rsyncd.conf

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

NAME

   rsyncd.conf - configuration file for rsync in daemon mode

SYNOPSIS

   rsyncd.conf

   The online version of this manpage (that includes cross-linking of topics) is available at https://download.samba.org/pub/rsync/rsyncd.conf.5.

DESCRIPTION

   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

   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  para
   meter 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

   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

   The first parameters in the file (before a [module] header) are the global parameters:

   motd file
          This  parameter allows you to specify a "message of the day" (MOTD) to display to clients on each connect. This usually contains site information and any legal notices. The de
          fault 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 --ad
          dress 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 manpage 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.

   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 char
   acters 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 %%.

MODULE PARAMETERS

   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  se
   quence of whitespace will be changed into a single space, while leading or trailing whitespace will be discarded.

   There  is  also  a  special module name of "[global]" that does not define a module but instead switches back to the global settings context where default parameters can be specified.
   Because each defined module gets its full set of parameters as a combination of the default values that are set at that position in the config file plus its own  parameter  list,  the
   use of a "[global]" section can help to maintain shared config values for multiple modules.

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

          If  the value contains a "/./" element then the path will be divided at that point into a chroot dir and an inner-chroot subdir.  If use chroot is set to false, though, the ex‐
          traneous dot dir is just cleaned out of the path.  An example of this idiom is:

              path = /var/rsync/./module1

          This will (when chrooting) chroot to "/var/rsync" and set the inside-chroot path to "/module1".

          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  pos
          sible  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).

          If use chroot is not set, it defaults to trying to enable a chroot but allows the daemon to continue (after logging a warning) if it fails. The one exception to this is when  a
          module's path has a "/./" chroot divider in it -- this causes an unset value to be treated as true for that module.

          Prior  to  rsync  3.2.7, the default value was "true".  The new "unset" default makes it easier to setup an rsync daemon as a non-root user or to run a daemon on a system where
          chroot fails.  Explicitly setting the value to "true" in rsyncd.conf will always require the chroot to succeed.

          It is also possible to specify a dot-dir in the module's "path" to indicate that you want to chdir to the earlier part of the path and then serve files from inside  the  latter
          part  of the path (with sanitizing and default symlink munging).  This can be useful if you need some library dirs inside the chroot (typically for uid & gid lookups) but don't
          want to put the lib dir into the top of the served path (even though they can be hidden with an exclude directive).  However, a better choice for a modern rsync setup is to use
          a name converter" and try to avoid inner lib dirs altogether.  See also the daemon chroot parameter, which causes rsync to chroot into its own  chroot  area  before  doing  any
          path-related chrooting.

          If the daemon is serving the "/" dir (either directly or due to being chrooted to the module's path), rsync does not do any path sanitizing or (default) munging.

          When  it  has to limit access to a particular subdir (either due to chroot being disabled or having an inside-chroot path set), rsync will munge symlinks (by default) and sani
          tize paths.  Those that dislike munged symlinks (and really, really trust their users to not break out of the subdir) can disable the symlink munging via the  "munge  symlinks"
          parameter.

          When  rsync is sanitizing paths, it trims ".." path elements from args that it believes would escape the module hierarchy. It also substitutes leading slashes in absolute paths
          with the module's path (so that options such as --backup-dir & --compare-dest interpret an absolute path as rooted in the module's "path" dir).

          When a chroot is in effect 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  conver
          sion 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 documenta
          tion 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 ch
          root 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 nec
          essary 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  "dae‐
          mon 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 bet‐
          ter 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  de
          fault 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 updat‐
          ing 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-su
          per-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 re
          ceived 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 supple
          mental 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 an
          chored 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 af
          fect 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 dae
          mon).  These changes happen after all other permission calculations, and this will even override destination-default and/or existing permissions when the client does not  spec
          ify --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 dae
          mon).  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 for
          mat 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  mod
          ule.  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 trail
          ing 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  con
          sulted 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 ei‐
          ther 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 an "auth users" 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 accom‐
          modate 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 di
          rectories, 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-char‐
          acter  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, --seclude-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 may be better to set the "dont compress" daemon parameter to "*" and ensure that RSYNC_COMPRESS_LIST=zlib is set in  the  environment  of  the
          daemon in order to disable 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 may want to match "!compress*" if you also want to allow the --compress-level option.

          Note  that  the  "copy-devices" & "write-devices" options are refused by default, but they can be explicitly accepted with "!copy-devices" and/or "!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      --seclude-args, -s: Is the oldest arg-protection method.

          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
          NOTE:  This  parameter currently has no effect except in one instance: if it is set to "*" then it minimizes or disables compression for all files (for those that don't want to
          refuse the --compress option completely).

          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 gov‐
          ern 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, then no compression occurs for those files.  If an algorithms has the ability to change the
          level in mid-stream, it will be minimized to reduce 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 skipped by default if this parameter is not set.

   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 er‐
          ror 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-detach 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  de‐
          crypt  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 op‐
          tion, 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

   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 an
   other 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  recur
   sive 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

   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  algo
   rithm  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

   When setting up an rsync daemon for access via SSL/TLS, you will need to configure a TCP 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 local
          host is a good idea.

   o      You should consider turning on the proxy protocol rsync-daemon 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 rsyncd.conf "proxy protocol = true"
              proxy_timeout 1m;
              proxy_connect_timeout 5s;
          }
       }

   If rsyncd should be accessible encrypted and unencrypted at the same time make the proxy listen on port 873 as well and let it handle both streams.

DAEMON CONFIG EXAMPLES

   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

   /etc/rsyncd.conf or rsyncd.conf

SEE ALSO

   rsync(1), rsync-ssl(1)

BUGS

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

VERSION

   This manpage is current for version 3.4.1 of rsync.

CREDITS

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

   An rsync web site is available at https://rsync.samba.org/ and its github project is https://github.com/RsyncProject/rsync.

THANKS

   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

   Rsync was originally written by Andrew Tridgell and Paul Mackerras.  Many people from around the world have helped to maintain and improve it.

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

rsyncd.conf from rsync 3.4.1 15 Jan 2025 rsyncd.conf(5)