Openwrt.wifi.脚本分析之/sbin/wifi

作用：

1.使用wifi脚本自动生成配置，命令是rm /etc/config/wireless; wifi detect > /etc/config/wireless

2.使用wifi脚本打开wifi功能。

3.使用wifi脚本查看当前wifi信息。

#!/bin/sh
# Copyright (C) 2006 OpenWrt.org

. /lib/functions.sh
. /usr/share/libubox/jshn.sh

usage() {
        cat </dev/null >/dev/null; then
                        eval "scan_$iftype '$device'"
                        eval "${1}_$iftype '$device'" || echo "$device($iftype): ${1} failed"
                elif [ ! -f /lib/netifd/wireless/$iftype.sh ]; then
                        echo "$device($iftype): Interface type not supported"
                fi
        ); done
}

wifi_updown() {
        cmd=down
        [ enable = "$1" ] && {
                _wifi_updown disable "$2"
                ubus_wifi_cmd "$cmd" "$2"
                scan_wifi
                cmd=up
        }
        ubus_wifi_cmd "$cmd" "$2"
        _wifi_updown "$@"
}

wifi_reload_legacy() {
        _wifi_updown "disable" "$1"
        scan_wifi
        _wifi_updown "enable" "$1"
}

wifi_reload() {
        ubus call network reload
        wifi_reload_legacy
}

wifi_detect() {
        for driver in ${2:-$DRIVERS}; do (
                if eval "type detect_$driver" 2>/dev/null >/dev/null; then
                        eval "detect_$driver" || echo "$driver: Detect failed" >&2
                else
                        echo "$driver: Hardware detection not supported" >&2
                fi
        ); done
}

start_net() {(
        local iface="$1"
        local config="$2"
        local vifmac="$3"

        [ -f "/var/run/$iface.pid" ] && kill "$(cat /var/run/${iface}.pid)" 2>/dev/null
        [ -z "$config" ] || {
                include /lib/network
                scan_interfaces
                for config in $config; do
                        setup_interface "$iface" "$config" "" "$vifmac"
                done
        }
)}

set_wifi_up() {
        local cfg="$1"
        local ifname="$2"
        uci_set_state wireless "$cfg" up 1
        uci_set_state wireless "$cfg" ifname "$ifname"
}

set_wifi_down() {
        local cfg="$1"
        local vifs vif vifstr

        [ -f "/var/run/wifi-${cfg}.pid" ] &&
                kill "$(cat "/var/run/wifi-${cfg}.pid")" 2>/dev/null
        uci_revert_state wireless "$cfg"
        config_get vifs "$cfg" vifs
        for vif in $vifs; do
                uci_revert_state wireless "$vif"
        done
}

scan_wifi() {
        local cfgfile="$1"
        DEVICES=
        config_cb() {
                local type="$1"
                local section="$2"

                # section start
                case "$type" in
                        wifi-device)
                                append DEVICES "$section"
                                config_set "$section" vifs ""
                                config_set "$section" ht_capab ""
                        ;;
                esac

                # section end
                config_get TYPE "$CONFIG_SECTION" TYPE
                case "$TYPE" in
                        wifi-iface)
                                config_get device "$CONFIG_SECTION" device
                                config_get vifs "$device" vifs
                                append vifs "$CONFIG_SECTION"
                                config_set "$device" vifs "$vifs"
                        ;;
                esac
        }
        config_load "${cfgfile:-wireless}"
}

DEVICES=
DRIVERS=
include /lib/wifi
scan_wifi

case "$1" in
        down) wifi_updown "disable" "$2";;
        detect) wifi_detect "$2";;
        status) ubus_wifi_cmd "status" "$2";;
        reload) wifi_reload "$2";;
        reload_legacy) wifi_reload_legacy "$2";;
        --help|help) usage;;
        *) ubus call network reload; wifi_updown "enable" "$2";;
esac

前面定义函数，后面定义执行任务。

wifi up  wlan3：执行 ubus call network reload，对network进行了reload ，而后执行 wifi_updown “enable” “wlan3".2”
wifi down   ：
wifi detect >/etc/config/wireless：
wifi status ：json格式返回当前的wifi状态信息。

root@OpenWrt:~# wifi status
{
        "radio0": {
                "up": true,
                "pending": false,
                "autostart": true,
                "disabled": false,
                "config": {
                        "hwmode": "11ng",
                        "path": "10180000.wmac",
                        "htmode": "HT20",
                        "ht_capab": [
                                "GF",
                                "SHORT-GI-20",
                                "SHORT-GI-40",
                                "RX-STBC1"
                        ],
                        "country": "00",
                        "txpower": 15,
                        "channel": "3",
                        "disabled": false
                },
                "interfaces": [
                        {
                                "section": "@wifi-iface[0]",
                                "ifname": "wlan0",
                                "config": {
                                        "mode": "ap",
                                        "encryption": "psk-mixed",
                                        "ssid": "LE20903",
                                        "key": "LLE20903",
                                        "mode": "ap",
                                        "network": [
                                                "lan"
                                        ],
                                        "disabled": false
                                }
                        },
                        {
                                "section": "@wifi-iface[1]",
                                "ifname": "wlan0-1",
                                "config": {
                                        "mode": "ap",
                                        "encryption": "psk-mixed",
                                        "ssid": "LL20903",
                                        "key": "157AECC4C364",
                                        "mode": "ap",
                                        "network": [
                                                "lan"
                                        ],
                                        "disabled": false
                                }
                        }
                ]
        }
}