From time to time, the length of the radiotap header (rtap_bytes in
read_packet()) is 65535. This is a quick & dirty fix to avoid segfaults,
but we should search for the reason why this value sometimes appears.
Modify the *time*() functions to avoid passing structures in arguments
(using const pointers instead) or returning structures (using result
arguments instead).
In the listener & aggregator, the signal strength is stored as an
unsigned byte. To display the actual (negative) value, one must
substract 256 (0x100) to the unsigned value.
This commit changes several things:
- Use the decimal (256) instead of the hexadecimal value (0x100).
- Don't substract 256 when copying the value to another unsigned byte
(aggregator).
- Be careful with the type length. In the positioning server, a SS
could be copied to a signed byte, while (theoretically) the negative
value can exceed the capacity of the signed byte. measurement.hh now
defines a type ss_t to store a signal strength value with the good
size (it is currently an int_fast16_t).
"start_time" was meaningless in the global data structures of owlps.h,
and could lead to errors in the aggregator, since it defines a field
start_time in one of its internal structures.
Add the compile-time option ENABLE_KEEP_MONITOR to enable/disable the
option -K. That allows to make optional the dependency on iwlib.
This option is disabled by default in the Makefiles.
The configuration parsing function could call exit() (e.g. with -h, -V,
or in case of error), implying a memory leak. This is fixed.
Additionally, minor cleaning in the configuration functions.
Instead of #define DEBUG, we now prefer to use either verbose levels
or, when needed, NDEBUG. Each Makefile was modified to be able to pass
-D NDEBUG to the compiler (but the corresponding lines are commented),
except in the modules where assert is never used, in which case the
Makefile passes -D DEBUG.
Long story short: to totally disable debugging code, comment-out the
"-D DEBUG" lines and uncomment the "-D NDEBUG" lines, in every Makefile.
owl_mac_bytes_to_string() now uses a static buffer, so the caller do not
need to free the returned buffer manually. Because of this static
buffer, it is not thread-safe anymore, therefore we introduce
owl_mac_bytes_to_string_r() that is a thread-safe version.
In capture(), the pcap_loop() call was blocking, so the program did not
quit if no packet came on rtap_iface. This is now fixed by a call to
pcap_breakloop() in the signal handlers.