openwrt的network文件，或者说在/etc/config下的文件，都是动态生成的。
脚本的函数定义在openwrt1407/package/base-files/files/lib/functions中，有以下几个文件：
tf@ubuntu:~/projects/openwrt1407/package/base-files/files/lib/functions$ ls
leds.sh network.sh preinit.sh service.sh system.sh uci-defaults.sh
其中uci-defaults.sh会生成默认的/etc/config下的文件，而其它文件是它的“库”。
我们看一看uci-default.sh的内容
#!/bin/sh
# Copyright (C) OpenWrt.org UCIDEF_LEDS_CHANGED= ucidef_set_led_netdev() {
local cfg="led_$1"
local name=$
local sysfs=$
local dev=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.trigger='netdev'
set system.$cfg.dev='$dev'
set system.$cfg.mode='link tx rx'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_led_usbdev() {
local cfg="led_$1"
local name=$
local sysfs=$
local dev=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.trigger='usbdev'
set system.$cfg.dev='$dev'
set system.$cfg.interval=''
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_led_wlan() {
local cfg="led_$1"
local name=$
local sysfs=$
local trigger=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.trigger='$trigger'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_led_switch() {
local cfg="led_$1"
local name=$
local sysfs=$
local trigger=$
local port_mask=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.trigger='$trigger'
set system.$cfg.port_mask='$port_mask'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_led_default() {
local cfg="led_$1"
local name=$
local sysfs=$
local default=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.default='$default'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_led_rssi() {
local cfg="led_$1"
local name=$
local sysfs=$
local iface=$
local minq=$
local maxq=$
local offset=$
local factor=$ uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='led'
set system.$cfg.name='$name'
set system.$cfg.sysfs='$sysfs'
set system.$cfg.trigger='rssi'
set system.$cfg.iface='rssid_$iface'
set system.$cfg.minq='$minq'
set system.$cfg.maxq='$maxq'
set system.$cfg.offset='$offset'
set system.$cfg.factor='$factor'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_set_rssimon() {
local dev="$1"
local refresh="$2"
local threshold="$3" local cfg="rssid_$dev" uci -q get system.$cfg && return uci batch <<EOF
set system.$cfg='rssid'
set system.$cfg.dev='$dev'
set system.$cfg.refresh='$refresh'
set system.$cfg.threshold='$threshold'
EOF
UCIDEF_LEDS_CHANGED=
} ucidef_commit_leds()
{
[ "$UCIDEF_LEDS_CHANGED" == "" ] && uci commit system
} ucidef_set_interface_loopback() {
uci batch <<EOF
set network.loopback='interface'
set network.loopback.ifname='lo'
set network.loopback.proto='static'
set network.loopback.ipaddr='127.0.0.1'
set network.loopback.netmask='255.0.0.0'
set network.globals='globals'
set network.globals.ula_prefix='auto'
EOF
} ucidef_set_interface_raw() {
local cfg=$
local ifname=$ uci batch <<EOF
set network.$cfg='interface'
set network.$cfg.ifname='$ifname'
set network.$cfg.proto='none'
EOF
} ucidef_set_interface_lan() {
local ifname=$ uci batch <<EOF
set network.lan='interface'
set network.lan.ifname='$ifname'
set network.lan.force_link=
set network.lan.type='bridge'
set network.lan.proto='static'
set network.lan.ipaddr='192.168.1.1'
set network.lan.netmask='255.255.255.0'
set network.lan.ip6assign=''
EOF
} ucidef_set_interface_wan() {
local ifname=$ uci batch <<EOF
set network.wan='interface'
set network.wan.ifname='$ifname'
set network.wan.proto='dhcp'
set network.wan6='interface'
set network.wan6.ifname='@wan'
set network.wan6.proto='dhcpv6'
EOF
} ucidef_set_interfaces_lan_wan() {
local lan_ifname=$
local wan_ifname=$ ucidef_set_interface_lan "$lan_ifname"
ucidef_set_interface_wan "$wan_ifname"
} ucidef_set_interface_macaddr() {
local ifname=$
local mac=$ uci batch <<EOF
set network.$ifname.macaddr='$mac'
EOF
} ucidef_add_switch() {
local name=$
local reset=$
local enable=$
uci batch <<EOF
add network switch
set network.@switch[-].name='$name'
set network.@switch[-].reset='$reset'
set network.@switch[-].enable_vlan='$enable'
EOF
} ucidef_add_switch_vlan() {
local device=$
local vlan=$
local ports=$
uci batch <<EOF
add network switch_vlan
set network.@switch_vlan[-].device='$device'
set network.@switch_vlan[-].vlan='$vlan'
set network.@switch_vlan[-].ports='$ports'
EOF
} ucidef_add_switch_port() {
local device=$
local port=$
uci batch <<EOF
add network switch_port
set network.@switch_port[-].device='$device'
set network.@switch_port[-].port='$port'
EOF
}
看到了吧，改这里的内容就会改到openwrt固件的默认配置了。
调用这些库的函数在这里：
tf@ubuntu:~/projects/openwrt1407/target/linux/ar71xx/base-files/etc/uci-defaults$ ls
01_leds 03_network-vlan-migration 09_fix-trx-header
02_network 04_led_migration
03_network-switchX-migration 09_fix-seama-header
对于网络，则是02_network文件，看看该文件的开头内容为：
#!/bin/sh
#
# Copyright (C) OpenWrt.org
# [ -e /etc/config/network ] && exit touch /etc/config/network . /lib/functions/uci-defaults.sh
. /lib/ar71xx.sh ucidef_set_interface_loopback board=$(ar71xx_board_name) ...
这样就清晰了。