On a way to factoring out OpenSSL support to a standalone file to ease
addition of other crypto libraries support in the future, move helpers
providing random numbers/data generation to crypto-utils.{c,h}. OpenSSL-
related functionality (generation of cryptographically strong random
data) is moved to crypto-utils-openssl.c.
Rename functions to follow currently accepted style:
* tr_cryptoRandBuf -> tr_rand_buffer
* tr_cryptoRandInt -> tr_rand_int
* tr_cryptoWeakRandInt -> tr_rand_int_weak
Fix rare case of invalid value being returned from tr_rand_int. Return
value for abs(INT_MIN) may be undefined and thus negative, and so
tr_rand_int will return negative value which is incorrect (out of
requested and expected range).
Previously we made sure to include stdbool.h (via transmission.h) before utp.h, since the latter used 'bool' without defining it. The new snapshot defines it unconditionally in non-C++ code, so now we need to include it first.
This is a little overlapping since the utp code can be closed more-or-less immediately, but the udp manager needs to stay open in order to process the udp tracker connection requests before sending out event=stopped. Moreover DNS resolver can be shut down after the UDP tracker is shutdown.
This handles converting the data in a sockaddr_storage to a tr_address + port, and removes redundant code from fdlimit.c and tr-udp.c that previously did this work.
There's no need to test for DHT/uTP being enabled in tr-udp. The DHT
will silently discard any packets directed at the wrong session (see the
beginning of dhtCallback). As to uTP, we need to grok uTP packets
to close any remaining connections after we disabled uTP, so it's better
to participate in uTP, just reject any incoming connections.
This adds code to participate in the UTP protocol, but without doing anything
useful yet -- we just shut down immediately any incoming connexion request.
Mike Gelfand