Re: [PATCH net-next v8 02/14] ethtool: helper functions for netlink interface
From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2019-12-24 04:09:00
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On 12/22/2019 3:45 PM, Michal Kubecek wrote:
Add common request/reply header definition and helpers to parse request header and fill reply header. Provide ethnl_update_* helpers to update structure members from request attributes (to be used for *_SET requests). Signed-off-by: Michal Kubecek <redacted> ---
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+/** + * ethnl_update_u32() - update u32 value from NLA_U32 attribute + * @dst: value to update + * @attr: netlink attribute with new value or null + * @mod: pointer to bool for modification tracking + * + * Copy the u32 value from NLA_U32 netlink attribute @attr into variable + * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod + * is set to true if this function changed the value of *dst, otherwise it + * is left as is. + */
I would find it more intuitive if an integer was returned: < 0 in case of error, 0 if no change and 1 if something changed.
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+static inline void ethnl_update_u32(u32 *dst, const struct nlattr *attr, + bool *mod) +{ + u32 val; + + if (!attr) + return; + val = nla_get_u32(attr); + if (*dst == val) + return; + + *dst = val; + *mod = true; +} + +/** + * ethnl_update_u8() - update u8 value from NLA_U8 attribute + * @dst: value to update + * @attr: netlink attribute with new value or null + * @mod: pointer to bool for modification tracking + * + * Copy the u8 value from NLA_U8 netlink attribute @attr into variable + * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod + * is set to true if this function changed the value of *dst, otherwise it + * is left as is. + */ +static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr, + bool *mod) +{ + u8 val; + + if (!attr) + return; + val = nla_get_u32(attr);
Should not this be nla_get_u8() here? This sounds like it is going to break on BE machines. -- Florian