networkd: merge DHCPv4 and DHCPv6 config

If there are v4 or v6 specific options we can keep those in separate sections,
but for the common options, we will use only one.

Moreovere only use DHCP=[yes/both|no/none|v4|v6] to enable or disable the clients.

5 files changed, 92 insertions, 16 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 5bff4d9d87..67f10e1ef5 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -195,7 +195,9 @@
                                 <varlistentry>
                                         <term><varname>DHCP=</varname></term>
                                         <listitem>
-                                                <para>A boolean. When true, enables basic DHCPv4 support.</para>
+                                                <para>Enables DHCPv4 and/or DHCPv6 support. Accepts
+                                                <literal>both</literal>, <literal>none</literal>,
+                                                <literal>v4</literal> or <literal>v6</literal>.</para>
                                         </listitem>
                                 </varlistentry>
                                 <varlistentry>
@@ -361,8 +363,8 @@
         </refsect1>
 
         <refsect1>
-                <title>[DHCPv4] Section Options</title>
-                        <para>The <literal>[DHCPv4]</literal> section accepts the following keys:</para>
+                <title>[DHCP] Section Options</title>
+                        <para>The <literal>[DHCP]</literal> section accepts the following keys:</para>
 
                         <variablelist class='network-directives'>
                                 <varlistentry>
diff --git a/network/80-container-host0.network b/network/80-container-host0.network
index 76c0f1db4b..6863ca9ce9 100644
--- a/network/80-container-host0.network
+++ b/network/80-container-host0.network
@@ -10,6 +10,5 @@ Virtualization=container
 Name=host0
 
 [Network]
-DHCP=yes
-DHCPv6=yes
+DHCP=both
 IPv4LL=yes
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 6bff73d42d..5d280b5b82 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -29,6 +29,7 @@
 #include "virt.h"
 #include "bus-util.h"
 #include "network-internal.h"
+#include "conf-parser.h"
 
 #include "network-util.h"
 #include "dhcp-lease-internal.h"
@@ -205,7 +206,7 @@ static int link_stop_clients(Link *link) {
         if (!link->network)
                 return 0;
 
-        if (link->network->dhcp) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V6)) {
                 assert(link->dhcp_client);
 
                 k = sd_dhcp_client_stop(link->dhcp_client);
@@ -235,7 +236,7 @@ static int link_stop_clients(Link *link) {
                 }
         }
 
-        if (link->network->dhcp6) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V6)) {
                 assert(link->icmp6_router_discovery);
 
                 if (link->dhcp6_client) {
@@ -1456,7 +1457,7 @@ static int link_acquire_conf(Link *link) {
                 }
         }
 
-        if (link->network->dhcp) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V4)) {
                 assert(link->dhcp_client);
 
                 log_debug_link(link, "acquiring DHCPv4 lease");
@@ -1469,7 +1470,7 @@ static int link_acquire_conf(Link *link) {
                 }
         }
 
-        if (link->network->dhcp6) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V6)) {
                 assert(link->icmp6_router_discovery);
 
                 log_debug_link(link, "discovering IPv6 routers");
@@ -1682,7 +1683,7 @@ static int link_enslaved(Link *link) {
                 }
         }
 
-        if (!link->network->dhcp && !link->network->ipv4ll)
+        if ((link->network->dhcp == DHCP_SUPPORT_NONE) && !link->network->ipv4ll)
                 return link_enter_set_addresses(link);
 
         return 0;
@@ -1925,7 +1926,7 @@ static int link_configure(Link *link) {
                         return r;
         }
 
-        if (link->network->dhcp) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V4)) {
                 r = sd_dhcp_client_new(&link->dhcp_client);
                 if (r < 0)
                         return r;
@@ -1963,7 +1964,7 @@ static int link_configure(Link *link) {
                         return r;
         }
 
-        if (link->network->dhcp6) {
+        if (IN_SET(link->network->dhcp, DHCP_SUPPORT_BOTH, DHCP_SUPPORT_V6)) {
                 r = sd_icmp6_nd_new(&link->icmp6_router_discovery);
                 if (r < 0)
                         return r;
@@ -2496,3 +2497,55 @@ static const char* const link_operstate_table[_LINK_OPERSTATE_MAX] = {
 };
 
 DEFINE_STRING_TABLE_LOOKUP(link_operstate, LinkOperationalState);
+
+static const char* const dhcp_support_table[_DHCP_SUPPORT_MAX] = {
+        [DHCP_SUPPORT_NONE] = "none",
+        [DHCP_SUPPORT_BOTH] = "both",
+        [DHCP_SUPPORT_V4] = "v4",
+        [DHCP_SUPPORT_V6] = "v6",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(dhcp_support, DHCPSupport);
+
+int config_parse_dhcp(
+                const char* unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        DHCPSupport *dhcp = data;
+        int k;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        /* Our enum shall be a superset of booleans, hence first try
+         * to parse as boolean, and then as enum */
+
+        k = parse_boolean(rvalue);
+        if (k > 0)
+                *dhcp = DHCP_SUPPORT_BOTH;
+        else if (k == 0)
+                *dhcp = DHCP_SUPPORT_NONE;
+        else {
+                DHCPSupport s;
+
+                s = dhcp_support_from_string(rvalue);
+                if (s < 0){
+                        log_syntax(unit, LOG_ERR, filename, line, -s, "Failed to parse DHCP option, ignoring: %s", rvalue);
+                        return 0;
+                }
+
+                *dhcp = s;
+        }
+
+        return 0;
+}
diff --git a/src/network/networkd-network-gperf.gperf b/src/network/networkd-network-gperf.gperf
index 469e028687..c8610d14f4 100644
--- a/src/network/networkd-network-gperf.gperf
+++ b/src/network/networkd-network-gperf.gperf
@@ -30,10 +30,9 @@ Network.Bond,                config_parse_netdev,                0,
 Network.VLAN,                config_parse_netdev,                0,                             offsetof(Network, vlans)
 Network.MACVLAN,             config_parse_netdev,                0,                             offsetof(Network, macvlans)
 Network.VXLAN,               config_parse_netdev,                0,                             offsetof(Network, vxlans)
-Network.DHCP,                config_parse_bool,                  0,                             offsetof(Network, dhcp)
+Network.DHCP,                config_parse_dhcp,                  0,                             offsetof(Network, dhcp)
 Network.DHCPServer,          config_parse_bool,                  0,                             offsetof(Network, dhcp_server)
 Network.IPv4LL,              config_parse_bool,                  0,                             offsetof(Network, ipv4ll)
-Network.DHCPv6,              config_parse_bool,                  0,                             offsetof(Network, dhcp6)
 Network.Address,             config_parse_address,               0,                             0
 Network.Gateway,             config_parse_gateway,               0,                             0
 Network.DNS,                 config_parse_dns,                   0,                             offsetof(Network, dns)
@@ -44,6 +43,12 @@ Address.Broadcast,           config_parse_broadcast,             0,
 Address.Label,               config_parse_label,                 0,                             0
 Route.Gateway,               config_parse_gateway,               0,                             0
 Route.Destination,           config_parse_destination,           0,                             0
+DHCP.UseDNS,                 config_parse_bool,                  0,                             offsetof(Network, dhcp_dns)
+DHCP.UseMTU,                 config_parse_bool,                  0,                             offsetof(Network, dhcp_mtu)
+DHCP.UseHostname,            config_parse_bool,                  0,                             offsetof(Network, dhcp_hostname)
+DHCP.UseDomainName,          config_parse_bool,                  0,                             offsetof(Network, dhcp_domainname)
+DHCP.CriticalConnection,     config_parse_bool,                  0,                             offsetof(Network, dhcp_critical)
+/* backwards compatibility */
 DHCPv4.UseDNS,               config_parse_bool,                  0,                             offsetof(Network, dhcp_dns)
 DHCPv4.UseMTU,               config_parse_bool,                  0,                             offsetof(Network, dhcp_mtu)
 DHCPv4.UseHostname,          config_parse_bool,                  0,                             offsetof(Network, dhcp_hostname)
diff --git a/src/network/networkd.h b/src/network/networkd.h
index b7b1d903b2..67f70d9e60 100644
--- a/src/network/networkd.h
+++ b/src/network/networkd.h
@@ -131,6 +131,15 @@ struct NetDev {
         LIST_HEAD(netdev_enslave_callback, callbacks);
 };
 
+typedef enum DHCPSupport {
+        DHCP_SUPPORT_NONE,
+        DHCP_SUPPORT_BOTH,
+        DHCP_SUPPORT_V4,
+        DHCP_SUPPORT_V6,
+        _DHCP_SUPPORT_MAX,
+        _DHCP_SUPPORT_INVALID = -1,
+} DHCPSupport;
+
 struct Network {
         Manager *manager;
 
@@ -153,7 +162,7 @@ struct Network {
         Hashmap *vlans;
         Hashmap *macvlans;
         Hashmap *vxlans;
-        bool dhcp;
+        DHCPSupport dhcp;
         bool dhcp_dns;
         bool dhcp_ntp;
         bool dhcp_mtu;
@@ -161,7 +170,6 @@ struct Network {
         bool dhcp_domainname;
         bool dhcp_critical;
         bool ipv4ll;
-        bool dhcp6;
 
         bool dhcp_server;
 
@@ -472,6 +480,15 @@ LinkOperationalState link_operstate_from_string(const char *s) _pure_;
 DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_unref);
 #define _cleanup_link_unref_ _cleanup_(link_unrefp)
 
+/* DHCP support */
+
+const char* dhcp_support_to_string(DHCPSupport i) _const_;
+DHCPSupport dhcp_support_from_string(const char *s) _pure_;
+
+int config_parse_dhcp(const char *unit, const char *filename, unsigned line,
+                      const char *section, unsigned section_line, const char *lvalue,
+                      int ltype, const char *rvalue, void *data, void *userdata);
+
 /* Address Pool */
 
 int address_pool_new(Manager *m, AddressPool **ret, unsigned family, const union in_addr_union *u, unsigned prefixlen);