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 0x9404U
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_p_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_delaying_member(struct igmp_group
*group
, u8_t maxresp
);
143 static err_t
igmp_ip_output_if(struct pbuf
*p
, ip_addr_t
*src
, ip_addr_t
*dest
, struct netif
*netif
);
144 static void igmp_send(struct igmp_group
*group
, u8_t type
);
147 static struct igmp_group
* igmp_group_list
;
148 static ip_addr_t allsystems
;
149 static ip_addr_t allrouters
;
153 * Initialize the IGMP module
158 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_init: initializing\n"));
160 IP4_ADDR(&allsystems
, 224, 0, 0, 1);
161 IP4_ADDR(&allrouters
, 224, 0, 0, 2);
166 * Dump global IGMP groups list
169 igmp_dump_group_list()
171 struct igmp_group
*group
= igmp_group_list
;
173 while (group
!= NULL
) {
174 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_dump_group_list: [%"U32_F
"] ", (u32_t
)(group
->group_state
)));
175 ip_addr_debug_print(IGMP_DEBUG
, &group
->group_address
);
176 LWIP_DEBUGF(IGMP_DEBUG
, (" on if %p\n", group
->netif
));
179 LWIP_DEBUGF(IGMP_DEBUG
, ("\n"));
182 #define igmp_dump_group_list()
183 #endif /* LWIP_DEBUG */
186 * Start IGMP processing on interface
188 * @param netif network interface on which start IGMP processing
191 igmp_start(struct netif
*netif
)
193 struct igmp_group
* group
;
195 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_start: starting IGMP processing on if %p\n", netif
));
197 group
= igmp_lookup_group(netif
, &allsystems
);
200 group
->group_state
= IGMP_GROUP_IDLE_MEMBER
;
203 /* Allow the igmp messages at the MAC level */
204 if (netif
->igmp_mac_filter
!= NULL
) {
205 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_start: igmp_mac_filter(ADD "));
206 ip_addr_debug_print(IGMP_DEBUG
, &allsystems
);
207 LWIP_DEBUGF(IGMP_DEBUG
, (") on if %p\n", netif
));
208 netif
->igmp_mac_filter(netif
, &allsystems
, IGMP_ADD_MAC_FILTER
);
218 * Stop IGMP processing on interface
220 * @param netif network interface on which stop IGMP processing
223 igmp_stop(struct netif
*netif
)
225 struct igmp_group
*group
= igmp_group_list
;
226 struct igmp_group
*prev
= NULL
;
227 struct igmp_group
*next
;
229 /* look for groups joined on this interface further down the list */
230 while (group
!= NULL
) {
232 /* is it a group joined on this interface? */
233 if (group
->netif
== netif
) {
234 /* is it the first group of the list? */
235 if (group
== igmp_group_list
) {
236 igmp_group_list
= next
;
238 /* is there a "previous" group defined? */
242 /* disable the group at the MAC level */
243 if (netif
->igmp_mac_filter
!= NULL
) {
244 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_stop: igmp_mac_filter(DEL "));
245 ip_addr_debug_print(IGMP_DEBUG
, &group
->group_address
);
246 LWIP_DEBUGF(IGMP_DEBUG
, (") on if %p\n", netif
));
247 netif
->igmp_mac_filter(netif
, &(group
->group_address
), IGMP_DEL_MAC_FILTER
);
250 memp_free(MEMP_IGMP_GROUP
, group
);
252 /* change the "previous" */
262 * Report IGMP memberships for this interface
264 * @param netif network interface on which report IGMP memberships
267 igmp_report_groups(struct netif
*netif
)
269 struct igmp_group
*group
= igmp_group_list
;
271 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_report_groups: sending IGMP reports on if %p\n", netif
));
273 while (group
!= NULL
) {
274 if (group
->netif
== netif
) {
275 igmp_delaying_member(group
, IGMP_JOIN_DELAYING_MEMBER_TMR
);
282 * Search for a group in the global igmp_group_list
284 * @param ifp the network interface for which to look
285 * @param addr the group ip address to search for
286 * @return a struct igmp_group* if the group has been found,
287 * NULL if the group wasn't found.
290 igmp_lookfor_group(struct netif
*ifp
, ip_addr_t
*addr
)
292 struct igmp_group
*group
= igmp_group_list
;
294 while (group
!= NULL
) {
295 if ((group
->netif
== ifp
) && (ip_addr_cmp(&(group
->group_address
), addr
))) {
301 /* to be clearer, we return NULL here instead of
302 * 'group' (which is also NULL at this point).
308 * Search for a specific igmp group and create a new one if not found-
310 * @param ifp the network interface for which to look
311 * @param addr the group ip address to search
312 * @return a struct igmp_group*,
313 * NULL on memory error.
316 igmp_lookup_group(struct netif
*ifp
, ip_addr_t
*addr
)
318 struct igmp_group
*group
= igmp_group_list
;
320 /* Search if the group already exists */
321 group
= igmp_lookfor_group(ifp
, addr
);
323 /* Group already exists. */
327 /* Group doesn't exist yet, create a new one */
328 group
= (struct igmp_group
*)memp_malloc(MEMP_IGMP_GROUP
);
331 ip_addr_set(&(group
->group_address
), addr
);
332 group
->timer
= 0; /* Not running */
333 group
->group_state
= IGMP_GROUP_NON_MEMBER
;
334 group
->last_reporter_flag
= 0;
336 group
->next
= igmp_group_list
;
338 igmp_group_list
= group
;
341 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_lookup_group: %sallocated a new group with address ", (group
?"":"impossible to ")));
342 ip_addr_debug_print(IGMP_DEBUG
, addr
);
343 LWIP_DEBUGF(IGMP_DEBUG
, (" on if %p\n", ifp
));
349 * Remove a group in the global igmp_group_list
351 * @param group the group to remove from the global igmp_group_list
352 * @return ERR_OK if group was removed from the list, an err_t otherwise
355 igmp_remove_group(struct igmp_group
*group
)
359 /* Is it the first group? */
360 if (igmp_group_list
== group
) {
361 igmp_group_list
= group
->next
;
363 /* look for group further down the list */
364 struct igmp_group
*tmpGroup
;
365 for (tmpGroup
= igmp_group_list
; tmpGroup
!= NULL
; tmpGroup
= tmpGroup
->next
) {
366 if (tmpGroup
->next
== group
) {
367 tmpGroup
->next
= group
->next
;
371 /* Group not found in the global igmp_group_list */
372 if (tmpGroup
== NULL
)
376 memp_free(MEMP_IGMP_GROUP
, group
);
382 * Called from ip_input() if a new IGMP packet is received.
384 * @param p received igmp packet, p->payload pointing to the ip header
385 * @param inp network interface on which the packet was received
386 * @param dest destination ip address of the igmp packet
389 igmp_input(struct pbuf
*p
, struct netif
*inp
, ip_addr_t
*dest
)
391 struct ip_hdr
* iphdr
;
392 struct igmp_msg
* igmp
;
393 struct igmp_group
* group
;
394 struct igmp_group
* groupref
;
396 IGMP_STATS_INC(igmp
.recv
);
398 /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */
399 iphdr
= (struct ip_hdr
*)p
->payload
;
400 if (pbuf_header(p
, -(s16_t
)(IPH_HL(iphdr
) * 4)) || (p
->len
< IGMP_MINLEN
)) {
402 IGMP_STATS_INC(igmp
.lenerr
);
403 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: length error\n"));
407 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: message from "));
408 ip_addr_debug_print(IGMP_DEBUG
, &(iphdr
->src
));
409 LWIP_DEBUGF(IGMP_DEBUG
, (" to address "));
410 ip_addr_debug_print(IGMP_DEBUG
, &(iphdr
->dest
));
411 LWIP_DEBUGF(IGMP_DEBUG
, (" on if %p\n", inp
));
413 /* Now calculate and check the checksum */
414 igmp
= (struct igmp_msg
*)p
->payload
;
415 if (inet_chksum(igmp
, p
->len
)) {
417 IGMP_STATS_INC(igmp
.chkerr
);
418 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: checksum error\n"));
422 /* Packet is ok so find an existing group */
423 group
= igmp_lookfor_group(inp
, dest
); /* use the destination IP address of incoming packet */
425 /* If group can be found or create... */
428 IGMP_STATS_INC(igmp
.drop
);
429 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: IGMP frame not for us\n"));
433 /* NOW ACT ON THE INCOMING MESSAGE TYPE... */
434 switch (igmp
->igmp_msgtype
) {
435 case IGMP_MEMB_QUERY
: {
436 /* IGMP_MEMB_QUERY to the "all systems" address ? */
437 if ((ip_addr_cmp(dest
, &allsystems
)) && ip_addr_isany(&igmp
->igmp_group_address
)) {
438 /* THIS IS THE GENERAL QUERY */
439 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
)));
441 if (igmp
->igmp_maxresp
== 0) {
442 IGMP_STATS_INC(igmp
.rx_v1
);
443 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n"));
444 igmp
->igmp_maxresp
= IGMP_V1_DELAYING_MEMBER_TMR
;
446 IGMP_STATS_INC(igmp
.rx_general
);
449 groupref
= igmp_group_list
;
451 /* Do not send messages on the all systems group address! */
452 if ((groupref
->netif
== inp
) && (!(ip_addr_cmp(&(groupref
->group_address
), &allsystems
)))) {
453 igmp_delaying_member(groupref
, igmp
->igmp_maxresp
);
455 groupref
= groupref
->next
;
458 /* IGMP_MEMB_QUERY to a specific group ? */
459 if (!ip_addr_isany(&igmp
->igmp_group_address
)) {
460 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
461 ip_addr_debug_print(IGMP_DEBUG
, &igmp
->igmp_group_address
);
462 if (ip_addr_cmp(dest
, &allsystems
)) {
464 LWIP_DEBUGF(IGMP_DEBUG
, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp
->igmp_maxresp
)));
465 /* we first need to re-look for the group since we used dest last time */
466 ip_addr_copy(groupaddr
, igmp
->igmp_group_address
);
467 group
= igmp_lookfor_group(inp
, &groupaddr
);
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
);
476 IGMP_STATS_INC(igmp
.drop
);
479 IGMP_STATS_INC(igmp
.proterr
);
484 case IGMP_V2_MEMB_REPORT
: {
485 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));
486 IGMP_STATS_INC(igmp
.rx_report
);
487 if (group
->group_state
== IGMP_GROUP_DELAYING_MEMBER
) {
488 /* This is on a specific group we have already looked up */
489 group
->timer
= 0; /* stopped */
490 group
->group_state
= IGMP_GROUP_IDLE_MEMBER
;
491 group
->last_reporter_flag
= 0;
496 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_input: unexpected msg %d in state %d on group %p on if %p\n",
497 igmp
->igmp_msgtype
, group
->group_state
, &group
, group
->netif
));
498 IGMP_STATS_INC(igmp
.proterr
);
508 * Join a group on one network interface.
510 * @param ifaddr ip address of the network interface which should join a new group
511 * @param groupaddr the ip address of the group which to join
512 * @return ERR_OK if group was joined on the netif(s), an err_t otherwise
515 igmp_joingroup(ip_addr_t
*ifaddr
, ip_addr_t
*groupaddr
)
517 err_t err
= ERR_VAL
; /* no matching interface */
518 struct igmp_group
*group
;
521 /* make sure it is multicast address */
522 LWIP_ERROR("igmp_joingroup: attempt to join non-multicast address", ip_addr_ismulticast(groupaddr
), return ERR_VAL
;);
523 LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip_addr_cmp(groupaddr
, &allsystems
)), return ERR_VAL
;);
525 /* loop through netif's */
527 while (netif
!= NULL
) {
528 /* Should we join this interface ? */
529 if ((netif
->flags
& NETIF_FLAG_IGMP
) && ((ip_addr_isany(ifaddr
) || ip_addr_cmp(&(netif
->ip_addr
), ifaddr
)))) {
530 /* find group or create a new one if not found */
531 group
= igmp_lookup_group(netif
, groupaddr
);
534 /* This should create a new group, check the state to make sure */
535 if (group
->group_state
!= IGMP_GROUP_NON_MEMBER
) {
536 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_joingroup: join to group not in state IGMP_GROUP_NON_MEMBER\n"));
538 /* OK - it was new group */
539 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_joingroup: join to new group: "));
540 ip_addr_debug_print(IGMP_DEBUG
, groupaddr
);
541 LWIP_DEBUGF(IGMP_DEBUG
, ("\n"));
543 /* If first use of the group, allow the group at the MAC level */
544 if ((group
->use
==0) && (netif
->igmp_mac_filter
!= NULL
)) {
545 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_joingroup: igmp_mac_filter(ADD "));
546 ip_addr_debug_print(IGMP_DEBUG
, groupaddr
);
547 LWIP_DEBUGF(IGMP_DEBUG
, (") on if %p\n", netif
));
548 netif
->igmp_mac_filter(netif
, groupaddr
, IGMP_ADD_MAC_FILTER
);
551 IGMP_STATS_INC(igmp
.tx_join
);
552 igmp_send(group
, IGMP_V2_MEMB_REPORT
);
554 igmp_start_timer(group
, IGMP_JOIN_DELAYING_MEMBER_TMR
);
556 /* Need to work out where this timer comes from */
557 group
->group_state
= IGMP_GROUP_DELAYING_MEMBER
;
559 /* Increment group use */
561 /* Join on this interface */
564 /* Return an error even if some network interfaces are joined */
565 /** @todo undo any other netif already joined */
566 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_joingroup: Not enought memory to join to group\n"));
570 /* proceed to next network interface */
578 * Leave a group on one network interface.
580 * @param ifaddr ip address of the network interface which should leave a group
581 * @param groupaddr the ip address of the group which to leave
582 * @return ERR_OK if group was left on the netif(s), an err_t otherwise
585 igmp_leavegroup(ip_addr_t
*ifaddr
, ip_addr_t
*groupaddr
)
587 err_t err
= ERR_VAL
; /* no matching interface */
588 struct igmp_group
*group
;
591 /* make sure it is multicast address */
592 LWIP_ERROR("igmp_leavegroup: attempt to leave non-multicast address", ip_addr_ismulticast(groupaddr
), return ERR_VAL
;);
593 LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip_addr_cmp(groupaddr
, &allsystems
)), return ERR_VAL
;);
595 /* loop through netif's */
597 while (netif
!= NULL
) {
598 /* Should we leave this interface ? */
599 if ((netif
->flags
& NETIF_FLAG_IGMP
) && ((ip_addr_isany(ifaddr
) || ip_addr_cmp(&(netif
->ip_addr
), ifaddr
)))) {
601 group
= igmp_lookfor_group(netif
, groupaddr
);
604 /* Only send a leave if the flag is set according to the state diagram */
605 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_leavegroup: Leaving group: "));
606 ip_addr_debug_print(IGMP_DEBUG
, groupaddr
);
607 LWIP_DEBUGF(IGMP_DEBUG
, ("\n"));
609 /* If there is no other use of the group */
610 if (group
->use
<= 1) {
611 /* If we are the last reporter for this group */
612 if (group
->last_reporter_flag
) {
613 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_leavegroup: sending leaving group\n"));
614 IGMP_STATS_INC(igmp
.tx_leave
);
615 igmp_send(group
, IGMP_LEAVE_GROUP
);
618 /* Disable the group at the MAC level */
619 if (netif
->igmp_mac_filter
!= NULL
) {
620 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_leavegroup: igmp_mac_filter(DEL "));
621 ip_addr_debug_print(IGMP_DEBUG
, groupaddr
);
622 LWIP_DEBUGF(IGMP_DEBUG
, (") on if %p\n", netif
));
623 netif
->igmp_mac_filter(netif
, groupaddr
, IGMP_DEL_MAC_FILTER
);
626 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_leavegroup: remove group: "));
627 ip_addr_debug_print(IGMP_DEBUG
, groupaddr
);
628 LWIP_DEBUGF(IGMP_DEBUG
, ("\n"));
631 igmp_remove_group(group
);
633 /* Decrement group use */
636 /* Leave on this interface */
639 /* It's not a fatal error on "leavegroup" */
640 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_leavegroup: not member of group\n"));
643 /* proceed to next network interface */
651 * The igmp timer function (both for NO_SYS=1 and =0)
652 * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default).
657 struct igmp_group
*group
= igmp_group_list
;
659 while (group
!= NULL
) {
660 if (group
->timer
> 0) {
662 if (group
->timer
== 0) {
671 * Called if a timeout for one group is reached.
672 * Sends a report for this group.
674 * @param group an igmp_group for which a timeout is reached
677 igmp_timeout(struct igmp_group
*group
)
679 /* If the state is IGMP_GROUP_DELAYING_MEMBER then we send a report for this group */
680 if (group
->group_state
== IGMP_GROUP_DELAYING_MEMBER
) {
681 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_timeout: report membership for group with address "));
682 ip_addr_debug_print(IGMP_DEBUG
, &(group
->group_address
));
683 LWIP_DEBUGF(IGMP_DEBUG
, (" on if %p\n", group
->netif
));
685 IGMP_STATS_INC(igmp
.tx_report
);
686 igmp_send(group
, IGMP_V2_MEMB_REPORT
);
691 * Start a timer for an igmp group
693 * @param group the igmp_group for which to start a timer
694 * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with
695 * every call to igmp_tmr())
698 igmp_start_timer(struct igmp_group
*group
, u8_t max_time
)
700 /* ensure the input value is > 0 */
704 /* ensure the random value is > 0 */
705 group
->timer
= (LWIP_RAND() % (max_time
- 1)) + 1;
709 * Delaying membership report for a group if necessary
711 * @param group the igmp_group for which "delaying" membership report
712 * @param maxresp query delay
715 igmp_delaying_member(struct igmp_group
*group
, u8_t maxresp
)
717 if ((group
->group_state
== IGMP_GROUP_IDLE_MEMBER
) ||
718 ((group
->group_state
== IGMP_GROUP_DELAYING_MEMBER
) &&
719 ((group
->timer
== 0) || (maxresp
< group
->timer
)))) {
720 igmp_start_timer(group
, maxresp
);
721 group
->group_state
= IGMP_GROUP_DELAYING_MEMBER
;
727 * Sends an IP packet on a network interface. This function constructs the IP header
728 * and calculates the IP header checksum. If the source IP address is NULL,
729 * the IP address of the outgoing network interface is filled in as source address.
731 * @param p the packet to send (p->payload points to the data, e.g. next
732 protocol header; if dest == IP_HDRINCL, p already includes an IP
733 header and p->payload points to that IP header)
734 * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
735 * IP address of the netif used to send is used as source address)
736 * @param dest the destination IP address to send the packet to
737 * @param ttl the TTL value to be set in the IP header
738 * @param proto the PROTOCOL to be set in the IP header
739 * @param netif the netif on which to send this packet
740 * @return ERR_OK if the packet was sent OK
741 * ERR_BUF if p doesn't have enough space for IP/LINK headers
742 * returns errors returned by netif->output
745 igmp_ip_output_if(struct pbuf
*p
, ip_addr_t
*src
, ip_addr_t
*dest
, struct netif
*netif
)
747 /* This is the "router alert" option */
749 ra
[0] = PP_HTONS(ROUTER_ALERT
);
750 ra
[1] = 0x0000; /* Router shall examine packet */
751 IGMP_STATS_INC(igmp
.xmit
);
752 return ip_output_if_opt(p
, src
, dest
, IGMP_TTL
, 0, IP_PROTO_IGMP
, netif
, ra
, ROUTER_ALERTLEN
);
756 * Send an igmp packet to a specific group.
758 * @param group the group to which to send the packet
759 * @param type the type of igmp packet to send
762 igmp_send(struct igmp_group
*group
, u8_t type
)
764 struct pbuf
* p
= NULL
;
765 struct igmp_msg
* igmp
= NULL
;
766 ip_addr_t src
= *IP_ADDR_ANY
;
767 ip_addr_t
* dest
= NULL
;
769 /* IP header + "router alert" option + IGMP header */
770 p
= pbuf_alloc(PBUF_TRANSPORT
, IGMP_MINLEN
, PBUF_RAM
);
773 igmp
= (struct igmp_msg
*)p
->payload
;
774 LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg",
775 (p
->len
>= sizeof(struct igmp_msg
)));
776 ip_addr_copy(src
, group
->netif
->ip_addr
);
778 if (type
== IGMP_V2_MEMB_REPORT
) {
779 dest
= &(group
->group_address
);
780 ip_addr_copy(igmp
->igmp_group_address
, group
->group_address
);
781 group
->last_reporter_flag
= 1; /* Remember we were the last to report */
783 if (type
== IGMP_LEAVE_GROUP
) {
785 ip_addr_copy(igmp
->igmp_group_address
, group
->group_address
);
789 if ((type
== IGMP_V2_MEMB_REPORT
) || (type
== IGMP_LEAVE_GROUP
)) {
790 igmp
->igmp_msgtype
= type
;
791 igmp
->igmp_maxresp
= 0;
792 igmp
->igmp_checksum
= 0;
793 igmp
->igmp_checksum
= inet_chksum(igmp
, IGMP_MINLEN
);
795 igmp_ip_output_if(p
, &src
, dest
, group
->netif
);
800 LWIP_DEBUGF(IGMP_DEBUG
, ("igmp_send: not enough memory for igmp_send\n"));
801 IGMP_STATS_INC(igmp
.memerr
);
805 #endif /* LWIP_IGMP */