abc/lwip
1
0
Fork 0
mirror of https://git.savannah.nongnu.org/git/lwip.git synced 2025-08-03 04:54:38 +08:00
Code Issues Packages Projects Releases Wiki Activity
lwip/src/core/ipv4/igmp.c

597 lines
19 KiB
C
Raw Blame History

/*
* 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.
*/
/************************************************************
In the spirit of LW (I hope)
-------------------------------------------------------------
note 1)
Although the rfc requires V1 AND V2 capability
we will only support v2 since now V1 is 5 years old
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
------------------------------------------------------------*/
/*-----------------------------------------------------------------------------
* Includes
*----------------------------------------------------------------------------*/
#include "lwip/debug.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/ip.h"
#include "lwip/inet.h"
#include "lwip/netif.h"
#include "lwip/icmp.h"
#include "lwip/udp.h"
#include "lwip/tcp.h"
#include "lwip/stats.h"
#include "lwip/igmp.h"
#include "arch/perf.h"
#include "string.h"
/* IGMP support available? */
#if defined(LWIP_IGMP) && (LWIP_IGMP > 0)
/*-----------------------------------------------------------------------------
* Globales
*----------------------------------------------------------------------------*/
static struct igmp_group* igmp_group_list;
static struct igmp_stats igmpstats;
static struct ip_addr allsystems;
static struct ip_addr allrouters;
/**
* Initialize this module
*
* Only network interfaces registered when this function is called
* are igmp-enabled.
*/
void
igmp_init(void)
{
struct igmp_group* group;
struct netif* netif;
LWIP_DEBUGF(IGMP_DEBUG, ("IGMP Initialising\n"));
IP4_ADDR(&allsystems, 224, 0, 0, 1);
IP4_ADDR(&allrouters, 224, 0, 0, 2);
igmp_group_list = NULL;
memset(&igmpstats, 0, sizeof(igmpstats));
for (netif = netif_list; netif != NULL; netif = netif->next) {
group = lookup_group(netif, &allsystems);
if (group) {
group->group_state = IDLE_MEMBER;
/* Allow the igmp messages at the MAC level */
if (netif->igmp_mac_filter != NULL) {
netif->igmp_mac_filter(netif, &allsystems, IGMP_ADD_MAC_FILTER);
netif->igmp_mac_filter(netif, &allrouters, IGMP_ADD_MAC_FILTER);
}
}
}
}
/**
* Search for a group in the global igmp_group_list
*
* @param ifp the network interfacefor which to look
* @param addr the group ip address to search
* @return a struct igmp_group* if the group has been found,
* NULL if the group wasn't found.
*/
struct igmp_group *
lookfor_group(struct netif *ifp, struct ip_addr *addr)
{
struct igmp_group *group = igmp_group_list;
while (group) {
if ((group->interface == ifp) && (ip_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 interfacefor which to look
* @param addr the group ip address to search
* @return a struct igmp_group*,
* NULL on memory error.
*/
struct igmp_group *
lookup_group(struct netif *ifp, struct ip_addr *addr)
{
struct igmp_group *group = igmp_group_list;
/* Search if the group already exists */
group = lookfor_group(ifp, addr);
if (group != NULL) {
/* Group already exists. */
return group;
}
/* Group doesn't exist yet, create a new one. */
group = mem_malloc(sizeof(struct igmp_group));
if (group) {
group->interface = ifp;
ip_addr_set(&(group->group_address), addr);
group->timer = 0; /* Not running */
group->group_state = NON_MEMBER;
group->last_reporter_flag = 0;
group->next = igmp_group_list;
igmp_group_list = group;
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %d allocated a new group with address %x on if %x \n", __LINE__, (int) addr, (int) ifp));
} else {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %d impossible to allocated a new group with address %x on if %x \n", __LINE__, (int) addr, (int) ifp));
}
return group;
}
/**
* Called from ip_input() if a new IGMP packet is received.
*
* @param p received igmp packet, p->payload pointing to the ip 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, struct ip_addr *dest)
{
struct ip_hdr * iphdr;
struct igmpmsg* igmp;
struct igmp_group* group;
struct igmp_group* groupref;
iphdr = p->payload;
igmp = (struct igmpmsg *)(((u8_t *)p->payload)+((u32_t)(IPH_HL(iphdr) * 4)));
LWIP_DEBUGF(IGMP_DEBUG, ("igmp message to address %l \n", (long)dest->addr));
if (p->len < IGMP_MINLEN) {
/* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */
pbuf_free(p);
igmpstats.igmp_length_err++;
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %x igmp length error\n", __LINE__));
return;
}
/* Now calculate and check the checksum */
if (inet_chksum(igmp, IGMP_MINLEN /*p->len*/)) {
pbuf_free(p);
igmpstats.igmp_checksum_err++;
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %d igmp checksum error\n", __LINE__));
return;
}
/* Packet is ok so find the group (or create a new one) */
group = lookup_group(inp, dest); /* use the incoming IP address! */
/* If group can be found or create... */
if (!group) {
pbuf_free(p);
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %d igmp allocation error\n", __LINE__));
return;
}
/* NOW ACT ON THE INCOMING MESSAGE TYPE... */
/* The membership query message goes to the all groups address */
/* and it control block does not have state */
if ((IGMP_MEMB_QUERY == igmp->igmp_msgtype) && (ip_addr_cmp(dest, &allsystems)) &&
(igmp->igmp_group_address.addr == 0)) {
/* THIS IS THE GENERAL QUERY */
LWIP_DEBUGF(IGMP_DEBUG, ("General IGMP_MEMB_QUERY on ALL SYSTEMS ADDRESS 224.0.0.1\n"));
if (0 ==igmp->igmp_maxresp) {
igmpstats.igmp_v1_rxed++;
igmp->igmp_maxresp = 10;
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %d got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n", __LINE__));
}
igmpstats.igmp_group_query_rxed++;
groupref = igmp_group_list;
while (groupref) {
if ((groupref->interface == inp) &&
(!(ip_addr_cmp(&(groupref->group_address), &allsystems)))) {
/* Do not send messages on the all systems group address! */
if ((groupref->group_state == IDLE_MEMBER) ||
((groupref->group_state == DELAYING_MEMBER) &&
(igmp->igmp_maxresp > groupref->timer))) {
igmp_start_timer(groupref, (igmp->igmp_maxresp)/2);
groupref->group_state = DELAYING_MEMBER;
}
}
groupref = groupref->next;
}
} else {
if ((IGMP_MEMB_QUERY == igmp->igmp_msgtype) && ip_addr_cmp (dest, &allsystems) &&
(group->group_address.addr != 0)) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %x got a query to a specific group using the allsystems address \n", __LINE__));
/* we first need to re-lookup the group since we used dest last time */
group = lookup_group(inp, &igmp->igmp_group_address); /* use the incoming IP address! */
igmpstats.igmp_unicast_query++;
if ((IDLE_MEMBER == group->group_state ) || ((DELAYING_MEMBER == group->group_state) &&
(igmp->igmp_maxresp > group->timer))) {
igmp_start_timer(group, (igmp->igmp_maxresp)/2);
group->group_state = DELAYING_MEMBER;
}
} else {
if ((IGMP_MEMB_QUERY == igmp->igmp_msgtype) && !(ip_addr_cmp (dest, &allsystems)) &&
(group->group_address.addr != 0)) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %x got a query to a specific group with the group address as destination \n", __LINE__));
igmpstats.igmp_unicast_query++; /* This is the unicast query */
if ((IDLE_MEMBER == group->group_state) || ((DELAYING_MEMBER == group->group_state) &&
(igmp->igmp_maxresp > group->timer))) {
igmp_start_timer(group, (igmp->igmp_maxresp)/2);
group->group_state = DELAYING_MEMBER;
}
} else {
if (IGMP_V2_MEMB_REPORT == igmp->igmp_msgtype) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c,Line %x got an IGMP_V2_MEMB_REPORT \n", __LINE__));
igmpstats.report_rxed++;
if (DELAYING_MEMBER == group->group_state) {
/* This is on a specific group we have already looked up */
group->timer = 0; /* stopped */
group->group_state = IDLE_MEMBER;
group->last_reporter_flag = 0;
}
} else {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input, Line %x unexpected msg %x in state %x on group %x at interface %x\n", __LINE__, (int) igmp->igmp_msgtype, (int) group->group_state, (int) &group, (int) group->interface));
}
}
}
}
pbuf_free(p);
return;
}
/**
* Join a group on one network interface.
*
* @param ifp 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, an err_t otherwise
*/
err_t
igmp_joingroup(struct netif *ifp, struct ip_addr *groupaddr)
{
struct igmp_group *group;
group = lookup_group(ifp, groupaddr);
if (group) {
/* This should create a new group, check the state to make sure */
if (group->group_state != NON_MEMBER) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c Line %x join to group not in state NON_MEMBER\n", __LINE__));
return ERR_OK;
}
/* OK - it was new group */
igmpstats.igmp_joins++;
LWIP_DEBUGF(IGMP_DEBUG, ("igmp join to new group\n"));
if (ifp->igmp_mac_filter != NULL) {
ifp->igmp_mac_filter(ifp, groupaddr, IGMP_ADD_MAC_FILTER);
}
igmp_send(group, IGMP_V2_MEMB_REPORT);
igmp_start_timer(group, 5);
/* Need to work out where this timer comes from */
group->group_state = DELAYING_MEMBER;
return ERR_OK;
}
return ERR_MEM;
}
/**
* Leave a group on one network interface.
*
* @param ifp 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, an err_t otherwise
*/
err_t
igmp_leavegroup(struct netif *ifp, struct ip_addr *groupaddr)
{
struct igmp_group *group;
group = lookup_group(ifp, groupaddr);
if (group) {
/* Only send a leave if the flag is set according to the state diagram */
if (group->last_reporter_flag) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c Line %x Leaving group\n", __LINE__));
igmpstats.igmp_leave_sent++;
igmp_send(group, IGMP_LEAVE_GROUP);
}
/* The block is not deleted since the group still exists and we may rejoin */
group->last_reporter_flag = 0;
group->group_state = NON_MEMBER;
group->timer = 0;
if (ifp->igmp_mac_filter != NULL) {
ifp->igmp_mac_filter(ifp, groupaddr, IGMP_DEL_MAC_FILTER);
}
return ERR_OK;
}
return ERR_MEM;
}
/**
* 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()
{
struct igmp_group *group = igmp_group_list;
while (group) {
if (group->timer != 0) {
group->timer -= 1;
if (group->timer == 0) {
igmp_timeout(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
*/
void
igmp_timeout(struct igmp_group *group)
{
/* If the state is DELAYING_MEMBER then we send a report for this group */
LWIP_DEBUGF(IGMP_DEBUG, ("igmp.c, got a timeout\n"));
if (DELAYING_MEMBER == group->group_state) {
igmp_send(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())
*/
void
igmp_start_timer(struct igmp_group *group, u8_t max_time)
{
/* Important !! this should be random 0 -> max_time
* find out how to do this
*/
group->timer = max_time;
}
/**
* Stop a timer for an igmp_group
*
* @param group the igmp_group for which to stop the timer
*/
void
igmp_stop_timer(struct igmp_group *group)
{
group->timer = 0;
}
/**
* 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 == 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 == IP_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 ttl the TTL value to be set in the IP header
* @param proto the PROTOCOL to be set in the IP header
* @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
*/
err_t
igmp_ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t proto, struct netif *netif)
{
static struct ip_hdr * iphdr = NULL;
static u16_t ip_id = 0;
u16_t * ra = NULL;
/* First write in the "router alert" */
if (pbuf_header(p, ROUTER_ALERTLEN)) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
return ERR_BUF;
}
/* This is the "router alert" option */
ra = p->payload;
ra[0] = htons (0x9404);
ra[1] = 0x0000;
/* now the normal ip header */
if (pbuf_header(p, IP_HLEN)) {
LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
return ERR_BUF;
}
iphdr = p->payload;
if (dest != IP_HDRINCL) {
iphdr->_ttl_proto = (proto<<8);
iphdr->_ttl_proto |= ttl;
/* iphdr->dest = dest->addr; */
ip_addr_set(&(iphdr->dest), dest);
#ifdef HAVE_BITFIELDS
iphdr->_v_hl_tos |= ((IP_HLEN+ ROUTER_ALERTLEN)/4)<<16;
iphdr->_v_hl_tos |= 4<<24;
#else
iphdr->_v_hl_tos = (4 << 4) | ((IP_HLEN + ROUTER_ALERTLEN)/ 4 & 0xf);
#endif /* HAVE_BITFIELDS */
iphdr->_v_hl_tos |= 0;
iphdr->_len = htons(p->tot_len);
iphdr->_offset = htons(0);
iphdr->_id = htons(ip_id++);
if (ip_addr_isany(src)) {
ip_addr_set(&(iphdr->src), &(netif->ip_addr));
} else {
ip_addr_set(&(iphdr->src), src);
}
iphdr->_chksum = 0;
iphdr->_chksum = inet_chksum(iphdr, IP_HLEN + ROUTER_ALERTLEN);
} else {
dest = &(iphdr->dest);
}
#if IP_DEBUG
ip_debug_print(p);
#endif
LWIP_DEBUGF(IGMP_DEBUG, ("IGMP sending to netif %x \n", (int) netif));
return netif->output(netif, p, dest);
}
/**
* Send an igmp packet to a specific group.
*
* @param the group to which to send the packet
* @param type the type of igmp packet to send
*/
void
igmp_send(struct igmp_group *group, u8_t type)
{
struct pbuf* p = NULL;
struct igmpmsg* igmp = NULL;
struct ip_addr src = {0};
struct ip_addr* dest = NULL;
/* IP header + IGMP header */
p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM);
if (p) {
igmp = p->payload;
LWIP_ASSERT("check that first pbuf can hold struct igmpmsg",
(p->len >= sizeof(struct igmpmsg)));
ip_addr_set(&src, &((group->interface)->ip_addr));
if (IGMP_V2_MEMB_REPORT == type) {
dest = &(group->group_address);
igmpstats.report_sent++;
ip_addr_set(&(igmp->igmp_group_address), &(group->group_address));
group->last_reporter_flag = 1; /* Remember we were the last to report */
} else {
if (IGMP_LEAVE_GROUP == type) {
dest = &allrouters;
ip_addr_set(&(igmp->igmp_group_address), &(group->group_address));
}
}
if ((IGMP_V2_MEMB_REPORT == type) || (IGMP_LEAVE_GROUP == type)) {
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, IGMP_TTL, IP_PROTO_IGMP, group->interface);
}
pbuf_free (p);
} else {
LWIP_DEBUGF(IGMP_DEBUG, ("IGMP, not enough memory for igmp_send\n"));
}
}
#endif /* LWIP_IGMP */
Reference in New Issue View Git Blame Copy Permalink