1 | /**
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2 | * @file
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3 | * Multicast listener discovery
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4 | *
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5 | * @defgroup mld6 MLD6
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6 | * @ingroup ip6
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7 | * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710.
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8 | * No support for MLDv2.\n
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9 | * Note: The allnodes (ff01::1, ff02::1) group is assumed be received by your
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10 | * netif since it must always be received for correct IPv6 operation (e.g. SLAAC).
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11 | * Ensure the netif filters are configured accordingly!\n
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12 | * The netif flags also need NETIF_FLAG_MLD6 flag set to enable MLD6 on a
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13 | * netif ("netif->flags |= NETIF_FLAG_MLD6;").\n
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14 | * To be called from TCPIP thread.
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15 | */
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16 |
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17 | /*
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18 | * Copyright (c) 2010 Inico Technologies Ltd.
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19 | * All rights reserved.
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20 | *
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21 | * Redistribution and use in source and binary forms, with or without modification,
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22 | * are permitted provided that the following conditions are met:
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23 | *
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24 | * 1. Redistributions of source code must retain the above copyright notice,
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25 | * this list of conditions and the following disclaimer.
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26 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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27 | * this list of conditions and the following disclaimer in the documentation
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28 | * and/or other materials provided with the distribution.
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29 | * 3. The name of the author may not be used to endorse or promote products
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30 | * derived from this software without specific prior written permission.
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31 | *
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32 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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33 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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34 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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35 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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36 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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37 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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38 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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39 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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41 | * OF SUCH DAMAGE.
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42 | *
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43 | * This file is part of the lwIP TCP/IP stack.
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44 | *
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45 | * Author: Ivan Delamer <delamer@inicotech.com>
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46 | *
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47 | *
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48 | * Please coordinate changes and requests with Ivan Delamer
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49 | * <delamer@inicotech.com>
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50 | */
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51 |
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52 | /* Based on igmp.c implementation of igmp v2 protocol */
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53 |
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54 | #include "lwip/opt.h"
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55 |
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56 | #if LWIP_IPV6 && LWIP_IPV6_MLD /* don't build if not configured for use in lwipopts.h */
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57 |
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58 | #include "lwip/mld6.h"
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59 | #include "lwip/prot/mld6.h"
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60 | #include "lwip/icmp6.h"
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61 | #include "lwip/ip6.h"
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62 | #include "lwip/ip6_addr.h"
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63 | #include "lwip/ip.h"
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64 | #include "lwip/inet_chksum.h"
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65 | #include "lwip/pbuf.h"
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66 | #include "lwip/netif.h"
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67 | #include "lwip/memp.h"
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68 | #include "lwip/stats.h"
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69 |
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70 | #include <string.h>
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71 |
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72 |
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73 | /*
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74 | * MLD constants
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75 | */
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76 | #define MLD6_HL 1
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77 | #define MLD6_JOIN_DELAYING_MEMBER_TMR_MS (500)
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78 |
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79 | #define MLD6_GROUP_NON_MEMBER 0
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80 | #define MLD6_GROUP_DELAYING_MEMBER 1
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81 | #define MLD6_GROUP_IDLE_MEMBER 2
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82 |
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83 | /* Forward declarations. */
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84 | static struct mld_group *mld6_new_group(struct netif *ifp, const ip6_addr_t *addr);
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85 | static err_t mld6_remove_group(struct netif *netif, struct mld_group *group);
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86 | static void mld6_delayed_report(struct mld_group *group, u16_t maxresp);
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87 | static void mld6_send(struct netif *netif, struct mld_group *group, u8_t type);
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88 |
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89 |
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90 | /**
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91 | * Stop MLD processing on interface
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92 | *
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93 | * @param netif network interface on which stop MLD processing
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94 | */
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95 | err_t
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96 | mld6_stop(struct netif *netif)
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97 | {
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98 | struct mld_group *group = netif_mld6_data(netif);
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99 |
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100 | netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, NULL);
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101 |
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102 | while (group != NULL) {
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103 | struct mld_group *next = group->next; /* avoid use-after-free below */
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104 |
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105 | /* disable the group at the MAC level */
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106 | if (netif->mld_mac_filter != NULL) {
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107 | netif->mld_mac_filter(netif, &(group->group_address), NETIF_DEL_MAC_FILTER);
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108 | }
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109 |
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110 | /* free group */
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111 | memp_free(MEMP_MLD6_GROUP, group);
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112 |
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113 | /* move to "next" */
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114 | group = next;
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115 | }
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116 | return ERR_OK;
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117 | }
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118 |
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119 | /**
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120 | * Report MLD memberships for this interface
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121 | *
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122 | * @param netif network interface on which report MLD memberships
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123 | */
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124 | void
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125 | mld6_report_groups(struct netif *netif)
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126 | {
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127 | struct mld_group *group = netif_mld6_data(netif);
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128 |
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129 | while (group != NULL) {
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130 | mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS);
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131 | group = group->next;
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132 | }
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133 | }
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134 |
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135 | /**
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136 | * Search for a group that is joined on a netif
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137 | *
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138 | * @param ifp the network interface for which to look
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139 | * @param addr the group ipv6 address to search for
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140 | * @return a struct mld_group* if the group has been found,
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141 | * NULL if the group wasn't found.
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142 | */
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143 | struct mld_group *
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144 | mld6_lookfor_group(struct netif *ifp, const ip6_addr_t *addr)
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145 | {
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146 | struct mld_group *group = netif_mld6_data(ifp);
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147 |
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148 | while (group != NULL) {
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149 | if (ip6_addr_cmp(&(group->group_address), addr)) {
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150 | return group;
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151 | }
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152 | group = group->next;
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153 | }
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154 |
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155 | return NULL;
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156 | }
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157 |
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158 |
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159 | /**
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160 | * create a new group
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161 | *
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162 | * @param ifp the network interface for which to create
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163 | * @param addr the new group ipv6
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164 | * @return a struct mld_group*,
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165 | * NULL on memory error.
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166 | */
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167 | static struct mld_group *
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168 | mld6_new_group(struct netif *ifp, const ip6_addr_t *addr)
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169 | {
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170 | struct mld_group *group;
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171 |
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172 | group = (struct mld_group *)memp_malloc(MEMP_MLD6_GROUP);
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173 | if (group != NULL) {
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174 | ip6_addr_set(&(group->group_address), addr);
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175 | group->timer = 0; /* Not running */
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176 | group->group_state = MLD6_GROUP_IDLE_MEMBER;
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177 | group->last_reporter_flag = 0;
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178 | group->use = 0;
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179 | group->next = netif_mld6_data(ifp);
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180 |
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181 | netif_set_client_data(ifp, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, group);
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182 | }
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183 |
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184 | return group;
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185 | }
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186 |
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187 | /**
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188 | * Remove a group from the mld_group_list, but do not free it yet
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189 | *
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190 | * @param group the group to remove
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191 | * @return ERR_OK if group was removed from the list, an err_t otherwise
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192 | */
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193 | static err_t
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194 | mld6_remove_group(struct netif *netif, struct mld_group *group)
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195 | {
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196 | err_t err = ERR_OK;
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197 |
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198 | /* Is it the first group? */
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199 | if (netif_mld6_data(netif) == group) {
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200 | netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, group->next);
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201 | } else {
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202 | /* look for group further down the list */
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203 | struct mld_group *tmpGroup;
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204 | for (tmpGroup = netif_mld6_data(netif); tmpGroup != NULL; tmpGroup = tmpGroup->next) {
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205 | if (tmpGroup->next == group) {
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206 | tmpGroup->next = group->next;
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207 | break;
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208 | }
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209 | }
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210 | /* Group not find group */
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211 | if (tmpGroup == NULL) {
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212 | err = ERR_ARG;
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213 | }
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214 | }
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215 |
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216 | return err;
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217 | }
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218 |
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219 |
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220 | /**
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221 | * Process an input MLD message. Called by icmp6_input.
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222 | *
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223 | * @param p the mld packet, p->payload pointing to the icmpv6 header
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224 | * @param inp the netif on which this packet was received
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225 | */
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226 | void
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227 | mld6_input(struct pbuf *p, struct netif *inp)
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228 | {
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229 | struct mld_header *mld_hdr;
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230 | struct mld_group *group;
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231 |
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232 | MLD6_STATS_INC(mld6.recv);
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233 |
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234 | /* Check that mld header fits in packet. */
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235 | if (p->len < sizeof(struct mld_header)) {
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236 | /* @todo debug message */
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237 | pbuf_free(p);
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238 | MLD6_STATS_INC(mld6.lenerr);
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239 | MLD6_STATS_INC(mld6.drop);
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240 | return;
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241 | }
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242 |
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243 | mld_hdr = (struct mld_header *)p->payload;
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244 |
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245 | switch (mld_hdr->type) {
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246 | case ICMP6_TYPE_MLQ: /* Multicast listener query. */
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247 | /* Is it a general query? */
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248 | if (ip6_addr_isallnodes_linklocal(ip6_current_dest_addr()) &&
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249 | ip6_addr_isany(&(mld_hdr->multicast_address))) {
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250 | MLD6_STATS_INC(mld6.rx_general);
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251 | /* Report all groups, except all nodes group, and if-local groups. */
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252 | group = netif_mld6_data(inp);
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253 | while (group != NULL) {
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254 | if ((!(ip6_addr_ismulticast_iflocal(&(group->group_address)))) &&
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255 | (!(ip6_addr_isallnodes_linklocal(&(group->group_address))))) {
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256 | mld6_delayed_report(group, mld_hdr->max_resp_delay);
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257 | }
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258 | group = group->next;
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259 | }
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260 | } else {
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261 | /* Have we joined this group?
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262 | * We use IP6 destination address to have a memory aligned copy.
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263 | * mld_hdr->multicast_address should be the same. */
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264 | MLD6_STATS_INC(mld6.rx_group);
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265 | group = mld6_lookfor_group(inp, ip6_current_dest_addr());
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266 | if (group != NULL) {
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267 | /* Schedule a report. */
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268 | mld6_delayed_report(group, mld_hdr->max_resp_delay);
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269 | }
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270 | }
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271 | break; /* ICMP6_TYPE_MLQ */
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272 | case ICMP6_TYPE_MLR: /* Multicast listener report. */
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273 | /* Have we joined this group?
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274 | * We use IP6 destination address to have a memory aligned copy.
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275 | * mld_hdr->multicast_address should be the same. */
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276 | MLD6_STATS_INC(mld6.rx_report);
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277 | group = mld6_lookfor_group(inp, ip6_current_dest_addr());
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278 | if (group != NULL) {
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279 | /* If we are waiting to report, cancel it. */
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280 | if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
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281 | group->timer = 0; /* stopped */
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282 | group->group_state = MLD6_GROUP_IDLE_MEMBER;
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283 | group->last_reporter_flag = 0;
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284 | }
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285 | }
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286 | break; /* ICMP6_TYPE_MLR */
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287 | case ICMP6_TYPE_MLD: /* Multicast listener done. */
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288 | /* Do nothing, router will query us. */
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289 | break; /* ICMP6_TYPE_MLD */
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290 | default:
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291 | MLD6_STATS_INC(mld6.proterr);
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292 | MLD6_STATS_INC(mld6.drop);
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293 | break;
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294 | }
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295 |
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296 | pbuf_free(p);
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297 | }
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298 |
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299 | /**
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300 | * @ingroup mld6
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301 | * Join a group on one or all network interfaces.
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302 | *
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303 | * If the group is to be joined on all interfaces, the given group address must
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304 | * not have a zone set (i.e., it must have its zone index set to IP6_NO_ZONE).
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305 | * If the group is to be joined on one particular interface, the given group
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306 | * address may or may not have a zone set.
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307 | *
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308 | * @param srcaddr ipv6 address (zoned) of the network interface which should
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309 | * join a new group. If IP6_ADDR_ANY6, join on all netifs
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310 | * @param groupaddr the ipv6 address of the group to join (possibly but not
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311 | * necessarily zoned)
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312 | * @return ERR_OK if group was joined on the netif(s), an err_t otherwise
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313 | */
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314 | err_t
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315 | mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
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316 | {
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317 | err_t err = ERR_VAL; /* no matching interface */
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318 | struct netif *netif;
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319 |
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320 | LWIP_ASSERT_CORE_LOCKED();
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321 |
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322 | /* loop through netif's */
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323 | NETIF_FOREACH(netif) {
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324 | /* Should we join this interface ? */
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325 | if (ip6_addr_isany(srcaddr) ||
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326 | netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
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327 | err = mld6_joingroup_netif(netif, groupaddr);
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328 | if (err != ERR_OK) {
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329 | return err;
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330 | }
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331 | }
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332 | }
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333 |
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334 | return err;
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335 | }
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336 |
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337 | /**
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338 | * @ingroup mld6
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339 | * Join a group on a network interface.
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340 | *
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341 | * @param netif the network interface which should join a new group.
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342 | * @param groupaddr the ipv6 address of the group to join (possibly but not
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343 | * necessarily zoned)
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344 | * @return ERR_OK if group was joined on the netif, an err_t otherwise
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345 | */
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346 | err_t
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347 | mld6_joingroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
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348 | {
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349 | struct mld_group *group;
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350 | #if LWIP_IPV6_SCOPES
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351 | ip6_addr_t ip6addr;
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352 |
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353 | /* If the address has a particular scope but no zone set, use the netif to
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354 | * set one now. Within the mld6 module, all addresses are properly zoned. */
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355 | if (ip6_addr_lacks_zone(groupaddr, IP6_MULTICAST)) {
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356 | ip6_addr_set(&ip6addr, groupaddr);
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357 | ip6_addr_assign_zone(&ip6addr, IP6_MULTICAST, netif);
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358 | groupaddr = &ip6addr;
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359 | }
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360 | IP6_ADDR_ZONECHECK_NETIF(groupaddr, netif);
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361 | #endif /* LWIP_IPV6_SCOPES */
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362 |
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363 | LWIP_ASSERT_CORE_LOCKED();
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364 |
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365 | /* find group or create a new one if not found */
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366 | group = mld6_lookfor_group(netif, groupaddr);
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367 |
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368 | if (group == NULL) {
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369 | /* Joining a new group. Create a new group entry. */
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370 | group = mld6_new_group(netif, groupaddr);
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371 | if (group == NULL) {
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372 | return ERR_MEM;
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373 | }
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374 |
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375 | /* Activate this address on the MAC layer. */
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376 | if (netif->mld_mac_filter != NULL) {
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377 | netif->mld_mac_filter(netif, groupaddr, NETIF_ADD_MAC_FILTER);
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378 | }
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379 |
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380 | /* Report our membership. */
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381 | MLD6_STATS_INC(mld6.tx_report);
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382 | mld6_send(netif, group, ICMP6_TYPE_MLR);
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383 | mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS);
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384 | }
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385 |
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386 | /* Increment group use */
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387 | group->use++;
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388 | return ERR_OK;
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389 | }
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390 |
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391 | /**
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392 | * @ingroup mld6
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393 | * Leave a group on a network interface.
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394 | *
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395 | * Zoning of address follows the same rules as @ref mld6_joingroup.
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396 | *
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397 | * @param srcaddr ipv6 address (zoned) of the network interface which should
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398 | * leave the group. If IP6_ADDR_ANY6, leave on all netifs
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399 | * @param groupaddr the ipv6 address of the group to leave (possibly, but not
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400 | * necessarily zoned)
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401 | * @return ERR_OK if group was left on the netif(s), an err_t otherwise
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402 | */
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403 | err_t
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404 | mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
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405 | {
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406 | err_t err = ERR_VAL; /* no matching interface */
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407 | struct netif *netif;
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408 |
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409 | LWIP_ASSERT_CORE_LOCKED();
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410 |
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411 | /* loop through netif's */
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412 | NETIF_FOREACH(netif) {
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413 | /* Should we leave this interface ? */
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414 | if (ip6_addr_isany(srcaddr) ||
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415 | netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
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416 | err_t res = mld6_leavegroup_netif(netif, groupaddr);
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417 | if (err != ERR_OK) {
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418 | /* Store this result if we have not yet gotten a success */
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419 | err = res;
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420 | }
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421 | }
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422 | }
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423 |
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424 | return err;
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425 | }
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426 |
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427 | /**
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428 | * @ingroup mld6
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429 | * Leave a group on a network interface.
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430 | *
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431 | * @param netif the network interface which should leave the group.
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432 | * @param groupaddr the ipv6 address of the group to leave (possibly, but not
|
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433 | * necessarily zoned)
|
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434 | * @return ERR_OK if group was left on the netif, an err_t otherwise
|
---|
435 | */
|
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436 | err_t
|
---|
437 | mld6_leavegroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
|
---|
438 | {
|
---|
439 | struct mld_group *group;
|
---|
440 | #if LWIP_IPV6_SCOPES
|
---|
441 | ip6_addr_t ip6addr;
|
---|
442 |
|
---|
443 | if (ip6_addr_lacks_zone(groupaddr, IP6_MULTICAST)) {
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444 | ip6_addr_set(&ip6addr, groupaddr);
|
---|
445 | ip6_addr_assign_zone(&ip6addr, IP6_MULTICAST, netif);
|
---|
446 | groupaddr = &ip6addr;
|
---|
447 | }
|
---|
448 | IP6_ADDR_ZONECHECK_NETIF(groupaddr, netif);
|
---|
449 | #endif /* LWIP_IPV6_SCOPES */
|
---|
450 |
|
---|
451 | LWIP_ASSERT_CORE_LOCKED();
|
---|
452 |
|
---|
453 | /* find group */
|
---|
454 | group = mld6_lookfor_group(netif, groupaddr);
|
---|
455 |
|
---|
456 | if (group != NULL) {
|
---|
457 | /* Leave if there is no other use of the group */
|
---|
458 | if (group->use <= 1) {
|
---|
459 | /* Remove the group from the list */
|
---|
460 | mld6_remove_group(netif, group);
|
---|
461 |
|
---|
462 | /* If we are the last reporter for this group */
|
---|
463 | if (group->last_reporter_flag) {
|
---|
464 | MLD6_STATS_INC(mld6.tx_leave);
|
---|
465 | mld6_send(netif, group, ICMP6_TYPE_MLD);
|
---|
466 | }
|
---|
467 |
|
---|
468 | /* Disable the group at the MAC level */
|
---|
469 | if (netif->mld_mac_filter != NULL) {
|
---|
470 | netif->mld_mac_filter(netif, groupaddr, NETIF_DEL_MAC_FILTER);
|
---|
471 | }
|
---|
472 |
|
---|
473 | /* free group struct */
|
---|
474 | memp_free(MEMP_MLD6_GROUP, group);
|
---|
475 | } else {
|
---|
476 | /* Decrement group use */
|
---|
477 | group->use--;
|
---|
478 | }
|
---|
479 |
|
---|
480 | /* Left group */
|
---|
481 | return ERR_OK;
|
---|
482 | }
|
---|
483 |
|
---|
484 | /* Group not found */
|
---|
485 | return ERR_VAL;
|
---|
486 | }
|
---|
487 |
|
---|
488 |
|
---|
489 | /**
|
---|
490 | * Periodic timer for mld processing. Must be called every
|
---|
491 | * MLD6_TMR_INTERVAL milliseconds (100).
|
---|
492 | *
|
---|
493 | * When a delaying member expires, a membership report is sent.
|
---|
494 | */
|
---|
495 | void
|
---|
496 | mld6_tmr(void)
|
---|
497 | {
|
---|
498 | struct netif *netif;
|
---|
499 |
|
---|
500 | NETIF_FOREACH(netif) {
|
---|
501 | struct mld_group *group = netif_mld6_data(netif);
|
---|
502 |
|
---|
503 | while (group != NULL) {
|
---|
504 | if (group->timer > 0) {
|
---|
505 | group->timer--;
|
---|
506 | if (group->timer == 0) {
|
---|
507 | /* If the state is MLD6_GROUP_DELAYING_MEMBER then we send a report for this group */
|
---|
508 | if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
|
---|
509 | MLD6_STATS_INC(mld6.tx_report);
|
---|
510 | mld6_send(netif, group, ICMP6_TYPE_MLR);
|
---|
511 | group->group_state = MLD6_GROUP_IDLE_MEMBER;
|
---|
512 | }
|
---|
513 | }
|
---|
514 | }
|
---|
515 | group = group->next;
|
---|
516 | }
|
---|
517 | }
|
---|
518 | }
|
---|
519 |
|
---|
520 | /**
|
---|
521 | * Schedule a delayed membership report for a group
|
---|
522 | *
|
---|
523 | * @param group the mld_group for which "delaying" membership report
|
---|
524 | * should be sent
|
---|
525 | * @param maxresp_in the max resp delay provided in the query
|
---|
526 | */
|
---|
527 | static void
|
---|
528 | mld6_delayed_report(struct mld_group *group, u16_t maxresp_in)
|
---|
529 | {
|
---|
530 | /* Convert maxresp from milliseconds to tmr ticks */
|
---|
531 | u16_t maxresp = maxresp_in / MLD6_TMR_INTERVAL;
|
---|
532 | if (maxresp == 0) {
|
---|
533 | maxresp = 1;
|
---|
534 | }
|
---|
535 |
|
---|
536 | #ifdef LWIP_RAND
|
---|
537 | /* Randomize maxresp. (if LWIP_RAND is supported) */
|
---|
538 | maxresp = (u16_t)(LWIP_RAND() % maxresp);
|
---|
539 | if (maxresp == 0) {
|
---|
540 | maxresp = 1;
|
---|
541 | }
|
---|
542 | #endif /* LWIP_RAND */
|
---|
543 |
|
---|
544 | /* Apply timer value if no report has been scheduled already. */
|
---|
545 | if ((group->group_state == MLD6_GROUP_IDLE_MEMBER) ||
|
---|
546 | ((group->group_state == MLD6_GROUP_DELAYING_MEMBER) &&
|
---|
547 | ((group->timer == 0) || (maxresp < group->timer)))) {
|
---|
548 | group->timer = maxresp;
|
---|
549 | group->group_state = MLD6_GROUP_DELAYING_MEMBER;
|
---|
550 | }
|
---|
551 | }
|
---|
552 |
|
---|
553 | /**
|
---|
554 | * Send a MLD message (report or done).
|
---|
555 | *
|
---|
556 | * An IPv6 hop-by-hop options header with a router alert option
|
---|
557 | * is prepended.
|
---|
558 | *
|
---|
559 | * @param group the group to report or quit
|
---|
560 | * @param type ICMP6_TYPE_MLR (report) or ICMP6_TYPE_MLD (done)
|
---|
561 | */
|
---|
562 | static void
|
---|
563 | mld6_send(struct netif *netif, struct mld_group *group, u8_t type)
|
---|
564 | {
|
---|
565 | struct mld_header *mld_hdr;
|
---|
566 | struct pbuf *p;
|
---|
567 | const ip6_addr_t *src_addr;
|
---|
568 |
|
---|
569 | /* Allocate a packet. Size is MLD header + IPv6 Hop-by-hop options header. */
|
---|
570 | p = pbuf_alloc(PBUF_IP, sizeof(struct mld_header) + MLD6_HBH_HLEN, PBUF_RAM);
|
---|
571 | if (p == NULL) {
|
---|
572 | MLD6_STATS_INC(mld6.memerr);
|
---|
573 | return;
|
---|
574 | }
|
---|
575 |
|
---|
576 | /* Move to make room for Hop-by-hop options header. */
|
---|
577 | if (pbuf_remove_header(p, MLD6_HBH_HLEN)) {
|
---|
578 | pbuf_free(p);
|
---|
579 | MLD6_STATS_INC(mld6.lenerr);
|
---|
580 | return;
|
---|
581 | }
|
---|
582 |
|
---|
583 | /* Select our source address. */
|
---|
584 | if (!ip6_addr_isvalid(netif_ip6_addr_state(netif, 0))) {
|
---|
585 | /* This is a special case, when we are performing duplicate address detection.
|
---|
586 | * We must join the multicast group, but we don't have a valid address yet. */
|
---|
587 | src_addr = IP6_ADDR_ANY6;
|
---|
588 | } else {
|
---|
589 | /* Use link-local address as source address. */
|
---|
590 | src_addr = netif_ip6_addr(netif, 0);
|
---|
591 | }
|
---|
592 |
|
---|
593 | /* MLD message header pointer. */
|
---|
594 | mld_hdr = (struct mld_header *)p->payload;
|
---|
595 |
|
---|
596 | /* Set fields. */
|
---|
597 | mld_hdr->type = type;
|
---|
598 | mld_hdr->code = 0;
|
---|
599 | mld_hdr->chksum = 0;
|
---|
600 | mld_hdr->max_resp_delay = 0;
|
---|
601 | mld_hdr->reserved = 0;
|
---|
602 | ip6_addr_copy_to_packed(mld_hdr->multicast_address, group->group_address);
|
---|
603 |
|
---|
604 | #if CHECKSUM_GEN_ICMP6
|
---|
605 | IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP6) {
|
---|
606 | mld_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len,
|
---|
607 | src_addr, &(group->group_address));
|
---|
608 | }
|
---|
609 | #endif /* CHECKSUM_GEN_ICMP6 */
|
---|
610 |
|
---|
611 | /* Add hop-by-hop headers options: router alert with MLD value. */
|
---|
612 | ip6_options_add_hbh_ra(p, IP6_NEXTH_ICMP6, IP6_ROUTER_ALERT_VALUE_MLD);
|
---|
613 |
|
---|
614 | if (type == ICMP6_TYPE_MLR) {
|
---|
615 | /* Remember we were the last to report */
|
---|
616 | group->last_reporter_flag = 1;
|
---|
617 | }
|
---|
618 |
|
---|
619 | /* Send the packet out. */
|
---|
620 | MLD6_STATS_INC(mld6.xmit);
|
---|
621 | ip6_output_if(p, (ip6_addr_isany(src_addr)) ? NULL : src_addr, &(group->group_address),
|
---|
622 | MLD6_HL, 0, IP6_NEXTH_HOPBYHOP, netif);
|
---|
623 | pbuf_free(p);
|
---|
624 | }
|
---|
625 |
|
---|
626 | #endif /* LWIP_IPV6 */
|
---|