diff options
Diffstat (limited to 'lwip/src/core/ipv6/mld6.c')
| -rw-r--r-- | lwip/src/core/ipv6/mld6.c | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/lwip/src/core/ipv6/mld6.c b/lwip/src/core/ipv6/mld6.c new file mode 100644 index 0000000..6387d46 --- /dev/null +++ b/lwip/src/core/ipv6/mld6.c @@ -0,0 +1,626 @@ +/** + * @file + * Multicast listener discovery + * + * @defgroup mld6 MLD6 + * @ingroup ip6 + * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710. + * No support for MLDv2.\n + * Note: The allnodes (ff01::1, ff02::1) group is assumed be received by your + * netif since it must always be received for correct IPv6 operation (e.g. SLAAC). + * Ensure the netif filters are configured accordingly!\n + * The netif flags also need NETIF_FLAG_MLD6 flag set to enable MLD6 on a + * netif ("netif->flags |= NETIF_FLAG_MLD6;").\n + * To be called from TCPIP thread. + */ + +/* + * 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/prot/mld6.h" +#include "lwip/icmp6.h" +#include "lwip/ip6.h" +#include "lwip/ip6_addr.h" +#include "lwip/ip.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 + +/* Forward declarations. */ +static struct mld_group *mld6_new_group(struct netif *ifp, const ip6_addr_t *addr); +static err_t mld6_remove_group(struct netif *netif, struct mld_group *group); +static void mld6_delayed_report(struct mld_group *group, u16_t maxresp); +static void mld6_send(struct netif *netif, 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) +{ + struct mld_group *group = netif_mld6_data(netif); + + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, NULL); + + while (group != NULL) { + struct mld_group *next = group->next; /* avoid use-after-free below */ + + /* disable the group at the MAC level */ + if (netif->mld_mac_filter != NULL) { + netif->mld_mac_filter(netif, &(group->group_address), NETIF_DEL_MAC_FILTER); + } + + /* free group */ + memp_free(MEMP_MLD6_GROUP, group); + + /* move to "next" */ + group = next; + } + return ERR_OK; +} + +/** + * 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 = netif_mld6_data(netif); + + while (group != NULL) { + 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, const ip6_addr_t *addr) +{ + struct mld_group *group = netif_mld6_data(ifp); + + while (group != NULL) { + if (ip6_addr_cmp(&(group->group_address), addr)) { + return group; + } + group = group->next; + } + + return NULL; +} + + +/** + * 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, const ip6_addr_t *addr) +{ + struct mld_group *group; + + group = (struct mld_group *)memp_malloc(MEMP_MLD6_GROUP); + if (group != NULL) { + 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 = netif_mld6_data(ifp); + + netif_set_client_data(ifp, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, group); + } + + return group; +} + +/** + * Remove a group from the mld_group_list, but do not free it yet + * + * @param group the group to remove + * @return ERR_OK if group was removed from the list, an err_t otherwise + */ +static err_t +mld6_remove_group(struct netif *netif, struct mld_group *group) +{ + err_t err = ERR_OK; + + /* Is it the first group? */ + if (netif_mld6_data(netif) == group) { + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_MLD6, group->next); + } else { + /* look for group further down the list */ + struct mld_group *tmpGroup; + for (tmpGroup = netif_mld6_data(netif); tmpGroup != NULL; tmpGroup = tmpGroup->next) { + if (tmpGroup->next == group) { + tmpGroup->next = group->next; + break; + } + } + /* Group not find group */ + if (tmpGroup == NULL) { + err = ERR_ARG; + } + } + + 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 = netif_mld6_data(inp); + while (group != NULL) { + if ((!(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); +} + +/** + * @ingroup mld6 + * Join a group on one or all network interfaces. + * + * If the group is to be joined on all interfaces, the given group address must + * not have a zone set (i.e., it must have its zone index set to IP6_NO_ZONE). + * If the group is to be joined on one particular interface, the given group + * address may or may not have a zone set. + * + * @param srcaddr ipv6 address (zoned) of the network interface which should + * join a new group. If IP6_ADDR_ANY6, join on all netifs + * @param groupaddr the ipv6 address of the group to join (possibly but not + * necessarily zoned) + * @return ERR_OK if group was joined on the netif(s), an err_t otherwise + */ +err_t +mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we join this interface ? */ + if (ip6_addr_isany(srcaddr) || + netif_get_ip6_addr_match(netif, srcaddr) >= 0) { + err = mld6_joingroup_netif(netif, groupaddr); + if (err != ERR_OK) { + return err; + } + } + } + + return err; +} + +/** + * @ingroup mld6 + * Join a group on a network interface. + * + * @param netif the network interface which should join a new group. + * @param groupaddr the ipv6 address of the group to join (possibly but not + * necessarily zoned) + * @return ERR_OK if group was joined on the netif, an err_t otherwise + */ +err_t +mld6_joingroup_netif(struct netif *netif, const ip6_addr_t *groupaddr) +{ + struct mld_group *group; +#if LWIP_IPV6_SCOPES + ip6_addr_t ip6addr; + + /* If the address has a particular scope but no zone set, use the netif to + * set one now. Within the mld6 module, all addresses are properly zoned. */ + if (ip6_addr_lacks_zone(groupaddr, IP6_MULTICAST)) { + ip6_addr_set(&ip6addr, groupaddr); + ip6_addr_assign_zone(&ip6addr, IP6_MULTICAST, netif); + groupaddr = &ip6addr; + } + IP6_ADDR_ZONECHECK_NETIF(groupaddr, netif); +#endif /* LWIP_IPV6_SCOPES */ + + LWIP_ASSERT_CORE_LOCKED(); + + /* 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) { + netif->mld_mac_filter(netif, groupaddr, NETIF_ADD_MAC_FILTER); + } + + /* Report our membership. */ + MLD6_STATS_INC(mld6.tx_report); + mld6_send(netif, group, ICMP6_TYPE_MLR); + mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS); + } + + /* Increment group use */ + group->use++; + return ERR_OK; +} + +/** + * @ingroup mld6 + * Leave a group on a network interface. + * + * Zoning of address follows the same rules as @ref mld6_joingroup. + * + * @param srcaddr ipv6 address (zoned) of the network interface which should + * leave the group. If IP6_ADDR_ANY6, leave on all netifs + * @param groupaddr the ipv6 address of the group to leave (possibly, but not + * necessarily zoned) + * @return ERR_OK if group was left on the netif(s), an err_t otherwise + */ +err_t +mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we leave this interface ? */ + if (ip6_addr_isany(srcaddr) || + netif_get_ip6_addr_match(netif, srcaddr) >= 0) { + err_t res = mld6_leavegroup_netif(netif, groupaddr); + if (err != ERR_OK) { + /* Store this result if we have not yet gotten a success */ + err = res; + } + } + } + + return err; +} + +/** + * @ingroup mld6 + * Leave a group on a network interface. + * + * @param netif the network interface which should leave the group. + * @param groupaddr the ipv6 address of the group to leave (possibly, but not + * necessarily zoned) + * @return ERR_OK if group was left on the netif, an err_t otherwise + */ +err_t +mld6_leavegroup_netif(struct netif *netif, const ip6_addr_t *groupaddr) +{ + struct mld_group *group; +#if LWIP_IPV6_SCOPES + ip6_addr_t ip6addr; + + if (ip6_addr_lacks_zone(groupaddr, IP6_MULTICAST)) { + ip6_addr_set(&ip6addr, groupaddr); + ip6_addr_assign_zone(&ip6addr, IP6_MULTICAST, netif); + groupaddr = &ip6addr; + } + IP6_ADDR_ZONECHECK_NETIF(groupaddr, netif); +#endif /* LWIP_IPV6_SCOPES */ + + LWIP_ASSERT_CORE_LOCKED(); + + /* find group */ + group = mld6_lookfor_group(netif, groupaddr); + + if (group != NULL) { + /* Leave if there is no other use of the group */ + if (group->use <= 1) { + /* Remove the group from the list */ + mld6_remove_group(netif, group); + + /* If we are the last reporter for this group */ + if (group->last_reporter_flag) { + MLD6_STATS_INC(mld6.tx_leave); + mld6_send(netif, group, ICMP6_TYPE_MLD); + } + + /* Disable the group at the MAC level */ + if (netif->mld_mac_filter != NULL) { + netif->mld_mac_filter(netif, groupaddr, NETIF_DEL_MAC_FILTER); + } + + /* free group struct */ + memp_free(MEMP_MLD6_GROUP, group); + } else { + /* Decrement group use */ + group->use--; + } + + /* Left group */ + return ERR_OK; + } + + /* Group not found */ + return ERR_VAL; +} + + +/** + * Periodic timer for mld processing. Must be called every + * MLD6_TMR_INTERVAL milliseconds (100). + * + * When a delaying member expires, a membership report is sent. + */ +void +mld6_tmr(void) +{ + struct netif *netif; + + NETIF_FOREACH(netif) { + struct mld_group *group = netif_mld6_data(netif); + + 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(netif, group, ICMP6_TYPE_MLR); + group->group_state = MLD6_GROUP_IDLE_MEMBER; + } + } + } + group = group->next; + } + } +} + +/** + * Schedule a delayed membership report for a group + * + * @param group the mld_group for which "delaying" membership report + * should be sent + * @param maxresp_in the max resp delay provided in the query + */ +static void +mld6_delayed_report(struct mld_group *group, u16_t maxresp_in) +{ + /* Convert maxresp from milliseconds to tmr ticks */ + u16_t maxresp = maxresp_in / MLD6_TMR_INTERVAL; + if (maxresp == 0) { + maxresp = 1; + } + +#ifdef LWIP_RAND + /* Randomize maxresp. (if LWIP_RAND is supported) */ + maxresp = (u16_t)(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 netif *netif, struct mld_group *group, u8_t type) +{ + struct mld_header *mld_hdr; + struct pbuf *p; + const 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) + MLD6_HBH_HLEN, PBUF_RAM); + if (p == NULL) { + MLD6_STATS_INC(mld6.memerr); + return; + } + + /* Move to make room for Hop-by-hop options header. */ + if (pbuf_remove_header(p, MLD6_HBH_HLEN)) { + pbuf_free(p); + MLD6_STATS_INC(mld6.lenerr); + return; + } + + /* Select our source address. */ + if (!ip6_addr_isvalid(netif_ip6_addr_state(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_ANY6; + } else { + /* Use link-local address as source address. */ + src_addr = netif_ip6_addr(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_copy_to_packed(mld_hdr->multicast_address, group->group_address); + +#if CHECKSUM_GEN_ICMP6 + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP6) { + mld_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len, + src_addr, &(group->group_address)); + } +#endif /* CHECKSUM_GEN_ICMP6 */ + + /* 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); + + if (type == ICMP6_TYPE_MLR) { + /* Remember we were the last to report */ + group->last_reporter_flag = 1; + } + + /* 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, netif); + pbuf_free(p); +} + +#endif /* LWIP_IPV6 */ |