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;
}
}
}
static int
readPacket (BrailleDisplay *brl, InputPacket *packet) {
typedef enum {
IPG_PRODUCT,
IPG_KEY,
IPG_DEFAULT
} InputPacketGroup;
InputPacketGroup group = IPG_DEFAULT;
int length = 1;
int offset = 0;
while (1) {
unsigned char byte;
{
int started = offset > 0;
if (!readByte(&byte, started)) {
if (started) logPartialPacket(packet->bytes, offset);
return 0;
}
}
gotByte:
if (!offset) {
switch (byte) {
case IPT_KEY_NAVIGATION:
case IPT_KEY_SIMULATION:
case IPT_KEY_ROUTING:
group = IPG_KEY;
length = 4;
break;
default:
if (byte == productPrefix[0]) {
group = IPG_PRODUCT;
length = sizeof(packet->product) - 1;
} else {
logIgnoredByte(byte);
continue;
}
break;
}
} else {
int unexpected = 0;
switch (group) {
case IPG_PRODUCT:
if (offset < productPrefixLength) {
if (byte != productPrefix[offset]) unexpected = 1;
} else if (byte == '@') {
length = offset + 1;
}
break;
case IPG_KEY:
if (offset == 1) {
if (byte != packet->bytes[0]) unexpected = 1;
} else if (offset == 3) {
if (byte != 0X19) unexpected = 1;
}
break;
default:
break;
}
if (unexpected) {
logShortPacket(packet->bytes, offset);
group = IPG_DEFAULT;
offset = 0;
length = 1;
goto gotByte;
}
}
packet->bytes[offset++] = byte;
if (offset == length) {
if (group == IPG_PRODUCT) {
packet->bytes[length] = 0;
}
logInputPacket(packet->bytes, 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);
}
}
}
