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-rw-r--r--packet/src/buffer.rs192
1 files changed, 0 insertions, 192 deletions
diff --git a/packet/src/buffer.rs b/packet/src/buffer.rs
deleted file mode 100644
index 4394705..0000000
--- a/packet/src/buffer.rs
+++ /dev/null
@@ -1,192 +0,0 @@
-use super::Result;
-
-pub struct PacketBuffer {
- pub buf: [u8; 512],
- pub pos: usize,
-}
-
-impl PacketBuffer {
- pub fn new() -> Self {
- Self {
- buf: [0; 512],
- pos: 0,
- }
- }
-
- pub fn pos(&self) -> usize {
- self.pos
- }
-
- pub fn step(&mut self, steps: usize) -> Result<()> {
- self.pos += steps;
-
- Ok(())
- }
-
- pub fn seek(&mut self, pos: usize) -> Result<()> {
- self.pos = pos;
-
- Ok(())
- }
-
- pub fn read(&mut self) -> Result<u8> {
- if self.pos >= 512 {
- return Err("End of buffer".into());
- }
- let res = self.buf[self.pos];
- self.pos += 1;
-
- Ok(res)
- }
-
- pub fn get(&mut self, pos: usize) -> Result<u8> {
- if pos >= 512 {
- return Err("End of buffer".into());
- }
- 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());
- }
- Ok(&self.buf[start..start + len])
- }
-
- pub fn read_u16(&mut self) -> Result<u16> {
- let res = ((self.read()? as u16) << 8) | (self.read()? as u16);
-
- Ok(res)
- }
-
- pub fn read_u32(&mut self) -> Result<u32> {
- let res = ((self.read()? as u32) << 24)
- | ((self.read()? as u32) << 16)
- | ((self.read()? as u32) << 8)
- | (self.read()? as u32);
-
- Ok(res)
- }
-
- pub fn read_qname(&mut self, outstr: &mut String) -> Result<()> {
- let mut pos = self.pos();
- let mut jumped = false;
-
- let mut delim = "";
- let max_jumps = 5;
- let mut jumps_performed = 0;
- loop {
- // Dns Packets are untrusted data, so we need to be paranoid. Someone
- // can craft a packet with a cycle in the jump instructions. This guards
- // against such packets.
- if jumps_performed > max_jumps {
- return Err(format!("Limit of {max_jumps} jumps exceeded").into());
- }
-
- 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)?;
- }
-
- let b2 = self.get(pos + 1)? as u16;
- let offset = (((len as u16) ^ 0xC0) << 8) | b2;
- pos = offset as usize;
- jumped = true;
- jumps_performed += 1;
- continue;
- }
-
- pos += 1;
-
- // Names are terminated by an empty label of length 0
- if len == 0 {
- break;
- }
-
- outstr.push_str(delim);
-
- let str_buffer = self.get_range(pos, len as usize)?;
- outstr.push_str(&String::from_utf8_lossy(str_buffer).to_lowercase());
-
- delim = ".";
-
- pos += len as usize;
- }
-
- if !jumped {
- self.seek(pos)?;
- }
-
- Ok(())
- }
-
- pub fn write(&mut self, val: u8) -> Result<()> {
- if self.pos >= 512 {
- return Err("End of buffer".into());
- }
- self.buf[self.pos] = val;
- self.pos += 1;
- Ok(())
- }
-
- pub fn write_u8(&mut self, val: u8) -> Result<()> {
- self.write(val)?;
-
- Ok(())
- }
-
- pub fn write_u16(&mut self, val: u16) -> Result<()> {
- self.write((val >> 8) as u8)?;
- self.write((val & 0xFF) as u8)?;
-
- Ok(())
- }
-
- pub fn write_u32(&mut self, val: u32) -> Result<()> {
- self.write(((val >> 24) & 0xFF) as u8)?;
- self.write(((val >> 16) & 0xFF) as u8)?;
- self.write(((val >> 8) & 0xFF) as u8)?;
- self.write((val & 0xFF) as u8)?;
-
- Ok(())
- }
-
- 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() {
- self.write_u8(*b)?;
- }
- }
-
- self.write_u8(0)?;
-
- Ok(())
- }
-
- pub fn set(&mut self, pos: usize, val: u8) -> Result<()> {
- self.buf[pos] = val;
-
- Ok(())
- }
-
- pub fn set_u16(&mut self, pos: usize, val: u16) -> Result<()> {
- self.set(pos, (val >> 8) as u8)?;
- self.set(pos + 1, (val & 0xFF) as u8)?;
-
- Ok(())
- }
-} \ No newline at end of file