ddns-scripts-principle-of-bb-on-openwrt

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更新的url

更新的url全部都记录在/usr/lib/ddns/services，如需增加新的ddns服务商，则需要把该服务商的更新url填于此处。

更新的url网上找来

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http://[USERNAME]:[PASSWORD]@ddns.oray.com/ph/update?hostname=[DOMAIN]&myip=[IP]

更新的url, 公云API有提供：http://www.pubyun.com/wiki/%E5%B8%AE%E5%8A%A9:api

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http://[USERNAME]:[PASSWORD]@members.3322.org/dyndns/update?system=dyndns&hostname=[DOMAIN]&myip=[IP]

上报流程

启动/etc/init.d/ddns start。

拿出/usr/lib/ddns/services里面的对应更新url，并存于update_url变量中。

然后将update_url里面的USERNAME、PASSWORD和DOMAIN分别用配置文件/etc/config/ddns中的username、password和domain替换（以上面的花生壳更新url为例）。

update_url中的IP用当前路由器wan口ip替换掉，最终存于final_url变量中。

然后通过nslookup [DOMAIN]命令查找到域名的公网IP，存于registered_ip变量中。

然后registered_ip与路由器的wan口IP进行比较：

  • 相同的话则不上报
  • 不相同的话，则通过/usr/bin/wget -O - ${final_url}上报给ddns服务商。

相关配置参数

/etc/config/ddns
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config service 'oray'
    option enabled        '1'
    option service_name   'oray.com'

    option domain         '' # 注册的域名
    option username       '' # 账号名
    option password       '' # 密码

    option ip_source      'network'
    option ip_network     'wan'

    option check_interval '5'
    option check_unit     'minutes'

    option force_interval '12'
    option force_unit     'hours'

ip_source和ip_network的解释如下：

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# If "ip_source" is "network" you specify a network section in your
# /etc/network config file (e.g. "wan", which is the default) with
# the "ip_network" option.  If you specify "wan", you will update
# with whatever the ip for your wan is.
#
# If "ip_source" is "interface" you specify a hardware interface
# (e.g. "eth1") and whatever the current ip of this interface is
# will be associated with the domain when an update is performed.
#
# If "ip_source" is "script" you specify a script to obtain ip address.
# The "ip_script" option should contain path to your script.
#
# The last possibility is that "ip_source" is "web", which means
# that in order to obtain our ip address we will connect to a
# website, and the first valid ip address listed on that page
# will be assumed to be ours.  If you are behind another firewall
# this is the best option since none of the local networks or
# interfaces will have the external ip.  The website to connect
# to is specified by the "ip_url" option.  You may specify multiple
# urls in the option, separated by whitespace.

配合ddns的默认配置可看出，ip_source和ip_network是成对出现的：

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#option ip_source  "network"
#option ip_network "wan"
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#option ip_source  "interface"
#option ip_network "eth0.1"
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#option ip_source  "script"
#option ip_network "path to your script"

按照上面的ddns配置，如果你的路由是二级路由，那么wan口ip是局域网地址时，也照样会把本wan口的ip上报给ddns服务商的。

ip_url参数：

此配置没有填写ip_url参数，因为ddns脚本获取当前wan口ip时，先判断ip_source参数

  • ip_source = "network"，则最终通过ubus call network.interface dump拿到wan口ip。
  • ip_source = "interface"，则通过ifconfig拿到对应网口ip。
  • ip_source = "script"，则执行自定义脚本。
  • 以上都不是（相当于ip_source = “web”），则通过命令wget -O - ${ip_url}拿到公网ip，即访问${ip_url}地址来得到公网ip。如果还拿不到那就访问默认的http://checkip.dyndns.org网址拿公网ip。