networkd: Introduce Link Layer Discovery Protocol (LLDP)

This patch introduces LLDP support to networkd. it implements the
receiver side of the protocol.

The Link Layer Discovery Protocol (LLDP) is an industry-standard,
vendor-neutral method to allow networked devices to advertise
capabilities, identity, and other information onto a LAN. The Layer 2
protocol, detailed in IEEE 802.1AB-2005.LLDP allows network devices
that operate at the lower layers of a protocol stack (such as
Layer 2 bridges and switches) to learn some of the capabilities
and characteristics of LAN devices available to higher
layer protocols.

1 files changed, 116 insertions, 0 deletions

diff --git a/src/libsystemd-network/lldp-port.c b/src/libsystemd-network/lldp-port.c
new file mode 100644
index 0000000000..12b72eedc7
--- /dev/null
+++ b/src/libsystemd-network/lldp-port.c
@@ -0,0 +1,116 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 Tom Gundersen
+  Copyright (C) 2014 Susant Sahani
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "async.h"
+#include "lldp-port.h"
+#include "lldp-network.h"
+
+int lldp_port_start(lldp_port *p) {
+        int r;
+
+        assert_return(p, -EINVAL);
+
+        r = lldp_network_bind_raw_socket(p->ifindex);
+        if (r < 0)
+                return r;
+
+        p->rawfd = r;
+
+        r = sd_event_add_io(p->event, &p->lldp_port_rx,
+                            p->rawfd, EPOLLIN, lldp_receive_packet, p);
+        if (r < 0) {
+                log_debug("Failed to allocate event source: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_event_source_set_priority(p->lldp_port_rx, p->event_priority);
+        if (r < 0) {
+                log_debug("Failed to set event priority: %s", strerror(-r));
+                goto fail;
+        }
+
+        r = sd_event_source_set_description(p->lldp_port_rx, "lldp-port-rx");
+        if (r < 0) {
+                log_debug("Failed to set event name: %s", strerror(-r));
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        lldp_port_stop(p);
+
+        return r;
+}
+
+int lldp_port_stop(lldp_port *p) {
+
+        assert_return(p, -EINVAL);
+
+        p->rawfd = asynchronous_close(p->rawfd);
+        p->lldp_port_rx = sd_event_source_unref(p->lldp_port_rx);
+
+        return 0;
+}
+
+void lldp_port_free(lldp_port *p) {
+        if (!p)
+                return;
+
+        lldp_port_stop(p);
+
+        free(p->ifname);
+        free(p);
+}
+
+int lldp_port_new(int ifindex,
+                  char *ifname,
+                  const struct ether_addr *addr,
+                  void *userdata,
+                  lldp_port **ret) {
+        _cleanup_free_ lldp_port *p = NULL;
+
+        assert_return(ifindex, -EINVAL);
+        assert_return(ifname, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        p = new0(lldp_port, 1);
+        if (!p)
+                return -ENOMEM;
+
+        p->rawfd = -1;
+        p->ifindex = ifindex;
+
+        p->ifname = strdup(ifname);
+        if (!p->ifname)
+                return -ENOMEM;
+
+        memcpy(&p->mac, addr, ETH_ALEN);
+
+        p->userdata = userdata;
+
+        *ret = p;
+
+        p = NULL;
+
+        return 0;
+}