Add Android port

Signed-off-by: Andreas Zisowsky <zisowsky@lynxtechnology.com>
Change-Id: I8b69b2aa1049b0789e132dd3a7a889335e7244d3
Reviewed-on: https://gerrit.iotivity.org/gerrit/26099Tested-by: IoTivity Jenkins <jenkins-daemon@iotivity.org>
Reviewed-by: Kishen Maloor <kishen.maloor@intel.com>

port/android/Makefile

+# Port for native Android compilation (without Java).
+# Tested NDK versions:
+# API	Android version
+#  19	4.4
+#  21	5.0
+#  23	6.0
+#  24	7.0
+#
+# API version 24 is closest to regular Linux so far.
+# With API 24 the Android port is almost identical to the Linux port
+# except for the removal of the unsupported pthread_cancel and that
+# the IP adapter assures that interfaces have multicast and broadcast
+# enabled to avoid 3G/4G/5G interfaces.
+#
+# It is expected that higher versions then API 24 should work without any
+# further modifications.
+#
+# Testing compilations on non-rooted Android phones:
+# - Enable USB debugging on your phone.
+# - Install ADB or Android Studio
+# - adb start-server
+#   Your phone should query now if you trust the computer. Hit OK.
+# - adb push simpleclient /data/local/tmp/
+#   Most likely your phone gives you in /data/local some more permissions
+#   Non-rooted devices are a bit restrictive what you can do in the file system.
+# - adb shell
+# - cd /data/local/tmp
+# - chmod 755 simpleclient
+#   It was observed that the file has read-write permissions only after the upload
+#   on Android 7.
+# - In a different terminal window start simpleserver on your developer box.
+# - ./simpleclient
+# - Kill client with Ctrl-C or Ctrl-\
+# - exit
+# - *** DISABLE USB debugging!!! *** (security issue if left on)
+#
+# Note: On regular Android phones the server versions will not be found
+#       (ie. simpleserver will not be discovered). But the clients
+#       should work.
+#
+# Download NDK: https://developer.android.com/ndk/downloads/index.html
+# Unzip downloaded package.
+# Choose architecture and API level.
+# cd <NDK>/build/tools
+# ./make_standalone_toolchain.py --arch <architecture> --api <level> --install-dir <path>
+# For example: ./make_standalone_toolchain.py --arch arm --api 23 --install-dir ~/android-arm-23
+# This makefile uses then the NDK in <install-dir>.
+# For further setup see: https://developer.android.com/ndk/guides/standalone_toolchain.html
+#
+# Either set ANDROID_API and ANDROID_BASE in this makefile
+# or invoke like this: make NDK_HOME=/opt/android-ndk ANDROID_API=24
+
+# Location of the installation directory and the API level.
+ANDROID_API := 19
+ifeq (${NDK_HOME},)
+ANDROID_BASE := "${HOME}/android-arm-${ANDROID_API}"
+else
+ANDROID_BASE := "${NDK_HOME}"
+endif
+# Compiler prefix
+ANDROID_HOST := arm-linux-androideabi-
+
+BIN_BASE := ${ANDROID_BASE}/bin/${ANDROID_HOST}
+ifeq ($(origin CC),default)
+CC := ${BIN_BASE}gcc
+endif
+ifeq ($(origin AR),default)
+AR := ${BIN_BASE}ar
+endif
+RM ?= rm
+MKDIR ?= mkdir
+
+ROOT_DIR = ../..
+OBJDIR ?= ./${ANDROID_HOST}obj
+MBEDTLS_DIR := $(ROOT_DIR)/deps/mbedtls
+
+DTLS= 	aes.c		aesni.c 	arc4.c  	asn1parse.c	asn1write.c	base64.c	\
+	bignum.c	blowfish.c	camellia.c	ccm.c		cipher.c	cipher_wrap.c	\
+	cmac.c		ctr_drbg.c	des.c		dhm.c		ecdh.c		ecdsa.c		\
+	ecjpake.c	ecp.c		ecp_curves.c	entropy.c	entropy_poll.c	error.c		\
+	gcm.c		havege.c	hmac_drbg.c	md.c		md2.c		md4.c		\
+	md5.c		md_wrap.c	oid.c		padlock.c	\
+	pem.c		pk.c		pk_wrap.c	pkcs12.c	pkcs5.c		pkparse.c	\
+	pkwrite.c	platform.c	ripemd160.c	rsa.c		sha1.c		sha256.c	\
+	sha512.c	threading.c	timing.c	version.c	version_features.c		\
+	xtea.c  	pkcs11.c 	x509.c 		x509_crt.c	debug.c		net_sockets.c	\
+	ssl_cache.c	ssl_ciphersuites.c		ssl_cli.c	ssl_cookie.c			\
+	ssl_srv.c	ssl_ticket.c	ssl_tls.c	rsa_internal.c
+DTLSFLAGS=-I../../deps/mbedtls/include -D__OC_RANDOM
+
+CBOR=../../deps/tinycbor/src/cborencoder.c ../../deps/tinycbor/src/cborencoder_close_container_checked.c ../../deps/tinycbor/src/cborparser.c# ../../deps/tinycbor/src/cbortojson.c ../../deps/tinycbor/src/cborpretty.c ../../deps/tinycbor/src/cborparser_dup_string.c
+
+SRC_COMMON:=$(wildcard ../../util/*.c) ${CBOR}
+SRC:=$(wildcard ../../messaging/coap/*.c ../../api/*.c ../../port/android/*.c)
+
+# From API level 24 on Android supports getifaddrs itself.
+ifeq ($(shell if [ ${ANDROID_API} -gt 23 ]; then echo gt; fi),gt)
+	SRC:=$(filter-out ../../port/android/ifaddrs-android.c,${SRC})
+endif
+
+HEADERS = $(wildcard ../../include/*.h)
+HEADERS += ../../port/android/config.h
+
+HEADERS_COAP = $(wildcard ../../messaging/coap/*.h)
+HEADERS_UTIL = $(wildcard ../../util/*.h)
+HEADERS_UTIL_PT = $(wildcard ../../util/pt/*.h)
+HEADERS_PORT = $(wildcard ../../port/*.h)
+HEADERS_TINYCBOR = $(wildcard ../../deps/tinycbor/src/*.h)
+
+CFLAGS?=-fPIE -pie -fno-asynchronous-unwind-tables -fno-omit-frame-pointer -ffreestanding -Os -fno-stack-protector -ffunction-sections -fdata-sections -fno-reorder-functions -fno-defer-pop -fno-strict-overflow -I./ -I../../include/ -I../../ -std=gnu99 -Wall -D__ANDROID_API__=${ANDROID_API}
+OBJ_COMMON=$(addprefix ${OBJDIR}/,$(notdir $(SRC_COMMON:.c=.o)))
+OBJ_CLIENT=$(addprefix ${OBJDIR}/client/,$(notdir $(SRC:.c=.o)))
+OBJ_SERVER=$(addprefix ${OBJDIR}/server/,$(filter-out oc_obt.o,$(notdir $(SRC:.c=.o))))
+OBJ_CLIENT_SERVER=$(addprefix ${OBJDIR}/client_server/,$(notdir $(SRC:.c=.o)))
+VPATH=../../messaging/coap/:../../util/:../../api/:../../deps/tinycbor/src/:../../deps/mbedtls/library:
+LIBS?= -lm
+
+SAMPLES := server client temp_sensor simpleserver simpleclient client_collections_linux \
+	  server_collections_linux server_block_linux client_block_linux smart_home_server_linux multi_device_server multi_device_client \
+	  smart_lock server_multithread_linux client_multithread_linux
+
+OBT = onboarding_tool
+
+ifeq ($(DEBUG),1)
+	CFLAGS += -DOC_DEBUG -g -O0
+else
+	CFLAGS += -Wl,--gc-sections
+endif
+
+ifeq ($(DYNAMIC),1)
+	CFLAGS += -DOC_DYNAMIC_ALLOCATION
+endif
+
+ifneq ($(SECURE),0)
+	SRC += $(addprefix ../../security/,oc_acl.c oc_cred.c oc_doxm.c oc_pstat.c oc_tls.c oc_svr.c oc_store.c)
+	SRC_COMMON += $(addprefix $(MBEDTLS_DIR)/library/,${DTLS})
+	MBEDTLS_PATCH_FILE := $(MBEDTLS_DIR)/patched.txt
+ifeq ($(DYNAMIC),1)
+	SRC += ../../security/oc_obt.c
+	SAMPLES += ${OBT}
+else
+	SRC_COMMON += $(MBEDTLS_DIR)/library/memory_buffer_alloc.c
+endif
+	CFLAGS += ${DTLSFLAGS} -DOC_SECURITY
+	VPATH += ../../security/:../../deps/mbedtls/library:
+endif
+
+ifeq ($(IPV4),1)
+	CFLAGS += -DOC_IPV4
+endif
+
+ifeq ($(TCP),1)
+	EXTRA_CFLAGS += -DOC_TCP
+endif
+
+CONSTRAINED_LIBS = libiotivity-constrained-server.a libiotivity-constrained-client.a \
+		    libiotivity-constrained-client-server.a
+
+all: $(CONSTRAINED_LIBS) $(SAMPLES)
+
+.PHONY: clean
+
+${SRC} ${SRC_COMMON}: $(MBEDTLS_PATCH_FILE)
+
+${OBJDIR}/%.o: %.c
+	@mkdir -p ${@D}
+	${CC} -c -o $@ $< ${CFLAGS}
+
+${OBJDIR}/server/%.o: %.c
+	@mkdir -p ${@D}
+	${CC} -c -o $@ $< ${CFLAGS} -DOC_SERVER
+
+${OBJDIR}/client/%.o: %.c
+	@mkdir -p ${@D}
+	${CC} -c -o $@ $< ${CFLAGS} -DOC_CLIENT
+
+${OBJDIR}/client_server/%.o: %.c
+	@mkdir -p ${@D}
+	${CC} -c -o $@ $< ${CFLAGS} -DOC_CLIENT -DOC_SERVER
+
+libiotivity-constrained-server.a: $(OBJ_COMMON) $(OBJ_SERVER)
+	$(AR) -rcs $@ $(OBJ_COMMON) $(OBJ_SERVER)
+
+libiotivity-constrained-client.a: $(OBJ_COMMON) $(OBJ_CLIENT)
+	$(AR) -rcs $@ $(OBJ_COMMON) $(OBJ_CLIENT)
+
+libiotivity-constrained-client-server.a: $(OBJ_COMMON) $(OBJ_CLIENT_SERVER)
+	$(AR) -rcs $@ $(OBJ_COMMON) $(OBJ_CLIENT_SERVER)
+
+server: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/server_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+client: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/client_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS} ${LIBS}
+
+smart_lock: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/smart_lock_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS} ${LIBS}
+
+temp_sensor: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/temp_sensor_client_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS} ${LIBS}
+
+simpleserver: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/simpleserver.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS}  ${LIBS}
+
+simpleclient: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/simpleclient.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+client_collections_linux: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/client_collections_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+server_collections_linux: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/server_collections_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+client_block_linux: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/client_block_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+server_block_linux: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/server_block_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+smart_home_server_linux: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/smart_home_server_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+multi_device_server: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/multi_device_server_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+multi_device_client: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/multi_device_client_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+${OBT}: libiotivity-constrained-client.a
+	${CC} -o $@ ../../onboarding_tool/obtmain.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+server_multithread_linux: libiotivity-constrained-server.a
+	${CC} -o $@ ../../apps/server_multithread_linux.c libiotivity-constrained-server.a -DOC_SERVER ${CFLAGS} ${LIBS}
+
+client_multithread_linux: libiotivity-constrained-client.a
+	${CC} -o $@ ../../apps/client_multithread_linux.c libiotivity-constrained-client.a -DOC_CLIENT ${CFLAGS}  ${LIBS}
+
+ifneq ($(SECURE),0)
+MBEDTLS_PATCHES ?= $(sort $(wildcard ../../patches/*.patch))
+${MBEDTLS_DIR}/.git:
+	git submodule update --init ${@D}
+
+$(MBEDTLS_PATCH_FILE): ${MBEDTLS_DIR}/.git ${MBEDTLS_PATCHES}
+	if [ -d ${MBEDTLS_DIR} ]; then \
+	cd ${MBEDTLS_DIR} && \
+	git clean -fdx . && \
+	git reset --hard && \
+	cd -; \
+	fi && \
+	git submodule update --init && \
+	cd ${MBEDTLS_DIR} && \
+	for patch in $(MBEDTLS_PATCHES); do patch -r - -s -N -p1 < $${patch} ; done && \
+	echo "Patches applied in $^" > ${@F}
+endif
+
+clean:
+	$(RM) -rf ${OBJDIR} $(CONSTRAINED_LIBS)
+
+cleanall: clean
+	$(RM) -rf ${all} $(SAMPLES) $(OBT) $(MBEDTLS_PATCH_FILE)
+
+distclean: cleanall

port/android/abort.c

+/*
+// Copyright (c) 2017 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#include "port/oc_assert.h"
+#include <stdlib.h>
+
+void
+abort_impl(void)
+{
+  abort();
+}
+
+void
+exit_impl(int status)
+{
+  exit(status);
+}

port/android/clock.c

+/*
+// Copyright (c) 2016 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#include "port/oc_clock.h"
+#include "port/oc_log.h"
+#include <math.h>
+#include <time.h>
+#include <unistd.h>
+
+void
+oc_clock_init(void)
+{}
+
+oc_clock_time_t
+oc_clock_time(void)
+{
+  oc_clock_time_t time = 0;
+  struct timespec t;
+  if (clock_gettime(CLOCK_REALTIME, &t) != -1) {
+    time = (oc_clock_time_t)t.tv_sec * OC_CLOCK_SECOND +
+           (oc_clock_time_t)ceil(t.tv_nsec / (1.e09 / OC_CLOCK_SECOND));
+  }
+  return time;
+}
+
+unsigned long
+oc_clock_seconds(void)
+{
+  struct timespec t;
+  if (clock_gettime(CLOCK_REALTIME, &t) != -1) {
+    return t.tv_sec;
+  }
+  return 0;
+}
+
+void
+oc_clock_wait(oc_clock_time_t t)
+{
+  usleep(t * 1.e03);
+}

port/android/config.h

+#ifndef CONFIG_H
+#define CONFIG_H
+
+/* Time resolution */
+#include <stdint.h>
+#include <time.h>
+typedef uint64_t oc_clock_time_t;
+#define OC_CLOCK_CONF_TICKS_PER_SECOND CLOCKS_PER_SEC
+
+/* Security Layer */
+/* Max inactivity timeout before tearing down DTLS connection */
+#define OC_DTLS_INACTIVITY_TIMEOUT (600)
+
+/* Add support for passing network up/down events to the app */
+#define OC_NETWORK_MONITOR
+/* Add support for passing TCP/TLS/DTLS session connection events to the app */
+#define OC_SESSION_EVENTS
+
+/* Add support for dns lookup to the endpoint */
+#define OC_DNS_LOOKUP
+#define OC_DNS_LOOKUP_IPV6
+
+/* If we selected support for dynamic memory allocation */
+#ifdef OC_DYNAMIC_ALLOCATION
+#define OC_COLLECTIONS
+#define OC_BLOCK_WISE
+
+#else /* OC_DYNAMIC_ALLOCATION */
+/* List of constraints below for a build that does not employ dynamic
+   memory allocation
+*/
+/* Memory pool sizes */
+#define OC_BYTES_POOL_SIZE (1800)
+#define OC_INTS_POOL_SIZE (100)
+#define OC_DOUBLES_POOL_SIZE (4)
+
+/* Server-side parameters */
+/* Maximum number of server resources */
+#define OC_MAX_APP_RESOURCES (4)
+
+#define OC_MAX_NUM_COLLECTIONS (1)
+
+/* Common paramters */
+/* Prescriptive lower layers MTU size, enable block-wise transfers */
+#define OC_BLOCK_WISE_SET_MTU (700)
+
+/* Maximum size of request/response payloads */
+#define OC_MAX_APP_DATA_SIZE (2048)
+
+/* Maximum number of concurrent requests */
+#define OC_MAX_NUM_CONCURRENT_REQUESTS (3)
+
+/* Maximum number of nodes in a payload tree structure */
+#define OC_MAX_NUM_REP_OBJECTS (150)
+
+/* Number of devices on the OCF platform */
+#define OC_MAX_NUM_DEVICES (2)
+
+/* Maximum number of endpoints */
+#define OC_MAX_NUM_ENDPOINTS (20)
+
+/* Security layer */
+/* Maximum number of authorized clients */
+#define OC_MAX_NUM_SUBJECTS (2)
+
+/* Maximum number of concurrent (D)TLS sessions */
+#define OC_MAX_TLS_PEERS (1)
+
+/* Maximum number of peer for TCP channel */
+#define OC_MAX_TCP_PEERS (2)
+
+/* Maximum number of interfaces for IP adapter */
+/* Warning: Android has often over 10 interfaces. */
+#define OC_MAX_IP_INTERFACES (20)
+
+/* Maximum number of callbacks for Network interface event monitoring */
+#define OC_MAX_NETWORK_INTERFACE_CBS (2)
+
+/* Maximum number of callbacks for connection of session */
+#define OC_MAX_SESSION_EVENT_CBS (2)
+
+#endif /* !OC_DYNAMIC_ALLOCATION */
+
+#endif /* CONFIG_H */

port/android/ifaddrs-android.c

+/*
+Copyright (c) 2011, The WebRTC project authors. 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.
+
+  * Neither the name of Google nor the names of its contributors may
+    be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+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
+HOLDER 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 "ifaddrs-android.h"
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/utsname.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+#include <net/if.h>
+#include <unistd.h>
+#include <errno.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+struct netlinkrequest
+{
+  struct nlmsghdr header;
+  struct ifaddrmsg msg;
+};
+
+static const int kMaxReadSize = 4096;
+
+static int
+set_ifname(struct ifaddrs *ifaddr, int interface)
+{
+  char buf[IFNAMSIZ] = { 0 };
+  char *name = if_indextoname(interface, buf);
+  if (name == NULL) {
+    return -1;
+  }
+  ifaddr->ifa_name = malloc(strlen(name) + 1);
+  strncpy(ifaddr->ifa_name, name, strlen(name) + 1);
+  return 0;
+}
+
+static int
+set_flags(struct ifaddrs *ifaddr)
+{
+  int fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (fd == -1) {
+    return -1;
+  }
+  struct ifreq ifr;
+  memset(&ifr, 0, sizeof(ifr));
+  strncpy(ifr.ifr_name, ifaddr->ifa_name, IFNAMSIZ - 1);
+  int rc = ioctl(fd, SIOCGIFFLAGS, &ifr);
+  close(fd);
+  if (rc == -1) {
+    return -1;
+  }
+  ifaddr->ifa_flags = ifr.ifr_flags;
+  return 0;
+}
+
+static int
+set_addresses(struct ifaddrs *ifaddr, struct ifaddrmsg *msg, void *data,
+              size_t len)
+{
+  if (msg->ifa_family == AF_INET) {
+    struct sockaddr_in *sa = malloc(sizeof(struct sockaddr_in));
+    memset(sa, 0, sizeof(struct sockaddr_in));
+    sa->sin_family = AF_INET;
+    memcpy(&sa->sin_addr, data, len);
+    ifaddr->ifa_addr = (struct sockaddr *)sa;
+  } else if (msg->ifa_family == AF_INET6) {
+    struct sockaddr_in6 *sa = malloc(sizeof(struct sockaddr_in6));
+    memset(sa, 0, sizeof(struct sockaddr_in6));
+    sa->sin6_family = AF_INET6;
+    sa->sin6_scope_id = msg->ifa_index;
+    memcpy(&sa->sin6_addr, data, len);
+    ifaddr->ifa_addr = (struct sockaddr *)sa;
+  } else {
+    return -1;
+  }
+  return 0;
+}
+
+static int
+make_prefixes(struct ifaddrs *ifaddr, int family, int prefixlen)
+{
+  char *prefix = NULL;
+  if (family == AF_INET) {
+    struct sockaddr_in *mask = malloc(sizeof(struct sockaddr_in));
+    memset(mask, 0, sizeof(struct sockaddr_in));
+    mask->sin_family = AF_INET;
+    memset(&mask->sin_addr, 0, sizeof(struct in_addr));
+    ifaddr->ifa_netmask = (struct sockaddr *)mask;
+    if (prefixlen > 32) {
+      prefixlen = 32;
+    }
+    prefix = (char *)&mask->sin_addr;
+  } else if (family == AF_INET6) {
+    struct sockaddr_in6 *mask = malloc(sizeof(struct sockaddr_in6));
+    memset(mask, 0, sizeof(struct sockaddr_in6));
+    mask->sin6_family = AF_INET6;
+    memset(&mask->sin6_addr, 0, sizeof(struct in6_addr));
+    ifaddr->ifa_netmask = (struct sockaddr *)mask;
+    if (prefixlen > 128) {
+      prefixlen = 128;
+    }
+    prefix = (char *)&mask->sin6_addr;
+  } else {
+    return -1;
+  }
+  for (int i = 0; i < (prefixlen / 8); i++) {
+    *prefix++ = 0xFF;
+  }
+  char remainder = 0xff;
+  remainder <<= (8 - prefixlen % 8);
+  *prefix = remainder;
+  return 0;
+}
+
+static int
+populate_ifaddrs(struct ifaddrs *ifaddr, struct ifaddrmsg *msg, void *bytes,
+                 size_t len)
+{
+  if (set_ifname(ifaddr, msg->ifa_index) != 0) {
+    return -1;
+  }
+  if (set_flags(ifaddr) != 0) {
+    return -1;
+  }
+  if (set_addresses(ifaddr, msg, bytes, len) != 0) {
+    return -1;
+  }
+  if (make_prefixes(ifaddr, msg->ifa_family, msg->ifa_prefixlen) != 0) {
+    return -1;
+  }
+  return 0;
+}
+
+int
+android_getifaddrs(struct ifaddrs **result)
+{
+  int fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+  if (fd < 0) {
+    return -1;
+  }
+
+  struct netlinkrequest ifaddr_request;
+  memset(&ifaddr_request, 0, sizeof(ifaddr_request));
+  ifaddr_request.header.nlmsg_flags = NLM_F_ROOT | NLM_F_REQUEST;
+  ifaddr_request.header.nlmsg_type = RTM_GETADDR;
+  ifaddr_request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
+
+  ssize_t count = send(fd, &ifaddr_request, ifaddr_request.header.nlmsg_len, 0);
+  if ((size_t)count != ifaddr_request.header.nlmsg_len) {
+    close(fd);
+    return -1;
+  }
+  struct ifaddrs *start = NULL;
+  struct ifaddrs *current = NULL;
+  char buf[kMaxReadSize];
+  ssize_t amount_read = recv(fd, &buf, kMaxReadSize, 0);
+  while (amount_read > 0) {
+    struct nlmsghdr *header = (struct nlmsghdr *)&buf[0];
+    size_t header_size = (size_t)amount_read;
+    for (; NLMSG_OK(header, header_size);
+         header = NLMSG_NEXT(header, header_size)) {
+      switch (header->nlmsg_type) {
+      case NLMSG_DONE:
+        /* Success. Return. */
+        *result = start;
+        close(fd);
+        return 0;
+      case NLMSG_ERROR:
+        close(fd);
+        android_freeifaddrs(start);
+        return -1;
+      case RTM_NEWADDR: {
+        struct ifaddrmsg *address_msg = (struct ifaddrmsg *)NLMSG_DATA(header);
+        struct rtattr *rta = IFA_RTA(address_msg);
+        ssize_t payload_len = IFA_PAYLOAD(header);
+        while (RTA_OK(rta, payload_len)) {
+          if (rta->rta_type == IFA_ADDRESS) {
+            int family = address_msg->ifa_family;
+            if (family == AF_INET || family == AF_INET6) {
+              struct ifaddrs *newest = malloc(sizeof(struct ifaddrs));
+              memset(newest, 0, sizeof(struct ifaddrs));
+              if (current) {
+                current->ifa_next = newest;
+              } else {