diff --git a/Cargo.lock b/Cargo.lock
index 1c5c1a3..6cdf533 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -33,6 +33,7 @@ dependencies = [
 name = "aquatic_udp"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "aquatic_common",
  "bittorrent_udp",
  "cli_helpers",
@@ -55,6 +56,7 @@ dependencies = [
 name = "aquatic_udp_bench"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "aquatic_udp",
  "bittorrent_udp",
  "cli_helpers",
@@ -72,6 +74,7 @@ dependencies = [
 name = "aquatic_udp_load_test"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "bittorrent_udp",
  "cli_helpers",
  "crossbeam-channel",
@@ -91,6 +94,7 @@ dependencies = [
 name = "aquatic_ws"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "aquatic_common",
  "cli_helpers",
  "either",
diff --git a/TODO.md b/TODO.md
index 68aead1..de95477 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,10 +3,7 @@
 ## aquatic_ws
 * ipv4 / ipv6 split state?
 * network
-  * handle tls certificate parse errors etc better
-    * parse once only
-    * exit with error message, not with panic, use anyhow
-  * handle socket binding errors better (print them and exit), use anyhow
+  * panic/error in workers: exit program with non-zero exit code
   * send/recv buffer size config
   * limit ws message sizes?
   * poll: check if event is readable first, otherwise run `continue`
diff --git a/aquatic_udp/Cargo.toml b/aquatic_udp/Cargo.toml
index 69172d2..b89eaab 100644
--- a/aquatic_udp/Cargo.toml
+++ b/aquatic_udp/Cargo.toml
@@ -13,6 +13,7 @@ path = "src/lib/lib.rs"
 name = "aquatic_udp"
 
 [dependencies]
+anyhow = "1"
 aquatic_common = { path = "../aquatic_common" }
 bittorrent_udp = { path = "../bittorrent_udp" }
 cli_helpers = { path = "../cli_helpers" }
diff --git a/aquatic_udp/src/lib/lib.rs b/aquatic_udp/src/lib/lib.rs
index 07f0476..089d31a 100644
--- a/aquatic_udp/src/lib/lib.rs
+++ b/aquatic_udp/src/lib/lib.rs
@@ -15,7 +15,7 @@ use config::Config;
 use common::State;
 
 
-pub fn run(config: Config){
+pub fn run(config: Config) -> ::anyhow::Result<()> {
     let state = State::new();
 
     let (request_sender, request_receiver) = unbounded();
diff --git a/aquatic_udp_bench/Cargo.toml b/aquatic_udp_bench/Cargo.toml
index 4900bdc..03257cb 100644
--- a/aquatic_udp_bench/Cargo.toml
+++ b/aquatic_udp_bench/Cargo.toml
@@ -15,6 +15,7 @@ name = "aquatic_udp_bench_handlers"
 name = "plot_pareto"
 
 [dependencies]
+anyhow = "1"
 aquatic_udp = { path = "../aquatic_udp" }
 bittorrent_udp = { path = "../bittorrent_udp" }
 cli_helpers = { path = "../cli_helpers" }
diff --git a/aquatic_udp_bench/src/bin/aquatic_udp_bench_handlers/main.rs b/aquatic_udp_bench/src/bin/aquatic_udp_bench_handlers/main.rs
index f81b674..c450134 100644
--- a/aquatic_udp_bench/src/bin/aquatic_udp_bench_handlers/main.rs
+++ b/aquatic_udp_bench/src/bin/aquatic_udp_bench_handlers/main.rs
@@ -45,7 +45,7 @@ fn main(){
 }
 
 
-pub fn run(bench_config: BenchConfig){
+pub fn run(bench_config: BenchConfig) -> ::anyhow::Result<()> {
     // Setup common state, spawn request handlers
 
     let state = State::new();
@@ -111,6 +111,8 @@ pub fn run(bench_config: BenchConfig){
     print_results("Connect: ", c.0, c.1);
     print_results("Announce:", a.0, a.1);
     print_results("Scrape:  ", s.0, s.1);
+
+    Ok(())
 }
 
 
diff --git a/aquatic_udp_load_test/Cargo.toml b/aquatic_udp_load_test/Cargo.toml
index 8c7b62a..da6fca1 100644
--- a/aquatic_udp_load_test/Cargo.toml
+++ b/aquatic_udp_load_test/Cargo.toml
@@ -9,6 +9,7 @@ license = "Apache-2.0"
 name = "aquatic_udp_load_test"
 
 [dependencies]
+anyhow = "1"
 bittorrent_udp = { path = "../bittorrent_udp" }
 cli_helpers = { path = "../cli_helpers" }
 crossbeam-channel = "0.4"
diff --git a/aquatic_udp_load_test/src/main.rs b/aquatic_udp_load_test/src/main.rs
index 239d543..f8a6127 100644
--- a/aquatic_udp_load_test/src/main.rs
+++ b/aquatic_udp_load_test/src/main.rs
@@ -32,7 +32,7 @@ pub fn main(){
 }
 
 
-fn run(config: Config){
+fn run(config: Config) -> ::anyhow::Result<()> {
     if config.handler.weight_announce + config.handler.weight_connect + config.handler.weight_scrape == 0 {
         panic!("Error: at least one weight must be larger than zero.");
     }
@@ -129,7 +129,9 @@ fn run(config: Config){
     monitor_statistics(
         state,
         &config
-    )
+    );
+
+    Ok(())
 }
 
 
diff --git a/aquatic_ws/Cargo.toml b/aquatic_ws/Cargo.toml
index 2601720..0a19ce9 100644
--- a/aquatic_ws/Cargo.toml
+++ b/aquatic_ws/Cargo.toml
@@ -14,6 +14,7 @@ name = "aquatic_ws"
 path = "src/bin/main.rs"
 
 [dependencies]
+anyhow = "1"
 aquatic_common = { path = "../aquatic_common" }
 cli_helpers = { path = "../cli_helpers" }
 either = "1"
diff --git a/aquatic_ws/src/lib/lib.rs b/aquatic_ws/src/lib/lib.rs
index a58185d..510cb4a 100644
--- a/aquatic_ws/src/lib/lib.rs
+++ b/aquatic_ws/src/lib/lib.rs
@@ -1,4 +1,7 @@
 use std::time::Duration;
+use std::fs::File;
+use std::io::Read;
+use native_tls::{Identity, TlsAcceptor};
 
 pub mod common;
 pub mod config;
@@ -11,7 +14,9 @@ use common::*;
 use config::Config;
 
 
-pub fn run(config: Config){
+pub fn run(config: Config) -> anyhow::Result<()> {
+    let opt_tls_acceptor = create_tls_acceptor(&config)?;
+
     let state = State::default();
 
     let (in_message_sender, in_message_receiver) = ::flume::unbounded();
@@ -21,6 +26,7 @@ pub fn run(config: Config){
     for i in 0..config.socket_workers {
         let config = config.clone();
         let in_message_sender = in_message_sender.clone();
+        let opt_tls_acceptor = opt_tls_acceptor.clone();
 
         let (out_message_sender, out_message_receiver) = ::flume::unbounded();
 
@@ -32,6 +38,7 @@ pub fn run(config: Config){
                 i,
                 in_message_sender,
                 out_message_receiver,
+                opt_tls_acceptor
             );
         });
     }
@@ -57,4 +64,27 @@ pub fn run(config: Config){
 
         tasks::clean_torrents(&state);
     }
+}
+
+
+pub fn create_tls_acceptor(
+    config: &Config,
+) -> anyhow::Result<Option<TlsAcceptor>> {
+    if config.network.use_tls {
+        let mut identity_bytes = Vec::new();
+        let mut file = File::open(&config.network.tls_pkcs12_path)?;
+
+        file.read_to_end(&mut identity_bytes)?;
+
+        let identity = Identity::from_pkcs12(
+            &mut identity_bytes,
+            &config.network.tls_pkcs12_password
+        )?;
+
+        let acceptor = TlsAcceptor::new(identity)?;
+
+        Ok(Some(acceptor))
+    } else {
+        Ok(None)
+    }
 }
\ No newline at end of file
diff --git a/aquatic_ws/src/lib/network/mod.rs b/aquatic_ws/src/lib/network/mod.rs
index 8239fd6..31a21d6 100644
--- a/aquatic_ws/src/lib/network/mod.rs
+++ b/aquatic_ws/src/lib/network/mod.rs
@@ -23,12 +23,39 @@ pub fn run_socket_worker(
     socket_worker_index: usize,
     in_message_sender: InMessageSender,
     out_message_receiver: OutMessageReceiver,
+    opt_tls_acceptor: Option<TlsAcceptor>,
+){
+    match create_listener(&config){
+        Ok(listener) => {
+            run_poll_loop(
+                config,
+                socket_worker_index,
+                in_message_sender,
+                out_message_receiver,
+                listener,
+                opt_tls_acceptor
+            );
+        },
+        Err(err) => {
+            eprintln!("Couldn't create TCP listener: {}", err)
+        }
+    }
+}
+
+
+pub fn run_poll_loop(
+    config: Config,
+    socket_worker_index: usize,
+    in_message_sender: InMessageSender,
+    out_message_receiver: OutMessageReceiver,
+    listener: ::std::net::TcpListener,
+    opt_tls_acceptor: Option<TlsAcceptor>,
 ){
     let poll_timeout = Duration::from_millis(
         config.network.poll_timeout_milliseconds
     );
 
-    let mut listener = TcpListener::from_std(create_listener(&config));
+    let mut listener = TcpListener::from_std(listener);
     let mut poll = Poll::new().expect("create poll");
     let mut events = Events::with_capacity(config.network.poll_event_capacity);
 
@@ -36,12 +63,6 @@ pub fn run_socket_worker(
         .register(&mut listener, Token(0), Interest::READABLE)
         .unwrap();
 
-    let opt_tls_acceptor = if config.network.use_tls {
-        Some(create_tls_acceptor(&config))
-    } else {
-        None
-    };
-
     let mut connections: ConnectionMap = HashMap::new();
 
     let mut poll_token_counter = Token(0usize);
diff --git a/aquatic_ws/src/lib/network/utils.rs b/aquatic_ws/src/lib/network/utils.rs
index 0cbb840..45ca98e 100644
--- a/aquatic_ws/src/lib/network/utils.rs
+++ b/aquatic_ws/src/lib/network/utils.rs
@@ -1,9 +1,6 @@
-use std::fs::File;
-use std::io::Read;
 use std::time::Instant;
 
 use mio::Token;
-use native_tls::{Identity, TlsAcceptor};
 use net2::{TcpBuilder, unix::UnixTcpBuilderExt};
 
 use crate::config::Config;
@@ -11,53 +8,26 @@ use crate::config::Config;
 use super::connection::*;
 
 
-pub fn create_listener(config: &Config) -> ::std::net::TcpListener {
-    let mut builder = &{
-        if config.network.address.is_ipv4(){
-            TcpBuilder::new_v4().expect("socket: build")
-        } else {
-            TcpBuilder::new_v6().expect("socket: build")
-        }
-    };
+pub fn create_listener(
+    config: &Config
+) -> ::anyhow::Result<::std::net::TcpListener> {
+    let builder = if config.network.address.is_ipv4(){
+        TcpBuilder::new_v4()
+    } else {
+        TcpBuilder::new_v6()
+    }?;
 
-    builder = builder.reuse_port(true)
-        .expect("socket: set reuse port");
+    let builder = builder.reuse_port(true)?;
+    let builder = builder.bind(&config.network.address)?;
 
-    builder = builder.bind(&config.network.address)
-        .expect(&format!("socket: bind to {}", &config.network.address));
+    let listener = builder.listen(128)?;
 
-    let listener = builder.listen(128)
-        .expect("tcpbuilder to tcp listener");
+    listener.set_nonblocking(true)?;
 
-    listener.set_nonblocking(true)
-        .expect("socket: set nonblocking");
-
-    listener
+    Ok(listener)
 }
 
 
-pub fn create_tls_acceptor(
-    config: &Config,
-) -> TlsAcceptor {
-    let mut identity_bytes = Vec::new();
-    let mut file = File::open(&config.network.tls_pkcs12_path)
-        .expect("open pkcs12 file");
-
-    file.read_to_end(&mut identity_bytes).expect("read pkcs12 file");
-
-    let identity = Identity::from_pkcs12(
-        &mut identity_bytes,
-        &config.network.tls_pkcs12_password
-    ).expect("create pkcs12 identity");
-
-    let acceptor = TlsAcceptor::new(identity)   
-        .expect("create TlsAcceptor");
-
-    acceptor
-}
-
-
-
 /// Don't bother with deregistering from Poll. In my understanding, this is
 /// done automatically when the stream is dropped, as long as there are no
 /// other references to the file descriptor, such as when it is accessed
diff --git a/cli_helpers/src/lib.rs b/cli_helpers/src/lib.rs
index 020e318..858cd34 100644
--- a/cli_helpers/src/lib.rs
+++ b/cli_helpers/src/lib.rs
@@ -18,6 +18,49 @@ struct AppOptions {
 }
 
 
+pub fn run_app_with_cli_and_config<T>(
+    title: &str,
+    // Function that takes config file and runs application
+    app_fn: fn(T) -> anyhow::Result<()>,
+) where T: Default + Serialize + DeserializeOwned {
+    ::std::process::exit(match run_inner(title, app_fn) {
+        Ok(()) => 0,
+        Err(err) => {
+            print_help(title, Some(err));
+
+            1
+        },
+    })
+}
+
+
+fn run_inner<T>(
+    title: &str,
+    // Function that takes config file and runs application
+    app_fn: fn(T) -> anyhow::Result<()>,
+) -> anyhow::Result<()> where T: Default + Serialize + DeserializeOwned {
+    let args: Vec<String> = ::std::env::args().collect();
+
+    let opts = AppOptions::parse_args_default(&args[1..])?;
+
+    if opts.help_requested(){
+        print_help(title, None);
+
+        Ok(())
+    } else if opts.print_config {
+        print!("{}", default_config_as_toml::<T>());
+
+        Ok(())
+    } else if let Some(config_file) = opts.config_file {
+        let config = config_from_toml_file(config_file)?;
+
+        app_fn(config)
+    } else {
+        app_fn(T::default())
+    }
+}
+
+
 fn config_from_toml_file<T>(path: String) -> anyhow::Result<T>
     where T: DeserializeOwned
 {
@@ -28,6 +71,7 @@ fn config_from_toml_file<T>(path: String) -> anyhow::Result<T>
     toml::from_str(&data).map_err(|e| anyhow::anyhow!("Parse failed: {}", e))
 }
 
+
 fn default_config_as_toml<T>() -> String
     where T: Default + Serialize
 {
@@ -36,40 +80,7 @@ fn default_config_as_toml<T>() -> String
 }
 
 
-pub fn run_app_with_cli_and_config<T>(
-    title: &str,
-    // Function that takes config file and runs application
-    app_fn: fn(T),
-) where T: Default + Serialize + DeserializeOwned {
-    let args: Vec<String> = ::std::env::args().collect();
-
-    match AppOptions::parse_args_default(&args[1..]){
-        Ok(opts) => {
-            if opts.help_requested(){
-                print_help(title, None);
-            } else if opts.print_config {
-                print!("{}", default_config_as_toml::<T>());
-            } else if let Some(config_file) = opts.config_file {
-                match config_from_toml_file(config_file){
-                    Ok(config) => app_fn(config),
-                    Err(err) => {
-                        eprintln!("Error while reading config file: {}", err);
-
-                        ::std::process::exit(1);
-                    }
-                }
-            } else {
-                app_fn(T::default())
-            }
-        },
-        Err(err) => {
-            print_help(title, Some(&format!("{}", err)))
-        }
-    }
-}
-
-
-fn print_help(title: &str, opt_error: Option<&str>){
+fn print_help(title: &str, opt_error: Option<anyhow::Error>){
     println!("{}", title);
 
     if let Some(error) = opt_error {