我编写了 wlan 管理器脚本来处理开放/ad-hoc/wep/wpa2 网络。现在我尝试解析 iw wlan0 扫描输出,以便为我的脚本获得良好的扫描功能。我的目标是得到这样的输出:
SSID channel signal encryption
wlan-ap 6 70% wpa2-psk
test 1 55% wep
我已经实现的输出是这样的:
$ iw wlan0 scan | grep 'SSID\|freq\|signal\|capability' | tac
SSID: Koti783
signal: -82.00 dBm
capability: ESS Privacy ShortPreamble SpectrumMgmt ShortSlotTime (0x0531)
freq: 2437
我一直在尝试研究 bash/sed/awk 但还没有找到一种方法来实现我正在尝试的目标。那么实现这一目标的好方法是什么?
这是我基于 Sudo_O 答案的最终解决方案:
$1 == "BSS" {
MAC = $2
wifi[MAC]["enc"] = "Open"
}
$1 == "SSID:" {
wifi[MAC]["SSID"] = $2
}
$1 == "freq:" {
wifi[MAC]["freq"] = $NF
}
$1 == "signal:" {
wifi[MAC]["sig"] = $2 " " $3
}
$1 == "WPA:" {
wifi[MAC]["enc"] = "WPA"
}
$1 == "WEP:" {
wifi[MAC]["enc"] = "WEP"
}
END {
printf "%s\t\t%s\t%s\t\t%s\n","SSID","Frequency","Signal","Encryption"
for (w in wifi) {
printf "%s\t\t%s\t\t%s\t%s\n",wifi[w]["SSID"],wifi[w]["freq"],wifi[w]["sig"],wifi[w]["enc"]
}
}'
输出:
$ sudo iw wlan0 scan | awk -f scan.awk
SSID Frequency Signal Encryption
netti 2437 -31.00 dBm Open
Koti783 2437 -84.00 dBm WPA
WLAN-AP 2462 -85.00 dBm WPA
这里有一个
GNU awk
脚本可以帮助您获取每个唯一 BSS 的 SSID 和通道:
/^BSS / {
MAC = $2
}
/SSID/ {
wifi[MAC]["SSID"] = $2
}
/primary channel/ {
wifi[MAC]["channel"] = $NF
}
# Insert new block here
END {
printf "%s\t\t%s\n","SSID","channel"
for (w in wifi) {
printf "%s\t\t%s\n",wifi[w]["SSID"],wifi[w]["channel"]
}
}
考虑到您一直在做的所有学习,您应该很容易添加新的信号和加密块。
将脚本保存到文件,例如
wifi.awk
并运行:
$ sudo iw wlan0 scan | awk -f wifi.awk
输出将采用请求的格式:
SSID channel
wlan-ap 6
test 1
这是一个简单的 Bash 函数,它专门使用 Bash 内部结构并仅生成一个子 shell:
#!/bin/bash
function iwScan() {
# disable globbing to avoid surprises
set -o noglob
# make temporary variables local to our function
local AP S
# read stdin of the function into AP variable
while read -r AP; do
## print lines only containing needed fields
[[ "${AP//'SSID: '*}" == '' ]] && printf '%b' "${AP/'SSID: '}\n"
[[ "${AP//'signal: '*}" == '' ]] && ( S=( ${AP/'signal: '} ); printf '%b' "${S[0]},";)
done
set +o noglob
}
iwScan <<< "$(iw wlan0 scan)"
输出:
-66.00,FRITZ!Box 7312
-56.00,ALICE-WLAN01
-78.00,o2-WLAN93
-78.00,EasyBox-7A2302
-62.00,dlink
-74.00,EasyBox-59DF56
-76.00,BELAYS_Network
-82.00,o2-WLAN20
-82.00,BPPvM
可以通过在 while read -r AP while 循环中添加必要的过滤器来轻松修改该函数以提供其他字段,例如:
[[ "${AP//'last seen: '*}" == '' ]] && ( S=( ${AP/'last seen: '} ); printf '%b' "${S[0]},";)
输出:
-64.00,1000,FRITZ!Box 7312
-54.00,492,ALICE-WLAN01
-76.00,2588,o2-WLAN93
-78.00,652,LN8-Gast
-72.00,2916,WHITE-BOX
-66.00,288,ALICE-WLAN
-78.00,800,EasyBox-59DF56
-80.00,720,EasyBox-7A2302
-84.00,596,ALICE-WLAN08
我正在为 openwrt 使用这样的解决方案:
wlan_scan.sh
#!/bin/sh
sudo iw dev wlan0 scan | awk -f wlan_scan.awk | sort
wlan_scan.awk
/^BSS/ {
mac = gensub ( /^BSS[[:space:]]*([0-9a-fA-F:]+).*?$/, "\\1", "g", $0 );
}
/^[[:space:]]*signal:/ {
signal = gensub ( /^[[:space:]]*signal:[[:space:]]*(\-?[0-9.]+).*?$/, "\\1", "g", $0 );
}
/^[[:space:]]*SSID:/ {
ssid = gensub ( /^[[:space:]]*SSID:[[:space:]]*([^\n]*).*?$/, "\\1", "g", $0 );
printf ( "%s %s %s\n", signal, mac, ssid );
}
结果
-62.00 c8:64:c7:54:d9:05 a
-72.00 70:72:3c:1c:af:17 b
-81.00 78:f5:fd:be:33:cb c
上面的 awk 脚本中有一个错误。
如果 SSID 名称中包含空格,则以下代码将不起作用。收到的结果将只是 SSID 名称的第一个令牌。
$1 == "SSID:" {
wifi[MAC]["SSID"] = $2
}
打印$0、$1、$2时:
$0: SSID: DIRECT-82-HP OfficeJet 8700
$1: SSID:
$2: DIRECT-82-HP
一种可能的解决方案是采用 $0 的子字符串,其中包含前导空格、令牌“SSID:”和提供的多令牌网络名称。
还有其他建议吗?
我从Ari Malinen获取了awk代码并对其进行了一些修改,因为iw输出不稳定并且发生变化,还存在其他问题,例如SSID中的空格。我把它放在 github 上,以防将来我更改它。
#!/usr/bin/env awk -f
$1 ~ /^BSS/ {
if($2 !~ /Load:/) { #< Escape "BBS Load:" line
gsub("(\\(.*|:)", "", $2)
MAC = toupper($2)
wifi[MAC]["enc"] = "OPEN"
wifi[MAC]["WPS"] = "no"
wifi[MAC]["wpa1"] = ""
wifi[MAC]["wpa2"] = ""
wifi[MAC]["wep"] = ""
}
}
$1 == "SSID:" {
# Workaround spaces in SSID
FS=":" #< Changing field separator on ":", it should be
# forbidded sign for SSID name
$0=$0
sub(" ", "", $2) #< remove first whitespace
wifi[MAC]["SSID"] = $2
FS=" "
$0=$0
}
$1 == "capability:" {
for(i=2; i<=NF; i++) {
if($i ~ /0x[0-9]{4}/) {
gsub("(\\(|\\))", "", $i)
if (and(strtonum($i), 0x10))
wifi[MAC]["wep"] = "WEP"
}
}
}
$1 == "WPA:" {
wifi[MAC]["wpa1"] = "WPA1"
}
$1 == "RSN:" {
wifi[MAC]["wpa2"] = "WPA2"
}
$1 == "WPS:" {
wifi[MAC]["WPS"] = "yes"
}
$1 == "DS" {
wifi[MAC]["Ch"] = $5
}
$1 == "signal:" {
match($2, /-([0-9]{2})\.00/, m)
wifi[MAC]["Sig"] = m[1]
}
$1 == "TSF:" {
gsub("(\\(|d|,)", "", $4)
match($5, /([0-9]{2}):([0-9]{2}):/, m)
day = $4
hour = m[1]
min = m[2]
wifi[MAC]["TSF"] = day"d"hour"h"min"m"
}
END {
for (w in wifi) {
if (wifi[w]["wep"]) {
if (wifi[w]["wpa1"] || wifi[w]["wpa2"])
wifi[w]["enc"] = wifi[w]["wpa1"]wifi[w]["wpa2"]
else
wifi[w]["enc"] = "WEP"
}
printf "%s:%s:%s:%s:%s:%s:%s\n", w, wifi[w]["SSID"], wifi[w]["enc"], \
wifi[w]["WPS"], wifi[w]["Ch"], wifi[w]["Sig"], wifi[w]["TSF"]
}
}
输出:
A5FEF2C499BB:test-ssid2:OPEN:no:9:43:0d00h00m
039EFACA9A8B:test-ssid2:WPA1:no:9:33:0d00h00m
038BF3C1988B:test-ssid2:WPA2:no:9:35:0d00h00m
028EF3C2997B:test-ssid2:WPA1:no:9:35:0d00h03m
如果您想知道
if($2 !~ /Load:/)
的作用,那么在某些路由器上可能会有“BSS Load:”字符串。
您可以使用jc(JSON转换)
jc JSON 化了许多 CLI 工具、文件类型和常见字符串的输出,以便于在脚本中进行解析。
$ iw dev wlan0 scan | jc --iw-scan
或
$ jc iw dev wlan0 scan