tftp 使用记录
2010年1月21日 19:41
安装tftp可参考：
https://linuxlink.timesys.com/docs/linux_tftp
简要过程如下：
1. 安装
# apt-get install xinetd tftpd
2. 确保/etc/services中的tftp存在，且没有被注释掉
tftp 69/tcp tftp 69/udp
3. 在/etc/xinetd.d下创建名为tftp的文件，
内容如下：
# default: off
# description: The tftp server serves files using the Trivial File Transfer \
# Protocol. The tftp protocol is often used to boot diskless \
# workstations, download configuration files to network-aware printers, \
# and to start the installation process for some operating systems.
service tftp
{
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/in.tftpd
server_args = -s /tftpboot
disable = yes
}
4. 重启xinetd
# /etc/init.d/xinetd restart
5. 测试tftp服务器
# echo "Hello, embedded world" > /tftpboot/hello.txt"
# tftp localhost tftp> get hello.txt Received 23 bytes in 0.1 seconds tftp> quit
6. 注意事项
如果从tftp服务器下载失败，
要确保服务器的根目录有可执行的权限。
$ chmod -R 777 tftp
使用中发现能正常下载文件，
$ tftp 192.168.1.222
tftp> get zImage
Received 1692890 bytes in 0.2 seconds
可是上传文件不成功，
提示错误：
tftp> put dic.txt
Error code 2: Access violation
求助于google, 得下面一段说明，问题解决。
The tftp man page says:
Because there is no user-login or validation within the TFTP
protocol, the remote site will probably have some sort of
file-access restrictions in place. The exact methods are
specific to each site and therefore dif ficult to document here.
So apparently the site you're trying to get the file from has some
kind of access restrictions in place. Take a look at the tftpd man
page on the remote host. The linux tftpd manual says, in part, "Due to
the lack of authentication information, tftpd will allow only publicly
readable files to be accessed. Files may be written only if they
already exist and are publicly writable."
上面主要意思就是: tftp服务器缺少必要的身份验证，
所以默认只允许下载文件，要上传文件，必须是服务器中已存在同名的文件，
且该文件权限允许被覆盖。
所以首先在服务中创建一个与要上传的文件同名的文件，并更改权限。
$ touch dic.txt
$ chmod 777 dic.txt
重新上传，成功。
tftp> put dic.txt
Sent 13770 bytes in 0.0 seconds