From: Aki Tuomi <cmouse@cmouse.fi>
Date: Fri, 5 Mar 2021 09:57:04 +0000 (+0200)
Subject: global: Check setsockopt return value
X-Git-Tag: dnsdist-1.7.0-alpha1~10^2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8816bd4ebfe1db418743e4301510960b7332f839;p=thirdparty%2Fpdns.git

global: Check setsockopt return value
---

diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
index f6d4f1d9cb..60de4ecb43 100644
--- a/pdns/dnsdist.cc
+++ b/pdns/dnsdist.cc
@@ -2006,6 +2006,8 @@ static void checkFileDescriptorsLimits(size_t udpBindsCount, size_t tcpBindsCoun
   }
 }
 
+static bool g_warned_ipv6_recvpktinfo = false;
+
 static void setUpLocalBind(std::unique_ptr<ClientState>& cs)
 {
   /* skip some warnings if there is an identical UDP context */
@@ -2039,9 +2041,13 @@ static void setUpLocalBind(std::unique_ptr<ClientState>& cs)
 
   if(!cs->tcp && IsAnyAddress(cs->local)) {
     int one=1;
-    setsockopt(fd, IPPROTO_IP, GEN_IP_PKTINFO, &one, sizeof(one));     // linux supports this, so why not - might fail on other systems
+    (void)setsockopt(fd, IPPROTO_IP, GEN_IP_PKTINFO, &one, sizeof(one)); // linux supports this, so why not - might fail on other systems
 #ifdef IPV6_RECVPKTINFO
-    setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)) < 0 &&
+        !g_warned_ipv6_recvpktinfo) {
+        warnlog("Warning: IPV6_RECVPKTINFO setsockopt failed: %s", stringerror());
+        g_warned_ipv6_recvpktinfo = true;
+    }
 #endif
   }
 
diff --git a/pdns/nameserver.cc b/pdns/nameserver.cc
index 56c1fca68e..ce07abdc7d 100644
--- a/pdns/nameserver.cc
+++ b/pdns/nameserver.cc
@@ -118,11 +118,11 @@ void UDPNameserver::bindAddresses()
       throw PDNSException("Unable to set UDP socket " + locala.toStringWithPort() + " to non-blocking: "+stringerror());
 
     if(IsAnyAddress(locala)) {
-      setsockopt(s, IPPROTO_IP, GEN_IP_PKTINFO, &one, sizeof(one));
+      (void)setsockopt(s, IPPROTO_IP, GEN_IP_PKTINFO, &one, sizeof(one));
       if (locala.isIPv6()) {
-        setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));      // if this fails, we report an error in tcpreceiver too
+        (void)setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));      // if this fails, we report an error in tcpreceiver too
 #ifdef IPV6_RECVPKTINFO
-        setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
+        (void)setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
 #endif
       }
     }
diff --git a/pdns/rec_channel.cc b/pdns/rec_channel.cc
index 17d408398a..ff57095276 100644
--- a/pdns/rec_channel.cc
+++ b/pdns/rec_channel.cc
@@ -46,7 +46,7 @@ static void setSocketBuffer(int fd, int optname, uint32_t size)
     return;
   
   // failure to raise is not fatal
-  setsockopt(fd, SOL_SOCKET, optname, (const void*)&size, sizeof(size));
+  (void)setsockopt(fd, SOL_SOCKET, optname, (const void*)&size, sizeof(size));
 }