From e0e1becc2f9129203966e69b2919582c11ab86f7 Mon Sep 17 00:00:00 2001
From: Attila Molnar <attilamolnar@hush.com>
Date: Wed, 4 Mar 2015 20:18:37 +0100
Subject: [PATCH] Add SocketEngine::WriteV()

---
 include/socketengine.h      | 35 +++++++++++++++++++++++++++++++++++
 src/inspsocket.cpp          | 10 +---------
 src/socketengine.cpp        | 27 +++++++++++++++++++++++++++
 win/inspircd_win32wrapper.h |  7 +++++++
 4 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/include/socketengine.h b/include/socketengine.h
index 895457b89..f30289913 100644
--- a/include/socketengine.h
+++ b/include/socketengine.h
@@ -29,6 +29,14 @@
 #include "socket.h"
 #include "base.h"
 
+#ifndef _WIN32
+#include <sys/uio.h>
+#endif
+
+#ifndef IOV_MAX
+#define IOV_MAX 1024
+#endif
+
 /** Types of event an EventHandler may receive.
  * EVENT_READ is a readable file descriptor,
  * and EVENT_WRITE is a writeable file descriptor.
@@ -306,6 +314,12 @@ class CoreExport SocketEngine
 	}
 
 public:
+#ifndef _WIN32
+	typedef iovec IOVector;
+#else
+	typedef WindowsIOVec IOVector;
+#endif
+
 	/** Constructor.
 	 * The constructor transparently initializes
 	 * the socket engine which the ircd is using.
@@ -434,6 +448,27 @@ public:
 	 */
 	static int Send(EventHandler* fd, const void *buf, size_t len, int flags);
 
+	/** Abstraction for vector write function writev().
+	 * This function should emulate its namesake system call exactly.
+	 * @param fd EventHandler to send data with
+	 * @param iov Array of IOVectors containing the buffers to send and their lengths in the platform's
+	 * native format.
+	 * @param count Number of elements in iov.
+	 * @return This method should return exactly the same values as the system call it emulates.
+	 */
+	static int WriteV(EventHandler* fd, const IOVector* iov, int count);
+
+#ifdef _WIN32
+	/** Abstraction for vector write function writev() that accepts a POSIX format iovec.
+	 * This function should emulate its namesake system call exactly.
+	 * @param fd EventHandler to send data with
+	 * @param iov Array of iovecs containing the buffers to send and their lengths in POSIX format.
+	 * @param count Number of elements in iov.
+	 * @return This method should return exactly the same values as the system call it emulates.
+	 */
+	static int WriteV(EventHandler* fd, const iovec* iov, int count);
+#endif
+
 	/** Abstraction for BSD sockets recv(2).
 	 * This function should emulate its namesake system call exactly.
 	 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
diff --git a/src/inspsocket.cpp b/src/inspsocket.cpp
index ee5287e5f..db005b1a1 100644
--- a/src/inspsocket.cpp
+++ b/src/inspsocket.cpp
@@ -25,14 +25,6 @@
 #include "inspircd.h"
 #include "iohook.h"
 
-#ifndef DISABLE_WRITEV
-#include <sys/uio.h>
-#endif
-
-#ifndef IOV_MAX
-#define IOV_MAX 1024
-#endif
-
 BufferedSocket::BufferedSocket()
 {
 	Timeout = NULL;
@@ -348,7 +340,7 @@ void StreamSocket::DoWrite()
 					iovecs[i].iov_len = sendq[i].length();
 					rv_max += sendq[i].length();
 				}
-				rv = writev(fd, iovecs, bufcount);
+				rv = SocketEngine::WriteV(this, iovecs, bufcount);
 			}
 
 			if (rv == (int)sendq_len)
diff --git a/src/socketengine.cpp b/src/socketengine.cpp
index 1c91ccdea..eadfc73d3 100644
--- a/src/socketengine.cpp
+++ b/src/socketengine.cpp
@@ -224,6 +224,33 @@ int SocketEngine::SendTo(EventHandler* fd, const void *buf, size_t len, int flag
 	return nbSent;
 }
 
+int SocketEngine::WriteV(EventHandler* fd, const IOVector* iovec, int count)
+{
+	int sent = writev(fd->GetFd(), iovec, count);
+	if (sent > 0)
+		stats.Update(0, sent);
+	return sent;
+}
+
+#ifdef _WIN32
+int SocketEngine::WriteV(EventHandler* fd, const iovec* iovec, int count)
+{
+	// On Windows the fields in iovec are not in the order required by the Winsock API; IOVector has
+	// the fields in the correct order.
+	// Create temporary IOVectors from the iovecs and pass them to the WriteV() method that accepts the
+	// platform's native struct.
+	IOVector wiovec[128];
+	count = std::min(count, static_cast<int>(sizeof(wiovec) / sizeof(IOVector)));
+
+	for (int i = 0; i < count; i++)
+	{
+		wiovec[i].iov_len = iovec[i].iov_len;
+		wiovec[i].iov_base = reinterpret_cast<char*>(iovec[i].iov_base);
+	}
+	return WriteV(fd, wiovec, count);
+}
+#endif
+
 int SocketEngine::Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen)
 {
 	int ret = connect(fd->GetFd(), serv_addr, addrlen);
diff --git a/win/inspircd_win32wrapper.h b/win/inspircd_win32wrapper.h
index 361724a2f..013d4d154 100644
--- a/win/inspircd_win32wrapper.h
+++ b/win/inspircd_win32wrapper.h
@@ -219,6 +219,13 @@ private:
 // Same value as EXIT_STATUS_FORK (EXIT_STATUS_FORK is unused on Windows)
 #define EXIT_STATUS_SERVICE 4
 
+// POSIX iovec
+struct iovec
+{
+	void* iov_base; // Starting address
+	size_t iov_len; // Number of bytes to transfer
+};
+
 // Windows WSABUF with POSIX field names
 struct WindowsIOVec
 {
-- 
2.39.2