| 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 remaining 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 |
| |
| compile time options |
| ------------------- |
| |
| dhcpd.h contains the other two compile time options: |
| |
| LEASE_TIME: The default lease time if not specified in the config |
| file. |
| |
| DHCPD_CONFIG_FILE: The defualt config file to use. |