diff options
Diffstat (limited to 'bfdd/linux.c')
| -rw-r--r-- | bfdd/linux.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/bfdd/linux.c b/bfdd/linux.c new file mode 100644 index 0000000000..5f24ef4d19 --- /dev/null +++ b/bfdd/linux.c @@ -0,0 +1,221 @@ +/* + * 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 */ |