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diff --git a/rsyncd.conf.5.md b/rsyncd.conf.5.md new file mode 100644 index 0000000..91aaf6f --- /dev/null +++ b/rsyncd.conf.5.md @@ -0,0 +1,1273 @@ +## 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 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 + +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 @BINDIR@/rsync rsyncd --daemon + +Replace "@BINDIR@/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. 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 %%. + +[comment]: # (An OL starting at 0 is converted into a DL by the parser.) + +0. `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 default is no MOTD file. This can be overridden by the + `--dparam=motdfile=FILE` command-line option when starting the daemon. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `listen backlog` + + You can override the default backlog value when the daemon listens for + connections. It defaults to 5. + +## 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 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. + +0. `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. + +0. `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 extraneous 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. + +0. `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). + + 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 sanitize 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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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). + +0. `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% + +0. `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. + +0. `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`. + +0. `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. + +0. `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. + +0. `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`. + +0. `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. + +0. `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 = * + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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 an "[auth users](#)" module will be possible. + +0. `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. + +0. `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: + + - 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. + - 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. + - 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. + - 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). + - 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. + - 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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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. + +0. `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: + + - %a the remote IP address (only available for a daemon) + - %b the number of bytes actually transferred + - %B the permission bits of the file (e.g. rwxrwxrwt) + - %c the total size of the block checksums received for the basis file + (only when sending) + - %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. + - %f the filename (long form on sender; no trailing "/") + - %G the gid of the file (decimal) or "DEFAULT" + - %h the remote host name (only available for a daemon) + - %i an itemized list of what is being updated + - %l the length of the file in bytes + - %L the string "` -> SYMLINK`", "` => HARDLINK`", or "" (where `SYMLINK` + or `HARDLINK` is a filename) + - %m the module name + - %M the last-modified time of the file + - %n the filename (short form; trailing "/" on dir) + - %o the operation, which is "send", "recv", or "del." (the latter includes + the trailing period) + - %p the process ID of this rsync session + - %P the module path + - %t the current date time + - %u the authenticated username or an empty string + - %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. + +0. `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). + +0. `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: + + - `--server`: Required for rsync to even work. + - `--rsh`, `-e`: Required to convey compatibility flags to the server. + - `--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`. + - `--sender`: Use "[write only](#)" parameter instead of refusing this. + - `--dry-run`, `-n`: Who would want to disable this? + - `--seclude-args`, `-s`: Is the oldest arg-protection method. + - `--from0`, `-0`: Makes it easier to accept/refuse `--files-from` without + affecting this helpful modifier. + - `--iconv`: This is auto-disabled based on "[charset](#)" parameter. + - `--no-iconv`: Most transfers use this option. + - `--checksum-seed`: Is a fairly rare, safe option. + - `--write-devices`: Is non-wild but also auto-disabled. + +0. `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 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, 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. + +0. `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: + + - `RSYNC_MODULE_NAME`: The name of the module being accessed. + - `RSYNC_MODULE_PATH`: The path configured for the module. + - `RSYNC_HOST_ADDR`: The accessing host's IP address. + - `RSYNC_HOST_NAME`: The accessing host's name. + - `RSYNC_USER_NAME`: The accessing user's name (empty if no user). + - `RSYNC_PID`: A unique number for this transfer. + - `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. + - `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. + - `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. + - `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 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 + +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 + +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. + +- 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. +- 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; +> } +> } +> ``` + +## 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.1), [**rsync-ssl**(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 @VERSION@ of rsync. + +## CREDITS + +Rsync is distributed under the GNU General Public License. See the file +[COPYING](COPYING) for details. + +An rsync web site is available at <https://rsync.samba.org/> and its github +project is <https://github.com/WayneD/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 have later contributed to it. It is currently maintained by Wayne +Davison. + +Mailing lists for support and development are available at +<https://lists.samba.org/>. |