fix(utils): validate session name (#2607)

* fix(utils): validate session name

* cargo fmt

* refactor: assign constant values to variables

* refactor: move operations unrealted to the condition

---------

Co-authored-by: Jae-Heon Ji <atx6419@gmail.com>

zellij-utils/src/cli.rs

@@ -9,6 +9,30 @@ use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 use url::Url;
 
+fn validate_session(name: &str) -> Result<String, String> {
+    #[cfg(unix)]
+    {
+        use crate::consts::ZELLIJ_SOCK_MAX_LENGTH;
+
+        let mut socket_path = crate::consts::ZELLIJ_SOCK_DIR.clone();
+        socket_path.push(name);
+
+        if socket_path.as_os_str().len() >= ZELLIJ_SOCK_MAX_LENGTH {
+            // socket path must be less than 108 bytes
+            let available_length = ZELLIJ_SOCK_MAX_LENGTH
+                .saturating_sub(socket_path.as_os_str().len())
+                .saturating_sub(1);
+
+            return Err(format!(
+                "session name must be less than {} characters",
+                available_length
+            ));
+        };
+    };
+
+    Ok(name.to_owned())
+}
+
 #[derive(Parser, Default, Debug, Clone, Serialize, Deserialize)]
 #[clap(version, name = "zellij")]
 pub struct CliArgs {
@@ -25,7 +49,7 @@ pub struct CliArgs {
     pub server: Option<PathBuf>,
 
     /// Specify name of a new session
-    #[clap(long, short, overrides_with = "session", value_parser)]
+    #[clap(long, short, overrides_with = "session", value_parser = validate_session)]
     pub session: Option<String>,
 
     /// Name of a predefined layout inside the layout directory or the path to a layout file

zellij-utils/src/consts.rs

@@ -112,6 +112,8 @@ mod unix_only {
     use nix::unistd::Uid;
     use std::env::temp_dir;
 
+    pub const ZELLIJ_SOCK_MAX_LENGTH: usize = 108;
+
     lazy_static! {
         static ref UID: Uid = Uid::current();
         pub static ref ZELLIJ_TMP_DIR: PathBuf = temp_dir().join(format!("zellij-{}", *UID));