time question

[Brian Oleksa <oleksab () darkcornersoftware com>]

Wiresharkers

I am trying to dissect the time in a particular packet. Here is it's format:

"The time is the source computer's system time in Greenwich Mean Time 
(GMT)." The size is 32 bits or 4 bytes.

What is the best method to use to dissect this time..?? I tired 
this...but did not have any luck:

                        nstime_t t;
                        guint64 msecs_since_the_epoch;
                        struct tm *tmp;
                        msecs_since_the_epoch = tvb_get_ntoh64(tvb, offset);
                        t.secs = msecs_since_the_epoch / 1000;
                        t.nsecs = (msecs_since_the_epoch % 
1000)*1000000; /* milliseconds to nanoseconds */
                        tmp = gmtime(&t.secs);

                    if (tmp != NULL)
                        {
                        proto_tree_add_time_format(time_sub_tree, 
hf_helen_time, tvb, offset, 4, &t,
                                "Date: %s %2d, %d %02d:%02d:%02d UTC", 
mon_names[tmp->tm_mon], tmp->tm_mday,
                                tmp->tm_year + 1900, tmp->tm_hour, 
tmp->tm_min, tmp->tm_sec);
                        }
                        offset += 4




Also...I am trying to dissect longitude, latitude and altitude. Here is 
it's format. The size is also 32 bits or 4 bytes.

The <latitude>, <longitude>, and <altitude> fields contain values 
corresponding to GPS information for the MGEN source if it was 
available. The <latitude> and <longitude> fields are encoded as follows:

<fieldValue> = (unsigned long)((<actualValue>+180.0)*60000.0)

The <altitude> field is the direct representation of the altitude value 
available from the source's GPS system.

I tried this but had no luck:

            longitude = tvb_get_ntoh64(tvb, offset);
            longitude = (longitude+180)*60000;
            proto_tree_add_uint_format(mgen_sub_tree, hf_helen_length, 
tvb, offset, 4, 0,
                  "Longitude: %f", longitude);
            offset += 4;



Thanks,
Brian






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