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/* -*- 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,
};
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