From patchwork Mon Jun 6 00:54:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 12869870 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F33EDC433EF for ; Mon, 6 Jun 2022 00:48:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351893AbiFFAs2 (ORCPT ); Sun, 5 Jun 2022 20:48:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348528AbiFFAs1 (ORCPT ); Sun, 5 Jun 2022 20:48:27 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 173632BB1E; Sun, 5 Jun 2022 17:48:23 -0700 (PDT) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LGZZK0bcgzjXKN; Mon, 6 Jun 2022 08:47:05 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpeml500026.china.huawei.com (7.185.36.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 6 Jun 2022 08:48:20 +0800 From: Zhengchao Shao To: , , , , , , , , , , , , , , CC: , , Subject: [PATCH v6,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd Date: Mon, 6 Jun 2022 08:54:25 +0800 Message-ID: <20220606005425.261967-1-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpeml500026.china.huawei.com (7.185.36.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Before detach the prog, we should check detach prog exist or not. Signed-off-by: Zhengchao Shao Reviewed-by: Toke Høiland-Jørgensen --- samples/bpf/xdp_fwd_user.c | 55 +++++++++++++++++++++++++++++++++----- 1 file changed, 49 insertions(+), 6 deletions(-) diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c index 1828487bae9a..84f57f1209ce 100644 --- a/samples/bpf/xdp_fwd_user.c +++ b/samples/bpf/xdp_fwd_user.c @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) return err; } -static int do_detach(int idx, const char *name) +static int do_detach(int ifindex, const char *ifname, const char *app_name) { - int err; + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); + struct bpf_prog_info prog_info = {}; + char prog_name[BPF_OBJ_NAME_LEN]; + __u32 info_len, curr_prog_id; + int prog_fd; + int err = 1; + + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { + printf("ERROR: bpf_xdp_query_id failed (%s)\n", + strerror(errno)); + return err; + } - err = bpf_xdp_detach(idx, xdp_flags, NULL); - if (err < 0) - printf("ERROR: failed to detach program from %s\n", name); + if (!curr_prog_id) { + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", + xdp_flags, ifname); + return err; + } + info_len = sizeof(prog_info); + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); + if (prog_fd < 0) { + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", + strerror(errno)); + return prog_fd; + } + + err = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &info_len); + if (err) { + printf("ERROR: bpf_obj_get_info_by_fd failed (%s)\n", + strerror(errno)); + goto close_out; + } + snprintf(prog_name, sizeof(prog_name), "%s_prog", app_name); + prog_name[BPF_OBJ_NAME_LEN - 1] = '\0'; + + if (strcmp(prog_info.name, prog_name)) { + printf("ERROR: %s isn't attached to %s\n", app_name, ifname); + err = 1; + goto close_out; + } + + opts.old_prog_fd = prog_fd; + err = bpf_xdp_detach(ifindex, xdp_flags, &opts); + if (err < 0) + printf("ERROR: failed to detach program from %s (%s)\n", + ifname, strerror(errno)); /* TODO: Remember to cleanup map, when adding use of shared map * bpf_map_delete_elem((map_fd, &idx); */ +close_out: + close(prog_fd); return err; } @@ -169,7 +212,7 @@ int main(int argc, char **argv) return 1; } if (!attach) { - err = do_detach(idx, argv[i]); + err = do_detach(idx, argv[i], prog_name); if (err) ret = err; } else {