Backport "Squelch udp connect 'no route to host' errors" from upstream.

Problem reported and diff tested by danj@

From 5906811ff19f005110b2edbda5aa144ad5fa05b1 Mon Sep 17 00:00:00 2001
From: "W.C.A. Wijngaards" <wouter@nlnetlabs.nl>
Date: Tue, 1 Dec 2020 09:09:13 +0100
Subject: [PATCH] - Fix #358: Squelch udp connect 'no route to host' errors on
  low verbosity.

diff --git a/usr.sbin/unbound/services/outside_network.c b/usr.sbin/unbound/services/outside_network.c
index 11951ad..0886907 100644 (file)
--- a/usr.sbin/unbound/services/outside_network.c
+++ b/usr.sbin/unbound/services/outside_network.c
@@ -1745,6 +1745,33 @@ select_id(struct outside_network* outnet, struct pending* pend,
        return 1;
 }
 
+/** return true is UDP connect error needs to be logged */
+static int udp_connect_needs_log(int err)
+{
+       switch(err) {
+       case ECONNREFUSED:
+#  ifdef ENETUNREACH
+       case ENETUNREACH:
+#  endif
+#  ifdef EHOSTDOWN
+       case EHOSTDOWN:
+#  endif
+#  ifdef EHOSTUNREACH
+       case EHOSTUNREACH:
+#  endif
+#  ifdef ENETDOWN
+       case ENETDOWN:
+#  endif
+               if(verbosity >= VERB_ALGO)
+                       return 1;
+               return 0;
+       default:
+               break;
+       }
+       return 1;
+}
+
+
 /** Select random interface and port */
 static int
 select_ifport(struct outside_network* outnet, struct pending* pend,
@@ -1804,9 +1831,11 @@ select_ifport(struct outside_network* outnet, struct pending* pend,
                                /* connect() to the destination */
                                if(connect(fd, (struct sockaddr*)&pend->addr,
                                        pend->addrlen) < 0) {
-                                       log_err_addr("udp connect failed",
-                                               strerror(errno), &pend->addr,
-                                               pend->addrlen);
+                                       if(udp_connect_needs_log(errno)) {
+                                               log_err_addr("udp connect failed",
+                                                       strerror(errno), &pend->addr,
+                                                       pend->addrlen);
+                                       }
                                        sock_close(fd);
                                        return 0;
                                }