minix/lib/liblwip/core/ipv6/mld6.c
Ambarisha B 7e55dbac33 LIBLWIP - updated to LwIP trunk
commit a4a41b9023ef5b3a7c4a1cd82fb167fc63e706df
Author: goldsimon <goldsimon@gmx.de>
Date:   Wed Sep 26 21:50:42 2012 +0200

- This also brings in LwIP's IPv6 codebase

Signed-off-by: Tomas Hruby <tom@minix3.org>
2013-03-25 16:51:24 +01:00

580 lines
16 KiB
C

/**
* @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)
{
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) {
netif->mld_mac_filter(netif, &(group->group_address), MLD6_DEL_MAC_FILTER);
}
/* free group */
memp_free(MEMP_MLD6_GROUP, group);
} else {
/* change the "previous" */
prev = 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 = 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;
}
/**
* 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;
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) {
/* 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, MLD6_ADD_MAC_FILTER);
}
/* 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++;
err = ERR_OK;
}
/* 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) {
/* 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) {
netif->mld_mac_filter(netif, groupaddr, MLD6_DEL_MAC_FILTER);
}
/* Free the group */
mld6_free_group(group);
} else {
/* Decrement group use */
group->use--;
}
/* Leave on this interface */
err = ERR_OK;
}
}
/* 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.
*/
void
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;
}
}
/**
* 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 - 1)) + 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 */