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use std::path::{Path, PathBuf};
pub(crate) fn remote_ssh_config_paths() -> super::RemoteSshConfigPaths {
super::RemoteSshConfigPaths {
user_config: std::env::var_os("HOME")
.map(PathBuf::from)
.map(|home| home.join(".ssh").join("config")),
system_config: Some(PathBuf::from("/etc/ssh/ssh_config")),
multiplexing: true,
}
}
pub(crate) fn create_remote_ssh_config_dir(control_socket_name: &str) -> std::io::Result<PathBuf> {
use std::os::unix::fs::DirBuilderExt;
let mut bases = vec![std::env::temp_dir()];
let short_tmp = PathBuf::from("/tmp");
if bases.first() != Some(&short_tmp) {
bases.push(short_tmp);
}
let mut last_error = None;
let mut path_fits = false;
for base in bases {
for attempt in 0..100 {
let dir = base.join(format!("herdr-ssh-{}-{attempt}", std::process::id()));
if !fits_unix_socket_path(&dir.join(control_socket_name)) {
continue;
}
path_fits = true;
match std::fs::DirBuilder::new().mode(0o700).create(&dir) {
Ok(()) => return Ok(dir),
Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => continue,
Err(err) => {
last_error = Some(err);
break;
}
}
}
}
if let Some(err) = last_error {
return Err(err);
}
let message = if path_fits {
"failed to create private herdr ssh config directory"
} else {
"SSH control socket path exceeds the Unix socket length limit"
};
Err(std::io::Error::new(
if path_fits {
std::io::ErrorKind::AlreadyExists
} else {
std::io::ErrorKind::InvalidInput
},
message,
))
}
pub(crate) fn create_remote_ssh_config_file(path: &Path) -> std::io::Result<std::fs::File> {
use std::os::unix::fs::OpenOptionsExt;
std::fs::OpenOptions::new()
.write(true)
.create_new(true)
.mode(0o600)
.open(path)
}
pub(crate) fn create_remote_private_dir(path: &Path) -> std::io::Result<()> {
use std::os::unix::fs::DirBuilderExt;
std::fs::DirBuilder::new().mode(0o700).create(path)
}
pub(crate) fn remote_private_temp_base() -> PathBuf {
std::env::temp_dir()
}
pub(crate) fn remote_bridge_endpoint_path(readable_name: &str, short_name: &str) -> PathBuf {
let tmp = std::env::temp_dir();
let readable = tmp.join(readable_name);
if fits_unix_socket_path(&readable) {
return readable;
}
let short = tmp.join(short_name);
if fits_unix_socket_path(&short) {
return short;
}
PathBuf::from("/tmp").join(short_name)
}
pub(crate) fn remote_reattach_program(program: &str) -> String {
shell_quote(if program.is_empty() { "herdr" } else { program })
}
pub(crate) fn remote_reattach_argument(value: &str) -> String {
shell_quote(value)
}
fn shell_quote(value: &str) -> String {
if !value.is_empty()
&& value.chars().all(|ch| {
ch.is_ascii_alphanumeric()
|| matches!(
ch,
'@' | '%' | '_' | '+' | '=' | ':' | ',' | '.' | '/' | '-'
)
})
{
return value.to_string();
}
format!("'{}'", value.replace('\'', "'\\''"))
}
fn fits_unix_socket_path(path: &Path) -> bool {
use std::os::unix::ffi::OsStrExt;
path.as_os_str().as_bytes().len() <= 103
}
/// The machine's node name, as shown by tmux's `#h`.
pub(crate) fn hostname() -> Option<String> {
let mut buffer = [0_u8; 256];
let result =
unsafe { libc::gethostname(buffer.as_mut_ptr().cast::<libc::c_char>(), buffer.len()) };
if result != 0 {
return None;
}
let end = buffer
.iter()
.position(|&byte| byte == 0)
.unwrap_or(buffer.len());
let name = String::from_utf8_lossy(&buffer[..end]).into_owned();
(!name.is_empty()).then_some(name)
}
pub(crate) fn local_datetime() -> Option<time::PrimitiveDateTime> {
let mut timestamp: libc::time_t = 0;
if unsafe { libc::time(&mut timestamp) } == -1 {
return None;
}
let mut local: libc::tm = unsafe { std::mem::zeroed() };
if unsafe { libc::localtime_r(×tamp, &mut local) }.is_null() {
return None;
}
datetime_from_tm(&local)
}
pub(crate) fn status_commands_supported() -> bool {
true
}
pub(crate) fn configure_status_command(process: &mut std::process::Command) {
use std::os::unix::process::CommandExt;
process.process_group(0);
}
pub(crate) struct StatusCommandGuard {
process_group_id: Option<i32>,
}
impl StatusCommandGuard {
pub(crate) fn new(child: &tokio::process::Child) -> std::io::Result<Self> {
let process_id = child
.id()
.ok_or_else(|| std::io::Error::other("status command has no process id"))?;
let process_group_id = i32::try_from(process_id)
.map_err(|_| std::io::Error::other("status command process id exceeds i32"))?;
Ok(Self {
process_group_id: Some(process_group_id),
})
}
}
impl Drop for StatusCommandGuard {
fn drop(&mut self) {
if let Some(process_group_id) = self.process_group_id.take() {
// The command was spawned as this process group's leader. Killing the
// group also cleans up background descendants on completion/cancellation.
unsafe {
libc::kill(-process_group_id, libc::SIGKILL);
}
}
}
}
fn datetime_from_tm(value: &libc::tm) -> Option<time::PrimitiveDateTime> {
let month = time::Month::try_from(u8::try_from(value.tm_mon + 1).ok()?).ok()?;
let date = time::Date::from_calendar_date(
value.tm_year + 1900,
month,
u8::try_from(value.tm_mday).ok()?,
)
.ok()?;
let time = time::Time::from_hms(
u8::try_from(value.tm_hour).ok()?,
u8::try_from(value.tm_min).ok()?,
u8::try_from(value.tm_sec).ok()?,
)
.ok()?;
Some(time::PrimitiveDateTime::new(date, time))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn remote_ssh_config_dir_rejects_overlong_control_socket_name() {
let err = create_remote_ssh_config_dir(&"x".repeat(200)).unwrap_err();
assert_eq!(err.kind(), std::io::ErrorKind::InvalidInput);
}
}
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