Previously we were using router_get_by_id(foo) to test "do we have a
descriptor that will let us make an anonymous circuit to foo". But
that isn't right for microdescs: we should have been using node_t.
Fixes bug 3601; bugfix on 0.2.3.1-alpha.
Instead, use compare_tor_addr_to_node_policy everywhere.
One advantage of this is that compare_tor_addr_to_node_policy can
better distinguish 0.0.0.0 from "unknown", which caused a nasty bug
with microdesc users.
Previously, we had an issue where we'd treat an unknown address as
0, which turned into "0.0.0.0", which looked like a rejected
address. This meant in practice that as soon as we started doing
comparisons of unknown uint32 addresses to short policies, we'd get
'rejected' right away. Because of the circumstances under which
this would be called, it would only happen when we had local DNS
cached entries and we were looking to launch new circuits.
* Add some utility transport functions in circuitbuild.[ch] so that we
can use them from pt.c.
* Make the accounting system consider traffic coming from proxies.
* Make sure that we only fetch bridge descriptors when all the
transports are configured.
Rationale: right now there seems to be no way for our bootstrap
status to dip under 100% once it has reached 100%. Thus, recording
broken connections after that point is useless, and wastes memory.
If at some point in the future we allow our bootstrap level to go
backwards, then we should change this rule so that we disable
recording broken connection states _as long as_ the bootstrap status
is 100%.
- We were reporting the _bottom_ N failing states, not the top N.
- With bufferevents enabled, we logged all TLS states as being "in
bufferevent", which isn't actually informative.
- When we had nothing to report, we reported nothing too loudly.
- Also, we needed documentation.
This code lets us record the state of any outgoing OR connection
that fails before it becomes open, so we can notice if they're all
dying in the same SSL state or the same OR handshake state.
More work is still needed:
- We need documentation
- We need to actually call the code that reports the failure when
we realize that we're having a hard time connecting out or
making circuits.
- We need to periodically clear out all this data -- perhaps,
whenever we build a circuit successfully?
- We'll eventually want to expose it to controllers, perhaps.
Partial implementation of feature 3116.
It's very easy for nodelist_add_node_family(sl,node) to accidentally
add 'node', and kind of hard to make sure that it omits it. Instead
of taking pains to leave 'node' out, let's instead make sure that we
always include it.
I also rename the function to nodelist_add_node_and_family, and
audit its users so that they don't add the node itself any longer,
since the function will take care of that for them.
Resolves bug 2616, which was not actually a bug.
Previously, we'd just take all the nodes in EntryNodes, see which
ones were already in the guard list, and add the ones that weren't.
There were some problems there, though:
* We'd add _every_ entry in EntryNodes, and add them in the order
they appeared in the routerlist. This wasn't a problem
until we added the ability to give country-code or IP-range
entries in the EntryNodes set, but now that we did, it is.
(Fix: We now shuffle the entry nodes before adding them; only
add up to 10*NumEntryGuards)
* We didn't screen EntryNodes for the Guard flag. That's okay
if the user has specified two or three entry nodes manually,
but if they have listed a whole subcontinent, we should
restrict ourselves to the entries that are currently guards.
(Fix: separate out the new guard from the new non-guard nodes,
and add the Guards first.)
* We'd prepend new EntryNodes _before_ the already configured
EntryNodes. This could lead to churn.
(Fix: don't prepend these.)
This patch also pre-screens EntryNodes entries for
reachableaddresses/excludenodes, even though we check for that
later. This is important now, since we cap the number of entries
we'll add.
Just looking at the "latest" consensus could give us a microdesc
consensus, if microdescs were enabled. That would make us decide
that every routerdesc was unlisted in the latest consensus and drop
them all: Ouch.
Fixes bug 3113; bugfix on 0.2.3.1-alpha.
We have an invariant that a node_t should have an md only if it has
a routerstatus. nodelist_purge tried to preserve this by removing
all nodes without a routerstatus or a routerinfo. But this left
nodes with a routerinfo and a microdesc untouched, even if they had
a routerstatus.
Bug found by frosty_un.
All of the routerset_contains*() functions return 0 if their
routerset_t argument is NULL. Therefore, there's no point in
doing "if (ExcludeNodes && routerset_contains*(ExcludeNodes...))",
for example.
This patch fixes every instance of
if (X && routerstatus_contains*(X,...))
Note that there are other patterns that _aren't_ redundant. For
example, we *don't* want to change:
if (EntryNodes && !routerstatus_contains(EntryNodes,...))
Fixes#2797. No bug here; just needless code.
Previously, we'd get a new descriptor for free when
public_server_mode() changed, since it would count as
affects_workers, which would call init_keys(), which would make us
regenerate a new descriptor. But now that we fixed bug 3263,
init_keys() is no longer necessarily a new descriptor, and so we
need to make sure that public_server_mode() counts as a descriptor
transition.
The issue was that we overlooked the possibility of reverse DNS success
at the end of connection_ap_handshake_socks_resolved(). Issue discovered
by katmagic, thanks!
Returning a tristate is needless here; we can just use the yielded
transport/proxy_type field to tell whether there's a proxy, and have
the return indicate success/failure.
Also, store the proxy_type in the or_connection_t rather than letting
it get out of sync if a configuration reload happens between launching
the or_connection and deciding what to say with it.
- const-ify some transport_t pointers
- Remove a vestigial argument to parse_bridge_line
- Make it compile without warnings on my laptop with
--enable-gcc-warnings
We were using strncpy before, which isn't our style for stuff like
this.
This isn't a bug, though: before calling strncpy, we were checking
that strlen(src) was indeed == HEX_DIGEST_LEN, which is less than
sizeof(dst), so there was no way we could fail to NUL-terminate.
Still, strncpy(a,b,sizeof(a)) is an idiom that we ought to squash
everyplace.
Fixes CID #427.
Using strncpy meant that if listenaddress were ever >=
sizeof(sockaddr_un.sun_path), we would fail to nul-terminate
sun_path. This isn't a big deal: we never read sun_path, and the
kernel is smart enough to reject the sockaddr_un if it isn't
nul-terminated. Nonetheless, it's a dumb failure mode. Instead, we
should reject addresses that don't fit in sockaddr_un.sun_path.
Coverity found this; it's CID 428. Bugfix on 0.2.0.3-alpha.
When we rejected a descriptor for not being the one we wanted, we
were letting the parsed descriptor go out of scope.
Found by Coverity; CID # 30.
Bugfix on 0.2.1.26.
(No changes file yet, since this is not in any 0.2.1.x release.)
Every node_t has either a routerinfo_t or a routerstatus_t, so every
node_t *should* have a nickname. Nonetheless, let's make sure in
hex_digest_nickname_matches().
Should quiet CID 434.
This is a little error-prone when the local has a different type
from the parameter, and is very error-prone with both have the same
type. Let's not do this.
Fixes CID #437,438,439,440,441.
For some inexplicable reason, Coverity departs from its usual
standards of avoiding false positives here, and warns about all
sscanf usage, even when the formatting strings are totally safe.
Addresses CID # 447, 446.
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.
Multiple Bridge lines can point to the same one ClientTransportPlugin
line, and we can have multiple ClientTransportPlugin lines in our
configuration file that don't match with a bridge. We also issue a
warning when we have a Bridge line with a pluggable transport but we
can't match it to a ClientTransportPlugin line.
* Renamed transport_info_t to transport_t.
* Introduced transport_get_by_name().
* Killed match_bridges_with_transports().
We currently *don't* detect whether any bridges miss their transports,
of if any transports miss their bridges.
* Various code and aesthetic tweaks and English language changes.
A couple of places in control.c were using connection_handle_write()
to flush important stuff (the response to a SIGNAL command, an
ERR-level status event) before Tor went down. But
connection_handle_write() isn't meaningful for bufferevents, so we'd
crash.
This patch adds a new connection_flush() that works for all connection
backends, and makes control.c use that instead.
Fix for bug 3367; bugfix on 0.2.3.1-alpha.
debug-level since it will be quite common. logged at both client
and server side. this step should help us track what's going on
with people filtering tor connections by our ssl habits.
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!
Original message from bug3393:
check_private_dir() to ensure that ControlSocketsGroupWritable is
safe to use. Unfortunately, check_private_dir() only checks against
the currently running user… which can be root until privileges are
dropped to the user and group configured by the User config option.
The attached patch fixes the issue by adding a new effective_user
argument to check_private_dir() and updating the callers. It might
not be the best way to fix the issue, but it did in my tests.
(Code by lunar; changelog by nickm)
* Improved function documentation.
* Renamed find_bridge_transport_by_addrport() to
find_transport_by_bridge_addrport().
* Sanitized log severities we use.
* Ran check-spaces.
When we set a networkstatus in the non-preferred flavor, we'd check
the time in the current_consensus. But that might have been NULL,
which could produce a crash as seen in bug 3361.
When we added the check for key size, we required that the keys be
128 bytes. But RSA_size (which defers to BN_num_bytes) will return
128 for keys of length 1017..1024. This patch adds a new
crypto_pk_num_bits() that returns the actual number of significant
bits in the modulus, and uses that to enforce key sizes.
Also, credit the original bug3318 in the changes file.
UseBridges 1 now means "connect only to bridges; if you know no
bridges, don't make connections." UseBridges auto means "Use bridges
if they are known, and we have no EntryNodes set, and we aren't a
server." UseBridges 0 means "don't use bridges."
This merge was a bit nontrivial, since I had to write a new
node_is_a_configured_bridge to parallel router_is_a_configured_bridge.
Conflicts:
src/or/circuitbuild.c
options->DirPort is 0 in the unit tests, so
router_get_advertised_dir_port() would return 0 so we wouldn't pick a
dirport. This isn't what we want for the unit tests. Fixes bug
introduced in 95ac3ea594.
Previously, Tor would dereference a NULL pointer and crash if
lookup_last_hid_serv_request were called before the first call to
directory_clean_last_hid_serv_requests. As far as I can tell, that's
currently impossible, but I want that undocumented invariant to go away
in case I^Wwe break it someday.
If set to 1, Tor will attempt to prevent basic debugging
attachment attempts by other processes. (Default: 1)
Supports Mac OS X and Gnu/Linux.
Sebastian provided useful feedback and refactoring suggestions.
Signed-off-by: Jacob Appelbaum <jacob@appelbaum.net>
When we introduced NEED_KEY_1024 in routerparse.c back in
0.2.0.1-alpha, I forgot to add a *8 when logging the length of a
bad-length key.
Bugfix for 3318 on 0.2.0.1-alpha.
The patch for 3228 made us try to run init_keys() before we had loaded
our state file, resulting in an assert inside init_keys. We had moved
it too early in the function.
Now it's later in the function, but still above the accounting calls.
The conflicts were mainly caused by the routerinfo->node transition.
Conflicts:
src/or/circuitbuild.c
src/or/command.c
src/or/connection_edge.c
src/or/directory.c
src/or/dirserv.c
src/or/relay.c
src/or/rendservice.c
src/or/routerlist.c
The comment fixes are trivial. The defensive programming trick is to
tolerate receiving NULL inputs on the describe functions. That should
never actually happen, but it seems like the likeliest mistake for us
to make in the future.
Previously we did this nearer to the end (in the old_options &&
transition_affects_workers() block). But other stuff cares about
keys being consistent with options... particularly anything which
tries to access a key, which can die in assert_identity_keys_ok().
Fixes bug 3228; bugfix on 0.2.2.18-alpha.
Fixes part of #1297; bugfix on 48e0228f1e,
when circuit_expire_building was changed to assume that timestamp_dirty
was set when a circuit changed purpose to _C_REND_READY. (It wasn't.)
The previous attempt was incomplete: it told us not to publish a
descriptor, but didn't stop us from generating one. Now we treat an
absent OR port the same as not knowing our address. (This means
that when we _do_ get an OR port, we need to mark the descriptor
dirty.)
More attempt to fix bug3216.
This situation can happen easily if you set 'ORPort auto' and
'AccountingMax'. Doing so means that when you have no ORPort, you
won't be able to set an ORPort in a descriptor, so instead you would
just generate lots of invalid descriptors, freaking out all the time.
Possible fix for 3216; fix on 0.2.2.26-beta.
We had all the code in place to handle this right... except that we
were unconditionally opening a PF_INET socket instead of looking at
sa_family. Ow.
Fixes bug 2574; not a bugfix on any particular version, since this
never worked before.
Most instances were dead code; for those, I removed the assignments.
Some were pieces of info we don't currently plan to use, but which
we might in the future. For those, I added an explicit cast-to-void
to indicate that we know that the thing's unused. Finally, one was
a case where we were testing the wrong variable in a unit test.
That one I fixed.
This resolves bug 3208.
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.
We used to regenerate our descriptor whenever we'd get a sighup. This
was caused by a bug in options_transition_affects_workers() that would
return true even if the options were exactly the same. Down the call
path we'd call init_keys(), which made us make a new descriptor which
the authorities would reject, and the node would subsequently fall out
of the consensus.
This patch fixes only the first part of this bug:
options_transition_affects_workers() behaves correctly now. The second
part still wants a fix.
tor_process_monitor_new can't currently return NULL, but if it ever can,
we want that to be an explicitly fatal error, without relying on the fact
that monitor_owning_controller_process's chain of caller will exit if it
fails.
When we configure a new bridge via the controller, don't wait up to ten
seconds before trying to fetch its descriptor. This wasn't so bad when
you listed your bridges in torrc, but it's dreadful if you configure
your bridges via vidalia.
Bumped the char maximum to 512 for HTTPProxyAuthenticator &
HTTPSProxyAuthenticator. Now stripping all '\n' after base64
encoding in alloc_http_authenticator.
Rename crypto_pk_check_key_public_exponent to crypto_pk_public_exponent_ok:
it's nice to name predicates s.t. you can tell how to interpret true
and false.
Fixed a trivial conflict where this and the ControlSocketGroupWritable
code both added different functions to the same part of connection.c.
Conflicts:
src/or/connection.c
This patch introduces a few new functions in router.c to produce a
more helpful description of a node than its nickame, and then tweaks
nearly all log messages taking a nickname as an argument to call these
functions instead.
There are a few cases where I left the old log messages alone: in
these cases, the nickname was that of an authority (whose nicknames
are useful and unique), or the message already included an identity
and/or an address. I might have missed a couple more too.
This is a fix for bug 3045.
When running a system-wide instance of Tor on Unix-like systems, having
a ControlSocket is a quite handy mechanism to access Tor control
channel. But it would be easier if access to the Unix domain socket can
be granted by making control users members of the group running the Tor
process.
This change introduces a UnixSocketsGroupWritable option, which will
create Unix domain sockets (and thus ControlSocket) 'g+rw'. This allows
ControlSocket to offer same access control measures than
ControlPort+CookieAuthFileGroupReadable.
See <http://bugs.debian.org/552556> for more details.
This code changes it so that we don't remove bridges immediately when
we start re-parsing our configuration. Instead, we mark them all, and
remove all the marked ones after re-parsing our bridge lines. As we
add a bridge, we see if it's already in the list. If so, we just
unmark it.
This new behavior will lose the property we used to have that bridges
were in bridge_list in the same order in which they appeared in the
torrc. I took a quick look through the code, and I'm pretty sure we
didn't actually depend on that anywhere.
This is for bug 3019; it's a fix on 0.2.0.3-alpha.
rransom notes correctly that now that we aren't checking our HSDir
flag, we have no actual reason to check whether we are listed in the
consensus at all when determining if we should act like a hidden
service directory.
Previously, if they changed in torrc during a SIGHUP, all was well,
since we would just clear all transient entries from the addrmap
thanks to bug 1345. But if you changed them from the controller, Tor
would leave old mappings in place.
The VirtualAddrNetwork bug has been here since 0.1.1.19-rc; the
AutomapHosts* bug has been here since 0.2.0.1-alpha.
This bug couldn't happen when TrackExitHosts changed in torrc, since
the SIGHUP to reload the torrc would clear out all the transient
addressmap entries before. But if you used SETCONF to change
TrackExitHosts, old entries would be left alone: that's a bug, and so
this is a bugfix on Tor 0.1.0.1-rc.
If you really want to purge the client DNS cache, the TrackHostExits
mappings, and the virtual address mappings, you should be using NEWNYM
instead.
Fixes bug 1345; bugfix on Tor 0.1.0.1-rc.
Note that this needs more work: now that we aren't nuking the
transient addressmap entries on HUP, we need to make sure that
configuration changes to VirtualAddressMap and TrackHostExits actually
have a reasonable effect.
We'll eventually want to do more work here to make sure that the ports
are stable over multiple invocations. Otherwise, turning your node on
and off will get you a new DirPort/ORPort needlessly.
Otherwise, it will just immediately close any port declared with "auto"
on the grounds that it wasn't configured. Now, it will allow "auto" to
match any port.
This means FWIW if you configure a socks port with SocksPort 9999
and then transition to SocksPort auto, the original socksport will
not get closed and reopened. I'm considering this a feature.
HTTPS error code 403 is now reported as:
"The https proxy refused to allow connection".
Used a switch statement for additional error codes to be explained
in the future.
On IRC, wanoskarnet notes that if we ever do microdesc_free() on a
microdesc that's in the nodelist, we're in trouble. Also, we're in
trouble if we free one that's still in the microdesc_cache map.
This code adds a flag to microdesc_t to note where the microdesc is
referenced from, and checks those flags from microdesc_free(). I
don't believe we have any errors here now, but if we introduce some
later, let's log and recover from them rather than introducing
heisenbugs later on.
Addresses bug 3153.
The old behavior contributed to unreliability when hidden services and
hsdirs had different consensus versions, and so had different opinions
about who should be cacheing hsdir info.
Bugfix on 0.2.0.10-alpha; based on discussions surrounding bug 2732.
The new behavior is to try to rename the old file if there is one there
that we can't read. In all likelihood, that will fail too, but at least
we tried, and at least it won't crash.
Conflicts in various places, mainly node-related. Resolved them in
favor of HEAD, with copying of tor_mem* operations from bug3122_memcmp_022.
src/common/Makefile.am
src/or/circuitlist.c
src/or/connection_edge.c
src/or/directory.c
src/or/microdesc.c
src/or/networkstatus.c
src/or/router.c
src/or/routerlist.c
src/test/test_util.c
Conflicts throughout. All resolved in favor of taking HEAD and
adding tor_mem* or fast_mem* ops as appropriate.
src/common/Makefile.am
src/or/circuitbuild.c
src/or/directory.c
src/or/dirserv.c
src/or/dirvote.c
src/or/networkstatus.c
src/or/rendclient.c
src/or/rendservice.c
src/or/router.c
src/or/routerlist.c
src/or/routerparse.c
src/or/test.c
Here I looked at the results of the automated conversion and cleaned
them up as follows:
If there was a tor_memcmp or tor_memeq that was in fact "safe"[*] I
changed it to a fast_memcmp or fast_memeq.
Otherwise if there was a tor_memcmp that could turn into a
tor_memneq or tor_memeq, I converted it.
This wants close attention.
[*] I'm erring on the side of caution here, and leaving some things
as tor_memcmp that could in my opinion use the data-dependent
fast_memcmp variant.
Make that explicit by adding an assert and removing a null-check. All of
its callers currently depend on the argument being non-null anyway.
Silences a few clang complaints.
The analyzer assumed that bootstrap_percent could be less than 0 when we
call control_event_bootstrap_problem(), which would mean we're calling
log_fn() with undefined values. The assert makes it clear this can't
happen.
When configure tor with --enable-bufferevents and
--enable-static-libevent, libevent_openssl would still be linked
dynamically. Fix this and refactor src/or/Makefile.am along the way.
To make sure that a server learns if its IP has changed, the server
sometimes launches authority.z descriptor fetches from
update_router_descriptor_downloads. That's nice, but we're moving
towards a situation where update_router_descriptor_downloads doesn't
always get called. So this patch breaks the authority.z
check-and-fetch into a new function.
This function also renames last_routerdesc_download to a more
appropriate last_descriptor_download, and adds a new
update_all_descriptor_downloads() function.
(For now, this is unnecessary, since servers don't actually use
microdescriptors. But that could change, or bridges could start
using microdescriptors, and then we'll be glad this is refactored
nicely.)
To turn this on, set UseMicrodescriptors to "1" (or "auto" if you
want it on-if-you're-a-client). It should go auto-by-default once
0.2.3.1-alpha is released.
Because of our node logic, directory caches will never use
microdescriptors when they have the right routerinfo available.
See bug 2850 for rationale: it appears that on some busy exits, the OS
decides that every single port is now unusable because they have been
all used too recently.
Previously we ensured that it would get called periodically by doing
it from inside the code that added microdescriptors. That won't work
though: it would interfere with our code that tried to read microdescs
from disk initially. Instead, we should consider rebuilding the cache
periodically, and on startup.
Previously on 0.2.2, we'd never clean the cache. Now that we can
clean it, we want to add a condition to rebuild it: that should happen
whenever we have dropped enough microdescriptors that we could save a
lot of space.
No changes file, since 0.2.3 doesn't need one and 0.2.2 already has some
changes files for the backport of the microdesc_clean_cahce() function.
n_supported[i] has a random value prior to initialization, so a node
that doesn't have routerinfo available can have a random priority.
Patch contributed by wanoskarnet from #tor. Thanks!
Instead of just saying "boogity boogity!" let's actually warn people
that they need to configure stuff right to be safe, and point them
at instructions for how to do that.
Resolves bug 2474.
Clients and relays haven't used them since early 0.2.0.x. The only
remaining use by authorities learning about new relays ahead of scedule;
see proposal 147 for what we intend to do about that.
We're leaving in an option (FetchV2Networkstatus) to manually fetch v2
networkstatuses, because apparently dnsel and maybe bwauth want them.
This fixes bug 3022.
Previously it would erroneously return true if ListenAddr was set for
a client port, even if that port itself was 0. This would give false
positives, which were not previously harmful... but which were about
to become.
A v0 HS authority stores v0 HS descriptors in the same descriptor
cache that its HS client functionality uses. Thus, if the HS
authority operator clears its client HS descriptor cache, ALL v0
HS descriptors will be lost. That would be bad.
If the user sent a SIGNAL NEWNYM command after we fetched a rendezvous
descriptor, while we were building the introduction-point circuit, we
would give up entirely on trying to connect to the hidden service.
Original patch by rransom slightly edited to go into 0.2.1
Previously, it would remove every trackhostexits-derived mapping
*from* xyz.<exitname>.exit; it was supposed to remove every
trackhostexits-derived mapping *to* xyz.<exitname>.exit.
Bugfix on 0.2.0.20-rc: fixes an XXX020 added while staring at bug-1090
issues.
Resolved conflicts in:
doc/tor.1.txt
src/or/circuitbuild.c
src/or/circuituse.c
src/or/connection_edge.c
src/or/connection_edge.h
src/or/directory.c
src/or/rendclient.c
src/or/routerlist.c
src/or/routerlist.h
These were mostly releated to the routerinfo_t->node_t conversion.
Now we believe it to be the case that we never build a circuit for our
stream that has an unsuitable exit, so we'll never need to use such
a circuit. The risk is that we have some code that builds the circuit,
but now we refuse to use it, meaning we just build a bazillion circuits
and ignore them all.
This looked at first like another fun way around our node selection
logic: if we had introduction circuits, and we wound up building too
many, we would turn extras into general-purpose circuits. But when we
did so, we wouldn't necessarily check whether the general-purpose
circuits conformed to our node constraints. For example, the last
node could totally be in ExcludedExitNodes and we wouldn't have cared...
...except that the circuit should already be internal, so it won't get user
streams attached to it, so the transition should generally be allowed.
Add an assert to make sure we're right about this, and have it not
check whether ExitNodes is set, since that's irrelevant to internal
circuits.
IOW, if we were using TrackExitHosts, and we added an excluded node or
removed a node from exitnodes, we wouldn't actually remove the mapping
that points us at the new node.
Also, note with an XXX022 comment a place that I think we are looking
at the wrong string.
The routerset_equal function explicitly handles NULL inputs, so
there's no need to check inputs for NULL before calling it.
Also fix a bug in routerset_equal where a non-NULL routerset with no
entries didn't get counted as equal to a NULL routerset. This was
untriggerable, I think, but potentially annoying down the road.
ExcludeExitNodes foo now means that foo.exit doesn't work. If
StrictNodes is set, then ExcludeNodes foo also overrides foo.exit.
foo.exit , however, still works even if foo is not listed in ExitNodes.
This once maybe made sense when ExitNodes meant "Here are 3 exits;
use them all", but now it more typically means "Here are 3
countries; exit from there." Using non-Fast/Stable exits created a
potential partitioning opportunity and an annoying stability
problem.
(Don't worry about the case where all of our ExitNodes are non-Fast
or non-Stable: we handle that later in the function by retrying with
need_capacity and need_uptime set to 0.)
