53 lines
1.4 KiB
Rust
53 lines
1.4 KiB
Rust
use bytes::Bytes;
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use errors::*;
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use failure::Fail;
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use ser::packet::{DnsPacketData, DnsPacketWriteContext};
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use ser::text::{DnsTextData, DnsTextFormatter, DnsTextContext, next_field};
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use std::fmt;
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use std::io::Cursor;
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/// Optional TTL
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///
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/// Always present in wire format, but optional in zone; defaults to TTL
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/// of the RR.
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///
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/// Must be followed by a field that doesn't accept any unsigned 32-bit
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/// integer as text representation (like `TimeStrict` for `SIG`).
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///
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/// If field is missing in zone representation the context must provide
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/// a TTL.
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#[derive(Clone, PartialEq, Eq, Debug)]
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pub struct OptionalTTL(pub u32);
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impl DnsPacketData for OptionalTTL {
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fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
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Ok(OptionalTTL(DnsPacketData::deserialize(data)?))
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}
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fn serialize(&self, context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {
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self.0.serialize(context, packet)
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}
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}
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impl DnsTextData for OptionalTTL {
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fn dns_parse(context: &DnsTextContext, data: &mut &str) -> ::errors::Result<Self> {
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let mut data_found = *data;
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let field = next_field(&mut data_found)?;
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match field.parse::<u32>() {
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Ok(ttl) => {
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*data = data_found;
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Ok(OptionalTTL(ttl))
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},
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Err(e) => {
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Ok(OptionalTTL(context.last_ttl()
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.ok_or_else(|| e.context("TTL not available in context, failed parsing optional TTL"))?
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))
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},
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}
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}
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fn dns_format(&self, f: &mut DnsTextFormatter) -> fmt::Result {
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self.0.dns_format(f)
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}
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}
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