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Diffstat (limited to 'NetEx/NetGram.cpp')
-rw-r--r-- | NetEx/NetGram.cpp | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/NetEx/NetGram.cpp b/NetEx/NetGram.cpp new file mode 100644 index 0000000..3bb8f2a --- /dev/null +++ b/NetEx/NetGram.cpp @@ -0,0 +1,135 @@ +/* Starshatter OpenSource Distribution + Copyright (c) 1997-2004, Destroyer Studios LLC. + All Rights Reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + * Neither the name "Destroyer Studios" nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. + + SUBSYSTEM: NetEx.lib + FILE: NetGram.cpp + AUTHOR: John DiCamillo + + + OVERVIEW + ======== + Generic Network Packet (Datagram) Implementation +*/ + + +#include "MemDebug.h" +#include "NetGram.h" +#include "NetLayer.h" + +// +-------------------------------------------------------------------+ + +static DWORD net_gram_sequence = 1; + +// +-------------------------------------------------------------------+ + +/** + * NetGram constructor for ACK packets + */ +NetGram::NetGram() + : retries(0), packet_id(0), send_time(0) +{ } + +/** + * NetGram constructor for receiving packets from remote hosts + */ +NetGram::NetGram(const NetAddr& src, Text msg) + : addr(src), retries(0), send_time(0) +{ + body = msg; + + if (body.length() >= NET_GRAM_HEADER_SIZE) { + BYTE* data = (BYTE*) body.data(); + + packet_id = (((DWORD) data[0]) << 24) + + (((DWORD) data[1]) << 16) + + (((DWORD) data[2]) << 8) + + ((DWORD) data[3]); + } +} + +/** + * NetGram constructor for composing packets to send to remote hosts + */ +NetGram::NetGram(const NetAddr& dst, Text user_data, int r) + : addr(dst), retries(r) +{ + send_time = NetLayer::GetTime(); + packet_id = net_gram_sequence++; + + if (retries) + packet_id |= NET_GRAM_RELIABLE; + + static BYTE buf[NET_GRAM_MAX_SIZE]; + buf[0] = (BYTE) (packet_id >> 24) & 0xff; + buf[1] = (BYTE) (packet_id >> 16) & 0xff; + buf[2] = (BYTE) (packet_id >> 8) & 0xff; + buf[3] = (BYTE) (packet_id) & 0xff; + + int len = user_data.length(); + if (len >= NET_GRAM_MAX_SIZE - NET_GRAM_HEADER_SIZE) + len = NET_GRAM_MAX_SIZE - NET_GRAM_HEADER_SIZE - 1; + + CopyMemory(buf+NET_GRAM_HEADER_SIZE, user_data.data(), len); + + body = Text((char*) buf, len+NET_GRAM_HEADER_SIZE); +} + +// +--------------------------------------------------------------------+ + +void +NetGram::Retry() +{ + if (retries > 0) { + retries--; + send_time = NetLayer::GetTime(); + } +} + +// +--------------------------------------------------------------------+ + +NetGram +NetGram::Ack() +{ + NetGram ack; + + ack.packet_id = packet_id | NET_GRAM_ACK; + ack.send_time = NetLayer::GetTime(); + + static BYTE buf[NET_GRAM_HEADER_SIZE]; + buf[0] = (BYTE) (ack.packet_id >> 24) & 0xff; + buf[1] = (BYTE) (ack.packet_id >> 16) & 0xff; + buf[2] = (BYTE) (ack.packet_id >> 8) & 0xff; + buf[3] = (BYTE) (ack.packet_id) & 0xff; + + ack.body = Text((char*) buf, NET_GRAM_HEADER_SIZE); + + return ack; +} + + + |