mqtt-sni.patch

diff --git a/src/apps/altcp_tls/altcp_tls_mbedtls.c b/src/apps/altcp_tls/altcp_tls_mbedtls.c
index e787ae28..11dab664 100644
--- a/src/apps/altcp_tls/altcp_tls_mbedtls.c
+++ b/src/apps/altcp_tls/altcp_tls_mbedtls.c
@@ -107,6 +107,8 @@ struct altcp_tls_config {
   u8_t pkey_count;
   u8_t pkey_max;
   mbedtls_x509_crt *ca;
+  /** Server name for setting SNI */
+  const char *server_name;
 #if defined(MBEDTLS_SSL_CACHE_C) && ALTCP_MBEDTLS_USE_SESSION_CACHE
   /** Inter-connection cache for fast connection startup */
   struct mbedtls_ssl_cache_context cache;
@@ -611,6 +613,7 @@ altcp_mbedtls_setup(void *conf, struct altcp_pcb *conn, struct altcp_pcb *inner_
   int ret;
   struct altcp_tls_config *config = (struct altcp_tls_config *)conf;
   altcp_mbedtls_state_t *state;
+
   if (!conf) {
     return ERR_ARG;
   }
@@ -637,6 +640,15 @@ altcp_mbedtls_setup(void *conf, struct altcp_pcb *conn, struct altcp_pcb *inner_
   conn->inner_conn = inner_conn;
   conn->fns = &altcp_mbedtls_functions;
   conn->state = state;
+
+  if (config->server_name != NULL) {
+    if ((ret = mbedtls_ssl_set_hostname(&state->ssl_context, config->server_name)) != 0) {
+      LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_set_hostname failed\n"));
+    }
+    mbedtls_ssl_conf_authmode(&config->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
+  }
+
+
   return ERR_OK;
 }

@@ -1330,6 +1342,14 @@ altcp_mbedtls_dealloc(struct altcp_pcb *conn)
   }
 }

+void altcp_tls_set_server_name(struct altcp_tls_config *config, const char *server_name) {
+  config->server_name = server_name;
+}
+
+const char *altcp_tls_get_server_name(struct altcp_tls_config *config) {
+  return config->server_name;
+}
+
 const struct altcp_functions altcp_mbedtls_functions = {
   altcp_mbedtls_set_poll,
   altcp_mbedtls_recved,
diff --git a/src/include/lwip/altcp_tls.h b/src/include/lwip/altcp_tls.h
index fcb784d8..a62203e5 100644
--- a/src/include/lwip/altcp_tls.h
+++ b/src/include/lwip/altcp_tls.h
@@ -187,6 +187,11 @@ err_t altcp_tls_set_session(struct altcp_pcb *conn, struct altcp_tls_session *fr
  */
 void altcp_tls_free_session(struct altcp_tls_session *dest);

+
+void altcp_tls_set_server_name(struct altcp_tls_config *config, const char *server_name);
+
+const char *altcp_tls_get_server_name(struct altcp_tls_config *config);
+
 #ifdef __cplusplus
 }
 #endif