From patchwork Sat Jan 2 00:03:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Machata X-Patchwork-Id: 355955 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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED autolearn=ham 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 DAD62C433E6 for ; Sat, 2 Jan 2021 00:05:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A771A21D93 for ; Sat, 2 Jan 2021 00:05:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727306AbhABAFA (ORCPT ); Fri, 1 Jan 2021 19:05:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726991AbhABAE6 (ORCPT ); Fri, 1 Jan 2021 19:04:58 -0500 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [IPv6:2001:67c:2050::465:101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 840ADC0613ED for ; Fri, 1 Jan 2021 16:04:17 -0800 (PST) Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:105:465:1:2:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4D72Dw0bm5zQlLR; Sat, 2 Jan 2021 01:04:16 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pmachata.org; s=MBO0001; t=1609545854; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FJUI2dGhHtfKWleLwRophAipJoErJkQPpC8VPpOOkUo=; b=kv3WcbLOXJ9ugL/8ELOc+blq0mdpGMR0lsmweXSvDAuWIKjHBXb1iLpzYYrIWaHZuSdvJs CiXKmxOlyNZvmLELiJj+R9Dswc8D9Emx7n54meTyZ9kK0rkQ6u5NQzsGbK3DD7lsLKBUxW QfoBxK5t3USGdbW/KE0JmqAfKKRXlsXPF9bzQbkF7XET9+6ax49PjZLvLe9def989LosS2 Wn04bCWeQ7uR027ziOCAgQQL51yeavHAdvYmTrMF0YTwR//DUFcB7tA1seoTs/jNY5qAXi 5ylcVWd1rqf5k5cfwLYCuvZLShw3aoBnlahMV4ARduDL1AdZBWy5Oae4Y3QI+A== Received: from smtp2.mailbox.org ([80.241.60.241]) by hefe.heinlein-support.de (hefe.heinlein-support.de [91.198.250.172]) (amavisd-new, port 10030) with ESMTP id yl0vEKvbYo-y; Sat, 2 Jan 2021 01:04:10 +0100 (CET) From: Petr Machata To: netdev@vger.kernel.org, dsahern@gmail.com, stephen@networkplumber.org Cc: Petr Machata Subject: [PATCH iproute2-next v2 4/7] dcb: Generalize dcb_get_attribute() Date: Sat, 2 Jan 2021 01:03:38 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-MBO-SPAM-Probability: X-Rspamd-Score: -0.07 / 15.00 / 15.00 X-Rspamd-Queue-Id: 0CCEE1726 X-Rspamd-UID: 42578d Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The function dcb_get_attribute() assumes that the caller knows the exact size of the looked-for payload. It also assumes that the response comes wrapped in an DCB_ATTR_IEEE nest. The former assumption does not hold for the IEEE APP table, which has variable size. The latter one does not hold for DCBX, which is not IEEE-nested, and also for any CEE attributes, which would come CEE-nested. Factor out the payload extractor from the current dcb_get_attribute() code, and put into a helper. Then rewrite dcb_get_attribute() compatibly in terms of the new function. Introduce dcb_get_attribute_va() as a thin wrapper for IEEE-nested access, and dcb_get_attribute_bare() for access to attributes that are not nested. Signed-off-by: Petr Machata --- dcb/dcb.c | 79 ++++++++++++++++++++++++++++++++++++++++++++----------- dcb/dcb.h | 4 +++ 2 files changed, 68 insertions(+), 15 deletions(-) diff --git a/dcb/dcb.c b/dcb/dcb.c index 9bbbbfa74619..89f9b0ec7ef9 100644 --- a/dcb/dcb.c +++ b/dcb/dcb.c @@ -59,25 +59,19 @@ static void dcb_free(struct dcb *dcb) struct dcb_get_attribute { struct dcb *dcb; int attr; - void *data; - size_t data_len; + void *payload; + __u16 payload_len; }; static int dcb_get_attribute_attr_ieee_cb(const struct nlattr *attr, void *data) { struct dcb_get_attribute *ga = data; - uint16_t len; if (mnl_attr_get_type(attr) != ga->attr) return MNL_CB_OK; - len = mnl_attr_get_payload_len(attr); - if (len != ga->data_len) { - fprintf(stderr, "Wrong len %d, expected %zd\n", len, ga->data_len); - return MNL_CB_ERROR; - } - - memcpy(ga->data, mnl_attr_get_payload(attr), ga->data_len); + ga->payload = mnl_attr_get_payload(attr); + ga->payload_len = mnl_attr_get_payload_len(attr); return MNL_CB_STOP; } @@ -94,6 +88,16 @@ static int dcb_get_attribute_cb(const struct nlmsghdr *nlh, void *data) return mnl_attr_parse(nlh, sizeof(struct dcbmsg), dcb_get_attribute_attr_cb, data); } +static int dcb_get_attribute_bare_cb(const struct nlmsghdr *nlh, void *data) +{ + /* Bare attributes (e.g. DCB_ATTR_DCBX) are not wrapped inside an IEEE + * container, so this does not have to go through unpacking in + * dcb_get_attribute_attr_cb(). + */ + return mnl_attr_parse(nlh, sizeof(struct dcbmsg), + dcb_get_attribute_attr_ieee_cb, data); +} + struct dcb_set_attribute_response { int response_attr; }; @@ -155,25 +159,70 @@ static struct nlmsghdr *dcb_prepare(struct dcb *dcb, const char *dev, return nlh; } -int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len) +static int __dcb_get_attribute(struct dcb *dcb, int command, + const char *dev, int attr, + void **payload_p, __u16 *payload_len_p, + int (*get_attribute_cb)(const struct nlmsghdr *nlh, + void *data)) { struct dcb_get_attribute ga; struct nlmsghdr *nlh; int ret; - nlh = dcb_prepare(dcb, dev, RTM_GETDCB, DCB_CMD_IEEE_GET); + nlh = dcb_prepare(dcb, dev, RTM_GETDCB, command); ga = (struct dcb_get_attribute) { .dcb = dcb, .attr = attr, - .data = data, - .data_len = data_len, + .payload = NULL, }; - ret = dcb_talk(dcb, nlh, dcb_get_attribute_cb, &ga); + ret = dcb_talk(dcb, nlh, get_attribute_cb, &ga); if (ret) { perror("Attribute read"); return ret; } + if (ga.payload == NULL) { + perror("Attribute not found"); + return -ENOENT; + } + + *payload_p = ga.payload; + *payload_len_p = ga.payload_len; + return 0; +} + +int dcb_get_attribute_va(struct dcb *dcb, const char *dev, int attr, + void **payload_p, __u16 *payload_len_p) +{ + return __dcb_get_attribute(dcb, DCB_CMD_IEEE_GET, dev, attr, + payload_p, payload_len_p, + dcb_get_attribute_cb); +} + +int dcb_get_attribute_bare(struct dcb *dcb, int cmd, const char *dev, int attr, + void **payload_p, __u16 *payload_len_p) +{ + return __dcb_get_attribute(dcb, cmd, dev, attr, + payload_p, payload_len_p, + dcb_get_attribute_bare_cb); +} + +int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len) +{ + __u16 payload_len; + void *payload; + int ret; + + ret = dcb_get_attribute_va(dcb, dev, attr, &payload, &payload_len); + if (ret) + return ret; + + if (payload_len != data_len) { + fprintf(stderr, "Wrong len %d, expected %zd\n", payload_len, data_len); + return -EINVAL; + } + + memcpy(data, payload, data_len); return 0; } diff --git a/dcb/dcb.h b/dcb/dcb.h index da14937c8925..8c7327a43588 100644 --- a/dcb/dcb.h +++ b/dcb/dcb.h @@ -33,9 +33,13 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len); int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *data, size_t data_len); +int dcb_get_attribute_va(struct dcb *dcb, const char *dev, int attr, + void **payload_p, __u16 *payload_len_p); int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev, int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data), void *data); +int dcb_get_attribute_bare(struct dcb *dcb, int cmd, const char *dev, int attr, + void **payload_p, __u16 *payload_len_p); int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev, int attr, const void *data, size_t data_len, int response_attr);