None of the things we might exec() can possibly run under the
sanbox, so rather than crash later, we have to refuse to accept the
configuration nice and early.
The longer-term solution is to have an exec() helper, but wow is
that risky.
fixes 12043; bugfix on 0.2.5.1-alpha
When we converted the horrible set of options that previously
controlled "use ORPort or DirPort? Anonymously or Non-anonymouly?" to
a single 'indirection' argument, we missed
directory_post_to_dirservers.
The problematic code was introduced in 5cbeb6080, which went into
0.2.4.3-alpha. This is a fix for bug 11469.
When running with User set, we frequently try to look up our
information in the user database (e.g., /etc/passwd). The seccomp2
sandbox setup doesn't let us open /etc/passwd, and probably
shouldn't.
To fix this, we have a pair of wrappers for getpwnam and getpwuid.
When a real call to getpwnam or getpwuid fails, they fall back to a
cached value, if the uid/gid matches.
(Granting access to /etc/passwd isn't possible with the way we
handle opening files through the sandbox. It's not desirable either.)
On OpenBSD 5.4, time_t is a 32-bit integer. These instances contain
implicit treatment of long and time_t as comparable types, so explicitly
cast to time_t.
Apparently, there exist cross-compiling environments for arm7 where
you can compile a 64x64->128 multiply, but not link it.
Fixes bug 11729; bugfix on 0.2.4.8-alpha. Patch from 'conradev'.
on #9686, gmorehose reports that the 500 MB lower limit is too high
for raspberry pi users.
This is a backport of 647248729f to 0.2.4.
Note that in 0.2.4, the option is called MaxMemInCellQueues.
When clearing a list of tokens, it's important to do token_clear()
on them first, or else any keys they contain will leak. This didn't
leak memory on any of the successful microdescriptor parsing paths,
but it does leak on some failing paths when the failure happens
during tokenization.
Fixes bug 11618; bugfix on 0.2.2.6-alpha.
The python scripts invoked by 'make check' didn't work on python3
before. That was a problem on systems where 'python' is python3.
Fixes bug 11608; bugfix on 0.2.5.2-alpha.
If we can't detect the physical memory, the new default is 8 GB on
64-bit architectures, and 1 GB on 32-bit architectures.
If we *can* detect the physical memory, the new default is
CLAMP(256 MB, phys_mem * 0.75, MAX_DFLT)
where MAX_DFLT is 8 GB on 64-bit architectures and 2 GB on 32-bit
architectures.
You can still override the default by hand. The logic here is simply
trying to choose a lower default value on systems with less than 12 GB
of physical RAM.
Previously we said "Sandbox is not implemented on this platform" on
Linux boxes without libseccomp. Now we say that you need to build
Tor built with libseccomp. Fixes bug 11543; bugfix on 0.2.5.1-alpha.
Fixes a possible root cause of 11553 by only making 64 attempts at
most to pick a circuitID. Previously, we would test every possible
circuit ID until we found one or ran out.
This algorithm succeeds probabilistically. As the comment says:
This potentially causes us to give up early if our circuit ID
space is nearly full. If we have N circuit IDs in use, then we
will reject a new circuit with probability (N / max_range) ^
MAX_CIRCID_ATTEMPTS. This means that in practice, a few percent
of our circuit ID capacity will go unused.
The alternative here, though, is to do a linear search over the
whole circuit ID space every time we extend a circuit, which is
not so great either.
This makes new vs old clients distinguishable, so we should try to
batch it with other patches that do that, like 11438.
The server cipher list is (thanks to #11513) chosen systematically to
put the best choices for Tor first. The client cipher list is chosen
to resemble a browser. So let's set SSL_OP_CIPHER_SERVER_PREFERENCE
to have the servers pick according to their own preference order.
This isn't on by default; to get it, you need to set "TransProxyType
ipfw". (The original patch had automatic detection for whether
/dev/pf is present and openable, but that seems marginally fragile.)
