.:. PURE-FTPD .:. ------------------------ BLURB ------------------------ Pure-FTPd is a fast, production-quality, standard-conformant FTP server, based upon Troll-FTPd. Unlike other popular FTP servers, it's designed to be secure in default configuration, has no known buffer overflow, it is really trivial to set up and it is especially designed for modern kernels. It was successfully ported to Linux, FreeBSD, NetBSD, OpenBSD, Solaris, Darwin, Tru64, Irix and AtheOS. Features include chroot()ed and/or virtual chroot()ed home directories, virtual domains, built-in 'ls', anti-warez system, bounded ports for passive downloads, FXP protocol, bandwidth throttling, ratios, LDAP / MySQL / PostgreSQL-based authentication, fortune files, Apache-like log files, fast standalone mode, text / HTML / XML real-time status report, virtual users, virtual quotas and more. ------------------------ WHO'S USING IT? ------------------------ Many people new to Unix are running Pure-FTPd because they find it easy to install. But that software is also used on highly loaded production servers, especially for hosting services. Cable & Wireless NL switched from BSD FTPd (more than 3000 domains per machine), Cable & Wireless France is also using Pure-FTPd, and many hosting services are running it successfully on all their colocated servers. The Spanish National Research Network successfully switched their public FTP server to Pure-FTPd, running on a Solaris box. Lightning Instrumentation sells secure hardware routers for internetwork connectivity. Their routers include Pure-FTPd in the firmware. Pure-FTPd was also part of a crack-a-machine challenge with other software, and that machine never got compromised. For large sites with centralized user management, Pure-FTPd provides LDAP and flexible SQL support. ------------------------ COMPILATION ------------------------ In its current form, Pure-FTPd uses some OS-specific system calls. And altough some portability work has been done in order to ease its port to other operating systems, only Linux FreeBSD, NetBSD, OpenBSD, Darwin, Solaris, Tru64, Irix and AtheOS are known to work, other operating systems may need some tweaks. With Linux, any modern distribution should be ok. An unofficial Windows port is available from http://www.pureftpd.org/windows/ If you have Dialog or Xdialog installed on your system, try the following command to build and install Pure-FTPd : make -f Makefile.gui If you don't have Dialog or if you prefer the conventional way, here it is : ./configure make install-strip Et voila! The software is now installed in /usr/local/sbin/pure-ftpd To launch the server, just type the following command : /usr/local/sbin/pure-ftpd & If you installed a binary package (RPM, SLP, Debian), maybe use the following command instead : /usr/sbin/pure-ftpd & Your server is ready. Just type 'ftp localhost' to test it. If you want to automatically run the server when the system boots, add the previous command to /etc/rc.d/rc.local or /etc/rc.d/boot.local . Don't forget the '&' sign. Note 1: On Linux systems, you will notice that the server is always running as root. This is intentional, and more secure that servers who are changing their effective uid (and only effective uid, they still have root privileges in fact, use ps -U to see what servers are really running as root) . We are using Linux kernel-specific tricks to drop privileges that "ps" can't show. Nota 2: To compile under Irix, you have to issue this before typing ./configure : export CC=cc export CFLAGS=-I/usr/freeware/include export LDFLAGS=-L/usr/freeware/lib32 To compile under Solaris 8, use GNU Make, not Solaris basic make. Then do : export PATH=/usr/ccs/bin:$PATH export MAKE=gmake Nota 3: To deinstall Pure-FTPd (no, do you really want to do this?), use : ./configure make uninstall ------------------------ ADVANCED COMPILATION ------------------------ The "./configure" script accepts some arguments you might want to add before the compilation : --without-standalone : the FTP server can normally run in standalone-mode (without any super-server) . If you don't need that feature and if you want to save few code bytes, add this option. A super-server like g2s, xinetd or tcpserver will be mandatory to run the service. The standalone mode is the recommended mode of operation. --without-inetd : if you will always be running Pure-FTPd in standalone-mode, enabling this flag can save a few code bytes. Don't enable --without-inetd and --without-standalone, because it's impossible to run a server without one of them. These options aren't enabled on binary distributions of Pure-FTPd, so that both inetd-like and standalone mode are supported. --without-iplogging : don't log any IP address to protect confidentiality, especially for political servers. --without-capabilities : if the capabilities library (libcap) is found, PureFTPd will try to use it in order to enhance security. This option overrides the test to ignore the library. Try this if capabilities don't work properly on your system. libcap can be downloaded from ftp://ftp.kernel.org/pub/linux/libs/security/linux-privs/ . --without-shadow : ignore the shadow passwords, even though they are auto-detected. Usually a bad idea, unless you use PAM, LDAP or SQL. Pure-FTPd support expiration dates of shadow passwords (both for accounts and passwords) . --without-usernames : never outputs user and group names in directory listings, only UIDs and GIDs. It improves security and performances, but some people find this not user-friendly. --without-humor : if you find what this option does without peeking at the source code, you're a lucky guy! --without-longoptions : remove support for long options. By default, GNU-style options can be used and mixed with short command-line options. For instance, you can use '--maxclientsperip=12' instead of '-C 12' . Longer, but clearer. If you compile the server with '--without-longoptions', long options won't be available any more. '-C 12' will work, but not the '--maxclientsperip=12' alias. But it will save 1.2 Kb of executable code. --without-ascii : does not support 7-bits transfers (ASCII) . If you have customers using Windows clients to send scripts and HTML files, don't use this option or they will yell at you. --without-banner : don't display the initial banner. This is stupid security through obscurity. --without-globbing : don't include the globbing code. It reduces the memory footprint but regular expressions won't work any more (things like 'ls *.rpm') . Most people shouldn't use --without-globbing. Globbing is a nice feature. --without-nonalnum : paranoid file name checking : only allow basic alphanumeric characters. Never enable this switch blindly, or your customers will complain. --without-sendfile : on Linux and FreeBSD kernels, Pure-FTPd tries to reduce the CPU/memory usage by using a special system call (sendfile) . It works very well with most filesystems. However, this optimization is not implemented for all filesystems in current kernels. Users reported that downloading files with Pure-FTPd failed with SMBFS (Samba) on FreeBSD 4.3, and TmpFS on Linux (the error reported by the server is "broken pipe" or "Error during write to data connection") . If you are planning to serve files from these filesystems, you have to use the --without-sendfile switch to enable a workaround. --with-paranoidmsg : favor paranoid messages over sysadmin-friendly messages. When this option is enabled, login failures will show the same message to the user, regardless of the source of the problem. Without this option, "Authentication failure" is displayed when this is a password problem, and "Sorry, I can't trust you" is displayed when the user has been banned by the sysadmin. --with-sysquotas : support system quotas (not PureFTPd's virtual quotas) . Only enable this if you really plan to use system quotas. --with-brokenrealpath : some Solaris versions have a broken realpath() implementation. If altlog and/or pure-uploadscript doesn't seem to work properly on your system, try to recompile with this switch. --with-minimal : to efficiently use features of modern FTP clients, Pure-FTPd implements the basics of the FTP protocol, with many extensions (SITE IDLE, SITE CHMOD, MLSD, ...) . Using the --with-minimal directive, these extensions won't be compiled in. Also, there will be no standalone server, no lookup for user/group names, no humor, no ASCII support and no alternative long options. But the executable file size will be smaller than in a default installation. You need at least GCC 3.0 to compile with this option. Regular expressions are compiled in. If you still want to reduce the size, use --without-globbing in conjunction with --with-minimal. If you are building an embedded system, use this. In all other cases, to avoid complaints from customers (especially with Windoz clients), forget this. --with-pam : use pluggable authentification modules. Don't use this option if your login/passwd pairs are always refused (but the real fix would be to fix your PAM configuration). You need to create a /etc/pam.d/pure-ftpd file to properly use the PAM authentication. The 'pam' directory contains an example of such a file. --with-puredb : support virtual users, ie. a local users database, independent of your system accounts. Please read the README.Virtual-Users file for more info about virtual users. --with-ldap : use the native LDAP directory support. When this option is enabled, system accounts are bypassed. You need OpenLDAP to use that feature. If OpenLDAP is installed in a custom location, you can use the --with-ldap=<directory> syntax. See the README.LDAP file for more info about LDAP and Pure-FTPd. *** DON'T ENABLE LDAP SUPPORT IF YOU DON'T KNOW WHAT YOU ARE DOING *** --with-mysql : use the native MySQL support for users database. When this option is enabled, system accounts are bypassed. MySQL client libraries should be installed to use that feature. If MySQL is installed in a custom location, you can use the --with-mysql=<directory> syntax. See the README.MySQL file for more info about MySQL and Pure-FTPd. *** DON'T ENABLE MySQL SUPPORT IF YOU DON'T KNOW WHAT YOU ARE DOING *** --with-pgsql : use the native Postgres support for users database. When this option is enabled, system accounts are bypassed. Postgres client libraries should be installed to use that feature. If Postgres is installed in a custom location, you can use the --with-pgsql=<directory> syntax. See the README.PGSQL file for more info about Postgres and Pure-FTPd. *** DON'T ENABLE POSTGRES SUPPORT IF YOU DON'T KNOW WHAT YOU ARE DOING *** --with-altlog : in addition to the syslog output, support logging into a specific file, in an alternative format. Currently, the CLF, Stats and W3C formats are implemented. CLF (common log format) is the basic format produced by Apache, WebFS, Roxen and most web servers. These log files only record file transfers, and they can feed web statistic software (Analog, Webalizer, etc.) to analyze the load of your FTP server. The Stats format is a special output format, designed for log file analys software, especially ftpStats (http://www.shagged.org/ftpstats/) . The W3C format is a standard format parsed by most commercial log analyzers (all analyzers with support for IIS should deal with it) . Check the -O option later in this documentation for additional info. --with-cookie : display a fortune or a customized banner when an user logs in (see the '-F' option) . --with-throttling : support bandwidth throttling (see below). --with-ratios : support upload/download ratios, to please w4r3z fr34k2. --with-ftpwho : support for the 'pure-ftpwho' command. Enabling this feature needs some extra memory. Better use it when the server is run in standalone mode. It can be way slower in inetd mode. --with-welcomemsg : read 'welcome.msg' files for compatibility with some other FTP servers. This is a security flaw (anonymous users may upload 'welcome.msg' files to add random banners) . Pure-ftpd uses '.banner' files by default. --with-uploadscript : since 0.98, Pure-FTPd has a nice feature regarding uploads. Any external program or script can be automatically called after a successful upload. It needs another program installed by the Pure-FTPd package, called 'pure-uploadscript'. Check the man page for more info about this. --with-largefile : support downloading of files larger than 2 gigabytes on 32-bit architectures. Transfering so huge files through FTP is a strange idea. And your filesystem has to support it. Your kernel and your libc as well. And of course, the FTP client has to be safe against large files, too. And when this feature is enabled, downloads can be a bit slower (or more cpu-intensive) than without it, due to a limitation of actual Linux kernels. To summarize : don't enable this for fun, just if you are really planning to download files over 2 gigabytes. --with-virtualhosts : support virtual hosting. It means that you can have different anonymouns FTP areas for each IP address. If your server has only one IP address, you don't need that feature. But if you have multiple IP addresses, and if you want a client that connects to IP xxx to get the content of /etc/pure-ftpd/xxx/ instead of ~ftp/ , enable this option. And read the the "VIRTUAL SERVERS" section at the end of this file. --with-virtualchroot : usually, when an user is chrooted (-A and -a options), it's impossible to go out of his home directory. Enabling that feature makes it possible : symbolic links are always followed, even if they are pointing to directories not located in the user's home directory. This is very useful for having shared directories (for instance, have a symbolic link to /var/incoming in every home directory) . This feature isn't enabled by default. YOU MUST ENABLE IT ON ATHEOS, BECAUSE ATHEOS KERNEL CHROOT IS INSECURE. --with-diraliases : support directory aliases ("shortcuts" for the "cd" command) . Please read the appropriate section about this (further in this manual) . --with-nonroot : set up a server that doesn't need root privileges to be started. Any regular user can run the server (a la FTP4ALL) . It can be useful if you have a limited shell access to a non-dedicated hosting server. But passwords won't be checked and some features will be disabled. When virtual chroot is enabled, people will be restricted to the directory the server was started in. This is an insecure mode, designed for setting up very temporary servers by regular (non-root) users. Port 2121 will be listened by default in standalone mode. --with-quotas : enable virtual quotas. With virtual quotas, you can restrict the maximal number of files an user can store in his account. You can also of course restrict the total size. See the "quotas" section later in this document. --with-extauth : compiles support for external authentication modules. Please read README.Authentication-Modules and the pure-authd(8) man page before enabling this feature. Most users don't need it. --with-everything : build a big server with almost all features turned on : altlog, cookies, throttling, ratios, ftpwho, upload script, virtual users (puredb), quotas, virtual hosts, directory aliases and external authentication. --with-language=english --with-language=german --with-language=romanian --with-language=french --with-language=polish --with-language=spanish --with-language=danish --with-language=italian --with-language=brazilian-portuguese --with-language=slovak --with-language=dutch --with-language=korean --with-language=swedish : change the language of server messages. Default is english. If you want to contribute a translation, please translate the 'src/messages_en.h' file and send it to <j@pureftpd.org> . Other traditional autoconf options are of course recognised, like "--prefix=" to change the installation prefix, that defaults to "/usr/local/". FYI, the binary RPM packages of Pure-FTPd are configured with the following command line : ./configure --with-everything --with-paranoidmsg --without-capabilities \ --with-virtualchroot RPM packages are also compiled with --without-pam to enhance their portability. ------------------------ STANDALONE INSTALLATION ------------------------ Unless you compiled the server with "--without-standalone", running the server is as easy as typing : /usr/local/sbin/pure-ftpd & In the following examples, we will assume that the 'pure-ftpd' file is located in /usr/local/sbin. This is the default if you compiled the server from the source code tarball. But as I said earlier in this document, if you installed a binary package (RPM, SLP, DEB, TGZ), the server maybe installed in /usr/sbin/. So just replace '/usr/local/sbin/pure-ftpd' with '/usr/sbin/pure-ftpd'. When the previous command is run, the server will listen for incoming connections on every interface, all IP addresses, and the standard FTP port (21) . If your system has IPv6 addresses, they should work as well. Now, if you want to listen for an incoming connection on a non-standard port, just append '-S' and the port number : /usr/local/sbin/pure-ftpd -S 42 Service names are also allowed ('-S smtp' and the daemon will be accepting connections on the SMTP port (25) . Very uncommon, but we should please everybody anyway, even disturbed minds) . Now, what if your system has many IP addresses, and you want the FTP server to be reachable on only one of these addresses, let's say 192.168.0.42? Just use the following command line : /usr/local/sbin/pure-ftpd -S 192.168.0.42, The final coma is important, don't forget it. Actually, it's a shorthand for : /usr/local/sbin/pure-ftpd -S 192.168.0.42,21 If you prefer host names over IP addresses, it's your choice : /usr/local/sbin/pure-ftpd -S ftp.rtchat.com,21 IPv6 addresses are of course supported. With previous command lines, the server will run in the default configuration. Anonymous FTP logins will be allowed if there's a system account called 'ftp', and every user of your system will be able to access the FTP server using his regular login/password pair. If you need to tweak that default configuration, other command-lines options can be added. For instance : /usr/local/sbin/pure-ftpd -c 50 & or /usr/local/sbin/pure-ftpd -S ftp.rtchat.com,21 -c 50 & And only 50 simultanous connections will be allowed. To discover what options are available please jump to the 'OPTIONS' chapter below. If the server runs perfectly for you in standalone mode, you don't need to read the following chapter about super-servers. But read the options. '-m', and '-C' are recommended. '-D' is also a good choice if you (or your customers) use broken clients. Please read on. When you run 'ps auxw|grep pure-ftpd', the result looks like this : root 15211 0.1 0.3 1276 452 ? S 13:53 0:00 pure-ftpd [SERVER] root 15212 0.1 0.5 1340 672 ? S 13:54 0:00 pure-ftpd [IDLE] root 15214 0.0 0.5 1340 672 ? S 13:56 0:00 pure-ftpd [DOWNLOADING] [SERVER] is the main server. If you kill this process, the server will exit after the next connection. [IDLE] shows a client with no transfer activity. [DOWNLOADING] shows a client downloading a file. [UPLOADING] show a client uploading a file. For easy scripting, the file '/var/run/pure-ftpd.pid' is created, and it always contains the PID of the main server process. ------------------------ SUPER-SERVER INSTALLATION ------------------------ Pure-FTPd can also run with the help of a super-server, like telnet, wu-ftp, finger or Qmail. Using a super-server is usually slower than the standalone mode. But if you love tcpwrappers or built-in filtering abilities of your super-server, Pure-FTPd can cope with them. Unix has tons of super-servers : Inetd (the most common one), TCPserver, G2S, Xinetd, Rlinetd, ... Only the first three will be covered here, but integration with other super-servers should be painless. **** Usage with Inetd **** Important: if security matters for you, forget inetd. In the default configuration, inetd will stop a service after a high rate of connections to the same port. This creates an easy denial-of-service. Also, inetd doesn't have any concurrency limit. Bad guys can fill up your memory and your descriptor tables even if you are restricting the number of connections in pure-ftpd. Better use a modern replacement for inetd, or run pure-ftpd in standalone mode. 1) Check that inetd is up : ps auxw | grep inetd root 3699 0.0 0.3 1072 492 ? S 15:47 0:00 inetd 2) Edit /etc/inetd.conf and look for a line like : ftp stream tcp nowait root /usr/sbin/tcpd in.ftpd The line may also end with "proftpd" or "wuftpd", but it should start with "ftp stream tcp". 3) Replace that line with the following one : ftp stream tcp nowait root /usr/sbin/tcpd /usr/local/sbin/pure-ftpd If /usr/sbin/tcpd is missing on your system, try the following line instead : ftp stream tcp nowait root /usr/local/sbin/pure-ftpd pure-ftpd 4) Restart the inetd daemon : killall -HUP inetd If 'killall' is missing on your system, try this : kill -HUP $(cat /var/run/inetd.pid) **** Usage with Xinetd **** Add the following entry to the /etc/xinetd.conf file : service ftp { socket_type = stream server = /usr/local/sbin/pure-ftpd protocol = tcp user = root wait = no disable = no } On Redhat systems, you can also put this in a /etc/xinetd.d/pure-ftpd file. Then, restart the server : killall -USR2 xinetd **** Usage with TCPserver **** TCPServer is part of the ucspi-tcp package by Dan Bernstein. It's less bloated than inetd, less D.O.S.-prone, and has interesting filtering abilities. The simplest way of running Pure-FTPd with TCPserver is the following command : tcpserver -DHRl0 0 21 /usr/local/bin/pure-ftpd & You can add that line to your system local startup scripts (usually /etc/rc.d/boot.local or /etc/rc.d/rc.local) . If it doesn't work, replace 'tcpserver' with its full path (eg. '/usr/local/bin/tcpserver') . **** Usage with G2S **** Add the following lines to your /etc/jnetd.cf file (or whatever configuration file you choose for G2S) : { SERVICE ftp DESCRIPTION "Pure-FTPd" RUN /usr/local/sbin/pure-ftpd } Restart the 'jnetd' daemon and you're done. ------------------------ OPTIONS ------------------------ The previous steps should be enough to get a running FTP server. But you can add some command-line arguments to change its behavior. These arguments have to be added after the pure-ftpd path in your super-server configuration. For instance, you want to add the '-s' and '-a 42' flags. Here are what the configuration lines will look like in your super-server : - Inetd : ftp stream tcp nowait root /usr/sbin/tcpd /usr/local/sbin/pure-ftpd -s -a42 or ftp stream tcp nowait root /usr/local/sbin/pure-ftpd pure-ftpd -s -a42 If you use Inetd, don't put space between options and arguments. e.g. use -a42 instead of -a 42 . Inetd has trouble dealing with a lot of options, and with characters like ':' . - Xinetd : service ftp { socket_type = stream server = /usr/local/sbin/pure-ftpd server_args = -s -a 42 protocol = tcp user = root wait = no disable = no } - TCPserver : tcpserver -DHRl0 0 21 /usr/local/bin/pure-ftpd -s -a 42 & - G2S : { SERVICE ftp DESCRIPTION "Pure-FTPd" RUN /usr/local/sbin/pure-ftpd -s -a 42 } Users need a shell listed in /etc/shells to get restricted or unrestricted FTP access. Alternatively, you can give them "ftp" as a shell. Users with a "ftp" shell will be able to login through FTP only : no telnet, no SSH. And there's no need (and you shouldn't do so) for an "ftp" entry in /etc/shells. Here are the recognised switches : - '-1' : log the PID of each session in syslog output. - '-4' : only listen to IPv4 connections. YOU HAVE TO ENABLE THIS ON OPENBSD, NETBSD AND ATHEOS IF YOUR NETWORK IS NOT 100% IPV6! - '-a <gid>' : Authenticated users will be granted access to their home directory and nothing else (chroot) . This is especially useful for users without shell access, for instance, WWW-hosting services shared by several customers. Only member of group number <gid> will have unrestricted access to the whole filesystem. So add a "staff", "admin" or "ftpadmin" group and put your trusted users in. <gid> is a NUMERIC group number, not a group name. Note : 'root' always has full filesystem access. If you want to chroot() everyone, but root, use the following flag : - '-A' : chroot() everyone, but root. - '-b' : Ignore parts of RFC standards in order to deal with some totally broken FTP clients, or broken firewalls/NAT boxes. - '-B' : Have the standalone server start in background (daemonization). - '-c <number of clients>' : Allow a maximum of clients to be connected. For instance '-c 42' will limit access to simultaneous 42 clients. Their is a 50 client limit by default. - '-C <max connection per ip>' : Limit the number of simultanous connections coming from the same IP address. This is yet another very effective way to prevent stupid denial of services and bandwidth starvation by a single user. It works only when the server is launched in standalone mode (if you use a super-server, it is supposed to do that) . If the server is launched with '-C 2', it doesn't mean that the total number of connections is limited to 2. But the same client, coming from the same machine (or at least the same IP), can't have more than two simultaneous connections. This feature needs some memory to track IP addresses, but it's recommended to use it. - '-d' : Send various debugging messages to the syslog. Don't use this unless you really want to debug Pure-FTPd. Passwords aren't logged. Duplicate '-d' to log responses, too. - '-D' : List files beginning with a dot ('.') even when the client doesn't append the '-a' option to the list command. A workaround for badly configured FTP clients. If you are a purist, don't enable this. If you provide hosting services and if you have lousy customers, enable this. - '-e' : Only allow anonymous users. Use this on a public FTP site with no remote FTP access to real accounts. - '-E' : Only allow authenticated users. Anonymous logins are prohibited. - '-f <facility>' : Use that facility for syslog logging. It defaults to 'ftp' (or 'local2' if you got an obsolete libc without that facility). Logging can be disabled with '-f none' . - '-F <fortune file>' : Display a fortune cookie on login. The sentence is a random extract from the text file <fortune file>. This text file should be formatted like standard "fortune" files (fortunes are separated by a '%' sign on a single line) . Pure-FTPd has to be compiled with support for cookies (--with-cookie). If you just want a simple banner displayed before the login prompt, add the name of any text file here. - '-g <pid file>' : Change the location of the pid file when the server is run in standalone mode. The default is /var/run/pure-ftpd.pid . - '-H' : By default, fully-qualified host names are logged. To achieve this, DNS lookups are mandatory. The '-H' flag avoids host names resolution. ("213.41.14.252" will be logged instead of "www.toolinux.com") . It can significantly speed up connections and reduce bandwidth usage on busy servers. Use it especially on public FTP sites. Also, please note that without -H, host names are informative but shouldn't be trusted : no reverse mapping check is done to save DNS queries. - '-i' : Disallow upload for anonymous users, whatever directory permissions are. This option is especially useful for virtual hosting, to avoid your users creating warez sites in their account. - '-I <timeout>' : Change the maximum idle time. The timeout is in minutes and defaults to 15 minutes. Modern FTP clients are trying to fool timeouts by sending fake commands at regular interval. We disconnect these clients when they are idle for twice (because they are active anyway) the normal timeout. - '-j' : If the home directory of a user doesn't exist, automatically create it. The newly created home directory belongs to the user, and permissions are set according to the current directory mask. To avoid local attacks, the parent directory should never belong to an untrusted user. - '-K' : Allow users to resume and upload files, but *NOT* to delete or rename them. Directories can be removed, but only if they are empty. However, overwriting existing files is still allowed (to support upload resume) . If you want to disable this too, add -r (--autorename) . - '-k <percentage>' : Don't allow uploads if the partition is more than <percentage>% full. For instance, "-k 95%" will ensure your disks will never get filled more than 95% by FTP. - '-l <authentication>' or '-l <authentication>:<config file>' : Adds a new rule to the authentication chain. Please read the "Authentication" section, later in this README file. It's an important section. - '-L <max files>:<max depth>' : To avoid stupid denial-of-service attacks (or just CPU hogs), Pure-FTPd never displays more than 2000 files in response to an 'ls' command. Also, a recursive 'ls' (-R) never goes further than 5 subdirectories. You can increase/decrease those limits with the '-L' option. - '-M' : Allow anonymous users to create directories. - '-m <cpu load>' : Don't allow anonymous download if the load is above <cpu load> . A very efficient way to prevent overloading your server. Upload is still allowed, though. - '-N' : NAT mode. Force ACTIVE mode. If your FTP server is behind a NAT box that doesn't support applicative FTP proxying, or if you use port redirection without a transparent FTP proxy, use this. Well... the previous sentence isn't very clear. Okay : if your network looks like this : (FTP server)-------(NAT/masquerading gateway/router)------(Internet) and if you want people coming from the internet to have access to your FTP server, please try without this option first. If Netscape clients can connect without any problem, your NAT gateway rulez. If Netscape doesn't display directory listings, your NAT gateway sucks. Use '-N' as a workaround. - '-n <max files>:<max size>' : If the server has been compiled with support for virtual quotas, enforce these quota settings for all users (except members of the 'trusted' group) . <max size> is in Megabytes. See the "virtual quotas" section later in this document. - '-o' : Write all uploaded files to '/var/run/pure-ftpd.upload.pipe' so that the 'pure-uploadscript' program can run. Don't enable that option if you don't use 'pure-uploadscript'. There will be no sensitive performance bottleneck it will crunch two extra file descriptors per client. - '-O <format>:<log file>' : Record all file transfers into a specific log file, in an alternative format. Currently, three formats are supported : CLF (Apache-like), Stats and W3C. If you add '-O clf:/var/log/pureftpd.log' to your starting options, Pure-FTPd will log transfers in /var/log/pureftpd.log in a format similar to the Apache web server in default configuration. If you use '-O stats:/var/log/pureftpd.log' to your starting options, Pure-FTPd will create log files in a special format, designed for ftpStats (http://www.shagged.org/ftpstats/) . ftpStats creates nifty HTML reports of your FTP traffic, using MySQL and PHP. The Stats format is compact, more efficient and more accurate that CLF and the old broken "xferlog" format. The Stats format is : <date> <session id> <user> <ip> <U or D> <size> <duration> <file> <date> is a GMT timestamp (time()), and <session id> identifies the current session. <file> is unquoted, but it's always the last element of a log line. "U" means "Upload", and "D" means "Download". Warning: the session id is only designed for statistics purposes. While it's always an unique string in the real world, it's theoretically possible to have it non unique in very rare conditions. So don't rely on it for critical missions. A command called "pure-statsdecode" can be used to convert timestamps into human-readable dates. The W3C format is enabled with '-O w3c:/var/log/pureftpd.log' . For security purposes, the path must be absolute (eg. /var/log/pureftpd.log , not ../log/pureftpd.log) . If this log file is stored on a NFS volume, you must use at least version 3 of the NFS protocol. NFS 1 and 2 are unreliable with shared files (no locking) . - '-p <first port>:<last port>' : Use only ports in the range <first port> to <last port> inclusive for passive-mode downloads. This is especially useful if the server is behind a firewall without FTP connection tracking. Use high ports (40000-50000 for instance), where no regular server should be listening. - '-P <ip address>' : Force the specified IP address in reply to a PASV/EPSV/SPSV command. If the server is behind a masquerading (NAT) box that doesn't properly handle stateful FTP masquerading, put the ip address of that box here. - '-q <upload ratio>:<download ratio>' : Enable ratios for anonymous users. - '-Q <upload ratio>:<download ratio>' : Enable ratios for everybody (anonymous and non-anonymous). Members of the root (0, something called 'wheel') have no ratio. - '-r' : Never overwrite existing files. Uploading a file whoose name already exists cause an automatic rename. Files are called xyz, xyz.1, xyz.2, xyz.3, etc. Tip: if you compile with 'make AUTORENAME_REVERSE_ORDER=1' , the naming convention will be reversed. Files will be called xyz, 1.xyz, 2.xyz, 3.xyz, etc. - '-R' : Disallow users (even non-anonymous ones) usage of the CHMOD command. On hosting services, it may prevent newbies from making mistakes, like setting bad permissions on their home directory. Only root can use CHMOD when -R is enabled. - '-s' : The "waReZ protection". Don't allow anonymous users to download files owned by "ftp" (generally, files uploaded by other anonymous users) . So that uploads have to be validated by a system administrator (chown to another user) before being available for download. - '-S [<ip address>,|<hostname>,] [<port>|<service name>]'. This option is only effective when the server is launched as a standalone server. Connections are accepted on the specified IP and port. IPv4 and IPv6 are supported. Numeric and fully-qualified host names are accepted. A service name (see /etc/services) can be used instead of a numeric port number. - '-T <bandwidth>' and '-t <bandwidth>' : Enable bandwidth limitation (see below) . <bandwidth> is specified in kilobytes/seconds. To set up separate upload/download bandwidth, the [<upload>]:[<download>] syntax is supported. - '-u <uid>' : Don't allow uids below <uid> to log in. '-u 1' denies access to root (safe), '-u 100' denies access to virtual accounts on most Linux distros. - '-U <umask for files>:<umask for dirs>' : Change the file creation mask. The default is 133:022. If you want a new file uploaded by a user to only be readable by that user, use '-U 177:077'. If you want uploaded files to be executable, use 022:022 (files will be readable -but not writable- by other users) or 077:077 (files will only be executable and readable by their owner) . Please note that Pure-FTPd support the SITE CHMOD extension, so a user can change the permissions of his own files. - '-V <ip address>' : Allow non-anonymous FTP access only on this specific local IP address. All other IP addresses are only anonymous. With that option, you can have routed IPs for public access, and a local IP (like 10.x.x.x) for administration. You can also have a routable trusted IP protected by firewall rules, and only that IP can be used to login as a non-anonymous user. - '-W' : Support the FXP protocol. FXP allows transfers between two remote servers without any file data going to the client asking for the transfer. - '-w' : Support the FXP protocol only for authenticated users. FXP works with IPv4 and IPv6 addresses. However : **************************************************************************** *FXP IS AN INSECURE PROTOCOL* (third-party hosts can steal the current connection) . In Pure-FTPd, specific precautions have been taken to reduce FXP insertion attacks. But if your FTP server serves private data : NEVER ALLOW FXP ACCESS TO UNTRUSTED HOSTS. YOU CAN PLAY WITH IT ON AN INTERNAL SERVER, BUT _DON'T_ GIVE FXP ACCESS TO ANONYMOUS INTERNET USERS. **************************************************************************** It's why FXP is disabled by default on Pure-FTPd unless you explicitely enable it with '-W' or '-w'. - '-x' : In normal operation mode, authenticated users can read/write files beginning with a dot ('.') . Anonymous users can't, for security reasons (like changing banners or a forgotten .rhosts) . When '-x' is used, authenticated users can download dot-files, but not overwrite/create them, even if they own them. That way, you can prevent hosted users from messing .qmail files. If you want to give user access to a special dot-file, create a symbolic link to the dot-file with a file name that has no dot in it, and the client will be able to retrieve the file through that link. - '-X' : This flag is identical to the previous one (writing dot-files is prohibited), but in addition, users can't even *read* files and directories beginning with a dot (like "cd .ssh") . **************************************************************************** When used in conjunction with "-a", members of the trusted group can bypass '-x'/'-X' restrictions. **************************************************************************** - '-z' : Allow anonymous users to read files and directories starting with a dot ('.') . If you prefer long options (GNU-style) over standard ones, the following aliases are available. You can get this list at any time by typing 'pure-ftpd --help' . -4 --ipv4only -A --chrooteveryone -a --trustedgid <gid> -b --brokenclientscompatibility -c --maxclientsnumber <number> -B --daemonize -C --maxclientsperip <number> -d --verboselog -D --displaydotfiles -e --anonymousonly -E --noanonymous -f --syslogfacility <facility> -F --fortunesfile <file> -g --pidfile <path to pid file> -h --help -H --dontresolve -I --maxidletime <time (min)> -i --anonymouscantupload -j --createhomedir -K --keepallfiles -k --maxdiskusagepct <percentage> -l --login <auth> or <auth>:<config file> -L --limitrecursion <number:number> -M --anonymouscancreatedirs -m --maxload <load> -N --natmode -o --uploadscript -O --altlog <format>:<log file> -p --passiveportrange <minport:maxport> -P --forcepassiveip <ip address> -q --anonymousratio <upload ratio>:<download ratio> -Q --userratio <upload ratio>:<download ratio> -r --autorename -R --nochmod -s --antiwarez -S --bind <ip address,port> -t --anonymousbandwidth <bandwidth (Kb/s)> -T --userbandwidth <bandwidth (Kb/s)> or [<up bw>]:[<down bw>] -U --umask <mask> -u --minuid <uid> -V --trustedip <ip address> -w --allowuserfxp -W --allowanonymousfxp -x --prohibitdotfileswrite -X --prohibitdotfilesread -z --allowdotfiles ------------------------ SETTING UP AN ANONYMOUS FTP ------------------------ If a 'ftp' user exists, and its home directory is reachable, Pure-FTPd will accept anonymous login, as 'ftp' or 'anonymous'. Files have to be located in the home FTP directory. There's no need for 'bin', 'lib', 'etc' and 'dev' directories, nor any external program. Don't chown the public files to 'ftp', just writable directories ('incoming') . ------------------------ DISPLAYING BANNERS ------------------------ If a '.banner' file is located in the 'ftp' user home directory (or in the root directory of a virtual server, see below), it will be printed when the client logs in. Put a nice ASCII-art logo with your name in that file. This file shouldn't be larger than 4000 bytes, or it won't be displayed. In each directory, you may also have a '.message' file. Its content will be printed when a client enters the directory. Such a file can contain important information ("Don't download version 1.7, it's broken!") . ------------------------ DISPLAYING A COOKIE ------------------------ A funny random message can be displayed in the initial login banner. The random cookies are extracted from a text file, in the standard "fortune" format. If you installed the "fortune" package, you should have a directory (usually /usr/share/fortune) with binary files (xxxx.dat) and text files (without the .dat extension) . To use Pure-FTPd cookies, just add the name of a text file to the '-F' option. For instance : /usr/local/sbin/pure-ftpd -F /usr/share/fortune/zippy If you want to have your own fortune files, just create a text file with the following structure. Hello... this is the first fortune... % Welcome to the real world. % Follow the white rabbit. % Have fun... Well... lotsa fun! % Yop is good for you. Goddit? Fortunes are delimited by a '%' sign on a single line. But a fortune itself can be multi-line (see the fourth example) . For security paranoia, the text file has to be readable by everybody (chmod 644 the file if necessary), or the server will ignore it. Of course, the fortune file can contain a single message. ------------------------ PER-USER CHROOT() RULES ------------------------ Apart from the "-a" flag, Pure-FTPd has another way to fine-tune chroot() rules. Let's take an /etc/passwd entry : mimi:x:501:100:Mimi:/home/mimi:/bin/zsh Without any special rule, mimi will be able to log in and to retrieve any public-readable file in the filesystem. Now, let's change a bit of its home directory : mimi:x:501:100:Mimi:/home/mimi/./:/bin/zsh So what? Mimi's home directory is still the same, and common applications shouldn't notice any difference. But Pure-FTPd understands "chroot() until /./". So when mimi next carries out a FTP log in, only the /home/mimi directory will be reachable, not the whole filesystem. If you don't like the "-a" and its trusted gid thing, this is a good way to only chroot() some users. Another trick is to add something after "/./" : mimi:x:501:100:Mimi:/home/mimi/./public_html:/bin/zsh When Mimi will log in, two things will happen : - chroot("/home/mimi") so that Mimi can't see anything but her home directory. - chdir("public_html") so the session will start in the public_html directory. "cd .." is still allowed, though. That "url-style" handling is especially handy for FTP-only users (ie. without shell access) . If a user is chrooted with the /./ trick *and* belongs to the trusted group (-a) he *will* be chrooted, but he will have no ratio and will be allowed to access dot files. ------------------------ RATIOS ------------------------ If you want to force people to upload new files before being able to download other files, ratios are for you. It's a very good way to get lotsa fresh stuff on a public FTP server, and a must for warez traders. I don't like that kind of business, but well... Pure-FTPd has to be designed to please everybody. To enable ratios, just use the '-q' option, followed by the upload:download ratio : -q 2:5 ...means that an anonymous user has to upload at least 2 Mb of goodies to be able to download 5 Mb. If ratios should apply to everyone (anon and non-anon), use the '-Q' option the same way. Note : 'root' never has ratios. Neither have users of the trusted group when '-Q' in used with the '-a' or '-A' option. ------------------------ BANDWIDTH THROTTLING ------------------------ Pure-FTPd has an interesting built-in feature : simple bandwidth throttling. * You want to limit FTP throughput so that uploading and downloading files through that protocol can't fill up your network bandwidth. -> Compile Pure-FTPd with --with-throttling -> Run it with the '-T' flag, followed by a number. That number is the maximum bandwidth a user can use, in kilobytes/seconds. * You want to allow less bandwidth to your anonymous users than your authenticated ones. So that during a bandwidth starvation, real users can still upload/download properly. -> Compile Pure-FTPd with --with-throttling -> Run it with the '-t' flag, followed by a number. Example : /usr/local/sbin/pure-ftpd -t 64 And uploading/downloading files can't take more than 64 Kb/sec whatever real bandwidth you have. * It is possible to have different bandwidth limits for uploads and for downloads. '-t' and '-T' can indeed be followed by two numbers delimited by a column (':') . The first number is the upload bandwidth and the next one applies only to downloads. One of them can be left blank which means infinity. Example 1 : 256 Kb/s for uploads, 64 Kb/s for downloads /usr/local/sbin/pure-ftpd -t 256:64 Example 2 : 256 Kb/s for uploads, no limit for downloads /usr/local/sbin/pure-ftpd -t 256: Example 3 : no limit for uploads, 64 Kb/s for downloads /usr/local/sbin/pure-ftpd -t :64 With no column, the value applies to both, so '-t 64' is an alias for '-t 64:64' . * When Pure-FTPd serves a session with restricted bandwidth, it decreases its process priority to 10. So, '-t 0' makes sense : during a CPU starvation, authenticated sessions may be more responsible than anonymous ones. '-T 0' is quite useless, but it also works and it will always be nice to the server process. * If you need advanced bandwidth management, have a look at your kernel Q.O.S. abilities. ------------------------ VIRTUAL SERVERS ------------------------ Using Virtual servers is a convenient way of hosting several FTP sites on the same computer. Let's say, you got two customers. The former owns the 'c9x.org' domain name, while the latter owns the 'rtchat.com' domain name. Both are hosted on the same computer, but they don't want to share the same files. ftp://ftp.c9x.org/ should show different content than ftp://ftp.rtchat.com/ . The FTP protocol doesn't allow name-based selection. So, if you want to host <N> different virtual FTP servers on the same host, you need <N> different IP addresses. Yes, Sir. Or use HTTP. Assign the needed IP adresses to your network adapter (with "ifconfig eth0:x ..." or "ip addr add dev eth0 a.b.c.d"). Now, create a /etc/pure-ftpd directory if it doesn't exist : mkdir /etc/pure-ftpd To add a virtual FTP server, you only need to create a symbolic link in /etc/pure-ftpd/ from the virtual host IP to the directory that contains the file for that virtual host. Example : ln -s /home/customers/rtchat.com/ftp /etc/pure-ftpd/216.226.17.77 ln -s /home/customers/c9x.org/ftp /etc/pure-ftpd/212.73.209.252 Done! Put the C9X files in /home/customers/c9x.org/ftp/ and the RTChat files in /home/customers/rtchat.com/ftp/ . With that feature, every account on the server can have its own public anonymous FTP area. If you are providing hosting services, this is a nice feature for your customers. * WARNING * : it also means that your customers can create "incoming" directories with 1777 permissions. It can be nice, but it can also fill up your disk with warez. You can stop uploads for anonymous users with the '-i' (or --anonymouscantupload) option. By default, all IP addresses assigned to your server can be accessed by real or anonymous users. You can restrict this with -e (only anonymous) or -E (only real) . A more flexible way is to use '-V <ip address>' to define a "trusted" IP address. When a client connects to that trusted IP, anonymous and real logins are permitted. But on all other IP, only anonymous users are permitted. If you are a hosting service provider, and if each customer has its own IP address, it may be a nice idea to have a trusted IP you give to all your customers, so that they can manage the files in their account. That IP is the same for all customers. You can easily restrict access to that IP with firewall rules if your customers have static IP addresses. Use '-V <trusted ip>', and link /etc/pure-ftpd/<customer ip> to ~customer/ftp . Every customer will have his own *anonymous only* FTP server, and hackers will have to find the trusted IP to get in. ------------------------ IPv6 SUPPORT ------------------------ Pure-FTPd has full IPv6 support (native IPv6 addresses and 4-in-6 addresses). But use a super-server that also understands the IPv6 protocol, like Rlinetd or Xinetd. Recent versions of Inetd should also be ok (unverified). IPv6 is supported everywhere : logging, configuration switches, virtual hosts, protocol (EPSV/EPRT support), name resolution... --------------------- LOGGING --------------------- Log messages are sent to the syslog daemon. You can disable logging with '-f none'. If you want all FTP messages to be redirected to a file, say /var/log/ftp, add this line to your /etc/syslog.conf file : ftp.* /var/log/ftp Then restart your syslogd daemon : killall -HUP syslogd You can also drop your old "syslogd" and "klogd" programs for Metalog, an efficient alternative : http://metalog.sourceforge.net Names of uploaded/downloaded files are logged with paths like this : /home/ftp//pub/bla.jpg The double-slash ('//') is the chroot limit. --------------------- WATCHING CURRENT SESSIONS --------------------- Since 0.97.7, you can type 'pure-ftpwho' at any time to watch current active sessions. If typing 'pure-ftpwho' answers 'Command not found', you have to add /usr/local/sbin in your PATH environment variable. The default output looks like this : +------+---------+-------+------+-------------------------------------------+ | PID | Login |For/Spd| What | File/IP | +------+---------+-------+------+-------------------------------------------+ | 2239 | jedi | 00:17 | D/L | XFree86-clients-4.0.3.tar.gz | | '' | '' | 41K/s| 33% | -> nestea.funboard.de | +------+---------+-------+------+-------------------------------------------+ | 2385 | ftp | 00:02 | IDLE | | | '' | '' | | | -> gw2.crn.kjop.co.uk | +------+---------+-------+------+-------------------------------------------+ 'D/L' means that the client is downloading, and 'U/L' means he's uploading some file whose name is shown in the next column. '33%' is the real-time completion of the current operation. '41K/s' is the bandwidth used by the client. You can track down who's starving your bandwidth with this. The 'pureftp-who' command accepts interesting options : '-c' : the program is called via a web server (CGI interface) . Output is a full HTML page with the initial content-type header. This option is automatically enabled if an environment variable called GATEWAY_INTERFACE is found. This is the default if you can access the program from a CGI-enabled web server (Apache, Roxen, Caudium, WN, ...) . '-h' : show command-line options summary. '-n' : don't resolve host names, and only show IP addresses (faster). '-s' : output an easily parsable format for shell scripts (but not very user friendly) . There's only one line per client, with only numeric data, delimited by a '|' character. It's not very human-readable, but it's designed for easy parsing by shell scripts (cut/sed) . '|' characters in user names or file names are quoted ('|' becomes '\|') . Type 'pure-ftpwho -h' to check the format. '-w' : output a complete HTML page (web mode). '-W' : output an HTML page with no header and no footer. This is an embedded mode, suitable for inline calls from CGI, SSI or PHP scripts. '-x' : output well-formed XML data for post-processing. This is the most acurate mode. Time is in seconds, and file sizes are in bytes (in other output formats, sizes are in kbytes for easier readability) . '-v' : verbose output in text mode. Additional info includes the size of files being downloaded/uploaded, the local IP or local host name, and the connection port. This is especially useful for virtual hosts. Here's a sample output of 'pure-ftpwho -v' : +------+---------+-------+------+-------------------------------------------+ | PID | Login |For/Spd| What | File/Remote IP/Size(Kb)/Local IP | +------+---------+-------+------+-------------------------------------------+ | 9086 | j | 00:04 | DL | linux-2.4.4.tar.bz2 | | '' | '' | 22K/s| 27% | -> localhost | | '' | '' | | | Total size: 20859 Transfered: 5632 | | '' | '' | | | <- localhost:21 | +------+---------+-------+------+-------------------------------------------+ ------------------------ AFTER AN UPLOAD ------------------------ After a successful upload, any external program or shell script can be spawned with the name of the newly uploaded file as an argument. You can use that feature to automatically send a mail when a new file arrives. Or you can pass it to a moderation system, an anti-virus, a MD5 signature generator or whatever you decide can be done with a file. To support this, the server has to be configured --with-uploadscript at compilation time. Then, the FTP server has to be launched with the '-o' run-time option. Finally, you have to run another daemon called 'pure-uploadscript' provided by this package. For security and efficiency purposes, the server never launches any external program. It's why there is a separate daemon, that reads new uploads pushed into a named pipe by the server. The easiest way to run pure-uploadscript is 'pure-uploadscript -r <script>' : /usr/local/sbin/pure-uploadscript -r /bin/antivirus.sh The absolute path of the newly uploaded file is passed as a first argument. Some environment variables are also filled with interesting values : - UPLOAD_SIZE : the size of the file, in bytes. - UPLOAD_PERMS : the permissions, as an octal value. - UPLOAD_UID : the uid of the owner. - UPLOAD_GID : the group the file belongs to. - UPLOAD_USER : the name of the owner. - UPLOAD_GROUP : the group name the file belongs to. - UPLOAD_VUSER : the full user name, or the virtual user name. (127 chars max) There are also some options to "pure-uploadscript" : - '-u <uid>' and '-g <gid>' to switch the account pure-uploadscript will run as. The script will be spawned with the same identity. - '-B' to fork in background. Please have a look at the man page ('man pure-uploadscript') for additional info. ------------------------ LISTING DIRECTORIES ------------------------ The built-in 'ls' supports all common options of a regular 'ls' command. Here are the ones you should know for a better life with FTP : - '-l' : verbose listing, reporting dates, owners, perms and sizes. - '-a' : also lists files and directories beginning with a dot. - '-F' : adds a '/' after directory names. - '-d' : list the directory itself, not its content. - '-R' : recursive listing. - '-S' : sort by size. - '-t' : sort by date. - '-r' : reverse the sorting order. If you aren't very familiar with Unix, log in to your FTP server, and try these variants : ls ls -F ls -l ls -la ls -lR ls -Sl ls -Slr ls -tl ls -tlr Globbing is also supported. So if you are looking for a GNOME RPM in <I don't know the directory name>/gnome-xxxxxxxx.rpm , you can find it that way : ls */gnome*.rpm ------------------------ VIRTUAL QUOTAS ------------------------ With virtual quotas, you can restrict the maximum number of files, and the total size of a user directory. These quotas are "virtual" because they aren't handled at kernel-level, but by the FTP server itself. There are some advantages over kernel quotas : - Virtual quotas are specific to the FTP server. You can have different system quotas to handle other files (eg. mail) on the same partition. - You can have different virtual quotas for every user, even if they share the same system uid. - Virtual quotas are working even on filesystems that don't support system quotas. However, virtual quotas are slower and can't be as reliable as kernel quotas. Virtual quotas are implemented in Pure-FTPd as simple files called ".ftpquota", located in the home directory of chrooted users. This file only contains two numbers : the current number of files for this user and the total size of the directory (+ its subdirectories), in bytes. When a new file is uploaded, these numbers grow. When a file is deleted, these numbers get smaller. Simple. Of course, when virtual quotas are enabled for one user, that user must be 1) chrooted, 2) not allowed to write quota files, 3) not allowed to forbid access to some directories to fool the counter. Quotas can be enabled for all users for the -n (--quotas) option. This option is followed by the max number of files, and the max size (in Megabytes) . Every user will have the same quota. Exception: members of the trusted group, if -a is enabled. You can also have different quotas for every user if you use PureDB or SQL databases. See the "README.Virtual-Users" file for more info about PureDB databases. So, if you want 1000 files max, and 10 Mb max for all your customers, run the server like this : /usr/local/sbin/pure-ftpd -n 1000:10 ".ftpquota" files are created on demand when they are missing. However, when they are created, the server assumes that the account was empty. If this is not the case, you must run the "pure-quotacheck" utility to create an initial ".ftpquota" file. "pure-quotacheck" is a tool that computes the size and the number of files in a directory, and create a ".ftpquota" file with this info. The syntax is : pure-quotacheck -u username/gid -d home directory [-g group/gid] For instance, if you want to summarize usage for the /home/ftpusers/john directory, whoose files are owned by the "ftpusers" system account, just run : pure-quotacheck -u ftpusers -d /home/ftpusers/john You can run pure-quotacheck whenever you want, even when ".ftpquota" files are already there. This is even a good idea to run this for all users in crontab, so that stored quotas are always exact, even if something went wrong (server bug, filesystem corruption, savagely killed server, etc) . With traditional quotas, when a hard limit is reached, it's impossible to write new data. It's nice for files that are created fastly (operations on local filesystems) . But it's really frustrating when transfering files through networks. Virtual quotas are working in a (somewhat strange) but handy way. When an user begins an upload, the newly uploaded file can be as huge as his total quota. It means that if his quota is 10 Mb, he can upload a 10 Mb file, even if he already has 9 Mb of other files in his directory. The idea is that while he's uploading the file, he can realize that his quota will be reached, and he can move/compress/delete other files to save space before the end of the upload. And only after completion of the upload, the quota is checked. If the quota is still crunched, the newly uploaded file will be deleted. ------------------------ AUTHENTICATION ------------------------ Pure-FTPd supports multiple methods of authentication. To use a method, you must have it compiled in (check the ./configure options) . - To use Unix authentication (the traditional /etc/passwd file), add the following option when you run the server : -l unix - To use PAM authentication, add this : -l pam - To use PureDB (virtual users), add this : -l puredb:/path/to/puredb_database (read README.Virtual-Users for more info about PureDB indexed files) - To use LDAP directories, add this : -l ldap:/path/to/ldap_config_file (read README.LDAP for more info about LDAP directories) - To use MySQL databases, add this : -l mysql:/path/to/ldap_config_file (read README.MySQL for more info about MySQL databases) - To use Postgres databases, add this: -l pgsql:/path/to/postgres_config_file (read README.PGSQL for more info about Postgres databases) - To use external authentication handlers (with pure-authd), use : -l extauth:/path/to/authd/socket (read README.Authentication-Modules for more info about external authentication) Multiple authentication methods can be chained. For instance, you can run the server like this : /usr/local/sbin/pure-ftpd -lldap:/etc/pureftpd-ldap.conf \ -lpuredb:/etc/pureftpd.pdb -lunix Every method is tried in order. With the previous command line, an LDAP directory is probed first. If a user isn't found in the directory, a PureDB database is scanned for the same user name. If that user is still not found, /etc/passwd is scanned. If the user is found in the LDAP directory, but the given password is wrong, further authentication methods are skipped. If you don't specify any -l option, PAM is assumed by default if the server is compiled with PAM support, and Unix is assumed by default otherwise. ------------------------ DIRECTORY ALIASES ------------------------ Directory aliases provides "shortcuts" for the "cd" command. For instance, if you define an alias called "pictures" for "/usr/misc/pictures", when an user will type "cd pictures", and if no real "pictures" directory exists, he will be automatically redirected to "/usr/misc/pictures". Unlike symbolic links, "cd pictures" will work from any directory. Tildes are *not* expanded. An user can get the list of available aliases with the following command : SITE ALIAS To support that feature, the server must be compiled with --with-diraliases passed to ./configure . To define alias/directory pairs, you must create a file called /etc/pureftpd-dir-aliases, whoose format is : Alternating lines of alias and dir (this enables embeded whitespace in dir and alias without quoting rules) Optional blank lines Optional lines beginning with '#' as comments (no you can't put a '#' just anywhere) Example : pictures /usr/misc/pictures sources /usr/src # This is for the OpenBSD port tree pureftpd-port /usr/ports/net/pure-ftpd ------------------------ OPTIMIZING FOR HIGH LOAD ------------------------ If you are going to use Pure-FTPd on a highly loaded server, here are some hints to get the best performances : - Compile with : env CFLAGS="-O2 -fomit-frame-pointer -fgcse -Os" ./configure --with-minimal --without-inetd --without-pam make install-strip - Run it in standalone mode. Don't use -C, don't enable pure-ftpwho nor pure-uploadscript (-o) . - Increase your system max descriptors number and local port range. On a Linux kernel, you can try : echo 2000 > /proc/sys/fs/super-max echo 60000 > /proc/sys/fs/file-max ulimit -n 60000 echo 30000 65534 > /proc/sys/net/ipv4/ip_local_port_range - On a Linux kernel, disable syncookies, ecn, timestamps and window scaling : echo 0 > /proc/sys/net/ipv4/tcp_syncookies echo 0 > /proc/sys/net/ipv4/tcp_ecn echo 0 > /proc/sys/net/ipv4/tcp_timestamps echo 0 > /proc/sys/net/ipv4/tcp_window_scaling - Disable access time update on your mounted filesystems. On a Linux system, just add 'noatime,nodiratime' for each mount point in your /etc/fstab file. - Disable syslog output and DNS lookups. Run it with : /usr/local/sbin/pure-ftpd -f none -H For FreeBSD, DJ_Oggy recommends the following setting : >>> QUOTE : Drop into single user mode (do a shutdown now or boot -s) and enter tunefs -n enable <filesystem> i sugest / /usr /var In /etc/fstab add ",noatime" to the options of all filesystems. In /boot/loader.conf add the following: hw.ata.wc="1" kern.ipc.nmbclusters="60000" In /etc/sysctl.conf add the following: vfs.vmiodirenable=1 kern.ipc.maxsockbuf=2097152 kern.ipc.somaxconn=8192 kern.ipc.maxsockets=16424 kern.maxfiles=65536 kern.maxfilesperproc=32768 net.inet.tcp.rfc1323=1 net.inet.tcp.delayed_ack=0 net.inet.tcp.sendspace=65535 net.inet.tcp.recvspace=65535 net.inet.udp.recvspace=65535 net.inet.udp.maxdgram=57344 net.local.stream.recvspace=65535 net.local.stream.sendspace=65535 give it two asprin, a reboot and call me in the morning!!!!! <<< END OF QUOTE ------------------------ KNOWN ISSUES ------------------------ - On non-linux systems, '-c' only works in standalone mode. - You should always avoid the use of spaces in login names : applications that are parsing log files often choke on this. - Incomplete transfers aren't logged in alternative formats. - On Solaris (at least Solaris 8), the large files + virtualchroot combination doesn't compile (we need to use struct stat64 in place of stat everywhere) . - On Solaris, to get chroot to work with pure-ftpd you need a dev directory in your new rootdir with these : crw-rw-rw- 1 root other 11, 42 Dec 10 15:02 tcp crw-rw-rw- 1 root other 105, 1 Dec 10 15:02 ticotsord crw-rw-rw- 1 root other 11, 41 Dec 10 15:03 udp crw-rw-rw- 1 root other 13, 12 Dec 10 15:03 zero else you get this ftp> ls 425 Can't create the data socket: Bad file number. If all your users are chrooted, you have to create these files in every home directory. Here's how : mkdir dev mknod dev/tcp c 11 42 chmod 0666 dev/tcp mknod dev/udp c 11 41 mknod dev/zero c 13 12 mknod dev/ticotsord c 105 1 (Reported by Kenneth Stailey) - Resuming ASCII transfers is refused. ASCII transfers are hell, because they are consuming CPU time both at client and server sides. And they even consume *more* bandwidth than binary transfers. But they allow Windows clients to upload scripts to Unix servers, stripping these nasty ^M signs. ASCII transfers are implemented in Pure-FTPd. But they can't be resumed, and this is intentional. To restart an ASCII transfer, the file has to be read and analyzed byte by byte. It can be very long, and by sending two trivial commands, a client can completely kill a server (take a lot of CPU and disk resources) . And there's no workaround. Another point is that while RFC describe a way to resume ASCII transfers, many clients and servers implement them in another way. The result is that resumed ASCII transfers can lead to data corruption. Some major servers didn't follow RFC, so some clients did the same mistake to support these servers, while some other modern clients and servers are trying to fully conform to RFC. So when clients and servers are speaking the same dialect, it works. When it's not the case, you get corrupted files. Messy, eh? And what if a customer uploads a script to your server, and thinks he can safely delete it from its hard disk? If the remote file is corrupted, he will get really angry. It's why Pure-FTPd *refuses* to resume ASCII transfers. If a customer tells you that he isn't able to upload/download a partially transfered ASCII file, please tell him to remove the partial file and to retransfer it again. This is a safe bet. ------------------------ DOWNLOADING PURE-FTPD ------------------------ Pure-FTPd home page is : http://www.pureftpd.org . Pure-FTPd mailing-list : http://www.pureftpd.org/ml/ You can also fetch the latest snapshots by CVS : cvs -d:pserver:anonymous@cvs.pureftpd.sourceforge.net:/cvsroot/pureftpd login (hit return without entering any password) cvs -z3 -d:pserver:anonymous@cvs.pureftpd.sourceforge.net:/cvsroot/pureftpd co pureftpd cd pureftpd ./autogen.sh FreeBSD port is available in : ports/ftp/pure-ftpd OpenBSD port is available in : ports/net/pure-ftpd Open Packages (C&W multiple-architectures OpenPKG standard packages) for Pure-FTPd are available from http://www.openpkg.org/download.html . Pre-built Solaris binary packages are available from the same location. MacOS X packages are available from Fink : http://fink.sourceforge.net/pdb/package.php/pure-ftpd Latest releases and regular snapshots are always available from : ftp://9x.2y.net/pure-ftpd/ (master, slow) ftp//mirror.widexs.nl/pub/pure-ftpd/ (mirror, fast) If you have question, suggestions or patches, feel free to post them to the mailing list. Newbies and silly ideas are welcome. Thank you, -Frank DENIS "Jedi/Sector One" <j@pureftpd.org> . * Please also read the CONTACT file.