File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / rsync / rsyncd.conf.5.md
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Wed Mar 17 00:32:36 2021 UTC (3 years, 3 months ago) by misho
Branches: rsync, MAIN
CVS tags: v3_2_3, HEAD
rsync 3.2.3

    1: # NAME
    2: 
    3: rsyncd.conf - configuration file for rsync in daemon mode
    4: 
    5: # SYNOPSIS
    6: 
    7: rsyncd.conf
    8: 
    9: # DESCRIPTION
   10: 
   11: The rsyncd.conf file is the runtime configuration file for rsync when run as an
   12: rsync daemon.
   13: 
   14: The rsyncd.conf file controls authentication, access, logging and available
   15: modules.
   16: 
   17: # FILE FORMAT
   18: 
   19: The file consists of modules and parameters. A module begins with the name of
   20: the module in square brackets and continues until the next module begins.
   21: Modules contain parameters of the form `name = value`.
   22: 
   23: The file is line-based -- that is, each newline-terminated line represents
   24: either a comment, a module name or a parameter.
   25: 
   26: Only the first equals sign in a parameter is significant. Whitespace before or
   27: after the first equals sign is discarded. Leading, trailing and internal
   28: whitespace in module and parameter names is irrelevant. Leading and trailing
   29: whitespace in a parameter value is discarded. Internal whitespace within a
   30: parameter value is retained verbatim.
   31: 
   32: Any line **beginning** with a hash (`#`) is ignored, as are lines containing
   33: only whitespace. (If a hash occurs after anything other than leading
   34: whitespace, it is considered a part of the line's content.)
   35: 
   36: Any line ending in a `\` is "continued" on the next line in the customary UNIX
   37: fashion.
   38: 
   39: The values following the equals sign in parameters are all either a string (no
   40: quotes needed) or a boolean, which may be given as yes/no, 0/1 or true/false.
   41: Case is not significant in boolean values, but is preserved in string values.
   42: 
   43: # LAUNCHING THE RSYNC DAEMON
   44: 
   45: The rsync daemon is launched by specifying the `--daemon` option to
   46: rsync.
   47: 
   48: The daemon must run with root privileges if you wish to use chroot, to bind to
   49: a port numbered under 1024 (as is the default 873), or to set file ownership.
   50: Otherwise, it must just have permission to read and write the appropriate data,
   51: log, and lock files.
   52: 
   53: You can launch it either via inetd, as a stand-alone daemon, or from an rsync
   54: client via a remote shell.  If run as a stand-alone daemon then just run the
   55: command "`rsync --daemon`" from a suitable startup script.
   56: 
   57: When run via inetd you should add a line like this to /etc/services:
   58: 
   59: >     rsync           873/tcp
   60: 
   61: and a single line something like this to /etc/inetd.conf:
   62: 
   63: >     rsync   stream  tcp     nowait  root   /usr/bin/rsync rsyncd --daemon
   64: 
   65: Replace "/usr/bin/rsync" with the path to where you have rsync installed on
   66: your system.  You will then need to send inetd a HUP signal to tell it to
   67: reread its config file.
   68: 
   69: Note that you should **not** send the rsync daemon a HUP signal to force it to
   70: reread the `rsyncd.conf` file. The file is re-read on each client connection.
   71: 
   72: # GLOBAL PARAMETERS
   73: 
   74: The first parameters in the file (before a [module] header) are the global
   75: parameters.  Rsync also allows for the use of a "[global]" module name to
   76: indicate the start of one or more global-parameter sections (the name must be
   77: lower case).
   78: 
   79: You may also include any module parameters in the global part of the config
   80: file in which case the supplied value will override the default for that
   81: parameter.
   82: 
   83: You may use references to environment variables in the values of parameters.
   84: String parameters will have %VAR% references expanded as late as possible (when
   85: the string is first used in the program), allowing for the use of variables
   86: that rsync sets at connection time, such as RSYNC_USER_NAME.  Non-string
   87: parameters (such as true/false settings) are expanded when read from the config
   88: file.  If a variable does not exist in the environment, or if a sequence of
   89: characters is not a valid reference (such as an un-paired percent sign), the
   90: raw characters are passed through unchanged.  This helps with backward
   91: compatibility and safety (e.g. expanding a non-existent %VAR% to an empty
   92: string in a path could result in a very unsafe path).  The safest way to insert
   93: a literal % into a value is to use %%.
   94: 
   95: [comment]: # (An OL starting at 0 is converted into a DL by the parser.)
   96: 
   97: 0.  `motd file`
   98: 
   99:     This parameter allows you to specify a "message of the day" to display to
  100:     clients on each connect. This usually contains site information and any
  101:     legal notices. The default is no motd file.  This can be overridden by the
  102:     `--dparam=motdfile=FILE` command-line option when starting the daemon.
  103: 
  104: 0.  `pid file`
  105: 
  106:     This parameter tells the rsync daemon to write its process ID to that file.
  107:     The rsync keeps the file locked so that it can know when it is safe to
  108:     overwrite an existing file.
  109: 
  110:     The filename can be overridden by the `--dparam=pidfile=FILE` command-line
  111:     option when starting the daemon.
  112: 
  113: 0.  `port`
  114: 
  115:     You can override the default port the daemon will listen on by specifying
  116:     this value (defaults to 873).  This is ignored if the daemon is being run
  117:     by inetd, and is superseded by the `--port` command-line option.
  118: 
  119: 0.  `address`
  120: 
  121:     You can override the default IP address the daemon will listen on by
  122:     specifying this value.  This is ignored if the daemon is being run by
  123:     inetd, and is superseded by the `--address` command-line option.
  124: 
  125: 0.  `socket options`
  126: 
  127:     This parameter can provide endless fun for people who like to tune their
  128:     systems to the utmost degree. You can set all sorts of socket options which
  129:     may make transfers faster (or slower!). Read the man page for the
  130:     **setsockopt()** system call for details on some of the options you may be
  131:     able to set. By default no special socket options are set.  These settings
  132:     can also be specified via the `--sockopts` command-line option.
  133: 
  134: 0.  `listen backlog`
  135: 
  136:     You can override the default backlog value when the daemon listens for
  137:     connections.  It defaults to 5.
  138: 
  139: 0.  `use slp`
  140: 
  141:     You can enable Service Location Protocol support by enabling this global
  142:     parameter.  The default is "false".
  143: 
  144: 0.  `slp refresh`
  145: 
  146:     This parameter is used to determine how long service advertisements are
  147:     valid (measured in seconds), and is only applicable if you have Service
  148:     Location Protocol support compiled in. If this is not set or is set to
  149:     zero, then service advertisements never time out. If this is set to less
  150:     than 120 seconds, then 120 seconds is used. If it is set to more than
  151:     65535, then 65535 is used (which is a limitation of SLP).  Using 3600
  152:     (one hour) is a good number if you tend to change your configuration.
  153: 
  154: # MODULE PARAMETERS
  155: 
  156: After the global parameters you should define a number of modules, each module
  157: exports a directory tree as a symbolic name. Modules are exported by specifying
  158: a module name in square brackets [module] followed by the parameters for that
  159: module.  The module name cannot contain a slash or a closing square bracket.
  160: If the name contains whitespace, each internal sequence of whitespace will be
  161: changed into a single space, while leading or trailing whitespace will be
  162: discarded.  Also, the name cannot be "global" as that exact name indicates that
  163: global parameters follow (see above).
  164: 
  165: As with GLOBAL PARAMETERS, you may use references to environment variables in
  166: the values of parameters.  See the GLOBAL PARAMETERS section for more details.
  167: 
  168: 0.  `comment`
  169: 
  170:     This parameter specifies a description string that is displayed next to the
  171:     module name when clients obtain a list of available modules. The default is
  172:     no comment.
  173: 
  174: 0.  `path`
  175: 
  176:     This parameter specifies the directory in the daemon's filesystem to make
  177:     available in this module.  You must specify this parameter for each module
  178:     in `rsyncd.conf`.
  179: 
  180:     You may base the path's value off of an environment variable by surrounding
  181:     the variable name with percent signs.  You can even reference a variable
  182:     that is set by rsync when the user connects.  For example, this would use
  183:     the authorizing user's name in the path:
  184: 
  185:     >     path = /home/%RSYNC_USER_NAME%
  186: 
  187:     It is fine if the path includes internal spaces -- they will be retained
  188:     verbatim (which means that you shouldn't try to escape them).  If your
  189:     final directory has a trailing space (and this is somehow not something you
  190:     wish to fix), append a trailing slash to the path to avoid losing the
  191:     trailing whitespace.
  192: 
  193: 0.  `use chroot`
  194: 
  195:     If "use chroot" is true, the rsync daemon will chroot to the "path" before
  196:     starting the file transfer with the client.  This has the advantage of
  197:     extra protection against possible implementation security holes, but it has
  198:     the disadvantages of requiring super-user privileges, of not being able to
  199:     follow symbolic links that are either absolute or outside of the new root
  200:     path, and of complicating the preservation of users and groups by name (see
  201:     below).
  202: 
  203:     As an additional safety feature, you can specify a dot-dir in the module's
  204:     "path" to indicate the point where the chroot should occur.  This allows
  205:     rsync to run in a chroot with a non-"/" path for the top of the transfer
  206:     hierarchy.  Doing this guards against unintended library loading (since
  207:     those absolute paths will not be inside the transfer hierarchy unless you
  208:     have used an unwise pathname), and lets you setup libraries for the chroot
  209:     that are outside of the transfer.  For example, specifying
  210:     "/var/rsync/./module1" will chroot to the "/var/rsync" directory and set
  211:     the inside-chroot path to "/module1".  If you had omitted the dot-dir, the
  212:     chroot would have used the whole path, and the inside-chroot path would
  213:     have been "/".
  214: 
  215:     When both "use chroot" and "daemon chroot" are false, OR the inside-chroot
  216:     path of "use chroot" is not "/", rsync will: (1) munge symlinks by default
  217:     for security reasons (see "munge symlinks" for a way to turn this off, but
  218:     only if you trust your users), (2) substitute leading slashes in absolute
  219:     paths with the module's path (so that options such as `--backup-dir`,
  220:     `--compare-dest`, etc. interpret an absolute path as rooted in the module's
  221:     "path" dir), and (3) trim ".." path elements from args if rsync believes
  222:     they would escape the module hierarchy.  The default for "use chroot" is
  223:     true, and is the safer choice (especially if the module is not read-only).
  224: 
  225:     When this parameter is enabled *and* the "name converter" parameter is
  226:     *not* set, the "numeric ids" parameter will default to being enabled
  227:     (disabling name lookups).  This means that if you manually setup
  228:     name-lookup libraries in your chroot (instead of using a name converter)
  229:     that you need to explicitly set `numeric ids = false` for rsync to do name
  230:     lookups.
  231: 
  232:     If you copy library resources into the module's chroot area, you should
  233:     protect them through your OS's normal user/group or ACL settings (to
  234:     prevent the rsync module's user from being able to change them), and then
  235:     hide them from the user's view via "exclude" (see how in the discussion of
  236:     that parameter).  However, it's easier and safer to setup a name converter.
  237: 
  238: 0.  `daemon chroot`
  239: 
  240:     This parameter specifies a path to which the daemon will chroot before
  241:     beginning communication with clients. Module paths (and any "use chroot"
  242:     settings) will then be related to this one. This lets you choose if you
  243:     want the whole daemon to be chrooted (with this setting), just the
  244:     transfers to be chrooted (with "use chroot"), or both.  Keep in mind that
  245:     the "daemon chroot" area may need various OS/lib/etc files installed to
  246:     allow the daemon to function.  By default the daemon runs without any
  247:     chrooting.
  248: 
  249: 0.  `proxy protocol`
  250: 
  251:     When this parameter is enabled, all incoming connections must start with a
  252:     V1 or V2 proxy protocol header.  If the header is not found, the connection
  253:     is closed.
  254: 
  255:     Setting this to `true` requires a proxy server to forward source IP
  256:     information to rsync, allowing you to log proper IP/host info and make use
  257:     of client-oriented IP restrictions.  The default of `false` means that the
  258:     IP information comes directly from the socket's metadata.  If rsync is not
  259:     behind a proxy, this should be disabled.
  260: 
  261:     _CAUTION_: using this option can be dangerous if you do not ensure that
  262:     only the proxy is allowed to connect to the rsync port.  If any non-proxied
  263:     connections are allowed through, the client will be able to use a modified
  264:     rsync to spoof any remote IP address that they desire.  You can lock this
  265:     down using something like iptables `-uid-owner root` rules (for strict
  266:     localhost access), various firewall rules, or you can require password
  267:     authorization so that any spoofing by users will not grant extra access.
  268: 
  269:     This setting is global.  If you need some modules to require this and not
  270:     others, then you will need to setup multiple rsync daemon processes on
  271:     different ports.
  272: 
  273: 0.  `name converter`
  274: 
  275:     This parameter lets you specify a program that will be run by the rsync
  276:     daemon to do user & group conversions between names & ids.  This script
  277:     is started prior to any chroot being setup, and runs as the daemon user
  278:     (not the transfer user).  You can specify a fully qualified pathname or
  279:     a program name that is on the $PATH.
  280: 
  281:     The program can be used to do normal user & group lookups without having to
  282:     put any extra files into the chroot area of the module *or* you can do
  283:     customized conversions.
  284: 
  285:     The nameconvert program has access to all of the environment variables that
  286:     are described in the section on `pre-xfer exec`.  This is useful if you
  287:     want to customize the conversion using information about the module and/or
  288:     the copy request.
  289: 
  290:     There is a sample python script in the support dir named "nameconvert" that
  291:     implements the normal user & group lookups.  Feel free to customize it or
  292:     just use it as documentation to implement your own.
  293: 
  294: 0.  `numeric ids`
  295: 
  296:     Enabling this parameter disables the mapping of users and groups by name
  297:     for the current daemon module.  This prevents the daemon from trying to
  298:     load any user/group-related files or libraries.  This enabling makes the
  299:     transfer behave as if the client had passed the `--numeric-ids`
  300:     command-line option.  By default, this parameter is enabled for chroot
  301:     modules and disabled for non-chroot modules.  Also keep in mind that
  302:     uid/gid preservation requires the module to be running as root (see "uid")
  303:     or for "fake super" to be configured.
  304: 
  305:     A chroot-enabled module should not have this parameter set to false unless
  306:     you're using a "name converter" program *or* you've taken steps to ensure
  307:     that the module has the necessary resources it needs to translate names and
  308:     that it is not possible for a user to change those resources.
  309: 
  310: 0.  `munge symlinks`
  311: 
  312:     This parameter tells rsync to modify all symlinks in the same way as the
  313:     (non-daemon-affecting) `--munge-links` command-line option (using a method
  314:     described below).  This should help protect your files from user trickery
  315:     when your daemon module is writable.  The default is disabled when
  316:     "use chroot" is on with an inside-chroot path of "/", OR if "daemon chroot"
  317:     is on, otherwise it is enabled.
  318: 
  319:     If you disable this parameter on a daemon that is not read-only, there are
  320:     tricks that a user can play with uploaded symlinks to access
  321:     daemon-excluded items (if your module has any), and, if "use chroot" is
  322:     off, rsync can even be tricked into showing or changing data that is
  323:     outside the module's path (as access-permissions allow).
  324: 
  325:     The way rsync disables the use of symlinks is to prefix each one with the
  326:     string "/rsyncd-munged/".  This prevents the links from being used as long
  327:     as that directory does not exist.  When this parameter is enabled, rsync
  328:     will refuse to run if that path is a directory or a symlink to a directory.
  329:     When using the "munge symlinks" parameter in a chroot area that has an
  330:     inside-chroot path of "/", you should add "/rsyncd-munged/" to the exclude
  331:     setting for the module so that a user can't try to create it.
  332: 
  333:     Note:  rsync makes no attempt to verify that any pre-existing symlinks in
  334:     the module's hierarchy are as safe as you want them to be (unless, of
  335:     course, it just copied in the whole hierarchy).  If you setup an rsync
  336:     daemon on a new area or locally add symlinks, you can manually protect your
  337:     symlinks from being abused by prefixing "/rsyncd-munged/" to the start of
  338:     every symlink's value.  There is a perl script in the support directory of
  339:     the source code named "munge-symlinks" that can be used to add or remove
  340:     this prefix from your symlinks.
  341: 
  342:     When this parameter is disabled on a writable module and "use chroot" is
  343:     off (or the inside-chroot path is not "/"), incoming symlinks will be
  344:     modified to drop a leading slash and to remove ".." path elements that
  345:     rsync believes will allow a symlink to escape the module's hierarchy.
  346:     There are tricky ways to work around this, though, so you had better trust
  347:     your users if you choose this combination of parameters.
  348: 
  349: 0.  `charset`
  350: 
  351:     This specifies the name of the character set in which the module's
  352:     filenames are stored.  If the client uses an `--iconv` option, the daemon
  353:     will use the value of the "charset" parameter regardless of the character
  354:     set the client actually passed.  This allows the daemon to support charset
  355:     conversion in a chroot module without extra files in the chroot area, and
  356:     also ensures that name-translation is done in a consistent manner.  If the
  357:     "charset" parameter is not set, the `--iconv` option is refused, just as if
  358:     "iconv" had been specified via "refuse options".
  359: 
  360:     If you wish to force users to always use `--iconv` for a particular module,
  361:     add "no-iconv" to the "refuse options" parameter.  Keep in mind that this
  362:     will restrict access to your module to very new rsync clients.
  363: 
  364: 0.  `max connections`
  365: 
  366:     This parameter allows you to specify the maximum number of simultaneous
  367:     connections you will allow.  Any clients connecting when the maximum has
  368:     been reached will receive a message telling them to try later.  The default
  369:     is 0, which means no limit.  A negative value disables the module.  See
  370:     also the "lock file" parameter.
  371: 
  372: 0.  `link by hash dir`
  373: 
  374:     When the "link by hash dir" parameter is set to a non-empty string,
  375:     received files will be hard linked into **DIR**, a link farm arranged by
  376:     MD5 file hash. See the `--link-by-hash` option for a full explanation.
  377: 
  378:     The **DIR** must be accessible inside any chroot restrictions for the
  379:     module, but can exist outside the transfer location if there is an
  380:     inside-the-chroot path to the module (see "use chroot").  Note that a
  381:     user-specified option does not allow this outside-the-transfer-area
  382:     placement.
  383: 
  384:     If this parameter is set, it will disable the `--link-by-hash` command-line
  385:     option for copies into the module.
  386: 
  387: The default is for this parameter to be unset.
  388: 
  389: 0.  `log file`
  390: 
  391:     When the "log file" parameter is set to a non-empty string, the rsync
  392:     daemon will log messages to the indicated file rather than using syslog.
  393:     This is particularly useful on systems (such as AIX) where **syslog()**
  394:     doesn't work for chrooted programs.  The file is opened before **chroot()**
  395:     is called, allowing it to be placed outside the transfer.  If this value is
  396:     set on a per-module basis instead of globally, the global log will still
  397:     contain any authorization failures or config-file error messages.
  398: 
  399:     If the daemon fails to open the specified file, it will fall back to using
  400:     syslog and output an error about the failure.  (Note that the failure to
  401:     open the specified log file used to be a fatal error.)
  402: 
  403:     This setting can be overridden by using the `--log-file=FILE` or
  404:     `--dparam=logfile=FILE` command-line options.  The former overrides all the
  405:     log-file parameters of the daemon and all module settings.  The latter sets
  406:     the daemon's log file and the default for all the modules, which still
  407:     allows modules to override the default setting.
  408: 
  409: 0.  `syslog facility`
  410: 
  411:     This parameter allows you to specify the syslog facility name to use when
  412:     logging messages from the rsync daemon. You may use any standard syslog
  413:     facility name which is defined on your system. Common names are auth,
  414:     authpriv, cron, daemon, ftp, kern, lpr, mail, news, security, syslog, user,
  415:     uucp, local0, local1, local2, local3, local4, local5, local6 and local7.
  416:     The default is daemon.  This setting has no effect if the "log file"
  417:     setting is a non-empty string (either set in the per-modules settings, or
  418:     inherited from the global settings).
  419: 
  420: 0.  `syslog tag`
  421: 
  422:     This parameter allows you to specify the syslog tag to use when logging
  423:     messages from the rsync daemon. The default is "rsyncd".  This setting has
  424:     no effect if the "log file" setting is a non-empty string (either set in
  425:     the per-modules settings, or inherited from the global settings).
  426: 
  427:     For example, if you wanted each authenticated user's name to be included in
  428:     the syslog tag, you could do something like this:
  429: 
  430:     >     syslog tag = rsyncd.%RSYNC_USER_NAME%
  431: 
  432: 0.  `max verbosity`
  433: 
  434:     This parameter allows you to control the maximum amount of verbose
  435:     information that you'll allow the daemon to generate (since the information
  436:     goes into the log file). The default is 1, which allows the client to
  437:     request one level of verbosity.
  438: 
  439:     This also affects the user's ability to request higher levels of `--info`
  440:     and `--debug` logging.  If the max value is 2, then no info and/or debug
  441:     value that is higher than what would be set by `-vv` will be honored by the
  442:     daemon in its logging.  To see how high of a verbosity level you need to
  443:     accept for a particular info/debug level, refer to `rsync --info=help` and
  444:     `rsync --debug=help`.  For instance, it takes max-verbosity 4 to be able to
  445:     output debug TIME2 and FLIST3.
  446: 
  447: 0.  `lock file`
  448: 
  449:     This parameter specifies the file to use to support the "max connections"
  450:     parameter. The rsync daemon uses record locking on this file to ensure that
  451:     the max connections limit is not exceeded for the modules sharing the lock
  452:     file.  The default is `/var/run/rsyncd.lock`.
  453: 
  454: 0.  `checksum files`
  455: 
  456:     This parameter tells rsync to make use of any cached checksum information
  457:     it finds in per-directory .rsyncsums files when the current transfer is
  458:     using the `--checksum` option.  The value can be set to either "lax",
  459:     "strict", "+lax", "+strict", "++lax", "++strict", or +"none".  See the
  460:     client's `--sumfiles` option for what these choices do.
  461: 
  462:     Note also that the client's command-line option, `--sumfiles`, has no
  463:     effect on a daemon.  A daemon will only access checksum files if this
  464:     config option tells it to.  You can configure updating of the .rsyncsums
  465:     files even if the module itself is configured to be read-only.  See also
  466:     the `exclude` directive for a way to hide the .rsyncsums files from the
  467:     user.
  468: 
  469: 0.  `read only`
  470: 
  471:     This parameter determines whether clients will be able to upload files or
  472:     not. If "read only" is true then any attempted uploads will fail. If
  473:     "read only" is false then uploads will be possible if file permissions on
  474:     the daemon side allow them. The default is for all modules to be read only.
  475: 
  476:     Note that "auth users" can override this setting on a per-user basis.
  477: 
  478: 0.  `write only`
  479: 
  480:     This parameter determines whether clients will be able to download files or
  481:     not. If "write only" is true then any attempted downloads will fail. If
  482:     "write only" is false then downloads will be possible if file permissions
  483:     on the daemon side allow them.  The default is for this parameter to be
  484:     disabled.
  485: 
  486:     Helpful hint: you probably want to specify "refuse options = delete" for a
  487:     write-only module.
  488: 
  489: 0.  `open noatime`
  490: 
  491:     When set to True, this parameter tells the rsync daemon to open files with
  492:     the O_NOATIME flag
  493:     (on systems that support it) to avoid changing the access time of the files
  494:     that are being transferred.  If your OS does not support the O_NOATIME flag
  495:     then rsync will silently ignore this option.  Note also that some
  496:     filesystems are mounted to avoid updating the atime on read access even
  497:     without the O_NOATIME flag being set.
  498: 
  499:     When set to False, this parameters ensures that files on the server are not
  500:     opened with O_NOATIME.
  501: 
  502:     When set to Unset (the default) the user controls the setting via
  503:     `--open-noatime`.
  504: 
  505: 0.  `list`
  506: 
  507:     This parameter determines whether this module is listed when the client
  508:     asks for a listing of available modules.  In addition, if this is false,
  509:     the daemon will pretend the module does not exist when a client denied by
  510:     "hosts allow" or "hosts deny" attempts to access it.  Realize that if
  511:     "reverse lookup" is disabled globally but enabled for the module, the
  512:     resulting reverse lookup to a potentially client-controlled DNS server may
  513:     still reveal to the client that it hit an existing module.  The default is
  514:     for modules to be listable.
  515: 
  516: 0.  `uid`
  517: 
  518:     This parameter specifies the user name or user ID that file transfers to
  519:     and from that module should take place as when the daemon was run as root.
  520:     In combination with the "gid" parameter this determines what file
  521:     permissions are available. The default when run by a super-user is to
  522:     switch to the system's "nobody" user.  The default for a non-super-user is
  523:     to not try to change the user.  See also the "gid" parameter.
  524: 
  525:     The RSYNC_USER_NAME environment variable may be used to request that rsync
  526:     run as the authorizing user.  For example, if you want a rsync to run as
  527:     the same user that was received for the rsync authentication, this setup is
  528:     useful:
  529: 
  530:     >     uid = %RSYNC_USER_NAME%
  531:     >     gid = *
  532: 
  533: 0.  `gid`
  534: 
  535:     This parameter specifies one or more group names/IDs that will be used when
  536:     accessing the module.  The first one will be the default group, and any
  537:     extra ones be set as supplemental groups.  You may also specify a "`*`" as
  538:     the first gid in the list, which will be replaced by all the normal groups
  539:     for the transfer's user (see "uid").  The default when run by a super-user
  540:     is to switch to your OS's "nobody" (or perhaps "nogroup") group with no
  541:     other supplementary groups.  The default for a non-super-user is to not
  542:     change any group attributes (and indeed, your OS may not allow a
  543:     non-super-user to try to change their group settings).
  544: 
  545:     The specified list is normally split into tokens based on spaces and
  546:     commas.  However, if the list starts with a comma, then the list is only
  547:     split on commas, which allows a group name to contain a space.  In either
  548:     case any leading and/or trailing whitespace is removed from the tokens and
  549:     empty tokens are ignored.
  550: 
  551: 0.  `daemon uid`
  552: 
  553:     This parameter specifies a uid under which the daemon will run. The daemon
  554:     usually runs as user root, and when this is left unset the user is left
  555:     unchanged. See also the "uid" parameter.
  556: 
  557: 0.  `daemon gid`
  558: 
  559:     This parameter specifies a gid under which the daemon will run. The daemon
  560:     usually runs as group root, and when this is left unset, the group is left
  561:     unchanged. See also the "gid" parameter.
  562: 
  563: 0.  `fake super`
  564: 
  565:     Setting "fake super = yes" for a module causes the daemon side to behave as
  566:     if the `--fake-super` command-line option had been specified.  This allows
  567:     the full attributes of a file to be stored without having to have the
  568:     daemon actually running as root.
  569: 
  570: 0.  `filter`
  571: 
  572:     The daemon has its own filter chain that determines what files it will let
  573:     the client access.  This chain is not sent to the client and is independent
  574:     of any filters the client may have specified.  Files excluded by the daemon
  575:     filter chain (`daemon-excluded` files) are treated as non-existent if the
  576:     client tries to pull them, are skipped with an error message if the client
  577:     tries to push them (triggering exit code 23), and are never deleted from
  578:     the module.  You can use daemon filters to prevent clients from downloading
  579:     or tampering with private administrative files, such as files you may add
  580:     to support uid/gid name translations.
  581: 
  582:     The daemon filter chain is built from the "filter", "include from",
  583:     "include", "exclude from", and "exclude" parameters, in that order of
  584:     priority.  Anchored patterns are anchored at the root of the module.  To
  585:     prevent access to an entire subtree, for example, "`/secret`", you **must**
  586:     exclude everything in the subtree; the easiest way to do this is with a
  587:     triple-star pattern like "`/secret/***`".
  588: 
  589:     The "filter" parameter takes a space-separated list of daemon filter rules,
  590:     though it is smart enough to know not to split a token at an internal space
  591:     in a rule (e.g. "`- /foo  - /bar`" is parsed as two rules).  You may specify
  592:     one or more merge-file rules using the normal syntax.  Only one "filter"
  593:     parameter can apply to a given module in the config file, so put all the
  594:     rules you want in a single parameter.  Note that per-directory merge-file
  595:     rules do not provide as much protection as global rules, but they can be
  596:     used to make `--delete` work better during a client download operation if
  597:     the per-dir merge files are included in the transfer and the client
  598:     requests that they be used.
  599: 
  600: 0.  `exclude`
  601: 
  602:     This parameter takes a space-separated list of daemon exclude patterns.  As
  603:     with the client `--exclude` option, patterns can be qualified with "`- `" or
  604:     "`+ `" to explicitly indicate exclude/include.  Only one "exclude" parameter
  605:     can apply to a given module.  See the "filter" parameter for a description
  606:     of how excluded files affect the daemon.
  607: 
  608: 0.  `include`
  609: 
  610:     Use an "include" to override the effects of the "exclude" parameter.  Only
  611:     one "include" parameter can apply to a given module.  See the "filter"
  612:     parameter for a description of how excluded files affect the daemon.
  613: 
  614: 0.  `exclude from`
  615: 
  616:     This parameter specifies the name of a file on the daemon that contains
  617:     daemon exclude patterns, one per line.  Only one "exclude from" parameter
  618:     can apply to a given module; if you have multiple exclude-from files, you
  619:     can specify them as a merge file in the "filter" parameter.  See the
  620:     "filter" parameter for a description of how excluded files affect the
  621:     daemon.
  622: 
  623: 0.  `include from`
  624: 
  625:     Analogue of "exclude from" for a file of daemon include patterns.  Only one
  626:     "include from" parameter can apply to a given module.  See the "filter"
  627:     parameter for a description of how excluded files affect the daemon.
  628: 
  629: 0.  `incoming chmod`
  630: 
  631:     This parameter allows you to specify a set of comma-separated chmod strings
  632:     that will affect the permissions of all incoming files (files that are
  633:     being received by the daemon).  These changes happen after all other
  634:     permission calculations, and this will even override destination-default
  635:     and/or existing permissions when the client does not specify `--perms`.
  636:     See the description of the `--chmod` rsync option and the **chmod**(1)
  637:     manpage for information on the format of this string.
  638: 
  639: 0.  `outgoing chmod`
  640: 
  641:     This parameter allows you to specify a set of comma-separated chmod strings
  642:     that will affect the permissions of all outgoing files (files that are
  643:     being sent out from the daemon).  These changes happen first, making the
  644:     sent permissions appear to be different than those stored in the filesystem
  645:     itself.  For instance, you could disable group write permissions on the
  646:     server while having it appear to be on to the clients.  See the description
  647:     of the `--chmod` rsync option and the **chmod**(1) manpage for information
  648:     on the format of this string.
  649: 
  650: 0.  `auth users`
  651: 
  652:     This parameter specifies a comma and/or space-separated list of
  653:     authorization rules.  In its simplest form, you list the usernames that
  654:     will be allowed to connect to this module. The usernames do not need to
  655:     exist on the local system. The rules may contain shell wildcard characters
  656:     that will be matched against the username provided by the client for
  657:     authentication. If "auth users" is set then the client will be challenged
  658:     to supply a username and password to connect to the module. A challenge
  659:     response authentication protocol is used for this exchange. The plain text
  660:     usernames and passwords are stored in the file specified by the
  661:     "secrets file" parameter. The default is for all users to be able to
  662:     connect without a password (this is called "anonymous rsync").
  663: 
  664:     In addition to username matching, you can specify groupname matching via a
  665:     '@' prefix.  When using groupname matching, the authenticating username
  666:     must be a real user on the system, or it will be assumed to be a member of
  667:     no groups.  For example, specifying "@rsync" will match the authenticating
  668:     user if the named user is a member of the rsync group.
  669: 
  670:     Finally, options may be specified after a colon (:).  The options allow you
  671:     to "deny" a user or a group, set the access to "ro" (read-only), or set the
  672:     access to "rw" (read/write).  Setting an auth-rule-specific ro/rw setting
  673:     overrides the module's "read only" setting.
  674: 
  675:     Be sure to put the rules in the order you want them to be matched, because
  676:     the checking stops at the first matching user or group, and that is the
  677:     only auth that is checked.  For example:
  678: 
  679:     >     auth users = joe:deny @guest:deny admin:rw @rsync:ro susan joe sam
  680: 
  681:     In the above rule, user joe will be denied access no matter what.  Any user
  682:     that is in the group "guest" is also denied access.  The user "admin" gets
  683:     access in read/write mode, but only if the admin user is not in group
  684:     "guest" (because the admin user-matching rule would never be reached if the
  685:     user is in group "guest").  Any other user who is in group "rsync" will get
  686:     read-only access.  Finally, users susan, joe, and sam get the ro/rw setting
  687:     of the module, but only if the user didn't match an earlier group-matching
  688:     rule.
  689: 
  690:     If you need to specify a user or group name with a space in it, start your
  691:     list with a comma to indicate that the list should only be split on commas
  692:     (though leading and trailing whitespace will also be removed, and empty
  693:     entries are just ignored).  For example:
  694: 
  695:     >     auth users = , joe:deny, @Some Group:deny, admin:rw, @RO Group:ro
  696: 
  697:     See the description of the secrets file for how you can have per-user
  698:     passwords as well as per-group passwords.  It also explains how a user can
  699:     authenticate using their user password or (when applicable) a group
  700:     password, depending on what rule is being authenticated.
  701: 
  702:     See also the section entitled "USING RSYNC-DAEMON FEATURES VIA A REMOTE
  703:     SHELL CONNECTION" in **rsync**(1) for information on how handle an
  704:     rsyncd.conf-level username that differs from the remote-shell-level
  705:     username when using a remote shell to connect to an rsync daemon.
  706: 
  707: 0.  `secrets file`
  708: 
  709:     This parameter specifies the name of a file that contains the
  710:     username:password and/or @groupname:password pairs used for authenticating
  711:     this module. This file is only consulted if the "auth users" parameter is
  712:     specified.  The file is line-based and contains one name:password pair per
  713:     line.  Any line has a hash (#) as the very first character on the line is
  714:     considered a comment and is skipped.  The passwords can contain any
  715:     characters but be warned that many operating systems limit the length of
  716:     passwords that can be typed at the client end, so you may find that
  717:     passwords longer than 8 characters don't work.
  718: 
  719:     The use of group-specific lines are only relevant when the module is being
  720:     authorized using a matching "@groupname" rule.  When that happens, the user
  721:     can be authorized via either their "username:password" line or the
  722:     "@groupname:password" line for the group that triggered the authentication.
  723: 
  724:     It is up to you what kind of password entries you want to include, either
  725:     users, groups, or both.  The use of group rules in "auth users" does not
  726:     require that you specify a group password if you do not want to use shared
  727:     passwords.
  728: 
  729:     There is no default for the "secrets file" parameter, you must choose a
  730:     name (such as `/etc/rsyncd.secrets`).  The file must normally not be
  731:     readable by "other"; see "strict modes".  If the file is not found or is
  732:     rejected, no logins for a "user auth" module will be possible.
  733: 
  734: 0.  `strict modes`
  735: 
  736:     This parameter determines whether or not the permissions on the secrets
  737:     file will be checked.  If "strict modes" is true, then the secrets file
  738:     must not be readable by any user ID other than the one that the rsync
  739:     daemon is running under.  If "strict modes" is false, the check is not
  740:     performed.  The default is true.  This parameter was added to accommodate
  741:     rsync running on the Windows operating system.
  742: 
  743: 0.  `hosts allow`
  744: 
  745:     This parameter allows you to specify a list of comma- and/or
  746:     whitespace-separated patterns that are matched against a connecting
  747:     client's hostname and IP address.  If none of the patterns match, then the
  748:     connection is rejected.
  749: 
  750:     Each pattern can be in one of six forms:
  751: 
  752:     - a dotted decimal IPv4 address of the form a.b.c.d, or an IPv6 address of
  753:       the form a:b:c::d:e:f. In this case the incoming machine's IP address
  754:       must match exactly.
  755:     - an address/mask in the form ipaddr/n where ipaddr is the IP address and n
  756:       is the number of one bits in the netmask.  All IP addresses which match
  757:       the masked IP address will be allowed in.
  758:     - an address/mask in the form ipaddr/maskaddr where ipaddr is the IP
  759:       address and maskaddr is the netmask in dotted decimal notation for IPv4,
  760:       or similar for IPv6, e.g. ffff:ffff:ffff:ffff:: instead of /64. All IP
  761:       addresses which match the masked IP address will be allowed in.
  762:     - a hostname pattern using wildcards. If the hostname of the connecting IP
  763:       (as determined by a reverse lookup) matches the wildcarded name (using
  764:       the same rules as normal unix filename matching), the client is allowed
  765:       in.  This only works if "reverse lookup" is enabled (the default).
  766:     - a hostname. A plain hostname is matched against the reverse DNS of the
  767:       connecting IP (if "reverse lookup" is enabled), and/or the IP of the
  768:       given hostname is matched against the connecting IP (if "forward lookup"
  769:       is enabled, as it is by default).  Any match will be allowed in.
  770:     - an '@' followed by a netgroup name, which will match if the reverse DNS
  771:       of the connecting IP is in the specified netgroup.
  772: 
  773:     Note IPv6 link-local addresses can have a scope in the address
  774:     specification:
  775: 
  776:     >     fe80::1%link1
  777:     >     fe80::%link1/64
  778:     >     fe80::%link1/ffff:ffff:ffff:ffff::
  779: 
  780:     You can also combine "hosts allow" with "hosts deny" as a way to add
  781:     exceptions to your deny list.  When both parameters are specified, the
  782:     "hosts allow" parameter is checked first and a match results in the client
  783:     being able to connect.  A non-allowed host is then matched against the
  784:     "hosts deny" list to see if it should be rejected.  A host that does not
  785:     match either list is allowed to connect.
  786: 
  787:     The default is no "hosts allow" parameter, which means all hosts can
  788:     connect.
  789: 
  790: 0.  `hosts deny`
  791: 
  792:     This parameter allows you to specify a list of comma- and/or
  793:     whitespace-separated patterns that are matched against a connecting clients
  794:     hostname and IP address. If the pattern matches then the connection is
  795:     rejected. See the "hosts allow" parameter for more information.
  796: 
  797:     The default is no "hosts deny" parameter, which means all hosts can
  798:     connect.
  799: 
  800: 0.  `reverse lookup`
  801: 
  802:     Controls whether the daemon performs a reverse lookup on the client's IP
  803:     address to determine its hostname, which is used for "hosts allow" &
  804:     "hosts deny" checks and the "%h" log escape.  This is enabled by default,
  805:     but you may wish to disable it to save time if you know the lookup will not
  806:     return a useful result, in which case the daemon will use the name
  807:     "UNDETERMINED" instead.
  808: 
  809:     If this parameter is enabled globally (even by default), rsync performs the
  810:     lookup as soon as a client connects, so disabling it for a module will not
  811:     avoid the lookup.  Thus, you probably want to disable it globally and then
  812:     enable it for modules that need the information.
  813: 
  814: 0.  `forward lookup`
  815: 
  816:     Controls whether the daemon performs a forward lookup on any hostname
  817:     specified in an hosts allow/deny setting.  By default this is enabled,
  818:     allowing the use of an explicit hostname that would not be returned by
  819:     reverse DNS of the connecting IP.
  820: 
  821: 0.  `ignore errors`
  822: 
  823:     This parameter tells rsyncd to ignore I/O errors on the daemon when
  824:     deciding whether to run the delete phase of the transfer. Normally rsync
  825:     skips the `--delete` step if any I/O errors have occurred in order to
  826:     prevent disastrous deletion due to a temporary resource shortage or other
  827:     I/O error. In some cases this test is counter productive so you can use
  828:     this parameter to turn off this behavior.
  829: 
  830: 0.  `ignore nonreadable`
  831: 
  832:     This tells the rsync daemon to completely ignore files that are not
  833:     readable by the user. This is useful for public archives that may have some
  834:     non-readable files among the directories, and the sysadmin doesn't want
  835:     those files to be seen at all.
  836: 
  837: 0.  `transfer logging`
  838: 
  839:     This parameter enables per-file logging of downloads and uploads in a
  840:     format somewhat similar to that used by ftp daemons.  The daemon always
  841:     logs the transfer at the end, so if a transfer is aborted, no mention will
  842:     be made in the log file.
  843: 
  844:     If you want to customize the log lines, see the "log format" parameter.
  845: 
  846: 0.  `log format`
  847: 
  848:     This parameter allows you to specify the format used for logging file
  849:     transfers when transfer logging is enabled.  The format is a text string
  850:     containing embedded single-character escape sequences prefixed with a
  851:     percent (%) character.  An optional numeric field width may also be
  852:     specified between the percent and the escape letter (e.g.
  853:     "`%-50n %8l %07p`").  In addition, one or more apostrophes may be specified
  854:     prior to a numerical escape to indicate that the numerical value should be
  855:     made more human-readable.  The 3 supported levels are the same as for the
  856:     `--human-readable` command-line option, though the default is for
  857:     human-readability to be off.  Each added apostrophe increases the level
  858:     (e.g. "`%''l %'b %f`").
  859: 
  860:     The default log format is "`%o %h [%a] %m (%u) %f %l`", and a "`%t [%p] `"
  861:     is always prefixed when using the "log file" parameter.  (A perl script
  862:     that will summarize this default log format is included in the rsync source
  863:     code distribution in the "support" subdirectory: rsyncstats.)
  864: 
  865:     The single-character escapes that are understood are as follows:
  866: 
  867:     - %a the remote IP address (only available for a daemon)
  868:     - %b the number of bytes actually transferred
  869:     - %B the permission bits of the file (e.g. rwxrwxrwt)
  870:     - %c the total size of the block checksums received for the basis file
  871:       (only when sending)
  872:     - %C the full-file checksum if it is known for the file. For older rsync
  873:       protocols/versions, the checksum was salted, and is thus not a useful
  874:       value (and is not displayed when that is the case). For the checksum to
  875:       output for a file, either the `--checksum` option must be in-effect or
  876:       the file must have been transferred without a salted checksum being used.
  877:       See the `--checksum-choice` option for a way to choose the algorithm.
  878:     - %f the filename (long form on sender; no trailing "/")
  879:     - %G the gid of the file (decimal) or "DEFAULT"
  880:     - %h the remote host name (only available for a daemon)
  881:     - %i an itemized list of what is being updated
  882:     - %l the length of the file in bytes
  883:     - %L the string "` -> SYMLINK`", "` => HARDLINK`", or "" (where `SYMLINK`
  884:       or `HARDLINK` is a filename)
  885:     - %m the module name
  886:     - %M the last-modified time of the file
  887:     - %n the filename (short form; trailing "/" on dir)
  888:     - %o the operation, which is "send", "recv", or "del." (the latter includes
  889:       the trailing period)
  890:     - %p the process ID of this rsync session
  891:     - %P the module path
  892:     - %t the current date time
  893:     - %u the authenticated username or an empty string
  894:     - %U the uid of the file (decimal)
  895: 
  896:     For a list of what the characters mean that are output by "%i", see the
  897:     `--itemize-changes` option in the rsync manpage.
  898: 
  899:     Note that some of the logged output changes when talking with older rsync
  900:     versions.  For instance, deleted files were only output as verbose messages
  901:     prior to rsync 2.6.4.
  902: 
  903: 0.  `timeout`
  904: 
  905:     This parameter allows you to override the clients choice for I/O timeout
  906:     for this module. Using this parameter you can ensure that rsync won't wait
  907:     on a dead client forever. The timeout is specified in seconds. A value of
  908:     zero means no timeout and is the default. A good choice for anonymous rsync
  909:     daemons may be 600 (giving a 10 minute timeout).
  910: 
  911: 0.  `refuse options`
  912: 
  913:     This parameter allows you to specify a space-separated list of rsync
  914:     command-line options that will be refused by your rsync daemon.  You may
  915:     specify the full option name, its one-letter abbreviation, or a wild-card
  916:     string that matches multiple options. Beginning in 3.2.0, you can also
  917:     negate a match term by starting it with a "!".
  918: 
  919:     When an option is refused, the daemon prints an error message and exits.
  920: 
  921:     For example, this would refuse `--checksum` (`-c`) and all the various
  922:     delete options:
  923: 
  924:     >     refuse options = c delete
  925: 
  926:     The reason the above refuses all delete options is that the options imply
  927:     `--delete`, and implied options are refused just like explicit options.
  928: 
  929:     The use of a negated match allows you to fine-tune your refusals after a
  930:     wild-card, such as this:
  931: 
  932:     >     refuse options = delete-* !delete-during
  933: 
  934:     Negated matching can also turn your list of refused options into a list of
  935:     accepted options. To do this, begin the list with a "`*`" (to refuse all
  936:     options) and then specify one or more negated matches to accept.  For
  937:     example:
  938: 
  939:     >     refuse options = * !a !v !compress*
  940: 
  941:     Don't worry that the "`*`" will refuse certain vital options such as
  942:     `--dry-run`, `--server`, `--no-iconv`, `--protect-args`, etc. These
  943:     important options are not matched by wild-card, so they must be overridden
  944:     by their exact name.  For instance, if you're forcing iconv transfers you
  945:     could use something like this:
  946: 
  947:     >     refuse options = * no-iconv !a !v
  948: 
  949:     As an additional aid (beginning in 3.2.0), refusing (or "`!refusing`") the
  950:     "a" or "archive"  option also affects all the options that the `--archive`
  951:     option implies (`-rdlptgoD`), but only if the option  is matched explicitly
  952:     (not using a wildcard). If you want to do something tricky, you can use
  953:     "`archive*`" to avoid this side-effect, but keep in mind that no normal
  954:     rsync client ever sends the actual archive option to the server.
  955: 
  956:     As an additional safety feature, the refusal of "delete" also refuses
  957:     `remove-source-files` when the daemon is the sender; if you want the latter
  958:     without the former, instead refuse "`delete-*`" as that refuses all the
  959:     delete modes without affecting `--remove-source-files`. (Keep in mind that
  960:     the client's `--delete` option typically results in `--delete-during`.)
  961: 
  962:     When un-refusing delete options, you should either specify "`!delete*`" (to
  963:     accept all delete options) or specify a limited set that includes "delete",
  964:     such as:
  965: 
  966:     >     refuse options = * !a !delete !delete-during
  967: 
  968:     ... whereas this accepts any delete option except `--delete-after`:
  969: 
  970:     >     refuse options = * !a !delete* delete-after
  971: 
  972:     A note on refusing "compress" -- it is better to set the "dont compress"
  973:     daemon parameter to "`*`" because that disables compression silently
  974:     instead of returning an error that forces the client to remove the `-z`
  975:     option.
  976: 
  977:     If you are un-refusing the compress option, you probably want to match
  978:     "`!compress*`" so that you also accept the `--compress-level` option.
  979: 
  980:     Note that the "copy-devices" & "write-devices" options are refused by
  981:     default, but they can be explicitly accepted with "`!copy-devices`" and/or
  982:     "`!write-devices`".  The options "log-file" and "log-file-format" are
  983:     forcibly refused and cannot be accepted.
  984: 
  985:     Here are all the options that are not matched by wild-cards:
  986: 
  987:     - `--server`: Required for rsync to even work.
  988:     - `--rsh`, `-e`: Required to convey compatibility flags to the server.
  989:     - `--out-format`: This is required to convey output behavior to a remote
  990:       receiver.  While rsync passes the older alias `--log-format` for
  991:       compatibility reasons, this options should not be confused with
  992:       `--log-file-format`.
  993:     - `--sender`: Use "write only" parameter instead of refusing this.
  994:     - `--dry-run`, `-n`: Who would want to disable this?
  995:     - `--protect-args`, `-s`: This actually makes transfers safer.
  996:     - `--from0`, `-0`: Makes it easier to accept/refuse `--files-from` without
  997:       affecting this helpful modifier.
  998:     - `--iconv`: This is auto-disabled based on "charset" parameter.
  999:     - `--no-iconv`: Most transfers use this option.
 1000:     - `--checksum-seed`: Is a fairly rare, safe option.
 1001:     - `--write-devices`: Is non-wild but also auto-disabled.
 1002: 
 1003: 0.  `dont compress`
 1004: 
 1005:     This parameter allows you to select filenames based on wildcard patterns
 1006:     that should not be compressed when pulling files from the daemon (no
 1007:     analogous parameter exists to govern the pushing of files to a daemon).
 1008:     Compression can be expensive in terms of CPU usage, so it is usually good
 1009:     to not try to compress files that won't compress well, such as already
 1010:     compressed files.
 1011: 
 1012:     The "dont compress" parameter takes a space-separated list of
 1013:     case-insensitive wildcard patterns. Any source filename matching one of the
 1014:     patterns will be compressed as little as possible during the transfer.  If
 1015:     the compression algorithm has an "off" level (such as zlib/zlibx) then no
 1016:     compression occurs for those files.  Other algorithms have the level
 1017:     minimized to reduces the CPU usage as much as possible.
 1018: 
 1019:     See the `--skip-compress` parameter in the **rsync**(1) manpage for the
 1020:     list of file suffixes that are not compressed by default.  Specifying a
 1021:     value for the "dont compress" parameter changes the default when the daemon
 1022:     is the sender.
 1023: 
 1024: 0.  `early exec`, `pre-xfer exec`, `post-xfer exec`
 1025: 
 1026:     You may specify a command to be run in the early stages of the connection,
 1027:     or right before and/or after the transfer.  If the `early exec` or
 1028:     `pre-xfer exec` command returns an error code, the transfer is aborted
 1029:     before it begins.  Any output from the `pre-xfer exec` command on stdout
 1030:     (up to several KB) will be displayed to the user when aborting, but is
 1031:     _not_ displayed if the script returns success.  The other programs cannot
 1032:     send any text to the user.  All output except for the `pre-xfer exec`
 1033:     stdout goes to the corresponding daemon's stdout/stderr, which is typically
 1034:     discarded.  See the `--no-detatch` option for a way to see the daemon's
 1035:     output, which can assist with debugging.
 1036: 
 1037:     Note that the `early exec` command runs before any part of the transfer
 1038:     request is known except for the module name.  This helper script can be
 1039:     used to setup a disk mount or decrypt some data into a module dir, but you
 1040:     may need to use `lock file` and `max connections` to avoid concurrency
 1041:     issues.  If the client rsync specified the `--early-input=FILE` option, it
 1042:     can send up to about 5K of data to the stdin of the early script.  The
 1043:     stdin will otherwise be empty.
 1044: 
 1045:     Note that the `post-xfer exec` command is still run even if one of the
 1046:     other scripts returns an error code. The `pre-xfer exec` command will _not_
 1047:     be run, however, if the `early exec` command fails.
 1048: 
 1049:     The following environment variables will be set, though some are specific
 1050:     to the pre-xfer or the post-xfer environment:
 1051: 
 1052:     - `RSYNC_MODULE_NAME`: The name of the module being accessed.
 1053:     - `RSYNC_MODULE_PATH`: The path configured for the module.
 1054:     - `RSYNC_HOST_ADDR`: The accessing host's IP address.
 1055:     - `RSYNC_HOST_NAME`: The accessing host's name.
 1056:     - `RSYNC_USER_NAME`: The accessing user's name (empty if no user).
 1057:     - `RSYNC_PID`: A unique number for this transfer.
 1058:     - `RSYNC_REQUEST`: (pre-xfer only) The module/path info specified by the
 1059:       user.  Note that the user can specify multiple source files, so the
 1060:       request can be something like "mod/path1 mod/path2", etc.
 1061:     - `RSYNC_ARG#`: (pre-xfer only) The pre-request arguments are set in these
 1062:       numbered values. RSYNC_ARG0 is always "rsyncd", followed by the options
 1063:       that were used in RSYNC_ARG1, and so on.  There will be a value of "."
 1064:       indicating that the options are done and the path args are beginning --
 1065:       these contain similar information to RSYNC_REQUEST, but with values
 1066:       separated and the module name stripped off.
 1067:     - `RSYNC_EXIT_STATUS`: (post-xfer only) the server side's exit value.  This
 1068:       will be 0 for a successful run, a positive value for an error that the
 1069:       server generated, or a -1 if rsync failed to exit properly.  Note that an
 1070:       error that occurs on the client side does not currently get sent to the
 1071:       server side, so this is not the final exit status for the whole transfer.
 1072:     - `RSYNC_RAW_STATUS`: (post-xfer only) the raw exit value from
 1073:       **waitpid()**.
 1074: 
 1075:     Even though the commands can be associated with a particular module, they
 1076:     are run using the permissions of the user that started the daemon (not the
 1077:     module's uid/gid setting) without any chroot restrictions.
 1078: 
 1079:     These settings honor 2 environment variables: use RSYNC_SHELL to set a
 1080:     shell to use when running the command (which otherwise uses your
 1081:     **system()** call's default shell), and use RSYNC_NO_XFER_EXEC to disable
 1082:     both options completely.
 1083: 
 1084: # CONFIG DIRECTIVES
 1085: 
 1086: There are currently two config directives available that allow a config file to
 1087: incorporate the contents of other files:  `&include` and `&merge`.  Both allow
 1088: a reference to either a file or a directory.  They differ in how segregated the
 1089: file's contents are considered to be.
 1090: 
 1091: The `&include` directive treats each file as more distinct, with each one
 1092: inheriting the defaults of the parent file, starting the parameter parsing as
 1093: globals/defaults, and leaving the defaults unchanged for the parsing of the
 1094: rest of the parent file.
 1095: 
 1096: The `&merge` directive, on the other hand, treats the file's contents as if it
 1097: were simply inserted in place of the directive, and thus it can set parameters
 1098: in a module started in another file, can affect the defaults for other files,
 1099: etc.
 1100: 
 1101: When an `&include` or `&merge` directive refers to a directory, it will read in
 1102: all the `*.conf` or `*.inc` files (respectively) that are contained inside that
 1103: directory (without any recursive scanning), with the files sorted into alpha
 1104: order.  So, if you have a directory named "rsyncd.d" with the files "foo.conf",
 1105: "bar.conf", and "baz.conf" inside it, this directive:
 1106: 
 1107: >     &include /path/rsyncd.d
 1108: 
 1109: would be the same as this set of directives:
 1110: 
 1111: >     &include /path/rsyncd.d/bar.conf
 1112: >     &include /path/rsyncd.d/baz.conf
 1113: >     &include /path/rsyncd.d/foo.conf
 1114: 
 1115: except that it adjusts as files are added and removed from the directory.
 1116: 
 1117: The advantage of the `&include` directive is that you can define one or more
 1118: modules in a separate file without worrying about unintended side-effects
 1119: between the self-contained module files.
 1120: 
 1121: The advantage of the `&merge` directive is that you can load config snippets
 1122: that can be included into multiple module definitions, and you can also set
 1123: global values that will affect connections (such as `motd file`), or globals
 1124: that will affect other include files.
 1125: 
 1126: For example, this is a useful /etc/rsyncd.conf file:
 1127: 
 1128: >     port = 873
 1129: >     log file = /var/log/rsync.log
 1130: >     pid file = /var/lock/rsync.lock
 1131: >
 1132: >     &merge /etc/rsyncd.d
 1133: >     &include /etc/rsyncd.d
 1134: 
 1135: This would merge any `/etc/rsyncd.d/*.inc` files (for global values that should
 1136: stay in effect), and then include any `/etc/rsyncd.d/*.conf` files (defining
 1137: modules without any global-value cross-talk).
 1138: 
 1139: # AUTHENTICATION STRENGTH
 1140: 
 1141: The authentication protocol used in rsync is a 128 bit MD4 based challenge
 1142: response system. This is fairly weak protection, though (with at least one
 1143: brute-force hash-finding algorithm publicly available), so if you want really
 1144: top-quality security, then I recommend that you run rsync over ssh.  (Yes, a
 1145: future version of rsync will switch over to a stronger hashing method.)
 1146: 
 1147: Also note that the rsync daemon protocol does not currently provide any
 1148: encryption of the data that is transferred over the connection. Only
 1149: authentication is provided. Use ssh as the transport if you want encryption.
 1150: 
 1151: You can also make use of SSL/TLS encryption if you put rsync behind an
 1152: SSL proxy.
 1153: 
 1154: # SSL/TLS Daemon Setup
 1155: 
 1156: When setting up an rsync daemon for access via SSL/TLS, you will need to
 1157: configure a proxy (such as haproxy or nginx) as the front-end that handles the
 1158: encryption.
 1159: 
 1160: - You should limit the access to the backend-rsyncd port to only allow the
 1161:   proxy to connect.  If it is on the same host as the proxy, then configuring
 1162:   it to only listen on localhost is a good idea.
 1163: - You should consider turning on the `proxy protocol` parameter if your proxy
 1164:   supports sending that information.  The examples below assume that this is
 1165:   enabled.
 1166: 
 1167: An example haproxy setup is as follows:
 1168: 
 1169: > ```
 1170: > frontend fe_rsync-ssl
 1171: >    bind :::874 ssl crt /etc/letsencrypt/example.com/combined.pem
 1172: >    mode tcp
 1173: >    use_backend be_rsync
 1174: >
 1175: > backend be_rsync
 1176: >    mode tcp
 1177: >    server local-rsync 127.0.0.1:873 check send-proxy
 1178: > ```
 1179: 
 1180: An example nginx proxy setup is as follows:
 1181: 
 1182: > ```
 1183: > stream {
 1184: >    server {
 1185: >        listen 874 ssl;
 1186: >        listen [::]:874 ssl;
 1187: >
 1188: >        ssl_certificate /etc/letsencrypt/example.com/fullchain.pem;
 1189: >        ssl_certificate_key /etc/letsencrypt/example.com/privkey.pem;
 1190: >
 1191: >        proxy_pass localhost:873;
 1192: >        proxy_protocol on; # Requires "proxy protocol = true"
 1193: >        proxy_timeout 1m;
 1194: >        proxy_connect_timeout 5s;
 1195: >    }
 1196: > }
 1197: > ```
 1198: 
 1199: # EXAMPLES
 1200: 
 1201: A simple rsyncd.conf file that allow anonymous rsync to a ftp area at
 1202: `/home/ftp` would be:
 1203: 
 1204: > ```
 1205: > [ftp]
 1206: >         path = /home/ftp
 1207: >         comment = ftp export area
 1208: > ```
 1209: 
 1210: A more sophisticated example would be:
 1211: 
 1212: > ```
 1213: > uid = nobody
 1214: > gid = nobody
 1215: > use chroot = yes
 1216: > max connections = 4
 1217: > syslog facility = local5
 1218: > pid file = /var/run/rsyncd.pid
 1219: > slp refresh = 3600
 1220: >
 1221: > [ftp]
 1222: >         path = /var/ftp/./pub
 1223: >         comment = whole ftp area (approx 6.1 GB)
 1224: >
 1225: > [sambaftp]
 1226: >         path = /var/ftp/./pub/samba
 1227: >         comment = Samba ftp area (approx 300 MB)
 1228: >
 1229: > [rsyncftp]
 1230: >         path = /var/ftp/./pub/rsync
 1231: >         comment = rsync ftp area (approx 6 MB)
 1232: >
 1233: > [sambawww]
 1234: >         path = /public_html/samba
 1235: >         comment = Samba WWW pages (approx 240 MB)
 1236: >
 1237: > [cvs]
 1238: >         path = /data/cvs
 1239: >         comment = CVS repository (requires authentication)
 1240: >         auth users = tridge, susan
 1241: >         secrets file = /etc/rsyncd.secrets
 1242: > ```
 1243: 
 1244: The /etc/rsyncd.secrets file would look something like this:
 1245: 
 1246: >     tridge:mypass
 1247: >     susan:herpass
 1248: 
 1249: # FILES
 1250: 
 1251: /etc/rsyncd.conf or rsyncd.conf
 1252: 
 1253: # SEE ALSO
 1254: 
 1255: **rsync**(1), **rsync-ssl**(1)
 1256: 
 1257: # BUGS
 1258: 
 1259: Please report bugs! The rsync bug tracking system is online at
 1260: <https://rsync.samba.org/>.
 1261: 
 1262: # VERSION
 1263: 
 1264: This man page is current for version @VERSION@ of rsync.
 1265: 
 1266: # CREDITS
 1267: 
 1268: rsync is distributed under the GNU General Public License.  See the file
 1269: COPYING for details.
 1270: 
 1271: The primary ftp site for rsync is <ftp://rsync.samba.org/pub/rsync>
 1272: 
 1273: A web site is available at <https://rsync.samba.org/>.
 1274: 
 1275: We would be delighted to hear from you if you like this program.
 1276: 
 1277: This program uses the zlib compression library written by Jean-loup Gailly and
 1278: Mark Adler.
 1279: 
 1280: # THANKS
 1281: 
 1282: Thanks to Warren Stanley for his original idea and patch for the rsync daemon.
 1283: Thanks to Karsten Thygesen for his many suggestions and documentation!
 1284: 
 1285: # AUTHOR
 1286: 
 1287: rsync was written by Andrew Tridgell and Paul Mackerras.  Many people have
 1288: later contributed to it.
 1289: 
 1290: Mailing lists for support and development are available at
 1291: <https://lists.samba.org/>.

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