netstack_testing_common/
nud.rs

1// Copyright 2023 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Useful NUD functions for tests.
6
7use anyhow::Context;
8use futures::StreamExt as _;
9use net_types::SpecifiedAddress as _;
10use {
11    fidl_fuchsia_net_interfaces_admin as fnet_interfaces_admin,
12    fidl_fuchsia_net_interfaces_ext as fnet_interfaces_ext,
13};
14
15/// Frame metadata of interest to neighbor tests.
16#[derive(Debug, Eq, PartialEq)]
17pub enum FrameMetadata {
18    /// An ARP request or NDP Neighbor Solicitation target address.
19    NeighborSolicitation(fidl_fuchsia_net::IpAddress),
20    /// A UDP datagram destined to the address.
21    Udp(fidl_fuchsia_net::IpAddress),
22    /// Any other successfully parsed frame.
23    Other,
24}
25
26/// Helper function to extract specific frame metadata from a raw Ethernet
27/// frame.
28///
29/// Returns `Err` if the frame can't be parsed or `Ok(FrameMetadata)` with any
30/// interesting metadata of interest to neighbor tests.
31fn extract_frame_metadata(data: Vec<u8>) -> crate::Result<FrameMetadata> {
32    use packet::ParsablePacket;
33    use packet_formats::arp::{ArpOp, ArpPacket};
34    use packet_formats::ethernet::{EtherType, EthernetFrame, EthernetFrameLengthCheck};
35    use packet_formats::icmp::ndp::NdpPacket;
36    use packet_formats::icmp::{IcmpParseArgs, Icmpv6Packet};
37    use packet_formats::ip::{IpPacket, IpProto, Ipv6Proto};
38    use packet_formats::ipv4::Ipv4Packet;
39    use packet_formats::ipv6::Ipv6Packet;
40
41    let mut bv = &data[..];
42    let ethernet = EthernetFrame::parse(&mut bv, EthernetFrameLengthCheck::NoCheck)
43        .context("failed to parse Ethernet frame")?;
44    match ethernet
45        .ethertype()
46        .ok_or_else(|| anyhow::anyhow!("missing ethertype in Ethernet frame"))?
47    {
48        EtherType::Ipv4 => {
49            let ipv4 = Ipv4Packet::parse(&mut bv, ()).context("failed to parse IPv4 packet")?;
50            if ipv4.proto() != IpProto::Udp.into() {
51                return Ok(FrameMetadata::Other);
52            }
53            Ok(FrameMetadata::Udp(fidl_fuchsia_net::IpAddress::Ipv4(
54                fidl_fuchsia_net::Ipv4Address { addr: ipv4.dst_ip().ipv4_bytes() },
55            )))
56        }
57        EtherType::Arp => {
58            let arp = ArpPacket::<_, net_types::ethernet::Mac, net_types::ip::Ipv4Addr>::parse(
59                &mut bv,
60                (),
61            )
62            .context("failed to parse ARP packet")?;
63            match arp.operation() {
64                ArpOp::Request => Ok(FrameMetadata::NeighborSolicitation(
65                    fidl_fuchsia_net::IpAddress::Ipv4(fidl_fuchsia_net::Ipv4Address {
66                        addr: arp.target_protocol_address().ipv4_bytes(),
67                    }),
68                )),
69                ArpOp::Response => Ok(FrameMetadata::Other),
70                ArpOp::Other(other) => Err(anyhow::anyhow!("unrecognized ARP operation {}", other)),
71            }
72        }
73        EtherType::Ipv6 => {
74            let ipv6 = Ipv6Packet::parse(&mut bv, ()).context("failed to parse IPv6 packet")?;
75            match ipv6.proto() {
76                Ipv6Proto::Icmpv6 => {
77                    // NB: filtering out packets with an unspecified source address will
78                    // filter out DAD-related solicitations.
79                    if !ipv6.src_ip().is_specified() {
80                        return Ok(FrameMetadata::Other);
81                    }
82                    let parse_args = IcmpParseArgs::new(ipv6.src_ip(), ipv6.dst_ip());
83                    match Icmpv6Packet::parse(&mut bv, parse_args)
84                        .context("failed to parse ICMP packet")?
85                    {
86                        Icmpv6Packet::Ndp(NdpPacket::NeighborSolicitation(solicit)) => {
87                            Ok(FrameMetadata::NeighborSolicitation(
88                                fidl_fuchsia_net::IpAddress::Ipv6(fidl_fuchsia_net::Ipv6Address {
89                                    addr: solicit.message().target_address().ipv6_bytes(),
90                                }),
91                            ))
92                        }
93                        _ => Ok(FrameMetadata::Other),
94                    }
95                }
96                Ipv6Proto::Proto(IpProto::Udp) => {
97                    Ok(FrameMetadata::Udp(fidl_fuchsia_net::IpAddress::Ipv6(
98                        fidl_fuchsia_net::Ipv6Address { addr: ipv6.dst_ip().ipv6_bytes() },
99                    )))
100                }
101                _ => Ok(FrameMetadata::Other),
102            }
103        }
104        EtherType::Other(other) => {
105            Err(anyhow::anyhow!("unrecognized ethertype in Ethernet frame {}", other))
106        }
107    }
108}
109
110/// Creates a fake endpoint that extracts [`FrameMetadata`] from exchanged
111/// frames in `network`.
112pub fn create_metadata_stream<'a>(
113    ep: &'a netemul::TestFakeEndpoint<'a>,
114) -> impl futures::Stream<Item = crate::Result<FrameMetadata>> + 'a {
115    ep.frame_stream().map(|r| {
116        let (data, dropped) = r.context("fake_ep FIDL error")?;
117        if dropped != 0 {
118            Err(anyhow::anyhow!("dropped {} frames on fake endpoint", dropped))
119        } else {
120            extract_frame_metadata(data)
121        }
122    })
123}
124
125/// Works around CQ timing flakes due to NUD failures.
126///
127/// Many tests can have flakes reduced by applying this workaround. Typically
128/// tests that have more than 1 netstack and use pings or sockets between stacks
129/// can observe spurious NUD failures due to infra timing woes. That can be
130/// worked around by setting the number of NUD probes to a very high value. Any
131/// test that is not directly verifying neighbor behavior can use this
132/// workaround to get rid of flakes.
133pub async fn apply_nud_flake_workaround(
134    control: &fnet_interfaces_ext::admin::Control,
135) -> crate::Result {
136    control
137        .set_configuration(&fnet_interfaces_admin::Configuration {
138            ipv4: Some(fnet_interfaces_admin::Ipv4Configuration {
139                arp: Some(fnet_interfaces_admin::ArpConfiguration {
140                    nud: Some(fnet_interfaces_admin::NudConfiguration {
141                        max_multicast_solicitations: Some(u16::MAX),
142                        ..Default::default()
143                    }),
144                    ..Default::default()
145                }),
146                ..Default::default()
147            }),
148            ipv6: Some(fnet_interfaces_admin::Ipv6Configuration {
149                ndp: Some(fnet_interfaces_admin::NdpConfiguration {
150                    nud: Some(fnet_interfaces_admin::NudConfiguration {
151                        max_multicast_solicitations: Some(u16::MAX),
152                        ..Default::default()
153                    }),
154                    ..Default::default()
155                }),
156                ..Default::default()
157            }),
158            ..Default::default()
159        })
160        .await
161        .map_err(|e| e.into())
162        .and_then(|r| {
163            r.map(|fnet_interfaces_admin::Configuration { .. }| ())
164                .map_err(|e| anyhow::anyhow!("can't set device configuration: {e:?}"))
165        })
166        .context("apply nud flake workaround")
167}
netstack_testing_common/nud.rs

netstack_testing_common/
nud.rs
