From 213207da55ca1e23ff4b8098b621d39b9f711022 Mon Sep 17 00:00:00 2001
From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Thu, 22 Feb 2018 10:31:19 +0100
Subject: [PATCH] ixfrdist: fix reading nits

---
 pdns/ixfrdist.cc | 44 +++++++++++++-------------------------------
 1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/pdns/ixfrdist.cc b/pdns/ixfrdist.cc
index c6337553ef..7922074bca 100644
--- a/pdns/ixfrdist.cc
+++ b/pdns/ixfrdist.cc
@@ -620,33 +620,15 @@ void handleTCPRequest(int fd, boost::any&) {
     return;
   }
 
-  char buf[65535];
-  int res;
-  res = recv(cfd, &buf, 2, 0);
-  if (res != 2) {
-    if (res == 0) { // Connection is closed
-      close(cfd);
-      return;
-    }
-    if (res == -1) {
-      auto savedErrno = errno;
-      cerr<<"[WARNING] Could not read message from "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
-      close(cfd);
-      return;
-    }
-  }
-
-  size_t toRead = std::min(static_cast<size_t>(ntohs((buf[0]<<8) + buf[1])), sizeof(buf));
-  res = recv(cfd, &buf, toRead, 0);
-
-  if (res == -1) {
-    auto savedErrno = errno;
-    cerr<<"[WARNING] Could not read message from "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
-    close(cfd);
-    return;
-  }
-
-  if (res == 0) { // Connection is closed
+  char buf[4096];
+  ssize_t res;
+  try {
+    uint16_t toRead;
+    readn2(cfd, &toRead, sizeof(toRead));
+    toRead = std::min(ntohs(toRead), static_cast<uint16_t>(sizeof(buf)));
+    res = readn2WithTimeout(cfd, &buf, toRead, 2);
+  } catch (runtime_error &e) {
+    cerr<<"[WARNING] Could not read message from "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
     close(cfd);
     return;
   }
@@ -708,11 +690,11 @@ void handleTCPRequest(int fd, boost::any&) {
     } /* if (mdp.d_qtype == QType::IXFR) */
 
     for (const auto& packet : packets) {
-      char buf[2];
-      buf[0]=packet.size()/256;
-      buf[1]=packet.size()%256;
+      char sendBuf[2];
+      sendBuf[0]=packet.size()/256;
+      sendBuf[1]=packet.size()%256;
 
-      int send = writen2(cfd, buf, 2);
+      ssize_t send = writen2(cfd, sendBuf, 2);
       send += writen2(cfd, &packet[0], packet.size());
     }
     shutdown(cfd, 2);
-- 
2.47.2