From patchwork Thu Apr 30 20:13:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 215770 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 24116C47247 for ; Thu, 30 Apr 2020 20:13:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9ABD20774 for ; Thu, 30 Apr 2020 20:13:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbgD3UNZ (ORCPT ); Thu, 30 Apr 2020 16:13:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727086AbgD3UNY (ORCPT ); Thu, 30 Apr 2020 16:13:24 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 599ABC035495; Thu, 30 Apr 2020 13:13:24 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.93) (envelope-from ) id 1jUFYf-002qzz-Qj; Thu, 30 Apr 2020 22:13:21 +0200 From: Johannes Berg To: netdev@vger.kernel.org Cc: Antonio Quartulli , linux-wireless@vger.kernel.org, Johannes Berg Subject: [PATCH v2 1/8] netlink: remove type-unsafe validation_data pointer Date: Thu, 30 Apr 2020 22:13:05 +0200 Message-Id: <20200430221106.01f758365b94.Ib760259c7f93e40ef3dfcb23b187684bc19e4e26@changeid> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200430201312.60143-1-johannes@sipsolutions.net> References: <20200430201312.60143-1-johannes@sipsolutions.net> MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg In the netlink policy, we currently have a void *validation_data that's pointing to different things: * a u32 value for bitfield32, * the netlink policy for nested/nested array * the string for NLA_REJECT Remove the pointer and place appropriate type-safe items in the union instead. While at it, completely dissolve the pointer for the bitfield32 case and just put the value there directly. Signed-off-by: Johannes Berg --- include/net/netlink.h | 60 +++++++++++++++++++++++-------------------- lib/nlattr.c | 20 +++++++-------- net/sched/act_api.c | 13 +++------- net/sched/sch_red.c | 9 +++---- 4 files changed, 49 insertions(+), 53 deletions(-) diff --git a/include/net/netlink.h b/include/net/netlink.h index 67c57d6942e3..671b29d170a8 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -217,7 +217,7 @@ enum nla_policy_validation { * NLA_NESTED, * NLA_NESTED_ARRAY Length verification is done by checking len of * nested header (or empty); len field is used if - * validation_data is also used, for the max attr + * nested_policy is also used, for the max attr * number in the nested policy. * NLA_U8, NLA_U16, * NLA_U32, NLA_U64, @@ -235,27 +235,25 @@ enum nla_policy_validation { * NLA_MIN_LEN Minimum length of attribute payload * All other Minimum length of attribute payload * - * Meaning of `validation_data' field: + * Meaning of validation union: * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and - * validation data must point to a u32 value of valid - * flags - * NLA_REJECT This attribute is always rejected and validation data + * `bitfield32_valid' is the u32 value of valid flags + * NLA_REJECT This attribute is always rejected and `reject_message' * may point to a string to report as the error instead * of the generic one in extended ACK. - * NLA_NESTED Points to a nested policy to validate, must also set - * `len' to the max attribute number. + * NLA_NESTED `nested_policy' to a nested policy to validate, must + * also set `len' to the max attribute number. Use the + * provided NLA_POLICY_NESTED() macro. * Note that nla_parse() will validate, but of course not * parse, the nested sub-policies. - * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set - * `len' to the max attribute number. The difference to - * NLA_NESTED is the structure - NLA_NESTED has the - * nested attributes directly inside, while an array has - * the nested attributes at another level down and the - * attributes directly in the nesting don't matter. - * All other Unused - but note that it's a union - * - * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX - * and NLA_POLICY_RANGE: + * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate, + * must also set `len' to the max attribute number. Use + * the provided NLA_POLICY_NESTED_ARRAY() macro. + * The difference to NLA_NESTED is the structure: + * NLA_NESTED has the nested attributes directly inside + * while an array has the nested attributes at another + * level down and the attribute types directly in the + * nesting don't matter. * NLA_U8, * NLA_U16, * NLA_U32, @@ -263,29 +261,31 @@ enum nla_policy_validation { * NLA_S8, * NLA_S16, * NLA_S32, - * NLA_S64 These are used depending on the validation_type - * field, if that is min/max/range then the minimum, - * maximum and both are used (respectively) to check + * NLA_S64 The `min' and `max' fields are used depending on the + * validation_type field, if that is min/max/range then + * the min, max or both are used (respectively) to check * the value of the integer attribute. * Note that in the interest of code simplicity and * struct size both limits are s16, so you cannot * enforce a range that doesn't fall within the range * of s16 - do that as usual in the code instead. + * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and + * NLA_POLICY_RANGE() macros. * All other Unused - but note that it's a union * * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: - * NLA_BINARY Validation function called for the attribute, - * not compatible with use of the validation_data - * as in NLA_BITFIELD32, NLA_REJECT, NLA_NESTED and - * NLA_NESTED_ARRAY. + * NLA_BINARY Validation function called for the attribute. * All other Unused - but note that it's a union * * Example: + * + * static const u32 myvalidflags = 0xff231023; + * * static const struct nla_policy my_policy[ATTR_MAX+1] = { * [ATTR_FOO] = { .type = NLA_U16 }, * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) }, - * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags }, + * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags), * }; */ struct nla_policy { @@ -293,7 +293,9 @@ struct nla_policy { u8 validation_type; u16 len; union { - const void *validation_data; + const u32 bitfield32_valid; + const char *reject_message; + const struct nla_policy *nested_policy; struct { s16 min, max; }; @@ -329,13 +331,15 @@ struct nla_policy { #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) #define _NLA_POLICY_NESTED(maxattr, policy) \ - { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } + { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr } #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ - { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } + { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr } #define NLA_POLICY_NESTED(policy) \ _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) #define NLA_POLICY_NESTED_ARRAY(policy) \ _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) +#define NLA_POLICY_BITFIELD32(valid) \ + { .type = NLA_BITFIELD32, .bitfield32_valid = valid } #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) #define NLA_ENSURE_INT_TYPE(tp) \ diff --git a/lib/nlattr.c b/lib/nlattr.c index cace9b307781..3df05db732ca 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -45,7 +45,7 @@ static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { }; static int validate_nla_bitfield32(const struct nlattr *nla, - const u32 *valid_flags_mask) + const u32 valid_flags_mask) { const struct nla_bitfield32 *bf = nla_data(nla); @@ -53,11 +53,11 @@ static int validate_nla_bitfield32(const struct nlattr *nla, return -EINVAL; /*disallow invalid bit selector */ - if (bf->selector & ~*valid_flags_mask) + if (bf->selector & ~valid_flags_mask) return -EINVAL; /*disallow invalid bit values */ - if (bf->value & ~*valid_flags_mask) + if (bf->value & ~valid_flags_mask) return -EINVAL; /*disallow valid bit values that are not selected*/ @@ -206,9 +206,9 @@ static int validate_nla(const struct nlattr *nla, int maxtype, break; case NLA_REJECT: - if (extack && pt->validation_data) { + if (extack && pt->reject_message) { NL_SET_BAD_ATTR(extack, nla); - extack->_msg = pt->validation_data; + extack->_msg = pt->reject_message; return -EINVAL; } err = -EINVAL; @@ -223,7 +223,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype, if (attrlen != sizeof(struct nla_bitfield32)) goto out_err; - err = validate_nla_bitfield32(nla, pt->validation_data); + err = validate_nla_bitfield32(nla, pt->bitfield32_valid); if (err) goto out_err; break; @@ -268,9 +268,9 @@ static int validate_nla(const struct nlattr *nla, int maxtype, break; if (attrlen < NLA_HDRLEN) goto out_err; - if (pt->validation_data) { + if (pt->nested_policy) { err = __nla_validate(nla_data(nla), nla_len(nla), pt->len, - pt->validation_data, validate, + pt->nested_policy, validate, extack); if (err < 0) { /* @@ -289,11 +289,11 @@ static int validate_nla(const struct nlattr *nla, int maxtype, break; if (attrlen < NLA_HDRLEN) goto out_err; - if (pt->validation_data) { + if (pt->nested_policy) { int err; err = nla_validate_array(nla_data(nla), nla_len(nla), - pt->len, pt->validation_data, + pt->len, pt->nested_policy, extack, validate); if (err < 0) { /* diff --git a/net/sched/act_api.c b/net/sched/act_api.c index df4560909157..fbbec2e562f5 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -876,19 +876,14 @@ static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr) return hw_stats_bf.value; } -static const u32 tca_act_flags_allowed = TCA_ACT_FLAGS_NO_PERCPU_STATS; -static const u32 tca_act_hw_stats_allowed = TCA_ACT_HW_STATS_ANY; - static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = { [TCA_ACT_KIND] = { .type = NLA_STRING }, [TCA_ACT_INDEX] = { .type = NLA_U32 }, [TCA_ACT_COOKIE] = { .type = NLA_BINARY, .len = TC_COOKIE_MAX_SIZE }, [TCA_ACT_OPTIONS] = { .type = NLA_NESTED }, - [TCA_ACT_FLAGS] = { .type = NLA_BITFIELD32, - .validation_data = &tca_act_flags_allowed }, - [TCA_ACT_HW_STATS] = { .type = NLA_BITFIELD32, - .validation_data = &tca_act_hw_stats_allowed }, + [TCA_ACT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS), + [TCA_ACT_HW_STATS] = NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY), }; struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp, @@ -1454,10 +1449,8 @@ static int tcf_action_add(struct net *net, struct nlattr *nla, return ret; } -static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON; static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = { - [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32, - .validation_data = &tcaa_root_flags_allowed }, + [TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_FLAG_LARGE_DUMP_ON), [TCA_ROOT_TIME_DELTA] = { .type = NLA_U32 }, }; diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index c7de47c942e3..555a1b9e467f 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -48,7 +48,7 @@ struct red_sched_data { struct Qdisc *qdisc; }; -static const u32 red_supported_flags = TC_RED_HISTORIC_FLAGS | TC_RED_NODROP; +#define TC_RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP) static inline int red_use_ecn(struct red_sched_data *q) { @@ -212,8 +212,7 @@ static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, [TCA_RED_MAX_P] = { .type = NLA_U32 }, - [TCA_RED_FLAGS] = { .type = NLA_BITFIELD32, - .validation_data = &red_supported_flags }, + [TCA_RED_FLAGS] = NLA_POLICY_BITFIELD32(TC_RED_SUPPORTED_FLAGS), }; static int red_change(struct Qdisc *sch, struct nlattr *opt, @@ -248,7 +247,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt, return -EINVAL; err = red_get_flags(ctl->flags, TC_RED_HISTORIC_FLAGS, - tb[TCA_RED_FLAGS], red_supported_flags, + tb[TCA_RED_FLAGS], TC_RED_SUPPORTED_FLAGS, &flags_bf, &userbits, extack); if (err) return err; @@ -372,7 +371,7 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb) if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) || nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P) || nla_put_bitfield32(skb, TCA_RED_FLAGS, - q->flags, red_supported_flags)) + q->flags, TC_RED_SUPPORTED_FLAGS)) goto nla_put_failure; return nla_nest_end(skb, opts);