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Diffstat (limited to 'packet/src/record.rs')
| -rw-r--r-- | packet/src/record.rs | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/packet/src/record.rs b/packet/src/record.rs new file mode 100644 index 0000000..bc9b694 --- /dev/null +++ b/packet/src/record.rs @@ -0,0 +1,227 @@ +use std::net::{Ipv4Addr, Ipv6Addr}; + +use super::{query::QueryType, buffer::PacketBuffer, Result}; + +#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)] +#[allow(dead_code)] +pub enum DnsRecord { + UNKNOWN { + domain: String, + qtype: u16, + data_len: u16, + ttl: u32, + }, // 0 + A { + domain: String, + addr: Ipv4Addr, + ttl: u32, + }, // 1 + NS { + domain: String, + host: String, + ttl: u32, + }, // 2 + CNAME { + domain: String, + host: String, + ttl: u32, + }, // 5 + MX { + domain: String, + priority: u16, + host: String, + ttl: u32, + }, // 15 + AAAA { + domain: String, + addr: Ipv6Addr, + ttl: u32, + }, // 28 +} + +impl DnsRecord { + pub fn read(buffer: &mut PacketBuffer) -> Result<DnsRecord> { + let mut domain = String::new(); + buffer.read_qname(&mut domain)?; + + let qtype_num = buffer.read_u16()?; + let qtype = QueryType::from_num(qtype_num); + let _ = buffer.read_u16()?; + let ttl = buffer.read_u32()?; + let data_len = buffer.read_u16()?; + + match qtype { + QueryType::A => { + let raw_addr = buffer.read_u32()?; + let addr = Ipv4Addr::new( + ((raw_addr >> 24) & 0xFF) as u8, + ((raw_addr >> 16) & 0xFF) as u8, + ((raw_addr >> 8) & 0xFF) as u8, + ((raw_addr >> 0) & 0xFF) as u8, + ); + + Ok(DnsRecord::A { domain, addr, ttl }) + } + QueryType::AAAA => { + let raw_addr1 = buffer.read_u32()?; + let raw_addr2 = buffer.read_u32()?; + let raw_addr3 = buffer.read_u32()?; + let raw_addr4 = buffer.read_u32()?; + let addr = Ipv6Addr::new( + ((raw_addr1 >> 16) & 0xFFFF) as u16, + ((raw_addr1 >> 0) & 0xFFFF) as u16, + ((raw_addr2 >> 16) & 0xFFFF) as u16, + ((raw_addr2 >> 0) & 0xFFFF) as u16, + ((raw_addr3 >> 16) & 0xFFFF) as u16, + ((raw_addr3 >> 0) & 0xFFFF) as u16, + ((raw_addr4 >> 16) & 0xFFFF) as u16, + ((raw_addr4 >> 0) & 0xFFFF) as u16, + ); + + Ok(DnsRecord::AAAA { domain, addr, ttl }) + } + QueryType::NS => { + let mut ns = String::new(); + buffer.read_qname(&mut ns)?; + + Ok(DnsRecord::NS { + domain, + host: ns, + ttl, + }) + } + QueryType::CNAME => { + let mut cname = String::new(); + buffer.read_qname(&mut cname)?; + + Ok(DnsRecord::CNAME { + domain, + host: cname, + ttl, + }) + } + QueryType::MX => { + let priority = buffer.read_u16()?; + let mut mx = String::new(); + buffer.read_qname(&mut mx)?; + + Ok(DnsRecord::MX { + domain, + priority, + host: mx, + ttl, + }) + } + QueryType::UNKNOWN(_) => { + buffer.step(data_len as usize)?; + + Ok(DnsRecord::UNKNOWN { + domain, + qtype: qtype_num, + data_len, + ttl, + }) + } + } + } + + pub fn write(&self, buffer: &mut PacketBuffer) -> Result<usize> { + let start_pos = buffer.pos(); + + match *self { + DnsRecord::A { + ref domain, + ref addr, + ttl, + } => { + buffer.write_qname(domain)?; + buffer.write_u16(QueryType::A.to_num())?; + buffer.write_u16(1)?; + buffer.write_u32(ttl)?; + buffer.write_u16(4)?; + + let octets = addr.octets(); + buffer.write_u8(octets[0])?; + buffer.write_u8(octets[1])?; + buffer.write_u8(octets[2])?; + buffer.write_u8(octets[3])?; + } + DnsRecord::NS { + ref domain, + ref host, + ttl, + } => { + buffer.write_qname(domain)?; + buffer.write_u16(QueryType::NS.to_num())?; + buffer.write_u16(1)?; + buffer.write_u32(ttl)?; + + let pos = buffer.pos(); + buffer.write_u16(0)?; + + buffer.write_qname(host)?; + + let size = buffer.pos() - (pos + 2); + buffer.set_u16(pos, size as u16)?; + } + DnsRecord::CNAME { + ref domain, + ref host, + ttl, + } => { + buffer.write_qname(domain)?; + buffer.write_u16(QueryType::CNAME.to_num())?; + buffer.write_u16(1)?; + buffer.write_u32(ttl)?; + + let pos = buffer.pos(); + buffer.write_u16(0)?; + + buffer.write_qname(host)?; + + let size = buffer.pos() - (pos + 2); + buffer.set_u16(pos, size as u16)?; + } + DnsRecord::MX { + ref domain, + priority, + ref host, + ttl, + } => { + buffer.write_qname(domain)?; + buffer.write_u16(QueryType::MX.to_num())?; + buffer.write_u16(1)?; + buffer.write_u32(ttl)?; + + let pos = buffer.pos(); + buffer.write_u16(0)?; + + buffer.write_u16(priority)?; + buffer.write_qname(host)?; + + let size = buffer.pos() - (pos + 2); + buffer.set_u16(pos, size as u16)?; + } + DnsRecord::AAAA { + ref domain, + ref addr, + ttl, + } => { + buffer.write_qname(domain)?; + buffer.write_u16(QueryType::AAAA.to_num())?; + buffer.write_u16(1)?; + buffer.write_u32(ttl)?; + buffer.write_u16(16)?; + + for octet in &addr.segments() { + buffer.write_u16(*octet)?; + } + } + DnsRecord::UNKNOWN { .. } => { + println!("Skipping record: {:?}", self); + } + } + + Ok(buffer.pos() - start_pos) + } +}
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