1 files changed, 38 insertions, 3 deletions

diff --git a/thirdparty/lws/mbedtls_wrapper/platform/ssl_pm.c b/thirdparty/lws/mbedtls_wrapper/platform/ssl_pm.c
index 536733fbab..63504919ce 100644
--- a/thirdparty/lws/mbedtls_wrapper/platform/ssl_pm.c
+++ b/thirdparty/lws/mbedtls_wrapper/platform/ssl_pm.c
@@ -360,17 +360,52 @@ int ssl_pm_read(SSL *ssl, void *buffer, int len)
     return ret;
 }
 
+/*
+ * This returns -1, or the length sent.
+ * If -1, then you need to find out if the error was
+ * fatal or recoverable using SSL_get_error()
+ */
 int ssl_pm_send(SSL *ssl, const void *buffer, int len)
 {
     int ret;
     struct ssl_pm *ssl_pm = (struct ssl_pm *)ssl->ssl_pm;
 
     ret = mbedtls_ssl_write(&ssl_pm->ssl, buffer, len);
+    /*
+     * We can get a positive number, which may be less than len... that
+     * much was sent successfully and you can call again to send more.
+     *
+     * We can get a negative mbedtls error code... if WANT_WRITE or WANT_READ,
+     * it's nonfatal and means it should be retried as-is.  If something else,
+     * it's fatal actually.
+     *
+     * If this function returns something other than a positive value or
+     * MBEDTLS_ERR_SSL_WANT_READ/WRITE, the ssl context becomes unusable, and
+     * you should either free it or call mbedtls_ssl_session_reset() on it
+     * before re-using it for a new connection; the current connection must
+     * be closed.
+     *
+     * When this function returns MBEDTLS_ERR_SSL_WANT_WRITE/READ, it must be
+     * called later with the same arguments, until it returns a positive value.
+     */
+
     if (ret < 0) {
-	if (ret == MBEDTLS_ERR_NET_CONN_RESET)
+	    SSL_DEBUG(SSL_PLATFORM_ERROR_LEVEL, "mbedtls_ssl_write() return -0x%x", -ret);
+	switch (ret) {
+	case MBEDTLS_ERR_NET_CONN_RESET:
 		ssl->err = SSL_ERROR_SYSCALL;
-        SSL_DEBUG(SSL_PLATFORM_ERROR_LEVEL, "mbedtls_ssl_write() return -0x%x", -ret);
-        ret = -1;
+		break;
+	case MBEDTLS_ERR_SSL_WANT_WRITE:
+		ssl->err = SSL_ERROR_WANT_WRITE;
+		break;
+	case MBEDTLS_ERR_SSL_WANT_READ:
+		ssl->err = SSL_ERROR_WANT_READ;
+		break;
+	default:
+		break;
+	}
+
+	ret = -1;
     }
 
     return ret;