1 files changed, 117 insertions, 0 deletions
diff --git a/src/daemon/interfaces-bpf.c b/src/daemon/interfaces-bpf.c
new file mode 100644
index 0000000..2091eaf
--- /dev/null
+++ b/src/daemon/interfaces-bpf.c
@@ -0,0 +1,117 @@
+/* -*- mode: c; c-file-style: "openbsd" -*- */
+/*
+ * Copyright (c) 2013 Vincent Bernat <bernat@luffy.cx>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "lldpd.h"
+#include <unistd.h>
+#include <errno.h>
+#include <net/bpf.h>
+
+struct bpf_buffer {
+	size_t len; /* Total length of the buffer */
+	struct bpf_hdr data[0];
+};
+
+int
+ifbpf_phys_init(struct lldpd *cfg, struct lldpd_hardware *hardware)
+{
+	struct bpf_buffer *buffer = NULL;
+	int fd = -1;
+
+	log_debug("interfaces", "initialize ethernet device %s", hardware->h_ifname);
+	if ((fd = priv_iface_init(hardware->h_ifindex, hardware->h_ifname)) == -1)
+		return -1;
+
+	/* Allocate receive buffer */
+	hardware->h_data = buffer = malloc(ETHER_MAX_LEN +
+	    BPF_WORDALIGN(sizeof(struct bpf_hdr)) + sizeof(struct bpf_buffer));
+	if (buffer == NULL) {
+		log_warn("interfaces", "unable to allocate buffer space for BPF on %s",
+		    hardware->h_ifname);
+		goto end;
+	}
+	buffer->len = ETHER_MAX_LEN + BPF_WORDALIGN(sizeof(struct bpf_hdr));
+
+	/* Setup multicast */
+	interfaces_setup_multicast(cfg, hardware->h_ifname, 0);
+
+	hardware->h_sendfd = fd; /* Send */
+
+	levent_hardware_add_fd(hardware, fd); /* Receive */
+	log_debug("interfaces", "interface %s initialized (fd=%d)", hardware->h_ifname,
+	    fd);
+	return 0;
+
+end:
+	if (fd >= 0) close(fd);
+	free(buffer);
+	hardware->h_data = NULL;
+	return -1;
+}
+
+/* Ethernet send/receive through BPF */
+static int
+ifbpf_eth_send(struct lldpd *cfg, struct lldpd_hardware *hardware, char *buffer,
+    size_t size)
+{
+	log_debug("interfaces", "send PDU to ethernet device %s (fd=%d)",
+	    hardware->h_ifname, hardware->h_sendfd);
+	return write(hardware->h_sendfd, buffer, size);
+}
+
+static int
+ifbpf_eth_recv(struct lldpd *cfg, struct lldpd_hardware *hardware, int fd, char *buffer,
+    size_t size)
+{
+	struct bpf_buffer *bpfbuf = hardware->h_data;
+	struct bpf_hdr *bh;
+	log_debug("interfaces", "receive PDU from ethernet device %s",
+	    hardware->h_ifname);
+
+	/* We assume we have only receive one packet (unbuffered mode). Dunno if
+	 * this is correct. */
+	if (read(fd, bpfbuf->data, bpfbuf->len) == -1) {
+		if (errno == ENETDOWN) {
+			log_debug("interfaces",
+			    "error while receiving frame on %s (network down)",
+			    hardware->h_ifname);
+		} else {
+			log_warn("interfaces", "error while receiving frame on %s",
+			    hardware->h_ifname);
+			hardware->h_rx_discarded_cnt++;
+		}
+		return -1;
+	}
+	bh = (struct bpf_hdr *)bpfbuf->data;
+	if (bh->bh_caplen < size) size = bh->bh_caplen;
+	memcpy(buffer, (char *)bpfbuf->data + bh->bh_hdrlen, size);
+
+	return size;
+}
+
+static int
+ifbpf_eth_close(struct lldpd *cfg, struct lldpd_hardware *hardware)
+{
+	log_debug("interfaces", "close ethernet device %s", hardware->h_ifname);
+	interfaces_setup_multicast(cfg, hardware->h_ifname, 1);
+	return 0;
+}
+
+struct lldpd_ops bpf_ops = {
+	.send = ifbpf_eth_send,
+	.recv = ifbpf_eth_recv,
+	.cleanup = ifbpf_eth_close,
+};