xnu-4570.31.3.tar.gz

[apple/xnu.git] / bsd / net / if_loop.c

diff --git a/bsd/net/if_loop.c b/bsd/net/if_loop.c
index 00a8345e3a8fe7a8536f9d47fe802e144b58edbd..cc2089cb629fd9c515b490d0917f456aac34c1f2 100644 (file)
--- a/bsd/net/if_loop.c
+++ b/bsd/net/if_loop.c
@@ -698,6 +698,13 @@ loopattach(void)
                    __func__, result);
                /* NOTREACHED */
        }
+       /*
+        * Disable ECN on loopback as ECN serves no purpose and otherwise
+        * TCP connections are subject to heuristics like SYN retransmits on RST
+        */
+       lo_ifp->if_eflags &= ~IFEF_ECN_ENABLE;
+       lo_ifp->if_eflags |= IFEF_ECN_DISABLE;
+
        bpfattach(lo_ifp, DLT_NULL, sizeof (u_int32_t));
 }