/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef _NET_ETHTOOL_NETLINK_H #define _NET_ETHTOOL_NETLINK_H #include #include #include #include struct ethnl_req_info; int ethnl_parse_header(struct ethnl_req_info *req_info, const struct nlattr *nest, struct net *net, struct netlink_ext_ack *extack, bool require_dev); int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev, u16 attrtype); struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd, u16 hdr_attrtype, struct genl_info *info, void **ehdrp); /** * ethnl_strz_size() - calculate attribute length for fixed size string * @s: ETH_GSTRING_LEN sized string (may not be null terminated) * * Return: total length of an attribute with null terminated string from @s */ static inline int ethnl_strz_size(const char *s) { return nla_total_size(strnlen(s, ETH_GSTRING_LEN) + 1); } /** * ethnl_put_strz() - put string attribute with fixed size string * @skb: skb with the message * @attrype: attribute type * @s: ETH_GSTRING_LEN sized string (may not be null terminated) * * Puts an attribute with null terminated string from @s into the message. * * Return: 0 on success, negative error code on failure */ static inline int ethnl_put_strz(struct sk_buff *skb, u16 attrtype, const char *s) { unsigned int len = strnlen(s, ETH_GSTRING_LEN); struct nlattr *attr; attr = nla_reserve(skb, attrtype, len + 1); if (!attr) return -EMSGSIZE; memcpy(nla_data(attr), s, len); ((char *)nla_data(attr))[len] = '\0'; return 0; } /** * 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. */ 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_u8(attr); if (*dst == val) return; *dst = val; *mod = true; } /** * ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute * @dst: value to update * @attr: netlink attribute with new value or null * @mod: pointer to bool for modification tracking * * Use the u8 value from NLA_U8 netlink attribute @attr to set u32 variable * pointed to by @dst to 0 (if zero) or 1 (if not); do nothing if @attr is * null. Bool pointed to by @mod is set to true if this function changed the * logical value of *dst, otherwise it is left as is. */ static inline void ethnl_update_bool32(u32 *dst, const struct nlattr *attr, bool *mod) { u8 val; if (!attr) return; val = !!nla_get_u8(attr); if (!!*dst == val) return; *dst = val; *mod = true; } /** * ethnl_update_binary() - update binary data from NLA_BINARY atribute * @dst: value to update * @len: destination buffer length * @attr: netlink attribute with new value or null * @mod: pointer to bool for modification tracking * * Use the u8 value from NLA_U8 netlink attribute @attr to rewrite data block * of length @len at @dst by attribute payload; do nothing if @attr is null. * Bool pointed to by @mod is set to true if this function changed the logical * value of *dst, otherwise it is left as is. */ static inline void ethnl_update_binary(void *dst, unsigned int len, const struct nlattr *attr, bool *mod) { if (!attr) return; if (nla_len(attr) < len) len = nla_len(attr); if (!memcmp(dst, nla_data(attr), len)) return; memcpy(dst, nla_data(attr), len); *mod = true; } /** * ethnl_update_bitfield32() - update u32 value from NLA_BITFIELD32 attribute * @dst: value to update * @attr: netlink attribute with new value or null * @mod: pointer to bool for modification tracking * * Update bits in u32 value which are set in attribute's mask to values from * attribute's value. Do nothing if @attr is null or the value wouldn't change; * otherwise, set bool pointed to by @mod to true. */ static inline void ethnl_update_bitfield32(u32 *dst, const struct nlattr *attr, bool *mod) { struct nla_bitfield32 change; u32 newval; if (!attr) return; change = nla_get_bitfield32(attr); newval = (*dst & ~change.selector) | (change.value & change.selector); if (*dst == newval) return; *dst = newval; *mod = true; } /** * ethnl_reply_header_size() - total size of reply header * * This is an upper estimate so that we do not need to hold RTNL lock longer * than necessary (to prevent rename between size estimate and composing the * message). Accounts only for device ifindex and name as those are the only * attributes ethnl_fill_reply_header() puts into the reply header. */ static inline unsigned int ethnl_reply_header_size(void) { return nla_total_size(nla_total_size(sizeof(u32)) + nla_total_size(IFNAMSIZ)); } /* GET request handling */ /* Unified processing of GET requests uses two data structures: request info * and reply data. Request info holds information parsed from client request * and its stays constant through all request processing. Reply data holds data * retrieved from ethtool_ops callbacks or other internal sources which is used * to compose the reply. When processing a dump request, request info is filled * only once (when the request message is parsed) but reply data is filled for * each reply message. * * Both structures consist of part common for all request types (struct * ethnl_req_info and struct ethnl_reply_data defined below) and optional * parts specific for each request type. Common part always starts at offset 0. */ /** * struct ethnl_req_info - base type of request information for GET requests * @dev: network device the request is for (may be null) * @flags: request flags common for all request types * * This is a common base for request specific structures holding data from * parsed userspace request. These always embed struct ethnl_req_info at * zero offset. */ struct ethnl_req_info { struct net_device *dev; u32 flags; }; /** * struct ethnl_reply_data - base type of reply data for GET requests * @dev: device for current reply message; in single shot requests it is * equal to ðnl_req_info.dev; in dumps it's different for each * reply message * * This is a common base for request specific structures holding data for * kernel reply message. These always embed struct ethnl_reply_data at zero * offset. */ struct ethnl_reply_data { struct net_device *dev; }; static inline int ethnl_ops_begin(struct net_device *dev) { if (dev && dev->ethtool_ops->begin) return dev->ethtool_ops->begin(dev); else return 0; } static inline void ethnl_ops_complete(struct net_device *dev) { if (dev && dev->ethtool_ops->complete) dev->ethtool_ops->complete(dev); } /** * struct ethnl_request_ops - unified handling of GET requests * @request_cmd: command id for request (GET) * @reply_cmd: command id for reply (GET_REPLY) * @hdr_attr: attribute type for request header * @max_attr: maximum (top level) attribute type * @req_info_size: size of request info * @reply_data_size: size of reply data * @request_policy: netlink policy for message contents * @allow_nodev_do: allow non-dump request with no device identification * @parse_request: * Parse request except common header (struct ethnl_req_info). Common * header is already filled on entry, the rest up to @repdata_offset * is zero initialized. This callback should only modify type specific * request info by parsed attributes from request message. * @prepare_data: * Retrieve and prepare data needed to compose a reply message. Calls to * ethtool_ops handlers are limited to this callback. Common reply data * (struct ethnl_reply_data) is filled on entry, type specific part after * it is zero initialized. This callback should only modify the type * specific part of reply data. Device identification from struct * ethnl_reply_data is to be used as for dump requests, it iterates * through network devices while dev member of struct ethnl_req_info * points to the device from client request. * @reply_size: * Estimate reply message size. Returned value must be sufficient for * message payload without common reply header. The callback may returned * estimate higher than actual message size if exact calculation would * not be worth the saved memory space. * @fill_reply: * Fill reply message payload (except for common header) from reply data. * The callback must not generate more payload than previously called * ->reply_size() estimated. * @cleanup_data: * Optional cleanup called when reply data is no longer needed. Can be * used e.g. to free any additional data structures outside the main * structure which were allocated by ->prepare_data(). When processing * dump requests, ->cleanup() is called for each message. * * Description of variable parts of GET request handling when using the * unified infrastructure. When used, a pointer to an instance of this * structure is to be added to ðnl_default_requests array and generic * handlers ethnl_default_doit(), ethnl_default_dumpit(), * ethnl_default_start() and ethnl_default_done() used in @ethtool_genl_ops; * ethnl_default_notify() can be used in @ethnl_notify_handlers to send * notifications of the corresponding type. */ struct ethnl_request_ops { u8 request_cmd; u8 reply_cmd; u16 hdr_attr; unsigned int max_attr; unsigned int req_info_size; unsigned int reply_data_size; const struct nla_policy *request_policy; bool allow_nodev_do; int (*parse_request)(struct ethnl_req_info *req_info, struct nlattr **tb, struct netlink_ext_ack *extack); int (*prepare_data)(const struct ethnl_req_info *req_info, struct ethnl_reply_data *reply_data, struct genl_info *info); int (*reply_size)(const struct ethnl_req_info *req_info, const struct ethnl_reply_data *reply_data); int (*fill_reply)(struct sk_buff *skb, const struct ethnl_req_info *req_info, const struct ethnl_reply_data *reply_data); void (*cleanup_data)(struct ethnl_reply_data *reply_data); }; /* request handlers */ extern const struct ethnl_request_ops ethnl_strset_request_ops; extern const struct ethnl_request_ops ethnl_linkinfo_request_ops; extern const struct ethnl_request_ops ethnl_linkmodes_request_ops; int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info); #endif /* _NET_ETHTOOL_NETLINK_H */