From dcc94e61da7bf88d484c04d49b7c7b594b5cc4bf Mon Sep 17 00:00:00 2001
From: Hanno Becker <hanno.becker@arm.com>
Date: Wed, 3 Jul 2019 17:05:43 +0100
Subject: [PATCH] Add IO wrappers to ssl_server2 as interm's between NET and
 SSL layer

---
 programs/ssl/ssl_server2.c | 78 ++++++++++++++++++++++++++++++++++----
 1 file changed, 71 insertions(+), 7 deletions(-)

diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index bbe93cb47..24c3ee9cb 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -728,7 +728,7 @@ exit:
  * Test recv/send functions that make sure each try returns
  * WANT_READ/WANT_WRITE at least once before sucesseding
  */
-static int my_recv( void *ctx, unsigned char *buf, size_t len )
+static int delayed_recv( void *ctx, unsigned char *buf, size_t len )
 {
     static int first_try = 1;
     int ret;
@@ -745,7 +745,7 @@ static int my_recv( void *ctx, unsigned char *buf, size_t len )
     return( ret );
 }
 
-static int my_send( void *ctx, const unsigned char *buf, size_t len )
+static int delayed_send( void *ctx, const unsigned char *buf, size_t len )
 {
     static int first_try = 1;
     int ret;
@@ -762,6 +762,70 @@ static int my_send( void *ctx, const unsigned char *buf, size_t len )
     return( ret );
 }
 
+typedef struct
+{
+    mbedtls_ssl_context *ssl;
+    mbedtls_net_context *net;
+} io_ctx_t;
+
+static int recv_cb( void *ctx, unsigned char *buf, size_t len )
+{
+    io_ctx_t *io_ctx = (io_ctx_t*) ctx;
+    size_t recv_len;
+    int ret;
+
+    if( opt.nbio == 2 )
+        ret = delayed_recv( io_ctx->net, buf, len );
+    else
+        ret = mbedtls_net_recv( io_ctx->net, buf, len );
+    if( ret < 0 )
+        return( ret );
+    recv_len = (size_t) ret;
+
+    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+    {
+        /* Here's the place to do any datagram/record checking
+         * in between receiving the packet from the underlying
+         * transport and passing it on to the TLS stack. */
+        mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len );
+    }
+
+    return( (int) recv_len );
+}
+
+static int recv_timeout_cb( void *ctx, unsigned char *buf, size_t len,
+                            uint32_t timeout )
+{
+    io_ctx_t *io_ctx = (io_ctx_t*) ctx;
+    int ret;
+    size_t recv_len;
+
+    ret = mbedtls_net_recv_timeout( io_ctx->net, buf, len, timeout );
+    if( ret < 0 )
+        return( ret );
+    recv_len = (size_t) ret;
+
+    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+    {
+        /* Here's the place to do any datagram/record checking
+         * in between receiving the packet from the underlying
+         * transport and passing it on to the TLS stack. */
+        mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len );
+    }
+
+    return( (int) recv_len );
+}
+
+static int send_cb( void *ctx, unsigned char const *buf, size_t len )
+{
+    io_ctx_t *io_ctx = (io_ctx_t*) ctx;
+
+    if( opt.nbio == 2 )
+        return( delayed_send( io_ctx->net, buf, len ) );
+
+    return( mbedtls_net_send( io_ctx->net, buf, len ) );
+}
+
 /*
  * Return authmode from string, or -1 on error
  */
@@ -1514,6 +1578,7 @@ int main( int argc, char *argv[] )
 {
     int ret = 0, len, written, frags, exchanges_left;
     int version_suites[4][2];
+    io_ctx_t io_ctx;
     unsigned char* buf = 0;
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -3170,11 +3235,10 @@ int main( int argc, char *argv[] )
         goto exit;
     }
 
-    if( opt.nbio == 2 )
-        mbedtls_ssl_set_bio( &ssl, &client_fd, my_send, my_recv, NULL );
-    else
-        mbedtls_ssl_set_bio( &ssl, &client_fd, mbedtls_net_send, mbedtls_net_recv,
-                             opt.nbio == 0 ? mbedtls_net_recv_timeout : NULL );
+    io_ctx.ssl = &ssl;
+    io_ctx.net = &client_fd;
+    mbedtls_ssl_set_bio( &ssl, &io_ctx, send_cb, recv_cb,
+                         opt.nbio == 0 ? recv_timeout_cb : NULL );
 
 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
     if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )