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Diffstat (limited to 'networking/udhcp/README')
| -rw-r--r-- | networking/udhcp/README | 151 |
1 files changed, 2 insertions, 149 deletions
diff --git a/networking/udhcp/README b/networking/udhcp/README index d3e5e3fbc..5f4bb78a8 100644 --- a/networking/udhcp/README +++ b/networking/udhcp/README @@ -5,155 +5,6 @@ The udhcp server/client package is primarily geared towards embedded systems. It does however, strive to be fully functional, and RFC compliant. -udhcp server (udhcpd) --------------------- - -The only command line argument to udhcpd is an optional specifed -config file. If no config file is specified, udhcpd uses the default -config file, /etc/udhcpd.conf. Ex: - -udhcpd /etc/udhcpd.eth1.conf - -The udhcp server employs a number of simple config files: - -udhcpd.leases ------------- - -The udhcpd.leases behavior is designed for an embedded system. The -file is written either every auto_time seconds, or when a SIGUSR1 -is received (the auto_time timer restarts if a SIGUSR1 is received). -If you send a SIGTERM to udhcpd directly after a SIGUSR1, udhcpd will -finish writing the leases file and wait for the aftermentioned script -to be executed and finish before quiting, so you do not need to sleep -between sending signals. When the file is written, a script can be -optionally called to commit the file to flash. Lease times are stored -in the file by time remaining in lease (for systems without clock -that works when there is no power), or by the absolute time that it -expires in seconds from epoch. In the remainig format, expired leases -are stored as zero. The file is of the format: - -16 byte MAC -4 byte ip address -u32 expire time -16 byte MAC -4 byte ip address -u32 expire time -. -etc. - -example: hexdump udhcpd.leases - -0000000 1000 c95a 27d9 0000 0000 0000 0000 0000 -0000010 a8c0 150a 0d00 2d29 5000 23fc 8566 0000 -0000020 0000 0000 0000 0000 a8c0 140a 0d00 4e29 -0000030 - - -udhcpd.conf ----------- - -The format is fairly simple, there is a sample file with all the -available options and comments describing them in samples/udhcpd.conf - - -udhcp client (udhcpc) --------------------- - -The udhcp client negotiates a lease with the DHCP server and notifies -a set of scripts when a leases is obtained or lost. The command line -options for the udhcp client are: - --c, --clientid=CLIENTID Client identifier --H, --hostname=HOSTNAME Client hostname --h, Alias for -H --f, --foreground Do not fork after getting lease --b, --background Fork to background if lease cannot be - immediately negotiated. --i, --interface=INTERFACE Interface to use (default: eth0) --n, --now Exit with failure if lease cannot be - immediately negotiated. --p, --pidfile=file Store process ID of daemon in file --q, --quit Quit after obtaining lease --r, --request=IP IP address to request (default: none) --s, --script=file Run file at dhcp events (default: - /usr/share/udhcpc/default.script) --v, --version Display version - -If the requested IP address cannot be obtained, the client accepts the -address that the server offers. - -When an event occurs, udhcpc calls the action script. The script by -default is /usr/share/udhcpc/default.script but this can be changed via -the command line arguments. The three possible arguments to the script -are: - - deconfig: This argument is used when udhcpc starts, and - when a leases is lost. The script should put the interface in an - up, but deconfigured state, ie: ifconfig $interface 0.0.0.0. - - bound: This argument is used when udhcpc moves from an - unbound, to a bound state. All of the paramaters are set in - enviromental variables, The script should configure the interface, - and set any other relavent parameters (default gateway, dns server, - etc). - - renew: This argument is used when a DHCP lease is renewed. All of - the paramaters are set in enviromental variables. This argument is - used when the interface is already configured, so the IP address, - will not change, however, the other DHCP paramaters, such as the - default gateway, subnet mask, and dns server may change. - - nak: This argument is used with udhcpc receives a NAK message. - The script with the deconfig argument will be called directly - afterwards, so no changes to the network interface are neccessary. - This hook is provided for purely informational purposes (the - message option may contain a reason for the NAK). - -The paramaters for enviromental variables are as follows: - - $HOME - The set $HOME env or "/" - $PATH - the set $PATH env or "/bin:/usr/bin:/sbin:/usr/sbin" - $1 - What action the script should perform - interface - The interface this was obtained on - ip - The obtained IP - siaddr - The bootp next server option - sname - The bootp server name option - boot_file - The bootp boot file option - subnet - The assigend subnet mask - timezone - Offset in seconds from UTC - router - A list of routers - timesvr - A list of time servers - namesvr - A list of IEN 116 name servers - dns - A list of DNS server - logsvr - A list of MIT-LCS UDP log servers - cookiesvr - A list of RFC 865 cookie servers - lprsvr - A list of LPR servers - hostname - The assigned hostname - bootsize - The length in 512 octect blocks of the bootfile - domain - The domain name of the network - swapsvr - The IP address of the client's swap server - rootpath - The path name of the client's root disk - ipttl - The TTL to use for this network - mtu - The MTU to use for this network - broadcast - The broadcast address for this network - ntpsrv - A list of NTP servers - wins - A list of WINS servers - lease - The lease time, in seconds - dhcptype - DHCP message type (safely ignored) - serverid - The IP of the server - message - Reason for a DHCPNAK - tftp - The TFTP server name - bootfile - The bootfile name - -additional options are easily added in options.c. - -udhcpc also responds to SIGUSR1 and SIGUSR2. SIGUSR1 will force a renew state, -and SIGUSR2 will force a release of the current lease, and cause udhcpc to -go into an inactive state (until it is killed, or receives a SIGUSR1). You do -not need to sleep between sending signals, as signals received are processed -sequencially in the order they are received. - - compile time options ------------------- @@ -185,6 +36,7 @@ options.c contains a set of dhcp options for the client: code: The DHCP code for this option + busybox drop-in -------------- udhcp is now a drop-in component for busybox (http://busybox.net). @@ -195,3 +47,4 @@ cp *.[ch] README AUTHORS COPYING ChangeLog TODO \ The only two files udhcp does not provide are config.in and Makefile.in, so these may need to be updated from time to time. + |