Add mtu option

apps/gpclient/src/connect.rs

@@ -37,6 +37,9 @@ pub(crate) struct ConnectArgs {
   #[arg(long, help = "Same as the '--csd-wrapper' option in the openconnect command")]
   csd_wrapper: Option<String>,
 
+  #[arg(short, long, help = "Request MTU from server (legacy servers only)")]
+  mtu: Option<u32>,
+
   #[arg(long, default_value = GP_USER_AGENT, help = "The user agent to use")]
   user_agent: String,
   #[arg(long, default_value = "Linux")]
@@ -152,12 +155,14 @@ impl<'a> ConnectHandler<'a> {
 
   async fn connect_gateway(&self, gateway: &str, cookie: &str) -> anyhow::Result<()> {
     let csd_uid = get_csd_uid(&self.args.csd_user)?;
+    let mtu = self.args.mtu.unwrap_or(0);
 
     let vpn = Vpn::builder(gateway, cookie)
       .user_agent(self.args.user_agent.clone())
       .script(self.args.script.clone())
       .csd_uid(csd_uid)
       .csd_wrapper(self.args.csd_wrapper.clone())
+      .mtu(mtu)
       .build();
 
     let vpn = Arc::new(vpn);

apps/gpservice/src/vpn_task.rs

@@ -39,6 +39,7 @@ impl VpnTaskContext {
       .script(args.vpnc_script())
       .csd_uid(args.csd_uid())
       .csd_wrapper(args.csd_wrapper())
+      .mtu(args.mtu())
       .os(args.openconnect_os())
       .build();
 

crates/gpapi/src/service/request.rs

@@ -34,6 +34,7 @@ pub struct ConnectArgs {
   user_agent: Option<String>,
   csd_uid: u32,
   csd_wrapper: Option<String>,
+  mtu: u32,
   os: Option<ClientOs>,
 }
 
@@ -46,6 +47,7 @@ impl ConnectArgs {
       os: None,
       csd_uid: 0,
       csd_wrapper: None,
+      mtu: 0,
     }
   }
 
@@ -72,6 +74,10 @@ impl ConnectArgs {
   pub fn csd_wrapper(&self) -> Option<String> {
     self.csd_wrapper.clone()
   }
+
+  pub fn mtu(&self) -> u32 {
+    self.mtu
+  }
 }
 
 #[derive(Debug, Deserialize, Serialize, Type)]
@@ -103,6 +109,11 @@ impl ConnectRequest {
     self
   }
 
+  pub fn with_mtu(mut self, mtu: u32) -> Self {
+    self.args.mtu = mtu;
+    self
+  }
+
   pub fn with_user_agent<T: Into<Option<String>>>(mut self, user_agent: T) -> Self {
     self.args.user_agent = user_agent.into();
     self

crates/openconnect/src/ffi/mod.rs

@@ -18,6 +18,8 @@ pub(crate) struct ConnectOptions {
 
   pub csd_uid: u32,
   pub csd_wrapper: *const c_char,
+
+  pub mtu: u32,
 }
 
 #[link(name = "vpn")]

crates/openconnect/src/ffi/vpn.c

@@ -63,6 +63,7 @@ int vpn_connect(const vpn_options *options, vpn_connected_callback callback)
     INFO("OS: %s", options->os);
     INFO("CSD_USER: %d", options->csd_uid);
     INFO("CSD_WRAPPER: %s", options->csd_wrapper);
+    INFO("MTU: %d", options->mtu);
 
     vpninfo = openconnect_vpninfo_new(options->user_agent, validate_peer_cert, NULL, NULL, print_progress, NULL);
 
@@ -97,6 +98,11 @@ int vpn_connect(const vpn_options *options, vpn_connected_callback callback)
         openconnect_setup_csd(vpninfo, options->csd_uid, 1, options->csd_wrapper);
     }
 
+    if (options->mtu > 0) {
+        int mtu = options->mtu < 576 ? 576 : options->mtu;
+        openconnect_set_reqmtu(vpninfo, mtu);
+    }
+
     g_cmd_pipe_fd = openconnect_setup_cmd_pipe(vpninfo);
     if (g_cmd_pipe_fd < 0)
     {

crates/openconnect/src/ffi/vpn.h

@@ -19,6 +19,8 @@ typedef struct vpn_options
 
     const uid_t csd_uid;
     const char *csd_wrapper;
+
+    const int mtu;
 } vpn_options;
 
 int vpn_connect(const vpn_options *options, vpn_connected_callback callback);

crates/openconnect/src/vpn.rs

@@ -21,6 +21,8 @@ pub struct Vpn {
   csd_uid: u32,
   csd_wrapper: Option<CString>,
 
+  mtu: u32,
+
   callback: OnConnectedCallback,
 }
 
@@ -62,6 +64,8 @@ impl Vpn {
 
       csd_uid: self.csd_uid,
       csd_wrapper: Self::option_to_ptr(&self.csd_wrapper),
+
+      mtu: self.mtu,
     }
   }
 
@@ -82,6 +86,8 @@ pub struct VpnBuilder {
 
   csd_uid: u32,
   csd_wrapper: Option<String>,
+
+  mtu: u32,
 }
 
 impl VpnBuilder {
@@ -94,6 +100,7 @@ impl VpnBuilder {
       os: None,
       csd_uid: 0,
       csd_wrapper: None,
+      mtu: 0,
     }
   }
 
@@ -122,6 +129,11 @@ impl VpnBuilder {
     self
   }
 
+  pub fn mtu(mut self, mtu: u32) -> Self {
+    self.mtu = mtu;
+    self
+  }
+
   pub fn build(self) -> Vpn {
     let user_agent = self.user_agent.unwrap_or_default();
     let script = self.script.or_else(find_default_vpnc_script).unwrap_or_default();
@@ -139,6 +151,8 @@ impl VpnBuilder {
       csd_uid: self.csd_uid,
       csd_wrapper: self.csd_wrapper.as_deref().map(Self::to_cstring),
 
+      mtu: self.mtu,
+
       callback: Default::default(),
     }
   }