Kernel: Implement IP multicast support

An IP socket can now join a multicast group by using the
IP_ADD_MEMBERSHIP sockopt, which will cause it to start receiving
packets sent to the multicast address, even though this address does
not belong to this host.

1 files changed, 8 insertions, 0 deletions

diff --git a/Userland/Libraries/LibC/netinet/in.h b/Userland/Libraries/LibC/netinet/in.h
index f6617c8bed..7d7bc6c938 100644
--- a/Userland/Libraries/LibC/netinet/in.h
+++ b/Userland/Libraries/LibC/netinet/in.h
@@ -22,6 +22,9 @@ in_addr_t inet_addr(const char*);
 #define IN_LOOPBACKNET 127
 
 #define IP_TTL 2
+#define IP_MULTICAST_LOOP 3
+#define IP_ADD_MEMBERSHIP 4
+#define IP_DROP_MEMBERSHIP 5
 
 #define IPPORT_RESERVED 1024
 #define IPPORT_USERRESERVED 5000
@@ -39,6 +42,11 @@ struct sockaddr_in {
     char sin_zero[8];
 };
 
+struct ip_mreq {
+    struct in_addr imr_multiaddr;
+    struct in_addr imr_interface;
+};
+
 struct in6_addr {
     uint8_t s6_addr[16];
 };