net/ethtool/netlink.h

   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_dev_get(struct ethnl_req_info *req_info,
  14                                const struct nlattr *nest, struct net *net,
  15                                struct netlink_ext_ack *extack,
  16                                bool require_dev);
  17 int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
  18                             u16 attrtype);
  19 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
  20                                  u16 hdr_attrtype, struct genl_info *info,
  21                                  void **ehdrp);
  22 void *ethnl_dump_put(struct sk_buff *skb, struct netlink_callback *cb, u8 cmd);
  23 void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd);
  24 int ethnl_multicast(struct sk_buff *skb, struct net_device *dev);
  25
  26 /**
  27  * ethnl_strz_size() - calculate attribute length for fixed size string
  28  * @s: ETH_GSTRING_LEN sized string (may not be null terminated)
  29  *
  30  * Return: total length of an attribute with null terminated string from @s
  31  */
  32 static inline int ethnl_strz_size(const char *s)
  33 {
  34         return nla_total_size(strnlen(s, ETH_GSTRING_LEN) + 1);
  35 }
  36
  37 /**
  38  * ethnl_put_strz() - put string attribute with fixed size string
  39  * @skb:     skb with the message
  40  * @attrype: attribute type
  41  * @s:       ETH_GSTRING_LEN sized string (may not be null terminated)
  42  *
  43  * Puts an attribute with null terminated string from @s into the message.
  44  *
  45  * Return: 0 on success, negative error code on failure
  46  */
  47 static inline int ethnl_put_strz(struct sk_buff *skb, u16 attrtype,
  48                                  const char *s)
  49 {
  50         unsigned int len = strnlen(s, ETH_GSTRING_LEN);
  51         struct nlattr *attr;
  52
  53         attr = nla_reserve(skb, attrtype, len + 1);
  54         if (!attr)
  55                 return -EMSGSIZE;
  56
  57         memcpy(nla_data(attr), s, len);
  58         ((char *)nla_data(attr))[len] = '\0';
  59         return 0;
  60 }
  61
  62 /**
  63  * ethnl_update_u32() - update u32 value from NLA_U32 attribute
  64  * @dst:  value to update
  65  * @attr: netlink attribute with new value or null
  66  * @mod:  pointer to bool for modification tracking
  67  *
  68  * Copy the u32 value from NLA_U32 netlink attribute @attr into variable
  69  * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
  70  * is set to true if this function changed the value of *dst, otherwise it
  71  * is left as is.
  72  */
  73 static inline void ethnl_update_u32(u32 *dst, const struct nlattr *attr,
  74                                     bool *mod)
  75 {
  76         u32 val;
  77
  78         if (!attr)
  79                 return;
  80         val = nla_get_u32(attr);
  81         if (*dst == val)
  82                 return;
  83
  84         *dst = val;
  85         *mod = true;
  86 }
  87
  88 /**
  89  * ethnl_update_u8() - update u8 value from NLA_U8 attribute
  90  * @dst:  value to update
  91  * @attr: netlink attribute with new value or null
  92  * @mod:  pointer to bool for modification tracking
  93  *
  94  * Copy the u8 value from NLA_U8 netlink attribute @attr into variable
  95  * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
  96  * is set to true if this function changed the value of *dst, otherwise it
  97  * is left as is.
  98  */
  99 static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr,
 100                                    bool *mod)
 101 {
 102         u8 val;
 103
 104         if (!attr)
 105                 return;
 106         val = nla_get_u8(attr);
 107         if (*dst == val)
 108                 return;
 109
 110         *dst = val;
 111         *mod = true;
 112 }
 113
 114 /**
 115  * ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute
 116  * @dst:  value to update
 117  * @attr: netlink attribute with new value or null
 118  * @mod:  pointer to bool for modification tracking
 119  *
 120  * Use the u8 value from NLA_U8 netlink attribute @attr to set u32 variable
 121  * pointed to by @dst to 0 (if zero) or 1 (if not); do nothing if @attr is
 122  * null. Bool pointed to by @mod is set to true if this function changed the
 123  * logical value of *dst, otherwise it is left as is.
 124  */
 125 static inline void ethnl_update_bool32(u32 *dst, const struct nlattr *attr,
 126                                        bool *mod)
 127 {
 128         u8 val;
 129
 130         if (!attr)
 131                 return;
 132         val = !!nla_get_u8(attr);
 133         if (!!*dst == val)
 134                 return;
 135
 136         *dst = val;
 137         *mod = true;
 138 }
 139
 140 /**
 141  * ethnl_update_binary() - update binary data from NLA_BINARY atribute
 142  * @dst:  value to update
 143  * @len:  destination buffer length
 144  * @attr: netlink attribute with new value or null
 145  * @mod:  pointer to bool for modification tracking
 146  *
 147  * Use the u8 value from NLA_U8 netlink attribute @attr to rewrite data block
 148  * of length @len at @dst by attribute payload; do nothing if @attr is null.
 149  * Bool pointed to by @mod is set to true if this function changed the logical
 150  * value of *dst, otherwise it is left as is.
 151  */
 152 static inline void ethnl_update_binary(void *dst, unsigned int len,
 153                                        const struct nlattr *attr, bool *mod)
 154 {
 155         if (!attr)
 156                 return;
 157         if (nla_len(attr) < len)
 158                 len = nla_len(attr);
 159         if (!memcmp(dst, nla_data(attr), len))
 160                 return;
 161
 162         memcpy(dst, nla_data(attr), len);
 163         *mod = true;
 164 }
 165
 166 /**
 167  * ethnl_update_bitfield32() - update u32 value from NLA_BITFIELD32 attribute
 168  * @dst:  value to update
 169  * @attr: netlink attribute with new value or null
 170  * @mod:  pointer to bool for modification tracking
 171  *
 172  * Update bits in u32 value which are set in attribute's mask to values from
 173  * attribute's value. Do nothing if @attr is null or the value wouldn't change;
 174  * otherwise, set bool pointed to by @mod to true.
 175  */
 176 static inline void ethnl_update_bitfield32(u32 *dst, const struct nlattr *attr,
 177                                            bool *mod)
 178 {
 179         struct nla_bitfield32 change;
 180         u32 newval;
 181
 182         if (!attr)
 183                 return;
 184         change = nla_get_bitfield32(attr);
 185         newval = (*dst & ~change.selector) | (change.value & change.selector);
 186         if (*dst == newval)
 187                 return;
 188
 189         *dst = newval;
 190         *mod = true;
 191 }
 192
 193 /**
 194  * ethnl_reply_header_size() - total size of reply header
 195  *
 196  * This is an upper estimate so that we do not need to hold RTNL lock longer
 197  * than necessary (to prevent rename between size estimate and composing the
 198  * message). Accounts only for device ifindex and name as those are the only
 199  * attributes ethnl_fill_reply_header() puts into the reply header.
 200  */
 201 static inline unsigned int ethnl_reply_header_size(void)
 202 {
 203         return nla_total_size(nla_total_size(sizeof(u32)) +
 204                               nla_total_size(IFNAMSIZ));
 205 }
 206
 207 /* GET request handling */
 208
 209 /* Unified processing of GET requests uses two data structures: request info
 210  * and reply data. Request info holds information parsed from client request
 211  * and its stays constant through all request processing. Reply data holds data
 212  * retrieved from ethtool_ops callbacks or other internal sources which is used
 213  * to compose the reply. When processing a dump request, request info is filled
 214  * only once (when the request message is parsed) but reply data is filled for
 215  * each reply message.
 216  *
 217  * Both structures consist of part common for all request types (struct
 218  * ethnl_req_info and struct ethnl_reply_data defined below) and optional
 219  * parts specific for each request type. Common part always starts at offset 0.
 220  */
 221
 222 /**
 223  * struct ethnl_req_info - base type of request information for GET requests
 224  * @dev:   network device the request is for (may be null)
 225  * @flags: request flags common for all request types
 226  *
 227  * This is a common base for request specific structures holding data from
 228  * parsed userspace request. These always embed struct ethnl_req_info at
 229  * zero offset.
 230  */
 231 struct ethnl_req_info {
 232         struct net_device       *dev;
 233         u32                     flags;
 234 };
 235
 236 /**
 237  * struct ethnl_reply_data - base type of reply data for GET requests
 238  * @dev:       device for current reply message; in single shot requests it is
 239  *             equal to &ethnl_req_info.dev; in dumps it's different for each
 240  *             reply message
 241  *
 242  * This is a common base for request specific structures holding data for
 243  * kernel reply message. These always embed struct ethnl_reply_data at zero
 244  * offset.
 245  */
 246 struct ethnl_reply_data {
 247         struct net_device               *dev;
 248 };
 249
 250 static inline int ethnl_ops_begin(struct net_device *dev)
 251 {
 252         if (dev && dev->ethtool_ops->begin)
 253                 return dev->ethtool_ops->begin(dev);
 254         else
 255                 return 0;
 256 }
 257
 258 static inline void ethnl_ops_complete(struct net_device *dev)
 259 {
 260         if (dev && dev->ethtool_ops->complete)
 261                 dev->ethtool_ops->complete(dev);
 262 }
 263
 264 /**
 265  * struct ethnl_request_ops - unified handling of GET requests
 266  * @request_cmd:      command id for request (GET)
 267  * @reply_cmd:        command id for reply (GET_REPLY)
 268  * @hdr_attr:         attribute type for request header
 269  * @max_attr:         maximum (top level) attribute type
 270  * @req_info_size:    size of request info
 271  * @reply_data_size:  size of reply data
 272  * @request_policy:   netlink policy for message contents
 273  * @allow_nodev_do:   allow non-dump request with no device identification
 274  * @parse_request:
 275  *      Parse request except common header (struct ethnl_req_info). Common
 276  *      header is already filled on entry, the rest up to @repdata_offset
 277  *      is zero initialized. This callback should only modify type specific
 278  *      request info by parsed attributes from request message.
 279  * @prepare_data:
 280  *      Retrieve and prepare data needed to compose a reply message. Calls to
 281  *      ethtool_ops handlers are limited to this callback. Common reply data
 282  *      (struct ethnl_reply_data) is filled on entry, type specific part after
 283  *      it is zero initialized. This callback should only modify the type
 284  *      specific part of reply data. Device identification from struct
 285  *      ethnl_reply_data is to be used as for dump requests, it iterates
 286  *      through network devices while dev member of struct ethnl_req_info
 287  *      points to the device from client request.
 288  * @reply_size:
 289  *      Estimate reply message size. Returned value must be sufficient for
 290  *      message payload without common reply header. The callback may returned
 291  *      estimate higher than actual message size if exact calculation would
 292  *      not be worth the saved memory space.
 293  * @fill_reply:
 294  *      Fill reply message payload (except for common header) from reply data.
 295  *      The callback must not generate more payload than previously called
 296  *      ->reply_size() estimated.
 297  * @cleanup_data:
 298  *      Optional cleanup called when reply data is no longer needed. Can be
 299  *      used e.g. to free any additional data structures outside the main
 300  *      structure which were allocated by ->prepare_data(). When processing
 301  *      dump requests, ->cleanup() is called for each message.
 302  *
 303  * Description of variable parts of GET request handling when using the
 304  * unified infrastructure. When used, a pointer to an instance of this
 305  * structure is to be added to &ethnl_default_requests array and generic
 306  * handlers ethnl_default_doit(), ethnl_default_dumpit(),
 307  * ethnl_default_start() and ethnl_default_done() used in @ethtool_genl_ops;
 308  * ethnl_default_notify() can be used in @ethnl_notify_handlers to send
 309  * notifications of the corresponding type.
 310  */
 311 struct ethnl_request_ops {
 312         u8                      request_cmd;
 313         u8                      reply_cmd;
 314         u16                     hdr_attr;
 315         unsigned int            max_attr;
 316         unsigned int            req_info_size;
 317         unsigned int            reply_data_size;
 318         const struct nla_policy *request_policy;
 319         bool                    allow_nodev_do;
 320
 321         int (*parse_request)(struct ethnl_req_info *req_info,
 322                              struct nlattr **tb,
 323                              struct netlink_ext_ack *extack);
 324         int (*prepare_data)(const struct ethnl_req_info *req_info,
 325                             struct ethnl_reply_data *reply_data,
 326                             struct genl_info *info);
 327         int (*reply_size)(const struct ethnl_req_info *req_info,
 328                           const struct ethnl_reply_data *reply_data);
 329         int (*fill_reply)(struct sk_buff *skb,
 330                           const struct ethnl_req_info *req_info,
 331                           const struct ethnl_reply_data *reply_data);
 332         void (*cleanup_data)(struct ethnl_reply_data *reply_data);
 333 };
 334
 335 /* request handlers */
 336
 337 extern const struct ethnl_request_ops ethnl_strset_request_ops;
 338 extern const struct ethnl_request_ops ethnl_linkinfo_request_ops;
 339 extern const struct ethnl_request_ops ethnl_linkmodes_request_ops;
 340 extern const struct ethnl_request_ops ethnl_linkstate_request_ops;
 341 extern const struct ethnl_request_ops ethnl_debug_request_ops;
 342 extern const struct ethnl_request_ops ethnl_wol_request_ops;
 343 extern const struct ethnl_request_ops ethnl_features_request_ops;
 344 extern const struct ethnl_request_ops ethnl_privflags_request_ops;
 345 extern const struct ethnl_request_ops ethnl_rings_request_ops;
 346 extern const struct ethnl_request_ops ethnl_channels_request_ops;
 347 extern const struct ethnl_request_ops ethnl_coalesce_request_ops;
 348 extern const struct ethnl_request_ops ethnl_pause_request_ops;
 349 extern const struct ethnl_request_ops ethnl_eee_request_ops;
 350 extern const struct ethnl_request_ops ethnl_tsinfo_request_ops;
 351
 352 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
 353 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
 354 int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info);
 355 int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info);
 356 int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
 357 int ethnl_set_privflags(struct sk_buff *skb, struct genl_info *info);
 358 int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info);
 359 int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info);
 360 int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info);
 361 int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info);
 362 int ethnl_set_eee(struct sk_buff *skb, struct genl_info *info);
 363 int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
 364 int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info);
 365 int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info);
 366 int ethnl_tunnel_info_start(struct netlink_callback *cb);
 367 int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 368
 369 #endif /* _NET_ETHTOOL_NETLINK_H */