From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 18 Mar 2022 09:32:42 +0000 (+0100)
Subject: dnsdist: Wrap the pipe descriptors earlier, do not leak on send errors
X-Git-Tag: rec-5.0.0-alpha1~161^2~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=52f6247b5a24ad58af41d085dfb049475b8a2ca5;p=thirdparty%2Fpdns.git

dnsdist: Wrap the pipe descriptors earlier, do not leak on send errors
---

diff --git a/pdns/dnsdistdist/channel.cc b/pdns/dnsdistdist/channel.cc
index 75cca8a706..dd25c6d34e 100644
--- a/pdns/dnsdistdist/channel.cc
+++ b/pdns/dnsdistdist/channel.cc
@@ -82,27 +82,23 @@ namespace channel
       throw std::runtime_error("Error creating notification channel pipe: " + stringerror());
     }
 
-    if (nonBlocking && !setNonBlocking(fds[0])) {
+    FDWrapper sender(fds[1]);
+    FDWrapper receiver(fds[0]);
+
+    if (nonBlocking && !setNonBlocking(receiver.getHandle())) {
       int err = errno;
-      close(fds[0]);
-      close(fds[1]);
       throw std::runtime_error("Error making notification channel pipe non-blocking: " + stringerror(err));
     }
 
-    if (nonBlocking && !setNonBlocking(fds[1])) {
+    if (nonBlocking && !setNonBlocking(sender.getHandle())) {
       int err = errno;
-      close(fds[0]);
-      close(fds[1]);
       throw std::runtime_error("Error making notification channel pipe non-blocking: " + stringerror(err));
     }
 
-    if (pipeBufferSize > 0 && getPipeBufferSize(fds[0]) < pipeBufferSize) {
-      setPipeBufferSize(fds[0], pipeBufferSize);
+    if (pipeBufferSize > 0 && getPipeBufferSize(receiver.getHandle()) < pipeBufferSize) {
+      setPipeBufferSize(receiver.getHandle(), pipeBufferSize);
     }
 
-    FDWrapper sender(fds[1]);
-    FDWrapper receiver(fds[0]);
-
     return std::pair(Notifier(std::move(sender)), Waiter(std::move(receiver)));
   }
 }
diff --git a/pdns/dnsdistdist/channel.hh b/pdns/dnsdistdist/channel.hh
index 55ee5f956d..5698fb7ba3 100644
--- a/pdns/dnsdistdist/channel.hh
+++ b/pdns/dnsdistdist/channel.hh
@@ -191,13 +191,13 @@ namespace channel
     ssize_t sent = write(d_fd.getHandle(), &ptr, sizeof(ptr));
 
     if (sent != sizeof(ptr)) {
+      delete ptr;
       if (errno == EAGAIN || errno == EWOULDBLOCK) {
         return false;
       }
       else {
         throw std::runtime_error("Unable to write to channel:" + stringerror());
       }
-      delete ptr;
     }
 
     return true;
@@ -234,27 +234,23 @@ namespace channel
       throw std::runtime_error("Error creating channel pipe: " + stringerror());
     }
 
-    if (nonBlocking && !setNonBlocking(fds[0])) {
+    FDWrapper sender(fds[1]);
+    FDWrapper receiver(fds[0]);
+
+    if (nonBlocking && !setNonBlocking(receiver.getHandle())) {
       int err = errno;
-      close(fds[0]);
-      close(fds[1]);
       throw std::runtime_error("Error making channel pipe non-blocking: " + stringerror(err));
     }
 
-    if (nonBlocking && !setNonBlocking(fds[1])) {
+    if (nonBlocking && !setNonBlocking(sender.getHandle())) {
       int err = errno;
-      close(fds[0]);
-      close(fds[1]);
       throw std::runtime_error("Error making channel pipe non-blocking: " + stringerror(err));
     }
 
-    if (pipeBufferSize > 0 && getPipeBufferSize(fds[0]) < pipeBufferSize) {
-      setPipeBufferSize(fds[0], pipeBufferSize);
+    if (pipeBufferSize > 0 && getPipeBufferSize(receiver.getHandle()) < pipeBufferSize) {
+      setPipeBufferSize(receiver.getHandle(), pipeBufferSize);
     }
 
-    FDWrapper sender(fds[1]);
-    FDWrapper receiver(fds[0]);
-
     return std::pair(Sender<T>(std::move(sender)), Receiver<T>(std::move(receiver)));
   }
 }