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-rw-r--r--packet/Cargo.lock7
-rw-r--r--packet/Cargo.toml6
-rw-r--r--packet/src/record.rs227
-rw-r--r--src/packet/buffer.rs (renamed from packet/src/buffer.rs)96
-rw-r--r--src/packet/header.rs (renamed from packet/src/header.rs)5
-rw-r--r--src/packet/mod.rs (renamed from packet/src/lib.rs)62
-rw-r--r--src/packet/query.rs (renamed from packet/src/query.rs)20
-rw-r--r--src/packet/question.rs (renamed from packet/src/question.rs)4
-rw-r--r--src/packet/result.rs (renamed from packet/src/result.rs)2
9 files changed, 112 insertions, 317 deletions
diff --git a/packet/Cargo.lock b/packet/Cargo.lock
deleted file mode 100644
index 3f0df66..0000000
--- a/packet/Cargo.lock
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "packet"
-version = "0.1.0"
diff --git a/packet/Cargo.toml b/packet/Cargo.toml
deleted file mode 100644
index 2e3797f..0000000
--- a/packet/Cargo.toml
+++ /dev/null
@@ -1,6 +0,0 @@
-[package]
-name = "packet"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
diff --git a/packet/src/record.rs b/packet/src/record.rs
deleted file mode 100644
index c7ff1ac..0000000
--- a/packet/src/record.rs
+++ /dev/null
@@ -1,227 +0,0 @@
-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<Self> {
- 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 & 0xFF) as u8,
- );
-
- Ok(Self::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 & 0xFFFF) as u16,
- ((raw_addr2 >> 16) & 0xFFFF) as u16,
- (raw_addr2 & 0xFFFF) as u16,
- ((raw_addr3 >> 16) & 0xFFFF) as u16,
- (raw_addr3 & 0xFFFF) as u16,
- ((raw_addr4 >> 16) & 0xFFFF) as u16,
- (raw_addr4 & 0xFFFF) as u16,
- );
-
- Ok(Self::AAAA { domain, addr, ttl })
- }
- QueryType::NS => {
- let mut ns = String::new();
- buffer.read_qname(&mut ns)?;
-
- Ok(Self::NS {
- domain,
- host: ns,
- ttl,
- })
- }
- QueryType::CNAME => {
- let mut cname = String::new();
- buffer.read_qname(&mut cname)?;
-
- Ok(Self::CNAME {
- domain,
- host: cname,
- ttl,
- })
- }
- QueryType::MX => {
- let priority = buffer.read_u16()?;
- let mut mx = String::new();
- buffer.read_qname(&mut mx)?;
-
- Ok(Self::MX {
- domain,
- priority,
- host: mx,
- ttl,
- })
- }
- QueryType::UNKNOWN(_) => {
- buffer.step(data_len as usize)?;
-
- Ok(Self::UNKNOWN {
- domain,
- qtype: qtype_num,
- data_len,
- ttl,
- })
- }
- }
- }
-
- pub fn write(&self, buffer: &mut PacketBuffer) -> Result<usize> {
- let start_pos = buffer.pos();
-
- match *self {
- Self::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])?;
- }
- Self::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)?;
- }
- Self::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)?;
- }
- Self::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)?;
- }
- Self::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)?;
- }
- }
- Self::UNKNOWN { .. } => {
- println!("Skipping record: {self:?}");
- }
- }
-
- Ok(buffer.pos() - start_pos)
- }
-} \ No newline at end of file
diff --git a/packet/src/buffer.rs b/src/packet/buffer.rs
index 4394705..4ecc605 100644
--- a/packet/src/buffer.rs
+++ b/src/packet/buffer.rs
@@ -1,15 +1,27 @@
use super::Result;
pub struct PacketBuffer {
- pub buf: [u8; 512],
+ pub buf: Vec<u8>,
pub pos: usize,
+ pub size: usize,
}
impl PacketBuffer {
- pub fn new() -> Self {
+ pub fn new(buf: Vec<u8>) -> Self {
Self {
- buf: [0; 512],
+ buf,
pos: 0,
+ size: 0,
+ }
+ }
+
+ fn check(&mut self, pos: usize) {
+ if self.size < pos {
+ self.size = pos;
+ }
+
+ if self.buf.len() <= self.size {
+ self.buf.resize(self.size + 1, 0x00);
}
}
@@ -30,9 +42,11 @@ impl PacketBuffer {
}
pub fn read(&mut self) -> Result<u8> {
- if self.pos >= 512 {
- return Err("End of buffer".into());
- }
+ // if self.pos >= 512 {
+ // error!("Tried to read past end of buffer");
+ // return Err("End of buffer".into());
+ // }
+ self.check(self.pos);
let res = self.buf[self.pos];
self.pos += 1;
@@ -40,16 +54,20 @@ impl PacketBuffer {
}
pub fn get(&mut self, pos: usize) -> Result<u8> {
- if pos >= 512 {
- return Err("End of buffer".into());
- }
+ // if pos >= 512 {
+ // error!("Tried to read past end of buffer");
+ // return Err("End of buffer".into());
+ // }
+ self.check(pos);
Ok(self.buf[pos])
}
pub fn get_range(&mut self, start: usize, len: usize) -> Result<&[u8]> {
- if start + len >= 512 {
- return Err("End of buffer".into());
- }
+ // if start + len >= 512 {
+ // error!("Tried to read past end of buffer");
+ // return Err("End of buffer".into());
+ // }
+ self.check(start + len);
Ok(&self.buf[start..start + len])
}
@@ -85,13 +103,7 @@ impl PacketBuffer {
let len = self.get(pos)?;
- // A two byte sequence, where the two highest bits of the first byte is
- // set, represents a offset relative to the start of the buffer. We
- // handle this by jumping to the offset, setting a flag to indicate
- // that we shouldn't update the shared buffer position once done.
if (len & 0xC0) == 0xC0 {
- // When a jump is performed, we only modify the shared buffer
- // position once, and avoid making the change later on.
if !jumped {
self.seek(pos + 2)?;
}
@@ -106,7 +118,6 @@ impl PacketBuffer {
pos += 1;
- // Names are terminated by an empty label of length 0
if len == 0 {
break;
}
@@ -128,10 +139,38 @@ impl PacketBuffer {
Ok(())
}
- pub fn write(&mut self, val: u8) -> Result<()> {
- if self.pos >= 512 {
- return Err("End of buffer".into());
+ pub fn read_string(&mut self, outstr: &mut String) -> Result<()> {
+ let len = self.read()?;
+
+ self.read_string_n(outstr, len)?;
+
+ Ok(())
+ }
+
+ pub fn read_string_n(&mut self, outstr: &mut String, len: u8) -> Result<()> {
+ let mut pos = self.pos;
+
+ let str_buffer = self.get_range(pos, len as usize)?;
+
+ let mut i = 0;
+ for b in str_buffer {
+ let c = *b as char;
+ if c == '\0' {
+ break;
+ }
+ outstr.push(c);
+ i += 1;
}
+
+ pos += i;
+ self.seek(pos)?;
+
+ Ok(())
+ }
+
+ pub fn write(&mut self, val: u8) -> Result<()> {
+ self.check(self.pos);
+
self.buf[self.pos] = val;
self.pos += 1;
Ok(())
@@ -162,9 +201,6 @@ impl PacketBuffer {
pub fn write_qname(&mut self, qname: &str) -> Result<()> {
for label in qname.split('.') {
let len = label.len();
- if len > 0x34 {
- return Err("Single label exceeds 63 characters of length".into());
- }
self.write_u8(len as u8)?;
for b in label.as_bytes() {
@@ -177,6 +213,14 @@ impl PacketBuffer {
Ok(())
}
+ pub fn write_string(&mut self, text: &str) -> Result<()> {
+ for b in text.as_bytes() {
+ self.write_u8(*b)?;
+ }
+
+ Ok(())
+ }
+
pub fn set(&mut self, pos: usize, val: u8) -> Result<()> {
self.buf[pos] = val;
@@ -189,4 +233,4 @@ impl PacketBuffer {
Ok(())
}
-} \ No newline at end of file
+}
diff --git a/packet/src/header.rs b/src/packet/header.rs
index b2bf1a1..a75f6ba 100644
--- a/packet/src/header.rs
+++ b/src/packet/header.rs
@@ -1,4 +1,4 @@
-use super::{buffer::PacketBuffer, Result, result::ResultCode};
+use super::{buffer::PacketBuffer, result::ResultCode, Result};
#[derive(Clone, Debug)]
pub struct DnsHeader {
@@ -48,7 +48,6 @@ impl DnsHeader {
pub fn read(&mut self, buffer: &mut PacketBuffer) -> Result<()> {
self.id = buffer.read_u16()?;
-
let flags = buffer.read_u16()?;
let a = (flags >> 8) as u8;
let b = (flags & 0xFF) as u8;
@@ -99,4 +98,4 @@ impl DnsHeader {
Ok(())
}
-} \ No newline at end of file
+}
diff --git a/packet/src/lib.rs b/src/packet/mod.rs
index c7a8eb9..0b7cb7b 100644
--- a/packet/src/lib.rs
+++ b/src/packet/mod.rs
@@ -1,16 +1,19 @@
use std::net::IpAddr;
-use self::{header::DnsHeader, question::DnsQuestion, record::DnsRecord, query::QueryType};
+use self::{
+ buffer::PacketBuffer, header::DnsHeader, query::QueryType, question::DnsQuestion,
+ record::DnsRecord,
+};
type Error = Box<dyn std::error::Error>;
pub type Result<T> = std::result::Result<T, Error>;
-mod buffer;
-mod header;
-mod query;
-mod question;
-mod record;
-mod result;
+pub mod buffer;
+pub mod header;
+pub mod query;
+pub mod question;
+pub mod record;
+pub mod result;
#[derive(Clone, Debug)]
pub struct Packet {
@@ -21,12 +24,6 @@ pub struct Packet {
pub resources: Vec<DnsRecord>,
}
-pub use buffer::PacketBuffer;
-pub use result::ResultCode;
-
-pub use query::QueryType as PacketType;
-pub use question::DnsQuestion as PacketQuestion;
-
impl Packet {
pub fn new() -> Self {
Self {
@@ -88,9 +85,6 @@ impl Packet {
Ok(())
}
- /// It's useful to be able to pick a random A record from a packet. When we
- /// get multiple IP's for a single name, it doesn't matter which one we
- /// choose, so in those cases we can now pick one at random.
pub fn get_random_a(&self) -> Option<IpAddr> {
self.answers
.iter()
@@ -102,55 +96,35 @@ impl Packet {
.next()
}
- /// A helper function which returns an iterator over all name servers in
- /// the authorities section, represented as (domain, host) tuples
fn get_ns<'a>(&'a self, qname: &'a str) -> impl Iterator<Item = (&'a str, &'a str)> {
self.authorities
.iter()
- // In practice, these are always NS records in well formed packages.
- // Convert the NS records to a tuple which has only the data we need
- // to make it easy to work with.
.filter_map(|record| match record {
DnsRecord::NS { domain, host, .. } => Some((domain.as_str(), host.as_str())),
_ => None,
})
- // Discard servers which aren't authoritative to our query
.filter(move |(domain, _)| qname.ends_with(*domain))
}
- /// We'll use the fact that name servers often bundle the corresponding
- /// A records when replying to an NS query to implement a function that
- /// returns the actual IP for an NS record if possible.
pub fn get_resolved_ns(&self, qname: &str) -> Option<IpAddr> {
- // Get an iterator over the nameservers in the authorities section
self.get_ns(qname)
- // Now we need to look for a matching A record in the additional
- // section. Since we just want the first valid record, we can just
- // build a stream of matching records.
.flat_map(|(_, host)| {
self.resources
.iter()
- // Filter for A records where the domain match the host
- // of the NS record that we are currently processing
.filter_map(move |record| match record {
- DnsRecord::A { domain, addr, .. } if domain == host => Some(IpAddr::V4(*addr)),
- DnsRecord::AAAA { domain, addr, .. } if domain == host => Some(IpAddr::V6(*addr)),
+ DnsRecord::A { domain, addr, .. } if domain == host => {
+ Some(IpAddr::V4(*addr))
+ }
+ DnsRecord::AAAA { domain, addr, .. } if domain == host => {
+ Some(IpAddr::V6(*addr))
+ }
_ => None,
})
})
- // Finally, pick the first valid entry
.next()
}
- /// However, not all name servers are as that nice. In certain cases there won't
- /// be any A records in the additional section, and we'll have to perform *another*
- /// lookup in the midst. For this, we introduce a method for returning the host
- /// name of an appropriate name server.
pub fn get_unresolved_ns<'a>(&'a self, qname: &'a str) -> Option<&'a str> {
- // Get an iterator over the nameservers in the authorities section
- self.get_ns(qname)
- .map(|(_, host)| host)
- // Finally, pick the first valid entry
- .next()
+ self.get_ns(qname).map(|(_, host)| host).next()
}
-} \ No newline at end of file
+}
diff --git a/packet/src/query.rs b/src/packet/query.rs
index 8804d15..cae6f09 100644
--- a/packet/src/query.rs
+++ b/src/packet/query.rs
@@ -4,8 +4,14 @@ pub enum QueryType {
A, // 1
NS, // 2
CNAME, // 5
+ SOA, // 6
+ PTR, // 12
MX, // 15
+ TXT, // 16
AAAA, // 28
+ SRV, // 33
+ OPT, // 41
+ CAA, // 257
}
impl QueryType {
@@ -15,8 +21,14 @@ impl QueryType {
Self::A => 1,
Self::NS => 2,
Self::CNAME => 5,
+ Self::SOA => 6,
+ Self::PTR => 12,
Self::MX => 15,
+ Self::TXT => 16,
Self::AAAA => 28,
+ Self::SRV => 33,
+ Self::OPT => 41,
+ Self::CAA => 257,
}
}
@@ -25,9 +37,15 @@ impl QueryType {
1 => Self::A,
2 => Self::NS,
5 => Self::CNAME,
+ 6 => Self::SOA,
+ 12 => Self::PTR,
15 => Self::MX,
+ 16 => Self::TXT,
28 => Self::AAAA,
+ 33 => Self::SRV,
+ 41 => Self::OPT,
+ 257 => Self::CAA,
_ => Self::UNKNOWN(num),
}
}
-} \ No newline at end of file
+}
diff --git a/packet/src/question.rs b/src/packet/question.rs
index 076de00..9042e1c 100644
--- a/packet/src/question.rs
+++ b/src/packet/question.rs
@@ -1,6 +1,6 @@
use super::{buffer::PacketBuffer, query::QueryType, Result};
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct DnsQuestion {
pub name: String,
pub qtype: QueryType,
@@ -28,4 +28,4 @@ impl DnsQuestion {
Ok(())
}
-} \ No newline at end of file
+}
diff --git a/packet/src/result.rs b/src/packet/result.rs
index f33bd7d..41c8ba9 100644
--- a/packet/src/result.rs
+++ b/src/packet/result.rs
@@ -19,4 +19,4 @@ impl ResultCode {
0 | _ => Self::NOERROR,
}
}
-} \ No newline at end of file
+}
generated by cgit v1.2.3-freya (git 2.51.0) at 2025-09-23 16:45:24 +0000