Right so I was wrong, netcfg reads the domain from here: /tmp/domain_name
which is filled by udhcpc default.script
The patch above won't work alone as we would need udhcpc to write the
search domain to a file and make a read function in netcfg to get the info
(or something along those lines)
Here is an updated version of the hack:
d-i preseed/early_command string \
sed -i 's|printf "\$domain" > /tmp/domain_name|printf "$search" >
/tmp/domain_name|' /etc/udhcpc/default.script; \
mv /sbin/udhcpc /sbin/udhcpc.real; \
echo '#!/bin/sh' > /sbin/udhcpc; \
echo 'exec /bin/busybox udhcpc -O search "$@"' >> /sbin/udhcpc; \
chmod +x /sbin/udhcpc
On Thu, Jul 3, 2025 at 12:30 PM Frédéric Guyot <guyot.frederi...@gmail.com>
wrote:
> Here is an updated patch for this issue:
>
> --- dhcp.c
> +++ dhcp.c
> @@ -41,6 +41,7 @@
> "domain",
> "hostname",
> "dns",
> + "search",
> "ntpsrv", /* extra */
> NULL };
>
> @@ -510,7 +511,7 @@
> * nameservers now so we can do rDNS lookups later to possibly
> * find out the domain.
> */
> - netcfg_write_resolv(NULL, interface);
> + netcfg_write_resolv(NULL, NULL, interface);
> state = HOSTNAME;
> break;
>
> @@ -613,7 +614,7 @@
> netcfg_write_common("", hostname, domain);
> netcfg_write_loopback();
> netcfg_write_interface(interface);
> - netcfg_write_resolv(domain, interface);
> + netcfg_write_resolv(domain, search, interface);
> #if !defined(__FreeBSD_kernel__)
> kill_dhcp_client();
> #endif
>
> --- static.c
> +++ static.c
> @@ -258,14 +258,16 @@
> return 1;
> }
>
> -int netcfg_write_resolv (const char *domain, const struct netcfg_interface
> *interface)
> +int netcfg_write_resolv (const char *domain , const char *search, const
> struct netcfg_interface *interface)
> {
> FILE* fp = NULL;
>
> if ((fp = file_open(RESOLV_FILE, "w"))) {
> unsigned int i = 0;
> + if (search && !empty_str(search))
> + fprintf(fp, "search %s\n", search);
> if (domain && !empty_str(domain))
> - fprintf(fp, "search %s\n", domain);
> + fprintf(fp, "domain %s\n", domain);
>
> for (i = 0; i < NETCFG_NAMESERVERS_MAX; i++)
> if (!empty_str(interface->nameservers[i]))
>
> This should do the trick.
>
> If someone comes across this issue and this patch hasn't been merged we found
> an ugly workaround using a preseed file:
>
> d-i preseed/early_command string \
> sed -i '/^case /i domain="$search"' /etc/udhcpc/default.script; \
> mv /sbin/udhcpc /sbin/udhcpc.real; \
> echo '#!/bin/sh' > /sbin/udhcpc; \
> echo 'exec /bin/busybox udhcpc -O search "$@"' >> /sbin/udhcpc; \
> chmod +x /sbin/udhcpc
>
> It will make a wrapper for udhcpc that will force netcfg to query search
> domains, patch the default.script callback script from udhcpc to make
> domain="$seach".
>
> regards
>
>
>
