Foreword:
As an operation and maintenance officer, you need knowledge about file systems, networks, file sharing, memory, CPU, and some application services and monitoring. learn. Today is my first time to build FTP (I have used smb, windows sharing, FTP before, and I also built SMB myself, but FTP is First time building it myself) After understanding, Linux's SMB has been broken in history, and there are no related rumors about FTP, but I am not sure that there is no "0day" loopholes. Among network file sharing protocols such as NFS, Samba, and FTP, FTP is currently the most widely used for sharing files. Common FTP products include: vsftp; proftp; wu-ftp, pureftp. There is no difference between them. Choose to practice by yourself Just use the one you are used to. This article chooses vsftp to record some usage habits of ftp file sharing. for reference only. When using it in a production environment, be sure to grant minimum permissions to the ftp user. The configuration of ftp must also be restricted. (- _ ^)
vsftp installation
sudo apt-get install vsftpd
Create ftp user folder and file storage folder
cd /home sudo mkdir bankdata cd bankdata sudo mkdir bankexcel bankresult
Add user account, specify user directory and log in to bash
sudo useradd bankdata-d /home/bankdata/ -s /bin/bash
Set user password
sudo passwd bankdata
Modify ftp configuration file
This configuration mainly restricts users to their own home directory and subdirectories, and is not allowed to visit anywhere else.
# Example config file /etc/vsftpd.conf # # The default compiled in settings are fairly paranoid. This sample file # loosens things up a bit, to make the ftp daemon more usable. # Please see vsftpd.conf.5 for all compiled in defaults. # # READ THIS: This example file is NOT an exhaustive list of vsftpd options. # Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's # capabilities. # # # Run standalone? vsftpd can run either from an inetd or as a standalone # daemon started from an initscript. listen=NO # # This directive enables listening on IPv6 sockets. By default, listening # on the IPv6 "any" address (::) will accept connections from both IPv6 # and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6 # sockets. If you want that (perhaps because you want to listen on specific # addresses) then you must run two copies of vsftpd with two configuration # files. listen_ipv6=YES # # Allow anonymous FTP? (Disabled by default). anonymous_enable=NO # # Uncomment this to allow local users to log in. local_enable=YES # # Uncomment this to enable any form of FTP write command. write_enable=YES # # Default umask for local users is 077. You may wish to change this to 022, # if your users expect that (022 is used by most other ftpd's) local_umask=022 # # Uncomment this to allow the anonymous FTP user to upload files. This only # has an effect if the above global write enable is activated. Also, you will # obviously need to create a directory writable by the FTP user. #anon_upload_enable=YES # # Uncomment this if you want the anonymous FTP user to be able to create # new directories. #anon_mkdir_write_enable=YES # # Activate directory messages - messages given to remote users when they # go into a certain directory. dirmessage_enable=YES # # If enabled, vsftpd will display directory listings with the time # in your local time zone. The default is to display GMT. The # times returned by the MDTM FTP command are also affected by this # option. use_localtime=YES # # Activate logging of uploads/downloads. xferlog_enable=YES # # Make sure PORT transfer connections originate from port 20 (ftp-data). connect_from_port_20=YES # # If you want, you can arrange for uploaded anonymous files to be owned by # a different user. Note! Using "root" for uploaded files is not # recommended! #chown_uploads=YES #chown_username=whoever # # You may override where the log file goes if you like. The default is shown # below. #xferlog_file=/var/log/vsftpd.log # # If you want, you can have your log file in standard ftpd xferlog format. # Note that the default log file location is /var/log/xferlog in this case. #xferlog_std_format=YES # # You may change the default value for timing out an idle session. #idle_session_timeout=600 # # You may change the default value for timing out a data connection. #data_connection_timeout=120 # # It is recommended that you define on your system a unique user which the # ftp server can be used as a totally isolated and unprivileged user. #nopriv_user=ftpsecure # # Enable this and the server will recognize asynchronous ABOR requests. Not # recommended for security (the code is non-trivial). Not enabling it, # however, may confuse older FTP clients. #async_abor_enable=YES # # By default the server will pretend to allow ASCII mode but in fact ignore # the request. Turn on the below options to have the server actually do ASCII # mangling on files when in ASCII mode. # Beware that on some FTP servers, ASCII support allows a denial of service # attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd # predicted this attack and has always been safe, reporting the size of the # raw file. # ASCII mangling is a horrible feature of the protocol. #ascii_upload_enable=YES #ascii_download_enable=YES # # You may fully customize the login banner string: #ftpd_banner=Welcome to blah FTP service. # # You may specify a file of disallowed anonymous e-mail addresses. Apparently # useful for combatting certain DoS attacks. #deny_email_enable=YES # (default follows) #banned_email_file=/etc/vsftpd.banned_emails # # You may restrict local users to their home directories. See the FAQ for # the possible risks in this before using chroot_local_user or # chroot_list_enable below. chroot_local_user=YES # # You may specify an explicit list of local users to chroot() to their home # directory. If chroot_local_user is YES, then this list becomes a list of # users to NOT chroot(). # (Warning! chroot'ing can be very dangerous. If using chroot, make sure that # the user does not have write access to the top level directory within the #chroot) #chroot_local_user=YES #chroot_list_enable=YES # (default follows) #chroot_list_file=/etc/vsftpd.chroot_list # # You may activate the "-R" option to the builtin ls. This is disabled by # default to avoid remote users being able to cause excessive I/O on large # sites. However, some broken FTP clients such as "ncftp" and "mirror" assume # the presence of the "-R" option, so there is a strong case for enabling it. #ls_recurse_enable=YES # #Customization # # Some of vsftpd's settings don't fit the filesystem layout by #default. # # This option should be the name of a directory which is empty. Also, the # directory should not be writable by the ftp user. This directory is used # as a secure chroot() jail at times vsftpd does not require filesystem # access. secure_chroot_dir=/var/run/vsftpd/empty # # This string is the name of the PAM service vsftpd will use. pam_service_name=vsftpd # # This option specifies the location of the RSA certificate to use for SSL # encrypted connections. rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key ssl_enable=NO # # Uncomment this to indicate that vsftpd use a utf8 filesystem. #utf8_filesystem=YES
Restart, start and stop services
sudo service vsftpd restart sudo systemctl start vsftpd sudo systemctl stop vsftpd
Notes
Common errors: "227 Entering Passive Mode" appears during FTP connection There are some differences between the active and passive modes of the client, and data transmission may fail due to some firewall policies. You need to pay attention to selecting the client's "active" or "passive" mode
Common commands
After the client successfully connects to the server, directly enter "help" as follows: ftp:/> help ascii set ascii transfer type bin set binary transfer type binary set binary transfer type cd change remote working directory cdup change remote working directory to parent directory delete delete remote file dir list contents of remote directory exit terminate ftp session and exit get receive file help print local help information lcd change local working directory ldir list contents of local directory lls list contents of local directory lpwd print working directory on local machine ls list contents of remote directory mget get multiple files mkdir make directory on the remote machine mput put multiple files mv rename file passive toggle passive transfer mode put send one file quit terminate ftp session and exit quote send arbitrary ftp command rename rename file rm delete remote file rmdir remove directory on the remote machine user send new user information ftp:/>