networkd: integrate LLDP

This patch integrates LLDP with networkd.

Example conf:
file : lldp.network

[Match]
Name=em1

[Network]
LLDP=yes

man/systemd.network.xml

@@ -257,6 +257,13 @@
                                                 announcement. Defaults to true.</para>
                                         </listitem>
                                 </varlistentry>
+                                <varlistentry>
+                                        <term><varname>LLDP=</varname></term>
+                                        <listitem>
+                                                <para>A boolean. When true, enables LLDP link receive support.
+                                                </para>
+                                        </listitem>
+                                </varlistentry>
                                 <varlistentry>
                                         <term><varname>Address=</varname></term>
                                         <listitem>

src/network/networkd-link.c

@@ -75,6 +75,19 @@ static bool link_ipv4ll_enabled(Link *link) {
         return link->network->ipv4ll;
 }
 
+static bool link_lldp_enabled(Link *link) {
+        if (link->flags & IFF_LOOPBACK)
+                return false;
+
+        if (!link->network)
+                return false;
+
+        if(link->network->bridge)
+                return false;
+
+        return link->network->lldp;
+}
+
 #define FLAG_STRING(string, flag, old, new) \
         (((old ^ new) & flag) \
                 ? ((old & flag) ? (" -" string) : (" +" string)) \
@@ -364,6 +377,16 @@ static int link_stop_clients(Link *link) {
                 }
         }
 
+        if (link->lldp) {
+
+                k = sd_lldp_stop(link->lldp);
+                if (k < 0) {
+                        log_link_warning(link, "Could not stop LLDP : %s",
+                                         strerror(-r));
+                        r = k;
+                }
+        }
+
         return r;
 }
 
@@ -919,6 +942,18 @@ static int link_acquire_conf(Link *link) {
                 }
         }
 
+        if (link_lldp_enabled(link)) {
+                assert(link->lldp);
+
+                log_link_debug(link, "Starting LLDP");
+
+                r = sd_lldp_start(link->lldp);
+                if (r < 0) {
+                        log_link_warning(link, "could not start LLDP ");
+                        return r;
+                }
+        }
+
         return 0;
 }
 
@@ -1194,6 +1229,16 @@ static int link_configure(Link *link) {
                         return r;
         }
 
+        if (link_lldp_enabled(link)) {
+                r = sd_lldp_new(link->ifindex, link->ifname, &link->mac, &link->lldp);
+                if (r < 0)
+                        return r;
+
+                r = sd_lldp_attach_event(link->lldp, NULL, 0);
+                if (r < 0)
+                        return r;
+        }
+
         if (link_has_carrier(link)) {
                 r = link_acquire_conf(link);
                 if (r < 0)

src/network/networkd-link.h

@@ -91,6 +91,8 @@ struct Link {
 
         sd_icmp6_nd *icmp6_router_discovery;
         sd_dhcp6_client *dhcp6_client;
+
+        sd_lldp *lldp;
 };
 
 Link *link_unref(Link *link);

src/network/networkd-network-gperf.gperf

@@ -37,6 +37,7 @@ Network.DHCP,                config_parse_dhcp,                  0,
 Network.DHCPServer,          config_parse_bool,                  0,                             offsetof(Network, dhcp_server)
 Network.IPv4LL,              config_parse_bool,                  0,                             offsetof(Network, ipv4ll)
 Network.IPv4LLRoute,         config_parse_bool,                  0,                             offsetof(Network, ipv4ll_route)
+Network.LLDP,                config_parse_bool,                  0,                             offsetof(Network, lldp)
 Network.Address,             config_parse_address,               0,                             0
 Network.Gateway,             config_parse_gateway,               0,                             0
 Network.Domains,             config_parse_domains,               0,                             offsetof(Network, domains)

src/network/networkd.h

@@ -32,6 +32,7 @@
 #include "sd-icmp6-nd.h"
 #include "sd-dhcp6-client.h"
 #include "udev.h"
+#include "sd-lldp.h"
 
 #include "rtnl-util.h"
 #include "hashmap.h"
@@ -122,6 +123,8 @@ struct Network {
         struct ether_addr *mac;
         unsigned mtu;
 
+        bool lldp;
+
         LIST_HEAD(Address, static_addresses);
         LIST_HEAD(Route, static_routes);
         LIST_HEAD(FdbEntry, static_fdb_entries);