From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 5 Jul 2019 08:19:04 +0000 (+0200)
Subject: dnsdist: Handle ENOTCONN on read() over TCP
X-Git-Tag: dnsdist-1.4.0-rc1^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F8030%2Fhead;p=thirdparty%2Fpdns.git

dnsdist: Handle ENOTCONN on read() over TCP

When a non-blocking connect() has returned `EINPROGRESS`, it looks
like BSD can return `ENOTCONN` on `read()` even after a `write()`
succeeded.
---

diff --git a/pdns/dnsdist-tcp.cc b/pdns/dnsdist-tcp.cc
index 994ba9a1bb..9ce3b74f4d 100644
--- a/pdns/dnsdist-tcp.cc
+++ b/pdns/dnsdist-tcp.cc
@@ -361,7 +361,7 @@ IOState tryRead(int fd, std::vector<uint8_t>& buffer, size_t& pos, size_t toRead
       throw runtime_error("EOF while reading message");
     }
     if (res < 0) {
-      if (errno == EAGAIN || errno == EWOULDBLOCK) {
+      if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOTCONN) {
         return IOState::NeedRead;
       }
       else {
diff --git a/pdns/tcpiohandler.hh b/pdns/tcpiohandler.hh
index 3e7f52b081..ac6525888a 100644
--- a/pdns/tcpiohandler.hh
+++ b/pdns/tcpiohandler.hh
@@ -214,7 +214,7 @@ public:
         throw runtime_error("EOF while reading message");
       }
       if (res < 0) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOTCONN) {
           return IOState::NeedRead;
         }
         else {
@@ -250,7 +250,7 @@ public:
         throw runtime_error("EOF while sending message");
       }
       if (res < 0) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOTCONN) {
           return IOState::NeedWrite;
         }
         else {