proxy: restrict functions for lua config vs route

Also changes the way the global context and thread contexts are fetched
from lua; via the VM extra space instead of upvalues, which is a little
faster and more universal.

It was always erroneous to run a lot of the config functions from routes
and vice versa, but there was no consistent strictness so users could
get into trouble.

1 files changed, 6 insertions, 4 deletions

diff --git a/proxy.h b/proxy.h
index f8ceec3..0ab3b91 100644
--- a/proxy.h
+++ b/proxy.h
@@ -76,10 +76,7 @@
 #define ENDSTR "END\r\n"
 #define ENDLEN sizeof(ENDSTR)-1
 
-#define MCP_THREAD_UPVALUE 1
-#define MCP_ATTACH_UPVALUE 2
-#define MCP_BACKEND_UPVALUE 3
-#define MCP_CONTEXT_UPVALUE 4
+#define MCP_BACKEND_UPVALUE 1
 
 #define MCP_YIELD_POOL 1
 #define MCP_YIELD_AWAIT 2
@@ -217,6 +214,11 @@ typedef struct {
     pthread_mutex_t stats_lock; // used for rare global counters
 } proxy_ctx_t;
 
+#define PROXY_GET_THR_CTX(L) ((*(LIBEVENT_THREAD **)lua_getextraspace(L))->proxy_ctx)
+#define PROXY_GET_THR(L) (*(LIBEVENT_THREAD **)lua_getextraspace(L))
+// Operations from the config VM don't have a libevent thread.
+#define PROXY_GET_CTX(L) (*(proxy_ctx_t **)lua_getextraspace(L))
+
 struct proxy_hook_tagged {
     uint64_t tag;
     int lua_ref;