
|
---|
1620 | while (pkt->answers_left) {
|
---|
1621 | struct mdns_answer ans;
|
---|
1622 | u8_t rev_v6;
|
---|
1623 | int match;
|
---|
1624 |
|
---|
1625 | res = mdns_read_answer(pkt, &ans);
|
---|
1626 | if (res != ERR_OK) {
|
---|
1627 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Failed to parse answer, skipping query packet\n"));
|
---|
1628 | goto cleanup;
|
---|
1629 | }
|
---|
1630 |
|
---|
1631 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Known answer for domain "));
|
---|
1632 | mdns_domain_debug_print(&ans.info.domain);
|
---|
1633 | LWIP_DEBUGF(MDNS_DEBUG, (" type %d class %d\n", ans.info.type, ans.info.klass));
|
---|
1634 |
|
---|
1635 |
|
---|
1636 | if (ans.info.type == DNS_RRTYPE_ANY || ans.info.klass == DNS_RRCLASS_ANY) {
|
---|
1637 | /* Skip known answers for ANY type & class */
|
---|
1638 | continue;
|
---|
1639 | }
|
---|
1640 |
|
---|
1641 | rev_v6 = 0;
|
---|
1642 | match = reply.host_replies & check_host(pkt->netif, &ans.info, &rev_v6);
|
---|
1643 | if (match && (ans.ttl > (mdns->dns_ttl / 2))) {
|
---|
1644 | /* The RR in the known answer matches an RR we are planning to send,
|
---|
1645 | * and the TTL is less than half gone.
|
---|
1646 | * If the payload matches we should not send that answer.
|
---|
1647 | */
|
---|
1648 | if (ans.info.type == DNS_RRTYPE_PTR) {
|
---|
1649 | /* Read domain and compare */
|
---|
1650 | struct mdns_domain known_ans, my_ans;
|
---|
1651 | u16_t len;
|
---|
1652 | len = mdns_readname(pkt->pbuf, ans.rd_offset, &known_ans);
|
---|
1653 | res = mdns_build_host_domain(&my_ans, mdns);
|
---|
1654 | if (len != MDNS_READNAME_ERROR && res == ERR_OK && mdns_domain_eq(&known_ans, &my_ans)) {
|
---|
1655 | #if LWIP_IPV4
|
---|
1656 | if (match & REPLY_HOST_PTR_V4) {
|
---|
1657 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: v4 PTR\n"));
|
---|
1658 | reply.host_replies &= ~REPLY_HOST_PTR_V4;
|
---|
1659 | }
|
---|
1660 | #endif
|
---|
1661 | #if LWIP_IPV6
|
---|
1662 | if (match & REPLY_HOST_PTR_V6) {
|
---|
1663 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: v6 PTR\n"));
|
---|
1664 | reply.host_reverse_v6_replies &= ~rev_v6;
|
---|
1665 | if (reply.host_reverse_v6_replies == 0) {
|
---|
1666 | reply.host_replies &= ~REPLY_HOST_PTR_V6;
|
---|
1667 | }
|
---|
1668 | }
|
---|
1669 | #endif
|
---|
1670 | }
|
---|
1671 | } else if (match & REPLY_HOST_A) {
|
---|
1672 | #if LWIP_IPV4
|
---|
1673 | if (ans.rd_length == sizeof(ip4_addr_t) &&
|
---|
1674 | pbuf_memcmp(pkt->pbuf, ans.rd_offset, netif_ip4_addr(pkt->netif), ans.rd_length) == 0) {
|
---|
1675 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: A\n"));
|
---|
1676 | reply.host_replies &= ~REPLY_HOST_A;
|
---|
1677 | }
|
---|
1678 | #endif
|
---|
1679 | } else if (match & REPLY_HOST_AAAA) {
|
---|
1680 | #if LWIP_IPV6
|
---|
1681 | if (ans.rd_length == sizeof(ip6_addr_p_t) &&
|
---|
1682 | /* TODO this clears all AAAA responses if first addr is set as known */
|
---|
1683 | pbuf_memcmp(pkt->pbuf, ans.rd_offset, netif_ip6_addr(pkt->netif, 0), ans.rd_length) == 0) {
|
---|
1684 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: AAAA\n"));
|
---|
1685 | reply.host_replies &= ~REPLY_HOST_AAAA;
|
---|
1686 | }
|
---|
1687 | #endif
|
---|
1688 | }
|
---|
1689 | }
|
---|
1690 |
|
---|
1691 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1692 | service = mdns->services[i];
|
---|
1693 | if (!service) {
|
---|
1694 | continue;
|
---|
1695 | }
|
---|
1696 | match = reply.serv_replies[i] & check_service(service, &ans.info);
|
---|
1697 | if (match && (ans.ttl > (service->dns_ttl / 2))) {
|
---|
1698 | /* The RR in the known answer matches an RR we are planning to send,
|
---|
1699 | * and the TTL is less than half gone.
|
---|
1700 | * If the payload matches we should not send that answer.
|
---|
1701 | */
|
---|
1702 | if (ans.info.type == DNS_RRTYPE_PTR) {
|
---|
1703 | /* Read domain and compare */
|
---|
1704 | struct mdns_domain known_ans, my_ans;
|
---|
1705 | u16_t len;
|
---|
1706 | len = mdns_readname(pkt->pbuf, ans.rd_offset, &known_ans);
|
---|
1707 | if (len != MDNS_READNAME_ERROR) {
|
---|
1708 | if (match & REPLY_SERVICE_TYPE_PTR) {
|
---|
1709 | res = mdns_build_service_domain(&my_ans, service, 0);
|
---|
1710 | if (res == ERR_OK && mdns_domain_eq(&known_ans, &my_ans)) {
|
---|
1711 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: service type PTR\n"));
|
---|
1712 | reply.serv_replies[i] &= ~REPLY_SERVICE_TYPE_PTR;
|
---|
1713 | }
|
---|
1714 | }
|
---|
1715 | if (match & REPLY_SERVICE_NAME_PTR) {
|
---|
1716 | res = mdns_build_service_domain(&my_ans, service, 1);
|
---|
1717 | if (res == ERR_OK && mdns_domain_eq(&known_ans, &my_ans)) {
|
---|
1718 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: service name PTR\n"));
|
---|
1719 | reply.serv_replies[i] &= ~REPLY_SERVICE_NAME_PTR;
|
---|
1720 | }
|
---|
1721 | }
|
---|
1722 | }
|
---|
1723 | } else if (match & REPLY_SERVICE_SRV) {
|
---|
1724 | /* Read and compare to my SRV record */
|
---|
1725 | u16_t field16, len, read_pos;
|
---|
1726 | struct mdns_domain known_ans, my_ans;
|
---|
1727 | read_pos = ans.rd_offset;
|
---|
1728 | do {
|
---|
1729 | /* Check priority field */
|
---|
1730 | len = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), read_pos);
|
---|
1731 | if (len != sizeof(field16) || lwip_ntohs(field16) != SRV_PRIORITY) {
|
---|
1732 | break;
|
---|
1733 | }
|
---|
1734 | read_pos += len;
|
---|
1735 | /* Check weight field */
|
---|
1736 | len = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), read_pos);
|
---|
1737 | if (len != sizeof(field16) || lwip_ntohs(field16) != SRV_WEIGHT) {
|
---|
1738 | break;
|
---|
1739 | }
|
---|
1740 | read_pos += len;
|
---|
1741 | /* Check port field */
|
---|
1742 | len = pbuf_copy_partial(pkt->pbuf, &field16, sizeof(field16), read_pos);
|
---|
1743 | if (len != sizeof(field16) || lwip_ntohs(field16) != service->port) {
|
---|
1744 | break;
|
---|
1745 | }
|
---|
1746 | read_pos += len;
|
---|
1747 | /* Check host field */
|
---|
1748 | len = mdns_readname(pkt->pbuf, read_pos, &known_ans);
|
---|
1749 | mdns_build_host_domain(&my_ans, mdns);
|
---|
1750 | if (len == MDNS_READNAME_ERROR || !mdns_domain_eq(&known_ans, &my_ans)) {
|
---|
1751 | break;
|
---|
1752 | }
|
---|
1753 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: SRV\n"));
|
---|
1754 | reply.serv_replies[i] &= ~REPLY_SERVICE_SRV;
|
---|
1755 | } while (0);
|
---|
1756 | } else if (match & REPLY_SERVICE_TXT) {
|
---|
1757 | mdns_prepare_txtdata(service);
|
---|
1758 | if (service->txtdata.length == ans.rd_length &&
|
---|
1759 | pbuf_memcmp(pkt->pbuf, ans.rd_offset, service->txtdata.name, ans.rd_length) == 0) {
|
---|
1760 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Skipping known answer: TXT\n"));
|
---|
1761 | reply.serv_replies[i] &= ~REPLY_SERVICE_TXT;
|
---|
1762 | }
|
---|
1763 | }
|
---|
1764 | }
|
---|
1765 | }
|
---|
1766 | }
|
---|
1767 |
|
---|
1768 | mdns_send_outpacket(&reply, DNS_FLAG1_RESPONSE | DNS_FLAG1_AUTHORATIVE);
|
---|
1769 |
|
---|
1770 | cleanup:
|
---|
1771 | if (reply.pbuf) {
|
---|
1772 | /* This should only happen if we fail to alloc/write question for legacy query */
|
---|
1773 | pbuf_free(reply.pbuf);
|
---|
1774 | reply.pbuf = NULL;
|
---|
1775 | }
|
---|
1776 | }
|
---|
1777 |
|
---|
1778 | /**
|
---|
1779 | * Handle response MDNS packet
|
---|
1780 | * Only prints debug for now. Will need more code to do conflict resolution.
|
---|
1781 | */
|
---|
1782 | static void
|
---|
1783 | mdns_handle_response(struct mdns_packet *pkt)
|
---|
1784 | {
|
---|
1785 | struct mdns_host* mdns = NETIF_TO_HOST(pkt->netif);
|
---|
1786 |
|
---|
1787 | /* Ignore all questions */
|
---|
1788 | while (pkt->questions_left) {
|
---|
1789 | struct mdns_question q;
|
---|
1790 | err_t res;
|
---|
1791 |
|
---|
1792 | res = mdns_read_question(pkt, &q);
|
---|
1793 | if (res != ERR_OK) {
|
---|
1794 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Failed to parse question, skipping response packet\n"));
|
---|
1795 | return;
|
---|
1796 | }
|
---|
1797 | }
|
---|
1798 |
|
---|
1799 | while (pkt->answers_left) {
|
---|
1800 | struct mdns_answer ans;
|
---|
1801 | err_t res;
|
---|
1802 |
|
---|
1803 | res = mdns_read_answer(pkt, &ans);
|
---|
1804 | if (res != ERR_OK) {
|
---|
1805 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Failed to parse answer, skipping response packet\n"));
|
---|
1806 | return;
|
---|
1807 | }
|
---|
1808 |
|
---|
1809 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Answer for domain "));
|
---|
1810 | mdns_domain_debug_print(&ans.info.domain);
|
---|
1811 | LWIP_DEBUGF(MDNS_DEBUG, (" type %d class %d\n", ans.info.type, ans.info.klass));
|
---|
1812 |
|
---|
1813 | /*"Apparently conflicting Multicast DNS responses received *before* the first probe packet is sent MUST
|
---|
1814 | be silently ignored" so drop answer if we haven't started probing yet*/
|
---|
1815 | if ((mdns->probing_state == MDNS_PROBING_ONGOING) && (mdns->probes_sent > 0)) {
|
---|
1816 | struct mdns_domain domain;
|
---|
1817 | u8_t i;
|
---|
1818 | u8_t conflict = 0;
|
---|
1819 |
|
---|
1820 | res = mdns_build_host_domain(&domain, mdns);
|
---|
1821 | if (res == ERR_OK && mdns_domain_eq(&ans.info.domain, &domain)) {
|
---|
1822 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Probe response matches host domain!"));
|
---|
1823 | conflict = 1;
|
---|
1824 | }
|
---|
1825 |
|
---|
1826 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1827 | struct mdns_service* service = mdns->services[i];
|
---|
1828 | if (!service) {
|
---|
1829 | continue;
|
---|
1830 | }
|
---|
1831 | res = mdns_build_service_domain(&domain, service, 1);
|
---|
1832 | if ((res == ERR_OK) && mdns_domain_eq(&ans.info.domain, &domain)) {
|
---|
1833 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Probe response matches service domain!"));
|
---|
1834 | conflict = 1;
|
---|
1835 | }
|
---|
1836 | }
|
---|
1837 |
|
---|
1838 | if (conflict != 0) {
|
---|
1839 | sys_untimeout(mdns_probe, pkt->netif);
|
---|
1840 | if (mdns_name_result_cb != NULL) {
|
---|
1841 | mdns_name_result_cb(pkt->netif, MDNS_PROBING_CONFLICT);
|
---|
1842 | }
|
---|
1843 | }
|
---|
1844 | }
|
---|
1845 | }
|
---|
1846 | }
|
---|
1847 |
|
---|
1848 | /**
|
---|
1849 | * Receive input function for MDNS packets.
|
---|
1850 | * Handles both IPv4 and IPv6 UDP pcbs.
|
---|
1851 | */
|
---|
1852 | static void
|
---|
1853 | mdns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
|
---|
1854 | {
|
---|
1855 | struct dns_hdr hdr;
|
---|
1856 | struct mdns_packet packet;
|
---|
1857 | struct netif *recv_netif = ip_current_input_netif();
|
---|
1858 | u16_t offset = 0;
|
---|
1859 |
|
---|
1860 | LWIP_UNUSED_ARG(arg);
|
---|
1861 | LWIP_UNUSED_ARG(pcb);
|
---|
1862 |
|
---|
1863 | LWIP_DEBUGF(MDNS_DEBUG, ("MDNS: Received IPv%d MDNS packet, len %d\n", IP_IS_V6(addr) ? 6 : 4, p->tot_len));
|
---|
1864 |
|
---|
1865 | if (NETIF_TO_HOST(recv_netif) == NULL) {
|
---|
1866 | /* From netif not configured for MDNS */
|
---|
1867 | goto dealloc;
|
---|
1868 | }
|
---|
1869 |
|
---|
1870 | if (pbuf_copy_partial(p, &hdr, SIZEOF_DNS_HDR, offset) < SIZEOF_DNS_HDR) {
|
---|
1871 | /* Too small */
|
---|
1872 | goto dealloc;
|
---|
1873 | }
|
---|
1874 | offset += SIZEOF_DNS_HDR;
|
---|
1875 |
|
---|
1876 | if (DNS_HDR_GET_OPCODE(&hdr)) {
|
---|
1877 | /* Ignore non-standard queries in multicast packets (RFC 6762, section 18.3) */
|
---|
1878 | goto dealloc;
|
---|
1879 | }
|
---|
1880 |
|
---|
1881 | memset(&packet, 0, sizeof(packet));
|
---|
1882 | SMEMCPY(&packet.source_addr, addr, sizeof(packet.source_addr));
|
---|
1883 | packet.source_port = port;
|
---|
1884 | packet.netif = recv_netif;
|
---|
1885 | packet.pbuf = p;
|
---|
1886 | packet.parse_offset = offset;
|
---|
1887 | packet.tx_id = lwip_ntohs(hdr.id);
|
---|
1888 | packet.questions = packet.questions_left = lwip_ntohs(hdr.numquestions);
|
---|
1889 | packet.answers = packet.answers_left = lwip_ntohs(hdr.numanswers) + lwip_ntohs(hdr.numauthrr) + lwip_ntohs(hdr.numextrarr);
|
---|
1890 |
|
---|
1891 | #if LWIP_IPV6
|
---|
1892 | if (IP_IS_V6(ip_current_dest_addr())) {
|
---|
1893 | /* instead of having one 'v6group' per netif, just compare zoneless here */
|
---|
1894 | if (!ip_addr_cmp_zoneless(ip_current_dest_addr(), &v6group)) {
|
---|
1895 | packet.recv_unicast = 1;
|
---|
1896 | }
|
---|
1897 | }
|
---|
1898 | #endif
|
---|
1899 | #if LWIP_IPV4
|
---|
1900 | if (!IP_IS_V6(ip_current_dest_addr())) {
|
---|
1901 | if (!ip_addr_cmp(ip_current_dest_addr(), &v4group)) {
|
---|
1902 | packet.recv_unicast = 1;
|
---|
1903 | }
|
---|
1904 | }
|
---|
1905 | #endif
|
---|
1906 |
|
---|
1907 | if (hdr.flags1 & DNS_FLAG1_RESPONSE) {
|
---|
1908 | mdns_handle_response(&packet);
|
---|
1909 | } else {
|
---|
1910 | mdns_handle_question(&packet);
|
---|
1911 | }
|
---|
1912 |
|
---|
1913 | dealloc:
|
---|
1914 | pbuf_free(p);
|
---|
1915 | }
|
---|
1916 |
|
---|
1917 | #if LWIP_NETIF_EXT_STATUS_CALLBACK && MDNS_RESP_USENETIF_EXTCALLBACK
|
---|
1918 | static void
|
---|
1919 | mdns_netif_ext_status_callback(struct netif *netif, netif_nsc_reason_t reason, const netif_ext_callback_args_t *args)
|
---|
1920 | {
|
---|
1921 | LWIP_UNUSED_ARG(args);
|
---|
1922 |
|
---|
1923 | /* MDNS enabled on netif? */
|
---|
1924 | if (NETIF_TO_HOST(netif) == NULL) {
|
---|
1925 | return;
|
---|
1926 | }
|
---|
1927 |
|
---|
1928 | if (reason & LWIP_NSC_STATUS_CHANGED) {
|
---|
1929 | if (args->status_changed.state != 0) {
|
---|
1930 | mdns_resp_restart(netif);
|
---|
1931 | }
|
---|
1932 | /* TODO: send goodbye message */
|
---|
1933 | }
|
---|
1934 | if (reason & LWIP_NSC_LINK_CHANGED) {
|
---|
1935 | if (args->link_changed.state != 0) {
|
---|
1936 | mdns_resp_restart(netif);
|
---|
1937 | }
|
---|
1938 | }
|
---|
1939 | if (reason & (LWIP_NSC_IPV4_ADDRESS_CHANGED | LWIP_NSC_IPV4_GATEWAY_CHANGED |
|
---|
1940 | LWIP_NSC_IPV4_NETMASK_CHANGED | LWIP_NSC_IPV4_SETTINGS_CHANGED |
|
---|
1941 | LWIP_NSC_IPV6_SET | LWIP_NSC_IPV6_ADDR_STATE_CHANGED)) {
|
---|
1942 | mdns_resp_announce(netif);
|
---|
1943 | }
|
---|
1944 | }
|
---|
1945 | #endif /* LWIP_NETIF_EXT_STATUS_CALLBACK && MDNS_RESP_USENETIF_EXTCALLBACK */
|
---|
1946 |
|
---|
1947 | static err_t
|
---|
1948 | mdns_send_probe(struct netif* netif, const ip_addr_t *destination)
|
---|
1949 | {
|
---|
1950 | struct mdns_host* mdns;
|
---|
1951 | struct mdns_outpacket pkt;
|
---|
1952 | struct mdns_domain domain;
|
---|
1953 | u8_t i;
|
---|
1954 | err_t res;
|
---|
1955 |
|
---|
1956 | mdns = NETIF_TO_HOST(netif);
|
---|
1957 |
|
---|
1958 | memset(&pkt, 0, sizeof(pkt));
|
---|
1959 | pkt.netif = netif;
|
---|
1960 |
|
---|
1961 | /* Add unicast questions with rtype ANY for all our desired records */
|
---|
1962 | mdns_build_host_domain(&domain, mdns);
|
---|
1963 | res = mdns_add_question(&pkt, &domain, DNS_RRTYPE_ANY, DNS_RRCLASS_IN, 1);
|
---|
1964 | if (res != ERR_OK) {
|
---|
1965 | goto cleanup;
|
---|
1966 | }
|
---|
1967 | pkt.questions++;
|
---|
1968 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1969 | struct mdns_service* service = mdns->services[i];
|
---|
1970 | if (!service) {
|
---|
1971 | continue;
|
---|
1972 | }
|
---|
1973 | mdns_build_service_domain(&domain, service, 1);
|
---|
1974 | res = mdns_add_question(&pkt, &domain, DNS_RRTYPE_ANY, DNS_RRCLASS_IN, 1);
|
---|
1975 | if (res != ERR_OK) {
|
---|
1976 | goto cleanup;
|
---|
1977 | }
|
---|
1978 | pkt.questions++;
|
---|
1979 | }
|
---|
1980 |
|
---|
1981 | /* Add answers to the questions above into the authority section for tiebreaking */
|
---|
1982 | #if LWIP_IPV4
|
---|
1983 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif))) {
|
---|
1984 | pkt.host_replies = REPLY_HOST_A;
|
---|
1985 | }
|
---|
1986 | #endif
|
---|
1987 | #if LWIP_IPV6
|
---|
1988 | for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
|
---|
1989 | if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i))) {
|
---|
1990 | pkt.host_replies |= REPLY_HOST_AAAA;
|
---|
1991 | }
|
---|
1992 | }
|
---|
1993 | #endif
|
---|
1994 |
|
---|
1995 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
1996 | struct mdns_service *serv = mdns->services[i];
|
---|
1997 | if (serv) {
|
---|
1998 | pkt.serv_replies[i] = REPLY_SERVICE_SRV | REPLY_SERVICE_TXT;
|
---|
1999 | }
|
---|
2000 | }
|
---|
2001 |
|
---|
2002 | pkt.tx_id = 0;
|
---|
2003 | pkt.dest_port = LWIP_IANA_PORT_MDNS;
|
---|
2004 | SMEMCPY(&pkt.dest_addr, destination, sizeof(pkt.dest_addr));
|
---|
2005 | res = mdns_send_outpacket(&pkt, 0);
|
---|
2006 |
|
---|
2007 | cleanup:
|
---|
2008 | if (pkt.pbuf) {
|
---|
2009 | pbuf_free(pkt.pbuf);
|
---|
2010 | pkt.pbuf = NULL;
|
---|
2011 | }
|
---|
2012 | return res;
|
---|
2013 | }
|
---|
2014 |
|
---|
2015 | /**
|
---|
2016 | * Timer callback for probing network.
|
---|
2017 | */
|
---|
2018 | static void
|
---|
2019 | mdns_probe(void* arg)
|
---|
2020 | {
|
---|
2021 | struct netif *netif = (struct netif *)arg;
|
---|
2022 | struct mdns_host* mdns = NETIF_TO_HOST(netif);
|
---|
2023 |
|
---|
2024 | if(mdns->probes_sent >= MDNS_PROBE_COUNT) {
|
---|
2025 | /* probing successful, announce the new name */
|
---|
2026 | mdns->probing_state = MDNS_PROBING_COMPLETE;
|
---|
2027 | mdns_resp_announce(netif);
|
---|
2028 | if (mdns_name_result_cb != NULL) {
|
---|
2029 | mdns_name_result_cb(netif, MDNS_PROBING_SUCCESSFUL);
|
---|
2030 | }
|
---|
2031 | } else {
|
---|
2032 | #if LWIP_IPV4
|
---|
2033 | /*if ipv4 wait with probing until address is set*/
|
---|
2034 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif)) &&
|
---|
2035 | mdns_send_probe(netif, IP4_ADDR_ANY) == ERR_OK)
|
---|
2036 | #endif
|
---|
2037 | {
|
---|
2038 | #if LWIP_IPV6
|
---|
2039 | if (mdns_send_probe(netif, IP6_ADDR_ANY) == ERR_OK)
|
---|
2040 | #endif
|
---|
2041 | {
|
---|
2042 | mdns->probes_sent++;
|
---|
2043 | }
|
---|
2044 | }
|
---|
2045 | sys_timeout(MDNS_PROBE_DELAY_MS, mdns_probe, netif);
|
---|
2046 | }
|
---|
2047 | }
|
---|
2048 |
|
---|
2049 | /**
|
---|
2050 | * @ingroup mdns
|
---|
2051 | * Activate MDNS responder for a network interface.
|
---|
2052 | * @param netif The network interface to activate.
|
---|
2053 | * @param hostname Name to use. Queries for <hostname>.local will be answered
|
---|
2054 | * with the IP addresses of the netif. The hostname will be copied, the
|
---|
2055 | * given pointer can be on the stack.
|
---|
2056 | * @param dns_ttl Validity time in seconds to send out for IP address data in DNS replies
|
---|
2057 | * @return ERR_OK if netif was added, an err_t otherwise
|
---|
2058 | */
|
---|
2059 | err_t
|
---|
2060 | mdns_resp_add_netif(struct netif *netif, const char *hostname, u32_t dns_ttl)
|
---|
2061 | {
|
---|
2062 | err_t res;
|
---|
2063 | struct mdns_host *mdns;
|
---|
2064 |
|
---|
2065 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2066 | LWIP_ERROR("mdns_resp_add_netif: netif != NULL", (netif != NULL), return ERR_VAL);
|
---|
2067 | LWIP_ERROR("mdns_resp_add_netif: Hostname too long", (strlen(hostname) <= MDNS_LABEL_MAXLEN), return ERR_VAL);
|
---|
2068 |
|
---|
2069 | LWIP_ASSERT("mdns_resp_add_netif: Double add", NETIF_TO_HOST(netif) == NULL);
|
---|
2070 | mdns = (struct mdns_host *) mem_calloc(1, sizeof(struct mdns_host));
|
---|
2071 | LWIP_ERROR("mdns_resp_add_netif: Alloc failed", (mdns != NULL), return ERR_MEM);
|
---|
2072 |
|
---|
2073 | netif_set_client_data(netif, mdns_netif_client_id, mdns);
|
---|
2074 |
|
---|
2075 | MEMCPY(&mdns->name, hostname, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(hostname)));
|
---|
2076 | mdns->dns_ttl = dns_ttl;
|
---|
2077 | mdns->probes_sent = 0;
|
---|
2078 | mdns->probing_state = MDNS_PROBING_NOT_STARTED;
|
---|
2079 |
|
---|
2080 | /* Join multicast groups */
|
---|
2081 | #if LWIP_IPV4
|
---|
2082 | res = igmp_joingroup_netif(netif, ip_2_ip4(&v4group));
|
---|
2083 | if (res != ERR_OK) {
|
---|
2084 | goto cleanup;
|
---|
2085 | }
|
---|
2086 | #endif
|
---|
2087 | #if LWIP_IPV6
|
---|
2088 | res = mld6_joingroup_netif(netif, ip_2_ip6(&v6group));
|
---|
2089 | if (res != ERR_OK) {
|
---|
2090 | goto cleanup;
|
---|
2091 | }
|
---|
2092 | #endif
|
---|
2093 |
|
---|
2094 | mdns_resp_restart(netif);
|
---|
2095 |
|
---|
2096 | return ERR_OK;
|
---|
2097 |
|
---|
2098 | cleanup:
|
---|
2099 | mem_free(mdns);
|
---|
2100 | netif_set_client_data(netif, mdns_netif_client_id, NULL);
|
---|
2101 | return res;
|
---|
2102 | }
|
---|
2103 |
|
---|
2104 | /**
|
---|
2105 | * @ingroup mdns
|
---|
2106 | * Stop responding to MDNS queries on this interface, leave multicast groups,
|
---|
2107 | * and free the helper structure and any of its services.
|
---|
2108 | * @param netif The network interface to remove.
|
---|
2109 | * @return ERR_OK if netif was removed, an err_t otherwise
|
---|
2110 | */
|
---|
2111 | err_t
|
---|
2112 | mdns_resp_remove_netif(struct netif *netif)
|
---|
2113 | {
|
---|
2114 | int i;
|
---|
2115 | struct mdns_host *mdns;
|
---|
2116 |
|
---|
2117 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2118 | LWIP_ASSERT("mdns_resp_remove_netif: Null pointer", netif);
|
---|
2119 | mdns = NETIF_TO_HOST(netif);
|
---|
2120 | LWIP_ERROR("mdns_resp_remove_netif: Not an active netif", (mdns != NULL), return ERR_VAL);
|
---|
2121 |
|
---|
2122 | if (mdns->probing_state == MDNS_PROBING_ONGOING) {
|
---|
2123 | sys_untimeout(mdns_probe, netif);
|
---|
2124 | }
|
---|
2125 |
|
---|
2126 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
2127 | struct mdns_service *service = mdns->services[i];
|
---|
2128 | if (service) {
|
---|
2129 | mem_free(service);
|
---|
2130 | }
|
---|
2131 | }
|
---|
2132 |
|
---|
2133 | /* Leave multicast groups */
|
---|
2134 | #if LWIP_IPV4
|
---|
2135 | igmp_leavegroup_netif(netif, ip_2_ip4(&v4group));
|
---|
2136 | #endif
|
---|
2137 | #if LWIP_IPV6
|
---|
2138 | mld6_leavegroup_netif(netif, ip_2_ip6(&v6group));
|
---|
2139 | #endif
|
---|
2140 |
|
---|
2141 | mem_free(mdns);
|
---|
2142 | netif_set_client_data(netif, mdns_netif_client_id, NULL);
|
---|
2143 | return ERR_OK;
|
---|
2144 | }
|
---|
2145 |
|
---|
2146 | /**
|
---|
2147 | * @ingroup mdns
|
---|
2148 | * Update MDNS hostname for a network interface.
|
---|
2149 | * @param netif The network interface to activate.
|
---|
2150 | * @param hostname Name to use. Queries for <hostname>.local will be answered
|
---|
2151 | * with the IP addresses of the netif. The hostname will be copied, the
|
---|
2152 | * given pointer can be on the stack.
|
---|
2153 | * @return ERR_OK if name could be set on netif, an err_t otherwise
|
---|
2154 | */
|
---|
2155 | err_t
|
---|
2156 | mdns_resp_rename_netif(struct netif *netif, const char *hostname)
|
---|
2157 | {
|
---|
2158 | struct mdns_host *mdns;
|
---|
2159 | size_t len;
|
---|
2160 |
|
---|
2161 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2162 | len = strlen(hostname);
|
---|
2163 | LWIP_ERROR("mdns_resp_rename_netif: netif != NULL", (netif != NULL), return ERR_VAL);
|
---|
2164 | LWIP_ERROR("mdns_resp_rename_netif: Hostname too long", (len <= MDNS_LABEL_MAXLEN), return ERR_VAL);
|
---|
2165 | mdns = NETIF_TO_HOST(netif);
|
---|
2166 | LWIP_ERROR("mdns_resp_rename_netif: Not an mdns netif", (mdns != NULL), return ERR_VAL);
|
---|
2167 |
|
---|
2168 | MEMCPY(&mdns->name, hostname, LWIP_MIN(MDNS_LABEL_MAXLEN, len));
|
---|
2169 | mdns->name[len] = '\0'; /* null termination in case new name is shorter than previous */
|
---|
2170 |
|
---|
2171 | mdns_resp_restart(netif);
|
---|
2172 |
|
---|
2173 | return ERR_OK;
|
---|
2174 | }
|
---|
2175 |
|
---|
2176 | /**
|
---|
2177 | * @ingroup mdns
|
---|
2178 | * Add a service to the selected network interface.
|
---|
2179 | * @param netif The network interface to publish this service on
|
---|
2180 | * @param name The name of the service
|
---|
2181 | * @param service The service type, like "_http"
|
---|
2182 | * @param proto The service protocol, DNSSD_PROTO_TCP for TCP ("_tcp") and DNSSD_PROTO_UDP
|
---|
2183 | * for others ("_udp")
|
---|
2184 | * @param port The port the service listens to
|
---|
2185 | * @param dns_ttl Validity time in seconds to send out for service data in DNS replies
|
---|
2186 | * @param txt_fn Callback to get TXT data. Will be called each time a TXT reply is created to
|
---|
2187 | * allow dynamic replies.
|
---|
2188 | * @param txt_data Userdata pointer for txt_fn
|
---|
2189 | * @return service_id if the service was added to the netif, an err_t otherwise
|
---|
2190 | */
|
---|
2191 | s8_t
|
---|
2192 | mdns_resp_add_service(struct netif *netif, const char *name, const char *service, enum mdns_sd_proto proto, u16_t port, u32_t dns_ttl, service_get_txt_fn_t txt_fn, void *txt_data)
|
---|
2193 | {
|
---|
2194 | s8_t i;
|
---|
2195 | s8_t slot = -1;
|
---|
2196 | struct mdns_service *srv;
|
---|
2197 | struct mdns_host *mdns;
|
---|
2198 |
|
---|
2199 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2200 | LWIP_ASSERT("mdns_resp_add_service: netif != NULL", netif);
|
---|
2201 | mdns = NETIF_TO_HOST(netif);
|
---|
2202 | LWIP_ERROR("mdns_resp_add_service: Not an mdns netif", (mdns != NULL), return ERR_VAL);
|
---|
2203 |
|
---|
2204 | LWIP_ERROR("mdns_resp_add_service: Name too long", (strlen(name) <= MDNS_LABEL_MAXLEN), return ERR_VAL);
|
---|
2205 | LWIP_ERROR("mdns_resp_add_service: Service too long", (strlen(service) <= MDNS_LABEL_MAXLEN), return ERR_VAL);
|
---|
2206 | LWIP_ERROR("mdns_resp_add_service: Bad proto (need TCP or UDP)", (proto == DNSSD_PROTO_TCP || proto == DNSSD_PROTO_UDP), return ERR_VAL);
|
---|
2207 |
|
---|
2208 | for (i = 0; i < MDNS_MAX_SERVICES; i++) {
|
---|
2209 | if (mdns->services[i] == NULL) {
|
---|
2210 | slot = i;
|
---|
2211 | break;
|
---|
2212 | }
|
---|
2213 | }
|
---|
2214 | LWIP_ERROR("mdns_resp_add_service: Service list full (increase MDNS_MAX_SERVICES)", (slot >= 0), return ERR_MEM);
|
---|
2215 |
|
---|
2216 | srv = (struct mdns_service *)mem_calloc(1, sizeof(struct mdns_service));
|
---|
2217 | LWIP_ERROR("mdns_resp_add_service: Alloc failed", (srv != NULL), return ERR_MEM);
|
---|
2218 |
|
---|
2219 | MEMCPY(&srv->name, name, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(name)));
|
---|
2220 | MEMCPY(&srv->service, service, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(service)));
|
---|
2221 | srv->txt_fn = txt_fn;
|
---|
2222 | srv->txt_userdata = txt_data;
|
---|
2223 | srv->proto = (u16_t)proto;
|
---|
2224 | srv->port = port;
|
---|
2225 | srv->dns_ttl = dns_ttl;
|
---|
2226 |
|
---|
2227 | mdns->services[slot] = srv;
|
---|
2228 |
|
---|
2229 | mdns_resp_restart(netif);
|
---|
2230 |
|
---|
2231 | return slot;
|
---|
2232 | }
|
---|
2233 |
|
---|
2234 | /**
|
---|
2235 | * @ingroup mdns
|
---|
2236 | * Delete a service on the selected network interface.
|
---|
2237 | * @param netif The network interface on which service should be removed
|
---|
2238 | * @param slot The service slot number returned by mdns_resp_add_service
|
---|
2239 | * @return ERR_OK if the service was removed from the netif, an err_t otherwise
|
---|
2240 | */
|
---|
2241 | err_t
|
---|
2242 | mdns_resp_del_service(struct netif *netif, s8_t slot)
|
---|
2243 | {
|
---|
2244 | struct mdns_host *mdns;
|
---|
2245 | struct mdns_service *srv;
|
---|
2246 | LWIP_ASSERT("mdns_resp_del_service: netif != NULL", netif);
|
---|
2247 | mdns = NETIF_TO_HOST(netif);
|
---|
2248 | LWIP_ERROR("mdns_resp_del_service: Not an mdns netif", (mdns != NULL), return ERR_VAL);
|
---|
2249 | LWIP_ERROR("mdns_resp_del_service: Invalid Service ID", (slot >= 0) && (slot < MDNS_MAX_SERVICES), return ERR_VAL);
|
---|
2250 | LWIP_ERROR("mdns_resp_del_service: Invalid Service ID", (mdns->services[slot] != NULL), return ERR_VAL);
|
---|
2251 |
|
---|
2252 | srv = mdns->services[slot];
|
---|
2253 | mdns->services[slot] = NULL;
|
---|
2254 | mem_free(srv);
|
---|
2255 | return ERR_OK;
|
---|
2256 | }
|
---|
2257 |
|
---|
2258 | /**
|
---|
2259 | * @ingroup mdns
|
---|
2260 | * Update name for an MDNS service.
|
---|
2261 | * @param netif The network interface to activate.
|
---|
2262 | * @param slot The service slot number returned by mdns_resp_add_service
|
---|
2263 | * @param name The new name for the service
|
---|
2264 | * @return ERR_OK if name could be set on service, an err_t otherwise
|
---|
2265 | */
|
---|
2266 | err_t
|
---|
2267 | mdns_resp_rename_service(struct netif *netif, s8_t slot, const char *name)
|
---|
2268 | {
|
---|
2269 | struct mdns_service *srv;
|
---|
2270 | struct mdns_host *mdns;
|
---|
2271 | size_t len;
|
---|
2272 |
|
---|
2273 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2274 | len = strlen(name);
|
---|
2275 | LWIP_ASSERT("mdns_resp_rename_service: netif != NULL", netif);
|
---|
2276 | mdns = NETIF_TO_HOST(netif);
|
---|
2277 | LWIP_ERROR("mdns_resp_rename_service: Not an mdns netif", (mdns != NULL), return ERR_VAL);
|
---|
2278 | LWIP_ERROR("mdns_resp_rename_service: Name too long", (len <= MDNS_LABEL_MAXLEN), return ERR_VAL);
|
---|
2279 | LWIP_ERROR("mdns_resp_rename_service: Invalid Service ID", (slot >= 0) && (slot < MDNS_MAX_SERVICES), return ERR_VAL);
|
---|
2280 | LWIP_ERROR("mdns_resp_rename_service: Invalid Service ID", (mdns->services[slot] != NULL), return ERR_VAL);
|
---|
2281 |
|
---|
2282 | srv = mdns->services[slot];
|
---|
2283 |
|
---|
2284 | MEMCPY(&srv->name, name, LWIP_MIN(MDNS_LABEL_MAXLEN, len));
|
---|
2285 | srv->name[len] = '\0'; /* null termination in case new name is shorter than previous */
|
---|
2286 |
|
---|
2287 | mdns_resp_restart(netif);
|
---|
2288 |
|
---|
2289 | return ERR_OK;
|
---|
2290 | }
|
---|
2291 |
|
---|
2292 | /**
|
---|
2293 | * @ingroup mdns
|
---|
2294 | * Call this function from inside the service_get_txt_fn_t callback to add text data.
|
---|
2295 | * Buffer for TXT data is 256 bytes, and each field is prefixed with a length byte.
|
---|
2296 | * @param service The service provided to the get_txt callback
|
---|
2297 | * @param txt String to add to the TXT field.
|
---|
2298 | * @param txt_len Length of string
|
---|
2299 | * @return ERR_OK if the string was added to the reply, an err_t otherwise
|
---|
2300 | */
|
---|
2301 | err_t
|
---|
2302 | mdns_resp_add_service_txtitem(struct mdns_service *service, const char *txt, u8_t txt_len)
|
---|
2303 | {
|
---|
2304 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2305 | LWIP_ASSERT("mdns_resp_add_service_txtitem: service != NULL", service);
|
---|
2306 |
|
---|
2307 | /* Use a mdns_domain struct to store txt chunks since it is the same encoding */
|
---|
2308 | return mdns_domain_add_label(&service->txtdata, txt, txt_len);
|
---|
2309 | }
|
---|
2310 |
|
---|
2311 | /**
|
---|
2312 | * @ingroup mdns
|
---|
2313 | * Send unsolicited answer containing all our known data
|
---|
2314 | * @param netif The network interface to send on
|
---|
2315 | */
|
---|
2316 | void
|
---|
2317 | mdns_resp_announce(struct netif *netif)
|
---|
2318 | {
|
---|
2319 | struct mdns_host* mdns;
|
---|
2320 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2321 | LWIP_ERROR("mdns_resp_announce: netif != NULL", (netif != NULL), return);
|
---|
2322 |
|
---|
2323 | mdns = NETIF_TO_HOST(netif);
|
---|
2324 | if (mdns == NULL) {
|
---|
2325 | return;
|
---|
2326 | }
|
---|
2327 |
|
---|
2328 | if (mdns->probing_state == MDNS_PROBING_COMPLETE) {
|
---|
2329 | /* Announce on IPv6 and IPv4 */
|
---|
2330 | #if LWIP_IPV6
|
---|
2331 | mdns_announce(netif, IP6_ADDR_ANY);
|
---|
2332 | #endif
|
---|
2333 | #if LWIP_IPV4
|
---|
2334 | if (!ip4_addr_isany_val(*netif_ip4_addr(netif))) {
|
---|
2335 | mdns_announce(netif, IP4_ADDR_ANY);
|
---|
2336 | }
|
---|
2337 | #endif
|
---|
2338 | } /* else: ip address changed while probing was ongoing? @todo reset counter to restart? */
|
---|
2339 | }
|
---|
2340 |
|
---|
2341 | /** Register a callback function that is called if probing is completed successfully
|
---|
2342 | * or with a conflict. */
|
---|
2343 | void
|
---|
2344 | mdns_resp_register_name_result_cb(mdns_name_result_cb_t cb)
|
---|
2345 | {
|
---|
2346 | mdns_name_result_cb = cb;
|
---|
2347 | }
|
---|
2348 |
|
---|
2349 | /**
|
---|
2350 | * @ingroup mdns
|
---|
2351 | * Restart mdns responder. Call this when cable is connected after being disconnected or
|
---|
2352 | * administrative interface is set up after being down
|
---|
2353 | * @param netif The network interface to send on
|
---|
2354 | */
|
---|
2355 | void
|
---|
2356 | mdns_resp_restart(struct netif *netif)
|
---|
2357 | {
|
---|
2358 | struct mdns_host* mdns;
|
---|
2359 | LWIP_ASSERT_CORE_LOCKED();
|
---|
2360 | LWIP_ERROR("mdns_resp_restart: netif != NULL", (netif != NULL), return);
|
---|
2361 |
|
---|
2362 | mdns = NETIF_TO_HOST(netif);
|
---|
2363 | if (mdns == NULL) {
|
---|
2364 | return;
|
---|
2365 | }
|
---|
2366 |
|
---|
2367 | if (mdns->probing_state == MDNS_PROBING_ONGOING) {
|
---|
2368 | sys_untimeout(mdns_probe, netif);
|
---|
2369 | }
|
---|
2370 | /* @todo if we've failed 15 times within a 10 second period we MUST wait 5 seconds (or wait 5 seconds every time except first)*/
|
---|
2371 | mdns->probes_sent = 0;
|
---|
2372 | mdns->probing_state = MDNS_PROBING_ONGOING;
|
---|
2373 | sys_timeout(MDNS_INITIAL_PROBE_DELAY_MS, mdns_probe, netif);
|
---|
2374 | }
|
---|
2375 |
|
---|
2376 | /**
|
---|
2377 | * @ingroup mdns
|
---|
2378 | * Initiate MDNS responder. Will open UDP sockets on port 5353
|
---|
2379 | */
|
---|
2380 | void
|
---|
2381 | mdns_resp_init(void)
|
---|
2382 | {
|
---|
2383 | err_t res;
|
---|
2384 |
|
---|
2385 | /* LWIP_ASSERT_CORE_LOCKED(); is checked by udp_new() */
|
---|
2386 |
|
---|
2387 | mdns_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
|
---|
2388 | LWIP_ASSERT("Failed to allocate pcb", mdns_pcb != NULL);
|
---|
2389 | #if LWIP_MULTICAST_TX_OPTIONS
|
---|
2390 | udp_set_multicast_ttl(mdns_pcb, MDNS_TTL);
|
---|
2391 | #else
|
---|
2392 | mdns_pcb->ttl = MDNS_TTL;
|
---|
2393 | #endif
|
---|
2394 | res = udp_bind(mdns_pcb, IP_ANY_TYPE, LWIP_IANA_PORT_MDNS);
|
---|
2395 | LWIP_UNUSED_ARG(res); /* in case of LWIP_NOASSERT */
|
---|
2396 | LWIP_ASSERT("Failed to bind pcb", res == ERR_OK);
|
---|
2397 | udp_recv(mdns_pcb, mdns_recv, NULL);
|
---|
2398 |
|
---|
2399 | mdns_netif_client_id = netif_alloc_client_data_id();
|
---|
2400 |
|
---|
2401 | #if MDNS_RESP_USENETIF_EXTCALLBACK
|
---|
2402 | /* register for netif events when started on first netif */
|
---|
2403 | netif_add_ext_callback(&netif_callback, mdns_netif_ext_status_callback);
|
---|
2404 | #endif
|
---|
2405 | }
|
---|
2406 |
|
---|
2407 | #endif /* LWIP_MDNS_RESPONDER */
|
---|