Add <netinet/igmp.h>.

Test: treehugger
Change-Id: I9252275173eab0219a0202463c6accba809a8e11
diff --git a/libc/include/netinet/igmp.h b/libc/include/netinet/igmp.h
new file mode 100644
index 0000000..497d02d
--- /dev/null
+++ b/libc/include/netinet/igmp.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file netinet/igmp.h
+ * @brief Internet Group Management Protocol (IGMP).
+ */
+
+#include <sys/cdefs.h>
+#include <netinet/in.h>
+
+#include <linux/igmp.h>
+
+/**
+ * The uapi type is called `igmphdr`,
+ * doesn't have the `igmp_` prefix on each field,
+ * and uses a `__be32` for the group address.
+ *
+ * This is the type that BSDs and musl/glibc expose to userspace.
+ */
+struct igmp {
+  uint8_t igmp_type;
+  uint8_t igmp_code;
+  uint16_t igmp_cksum;
+  struct in_addr igmp_group;
+};
+
+/** Commonly-used BSD synonym for the Linux constant. */
+#define IGMP_MEMBERSHIP_QUERY IGMP_HOST_MEMBERSHIP_QUERY
diff --git a/tests/Android.bp b/tests/Android.bp
index 9aca488..7769110 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -430,6 +430,7 @@
         "netdb_test.cpp",
         "net_if_test.cpp",
         "netinet_ether_test.cpp",
+        "netinet_igmp_test.cpp",
         "netinet_in_test.cpp",
         "netinet_ip_icmp_test.cpp",
         "netinet_udp_test.cpp",
diff --git a/tests/netinet_igmp_test.cpp b/tests/netinet_igmp_test.cpp
new file mode 100644
index 0000000..4cf7876
--- /dev/null
+++ b/tests/netinet_igmp_test.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include <netinet/igmp.h>
+
+TEST(netinet_igmp, smoke) {
+  // Just check that the fields exist, so code is likely to compile.
+  struct igmp i;
+  i.igmp_type = IGMP_MEMBERSHIP_QUERY;
+  i.igmp_code = 0;
+  i.igmp_cksum = 0;
+  i.igmp_group.s_addr = htonl(INADDR_ANY);
+}