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