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/*
* Linux specific code
*
* Copyright (C) 2018 Network Device Education Foundation, Inc. ("NetDEF")
*
* FRR is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* FRR 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with FRR; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <zebra.h>
#ifdef BFD_LINUX
/* XXX: fix compilation error on Ubuntu 16.04 or older. */
#ifndef _UAPI_IPV6_H
#define _UAPI_IPV6_H
#endif /* _UAPI_IPV6_H */
#include <linux/filter.h>
#include <linux/if_packet.h>
#include <netinet/if_ether.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include "bfd.h"
/* Berkeley Packet filter code to filter out BFD Echo packets.
* tcpdump -dd "(udp dst port 3785)"
*/
static struct sock_filter bfd_echo_filter[] = {
{0x28, 0, 0, 0x0000000c}, {0x15, 0, 4, 0x000086dd},
{0x30, 0, 0, 0x00000014}, {0x15, 0, 11, 0x00000011},
{0x28, 0, 0, 0x00000038}, {0x15, 8, 9, 0x00000ec9},
{0x15, 0, 8, 0x00000800}, {0x30, 0, 0, 0x00000017},
{0x15, 0, 6, 0x00000011}, {0x28, 0, 0, 0x00000014},
{0x45, 4, 0, 0x00001fff}, {0xb1, 0, 0, 0x0000000e},
{0x48, 0, 0, 0x00000010}, {0x15, 0, 1, 0x00000ec9},
{0x6, 0, 0, 0x0000ffff}, {0x6, 0, 0, 0x00000000},
};
/* Berkeley Packet filter code to filter out BFD vxlan packets.
* tcpdump -dd "(udp dst port 4789)"
*/
static struct sock_filter bfd_vxlan_filter[] = {
{0x28, 0, 0, 0x0000000c}, {0x15, 0, 4, 0x000086dd},
{0x30, 0, 0, 0x00000014}, {0x15, 0, 11, 0x00000011},
{0x28, 0, 0, 0x00000038}, {0x15, 8, 9, 0x000012b5},
{0x15, 0, 8, 0x00000800}, {0x30, 0, 0, 0x00000017},
{0x15, 0, 6, 0x00000011}, {0x28, 0, 0, 0x00000014},
{0x45, 4, 0, 0x00001fff}, {0xb1, 0, 0, 0x0000000e},
{0x48, 0, 0, 0x00000010}, {0x15, 0, 1, 0x000012b5},
{0x6, 0, 0, 0x0000ffff}, {0x6, 0, 0, 0x00000000},
};
/*
* Definitions.
*/
int ptm_bfd_fetch_ifindex(const char *ifname)
{
struct ifreq ifr;
if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name))
> sizeof(ifr.ifr_name))
log_error("interface-to-index: name truncated ('%s' -> '%s')",
ifr.ifr_name, ifname);
if (ioctl(bglobal.bg_shop, SIOCGIFINDEX, &ifr) == -1) {
log_error("interface-to-index: %s translation failed: %s",
ifname, strerror(errno));
return -1;
}
return ifr.ifr_ifindex;
}
void ptm_bfd_fetch_local_mac(const char *ifname, uint8_t *mac)
{
struct ifreq ifr;
if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name))
> sizeof(ifr.ifr_name))
log_error("interface-mac: name truncated ('%s' -> '%s')",
ifr.ifr_name, ifname);
if (ioctl(bglobal.bg_shop, SIOCGIFHWADDR, &ifr) == -1) {
log_error("interface-mac: %s MAC retrieval failed: %s", ifname,
strerror(errno));
return;
}
memcpy(mac, ifr.ifr_hwaddr.sa_data, ETHERNET_ADDRESS_LENGTH);
}
/* Was _fetch_portname_from_ifindex() */
void fetch_portname_from_ifindex(int ifindex, char *ifname, size_t ifnamelen)
{
struct ifreq ifr;
ifname[0] = 0;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_ifindex = ifindex;
if (ioctl(bglobal.bg_shop, SIOCGIFNAME, &ifr) == -1) {
log_error("index-to-interface: index %d failure: %s", ifindex,
strerror(errno));
return;
}
if (strlcpy(ifname, ifr.ifr_name, ifnamelen) >= ifnamelen)
log_debug("index-to-interface: name truncated '%s' -> '%s'",
ifr.ifr_name, ifname);
}
int ptm_bfd_echo_sock_init(void)
{
int s;
struct sock_fprog bpf = {.len = sizeof(bfd_echo_filter)
/ sizeof(bfd_echo_filter[0]),
.filter = bfd_echo_filter};
s = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP));
if (s == -1) {
log_error("echo-socket: creation failure: %s", strerror(errno));
return -1;
}
if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))
== -1) {
log_error("echo-socket: setsockopt(SO_ATTACH_FILTER): %s",
strerror(errno));
close(s);
return -1;
}
return s;
}
int ptm_bfd_vxlan_sock_init(void)
{
int s;
struct sock_fprog bpf = {.len = sizeof(bfd_vxlan_filter)
/ sizeof(bfd_vxlan_filter[0]),
.filter = bfd_vxlan_filter};
s = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP));
if (s == -1) {
log_error("vxlan-socket: creation failure: %s",
strerror(errno));
return -1;
}
if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))
== -1) {
log_error("vxlan-socket: setsockopt(SO_ATTACH_FILTER): %s",
strerror(errno));
close(s);
return -1;
}
return s;
}
int bp_bind_dev(int sd __attribute__((__unused__)),
const char *dev __attribute__((__unused__)))
{
/*
* TODO: implement this differently. It is not possible to
* SO_BINDTODEVICE after the daemon has dropped its privileges.
*/
#if 0
size_t devlen = strlen(dev) + 1;
if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, dev, devlen) == -1) {
log_warning("%s: setsockopt(SO_BINDTODEVICE, \"%s\"): %s",
__func__, dev, strerror(errno));
return -1;
}
#endif
return 0;
}
uint16_t udp4_checksum(struct iphdr *iph, uint8_t *buf, int len)
{
char *ptr;
struct udp_psuedo_header pudp_hdr;
uint16_t csum;
pudp_hdr.saddr = iph->saddr;
pudp_hdr.daddr = iph->daddr;
pudp_hdr.reserved = 0;
pudp_hdr.protocol = iph->protocol;
pudp_hdr.len = htons(len);
ptr = XMALLOC(MTYPE_BFDD_TMP, UDP_PSUEDO_HDR_LEN + len);
memcpy(ptr, &pudp_hdr, UDP_PSUEDO_HDR_LEN);
memcpy(ptr + UDP_PSUEDO_HDR_LEN, buf, len);
csum = checksum((uint16_t *)ptr, UDP_PSUEDO_HDR_LEN + len);
XFREE(MTYPE_BFDD_TMP, ptr);
return csum;
}
#endif /* BFD_LINUX */
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