Provided by: atftpd_0.7.git20120829-2.1_amd64 bug

NAME

       atftpd - Trivial File Transfer Protocol Server.

SYNOPSIS

       atftpd [options] directory

DESCRIPTION

       atftpd  is  a TFTP (RFC1350) server. By default it is started by inetd on most sytems, but
       may run as a stand alone daemon. This server is multi-threaded and  supports  all  options
       described  in  RFC2347  (option extension), RFC2348 (blksize), RFC2349 (tsize and timeout)
       and  RFC2090  (multicast  option).  It  also  supports  mtftp  as  defined  in   the   PXE
       specification.

OPTIONS

       This  program  supports both the usual GNU command line syntax, with long options starting
       with two dashes ('-') as well as short options. A description of the options  is  included
       below.

       -t, --tftpd-timeout <value>
              Number  of  seconds  of  inactivity before the server exits. This value has meaning
              only when the server is started by inetd. In daemon mode, the server  never  exits.
              Default is 300 seconds.

       -r, --retry-timeout <value>
              How  many  seconds to wait for a reply before retransmitting a packet. Default is 5
              seconds. This can be overridden by the TFTP client with the 'timeout' option.

       -m, --maxthread <value>
              Maximum number of concurrent threads allowed. Default is 100.

       -v, --verbose[=value]
              Increase or set the logging level. No arguments will increase by  one  the  current
              value. Default is LOG_NOTICE, see syslog(3) for log level. Valid value range from 0
              (LOG_EMERG) to 7 (LOG_DEBUG).

       --trace
              When verbose level is set to 7, this will output debug information for each  packet
              sent or received from the network.

       --no-timeout
              disable 'timeout' from RFC2349. This will prevent the server from acknowledging the
              'timeout' option requested by the client.

       --no-tsize
              disable 'tsize' from RFC2349. This will prevent the server from  acknowledging  the
              'tsize' option requested by the client.

       --no-blksize
              disable 'blksize' from RFC2348. This will prevent the server from acknowledging the
              'blksize' request by the client.

       --no-multicast
              disable 'multicast' from RFC2090. This will prevent the server  from  acknowledging
              the 'multicast' request by the client.

       --logfile <logfile>
              Log  to  a  specific file instead of only syslog. 'nobody' (or any user used to run
              the server) must  have  permissions  on  the  given  file.  Assuming  the  file  is
              /var/log/atftpd.log,  simply  run:  "touch  /var/log/atftpd.log"  and  then  "chown
              nobody.nogroup /var/log/atftpd.log".  When  the  server  is  run  in  daemon  mode,
              /dev/stdout  or  /dev/stderr can be used.  Specifying a single dash as the filename
              will send logs to stdout (file descriptor 1).

       --pidfile
              Write the PID of the server  to  the  specified  file.  This  may  be  useful  when
              automatically starting and stopping one or more instance of the server.

       --daemon
              Run as a daemon. Do not use this option if atftpd is started by inetd.

       --no-fork
              When  --daemon  is  specified,  this option will prevent the server from forking to
              background. It is useful for debugging purpose or specialized usage.

       --user <user[.group]>
              By default, the server change identity  to  the  user  nobody  and  group  nogroup.
              Specify an alternate user.group with this option.

       --group <group>
              Alternate  way  of  specifying  the  group.  If  group is specified with --user and
              --group, the last option will be used.

       --port <number>
              Specify the port on which  atftpd  listens.  Useful  when  --daemon  is  specified.
              Default is standard tftp port as determined by getservbyname(3).

       --bind-address <IP address>
              Specify  the  IP  address which atftpd binds to. Useful when --daemon is specified.
              Default is to bind to all interfaces. Only one address can be specified, the server
              can only listen to one or all interfaces.

       --mcast-ttl
              Specify the TTL to be used for multicast datagram. By default a value of 1 is used.
              Note that TTL has a special meaning in multicast as it is  used  to  determine  the
              scope  of  the  packets.  The  value  of  1 means the packets don't leave the local
              network, see ip(4). Scope may  also  be  determine  by  the  address  as  described
              RFC2365.

       --mcast-addr
              Specify  the  IP address range to be used for multicast transfer. Format string may
              comprise range and list of values: "239.255.0.0-31,128-132,200".  Default value  is
              "239.255.0.0-255". This address range is proposed in RFC2365 for local scope.

       --mcast-port
              Specify the UDP port to use for multicast transfer. Format string may contain range
              and list of port number: "1758-2000,8000-9000". default value is "1758".

       --pcre <file>
              Specify a pattern/replacement file to use. This allow  to  replace  requested  file
              name based on Perl Compatible Regular Expression. See README.PCRE.

       --pcre-test <file>
              Test  a pattern/replacement file. When using this option, the server will not start
              as usual but just read file name from stdin and printout the substitution.

       --mtftp <file>
              This will start a mtftp server thread for each valid entry in  the  supplied  file.
              See  PXE  specification  for detail about mtftp. An example file is provided in the
              source distribution.

       --mtftp-port <port>
              Port the mtftp server shall listen to for incomming request.

       --no-source-port-checking
              In some  specific  cases  of  networks  using  load  balancer  or  other  equipment
              performing  NAT  (network  address  translation), some needs to disable source port
              checking because port number as been translated. If you want to use  this  feature,
              you  must  know  why  you  need  it  and the implication. Be aware that this option
              violate the RFC1350. This option has effect only for non-multicast transfer.

       --mcast-switch-client
              This option allow the server to proceed with the next multicast client as  soon  as
              the  current  client  timeout.  When  the  current  master  client fails to send an
              acknowledge (ACK) to the server, the server will send an option acknowledge  (OACK)
              to  the  master  client  with the field MC (master client) set to false and send an
              OACK to the next multicast client with MC set to true.  Without  this  option,  the
              server  will  retry  the current master client up to 5 times and then mark it done,
              proceding with the next one.

       -V, --version
              Show version of program.

       -h, --help
              Show summary of options.

       path   This is the root directory used by the TFTP server. All requested files from a TFTP
              client  must  reside in this directory. If not specified, the directory defaults to
              /tftpboot. Since atftpd run as the nobody user, the  permission  of  the  directory
              must be set properly to allow file reading and writing.

STATS

       Starting  with  release  0.2,  the  server collects some statistics.  Currently the server
       compute system load, time between connections and some thread statistics  like  number  of
       file  sent,  received,  number of abort... To see those stats in the logs, you need to set
       --verbose=6 (LOG_NOTICE) or higher.

SECURITY

       TFTP by itself has no provision for security. There is no  user  authentication  and  TFTP
       clients  get  access to all files within the specified root directory for which the server
       has permission.

       Some level of security can be gained using atftp libwrap support. Adding proper  entry  to
       /etc/hosts.allow and /etc/hosts.deny will restrict access to trusted hosts. Daemon name to
       use in these files is in.tftpd.

PCRE

       The atftpd server provides a way to dynamically replace requested file name by a  new  one
       based  on  Perl  compatible regular expression. Pairs of pattern/replacement are read from
       the specified files. Upon reception of a read request, the server will first try  to  open
       the  file  name requested. If it fails, then it will search for a replacement based on the
       content of the pattern file. If this still fails, then  an  error  will  be  sent  to  the
       client.  This  feature  is  available  only for read request. It makes no sense doing this
       substitution for client writing files to the server.

MTFTP

       The mtftp name  refer  to  multicasrt  tftp  as  define  by  the  PXE  specification.  See
       pxespec.txt  for  the  source  of  the  specification.  Note  that this is not the same as
       RFC2090. PXE compliant boot implements mtftp, not RFC2090.

SEE ALSO

       inetd(8),hosts_access(5),libpcre(7),  RFC1350,  RFC2090,  RFC2347,  RFC2348,  RFC2349  and
       pxespec.pdf.

AUTHOR

       This  manual  page was written by Remi Lefebvre <remi@debian.org> and Jean-Pierre Lefebvre
       <helix@step.polymtl.ca>.

                                        December 27, 2000                               ATFTPD(8)