add systemd escape_unit and unescape_unit

This commit is contained in:
Dietmar Maurer 2021-09-22 12:05:31 +02:00
parent 0999494564
commit fc2253b3e8
2 changed files with 84 additions and 0 deletions

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@ -20,6 +20,7 @@ pub mod serde;
pub mod time;
pub mod uuid;
pub mod vec;
pub mod systemd;
#[cfg(feature = "tfa")]
pub mod tfa;

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@ -0,0 +1,83 @@
use anyhow::{bail, Error};
fn parse_hex_digit(d: u8) -> Result<u8, Error> {
if d >= b'0' && d <= b'9' {
return Ok(d - b'0');
}
if d >= b'A' && d <= b'F' {
return Ok(d - b'A' + 10);
}
if d >= b'a' && d <= b'f' {
return Ok(d - b'a' + 10);
}
bail!("got invalid hex digit");
}
/// Escape strings for usage in systemd unit names
pub fn escape_unit(mut unit: &str, is_path: bool) -> String {
if is_path {
unit = unit.trim_matches('/');
if unit.is_empty() {
return String::from("-");
}
}
let unit = unit.as_bytes();
let mut escaped = String::new();
for (i, c) in unit.iter().enumerate() {
if *c == b'/' {
escaped.push('-');
continue;
}
if (i == 0 && *c == b'.')
|| !(*c == b'_'
|| *c == b'.'
|| (*c >= b'0' && *c <= b'9')
|| (*c >= b'A' && *c <= b'Z')
|| (*c >= b'a' && *c <= b'z'))
{
escaped.push_str(&format!("\\x{:0x}", c));
} else {
escaped.push(*c as char);
}
}
escaped
}
/// Unescape strings used in systemd unit names
pub fn unescape_unit(text: &str) -> Result<String, Error> {
let mut i = text.as_bytes();
let mut data: Vec<u8> = Vec::new();
loop {
if i.is_empty() {
break;
}
let next = i[0];
if next == b'\\' {
if i.len() < 4 {
bail!("short input");
}
if i[1] != b'x' {
bail!("unkwnown escape sequence");
}
let h1 = parse_hex_digit(i[2])?;
let h0 = parse_hex_digit(i[3])?;
data.push(h1 << 4 | h0);
i = &i[4..]
} else if next == b'-' {
data.push(b'/');
i = &i[1..]
} else {
data.push(next);
i = &i[1..]
}
}
let text = String::from_utf8(data)?;
Ok(text)
}