mirror of
https://github.com/vishvananda/netlink.git
synced 2026-04-22 23:27:13 +08:00
Yutaro Hayakawa
6e61cd407d
Add a basic support of Linux's ip nexthop equivalent. In this PR, I specifically focused on implementing a minimal feature to accomplish IPv4 prefix with IPv6 (link-local) nexthop which is used by various implementation like FRR to support technique called BGP Unnumbered. The summary of the new features are: - Introduce a low level primitive for nexthop in the nl package - Introduce NexthopAdd/Del/List/Replace APIs (supports NHA_ID/BLACKHOLE/GATEWAY, and protocol field) - Introduce NHID field to the Route object which allows attaching nexthop to routes. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> === Squashed Commits === nl: Fix some wrong error and done message handling The current logic of parsing ERROR and DONE message is, first reads error field and when NLM_F_ACK_TLVS exists, tries to read the original request header, payload of the request, and extended ACK. We have three issues here: 1. The existence of the original request header is not indicated by NLM_F_ACK_TLVS flag. At least the original request header always exists. 2. We are missing the check for NLM_F_CAPPED flag. When the flag exists, the payload of the request doesn't exist. In that case, we shouldn't try to skip the payload. Otherwise, we may end up with the out-of-range read. 3. NLMSG_DONE doesn't contain the original request, so we shouldn't apply original request parsing logic to it. In this commit, we fix these issues by: 1. We first check the existence of the NLM_F_CAPPED. When it exists, only skip the original request header. Otherwise, skip the payload as well. Don't apply this logic to the DONE message. 2. After that, check the existence of the NLM_F_ACK_TLVS. When it exists, try to read extended ACK for both of DONE and ERROR messages. Otherwise, don't. Ref: https://docs.kernel.org/userspace-api/netlink/intro.html#netlink-message-types Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> nexthop: Add a low-level API for the nexthop Preparation for the support of the nexthop object. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> Add basic operation for nexthop Add a basic support of the Linux's nexthop object (ip nexthop XXX). This commit aims to introduce a basic operations (add, list, del) with minimal attributes. Further features can be added later incrementally. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> nexthop: Support NHA_OIF It can be used for expressing direct nexthop on specific link. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> nexthop: Support NHA_GATEWAY It can express an IP nexthop. A unique use case we can accomplish by this is attaching IPv6 nexthop to the routes with an IPv4 prefix which we cannot do with the existing `ip route` equivalents. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> nexthop: Support protocol Allow setting protocol for nexthop. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> route: Support RTA_NHID Support attaching nexthop object to route object via NHID field. Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com> nexthop: Add Replace operation support Add `ip nexthop replace` equivalent Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com>
34 lines
569 B
Go
34 lines
569 B
Go
package nl
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import (
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"unsafe"
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"golang.org/x/sys/unix"
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)
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const (
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// This is a workaround for missing SizeofNhmsg in the
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// golang.org/x/sys/unix. Once the SizeofNhmsg is added there, this
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// constant can be removed.
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sizeofNhmsg = 8
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)
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type Nhmsg struct {
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unix.Nhmsg
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}
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func (msg *Nhmsg) Len() int {
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return sizeofNhmsg
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}
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func DeserializeNhmsg(b []byte) *Nhmsg {
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if len(b) < sizeofNhmsg {
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return nil
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}
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return (*Nhmsg)(unsafe.Pointer(&b[0:sizeofNhmsg][0]))
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}
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func (msg *Nhmsg) Serialize() []byte {
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return (*(*[sizeofNhmsg]byte)(unsafe.Pointer(msg)))[:]
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}
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