/**
* 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, IGMP_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;
}
/**
* 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;
}
