rsyncd.conf(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | FILE FORMAT | LAUNCHING THE RSYNC DAEMON | GLOBAL PARAMETERS | MODULE PARAMETERS | CONFIG DIRECTIVES | AUTHENTICATION STRENGTH | SSL/TLS Daemon Setup | EXAMPLES | FILES | SEE ALSO | BUGS | VERSION | CREDITS | THANKS | AUTHOR | COLOPHON

rsyncd.conf(5)                User Commands               rsyncd.conf(5)

NAME         top

       rsyncd.conf - configuration file for rsync in daemon mode

SYNOPSIS         top

       rsyncd.conf

DESCRIPTION         top

       The rsyncd.conf file is the runtime configuration file for rsync
       when run as an rsync daemon.

       The rsyncd.conf file controls authentication, access, logging and
       available modules.

FILE FORMAT         top

       The file consists of modules and parameters. A module begins with
       the name of the module in square brackets and continues until the
       next module begins.  Modules contain parameters of the form
       name = value.

       The file is line-based -- that is, each newline-terminated line
       represents either a comment, a module name or a parameter.

       Only the first equals sign in a parameter is significant.
       Whitespace before or after the first equals sign is discarded.
       Leading, trailing and internal whitespace in module and parameter
       names is irrelevant. Leading and trailing whitespace in a
       parameter value is discarded. Internal whitespace within a
       parameter value is retained verbatim.

       Any line beginning with a hash (#) is ignored, as are lines
       containing only whitespace. (If a hash occurs after anything
       other than leading whitespace, it is considered a part of the
       line's content.)

       Any line ending in a \ is "continued" on the next line in the
       customary UNIX fashion.

       The values following the equals sign in parameters are all either
       a string (no quotes needed) or a boolean, which may be given as
       yes/no, 0/1 or true/false.  Case is not significant in boolean
       values, but is preserved in string values.

LAUNCHING THE RSYNC DAEMON         top

       The rsync daemon is launched by specifying the --daemon option to
       rsync.

       The daemon must run with root privileges if you wish to use
       chroot, to bind to a port numbered under 1024 (as is the default
       873), or to set file ownership.  Otherwise, it must just have
       permission to read and write the appropriate data, log, and lock
       files.

       You can launch it either via inetd, as a stand-alone daemon, or
       from an rsync client via a remote shell.  If run as a stand-alone
       daemon then just run the command "rsync --daemon" from a suitable
       startup script.

       When run via inetd you should add a line like this to
       /etc/services:

           rsync           873/tcp

       and a single line something like this to /etc/inetd.conf:

           rsync   stream  tcp     nowait  root   /usr/bin/rsync rsyncd --daemon

       Replace "/usr/bin/rsync" with the path to where you have rsync
       installed on your system.  You will then need to send inetd a HUP
       signal to tell it to reread its config file.

       Note that you should not send the rsync daemon a HUP signal to
       force it to reread the rsyncd.conf file. The file is re-read on
       each client connection.

GLOBAL PARAMETERS         top

       The first parameters in the file (before a [module] header) are
       the global parameters.  Rsync also allows for the use of a
       "[global]" module name to indicate the start of one or more
       global-parameter sections (the name must be lower case).

       You may also include any module parameters in the global part of
       the config file in which case the supplied value will override
       the default for that parameter.

       You may use references to environment variables in the values of
       parameters.  String parameters will have %VAR% references
       expanded as late as possible (when the string is first used in
       the program), allowing for the use of variables that rsync sets
       at connection time, such as RSYNC_USER_NAME.  Non-string
       parameters (such as true/false settings) are expanded when read
       from the config file.  If a variable does not exist in the
       environment, or if a sequence of characters is not a valid
       reference (such as an un-paired percent sign), the raw characters
       are passed through unchanged.  This helps with backward
       compatibility and safety (e.g. expanding a non-existent %VAR% to
       an empty string in a path could result in a very unsafe path).
       The safest way to insert a literal % into a value is to use %%.

       motd file
              This parameter allows you to specify a "message of the
              day" to display to clients on each connect. This usually
              contains site information and any legal notices. The
              default is no motd file.  This can be overridden by the
              --dparam=motdfile=FILE command-line option when starting
              the daemon.

       pid file
              This parameter tells the rsync daemon to write its process
              ID to that file.  The rsync keeps the file locked so that
              it can know when it is safe to overwrite an existing file.

              The filename can be overridden by the
              --dparam=pidfile=FILE command-line option when starting
              the daemon.

       port   You can override the default port the daemon will listen
              on by specifying this value (defaults to 873).  This is
              ignored if the daemon is being run by inetd, and is
              superseded by the --port command-line option.

       address
              You can override the default IP address the daemon will
              listen on by specifying this value.  This is ignored if
              the daemon is being run by inetd, and is superseded by the
              --address command-line option.

       socket options
              This parameter can provide endless fun for people who like
              to tune their systems to the utmost degree. You can set
              all sorts of socket options which may make transfers
              faster (or slower!). Read the man page for the
              setsockopt() system call for details on some of the
              options you may be able to set. By default no special
              socket options are set.  These settings can also be
              specified via the --sockopts command-line option.

       listen backlog
              You can override the default backlog value when the daemon
              listens for connections.  It defaults to 5.

MODULE PARAMETERS         top

       After the global parameters you should define a number of
       modules, each module exports a directory tree as a symbolic name.
       Modules are exported by specifying a module name in square
       brackets [module] followed by the parameters for that module.
       The module name cannot contain a slash or a closing square
       bracket.  If the name contains whitespace, each internal sequence
       of whitespace will be changed into a single space, while leading
       or trailing whitespace will be discarded.  Also, the name cannot
       be "global" as that exact name indicates that global parameters
       follow (see above).

       As with GLOBAL PARAMETERS, you may use references to environment
       variables in the values of parameters.  See the GLOBAL PARAMETERS
       section for more details.

       comment
              This parameter specifies a description string that is
              displayed next to the module name when clients obtain a
              list of available modules. The default is no comment.

       path   This parameter specifies the directory in the daemon's
              filesystem to make available in this module.  You must
              specify this parameter for each module in rsyncd.conf.

              You may base the path's value off of an environment
              variable by surrounding the variable name with percent
              signs.  You can even reference a variable that is set by
              rsync when the user connects.  For example, this would use
              the authorizing user's name in the path:

                  path = /home/%RSYNC_USER_NAME%

              It is fine if the path includes internal spaces -- they
              will be retained verbatim (which means that you shouldn't
              try to escape them).  If your final directory has a
              trailing space (and this is somehow not something you wish
              to fix), append a trailing slash to the path to avoid
              losing the trailing whitespace.

       use chroot
              If "use chroot" is true, the rsync daemon will chroot to
              the "path" before starting the file transfer with the
              client.  This has the advantage of extra protection
              against possible implementation security holes, but it has
              the disadvantages of requiring super-user privileges, of
              not being able to follow symbolic links that are either
              absolute or outside of the new root path, and of
              complicating the preservation of users and groups by name
              (see below).

              As an additional safety feature, you can specify a dot-dir
              in the module's "path" to indicate the point where the
              chroot should occur.  This allows rsync to run in a chroot
              with a non-"/" path for the top of the transfer hierarchy.
              Doing this guards against unintended library loading
              (since those absolute paths will not be inside the
              transfer hierarchy unless you have used an unwise
              pathname), and lets you setup libraries for the chroot
              that are outside of the transfer.  For example, specifying
              "/var/rsync/./module1" will chroot to the "/var/rsync"
              directory and set the inside-chroot path to "/module1".
              If you had omitted the dot-dir, the chroot would have used
              the whole path, and the inside-chroot path would have been
              "/".

              When both "use chroot" and "daemon chroot" are false, OR
              the inside-chroot path of "use chroot" is not "/", rsync
              will: (1) munge symlinks by default for security reasons
              (see "munge symlinks" for a way to turn this off, but only
              if you trust your users), (2) substitute leading slashes
              in absolute paths with the module's path (so that options
              such as --backup-dir, --compare-dest, etc. interpret an
              absolute path as rooted in the module's "path" dir), and
              (3) trim ".." path elements from args if rsync believes
              they would escape the module hierarchy.  The default for
              "use chroot" is true, and is the safer choice (especially
              if the module is not read-only).

              When this parameter is enabled and the "name converter"
              parameter is not set, the "numeric ids" parameter will
              default to being enabled (disabling name lookups).  This
              means that if you manually setup name-lookup libraries in
              your chroot (instead of using a name converter) that you
              need to explicitly set numeric ids = false for rsync to do
              name lookups.

              If you copy library resources into the module's chroot
              area, you should protect them through your OS's normal
              user/group or ACL settings (to prevent the rsync module's
              user from being able to change them), and then hide them
              from the user's view via "exclude" (see how in the
              discussion of that parameter).  However, it's easier and
              safer to setup a name converter.

       daemon chroot
              This parameter specifies a path to which the daemon will
              chroot before beginning communication with clients. Module
              paths (and any "use chroot" settings) will then be related
              to this one. This lets you choose if you want the whole
              daemon to be chrooted (with this setting), just the
              transfers to be chrooted (with "use chroot"), or both.
              Keep in mind that the "daemon chroot" area may need
              various OS/lib/etc files installed to allow the daemon to
              function.  By default the daemon runs without any
              chrooting.

       proxy protocol
              When this parameter is enabled, all incoming connections
              must start with a V1 or V2 proxy protocol header.  If the
              header is not found, the connection is closed.

              Setting this to true requires a proxy server to forward
              source IP information to rsync, allowing you to log proper
              IP/host info and make use of client-oriented IP
              restrictions.  The default of false means that the IP
              information comes directly from the socket's metadata.  If
              rsync is not behind a proxy, this should be disabled.

              CAUTION: using this option can be dangerous if you do not
              ensure that only the proxy is allowed to connect to the
              rsync port.  If any non-proxied connections are allowed
              through, the client will be able to use a modified rsync
              to spoof any remote IP address that they desire.  You can
              lock this down using something like iptables -uid-
              owner root rules (for strict localhost access), various
              firewall rules, or you can require password authorization
              so that any spoofing by users will not grant extra access.

              This setting is global.  If you need some modules to
              require this and not others, then you will need to setup
              multiple rsync daemon processes on different ports.

       name converter
              This parameter lets you specify a program that will be run
              by the rsync daemon to do user & group conversions between
              names & ids.  This script is started prior to any chroot
              being setup, and runs as the daemon user (not the transfer
              user).  You can specify a fully qualified pathname or a
              program name that is on the $PATH.

              The program can be used to do normal user & group lookups
              without having to put any extra files into the chroot area
              of the module or you can do customized conversions.

              The nameconvert program has access to all of the
              environment variables that are described in the section on
              pre-xfer exec.  This is useful if you want to customize
              the conversion using information about the module and/or
              the copy request.

              There is a sample python script in the support dir named
              "nameconvert" that implements the normal user & group
              lookups.  Feel free to customize it or just use it as
              documentation to implement your own.

       numeric ids
              Enabling this parameter disables the mapping of users and
              groups by name for the current daemon module.  This
              prevents the daemon from trying to load any user/group-
              related files or libraries.  This enabling makes the
              transfer behave as if the client had passed the --numeric-
              ids command-line option.  By default, this parameter is
              enabled for chroot modules and disabled for non-chroot
              modules.  Also keep in mind that uid/gid preservation
              requires the module to be running as root (see "uid") or
              for "fake super" to be configured.

              A chroot-enabled module should not have this parameter set
              to false unless you're using a "name converter" program or
              you've taken steps to ensure that the module has the
              necessary resources it needs to translate names and that
              it is not possible for a user to change those resources.

       munge symlinks
              This parameter tells rsync to modify all symlinks in the
              same way as the (non-daemon-affecting) --munge-links
              command-line option (using a method described below).
              This should help protect your files from user trickery
              when your daemon module is writable.  The default is
              disabled when "use chroot" is on with an inside-chroot
              path of "/", OR if "daemon chroot" is on, otherwise it is
              enabled.

              If you disable this parameter on a daemon that is not
              read-only, there are tricks that a user can play with
              uploaded symlinks to access daemon-excluded items (if your
              module has any), and, if "use chroot" is off, rsync can
              even be tricked into showing or changing data that is
              outside the module's path (as access-permissions allow).

              The way rsync disables the use of symlinks is to prefix
              each one with the string "/rsyncd-munged/".  This prevents
              the links from being used as long as that directory does
              not exist.  When this parameter is enabled, rsync will
              refuse to run if that path is a directory or a symlink to
              a directory.  When using the "munge symlinks" parameter in
              a chroot area that has an inside-chroot path of "/", you
              should add "/rsyncd-munged/" to the exclude setting for
              the module so that a user can't try to create it.

              Note:  rsync makes no attempt to verify that any pre-
              existing symlinks in the module's hierarchy are as safe as
              you want them to be (unless, of course, it just copied in
              the whole hierarchy).  If you setup an rsync daemon on a
              new area or locally add symlinks, you can manually protect
              your symlinks from being abused by prefixing "/rsyncd-
              munged/" to the start of every symlink's value.  There is
              a perl script in the support directory of the source code
              named "munge-symlinks" that can be used to add or remove
              this prefix from your symlinks.

              When this parameter is disabled on a writable module and
              "use chroot" is off (or the inside-chroot path is not
              "/"), incoming symlinks will be modified to drop a leading
              slash and to remove ".." path elements that rsync believes
              will allow a symlink to escape the module's hierarchy.
              There are tricky ways to work around this, though, so you
              had better trust your users if you choose this combination
              of parameters.

       charset
              This specifies the name of the character set in which the
              module's filenames are stored.  If the client uses an
              --iconv option, the daemon will use the value of the
              "charset" parameter regardless of the character set the
              client actually passed.  This allows the daemon to support
              charset conversion in a chroot module without extra files
              in the chroot area, and also ensures that name-translation
              is done in a consistent manner.  If the "charset"
              parameter is not set, the --iconv option is refused, just
              as if "iconv" had been specified via "refuse options".

              If you wish to force users to always use --iconv for a
              particular module, add "no-iconv" to the "refuse options"
              parameter.  Keep in mind that this will restrict access to
              your module to very new rsync clients.

       max connections
              This parameter allows you to specify the maximum number of
              simultaneous connections you will allow.  Any clients
              connecting when the maximum has been reached will receive
              a message telling them to try later.  The default is 0,
              which means no limit.  A negative value disables the
              module.  See also the "lock file" parameter.

       log file
              When the "log file" parameter is set to a non-empty
              string, the rsync daemon will log messages to the
              indicated file rather than using syslog.  This is
              particularly useful on systems (such as AIX) where
              syslog() doesn't work for chrooted programs.  The file is
              opened before chroot() is called, allowing it to be placed
              outside the transfer.  If this value is set on a per-
              module basis instead of globally, the global log will
              still contain any authorization failures or config-file
              error messages.

              If the daemon fails to open the specified file, it will
              fall back to using syslog and output an error about the
              failure.  (Note that the failure to open the specified log
              file used to be a fatal error.)

              This setting can be overridden by using the --log-
              file=FILE or --dparam=logfile=FILE command-line options.
              The former overrides all the log-file parameters of the
              daemon and all module settings.  The latter sets the
              daemon's log file and the default for all the modules,
              which still allows modules to override the default
              setting.

       syslog facility
              This parameter allows you to specify the syslog facility
              name to use when logging messages from the rsync daemon.
              You may use any standard syslog facility name which is
              defined on your system. Common names are auth, authpriv,
              cron, daemon, ftp, kern, lpr, mail, news, security,
              syslog, user, uucp, local0, local1, local2, local3,
              local4, local5, local6 and local7.  The default is daemon.
              This setting has no effect if the "log file" setting is a
              non-empty string (either set in the per-modules settings,
              or inherited from the global settings).

       syslog tag
              This parameter allows you to specify the syslog tag to use
              when logging messages from the rsync daemon. The default
              is "rsyncd".  This setting has no effect if the "log file"
              setting is a non-empty string (either set in the per-
              modules settings, or inherited from the global settings).

              For example, if you wanted each authenticated user's name
              to be included in the syslog tag, you could do something
              like this:

                  syslog tag = rsyncd.%RSYNC_USER_NAME%

       max verbosity
              This parameter allows you to control the maximum amount of
              verbose information that you'll allow the daemon to
              generate (since the information goes into the log file).
              The default is 1, which allows the client to request one
              level of verbosity.

              This also affects the user's ability to request higher
              levels of --info and --debug logging.  If the max value is
              2, then no info and/or debug value that is higher than
              what would be set by -vv will be honored by the daemon in
              its logging.  To see how high of a verbosity level you
              need to accept for a particular info/debug level, refer to
              rsync --info=help and rsync --debug=help.  For instance,
              it takes max-verbosity 4 to be able to output debug TIME2
              and FLIST3.

       lock file
              This parameter specifies the file to use to support the
              "max connections" parameter. The rsync daemon uses record
              locking on this file to ensure that the max connections
              limit is not exceeded for the modules sharing the lock
              file.  The default is /var/run/rsyncd.lock.

       read only
              This parameter determines whether clients will be able to
              upload files or not. If "read only" is true then any
              attempted uploads will fail. If "read only" is false then
              uploads will be possible if file permissions on the daemon
              side allow them. The default is for all modules to be read
              only.

              Note that "auth users" can override this setting on a per-
              user basis.

       write only
              This parameter determines whether clients will be able to
              download files or not. If "write only" is true then any
              attempted downloads will fail. If "write only" is false
              then downloads will be possible if file permissions on the
              daemon side allow them.  The default is for this parameter
              to be disabled.

              Helpful hint: you probably want to specify "refuse options
              = delete" for a write-only module.

       open noatime
              When set to True, this parameter tells the rsync daemon to
              open files with the O_NOATIME flag (on systems that
              support it) to avoid changing the access time of the files
              that are being transferred.  If your OS does not support
              the O_NOATIME flag then rsync will silently ignore this
              option.  Note also that some filesystems are mounted to
              avoid updating the atime on read access even without the
              O_NOATIME flag being set.

              When set to False, this parameters ensures that files on
              the server are not opened with O_NOATIME.

              When set to Unset (the default) the user controls the
              setting via --open-noatime.

       list   This parameter determines whether this module is listed
              when the client asks for a listing of available modules.
              In addition, if this is false, the daemon will pretend the
              module does not exist when a client denied by "hosts
              allow" or "hosts deny" attempts to access it.  Realize
              that if "reverse lookup" is disabled globally but enabled
              for the module, the resulting reverse lookup to a
              potentially client-controlled DNS server may still reveal
              to the client that it hit an existing module.  The default
              is for modules to be listable.

       uid    This parameter specifies the user name or user ID that
              file transfers to and from that module should take place
              as when the daemon was run as root.  In combination with
              the "gid" parameter this determines what file permissions
              are available. The default when run by a super-user is to
              switch to the system's "nobody" user.  The default for a
              non-super-user is to not try to change the user.  See also
              the "gid" parameter.

              The RSYNC_USER_NAME environment variable may be used to
              request that rsync run as the authorizing user.  For
              example, if you want a rsync to run as the same user that
              was received for the rsync authentication, this setup is
              useful:

                  uid = %RSYNC_USER_NAME%
                  gid = *

       gid    This parameter specifies one or more group names/IDs that
              will be used when accessing the module.  The first one
              will be the default group, and any extra ones be set as
              supplemental groups.  You may also specify a "*" as the
              first gid in the list, which will be replaced by all the
              normal groups for the transfer's user (see "uid").  The
              default when run by a super-user is to switch to your OS's
              "nobody" (or perhaps "nogroup") group with no other
              supplementary groups.  The default for a non-super-user is
              to not change any group attributes (and indeed, your OS
              may not allow a non-super-user to try to change their
              group settings).

              The specified list is normally split into tokens based on
              spaces and commas.  However, if the list starts with a
              comma, then the list is only split on commas, which allows
              a group name to contain a space.  In either case any
              leading and/or trailing whitespace is removed from the
              tokens and empty tokens are ignored.

       daemon uid
              This parameter specifies a uid under which the daemon will
              run. The daemon usually runs as user root, and when this
              is left unset the user is left unchanged. See also the
              "uid" parameter.

       daemon gid
              This parameter specifies a gid under which the daemon will
              run. The daemon usually runs as group root, and when this
              is left unset, the group is left unchanged. See also the
              "gid" parameter.

       fake super
              Setting "fake super = yes" for a module causes the daemon
              side to behave as if the --fake-super command-line option
              had been specified.  This allows the full attributes of a
              file to be stored without having to have the daemon
              actually running as root.

       filter The daemon has its own filter chain that determines what
              files it will let the client access.  This chain is not
              sent to the client and is independent of any filters the
              client may have specified.  Files excluded by the daemon
              filter chain (daemon-excluded files) are treated as non-
              existent if the client tries to pull them, are skipped
              with an error message if the client tries to push them
              (triggering exit code 23), and are never deleted from the
              module.  You can use daemon filters to prevent clients
              from downloading or tampering with private administrative
              files, such as files you may add to support uid/gid name
              translations.

              The daemon filter chain is built from the "filter",
              "include from", "include", "exclude from", and "exclude"
              parameters, in that order of priority.  Anchored patterns
              are anchored at the root of the module.  To prevent access
              to an entire subtree, for example, "/secret", you must
              exclude everything in the subtree; the easiest way to do
              this is with a triple-star pattern like "/secret/***".

              The "filter" parameter takes a space-separated list of
              daemon filter rules, though it is smart enough to know not
              to split a token at an internal space in a rule (e.g.
              "- /foo - /bar" is parsed as two rules).  You may specify
              one or more merge-file rules using the normal syntax.
              Only one "filter" parameter can apply to a given module in
              the config file, so put all the rules you want in a single
              parameter.  Note that per-directory merge-file rules do
              not provide as much protection as global rules, but they
              can be used to make --delete work better during a client
              download operation if the per-dir merge files are included
              in the transfer and the client requests that they be used.

       exclude
              This parameter takes a space-separated list of daemon
              exclude patterns.  As with the client --exclude option,
              patterns can be qualified with "-" or "+" to explicitly
              indicate exclude/include.  Only one "exclude" parameter
              can apply to a given module.  See the "filter" parameter
              for a description of how excluded files affect the daemon.

       include
              Use an "include" to override the effects of the "exclude"
              parameter.  Only one "include" parameter can apply to a
              given module.  See the "filter" parameter for a
              description of how excluded files affect the daemon.

       exclude from
              This parameter specifies the name of a file on the daemon
              that contains daemon exclude patterns, one per line.  Only
              one "exclude from" parameter can apply to a given module;
              if you have multiple exclude-from files, you can specify
              them as a merge file in the "filter" parameter.  See the
              "filter" parameter for a description of how excluded files
              affect the daemon.

       include from
              Analogue of "exclude from" for a file of daemon include
              patterns.  Only one "include from" parameter can apply to
              a given module.  See the "filter" parameter for a
              description of how excluded files affect the daemon.

       incoming chmod
              This parameter allows you to specify a set of comma-
              separated chmod strings that will affect the permissions
              of all incoming files (files that are being received by
              the daemon).  These changes happen after all other
              permission calculations, and this will even override
              destination-default and/or existing permissions when the
              client does not specify --perms.  See the description of
              the --chmod rsync option and the chmod(1) manpage for
              information on the format of this string.

       outgoing chmod
              This parameter allows you to specify a set of comma-
              separated chmod strings that will affect the permissions
              of all outgoing files (files that are being sent out from
              the daemon).  These changes happen first, making the sent
              permissions appear to be different than those stored in
              the filesystem itself.  For instance, you could disable
              group write permissions on the server while having it
              appear to be on to the clients.  See the description of
              the --chmod rsync option and the chmod(1) manpage for
              information on the format of this string.

       auth users
              This parameter specifies a comma and/or space-separated
              list of authorization rules.  In its simplest form, you
              list the usernames that will be allowed to connect to this
              module. The usernames do not need to exist on the local
              system. The rules may contain shell wildcard characters
              that will be matched against the username provided by the
              client for authentication. If "auth users" is set then the
              client will be challenged to supply a username and
              password to connect to the module. A challenge response
              authentication protocol is used for this exchange. The
              plain text usernames and passwords are stored in the file
              specified by the "secrets file" parameter. The default is
              for all users to be able to connect without a password
              (this is called "anonymous rsync").

              In addition to username matching, you can specify
              groupname matching via a '@' prefix.  When using groupname
              matching, the authenticating username must be a real user
              on the system, or it will be assumed to be a member of no
              groups.  For example, specifying "@rsync" will match the
              authenticating user if the named user is a member of the
              rsync group.

              Finally, options may be specified after a colon (:).  The
              options allow you to "deny" a user or a group, set the
              access to "ro" (read-only), or set the access to "rw"
              (read/write).  Setting an auth-rule-specific ro/rw setting
              overrides the module's "read only" setting.

              Be sure to put the rules in the order you want them to be
              matched, because the checking stops at the first matching
              user or group, and that is the only auth that is checked.
              For example:

                  auth users = joe:deny @guest:deny admin:rw @rsync:ro susan joe sam

              In the above rule, user joe will be denied access no
              matter what.  Any user that is in the group "guest" is
              also denied access.  The user "admin" gets access in
              read/write mode, but only if the admin user is not in
              group "guest" (because the admin user-matching rule would
              never be reached if the user is in group "guest").  Any
              other user who is in group "rsync" will get read-only
              access.  Finally, users susan, joe, and sam get the ro/rw
              setting of the module, but only if the user didn't match
              an earlier group-matching rule.

              If you need to specify a user or group name with a space
              in it, start your list with a comma to indicate that the
              list should only be split on commas (though leading and
              trailing whitespace will also be removed, and empty
              entries are just ignored).  For example:

                  auth users = , joe:deny, @Some Group:deny, admin:rw, @RO Group:ro

              See the description of the secrets file for how you can
              have per-user passwords as well as per-group passwords.
              It also explains how a user can authenticate using their
              user password or (when applicable) a group password,
              depending on what rule is being authenticated.

              See also the section entitled "USING RSYNC-DAEMON FEATURES
              VIA A REMOTE SHELL CONNECTION" in rsync(1) for information
              on how handle an rsyncd.conf-level username that differs
              from the remote-shell-level username when using a remote
              shell to connect to an rsync daemon.

       secrets file
              This parameter specifies the name of a file that contains
              the username:password and/or @groupname:password pairs
              used for authenticating this module. This file is only
              consulted if the "auth users" parameter is specified.  The
              file is line-based and contains one name:password pair per
              line.  Any line has a hash (#) as the very first character
              on the line is considered a comment and is skipped.  The
              passwords can contain any characters but be warned that
              many operating systems limit the length of passwords that
              can be typed at the client end, so you may find that
              passwords longer than 8 characters don't work.

              The use of group-specific lines are only relevant when the
              module is being authorized using a matching "@groupname"
              rule.  When that happens, the user can be authorized via
              either their "username:password" line or the
              "@groupname:password" line for the group that triggered
              the authentication.

              It is up to you what kind of password entries you want to
              include, either users, groups, or both.  The use of group
              rules in "auth users" does not require that you specify a
              group password if you do not want to use shared passwords.

              There is no default for the "secrets file" parameter, you
              must choose a name (such as /etc/rsyncd.secrets).  The
              file must normally not be readable by "other"; see "strict
              modes".  If the file is not found or is rejected, no
              logins for a "user auth" module will be possible.

       strict modes
              This parameter determines whether or not the permissions
              on the secrets file will be checked.  If "strict modes" is
              true, then the secrets file must not be readable by any
              user ID other than the one that the rsync daemon is
              running under.  If "strict modes" is false, the check is
              not performed.  The default is true.  This parameter was
              added to accommodate rsync running on the Windows
              operating system.

       hosts allow
              This parameter allows you to specify a list of comma-
              and/or whitespace-separated patterns that are matched
              against a connecting client's hostname and IP address.  If
              none of the patterns match, then the connection is
              rejected.

              Each pattern can be in one of six forms:

              o      a dotted decimal IPv4 address of the form a.b.c.d,
                     or an IPv6 address of the form a:b:c::d:e:f. In
                     this case the incoming machine's IP address must
                     match exactly.

              o      an address/mask in the form ipaddr/n where ipaddr
                     is the IP address and n is the number of one bits
                     in the netmask.  All IP addresses which match the
                     masked IP address will be allowed in.

              o      an address/mask in the form ipaddr/maskaddr where
                     ipaddr is the IP address and maskaddr is the
                     netmask in dotted decimal notation for IPv4, or
                     similar for IPv6, e.g. ffff:ffff:ffff:ffff::
                     instead of /64. All IP addresses which match the
                     masked IP address will be allowed in.

              o      a hostname pattern using wildcards. If the hostname
                     of the connecting IP (as determined by a reverse
                     lookup) matches the wildcarded name (using the same
                     rules as normal unix filename matching), the client
                     is allowed in.  This only works if "reverse lookup"
                     is enabled (the default).

              o      a hostname. A plain hostname is matched against the
                     reverse DNS of the connecting IP (if "reverse
                     lookup" is enabled), and/or the IP of the given
                     hostname is matched against the connecting IP (if
                     "forward lookup" is enabled, as it is by default).
                     Any match will be allowed in.

              o      an '@' followed by a netgroup name, which will
                     match if the reverse DNS of the connecting IP is in
                     the specified netgroup.

              Note IPv6 link-local addresses can have a scope in the
              address specification:

                  fe80::1%link1
                  fe80::%link1/64
                  fe80::%link1/ffff:ffff:ffff:ffff::

              You can also combine "hosts allow" with "hosts deny" as a
              way to add exceptions to your deny list.  When both
              parameters are specified, the "hosts allow" parameter is
              checked first and a match results in the client being able
              to connect.  A non-allowed host is then matched against
              the "hosts deny" list to see if it should be rejected.  A
              host that does not match either list is allowed to
              connect.

              The default is no "hosts allow" parameter, which means all
              hosts can connect.

       hosts deny
              This parameter allows you to specify a list of comma-
              and/or whitespace-separated patterns that are matched
              against a connecting clients hostname and IP address. If
              the pattern matches then the connection is rejected. See
              the "hosts allow" parameter for more information.

              The default is no "hosts deny" parameter, which means all
              hosts can connect.

       reverse lookup
              Controls whether the daemon performs a reverse lookup on
              the client's IP address to determine its hostname, which
              is used for "hosts allow" & "hosts deny" checks and the
              "%h" log escape.  This is enabled by default, but you may
              wish to disable it to save time if you know the lookup
              will not return a useful result, in which case the daemon
              will use the name "UNDETERMINED" instead.

              If this parameter is enabled globally (even by default),
              rsync performs the lookup as soon as a client connects, so
              disabling it for a module will not avoid the lookup.
              Thus, you probably want to disable it globally and then
              enable it for modules that need the information.

       forward lookup
              Controls whether the daemon performs a forward lookup on
              any hostname specified in an hosts allow/deny setting.  By
              default this is enabled, allowing the use of an explicit
              hostname that would not be returned by reverse DNS of the
              connecting IP.

       ignore errors
              This parameter tells rsyncd to ignore I/O errors on the
              daemon when deciding whether to run the delete phase of
              the transfer. Normally rsync skips the --delete step if
              any I/O errors have occurred in order to prevent
              disastrous deletion due to a temporary resource shortage
              or other I/O error. In some cases this test is counter
              productive so you can use this parameter to turn off this
              behavior.

       ignore nonreadable
              This tells the rsync daemon to completely ignore files
              that are not readable by the user. This is useful for
              public archives that may have some non-readable files
              among the directories, and the sysadmin doesn't want those
              files to be seen at all.

       transfer logging
              This parameter enables per-file logging of downloads and
              uploads in a format somewhat similar to that used by ftp
              daemons.  The daemon always logs the transfer at the end,
              so if a transfer is aborted, no mention will be made in
              the log file.

              If you want to customize the log lines, see the "log
              format" parameter.

       log format
              This parameter allows you to specify the format used for
              logging file transfers when transfer logging is enabled.
              The format is a text string containing embedded single-
              character escape sequences prefixed with a percent (%)
              character.  An optional numeric field width may also be
              specified between the percent and the escape letter (e.g.
              "%-50n %8l %07p").  In addition, one or more apostrophes
              may be specified prior to a numerical escape to indicate
              that the numerical value should be made more human-
              readable.  The 3 supported levels are the same as for the
              --human-readable command-line option, though the default
              is for human-readability to be off.  Each added apostrophe
              increases the level (e.g. "%''l %'b %f").

              The default log format is "%o %h [%a] %m (%u) %f %l", and
              a "%t [%p]" is always prefixed when using the "log file"
              parameter.  (A perl script that will summarize this
              default log format is included in the rsync source code
              distribution in the "support" subdirectory: rsyncstats.)

              The single-character escapes that are understood are as
              follows:

              o      %a the remote IP address (only available for a
                     daemon)

              o      %b the number of bytes actually transferred

              o      %B the permission bits of the file (e.g. rwxrwxrwt)

              o      %c the total size of the block checksums received
                     for the basis file (only when sending)

              o      %C the full-file checksum if it is known for the
                     file. For older rsync protocols/versions, the
                     checksum was salted, and is thus not a useful value
                     (and is not displayed when that is the case). For
                     the checksum to output for a file, either the
                     --checksum option must be in-effect or the file
                     must have been transferred without a salted
                     checksum being used.  See the --checksum-choice
                     option for a way to choose the algorithm.

              o      %f the filename (long form on sender; no trailing
                     "/")

              o      %G the gid of the file (decimal) or "DEFAULT"

              o      %h the remote host name (only available for a
                     daemon)

              o      %i an itemized list of what is being updated

              o      %l the length of the file in bytes

              o      %L the string "-> SYMLINK", "=> HARDLINK", or ""
                     (where SYMLINK or HARDLINK is a filename)

              o      %m the module name

              o      %M the last-modified time of the file

              o      %n the filename (short form; trailing "/" on dir)

              o      %o the operation, which is "send", "recv", or
                     "del." (the latter includes the trailing period)

              o      %p the process ID of this rsync session

              o      %P the module path

              o      %t the current date time

              o      %u the authenticated username or an empty string

              o      %U the uid of the file (decimal)

              For a list of what the characters mean that are output by
              "%i", see the --itemize-changes option in the rsync
              manpage.

              Note that some of the logged output changes when talking
              with older rsync versions.  For instance, deleted files
              were only output as verbose messages prior to rsync 2.6.4.

       timeout
              This parameter allows you to override the clients choice
              for I/O timeout for this module. Using this parameter you
              can ensure that rsync won't wait on a dead client forever.
              The timeout is specified in seconds. A value of zero means
              no timeout and is the default. A good choice for anonymous
              rsync daemons may be 600 (giving a 10 minute timeout).

       refuse options
              This parameter allows you to specify a space-separated
              list of rsync command-line options that will be refused by
              your rsync daemon.  You may specify the full option name,
              its one-letter abbreviation, or a wild-card string that
              matches multiple options. Beginning in 3.2.0, you can also
              negate a match term by starting it with a "!".

              When an option is refused, the daemon prints an error
              message and exits.

              For example, this would refuse --checksum (-c) and all the
              various delete options:

                  refuse options = c delete

              The reason the above refuses all delete options is that
              the options imply --delete, and implied options are
              refused just like explicit options.

              The use of a negated match allows you to fine-tune your
              refusals after a wild-card, such as this:

                  refuse options = delete-* !delete-during

              Negated matching can also turn your list of refused
              options into a list of accepted options. To do this, begin
              the list with a "*" (to refuse all options) and then
              specify one or more negated matches to accept.  For
              example:

                  refuse options = * !a !v !compress*

              Don't worry that the "*" will refuse certain vital options
              such as --dry-run, --server, --no-iconv, --protect-args,
              etc. These important options are not matched by wild-card,
              so they must be overridden by their exact name.  For
              instance, if you're forcing iconv transfers you could use
              something like this:

                  refuse options = * no-iconv !a !v

              As an additional aid (beginning in 3.2.0), refusing (or
              "!refusing") the "a" or "archive"  option also affects all
              the options that the --archive option implies (-rdlptgoD),
              but only if the option  is matched explicitly (not using a
              wildcard). If you want to do something tricky, you can use
              "archive*" to avoid this side-effect, but keep in mind
              that no normal rsync client ever sends the actual archive
              option to the server.

              As an additional safety feature, the refusal of "delete"
              also refuses remove-source-files when the daemon is the
              sender; if you want the latter without the former, instead
              refuse "delete-*" as that refuses all the delete modes
              without affecting --remove-source-files. (Keep in mind
              that the client's --delete option typically results in
              --delete-during.)

              When un-refusing delete options, you should either specify
              "!delete*" (to accept all delete options) or specify a
              limited set that includes "delete", such as:

                  refuse options = * !a !delete !delete-during

              ... whereas this accepts any delete option except
              --delete-after:

                  refuse options = * !a !delete* delete-after

              A note on refusing "compress" -- it is better to set the
              "dont compress" daemon parameter to "*" because that
              disables compression silently instead of returning an
              error that forces the client to remove the -z option.

              If you are un-refusing the compress option, you probably
              want to match "!compress*" so that you also accept the
              --compress-level option.

              Note that the "write-devices" option is refused by
              default, but can be explicitly accepted with "!write-
              devices".  The options "log-file" and "log-file-format"
              are forcibly refused and cannot be accepted.

              Here are all the options that are not matched by wild-
              cards:

              o      --server: Required for rsync to even work.

              o      --rsh, -e: Required to convey compatibility flags
                     to the server.

              o      --out-format: This is required to convey output
                     behavior to a remote receiver.  While rsync passes
                     the older alias --log-format for compatibility
                     reasons, this options should not be confused with
                     --log-file-format.

              o      --sender: Use "write only" parameter instead of
                     refusing this.

              o      --dry-run, -n: Who would want to disable this?

              o      --protect-args, -s: This actually makes transfers
                     safer.

              o      --from0, -0: Makes it easier to accept/refuse
                     --files-from without affecting this helpful
                     modifier.

              o      --iconv: This is auto-disabled based on "charset"
                     parameter.

              o      --no-iconv: Most transfers use this option.

              o      --checksum-seed: Is a fairly rare, safe option.

              o      --write-devices: Is non-wild but also auto-
                     disabled.

       dont compress
              This parameter allows you to select filenames based on
              wildcard patterns that should not be compressed when
              pulling files from the daemon (no analogous parameter
              exists to govern the pushing of files to a daemon).
              Compression can be expensive in terms of CPU usage, so it
              is usually good to not try to compress files that won't
              compress well, such as already compressed files.

              The "dont compress" parameter takes a space-separated list
              of case-insensitive wildcard patterns. Any source filename
              matching one of the patterns will be compressed as little
              as possible during the transfer.  If the compression
              algorithm has an "off" level (such as zlib/zlibx) then no
              compression occurs for those files.  Other algorithms have
              the level minimized to reduces the CPU usage as much as
              possible.

              See the --skip-compress parameter in the rsync(1) manpage
              for the list of file suffixes that are not compressed by
              default.  Specifying a value for the "dont compress"
              parameter changes the default when the daemon is the
              sender.

       early exec, pre-xfer exec, post-xfer exec
              You may specify a command to be run in the early stages of
              the connection, or right before and/or after the transfer.
              If the early exec or pre-xfer exec command returns an
              error code, the transfer is aborted before it begins.  Any
              output from the pre-xfer exec command on stdout (up to
              several KB) will be displayed to the user when aborting,
              but is not displayed if the script returns success.  The
              other programs cannot send any text to the user.  All
              output except for the pre-xfer exec stdout goes to the
              corresponding daemon's stdout/stderr, which is typically
              discarded.  See the --no-detatch option for a way to see
              the daemon's output, which can assist with debugging.

              Note that the early exec command runs before any part of
              the transfer request is known except for the module name.
              This helper script can be used to setup a disk mount or
              decrypt some data into a module dir, but you may need to
              use lock file and max connections to avoid concurrency
              issues.  If the client rsync specified the --early-
              input=FILE option, it can send up to about 5K of data to
              the stdin of the early script.  The stdin will otherwise
              be empty.

              Note that the post-xfer exec command is still run even if
              one of the other scripts returns an error code. The pre-
              xfer exec command will not be run, however, if the
              early exec command fails.

              The following environment variables will be set, though
              some are specific to the pre-xfer or the post-xfer
              environment:

              o      RSYNC_MODULE_NAME: The name of the module being
                     accessed.

              o      RSYNC_MODULE_PATH: The path configured for the
                     module.

              o      RSYNC_HOST_ADDR: The accessing host's IP address.

              o      RSYNC_HOST_NAME: The accessing host's name.

              o      RSYNC_USER_NAME: The accessing user's name (empty
                     if no user).

              o      RSYNC_PID: A unique number for this transfer.

              o      RSYNC_REQUEST: (pre-xfer only) The module/path info
                     specified by the user.  Note that the user can
                     specify multiple source files, so the request can
                     be something like "mod/path1 mod/path2", etc.

              o      RSYNC_ARG#: (pre-xfer only) The pre-request
                     arguments are set in these numbered values.
                     RSYNC_ARG0 is always "rsyncd", followed by the
                     options that were used in RSYNC_ARG1, and so on.
                     There will be a value of "."  indicating that the
                     options are done and the path args are beginning --
                     these contain similar information to RSYNC_REQUEST,
                     but with values separated and the module name
                     stripped off.

              o      RSYNC_EXIT_STATUS: (post-xfer only) the server
                     side's exit value.  This will be 0 for a successful
                     run, a positive value for an error that the server
                     generated, or a -1 if rsync failed to exit
                     properly.  Note that an error that occurs on the
                     client side does not currently get sent to the
                     server side, so this is not the final exit status
                     for the whole transfer.

              o      RSYNC_RAW_STATUS: (post-xfer only) the raw exit
                     value from waitpid().

              Even though the commands can be associated with a
              particular module, they are run using the permissions of
              the user that started the daemon (not the module's uid/gid
              setting) without any chroot restrictions.

              These settings honor 2 environment variables: use
              RSYNC_SHELL to set a shell to use when running the command
              (which otherwise uses your system() call's default shell),
              and use RSYNC_NO_XFER_EXEC to disable both options
              completely.

CONFIG DIRECTIVES         top

       There are currently two config directives available that allow a
       config file to incorporate the contents of other files:  &include
       and &merge.  Both allow a reference to either a file or a
       directory.  They differ in how segregated the file's contents are
       considered to be.

       The &include directive treats each file as more distinct, with
       each one inheriting the defaults of the parent file, starting the
       parameter parsing as globals/defaults, and leaving the defaults
       unchanged for the parsing of the rest of the parent file.

       The &merge directive, on the other hand, treats the file's
       contents as if it were simply inserted in place of the directive,
       and thus it can set parameters in a module started in another
       file, can affect the defaults for other files, etc.

       When an &include or &merge directive refers to a directory, it
       will read in all the *.conf or *.inc files (respectively) that
       are contained inside that directory (without any recursive
       scanning), with the files sorted into alpha order.  So, if you
       have a directory named "rsyncd.d" with the files "foo.conf",
       "bar.conf", and "baz.conf" inside it, this directive:

           &include /path/rsyncd.d

       would be the same as this set of directives:

           &include /path/rsyncd.d/bar.conf
           &include /path/rsyncd.d/baz.conf
           &include /path/rsyncd.d/foo.conf

       except that it adjusts as files are added and removed from the
       directory.

       The advantage of the &include directive is that you can define
       one or more modules in a separate file without worrying about
       unintended side-effects between the self-contained module files.

       The advantage of the &merge directive is that you can load config
       snippets that can be included into multiple module definitions,
       and you can also set global values that will affect connections
       (such as motd file), or globals that will affect other include
       files.

       For example, this is a useful /etc/rsyncd.conf file:

           port = 873
           log file = /var/log/rsync.log
           pid file = /var/lock/rsync.lock

           &merge /etc/rsyncd.d
           &include /etc/rsyncd.d

       This would merge any /etc/rsyncd.d/*.inc files (for global values
       that should stay in effect), and then include any
       /etc/rsyncd.d/*.conf files (defining modules without any global-
       value cross-talk).

AUTHENTICATION STRENGTH         top

       The authentication protocol used in rsync is a 128 bit MD4 based
       challenge response system. This is fairly weak protection, though
       (with at least one brute-force hash-finding algorithm publicly
       available), so if you want really top-quality security, then I
       recommend that you run rsync over ssh.  (Yes, a future version of
       rsync will switch over to a stronger hashing method.)

       Also note that the rsync daemon protocol does not currently
       provide any encryption of the data that is transferred over the
       connection. Only authentication is provided. Use ssh as the
       transport if you want encryption.

       You can also make use of SSL/TLS encryption if you put rsync
       behind an SSL proxy.

SSL/TLS Daemon Setup         top

       When setting up an rsync daemon for access via SSL/TLS, you will
       need to configure a proxy (such as haproxy or nginx) as the
       front-end that handles the encryption.

       o      You should limit the access to the backend-rsyncd port to
              only allow the proxy to connect.  If it is on the same
              host as the proxy, then configuring it to only listen on
              localhost is a good idea.

       o      You should consider turning on the proxy protocol
              parameter if your proxy supports sending that information.
              The examples below assume that this is enabled.

       An example haproxy setup is as follows:

           frontend fe_rsync-ssl
              bind :::874 ssl crt /etc/letsencrypt/example.com/combined.pem
              mode tcp
              use_backend be_rsync

           backend be_rsync
              mode tcp
              server local-rsync 127.0.0.1:873 check send-proxy

       An example nginx proxy setup is as follows:

           stream {
              server {
                  listen 874 ssl;
                  listen [::]:874 ssl;

                  ssl_certificate /etc/letsencrypt/example.com/fullchain.pem;
                  ssl_certificate_key /etc/letsencrypt/example.com/privkey.pem;

                  proxy_pass localhost:873;
                  proxy_protocol on; # Requires "proxy protocol = true"
                  proxy_timeout 1m;
                  proxy_connect_timeout 5s;
              }
           }

EXAMPLES         top

       A simple rsyncd.conf file that allow anonymous rsync to a ftp
       area at /home/ftp would be:

           [ftp]
                   path = /home/ftp
                   comment = ftp export area

       A more sophisticated example would be:

           uid = nobody
           gid = nobody
           use chroot = yes
           max connections = 4
           syslog facility = local5
           pid file = /var/run/rsyncd.pid

           [ftp]
                   path = /var/ftp/./pub
                   comment = whole ftp area (approx 6.1 GB)

           [sambaftp]
                   path = /var/ftp/./pub/samba
                   comment = Samba ftp area (approx 300 MB)

           [rsyncftp]
                   path = /var/ftp/./pub/rsync
                   comment = rsync ftp area (approx 6 MB)

           [sambawww]
                   path = /public_html/samba
                   comment = Samba WWW pages (approx 240 MB)

           [cvs]
                   path = /data/cvs
                   comment = CVS repository (requires authentication)
                   auth users = tridge, susan
                   secrets file = /etc/rsyncd.secrets

       The /etc/rsyncd.secrets file would look something like this:

           tridge:mypass
           susan:herpass

FILES         top

       /etc/rsyncd.conf or rsyncd.conf

SEE ALSO         top

       rsync(1), rsync-ssl(1)

BUGS         top

       Please report bugs! The rsync bug tracking system is online at
       https://rsync.samba.org/.

VERSION         top

       This man page is current for version 3.2.3 of rsync.

CREDITS         top

       rsync is distributed under the GNU General Public License.  See
       the file COPYING for details.

       The primary ftp site for rsync is ftp://rsync.samba.org/pub/rsync

       A web site is available at https://rsync.samba.org/.

       We would be delighted to hear from you if you like this program.

       This program uses the zlib compression library written by Jean-
       loup Gailly and Mark Adler.

THANKS         top

       Thanks to Warren Stanley for his original idea and patch for the
       rsync daemon.  Thanks to Karsten Thygesen for his many
       suggestions and documentation!

AUTHOR         top

       rsync was written by Andrew Tridgell and Paul Mackerras.  Many
       people have later contributed to it.

       Mailing lists for support and development are available at
       https://lists.samba.org/.

COLOPHON         top

       This page is part of the rsync (a fast, versatile, remote (and
       local) file-copying tool) project.  Information about the project
       can be found at ⟨https://rsync.samba.org/⟩.  If you have a bug
       report for this manual page, see
       ⟨https://rsync.samba.org/bugzilla.html⟩.  This page was obtained
       from the tarball fetched from
       ⟨https://download.samba.org/pub/rsync/⟩ on 2021-06-20.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

rsyncd.conf 3.2.3              06 Aug 2020                rsyncd.conf(5)

Pages that refer to this page: rsync(1)rsync-ssl(1)