On Mon, Jun 01, 2026 at 01:07:56PM +0530, Anshu Kumari wrote:
> Document the new --dhcp-boot and --dhcp-opt command-line options in
> the passt(1) man page, including supported option codes grouped by
> value type and usage examples.
> 
> Link: https://bugs.passt.top/show_bug.cgi?id=192
> Signed-off-by: Anshu Kumari <anskuma@redhat.com>

Note that as a general rule, I think it's preferable to include
manpage / doc updates with the patch that implements the code change.
That can get fuzzy when the implementation is across several patches
of course.  In any case, not worth reworking here.

These options should probably also be mentioned in usage() output
(though with a much briefer description).

> ---
> v3:
>   - Removed options 33, 55, 61, 119 from supported codes list
>   - Added note: "If the same name option code is given more than once,
>     the last value wins".
> 
> v2:
>   - Updated --dhcp-boot description.
>   - Highlighted cross-referenced options with \fB...\fR.
>   - Updated IP list format from "space-separated within quotes" to "comma-separated".
>   - option 121 dropped.
>   - Added option 55 to string options list.
>   - Removed --dhcp-boot override reference from --dhcp-opt description.
> ---
>  passt.1 | 41 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/passt.1 b/passt.1
> index 908fd4a..57e2cc1 100644
> --- a/passt.1
> +++ b/passt.1
> @@ -430,6 +430,47 @@ Send \fIname\fR as DHCP option 12 (hostname).
>  FQDN to configure the client with.
>  Send \fIname\fR as Client FQDN: DHCP option 81 and DHCPv6 option 39.
>  
> +.TP
> +.BR \-\-dhcp-boot " " \fIurl
> +Convenience shorthand for \fB\-\-dhcp-opt\fR 67,\fIurl\fR.
> +Sets the boot file name (DHCP option 67) for network boot.
> +For UEFI HTTP boot, also set the vendor class identifier using
> +\fB\-\-dhcp-opt\fR 60,HTTPClient.
> +
> +.TP
> +.BR \-\-dhcp-opt " " \fICODE\fR,\fIVALUE\fR
> +Set a DHCP option by numeric code. The value format is determined automatically
> +from the option code. Multiple IPv4 addresses are comma-separated.
> +This option can be specified multiple times. If the same option code is
> +given more than once, the last value wins. Options set with
> +\fB\-\-dhcp-opt\fR override built-in values.
> +Only the following option codes are supported (unsupported codes cause an error):
> +.RS
> +.TP
> +.B IPv4 address options
> +1 (Subnet Mask), 16 (Swap Server), 28 (Broadcast Address), 50 (Requested IP),
> +54 (Server Identifier)
> +.TP
> +.B IPv4 address list options (comma-separated)
> +3 (Router), 4 (Time Server), 5 (Name Server), 6 (DNS), 7 (Log Server),
> +8 (Cookie Server), 9 (LPR Server), 10 (Impress Server),
> +11 (Resource Location Server), 41 (NIS Servers),
> +42 (NTP Servers), 44 (NetBIOS Name Server)
> +.TP
> +.B Integer options
> +2 (Time Offset, 32-bit), 13 (Boot File Size, 16-bit), 19 (IP Forwarding, 8-bit),
> +23 (Default IP TTL, 8-bit), 26 (Interface MTU, 16-bit),
> +37 (TCP Default TTL, 8-bit), 38 (TCP Keepalive Interval, 32-bit),
> +51 (IP Address Lease Time, 32-bit),
> +53 (DHCP Message Type, 8-bit), 57 (Max DHCP Message Size, 16-bit),
> +58 (Renewal Time, 32-bit), 59 (Rebinding Time, 32-bit)
> +.TP
> +.B String options
> +12 (Host Name), 15 (Domain Name), 17 (Root Path), 40 (NIS Domain Name),
> +60 (Vendor Class Identifier), 66 (TFTP Server Name),
> +67 (Bootfile Name), 252 (WPAD URL)
> +.RE
> +
>  .TP
>  .BR \-t ", " \-\-tcp-ports " " \fIspec
>  Configure TCP port forwarding to guest or namespace. \fIspec\fR can be one of:
> -- 
> 2.54.0
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson