1 files changed, 216 insertions, 0 deletions
diff --git a/network/core/packet.c b/network/core/packet.c
new file mode 100644
index 000000000..957bd2ad6
--- /dev/null
+++ b/network/core/packet.c
@@ -0,0 +1,216 @@
+/* $Id$ */
+
+#ifdef ENABLE_NETWORK
+
+#include "../../stdafx.h"
+#include "../../macros.h"
+#include "../../string.h"
+
+#include "os_abstraction.h"
+#include "config.h"
+#include "packet.h"
+
+/**
+ * @file packet.h Basic functions to create, fill and read packets.
+ */
+
+
+/* Do not want to include functions.h and all required headers */
+extern void NORETURN CDECL error(const char *str, ...);
+
+
+/**
+ * Create a packet for sending
+ * @param type the of packet
+ * @return the newly created packet
+ */
+Packet *NetworkSend_Init(PacketType type)
+{
+	Packet *packet = malloc(sizeof(Packet));
+	/* An error is inplace here, because it simply means we ran out of memory. */
+	if (packet == NULL) error("Failed to allocate Packet");
+
+	/* Skip the size so we can write that in before sending the packet */
+	packet->size = sizeof(packet->size);
+	packet->buffer[packet->size++] = type;
+	packet->pos = 0;
+
+	return packet;
+}
+
+/**
+ * Writes the packet size from the raw packet from packet->size
+ * @param packet the packet to write the size of
+ */
+void NetworkSend_FillPacketSize(Packet *packet)
+{
+	packet->buffer[0] = GB(packet->size, 0, 8);
+	packet->buffer[1] = GB(packet->size, 8, 8);
+}
+
+/**
+ * The next couple of functions make sure we can send
+ *  uint8, uint16, uint32 and uint64 endian-safe
+ *  over the network. The least significant bytes are
+ *  sent first.
+ *
+ *  So 0x01234567 would be sent as 67 45 23 01.
+ */
+
+void NetworkSend_uint8(Packet *packet, uint8 data)
+{
+	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
+	packet->buffer[packet->size++] = data;
+}
+
+void NetworkSend_uint16(Packet *packet, uint16 data)
+{
+	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
+	packet->buffer[packet->size++] = GB(data, 0, 8);
+	packet->buffer[packet->size++] = GB(data, 8, 8);
+}
+
+void NetworkSend_uint32(Packet *packet, uint32 data)
+{
+	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
+	packet->buffer[packet->size++] = GB(data,  0, 8);
+	packet->buffer[packet->size++] = GB(data,  8, 8);
+	packet->buffer[packet->size++] = GB(data, 16, 8);
+	packet->buffer[packet->size++] = GB(data, 24, 8);
+}
+
+void NetworkSend_uint64(Packet *packet, uint64 data)
+{
+	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
+	packet->buffer[packet->size++] = GB(data,  0, 8);
+	packet->buffer[packet->size++] = GB(data,  8, 8);
+	packet->buffer[packet->size++] = GB(data, 16, 8);
+	packet->buffer[packet->size++] = GB(data, 24, 8);
+	packet->buffer[packet->size++] = GB(data, 32, 8);
+	packet->buffer[packet->size++] = GB(data, 40, 8);
+	packet->buffer[packet->size++] = GB(data, 48, 8);
+	packet->buffer[packet->size++] = GB(data, 56, 8);
+}
+
+/**
+ *  Sends a string over the network. It sends out
+ *  the string + '\0'. No size-byte or something.
+ */
+void NetworkSend_string(Packet *packet, const char* data)
+{
+	assert(data != NULL);
+	assert(packet->size < sizeof(packet->buffer) - strlen(data) - 1);
+	while ((packet->buffer[packet->size++] = *data++) != '\0') {}
+}
+
+
+/**
+ * Receiving commands
+ * Again, the next couple of functions are endian-safe
+ *  see the comment before NetworkSend_uint8 for more info.
+ */
+
+
+extern uint CloseConnection(NetworkClientState *cs);
+
+/** Is it safe to read from the packet, i.e. didn't we run over the buffer ? */
+static inline bool CanReadFromPacket(NetworkClientState *cs, Packet *packet, uint bytes_to_read)
+{
+	/* Don't allow reading from a closed socket */
+	if (HasClientQuit(cs)) return false;
+
+	/* Check if variable is within packet-size */
+	if (packet->pos + bytes_to_read > packet->size) {
+		CloseConnection(cs);
+		return false;
+	}
+
+	return true;
+}
+
+/**
+ * Reads the packet size from the raw packet and stores it in the packet->size
+ * @param packet the packet to read the size of
+ */
+void NetworkRecv_ReadPacketSize(Packet *packet)
+{
+	packet->size  = (uint16)packet->buffer[0];
+	packet->size += (uint16)packet->buffer[1] << 8;
+}
+
+uint8 NetworkRecv_uint8(NetworkClientState *cs, Packet *packet)
+{
+	uint8 n;
+
+	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
+
+	n = packet->buffer[packet->pos++];
+	return n;
+}
+
+uint16 NetworkRecv_uint16(NetworkClientState *cs, Packet *packet)
+{
+	uint16 n;
+
+	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
+
+	n  = (uint16)packet->buffer[packet->pos++];
+	n += (uint16)packet->buffer[packet->pos++] << 8;
+	return n;
+}
+
+uint32 NetworkRecv_uint32(NetworkClientState *cs, Packet *packet)
+{
+	uint32 n;
+
+	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
+
+	n  = (uint32)packet->buffer[packet->pos++];
+	n += (uint32)packet->buffer[packet->pos++] << 8;
+	n += (uint32)packet->buffer[packet->pos++] << 16;
+	n += (uint32)packet->buffer[packet->pos++] << 24;
+	return n;
+}
+
+uint64 NetworkRecv_uint64(NetworkClientState *cs, Packet *packet)
+{
+	uint64 n;
+
+	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
+
+	n  = (uint64)packet->buffer[packet->pos++];
+	n += (uint64)packet->buffer[packet->pos++] << 8;
+	n += (uint64)packet->buffer[packet->pos++] << 16;
+	n += (uint64)packet->buffer[packet->pos++] << 24;
+	n += (uint64)packet->buffer[packet->pos++] << 32;
+	n += (uint64)packet->buffer[packet->pos++] << 40;
+	n += (uint64)packet->buffer[packet->pos++] << 48;
+	n += (uint64)packet->buffer[packet->pos++] << 56;
+	return n;
+}
+
+/** Reads a string till it finds a '\0' in the stream */
+void NetworkRecv_string(NetworkClientState *cs, Packet *p, char *buffer, size_t size)
+{
+	PacketSize pos;
+	char *bufp = buffer;
+
+	/* Don't allow reading from a closed socket */
+	if (HasClientQuit(cs)) return;
+
+	pos = p->pos;
+	while (--size > 0 && pos < p->size && (*buffer++ = p->buffer[pos++]) != '\0') {}
+
+	if (size == 0 || pos == p->size) {
+		*buffer = '\0';
+		/* If size was sooner to zero then the string in the stream
+		 *  skip till the \0, so than packet can be read out correctly for the rest */
+		while (pos < p->size && p->buffer[pos] != '\0') pos++;
+		pos++;
+	}
+	p->pos = pos;
+
+	str_validate(bufp);
+}
+
+#endif /* ENABLE_NETWORK */