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Diffstat (limited to 'net/ethtool/netlink.h')
| -rw-r--r-- | net/ethtool/netlink.h | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h new file mode 100644 index 000000000000..60efd87686ad --- /dev/null +++ b/net/ethtool/netlink.h @@ -0,0 +1,345 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _NET_ETHTOOL_NETLINK_H +#define _NET_ETHTOOL_NETLINK_H + +#include <linux/ethtool_netlink.h> +#include <linux/netdevice.h> +#include <net/genetlink.h> +#include <net/sock.h> + +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; +extern const struct ethnl_request_ops ethnl_linkstate_request_ops; +extern const struct ethnl_request_ops ethnl_debug_request_ops; +extern const struct ethnl_request_ops ethnl_wol_request_ops; + +int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info); +int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info); +int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info); +int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info); + +#endif /* _NET_ETHTOOL_NETLINK_H */ |