[dhcpv6] Appease implicit drop rules
Avoid the appearance of implicit drops by:
- Replacing match <bool> with if-else
- Annotating binding types
- Using Into::into rather than `as` casts
Change-Id: Ia090ed1329adae5f828814432b9231abef67caab
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/514261
Fuchsia-Auto-Submit: Tamir Duberstein <tamird@google.com>
Reviewed-by: Marina Ciocea <marinaciocea@google.com>
Commit-Queue: Marina Ciocea <marinaciocea@google.com>
diff --git a/src/lib/network/packet-formats-dhcp/src/v6.rs b/src/lib/network/packet-formats-dhcp/src/v6.rs
index a68d56f..92470f0 100644
--- a/src/lib/network/packet-formats-dhcp/src/v6.rs
+++ b/src/lib/network/packet-formats-dhcp/src/v6.rs
@@ -283,44 +283,51 @@
let opt = match opt_code {
OptionCode::ClientId => Ok(DhcpOption::ClientId(opt_val)),
OptionCode::ServerId => Ok(DhcpOption::ServerId(opt_val)),
- OptionCode::Oro => match opt_len % 2 {
- 0 => Ok(DhcpOption::Oro(
- opt_val
- .chunks(2)
- .map(|opt| OptionCode::try_from(NetworkEndian::read_u16(opt)))
- .collect::<Result<Vec<OptionCode>, ParseError>>()?,
- )),
- _ => Err(ParseError::InvalidOpLen(OptionCode::Oro, opt_len)),
- },
+ OptionCode::Oro => {
+ if opt_len % 2 == 0 {
+ Ok(DhcpOption::Oro(
+ opt_val
+ .chunks(2)
+ .map(|opt| OptionCode::try_from(NetworkEndian::read_u16(opt)))
+ .collect::<Result<Vec<OptionCode>, ParseError>>()?,
+ ))
+ } else {
+ Err(ParseError::InvalidOpLen(OptionCode::Oro, opt_len))
+ }
+ }
OptionCode::Preference => match opt_val {
&[b] => Ok(DhcpOption::Preference(b)),
- _ => Err(ParseError::InvalidOpLen(OptionCode::Preference, opt_val.len())),
+ opt_val => Err(ParseError::InvalidOpLen(OptionCode::Preference, opt_val.len())),
},
OptionCode::ElapsedTime => match opt_val {
&[b0, b1] => Ok(DhcpOption::ElapsedTime(u16::from_be_bytes([b0, b1]))),
- _ => Err(ParseError::InvalidOpLen(OptionCode::ElapsedTime, opt_val.len())),
+ opt_val => Err(ParseError::InvalidOpLen(OptionCode::ElapsedTime, opt_val.len())),
},
OptionCode::InformationRefreshTime => match opt_val {
&[b0, b1, b2, b3] => {
Ok(DhcpOption::InformationRefreshTime(u32::from_be_bytes([b0, b1, b2, b3])))
}
- _ => {
+ opt_val => {
Err(ParseError::InvalidOpLen(OptionCode::InformationRefreshTime, opt_val.len()))
}
},
- OptionCode::DnsServers => match opt_len % 16 {
- 0 => Ok(DhcpOption::DnsServers(
- opt_val
- .chunks(16)
- .map(|opt| {
- let opt: [u8; 16] =
- opt.try_into().expect("unexpected byte slice length after chunk");
- Ipv6Addr::from(opt)
- })
- .collect::<Vec<Ipv6Addr>>(),
- )),
- _ => Err(ParseError::InvalidOpLen(OptionCode::DnsServers, opt_len)),
- },
+ OptionCode::DnsServers => {
+ if opt_len % 16 == 0 {
+ Ok(DhcpOption::DnsServers(
+ opt_val
+ .chunks(16)
+ .map(|opt| {
+ let opt: [u8; 16] = opt
+ .try_into()
+ .expect("unexpected byte slice length after chunk");
+ Ipv6Addr::from(opt)
+ })
+ .collect::<Vec<Ipv6Addr>>(),
+ ))
+ } else {
+ Err(ParseError::InvalidOpLen(OptionCode::DnsServers, opt_len))
+ }
+ }
OptionCode::DomainList => {
let mut opt_val = &mut opt_val;
let mut domains = Vec::new();
@@ -366,18 +373,19 @@
fn record_length(opt: &Self::Record) -> usize {
4 + match opt {
DhcpOption::ClientId(duid) | DhcpOption::ServerId(duid) => {
- u16::try_from(duid.len()).unwrap_or(18) as usize
+ u16::try_from(duid.len()).unwrap_or(18).into()
}
- DhcpOption::Oro(opts) => u16::try_from(2 * opts.len()).unwrap_or(0) as usize,
- DhcpOption::Preference(_) => 1,
- DhcpOption::ElapsedTime(_) => 2,
- DhcpOption::InformationRefreshTime(_) => 4,
+ DhcpOption::Oro(opts) => u16::try_from(2 * opts.len()).unwrap_or(0).into(),
+ DhcpOption::Preference(v) => std::mem::size_of_val(v),
+ DhcpOption::ElapsedTime(v) => std::mem::size_of_val(v),
+ DhcpOption::InformationRefreshTime(v) => std::mem::size_of_val(v),
DhcpOption::DnsServers(recursive_name_servers) => {
- u16::try_from(16 * recursive_name_servers.len()).unwrap_or(0) as usize
+ u16::try_from(16 * recursive_name_servers.len()).unwrap_or(0).into()
}
DhcpOption::DomainList(domains) => {
u16::try_from(domains.iter().fold(0, |tot, domain| tot + domain.bytes_len()))
- .unwrap_or(0) as usize
+ .unwrap_or(0)
+ .into()
}
}
}
@@ -663,7 +671,7 @@
DhcpOption::Preference(42),
DhcpOption::ElapsedTime(3600),
DhcpOption::InformationRefreshTime(86400),
- DhcpOption::DnsServers(vec![Ipv6Addr::from(0 as u128)]),
+ DhcpOption::DnsServers(vec![Ipv6Addr::from(0)]),
DhcpOption::DomainList(vec![
checked::Domain::from_str("fuchsia.dev").expect("failed to construct test domain"),
checked::Domain::from_str("www.google.com")
@@ -682,9 +690,12 @@
assert_eq!(got_options, options);
}
+ // We're forced into an `as` cast because From::from is not a const fn.
+ const OVERFLOW_LENGTH: usize = u16::MAX as usize + 1;
+
#[test]
fn test_message_serialization_duid_too_long() {
- let options = [DhcpOption::ClientId(&[0u8; (u16::MAX as usize) + 1])];
+ let options = [DhcpOption::ClientId(&[0u8; OVERFLOW_LENGTH])];
let builder = MessageBuilder::new(MessageType::Solicit, [1, 2, 3], &options);
let mut buf = vec![0; builder.bytes_len()];
let () = builder.serialize(&mut buf);
@@ -701,12 +712,12 @@
// Make sure the buffer is still parsable.
let mut buf = &buf[..];
- let _ = Message::parse(&mut buf, ()).expect("parse should succeed");
+ let _: Message<'_, _> = Message::parse(&mut buf, ()).expect("parse should succeed");
}
#[test]
fn test_message_serialization_oro_too_long() {
- let options = [DhcpOption::Oro(vec![OptionCode::Preference; (u16::MAX as usize) + 1])];
+ let options = [DhcpOption::Oro(vec![OptionCode::Preference; OVERFLOW_LENGTH])];
let builder = MessageBuilder::new(MessageType::Solicit, [1, 2, 3], &options);
let mut buf = vec![0; builder.bytes_len()];
let () = builder.serialize(&mut buf);
@@ -722,7 +733,7 @@
// Make sure the buffer is still parsable.
let mut buf = &buf[..];
- let _ = Message::parse(&mut buf, ()).expect("parse should succeed");
+ let _: Message<'_, _> = Message::parse(&mut buf, ()).expect("parse should succeed");
}
#[test]
