In short: epee's http client is garbage, standard violating, and
unreliable.
This completely removes the epee http client support and replaces it
with cpr, a curl-based C++ wrapper. rpc/http_client.h wraps cpr for RPC
requests specifically, but it is also usable directly.
This replacement has a number of advantages:
- requests are considerably more reliable. The epee http client code
assumes that a connection will be kept alive forever, and returns a
failure if a connection is ever closed. This results in some very
annoying things: for example, preparing a transaction and then waiting
a long tim before confirming it will usually result in an error
communication with the daemon. This is just terribly behaviour: the
right thing to do on a connection failure is to resubmit the request.
- epee's http client is broken in lots of other ways: for example, it
tries throwing SSL at the port to see if it is HTTPS, but this is
protocol violating and just breaks (with a several second timeout) on
anything that *isn't* epee http server (for example, when lokid is
behind a proxying server).
- even when it isn't doing the above, the client breaks in other ways:
for example, there is a comment (replaced in this PR) in the Trezor PR
code that forces a connection close after every request because epee's
http client doesn't do proper keep-alive request handling.
- it seems noticeably faster to me in practical use in this PR; both
simple requests (for example, when running `lokid status`) and
wallet<->daemon connections are faster, probably because of crappy
code in epee. (I think this is also related to the throw-ssl-at-it
junk above: the epee client always generates an ssl certificate during
static initialization because it might need one at some point).
- significantly reduces the amount of code we have to maintain.
- removes all the epee ssl option code: curl can handle all of that just
fine.
- removes the epee socks proxy code; curl can handle that just fine.
(And can do more: it also supports using HTTP/HTTPS proxies).
- When a cli wallet connection fails we know show why it failed (which
now is an error message from curl), which could have all sorts of
reasons like hostname resolution failure, bad ssl certificate, etc.
Previously you just got a useless generic error that tells you
nothing.
Other related changes in this PR:
- Drops the check-for-update and download-update code. To the best of
my knowledge these have never been supported in loki-core and so it
didn't seem worth the trouble to convert them to use cpr for the
requests.
- Cleaned up node_rpc_proxy return values: there was an inconsistent mix
of ways to return errors and how the returned strings were handled.
Instead this cleans it up to return a pair<bool, val>, which (with
C++17) can be transparently captured as:
auto [success, val] = node.whatever(req);
This drops the failure message string, but it was almost always set to
something fairly useless (if we want to resurrect it we could easily
change the first element to be a custom type with a bool operator for
success, and a `.error` attribute containing some error string, but
for the most part the current code wasn't doing much useful with the
failure string).
- changed local detection (for automatic trusted daemon determination)
to just look for localhost, and to not try to resolve anything.
Trusting non-public IPs does not work well (e.g. with lokinet where
all .loki addresses resolve to a local IP).
- ssl fingerprint option is removed; this isn't supported by curl
(because it is essentially just duplicating what a custom cainfo
bundle does)
- --daemon-ssl-allow-chained is removed; it wasn't a useful option (if
you don't want chaining, don't specify a cainfo chain).
- --daemon-address is now a URL instead of just host:port. (If you omit
the protocol, http:// is prepended).
- --daemon-host and --daemon-port are now deprecated and produce a
warning (in simplewallet) if used; the replacement is to use
--daemon-address.
- --daemon-ssl is deprecated; specify --daemon-address=https://whatever
instead.
- the above three are now hidden from --help
- reordered the wallet connection options to make more logical sense.
- Add libuv submodule (only needed and built on Windows)
- Temporarily switch uWebSockets to my github repo: I submitted some
mingw compilation fixes upstream; as soon as a new upstream release
comes out we will switch this back to the upstream repo.
- Switch BOOST_SCOPE_EXIT to LOKI_DEFER
- Don't compile `closefrom()` on Windows (it isn't used, and generates
an unused function warning).
This replaces the NIH epee http server which does not work all that well
with an external C++ library called uWebSockets. Fundamentally this
gives the following advantages:
- Much less code to maintain
- Just one thread for handling HTTP connections versus epee's pool of
threads
- Uses existing LokiMQ job server and existing thread pool for handling
the actual tasks; they are processed/scheduled in the same "rpc" or
"admin" queues as lokimq rpc calls. One notable benefit is that "admin"
rpc commands get their own queue (and thus cannot be delayed by long rpc
commands). Currently the lokimq threads and the http rpc thread pool
and the p2p thread pool and the job queue thread pool and the dns lookup
thread pool and... are *all* different thread pools; this is a step
towards consolidating them.
- Very little mutex contention (which has been a major problem with epee
RPC in the past): there is one mutex (inside uWebSockets) for putting
responses back into the thread managing the connection; everything
internally gets handled through (lock-free) lokimq inproc sockets.
- Faster RPC performance on average, and much better worst case
performance. Epee's http interface seems to have some race condition
that ocassionally stalls a request (even a very simple one) for a dozen
or more seconds for no good reason.
- Long polling gets redone here to no longer need threads; instead we
just store the request and respond when the thread pool, or else in a
timer (that runs once/second) for timing out long polls.
---
The basic idea of how this works from a high level:
We launch a single thread to handle HTTP RPC requests and response data.
This uWebSockets thread is essentially running an event loop: it never
actually handles any logic; it only serves to shuttle data that arrives
in a request to some other thread, and then, at some later point, to
send some reply back to that waiting connection. Everything is
asynchronous and non-blocking here: the basic uWebSockets event loop
just operates as things arrive, passes it off immediately, and goes back
to waiting for the next thing to arrive.
The basic flow is like this:
0. uWS thread -- listens on localhost:22023
1. uWS thread -- incoming request on localhost:22023
2. uWS thread -- fires callback, which injects the task into the LokiMQ job queue
3. LMQ main loop -- schedules it as an RPC job
4. LMQ rpc thread -- Some LokiMQ thread runs it, gets the result
5. LMQ rpc thread -- Result gets queued up for the uWS thread
6. uWS thread -- takes the request and starts sending it
(asynchronously) back to the requestor.
In more detail:
uWebSockets has registered has registered handlers for non-jsonrpc
requests (legacy JSON or binary). If the port is restricted then admin
commands get mapped to a "Access denied" response handler, otherwise
public commands (and admin commands on an unrestricted port) go to the
rpc command handler.
POST requests to /json_rpc have their own handler; this is a little
different than the above because it has to parse the request before it
can determine whether it is allowed or not, but once this is done it
continues roughly the same as legacy/binary requests.
uWebSockets then listens on the given IP/port for new incoming requests,
and starts listening for requests in a thread (we own this thread).
When a request arrives, it fires the event handler for that request.
(This may happen multiple times, if the client is sending a bunch of
data in a POST request). Once we have the full request, we then queue
the job in LokiMQ, putting it in the "rpc" or "admin" command
categories. (The one practical different here is that "admin" is
configured to be allowed to start up its own thread if all other threads
are busy, while "rpc" commands are prioritized along with everything
else.) LokiMQ then schedules this, along with native LokiMQ "rpc." or
"admin." requests.
When a LMQ worker thread becomes available, the RPC command gets called
in it and runs. Whatever output it produces (or error message, if it
throws) then gets wrapped up in jsonrpc boilerplate (if necessary), and
delivered to the uWebSockets thread to be sent in reply to that request.
uWebSockets picks up the data and sends whatever it can without
blocking, then buffers whatever it couldn't send to be sent again in a
later event loop iteration once the requestor can accept more data.
(This part is outside lokid; we only have to give uWS the data and let
it worry about delivery).
---
PR specifics:
Things removed from this PR:
1. ssl settings; with this PR the HTTP RPC interface is plain-text. The
previous default generated a self-signed certificate for the server on
startup and then the client accepted any certificate. This is actually
*worse* than unencrypted because it is entirely MITM-readable and yet
might make people think that their RPC communication is encrypted, and
setting up actual certificates is difficult enough that I think most
people don't bother.
uWebSockets *does* support HTTPS, and we could glue the existing options
into it, but I'm not convinced it's worthwhile: it works much better to
put HTTPS in a front-end proxy holding the certificate that proxies
requests to the backend (which can then listen in restricted mode on
some localhost port). One reason this is better is that it is much
easier to reload and/or restart such a front-end server, while
certificate updates with lokid require a full restart. Another reason
is that you get an error page instead of a timeout if something is wrong
with the backend. Finally we also save having to generate a temporary
certificate on *every* lokid invocation.
2. HTTP Digest authentication. Digest authentication is obsolete (and
was already obsolete when it got added to Monero). HTTP-Digest was
originally an attempt to provide a password authentication mechanism
that does not leak the password in transit, but still required that the
server know the password. It only has marginal value against replay
attacks, and is made entirely obsolete by sending traffic over HTTPS
instead. No client out there supports Digest but *not* Basic auth, and
so given the limited usefulness it seems pointless to support more than
Basic auth for HTTP RPC login.
What's worse is that epee's HTTP Digest authentication is a terrible
implementation: it uses boost::spirit -- a recursive descent parser
meant for building complex language grammars -- just to parse a single
HTTP header for Digest auth. This is a big load of crap that should
never have been accepted upstream, and that we should get rid of (even
if we wanted to support Digest auth it takes less than 100 lines of code
to do it when *not* using a recursive descent parser).
Switch loki dev branch to C++17 compilation, and update the code with
various C++17 niceties.
- stop including the (deprecated) lokimq/string_view.h header and
instead switch everything to use std::string_view and `""sv` instead of
`""_sv`.
- std::string_view is much nicer than epee::span, so updated various
loki-specific code to use it instead.
- made epee "portable storage" serialization accept a std::string_view
instead of const lvalue std::string so that we can avoid copying.
- switched from mapbox::variant to std::variant
- use `auto [a, b] = whatever()` instead of `T1 a; T2 b; std::tie(a, b)
= whatever()` in a couple places (in the wallet code).
- switch to std::lock(...) instead of boost::lock(...) for simultaneous
lock acquisition. boost::lock() won't compile in C++17 mode when given
locks of different types.
- removed various pre-C++17 workarounds, e.g. for fold expressions,
unused argument attributes, and byte-spannable object detection.
- class template deduction means lock types no longer have to specify
the mutex, so `std::unique_lock<std::mutex> lock{mutex}` can become
`std::unique_lock lock{mutex}`. This will make switching any mutex
types (e.g. from boost to std mutexes) far easier as you just have to
update the type in the header and everything should work. This also
makes the tools::unique_lock and tools::shared_lock methods redundant
(which were a sort of poor-mans-pre-C++17 way to eliminate the
redundancy) so they are now gone and replaced with direct unique_lock or
shared_lock constructions.
- Redid the LNS validation using a string_view; instead of using raw
char pointers the code now uses a string view and chops off parts of the
view as it validates. So, for instance, it starts with "abcd.loki",
validates the ".loki" and chops the view to "abcd", then validates the
first character and chops to "bcd", validates the last and chops to
"bc", then can just check everything remaining for is-valid-middle-char.
- LNS validation gained a couple minor validation checks in the process:
- slightly tightened the requirement on lokinet addresses to require
that the last character of the mapped address is 'y' or 'o' (the
last base32z char holds only one significant bit).
- In parse_owner_to_generic_owner made sure that the owner value has
the correct size (otherwise we could up end not filling or
overfilling the pubkey buffer).
- Replaced base32z/base64/hex conversions with lokimq's versions which
have a nicer interface, are better optimized, and don't depend on epee.
This adds a static dependency script for libraries like boost, unbound,
etc. to cmake, invokable with:
cmake .. -DBUILD_STATIC_DEPS=ON
which downloads and builds static versions of all our required
dependencies (boost, unbound, openssl, ncurses, etc.). It also implies
-DSTATIC=ON to build other vendored deps (like miniupnpc, lokimq) as
static as well.
Unlike the contrib/depends system, this is easier to maintain (one
script using nicer cmake with functions instead of raw Makefile
spaghetti code), and isn't concerned with reproducible builds -- this
doesn't rebuild the compiler, for instance. It also works with the
existing build system so that it is simply another way to invoke the
cmake build scripts but doesn't require any external tooling.
This works on Linux, Mac, and Windows.
Some random comments on this commit (for preserving history):
- Don't use target_link_libraries on imported targets. Newer cmake is
fine with it, but Bionic's cmake doesn't like it but seems okay with
setting the properties directly.
- This rebuilds libzmq and libsodium, even though there is some
provision already within loki-core to do so: however, the existing
embedded libzmq fails with the static deps because it uses libzmq's
cmake build script, which relies on pkg-config to find libsodium which
ends up finding the system one (or not finding any), rather than the one
we build with DownloadLibSodium. Since both libsodium and libzmq are
faily simple builds it seemed easiest to just add them to the cmake
static build rather than trying to shoehorn the current code into the
static build script.
- Half of the protobuf build system ignores CC/CXX just because Google,
and there's no documentation anywhere except for a random closed bug
report about needing to set these other variables (CC_FOR_BUILD,
CXX_FOR_BUILD) instead, but you need to. Thanks Google.
- The boost build is set to output very little because even the minimum
-d1 output level spams ~15k lines of output just for the headers it
installs.
There's really no reason to submodule it - we work with pretty much any
libunbound version, and it's a very commonly available library
(comparable to sqlite3 or boost, which we don't submodule).
This removes the submodule and switches it to a hard dependency.
Change the blink quorum checksum value on the wire to a positive
uint64_t rather than the 2s complement int64_t encoded value that
bt_value produces by default. Also updates the bt_dict_consumer code
to handle the needed int64_t -> uint64_t conversion if a negative
int64_t (from a previous lokid version) arrives on the wire.
LokiMQ's ConnectionID wasn't working properly for routing replies to
incoming connections from non-service nodes; I already noticed and fixed
this in the lokimq update in the LMQ RPC overhaul branch, but we need to
bring it back into master.
This also changes the SN selection for blink submissions so that we
always prefer submitting to higher version service nodes (and then
randomize among SNs with the same version). This should make blinks
work robustly again: as long as the daemon the wallet talks to and at
least *one* of the 20 quorum members is upgraded we should get a reply
properly.
With the 1.1.0 update, rather than LokiMQ getting a callback that it
invokes on connection to get auth level for the duration of that
connection, it now checks authentication each time a command is invoked.
This improves message reliability (because on an invocation failure the
remote doesn't have to reconnect to be reauthenticated).
This helps storage server greatly (which has some tricky initialization
issue that requires it to initialize lokimq before it has the SN list);
it is less needed for quorumnet communications (which have been all
using connection-time authenciation for a while now), but this change
does some one "weirdness" that a remote client may be unable to issue a
command that they *can* issue if they reconnect.
The lokid update here piggypacks the call into quorumnet in quorum_cop's
`add_block` callback to make the call; this would be far cleaner if we
replaced the callbacks with stateful std::function's instead of
inherited base class pointers, but I didn't want to go that far in this
PR.
- set WITH_SYSTEMD=OFF in contrib/depends so that we don't try to go
look for it on the host system.
- link icu libs properly
- don't build embedded zmq but rather set up a target so that loki-mq
uses the externally built one
- fix OpenSSL::Crypto not properly depending on ws2_32
- build boost atomic in the built boost because boost::thread depends on
it (and we were just getting lucky before by not happening to touch
anything that needed it)
- make bundled unbound link against the `extra` interface for various
required windows crap (ws2_32 and other stuff).
- updating to latest loki-mq (1.0.0 + various linking fixes)
- BUILD_SHARED_LIBS was being handled very strangely; make it a full
option instead (defaulting to off) that a cmake invoker can specify, as
per cmake recommendations.
- travis ci tweaks/changes:
- Add a static bionic build
- Simplify cmake argument code
- Add `--version` invocation for lokid and loki-wallet-cli to test
that the binaries were linked properly.
- always build an embedded sodium statically; if we do it dynamically
and an older system one exists we are going to have trouble.
- don't force epee and blocks to be static; rather they get controlled
by the above BUILD_SHARED_LIBS, just like all the other internal
libraries.
- use some PkgConfig:: imported targets rather than bunch-of-variables.
This adds the loki-mq dependency and replaces SNNetwork with it (along
with some syntax updates for how loki-mq changed a bit from SNNetwork).
This also replaces common/hex.h and common/string_view.h with loki-mq's
faster (hex) and more complete and tested (string_view) implementations.
The archaic (i.e. decade old) cmake usage here really got in the way of
trying to properly use newer libraries (like lokimq), so this undertakes
overhauling it considerably to make it much more sane (and significantly
reduce the size).
I left more of the architecture-specific bits in the top-level
CMakeLists.txt intact; most of the efforts here are about properly
loading dependencies, specifying dependencies and avoiding a whole pile
of cmake antipatterns.
This bumps the required cmake version to 3.5, which is what xenial comes
with.
- extensive use of interface libraries to include libraries,
definitions, and include paths
- use Boost::whatever instead of ${Boost_WHATEVER_LIBRARY}. The
interface targets are (again) much better as they also give you any
needed include or linking flags without needing to worry about them.
- don't list header files when building things. This has *never* been
correct cmake usage (cmake has always known how to wallet_rpc_headers
the headers that .cpp files include to know about build changes).
- remove the loki_add_library monstrosity; it breaks target names and
makes compiling less efficient because the author couldn't figure out
how to link things together.
- make loki_add_executable take the output filename, and set the output
path to bin/ and install to bin because *every single usage* of
loki_add_executable was immediately followed by setting the output
filename and setting the output path to bin/ and installing to bin.
- move a bunch of crap that is only used in one particular
src/whatever/CMakeLists.txt into that particular CMakeLists.txt instead
of the top level CMakeLists.txt (or src/CMakeLists.txt).
- Remove a bunch of redundant dependencies; most of them look like they
were just copy-and-pasted in, and many more aren't needed (since they
are implied by the PUBLIC linking of other dependencies).
- Removed `die` since it just does a FATAL_ERROR, but adds color (which
is useless since CMake already makes FATAL_ERRORs perfectly visible).
- Change the way LOKI_DAEMON_AND_WALLET_ONLY works to just change the
make targets to daemon and simplewallet rather than changing the build
process (this should make it faster, too, since there are various other
things that will be excluded).
We unnecessarily vendor this much of the time because the existing
search code is primitive; use pkg-config instead which works much
better, and lets us properly depend on particular versions.
This lets us reenable the system miniupnpc for >=2.1, saving an
unnecessary compilation most of the time. From the git history it
appears that it is built from source always unconditionally in a fit of
rage.
42397359 Fixup 32bit arm build (TheCharlatan)
a06d2581 Fix Windows build (TheCharlatan)
ecaf5b3f Add libsodium to the packages, the arm build was complaining about it. (TheCharlatan)
cbbf4d24 Adapt translations to upstream changes (TheCharlatan)
db571546 Updated pcsc url (TheCharlatan)
f0ba19fd Add lrelease to the depends (TheCharlatan)
cfb30462 Add Miniupnp submodule (TheCharlatan)
5f7da005 Unbound is now a submodule. Adapt depends for this. (TheCharlatan)
d6b9bdd3 Update readmes to reflect the usage of depends (TheCharlatan)
56b6e41e Add support for apple and arm building (TheCharlatan)
29311fd1 Disable stack unwinding for mingw32 depends build. (TheCharlatan)
8db3d573 Modify depends for monero's dependencies (TheCharlatan)
0806a23a Initial depends addition (TheCharlatan)
Drop miniupnp and unbound depends builds. Make sure that build variables are propageted properly to unbound and miniupnp.
Rebase to after the v0.12 release
Add readline, ldns, graphviz, unbound to depends packages
Add a cmake toolchain file to depends that is uniquely created for every build and placed in triple/share/toolchain.cmake
This file is then passed to cmake with -DCMAKE_TOOLCHAIN_FILE=/path/to/triple/share/toolchain.cmake
Add the boost locale package to depends
In the depends cmake toolchain file, a DEPENDS flag is added
to exclude, or change cmake checks done that are required for depends
Link miniupnpc and unwind from depends and not external
Add libiconv and icu4c to depends, required for mingw32 builds.
Headers (winsock) need to be lower case in order to compile on unix systems.
This should not affect building on windows.
This allows the OpenSSL function checks to compile in unbound's CMake
configuration.
Otherwise, the functions SHA256() and EVP_sha512() won't be called from
libunbound as possible algorithms.
They had not been compiling because static OpenSSL libraries were being
used, along with lack of -ldl. The static library preference is
unnecessary for the checks, so use default suffixes ordering for
CMAKE_FIND_LIBRARY_SUFFIXES when building unbound.
Related files:
configure_checks.cmake
external/unbound/validator/val_secalgo.c
secalgo_ds_digest(), setup_key_digest()
Forgot that CMake vars set to PARENT_SCOPE will still vanish if that
parent scope goes...out of scope. LMDB vars elevated one more scope to
compensate for moving db_drivers/ into external/
