From patchwork Thu Nov 19 17:24:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yves-Alexis Perez X-Patchwork-Id: 328876 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE0BCC63697 for ; Thu, 19 Nov 2020 17:26:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82E3224695 for ; Thu, 19 Nov 2020 17:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727755AbgKSRZ7 (ORCPT ); Thu, 19 Nov 2020 12:25:59 -0500 Received: from smtp2-g21.free.fr ([212.27.42.2]:25627 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727195AbgKSRZ7 (ORCPT ); Thu, 19 Nov 2020 12:25:59 -0500 Received: from mail.corsac.net (unknown [78.194.244.226]) by smtp2-g21.free.fr (Postfix) with ESMTPS id 079A82003A4 for ; Thu, 19 Nov 2020 18:25:27 +0100 (CET) Received: from scapa.corsac.net (unknown [IPv6:2a01:e34:ec2f:4e20:6af7:28ff:fe8d:2119]) by mail.corsac.net (Postfix) with ESMTPS id 773F698 for ; Thu, 19 Nov 2020 18:24:55 +0100 (CET) Received: from corsac (uid 1000) (envelope-from corsac@corsac.net) id a024c by scapa.corsac.net (DragonFly Mail Agent v0.12); Thu, 19 Nov 2020 18:24:55 +0100 From: Yves-Alexis Perez To: "David S. Miller" , Jakub Kicinski , Martin Habets , Luc Van Oostenryck , Shannon Nelson , "Michael S. Tsirkin" , linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Yves-Alexis Perez , Matti Vuorela , stable@vger.kernel.org Subject: [PATCH] usbnet: ipheth: fix connectivity with iOS 14 Date: Thu, 19 Nov 2020 18:24:39 +0100 Message-Id: <20201119172439.94988-1-corsac@corsac.net> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Starting with iOS 14 released in September 2020, connectivity using the personal hotspot USB tethering function of iOS devices is broken. Communication between the host and the device (for example ICMP traffic or DNS resolution using the DNS service running in the device itself) works fine, but communication to endpoints further away doesn't work. Investigation on the matter shows that UDP and ICMP traffic from the tethered host is reaching the Internet at all. For TCP traffic there are exchanges between tethered host and server but packets are modified in transit leading to impossible communication. After some trials Matti Vuorela discovered that reducing the URB buffer size by two bytes restored the previous behavior. While a better solution might exist to fix the issue, since the protocol is not publicly documented and considering the small size of the fix, let's do that. Tested-by: Matti Vuorela Signed-off-by: Yves-Alexis Perez Link: https://lore.kernel.org/linux-usb/CAAn0qaXmysJ9vx3ZEMkViv_B19ju-_ExN8Yn_uSefxpjS6g4Lw@mail.gmail.com/ Link: https://github.com/libimobiledevice/libimobiledevice/issues/1038 Cc: stable@vger.kernel.org --- drivers/net/usb/ipheth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c index b09b45382faf..207e59e74935 100644 --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -59,7 +59,7 @@ #define IPHETH_USBINTF_SUBCLASS 253 #define IPHETH_USBINTF_PROTO 1 -#define IPHETH_BUF_SIZE 1516 +#define IPHETH_BUF_SIZE 1514 #define IPHETH_IP_ALIGN 2 /* padding at front of URB */ #define IPHETH_TX_TIMEOUT (5 * HZ)