From patchwork Tue Oct 2 17:51:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 10623929 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A179215E8 for ; Tue, 2 Oct 2018 17:51:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9002627D0E for ; Tue, 2 Oct 2018 17:51:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 83AD827E5A; Tue, 2 Oct 2018 17:51:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5195627D0E for ; Tue, 2 Oct 2018 17:51:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726233AbeJCAgA (ORCPT ); Tue, 2 Oct 2018 20:36:00 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:47550 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726492AbeJCAgA (ORCPT ); Tue, 2 Oct 2018 20:36:00 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.91) (envelope-from ) id 1g7OpQ-0003Fx-3n; Tue, 02 Oct 2018 19:51:24 +0200 From: Johannes Berg To: backports@vger.kernel.org Cc: Johannes Berg Subject: [PATCH 4/6] backports: backport most of improved netlink policy validation Date: Tue, 2 Oct 2018 19:51:05 +0200 Message-Id: <20181002175107.16336-4-johannes@sipsolutions.net> X-Mailer: git-send-email 2.14.4 In-Reply-To: <20181002175107.16336-1-johannes@sipsolutions.net> References: <20181002175107.16336-1-johannes@sipsolutions.net> Sender: backports-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: backports@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Johannes Berg Signed-off-by: Johannes Berg --- backport/backport-include/linux/netlink.h | 19 ++ backport/backport-include/net/netlink.h | 185 ++++++++++++++- backport/compat/Makefile | 1 + backport/compat/backport-4.20.c | 379 ++++++++++++++++++++++++++++++ 4 files changed, 572 insertions(+), 12 deletions(-) create mode 100644 backport/compat/backport-4.20.c diff --git a/backport/backport-include/linux/netlink.h b/backport/backport-include/linux/netlink.h index 468a12d15dbe..366c9e27e8c2 100644 --- a/backport/backport-include/linux/netlink.h +++ b/backport/backport-include/linux/netlink.h @@ -3,6 +3,13 @@ #include_next #include +#if LINUX_VERSION_IS_LESS(4,14,0) +struct nla_bitfield32 { + __u32 value; + __u32 selector; +}; +#endif + #if LINUX_VERSION_IS_LESS(4,12,0) #define NETLINK_MAX_COOKIE_LEN 20 @@ -23,6 +30,18 @@ struct netlink_ext_ack { } while (0) #endif +#ifndef NL_SET_ERR_MSG_ATTR +#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \ + static const char __msg[] = msg; \ + struct netlink_ext_ack *__extack = (extack); \ + \ + if (__extack) { \ + __extack->_msg = __msg; \ + __extack->bad_attr = (attr); \ + } \ +} while (0) +#endif + /* this is for patches we apply */ #if LINUX_VERSION_IS_LESS(3,7,0) #define netlink_notify_portid(__notify) (__notify->pid) diff --git a/backport/backport-include/net/netlink.h b/backport/backport-include/net/netlink.h index 7775bc8295c3..4af73631115e 100644 --- a/backport/backport-include/net/netlink.h +++ b/backport/backport-include/net/netlink.h @@ -4,6 +4,162 @@ #include #include +#if LINUX_VERSION_IS_LESS(4,20,0) +/* can't backport using the enum - need to override */ +#define NLA_UNSPEC 0 +#define NLA_U8 1 +#define NLA_U16 2 +#define NLA_U32 3 +#define NLA_U64 4 +#define NLA_STRING 5 +#define NLA_FLAG 6 +#define NLA_MSECS 7 +#define NLA_NESTED 8 +#define NLA_NESTED_ARRAY 9 +#define NLA_NUL_STRING 10 +#define NLA_BINARY 11 +#define NLA_S8 12 +#define NLA_S16 13 +#define NLA_S32 14 +#define NLA_S64 15 +#define NLA_BITFIELD32 16 +#define NLA_REJECT 17 +#define NLA_EXACT_LEN 18 +#define NLA_EXACT_LEN_WARN 19 +#define __NLA_TYPE_MAX 20 +#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) + +enum nla_policy_validation { + NLA_VALIDATE_NONE, + NLA_VALIDATE_RANGE, + NLA_VALIDATE_MIN, + NLA_VALIDATE_MAX, + NLA_VALIDATE_FUNCTION, +}; + +struct backport_nla_policy { + u8 type; + u8 validation_type; + u16 len; + union { + const void *validation_data; + struct { + s16 min, max; + }; + int (*validate)(const struct nlattr *attr, + struct netlink_ext_ack *extack); + }; +}; +#define nla_policy backport_nla_policy + +#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } +#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ + .len = _len } + +#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) +#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 } +#define NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ + { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } + +#define __NLA_ENSURE(condition) (sizeof(char[1 - 2*!(condition)]) - 1) +#define NLA_ENSURE_INT_TYPE(tp) \ + (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ + tp == NLA_S16 || tp == NLA_U16 || \ + tp == NLA_S32 || tp == NLA_U32 || \ + tp == NLA_S64 || tp == NLA_U64) + tp) +#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ + (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ + tp != NLA_REJECT && \ + tp != NLA_NESTED && \ + tp != NLA_NESTED_ARRAY) + tp) + +#define NLA_POLICY_RANGE(tp, _min, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_RANGE, \ + .min = _min, \ + .max = _max \ +} + +#define NLA_POLICY_MIN(tp, _min) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MIN, \ + .min = _min, \ +} + +#define NLA_POLICY_MAX(tp, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MAX, \ + .max = _max, \ +} + +#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ + .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ + .validation_type = NLA_VALIDATE_FUNCTION, \ + .validate = fn, \ + .len = __VA_ARGS__ + 0, \ +} + +#define nla_validate LINUX_BACKPORT(nla_validate) +int nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack); +#define nla_parse LINUX_BACKPORT(nla_parse) +int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy, + struct netlink_ext_ack *extack); +#define nla_policy_len LINUX_BACKPORT(nla_policy_len) +int nla_policy_len(const struct nla_policy *, int); + +#define nlmsg_parse LINUX_BACKPORT(nlmsg_parse) +static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr *tb[], int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + return -EINVAL; + + return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), policy, extack); +} + +#define nlmsg_validate LINUX_BACKPORT(nlmsg_validate) +static inline int nlmsg_validate(const struct nlmsghdr *nlh, + int hdrlen, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + return -EINVAL; + + return nla_validate(nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), maxtype, policy, + extack); +} + +#define nla_parse_nested LINUX_BACKPORT(nla_parse_nested) +static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, + const struct nlattr *nla, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, + extack); +} + +#define nla_validate_nested LINUX_BACKPORT(nla_validate_nested) +static inline int nla_validate_nested(const struct nlattr *start, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return nla_validate(nla_data(start), nla_len(start), maxtype, policy, + extack); +} +#endif /* < 4.20 */ + #if LINUX_VERSION_IS_LESS(4,12,0) #include @@ -12,13 +168,13 @@ static inline int _nla_validate5(const struct nlattr *head, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nla_validate(head, len, maxtype, policy); + return nla_validate(head, len, maxtype, policy, extack); } static inline int _nla_validate4(const struct nlattr *head, int len, int maxtype, const struct nla_policy *policy) { - return nla_validate(head, len, maxtype, policy); + return nla_validate(head, len, maxtype, policy, NULL); } #undef nla_validate #define nla_validate(...) \ @@ -29,14 +185,15 @@ static inline int _nla_parse6(struct nlattr **tb, int maxtype, int len, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nla_parse(tb, maxtype, head, len, policy); + return nla_parse(tb, maxtype, head, len, policy, extack); } static inline int _nla_parse5(struct nlattr **tb, int maxtype, const struct nlattr *head, int len, const struct nla_policy *policy) { - return nla_parse(tb, maxtype, head, len, policy); + return nla_parse(tb, maxtype, head, len, policy, NULL); } +#undef nla_parse #define nla_parse(...) \ macro_dispatcher(_nla_parse, __VA_ARGS__)(__VA_ARGS__) @@ -45,14 +202,15 @@ static inline int _nlmsg_parse6(const struct nlmsghdr *nlh, int hdrlen, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nlmsg_parse(nlh, hdrlen, tb, maxtype, policy); + return nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, extack); } static inline int _nlmsg_parse5(const struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, const struct nla_policy *policy) { - return nlmsg_parse(nlh, hdrlen, tb, maxtype, policy); + return nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, NULL); } +#undef nlmsg_parse #define nlmsg_parse(...) \ macro_dispatcher(_nlmsg_parse, __VA_ARGS__)(__VA_ARGS__) @@ -61,14 +219,15 @@ static inline int _nlmsg_validate5(const struct nlmsghdr *nlh, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nlmsg_validate(nlh, hdrlen, maxtype, policy); + return nlmsg_validate(nlh, hdrlen, maxtype, policy, extack); } static inline int _nlmsg_validate4(const struct nlmsghdr *nlh, int hdrlen, int maxtype, const struct nla_policy *policy) { - return nlmsg_validate(nlh, hdrlen, maxtype, policy); + return nlmsg_validate(nlh, hdrlen, maxtype, policy, NULL); } +#undef nlmsg_validate #define nlmsg_validate(...) \ macro_dispatcher(_nlmsg_validate, __VA_ARGS__)(__VA_ARGS__) @@ -77,14 +236,15 @@ static inline int _nla_parse_nested5(struct nlattr *tb[], int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nla_parse_nested(tb, maxtype, nla, policy); + return nla_parse_nested(tb, maxtype, nla, policy, extack); } static inline int _nla_parse_nested4(struct nlattr *tb[], int maxtype, const struct nlattr *nla, const struct nla_policy *policy) { - return nla_parse_nested(tb, maxtype, nla, policy); + return nla_parse_nested(tb, maxtype, nla, policy, NULL); } +#undef nla_parse_nested #define nla_parse_nested(...) \ macro_dispatcher(_nla_parse_nested, __VA_ARGS__)(__VA_ARGS__) @@ -92,13 +252,14 @@ static inline int _nla_validate_nested4(const struct nlattr *start, int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nla_validate_nested(start, maxtype, policy); + return nla_validate_nested(start, maxtype, policy, extack); } static inline int _nla_validate_nested3(const struct nlattr *start, int maxtype, const struct nla_policy *policy) { - return nla_validate_nested(start, maxtype, policy); + return nla_validate_nested(start, maxtype, policy, NULL); } +#undef nla_validate_nested #define nla_validate_nested(...) \ macro_dispatcher(_nla_validate_nested, __VA_ARGS__)(__VA_ARGS__) #endif /* LINUX_VERSION_IS_LESS(4,12,0) */ diff --git a/backport/compat/Makefile b/backport/compat/Makefile index f5b1886e2d8e..ff6c7e658380 100644 --- a/backport/compat/Makefile +++ b/backport/compat/Makefile @@ -38,6 +38,7 @@ compat-$(CPTCFG_KERNEL_4_8) += backport-4.8.o compat-$(CPTCFG_KERNEL_4_10) += backport-4.10.o compat-$(CPTCFG_KERNEL_4_12) += backport-4.12.o compat-$(CPTCFG_KERNEL_4_18) += backport-4.18.o +compat-$(CPTCFG_KERNEL_4_20) += backport-4.20.o compat-$(CPTCFG_BPAUTO_CRYPTO_SKCIPHER) += crypto-skcipher.o diff --git a/backport/compat/backport-4.20.c b/backport/compat/backport-4.20.c new file mode 100644 index 000000000000..e26f3b52fbbe --- /dev/null +++ b/backport/compat/backport-4.20.c @@ -0,0 +1,379 @@ +/* + * Copyright (C) 2018 Intel Corporation + * + * Backport functionality introduced in Linux 4.20. + * This is basically upstream lib/nlattr.c. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +static const u8 nla_attr_len[NLA_TYPE_MAX+1] = { + [NLA_U8] = sizeof(u8), + [NLA_U16] = sizeof(u16), + [NLA_U32] = sizeof(u32), + [NLA_U64] = sizeof(u64), + [NLA_S8] = sizeof(s8), + [NLA_S16] = sizeof(s16), + [NLA_S32] = sizeof(s32), + [NLA_S64] = sizeof(s64), +}; + +static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { + [NLA_U8] = sizeof(u8), + [NLA_U16] = sizeof(u16), + [NLA_U32] = sizeof(u32), + [NLA_U64] = sizeof(u64), + [NLA_MSECS] = sizeof(u64), + [NLA_NESTED] = NLA_HDRLEN, + [NLA_S8] = sizeof(s8), + [NLA_S16] = sizeof(s16), + [NLA_S32] = sizeof(s32), + [NLA_S64] = sizeof(s64), +}; + +static int validate_nla_bitfield32(const struct nlattr *nla, + const u32 *valid_flags_mask) +{ + const struct nla_bitfield32 *bf = nla_data(nla); + + if (!valid_flags_mask) + return -EINVAL; + + /*disallow invalid bit selector */ + if (bf->selector & ~*valid_flags_mask) + return -EINVAL; + + /*disallow invalid bit values */ + if (bf->value & ~*valid_flags_mask) + return -EINVAL; + + /*disallow valid bit values that are not selected*/ + if (bf->value & ~bf->selector) + return -EINVAL; + + return 0; +} + +static int nla_validate_array(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + const struct nlattr *entry; + int rem; + + nla_for_each_attr(entry, head, len, rem) { + int ret; + + if (nla_len(entry) == 0) + continue; + + if (nla_len(entry) < NLA_HDRLEN) { + NL_SET_ERR_MSG_ATTR(extack, entry, + "Array element too short"); + return -ERANGE; + } + + ret = nla_validate(nla_data(entry), nla_len(entry), + maxtype, policy, extack); + if (ret < 0) + return ret; + } + + return 0; +} + +static int nla_validate_int_range(const struct nla_policy *pt, + const struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + bool validate_min, validate_max; + s64 value; + + validate_min = pt->validation_type == NLA_VALIDATE_RANGE || + pt->validation_type == NLA_VALIDATE_MIN; + validate_max = pt->validation_type == NLA_VALIDATE_RANGE || + pt->validation_type == NLA_VALIDATE_MAX; + + switch (pt->type) { + case NLA_U8: + value = nla_get_u8(nla); + break; + case NLA_U16: + value = nla_get_u16(nla); + break; + case NLA_U32: + value = nla_get_u32(nla); + break; + case NLA_S8: + value = nla_get_s8(nla); + break; + case NLA_S16: + value = nla_get_s16(nla); + break; + case NLA_S32: + value = nla_get_s32(nla); + break; + case NLA_S64: + value = nla_get_s64(nla); + break; + case NLA_U64: + /* treat this one specially, since it may not fit into s64 */ + if ((validate_min && nla_get_u64(nla) < pt->min) || + (validate_max && nla_get_u64(nla) > pt->max)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; + } + return 0; + default: + WARN_ON(1); + return -EINVAL; + } + + if ((validate_min && value < pt->min) || + (validate_max && value > pt->max)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "integer out of range"); + return -ERANGE; + } + + return 0; +} + +static int validate_nla(const struct nlattr *nla, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + const struct nla_policy *pt; + int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); + int err = -ERANGE; + + if (type <= 0 || type > maxtype) + return 0; + + pt = &policy[type]; + + BUG_ON(pt->type > NLA_TYPE_MAX); + + if ((nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) || + (pt->type == NLA_EXACT_LEN_WARN && attrlen != pt->len)) { + pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", + current->comm, type); + } + + switch (pt->type) { + case NLA_EXACT_LEN: + if (attrlen != pt->len) + goto out_err; + break; + + case NLA_REJECT: + if (extack && pt->validation_data) { + NL_SET_BAD_ATTR(extack, nla); + extack->_msg = pt->validation_data; + return -EINVAL; + } + err = -EINVAL; + goto out_err; + + case NLA_FLAG: + if (attrlen > 0) + goto out_err; + break; + + case NLA_BITFIELD32: + if (attrlen != sizeof(struct nla_bitfield32)) + goto out_err; + + err = validate_nla_bitfield32(nla, pt->validation_data); + if (err) + goto out_err; + break; + + case NLA_NUL_STRING: + if (pt->len) + minlen = min_t(int, attrlen, pt->len + 1); + else + minlen = attrlen; + + if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) { + err = -EINVAL; + goto out_err; + } + /* fall through */ + + case NLA_STRING: + if (attrlen < 1) + goto out_err; + + if (pt->len) { + char *buf = nla_data(nla); + + if (buf[attrlen - 1] == '\0') + attrlen--; + + if (attrlen > pt->len) + goto out_err; + } + break; + + case NLA_BINARY: + if (pt->len && attrlen > pt->len) + goto out_err; + break; + + case NLA_NESTED: + /* a nested attributes is allowed to be empty; if its not, + * it must have a size of at least NLA_HDRLEN. + */ + if (attrlen == 0) + break; + if (attrlen < NLA_HDRLEN) + goto out_err; + if (pt->validation_data) { + err = nla_validate(nla_data(nla), nla_len(nla), pt->len, + pt->validation_data, extack); + if (err < 0) { + /* + * return directly to preserve the inner + * error message/attribute pointer + */ + return err; + } + } + break; + case NLA_NESTED_ARRAY: + /* a nested array attribute is allowed to be empty; if its not, + * it must have a size of at least NLA_HDRLEN. + */ + if (attrlen == 0) + break; + if (attrlen < NLA_HDRLEN) + goto out_err; + if (pt->validation_data) { + int err; + + err = nla_validate_array(nla_data(nla), nla_len(nla), + pt->len, pt->validation_data, + extack); + if (err < 0) { + /* + * return directly to preserve the inner + * error message/attribute pointer + */ + return err; + } + } + break; + default: + if (pt->len) + minlen = pt->len; + else if (pt->type != NLA_UNSPEC) + minlen = nla_attr_minlen[pt->type]; + + if (attrlen < minlen) + goto out_err; + } + + /* further validation */ + switch (pt->validation_type) { + case NLA_VALIDATE_NONE: + /* nothing to do */ + break; + case NLA_VALIDATE_RANGE: + case NLA_VALIDATE_MIN: + case NLA_VALIDATE_MAX: + err = nla_validate_int_range(pt, nla, extack); + if (err) + return err; + break; + case NLA_VALIDATE_FUNCTION: + if (pt->validate) { + err = pt->validate(nla, extack); + if (err) + return err; + } + break; + } + + return 0; +out_err: + NL_SET_ERR_MSG_ATTR(extack, nla, "Attribute failed policy validation"); + return err; +} + +int backport_nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + const struct nlattr *nla; + int rem; + + nla_for_each_attr(nla, head, len, rem) { + int err = validate_nla(nla, maxtype, policy, extack); + + if (err < 0) + return err; + } + + return 0; +} +EXPORT_SYMBOL_GPL(backport_nla_validate); + +int backport_nla_policy_len(const struct nla_policy *p, int n) +{ + int i, len = 0; + + for (i = 0; i < n; i++, p++) { + if (p->len) + len += nla_total_size(p->len); + else if (nla_attr_len[p->type]) + len += nla_total_size(nla_attr_len[p->type]); + else if (nla_attr_minlen[p->type]) + len += nla_total_size(nla_attr_minlen[p->type]); + } + + return len; +} +EXPORT_SYMBOL_GPL(backport_nla_policy_len); + +int backport_nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, + int len, const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + const struct nlattr *nla; + int rem; + + memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); + + nla_for_each_attr(nla, head, len, rem) { + u16 type = nla_type(nla); + + if (type > 0 && type <= maxtype) { + if (policy) { + int err = validate_nla(nla, maxtype, policy, + extack); + + if (err < 0) + return err; + } + + tb[type] = (struct nlattr *)nla; + } + } + + if (unlikely(rem > 0)) + pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", + rem, current->comm); + + return 0; +} +EXPORT_SYMBOL(backport_nla_parse);