From eb8f2974b1a06e1727c83b0b6def2e48da47bade Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Mon, 25 Apr 2022 14:43:14 +0200
Subject: [PATCH] Abort when libuv at runtime mismatches libuv at compile time

When we compile with libuv that has some capabilities via flags passed
to f.e. uv_udp_listen() or uv_udp_bind(), the call with such flags would
fail with invalid arguments when older libuv version is linked at the
runtime that doesn't understand the flag that was available at the
compile time.

Enforce minimal libuv version when flags have been available at the
compile time, but are not available at the runtime.  This check is less
strict than enforcing the runtime libuv version to be same or higher
than compile time libuv version.
---
 lib/isc/netmgr/netmgr.c    | 20 ++++++++++++++++++++
 lib/isc/netmgr/uv-compat.h | 17 +++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index a73223942c..df8065daf5 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -207,6 +207,18 @@ isc__nm_threadpool_initialize(uint32_t workers) {
 	}
 }
 
+#if HAVE_DECL_UV_UDP_LINUX_RECVERR
+#define MINIMAL_UV_VERSION UV_VERSION(1, 42, 0)
+#elif HAVE_DECL_UV_UDP_MMSG_FREE
+#define MINIMAL_UV_VERSION UV_VERSION(1, 40, 0)
+#elif HAVE_DECL_UV_UDP_RECVMMSG
+#define MINIMAL_UV_VERSION UV_VERSION(1, 37, 0)
+#elif HAVE_DECL_UV_UDP_MMSG_CHUNK
+#define MINIMAL_UV_VERSION UV_VERSION(1, 35, 0)
+#else
+#define MINIMAL_UV_VERSION UV_VERSION(1, 0, 0)
+#endif
+
 void
 isc__netmgr_create(isc_mem_t *mctx, uint32_t workers, isc_nm_t **netmgrp) {
 	isc_nm_t *mgr = NULL;
@@ -214,6 +226,14 @@ isc__netmgr_create(isc_mem_t *mctx, uint32_t workers, isc_nm_t **netmgrp) {
 
 	REQUIRE(workers > 0);
 
+	if (uv_version() < MINIMAL_UV_VERSION) {
+		isc_error_fatal(__FILE__, __LINE__,
+				"libuv version too old: running with libuv %s "
+				"when compiled with libuv %s will lead to "
+				"libuv failures because of unknown flags",
+				uv_version_string(), UV_VERSION_STRING);
+	}
+
 	isc__nm_threadpool_initialize(workers);
 
 	mgr = isc_mem_get(mctx, sizeof(*mgr));
diff --git a/lib/isc/netmgr/uv-compat.h b/lib/isc/netmgr/uv-compat.h
index 387d3c6940..3a103874e4 100644
--- a/lib/isc/netmgr/uv-compat.h
+++ b/lib/isc/netmgr/uv-compat.h
@@ -23,6 +23,23 @@
 
 #define UV_VERSION(major, minor, patch) ((major << 16) | (minor << 8) | (patch))
 
+/*
+ * Copied verbatim from libuv/src/version.c
+ */
+
+#define UV_STRINGIFY(v)	       UV_STRINGIFY_HELPER(v)
+#define UV_STRINGIFY_HELPER(v) #v
+
+#define UV_VERSION_STRING_BASE         \
+	UV_STRINGIFY(UV_VERSION_MAJOR) \
+	"." UV_STRINGIFY(UV_VERSION_MINOR) "." UV_STRINGIFY(UV_VERSION_PATCH)
+
+#if UV_VERSION_IS_RELEASE
+#define UV_VERSION_STRING UV_VERSION_STRING_BASE
+#else
+#define UV_VERSION_STRING UV_VERSION_STRING_BASE "-" UV_VERSION_SUFFIX
+#endif
+
 #if !defined(UV__ERR)
 #define UV__ERR(x) (-(x))
 #endif