Netlinks is a communication protocol currently used in Linux kernel to modify, read and subscribe for nearly all networking state. Interfaces, addresses, routes, firewall, fibs, vnets, etc are controlled via netlink. It is async, TLV-based protocol, providing 1-1 and 1-many communications. The current implementation supports the subset of NETLINK_ROUTE family. To be more specific, the following is supported: * Dumps: - routes - nexthops / nexthop groups - interfaces - interface addresses - neighbors (arp/ndp) * Notifications: - interface arrival/departure - interface address arrival/departure - route addition/deletion * Modifications: - adding/deleting routes - adding/deleting nexthops/nexthops groups - adding/deleting neghbors - adding/deleting interfaces (basic support only) * Rtsock interaction - route events are bridged both ways The implementation also supports the NETLINK_GENERIC family framework. Implementation notes: Netlink is implemented via loadable/unloadable kernel module, not touching many kernel parts. Each netlink socket uses dedicated taskqueue to support async operations that can sleep, such as interface creation. All message processing is performed within these taskqueues. Compatibility: Most of the Netlink data models specified above maps to FreeBSD concepts nicely. Unmodified ip(8) binary correctly works with interfaces, addresses, routes, nexthops and nexthop groups. Some software such as net/bird require header-only modifications to compile and work with FreeBSD netlink. Reviewed by: imp Differential Revision: https://reviews.freebsd.org/D36002 MFC after: 2 months
103 lines
3.5 KiB
C
103 lines
3.5 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* NEXTHOP-related (RTM_<NEW|DEL|GET>NEXTHOP) message header and attributes.
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*/
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#ifndef _NETLINK_ROUTE_NEXTHOP_H_
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#define _NETLINK_ROUTE_NEXTHOP_H_
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/* Base header for all of the relevant messages */
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struct nhmsg {
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unsigned char nh_family; /* transport family */
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unsigned char nh_scope; /* ignored on RX, filled by kernel */
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unsigned char nh_protocol; /* Routing protocol that installed nh */
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unsigned char resvd;
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unsigned int nh_flags; /* RTNH_F_* flags from route.h */
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};
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enum {
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NHA_UNSPEC,
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NHA_ID, /* u32: nexthop userland index, auto-assigned if 0 */
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NHA_GROUP, /* binary: array of struct nexthop_grp */
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NHA_GROUP_TYPE, /* u16: set to NEXTHOP_GRP_TYPE */
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NHA_BLACKHOLE, /* flag: nexthop used to blackhole packets */
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NHA_OIF, /* u32: transmit ifindex */
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NHA_GATEWAY, /* network: IPv4/IPv6 gateway addr */
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NHA_ENCAP_TYPE, /* not supported */
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NHA_ENCAP, /* not supported */
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NHA_GROUPS, /* flag: match nexthop groups */
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NHA_MASTER, /* not supported */
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NHA_FDB, /* not supported */
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NHA_RES_GROUP, /* not supported */
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NHA_RES_BUCKET, /* not supported */
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__NHA_MAX,
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};
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#define NHA_MAX (__NHA_MAX - 1)
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/*
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* Attributes that can be used as filters:
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* NHA_ID (nexhop or group), NHA_OIF, NHA_GROUPS,
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*/
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/*
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* NHA_GROUP: array of the following structures.
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* If attribute is set, the only other valid attributes are
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* NHA_ID and NHA_GROUP_TYPE.
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* NHA_RES_GROUP and NHA_RES_BUCKET are not supported yet
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*/
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struct nexthop_grp {
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uint32_t id; /* nexhop userland index */
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uint8_t weight; /* weight of this nexthop */
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uint8_t resvd1;
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uint16_t resvd2;
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};
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/* NHA_GROUP_TYPE: u16 */
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enum {
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NEXTHOP_GRP_TYPE_MPATH, /* default nexthop group */
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NEXTHOP_GRP_TYPE_RES, /* resilient nexthop group */
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__NEXTHOP_GRP_TYPE_MAX,
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};
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#define NEXTHOP_GRP_TYPE_MAX (__NEXTHOP_GRP_TYPE_MAX - 1)
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/* NHA_RES_GROUP */
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enum {
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NHA_RES_GROUP_UNSPEC,
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NHA_RES_GROUP_PAD = NHA_RES_GROUP_UNSPEC,
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NHA_RES_GROUP_BUCKETS,
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NHA_RES_GROUP_IDLE_TIMER,
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NHA_RES_GROUP_UNBALANCED_TIMER,
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NHA_RES_GROUP_UNBALANCED_TIME,
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__NHA_RES_GROUP_MAX,
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};
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#define NHA_RES_GROUP_MAX (__NHA_RES_GROUP_MAX - 1)
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#endif
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