FlapJackApps/libdivecomputer
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Use a temporary buffer to download the data.

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This commit is contained in:
Jef Driesen 2008-06-15 14:10:28 +00:00
parent 2d88237949
commit 330e6a07ad
1 changed files with 28 additions and 21 deletions
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49
src/uwatec_aladin.c
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@ -10,6 +10,10 @@
message ("%s:%d: %s\n", __FILE__, __LINE__, expr); \
}
#define EXITCODE(rc) \
( \
rc == -1 ? UWATEC_ERROR_IO : UWATEC_ERROR_TIMEOUT \
)
struct aladin {
struct serial *port;
@ -150,44 +154,47 @@ uwatec_aladin_read (aladin *device, unsigned char data[], unsigned int size)
if (device == NULL)
return UWATEC_ERROR;
if (size < UWATEC_ALADIN_MEMORY_SIZE)
return UWATEC_ERROR_MEMORY;
unsigned char answer[UWATEC_ALADIN_MEMORY_SIZE + 2] = {0};
// Receive the header of the package.
for (unsigned int i = 0; i < 4;) {
int rc = serial_read (device->port, data + i, 1);
int rc = serial_read (device->port, answer + i, 1);
if (rc != 1) {
WARNING ("Cannot read from device.");
return UWATEC_ERROR;
WARNING ("Failed to receive the answer.");
return EXITCODE (rc);
}
if (data[i] == (i < 3 ? 0x55 : 0x00)) {
if (answer[i] == (i < 3 ? 0x55 : 0x00)) {
i++; // Continue.
} else {
i = 0; // Reset.
}
}
// Receive the contents of the package.
int rc = serial_read (device->port, data + 4, UWATEC_ALADIN_MEMORY_SIZE - 4);
if (rc != UWATEC_ALADIN_MEMORY_SIZE - 4) {
// Receive the remaining part of the package.
int rc = serial_read (device->port, answer + 4, sizeof (answer) - 4);
if (rc != sizeof (answer) - 4) {
WARNING ("Unexpected EOF in answer.");
return UWATEC_ERROR;
return EXITCODE (rc);
}
// Reverse the bit order.
uwatec_aladin_reverse_bits (data, UWATEC_ALADIN_MEMORY_SIZE);
uwatec_aladin_reverse_bits (answer, sizeof (answer));
// Calculate the checksum.
unsigned short ccrc = uwatec_aladin_checksum (data, UWATEC_ALADIN_MEMORY_SIZE);
// Receive (and verify) the checksum of the package.
unsigned char checksum[2] = {0};
rc = serial_read (device->port, checksum, sizeof (checksum));
uwatec_aladin_reverse_bits (checksum, sizeof (checksum));
unsigned short crc = (checksum[1] << 8) + checksum[0];
if (rc != sizeof (checksum) || ccrc != crc) {
// Verify the checksum of the package.
unsigned short crc =
answer[UWATEC_ALADIN_MEMORY_SIZE + 0] +
(answer[UWATEC_ALADIN_MEMORY_SIZE + 1] << 8);
unsigned short ccrc = uwatec_aladin_checksum (answer, UWATEC_ALADIN_MEMORY_SIZE);
if (ccrc != crc) {
WARNING ("Unexpected answer CRC.");
return UWATEC_ERROR;
return UWATEC_ERROR_PROTOCOL;
}
if (size >= UWATEC_ALADIN_MEMORY_SIZE) {
memcpy (data, answer, UWATEC_ALADIN_MEMORY_SIZE);
} else {
WARNING ("Insufficient buffer space available.");
return UWATEC_ERROR_MEMORY;
}
return UWATEC_SUCCESS;