From b023b78590c77b444c46fc772caaffb78035ab36 Mon Sep 17 00:00:00 2001
From: Jon Shallow <supjps-libcoap@jpshallow.com>
Date: Thu, 5 Dec 2024 11:53:56 +0000
Subject: [PATCH] LwIP: Support Server Multicast registration

---
 examples/lwip/Makefile          |  3 ++-
 examples/lwip/config/lwipopts.h | 11 ++++++++++-
 examples/lwip/server.c          | 31 +++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/examples/lwip/Makefile b/examples/lwip/Makefile
index 5bbadc95ad..b7b556d2f3 100644
--- a/examples/lwip/Makefile
+++ b/examples/lwip/Makefile
@@ -105,7 +105,8 @@ CFLAGS += -Ilwip/src/include/ -Ilwip/src/include/ipv4/ \
 
 LWIP_SRC = def.c init.c tapif.c etharp.c netif.c timeouts.c stats.c udp.c \
 	   tcp.c pbuf.c ip4_addr.c ip4.c inet_chksum.c tcp_in.c tcp_out.c \
-	   icmp.c raw.c ip4_frag.c sys_arch.c ethernet.c ip.c mem.c memp.c tcpip.c
+	   icmp.c raw.c ip4_frag.c sys_arch.c ethernet.c ip.c mem.c memp.c \
+	   igmp.c tcpip.c
 vpath %.c lwip/src/core/ lwip/contrib/ports/unix/proj/minimal/ \
 	  lwip/src/netif/ lwip/src/core/ipv4/ lwip/contrib/ports/unix/port/ \
 	  lwip/contrib/ports/unix/port/netif/ lwip/src/api/
diff --git a/examples/lwip/config/lwipopts.h b/examples/lwip/config/lwipopts.h
index 78bdea24a6..9361c13fe1 100644
--- a/examples/lwip/config/lwipopts.h
+++ b/examples/lwip/config/lwipopts.h
@@ -27,12 +27,21 @@
 #define LWIP_IPV6                       1
 #define LWIP_IPV6_REASS                 0
 
-#define LWIP_IPV6_MLD                   0
 #define LWIP_ICMP6                 (LWIP_IPV6==1)
 
 /* Set to 1 if TCP support is required */
 #define LWIP_TCP                        0
 
+#if LWIP_IPV4
+/* Set to 1 if Multicast registration support is required for IPv4 */
+#define LWIP_IGMP                       0
+#endif
+
+#if LWIP_IPV6
+/* Set to 1 if Multicast registration support is required for IPv6 */
+#define LWIP_IPV6_MLD                   0
+#endif
+
 #ifndef netif_get_index
 #define netif_get_index(netif)      ((u8_t)((netif)->num + 1))
 #endif
diff --git a/examples/lwip/server.c b/examples/lwip/server.c
index 91662156b1..356a4788de 100644
--- a/examples/lwip/server.c
+++ b/examples/lwip/server.c
@@ -38,6 +38,12 @@
 
 #include <lwip/init.h>
 #include <lwip/timeouts.h>
+#if LWIP_IGMP && LWIP_IPV4
+#include <lwip/igmp.h>
+#endif /* LWIP_IGMP && LWIP_IPV4 */
+#if LWIP_IPV6_MLD && LWIP_IPV6
+#include <lwip/mld6.h>
+#endif /* LWIP_IPV6_MLD && LWIP_IPV6 */
 
 #include <netif/etharp.h>
 #include <netif/tapif.h>
@@ -46,8 +52,17 @@
 
 #if LWIP_IPV4
 static ip4_addr_t ipaddr, netmask, gw;
+#if LWIP_IGMP
+static ip4_addr_t v4group;
+#endif /* LWIP_IGMP */
 #endif /* LWIP_IPV4 */
 
+#if LWIP_IPV6
+#if LWIP_IPV6_MLD
+static ip6_addr_t v6group;
+#endif /* LWIP_IPV6_MLD */
+#endif /* LWIP_IPV6 */
+
 static int quit = 0;
 
 void
@@ -100,7 +115,13 @@ main(int argc, char **argv) {
   IP4_ADDR(&gw, 192,168,113,1);
   IP4_ADDR(&ipaddr, 192,168,113,2);
   IP4_ADDR(&netmask, 255,255,255,0);
+#if LWIP_IGMP
+  IP4_ADDR(&v4group, 224,0,1,187);
+#endif /* LWIP_IGMP */
 #endif /* LWIP_IPV4 */
+#if LWIP_IPV6_MLD
+  IP6_ADDR(&v6group, PP_HTONL(0xff020000),0,0,PP_HTONL(0xfd));
+#endif /* LWIP_IPV6_MLD */
 
 #if NO_SYS
   lwip_init();
@@ -120,6 +141,11 @@ main(int argc, char **argv) {
   netif_set_up(&netif);
 #if LWIP_IPV4
   printf("IP4 %s\n", ip4addr_ntoa(ip_2_ip4(&netif.ip_addr)));
+#if LWIP_IGMP
+  if (igmp_joingroup_netif(&netif, &v4group) == ERR_OK) {
+    printf("mIP4 %s\n", ip4addr_ntoa(&v4group));
+  }
+#endif /* LWIP_IGMP */
 #endif /* LWIP_IPV4 */
 #if LWIP_IPV6
   netif_create_ip6_linklocal_address(&netif, 1);
@@ -128,6 +154,11 @@ main(int argc, char **argv) {
 #else /* ! LWIP_IPV4 */
   printf("IP6 [%s]\n", ip6addr_ntoa(&netif.ip6_addr[0].addr));
 #endif /* ! LWIP_IPV4 */
+#if LWIP_IPV6_MLD
+  if (mld6_joingroup_netif(&netif, &v6group) == ERR_OK) {
+    printf("mIP6 [%s]\n", ip6addr_ntoa(&v6group));
+  }
+#endif /* LWIP_IPV6_MLD */
 #endif /* LWIP_IPV6 */
 
   /* start applications here */