From c2f1f13bb3b8e6b51e882ca33494f14f99a13cb7 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Fri, 28 Jan 2022 08:39:47 -0800
Subject: [PATCH] server: fix beacons TX on Linux

---
 src/config.cpp      | 14 +++++++++++---
 src/server.cpp      |  2 ++
 test/testconfig.cpp | 34 +++++++++++++++++++++++++++++++++-
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/config.cpp b/src/config.cpp
index 3ed5337..4dcb729 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -288,10 +288,18 @@ void expandAddrList(const std::vector<SockEndpoint>& ifaces,
     evsocket dummy(AF_INET, SOCK_DGRAM, 0);
 
     for(auto& saddr : ifaces) {
-        if(saddr.addr.family()!=AF_INET)
-            continue;
+        auto matchAddr = &saddr.addr;
 
-        for(auto& addr : dummy.broadcasts(&saddr.addr)) {
+        if(evsocket::ipstack==evsocket::Linsock && saddr.addr.family()==AF_INET6 && saddr.addr.isAny()) {
+            // special case handling to match "promote" in server::Config::expand()
+            // treat [::] as 0.0.0.0
+            matchAddr = nullptr;
+
+        } else if(saddr.addr.family()!=AF_INET) {
+            continue;
+        }
+
+        for(auto& addr : dummy.broadcasts(matchAddr)) {
             addr.setPort(0u);
             addrs.emplace_back(addr);
         }
diff --git a/src/server.cpp b/src/server.cpp
index e95d171..ad506f6 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -458,6 +458,8 @@ Server::Pvt::Pvt(const Config &conf)
 
         for(const auto& addr : effective.beaconDestinations) {
             beaconDest.emplace_back(addr.c_str(), effective.udp_port);
+            log_debug_printf(serversetup, "Will send beacons to %s\n",
+                             std::string(SB()<<beaconDest.back()).c_str());
         }
     });
 
diff --git a/test/testconfig.cpp b/test/testconfig.cpp
index 437129e..5c845ea 100644
--- a/test/testconfig.cpp
+++ b/test/testconfig.cpp
@@ -145,15 +145,47 @@ void testDefs()
     }
 }
 
+void testServerAuto()
+{
+    testShow()<<__func__;
+
+    /* We assume that the test host has at least
+     * one interface other than localhost configured.
+     * It need not be usable (eg. due to firewall).
+     */
+    server::Config conf;
+    conf.expand();
+
+    testFalse(conf.interfaces.empty())<<conf.interfaces;
+    testFalse(conf.beaconDestinations.empty())<<conf.beaconDestinations;
 }
 
+void testClientAuto()
+{
+    testShow()<<__func__;
+
+    /* We assume that the test host has at least
+     * one interface other than localhost configured.
+     * It need not be usable (eg. due to firewall).
+     */
+    client::Config conf;
+    conf.expand();
+
+    testFalse(conf.interfaces.empty())<<conf.interfaces;
+    testFalse(conf.addressList.empty())<<conf.addressList;
+}
+
+} // namespace
+
 MAIN(testconfig)
 {
-    testPlan(27);
+    testPlan(31);
     testSetup();
     testDefs();
     logger_config_env();
     testParse();
+    testServerAuto();
+    testClientAuto();
     cleanup_for_valgrind();
     return testDone();
 }