mirror of
https://github.com/nmap/nmap.git
synced 2026-02-12 00:16:35 +00:00
eb7fda541e
Like ultra_scan, OS scan has global and host-based congestion control mechanisms like those in TCP. Part of global congestion control is keeping track of how many probes are outstanding in the network; OS scan keeps the number in a member variable called num_probes_active. num_probes_active is meant to be the sum of the sizes of each host's list of outstanding probes. It was correctly being decremented whenever a probe was removed from an active list, but it was never incremented. num_probes_active was always zero or negative, and therefore never exceeded the global congestion window. This almost completely disabled global congestion control. With this fix OS scan will send a maximum of ten probes immediately at the beginning of the scan. Previously it was limited only by the number of hosts being scanned (20 or 30).
Here is some documentation for Nmap, but these files are much less comprehensive than what you'll find at the actual Nmap documentation site ( http://nmap.org ).