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Diffstat (limited to 'src/libsystemd-network/lldp-network.c')
-rw-r--r--src/libsystemd-network/lldp-network.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/src/libsystemd-network/lldp-network.c b/src/libsystemd-network/lldp-network.c
new file mode 100644
index 0000000000..cfab91146c
--- /dev/null
+++ b/src/libsystemd-network/lldp-network.c
@@ -0,0 +1,111 @@
+/*-*- 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 <linux/filter.h>
+#include <linux/if_ether.h>
+
+#include "socket-util.h"
+#include "lldp-tlv.h"
+#include "lldp-network.h"
+#include "sd-lldp.h"
+
+int lldp_network_bind_raw_socket(int ifindex) {
+ typedef struct LLDPFrame {
+ struct ethhdr hdr;
+ uint8_t tlvs[0];
+ } LLDPFrame;
+
+ struct sock_filter filter[] = {
+ BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(LLDPFrame, hdr.h_dest)), /* A <- 4 bytes of destination MAC */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0180c200, 1, 0), /* A != 01:80:c2:00 */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(LLDPFrame, hdr.h_dest) + 4), /* A <- remaining 2 bytes of destination MAC */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0000, 3, 0), /* A != 00:00 */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0003, 2, 0), /* A != 00:03 */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x000e, 1, 0), /* A != 00:0e */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(LLDPFrame, hdr.h_proto)), /* A <- protocol */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_LLDP, 1, 0), /* A != ETHERTYPE_LLDP */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
+ BPF_STMT(BPF_RET + BPF_K, (uint32_t) -1), /* accept packet */
+ };
+
+ struct sock_fprog fprog = {
+ .len = ELEMENTSOF(filter),
+ .filter = filter
+ };
+
+ _cleanup_close_ int s = -1;
+
+ union sockaddr_union saddrll = {
+ .ll.sll_family = AF_PACKET,
+ .ll.sll_ifindex = ifindex,
+ };
+
+ int r;
+
+ assert(ifindex > 0);
+
+ s = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+ if (s < 0)
+ return -errno;
+
+ r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog));
+ if (r < 0)
+ return -errno;
+
+ r = bind(s, &saddrll.sa, sizeof(saddrll.ll));
+ if (r < 0)
+ return -errno;
+
+ r = s;
+ s = -1;
+
+ return r;
+}
+
+int lldp_receive_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ _cleanup_tlv_packet_free_ tlv_packet *packet = NULL;
+ tlv_packet *p;
+ uint16_t length;
+ int r;
+
+ assert(fd);
+ assert(userdata);
+
+ r = tlv_packet_new(&packet);
+ if (r < 0)
+ return r;
+
+ length = read(fd, &packet->pdu, sizeof(packet->pdu));
+
+ /* Silently drop the packet */
+ if ((size_t) length > ETHER_MAX_LEN)
+ return 0;
+
+ packet->userdata = userdata;
+
+ p = packet;
+ packet = NULL;
+
+ return lldp_handle_packet(p, (uint16_t) length);
+}