diff options
Diffstat (limited to 'lwip/src/core/ipv4/igmp.c')
| -rw-r--r-- | lwip/src/core/ipv4/igmp.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/lwip/src/core/ipv4/igmp.c b/lwip/src/core/ipv4/igmp.c new file mode 100644 index 0000000..b655aa3 --- /dev/null +++ b/lwip/src/core/ipv4/igmp.c @@ -0,0 +1,801 @@ +/** + * @file + * IGMP - Internet Group Management Protocol + * + * @defgroup igmp IGMP + * @ingroup ip4 + * To be called from TCPIP thread + */ + +/* + * Copyright (c) 2002 CITEL 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. Neither the name of CITEL Technologies Ltd nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY CITEL TECHNOLOGIES AND CONTRIBUTORS ``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 CITEL TECHNOLOGIES OR CONTRIBUTORS 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 a contribution to the lwIP TCP/IP stack. + * The Swedish Institute of Computer Science and Adam Dunkels + * are specifically granted permission to redistribute this + * source code. +*/ + +/*------------------------------------------------------------- +Note 1) +Although the rfc requires V1 AND V2 capability +we will only support v2 since now V1 is very old (August 1989) +V1 can be added if required + +a debug print and statistic have been implemented to +show this up. +------------------------------------------------------------- +------------------------------------------------------------- +Note 2) +A query for a specific group address (as opposed to ALLHOSTS) +has now been implemented as I am unsure if it is required + +a debug print and statistic have been implemented to +show this up. +------------------------------------------------------------- +------------------------------------------------------------- +Note 3) +The router alert rfc 2113 is implemented in outgoing packets +but not checked rigorously incoming +------------------------------------------------------------- +Steve Reynolds +------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------- + * RFC 988 - Host extensions for IP multicasting - V0 + * RFC 1054 - Host extensions for IP multicasting - + * RFC 1112 - Host extensions for IP multicasting - V1 + * RFC 2236 - Internet Group Management Protocol, Version 2 - V2 <- this code is based on this RFC (it's the "de facto" standard) + * RFC 3376 - Internet Group Management Protocol, Version 3 - V3 + * RFC 4604 - Using Internet Group Management Protocol Version 3... - V3+ + * RFC 2113 - IP Router Alert Option - + *----------------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------- + * Includes + *----------------------------------------------------------------------------*/ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_IGMP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/igmp.h" +#include "lwip/debug.h" +#include "lwip/def.h" +#include "lwip/mem.h" +#include "lwip/ip.h" +#include "lwip/inet_chksum.h" +#include "lwip/netif.h" +#include "lwip/stats.h" +#include "lwip/prot/igmp.h" + +#include <string.h> + +static struct igmp_group *igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr); +static err_t igmp_remove_group(struct netif *netif, struct igmp_group *group); +static void igmp_timeout(struct netif *netif, struct igmp_group *group); +static void igmp_start_timer(struct igmp_group *group, u8_t max_time); +static void igmp_delaying_member(struct igmp_group *group, u8_t maxresp); +static err_t igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif); +static void igmp_send(struct netif *netif, struct igmp_group *group, u8_t type); + +static ip4_addr_t allsystems; +static ip4_addr_t allrouters; + +/** + * Initialize the IGMP module + */ +void +igmp_init(void) +{ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_init: initializing\n")); + + IP4_ADDR(&allsystems, 224, 0, 0, 1); + IP4_ADDR(&allrouters, 224, 0, 0, 2); +} + +/** + * Start IGMP processing on interface + * + * @param netif network interface on which start IGMP processing + */ +err_t +igmp_start(struct netif *netif) +{ + struct igmp_group *group; + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: starting IGMP processing on if %p\n", (void *)netif)); + + group = igmp_lookup_group(netif, &allsystems); + + if (group != NULL) { + group->group_state = IGMP_GROUP_IDLE_MEMBER; + group->use++; + + /* Allow the igmp messages at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: igmp_mac_filter(ADD ")); + ip4_addr_debug_print_val(IGMP_DEBUG, allsystems); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, &allsystems, NETIF_ADD_MAC_FILTER); + } + + return ERR_OK; + } + + return ERR_MEM; +} + +/** + * Stop IGMP processing on interface + * + * @param netif network interface on which stop IGMP processing + */ +err_t +igmp_stop(struct netif *netif) +{ + struct igmp_group *group = netif_igmp_data(netif); + + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_IGMP, NULL); + + while (group != NULL) { + struct igmp_group *next = group->next; /* avoid use-after-free below */ + + /* disable the group at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_stop: igmp_mac_filter(DEL ")); + ip4_addr_debug_print_val(IGMP_DEBUG, group->group_address); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, &(group->group_address), NETIF_DEL_MAC_FILTER); + } + + /* free group */ + memp_free(MEMP_IGMP_GROUP, group); + + /* move to "next" */ + group = next; + } + return ERR_OK; +} + +/** + * Report IGMP memberships for this interface + * + * @param netif network interface on which report IGMP memberships + */ +void +igmp_report_groups(struct netif *netif) +{ + struct igmp_group *group = netif_igmp_data(netif); + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_report_groups: sending IGMP reports on if %p\n", (void *)netif)); + + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + if (group != NULL) { + group = group->next; + } + + while (group != NULL) { + igmp_delaying_member(group, IGMP_JOIN_DELAYING_MEMBER_TMR); + group = group->next; + } +} + +/** + * Search for a group in the netif's igmp group list + * + * @param ifp the network interface for which to look + * @param addr the group ip address to search for + * @return a struct igmp_group* if the group has been found, + * NULL if the group wasn't found. + */ +struct igmp_group * +igmp_lookfor_group(struct netif *ifp, const ip4_addr_t *addr) +{ + struct igmp_group *group = netif_igmp_data(ifp); + + while (group != NULL) { + if (ip4_addr_cmp(&(group->group_address), addr)) { + return group; + } + group = group->next; + } + + /* to be clearer, we return NULL here instead of + * 'group' (which is also NULL at this point). + */ + return NULL; +} + +/** + * Search for a specific igmp group and create a new one if not found- + * + * @param ifp the network interface for which to look + * @param addr the group ip address to search + * @return a struct igmp_group*, + * NULL on memory error. + */ +static struct igmp_group * +igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr) +{ + struct igmp_group *group; + struct igmp_group *list_head = netif_igmp_data(ifp); + + /* Search if the group already exists */ + group = igmp_lookfor_group(ifp, addr); + if (group != NULL) { + /* Group already exists. */ + return group; + } + + /* Group doesn't exist yet, create a new one */ + group = (struct igmp_group *)memp_malloc(MEMP_IGMP_GROUP); + if (group != NULL) { + ip4_addr_set(&(group->group_address), addr); + group->timer = 0; /* Not running */ + group->group_state = IGMP_GROUP_NON_MEMBER; + group->last_reporter_flag = 0; + group->use = 0; + + /* Ensure allsystems group is always first in list */ + if (list_head == NULL) { + /* this is the first entry in linked list */ + LWIP_ASSERT("igmp_lookup_group: first group must be allsystems", + (ip4_addr_cmp(addr, &allsystems) != 0)); + group->next = NULL; + netif_set_client_data(ifp, LWIP_NETIF_CLIENT_DATA_INDEX_IGMP, group); + } else { + /* append _after_ first entry */ + LWIP_ASSERT("igmp_lookup_group: all except first group must not be allsystems", + (ip4_addr_cmp(addr, &allsystems) == 0)); + group->next = list_head->next; + list_head->next = group; + } + } + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_lookup_group: %sallocated a new group with address ", (group ? "" : "impossible to "))); + ip4_addr_debug_print(IGMP_DEBUG, addr); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)ifp)); + + return group; +} + +/** + * Remove a group from netif's igmp group list, but don't free it yet + * + * @param group the group to remove from the netif's igmp group list + * @return ERR_OK if group was removed from the list, an err_t otherwise + */ +static err_t +igmp_remove_group(struct netif *netif, struct igmp_group *group) +{ + err_t err = ERR_OK; + struct igmp_group *tmp_group; + + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + for (tmp_group = netif_igmp_data(netif); tmp_group != NULL; tmp_group = tmp_group->next) { + if (tmp_group->next == group) { + tmp_group->next = group->next; + break; + } + } + /* Group not found in netif's igmp group list */ + if (tmp_group == NULL) { + err = ERR_ARG; + } + + return err; +} + +/** + * Called from ip_input() if a new IGMP packet is received. + * + * @param p received igmp packet, p->payload pointing to the igmp header + * @param inp network interface on which the packet was received + * @param dest destination ip address of the igmp packet + */ +void +igmp_input(struct pbuf *p, struct netif *inp, const ip4_addr_t *dest) +{ + struct igmp_msg *igmp; + struct igmp_group *group; + struct igmp_group *groupref; + + IGMP_STATS_INC(igmp.recv); + + /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */ + if (p->len < IGMP_MINLEN) { + pbuf_free(p); + IGMP_STATS_INC(igmp.lenerr); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n")); + return; + } + + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from ")); + ip4_addr_debug_print_val(IGMP_DEBUG, ip4_current_header()->src); + LWIP_DEBUGF(IGMP_DEBUG, (" to address ")); + ip4_addr_debug_print_val(IGMP_DEBUG, ip4_current_header()->dest); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)inp)); + + /* Now calculate and check the checksum */ + igmp = (struct igmp_msg *)p->payload; + if (inet_chksum(igmp, p->len)) { + pbuf_free(p); + IGMP_STATS_INC(igmp.chkerr); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n")); + return; + } + + /* Packet is ok so find an existing group */ + group = igmp_lookfor_group(inp, dest); /* use the destination IP address of incoming packet */ + + /* If group can be found or create... */ + if (!group) { + pbuf_free(p); + IGMP_STATS_INC(igmp.drop); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n")); + return; + } + + /* NOW ACT ON THE INCOMING MESSAGE TYPE... */ + switch (igmp->igmp_msgtype) { + case IGMP_MEMB_QUERY: + /* IGMP_MEMB_QUERY to the "all systems" address ? */ + if ((ip4_addr_cmp(dest, &allsystems)) && ip4_addr_isany(&igmp->igmp_group_address)) { + /* THIS IS THE GENERAL QUERY */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: General IGMP_MEMB_QUERY on \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + + if (igmp->igmp_maxresp == 0) { + IGMP_STATS_INC(igmp.rx_v1); + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n")); + igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR; + } else { + IGMP_STATS_INC(igmp.rx_general); + } + + groupref = netif_igmp_data(inp); + + /* Do not send messages on the all systems group address! */ + /* Skip the first group in the list, it is always the allsystems group added in igmp_start() */ + if (groupref != NULL) { + groupref = groupref->next; + } + + while (groupref) { + igmp_delaying_member(groupref, igmp->igmp_maxresp); + groupref = groupref->next; + } + } else { + /* IGMP_MEMB_QUERY to a specific group ? */ + if (!ip4_addr_isany(&igmp->igmp_group_address)) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group ")); + ip4_addr_debug_print_val(IGMP_DEBUG, igmp->igmp_group_address); + if (ip4_addr_cmp(dest, &allsystems)) { + ip4_addr_t groupaddr; + LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + /* we first need to re-look for the group since we used dest last time */ + ip4_addr_copy(groupaddr, igmp->igmp_group_address); + group = igmp_lookfor_group(inp, &groupaddr); + } else { + LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp))); + } + + if (group != NULL) { + IGMP_STATS_INC(igmp.rx_group); + igmp_delaying_member(group, igmp->igmp_maxresp); + } else { + IGMP_STATS_INC(igmp.drop); + } + } else { + IGMP_STATS_INC(igmp.proterr); + } + } + break; + case IGMP_V2_MEMB_REPORT: + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n")); + IGMP_STATS_INC(igmp.rx_report); + if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) { + /* This is on a specific group we have already looked up */ + group->timer = 0; /* stopped */ + group->group_state = IGMP_GROUP_IDLE_MEMBER; + group->last_reporter_flag = 0; + } + break; + default: + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %d in state %d on group %p on if %p\n", + igmp->igmp_msgtype, group->group_state, (void *)&group, (void *)inp)); + IGMP_STATS_INC(igmp.proterr); + break; + } + + pbuf_free(p); + return; +} + +/** + * @ingroup igmp + * Join a group on one network interface. + * + * @param ifaddr ip address of the network interface which should join a new group + * @param groupaddr the ip address of the group which to join + * @return ERR_OK if group was joined on the netif(s), an err_t otherwise + */ +err_t +igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_joingroup: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we join this interface ? */ + if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) { + err = igmp_joingroup_netif(netif, groupaddr); + if (err != ERR_OK) { + /* Return an error even if some network interfaces are joined */ + /** @todo undo any other netif already joined */ + return err; + } + } + } + + return err; +} + +/** + * @ingroup igmp + * Join a group on one network interface. + * + * @param netif the network interface which should join a new group + * @param groupaddr the ip address of the group which to join + * @return ERR_OK if group was joined on the netif, an err_t otherwise + */ +err_t +igmp_joingroup_netif(struct netif *netif, const ip4_addr_t *groupaddr) +{ + struct igmp_group *group; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_joingroup_netif: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_joingroup_netif: attempt to join allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;); + + /* make sure it is an igmp-enabled netif */ + LWIP_ERROR("igmp_joingroup_netif: attempt to join on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;); + + /* find group or create a new one if not found */ + group = igmp_lookup_group(netif, groupaddr); + + if (group != NULL) { + /* This should create a new group, check the state to make sure */ + if (group->group_state != IGMP_GROUP_NON_MEMBER) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to group not in state IGMP_GROUP_NON_MEMBER\n")); + } else { + /* OK - it was new group */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to new group: ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, ("\n")); + + /* If first use of the group, allow the group at the MAC level */ + if ((group->use == 0) && (netif->igmp_mac_filter != NULL)) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: igmp_mac_filter(ADD ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, groupaddr, NETIF_ADD_MAC_FILTER); + } + + IGMP_STATS_INC(igmp.tx_join); + igmp_send(netif, group, IGMP_V2_MEMB_REPORT); + + igmp_start_timer(group, IGMP_JOIN_DELAYING_MEMBER_TMR); + + /* Need to work out where this timer comes from */ + group->group_state = IGMP_GROUP_DELAYING_MEMBER; + } + /* Increment group use */ + group->use++; + /* Join on this interface */ + return ERR_OK; + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: Not enough memory to join to group\n")); + return ERR_MEM; + } +} + +/** + * @ingroup igmp + * Leave a group on one network interface. + * + * @param ifaddr ip address of the network interface which should leave a group + * @param groupaddr the ip address of the group which to leave + * @return ERR_OK if group was left on the netif(s), an err_t otherwise + */ +err_t +igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr) +{ + err_t err = ERR_VAL; /* no matching interface */ + struct netif *netif; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_leavegroup: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;); + + /* loop through netif's */ + NETIF_FOREACH(netif) { + /* Should we leave this interface ? */ + if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) { + err_t res = igmp_leavegroup_netif(netif, groupaddr); + if (err != ERR_OK) { + /* Store this result if we have not yet gotten a success */ + err = res; + } + } + } + + return err; +} + +/** + * @ingroup igmp + * Leave a group on one network interface. + * + * @param netif the network interface which should leave a group + * @param groupaddr the ip address of the group which to leave + * @return ERR_OK if group was left on the netif, an err_t otherwise + */ +err_t +igmp_leavegroup_netif(struct netif *netif, const ip4_addr_t *groupaddr) +{ + struct igmp_group *group; + + LWIP_ASSERT_CORE_LOCKED(); + + /* make sure it is multicast address */ + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;); + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;); + + /* make sure it is an igmp-enabled netif */ + LWIP_ERROR("igmp_leavegroup_netif: attempt to leave on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;); + + /* find group */ + group = igmp_lookfor_group(netif, groupaddr); + + if (group != NULL) { + /* Only send a leave if the flag is set according to the state diagram */ + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: Leaving group: ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, ("\n")); + + /* If there is no other use of the group */ + if (group->use <= 1) { + /* Remove the group from the list */ + igmp_remove_group(netif, group); + + /* If we are the last reporter for this group */ + if (group->last_reporter_flag) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: sending leaving group\n")); + IGMP_STATS_INC(igmp.tx_leave); + igmp_send(netif, group, IGMP_LEAVE_GROUP); + } + + /* Disable the group at the MAC level */ + if (netif->igmp_mac_filter != NULL) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: igmp_mac_filter(DEL ")); + ip4_addr_debug_print(IGMP_DEBUG, groupaddr); + LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void *)netif)); + netif->igmp_mac_filter(netif, groupaddr, NETIF_DEL_MAC_FILTER); + } + + /* Free group struct */ + memp_free(MEMP_IGMP_GROUP, group); + } else { + /* Decrement group use */ + group->use--; + } + return ERR_OK; + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: not member of group\n")); + return ERR_VAL; + } +} + +/** + * The igmp timer function (both for NO_SYS=1 and =0) + * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default). + */ +void +igmp_tmr(void) +{ + struct netif *netif; + + NETIF_FOREACH(netif) { + struct igmp_group *group = netif_igmp_data(netif); + + while (group != NULL) { + if (group->timer > 0) { + group->timer--; + if (group->timer == 0) { + igmp_timeout(netif, group); + } + } + group = group->next; + } + } +} + +/** + * Called if a timeout for one group is reached. + * Sends a report for this group. + * + * @param group an igmp_group for which a timeout is reached + */ +static void +igmp_timeout(struct netif *netif, struct igmp_group *group) +{ + /* If the state is IGMP_GROUP_DELAYING_MEMBER then we send a report for this group + (unless it is the allsystems group) */ + if ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && + (!(ip4_addr_cmp(&(group->group_address), &allsystems)))) { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_timeout: report membership for group with address ")); + ip4_addr_debug_print_val(IGMP_DEBUG, group->group_address); + LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void *)netif)); + + group->group_state = IGMP_GROUP_IDLE_MEMBER; + + IGMP_STATS_INC(igmp.tx_report); + igmp_send(netif, group, IGMP_V2_MEMB_REPORT); + } +} + +/** + * Start a timer for an igmp group + * + * @param group the igmp_group for which to start a timer + * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with + * every call to igmp_tmr()) + */ +static void +igmp_start_timer(struct igmp_group *group, u8_t max_time) +{ +#ifdef LWIP_RAND + group->timer = (u16_t)(max_time > 2 ? (LWIP_RAND() % max_time) : 1); +#else /* LWIP_RAND */ + /* ATTENTION: use this only if absolutely necessary! */ + group->timer = max_time / 2; +#endif /* LWIP_RAND */ + + if (group->timer == 0) { + group->timer = 1; + } +} + +/** + * Delaying membership report for a group if necessary + * + * @param group the igmp_group for which "delaying" membership report + * @param maxresp query delay + */ +static void +igmp_delaying_member(struct igmp_group *group, u8_t maxresp) +{ + if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) || + ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && + ((group->timer == 0) || (maxresp < group->timer)))) { + igmp_start_timer(group, maxresp); + group->group_state = IGMP_GROUP_DELAYING_MEMBER; + } +} + + +/** + * Sends an IP packet on a network interface. This function constructs the IP header + * and calculates the IP header checksum. If the source IP address is NULL, + * the IP address of the outgoing network interface is filled in as source address. + * + * @param p the packet to send (p->payload points to the data, e.g. next + protocol header; if dest == LWIP_IP_HDRINCL, p already includes an + IP header and p->payload points to that IP header) + * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the + * IP address of the netif used to send is used as source address) + * @param dest the destination IP address to send the packet to + * @param netif the netif on which to send this packet + * @return ERR_OK if the packet was sent OK + * ERR_BUF if p doesn't have enough space for IP/LINK headers + * returns errors returned by netif->output + */ +static err_t +igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif) +{ + /* This is the "router alert" option */ + u16_t ra[2]; + ra[0] = PP_HTONS(ROUTER_ALERT); + ra[1] = 0x0000; /* Router shall examine packet */ + IGMP_STATS_INC(igmp.xmit); + return ip4_output_if_opt(p, src, dest, IGMP_TTL, 0, IP_PROTO_IGMP, netif, ra, ROUTER_ALERTLEN); +} + +/** + * Send an igmp packet to a specific group. + * + * @param group the group to which to send the packet + * @param type the type of igmp packet to send + */ +static void +igmp_send(struct netif *netif, struct igmp_group *group, u8_t type) +{ + struct pbuf *p = NULL; + struct igmp_msg *igmp = NULL; + ip4_addr_t src = *IP4_ADDR_ANY4; + ip4_addr_t *dest = NULL; + + /* IP header + "router alert" option + IGMP header */ + p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM); + + if (p) { + igmp = (struct igmp_msg *)p->payload; + LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg", + (p->len >= sizeof(struct igmp_msg))); + ip4_addr_copy(src, *netif_ip4_addr(netif)); + + if (type == IGMP_V2_MEMB_REPORT) { + dest = &(group->group_address); + ip4_addr_copy(igmp->igmp_group_address, group->group_address); + group->last_reporter_flag = 1; /* Remember we were the last to report */ + } else { + if (type == IGMP_LEAVE_GROUP) { + dest = &allrouters; + ip4_addr_copy(igmp->igmp_group_address, group->group_address); + } + } + + if ((type == IGMP_V2_MEMB_REPORT) || (type == IGMP_LEAVE_GROUP)) { + igmp->igmp_msgtype = type; + igmp->igmp_maxresp = 0; + igmp->igmp_checksum = 0; + igmp->igmp_checksum = inet_chksum(igmp, IGMP_MINLEN); + + igmp_ip_output_if(p, &src, dest, netif); + } + + pbuf_free(p); + } else { + LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n")); + IGMP_STATS_INC(igmp.memerr); + } +} + +#endif /* LWIP_IPV4 && LWIP_IGMP */ |