Design goals:
* Only keep a limited number of addresses around, so that addr.dat does not grow without bound.
* Keep the address tables in-memory, and occasionally write the table to addr.dat.
* Make sure no (localized) attacker can fill the entire table with his nodes/addresses.
See comments in addrman.h for more detailed information.
* do not let vnThreadsRunning[1] go negative
* do not perform locking operations while vnThreadsRunning[1] is decreased
* check vnThreadsRunning[1] at exit
This fixes a potential bug where some NATs may replace the node's
interal IP with its external IP in version messages, causing
incorrect checksums when version messages begin being checksummed
on February 14, 2012.
This also avoids flushing setAddrKnown until 24 hours has passed,
and avoids contacting the external IP services when not listening.
Advertising non-listening nodes is just addr message spam.
It doesn't help the network, in fact it hurts the network,
and it also hurts user's privacy.
Advertising far out of sync nodes doesn't help the network—
they can't even forward (most) transactions and wastes nodes
outbound slots.
This turns on most gcc warnings, and removes some unused variables and other code that triggers warnings.
Exceptions are:
-Wno-sign-compare : triggered by lots of comparisons of signed integer to foo.size(), which is unsigned.
-Wno-char-subscripts : triggered by the convert-to-hex functions (I may fix this in a future commit).
This introduces CNetAddr and CService, respectively wrapping an
(IPv6) IP address and an IP+port combination. This functionality used
to be part of CAddress, which also contains network flags and
connection attempt information. These extra fields are however not
always necessary.
These classes, along with logic for creating connections and doing
name lookups, are moved to netbase.{h,cpp}, which does not depend on
headers.h.
Furthermore, CNetAddr is mostly IPv6-ready, though IPv6
functionality is not yet enabled for the application itself.
Made three critical blocks for cs_mapAddresses smaller, and moved
writing to the database out of them. This should also improve the
concurrency of the code.
Replaced all occurrences of #if* __WXMSW__ with WIN32,
and all occurrences of __WXMAC_OSX__ with MAC_OSX, and made
sure those are defined appropriately in the makefile and bitcoin-qt.pro.
Explicitly make these global variables less-global to reduce the maximum
scope of this global state.
In my experience global variables tend to be a major source of bugs. As
such the less accessible they are the less likely they are to be the
source of a bug.
Signed-off-by: Giel van Schijndel <me@mortis.eu>
Don't check for a negative parameter count, because not only will it
never happen, it doesn't make any sense either.
Invalid sockets (as returned by socket(2)) are always exactly -1 (not
just negative as negative file descriptors are technically not
prohibited by POSIX) on POSIX systems. Since we store them in SOCKET
(unsigned int), however, that really is ~0U (or MAX_UINT) which happens
to be what INVALID_SOCKET is already defined to, so an additional check
for being negative is not only unnecessary (unsigned integers aren't
*ever* negative) its redundant as well (the INVALID_SOCKET comparison is
enough).
Signed-off-by: Giel van Schijndel <me@mortis.eu>
Pieter Wuille