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You are here: manpages

rsyncd.conf

Section: (5)
Updated: 21 Dec 2015
Index Return to Main Contents

NAME

rsyncd.conf - configuration file for rsync in daemon mode

SYNOPSIS

rsyncd.conf

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 dqname = valuedq.

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 linecqs content.)

Any line ending in a \ is dqcontinueddq 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 dqrsync --daemondq 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 dq/usr/bin/rsyncdq 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 dq[global]dq 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 used in the program), allowing for the use of variables that rsync sets at connection time, such as RSYNC_USER_NAME. Non-string parameters (such as true/false settings) are expanded when read from the config file. If a variable does not exist in the environment, or if a sequence of characters is not a valid reference (such as an un-paired percent sign), the raw characters are passed through unchanged. This helps with backward compatibility and safety (e.g. expanding a non-existent %VAR% to an empty string in a path could result in a very unsafe path). The safest way to insert a literal % into a value is to use %%.

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

pid file: This parameter tells the rsync daemon to write its process ID to that file. If the file already exists, the rsync daemon will abort rather than overwrite the file. This can be overridden by the --dparam=pidfile=FILE command-line option when starting the daemon.

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 This is ignored if the daemon is being run by inetd, and is superseded by the --port command-line option.

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 This is ignored if the daemon is being run by inetd, and is superseded by the --address command-line option.

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

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

MODULE PARAMETERS

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 dqglobaldq as that exact name indicates that global parameters follow (see above).

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

comment

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

path

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

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

As an additional safety feature, you can specify a dot-dir in the modulecqs dqpathdq to indicate the point where the chroot should occur. This allows rsync to run in a chroot with a non-dq/dq path for the top of the transfer hierarchy. Doing this guards against unintended library loading (since those absolute paths will not be inside the transfer hierarchy unless you have used an unwise pathname), and lets you setup libraries for the chroot that are outside of the transfer. For example, specifying dq/var/rsync/./module1dq will chroot to the dq/var/rsyncdq directory and set the inside-chroot path to dq/module1dq. If you had omitted the dot-dir, the chroot would have used the whole path, and the inside-chroot path would have been dq/dq.

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

When this parameter is enabled, the dqnumeric-idsdq option will also default to being enabled (disabling name lookups). See below for what a chroot needs in order for name lookups to succeed.

If you copy library resources into the modulecqs chroot area, you should protect them through your OScqs normal user/group or ACL settings (to prevent the rsync modulecqs user from being able to change them), and then hide them from the usercqs view via dqexcludedq (see how in the discussion of that parameter). At that point it will be safe to enable the mapping of users and groups by name using this dqnumeric idsdq daemon parameter.

Note also that you are free to setup custom user/group information in the chroot area that is different from your normal system. For example, you could abbreviate the list of users and groups.

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 dquiddq) or for dqfake superdq to be configured.

A chroot-enabled module should not have this parameter enabled unless youcqve 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. That includes being the code being able to call functions like getpwuid() , getgrgid() , getpwname() , and getgrnam() ). You should test what libraries and config files are required for your OS and get those setup before starting to test name mapping in rsync.

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 dquse chrootdq is on and the inside-chroot path is dq/dq, 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 dquse chrootdq is off, rsync can even be tricked into showing or changing data that is outside the modulecqs path (as access-permissions allow).

The way rsync disables the use of symlinks is to prefix each one with the string dq/rsyncd-munged/dq. 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 dqmunge symlinksdq parameter in a chroot area that has an inside-chroot path of dq/dq, you should add dq/rsyncd-munged/dq to the exclude setting for the module so that a user cancqt try to create it.

Note: rsync makes no attempt to verify that any pre-existing symlinks in the modulecqs 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 dq/rsyncd-munged/dq to the start of every symlinkcqs value. There is a perl script in the support directory of the source code named dqmunge-symlinksdq that can be used to add or remove this prefix from your symlinks.

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

charset

This specifies the name of the character set in which the modulecqs filenames are stored. If the client uses an --iconv option, the daemon will use the value of the dqcharsetdq 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 dqcharsetdq parameter is not set, the --iconv option is refused, just as if dqiconvdq had been specified via dqrefuse optionsdq.

If you wish to force users to always use --iconv for a particular module, add dqno-iconvdq to the dqrefuse optionsdq 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 dqlock filedq parameter.

log file

When the dqlog filedq 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() doesncqt 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 daemoncqs 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 dqlog filedq setting is a non-empty string (either set in the per-modules settings, or inherited from the global settings).

max verbosity

This parameter allows you to control the maximum amount of verbose information that youcqll 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 usercqs 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 dqrsync --info=helpdq and dqrsync --debug=helpdq. 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 dqmax connectionsdq 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 dqread onlydq is true then any attempted uploads will fail. If dqread onlydq 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 dqauth usersdq 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 dqwrite onlydq is true then any attempted downloads will fail. If dqwrite onlydq 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.

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 dqhosts allowdq or dqhosts denydq attempts to access it. Realize that if dqreverse lookupdq 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 dqgiddq parameter this determines what file permissions are available. The default when run by a super-user is to switch to the systemcqs dqnobodydq user. The default for a non-super-user is to not try to change the user. See also the dqgiddq parameter.

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

    uid = %RSYNC_USER_NAME%
    gid = *

gid

This parameter specifies one or more group names/IDs that will be used when accessing the module. The first one will be the default group, and any extra ones be set as supplemental groups. You may also specify a dq*dq as the first gid in the list, which will be replaced by all the normal groups for the transfercqs user (see dquiddq). The default when run by a super-user is to switch to your OScqs dqnobodydq (or perhaps dqnogroupdq) 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).

fake super

Setting dqfake super = yesdq 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 dqfilterdq, dqinclude fromdq, dqincludedq, dqexclude fromdq, and dqexcludedq 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, dq/secretdq, you must exclude everything in the subtree; the easiest way to do this is with a triple-star pattern like dq/secret/***dq.

The dqfilterdq 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. dq- /foo - /bardq is parsed as two rules). You may specify one or more merge-file rules using the normal syntax. Only one dqfilterdq 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 dq- dq or dq+ dq to explicitly indicate exclude/include. Only one dqexcludedq parameter can apply to a given module. See the dqfilterdq parameter for a description of how excluded files affect the daemon.

include

Use an dqincludedq to override the effects of the dqexcludedq parameter. Only one dqincludedq parameter can apply to a given module. See the dqfilterdq 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 dqexclude fromdq parameter can apply to a given module; if you have multiple exclude-from files, you can specify them as a merge file in the dqfilterdq parameter. See the dqfilterdq parameter for a description of how excluded files affect the daemon.

include from

Analogue of dqexclude fromdq for a file of daemon include patterns. Only one dqinclude fromdq parameter can apply to a given module. See the dqfilterdq parameter for a description of how excluded files affect the daemon.

incoming chmod

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

outgoing chmod

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

auth users

This parameter specifies a comma and/or space-separated list of authorization rules. In its simplest form, you list the usernames that will be allowed to connect to this module. The usernames do not need to exist on the local system. The rules may contain shell wildcard characters that will be matched against the username provided by the client for authentication. If dqauth usersdq 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 dqsecrets filedq parameter. The default is for all users to be able to connect without a password (this is called dqanonymous rsyncdq).

In addition to username matching, you can specify groupname matching via a cq@cq 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 dq@rsyncdq 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 dqdenydq a user or a group, set the access to dqrodq (read-only), or set the access to dqrwdq (read/write). Setting an auth-rule-specific ro/rw setting overrides the modulecqs dqread onlydq 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 dqguestdq is also denied access. The user dqadmindq gets access in read/write mode, but only if the admin user is not in group dqguestdq (because the admin user-matching rule would never be reached if the user is in group dqguestdq). Any other user who is in group dqrsyncdq will get read-only access. Finally, users susan, joe, and sam get the ro/rw setting of the module, but only if the user didncqt match an earlier group-matching rule.

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

secrets file

This parameter specifies the name of a file that contains the username:password and/or @groupname:password pairs used for authenticating this module. This file is only consulted if the dqauth usersdq 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 doncqt work.

The use of group-specific lines are only relevant when the module is being authorized using a matching dq@groupnamedq rule. When that happens, the user can be authorized via either their dqusername:passworddq line or the dq@groupname:passworddq 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 dqauth usersdq does not require that you specify a group password if you do not want to use shared passwords.

There is no default for the dqsecrets filedq parameter, you must choose a name (such as /etc/rsyncd.secrets). The file must normally not be readable by dqotherdq; see dqstrict modesdq. If the file is not found or is rejected, no logins for a dquser authdq module will be possible.

strict modes

This parameter determines whether or not the permissions on the secrets file will be checked. If dqstrict modesdq 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 dqstrict modesdq is false, the check is not performed. The default is true. This parameter was added to accommodate rsync running on the Windows operating system.

hosts allow

This parameter allows you to specify a list of patterns that are matched against a connecting clients hostname and IP address. If none of the patterns match then the connection is rejected.

Each pattern can be in one of five 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 machinecqs 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 dqreverse lookupdq is enabled (the default).
o: a hostname. A plain hostname is matched against the reverse DNS of the connecting IP (if dqreverse lookupdq is enabled), and/or the IP of the given hostname is matched against the connecting IP (if dqforward lookupdq is enabled, as it is by default). Any match will be allowed in.

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 dqhosts allowdq with a separate dqhosts denydq parameter. If both parameters are specified then the dqhosts allowdq parameter is checked first and a match results in the client being able to connect. The dqhosts denydq parameter is then checked and a match means that the host is rejected. If the host does not match either the dqhosts allowdq or the dqhosts denydq patterns then it is allowed to connect.

The default is no dqhosts allowdq parameter, which means all hosts can connect.

hosts deny

This parameter allows you to specify a list of patterns that are matched against a connecting clients hostname and IP address. If the pattern matches then the connection is rejected. See the dqhosts allowdq parameter for more information.

The default is no dqhosts denydq parameter, which means all hosts can connect.

reverse lookup

Controls whether the daemon performs a reverse lookup on the clientcqs IP address to determine its hostname, which is used for dqhosts allowdq/dqhosts denydq checks and the dq%hdq 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 dqUNDETERMINEDdq instead.

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

forward lookup

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

ignore errors

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

ignore nonreadable

This tells the rsync daemon to completely ignore files that are not readable by the user. This is useful for public archives that may have some non-readable files among the directories, and the sysadmin doesncqt 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 dqlog formatdq parameter.

log format

This parameter allows you to specify the format used for logging file transfers when transfer logging is enabled. The format is a text string containing embedded single-character escape sequences prefixed with a percent (%) character. An optional numeric field width may also be specified between the percent and the escape letter (e.g. dq%-50n %8l %07pdq). 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. dq%''l %'b %fdq).

The default log format is dq%o %h [%a] %m (%u) %f %ldq, and a dq%t [%p] dq is always prefixed when using the dqlog filedq parameter. (A perl script that will summarize this default log format is included in the rsync source code distribution in the dqsupportdq 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 MD5 checksum if --checksum is enabled or a file was transferred (only for protocol 30 or above).
o: %f the filename (long form on sender; no trailing dq/dq)
o: %G the gid of the file (decimal) or dqDEFAULTdq
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 dq -> SYMLINKdq, dq => HARDLINKdq, or dqdq (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 dq/dq on dir)
o: %o the operation, which is dqsenddq, dqrecvdq, or dqdel.dq (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 dq%idq, 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 woncqt 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. 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. As an additional safety feature, the refusal of dqdeletedq also refuses remove-source-files when the daemon is the sender; if you want the latter without the former, instead refuse dqdelete-*dq -- that refuses all the delete modes without affecting --remove-source-files.

When an option is refused, the daemon prints an error message and exits. To prevent all compression when serving files, you can use dqdont compress = *dq (see below) instead of dqrefuse options = compressdq to avoid returning an error to a client that requests compression.

dont compress

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

The dqdont compressdq parameter takes a space-separated list of case-insensitive wildcard patterns. Any source filename matching one of the patterns will not be compressed during transfer.

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

pre-xfer exec, post-xfer exec

You may specify a command to be run before and/or after the transfer. If the pre-xfer exec command fails, the transfer is aborted before it begins. Any output from the script on stdout (up to several KB) will be displayed to the user when aborting, but is NOT displayed if the script returns success. Any output from the script on stderr goes to the daemoncqs stderr, which is typically discarded (though see --no-detatch option for a way to see the stderr output, which can assist with debugging).

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 hostcqs IP address.
o: RSYNC_HOST_NAME: The accessing hostcqs name.
o: RSYNC_USER_NAME: The accessing usercqs 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 dqmod/path1 mod/path2dq, etc.
o: RSYNC_ARG#: (pre-xfer only) The pre-request arguments are set in these numbered values. RSYNC_ARG0 is always dqrsyncddq, followed by the options that were used in RSYNC_ARG1, and so on. There will be a value of dq.dq 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 sidecqs 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 modulecqs uid/gid setting) without any chroot restrictions.

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 filecqs 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 filecqs 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 dqrsyncd.ddq with the files dqfoo.confdq, dqbar.confdq, and dqbaz.confdq 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.

Future versions of rsync may support SSL for better authentication and encryption, but that is still being investigated.

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: