3 * IGMP - Internet Group Management Protocol
8 * Copyright (c) 2002 CITEL Technologies Ltd.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of CITEL Technologies Ltd nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY CITEL TECHNOLOGIES AND CONTRIBUTORS ``AS IS''
24 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL CITEL TECHNOLOGIES OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * This file is a contribution to the lwIP TCP/IP stack.
36 * The Swedish Institute of Computer Science and Adam Dunkels
37 * are specifically granted permission to redistribute this
41 /*-------------------------------------------------------------
43 Although the rfc requires V1 AND V2 capability
44 we will only support v2 since now V1 is very old (August 1989)
45 V1 can be added if required
47 a debug print and statistic have been implemented to
49 -------------------------------------------------------------
50 -------------------------------------------------------------
52 A query for a specific group address (as opposed to ALLHOSTS)
53 has now been implemented as I am unsure if it is required
55 a debug print and statistic have been implemented to
57 -------------------------------------------------------------
58 -------------------------------------------------------------
60 The router alert rfc 2113 is implemented in outgoing packets
61 but not checked rigorously incoming
62 -------------------------------------------------------------
64 ------------------------------------------------------------*/
66 /*-----------------------------------------------------------------------------
67 * RFC 988 - Host extensions for IP multicasting - V0
68 * RFC 1054 - Host extensions for IP multicasting -
69 * RFC 1112 - Host extensions for IP multicasting - V1
70 * RFC 2236 - Internet Group Management Protocol, Version 2 - V2 <- this code is based on this RFC (it's the "de facto" standard)
71 * RFC 3376 - Internet Group Management Protocol, Version 3 - V3
72 * RFC 4604 - Using Internet Group Management Protocol Version 3... - V3+
73 * RFC 2113 - IP Router Alert Option -
74 *----------------------------------------------------------------------------*/
76 /*-----------------------------------------------------------------------------
78 *----------------------------------------------------------------------------*/
80 #include "lwip/debug.h"
84 #include "lwip/inet.h"
85 #include "lwip/netif.h"
86 #include "lwip/icmp.h"
89 #include "lwip/stats.h"
90 #include "lwip/igmp.h"
92 #include "arch/perf.h"
96 /* IGMP support available? */
97 #if defined(LWIP_IGMP) && (LWIP_IGMP > 0)
99 /*-----------------------------------------------------------------------------
101 *----------------------------------------------------------------------------*/
103 static struct igmp_group* igmp_group_list;
104 static struct ip_addr allsystems;
105 static struct ip_addr allrouters;
108 * Initialize the IGMP module
113 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_init: initializing\n"));
115 IP4_ADDR(&allsystems, 224, 0, 0, 1);
116 IP4_ADDR(&allrouters, 224, 0, 0, 2);
118 igmp_group_list = NULL;
122 * Start IGMP processing on interface
124 * @param netif network interface on which start IGMP processing
127 igmp_start(struct netif *netif)
129 struct igmp_group* group;
131 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: starting IGMP processing on if %x\n", (int) netif));
133 group = igmp_lookup_group(netif, &allsystems);
136 group->group_state = IDLE_MEMBER;
138 /* Allow the igmp messages at the MAC level */
139 if (netif->igmp_mac_filter != NULL) {
140 netif->igmp_mac_filter( netif, &allsystems, IGMP_ADD_MAC_FILTER);
150 * Search for a group in the global igmp_group_list
152 * @param ifp the network interface for which to look
153 * @param addr the group ip address to search for
154 * @return a struct igmp_group* if the group has been found,
155 * NULL if the group wasn't found.
158 igmp_lookfor_group(struct netif *ifp, struct ip_addr *addr)
160 struct igmp_group *group = igmp_group_list;
163 if ((group->interface == ifp) && (ip_addr_cmp(&(group->group_address), addr))) {
169 /* to be clearer, we return NULL here instead of
170 * 'group' (which is also NULL at this point).
176 * Search for a specific igmp group and create a new one if not found-
178 * @param ifp the network interface for which to look
179 * @param addr the group ip address to search
180 * @return a struct igmp_group*,
181 * NULL on memory error.
184 igmp_lookup_group(struct netif *ifp, struct ip_addr *addr)
186 struct igmp_group *group = igmp_group_list;
188 /* Search if the group already exists */
189 group = igmp_lookfor_group(ifp, addr);
191 /* Group already exists. */
195 /* Group doesn't exist yet, create a new one. */
196 group = mem_malloc(sizeof(struct igmp_group));
198 group->interface = ifp;
199 ip_addr_set(&(group->group_address), addr);
200 group->timer = 0; /* Not running */
201 group->group_state = NON_MEMBER;
202 group->last_reporter_flag = 0;
203 group->next = igmp_group_list;
205 igmp_group_list = group;
208 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_lookup_group: %sallocated a new group with address ", (group?"":"impossible to ")));
209 ip_addr_debug_print(IGMP_DEBUG, addr);
210 LWIP_DEBUGF(IGMP_DEBUG, (" on if %x\n", (int) ifp));
216 * Called from ip_input() if a new IGMP packet is received.
218 * @param p received igmp packet, p->payload pointing to the ip header
219 * @param inp network interface on which the packet was received
220 * @param dest destination ip address of the igmp packet
223 igmp_input(struct pbuf *p, struct netif *inp, struct ip_addr *dest)
225 struct ip_hdr * iphdr;
226 struct igmp_msg* igmp;
227 struct igmp_group* group;
228 struct igmp_group* groupref;
230 /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */
232 if (pbuf_header(p, -(IPH_HL(iphdr) * 4)) || (p->len < IGMP_MINLEN)) {
234 IGMP_STATS_INC(igmp.lenerr);
235 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n"));
239 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from "));
240 ip_addr_debug_print(IGMP_DEBUG, &(iphdr->src));
241 LWIP_DEBUGF(IGMP_DEBUG, (" to address "));
242 ip_addr_debug_print(IGMP_DEBUG, &(iphdr->dest));
243 LWIP_DEBUGF(IGMP_DEBUG, (" on if %x\n", (int) inp));
245 /* Now calculate and check the checksum */
246 igmp = (struct igmp_msg *)p->payload;
247 if (inet_chksum(igmp, p->len)) {
249 IGMP_STATS_INC(igmp.chkerr);
250 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n"));
254 /* Packet is ok so find an existing group */
255 group = igmp_lookfor_group(inp, dest); /* use the incoming IP address! */
257 /* If group can be found or create... */
260 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n"));
264 /* NOW ACT ON THE INCOMING MESSAGE TYPE... */
265 switch (igmp->igmp_msgtype) {
266 case IGMP_MEMB_QUERY: {
267 /* IGMP_MEMB_QUERY to the "all systems" address ? */
268 if ((ip_addr_cmp(dest, &allsystems)) && (igmp->igmp_group_address.addr == 0)) {
269 /* THIS IS THE GENERAL QUERY */
270 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)));
272 if (igmp->igmp_maxresp == 0) {
273 IGMP_STATS_INC(igmp.v1_rxed);
274 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n"));
275 igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR;
278 IGMP_STATS_INC(igmp.group_query_rxed);
279 groupref = igmp_group_list;
281 /* Do not send messages on the all systems group address! */
282 if ((groupref->interface == inp) && (!(ip_addr_cmp(&(groupref->group_address), &allsystems)))) {
283 igmp_delaying_member( groupref, igmp->igmp_maxresp);
285 groupref = groupref->next;
288 /* IGMP_MEMB_QUERY to a specific group ? */
289 if (group->group_address.addr != 0) {
290 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
291 ip_addr_debug_print(IGMP_DEBUG, &group->group_address);
292 if (ip_addr_cmp (dest, &allsystems)) {
293 LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
294 /* we first need to re-lookfor the group since we used dest last time */
295 group = igmp_lookfor_group(inp, &igmp->igmp_group_address);
297 LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
301 IGMP_STATS_INC(igmp.unicast_query);
302 igmp_delaying_member( group, igmp->igmp_maxresp);
308 case IGMP_V2_MEMB_REPORT: {
309 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));
311 IGMP_STATS_INC(igmp.report_rxed);
312 if (group->group_state == DELAYING_MEMBER) {
313 /* This is on a specific group we have already looked up */
314 group->timer = 0; /* stopped */
315 group->group_state = IDLE_MEMBER;
316 group->last_reporter_flag = 0;
321 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %x in state %x on group %x on if %x\n", (int) igmp->igmp_msgtype, (int) group->group_state, (int) &group, (int) group->interface));
331 * Join a group on one network interface.
333 * @param ifp the network interface which should join a new group
334 * @param groupaddr the ip address of the group which to join
335 * @return ERR_OK if group was joined, an err_t otherwise
338 igmp_joingroup(struct netif *ifp, struct ip_addr *groupaddr)
340 struct igmp_group *group;
342 /* make sure it is multicast address */
343 if (!ip_addr_ismulticast(groupaddr)) {
344 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: attempt to join non-multicast address\n"));
348 /* find group or create a new one if not found */
349 group = igmp_lookup_group(ifp, groupaddr);
352 /* This should create a new group, check the state to make sure */
353 if (group->group_state != NON_MEMBER) {
354 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: join to group not in state NON_MEMBER\n"));
358 /* OK - it was new group */
359 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: join to new group: "));
360 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
361 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
363 if (ifp->igmp_mac_filter != NULL) {
364 ifp->igmp_mac_filter(ifp, groupaddr, IGMP_ADD_MAC_FILTER);
367 IGMP_STATS_INC(igmp.join_sent);
368 igmp_send(group, IGMP_V2_MEMB_REPORT);
370 igmp_start_timer(group, IGMP_JOIN_DELAYING_MEMBER_TMR);
372 /* Need to work out where this timer comes from */
373 group->group_state = DELAYING_MEMBER;
382 * Leave a group on one network interface.
384 * @param ifp the network interface which should leave a group
385 * @param groupaddr the ip address of the group which to leave
386 * @return ERR_OK if group was left, an err_t otherwise
389 igmp_leavegroup(struct netif *ifp, struct ip_addr *groupaddr)
391 struct igmp_group *group;
393 group = igmp_lookfor_group(ifp, groupaddr);
396 /* Only send a leave if the flag is set according to the state diagram */
397 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: Leaving group: "));
398 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
399 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
401 if (group->last_reporter_flag) {
402 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: sending leaving group\n"));
403 IGMP_STATS_INC(igmp.leave_sent);
404 igmp_send(group, IGMP_LEAVE_GROUP);
407 /* The block is not deleted since the group still exists and we may rejoin */
408 group->last_reporter_flag = 0;
409 group->group_state = NON_MEMBER;
412 if (ifp->igmp_mac_filter != NULL) {
413 ifp->igmp_mac_filter(ifp, groupaddr, IGMP_DEL_MAC_FILTER);
419 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: not member of group\n"));
425 * The igmp timer function (both for NO_SYS=1 and =0)
426 * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default).
431 struct igmp_group *group = igmp_group_list;
433 while (group != NULL) {
434 if (group->timer != 0) {
436 if (group->timer == 0) {
445 * Called if a timeout for one group is reached.
446 * Sends a report for this group.
448 * @param group an igmp_group for which a timeout is reached
451 igmp_timeout(struct igmp_group *group)
453 /* If the state is DELAYING_MEMBER then we send a report for this group */
454 if (group->group_state == DELAYING_MEMBER) {
455 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_timeout: report membership for group with address "));
456 ip_addr_debug_print(IGMP_DEBUG, &(group->group_address));
457 LWIP_DEBUGF(IGMP_DEBUG, (" on if %x\n", (int) group->interface));
459 igmp_send(group, IGMP_V2_MEMB_REPORT);
464 * Start a timer for an igmp group
466 * @param group the igmp_group for which to start a timer
467 * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with
468 * every call to igmp_tmr())
471 igmp_start_timer(struct igmp_group *group, u8_t max_time)
474 * @todo Important !! this should be random 0 -> max_time. Find out how to do this
476 group->timer = max_time;
480 * Stop a timer for an igmp_group
482 * @param group the igmp_group for which to stop the timer
485 igmp_stop_timer(struct igmp_group *group)
491 * Delaying membership report for a group if necessary
493 * @param group the igmp_group for which "delaying" membership report
494 * @param maxresp query delay
497 igmp_delaying_member( struct igmp_group *group, u8_t maxresp)
499 if ((group->group_state == IDLE_MEMBER) || ((group->group_state == DELAYING_MEMBER) && (maxresp > group->timer))) {
500 igmp_start_timer(group, (maxresp)/2);
501 group->group_state = DELAYING_MEMBER;
507 * Sends an IP packet on a network interface. This function constructs the IP header
508 * and calculates the IP header checksum. If the source IP address is NULL,
509 * the IP address of the outgoing network interface is filled in as source address.
511 * @param p the packet to send (p->payload points to the data, e.g. next
512 protocol header; if dest == IP_HDRINCL, p already includes an IP
513 header and p->payload points to that IP header)
514 * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
515 * IP address of the netif used to send is used as source address)
516 * @param dest the destination IP address to send the packet to
517 * @param ttl the TTL value to be set in the IP header
518 * @param proto the PROTOCOL to be set in the IP header
519 * @param netif the netif on which to send this packet
520 * @return ERR_OK if the packet was sent OK
521 * ERR_BUF if p doesn't have enough space for IP/LINK headers
522 * returns errors returned by netif->output
525 igmp_ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
526 u8_t ttl, u8_t proto, struct netif *netif)
528 static u16_t ip_id = 0;
529 struct ip_hdr * iphdr = NULL;
532 /* First write in the "router alert" */
533 if (pbuf_header(p, ROUTER_ALERTLEN)) {
534 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
538 /* This is the "router alert" option */
540 ra[0] = htons (0x9404);
543 /* now the normal ip header */
544 if (pbuf_header(p, IP_HLEN)) {
545 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
550 if (dest != IP_HDRINCL) {
551 iphdr->_ttl_proto = (proto<<8);
552 iphdr->_ttl_proto |= ttl;
554 /* iphdr->dest = dest->addr; */
555 ip_addr_set(&(iphdr->dest), dest);
556 #ifdef HAVE_BITFIELDS
557 iphdr->_v_hl_tos |= ((IP_HLEN+ ROUTER_ALERTLEN)/4)<<16;
558 iphdr->_v_hl_tos |= 4<<24;
560 iphdr->_v_hl_tos = (4 << 4) | ((IP_HLEN + ROUTER_ALERTLEN)/ 4 & 0xf);
561 #endif /* HAVE_BITFIELDS */
563 iphdr->_v_hl_tos |= 0;
564 iphdr->_len = htons(p->tot_len);
565 iphdr->_offset = htons(0);
566 iphdr->_id = htons(ip_id++);
568 if (ip_addr_isany(src)) {
569 ip_addr_set(&(iphdr->src), &(netif->ip_addr));
571 ip_addr_set(&(iphdr->src), src);
575 iphdr->_chksum = inet_chksum(iphdr, IP_HLEN + ROUTER_ALERTLEN);
577 dest = &(iphdr->dest);
584 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: sending to if %x\n", (int) netif));
586 return netif->output(netif, p, dest);
590 * Send an igmp packet to a specific group.
592 * @param group the group to which to send the packet
593 * @param type the type of igmp packet to send
596 igmp_send(struct igmp_group *group, u8_t type)
598 struct pbuf* p = NULL;
599 struct igmp_msg* igmp = NULL;
600 struct ip_addr src = {0};
601 struct ip_addr* dest = NULL;
603 /* IP header + IGMP header */
604 p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM);
608 LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg",
609 (p->len >= sizeof(struct igmp_msg)));
610 ip_addr_set(&src, &((group->interface)->ip_addr));
612 if (type == IGMP_V2_MEMB_REPORT) {
613 dest = &(group->group_address);
614 IGMP_STATS_INC(igmp.report_sent);
615 ip_addr_set(&(igmp->igmp_group_address), &(group->group_address));
616 group->last_reporter_flag = 1; /* Remember we were the last to report */
618 if (type == IGMP_LEAVE_GROUP) {
620 ip_addr_set(&(igmp->igmp_group_address), &(group->group_address));
624 if ((type == IGMP_V2_MEMB_REPORT) || (type == IGMP_LEAVE_GROUP)) {
625 igmp->igmp_msgtype = type;
626 igmp->igmp_maxresp = 0;
627 igmp->igmp_checksum = 0;
628 igmp->igmp_checksum = inet_chksum( igmp, IGMP_MINLEN);
630 igmp_ip_output_if( p, &src, dest, IGMP_TTL, IP_PROTO_IGMP, group->interface);
635 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n"));
639 #endif /* LWIP_IGMP */