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 *----------------------------------------------------------------------------*/
82 #if LWIP_IGMP /* don't build if not configured for use in lwipopts.h */
84 #include "lwip/igmp.h"
85 #include "lwip/debug.h"
89 #include "lwip/inet_chksum.h"
90 #include "lwip/netif.h"
91 #include "lwip/icmp.h"
94 #include "lwip/stats.h"
102 #define IGMP_MINLEN 8
103 #define ROUTER_ALERT 0x9404
104 #define ROUTER_ALERTLEN 4
107 * IGMP message types, including version number.
109 #define IGMP_MEMB_QUERY 0x11 /* Membership query */
110 #define IGMP_V1_MEMB_REPORT 0x12 /* Ver. 1 membership report */
111 #define IGMP_V2_MEMB_REPORT 0x16 /* Ver. 2 membership report */
112 #define IGMP_LEAVE_GROUP 0x17 /* Leave-group message */
114 /* Group membership states */
115 #define IGMP_GROUP_NON_MEMBER 0
116 #define IGMP_GROUP_DELAYING_MEMBER 1
117 #define IGMP_GROUP_IDLE_MEMBER 2
120 * IGMP packet format.
122 #ifdef PACK_STRUCT_USE_INCLUDES
123 # include "arch/bpstruct.h"
127 PACK_STRUCT_FIELD(u8_t igmp_msgtype);
128 PACK_STRUCT_FIELD(u8_t igmp_maxresp);
129 PACK_STRUCT_FIELD(u16_t igmp_checksum);
130 PACK_STRUCT_FIELD(ip_addr_t igmp_group_address);
131 } PACK_STRUCT_STRUCT;
133 #ifdef PACK_STRUCT_USE_INCLUDES
134 # include "arch/epstruct.h"
138 static struct igmp_group *igmp_lookup_group(struct netif *ifp, ip_addr_t *addr);
139 static err_t igmp_remove_group(struct igmp_group *group);
140 static void igmp_timeout( struct igmp_group *group);
141 static void igmp_start_timer(struct igmp_group *group, u8_t max_time);
142 static void igmp_stop_timer(struct igmp_group *group);
143 static void igmp_delaying_member(struct igmp_group *group, u8_t maxresp);
144 static err_t igmp_ip_output_if(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, struct netif *netif);
145 static void igmp_send(struct igmp_group *group, u8_t type);
148 static struct igmp_group* igmp_group_list;
149 static ip_addr_t allsystems;
150 static ip_addr_t allrouters;
154 * Initialize the IGMP module
159 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_init: initializing\n"));
161 IP4_ADDR(&allsystems, 224, 0, 0, 1);
162 IP4_ADDR(&allrouters, 224, 0, 0, 2);
167 * Dump global IGMP groups list
170 igmp_dump_group_list()
172 struct igmp_group *group = igmp_group_list;
174 while (group != NULL) {
175 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_dump_group_list: [%"U32_F"] ", (u32_t)(group->group_state)));
176 ip_addr_debug_print(IGMP_DEBUG, &group->group_address);
177 LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", group->netif));
180 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
183 #define igmp_dump_group_list()
184 #endif /* LWIP_DEBUG */
187 * Start IGMP processing on interface
189 * @param netif network interface on which start IGMP processing
192 igmp_start(struct netif *netif)
194 struct igmp_group* group;
196 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: starting IGMP processing on if %p\n", netif));
198 group = igmp_lookup_group(netif, &allsystems);
201 group->group_state = IGMP_GROUP_IDLE_MEMBER;
204 /* Allow the igmp messages at the MAC level */
205 if (netif->igmp_mac_filter != NULL) {
206 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: igmp_mac_filter(ADD "));
207 ip_addr_debug_print(IGMP_DEBUG, &allsystems);
208 LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", netif));
209 netif->igmp_mac_filter(netif, &allsystems, IGMP_ADD_MAC_FILTER);
219 * Stop IGMP processing on interface
221 * @param netif network interface on which stop IGMP processing
224 igmp_stop(struct netif *netif)
226 struct igmp_group *group = igmp_group_list;
227 struct igmp_group *prev = NULL;
228 struct igmp_group *next;
230 /* look for groups joined on this interface further down the list */
231 while (group != NULL) {
233 /* is it a group joined on this interface? */
234 if (group->netif == netif) {
235 /* is it the first group of the list? */
236 if (group == igmp_group_list) {
237 igmp_group_list = next;
239 /* is there a "previous" group defined? */
243 /* disable the group at the MAC level */
244 if (netif->igmp_mac_filter != NULL) {
245 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_stop: igmp_mac_filter(DEL "));
246 ip_addr_debug_print(IGMP_DEBUG, &group->group_address);
247 LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", netif));
248 netif->igmp_mac_filter(netif, &(group->group_address), IGMP_DEL_MAC_FILTER);
251 memp_free(MEMP_IGMP_GROUP, group);
253 /* change the "previous" */
263 * Report IGMP memberships for this interface
265 * @param netif network interface on which report IGMP memberships
268 igmp_report_groups(struct netif *netif)
270 struct igmp_group *group = igmp_group_list;
272 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_report_groups: sending IGMP reports on if %p\n", netif));
274 while (group != NULL) {
275 if (group->netif == netif) {
276 igmp_delaying_member(group, IGMP_JOIN_DELAYING_MEMBER_TMR);
283 * Search for a group in the global igmp_group_list
285 * @param ifp the network interface for which to look
286 * @param addr the group ip address to search for
287 * @return a struct igmp_group* if the group has been found,
288 * NULL if the group wasn't found.
291 igmp_lookfor_group(struct netif *ifp, ip_addr_t *addr)
293 struct igmp_group *group = igmp_group_list;
295 while (group != NULL) {
296 if ((group->netif == ifp) && (ip_addr_cmp(&(group->group_address), addr))) {
302 /* to be clearer, we return NULL here instead of
303 * 'group' (which is also NULL at this point).
309 * Search for a specific igmp group and create a new one if not found-
311 * @param ifp the network interface for which to look
312 * @param addr the group ip address to search
313 * @return a struct igmp_group*,
314 * NULL on memory error.
317 igmp_lookup_group(struct netif *ifp, ip_addr_t *addr)
319 struct igmp_group *group = igmp_group_list;
321 /* Search if the group already exists */
322 group = igmp_lookfor_group(ifp, addr);
324 /* Group already exists. */
328 /* Group doesn't exist yet, create a new one */
329 group = memp_malloc(MEMP_IGMP_GROUP);
332 ip_addr_set(&(group->group_address), addr);
333 group->timer = 0; /* Not running */
334 group->group_state = IGMP_GROUP_NON_MEMBER;
335 group->last_reporter_flag = 0;
337 group->next = igmp_group_list;
339 igmp_group_list = group;
342 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_lookup_group: %sallocated a new group with address ", (group?"":"impossible to ")));
343 ip_addr_debug_print(IGMP_DEBUG, addr);
344 LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", ifp));
350 * Remove a group in the global igmp_group_list
352 * @param group the group to remove from the global igmp_group_list
353 * @return ERR_OK if group was removed from the list, an err_t otherwise
356 igmp_remove_group(struct igmp_group *group)
360 /* Is it the first group? */
361 if (igmp_group_list == group) {
362 igmp_group_list = group->next;
364 /* look for group further down the list */
365 struct igmp_group *tmpGroup;
366 for (tmpGroup = igmp_group_list; tmpGroup != NULL; tmpGroup = tmpGroup->next) {
367 if (tmpGroup->next == group) {
368 tmpGroup->next = group->next;
372 /* Group not found in the global igmp_group_list */
373 if (tmpGroup == NULL)
377 memp_free(MEMP_IGMP_GROUP, group);
383 * Called from ip_input() if a new IGMP packet is received.
385 * @param p received igmp packet, p->payload pointing to the ip header
386 * @param inp network interface on which the packet was received
387 * @param dest destination ip address of the igmp packet
390 igmp_input(struct pbuf *p, struct netif *inp, ip_addr_t *dest)
392 struct ip_hdr * iphdr;
393 struct igmp_msg* igmp;
394 struct igmp_group* group;
395 struct igmp_group* groupref;
397 IGMP_STATS_INC(igmp.recv);
399 /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */
401 if (pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4)) || (p->len < IGMP_MINLEN)) {
403 IGMP_STATS_INC(igmp.lenerr);
404 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n"));
408 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from "));
409 ip_addr_debug_print(IGMP_DEBUG, &(iphdr->src));
410 LWIP_DEBUGF(IGMP_DEBUG, (" to address "));
411 ip_addr_debug_print(IGMP_DEBUG, &(iphdr->dest));
412 LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", inp));
414 /* Now calculate and check the checksum */
415 igmp = (struct igmp_msg *)p->payload;
416 if (inet_chksum(igmp, p->len)) {
418 IGMP_STATS_INC(igmp.chkerr);
419 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n"));
423 /* Packet is ok so find an existing group */
424 group = igmp_lookfor_group(inp, dest); /* use the destination IP address of incoming packet */
426 /* If group can be found or create... */
429 IGMP_STATS_INC(igmp.drop);
430 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n"));
434 /* NOW ACT ON THE INCOMING MESSAGE TYPE... */
435 switch (igmp->igmp_msgtype) {
436 case IGMP_MEMB_QUERY: {
437 /* IGMP_MEMB_QUERY to the "all systems" address ? */
438 if ((ip_addr_cmp(dest, &allsystems)) && ip_addr_isany(&igmp->igmp_group_address)) {
439 /* THIS IS THE GENERAL QUERY */
440 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)));
442 if (igmp->igmp_maxresp == 0) {
443 IGMP_STATS_INC(igmp.rx_v1);
444 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n"));
445 igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR;
448 IGMP_STATS_INC(igmp.rx_general);
451 groupref = igmp_group_list;
453 /* Do not send messages on the all systems group address! */
454 if ((groupref->netif == inp) && (!(ip_addr_cmp(&(groupref->group_address), &allsystems)))) {
455 igmp_delaying_member(groupref, igmp->igmp_maxresp);
457 groupref = groupref->next;
460 /* IGMP_MEMB_QUERY to a specific group ? */
461 if (!ip_addr_isany(&igmp->igmp_group_address)) {
462 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
463 ip_addr_debug_print(IGMP_DEBUG, &igmp->igmp_group_address);
464 if (ip_addr_cmp(dest, &allsystems)) {
465 LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
466 /* we first need to re-lookfor the group since we used dest last time */
467 group = igmp_lookfor_group(inp, &igmp->igmp_group_address);
469 LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
473 IGMP_STATS_INC(igmp.rx_group);
474 igmp_delaying_member(group, igmp->igmp_maxresp);
477 IGMP_STATS_INC(igmp.drop);
481 IGMP_STATS_INC(igmp.proterr);
486 case IGMP_V2_MEMB_REPORT: {
487 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));
488 IGMP_STATS_INC(igmp.rx_report);
489 if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) {
490 /* This is on a specific group we have already looked up */
491 group->timer = 0; /* stopped */
492 group->group_state = IGMP_GROUP_IDLE_MEMBER;
493 group->last_reporter_flag = 0;
498 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %d in state %d on group %p on if %p\n",
499 igmp->igmp_msgtype, group->group_state, &group, group->netif));
500 IGMP_STATS_INC(igmp.proterr);
510 * Join a group on one network interface.
512 * @param ifaddr ip address of the network interface which should join a new group
513 * @param groupaddr the ip address of the group which to join
514 * @return ERR_OK if group was joined on the netif(s), an err_t otherwise
517 igmp_joingroup(ip_addr_t *ifaddr, ip_addr_t *groupaddr)
519 err_t err = ERR_VAL; /* no matching interface */
520 struct igmp_group *group;
523 /* make sure it is multicast address */
524 LWIP_ERROR("igmp_joingroup: attempt to join non-multicast address", ip_addr_ismulticast(groupaddr), return ERR_VAL;);
525 LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
527 /* loop through netif's */
529 while (netif != NULL) {
530 /* Should we join this interface ? */
531 if ((netif->flags & NETIF_FLAG_IGMP) && ((ip_addr_isany(ifaddr) || ip_addr_cmp(&(netif->ip_addr), ifaddr)))) {
532 /* find group or create a new one if not found */
533 group = igmp_lookup_group(netif, groupaddr);
536 /* This should create a new group, check the state to make sure */
537 if (group->group_state != IGMP_GROUP_NON_MEMBER) {
538 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: join to group not in state IGMP_GROUP_NON_MEMBER\n"));
540 /* OK - it was new group */
541 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: join to new group: "));
542 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
543 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
545 /* If first use of the group, allow the group at the MAC level */
546 if ((group->use==0) && (netif->igmp_mac_filter != NULL)) {
547 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: igmp_mac_filter(ADD "));
548 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
549 LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", netif));
550 netif->igmp_mac_filter(netif, groupaddr, IGMP_ADD_MAC_FILTER);
553 IGMP_STATS_INC(igmp.tx_join);
554 igmp_send(group, IGMP_V2_MEMB_REPORT);
556 igmp_start_timer(group, IGMP_JOIN_DELAYING_MEMBER_TMR);
558 /* Need to work out where this timer comes from */
559 group->group_state = IGMP_GROUP_DELAYING_MEMBER;
561 /* Increment group use */
563 /* Join on this interface */
566 /* Return an error even if some network interfaces are joined */
567 /** @todo undo any other netif already joined */
568 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup: Not enought memory to join to group\n"));
572 /* proceed to next network interface */
580 * Leave a group on one network interface.
582 * @param ifaddr ip address of the network interface which should leave a group
583 * @param groupaddr the ip address of the group which to leave
584 * @return ERR_OK if group was left on the netif(s), an err_t otherwise
587 igmp_leavegroup(ip_addr_t *ifaddr, ip_addr_t *groupaddr)
589 err_t err = ERR_VAL; /* no matching interface */
590 struct igmp_group *group;
593 /* make sure it is multicast address */
594 LWIP_ERROR("igmp_leavegroup: attempt to leave non-multicast address", ip_addr_ismulticast(groupaddr), return ERR_VAL;);
595 LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
597 /* loop through netif's */
599 while (netif != NULL) {
600 /* Should we leave this interface ? */
601 if ((netif->flags & NETIF_FLAG_IGMP) && ((ip_addr_isany(ifaddr) || ip_addr_cmp(&(netif->ip_addr), ifaddr)))) {
603 group = igmp_lookfor_group(netif, groupaddr);
606 /* Only send a leave if the flag is set according to the state diagram */
607 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: Leaving group: "));
608 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
609 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
611 /* If there is no other use of the group */
612 if (group->use <= 1) {
613 /* If we are the last reporter for this group */
614 if (group->last_reporter_flag) {
615 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: sending leaving group\n"));
616 IGMP_STATS_INC(igmp.tx_leave);
617 igmp_send(group, IGMP_LEAVE_GROUP);
620 /* Disable the group at the MAC level */
621 if (netif->igmp_mac_filter != NULL) {
622 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: igmp_mac_filter(DEL "));
623 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
624 LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", netif));
625 netif->igmp_mac_filter(netif, groupaddr, IGMP_DEL_MAC_FILTER);
628 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: remove group: "));
629 ip_addr_debug_print(IGMP_DEBUG, groupaddr);
630 LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
633 igmp_remove_group(group);
635 /* Decrement group use */
638 /* Leave on this interface */
641 /* It's not a fatal error on "leavegroup" */
642 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup: not member of group\n"));
645 /* proceed to next network interface */
653 * The igmp timer function (both for NO_SYS=1 and =0)
654 * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default).
659 struct igmp_group *group = igmp_group_list;
661 while (group != NULL) {
662 if (group->timer > 0) {
664 if (group->timer == 0) {
673 * Called if a timeout for one group is reached.
674 * Sends a report for this group.
676 * @param group an igmp_group for which a timeout is reached
679 igmp_timeout(struct igmp_group *group)
681 /* If the state is IGMP_GROUP_DELAYING_MEMBER then we send a report for this group */
682 if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) {
683 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_timeout: report membership for group with address "));
684 ip_addr_debug_print(IGMP_DEBUG, &(group->group_address));
685 LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", group->netif));
687 IGMP_STATS_INC(igmp.tx_report);
688 igmp_send(group, IGMP_V2_MEMB_REPORT);
693 * Start a timer for an igmp group
695 * @param group the igmp_group for which to start a timer
696 * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with
697 * every call to igmp_tmr())
700 igmp_start_timer(struct igmp_group *group, u8_t max_time)
702 /* ensure the input value is > 0 */
706 /* ensure the random value is > 0 */
707 group->timer = (LWIP_RAND() % (max_time - 1)) + 1;
711 * Stop a timer for an igmp_group
713 * @param group the igmp_group for which to stop the timer
716 igmp_stop_timer(struct igmp_group *group)
722 * Delaying membership report for a group if necessary
724 * @param group the igmp_group for which "delaying" membership report
725 * @param maxresp query delay
728 igmp_delaying_member(struct igmp_group *group, u8_t maxresp)
730 if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) ||
731 ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) &&
732 ((group->timer == 0) || (maxresp < group->timer)))) {
733 igmp_start_timer(group, maxresp);
734 group->group_state = IGMP_GROUP_DELAYING_MEMBER;
740 * Sends an IP packet on a network interface. This function constructs the IP header
741 * and calculates the IP header checksum. If the source IP address is NULL,
742 * the IP address of the outgoing network interface is filled in as source address.
744 * @param p the packet to send (p->payload points to the data, e.g. next
745 protocol header; if dest == IP_HDRINCL, p already includes an IP
746 header and p->payload points to that IP header)
747 * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
748 * IP address of the netif used to send is used as source address)
749 * @param dest the destination IP address to send the packet to
750 * @param ttl the TTL value to be set in the IP header
751 * @param proto the PROTOCOL to be set in the IP header
752 * @param netif the netif on which to send this packet
753 * @return ERR_OK if the packet was sent OK
754 * ERR_BUF if p doesn't have enough space for IP/LINK headers
755 * returns errors returned by netif->output
758 igmp_ip_output_if(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, struct netif *netif)
760 /* This is the "router alert" option */
762 ra[0] = PP_HTONS(ROUTER_ALERT);
763 ra[1] = 0x0000; /* Router shall examine packet */
764 IGMP_STATS_INC(igmp.xmit);
765 return ip_output_if_opt(p, src, dest, IGMP_TTL, 0, IP_PROTO_IGMP, netif, ra, ROUTER_ALERTLEN);
769 * Send an igmp packet to a specific group.
771 * @param group the group to which to send the packet
772 * @param type the type of igmp packet to send
775 igmp_send(struct igmp_group *group, u8_t type)
777 struct pbuf* p = NULL;
778 struct igmp_msg* igmp = NULL;
779 ip_addr_t src = *IP_ADDR_ANY;
780 ip_addr_t* dest = NULL;
782 /* IP header + "router alert" option + IGMP header */
783 p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM);
787 LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg",
788 (p->len >= sizeof(struct igmp_msg)));
789 ip_addr_copy(src, group->netif->ip_addr);
791 if (type == IGMP_V2_MEMB_REPORT) {
792 dest = &(group->group_address);
793 ip_addr_copy(igmp->igmp_group_address, group->group_address);
794 group->last_reporter_flag = 1; /* Remember we were the last to report */
796 if (type == IGMP_LEAVE_GROUP) {
798 ip_addr_copy(igmp->igmp_group_address, group->group_address);
802 if ((type == IGMP_V2_MEMB_REPORT) || (type == IGMP_LEAVE_GROUP)) {
803 igmp->igmp_msgtype = type;
804 igmp->igmp_maxresp = 0;
805 igmp->igmp_checksum = 0;
806 igmp->igmp_checksum = inet_chksum(igmp, IGMP_MINLEN);
808 igmp_ip_output_if(p, &src, dest, group->netif);
813 LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n"));
814 IGMP_STATS_INC(igmp.memerr);
818 #endif /* LWIP_IGMP */