tor-android/external/badvpn_dns/flow/PacketBuffer.c

132 lines
4.4 KiB
C

/**
* @file PacketBuffer.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the author 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 AUTHOR 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.
*/
#include <stdlib.h>
#include <misc/debug.h>
#include <misc/balloc.h>
#include <flow/PacketBuffer.h>
static void input_handler_done (PacketBuffer *buf, int in_len);
static void output_handler_done (PacketBuffer *buf);
void input_handler_done (PacketBuffer *buf, int in_len)
{
ASSERT(in_len >= 0)
ASSERT(in_len <= buf->input_mtu)
DebugObject_Access(&buf->d_obj);
// remember if buffer is empty
int was_empty = (buf->buf.output_avail < 0);
// submit packet to buffer
ChunkBuffer2_SubmitPacket(&buf->buf, in_len);
// if there is space, schedule receive
if (buf->buf.input_avail >= buf->input_mtu) {
PacketRecvInterface_Receiver_Recv(buf->input, buf->buf.input_dest);
}
// if buffer was empty, schedule send
if (was_empty) {
PacketPassInterface_Sender_Send(buf->output, buf->buf.output_dest, buf->buf.output_avail);
}
}
void output_handler_done (PacketBuffer *buf)
{
DebugObject_Access(&buf->d_obj);
// remember if buffer is full
int was_full = (buf->buf.input_avail < buf->input_mtu);
// remove packet from buffer
ChunkBuffer2_ConsumePacket(&buf->buf);
// if buffer was full and there is space, schedule receive
if (was_full && buf->buf.input_avail >= buf->input_mtu) {
PacketRecvInterface_Receiver_Recv(buf->input, buf->buf.input_dest);
}
// if there is more data, schedule send
if (buf->buf.output_avail >= 0) {
PacketPassInterface_Sender_Send(buf->output, buf->buf.output_dest, buf->buf.output_avail);
}
}
int PacketBuffer_Init (PacketBuffer *buf, PacketRecvInterface *input, PacketPassInterface *output, int num_packets, BPendingGroup *pg)
{
ASSERT(PacketPassInterface_GetMTU(output) >= PacketRecvInterface_GetMTU(input))
ASSERT(num_packets > 0)
// init arguments
buf->input = input;
buf->output = output;
// init input
PacketRecvInterface_Receiver_Init(buf->input, (PacketRecvInterface_handler_done)input_handler_done, buf);
// set input MTU
buf->input_mtu = PacketRecvInterface_GetMTU(buf->input);
// init output
PacketPassInterface_Sender_Init(buf->output, (PacketPassInterface_handler_done)output_handler_done, buf);
// allocate buffer
int num_blocks = ChunkBuffer2_calc_blocks(buf->input_mtu, num_packets);
if (num_blocks < 0) {
goto fail0;
}
if (!(buf->buf_data = (struct ChunkBuffer2_block *)BAllocArray(num_blocks, sizeof(buf->buf_data[0])))) {
goto fail0;
}
// init buffer
ChunkBuffer2_Init(&buf->buf, buf->buf_data, num_blocks, buf->input_mtu);
// schedule receive
PacketRecvInterface_Receiver_Recv(buf->input, buf->buf.input_dest);
DebugObject_Init(&buf->d_obj);
return 1;
fail0:
return 0;
}
void PacketBuffer_Free (PacketBuffer *buf)
{
DebugObject_Free(&buf->d_obj);
// free buffer
BFree(buf->buf_data);
}