Refactor the buffer resize feature to reduce codesize

Extract a common part of the code to a function.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 8a014ce..2edec16 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -666,6 +666,66 @@
 
     return 0;
 }
+
+static void handle_buffer_resizing( mbedtls_ssl_context *ssl, int downsizing,
+                                    uint32_t in_buf_new_len,
+                                    uint32_t out_buf_new_len )
+{
+    int modified = 0;
+    size_t written_in = 0, len_offset_in = 0;
+    size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
+    if( ssl->in_buf != NULL )
+    {
+        written_in = ssl->in_msg - ssl->in_buf;
+        len_offset_in = ssl->in_len - ssl->in_buf;
+        if( ( downsizing && ssl->in_buf_len > in_buf_new_len && ssl->in_left < in_buf_new_len ) ||
+            ( !downsizing && ssl->in_buf_len < in_buf_new_len ) )
+        {
+            if( resize_buffer( &ssl->in_buf, in_buf_new_len, &ssl->in_buf_len ) != 0 )
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
+            }
+            else
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", in_buf_new_len ) );
+                modified = 1;
+            }
+        }
+    }
+
+    if( ssl->out_buf != NULL )
+    {
+        written_out = ssl->out_msg - ssl->out_buf;
+        iv_offset_out = ssl->out_iv - ssl->out_buf;
+        len_offset_out = ssl->out_len - ssl->out_buf;
+        if( ( downsizing && ssl->out_buf_len > out_buf_new_len && ssl->out_left < out_buf_new_len ) ||
+            ( !downsizing && ssl->out_buf_len < out_buf_new_len ) )
+        {
+            if( resize_buffer( &ssl->out_buf, out_buf_new_len, &ssl->out_buf_len ) != 0 )
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
+            }
+            else
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", out_buf_new_len ) );
+                modified = 1;
+            }
+        }
+    }
+    if( modified )
+    {
+        /* Update pointers here to avoid doing it twice. */
+        ssl_reset_in_out_pointers( ssl );
+        /* Fields below might not be properly updated with record
+         * splitting or with CID, so they are manually updated here. */
+        ssl->out_msg = ssl->out_buf + written_out;
+        ssl->out_len = ssl->out_buf + len_offset_out;
+        ssl->out_iv = ssl->out_buf + iv_offset_out;
+
+        ssl->in_msg = ssl->in_buf + written_in;
+        ssl->in_len = ssl->in_buf + len_offset_in;
+    }
+}
 #endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
 
 #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
@@ -8814,62 +8874,8 @@
 
 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
     /* If the buffers are too small - reallocate */
-    {
-        int modified = 0;
-        size_t written_in = 0, len_offset_in = 0;
-        size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
-        if( ssl->in_buf != NULL )
-        {
-            written_in = ssl->in_msg - ssl->in_buf;
-            len_offset_in = ssl->in_len - ssl->in_buf;
-            if( ssl->in_buf_len < MBEDTLS_SSL_IN_BUFFER_LEN )
-            {
-                if( resize_buffer( &ssl->in_buf, MBEDTLS_SSL_IN_BUFFER_LEN,
-                                   &ssl->in_buf_len ) != 0 )
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
-                }
-                else
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", MBEDTLS_SSL_IN_BUFFER_LEN ) );
-                    modified = 1;
-                }
-            }
-        }
-
-        if( ssl->out_buf != NULL )
-        {
-            written_out = ssl->out_msg - ssl->out_buf;
-            iv_offset_out = ssl->out_iv - ssl->out_buf;
-            len_offset_out = ssl->out_len - ssl->out_buf;
-            if( ssl->out_buf_len < MBEDTLS_SSL_OUT_BUFFER_LEN )
-            {
-                if( resize_buffer( &ssl->out_buf, MBEDTLS_SSL_OUT_BUFFER_LEN,
-                                   &ssl->out_buf_len ) != 0 )
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
-                }
-                else
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", MBEDTLS_SSL_OUT_BUFFER_LEN ) );
-                    modified = 1;
-                }
-            }
-        }
-        if( modified )
-        {
-            /* Update pointers here to avoid doing it twice. */
-            ssl_reset_in_out_pointers( ssl );
-            /* Fields below might not be properly updated with record
-             * splitting or with CID, so they are manually updated here. */
-            ssl->out_msg = ssl->out_buf + written_out;
-            ssl->out_len = ssl->out_buf + len_offset_out;
-            ssl->out_iv = ssl->out_buf + iv_offset_out;
-
-            ssl->in_msg = ssl->in_buf + written_in;
-            ssl->in_len = ssl->in_buf + len_offset_in;
-        }
-    }
+    handle_buffer_resizing( ssl, 0, MBEDTLS_SSL_IN_BUFFER_LEN,
+                                    MBEDTLS_SSL_OUT_BUFFER_LEN );
 #endif
 
     /* All pointers should exist and can be directly freed without issue */
@@ -12060,64 +12066,8 @@
      * processes datagrams and the fact that a datagram is allowed to have
      * several records in it, it is possible that the I/O buffers are not
      * empty at this stage */
-    {
-        int modified = 0;
-        uint32_t buf_len = mbedtls_ssl_get_input_buflen( ssl );
-        size_t written_in = 0, len_offset_in = 0;
-        size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
-        if( ssl->in_buf != NULL )
-        {
-            written_in = ssl->in_msg - ssl->in_buf;
-            len_offset_in = ssl->in_len - ssl->in_buf;
-            if( ssl->in_buf_len > buf_len && ssl->in_left < buf_len )
-            {
-                if( resize_buffer( &ssl->in_buf, buf_len, &ssl->in_buf_len ) != 0 )
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
-                }
-                else
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", buf_len ) );
-                    modified = 1;
-                }
-            }
-        }
-
-
-        buf_len = mbedtls_ssl_get_output_buflen( ssl );
-        if( ssl->out_buf != NULL )
-        {
-            written_out = ssl->out_msg - ssl->out_buf;
-            iv_offset_out = ssl->out_iv - ssl->out_buf;
-            len_offset_out = ssl->out_len - ssl->out_buf;
-            if( ssl->out_buf_len > mbedtls_ssl_get_output_buflen( ssl ) &&
-                ssl->out_left < buf_len )
-            {
-                if( resize_buffer( &ssl->out_buf, buf_len, &ssl->out_buf_len ) != 0 )
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
-                }
-                else
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", buf_len ) );
-                    modified = 1;
-                }
-            }
-        }
-        if( modified )
-        {
-            /* Update pointers here to avoid doing it twice. */
-            ssl_reset_in_out_pointers( ssl );
-            /* Fields below might not be properly updated with record
-             * splitting or with CID, so they are manually updated here. */
-            ssl->out_msg = ssl->out_buf + written_out;
-            ssl->out_len = ssl->out_buf + len_offset_out;
-            ssl->out_iv = ssl->out_buf + iv_offset_out;
-
-            ssl->in_msg = ssl->in_buf + written_in;
-            ssl->in_len = ssl->in_buf + len_offset_in;
-        }
-    }
+    handle_buffer_resizing( ssl, 1, mbedtls_ssl_get_input_buflen( ssl ),
+                                    mbedtls_ssl_get_output_buflen( ssl ) );
 #endif
 }