From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from paleale.coelho.fi ([176.9.41.70]:56666 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751440AbcFJQ7d (ORCPT ); Fri, 10 Jun 2016 12:59:33 -0400 Received: from [192.40.95.7] (helo=dubbel.ger.corp.intel.com) by farmhouse.coelho.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1bBPUU-0004sB-8I for backports@vger.kernel.org; Fri, 10 Jun 2016 19:41:03 +0300 From: Luca Coelho To: backports@vger.kernel.org Date: Fri, 10 Jun 2016 19:40:58 +0300 Message-Id: <1465576858-1524-1-git-send-email-luca@coelho.fi> (sfid-20160610_185935_647479_5298058E) Subject: [PATCH] backport: define nla_put_u64_64bit() for < 4.7 kernels Sender: backports-owner@vger.kernel.org List-ID: From: Luca Coelho The nla_put_u64_64_bit() function was introduced in v4.7. Define it in netlink.h if the kernel is < 4.7. Signed-off-by: Luca Coelho --- backport/backport-include/net/netlink.h | 68 +++++++++++++++++++++++++++++ backport/compat/backport-4.6.c | 77 +++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+) diff --git a/backport/backport-include/net/netlink.h b/backport/backport-include/net/netlink.h index 40160b5..1bc6e0e 100644 --- a/backport/backport-include/net/netlink.h +++ b/backport/backport-include/net/netlink.h @@ -189,4 +189,72 @@ static inline __le64 nla_get_le64(const struct nlattr *nla) } #endif /* < 4.4 */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0) + +int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr); + +static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, + u64 value, int padattr) +{ + return nla_put_64bit(skb, attrtype, sizeof(u64), &value, padattr); +} + +/** + * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute + * @skb: socket buffer the message is stored in + * + * Return true if padding is needed to align the next attribute (nla_data()) to + * a 64-bit aligned area. + */ +static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + /* The nlattr header is 4 bytes in size, that's why we test + * if the skb->data _is_ aligned. A NOP attribute, plus + * nlattr header for next attribute, will make nla_data() + * 8-byte aligned. + */ + if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) + return true; +#endif + return false; +} + +/** + * nla_align_64bit - 64-bit align the nla_data() of next attribute + * @skb: socket buffer the message is stored in + * @padattr: attribute type for the padding + * + * Conditionally emit a padding netlink attribute in order to make + * the next attribute we emit have a 64-bit aligned nla_data() area. + * This will only be done in architectures which do not have + * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. + * + * Returns zero on success or a negative error code. + */ +static inline int nla_align_64bit(struct sk_buff *skb, int padattr) +{ + if (nla_need_padding_for_64bit(skb) && + !nla_reserve(skb, padattr, 0)) + return -EMSGSIZE; + + return 0; +} + +/** + * nla_total_size_64bit - total length of attribute including padding + * @payload: length of payload + */ +static inline int nla_total_size_64bit(int payload) +{ + return NLA_ALIGN(nla_attr_size(payload)) +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + + NLA_ALIGN(nla_attr_size(0)) +#endif + ; +} + +#endif /* < 4.7 */ + #endif /* __BACKPORT_NET_NETLINK_H */ diff --git a/backport/compat/backport-4.6.c b/backport/compat/backport-4.6.c index 54ff669..9572524 100644 --- a/backport/compat/backport-4.6.c +++ b/backport/compat/backport-4.6.c @@ -12,6 +12,13 @@ #include #include +#include +#include +#include +#include +#include +#include + /** * kstrtobool - convert common user inputs into boolean values * @s: input string @@ -75,3 +82,73 @@ int kstrtobool_from_user(const char __user *s, size_t count, bool *res) return kstrtobool(buf, res); } EXPORT_SYMBOL_GPL(kstrtobool_from_user); + +/** + * __nla_reserve_64bit - reserve room for attribute on the skb and align it + * @skb: socket buffer to reserve room on + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @padattr: attribute type for the padding + * + * Adds a netlink attribute header to a socket buffer and reserves + * room for the payload but does not copy it. It also ensure that this + * attribute will have a 64-bit aligned nla_data() area. + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr) +{ + if (nla_need_padding_for_64bit(skb)) + nla_align_64bit(skb, padattr); + + return __nla_reserve(skb, attrtype, attrlen); +} + +/** + * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr) +{ + struct nlattr *nla; + + nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr); + memcpy(nla_data(nla), data, attrlen); +} +EXPORT_SYMBOL(__nla_put_64bit); + +/** + * nla_put_64bit - Add a netlink attribute to a socket buffer and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr) +{ + size_t len; + + if (nla_need_padding_for_64bit(skb)) + len = nla_total_size_64bit(attrlen); + else + len = nla_total_size(attrlen); + if (unlikely(skb_tailroom(skb) < len)) + return -EMSGSIZE; + + __nla_put_64bit(skb, attrtype, attrlen, data, padattr); + return 0; +} +EXPORT_SYMBOL(nla_put_64bit); -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe backports" in