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, 87 insertions, 0 deletions

diff --git a/src/libsystemd-network/lldp-tlv.h b/src/libsystemd-network/lldp-tlv.h
new file mode 100644
index 0000000000..ce3334e115
--- /dev/null
+++ b/src/libsystemd-network/lldp-tlv.h
@@ -0,0 +1,87 @@
+/*-*- 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/>.
+***/
+
+#pragma once
+
+#include <net/ethernet.h>
+
+#include "util.h"
+#include "lldp.h"
+#include "list.h"
+
+typedef struct tlv_packet tlv_packet;
+typedef struct tlv_section tlv_section;
+
+struct tlv_section {
+        uint16_t type;
+        uint16_t length;
+
+        uint8_t *read_pos;
+        uint8_t *data;
+
+        LIST_FIELDS(tlv_section, section);
+};
+
+int tlv_section_new(tlv_section **ret);
+void tlv_section_free(tlv_section *ret);
+
+struct tlv_packet {
+        uint16_t type;
+        uint16_t length;
+        usec_t ts;
+
+        uint8_t *container_pos;
+        uint8_t pdu[ETHER_MAX_LEN];
+
+        void *userdata;
+
+        struct ether_addr mac;
+        tlv_section *container;
+
+        LIST_HEAD(tlv_section, sections);
+};
+
+int tlv_packet_new(tlv_packet **ret);
+void tlv_packet_free(tlv_packet *m);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(tlv_packet*, tlv_packet_free);
+#define _cleanup_tlv_packet_free_ _cleanup_(tlv_packet_freep)
+
+int lldp_tlv_packet_open_container(tlv_packet *m, uint16_t type);
+int lldp_tlv_packet_close_container(tlv_packet *m);
+
+int tlv_packet_append_bytes(tlv_packet *m, const void *data, size_t data_length);
+int tlv_packet_append_u8(tlv_packet *m, uint8_t data);
+int tlv_packet_append_u16(tlv_packet *m, uint16_t data);
+int tlv_packet_append_u32(tlv_packet *m, uint32_t data);
+int tlv_packet_append_string(tlv_packet *m, char *data, uint16_t size);
+
+int lldp_tlv_packet_enter_container(tlv_packet *m, uint16_t type);
+int lldp_tlv_packet_exit_container(tlv_packet *m);
+
+int tlv_packet_read_bytes(tlv_packet *m, uint8_t **data, uint16_t *data_length);
+int tlv_packet_read_string(tlv_packet *m, char **data, uint16_t *data_length);
+int tlv_packet_read_u8(tlv_packet *m, uint8_t *data);
+int tlv_packet_read_u16(tlv_packet *m, uint16_t *data);
+int tlv_packet_read_u32(tlv_packet *m, uint32_t *data);
+
+int tlv_packet_parse_pdu(tlv_packet *t, uint16_t size);