1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 #ifndef _NET_ETHTOOL_NETLINK_H 4 #define _NET_ETHTOOL_NETLINK_H 5 6 #include <linux/ethtool_netlink.h> 7 #include <linux/netdevice.h> 8 #include <net/genetlink.h> 9 #include <net/sock.h> 10 11 struct ethnl_req_info; 12 13 int ethnl_parse_header(struct ethnl_req_info *req_info, 14 const struct nlattr *nest, struct net *net, 15 struct netlink_ext_ack *extack, bool require_dev); 16 int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev, 17 u16 attrtype); 18 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd, 19 u16 hdr_attrtype, struct genl_info *info, 20 void **ehdrp); 21 22 /** 23 * ethnl_strz_size() - calculate attribute length for fixed size string 24 * @s: ETH_GSTRING_LEN sized string (may not be null terminated) 25 * 26 * Return: total length of an attribute with null terminated string from @s 27 */ 28 static inline int ethnl_strz_size(const char *s) 29 { 30 return nla_total_size(strnlen(s, ETH_GSTRING_LEN) + 1); 31 } 32 33 /** 34 * ethnl_put_strz() - put string attribute with fixed size string 35 * @skb: skb with the message 36 * @attrype: attribute type 37 * @s: ETH_GSTRING_LEN sized string (may not be null terminated) 38 * 39 * Puts an attribute with null terminated string from @s into the message. 40 * 41 * Return: 0 on success, negative error code on failure 42 */ 43 static inline int ethnl_put_strz(struct sk_buff *skb, u16 attrtype, 44 const char *s) 45 { 46 unsigned int len = strnlen(s, ETH_GSTRING_LEN); 47 struct nlattr *attr; 48 49 attr = nla_reserve(skb, attrtype, len + 1); 50 if (!attr) 51 return -EMSGSIZE; 52 53 memcpy(nla_data(attr), s, len); 54 ((char *)nla_data(attr))[len] = '\0'; 55 return 0; 56 } 57 58 /** 59 * ethnl_update_u32() - update u32 value from NLA_U32 attribute 60 * @dst: value to update 61 * @attr: netlink attribute with new value or null 62 * @mod: pointer to bool for modification tracking 63 * 64 * Copy the u32 value from NLA_U32 netlink attribute @attr into variable 65 * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod 66 * is set to true if this function changed the value of *dst, otherwise it 67 * is left as is. 68 */ 69 static inline void ethnl_update_u32(u32 *dst, const struct nlattr *attr, 70 bool *mod) 71 { 72 u32 val; 73 74 if (!attr) 75 return; 76 val = nla_get_u32(attr); 77 if (*dst == val) 78 return; 79 80 *dst = val; 81 *mod = true; 82 } 83 84 /** 85 * ethnl_update_u8() - update u8 value from NLA_U8 attribute 86 * @dst: value to update 87 * @attr: netlink attribute with new value or null 88 * @mod: pointer to bool for modification tracking 89 * 90 * Copy the u8 value from NLA_U8 netlink attribute @attr into variable 91 * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod 92 * is set to true if this function changed the value of *dst, otherwise it 93 * is left as is. 94 */ 95 static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr, 96 bool *mod) 97 { 98 u8 val; 99 100 if (!attr) 101 return; 102 val = nla_get_u8(attr); 103 if (*dst == val) 104 return; 105 106 *dst = val; 107 *mod = true; 108 } 109 110 /** 111 * ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute 112 * @dst: value to update 113 * @attr: netlink attribute with new value or null 114 * @mod: pointer to bool for modification tracking 115 * 116 * Use the u8 value from NLA_U8 netlink attribute @attr to set u32 variable 117 * pointed to by @dst to 0 (if zero) or 1 (if not); do nothing if @attr is 118 * null. Bool pointed to by @mod is set to true if this function changed the 119 * logical value of *dst, otherwise it is left as is. 120 */ 121 static inline void ethnl_update_bool32(u32 *dst, const struct nlattr *attr, 122 bool *mod) 123 { 124 u8 val; 125 126 if (!attr) 127 return; 128 val = !!nla_get_u8(attr); 129 if (!!*dst == val) 130 return; 131 132 *dst = val; 133 *mod = true; 134 } 135 136 /** 137 * ethnl_update_binary() - update binary data from NLA_BINARY atribute 138 * @dst: value to update 139 * @len: destination buffer length 140 * @attr: netlink attribute with new value or null 141 * @mod: pointer to bool for modification tracking 142 * 143 * Use the u8 value from NLA_U8 netlink attribute @attr to rewrite data block 144 * of length @len at @dst by attribute payload; do nothing if @attr is null. 145 * Bool pointed to by @mod is set to true if this function changed the logical 146 * value of *dst, otherwise it is left as is. 147 */ 148 static inline void ethnl_update_binary(void *dst, unsigned int len, 149 const struct nlattr *attr, bool *mod) 150 { 151 if (!attr) 152 return; 153 if (nla_len(attr) < len) 154 len = nla_len(attr); 155 if (!memcmp(dst, nla_data(attr), len)) 156 return; 157 158 memcpy(dst, nla_data(attr), len); 159 *mod = true; 160 } 161 162 /** 163 * ethnl_update_bitfield32() - update u32 value from NLA_BITFIELD32 attribute 164 * @dst: value to update 165 * @attr: netlink attribute with new value or null 166 * @mod: pointer to bool for modification tracking 167 * 168 * Update bits in u32 value which are set in attribute's mask to values from 169 * attribute's value. Do nothing if @attr is null or the value wouldn't change; 170 * otherwise, set bool pointed to by @mod to true. 171 */ 172 static inline void ethnl_update_bitfield32(u32 *dst, const struct nlattr *attr, 173 bool *mod) 174 { 175 struct nla_bitfield32 change; 176 u32 newval; 177 178 if (!attr) 179 return; 180 change = nla_get_bitfield32(attr); 181 newval = (*dst & ~change.selector) | (change.value & change.selector); 182 if (*dst == newval) 183 return; 184 185 *dst = newval; 186 *mod = true; 187 } 188 189 /** 190 * ethnl_reply_header_size() - total size of reply header 191 * 192 * This is an upper estimate so that we do not need to hold RTNL lock longer 193 * than necessary (to prevent rename between size estimate and composing the 194 * message). Accounts only for device ifindex and name as those are the only 195 * attributes ethnl_fill_reply_header() puts into the reply header. 196 */ 197 static inline unsigned int ethnl_reply_header_size(void) 198 { 199 return nla_total_size(nla_total_size(sizeof(u32)) + 200 nla_total_size(IFNAMSIZ)); 201 } 202 203 /* GET request handling */ 204 205 /* Unified processing of GET requests uses two data structures: request info 206 * and reply data. Request info holds information parsed from client request 207 * and its stays constant through all request processing. Reply data holds data 208 * retrieved from ethtool_ops callbacks or other internal sources which is used 209 * to compose the reply. When processing a dump request, request info is filled 210 * only once (when the request message is parsed) but reply data is filled for 211 * each reply message. 212 * 213 * Both structures consist of part common for all request types (struct 214 * ethnl_req_info and struct ethnl_reply_data defined below) and optional 215 * parts specific for each request type. Common part always starts at offset 0. 216 */ 217 218 /** 219 * struct ethnl_req_info - base type of request information for GET requests 220 * @dev: network device the request is for (may be null) 221 * @flags: request flags common for all request types 222 * 223 * This is a common base for request specific structures holding data from 224 * parsed userspace request. These always embed struct ethnl_req_info at 225 * zero offset. 226 */ 227 struct ethnl_req_info { 228 struct net_device *dev; 229 u32 flags; 230 }; 231 232 /** 233 * struct ethnl_reply_data - base type of reply data for GET requests 234 * @dev: device for current reply message; in single shot requests it is 235 * equal to ðnl_req_info.dev; in dumps it's different for each 236 * reply message 237 * 238 * This is a common base for request specific structures holding data for 239 * kernel reply message. These always embed struct ethnl_reply_data at zero 240 * offset. 241 */ 242 struct ethnl_reply_data { 243 struct net_device *dev; 244 }; 245 246 static inline int ethnl_ops_begin(struct net_device *dev) 247 { 248 if (dev && dev->ethtool_ops->begin) 249 return dev->ethtool_ops->begin(dev); 250 else 251 return 0; 252 } 253 254 static inline void ethnl_ops_complete(struct net_device *dev) 255 { 256 if (dev && dev->ethtool_ops->complete) 257 dev->ethtool_ops->complete(dev); 258 } 259 260 /** 261 * struct ethnl_request_ops - unified handling of GET requests 262 * @request_cmd: command id for request (GET) 263 * @reply_cmd: command id for reply (GET_REPLY) 264 * @hdr_attr: attribute type for request header 265 * @max_attr: maximum (top level) attribute type 266 * @req_info_size: size of request info 267 * @reply_data_size: size of reply data 268 * @request_policy: netlink policy for message contents 269 * @allow_nodev_do: allow non-dump request with no device identification 270 * @parse_request: 271 * Parse request except common header (struct ethnl_req_info). Common 272 * header is already filled on entry, the rest up to @repdata_offset 273 * is zero initialized. This callback should only modify type specific 274 * request info by parsed attributes from request message. 275 * @prepare_data: 276 * Retrieve and prepare data needed to compose a reply message. Calls to 277 * ethtool_ops handlers are limited to this callback. Common reply data 278 * (struct ethnl_reply_data) is filled on entry, type specific part after 279 * it is zero initialized. This callback should only modify the type 280 * specific part of reply data. Device identification from struct 281 * ethnl_reply_data is to be used as for dump requests, it iterates 282 * through network devices while dev member of struct ethnl_req_info 283 * points to the device from client request. 284 * @reply_size: 285 * Estimate reply message size. Returned value must be sufficient for 286 * message payload without common reply header. The callback may returned 287 * estimate higher than actual message size if exact calculation would 288 * not be worth the saved memory space. 289 * @fill_reply: 290 * Fill reply message payload (except for common header) from reply data. 291 * The callback must not generate more payload than previously called 292 * ->reply_size() estimated. 293 * @cleanup_data: 294 * Optional cleanup called when reply data is no longer needed. Can be 295 * used e.g. to free any additional data structures outside the main 296 * structure which were allocated by ->prepare_data(). When processing 297 * dump requests, ->cleanup() is called for each message. 298 * 299 * Description of variable parts of GET request handling when using the 300 * unified infrastructure. When used, a pointer to an instance of this 301 * structure is to be added to ðnl_default_requests array and generic 302 * handlers ethnl_default_doit(), ethnl_default_dumpit(), 303 * ethnl_default_start() and ethnl_default_done() used in @ethtool_genl_ops; 304 * ethnl_default_notify() can be used in @ethnl_notify_handlers to send 305 * notifications of the corresponding type. 306 */ 307 struct ethnl_request_ops { 308 u8 request_cmd; 309 u8 reply_cmd; 310 u16 hdr_attr; 311 unsigned int max_attr; 312 unsigned int req_info_size; 313 unsigned int reply_data_size; 314 const struct nla_policy *request_policy; 315 bool allow_nodev_do; 316 317 int (*parse_request)(struct ethnl_req_info *req_info, 318 struct nlattr **tb, 319 struct netlink_ext_ack *extack); 320 int (*prepare_data)(const struct ethnl_req_info *req_info, 321 struct ethnl_reply_data *reply_data, 322 struct genl_info *info); 323 int (*reply_size)(const struct ethnl_req_info *req_info, 324 const struct ethnl_reply_data *reply_data); 325 int (*fill_reply)(struct sk_buff *skb, 326 const struct ethnl_req_info *req_info, 327 const struct ethnl_reply_data *reply_data); 328 void (*cleanup_data)(struct ethnl_reply_data *reply_data); 329 }; 330 331 /* request handlers */ 332 333 extern const struct ethnl_request_ops ethnl_strset_request_ops; 334 extern const struct ethnl_request_ops ethnl_linkinfo_request_ops; 335 extern const struct ethnl_request_ops ethnl_linkmodes_request_ops; 336 extern const struct ethnl_request_ops ethnl_linkstate_request_ops; 337 extern const struct ethnl_request_ops ethnl_debug_request_ops; 338 extern const struct ethnl_request_ops ethnl_wol_request_ops; 339 340 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info); 341 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info); 342 int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info); 343 int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info); 344 345 #endif /* _NET_ETHTOOL_NETLINK_H */ 346