From patchwork Tue May 31 12:18:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 12865447 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 8179EC433FE for ; Tue, 31 May 2022 12:11:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344098AbiEaMLx (ORCPT ); Tue, 31 May 2022 08:11:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233894AbiEaMLu (ORCPT ); Tue, 31 May 2022 08:11:50 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB2C3633E; Tue, 31 May 2022 05:11:48 -0700 (PDT) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LCB2v0YxvzDqXd; Tue, 31 May 2022 20:11:35 +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; Tue, 31 May 2022 20:11:44 +0800 From: Zhengchao Shao To: , , , , , , , , , , , , , , CC: , , Subject: [PATCH v4,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd Date: Tue, 31 May 2022 20:18:04 +0800 Message-ID: <20220531121804.194901-1-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) 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 --- samples/bpf/xdp_fwd_user.c | 62 ++++++++++++++++++++++++++++++++------ 1 file changed, 53 insertions(+), 9 deletions(-) diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c index 1828487bae9a..a4ba53891653 100644 --- a/samples/bpf/xdp_fwd_user.c +++ b/samples/bpf/xdp_fwd_user.c @@ -47,17 +47,61 @@ 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 -errno; + } + + if (!curr_prog_id) { + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", + xdp_flags, ifname); + goto err_out; + } - err = bpf_xdp_detach(idx, xdp_flags, NULL); - if (err < 0) - printf("ERROR: failed to detach program from %s\n", name); + 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 -errno; + } + + 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; + } else { + 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); + */ + } - /* TODO: Remember to cleanup map, when adding use of shared map - * bpf_map_delete_elem((map_fd, &idx); - */ +close_out: + close(prog_fd); +err_out: return err; } @@ -169,7 +213,7 @@ 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 {