Move to new Error System ~ Failure and provide new result-based opera…

…tors (#57)

* Move to new Error System ~ Failure and provide new result-based operators for transform and map
* error-chain -> failure
* return failure ERROR types as the wrapper, for auto causes and backtraces
* prints become logs
* `transform-errors` test to demonstrate handling results
* revise drop_packets: return result / log errors
  * updates the drop_packets trait function to return a result
* result-operators drop Err'ed packets from a batch
* create error_chain and warn_chain, etc... macros for use where we want to have backtraces + nicely formatted error strings + causes
  * under the hood, an error -> String fn for any log level to use though
* bit of added cleanup on graceful exits on configuration/startup errors

.gitignore

@@ -47,6 +47,7 @@ Vagrantfile
 
 # pcap
 out.pcap
+*.lnk
 
 # logs
 *.log

Cargo.toml

@@ -11,7 +11,8 @@ members=["framework",
         "test/srv6-inject",
         "test/tcp-checksum",
         "test/icmpv6",
-        "test/mtu-too-big"
+        "test/mtu-too-big",
+        "test/transform-error"
         # "test/delay-test",
         # "test/chain-test",
         # "test/shutdown-test",

examples.sh

@@ -14,6 +14,7 @@ export examples=(
         test/tcp-checksum
         test/icmpv6
         test/mtu-too-big
+        test/transform-error
         # test/delay-test
         # test/chain-test
         # test/shutdown-test

framework/Cargo.toml

@@ -8,34 +8,33 @@ build = "build.rs"
 doctest = false
 
 [dependencies]
-libc = ">= 0.2.4"
-time = ">=0.1.0"
-getopts = "*"
 byteorder = "*"
 clippy = { version = ">=0.0.197", optional = true }
+crossbeam = "=0.4"
+enum_primitive = "0.1.1"
+failure = "0.1.5"
 fnv = "*"
-twox-hash = "*"
-regex = "*"
+generic-array = ">=0.11.0"
+getopts = "*"
+hex = "0.3.2"
 lazy_static = "*"
+libc = ">= 0.2.4"
+log = { version = "0.4", features = ["std", "serde"]}
 net2 = "*"
 # NIX restricts us to just unix for now, we can fix this if someone cares at a later point.
 nix = "*"
-# Figure out if we want this permanently or just for now.
-rust-sctp = { git="https://github.com/netsys/rust-sctp", optional = true}
-toml = "*"
-serde = "1.0"
-serde_derive = "1.0"
-# Hack for SHM
-uuid = { version = "*", features=["v4"] }
-error-chain = "0.12.0"
 num = "0.1"
 num-derive="0.2"
 num-traits = "0.2"
-generic-array = ">=0.11.0"
-crossbeam = "=0.4"
 rayon = "1.0.3"
-hex = "0.3.2"
-enum_primitive = "0.1.1"
+regex = "*"
+rust-sctp = { git="https://github.com/netsys/rust-sctp", optional = true}
+serde = "1.0"
+serde_derive = "1.0"
+time = ">=0.1.0"
+toml = "*"
+twox-hash = "*"
+uuid = { version = "*", features = ["v4"] }
 
 [features]
 default = []

framework/src/common/errors.rs

@@ -1,98 +1,112 @@
-error_chain! {
-    errors {
-        FailedAllocation {
-            description("Failed to allocate memory")
-            display("Failed to allocate memory")
-        }
-        FailedDeallocation {
-            description("Failed to deallocate memory")
-            display("Failed to deallocate memory")
-        }
-        FailedToInitializePort(port: i32) {
-            description("Failed to initialize port")
-            display("Failed to initialize port: {}", port)
-        }
-        BadQueue {
-            description("Invalid queue request")
-            display("Invalid queue request")
-        }
-        CannotSend {
-            description("Cannot send data out port")
-            display("Cannot send data out port")
-        }
-        BadDev(dev: String) {
-            description("Cannot find device")
-            display("Cannot find device: {}", dev)
-        }
-        BadVdev(vdev: String) {
-            description("Bad vdev specification")
-            display("Bad vdev specification: {}", vdev)
-        }
-        BadTxQueue(port: i32, queue: i32) {
-            description("Bad TX queue")
-            display("Bad TX queue {} for port {}", queue, port)
-        }
-        BadRxQueue(port: i32, queue: i32) {
-            description("Bad RX queue")
-            display("Bad RX queue {} for port {}", queue, port)
-        }
-        BadOffset(offset: usize) {
-            description("Attempt to access bad packet offset")
-            display("Attempt to access bad packet offset {}", offset)
-        }
-
-        MetadataTooLarge {
-            description("Metadata is too large")
-            display("Metadata is too large")
-        }
-
-        RingAllocationFailure {
-            description("Could not allocate ring")
-            display("Could not allocate ring")
-        }
-
-        InvalidRingSize(size: usize) {
-            description("Bad ring size, must be power of 2")
-            display("Bad ring size {}, must be a power of 2", size)
-        }
-
-        RingDuplicationFailure {
-            description("Address of second copy of ring does not match expected address")
-            display("Address of second copy of ring does not match expected address")
-        }
-
-        ConfigurationError(description: String) {
-            description("Configuration error")
-            display("Configuration error: {}", description)
-        }
-
-        NoRunningSchedulerOnCore(core: i32) {
-            description("No scheduler running on core")
-            display("No scheduler running on core {}", core)
-        }
-
-        FailedToInsertHeader {
-            description("Failed to insert header into packet")
-            display("Failed to insert header into packet")
-        }
-
-        FailedToSwapHeader(new_header: String) {
-            description("Failed to swap-in new header in packet")
-                display("Failed to swap-in new header - {} - in packet", new_header)
-        }
-
-        FailedToRemoveHeader {
-            description("Failed to remove header from packet")
-                display("Failed to remove header from packet")
-        }
-
-        FailedToParseMacAddress(s: String) {
-            description("Failed to parse MAC address")
-                display("Failed to parse MAC address: '{}'", s)
-        }
+use failure::{Error, Fail};
+
+pub type Result<T> = ::std::result::Result<T, Error>;
+
+#[derive(Debug, Fail)]
+pub enum NetBricksError {
+    #[fail(display = "Failed to allocate memory")]
+    FailedAllocation,
+
+    #[fail(display = "Failed to free memory buffer (mbuf) {}", _0)]
+    FailedToFreeMBuf(i32),
+
+    #[fail(display = "Failed to remove/drop packets from buffer")]
+    FailedToDropPackets,
+
+    #[fail(display = "Failed to deallocate memory")]
+    FailedDeallocation,
+
+    #[fail(display = "Failed to initialize port: {}", _0)]
+    FailedToInitializePort(i32),
+
+    #[fail(display = "Invalid queue request")]
+    BadQueue,
+
+    #[fail(display = "Cannot send data out port")]
+    CannotSend,
+
+    #[fail(display = "Cannot find device: {}", _0)]
+    BadDev(String),
+
+    #[fail(display = "Bad vdev specification: {}", _0)]
+    BadVdev(String),
+
+    #[fail(display = "Bad TX queue {} for port {}", _0, _1)]
+    BadTxQueue(i32, i32),
+
+    #[fail(display = "Bad RX queue {} for port {}", _0, _1)]
+    BadRxQueue(i32, i32),
+
+    #[fail(display = "Attempt to access bad packet offset {}", _0)]
+    BadOffset(usize),
+
+    #[fail(display = "Metadata is too large")]
+    MetadataTooLarge,
+
+    #[fail(display = "Could not allocate ring")]
+    RingAllocationFailure,
+
+    #[fail(display = "Address of second copy of ring does not match expected address")]
+    RingDuplicationFailure,
+
+    #[fail(display = "Bad ring size {}, must be a power of 2", _0)]
+    InvalidRingSize(usize),
+
+    #[fail(display = "Configuration error: {}", _0)]
+    ConfigurationError(String),
+
+    #[fail(display = "No scheduler running on core {}", _0)]
+    NoRunningSchedulerOnCore(i32),
+
+    #[fail(display = "Failed to insert header into packet")]
+    FailedToInsertHeader,
+
+    #[fail(
+        display = "Failed to swap-in new header - {} - in packet, new_header",
+        _0
+    )]
+    FailedToSwapHeader(String),
+
+    #[fail(display = "Failed to remove header from packet")]
+    FailedToRemoveHeader,
+
+    #[fail(display = "Failed to parse MAC address: '{}'", _0)]
+    FailedToParseMacAddress(String),
+
+    #[fail(display = "_")]
+    #[doc(hidden)]
+    __Nonexhaustive,
+}
+
+#[macro_export]
+macro_rules! error_chain {
+    ($error:expr) => {
+        error!("{}", $crate::common::errors::string_chain($error))
+    };
+}
+
+#[macro_export]
+macro_rules! warn_chain {
+    ($error:expr) => {
+        warn!("{}", $crate::common::errors::string_chain($error))
+    };
+}
+
+/// Read a `failure` `Error` and print out the causes and a backtrace as
+/// `log::error`s
+pub fn string_chain(e: &Error) -> String {
+    let mut error = e.to_string();
+
+    for cause in e.iter_causes() {
+        error.push_str(&format!("\nCaused by: {}", cause));
     }
 
-    foreign_links {
-        Io(::std::io::Error);
+    if let Ok("1") = ::std::env::var("RUST_BACKTRACE")
+        .as_ref()
+        .map(|s| s.as_str())
+    {
+        error.push_str(&format!("\nBacktrace:\n{}", e.backtrace()))
     }
+
+    error
 }

framework/src/common/mod.rs

@@ -1,15 +1,7 @@
-mod errors;
 pub use self::errors::*;
 
+#[macro_use]
+pub mod errors;
+
 /// Null metadata associated with packets initially.
 pub struct EmptyMetadata;
-
-pub fn print_error(e: &Error) {
-    println!("Error: {}", e);
-    for e in e.iter().skip(1) {
-        println!("Cause: {}", e);
-    }
-    if let Some(backtrace) = e.backtrace() {
-        println!("Backtrace: {:?}", backtrace);
-    }
-}