static int
readPacket (unsigned char *packet, int size) {
int offset = 0;
int length = 0;
while (1) {
unsigned char byte;
if (!gioReadByte(gioEndpoint, &byte, (offset > 0))) {
if (offset > 0) logPartialPacket(packet, offset);
return 0;
}
if (offset < size) {
if (offset == 0) {
switch (byte) {
case BN_RSP_DISPLAY:
length = 1;
break;
case BN_RSP_CHARACTER:
case BN_RSP_SPACE:
case BN_RSP_BACKSPACE:
case BN_RSP_ENTER:
case BN_RSP_THUMB:
case BN_RSP_ROUTE:
length = 2;
break;
case BN_RSP_DESCRIBE:
length = 3;
break;
default:
logUnknownPacket(byte);
offset = 0;
length = 0;
continue;
}
}
packet[offset] = byte;
} else {
if (offset == size) logTruncatedPacket(packet, offset);
logDiscardedByte(byte);
}
if (++offset == length) {
if (offset > size) {
offset = 0;
length = 0;
continue;
}
logInputPacket(packet, offset);
return length;
}
}
}
static int
readPacket (BrailleDisplay *brl, unsigned char *packet, int length) {
size_t offset = 0;
int size = -1;
while (offset < length) {
const unsigned char *byte = &packet[offset];
if (!serialReadChunk(serialDevice, packet, &offset, 1, 0, 1000)) {
if (errno == EAGAIN) {
if (!offset) return 0;
logPartialPacket(packet, offset);
}
return -1;
}
if (offset == 1) {
if (*byte) {
logDiscardedByte(packet[0]);
offset = 0;
}
} else {
if (offset == 2) {
switch (*byte) {
default:
size = 1;
break;
}
size += offset;
}
if (offset == size) {
logInputPacket(packet, offset);
return offset;
}
}
}
logTruncatedPacket(packet, offset);
return 0;
}
static size_t
readPacket (BrailleDisplay *brl, void *packet, size_t size) {
unsigned char *bytes = packet;
size_t offset = 0;
size_t length = 0;
while (1) {
unsigned char byte;
{
int started = offset > 0;
if (!gioReadByte(brl->gioEndpoint, &byte, started)) {
if (started) logPartialPacket(bytes, offset);
return 0;
}
}
gotByte:
if (offset == 0) {
switch (byte) {
case 0XFC:
length = 2;
break;
case 0XFD:
length = 2;
break;
default:
logIgnoredByte(byte);
continue;
}
} else {
int unexpected = 0;
if (offset == 1) {
if (bytes[0] == 0XFD) {
switch (byte) {
case 0X2F:
length = 3;
break;
default:
unexpected = 1;
break;
}
}
}
if (unexpected) {
logShortPacket(bytes, offset);
offset = 0;
length = 0;
goto gotByte;
}
}
if (offset < size) {
bytes[offset] = byte;
if (offset == (length - 1)) {
logInputPacket(bytes, length);
return length;
}
} else {
if (offset == size) logTruncatedPacket(bytes, offset);
logDiscardedByte(byte);
}
offset += 1;
}
}
static int
readSerialPacket (BrailleDisplay *brl, unsigned char *packet, int size) {
int started = 0;
int escape = 0;
int offset = 0;
int length = 0;
while (1) {
unsigned char byte;
if (!gioReadByte(brl->gioEndpoint, &byte, (started || escape))) {
if (started) logPartialPacket(packet, offset);
return 0;
}
if (byte == ESC) {
if ((escape = !escape)) continue;
} else if (escape) {
escape = 0;
if (offset > 0) {
logShortPacket(packet, offset);
offset = 0;
length = 0;
} else {
started = 1;
}
}
if (!started) {
logIgnoredByte(byte);
continue;
}
if (offset < size) {
if (offset == 0) {
switch (byte) {
case 0X43:
case 0X47:
length = 2;
break;
case 0X4C:
length = 3;
break;
case 0X46:
case 0X48:
length = 5;
break;
case 0X4B:
length = 9;
break;
case 0X53:
length = 10;
break;
default:
logUnknownPacket(byte);
started = 0;
continue;
}
}
packet[offset] = byte;
} else {
if (offset == size) logTruncatedPacket(packet, offset);
logDiscardedByte(byte);
}
if (++offset == length) {
if (offset > size) {
offset = 0;
length = 0;
started = 0;
continue;
}
logInputPacket(packet, offset);
return length;
}
}
}
size_t
readBraillePacket (
BrailleDisplay *brl,
GioEndpoint *endpoint,
void *packet, size_t size,
BraillePacketVerifier *verifyPacket, void *data
) {
unsigned char *bytes = packet;
size_t count = 0;
size_t length = 1;
if (!endpoint) endpoint = brl->gioEndpoint;
while (1) {
unsigned char byte;
{
int started = count > 0;
if (!gioReadByte(endpoint, &byte, started)) {
if (started) logPartialPacket(bytes, count);
return 0;
}
}
gotByte:
if (count < size) {
bytes[count++] = byte;
{
BraillePacketVerifierResult result = verifyPacket(brl, bytes, count, &length, data);
switch (result) {
case BRL_PVR_EXCLUDE:
count -= 1;
case BRL_PVR_INCLUDE:
break;
default:
logMessage(LOG_WARNING, "unimplemented braille packet verifier result: %u", result);
case BRL_PVR_INVALID:
if (--count) {
logShortPacket(bytes, count);
count = 0;
length = 1;
goto gotByte;
}
logIgnoredByte(byte);
continue;
}
}
if (count == length) {
logInputPacket(bytes, length);
return length;
}
} else {
if (count++ == size) logTruncatedPacket(bytes, size);
logDiscardedByte(byte);
}
}
}
