Created attachment 7566 [details] Patch to enable "Merit Dump" DHCP option. The "Merit Dump" DHCP option can be used to pass an arbitrary string from a DHCP server to a DHCP client. I use it for passing NFS mount points to a Linux netboot client. Patch for 1.28.3 attached.
I added support for arbitrary options to be specified as strings: BusyBox v1.29.0.git (2018-04-01 19:58:41 CEST) multi-call binary. Usage: udhcpc [-fbqvRB] [-a[MSEC]] [-t N] [-T SEC] [-A SEC/-n] [-i IFACE] [-s PROG] [-p PIDFILE] [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]... -i IFACE Interface to use (default eth0) -s PROG Run PROG at DHCP events (default /usr/share/udhcpc/default.script) -p FILE Create pidfile -B Request broadcast replies -t N Send up to N discover packets (default 3) -T SEC Pause between packets (default 3) -A SEC Wait if lease is not obtained (default 20) -n Exit if lease is not obtained -q Exit after obtaining lease -R Release IP on exit -f Run in foreground -b Background if lease is not obtained -S Log to syslog too -a[MSEC] Validate offered address with ARP ping -r IP Request this IP address -o Don't request any options (unless -O is given) -O OPT Request option OPT from server (cumulative) -x OPT:VAL Include option OPT in sent packets (cumulative) Examples of string, numeric, and hex byte opts: -x hostname:bbox - option 12 -x lease:3600 - option 51 (lease time) -x 0x3d:0100BEEFC0FFEE - option 61 (client id) -x 14:'"dumpfile"' - option 14 (shell-quoted) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -F NAME Ask server to update DNS mapping for NAME -V VENDOR Vendor identifier (default 'udhcp VERSION') -C Don't send MAC as client identifier -v Verbose examples/udhcp/udhcpd.conf: ......... option lease 864000 # default: 10 days option msstaticroutes 10.0.0.0/8 10.127.0.1 # single static route option staticroutes 10.0.0.0/8 10.127.0.1, 10.11.12.0/24 10.11.12.1 # Arbitrary option in hex or string form: option 0x08 01020304 # option 8: "cookie server IP addr: 1.2.3.4" option 14 "dumpfile"