nfs: bound namemap by using lru

Ticket: 8418

rust/src/nfs/nfs.rs

@@ -20,7 +20,6 @@
 use lru::LruCache;
 use std;
 use std::cmp;
-use std::collections::HashMap;
 use std::ffi::CString;
 use std::num::NonZeroUsize;
 
@@ -102,6 +101,7 @@ static mut ALPROTO_NFS: AppProto = ALPROTO_UNKNOWN;
  */
 
 pub static mut NFS_CFG_MAX_REQ: usize = 512;
+pub static mut NFS_CFG_MAX_NAMES: usize = 512;
 
 #[derive(AppLayerFrameType)]
 pub enum NFSFrameType {
@@ -364,7 +364,7 @@ pub struct NFSState {
     pub requestmap: LruCache<u32, NFSRequestXidMap>,
 
     /// map file handle (1) to name (2)
-    pub namemap: HashMap<Vec<u8>, Vec<u8>>,
+    pub namemap: LruCache<Vec<u8>, Vec<u8>>,
 
     /// transactions list
     pub transactions: Vec<NFSTransaction>,
@@ -423,7 +423,7 @@ impl NFSState {
         NFSState {
             state_data: AppLayerStateData::default(),
             requestmap: LruCache::new(NonZeroUsize::new(unsafe { NFS_CFG_MAX_REQ }).unwrap()),
-            namemap: HashMap::new(),
+            namemap: LruCache::new(NonZeroUsize::new(unsafe { NFS_CFG_MAX_NAMES }).unwrap()),
             transactions: Vec::new(),
             ts_chunk_xid: 0,
             tc_chunk_xid: 0,
@@ -2390,6 +2390,18 @@ pub unsafe extern "C" fn SCRegisterNfsParser() {
                 SCLogError!("Invalid max-requests value");
             }
         }
+        let retval = conf_get("app-layer.protocols.nfs.max-names");
+        if let Some(val) = retval {
+            if let Ok(v) = val.parse::<usize>() {
+                if v > 0 {
+                    NFS_CFG_MAX_NAMES = v;
+                } else {
+                    SCLogError!("Invalid max-names value, must be >0");
+                }
+            } else {
+                SCLogError!("Invalid max-names value");
+            }
+        }
     } else {
         SCLogDebug!("Protocol detector and parser disabled for nfs.");
     }

rust/src/nfs/nfs3.rs

@@ -209,7 +209,7 @@ impl NFSState {
 
                 SCLogDebug!("LOOKUP handle {:?}", rd.handle);
                 self.namemap
-                    .insert(rd.handle.value.to_vec(), xidmap.file_name.to_vec());
+                    .put(rd.handle.value.to_vec(), xidmap.file_name.to_vec());
                 resp_handle = rd.handle.value.to_vec();
             } else {
                 self.set_event(NFSEvent::MalformedData);
@@ -223,7 +223,7 @@ impl NFSState {
                 if let Some(h) = rd.handle {
                     SCLogDebug!("handle {:?}", h);
                     self.namemap
-                        .insert(h.value.to_vec(), xidmap.file_name.to_vec());
+                        .put(h.value.to_vec(), xidmap.file_name.to_vec());
                     resp_handle = h.value.to_vec();
                 }
             } else {
@@ -256,7 +256,7 @@ impl NFSState {
                             SCLogDebug!("e {:?}", e);
                             if let Some(ref h) = e.handle {
                                 SCLogDebug!("h {:?}", h);
-                                self.namemap.insert(h.value.to_vec(), e.name_vec.to_vec());
+                                self.namemap.put(h.value.to_vec(), e.name_vec.to_vec());
                             }
                         }
                     }

rust/src/nfs/nfs4.rs

@@ -376,7 +376,7 @@ impl NFSState {
                 }
                 Nfs4ResponseContent::GetFH(_s, Some(ref rd)) if insert_filename_with_getfh => {
                     self.namemap
-                        .insert(rd.value.to_vec(), xidmap.file_name.to_vec());
+                        .put(rd.value.to_vec(), xidmap.file_name.to_vec());
                 }
                 Nfs4ResponseContent::PutRootFH(s) if s == NFS4_OK && xidmap.file_name.is_empty() => {
                         xidmap.file_name = b"<mount_root>".to_vec();