Add more error handling for close() calls.

src/ChunkedIO.cc

@@ -76,7 +76,7 @@ void ChunkedIO::DumpDebugData(const char* basefnname, bool want_reads)
 		ChunkedIOFd io(fd, "dump-file");
 		io.Write(*i);
 		io.Flush();
-		close(fd);
+		safe_close(fd);
 		}
 
 	l->clear();
@@ -127,7 +127,7 @@ ChunkedIOFd::~ChunkedIOFd()
 
 	delete [] read_buffer;
 	delete [] write_buffer;
-	close(fd);
+	safe_close(fd);
 
 	if ( partial )
 		{
@@ -686,7 +686,7 @@ ChunkedIOSSL::~ChunkedIOSSL()
 		ssl = 0;
 		}
 
-	close(socket);
+	safe_close(socket);
 	}
 
 

src/FlowSrc.cc

@@ -58,7 +58,7 @@ void FlowSrc::Process()
 
 void FlowSrc::Close()
 	{
-	close(selectable_fd);
+	safe_close(selectable_fd);
 	}
 
 

src/RemoteSerializer.cc

@@ -647,7 +647,7 @@ void RemoteSerializer::Fork()
 			exit(1); // FIXME: Better way to handle this?
 			}
 
-		close(pipe[1]);
+		safe_close(pipe[1]);
 
 		return;
 		}
@@ -664,12 +664,12 @@ void RemoteSerializer::Fork()
 			}
 
 		child.SetParentIO(io);
-		close(pipe[0]);
+		safe_close(pipe[0]);
 
 		// Close file descriptors.
-		close(0);
+		safe_close(0);
-		close(1);
+		safe_close(1);
-		close(2);
+		safe_close(2);
 
 		// Be nice.
 		setpriority(PRIO_PROCESS, 0, 5);
@@ -4001,7 +4001,7 @@ bool SocketComm::Connect(Peer* peer)
 		if ( connect(sockfd, res->ai_addr, res->ai_addrlen) < 0 )
 			{
 			Error(fmt("connect failed: %s", strerror(errno)), peer);
-			close(sockfd);
+			safe_close(sockfd);
 			sockfd = -1;
 			continue;
 			}
@@ -4174,16 +4174,18 @@ bool SocketComm::Listen()
 			{
 			Error(fmt("can't bind to %s:%s, %s", l_addr_str.c_str(),
 			          port_str, strerror(errno)));
-			close(fd);
 
 			if ( errno == EADDRINUSE )
 				{
 				// Abandon completely this attempt to set up listening sockets,
 				// try again later.
+				safe_close(fd);
 				CloseListenFDs();
 				listen_next_try = time(0) + bind_retry_interval;
 				return false;
 				}
+
+			safe_close(fd);
 			continue;
 			}
 
@@ -4191,7 +4193,7 @@ bool SocketComm::Listen()
 			{
 			Error(fmt("can't listen on %s:%s, %s", l_addr_str.c_str(),
 			          port_str, strerror(errno)));
-			close(fd);
+			safe_close(fd);
 			continue;
 			}
 
@@ -4227,7 +4229,7 @@ bool SocketComm::AcceptConnection(int fd)
 		{
 		Error(fmt("accept fail, unknown address family %d",
 		          client.ss.ss_family));
-		close(clientfd);
+		safe_close(clientfd);
 		return false;
 		}
 
@@ -4298,7 +4300,7 @@ const char* SocketComm::MakeLogString(const char* msg, Peer* peer)
 void SocketComm::CloseListenFDs()
 	{
 	for ( size_t i = 0; i < listen_fds.size(); ++i )
-		close(listen_fds[i]);
+		safe_close(listen_fds[i]);
 
 	listen_fds.clear();
 	}

src/Serializer.cc

@@ -746,7 +746,7 @@ FileSerializer::~FileSerializer()
 	if ( io )
 		delete io;  // destructor will call close() on fd
 	else if ( fd >= 0 )
-		close(fd);
+		safe_close(fd);
 	}
 
 bool FileSerializer::Open(const char* file, bool pure)
@@ -810,7 +810,7 @@ void FileSerializer::CloseFile()
 		io->Flush();
 
 	if ( fd >= 0 && ! io ) // destructor of io calls close() on fd
-		close(fd);
+		safe_close(fd);
 	fd = -1;
 
 	delete [] file;

src/logging/writers/Ascii.cc

@@ -86,7 +86,7 @@ void Ascii::CloseFile(double t)
 		WriteHeaderField("end", ts);
 		}
 
-	close(fd);
+	safe_close(fd);
 	fd = 0;
 	}
 

src/util.cc

@@ -722,7 +722,7 @@ void init_random_seed(uint32 seed, const char* read_file, const char* write_file
 			{
 			int amt = read(fd, buf + pos,
 					sizeof(uint32) * (bufsiz - pos));
-			close(fd);
+			safe_close(fd);
 
 			if ( amt > 0 )
 				pos += amt / sizeof(uint32);
@@ -1204,7 +1204,7 @@ void _set_processing_status(const char* status)
 		len -= n;
 		}
 
-	close(fd);
+	safe_close(fd);
 
 	errno = old_errno;
 	}
@@ -1353,6 +1353,29 @@ bool safe_write(int fd, const char* data, int len)
 	return true;
 	}
 
+void safe_close(int fd)
+	{
+	/*
+	 * Failure cases of close(2) are ...
+	 * EBADF: Indicative of programming logic error that needs to be fixed, we
+	 *        should always be attempting to close a valid file descriptor.
+	 * EINTR: Ignore signal interruptions, most implementations will actually
+	 *        reclaim the open descriptor and POSIX standard doesn't leave many
+	 *        options by declaring the state of the descriptor as "unspecified".
+	 *        Attempting to inspect actual state or re-attempt close() is not
+	 *        thread safe.
+	 * EIO:   Again the state of descriptor is "unspecified", but don't recover
+	 *        from an I/O error, safe_write() won't either.
+	 */
+	if ( close(fd) < 0 && errno != EINTR )
+		{
+		char buf[128];
+		strerror_r(errno, buf, sizeof(buf));
+		fprintf(stderr, "safe_close error %d: %s\n", errno, buf);
+		abort();
+		}
+	}
+
 void out_of_memory(const char* where)
 	{
 	reporter->FatalError("out of memory in %s.\n", where);

src/util.h

@@ -297,6 +297,9 @@ inline size_t pad_size(size_t size)
 // thread-safe as long as no two threads write to the same descriptor.
 extern bool safe_write(int fd, const char* data, int len);
 
+// Wraps close(2) to emit error messages and abort on unrecoverable errors.
+extern void safe_close(int fd);
+
 extern void out_of_memory(const char* where);
 
 inline void* safe_realloc(void* ptr, size_t size)