Grab Context.{set,get}_session_cache_mode from the sessions branch, plus the unit tests.
diff --git a/OpenSSL/ssl/ssl.c b/OpenSSL/ssl/ssl.c
index cee3661..a68f447 100644
--- a/OpenSSL/ssl/ssl.c
+++ b/OpenSSL/ssl/ssl.c
@@ -274,6 +274,20 @@
     PyModule_AddIntConstant(module, "SSLEAY_PLATFORM", SSLEAY_PLATFORM);
     PyModule_AddIntConstant(module, "SSLEAY_DIR", SSLEAY_DIR);
 
+    /* Cache modes */
+#define CACHE_MODE(mode) \
+    PyModule_AddIntConstant(module, "SESS_CACHE_" #mode, SSL_SESS_CACHE_##mode)
+
+    CACHE_MODE(OFF);
+    CACHE_MODE(CLIENT);
+    CACHE_MODE(SERVER);
+    CACHE_MODE(BOTH);
+    CACHE_MODE(NO_AUTO_CLEAR);
+    CACHE_MODE(NO_INTERNAL_LOOKUP);
+    CACHE_MODE(NO_INTERNAL_STORE);
+    CACHE_MODE(NO_INTERNAL);
+#undef CACHE_MODE
+
     /* Straight up version number */
     PyModule_AddIntConstant(module, "OPENSSL_VERSION_NUMBER", OPENSSL_VERSION_NUMBER);