A UDP service now runs in its own thread alone (udploop()): it reads the
service's socket and the sockets of its sessions towards their
destinations, keeps their deadlines, and answers every client from the
service's socket. A session is a struct clientparam as a client thread's
would be, with a slot of maxchild, among the service's children and
counted on its listener, but without a thread. The services supply
handlers (struct udpservice, childdef.udp): udppm keeps a session per
client address, forwarding its datagrams, behind the headers of a
parent chain, from a socket of its own and answering what comes back,
until STRING_L of silence or, with -s, the first answer; dnspr makes a
session of each query, answered at once from the fake address, the
name cache or the resolver, or sent on to the first name server over
UDP, whose answer is waited for in the loop up to DNS_TO (a name server
over TCP is still waited for in place). Authentication stays in the
loop for now; datagrams over a bandwidth limit, or of a client without
a free slot, are dropped.
On a reload the old service goes on serving the socket until it sees
its configuration replaced, then hands its sessions to the listener;
the newest service of its kind there, which until then does not read
the socket so that no client gets two sessions, adopts them: a slot of
its own, the old one given back, its filters and limits, and
re-authentication. A session is ended with 26 if the newest service is
of another kind, 27 without a slot, or with what the authentication
says; sessions nobody is left to adopt are ended by the last service to
stop on the listener.
On Windows a send on a socket waited while another thread polled it,
which delayed udppm's answers by up to a second, and old UDP services
did not exit after a reload; with one thread per socket neither
happens, and the second socket bound to the service's address
(NO_SHARE_UDP_SOCKET) is gone from the code and the build files.
udpinit, the global udp_table, udpnext(), udppmchild() and
dnsprchild() are gone; udpsockmap() serves SOCKS5 UDP ASSOCIATE only.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
