commit a58a89617236afb724d7dc0ef9393d906b0c8133
author Hanno Becker <hanno.becker@arm.com> Thu Jun 13 16:11:15 2019 +0100
committer Hanno Becker <hanno.becker@arm.com> Thu Jul 04 10:28:55 2019 +0100
tree 9fc13aefd315097bd1e7bb75255e31372a43c61b
parent ece325c8dd0e4fb1847b92530bfaaddc88e8d467

Allow compile-time configuration of I/O function pointers

Introduce the compile-time options
- MBEDTLS_SSL_CONF_RECV
- MBEDTLS_SSL_CONF_SEND
- MBEDTLS_SSL_CONF_RECV_TIMEOUT
which can be used to configure the callbacks for the underlying
transport at compile-time.

Code-size impact:

|  | GCC 8.2.1 | ARMC5 5.06 | ARMC6 6.12 |
| --- | --- | --- | --- |
| `libmbedtls.a` before | 23471 | 24077 | 27045 |
| `libmbedtls.a` before | 23379 | 23981 | 26941 |
| gain in Bytes | 92 | 96 | 104 |

include/mbedtls/ssl_internal.h

diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 52835b4..8d5170c 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -1291,8 +1291,68 @@
 
 typedef int (*mbedtls_frng_t)( void*, unsigned char*, size_t );
 
+#if !defined(MBEDTLS_SSL_CONF_RECV)
+static inline mbedtls_ssl_recv_t* mbedtls_ssl_get_recv(
+    mbedtls_ssl_context const *ssl )
+{
+    return( ssl->f_recv );
+}
+#else /* !MBEDTLS_SSL_CONF_RECV */
+
+#define mbedtls_ssl_conf_recv_func MBEDTLS_SSL_CONF_RECV
+extern int mbedtls_ssl_conf_recv_func( void*, unsigned char*, size_t );
+
+static inline mbedtls_ssl_recv_t* mbedtls_ssl_get_recv(
+    mbedtls_ssl_context const *ssl )
+{
+    ((void) ssl);
+    return ((mbedtls_ssl_recv_t*) mbedtls_ssl_conf_recv_func);
+}
+#endif /* MBEDTLS_SSL_CONF_RECV */
+
+#if !defined(MBEDTLS_SSL_CONF_SEND)
+static inline mbedtls_ssl_send_t* mbedtls_ssl_get_send(
+    mbedtls_ssl_context const *ssl )
+{
+    return( ssl->f_send );
+}
+#else /* !MBEDTLS_SSL_CONF_SEND */
+
+#define mbedtls_ssl_conf_send_func MBEDTLS_SSL_CONF_SEND
+extern int mbedtls_ssl_conf_send_func( void*, unsigned char const*, size_t );
+
+static inline mbedtls_ssl_send_t* mbedtls_ssl_get_send(
+    mbedtls_ssl_context const *ssl )
+{
+    ((void) ssl);
+    return ((mbedtls_ssl_send_t*) mbedtls_ssl_conf_send_func);
+}
+#endif /* MBEDTLS_SSL_CONF_SEND */
+
+#if !defined(MBEDTLS_SSL_CONF_RECV_TIMEOUT)
+static inline mbedtls_ssl_recv_timeout_t* mbedtls_ssl_get_recv_timeout(
+    mbedtls_ssl_context const *ssl )
+{
+    return( ssl->f_recv_timeout );
+}
+#else /* !MBEDTLS_SSL_CONF_RECV_TIMEOUT */
+
+#define mbedtls_ssl_conf_recv_timeout_func MBEDTLS_SSL_CONF_RECV_TIMEOUT
+extern int mbedtls_ssl_conf_recv_timeout_func(
+    void*, unsigned char*, size_t, uint32_t );
+
+static inline mbedtls_ssl_recv_timeout_t* mbedtls_ssl_get_recv_timeout(
+    mbedtls_ssl_context const *ssl )
+{
+    ((void) ssl);
+    return ((mbedtls_ssl_recv_timeout_t*) mbedtls_ssl_conf_recv_timeout_func);
+}
+#endif /* MBEDTLS_SSL_CONF_RECV_TIMEOUT */
+
+typedef int mbedtls_frng_t( void*, unsigned char*, size_t );
+
 #if !defined(MBEDTLS_SSL_CONF_RNG)
-static inline mbedtls_frng_t mbedtls_ssl_conf_get_frng(
+static inline mbedtls_frng_t* mbedtls_ssl_conf_get_frng(
     mbedtls_ssl_config const *conf )
 {
     return( conf->f_rng );
@@ -1302,7 +1362,7 @@
 #define mbedtls_ssl_conf_rng_func MBEDTLS_SSL_CONF_RNG
 extern int mbedtls_ssl_conf_rng_func( void*, unsigned char*, size_t );
 
-static inline mbedtls_frng_t mbedtls_ssl_conf_get_frng(
+static inline mbedtls_frng_t* mbedtls_ssl_conf_get_frng(
     mbedtls_ssl_config const *conf )
 {
     ((void) conf);