实现的功能
先使用nanohttpd在安卓内实现http server的功能，然后在已经移植并开启wifidog的安卓平台开启热点，当其它的手机连接到此热点时，手机上会弹出我们在手机上搭建的http server中运行的指定的网页。如果我们的安卓平台是有多网卡的话，我们也能指定手机连接到此热点时打开外部其他网站的网页。因为是单网卡的设备即时指定了外部的网页，手机连接到此热点因为未连接到互联网，也无法打开外部的网页。
所需内容
1.NanoHttpd是一个安卓平台的Http Server，具体可看github上的介绍，本文主要说wifidog在安卓平台的编译，对NanoHttpd的使用不做介绍。
2.wifidog源码。
来自github的简介：The WiFi Guard Dog project is a complete and
embeddable captive portal solution for wireless community groups
or individuals who wish to open a free hotspot while still
preventing abuse of their Internet connection.
3.移植目标的安卓平台源码。本文针对的目标平台是基于三星4418平台的安卓开发板。
以上列表中所需的1，2两项的源码链接地址如下：
-NanoHttpd
-wifidog
移植步骤
1.使用NanoHttpd在安卓平台搭建HttpServer（编写apk程序即可，具体步骤可见NanoHttpd 在github上的介绍）
2.在安卓平台的源码external目录下新建文件夹命名为wifidog，
3.下载wifidog源码，并将下载到的源码放入第2步中新建的wifidog文件夹中
4.在wifidog目录下新建config.h文件，在文件中写入以下代码：
#define VERSION "v1.0"
#define HAVE_STDARG_H
#define __ANDROID__
5.在wifidog目录下新建Android.mk文件，在文件中写入以下内容：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := wifidog
LOCAL_C_INCLUDES=$(LOCAL_PATH)/libhttpd
LOCAL_SRC_FILES = src/gateway.c \
src/auth.c \
src/client_list.c \
src/conf.c \
src/firewall.c \
src/http.c \
src/safe.c \
src/centralserver.c \
src/commandline.c \
src/debug.c \
src/fw_iptables.c \
src/httpd_thread.c \
src/ping_thread.c \
src/util.c \
src/wdctl_thread.c \
src/simple_http.c \
src/pstring.c \
src/wd_util.c \
src/main.c \
./libhttpd/api.c \
./libhttpd/ip_acl.c \
./libhttpd/protocol.c \
./libhttpd/version.c
LOCAL_SHARED_LIBRARIES = $(SHARED_LIBRARIES)
include $(BUILD_EXECUTABLE)
以上步骤完成了对代码的准备，此时进入wifidog目录下使用mm命令已经可以编译通过了，但是还没有完成对wifidog的配置，接下来的我们需要修改配置文件和增加启动脚本。
6.在wifidog目录下找到wifidog.conf配置文件，修改此文件内容：
ExternalInterface lo #如果双网卡设备此处可设定为开启wifi热点网卡的另外一块网卡，因为我们的开发板为单网卡，此处指定了回环
GatewayInterface wlan0 #指定我们开启了热点的网卡设备名称
AuthServer {
Hostname 192.168.43.1 #http server 地址
HTTPPort 8080 #http server端口
SSLAvailable no #https是否可用
Path / #http页面路径
LoginScriptPathFragment /
PortalScriptPathFragment /
MsgScriptPathFragment /
PingScriptPathFragment /
AuthScriptPathFragment /
}
以上未注释的配置项的意思在下发完整的配置文件中有解释
修改完成后的配置文件内容如下：
# $Id$
# WiFiDog Configuration file
# Parameter: GatewayID
# Default: default
# Optional
#
# Set this to the node ID on the auth server
# This is used to give a customized login page to the clients and for
# monitoring/statistics purpose. If you run multiple gateways on the same
# machine each gateway needs to have a different gateway id.
# If none is supplied, the mac address of the GatewayInterface interface will be used,
# without the : separators
# GatewayID default
# Parameter: ExternalInterface
# Default: NONE
# Optional
#
# Set this to the external interface (the one going out to the Inernet or your larger LAN).
# Typically vlan1 for OpenWrt, and eth0 or ppp0 otherwise,
# Normally autodetected
ExternalInterface lo
# Parameter: GatewayInterface
# Default: NONE
# Mandatory
#
# Set this to the internal interface (typically your wifi interface).
# Typically br-lan for Openwrt (by default the wifi interface is bridged with wired lan in openwrt)
# and eth1, wlan0, ath0, etc. otherwise
# You can get this interface with the ifconfig command and finding your wifi interface
GatewayInterface wlan0
# Parameter: GatewayAddress
# Default: Find it from GatewayInterface
# Optional
#
# Set this to the internal IP address of the gateway. Not normally required.
# GatewayAddress 192.168.43.1
# Parameter: HtmlMessageFile
# Default: wifidog-msg.html
# Optional
#
# This allows you to specify a custome HTML file which will be used for
# system errors by the gateway. Any $title, $message and $node variables
# used inside the file will be replaced.
#
# HtmlMessageFile /opt/wifidog/etc/wifidog-.html
# Parameter: AuthServer
# Default: NONE
# Mandatory, repeatable
#
# This allows you to configure your auth server(s). Each one will be tried in order, untill one responds.
# Set this to the hostname or IP of your auth server(s), the path where
# WiFiDog-auth resides in and the port it listens on.
#AuthServer {
# Hostname (Mandatory; Default: NONE)
# SSLAvailable (Optional; Default: no; Possible values: yes, no)
# SSLPort (Optional; Default: 443)
# HTTPPort (Optional; Default: 80)
# Path (Optional; Default: /wifidog/ Note: The path must be both prefixed and suffixed by /. Use a single / for server root.)
# LoginScriptPathFragment (Optional; Default: login/? Note: This is the script the user will be sent to for login.)
# PortalScriptPathFragment (Optional; Default: portal/? Note: This is the script the user will be sent to after a successfull login.)
# MsgScriptPathFragment (Optional; Default: gw_message.php? Note: This is the script the user will be sent to upon error to read a readable message.)
# PingScriptPathFragment (Optional; Default: ping/? Note: This is the wifidog-ping protocol. See http://dev.wifidog.org/wiki/doc/developer/WiFiDogProtocol_V1)
# AuthScriptPathFragment (Optional; Default: auth/? Note: This is the wifidog-auth protocol. See http://dev.wifidog.org/wiki/doc/developer/WiFiDogProtocol_V1)
#}
# If SSLAvailable is set, then the client will be redirected to the
# auth daemon on its HTTPS port. If Wifidog is compiled with SSL support,
# then Wifidog will also use HTTPS to talk to the auth server instead of
# plain HTTP.
#
AuthServer {
Hostname 192.168.43.1
HTTPPort 8080
SSLAvailable no
Path /
LoginScriptPathFragment /
PortalScriptPathFragment /
MsgScriptPathFragment /
PingScriptPathFragment /
AuthScriptPathFragment /
}
#AuthServer {
# Hostname auth2.ilesansfil.org
# SSLAvailable yes
# Path /
#}
# Parameter: DeltaTraffic
# Default: no
# Optional
#
# Set this to true if you want to reset each user's traffic (Outgoing and Incoming) value after each Auth operation.
# If this is enabled, Wifidog will add two new parameters to the AuthScriptPathFragment: Incoming_Delta, Outgoing_delta.
# DeltaTraffic no
# Parameter: Daemon
# Default: 1
# Optional
#
# Set this to true if you want to run as a daemon
# Daemon 1
# Parameter: GatewayPort
# Default: 2060
# Optional
#
# Listen on this port
# GatewayPort 2060
# Parameter: ProxyPort
# Default: 0 (disable)
# Optional
#
# Redirect http traffic of knowns & probations users
# to a local transparent proxy listening on ProxyPort port
# ProxyPort 0
# Parameter: HTTPDName
# Default: WiFiDog
# Optional
#
# Define what name the HTTPD server will respond
# HTTPDName WiFiDog
# Parameter: HTTPDMaxConn
# Default: 10
# Optional
#
# How many sockets to listen to
# HTTPDMaxConn 10
# Parameter: HTTPDRealm
# Default: WiFiDog
# Optional
#
# The name of the HTTP authentication realm. This only used when a user
# tries to access a protected WiFiDog internal page. See HTTPUserName.
# HTTPDRealm WiFiDog
# Parameter: HTTPDUserName / HTTPDPassword
# Default: unset
# Optional
#
# The gateway exposes some information such as the status page through its web
# interface. This information can be protected with a username and password,
# which can be set through the HTTPDUserName and HTTPDPassword parameters.
# HTTPDUserName admin
# HTTPDPassword secret
# Parameter: CheckInterval
# Default: 60
# Optional
#
# How many seconds should we wait between timeout checks. This is also
# how often the gateway will ping the auth server and how often it will
# update the traffic counters on the auth server. Setting this too low
# wastes bandwidth, setting this too high will cause the gateway to take
# a long time to switch to it's backup auth server(s).
# CheckInterval 60
# Parameter: ClientTimeout
# Default: 5
# Optional
#
# Set this to the desired of number of CheckInterval of inactivity before a client is logged out
# The timeout will be INTERVAL * TIMEOUT
ClientTimeout 5
# Parameter: SSLPeerVerification
# Default: yes
# Optional
#
# Enable peer certificate verification when talking to the auth
# server over SSL/TLS. Disabling this setting is mainly useful if
# you do not want to install ca-certificates.
#
# If this setting is set to yes, then the certificates in
# the directory indicated by SSLCertPath will be used to
# verify the auth server.
#
# This setting requires that WifiDog is compiled with SSL support.
# It will be ignored otherwise.
#
# To disable SSL completely for testing purposes, set SSLAvailable
# to False for the auth server in question. Note that this will disable
# HTTPS when redirecting clients to your auth server.
#
# SSLPeerVerification yes
# Parameter: SSLCertPath
# Default: /etc/ssl/certs/
# Optional
#
# Where to look for SSL certificates to verify the auth servers
# certificate. Note that these will only be used if the auth server
# in question is configured with SSLAvailable yes.
#
# The certificates in this directory must be named by their hash
# value. For OpenWRT, you need a ca-certificates package newer
# than what is shipped in Barrier Breaker (see
# https://dev.openwrt.org/ticket/16537).
#
# This setting requires that WifiDog is compiled with SSL support.
# It will be ignored otherwise.
#
# SSLCertPath /etc/ssl/certs/
# Parameter: SSLAllowedCipherList
# Default: all ciphers supported
# Optional
#
# Which cipher suite to allow. Note that CyaSSL will ignore cipher
# suites that use algorithms that aren't compiled in or cipher
# suites *WITH ERRORS IN THEIR NAMES*.
#
# Please see CyaSSL documentation for allowed values, format is a
# string where the ciphers are separated by colons (:) with no
# spaces. Ciphers are ordered from most desirable to least desirable.
#
# SSLAllowedCipherList ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:ECDH-ECDSA-AES128-GCM-SHA256:ECDH-ECDSA-AES256-GCM-SHA384:ECDH-RSA-AES128-GCM-SHA256:ECDH-RSA-AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:ECDH-ECDSA-AES128-SHA:ECDH-ECDSA-AES256-SHA:ECDH-RSA-AES128-SHA:ECDH-RSA-AES256-SHA:AES128-SHA:AES256-SHA
# Parameter: SSLUseSNI
# Default: no
# Optional
#
# Enable SNI (Server Name Indication) TLS extension.
# Enabling this setting is mainly useful if the auth server is hosted
# multiple secure (HTTPS) websites. The WifiDog should indicate which hostname
# it is attempting to connect to at the start of the handshaking process.
#
# This setting requires that WifiDog is compiled with SSL support.
# It will be ignored otherwise.
#
# SSLUseSNI no
# Parameter: TrustedMACList
# Default: none
# Optional
#
# Check DNS health by querying IPs of these hosts
PopularServers kernel.org,ieee.org
# Comma separated list of MAC addresses who are allowed to pass
# through without authentication.
# N.B.: weak security, since MAC addresses are easy to spoof.
#
#TrustedMACList 00:00:DE:AD:BE:AF,00:00:C0:1D:F0:0D
# Parameter: FirewallRuleSet
# Default: none
# Mandatory
#
# Groups a number of FirewallRule statements together.
# Parameter: FirewallRule
# Default: none
#
# Define one firewall rule in a rule set.
# Rule Set: global
#
# Used for rules to be applied to all other rulesets except locked.
FirewallRuleSet global {
# FirewallRule syntax:
# FirewallRule (block|drop|allow|log|ulog) [(tcp|udp|icmp) [port X or port-range X:Y]] [to IP/CIDR]
## To block SMTP out, as it's a tech support nightmare, and a legal liability
#FirewallRule block tcp port 25
## Use the following if you don't want clients to be able to access machines on
## the private LAN that gives internet access to wifidog. Note that this is not
## client isolation; The laptops will still be able to talk to one another, as
## well as to any machine bridged to the wifi of the router.
# FirewallRule block to 192.168.0.0/16
# FirewallRule block to 172.16.0.0/12
# FirewallRule block to 10.0.0.0/8
## This is an example ruleset for the Teliphone service.
#FirewallRule allow udp to 69.90.89.192/27
#FirewallRule allow udp to 69.90.85.0/27
#FirewallRule allow tcp port 80 to 69.90.89.205
## This is an example ruleset for example.com
## example.com means example.com and *.example.com
#FirewallRule allow tcp to example.com
## Use the following if you are having problems with Apple iOS 7 clients.
## See #7 and #14 at https://github.com/wifidog/wifidog-gateway/issues/
#FirewallRule allow tcp to apple.com
#FirewallRule allow tcp to icloud.com
## Use the following to log or ulog the traffic you want to allow or block.
# For OPENWRT: use of these feature requires modules ipt_LOG or ipt_ULOG present in dependencies
# iptables-mod-extra and iptables-mod-ulog (to adapt it to the linux distribution).
# Note: the log or ulog rule must be passed before, the rule you want to match.
# for openwrt: use of these feature requires modules ipt_LOG or ipt_ULOG present in dependencies
# iptables-mod-extra and iptables-mod-ulog
# For example, you want to log (ulog works the same way) the traffic allowed on port 80 to the ip 69.90.89.205:
#FirewallRule log tcp port 80 to 69.90.89.205
#FirewallRule allow tcp port 80 to 69.90.89.205
# And you want to know, who matche your block rule:
#FirewallRule log to 0.0.0.0/0
#FirewallRule block to 0.0.0.0/0
}
# Rule Set: validating-users
#
# Used for new users validating their account
FirewallRuleSet validating-users {
FirewallRule allow to 0.0.0.0/0
}
# Rule Set: known-users
#
# Used for normal validated users.
FirewallRuleSet known-users {
FirewallRule allow to 0.0.0.0/0
}
# Rule Set: auth-is-down
#
# Does nothing when not configured.
#
# Used when auth server is down
#FirewallRuleSet auth-is-down {
# FirewallRule allow to 0.0.0.0/0
#}
# Rule Set: unknown-users
#
# Used for unvalidated users, this is the ruleset that gets redirected.
#
# XXX The redirect code adds the Default DROP clause.
FirewallRuleSet unknown-users {
# Use to-ipset to block or allow externally specified hosts.
# Ipsets are created with the ipset utility. This is useful to
# block or allow hosts at runtime externally.
# For example, if your auth server requires users to log in
# via Facebook, use the ipset feature built into dnsmasq to
# to populate a list of various IPs used by the Facebook networks.
#FirewallRule allow to-ipset fb
FirewallRule allow udp port 53
FirewallRule allow tcp port 53
FirewallRule allow udp port 67
FirewallRule allow tcp port 67
}
# Rule Set: locked-users
#
# Not currently used
FirewallRuleSet locked-users {
FirewallRule block to 0.0.0.0/0
}
7.在安卓平台源码中增加文件拷贝项，在编译时将此配置文件复制至/system/etc目录中。不同平台路径不完全一样，此处就不写我的路径了，具体方式可参考各平台的说明
8.修改启动脚本，在wifidog目录下找到scripts目录下的init.d文件夹，修改init.d文件夹中的wifidog文件内容
删除第一行的：#!/bin/sh
将以下两行内容修改:
IPT=/usr/sbin/iptables
WD_DIR=/usr/bin
为
IPT=/system/bin/iptables
WD_DIR=/system/bin
修改完成后的脚本内容为：
#
# Could be better, but it's working as expected
#
#
#
# chkconfig: 345 65 35
#
# description: Startup/shutdown script for Wifidog captive portal
# processname: wifidog
# Date : 2004-08-25
# Version : 1.0
IPT=/system/bin/iptables
WD_DIR=/system/bin
OPTIONS=""
case "$1" in
start)
echo "Starting Wifidog ... "
if $WD_DIR/wdctl status 2> /dev/null
then
echo "FAILED: Wifidog already running"
else
$0 test-module
if $WD_DIR/wifidog $OPTIONS
then
echo "OK"
else
echo "FAILED: Wifidog exited with non 0 status"
fi
fi
;;
restart)
$0 stop
sleep 2
$0 start
;;
reload)
$0 stop
sleep 2
$0 start
;;
stop)
echo "Stopping Wifidog ... "
if $WD_DIR/wdctl status 2> /dev/null
then
if $WD_DIR/wdctl stop
then
echo "OK"
else
echo "FAILED: wdctl stop exited with non 0 status"
fi
else
echo "FAILED: Wifidog was not running"
fi
;;
status)
$WD_DIR/wdctl status
;;
debug|test-module)
### Test ipt_mark with iptables
test_ipt_mark () {
IPTABLES_OK=$($IPT -A FORWARD -m mark --mark 2 -j ACCEPT 2>&1 | grep "No chain.target.match")
if [ -z "$IPTABLES_OK" ]; then
$IPT -D FORWARD -m mark --mark 2 -j ACCEPT 2>&1
echo 1
else
echo 0
fi
}
### Test ipt_mac with iptables
test_ipt_mac () {
IPTABLES_OK=$($IPT -A INPUT -m mac --mac-source 00:00:00:00:00:00 -j ACCEPT 2>&1 | grep "No chain.target.match")
if [ -z "$IPTABLES_OK" ]; then
$IPT -D INPUT -m mac --mac-source 00:00:00:00:00:00 -j ACCEPT 2>&1
echo 1
else
echo 0
fi
}
### Test ipt_REDIRECT with iptables
test_ipt_REDIRECT () {
IPTABLES_OK=$($IPT -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-ports 2060 2>&1 | grep "No chain.target.match")
if [ -z "$IPTABLES_OK" ]; then
$IPT -t nat -D PREROUTING -p tcp --dport 80 -j REDIRECT --to-ports 2060 2>&1
echo 1
else
echo 0
fi
}
### Find a module on disk
module_exists () {
echo " Looking for a module on disk"
EXIST=$(find /lib/modules/`uname -r` -name $1.*o 2>/dev/null)
if [ -n "$EXIST" ]; then
echo 1
else
echo 0
fi
}
### Test if a module is in memory
module_in_memory () {
MODULE=$(lsmod | grep $1 | awk '{print $1}')
if [ "$MODULE" = "$1" ]; then
echo 1
else
echo 0
fi
}
echo "Testing for iptables modules"
echo " Testing ipt_mac"
TEST_IPT_MAC=$(test_ipt_mac)
if [ "$TEST_IPT_MAC" = "0" ]; then
echo " iptables is not working with ipt_mac"
echo " Scanning disk for ipt_mac module"
TEST_IPT_MAC_MODULE_EXISTS=$(module_exists "ipt_mac")
if [ "$TEST_IPT_MAC_MODULE_EXISTS" = "0" ]; then
echo " ipt_mac module is missing, please install it (kernel or module)"
exit
else
echo " ipt_mac module exists, trying to load"
insmod ipt_mac > /dev/null
TEST_IPT_MAC_MODULE_MEMORY=$(module_in_memory "ipt_mac")
if [ "$TEST_IPT_MAC_MODULE_MEMORY" = "0" ]; then
echo " Error: ipt_mac not loaded"
exit
else
echo " ipt_mac loaded sucessfully"
fi
fi
else
echo " ipt_mac module is working"
fi
echo " Testing ipt_mark"
TEST_IPT_MARK=$(test_ipt_mark)
if [ "$TEST_IPT_MARK" = "0" ]; then
echo " iptables is not working with ipt_mark"
echo " Scanning disk for ipt_mark module"
TEST_IPT_MARK_MODULE_EXISTS=$(module_exists "ipt_mark")
if [ "$TEST_IPT_MARK_MODULE_EXISTS" = "0" ]; then
echo " iptables ipt_mark module missing, please install it (kernel or module)"
exit
else
echo " ipt_mark module exists, trying to load"
insmod ipt_mark
TEST_IPT_MARK_MODULE_MEMORY=$(module_in_memory "ipt_mark")
if [ "$TEST_IPT_MARK_MODULE_MEMORY" = "0" ]; then
echo " Error: ipt_mark not loaded"
exit
else
echo " ipt_mark loaded sucessfully"
fi
fi
else
echo " ipt_mark module is working"
fi
##TODO: This will not test if required iptables userspace (iptables-mod-nat on Kamikaze) is installed
echo " Testing ipt_REDIRECT"
TEST_IPT_MAC=$(test_ipt_REDIRECT)
if [ "$TEST_IPT_MAC" = "0" ]; then
echo " iptables is not working with ipt_REDIRECT"
echo " Scanning disk for ipt_REDIRECT module"
TEST_IPT_MAC_MODULE_EXISTS=$(module_exists "ipt_REDIRECT")
if [ "$TEST_IPT_MAC_MODULE_EXISTS" = "0" ]; then
echo " ipt_REDIRECT module is missing, please install it (kernel or module)"
exit
else
echo " ipt_REDIRECT module exists, trying to load"
insmod ipt_REDIRECT > /dev/null
TEST_IPT_MAC_MODULE_MEMORY=$(module_in_memory "ipt_REDIRECT")
if [ "$TEST_IPT_MAC_MODULE_MEMORY" = "0" ]; then
echo " Error: ipt_REDIRECT not loaded"
exit
else
echo " ipt_REDIRECT loaded sucessfully"
fi
fi
else
echo " ipt_REDIRECT module is working"
fi
;;
*)
echo "Usage: $0 {start|stop|restart|reload|status|test-module}"
exit 1
;;
esac
9.在安卓平台源码中增加文件拷贝项，在编译时将init.d目录连同底下的wifidog启动脚本复制至/system/etc目录中。不同平台路径不完全一样，此处就不写我的路径了，具体方式可参考各平台的说明
10.增加开机自启动wifidog的功能，修改安卓平台的init脚本
增加以下内容
on post-fs-data节点下增加：
chmod 0777 /etc/init.d/wifidog #为了给启动脚本增加执行权限
增加服务启动：
service wifiDog /system/etc/init.d/wifidog start
class late_start
user root
group root
oneshot
10.移植完成，开始愉快的编译安卓源码吧。