Merge pull request #38 from andrew-d/andrew-get-compression

Allow getting the compression used in a connection

src/ssl/ffi.rs

@@ -4,6 +4,7 @@ use libc::{c_int, c_void, c_long, c_ulong, c_char};
 
 pub type SSL_CTX = c_void;
 pub type SSL_METHOD = c_void;
+pub type COMP_METHOD = c_void;
 pub type SSL = c_void;
 pub type BIO = c_void;
 pub type BIO_METHOD = c_void;
@@ -145,12 +146,15 @@ extern "C" {
     pub fn SSL_write(ssl: *mut SSL, buf: *const c_void, num: c_int) -> c_int;
     pub fn SSL_get_ex_data_X509_STORE_CTX_idx() -> c_int;
     pub fn SSL_get_SSL_CTX(ssl: *mut SSL) -> *mut SSL_CTX;
+    pub fn SSL_get_current_compression(ssl: *mut SSL) -> *const COMP_METHOD;
 
     pub fn BIO_s_mem() -> *const BIO_METHOD;
     pub fn BIO_new(type_: *const BIO_METHOD) -> *mut BIO;
     pub fn BIO_free_all(a: *mut BIO);
     pub fn BIO_read(b: *mut BIO, buf: *mut c_void, len: c_int) -> c_int;
     pub fn BIO_write(b: *mut BIO, buf: *const c_void, len: c_int) -> c_int;
+
+    pub fn SSL_COMP_get_name(comp: *const COMP_METHOD) -> *const c_char;
 }
 
 #[cfg(target_os = "win32")]

src/ssl/mod.rs

@@ -3,6 +3,7 @@ use std::io::{IoResult, IoError, EndOfFile, Stream, Reader, Writer};
 use std::mem;
 use std::ptr;
 use std::rt::mutex::NativeMutex;
+use std::string;
 use sync::one::{Once, ONCE_INIT};
 
 use ssl::error::{SslError, SslSessionClosed, StreamError};
@@ -501,6 +502,21 @@ impl<S: Stream> SslStream<S> {
         }
         Ok(())
     }
+
+    /// Get the compression currently in use.  The result will be
+    /// either None, indicating no compression is in use, or a string
+    /// with the compression name.
+    pub fn get_compression(&self) -> Option<String> {
+        let ptr = unsafe { ffi::SSL_get_current_compression(self.ssl.ssl) };
+        if ptr == ptr::null() {
+            return None;
+        }
+
+        let meth = unsafe { ffi::SSL_COMP_get_name(ptr) };
+        let s = unsafe { string::raw::from_buf(meth as *const u8) };
+
+        Some(s)
+    }
 }
 
 impl<S: Stream> Reader for SslStream<S> {