/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Alexander V. Chernikov
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* This header file contains public definitions for the nexthop routing subsystem.
*/
#ifndef _NET_ROUTE_NHOP_H_
#define _NET_ROUTE_NHOP_H_
#include <netinet/in.h> /* sockaddr_in && sockaddr_in6 */
#include <sys/counter.h>
enum nhop_type {
NH_TYPE_IPV4_ETHER_RSLV = 1, /* IPv4 ethernet without GW */
NH_TYPE_IPV4_ETHER_NHOP = 2, /* IPv4 with pre-calculated ethernet encap */
NH_TYPE_IPV6_ETHER_RSLV = 3, /* IPv6 ethernet, without GW */
NH_TYPE_IPV6_ETHER_NHOP = 4 /* IPv6 with pre-calculated ethernet encap*/
};
#ifdef _KERNEL
/*
* Define shorter version of AF_LINK sockaddr.
*
* Currently the only use case of AF_LINK gateway is storing
* interface index of the interface of the source IPv6 address.
* This is used by the IPv6 code for the connections over loopback
* interface.
*
* The structure below copies 'struct sockaddr_dl', reducing the
* size of sdl_data buffer, as it is not used. This change
* allows to store the AF_LINK gateways in the nhop gateway itself,
* simplifying control plane handling.
*/
struct sockaddr_dl_short {
u_char sdl_len; /* Total length of sockaddr */
u_char sdl_family; /* AF_LINK */
u_short sdl_index; /* if != 0, system given index for interface */
u_char sdl_type; /* interface type */
u_char sdl_nlen; /* interface name length, no trailing 0 reqd. */
u_char sdl_alen; /* link level address length */
u_char sdl_slen; /* link layer selector length */
char sdl_data[8]; /* unused */
};
#define NHOP_RELATED_FLAGS \
(RTF_GATEWAY | RTF_HOST | RTF_REJECT | RTF_BLACKHOLE | \
RTF_FIXEDMTU | RTF_LOCAL | RTF_BROADCAST | RTF_MULTICAST)
struct nh_control;
struct nhop_priv;
/*
* Struct 'nhop_object' field description:
*
* nh_flags: NHF_ flags used in the dataplane code. NHF_GATEWAY or NHF_BLACKHOLE
* can be examples of such flags.
* nh_mtu: ready-to-use nexthop mtu. Already accounts for the link-level header,
* interface MTU and protocol-specific limitations.
* nh_prepend_len: link-level prepend length. Currently unused.
* nh_ifp: logical transmit interface. The one from which if_transmit() will be
* called. Guaranteed to be non-NULL.
* nh_aifp: ifnet of the source address. Same as nh_ifp except IPv6 loopback
* routes. See the example below.
* nh_ifa: interface address to use. Guaranteed to be non-NULL.
* nh_pksent: counter(9) reflecting the number of packets transmitted.
*
* gw_: storage suitable to hold AF_INET, AF_INET6 or AF_LINK gateway. More
* details ara available in the examples below.
*
* Examples:
*
* Direct routes (routes w/o gateway):
* NHF_GATEWAY is NOT set.
* nh_ifp denotes the logical transmit interface ().
* nh_aifp is the same as nh_ifp
* gw_sa contains AF_LINK sa with nh_aifp ifindex (compat)
* Loopback routes:
* NHF_GATEWAY is NOT set.
* nh_ifp points to the loopback interface (lo0).
* nh_aifp points to the interface where the destination address belongs to.
* This is useful in IPv6 link-local-over-loopback communications.
* gw_sa contains AF_LINK sa with nh_aifp ifindex (compat)
* GW routes:
* NHF_GATEWAY is set.
* nh_ifp denotes the logical transmit interface.
* nh_aifp is the same as nh_ifp
* gw_sa contains L3 address (either AF_INET or AF_INET6).
*
*
* Note: struct nhop_object fields are ordered in a way that
* supports memcmp-based comparisons.
*
*/
#define NHOP_END_CMP (__offsetof(struct nhop_object, nh_pksent))
struct nhop_object {
uint16_t nh_flags; /* nhop flags */
uint16_t nh_mtu; /* nexthop mtu */
union {
struct sockaddr_in gw4_sa; /* GW accessor as IPv4 */
struct sockaddr_in6 gw6_sa; /* GW accessor as IPv6 */
struct sockaddr gw_sa;
struct sockaddr_dl_short gwl_sa; /* AF_LINK gw (compat) */
char gw_buf[28];
};
struct ifnet *nh_ifp; /* Logical egress interface. Always != NULL */
struct ifaddr *nh_ifa; /* interface address to use. Always != NULL */
struct ifnet *nh_aifp; /* ifnet of the source address. Always != NULL */
counter_u64_t nh_pksent; /* packets sent using this nhop */
/* 32 bytes + 4xPTR == 64(amd64) / 48(i386) */
uint8_t nh_prepend_len; /* length of prepend data */
uint8_t spare[3];
uint32_t spare1; /* alignment */
char nh_prepend[48]; /* L2 prepend */
struct nhop_priv *nh_priv; /* control plane data */
/* -- 128 bytes -- */
};
/*
* Nhop validness.
*
* Currently we verify whether link is up or not on every packet, which can be
* quite costy.
* TODO: subscribe for the interface notifications and update the nexthops
* with NHF_INVALID flag.
*/
#define NH_IS_VALID(_nh) RT_LINK_IS_UP((_nh)->nh_ifp)
#define NH_IS_NHGRP(_nh) ((_nh)->nh_flags & NHF_MULTIPATH)
#define RT_GATEWAY(_rt) ((struct sockaddr *)&(_rt)->rt_nhop->gw4_sa)
#define RT_GATEWAY_CONST(_rt) ((const struct sockaddr *)&(_rt)->rt_nhop->gw4_sa)
#define NH_FREE(_nh) do { \
nhop_free(_nh); \
/* guard against invalid refs */ \
_nh = NULL; \
} while (0)
struct weightened_nhop {
struct nhop_object *nh;
uint32_t weight;
};
void nhop_free(struct nhop_object *nh);
struct sysctl_req;
struct sockaddr_dl;
struct rib_head;
uint32_t nhop_get_idx(const struct nhop_object *nh);
enum nhop_type nhop_get_type(const struct nhop_object *nh);
int nhop_get_rtflags(const struct nhop_object *nh);
struct vnet *nhop_get_vnet(const struct nhop_object *nh);
#endif /* _KERNEL */
/* Kernel <> userland structures */
/* Structure usage and layout are described in dump_nhop_entry() */
struct nhop_external {
uint32_t nh_len; /* length of the datastructure */
uint32_t nh_idx; /* Nexthop index */
uint32_t nh_fib; /* Fib nexhop is attached to */
uint32_t ifindex; /* transmit interface ifindex */
uint32_t aifindex; /* address ifindex */
uint8_t prepend_len; /* length of the prepend */
uint8_t nh_family; /* address family */
uint16_t nh_type; /* nexthop type */
uint16_t nh_mtu; /* nexthop mtu */
uint16_t nh_flags; /* nhop flags */
struct in_addr nh_addr; /* GW/DST IPv4 address */
struct in_addr nh_src; /* default source IPv4 address */
uint64_t nh_pksent;
/* control plane */
/* lookup key: address, family, type */
char nh_prepend[64]; /* L2 prepend */
uint64_t nh_refcount; /* number of references */
};
struct nhop_addrs {
uint32_t na_len; /* length of the datastructure */
uint16_t gw_sa_off; /* offset of gateway SA */
uint16_t src_sa_off; /* offset of src address SA */
};
#define NHG_C_TYPE_CNHOPS 0x1 /* Control plane nhops list */
#define NHG_C_TYPE_DNHOPS 0x2 /* Dataplane nhops list */
struct nhgrp_container {
uint32_t nhgc_len; /* container length */
uint16_t nhgc_count; /* number of items */
uint8_t nhgc_type; /* container type */
uint8_t nhgc_subtype; /* container subtype */
};
struct nhgrp_nhop_external {
uint32_t nh_idx;
uint32_t nh_weight;
};
/*
* Layout:
* - nhgrp_external
* - nhgrp_container (control plane nhops list)
* - nhgrp_nhop_external
* - nhgrp_nhop_external
* ..
* - nhgrp_container (dataplane nhops list)
* - nhgrp_nhop_external
* - nhgrp_nhop_external
*/
struct nhgrp_external {
uint32_t nhg_idx; /* Nexthop group index */
uint32_t nhg_refcount; /* number of references */
};
#endif