Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Linux WiMAX |
| 3 | * Generic messaging interface between userspace and driver/device |
| 4 | * |
| 5 | * |
| 6 | * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com> |
| 7 | * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License version |
| 11 | * 2 as published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 21 | * 02110-1301, USA. |
| 22 | * |
| 23 | * |
| 24 | * This implements a direct communication channel between user space and |
| 25 | * the driver/device, by which free form messages can be sent back and |
| 26 | * forth. |
| 27 | * |
| 28 | * This is intended for device-specific features, vendor quirks, etc. |
| 29 | * |
| 30 | * See include/net/wimax.h |
| 31 | * |
| 32 | * GENERIC NETLINK ENCODING AND CAPACITY |
| 33 | * |
| 34 | * A destination "pipe name" is added to each message; it is up to the |
| 35 | * drivers to assign or use those names (if using them at all). |
| 36 | * |
| 37 | * Messages are encoded as a binary netlink attribute using nla_put() |
| 38 | * using type NLA_UNSPEC (as some versions of libnl still in |
| 39 | * deployment don't yet understand NLA_BINARY). |
| 40 | * |
| 41 | * The maximum capacity of this transport is PAGESIZE per message (so |
| 42 | * the actual payload will be bit smaller depending on the |
| 43 | * netlink/generic netlink attributes and headers). |
| 44 | * |
| 45 | * RECEPTION OF MESSAGES |
| 46 | * |
| 47 | * When a message is received from user space, it is passed verbatim |
| 48 | * to the driver calling wimax_dev->op_msg_from_user(). The return |
| 49 | * value from this function is passed back to user space as an ack |
| 50 | * over the generic netlink protocol. |
| 51 | * |
| 52 | * The stack doesn't do any processing or interpretation of these |
| 53 | * messages. |
| 54 | * |
| 55 | * SENDING MESSAGES |
| 56 | * |
| 57 | * Messages can be sent with wimax_msg(). |
| 58 | * |
| 59 | * If the message delivery needs to happen on a different context to |
| 60 | * that of its creation, wimax_msg_alloc() can be used to get a |
| 61 | * pointer to the message that can be delivered later on with |
| 62 | * wimax_msg_send(). |
| 63 | * |
| 64 | * ROADMAP |
| 65 | * |
| 66 | * wimax_gnl_doit_msg_from_user() Process a message from user space |
| 67 | * wimax_dev_get_by_genl_info() |
| 68 | * wimax_dev->op_msg_from_user() Delivery of message to the driver |
| 69 | * |
| 70 | * wimax_msg() Send a message to user space |
| 71 | * wimax_msg_alloc() |
| 72 | * wimax_msg_send() |
| 73 | */ |
| 74 | #include <linux/device.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 75 | #include <linux/slab.h> |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 76 | #include <net/genetlink.h> |
| 77 | #include <linux/netdevice.h> |
| 78 | #include <linux/wimax.h> |
| 79 | #include <linux/security.h> |
Paul Gortmaker | bc3b2d7 | 2011-07-15 11:47:34 -0400 | [diff] [blame] | 80 | #include <linux/export.h> |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 81 | #include "wimax-internal.h" |
| 82 | |
| 83 | |
| 84 | #define D_SUBMODULE op_msg |
| 85 | #include "debug-levels.h" |
| 86 | |
| 87 | |
| 88 | /** |
| 89 | * wimax_msg_alloc - Create a new skb for sending a message to userspace |
| 90 | * |
| 91 | * @wimax_dev: WiMAX device descriptor |
| 92 | * @pipe_name: "named pipe" the message will be sent to |
| 93 | * @msg: pointer to the message data to send |
| 94 | * @size: size of the message to send (in bytes), including the header. |
| 95 | * @gfp_flags: flags for memory allocation. |
| 96 | * |
| 97 | * Returns: %0 if ok, negative errno code on error |
| 98 | * |
| 99 | * Description: |
| 100 | * |
| 101 | * Allocates an skb that will contain the message to send to user |
| 102 | * space over the messaging pipe and initializes it, copying the |
| 103 | * payload. |
| 104 | * |
| 105 | * Once this call is done, you can deliver it with |
| 106 | * wimax_msg_send(). |
| 107 | * |
| 108 | * IMPORTANT: |
| 109 | * |
| 110 | * Don't use skb_push()/skb_pull()/skb_reserve() on the skb, as |
| 111 | * wimax_msg_send() depends on skb->data being placed at the |
| 112 | * beginning of the user message. |
Inaky Perez-Gonzalez | 52a8d96 | 2009-05-05 21:05:16 -0700 | [diff] [blame] | 113 | * |
| 114 | * Unlike other WiMAX stack calls, this call can be used way early, |
| 115 | * even before wimax_dev_add() is called, as long as the |
| 116 | * wimax_dev->net_dev pointer is set to point to a proper |
| 117 | * net_dev. This is so that drivers can use it early in case they need |
| 118 | * to send stuff around or communicate with user space. |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 119 | */ |
| 120 | struct sk_buff *wimax_msg_alloc(struct wimax_dev *wimax_dev, |
| 121 | const char *pipe_name, |
| 122 | const void *msg, size_t size, |
| 123 | gfp_t gfp_flags) |
| 124 | { |
| 125 | int result; |
Inaky Perez-Gonzalez | 52a8d96 | 2009-05-05 21:05:16 -0700 | [diff] [blame] | 126 | struct device *dev = wimax_dev_to_dev(wimax_dev); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 127 | size_t msg_size; |
| 128 | void *genl_msg; |
| 129 | struct sk_buff *skb; |
| 130 | |
| 131 | msg_size = nla_total_size(size) |
| 132 | + nla_total_size(sizeof(u32)) |
| 133 | + (pipe_name ? nla_total_size(strlen(pipe_name)) : 0); |
| 134 | result = -ENOMEM; |
| 135 | skb = genlmsg_new(msg_size, gfp_flags); |
| 136 | if (skb == NULL) |
| 137 | goto error_new; |
| 138 | genl_msg = genlmsg_put(skb, 0, 0, &wimax_gnl_family, |
| 139 | 0, WIMAX_GNL_OP_MSG_TO_USER); |
| 140 | if (genl_msg == NULL) { |
| 141 | dev_err(dev, "no memory to create generic netlink message\n"); |
| 142 | goto error_genlmsg_put; |
| 143 | } |
| 144 | result = nla_put_u32(skb, WIMAX_GNL_MSG_IFIDX, |
| 145 | wimax_dev->net_dev->ifindex); |
| 146 | if (result < 0) { |
| 147 | dev_err(dev, "no memory to add ifindex attribute\n"); |
| 148 | goto error_nla_put; |
| 149 | } |
| 150 | if (pipe_name) { |
| 151 | result = nla_put_string(skb, WIMAX_GNL_MSG_PIPE_NAME, |
| 152 | pipe_name); |
| 153 | if (result < 0) { |
| 154 | dev_err(dev, "no memory to add pipe_name attribute\n"); |
| 155 | goto error_nla_put; |
| 156 | } |
| 157 | } |
| 158 | result = nla_put(skb, WIMAX_GNL_MSG_DATA, size, msg); |
| 159 | if (result < 0) { |
Inaky Perez-Gonzalez | d1a2627 | 2009-03-30 17:50:17 -0700 | [diff] [blame] | 160 | dev_err(dev, "no memory to add payload (msg %p size %zu) in " |
| 161 | "attribute: %d\n", msg, size, result); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 162 | goto error_nla_put; |
| 163 | } |
| 164 | genlmsg_end(skb, genl_msg); |
| 165 | return skb; |
| 166 | |
| 167 | error_nla_put: |
| 168 | error_genlmsg_put: |
| 169 | error_new: |
| 170 | nlmsg_free(skb); |
| 171 | return ERR_PTR(result); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 172 | } |
| 173 | EXPORT_SYMBOL_GPL(wimax_msg_alloc); |
| 174 | |
| 175 | |
| 176 | /** |
| 177 | * wimax_msg_data_len - Return a pointer and size of a message's payload |
| 178 | * |
| 179 | * @msg: Pointer to a message created with wimax_msg_alloc() |
| 180 | * @size: Pointer to where to store the message's size |
| 181 | * |
| 182 | * Returns the pointer to the message data. |
| 183 | */ |
| 184 | const void *wimax_msg_data_len(struct sk_buff *msg, size_t *size) |
| 185 | { |
| 186 | struct nlmsghdr *nlh = (void *) msg->head; |
| 187 | struct nlattr *nla; |
| 188 | |
| 189 | nla = nlmsg_find_attr(nlh, sizeof(struct genlmsghdr), |
| 190 | WIMAX_GNL_MSG_DATA); |
| 191 | if (nla == NULL) { |
Fabian Frederick | 28b7dea | 2014-10-07 22:12:03 +0200 | [diff] [blame] | 192 | pr_err("Cannot find attribute WIMAX_GNL_MSG_DATA\n"); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 193 | return NULL; |
| 194 | } |
| 195 | *size = nla_len(nla); |
| 196 | return nla_data(nla); |
| 197 | } |
| 198 | EXPORT_SYMBOL_GPL(wimax_msg_data_len); |
| 199 | |
| 200 | |
| 201 | /** |
| 202 | * wimax_msg_data - Return a pointer to a message's payload |
| 203 | * |
| 204 | * @msg: Pointer to a message created with wimax_msg_alloc() |
| 205 | */ |
| 206 | const void *wimax_msg_data(struct sk_buff *msg) |
| 207 | { |
| 208 | struct nlmsghdr *nlh = (void *) msg->head; |
| 209 | struct nlattr *nla; |
| 210 | |
| 211 | nla = nlmsg_find_attr(nlh, sizeof(struct genlmsghdr), |
| 212 | WIMAX_GNL_MSG_DATA); |
| 213 | if (nla == NULL) { |
Fabian Frederick | 28b7dea | 2014-10-07 22:12:03 +0200 | [diff] [blame] | 214 | pr_err("Cannot find attribute WIMAX_GNL_MSG_DATA\n"); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 215 | return NULL; |
| 216 | } |
| 217 | return nla_data(nla); |
| 218 | } |
| 219 | EXPORT_SYMBOL_GPL(wimax_msg_data); |
| 220 | |
| 221 | |
| 222 | /** |
| 223 | * wimax_msg_len - Return a message's payload length |
| 224 | * |
| 225 | * @msg: Pointer to a message created with wimax_msg_alloc() |
| 226 | */ |
| 227 | ssize_t wimax_msg_len(struct sk_buff *msg) |
| 228 | { |
| 229 | struct nlmsghdr *nlh = (void *) msg->head; |
| 230 | struct nlattr *nla; |
| 231 | |
| 232 | nla = nlmsg_find_attr(nlh, sizeof(struct genlmsghdr), |
| 233 | WIMAX_GNL_MSG_DATA); |
| 234 | if (nla == NULL) { |
Fabian Frederick | 28b7dea | 2014-10-07 22:12:03 +0200 | [diff] [blame] | 235 | pr_err("Cannot find attribute WIMAX_GNL_MSG_DATA\n"); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 236 | return -EINVAL; |
| 237 | } |
| 238 | return nla_len(nla); |
| 239 | } |
| 240 | EXPORT_SYMBOL_GPL(wimax_msg_len); |
| 241 | |
| 242 | |
| 243 | /** |
| 244 | * wimax_msg_send - Send a pre-allocated message to user space |
| 245 | * |
| 246 | * @wimax_dev: WiMAX device descriptor |
| 247 | * |
| 248 | * @skb: &struct sk_buff returned by wimax_msg_alloc(). Note the |
| 249 | * ownership of @skb is transferred to this function. |
| 250 | * |
| 251 | * Returns: 0 if ok, < 0 errno code on error |
| 252 | * |
| 253 | * Description: |
| 254 | * |
| 255 | * Sends a free-form message that was preallocated with |
| 256 | * wimax_msg_alloc() and filled up. |
| 257 | * |
| 258 | * Assumes that once you pass an skb to this function for sending, it |
| 259 | * owns it and will release it when done (on success). |
| 260 | * |
| 261 | * IMPORTANT: |
| 262 | * |
| 263 | * Don't use skb_push()/skb_pull()/skb_reserve() on the skb, as |
| 264 | * wimax_msg_send() depends on skb->data being placed at the |
| 265 | * beginning of the user message. |
Inaky Perez-Gonzalez | 52a8d96 | 2009-05-05 21:05:16 -0700 | [diff] [blame] | 266 | * |
| 267 | * Unlike other WiMAX stack calls, this call can be used way early, |
| 268 | * even before wimax_dev_add() is called, as long as the |
| 269 | * wimax_dev->net_dev pointer is set to point to a proper |
| 270 | * net_dev. This is so that drivers can use it early in case they need |
| 271 | * to send stuff around or communicate with user space. |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 272 | */ |
| 273 | int wimax_msg_send(struct wimax_dev *wimax_dev, struct sk_buff *skb) |
| 274 | { |
Inaky Perez-Gonzalez | 52a8d96 | 2009-05-05 21:05:16 -0700 | [diff] [blame] | 275 | struct device *dev = wimax_dev_to_dev(wimax_dev); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 276 | void *msg = skb->data; |
| 277 | size_t size = skb->len; |
| 278 | might_sleep(); |
| 279 | |
| 280 | d_printf(1, dev, "CTX: wimax msg, %zu bytes\n", size); |
| 281 | d_dump(2, dev, msg, size); |
Johannes Berg | 2a94fe4 | 2013-11-19 15:19:39 +0100 | [diff] [blame] | 282 | genlmsg_multicast(&wimax_gnl_family, skb, 0, 0, GFP_KERNEL); |
Pablo Neira Ayuso | ff491a7 | 2009-02-05 23:56:36 -0800 | [diff] [blame] | 283 | d_printf(1, dev, "CTX: genl multicast done\n"); |
| 284 | return 0; |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 285 | } |
| 286 | EXPORT_SYMBOL_GPL(wimax_msg_send); |
| 287 | |
| 288 | |
| 289 | /** |
| 290 | * wimax_msg - Send a message to user space |
| 291 | * |
| 292 | * @wimax_dev: WiMAX device descriptor (properly referenced) |
| 293 | * @pipe_name: "named pipe" the message will be sent to |
| 294 | * @buf: pointer to the message to send. |
| 295 | * @size: size of the buffer pointed to by @buf (in bytes). |
| 296 | * @gfp_flags: flags for memory allocation. |
| 297 | * |
| 298 | * Returns: %0 if ok, negative errno code on error. |
| 299 | * |
| 300 | * Description: |
| 301 | * |
| 302 | * Sends a free-form message to user space on the device @wimax_dev. |
| 303 | * |
| 304 | * NOTES: |
| 305 | * |
| 306 | * Once the @skb is given to this function, who will own it and will |
| 307 | * release it when done (unless it returns error). |
| 308 | */ |
| 309 | int wimax_msg(struct wimax_dev *wimax_dev, const char *pipe_name, |
| 310 | const void *buf, size_t size, gfp_t gfp_flags) |
| 311 | { |
| 312 | int result = -ENOMEM; |
| 313 | struct sk_buff *skb; |
| 314 | |
| 315 | skb = wimax_msg_alloc(wimax_dev, pipe_name, buf, size, gfp_flags); |
Inaky Perez-Gonzalez | d1a2627 | 2009-03-30 17:50:17 -0700 | [diff] [blame] | 316 | if (IS_ERR(skb)) |
| 317 | result = PTR_ERR(skb); |
| 318 | else |
| 319 | result = wimax_msg_send(wimax_dev, skb); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 320 | return result; |
| 321 | } |
| 322 | EXPORT_SYMBOL_GPL(wimax_msg); |
| 323 | |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 324 | /* |
| 325 | * Relays a message from user space to the driver |
| 326 | * |
| 327 | * The skb is passed to the driver-specific function with the netlink |
| 328 | * and generic netlink headers already stripped. |
| 329 | * |
| 330 | * This call will block while handling/relaying the message. |
| 331 | */ |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 332 | int wimax_gnl_doit_msg_from_user(struct sk_buff *skb, struct genl_info *info) |
| 333 | { |
| 334 | int result, ifindex; |
| 335 | struct wimax_dev *wimax_dev; |
| 336 | struct device *dev; |
| 337 | struct nlmsghdr *nlh = info->nlhdr; |
| 338 | char *pipe_name; |
| 339 | void *msg_buf; |
| 340 | size_t msg_len; |
| 341 | |
| 342 | might_sleep(); |
| 343 | d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info); |
| 344 | result = -ENODEV; |
| 345 | if (info->attrs[WIMAX_GNL_MSG_IFIDX] == NULL) { |
Fabian Frederick | 28b7dea | 2014-10-07 22:12:03 +0200 | [diff] [blame] | 346 | pr_err("WIMAX_GNL_MSG_FROM_USER: can't find IFIDX attribute\n"); |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 347 | goto error_no_wimax_dev; |
| 348 | } |
| 349 | ifindex = nla_get_u32(info->attrs[WIMAX_GNL_MSG_IFIDX]); |
| 350 | wimax_dev = wimax_dev_get_by_genl_info(info, ifindex); |
| 351 | if (wimax_dev == NULL) |
| 352 | goto error_no_wimax_dev; |
| 353 | dev = wimax_dev_to_dev(wimax_dev); |
| 354 | |
| 355 | /* Unpack arguments */ |
| 356 | result = -EINVAL; |
| 357 | if (info->attrs[WIMAX_GNL_MSG_DATA] == NULL) { |
| 358 | dev_err(dev, "WIMAX_GNL_MSG_FROM_USER: can't find MSG_DATA " |
| 359 | "attribute\n"); |
| 360 | goto error_no_data; |
| 361 | } |
| 362 | msg_buf = nla_data(info->attrs[WIMAX_GNL_MSG_DATA]); |
| 363 | msg_len = nla_len(info->attrs[WIMAX_GNL_MSG_DATA]); |
| 364 | |
| 365 | if (info->attrs[WIMAX_GNL_MSG_PIPE_NAME] == NULL) |
| 366 | pipe_name = NULL; |
| 367 | else { |
| 368 | struct nlattr *attr = info->attrs[WIMAX_GNL_MSG_PIPE_NAME]; |
| 369 | size_t attr_len = nla_len(attr); |
| 370 | /* libnl-1.1 does not yet support NLA_NUL_STRING */ |
| 371 | result = -ENOMEM; |
| 372 | pipe_name = kstrndup(nla_data(attr), attr_len + 1, GFP_KERNEL); |
| 373 | if (pipe_name == NULL) |
| 374 | goto error_alloc; |
| 375 | pipe_name[attr_len] = 0; |
| 376 | } |
| 377 | mutex_lock(&wimax_dev->mutex); |
| 378 | result = wimax_dev_is_ready(wimax_dev); |
Inaky Perez-Gonzalez | de9315f | 2009-09-30 16:33:26 -0700 | [diff] [blame] | 379 | if (result == -ENOMEDIUM) |
| 380 | result = 0; |
Inaky Perez-Gonzalez | 3e65646 | 2008-12-20 16:57:38 -0800 | [diff] [blame] | 381 | if (result < 0) |
| 382 | goto error_not_ready; |
| 383 | result = -ENOSYS; |
| 384 | if (wimax_dev->op_msg_from_user == NULL) |
| 385 | goto error_noop; |
| 386 | |
| 387 | d_printf(1, dev, |
| 388 | "CRX: nlmsghdr len %u type %u flags 0x%04x seq 0x%x pid %u\n", |
| 389 | nlh->nlmsg_len, nlh->nlmsg_type, nlh->nlmsg_flags, |
| 390 | nlh->nlmsg_seq, nlh->nlmsg_pid); |
| 391 | d_printf(1, dev, "CRX: wimax message %zu bytes\n", msg_len); |
| 392 | d_dump(2, dev, msg_buf, msg_len); |
| 393 | |
| 394 | result = wimax_dev->op_msg_from_user(wimax_dev, pipe_name, |
| 395 | msg_buf, msg_len, info); |
| 396 | error_noop: |
| 397 | error_not_ready: |
| 398 | mutex_unlock(&wimax_dev->mutex); |
| 399 | error_alloc: |
| 400 | kfree(pipe_name); |
| 401 | error_no_data: |
| 402 | dev_put(wimax_dev->net_dev); |
| 403 | error_no_wimax_dev: |
| 404 | d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result); |
| 405 | return result; |
| 406 | } |
| 407 | |