Add parse module with array and env functions

5 files changed, 227 insertions, 0 deletions

diff --git a/talpid_openvpn_plugin/Cargo.lock b/talpid_openvpn_plugin/Cargo.lock
index 6bbe450750..78d4f1057a 100644
--- a/talpid_openvpn_plugin/Cargo.lock
+++ b/talpid_openvpn_plugin/Cargo.lock
@@ -2,13 +2,104 @@
 name = "talpid_openvpn_plugin"
 version = "0.1.0"
 dependencies = [
+ "error-chain 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "backtrace"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-demangle 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "backtrace-sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gcc 0.3.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cfg-if"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "dbghelp-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "error-chain"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gcc"
+version = "0.3.42"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "kernel32-sys"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "lazy_static"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "libc"
+version = "0.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rustc-demangle"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-build"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [metadata]
+"checksum backtrace 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f551bc2ddd53aea015d453ef0b635af89444afa5ed2405dd0b2062ad5d600d80"
+"checksum backtrace-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "3602e8d8c43336088a8505fa55cae2b3884a9be29440863a11528a42f46f6bb7"
+"checksum cfg-if 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de1e760d7b6535af4241fca8bd8adf68e2e7edacc6b29f5d399050c5e48cf88c"
+"checksum dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "97590ba53bcb8ac28279161ca943a924d1fd4a8fb3fa63302591647c4fc5b850"
+"checksum error-chain 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6930e04918388a9a2e41d518c25cf679ccafe26733fb4127dbf21993f2575d46"
+"checksum gcc 0.3.42 (registry+https://github.com/rust-lang/crates.io-index)" = "291055c78f59ca3d84c99026c9501c469413d386bb46be1e1cf1d285cd1db3b0"
+"checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lazy_static 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6abe0ee2e758cd6bc8a2cd56726359007748fbf4128da998b65d0b70f881e19b"
+"checksum libc 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)" = "684f330624d8c3784fb9558ca46c4ce488073a8d22450415c5eb4f4cfb0d11b5"
+"checksum rustc-demangle 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1430d286cadb237c17c885e25447c982c97113926bb579f4379c0eca8d9586dc"
+"checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
+"checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
diff --git a/talpid_openvpn_plugin/Cargo.toml b/talpid_openvpn_plugin/Cargo.toml
index be65a23f4a..8eff4c9c27 100644
--- a/talpid_openvpn_plugin/Cargo.toml
+++ b/talpid_openvpn_plugin/Cargo.toml
@@ -8,3 +8,4 @@ crate-type = ["dylib"]
 
 [dependencies]
 lazy_static = "0.2"
+error-chain = "0.8"
diff --git a/talpid_openvpn_plugin/src/ffi/mod.rs b/talpid_openvpn_plugin/src/ffi/mod.rs
index 019decf157..cf3b7fb42c 100644
--- a/talpid_openvpn_plugin/src/ffi/mod.rs
+++ b/talpid_openvpn_plugin/src/ffi/mod.rs
@@ -9,6 +9,8 @@ use std::os::raw::{c_char, c_int, c_uint, c_void};
 mod consts;
 use self::consts::*;
 
+mod parse;
+
 
 /// Struct sent to `openvpn_plugin_open_v3` containing input values.
 #[repr(C)]
diff --git a/talpid_openvpn_plugin/src/ffi/parse.rs b/talpid_openvpn_plugin/src/ffi/parse.rs
new file mode 100644
index 0000000000..72b46316f0
--- /dev/null
+++ b/talpid_openvpn_plugin/src/ffi/parse.rs
@@ -0,0 +1,130 @@
+use std::collections::HashMap;
+use std::ffi::CStr;
+use std::os::raw::c_char;
+
+error_chain!{
+    errors {
+        Null {
+            description("Null pointer")
+        }
+        NoEqual {
+            description("No equal sign in string")
+        }
+    }
+    foreign_links {
+        InvalidContent(::std::str::Utf8Error);
+    }
+}
+
+
+/// Parses a null terminated C string array into a Vec<String> for safe usage.
+///
+/// Returns an Err if given a null pointer or if a string is not valid utf-8.
+///
+/// # Segfaults
+///
+/// Can cause the program to crash if the pointer array starting at `ptr` is not correctly null
+/// terminated. Likewise, if any string pointed to is not properly null terminated it may crash.
+pub unsafe fn string_array(mut ptr: *const *const c_char) -> Result<Vec<String>> {
+    if ptr.is_null() {
+        Err(Error::from(ErrorKind::Null))
+    } else {
+        let mut strings = Vec::new();
+        while !(*ptr).is_null() {
+            let cstr = CStr::from_ptr(*ptr);
+            strings.push(cstr.to_str()?.to_owned());
+            ptr = ptr.offset(1);
+        }
+        Ok(strings)
+    }
+}
+
+
+/// Parses a null terminated array of C strings with "=" delimiters into a key-value map.
+///
+/// The input environment has to contain null terminated strings containing at least
+/// one equal sign ("="). Every string is split at the first equal sign and added to the map with
+/// the first part being the key and the second the value.
+///
+/// If multiple entries have the same key, the last one will be in the result map.
+///
+/// # Segfaults
+///
+/// Uses `string_array` internally and will segfault for the same reasons as that function.
+pub unsafe fn env(envptr: *const *const c_char) -> Result<HashMap<String, String>> {
+    let mut map = HashMap::new();
+    for string in string_array(envptr)? {
+        let mut iter = string.splitn(2, "=");
+        let key = iter.next().unwrap();
+        let value = iter.next().ok_or(Error::from(ErrorKind::NoEqual))?;
+        map.insert(key.to_owned(), value.to_owned());
+    }
+    Ok(map)
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::os::raw::c_char;
+    use std::ptr;
+
+    /// Assert macro that fails if the given pattern does not match the given expression
+    /// TODO(Linus): Very useful macro for asserting on patterns where the type does not implement
+    /// Eq. Thus it should probably be moved to a general place/crate when needed in more places.
+    macro_rules! assert_pat {
+        ($expected:pat, $actual:expr) => {{
+            if let $expected = $actual {} else {
+                let msg = stringify!($expected);
+                panic!("Expected {}. Got {:?}", msg, $actual);
+            }
+        }}
+    }
+
+    #[test]
+    fn string_array_null() {
+        let result = unsafe { string_array(ptr::null()) };
+        assert_pat!(Err(Error(ErrorKind::Null, _)), result);
+    }
+
+    #[test]
+    fn string_array_empty() {
+        let ptr_arr = [ptr::null()];
+        let result = unsafe { string_array(&ptr_arr as *const *const c_char).unwrap() };
+        assert!(result.is_empty());
+    }
+
+    #[test]
+    fn string_array_one_string() {
+        let test_str = "foobar\0";
+        let ptr_arr = [test_str as *const _ as *const c_char, ptr::null()];
+        let result = unsafe { string_array(&ptr_arr as *const *const c_char).unwrap() };
+        assert_eq!(["foobar"], &result[..]);
+    }
+
+    #[test]
+    fn env_one_value() {
+        let test_str = "var_a=value_b\0";
+        let ptr_arr = [test_str as *const _ as *const c_char, ptr::null()];
+        let result = unsafe { env(&ptr_arr as *const *const c_char).unwrap() };
+        assert_eq!(1, result.len());
+        assert_eq!(Some("value_b"), result.get("var_a").map(|s| &s[..]));
+    }
+
+    #[test]
+    fn env_no_equal() {
+        let test_str = "foobar\0";
+        let ptr_arr = [test_str as *const _ as *const c_char, ptr::null()];
+        let result = unsafe { env(&ptr_arr as *const *const c_char) };
+        assert_pat!(Err(Error(ErrorKind::NoEqual, _)), result);
+    }
+
+    #[test]
+    fn env_double_equal_trailing_space() {
+        let test_str = "foo=bar=baz \0";
+        let ptr_arr = [test_str as *const _ as *const c_char, ptr::null()];
+        let env = unsafe { env(&ptr_arr as *const *const c_char).unwrap() };
+        assert_eq!(1, env.len());
+        assert_eq!(Some("bar=baz "), env.get("foo").map(|s| &s[..]));
+    }
+}
diff --git a/talpid_openvpn_plugin/src/lib.rs b/talpid_openvpn_plugin/src/lib.rs
index a917ead7a5..91fcd34396 100644
--- a/talpid_openvpn_plugin/src/lib.rs
+++ b/talpid_openvpn_plugin/src/lib.rs
@@ -1,6 +1,9 @@
 #[macro_use]
 extern crate lazy_static;
 
+#[macro_use]
+extern crate error_chain;
+
 mod ffi;
 
 /// Publicly export the functions making up the public interface of the plugin. These are the C FFI