as a side effect of not updating the config pointer when loading
the config file fails, the "FIXME" level comment to take appropriate
action in that case has been removed. the only issue remaining
when receiving a SIGHUP and encountering a malformed config file would
now be the case that output to syslog/logfile won't be resumed, if
initially so configured.
this is required so we can elegantly swap out an old config for a
new one in the future and remove lots of boilerplate from config
initialization code.
unfortunately this is a quite intrusive change as the config struct
was accessed in numerous places, but frankly it should have been
done via a pointer right from the start.
right now, we simply point to a static struct in main.c, so there
shouldn't be any noticeable changes in behaviour.
if daemon mode is used and neither logfile nor syslog options specified,
this is clearly a misconfiguration issue. don't try to be smart and work
around that, so less global state information is required.
also, this case is already checked for in main.c:334.
it is quite easy to bring down a proxy server by forcing it to make
connections to one of its own ports, because this will result in an endless
loop spawning more and more connections, until all available fds are exhausted.
since there's a potentially infinite number of potential DNS/ip addresses
resolving to the proxy, it is impossible to detect an endless loop by simply
looking at the destination ip address and port.
what *is* possible though is to record the ip/port tuples assigned to outgoing
connections, and then compare them against new incoming connections. if they
match, the sender was the proxy itself and therefore needs to reject that
connection.
fixes#199.
tinyproxy used to do a full hostname resolution whenever a new client
connection happened, which could cause very long delays (as reported in #198).
there's only a single place/scenario that actually requires a hostname, and
that is when an Allow/Deny rule exists for a hostname or domain, rather than
a raw IP address. since it is very likely this feature is not very widely used,
it makes absolute sense to only do the costly resolution when it is unavoidable.
since the write syscall is used instead of stdio, accesses have been
safe already, but it's better to use a mutex anyway to prevent out-
of-order writes.
if we don't handle these gracefully, pretty much every existing config
file will fail with an error, which is probably not very friendly.
the obsoleted config items can be made hard errors after the next
release.
the existing codebase used an elaborate and complex approach for
its parallelism:
5 different config file options, namely
- MaxClients
- MinSpareServers
- MaxSpareServers
- StartServers
- MaxRequestsPerChild
were used to steer how (and how many) parallel processes tinyproxy
would spin up at start, how many processes at each point needed to
be idle, etc.
it seems all preforked processes would listen on the server port
and compete with each other about who would get assigned the new
incoming connections.
since some data needs to be shared across those processes, a half-
baked "shared memory" implementation was provided for this purpose.
that implementation used to use files in the filesystem, and since
it had a big FIXME comment, the author was well aware of how hackish
that approach was.
this entire complexity is now removed. the main thread enters
a loop which polls on the listening fds, then spins up a new
thread per connection, until the maximum number of connections
(MaxClients) is hit. this is the only of the 5 config options
left after this cleanup. since threads share the same address space,
the code necessary for shared memory access has been removed.
this means that the other 4 mentioned config option will now
produce a parse error, when encountered.
currently each thread uses a hardcoded default of 256KB per thread
for the thread stack size, which is quite lavish and should be
sufficient for even the worst C libraries, but people may want
to tweak this value to the bare minimum, thus we may provide a new
config option for this purpose in the future.
i suspect that on heavily optimized C libraries such a musl, a
stack size of 8-16 KB per thread could be sufficient.
since the existing list implementation in vector.c did not provide
a way to remove a single item from an existing list, i added my
own list implementation from my libulz library which offers this
functionality, rather than trying to add an ad-hoc, and perhaps
buggy implementation to the vector_t list code. the sblist
code is contained in an 80 line C file and as simple as it can get,
while offering good performance and is proven bugfree due to years
of use in other projects.
The new code skips leading whitespaces before removing trailing
whitespaces and comments.
Without doing this, lines with leading whitespace are treated like empty
lines (i.e. they are ignored).
it was reported that because the fdset was only initialized once,
tinyproxy would fail to properly listen on more than one interface.
closes#214closes#127
RFC 1929 specifies that the user/pass auth subnegotation repurposes the version
field for the version of that specification, which is 1, not 5.
however there's quite a good deal of software out there which got it wrong and
replies with version 5 to a successful authentication, so let's just accept both
forms - other socks5 client programs like curl do the same.
closes#172
sbin/ is meant for programs only usable by root, but in tinyproxy's
case, regular users can and *should* use tinyproxy; meaning it is
preferable from a security PoV to use tinyproxy as regular user.
closes#15 for real.
the previous patch that was merged[0] was halfbaked and only removed
the warning part of the original patch from openwrt[1], but didn't
actually activate bind support. further it invoked UB by removing
the return value from the function, if transparent proxy support was
compiled in.
[0]: d97d486d53
[1]: 7c01da4a72
just like the rest of the socks code, this was stolen from
proxychains-ng, of which i'm happen to be the maintainer of,
so it's not an issue (the licenses are identical, too).
tinyproxy uses a curious mechanism to log those early messages
that result from parsing the config file before the logging mechanism
has been properly set up yet by finishing parsing of the config file:
those early messages are written into a memory buffer and then
are printed later on. this slipped my attention when making it possible
to log to stdout in ccbbb81a.
using the "BasicAuth" keyword in tinyproxy.conf.
base64 code was written by myself and taken from my own library "libulz".
for this purpose it is relicensed under the usual terms of the tinyproxy
license.
original patch submitted in 2006 to debian mailing list:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=392848%29#12
this version was rebased to git and updated by Russ Dill <russ.dill@gmail.com>
in 2015 (the original patch used a different config file format).
as discussed in #40.
commit message by @rofl0r.
if using one of unsigned or signed char for the function prototype, one
gets nasty warnings when using it with the other type. the only proper
solution is to put void* into the prototype, and then specialize the pointer
inside the function using an automatic variable.
for exactly this reason, libc functions like read(), write(), etc use void*
too.
some users want to run tinyproxy on an as-needed basis in a terminal,
without setting it up permanently to run as a daemon/service.
in such use case, it is very annoying that tinyproxy didn't have
an option to log to stdout, so the user has to keep a second terminal
open to `tail -f` the log.
additionally, this precluded usage with runit service supervisor,
which runs all services in foreground and creates logfiles from the
service's stdout/stderr.
since logging to stdout doesn't make sense when daemonized, now if
no logfile is specified and daemon mode activated, a warning is
printed to stderr once, and nothing is logged.
the original idea was to fail with an error message, though some users
might actually want to run tinyproxy as daemon and no logging at all.
some people want to run tinyproxy with minimal configuration from
the command line (and as non-root), but tinyproxy insists on writing
a pid file, which only makes sense for usage as a service, hereby
forcing the user to either run it as root so it can write to the
default location, or start editing the default config file to work
around it.
and if no pidfile is specified in the config, it frankly doesn't
make sense to force creation of one anyway.
rofl0r
rofl0r
Martin Kutschker
Janosch Hoffmann
Vasily
Michael Adam
bertliao
John Weldon
Gonzalo Tornaria
Pablo Panero