第四章、連上 Internet

[root@linux ~]# cd /usr/src
[root@linux src]# ln -s kernels/2.6.9-34.0.1.EL-smp-i686/ linux
[root@linux src]# cd ~

[root@linux ~]# tar -jxvf install-8_40.tar.bz2
[root@linux ~]# cd DriverInstall
# 此時在該目錄下有個 README 的檔案，記得看一看，這個檔案內會說明很多資訊，
# 包括如何編譯，以及這個模組所支援的晶片組哩！
[root@linux DriverInstall]# ./install.sh

 eth0: network connection up using port A
     speed:           1000
     autonegotiation: yes
     duplex mode:     full
     flowctrl:        symmetric
     role:            slave
     irq moderation:  disabled
     scatter-gather:  enabled
     tx-checksum:     enabled
     rx-checksum:     enabled
     rx-polling:      enabled

[root@linux ~]# ls -l
drwxr-xr-x  2 root root   4096 Jul 20 11:57 sk98lin
[root@linux ~]# ls -l sk98lin
-rw-r--r--  1 root root 2666344 Jul 20 11:57 sk98lin.ko
# 上面那個目錄假設是我編譯出來的模組，裡面還會有一個檔案喔！那個檔案就是
# sk98lin.ko ，要注意，新的 2.6 版的核心模組副檔名都變成 .ko 的格式了！

[root@linux ~]# cp -a sk98lin /lib/modules/`uname -r`/kernel/drivers/net
# 注意啊！整個網路卡驅動模組就是放在上面的目錄中，不要寫錯了。

[root@linux ~]# depmod -a
# 將所有的模組進行重新分析的工作！建立關連檔案

[root@linux ~]# lsmod | grep 'sk98lin'
# 先確認『sk98lin』這個模組不存在，然後就可以開始測試：

[root@linux ~]# modprobe sk98lin
[root@linux ~]# lsmod | grep 'sk98lin'
# 如果有相關的字樣跑出來時，就表示這個模組可以順利的被載入啦！

[root@linux ~]# vi /etc/modprobe.conf
# 修改或增加底下這一行吧！
alias eth0 sk98lin

[root@linux ~]# sync; reboot

[root@linux ~]# ifconfig eth0 192.168.1.100
[root@linux ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:01:BA:77:16:52
          inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0
.....以下省略.....

[root@linux ~]# vi /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=centos.dm.tsai

[root@linux ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0                <== 網路卡代號，必須要 ifcfg-eth0 相對應
BOOTPROTO=static           <== 開機協定，有 dhcp 及 static 這裡是 static
BROADCAST=192.168.1.255    <== 就是廣播位址囉
HWADDR=00:40:D0:13:C3:46   <== 就是網路卡位址
IPADDR=192.168.1.13        <== 就是 IP 啊
NETMASK=255.255.255.0      <== 就是子遮罩網路
NETWORK=192.168.1.0        <== 就是網域啊！該網段的第一個 IP
GATEWAY=192.168.1.2        <== 就是預設路由！
ONBOOT=yes                 <== 是否開機啟動的意思
MTU=1500                   <== 就是最大傳輸單元的設定值。
#GATEWAYDEV=eth0           <== 主要路由的裝置為那個，通常不用設定

[root@linux ~]# ifup eth0
[root@linux ~]# ifdown eth0
# 上面的作法是針對 eth0 來進行啟動 (ifup) 與關閉 (ifdown) ；

[root@linux ~]# /etc/init.d/network restart
# 針對這部主機的所有網路介面 (包含 lo) 與通訊閘進行重新啟動，
# 所以網路會停頓再開喔！

[root@linux ~]# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:40:D0:13:C3:46
          inet addr:192.168.1.13  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::240:d0ff:fe13:c346/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:229458 errors:16 dropped:0 overruns:0 frame:0
          TX packets:117415 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:345006035 (329.0 MiB)  TX bytes:7177543 (6.8 MiB)
          Interrupt:5 Base address:0x3e00
# 記得啊！有出現上頭那個 IP 的資料才是正確的啟動；
# 另外，也注意一下那個 MTU 的數值吶！ ^_^

[root@linux ~]# ping -c 3 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=0.216 ms
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.227 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.222 ms

--- 192.168.1.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.216/0.221/0.227/0.017 ms, pipe 2
# 注意啊！有出現 ttl 才是正確的回應！如果出現『 Destination Host Unreachable 』
# 表示沒有成功的連線到您的 GATEWAY 那表示出問題啦！趕緊檢查有無設定錯誤。

[root@linux ~]# vi /etc/resolv.conf
nameserver 168.95.1.1
nameserver 139.175.10.20

[root@linux ~]# nslookup tw.yahoo.com
Server:         168.95.1.1
Address:        168.95.1.1#53

Non-authoritative answer:
tw.yahoo.com    canonical name = tw.yahoo-ap1.akadns.net.
Name:   tw.yahoo-ap1.akadns.net
Address: 202.43.195.52

[root@linux ~]# ifdown eth0
[root@linux ~]# ifconfig eth0 down

[root@linux ~]# adsl-setup
Welcome to the ADSL client setup.  First, I will run some checks on
your system to make sure the PPPoE client is installed properly...

LOGIN NAME
Enter your Login Name (default root): T1234567
# 注意啊！這個帳號名稱是 ISP 給的，其中如果是 SeedNet ，輸入如上，
# 如果是 Hinet 的話，就得要輸入 username@hinet.com.tw ，後面的主機名也要寫。

INTERFACE
Enter the Ethernet interface connected to the ADSL modem
For Solaris, this is likely to be something like /dev/hme0.
For Linux, it will be ethX, where 'X' is a number.
(default eth0): eth0
# 就是連接到 ADSL 數據機的那張網卡代號

Do you want the link to come up on demand, or stay up continuously?
If you want it to come up on demand, enter the idle time in seconds
after which the link should be dropped.  If you want the link to
stay up permanently, enter 'no' (two letters, lower-case.)
NOTE: Demand-activated links do not interact well with dynamic IP
addresses.  You may have some problems with demand-activated links.
Enter the demand value (default no): <==這裡按 Enter 確定不要即可

DNS
Enter the DNS information here: 168.95.1.1
Enter the secondary DNS server address here: 139.175.10.20
# 這兩個設定會影響 /etc/resolv.conf 的內容喔！

PASSWORD
Please enter your Password: <==這裡則是輸入您 ISP 給的密碼
Please re-enter your Password: <==再一次密碼

USERCTRL
Please enter 'yes' (two letters, lower-case.) if you want to allow
normal user to start or stop DSL connection (default yes): no
# 不讓使用者可以啟動或關閉 ADSL 的設定比較好吧！

The firewall choices are:
0 - NONE: This script will not set any firewall rules.  You are responsible
          for ensuring the security of your machine.  You are STRONGLY
          recommended to use some kind of firewall rules.
1 - STANDALONE: Appropriate for a basic stand-alone web-surfing workstation
2 - MASQUERADE: Appropriate for a machine acting as an Internet gateway
                for a LAN
Choose a type of firewall (0-2): 0
# 先不要密碼！後面我們會使用 Linux 本機的防火牆！

Start this connection at boot time
Do you want to start this connection at boot time?
Please enter no or yes (default no):yes
# 是否要開機的時候就撥接？

Ethernet Interface: eth0
User name:          T1234567
Activate-on-demand: No
Primary DNS:        168.95.1.1
Secondary DNS:      139.175.10.20
Firewalling:        NONE
User Control:       no
Accept these settings and adjust configuration files (y/n)? y
# 如果沒有問題就按下 y 開始寫入設定檔吧！
Adjusting /etc/sysconfig/network-scripts/ifcfg-ppp0
Adjusting /etc/resolv.conf
  (But first backing it up to /etc/resolv.conf.bak)
Adjusting /etc/ppp/chap-secrets and /etc/ppp/pap-secrets
  (But first backing it up to /etc/ppp/chap-secrets.bak)
  (But first backing it up to /etc/ppp/pap-secrets.bak)
# 上面的檔案很簡單吧！
# ifcfg-ppp0  ：亦即是 ppp0 這個網路介面的設定檔案；
# resolv.conf ：這個檔案會被備份後，然後以剛剛我們上面輸入的資料取代；
# pap-secrets, chap-secrets：我們輸入的密碼就放在這裡！

[root@linux ~]# adsl-start
....Connect!

[root@linux ~]# ifconfig ppp0
ppp0      Link encap:Point-to-Point Protocol 
          inet addr:211.74.249.38  P-t-P:172.16.11.8  Mask:255.255.255.255 
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1 
          RX packets:8356088 errors:0 dropped:0 overruns:0 frame:0 
          TX packets:8532063 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:10

[root@linux ~]# more /var/log/messages
May 10 18:02:22 testing pppoe[8527]: Bogus PPPoE length field (50)

  /* Check length */
    if (ntohs(packet.length) + HDR_SIZE > len) {
        syslog(LOG_ERR, "Bogus PPPoE length field (%u)",
               (unsigned int) ntohs(packet.length));
        return;
    }

    /* Check length */
    if (ntohs(packet.length) + HDR_SIZE > len) {
        /* syslog(LOG_ERR, "Bogus PPPoE length field (%u)",
               (unsigned int) ntohs(packet.length)); */
        return;
    }

    if (plen + HDR_SIZE > len) {
        syslog(LOG_ERR, "Bogus length field in session packet %d (%d)",
               (int) plen, (int) len);
        return;
    }

    if (plen + HDR_SIZE > len) {
        /* syslog(LOG_ERR, "Bogus length field in session packet %d (%d)",
               (int) plen, (int) len); */
        return;
    }

[root@linux ~]# cd /usr/local/src/rp-pppoe-3.5/src
[root@linux src]# ./configure
[root@linux src]# make
[root@linux src]# make install

[root@linux ~]# dmesg | grep usb
usb 4-1: new high speed USB device using address 2
# 這裡是說，有個高速 USB 裝置使用第二個 USB 位址的意思。
# 既然知道這個位址，我們來查一查這個裝置的內容吧！

[root@linux ~]# cat /proc/bus/usb/devices
T:  Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ff(vend.) Sub=ff Prot=ff MxPS=64 #Cfgs=  1
P:  Vendor=14ea ProdID=ab13 Rev=43.30
S:  Manufacturer=PCI
S:  Product=USB2.0 WLAN
.....後面省略.....
# 比較重要的就是上面的那個裝置碼以及廠商與產品代碼了！
# 先給他抄寫下來，因為等一下我們進行模組編譯時會用到！

[root@linux ~]# cd zd1211
# 這個目錄下有個 README 的檔案，請記得好好查閱一下喔！

[root@linux zd1211]# cd zdsta
[root@linux zdsta]# vi Makefile
# 先修改底下這一行，應該是在第 15 行的地方，這裡需要與你的核心對應喔！
# 我這裡是使用 CentOS 4.3 並且升級過核心作為範例的！
KERNEL_SOURCE=/lib/modules/2.6.9-34.0.2.EL/build

[root@linux zdsta]# vi src/zdusb.h
# 很奇怪，我的 CentOS 4.3 不支援太長的型號名稱，所以需要做個修改，
# 大約在第 16 行的地方，找到下列的字：
#define PRODUCT_GW-US54MINI    0xAB13
# 將他改成下列的模樣：
#define PRODUCT_US54MINI    0xAB13
# 順便仔細看一下第 15, 16 行，有沒有發現版本與型號最右側，
# 與我們剛剛使用 cat /proc/bus/usb/devices 的內容相同啊！ ^_^

[root@linux zdsta]# vi src/zdusb.c
# 找到 63 行左右的地方，如下所示：
    { USB_DEVICE(VENDOR_PLANEX, PRODUCT_GW-US54MINI )  },
# 將他改成與上述檔案相同的型號資料啊！
    { USB_DEVICE(VENDOR_PLANEX, PRODUCT_US54MINI )  },

[root@linux zdsta]# make
# 編譯完成後會產生 zd1211.ko 的模組檔案喔！
[root@linux zdsta]# make install
# 可以將模組安裝到核心模組放置的地方去了！

[root@linux ~]# modprobe zd1211
[root@linux ~]# lsmod | grep zd1211
zd1211                226768  0
# 是的！有啊！確實有載入啊！

[root@linux ~]# iwconfig
eth1      802.11b/g NIC  ESSID:""
          Mode:Managed  Frequency=2.462GHz  Access Point: 00:00:00:00:00:00
          Bit Rate:1Mb/s
          Retry:off   RTS thr=2432 B   Fragment thr:off
          Encryption key:off
          Power Management:off

[root@linux ~]# vi /etc/modprobe.conf
alias eth1 zd1211
將上面這一行新增到您的 Linux 當中啊！

[root@linux ~]# ifconfig eth1 up

[root@linux ~]# iwlist eth1 scanning
eth1      Scan completed :
          Cell 01 - Address: 00:90:CC:D6:A4:1C
                    ESSID:"BLW-VBIRD"
                    Mode:Master
                    Frequency:2.437GHz (Channel 6)
                    Quality:8/92  Signal level=54/154  Noise level=0/154
                    Encryption key:on
                    Bit Rate:1Mb/s
                    Bit Rate:2Mb/s
                    Bit Rate:5.5Mb/s
                    Bit Rate:11Mb/s
                    Bit Rate:6Mb/s
                    Bit Rate:9Mb/s
                    Bit Rate:12Mb/s
                    Bit Rate:18Mb/s
                    Bit Rate:24Mb/s
                    Bit Rate:36Mb/s
                    Bit Rate:48Mb/s
                    Bit Rate:54Mb/s

[root@linux ~]# iwconfig eth1 essid "BLW-VBIRD"  \
> key "12345678901234567890123456"

[root@linux ~]# iwconfig eth1
eth1      802.11b/g NIC  ESSID:"BLW-VBIRD"
          Mode:Managed  Frequency=2.437GHz  Access Point: 00:90:CC:D6:A4:1C
          Bit Rate:11Mb/s
          Retry:off   RTS thr=2432 B   Fragment thr:off
          Encryption key:****-****-****-****-****-****-**   Security mode:open
          Power Management:off

[root@linux ~]# cd /etc/sysconfig/network-scripts
[root@linux network-scripts]# vi ifcfg-eth1
DEVICE=eth1
BOOTPROTO=dhcp
ONBOOT=no
TYPE=wireless
ESSID=BLW-VBIRD
MODE=Managed
RATE=54M      <== 可以嚴格指定傳輸的速率，要與上面 iwconfig 相同，單位 b/s
KEY=12345678901234567890123456

[root@linux ~]# ifup eth1
# 如果上面的測試都沒有問題的話，那麼建議您繼續底下的動作

[root@linux ~]# iwconfig eth1
eth1      802.11b/g NIC  ESSID:"BLW-VBIRD"
          Mode:Managed  Frequency=2.437GHz  Access Point: 00:90:CC:D6:A4:1C
          Bit Rate:54Mb/s
          Retry:off   RTS thr=2432 B   Fragment thr:off
          Encryption key:****-****-****-****-****-****-**   Security mode:open
          Power Management:off

[root@linux ~]# vi /etc/rc.d/rc.local
# 加入底下這段：
/sbin/ifconfig eth1 up