From patchwork Thu Oct 1 22:59:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 267147 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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 28A6AC4727F for ; Thu, 1 Oct 2020 22:59:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2F9F20848 for ; Thu, 1 Oct 2020 22:59:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601593188; bh=RQob0IiZJuAeDDG6qEp9rtdjXVeZ4aU2sT60EAAlWIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vW326Xkz9+fuFfP1Skr43ebY9pEy+0CN0aWKsiERiL0jLGRUMros4ZypqWQtpdOwv L0nWUbtVc+n4X5sOZPt5RnSQpwKKweFkgjUcMHpQJZnIKW60PXCMRTXn6OqfyBsrr6 +Qx2Gd2Lf8YXY89zEDiW1uRVolTWueHtv/l+SMEg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733249AbgJAW7q (ORCPT ); Thu, 1 Oct 2020 18:59:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:40706 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733197AbgJAW7o (ORCPT ); Thu, 1 Oct 2020 18:59:44 -0400 Received: from kicinski-fedora-PC1C0HJN.thefacebook.com (unknown [163.114.132.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9F5EE21481; Thu, 1 Oct 2020 22:59:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601593184; bh=RQob0IiZJuAeDDG6qEp9rtdjXVeZ4aU2sT60EAAlWIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=viOUAPNY6w5dDBtzUFtl9/vvTHt/iXkAM5Yy70kUoYfUKWAMty2h+9QymC+ECXEdy rqg6P/Dl4Yqm8ISK8Mbz9wR7aYcTDmvUorf2S98l3SYQBSrnHhAIjdEML473qCd6RH U8xb/DhrE/tY8Py5LcJO3XmUHSgddZrwN+XT2Ogc= From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, andrew@lunn.ch, johannes@sipsolutions.net, jiri@resnulli.us, mkubecek@suse.cz, dsahern@kernel.org, pablo@netfilter.org, Jakub Kicinski Subject: [PATCH net-next v2 04/10] genetlink: add a structure for dump state Date: Thu, 1 Oct 2020 15:59:27 -0700 Message-Id: <20201001225933.1373426-5-kuba@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201001225933.1373426-1-kuba@kernel.org> References: <20201001225933.1373426-1-kuba@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Whenever netlink dump uses more than 2 cb->args[] entries code gets hard to read. We're about to add more state to ctrl_dumppolicy() so create a structure. Since the structure is typed and clearly named we can remove the local fam_id variable and use ctx->fam_id directly. v1: - s/nl_policy_dump/netlink_policy_dump_state/ - forward declare struct netlink_policy_dump_state, and move from passing unsigned long to actual pointer type - add build bug on - u16 fam_id - s/args/ctx/ Signed-off-by: Jakub Kicinski Reviewed-by: Johannes Berg --- include/net/netlink.h | 9 ++++++--- net/netlink/genetlink.c | 24 +++++++++++++++--------- net/netlink/policy.c | 29 +++++++++++++++-------------- 3 files changed, 36 insertions(+), 26 deletions(-) diff --git a/include/net/netlink.h b/include/net/netlink.h index b2cf34f53e55..7ddf92ffce5a 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -1935,10 +1935,13 @@ void nla_get_range_unsigned(const struct nla_policy *pt, void nla_get_range_signed(const struct nla_policy *pt, struct netlink_range_validation_signed *range); +struct netlink_policy_dump_state; + int netlink_policy_dump_start(const struct nla_policy *policy, unsigned int maxtype, - unsigned long *state); -bool netlink_policy_dump_loop(unsigned long *state); -int netlink_policy_dump_write(struct sk_buff *skb, unsigned long state); + struct netlink_policy_dump_state **state); +bool netlink_policy_dump_loop(struct netlink_policy_dump_state **state); +int netlink_policy_dump_write(struct sk_buff *skb, + struct netlink_policy_dump_state *state); #endif diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 094ebfff8889..c27653b61bcf 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1102,13 +1102,20 @@ static int genl_ctrl_event(int event, const struct genl_family *family, return 0; } +struct ctrl_dump_policy_ctx { + struct netlink_policy_dump_state *state; + u16 fam_id; +}; + static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) { + struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; const struct genl_family *rt; - unsigned int fam_id = cb->args[0]; int err; - if (!fam_id) { + BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); + + if (!ctx->fam_id) { struct nlattr *tb[CTRL_ATTR_MAX + 1]; err = genlmsg_parse(cb->nlh, &genl_ctrl, tb, @@ -1121,28 +1128,28 @@ static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) return -EINVAL; if (tb[CTRL_ATTR_FAMILY_ID]) { - fam_id = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]); + ctx->fam_id = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]); } else { rt = genl_family_find_byname( nla_data(tb[CTRL_ATTR_FAMILY_NAME])); if (!rt) return -ENOENT; - fam_id = rt->id; + ctx->fam_id = rt->id; } } - rt = genl_family_find_byid(fam_id); + rt = genl_family_find_byid(ctx->fam_id); if (!rt) return -ENOENT; if (!rt->policy) return -ENODATA; - err = netlink_policy_dump_start(rt->policy, rt->maxattr, &cb->args[1]); + err = netlink_policy_dump_start(rt->policy, rt->maxattr, &ctx->state); if (err) return err; - while (netlink_policy_dump_loop(&cb->args[1])) { + while (netlink_policy_dump_loop(&ctx->state)) { void *hdr; struct nlattr *nest; @@ -1159,7 +1166,7 @@ static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) if (!nest) goto nla_put_failure; - if (netlink_policy_dump_write(skb, cb->args[1])) + if (netlink_policy_dump_write(skb, ctx->state)) goto nla_put_failure; nla_nest_end(skb, nest); @@ -1172,7 +1179,6 @@ static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) break; } - cb->args[0] = fam_id; return skb->len; } diff --git a/net/netlink/policy.c b/net/netlink/policy.c index 62f977fa645a..5874734e41a1 100644 --- a/net/netlink/policy.c +++ b/net/netlink/policy.c @@ -14,7 +14,7 @@ #define INITIAL_POLICIES_ALLOC 10 -struct nl_policy_dump { +struct netlink_policy_dump_state { unsigned int policy_idx; unsigned int attr_idx; unsigned int n_alloc; @@ -24,11 +24,11 @@ struct nl_policy_dump { } policies[]; }; -static int add_policy(struct nl_policy_dump **statep, +static int add_policy(struct netlink_policy_dump_state **statep, const struct nla_policy *policy, unsigned int maxtype) { - struct nl_policy_dump *state = *statep; + struct netlink_policy_dump_state *state = *statep; unsigned int n_alloc, i; if (!policy || !maxtype) @@ -62,7 +62,7 @@ static int add_policy(struct nl_policy_dump **statep, return 0; } -static unsigned int get_policy_idx(struct nl_policy_dump *state, +static unsigned int get_policy_idx(struct netlink_policy_dump_state *state, const struct nla_policy *policy) { unsigned int i; @@ -78,14 +78,14 @@ static unsigned int get_policy_idx(struct nl_policy_dump *state, int netlink_policy_dump_start(const struct nla_policy *policy, unsigned int maxtype, - unsigned long *_state) + struct netlink_policy_dump_state **statep) { - struct nl_policy_dump *state; + struct netlink_policy_dump_state *state; unsigned int policy_idx; int err; /* also returns 0 if "*_state" is our ERR_PTR() end marker */ - if (*_state) + if (*statep) return 0; /* @@ -129,20 +129,21 @@ int netlink_policy_dump_start(const struct nla_policy *policy, } } - *_state = (unsigned long)state; + *statep = state; return 0; } -static bool netlink_policy_dump_finished(struct nl_policy_dump *state) +static bool +netlink_policy_dump_finished(struct netlink_policy_dump_state *state) { return state->policy_idx >= state->n_alloc || !state->policies[state->policy_idx].policy; } -bool netlink_policy_dump_loop(unsigned long *_state) +bool netlink_policy_dump_loop(struct netlink_policy_dump_state **statep) { - struct nl_policy_dump *state = (void *)*_state; + struct netlink_policy_dump_state *state = *statep; if (IS_ERR(state)) return false; @@ -150,16 +151,16 @@ bool netlink_policy_dump_loop(unsigned long *_state) if (netlink_policy_dump_finished(state)) { kfree(state); /* store end marker instead of freed state */ - *_state = (unsigned long)ERR_PTR(-ENOENT); + *statep = ERR_PTR(-ENOENT); return false; } return true; } -int netlink_policy_dump_write(struct sk_buff *skb, unsigned long _state) +int netlink_policy_dump_write(struct sk_buff *skb, + struct netlink_policy_dump_state *state) { - struct nl_policy_dump *state = (void *)_state; const struct nla_policy *pt; struct nlattr *policy, *attr; enum netlink_attribute_type type;