Previously, fetch_from_buf_socks() might return 0 if there was still
data on the buffer and a subsequent call to fetch_from_buf_socks()
would return 1. This was making some of the socks5 unit tests
harder to write, and could potentially have caused misbehavior with
some overly verbose SOCKS implementations. Now,
fetch_from_buf_socks() does as much processing as it can, and
returns 0 only if it really needs more data. This brings it into
line with the evbuffer socks implementation.
We added this back in 0649fa14 in 2006, to deal with the case where
the client unconditionally sent us authentication data. Hopefully,
that's not needed any longer, since we now can actually parse
authentication data.
This change also requires us to add and use a pair of
allocator/deallocator functions for socks_request_t, instead of
using tor_malloc_zero/tor_free directly.
In the code as it stood, we would accept any number of socks5
username/password authentication messages, regardless of whether we
had actually negotiated username/password authentication. Instead,
we should only accept one, and only if we have really negotiated
username/password authentication.
This patch also makes some fields of socks_request_t into uint8_t,
for safety.
This lets us make a lot of other stuff const, allows the compiler to
generate (slightly) better code, and will make me get slightly fewer
patches from folks who stick mutable stuff into or_options_t.
const: because not every input is an output!
On win64, sockets are of type UINT_PTR; on win32 they're u_int;
elsewhere they're int. The correct windows way to check a socket for
being set is to compare it with INVALID_SOCKET; elsewhere you see if
it is negative.
On Libevent 2, all callbacks take sockets as evutil_socket_t; we've
been passing them int.
This patch should fix compilation and correctness when built for
64-bit windows. Fixes bug 3270.
Previously, we only looked at up to 128 bytes. This is a bad idea
since socks messages can be at least 256+x bytes long. Now we look at
up to 512 bytes; this should be enough for 0.2.2.x to handle all valid
SOCKS messages. For 0.2.3.x, we can think about handling trickier
cases.
Fixes 2330. Bugfix on 0.2.0.16-alpha.
C99 allows a syntax for structures whose last element is of
unspecified length:
struct s {
int elt1;
...
char last_element[];
};
Recent (last-5-years) autoconf versions provide an
AC_C_FLEXIBLE_ARRAY_MEMBER test that defines FLEXIBLE_ARRAY_MEMBER
to either no tokens (if you have c99 flexible array support) or to 1
(if you don't). At that point you just use offsetof
[STRUCT_OFFSET() for us] to see where last_element begins, and
allocate your structures like:
struct s {
int elt1;
...
char last_element[FLEXIBLE_ARRAY_MEMBER];
};
tor_malloc(STRUCT_OFFSET(struct s, last_element) +
n_elements*sizeof(char));
The advantages are:
1) It's easier to see which structures and elements are of
unspecified length.
2) The compiler and related checking tools can also see which
structures and elements are of unspecified length, in case they
wants to try weird bounds-checking tricks or something.
3) The compiler can warn us if we do something dumb, like try
to stack-allocate a flexible-length structure.
evbuffer_pullup does nothing and returns NULL if the caller asks it to
linearize more data than the buffer contains.
Introduced in 9796b9bfa6.
Reported by piebeer; fixed with help from doors.
If a SOCKS5 client insists on authentication, allow it to
negotiate a connection with Tor's SOCKS server successfully.
Any credentials the client provides are ignored.
This allows Tor to work with SOCKS5 clients that can only
support 'authenticated' connections.
Also add a bunch of basic unit tests for SOCKS4/4a/5 support
in buffers.c.
Pick 5 seconds as the limit. 5 seconds is a compromise here between
making sure the user notices that the bad behaviour is (still) happening
and not spamming their log too much needlessly (the log message is
pretty long). We also keep warning every time if safesocks is
specified, because then the user presumably wants to hear about every
blocked instance.
(This is based on the original patch by Sebastian, then backported to
0.2.2 and with warnings split into their own function.)
Sending a log message to a control port can cause Tor to allocate a buffer,
thereby changing the length of the freelist behind buf_shrink_freelists's back,
thereby causing an assertion to fail.
Fixes bug #1125.
Sending a log message to a control port can cause Tor to allocate a buffer,
thereby changing the length of the freelist behind buf_shrink_freelists's back,
thereby causing an assertion to fail.
Fixes bug #1125.
