BUILD: tcp: use IPPROTO_IP when SOL_IP is not available
Dmitry Sivachenko reported a build failure on FreeBSD due to SOL_IP not
being defined. IPPROTO_IP must be used there instead.
diff --git a/include/common/compat.h b/include/common/compat.h
index 07dd01d..b2e16af 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -129,6 +129,11 @@
#endif
#endif
+/* FreeBSD doesn't define SOL_IP and prefers IPPROTO_IP */
+#ifndef SOL_IP
+#define SOL_IP IPPROTO_IP
+#endif
+
/* If IPv6 is supported, define IN6_IS_ADDR_V4MAPPED() if missing. */
#if defined(IPV6_TCLASS) && !defined(IN6_IS_ADDR_V4MAPPED)
#define IN6_IS_ADDR_V4MAPPED(a) \