| /** |
| * @file |
| * |
| * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710. |
| * No support for MLDv2. |
| */ |
| |
| /* |
| * Copyright (c) 2010 Inico Technologies Ltd. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without modification, |
| * are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| * OF SUCH DAMAGE. |
| * |
| * This file is part of the lwIP TCP/IP stack. |
| * |
| * Author: Ivan Delamer <delamer@inicotech.com> |
| * |
| * |
| * Please coordinate changes and requests with Ivan Delamer |
| * <delamer@inicotech.com> |
| */ |
| |
| /* Based on igmp.c implementation of igmp v2 protocol */ |
| |
| #include "lwip/opt.h" |
| |
| #if LWIP_IPV6 && LWIP_IPV6_MLD /* don't build if not configured for use in lwipopts.h */ |
| |
| #include "lwip/mld6.h" |
| #include "lwip/icmp6.h" |
| #include "lwip/ip6.h" |
| #include "lwip/ip6_addr.h" |
| #include "lwip/inet_chksum.h" |
| #include "lwip/pbuf.h" |
| #include "lwip/netif.h" |
| #include "lwip/memp.h" |
| #include "lwip/stats.h" |
| |
| #include <string.h> |
| |
| |
| /* |
| * MLD constants |
| */ |
| #define MLD6_HL 1 |
| #define MLD6_JOIN_DELAYING_MEMBER_TMR_MS (500) |
| |
| #define MLD6_GROUP_NON_MEMBER 0 |
| #define MLD6_GROUP_DELAYING_MEMBER 1 |
| #define MLD6_GROUP_IDLE_MEMBER 2 |
| |
| |
| /* The list of joined groups. */ |
| static struct mld_group* mld_group_list; |
| |
| |
| /* Forward declarations. */ |
| static struct mld_group * mld6_new_group(struct netif *ifp, ip6_addr_t *addr); |
| static err_t mld6_free_group(struct mld_group *group); |
| static void mld6_delayed_report(struct mld_group *group, u16_t maxresp); |
| static void mld6_send(struct mld_group *group, u8_t type); |
| |
| |
| /** |
| * Stop MLD processing on interface |
| * |
| * @param netif network interface on which stop MLD processing |
| */ |
| err_t |
| mld6_stop(struct netif *netif) |
| { |
| err_t err = ERR_OK; |
| struct mld_group *group = mld_group_list; |
| struct mld_group *prev = NULL; |
| struct mld_group *next; |
| |
| /* look for groups joined on this interface further down the list */ |
| while (group != NULL) { |
| next = group->next; |
| /* is it a group joined on this interface? */ |
| if (group->netif == netif) { |
| /* is it the first group of the list? */ |
| if (group == mld_group_list) { |
| mld_group_list = next; |
| } |
| /* is there a "previous" group defined? */ |
| if (prev != NULL) { |
| prev->next = next; |
| } |
| /* disable the group at the MAC level */ |
| if (netif->mld_mac_filter != NULL) { |
| err_t macFilterErr; |
| |
| macFilterErr = netif->mld_mac_filter(netif, &(group->group_address), MLD6_DEL_MAC_FILTER); |
| |
| /* If there was an error, don't overwrite it */ |
| if (macFilterErr != ERR_OK) { |
| err = macFilterErr; |
| } |
| } |
| /* free group */ |
| memp_free(MEMP_MLD6_GROUP, group); |
| } else { |
| /* change the "previous" */ |
| prev = group; |
| } |
| /* move to "next" */ |
| group = next; |
| } |
| return err; |
| } |
| |
| /** |
| * Report MLD memberships for this interface |
| * |
| * @param netif network interface on which report MLD memberships |
| */ |
| void |
| mld6_report_groups(struct netif *netif) |
| { |
| struct mld_group *group = mld_group_list; |
| |
| while (group != NULL) { |
| if (group->netif == netif) { |
| mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS); |
| } |
| group = group->next; |
| } |
| } |
| |
| /** |
| * Search for a group that is joined on a netif |
| * |
| * @param ifp the network interface for which to look |
| * @param addr the group ipv6 address to search for |
| * @return a struct mld_group* if the group has been found, |
| * NULL if the group wasn't found. |
| */ |
| struct mld_group * |
| mld6_lookfor_group(struct netif *ifp, ip6_addr_t *addr) |
| { |
| struct mld_group *group = mld_group_list; |
| |
| while (group != NULL) { |
| if ((group->netif == ifp) && (ip6_addr_cmp(&(group->group_address), addr))) { |
| return group; |
| } |
| group = group->next; |
| } |
| |
| return NULL; |
| } |
| |
| extern void mld6_timer(void *arg); |
| /** |
| * create a new group |
| * |
| * @param ifp the network interface for which to create |
| * @param addr the new group ipv6 |
| * @return a struct mld_group*, |
| * NULL on memory error. |
| */ |
| static struct mld_group * |
| mld6_new_group(struct netif *ifp, ip6_addr_t *addr) |
| { |
| struct mld_group *group; |
| |
| if (mld_group_list == NULL) |
| sys_timeout(MLD6_TMR_INTERVAL, mld6_timer, NULL); |
| |
| group = (struct mld_group *)memp_malloc(MEMP_MLD6_GROUP); |
| if (group != NULL) { |
| group->netif = ifp; |
| ip6_addr_set(&(group->group_address), addr); |
| group->timer = 0; /* Not running */ |
| group->group_state = MLD6_GROUP_IDLE_MEMBER; |
| group->last_reporter_flag = 0; |
| group->use = 0; |
| group->next = mld_group_list; |
| |
| mld_group_list = group; |
| } |
| |
| return group; |
| } |
| |
| /** |
| * Remove a group in the mld_group_list and free |
| * |
| * @param group the group to remove |
| * @return ERR_OK if group was removed from the list, an err_t otherwise |
| */ |
| static err_t |
| mld6_free_group(struct mld_group *group) |
| { |
| err_t err = ERR_OK; |
| |
| /* Is it the first group? */ |
| if (mld_group_list == group) { |
| mld_group_list = group->next; |
| } else { |
| /* look for group further down the list */ |
| struct mld_group *tmpGroup; |
| for (tmpGroup = mld_group_list; tmpGroup != NULL; tmpGroup = tmpGroup->next) { |
| if (tmpGroup->next == group) { |
| tmpGroup->next = group->next; |
| break; |
| } |
| } |
| /* Group not find group */ |
| if (tmpGroup == NULL) |
| err = ERR_ARG; |
| } |
| /* free group */ |
| memp_free(MEMP_MLD6_GROUP, group); |
| |
| return err; |
| } |
| |
| |
| /** |
| * Process an input MLD message. Called by icmp6_input. |
| * |
| * @param p the mld packet, p->payload pointing to the icmpv6 header |
| * @param inp the netif on which this packet was received |
| */ |
| void |
| mld6_input(struct pbuf *p, struct netif *inp) |
| { |
| struct mld_header * mld_hdr; |
| struct mld_group* group; |
| |
| MLD6_STATS_INC(mld6.recv); |
| |
| /* Check that mld header fits in packet. */ |
| if (p->len < sizeof(struct mld_header)) { |
| /* TODO debug message */ |
| pbuf_free(p); |
| MLD6_STATS_INC(mld6.lenerr); |
| MLD6_STATS_INC(mld6.drop); |
| return; |
| } |
| |
| mld_hdr = (struct mld_header *)p->payload; |
| |
| switch (mld_hdr->type) { |
| case ICMP6_TYPE_MLQ: /* Multicast listener query. */ |
| { |
| /* Is it a general query? */ |
| if (ip6_addr_isallnodes_linklocal(ip6_current_dest_addr()) && |
| ip6_addr_isany(&(mld_hdr->multicast_address))) { |
| MLD6_STATS_INC(mld6.rx_general); |
| /* Report all groups, except all nodes group, and if-local groups. */ |
| group = mld_group_list; |
| while (group != NULL) { |
| if ((group->netif == inp) && |
| (!(ip6_addr_ismulticast_iflocal(&(group->group_address)))) && |
| (!(ip6_addr_isallnodes_linklocal(&(group->group_address))))) { |
| mld6_delayed_report(group, mld_hdr->max_resp_delay); |
| } |
| group = group->next; |
| } |
| } |
| else { |
| /* Have we joined this group? |
| * We use IP6 destination address to have a memory aligned copy. |
| * mld_hdr->multicast_address should be the same. */ |
| MLD6_STATS_INC(mld6.rx_group); |
| group = mld6_lookfor_group(inp, ip6_current_dest_addr()); |
| if (group != NULL) { |
| /* Schedule a report. */ |
| mld6_delayed_report(group, mld_hdr->max_resp_delay); |
| } |
| } |
| break; /* ICMP6_TYPE_MLQ */ |
| } |
| case ICMP6_TYPE_MLR: /* Multicast listener report. */ |
| { |
| /* Have we joined this group? |
| * We use IP6 destination address to have a memory aligned copy. |
| * mld_hdr->multicast_address should be the same. */ |
| MLD6_STATS_INC(mld6.rx_report); |
| group = mld6_lookfor_group(inp, ip6_current_dest_addr()); |
| if (group != NULL) { |
| /* If we are waiting to report, cancel it. */ |
| if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) { |
| group->timer = 0; /* stopped */ |
| group->group_state = MLD6_GROUP_IDLE_MEMBER; |
| group->last_reporter_flag = 0; |
| } |
| } |
| break; /* ICMP6_TYPE_MLR */ |
| } |
| case ICMP6_TYPE_MLD: /* Multicast listener done. */ |
| { |
| /* Do nothing, router will query us. */ |
| break; /* ICMP6_TYPE_MLD */ |
| } |
| default: |
| MLD6_STATS_INC(mld6.proterr); |
| MLD6_STATS_INC(mld6.drop); |
| break; |
| } |
| |
| pbuf_free(p); |
| } |
| |
| /** |
| * Join a group on a network interface. |
| * |
| * @param srcaddr ipv6 address of the network interface which should |
| * join a new group. If IP6_ADDR_ANY, join on all netifs |
| * @param groupaddr the ipv6 address of the group to join |
| * @return ERR_OK if group was joined on the netif(s), an err_t otherwise |
| */ |
| err_t |
| mld6_joingroup(ip6_addr_t *srcaddr, ip6_addr_t *groupaddr) |
| { |
| err_t err = ERR_VAL; /* no matching interface */ |
| struct mld_group *group; |
| struct netif *netif; |
| u8_t match; |
| u8_t i; |
| |
| /* loop through netif's */ |
| netif = netif_list; |
| while (netif != NULL) { |
| /* Should we join this interface ? */ |
| match = 0; |
| if (ip6_addr_isany(srcaddr)) { |
| match = 1; |
| } |
| else { |
| for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) { |
| if (ip6_addr_cmp(srcaddr, netif_ip6_addr(netif, i))) { |
| match = 1; |
| break; |
| } |
| } |
| } |
| if (match) { |
| /* Indicate success when there is match for the first time */ |
| if (err == ERR_VAL) { |
| err = ERR_OK; |
| } |
| |
| /* find group or create a new one if not found */ |
| group = mld6_lookfor_group(netif, groupaddr); |
| |
| if (group == NULL) { |
| /* Joining a new group. Create a new group entry. */ |
| group = mld6_new_group(netif, groupaddr); |
| if (group == NULL) { |
| return ERR_MEM; |
| } |
| |
| /* Activate this address on the MAC layer. */ |
| if (netif->mld_mac_filter != NULL) { |
| err_t macFilterErr; |
| |
| macFilterErr = netif->mld_mac_filter(netif, groupaddr, MLD6_ADD_MAC_FILTER); |
| |
| /* If there was an error, don't overwrite it */ |
| if (macFilterErr != ERR_OK) { |
| err = macFilterErr; |
| } |
| } |
| |
| /* Report our membership. */ |
| MLD6_STATS_INC(mld6.tx_report); |
| mld6_send(group, ICMP6_TYPE_MLR); |
| mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS); |
| } |
| |
| /* Increment group use */ |
| group->use++; |
| } |
| |
| /* proceed to next network interface */ |
| netif = netif->next; |
| } |
| return err; |
| } |
| |
| /** |
| * Leave a group on a network interface. |
| * |
| * @param srcaddr ipv6 address of the network interface which should |
| * leave the group. If IP6_ISANY, leave on all netifs |
| * @param groupaddr the ipv6 address of the group to leave |
| * @return ERR_OK if group was left on the netif(s), an err_t otherwise |
| */ |
| err_t |
| mld6_leavegroup(ip6_addr_t *srcaddr, ip6_addr_t *groupaddr) |
| { |
| err_t err = ERR_VAL; /* no matching interface */ |
| struct mld_group *group; |
| struct netif *netif; |
| u8_t match; |
| u8_t i; |
| |
| /* loop through netif's */ |
| netif = netif_list; |
| while (netif != NULL) { |
| /* Should we leave this interface ? */ |
| match = 0; |
| if (ip6_addr_isany(srcaddr)) { |
| match = 1; |
| } |
| else { |
| for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) { |
| if (ip6_addr_cmp(srcaddr, netif_ip6_addr(netif, i))) { |
| match = 1; |
| break; |
| } |
| } |
| } |
| if (match) { |
| /* find group */ |
| group = mld6_lookfor_group(netif, groupaddr); |
| |
| if (group != NULL) { |
| /* Indicate success when there is a match for the first time */ |
| if (err == ERR_VAL) { |
| err = ERR_OK; |
| } |
| |
| /* Leave if there is no other use of the group */ |
| if (group->use <= 1) { |
| /* If we are the last reporter for this group */ |
| if (group->last_reporter_flag) { |
| MLD6_STATS_INC(mld6.tx_leave); |
| mld6_send(group, ICMP6_TYPE_MLD); |
| } |
| |
| /* Disable the group at the MAC level */ |
| if (netif->mld_mac_filter != NULL) { |
| err_t macFilterErr; |
| |
| macFilterErr = netif->mld_mac_filter(netif, groupaddr, MLD6_DEL_MAC_FILTER); |
| |
| /* If there was an error, don't overwrite it */ |
| if (macFilterErr != ERR_OK) { |
| err = macFilterErr; |
| } |
| } |
| |
| /* Free the group */ |
| mld6_free_group(group); |
| } else { |
| /* Decrement group use */ |
| group->use--; |
| } |
| } |
| } |
| /* proceed to next network interface */ |
| netif = netif->next; |
| } |
| return err; |
| } |
| |
| |
| /** |
| * Periodic timer for mld processing. Must be called every |
| * MLD6_TMR_INTERVAL milliseconds (100). |
| * |
| * When a delaying member expires, a membership report is sent. |
| */ |
| |
| err_t |
| mld6_tmr(void) |
| { |
| struct mld_group *group = mld_group_list; |
| |
| while (group != NULL) { |
| if (group->timer > 0) { |
| group->timer--; |
| if (group->timer == 0) { |
| /* If the state is MLD6_GROUP_DELAYING_MEMBER then we send a report for this group */ |
| if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) { |
| MLD6_STATS_INC(mld6.tx_report); |
| mld6_send(group, ICMP6_TYPE_MLR); |
| group->group_state = MLD6_GROUP_IDLE_MEMBER; |
| } |
| } |
| } |
| group = group->next; |
| } |
| return (mld_group_list != NULL) ? ERR_OK : -1; |
| } |
| |
| /** |
| * Schedule a delayed membership report for a group |
| * |
| * @param group the mld_group for which "delaying" membership report |
| * should be sent |
| * @param maxresp the max resp delay provided in the query |
| */ |
| static void |
| mld6_delayed_report(struct mld_group *group, u16_t maxresp) |
| { |
| /* Convert maxresp from milliseconds to tmr ticks */ |
| maxresp = maxresp / MLD6_TMR_INTERVAL; |
| if (maxresp == 0) { |
| maxresp = 1; |
| } |
| |
| #ifdef LWIP_RAND |
| /* Randomize maxresp. (if LWIP_RAND is supported) */ |
| maxresp = LWIP_RAND() % maxresp; |
| if (maxresp == 0) { |
| maxresp = 1; |
| } |
| #endif /* LWIP_RAND */ |
| |
| /* Apply timer value if no report has been scheduled already. */ |
| if ((group->group_state == MLD6_GROUP_IDLE_MEMBER) || |
| ((group->group_state == MLD6_GROUP_DELAYING_MEMBER) && |
| ((group->timer == 0) || (maxresp < group->timer)))) { |
| group->timer = maxresp; |
| group->group_state = MLD6_GROUP_DELAYING_MEMBER; |
| } |
| } |
| |
| /** |
| * Send a MLD message (report or done). |
| * |
| * An IPv6 hop-by-hop options header with a router alert option |
| * is prepended. |
| * |
| * @param group the group to report or quit |
| * @param type ICMP6_TYPE_MLR (report) or ICMP6_TYPE_MLD (done) |
| */ |
| static void |
| mld6_send(struct mld_group *group, u8_t type) |
| { |
| struct mld_header * mld_hdr; |
| struct pbuf * p; |
| ip6_addr_t * src_addr; |
| |
| /* Allocate a packet. Size is MLD header + IPv6 Hop-by-hop options header. */ |
| p = pbuf_alloc(PBUF_IP, sizeof(struct mld_header) + sizeof(struct ip6_hbh_hdr), PBUF_RAM); |
| if ((p == NULL) || (p->len < (sizeof(struct mld_header) + sizeof(struct ip6_hbh_hdr)))) { |
| /* We couldn't allocate a suitable pbuf. drop it. */ |
| if (p != NULL) { |
| pbuf_free(p); |
| } |
| MLD6_STATS_INC(mld6.memerr); |
| return; |
| } |
| |
| /* Move to make room for Hop-by-hop options header. */ |
| if (pbuf_header(p, -IP6_HBH_HLEN)) { |
| pbuf_free(p); |
| MLD6_STATS_INC(mld6.lenerr); |
| return; |
| } |
| |
| /* Select our source address. */ |
| if (!ip6_addr_isvalid(netif_ip6_addr_state(group->netif, 0))) { |
| /* This is a special case, when we are performing duplicate address detection. |
| * We must join the multicast group, but we don't have a valid address yet. */ |
| src_addr = IP6_ADDR_ANY; |
| } else { |
| /* Use link-local address as source address. */ |
| src_addr = netif_ip6_addr(group->netif, 0); |
| } |
| |
| /* MLD message header pointer. */ |
| mld_hdr = (struct mld_header *)p->payload; |
| |
| /* Set fields. */ |
| mld_hdr->type = type; |
| mld_hdr->code = 0; |
| mld_hdr->chksum = 0; |
| mld_hdr->max_resp_delay = 0; |
| mld_hdr->reserved = 0; |
| ip6_addr_set(&(mld_hdr->multicast_address), &(group->group_address)); |
| |
| mld_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len, |
| src_addr, &(group->group_address)); |
| |
| /* Add hop-by-hop headers options: router alert with MLD value. */ |
| ip6_options_add_hbh_ra(p, IP6_NEXTH_ICMP6, IP6_ROUTER_ALERT_VALUE_MLD); |
| |
| /* Send the packet out. */ |
| MLD6_STATS_INC(mld6.xmit); |
| ip6_output_if(p, (ip6_addr_isany(src_addr)) ? NULL : src_addr, &(group->group_address), |
| MLD6_HL, 0, IP6_NEXTH_HOPBYHOP, group->netif); |
| pbuf_free(p); |
| } |
| |
| |
| |
| #endif /* LWIP_IPV6 */ |