高通410随身wifi：Passwall2启动文件解析

背景

• 最近在搞随身wifi烧录openwrt系统，配置好passwall2后，系统隔20分钟就崩溃重启一下，初步分析原因可能是内存泄漏，因为passwall2占用的内存巨大无比，如下：
  
• 在关闭了docker等无关的组件后，仍然存在崩溃，且查看日志信息找不到重启的日志。因此分析下Passwall2的启动文件，并使用ulimit限制进程资源占用。
• passwall2的启动文件在/etc/init.d/passwall2文件中，具体内容如下

openwrt的启动文件夹：/etc/init.d/

• 文件夹说明如下：

  

• 实际该系统的/etc/init.d/如下：

  root@OpenWrt:~# ls /etc/init.d/ -all
  drwxr-xr-x    2 root     root          4096 Jul 13  2023 .
  drwxr-xr-x   36 root     root          4096 Jan  6 20:45 ..
  -rwxr-xr-x    1 root     root           402 Jul 13  2023 adbd
  -rwxr-xr-x    1 root     root          3648 Jul 13  2023 alist
  -rwxr-xr-x    1 root     root           300 Jul 13  2023 avahi-daemon
  -rwxr-xr-x    1 root     root          1399 Jul 13  2023 boot
  -rwxr-xr-x    1 root     root           213 Jul 13  2023 cgroupfs-mount
  -rwxr-xr-x    1 root     root          1637 Jul 13  2023 cpufreq
  -rwxr-xr-x    1 root     root           846 Jul 13  2023 cron
  -rwxr-xr-x    1 root     root           681 Jul 13  2023 dbus
  -rwxr-xr-x    1 root     root          1230 Jul 13  2023 ddns-go
  -rwxr-xr-x    1 root     root         35636 Jul 13  2023 dnsmasq
  -rwxr-xr-x    1 root     root          8301 Jul 13  2023 dockerd
  -rwxr-xr-x    1 root     root          3506 Jul 13  2023 dockerman
  -rwxr-xr-x    1 root     root           263 Jul 13  2023 done
  -rwxr-xr-x    1 root     root          6038 Jul 13  2023 dropbear
  -rwxr-xr-x    1 root     root           378 Jul 13  2023 firewall
  -rwxr-xr-x    1 root     root          1713 Jul 13  2023 frpc
  -rwxr-xr-x    1 root     root          1535 Jul 13  2023 gc
  -rwxr-xr-x    1 root     root          1379 Jul 13  2023 gpio_switch
  -rwxr-xr-x    1 root     root           585 Jul 13  2023 haproxy
  -rwxr-xr-x    1 root     root          3640 Jul 13  2023 led
  -rwxr-xr-x    1 root     root          2665 Jul 13  2023 log
  -rwxr-xr-x    1 root     root          1892 Jul 13  2023 microsocks
  -rwxr-xr-x    1 root     root          1260 Jul 13  2023 modemmanager
  -rwxr-xr-x    1 root     root          2706 Jul 13  2023 network
  -rwxr-xr-x    1 root     root           292 Jul 13  2023 odhcpd
  -rwxr-xr-x    1 root     root          1694 Jul 13  2023 openssl
  -rwxr-xr-x    1 root     root          1746 Jul 13  2023 p910nd
  -rwxr-xr-x    1 root     root           321 Jul 13  2023 packet_steering
  -rwxr-xr-x    1 root     root          1245 Jul 13  2023 passwall2
  -rwxr-xr-x    1 root     root           194 Jul 13  2023 passwall2_server
  -rwxr-xr-x    1 root     root           416 Jul 13  2023 qrtr
  -rwxr-xr-x    1 root     root           764 Jul 13  2023 rmtfs
  -rwxr-xr-x    1 root     root           393 Jul 13  2023 rpcd
  -rwxr-xr-x    1 root     root          1660 Jul 13  2023 rssileds
  -rwxr-xr-x    1 root     root          7996 Jul 13  2023 samba4
  -rwxr-xr-x    1 root     root          8902 Jul 13  2023 shadowsocks-libev
  -rwxr-xr-x    1 root     root          1095 Jul 13  2023 socat
  -rwxr-xr-x    1 root     root          4793 Jul 13  2023 socat_ser2net
  -rwxr-xr-x    1 root     root          1212 Jul 13  2023 sysctl
  -rwxr-xr-x    1 root     root           764 Jul 13  2023 sysfixtime
  -rwxr-xr-x    1 root     root          3226 Jul 13  2023 sysntpd
  -rwxr-xr-x    1 root     root          1007 Jul 13  2023 system
  -rwxr-xr-x    1 root     root          4035 Jul 13  2023 tasks
  -rwxr-xr-x    1 root     root          2036 Jul 13  2023 ttyd
  -rwxr-xr-x    1 root     root          1339 Jul 13  2023 ucitrack
  -rwxr-xr-x    1 root     root          6056 Jul 13  2023 uhttpd
  -rwxr-xr-x    1 root     root           125 Jul 13  2023 umount
  -rwxr-xr-x    1 root     root           239 Jul 13  2023 urandom_seed
  -rwxr-xr-x    1 root     root           220 Jul 13  2023 urngd
  -rwxr-xr-x    1 root     root           328 Jul 13  2023 usb_printer
  -rwxr-xr-x    1 root     root          1309 Jul 13  2023 v2ray
  -rwxr-xr-x    1 root     root          1262 Jul 13  2023 wpad
  -rwxr-xr-x    1 root     root          2715 Jul 13  2023 wsdd2
  -rwxr-xr-x    1 root     root          1269 Jul 13  2023 xray
  -rwxr-xr-x    1 root     root          2409 Jul 13  2023 zerotier
  

/etc/rc.d：启动链接管理文件夹

• 说明如下：

  

• 实际该系统的/etc/rc.d：

  root@OpenWrt:~# ls /etc/rc.d/ -all
  drwxr-xr-x    2 root     root          4096 Jan  6 22:12 .
  drwxr-xr-x   36 root     root          4096 Jan  6 20:45 ..
  lrwxrwxrwx    1 root     root            23 Jul 13  2023 K100socat_ser2net -> ../init.d/socat_ser2net
  lrwxrwxrwx    1 root     root            21 Jul 13  2023 K10gpio_switch -> ../init.d/gpio_switch
  lrwxrwxrwx    1 root     root            19 Jul 13  2023 K15passwall2 -> ../init.d/passwall2
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 K21wpad -> ../init.d/wpad
  lrwxrwxrwx    1 root     root            12 Jul 13  2023 K30gc -> ../init.d/gc
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 K50dropbear -> ../init.d/dropbear
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 K50ttyd -> ../init.d/ttyd
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 K80haproxy -> ../init.d/haproxy
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 K85odhcpd -> ../init.d/odhcpd
  lrwxrwxrwx    1 root     root            13 Jul 13  2023 K89log -> ../init.d/log
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 K89rssileds -> ../init.d/rssileds
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 K90boot -> ../init.d/boot
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 K90network -> ../init.d/network
  lrwxrwxrwx    1 root     root            20 Jul 13  2023 K90sysfixtime -> ../init.d/sysfixtime
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 K90umount -> ../init.d/umount
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 K99qrtr -> ../init.d/qrtr
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 K99rmtfs -> ../init.d/rmtfs
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 K99socat -> ../init.d/socat
  lrwxrwxrwx    1 root     root            20 Jul 13  2023 S00sysfixtime -> ../init.d/sysfixtime
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S00urngd -> ../init.d/urngd
  lrwxrwxrwx    1 root     root            24 Jul 13  2023 S01cgroupfs-mount -> ../init.d/cgroupfs-mount
  lrwxrwxrwx    1 root     root            23 Jul 13  2023 S100socat_ser2net -> ../init.d/socat_ser2net
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S10boot -> ../init.d/boot
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 S10system -> ../init.d/system
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 S11sysctl -> ../init.d/sysctl
  lrwxrwxrwx    1 root     root            13 Jul 13  2023 S12log -> ../init.d/log
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S12rpcd -> ../init.d/rpcd
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S13openssl -> ../init.d/openssl
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S15cpufreq -> ../init.d/cpufreq
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S19dnsmasq -> ../init.d/dnsmasq
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 S19dropbear -> ../init.d/dropbear
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 S19firewall -> ../init.d/firewall
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S19wpad -> ../init.d/wpad
  lrwxrwxrwx    1 root     root            12 Jul 13  2023 S20gc -> ../init.d/gc
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S20network -> ../init.d/network
  lrwxrwxrwx    1 root     root            25 Jul 13  2023 S25packet_steering -> ../init.d/packet_steering
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 S35odhcpd -> ../init.d/odhcpd
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S49tasks -> ../init.d/tasks
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S50cron -> ../init.d/cron
  lrwxrwxrwx    1 root     root            16 Jul 13  2023 S50uhttpd -> ../init.d/uhttpd
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S60dbus -> ../init.d/dbus
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S60qrtr -> ../init.d/qrtr
  lrwxrwxrwx    1 root     root            22 Jul 13  2023 S61avahi-daemon -> ../init.d/avahi-daemon
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S80rmtfs -> ../init.d/rmtfs
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 S80ucitrack -> ../init.d/ucitrack
  lrwxrwxrwx    1 root     root            21 Jul 13  2023 S94gpio_switch -> ../init.d/gpio_switch
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S95done -> ../init.d/done
  lrwxrwxrwx    1 root     root            20 Jul 13  2023 S95microsocks -> ../init.d/microsocks
  lrwxrwxrwx    1 root     root            13 Jul 13  2023 S96led -> ../init.d/led
  lrwxrwxrwx    1 root     root            18 Jul 13  2023 S96rssileds -> ../init.d/rssileds
  lrwxrwxrwx    1 root     root            17 Jan  1  1970 S98sysntpd -> ../init.d/sysntpd
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S99ddns-go -> ../init.d/ddns-go
  lrwxrwxrwx    1 root     root            17 Jul 13  2023 S99haproxy -> ../init.d/haproxy
  lrwxrwxrwx    1 root     root            19 Jul 13  2023 S99passwall2 -> ../init.d/passwall2
  lrwxrwxrwx    1 root     root            26 Jul 13  2023 S99passwall2_server -> ../init.d/passwall2_server
  lrwxrwxrwx    1 root     root            27 Jul 13  2023 S99shadowsocks-libev -> ../init.d/shadowsocks-libev
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S99socat -> ../init.d/socat
  lrwxrwxrwx    1 root     root            14 Jul 13  2023 S99ttyd -> ../init.d/ttyd
  lrwxrwxrwx    1 root     root            22 Jul 13  2023 S99urandom_seed -> ../init.d/urandom_seed
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S99v2ray -> ../init.d/v2ray
  lrwxrwxrwx    1 root     root            15 Jul 13  2023 S99wsdd2 -> ../init.d/wsdd2
  

启动程序源码：/etc/init.d/passwall2

• root@OpenWrt:~# cat /etc/init.d/passwall2
  #!/bin/sh /etc/rc.common
  
  START=99
  STOP=15
  
  CONFIG=passwall2
  APP_FILE=/usr/share/${CONFIG}/app.sh
  LOCK_FILE_DIR=/var/lock
  LOCK_FILE=${LOCK_FILE_DIR}/${CONFIG}.lock
  
  set_lock() {
          [ ! -d "$LOCK_FILE_DIR" ] && mkdir -p $LOCK_FILE_DIR
          exec 999>"$LOCK_FILE"
          flock -xn 999
  }
  
  unset_lock() {
          flock -u 999
          rm -rf "$LOCK_FILE"
  }
  
  unlock() {
          failcount=1
          while [ "$failcount" -le 10 ]; do
                  if [ -f "$LOCK_FILE" ]; then
                          let "failcount++"
                          sleep 1s
                          [ "$failcount" -ge 10 ] && unset_lock
                  else
                          break
                  fi
          done
  }
  
  boot() {
          local delay=$(uci -q get ${CONFIG}.@global_delay[0].start_delay || echo 1)
          if [ "$delay" -gt 0 ]; then
                  $APP_FILE echolog "执行启动延时 $delay 秒后再启动!"
                  sleep $delay
          fi
          restart
          touch ${LOCK_FILE_DIR}/${CONFIG}_ready.lock
  }
  
  start() {
          set_lock
          [ $? == 1 ] && $APP_FILE echolog "脚本已经在运行，不重复运行，退出." && exit 0
          $APP_FILE start
          unset_lock
  }
  
  stop() {
          unlock
          set_lock
          [ $? == 1 ] && $APP_FILE echolog "停止脚本等待超时，不重复运行，退出." && exit 0
          $APP_FILE stop
          unset_lock
  }
  
  restart() {
          set_lock
          [ $? == 1 ] && $APP_FILE echolog "脚本已经在运行，不重复运行，退出." && exit 0
          $APP_FILE stop
          $APP_FILE start
          unset_lock
  }
  
  

启动程序分析：/etc/init.d/passwall2

• 借助GPT4的解释，如下，较为详细准确：

备份passwall2启动脚本并添加ulimit资源限制

• 关于ulimit：

  

• 关于ulimit的作用范围：在哪个程序中使用ulimit，限制范围仅在该文件内。

  

• 因此，我们可以在/etc/init.d/passwall2文件的start函数中添加ulimit，来限制passwall进程可以使用的资源。在某个函数中添加ulimit，则只限制该函数中的进程。

参考

1、handsome大佬开源的linux镜像
2、linux教程