From 9c83a8975fe93568d4a3c44bd273e846b18d8e3f Mon Sep 17 00:00:00 2001
From: rubidium <rubidium@openttd.org>
Date: Tue, 30 Nov 2010 13:22:29 +0000
Subject: (svn r21357) -Codechange: make it possible to resize the packet's
 buffer

---
 src/network/core/packet.cpp | 28 +++++++++++++++++++---------
 src/network/core/packet.h   |  7 +++++--
 src/network/core/tcp.cpp    |  5 +++++
 src/network/core/udp.cpp    |  3 +--
 4 files changed, 30 insertions(+), 13 deletions(-)

(limited to 'src/network')

diff --git a/src/network/core/packet.cpp b/src/network/core/packet.cpp
index 5f48ed055..cc098793b 100644
--- a/src/network/core/packet.cpp
+++ b/src/network/core/packet.cpp
@@ -26,10 +26,11 @@ Packet::Packet(NetworkSocketHandler *cs)
 {
 	assert(cs != NULL);
 
-	this->cs   = cs;
-	this->next = NULL;
-	this->pos  = 0; // We start reading from here
-	this->size = 0;
+	this->cs     = cs;
+	this->next   = NULL;
+	this->pos    = 0; // We start reading from here
+	this->size   = 0;
+	this->buffer = MallocT<byte>(SEND_MTU);
 }
 
 /**
@@ -44,9 +45,18 @@ Packet::Packet(PacketType type)
 	/* Skip the size so we can write that in before sending the packet */
 	this->pos                  = 0;
 	this->size                 = sizeof(PacketSize);
+	this->buffer               = MallocT<byte>(SEND_MTU);
 	this->buffer[this->size++] = type;
 }
 
+/**
+ * Free the buffer of this packet.
+ */
+Packet::~Packet()
+{
+	free(this->buffer);
+}
+
 /**
  * Writes the packet size from the raw packet from packet->size
  */
@@ -79,20 +89,20 @@ void Packet::Send_bool(bool data)
 
 void Packet::Send_uint8(uint8 data)
 {
-	assert(this->size < sizeof(this->buffer) - sizeof(data));
+	assert(this->size < SEND_MTU - sizeof(data));
 	this->buffer[this->size++] = data;
 }
 
 void Packet::Send_uint16(uint16 data)
 {
-	assert(this->size < sizeof(this->buffer) - sizeof(data));
+	assert(this->size < SEND_MTU - sizeof(data));
 	this->buffer[this->size++] = GB(data, 0, 8);
 	this->buffer[this->size++] = GB(data, 8, 8);
 }
 
 void Packet::Send_uint32(uint32 data)
 {
-	assert(this->size < sizeof(this->buffer) - sizeof(data));
+	assert(this->size < SEND_MTU - sizeof(data));
 	this->buffer[this->size++] = GB(data,  0, 8);
 	this->buffer[this->size++] = GB(data,  8, 8);
 	this->buffer[this->size++] = GB(data, 16, 8);
@@ -101,7 +111,7 @@ void Packet::Send_uint32(uint32 data)
 
 void Packet::Send_uint64(uint64 data)
 {
-	assert(this->size < sizeof(this->buffer) - sizeof(data));
+	assert(this->size < SEND_MTU - sizeof(data));
 	this->buffer[this->size++] = GB(data,  0, 8);
 	this->buffer[this->size++] = GB(data,  8, 8);
 	this->buffer[this->size++] = GB(data, 16, 8);
@@ -121,7 +131,7 @@ void Packet::Send_string(const char *data)
 {
 	assert(data != NULL);
 	/* The <= *is* valid due to the fact that we are comparing sizes and not the index. */
-	assert(this->size + strlen(data) + 1 <= sizeof(this->buffer));
+	assert(this->size + strlen(data) + 1 <= SEND_MTU);
 	while ((this->buffer[this->size++] = *data++) != '\0') {}
 }
 
diff --git a/src/network/core/packet.h b/src/network/core/packet.h
index 38cd528ef..50a3f5cde 100644
--- a/src/network/core/packet.h
+++ b/src/network/core/packet.h
@@ -42,14 +42,17 @@ struct Packet {
 	PacketSize size;
 	/** The current read/write position in the packet */
 	PacketSize pos;
-	/** The buffer of this packet */
-	byte buffer[SEND_MTU];
+	/** The buffer of this packet, of basically variable length up to SEND_MTU. */
+	byte *buffer;
+
 private:
+	/** Socket we're associated with. */
 	NetworkSocketHandler *cs;
 
 public:
 	Packet(NetworkSocketHandler *cs);
 	Packet(PacketType type);
+	~Packet();
 
 	/* Sending/writing of packets */
 	void PrepareToSend();
diff --git a/src/network/core/tcp.cpp b/src/network/core/tcp.cpp
index 3f59efba9..c35b029a2 100644
--- a/src/network/core/tcp.cpp
+++ b/src/network/core/tcp.cpp
@@ -63,6 +63,11 @@ void NetworkTCPSocketHandler::Send_Packet(Packet *packet)
 
 	packet->PrepareToSend();
 
+	/* Reallocate the packet as in 99+% of the times we send at most 25 bytes and
+	 * keeping the other 1400+ bytes wastes memory, especially when someone tries
+	 * to do a denial of service attack! */
+	packet->buffer = ReallocT(packet->buffer, packet->size);
+
 	/* Locate last packet buffered for the client */
 	p = this->packet_queue;
 	if (p == NULL) {
diff --git a/src/network/core/udp.cpp b/src/network/core/udp.cpp
index 1163ee3bb..b153cdf88 100644
--- a/src/network/core/udp.cpp
+++ b/src/network/core/udp.cpp
@@ -121,12 +121,11 @@ void NetworkUDPSocketHandler::ReceivePackets()
 		memset(&client_addr, 0, sizeof(client_addr));
 
 		Packet p(this);
-		int packet_len = sizeof(p.buffer);
 		socklen_t client_len = sizeof(client_addr);
 
 		/* Try to receive anything */
 		SetNonBlocking(s->second); // Some OSes seem to lose the non-blocking status of the socket
-		int nbytes = recvfrom(s->second, (char*)p.buffer, packet_len, 0, (struct sockaddr *)&client_addr, &client_len);
+		int nbytes = recvfrom(s->second, (char*)p.buffer, SEND_MTU, 0, (struct sockaddr *)&client_addr, &client_len);
 
 		/* We got some bytes for the base header of the packet. */
 		if (nbytes > 2) {
-- 
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