Re: [PATCH 6/6] doc: Add --dhcp-boot and --dhcp-opt to man page

[Stefano Brivio <sbrivio@redhat.com>]

On Mon, 18 May 2026 18:50:02 +0530
Anshu Kumari <anskuma@redhat.com> 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>
> ---
>  passt.1 | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/passt.1 b/passt.1
> index 908fd4a..c39e5ec 100644
> --- a/passt.1
> +++ b/passt.1
> @@ -430,6 +430,50 @@ 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
> +Boot file URL for network boot.
> +Populates the boot file field in DHCP replies. For UEFI HTTP boot,
> +also set the vendor class identifier using \-\-dhcp-opt 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 IP addresses are space-separated within quotes.
> +This option can be specified multiple times. Options set with \-\-dhcp-opt
> +override built-in values and \-\-dhcp-boot settings.

When we refer to other options, we highlight them, say:

	\fB--dhcp-boot\fR

For further examples, look for "See option" or "Implies" in this file.

> +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
> +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), 33 (Static Routes), 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), 61 (Client Identifier), 66 (TFTP Server Name),
> +67 (Bootfile Name), 119 (Domain Search List), 252 (WPAD URL)
> +.TP
> +.B Classless static route options (RFC 3442 encoding)
> +121 (Classless Static Routes).
> +Format: "CIDR/mask,gateway" entries, space-separated.
> +Example: \-\-dhcp-opt 121,"10.0.1.0/24,10.0.0.1 0.0.0.0/0,10.0.0.1"
> +.RE
> +
>  .TP
>  .BR \-t ", " \-\-tcp-ports " " \fIspec
>  Configure TCP port forwarding to guest or namespace. \fIspec\fR can be one of:

Except for pending comments from David and myself, the whole series
looks good to me!

I suppose that addressing those comments especially around 2/6 and 3/6
might take a few iterations, though.

-- 
Stefano