static void parse_cochran_header(const char *filename,
const unsigned char *decode, unsigned mod,
const unsigned char *in, unsigned size)
{
char *buf = malloc(size);
/* Do the "null decode" using a one-byte decode array of '\0' */
partial_decode(0 , 0x0b14, "", 0, 1, in, size, buf);
/*
* The header scrambling is different form the dive
* scrambling. Oh yay!
*/
partial_decode(0x010e, 0x0b14, decode, 0, mod, in, size, buf);
partial_decode(0x0b14, 0x1b14, decode, 0, mod, in, size, buf);
partial_decode(0x1b14, 0x2b14, decode, 0, mod, in, size, buf);
partial_decode(0x2b14, 0x3b14, decode, 0, mod, in, size, buf);
partial_decode(0x3b14, 0x5414, decode, 0, mod, in, size, buf);
partial_decode(0x5414, size, decode, 0, mod, in, size, buf);
printf("\n%s, header\n\n", filename);
cochran_debug_write(filename, buf, size);
free(buf);
}
static void cochran_parse_header(const unsigned char *decode, unsigned mod,
const unsigned char *in, unsigned size)
{
unsigned char *buf = malloc(size);
/* Do the "null decode" using a one-byte decode array of '\0' */
/* Copies in plaintext, will be overwritten later */
partial_decode(0, 0x0102, (const unsigned char *)"", 0, 1, in, size, buf);
/*
* The header scrambling is different form the dive
* scrambling. Oh yay!
*/
partial_decode(0x0102, 0x010e, decode, 0, mod, in, size, buf);
partial_decode(0x010e, 0x0b14, decode, 0, mod, in, size, buf);
partial_decode(0x0b14, 0x1b14, decode, 0, mod, in, size, buf);
partial_decode(0x1b14, 0x2b14, decode, 0, mod, in, size, buf);
partial_decode(0x2b14, 0x3b14, decode, 0, mod, in, size, buf);
partial_decode(0x3b14, 0x5414, decode, 0, mod, in, size, buf);
partial_decode(0x5414, size, decode, 0, mod, in, size, buf);
// Detect log type
switch (buf[0x133]) {
case '2': // Cochran Commander, version II log format
config.logbook_size = 256;
if (buf[0x132] == 0x10) {
config.type = TYPE_GEMINI;
config.sample_size = 2; // Gemini with tank PSI samples
} else {
config.type = TYPE_COMMANDER;
config.sample_size = 2; // Commander
}
break;
case '3': // Cochran EMC, version III log format
config.type = TYPE_EMC;
config.logbook_size = 512;
config.sample_size = 3;
break;
default:
printf ("Unknown log format v%c\n", buf[0x137]);
free(buf);
exit(1);
break;
}
#ifdef COCHRAN_DEBUG
puts("Header\n======\n\n");
cochran_debug_write(buf, size);
#endif
free(buf);
}
/*
* The decode buffer size can be figured out by simply trying our the
* decode: we expect that the scrambled contents are largely random, and
* thus tend to have half the bits set. Summing over the bytes is going
* to give an average of 0x80 per byte.
*
* The decoded array is mostly full of zeroes, so the sum is lower.
*
* Works for me.
*/
static int figure_out_modulus(const unsigned char *decode, const unsigned char *dive, unsigned int size)
{
int mod, best = -1;
unsigned int min = ~0u;
if (size < 0x1000)
return best;
for (mod = 50; mod < 300; mod++) {
unsigned int sum;
sum = partial_decode(0, 0x0fff, decode, 1, mod, dive, size, NULL);
if (sum < min) {
min = sum;
best = mod;
}
}
return best;
}
static void parse_cochran_dive(const char *filename, int dive,
const unsigned char *decode, unsigned mod,
const unsigned char *in, unsigned size)
{
char *buf = malloc(size);
#ifdef DON
unsigned int offset = 0x4a14;
#else
unsigned int offset = 0x4b14;
#endif
/*
* The scrambling has odd boundaries. I think the boundaries
* match some data structure size, but I don't know. They were
* discovered the same way we dynamically discover the decode
* size: automatically looking for least random output.
*
* The boundaries are also this confused "off-by-one" thing,
* the same way the file size is off by one. It's as if the
* cochran software forgot to write one byte at the beginning.
*/
partial_decode(0 , 0x0fff, decode, 1, mod, in, size, buf);
partial_decode(0x0fff, 0x1fff, decode, 0, mod, in, size, buf);
partial_decode(0x1fff, 0x2fff, decode, 0, mod, in, size, buf);
partial_decode(0x2fff, 0x48ff, decode, 0, mod, in, size, buf);
/*
* This is not all the descrambling you need - the above are just
* what appears to be the fixed-size blocks. The rest is also
* scrambled, but there seems to be size differences in the data,
* so this just descrambles part of it:
*/
partial_decode(0x48ff, offset, decode, 0, mod, in, size, buf);
partial_decode(offset, size, decode, 0, mod, in, size, buf);
printf("\n%s, dive %d\n\n", filename, dive);
cochran_debug_write(filename, buf, size);
cochran_profile_write(buf + offset, size - offset);
free(buf);
}
static void cochran_parse_dive(const unsigned char *decode, unsigned mod,
const unsigned char *in, unsigned size,
struct dive_table *table)
{
unsigned char *buf = malloc(size);
struct dive *dive;
struct divecomputer *dc;
struct tm tm = {0};
uint32_t csum[5];
double max_depth, avg_depth, min_temp;
unsigned int duration = 0, corrupt_dive = 0;
/*
* The scrambling has odd boundaries. I think the boundaries
* match some data structure size, but I don't know. They were
* discovered the same way we dynamically discover the decode
* size: automatically looking for least random output.
*
* The boundaries are also this confused "off-by-one" thing,
* the same way the file size is off by one. It's as if the
* cochran software forgot to write one byte at the beginning.
*/
partial_decode(0, 0x0fff, decode, 1, mod, in, size, buf);
partial_decode(0x0fff, 0x1fff, decode, 0, mod, in, size, buf);
partial_decode(0x1fff, 0x2fff, decode, 0, mod, in, size, buf);
partial_decode(0x2fff, 0x48ff, decode, 0, mod, in, size, buf);
/*
* This is not all the descrambling you need - the above are just
* what appears to be the fixed-size blocks. The rest is also
* scrambled, but there seems to be size differences in the data,
* so this just descrambles part of it:
*/
if (size < 0x4914 + config.logbook_size) {
// Analyst calls this a "Corrupt Beginning Summary"
free(buf);
return;
}
// Decode log entry (512 bytes + random prefix)
partial_decode(0x48ff, 0x4914 + config.logbook_size, decode,
0, mod, in, size, buf);
unsigned int sample_size = size - 0x4914 - config.logbook_size;
int g;
unsigned int sample_pre_offset = 0, sample_end_offset = 0;
// Decode sample data
partial_decode(0x4914 + config.logbook_size, size, decode,
0, mod, in, size, buf);
#ifdef COCHRAN_DEBUG
// Display pre-logbook data
puts("\nPre Logbook Data\n");
cochran_debug_write(buf, 0x4914);
// Display log book
puts("\nLogbook Data\n");
cochran_debug_write(buf + 0x4914, config.logbook_size + 0x400);
// Display sample data
puts("\nSample Data\n");
#endif
dive = alloc_dive();
dc = &dive->dc;
unsigned char *log = (buf + 0x4914);
switch (config.type) {
case TYPE_GEMINI:
case TYPE_COMMANDER:
if (config.type == TYPE_GEMINI) {
dc->model = "Gemini";
dc->deviceid = buf[0x18c] * 256 + buf[0x18d]; // serial no
fill_default_cylinder(&dive->cylinder[0]);
dive->cylinder[0].gasmix.o2.permille = (log[CMD_O2_PERCENT] / 256
+ log[CMD_O2_PERCENT + 1]) * 10;
dive->cylinder[0].gasmix.he.permille = 0;
} else {
dc->model = "Commander";
dc->deviceid = array_uint32_le(buf + 0x31e); // serial no
for (g = 0; g < 2; g++) {
fill_default_cylinder(&dive->cylinder[g]);
dive->cylinder[g].gasmix.o2.permille = (log[CMD_O2_PERCENT + g * 2] / 256
+ log[CMD_O2_PERCENT + g * 2 + 1]) * 10;
dive->cylinder[g].gasmix.he.permille = 0;
}
}
tm.tm_year = log[CMD_YEAR];
tm.tm_mon = log[CMD_MON] - 1;
tm.tm_mday = log[CMD_DAY];
tm.tm_hour = log[CMD_HOUR];
tm.tm_min = log[CMD_MIN];
tm.tm_sec = log[CMD_SEC];
tm.tm_isdst = -1;
dive->when = dc->when = utc_mktime(&tm);
dive->number = log[CMD_NUMBER] + log[CMD_NUMBER + 1] * 256 + 1;
dc->duration.seconds = (log[CMD_BT] + log[CMD_BT + 1] * 256) * 60;
dc->surfacetime.seconds = (log[CMD_SIT] + log[CMD_SIT + 1] * 256) * 60;
dc->maxdepth.mm = lrint((log[CMD_MAX_DEPTH] +
log[CMD_MAX_DEPTH + 1] * 256) / 4 * FEET * 1000);
dc->meandepth.mm = lrint((log[CMD_AVG_DEPTH] +
log[CMD_AVG_DEPTH + 1] * 256) / 4 * FEET * 1000);
dc->watertemp.mkelvin = C_to_mkelvin((log[CMD_MIN_TEMP] / 32) - 1.8);
dc->surface_pressure.mbar = lrint(ATM / BAR * pow(1 - 0.0000225577
* (double) log[CMD_ALTITUDE] * 250 * FEET, 5.25588) * 1000);
dc->salinity = 10000 + 150 * log[CMD_WATER_CONDUCTIVITY];
SHA1(log + CMD_NUMBER, 2, (unsigned char *)csum);
dc->diveid = csum[0];
if (log[CMD_MAX_DEPTH] == 0xff && log[CMD_MAX_DEPTH + 1] == 0xff)
corrupt_dive = 1;
sample_pre_offset = array_uint32_le(log + CMD_PREDIVE_OFFSET);
sample_end_offset = array_uint32_le(log + CMD_END_OFFSET);
break;
case TYPE_EMC:
dc->model = "EMC";
dc->deviceid = array_uint32_le(buf + 0x31e); // serial no
for (g = 0; g < 4; g++) {
fill_default_cylinder(&dive->cylinder[g]);
dive->cylinder[g].gasmix.o2.permille =
(log[EMC_O2_PERCENT + g * 2] / 256
+ log[EMC_O2_PERCENT + g * 2 + 1]) * 10;
dive->cylinder[g].gasmix.he.permille =
(log[EMC_HE_PERCENT + g * 2] / 256
+ log[EMC_HE_PERCENT + g * 2 + 1]) * 10;
}
tm.tm_year = log[EMC_YEAR];
tm.tm_mon = log[EMC_MON] - 1;
tm.tm_mday = log[EMC_DAY];
tm.tm_hour = log[EMC_HOUR];
tm.tm_min = log[EMC_MIN];
tm.tm_sec = log[EMC_SEC];
tm.tm_isdst = -1;
dive->when = dc->when = utc_mktime(&tm);
dive->number = log[EMC_NUMBER] + log[EMC_NUMBER + 1] * 256 + 1;
dc->duration.seconds = (log[EMC_BT] + log[EMC_BT + 1] * 256) * 60;
dc->surfacetime.seconds = (log[EMC_SIT] + log[EMC_SIT + 1] * 256) * 60;
dc->maxdepth.mm = lrint((log[EMC_MAX_DEPTH] +
log[EMC_MAX_DEPTH + 1] * 256) / 4 * FEET * 1000);
dc->meandepth.mm = lrint((log[EMC_AVG_DEPTH] +
log[EMC_AVG_DEPTH + 1] * 256) / 4 * FEET * 1000);
dc->watertemp.mkelvin = C_to_mkelvin((log[EMC_MIN_TEMP] - 32) / 1.8);
dc->surface_pressure.mbar = lrint(ATM / BAR * pow(1 - 0.0000225577
* (double) log[EMC_ALTITUDE] * 250 * FEET, 5.25588) * 1000);
dc->salinity = 10000 + 150 * (log[EMC_WATER_CONDUCTIVITY] & 0x3);
SHA1(log + EMC_NUMBER, 2, (unsigned char *)csum);
dc->diveid = csum[0];
if (log[EMC_MAX_DEPTH] == 0xff && log[EMC_MAX_DEPTH + 1] == 0xff)
corrupt_dive = 1;
sample_pre_offset = array_uint32_le(log + EMC_PREDIVE_OFFSET);
sample_end_offset = array_uint32_le(log + EMC_END_OFFSET);
break;
}
// Use the log information to determine actual profile sample size
// Otherwise we will get surface time at end of dive.
if (sample_pre_offset < sample_end_offset && sample_end_offset != 0xffffffff)
sample_size = sample_end_offset - sample_pre_offset;
cochran_parse_samples(dive, buf + 0x4914, buf + 0x4914
+ config.logbook_size, sample_size,
&duration, &max_depth, &avg_depth, &min_temp);
// Check for corrupt dive
if (corrupt_dive) {
dc->maxdepth.mm = lrint(max_depth * FEET * 1000);
dc->meandepth.mm = lrint(avg_depth * FEET * 1000);
dc->watertemp.mkelvin = C_to_mkelvin((min_temp - 32) / 1.8);
dc->duration.seconds = duration;
}
record_dive_to_table(dive, table);
mark_divelist_changed(true);
free(buf);
}
