Discovery mode interferes with system DNS configuration

[kcning]

Hi, I can't launch librespot because of dns resolve failure. Below is the error msg.
update: backtrace with debug info.

> RUST_BACKTRACE=1 target/debug/librespot --name dummy -u $USERNAME
INFO:librespot: librespot d95c0b3 (2017-04-13). Built on 2017-04-25.
Password for $USERNAME: 
WARN:librespot::apresolve: Failed to resolve Access Point: HTTP error
WARN:librespot::apresolve: Using fallback "ap.spotify.com:80"
INFO:librespot::session: Connecting to AP "ap.spotify.com:80"
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error { repr: Custom(Custom { kind: Other, error: StringError("failed to lookup address information: Name or service not known") }) }', src/libcore/result.rs:868
stack backtrace:
   1:     0x55abe90f4fcc - std::sys::imp::backtrace::tracing::imp::write::h0263459999f7f6d4
   2:     0x55abe90f9fde - std::panicking::default_hook::{{closure}}::hfb43d85657ad3a4c
   3:     0x55abe90f9bda - std::panicking::default_hook::h2f5648e30de6b0b9
   4:     0x55abe90fa47b - std::panicking::rust_panic_with_hook::h9f3930ca8cee8a65
   5:     0x55abe90fa314 - std::panicking::begin_panic::hbe2663b4713ef886
   6:     0x55abe90fa239 - std::panicking::begin_panic_fmt::h6073f869f9b775fa
   7:     0x55abe90fa1c7 - rust_begin_unwind
   8:     0x55abe9145bed - core::panicking::panic_fmt::hc8432e9fe5639d04
   9:     0x55abe86a1702 - core::result::unwrap_failed::h5fbb3a08baa7f504
                        at /build/rust/src/rustc-1.16.0-src/src/libcore/macros.rs:29
  10:     0x55abe8655eb5 - <core::result::Result<T, E>>::unwrap::h2768ec1d3ab2ca21
                        at /build/rust/src/rustc-1.16.0-src/src/libcore/result.rs:745
  11:     0x55abe87df099 - librespot::connection::connect::h5067261cf9d99380
                        at /home/kcning/aur/librespot-git/src/librespot/src/lib.rs:70
  12:     0x55abe87cc2f8 - librespot::session::Session::connect::{{closure}}::h0a07c03a72a48a09
                        at /home/kcning/aur/librespot-git/src/librespot/src/session.rs:97
  13:     0x55abe859ae5c - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::{{closure}}::{{closure}}::hdb3830a9aeeacd30
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:33
  14:     0x55abe86492bc - <core::result::Result<T, E>>::map::h19ed940fdfb2bc33
                        at /build/rust/src/rustc-1.16.0-src/src/libcore/result.rs:465
  15:     0x55abe859a0c2 - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::{{closure}}::hffdfe43ed78d0e72
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:32
  16:     0x55abe870281f - <futures::future::chain::Chain<A, B, C>>::poll::h85c018433a68c8ca
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/chain.rs:38
  17:     0x55abe8598ffb - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::hbd89929e36d16ed7
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:31
  18:     0x55abe8706029 - <futures::future::chain::Chain<A, B, C>>::poll::hc116a2325d4863f3
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/chain.rs:25
  19:     0x55abe859913b - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::he4e9dcadb2f662a4
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:31
  20:     0x55abe87831ef - <futures::future::map::Map<A, F> as futures::future::Future>::poll::h49ff34c4d0b2e7c6
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/map.rs:29
  21:     0x55abe857f2c0 - <alloc::boxed::Box<F> as futures::future::Future>::poll::hc3476db098324739
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/mod.rs:104
  22:     0x55abe85906a8 - <librespot::Main as futures::future::Future>::poll::h0ff13c6db242c9e7
                        at /home/kcning/aur/librespot-git/src/librespot/src/main.rs:248
  23:     0x55abe854f7cc - <futures::task_impl::Spawn<F>>::poll_future::{{closure}}::h22d943f66342f469
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:311
  24:     0x55abe854f9fe - <futures::task_impl::Spawn<T>>::enter::{{closure}}::h69e10c8bee91c828
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:398
  25:     0x55abe85838cf - futures::task_impl::set::{{closure}}::ha22710dc29c990a1
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:50
  26:     0x55abe85561b5 - <std::thread::local::LocalKey<T>>::with::hd4e87ccf21a65c1f
                        at /build/rust/src/rustc-1.16.0-src/src/libstd/thread/local.rs:253
  27:     0x55abe85837ba - futures::task_impl::set::ha5863bcee66741b8
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:47
  28:     0x55abe854f912 - <futures::task_impl::Spawn<T>>::enter::hf638d413c2acf206
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:398
  29:     0x55abe854f76a - <futures::task_impl::Spawn<F>>::poll_future::hfc0a8c7fd581b0eb
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:311
  30:     0x55abe853c87e - tokio_core::reactor::Core::run::{{closure}}::hb121544ca881591c
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-core-0.1.4/src/reactor/mod.rs:231
  31:     0x55abe8549b74 - <scoped_tls::ScopedKey<T>>::set::h50d3deded1ff8c8c
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-0.1.0/src/lib.rs:135
  32:     0x55abe853c4ff - tokio_core::reactor::Core::run::h66fd7a71a0f0f3e4
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-core-0.1.4/src/reactor/mod.rs:230
  33:     0x55abe8591647 - librespot::main::h58bbb806c9a048c8
                        at /home/kcning/aur/librespot-git/src/librespot/src/main.rs:311
  34:     0x55abe91013fa - __rust_maybe_catch_panic
  35:     0x55abe90fabe6 - std::rt::lang_start::h1c5729a586411154
  36:     0x55abe85919b2 - main
  37:     0x7fb0d6837510 - __libc_start_main
  38:     0x55abe853c059 - _start
  39:                0x0 - <unknown>

I have dnscrypt and dnsmasq set up. dnsmasq binds to 127.0.0.1:53, which queries dnscrypt in case the address is not known. I have noticed that, when launching librespot,
I can't resolve any address (system-wide).

> RUST_BACKTRACE=1 librespot --name dummy                 
INFO:librespot: librespot d95c0b3 (2017-04-13). Built on 2017-04-25.
WARN:mdns::fsm: couldn't parse packet from V4(127.0.0.1:63410): packet has non-zero reserved bits

> dig www.google.com

It seems like all the dns resolves are intercepted by librespot. Is this normal? And is there a way to fix this?

[plietar]

librespot uses mDNS for zeroconf authentication by default. This may interfere with unusual DNS setups.
Can you run librespot with --disable-discovery ?

[kcning]

With this option it doesn't interfere with the DNS setups, but I could't login either. This is the backtrace with librespot built with debug info. I guess the dns issue is solved. I can close this thread and open a new one if you prefer that. It's possibly related to #167

> RUST_BACKTRACE=1 target/debug/librespot --disable-discovery --name $DEVNAME --cache /var/cache/librespot -v -u $USERNAME
INFO:librespot: librespot d95c0b3 (2017-04-13). Built on 2017-04-25.
Password for $USERNAME: 
INFO:librespot::session: Connecting to AP "gew1-accesspoint-a-tl61.ap.spotify.com:4070"
thread 'main' panicked at 'Authentication failed', /home/kcning/aur/librespot-git/src/librespot/target/debug/build/librespot-978c8c724a8d5e28/out/lib.rs:365
stack backtrace:
   1:     0x560a11cb1fcc - std::sys::imp::backtrace::tracing::imp::write::h0263459999f7f6d4
   2:     0x560a11cb6fde - std::panicking::default_hook::{{closure}}::hfb43d85657ad3a4c
   3:     0x560a11cb6bda - std::panicking::default_hook::h2f5648e30de6b0b9
   4:     0x560a11cb747b - std::panicking::rust_panic_with_hook::h9f3930ca8cee8a65
   5:     0x560a111c2693 - std::panicking::begin_panic::hde61f6fe38d54e70
                        at /build/rust/src/rustc-1.16.0-src/src/libstd/panicking.rs:517
   6:     0x560a1139cc1a - librespot::connection::authenticate::{{closure}}::hd6a2940cb52790ae
                        at /home/kcning/aur/librespot-git/src/librespot/src/lib.rs:70
   7:     0x560a1115761d - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::{{closure}}::{{closure}}::h479b989cda8c9f98
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:33
   8:     0x560a1120fda6 - <core::result::Result<T, E>>::map::hf2b0b0cacc60bb58
                        at /build/rust/src/rustc-1.16.0-src/src/libcore/result.rs:465
   9:     0x560a11156514 - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::{{closure}}::h3b2ac7974848acad
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:32
  10:     0x560a112b9888 - <futures::future::chain::Chain<A, B, C>>::poll::h0e8c7375b787f232
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/chain.rs:38
  11:     0x560a11155efb - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::h724442b22cb14f2f
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:31
  12:     0x560a112de080 - <alloc::boxed::Box<F> as futures::future::Future>::poll::h3a4fda7d4de739e0
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/mod.rs:104
  13:     0x560a112c304c - <futures::future::chain::Chain<A, B, C>>::poll::hc116a2325d4863f3
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/chain.rs:31
  14:     0x560a1115613b - <futures::future::and_then::AndThen<A, B, F> as futures::future::Future>::poll::he4e9dcadb2f662a4
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/and_then.rs:31
  15:     0x560a113401ef - <futures::future::map::Map<A, F> as futures::future::Future>::poll::h49ff34c4d0b2e7c6
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/map.rs:29
  16:     0x560a1113c2c0 - <alloc::boxed::Box<F> as futures::future::Future>::poll::hc3476db098324739
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/future/mod.rs:104
  17:     0x560a1114d6a8 - <librespot::Main as futures::future::Future>::poll::h0ff13c6db242c9e7
                        at /home/kcning/aur/librespot-git/src/librespot/src/main.rs:248
  18:     0x560a1110c7cc - <futures::task_impl::Spawn<F>>::poll_future::{{closure}}::h22d943f66342f469
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:311
  19:     0x560a1110c9fe - <futures::task_impl::Spawn<T>>::enter::{{closure}}::h69e10c8bee91c828
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:398
  20:     0x560a111408cf - futures::task_impl::set::{{closure}}::ha22710dc29c990a1
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:50
  21:     0x560a111131b5 - <std::thread::local::LocalKey<T>>::with::hd4e87ccf21a65c1f
                        at /build/rust/src/rustc-1.16.0-src/src/libstd/thread/local.rs:253
  22:     0x560a111407ba - futures::task_impl::set::ha5863bcee66741b8
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:47
  23:     0x560a1110c912 - <futures::task_impl::Spawn<T>>::enter::hf638d413c2acf206
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:398
  24:     0x560a1110c76a - <futures::task_impl::Spawn<F>>::poll_future::hfc0a8c7fd581b0eb
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.10/src/task_impl/mod.rs:311
  25:     0x560a110f987e - tokio_core::reactor::Core::run::{{closure}}::hb121544ca881591c
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-core-0.1.4/src/reactor/mod.rs:231
  26:     0x560a11106b74 - <scoped_tls::ScopedKey<T>>::set::h50d3deded1ff8c8c
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-0.1.0/src/lib.rs:135
  27:     0x560a110f94ff - tokio_core::reactor::Core::run::h66fd7a71a0f0f3e4
                        at /home/kcning/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-core-0.1.4/src/reactor/mod.rs:230
  28:     0x560a1114e647 - librespot::main::h58bbb806c9a048c8
                        at /home/kcning/aur/librespot-git/src/librespot/src/main.rs:311
  29:     0x560a11cbe3fa - __rust_maybe_catch_panic
  30:     0x560a11cb7be6 - std::rt::lang_start::h1c5729a586411154
  31:     0x560a1114e9b2 - main
  32:     0x7f1234d42510 - __libc_start_main
  33:     0x560a110f9059 - _start
  34:                0x0 - <unknown>

[plietar]

No, I'd prefer keeping this issue open. librespot shouldn't interfere with the system's DNS configuration, so this is still a bug.
Moving to #167 for the authentication failure issue.

[sandervandegeijn]

This looks a bit like the issue I'm experiencing: https://github.com/shanemeagher/service.librespot/issues/3

Doesn't resolve as well, no custom DNS setup btw, just libreelec out of the box and Openwrt on the router (gets results from provider DNS and Google as backup).

[dowhiletrue]

I use avahi daemon (zerconf) for several services. Whenever I want to use librespot I have to stop that daemon, which runs on port 5353, first. Does librespot has its own zeroconf functionality which interferes with avahi?

[shanemeagher]

@dowhiletrue yes, librespot has mdns / zeroconf built-in. Pull Request #246 allows librespot to be built to use an existing avahi install which should avoid this conflict.

Until this is merged, setting disallow-other-stacks=no in avahi-daemon.conf, should allow both to co-exist.