[未完成]优酷路由宝的一些脚本分析

首先，分析的是/etc/youku/rc.main这个文件，它负责优酷相关服务的初始化、启动和结束。

这个脚本一开始先export YoukuHome=”/tmp/youku”，设置一个路径。

接下来是几个无关紧要的函数

ylog()
{
#format: /etc/youku/rc.main ylog "logstring"
[ -n "$@" ] &&	echo `date +%Y-%m-%d-%H-%M-%m`"  $@" | tee -ai $YoukuHome/log/boot.log
}

#add by David
_log()
{
_DEBUG=0;
if [ "${_DEBUG}" -eq 1 ]; then
echo $1 >> $YoukuHome/log/rc.log
fi
}

help()
{
cat <<EOF
Syntax: $action
Available commands:
start       Start all youku services
stop        Stop  all youku services
ikuacc      start|stop
tf      mount|umount dectect TF storage card
usb     mount|umount dectect USB storage disk
help
EOF
}

start函数

在start函数中调用了六个函数执行不同的任务。bootup目录创建等一些准备工作，tf挂载tf卡，usb挂载u盘，setup设置，checkYoukuSN检查sn，还有versionupdate和youku_luci接下来会讲。

start() {

ylog "rc.main start ..."

bootup
tf  mount
usb mount
setup

checkYoukuSN
versionupdate

#       start youkucmc with procd.
#   ikuacc start

youku_luci

ylog "rc.main start finished"
return 0
}

bootup函数

bootup() {

[ -d "$YoukuHome" ] && return 0; #这段代码先测试了$YoukuHome是否存在，存在就不用再执行下去了,下面是不存在$YoukuHome的情况。

#  ensure youku directory structure and env var.

#use /tmp/youku/* to point the latest youku app, web, and script.
# use system tmpfs or ourselves. the later is easy to evaluation memory used.

mkdir -p $YoukuHome #建立$YoukuHome目录
mount -t tmpfs tmpfs $YoukuHome -o size=4m

#mkdir -p $YoukuHome/log
echo  `date +%Y-%m-%d-%H-%M-%S`"  rc.main bootup ..." > $YoukuHome/log/boot.log

mkdir -p $YoukuHome/mnt  #used for tf storage card and usb storage
mkdir -p $YoukuHome/sys

mkdir -p $YoukuHome/stat
mkdir -p $YoukuHome/cfg
mkdir -p $YoukuHome/bin
mkdir -p $YoukuHome/pub  #used for link shared resources which can be seen out of router.
mkdir -p $YoukuHome/ver  #used for save version info of firmware and packages.

mkdir -p $YoukuHome/data #used for storage big size of data.  visit if from  $YoukuHome/var
mount -t tmpfs tmpfs $YoukuHome/data -o size=4m  #give 4m as default,

ln  -sfn $YoukuHome/data $YoukuHome/pkg #redirect $YoukuHome/pkg to tf or usb storage if possible.
#ln  -sfn $YoukuHome/data $YoukuHome/var #redirect $YoukuHome/var to tf or usb storage if possible.
ln  -sfn $YoukuHome/data $YoukuHome/tmp #redirect $YoukuHome/tmp to tf or usb storage if possible.
ln  -sfn $YoukuHome/data $YoukuHome/log

mkdir -p $YoukuHome/var
mkdir -p $YoukuHome/var/ikucmc
mkdir -p $YoukuHome/var/ikuacc
#mkdir -p $YoukuHome/var/ikuacc/meta     #used for ikuacc meta
mkdir -p $YoukuHome/var/ikuacc/data     #used for ikuacc data, youkudisk.

#FIXME just for debug. yang,2014-09-05,let it to be seen in web, remove it when publish
#ylog "rc.main bootup  ln -sfn /  $YoukuHome/pub/root"
#ln -sfn /  $YoukuHome/pub/root

ylog "rc.main bootup finished."
return 0
}

第11行把tmpfs挂载到$YoukuHome。第17~26行建立了一些目录，

第27行又在$YoukuHome/data挂载tmpfs，第29~32行建立了一些软连接，第34~38行建立了ikuacc的一些目录。

挂载和卸载tf卡

tf() {

ylog "rc.main tf ....[$@]"

index=0;
###################################################
#partitions,add by David
partition_sd
RetTmp=$?
if [ "$RetTmp" -eq 1 ]; then
{
_log "RetTmp=$RetTmp, return"
return
}
fi

#do mount operation
if [ "-$1" = "-mount" ]; then
{

[ `find /dev/ -type b -name mmcblk* | wc -l` -gt 0 ] || {
ylog "rc.main tf: no tf device found, exit 1"
return 1
}

for devfile in `ls /dev/ | grep mmcblk | grep p`; do
{
_log "mount start"
mkdir $YoukuHome/mnt/tf$index
mount  /dev/$devfile $YoukuHome/mnt/tf$index -o errors=continue
RETVAL=$?
if [ $RETVAL = 0 ]; then
ylog "rc.main tf mounted: /dev/$devfile  ==> $YoukuHome/mnt/tf$index"
index=$(($index+1)) #prepare to mount next
else
ylog "rc.main tf mounted failure: /dev/$devfile  ==> $YoukuHome/mnt/tf$index"
rmdir $YoukuHome/mnt/tf$index
fi
}
done

#
last=$(($index-1))
for i in `seq 0 $last`; do
storage_mounted "tf" "$YoukuHome/mnt/tf$i" "$index" "$i"
done

}
fi

####################################################
#do unmount operation
if [ "-$1" = "-umount" ]; then
{
for tfdir in `ls $YoukuHome/mnt/ | grep tf`; do
{
umount $YoukuHome/mnt/$tfdir
rmdir  $YoukuHome/mnt/$tfdir
rm     $YoukuHome/pub/$tfdir
index=$(($index+1))

ylog "rc.main tf umounted ==> $YoukuHome/mnt/$tfdir"
}
done
}
fi

#setup bin links again if something changed.
[ $index -gt 0 ] && setup

return 0
}

第8~15行，调用了partition_sd，接下来会讲，检查partition_sd的返回值，没什么实际作用。

如果参数是mount，执行第17~49行挂载sd；如果参数是umount，执行第53~66行卸载sd卡。

第21~24行，看看设备中有没有块设备叫做mmcblk*的，这种不出意外就是sd卡了，否则就返回1。

第26~39就是枚举并挂载sd卡了。其中，第29行创建挂载的目录，第30行挂载sd卡到该目录。

第43~46行调用storage_mounted，这个函数里面创建了一些软连接，后面会讲。

第53~66行就是umount部分，卸载并删除挂载目录和软连接。特别注意还有个第69行，执行setup，后面会讲。

挂载和卸载USB存储器

usb() {
ylog "rc.main usb ....[$@]"

index=0;
###################################################
#do mount operation
if [ "-$1" = "-mount" ]; then
{

[ `find /dev/ -type b -name sd* | wc -l` -gt 0 ] || {
ylog "rc.main tf: no usb storage device found, exit 1"
return 1
}

for devfile in `ls /dev/ | grep -e sda -e sdb -e sdc`; do
{
mkdir $YoukuHome/mnt/usb$index
mount  /dev/$devfile $YoukuHome/mnt/usb$index
RETVAL=$?
if [ $RETVAL = 0 ]; then
ylog "rc.main usb mounted: /dev/$devfile  ==> $YoukuHome/mnt/usb$index"
index=$(($index+1)) #prepare to mount next
else
ylog "rc.main usb mounted failure: /dev/$devfile  ==> $YoukuHome/mnt/usb$index"
rmdir $YoukuHome/mnt/usb$index
fi
}
done

#
last=$(($index-1))
for i in `seq 0 $last`; do
storage_mounted "usb" "$YoukuHome/mnt/usb$i" "$index" "$i"
done

}
fi

####################################################
#do unmount operation
if [ "-$1" = "-umount" ]; then
{
for usbdir in `ls $YoukuHome/mnt/ | grep usb`; do
{
umount $YoukuHome/mnt/$usbdir
rmdir  $YoukuHome/mnt/$usbdir
rm     $YoukuHome/pub/$usbdir
index=$(($index+1))

ylog "rc.main usb umounted ==> $YoukuHome/mnt/$usbdir"
}
done
}
fi

#setup bin links again if something changed.
[ $index -gt 0 ] && setup

return 0;
}

过程跟挂载和卸载tf卡差不多。

setup函数

setup() {

ylog "rc.main setup ..."

#set default .or when some disk umounted
[ -L $YoukuHome/bin/youkucmc -a -f "`readlink -f $YoukuHome/bin/youkucmc`" ] || ln -sfn  /usr/sbin/guard    $YoukuHome/bin/youkucmc
[ -L $YoukuHome//bin/ikuacc  -a -f "`readlink -f $YoukuHome/bin/ikuacc`"   ] || ln -sfn  /usr/sbin/ikuacc   $YoukuHome/bin/ikuacc
[ -L $YoukuHome/bin/sn_youku -a -f "`readlink -f $YoukuHome/bin/sn_youku`" ] || ln -sfn  /usr/sbin/sn_youku    $YoukuHome/bin/sn_youku
[ -L $YoukuHome/www -a -d "`readlink -f $YoukuHome/www`" ] || ln -sfn /www/  $YoukuHome/www

#let publish resouces can be seen from web
[ -L $YoukuHome/www/pub -o -d $YoukuHome/www/pub ] || ln -sfn $YoukuHome/pub $YoukuHome/www/pub

ylog "rc.main setup: cur www path=>[`readlink -f $YoukuHome/www`]"
#####################################################################

#select space for save data,suck as ikuacc virtual disk and so on.
#[ -L $YoukuHome/var -a -d "`readlink -f $YoukuHome/var`" ] || ln -sfn $YoukuHome/data  $YoukuHome/var

ylog "rc.main setup: cur var path=>[`readlink -f $YoukuHome/var`]"

flag=0
minsize=0
maxsize=0
mindisk=0
maxdisk=0
cd $YoukuHome/mnt
#get smallest and biggest start partition
for p in `ls $YoukuHome/mnt | grep -e tf -e usb | sort`; do
{
newsize=`df -m | grep $YoukuHome/mnt/$p | awk '{print $2 }'`
[ -z $newsize ] && newsize=0
[ ${flag} -eq 0 ] && {
flag=1
minsize=${newsize}
maxsize=${newsize}
mindisk=${YoukuHome}/mnt/$p
maxdisk=${YoukuHome}/mnt/$p
}
[ ${newsize} -lt ${minsize} ] && {
mindisk=${YoukuHome}/mnt/$p
minsize=${newsize}
}
[ ${newsize} -gt ${maxsize} ] && {
maxdisk=${YoukuHome}/mnt/$p
maxsize=${newsize}
}
};
done

_log "minsize=${minsize}, mindisk=${mindisk}"
_log "maxsize=${maxsize}, maxdisk=${maxdisk}"

[ ${minsize} -gt 100 ] && {
if [ "${mindisk}/meta" != "`readlink -f ${YoukuHome}/var/ikuacc/meta`" ]; then
{
[ -d ${YoukuHome}/var/ikuacc/meta ] && cp -rfp ${YoukuHome}/var/ikuacc/meta/* ${mindisk}/youku/var/ikuacc/meta  #only copy meta to new space.
mkdir -p ${mindisk}/meta
#mkdir -p $YoukuHome/var/ikuacc/meta
ln -sfn ${mindisk}/meta ${YoukuHome}/var/ikuacc/meta
}
fi

if [ "`readlink -f $YoukuHome/pkg`" != "${mindisk}/youku/bin" ]; then
{
mkdir -p ${mindisk}/youku/bin
ln -sfn  ${mindisk}/youku/bin $YoukuHome/pkg
mkdir -p ${mindisk}/youku/tmp
ln -sfn  ${mindisk}/youku/tmp $YoukuHome/tmp
mkdir -p ${mindisk}/youku/log
ln -sfn  ${mindisk}/youku/log $YoukuHome/log
ylog "rc.main setup: set pkg path=>[size=$newsize Mb,${mindisk}/youku/bin"
ylog "rc.main setup: set tmp path=>[size=$newsize Mb,${mindisk}/youku/tmp"
}
fi
}
#mount data0~data3
cnt=0
for p in `ls $YoukuHome/mnt | grep -e tf | sort`; do
{
partsize=`df -m | grep $YoukuHome/mnt/$p | awk '{print $2 }'`
[ ${partsize} -gt 500 ] && {
_log "mount data, partsize=${partsize}"
#mkdir -p $YoukuHome/var/ikuacc/data/data${cnt}
ln -sfn $YoukuHome/mnt/$p $YoukuHome/var/ikuacc/data/data${cnt}
cnt=$((${cnt}+1))
}
};
done

#### add by xiongying for 1.5 branch patch
[ -f /usr/sbin/patch.sh ] && /bin/sh /usr/sbin/patch.sh

#####################################################################
#go to default work directory
cd $YoukuHome/tmp

ylog "rc.main setup finished."
return 1
}