networkd: DHCPv4 - allow opting out of using DNS servers

Setting UseDNS=no will ignore any received DNS servers.
This commit is contained in:
Tom Gundersen 2014-01-13 21:28:53 +01:00
parent 5681d7fb8b
commit 5be4d38e31
5 changed files with 34 additions and 6 deletions

View file

@ -192,6 +192,14 @@
. This is a short-hand for a [Route] section only containing a Gateway key.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DNS</varname></term>
<listitem>
<para>A DNS server address, which must be in the format described in
<citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Bridge</varname></term>
<listitem>
@ -233,7 +241,20 @@
prefixlength, if ommitted a full-length host route is assumed.</para>
</listitem>
</varlistentry>
</variablelist>
<para>The <literal>[DHCPv4]</literal> section accepts the following keys:</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>UseDNS</varname></term>
<listitem>
<para>When true (the default) the DNS servers received from the DHCP server will
be used, and take precedence over any statically configured ones.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>

View file

@ -30,5 +30,6 @@ Address.Address, config_parse_address, 0, 0
Address.Label, config_parse_label, 0, 0
Route.Gateway, config_parse_gateway, 0, 0
Route.Destination, config_parse_destination, 0, 0
DHCPv4.UseDNS, config_parse_bool, 0, offsetof(Network, dhcp_dns)
Bridge.Description, config_parse_string, 0, offsetof(Bridge, description)
Bridge.Name, config_parse_ifname, 0, offsetof(Bridge, name)

View file

@ -319,6 +319,7 @@ static void dhcp_handler(sd_dhcp_client *client, int event, void *userdata) {
int r;
assert(link);
assert(link->network);
if (link->state == LINK_STATE_FAILED)
return;
@ -421,11 +422,13 @@ static void dhcp_handler(sd_dhcp_client *client, int event, void *userdata) {
addr = NULL;
rt = NULL;
r = sd_dhcp_client_get_dns(client, &nameservers);
if (r >= 0) {
r = manager_update_resolv_conf(link->manager);
if (r < 0)
log_error("Failed to update resolv.conf");
if (link->network->dhcp_dns) {
r = sd_dhcp_client_get_dns(client, &nameservers);
if (r >= 0) {
r = manager_update_resolv_conf(link->manager);
if (r < 0)
log_error("Failed to update resolv.conf");
}
}
link_enter_set_addresses(link);

View file

@ -65,7 +65,9 @@ static int network_load_one(Manager *manager, const char *filename) {
if (!network->filename)
return log_oom();
r = config_parse(NULL, filename, file, "Match\0Network\0Address\0Route\0", config_item_perf_lookup,
network->dhcp_dns = true;
r = config_parse(NULL, filename, file, "Match\0Network\0Address\0Route\0DHCPv4\0", config_item_perf_lookup,
(void*) network_gperf_lookup, false, false, network);
if (r < 0) {
log_warning("Could not parse config file %s: %s", filename, strerror(-r));

View file

@ -85,6 +85,7 @@ struct Network {
char *description;
Bridge *bridge;
bool dhcp;
bool dhcp_dns;
LIST_HEAD(Address, static_addresses);
LIST_HEAD(Route, static_routes);