From 5ea12787f87f3ea60935b7a1f5b24be80cb2dec6 Mon Sep 17 00:00:00 2001
From: ame <ameliasquires@disroot.org>
Date: Mon, 1 Dec 2025 21:12:42 -0600
Subject: minor net changes, prevent buffer indexing evil metatables

---
 src/lua.c     | 5 +++++
 src/lua.h     | 1 +
 src/net.c     | 4 +++-
 src/net/lua.c | 6 +++---
 src/thread.c  | 6 ++++--
 5 files changed, 16 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/lua.c b/src/lua.c
index 587b291..bcec1ed 100644
--- a/src/lua.c
+++ b/src/lua.c
@@ -483,3 +483,8 @@ int lua_assign_upvalues(lua_State* L, int fidx){
 
   return 0;
 }
+
+int luaI_errtraceback(lua_State* L){
+  luaL_traceback(L, L, lua_tostring(L, -1), 1);
+  return 1;
+}
diff --git a/src/lua.h b/src/lua.h
index cfff148..ce3d0e4 100644
--- a/src/lua.h
+++ b/src/lua.h
@@ -43,6 +43,7 @@ void luaI_newstream(lua_State* L, stream_read_function, stream_free_function, vo
 int luaI_nothing(lua_State*);
 int env_table(lua_State* L, int provide_table);
 void luaI_jointable(lua_State* L);
+int luaI_errtraceback(lua_State* L);
 
 //generic macro that takes other macros (see below)
 #define _tset_b(L, Tidx, K, V, F)\
diff --git a/src/net.c b/src/net.c
index abab731..c9fdc08 100644
--- a/src/net.c
+++ b/src/net.c
@@ -843,6 +843,8 @@ void* handle_client(void *_arg){
 
         luaI_tsetv(L, res_idx, "header", header_idx);
 
+        lua_pushcfunction(L, luaI_errtraceback);
+        int errtraceback_idx = lua_gettop(L);
         //get all function that kinda match
         parray_t* owo = (parray_t*)v;
         for(int i = 0; i != owo->len; i++){
@@ -877,7 +879,7 @@ void* handle_client(void *_arg){
               lua_pushvalue(L, req_idx); //push info about the request
 
               //call the function
-              if(lua_pcall(L, 2, 0, 0) != 0){
+              if(lua_pcall(L, 2, 0, errtraceback_idx) != 0){
                 fprintf(stderr, "(net thread) %s\n", lua_tostring(L, -1));
                 //send an error message if send has not been called
                 if(client_fd >= 0) net_error(client_fd, 500);
diff --git a/src/net/lua.c b/src/net/lua.c
index 829c2f7..f005185 100644
--- a/src/net/lua.c
+++ b/src/net/lua.c
@@ -210,6 +210,9 @@ int l_sendfile(lua_State* L){
     if(!lua_isnil(L, -1)) filename = (char*)lua_tostring(L, -1);
   }
 
+  luaI_assert(L, !access(path, F_OK) /*file not found*/);
+  luaI_assert(L, !access(path, R_OK) /*missing permissions*/);
+
   lua_pushvalue(L, res_idx);
   lua_pushstring(L, "client_fd");
   lua_gettable(L, res_idx);
@@ -221,9 +224,6 @@ int l_sendfile(lua_State* L){
   lua_gettable(L, -2);
   int header = lua_gettop(L);
 
-  luaI_assert(L, !access(path, F_OK) /*file not found*/);
-  luaI_assert(L, !access(path, R_OK) /*missing permissions*/);
-
   lua_pushstring(L, "Content-Type");
   lua_gettable(L, header);
 
diff --git a/src/thread.c b/src/thread.c
index f166c3f..a5f5cc2 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -391,8 +391,10 @@ int _buffer_mod(lua_State* L){
     luaI_deepcopy(L, buffer->L, STRIP_GC | SKIP_LOCALS);
 
     lua_getmetatable(L, idx);
-    idx = lua_gettop(L);
-    luaI_tsetnil(L, idx, "__gc");
+    if(lua_type(L, -1) == LUA_TTABLE){
+      idx = lua_gettop(L);
+      luaI_tsetnil(L, idx, "__gc");
+    }
   }
 
   pthread_mutex_unlock(&*buffer->lock);
-- 
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