chcon命令：修改对象（文件）的安全上下文。比如：用户：角色：类型：安全级别。主要用在selinux中用来更改安全上下文。
命令格式：
Chcon [OPTIONS…] CONTEXT FILES…..
Chcon [OPTIONS…] –reference=PEF_FILES FILES…
说明：
CONTEXT 为要设置的安全上下文
FILES 对象（文件）
--reference 参照的对象
PEF_FILES 参照文件上下文
FILES 应用参照文件上下文为我的上下文。
OPTIONS 如下：
-f 强迫执行
-R 递归地修改对象的安全上下文
-r ROLE 修改安全上下文角色的配置
-t TYPE 修改安全上下文类型的配置
-u USER 修改安全上下文用户的配置
-v 显示冗长的信息
-l, --range=RANGE 修改安全上下文中的安全级别
范例：
1、ftp
//If you want to share files anonymously <如果你想把这个共享给匿名的话，需要开启以下>
chcon -R -t public_content_t /var/ftp
//If you want to setup a directory where you can upload files
＜如果你想让你设置的FTP目录可以上传文件的话，SELINUX需要设置＞
chcon -t public_content_rw_t /var/ftp/incoming
//You must also turn on the boolean allow_ftpd_anon_write <允许匿名用户写入权限＞
setsebool -P allow_ftpd_anon_write=1
//If you are setting up this machine as a ftpd server and wish to allow users to access their home directorories<如果你希望你的FTP用户可以访问自己的家目录的话，需要开启>
setsebool -P ftp_home_dir 1
//If you want to run ftpd as a daemon<如果你希望将vsftpd以daemon的方式运行的话，需要开启>
setsebool -P ftpd_is_daemon 1
//You can disable SELinux protection for the ftpd daemon<你可以让SElinux停止保护vsftpd的daemon方式动行>
setsebool -P ftpd_disable_trans 1
2、httpd
//If you want a particular domain to write to the public_content_rw_t domain
<如果希望具体个doman具有可写权限的话，需要设置>
setsebool -P allow_httpd_anon_write=1
or
setsebool -P allow_httpd_sys__anon_write=1
//httpd can be setup to allow cgi s to be executed <HTTP被设置允许cgi的设置>
setsebool -P httpd_enable_cgi 1
//If you want to allow access to users home directories<允许用户HHTP访问其家目录，该设定限仅于用户的家目录主页>
setsebool -P httpd_enable_homedirs 1
chcon -R -t httpd_sys_content_t ~user/public_html
//httpd is allowed access to the controling terminal<允许httpd访问终端＞
setsebool -P httpd_tty_comm 1
//such that one httpd service can not interfere with another
setsebool -P httpd_unified 0
//loadable modules run under the same context as httpd
setsebool -P httpd_builtin_ing 0
//httpd s are allowed to connect out to the network
setsebool -P httpd_can_network_connect 1
// You can disable suexec transition
setsebool -P httpd_suexec_disable_trans 1
//You can disable SELinux protection for the httpd daemon by executing <关闭Selinux的关于httpd进程守护的保护>
setsebool -P httpd_disable_trans 1
service httpd restart
3、named
//If you want to have named update the master zone files <关于named,master更新selinux设定>
setsebool -P named_write_master_zones 1
//You can disable SELinux protection for the named daemon by executing
<关闭named的进程守护保护>
setsebool -P named_disable_trans 1
service named restart
4、nfs
//If you want to setup this machine to share nfs partitions read only
<Selinux将本机的NFS共享设置成只读>
setsebool -P nfs_export_all_ro 1
//If you want to share files read/write<Selinux将本机的NFS共享设置成可读可写>
setsebool -P nfs_export_all_rw 1
//If you want to use a remote NFS server for the home directories on this machine
＜如果你想要将远程NFS的家目录共享到本机，需要开启>
setsebool -P use_nfs_home_dirs 1
5、samba
//If you want to share files other than home directorie
<如果你希望将目录共享给其他用户，你需要设置>
chcon -t samba_share_t /directory
//If you want to share files with multiple domains
如果samba服务器共享目录给多个域，则需要：
setsebool -P allow_smbd_anon_write=1
//If you are setting up this machine as a Samba server and wish to share the home directories
samba服务器要共享家目录时：
setsebool -P samba_enable_home_dirs 1
//If you want to use a remote Samba server for the home directories on this machine
如果你需在本机上使用远程samba服务器的家目录
setsebool -P use_samba_home_dirs 1
//You can disable SELinux protection for the samba daemon by executing
关闭selinux关于samba的进程守护的保护
setsebool -P smbd_disable_trans 1
service smb restart
6、rsync
//If you want to share files using the rsync daemon
共享rsync目录时：
chcon -t public_content_t /directories
//If you want to share files with multiple domains
允许其他用户写入时
setsebool -P allow_rsync_anon_write=1
//You can disable SELinux protection for the rsync daemon by executing
停止rsync的进程保护
setsebool -P rsync_disable_trans 1
7、kerberos
//allow your system to work properly in a Kerberos environment
允许系统使用kerberos
setsebool -P allow_kerberos 1
//If you are running Kerberos daemons kadmind or krb5kdc
setsebool -P krb5kdc_disable_trans 1
service krb5kdc restart
setsebool -P kadmind_disable_trans 1
service kadmind restart
8、nis
Allow your system to work properly in a NIS environment
系统工作在nis环境时
setsebool -P allow_ypbind 1