webrtc_mdns/message/
packer.rs

1use super::*;
2use crate::error::*;
3
4// pack_bytes appends the wire format of field to msg.
5pub(crate) fn pack_bytes(mut msg: Vec<u8>, field: &[u8]) -> Vec<u8> {
6    msg.extend_from_slice(field);
7    msg
8}
9
10pub(crate) fn unpack_bytes(msg: &[u8], off: usize, field: &mut [u8]) -> Result<usize> {
11    let new_off = off + field.len();
12    if new_off > msg.len() {
13        return Err(Error::ErrBaseLen);
14    }
15    field.copy_from_slice(&msg[off..new_off]);
16    Ok(new_off)
17}
18
19// pack_uint16 appends the wire format of field to msg.
20pub(crate) fn pack_uint16(mut msg: Vec<u8>, field: u16) -> Vec<u8> {
21    msg.extend_from_slice(&field.to_be_bytes());
22    msg
23}
24
25pub(crate) fn unpack_uint16(msg: &[u8], off: usize) -> Result<(u16, usize)> {
26    if off + UINT16LEN > msg.len() {
27        return Err(Error::ErrBaseLen);
28    }
29
30    Ok((
31        (msg[off] as u16) << 8 | (msg[off + 1] as u16),
32        off + UINT16LEN,
33    ))
34}
35
36pub(crate) fn skip_uint16(msg: &[u8], off: usize) -> Result<usize> {
37    if off + UINT16LEN > msg.len() {
38        return Err(Error::ErrBaseLen);
39    }
40    Ok(off + UINT16LEN)
41}
42
43// pack_uint32 appends the wire format of field to msg.
44pub(crate) fn pack_uint32(mut msg: Vec<u8>, field: u32) -> Vec<u8> {
45    msg.extend_from_slice(&field.to_be_bytes());
46    msg
47}
48
49pub(crate) fn unpack_uint32(msg: &[u8], off: usize) -> Result<(u32, usize)> {
50    if off + UINT32LEN > msg.len() {
51        return Err(Error::ErrBaseLen);
52    }
53    let v = (msg[off] as u32) << 24
54        | (msg[off + 1] as u32) << 16
55        | (msg[off + 2] as u32) << 8
56        | (msg[off + 3] as u32);
57    Ok((v, off + UINT32LEN))
58}
59
60pub(crate) fn skip_uint32(msg: &[u8], off: usize) -> Result<usize> {
61    if off + UINT32LEN > msg.len() {
62        return Err(Error::ErrBaseLen);
63    }
64    Ok(off + UINT32LEN)
65}
66
67// pack_text appends the wire format of field to msg.
68pub(crate) fn pack_str(mut msg: Vec<u8>, field: &str) -> Result<Vec<u8>> {
69    let l = field.len();
70    if l > 255 {
71        return Err(Error::ErrStringTooLong);
72    }
73    msg.push(l as u8);
74    msg.extend_from_slice(field.as_bytes());
75    Ok(msg)
76}
77
78pub(crate) fn unpack_str(msg: &[u8], off: usize) -> Result<(String, usize)> {
79    if off >= msg.len() {
80        return Err(Error::ErrBaseLen);
81    }
82    let begin_off = off + 1;
83    let end_off = begin_off + msg[off] as usize;
84    if end_off > msg.len() {
85        return Err(Error::ErrCalcLen);
86    }
87
88    Ok((
89        String::from_utf8(msg[begin_off..end_off].to_vec())?,
90        end_off,
91    ))
92}
webrtc_mdns/message/packer.rs

webrtc_mdns/message/
packer.rs
