net/wireless/nl80211.c

   1 /*
   2  * This is the new netlink-based wireless configuration interface.
   3  *
   4  * Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6
   7 #include <linux/if.h>
   8 #include <linux/module.h>
   9 #include <linux/err.h>
  10 #include <linux/mutex.h>
  11 #include <linux/list.h>
  12 #include <linux/if_ether.h>
  13 #include <linux/ieee80211.h>
  14 #include <linux/nl80211.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/netlink.h>
  17 #include <net/genetlink.h>
  18 #include <net/cfg80211.h>
  19 #include "core.h"
  20 #include "nl80211.h"
  21
  22 /* the netlink family */
  23 static struct genl_family nl80211_fam = {
  24         .id = GENL_ID_GENERATE, /* don't bother with a hardcoded ID */
  25         .name = "nl80211",      /* have users key off the name instead */
  26         .hdrsize = 0,           /* no private header */
  27         .version = 1,           /* no particular meaning now */
  28         .maxattr = NL80211_ATTR_MAX,
  29 };
  30
  31 /* internal helper: get drv and dev */
  32 static int get_drv_dev_by_info_ifindex(struct genl_info *info,
  33                                        struct cfg80211_registered_device **drv,
  34                                        struct net_device **dev)
  35 {
  36         int ifindex;
  37
  38         if (!info->attrs[NL80211_ATTR_IFINDEX])
  39                 return -EINVAL;
  40
  41         ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
  42         *dev = dev_get_by_index(&init_net, ifindex);
  43         if (!*dev)
  44                 return -ENODEV;
  45
  46         *drv = cfg80211_get_dev_from_ifindex(ifindex);
  47         if (IS_ERR(*drv)) {
  48                 dev_put(*dev);
  49                 return PTR_ERR(*drv);
  50         }
  51
  52         return 0;
  53 }
  54
  55 /* policy for the attributes */
  56 static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
  57         [NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
  58         [NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
  59                                       .len = BUS_ID_SIZE-1 },
  60
  61         [NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
  62         [NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
  63         [NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },
  64 };
  65
  66 /* message building helper */
  67 static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
  68                                    int flags, u8 cmd)
  69 {
  70         /* since there is no private header just add the generic one */
  71         return genlmsg_put(skb, pid, seq, &nl80211_fam, flags, cmd);
  72 }
  73
  74 /* netlink command implementations */
  75
  76 static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
  77                               struct cfg80211_registered_device *dev)
  78 {
  79         void *hdr;
  80
  81         hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_WIPHY);
  82         if (!hdr)
  83                 return -1;
  84
  85         NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
  86         NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
  87         return genlmsg_end(msg, hdr);
  88
  89  nla_put_failure:
  90         return genlmsg_cancel(msg, hdr);
  91 }
  92
  93 static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
  94 {
  95         int idx = 0;
  96         int start = cb->args[0];
  97         struct cfg80211_registered_device *dev;
  98
  99         mutex_lock(&cfg80211_drv_mutex);
 100         list_for_each_entry(dev, &cfg80211_drv_list, list) {
 101                 if (++idx < start)
 102                         continue;
 103                 if (nl80211_send_wiphy(skb, NETLINK_CB(cb->skb).pid,
 104                                        cb->nlh->nlmsg_seq, NLM_F_MULTI,
 105                                        dev) < 0)
 106                         break;
 107         }
 108         mutex_unlock(&cfg80211_drv_mutex);
 109
 110         cb->args[0] = idx;
 111
 112         return skb->len;
 113 }
 114
 115 static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
 116 {
 117         struct sk_buff *msg;
 118         struct cfg80211_registered_device *dev;
 119
 120         dev = cfg80211_get_dev_from_info(info);
 121         if (IS_ERR(dev))
 122                 return PTR_ERR(dev);
 123
 124         msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 125         if (!msg)
 126                 goto out_err;
 127
 128         if (nl80211_send_wiphy(msg, info->snd_pid, info->snd_seq, 0, dev) < 0)
 129                 goto out_free;
 130
 131         cfg80211_put_dev(dev);
 132
 133         return genlmsg_unicast(msg, info->snd_pid);
 134
 135  out_free:
 136         nlmsg_free(msg);
 137  out_err:
 138         cfg80211_put_dev(dev);
 139         return -ENOBUFS;
 140 }
 141
 142 static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 143 {
 144         struct cfg80211_registered_device *rdev;
 145         int result;
 146
 147         if (!info->attrs[NL80211_ATTR_WIPHY_NAME])
 148                 return -EINVAL;
 149
 150         rdev = cfg80211_get_dev_from_info(info);
 151         if (IS_ERR(rdev))
 152                 return PTR_ERR(rdev);
 153
 154         result = cfg80211_dev_rename(rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));
 155
 156         cfg80211_put_dev(rdev);
 157         return result;
 158 }
 159
 160
 161 static int nl80211_send_iface(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 162                               struct net_device *dev)
 163 {
 164         void *hdr;
 165
 166         hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_INTERFACE);
 167         if (!hdr)
 168                 return -1;
 169
 170         NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
 171         NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, dev->name);
 172         /* TODO: interface type */
 173         return genlmsg_end(msg, hdr);
 174
 175  nla_put_failure:
 176         return genlmsg_cancel(msg, hdr);
 177 }
 178
 179 static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *cb)
 180 {
 181         int wp_idx = 0;
 182         int if_idx = 0;
 183         int wp_start = cb->args[0];
 184         int if_start = cb->args[1];
 185         struct cfg80211_registered_device *dev;
 186         struct wireless_dev *wdev;
 187
 188         mutex_lock(&cfg80211_drv_mutex);
 189         list_for_each_entry(dev, &cfg80211_drv_list, list) {
 190                 if (++wp_idx < wp_start)
 191                         continue;
 192                 if_idx = 0;
 193
 194                 mutex_lock(&dev->devlist_mtx);
 195                 list_for_each_entry(wdev, &dev->netdev_list, list) {
 196                         if (++if_idx < if_start)
 197                                 continue;
 198                         if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).pid,
 199                                                cb->nlh->nlmsg_seq, NLM_F_MULTI,
 200                                                wdev->netdev) < 0)
 201                                 break;
 202                 }
 203                 mutex_unlock(&dev->devlist_mtx);
 204         }
 205         mutex_unlock(&cfg80211_drv_mutex);
 206
 207         cb->args[0] = wp_idx;
 208         cb->args[1] = if_idx;
 209
 210         return skb->len;
 211 }
 212
 213 static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
 214 {
 215         struct sk_buff *msg;
 216         struct cfg80211_registered_device *dev;
 217         struct net_device *netdev;
 218         int err;
 219
 220         err = get_drv_dev_by_info_ifindex(info, &dev, &netdev);
 221         if (err)
 222                 return err;
 223
 224         msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 225         if (!msg)
 226                 goto out_err;
 227
 228         if (nl80211_send_iface(msg, info->snd_pid, info->snd_seq, 0, netdev) < 0)
 229                 goto out_free;
 230
 231         dev_put(netdev);
 232         cfg80211_put_dev(dev);
 233
 234         return genlmsg_unicast(msg, info->snd_pid);
 235
 236  out_free:
 237         nlmsg_free(msg);
 238  out_err:
 239         dev_put(netdev);
 240         cfg80211_put_dev(dev);
 241         return -ENOBUFS;
 242 }
 243
 244 static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
 245 {
 246         struct cfg80211_registered_device *drv;
 247         int err, ifindex;
 248         enum nl80211_iftype type;
 249         struct net_device *dev;
 250
 251         if (info->attrs[NL80211_ATTR_IFTYPE]) {
 252                 type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
 253                 if (type > NL80211_IFTYPE_MAX)
 254                         return -EINVAL;
 255         } else
 256                 return -EINVAL;
 257
 258         err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
 259         if (err)
 260                 return err;
 261         ifindex = dev->ifindex;
 262         dev_put(dev);
 263
 264         if (!drv->ops->change_virtual_intf) {
 265                 err = -EOPNOTSUPP;
 266                 goto unlock;
 267         }
 268
 269         rtnl_lock();
 270         err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex, type);
 271         rtnl_unlock();
 272
 273  unlock:
 274         cfg80211_put_dev(drv);
 275         return err;
 276 }
 277
 278 static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
 279 {
 280         struct cfg80211_registered_device *drv;
 281         int err;
 282         enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED;
 283
 284         if (!info->attrs[NL80211_ATTR_IFNAME])
 285                 return -EINVAL;
 286
 287         if (info->attrs[NL80211_ATTR_IFTYPE]) {
 288                 type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
 289                 if (type > NL80211_IFTYPE_MAX)
 290                         return -EINVAL;
 291         }
 292
 293         drv = cfg80211_get_dev_from_info(info);
 294         if (IS_ERR(drv))
 295                 return PTR_ERR(drv);
 296
 297         if (!drv->ops->add_virtual_intf) {
 298                 err = -EOPNOTSUPP;
 299                 goto unlock;
 300         }
 301
 302         rtnl_lock();
 303         err = drv->ops->add_virtual_intf(&drv->wiphy,
 304                 nla_data(info->attrs[NL80211_ATTR_IFNAME]), type);
 305         rtnl_unlock();
 306
 307  unlock:
 308         cfg80211_put_dev(drv);
 309         return err;
 310 }
 311
 312 static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info)
 313 {
 314         struct cfg80211_registered_device *drv;
 315         int ifindex, err;
 316         struct net_device *dev;
 317
 318         err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
 319         if (err)
 320                 return err;
 321         ifindex = dev->ifindex;
 322         dev_put(dev);
 323
 324         if (!drv->ops->del_virtual_intf) {
 325                 err = -EOPNOTSUPP;
 326                 goto out;
 327         }
 328
 329         rtnl_lock();
 330         err = drv->ops->del_virtual_intf(&drv->wiphy, ifindex);
 331         rtnl_unlock();
 332
 333  out:
 334         cfg80211_put_dev(drv);
 335         return err;
 336 }
 337
 338 static struct genl_ops nl80211_ops[] = {
 339         {
 340                 .cmd = NL80211_CMD_GET_WIPHY,
 341                 .doit = nl80211_get_wiphy,
 342                 .dumpit = nl80211_dump_wiphy,
 343                 .policy = nl80211_policy,
 344                 /* can be retrieved by unprivileged users */
 345         },
 346         {
 347                 .cmd = NL80211_CMD_SET_WIPHY,
 348                 .doit = nl80211_set_wiphy,
 349                 .policy = nl80211_policy,
 350                 .flags = GENL_ADMIN_PERM,
 351         },
 352         {
 353                 .cmd = NL80211_CMD_GET_INTERFACE,
 354                 .doit = nl80211_get_interface,
 355                 .dumpit = nl80211_dump_interface,
 356                 .policy = nl80211_policy,
 357                 /* can be retrieved by unprivileged users */
 358         },
 359         {
 360                 .cmd = NL80211_CMD_SET_INTERFACE,
 361                 .doit = nl80211_set_interface,
 362                 .policy = nl80211_policy,
 363                 .flags = GENL_ADMIN_PERM,
 364         },
 365         {
 366                 .cmd = NL80211_CMD_NEW_INTERFACE,
 367                 .doit = nl80211_new_interface,
 368                 .policy = nl80211_policy,
 369                 .flags = GENL_ADMIN_PERM,
 370         },
 371         {
 372                 .cmd = NL80211_CMD_DEL_INTERFACE,
 373                 .doit = nl80211_del_interface,
 374                 .policy = nl80211_policy,
 375                 .flags = GENL_ADMIN_PERM,
 376         },
 377 };
 378
 379 /* multicast groups */
 380 static struct genl_multicast_group nl80211_config_mcgrp = {
 381         .name = "config",
 382 };
 383
 384 /* notification functions */
 385
 386 void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
 387 {
 388         struct sk_buff *msg;
 389
 390         msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 391         if (!msg)
 392                 return;
 393
 394         if (nl80211_send_wiphy(msg, 0, 0, 0, rdev) < 0) {
 395                 nlmsg_free(msg);
 396                 return;
 397         }
 398
 399         genlmsg_multicast(msg, 0, nl80211_config_mcgrp.id, GFP_KERNEL);
 400 }
 401
 402 /* initialisation/exit functions */
 403
 404 int nl80211_init(void)
 405 {
 406         int err, i;
 407
 408         err = genl_register_family(&nl80211_fam);
 409         if (err)
 410                 return err;
 411
 412         for (i = 0; i < ARRAY_SIZE(nl80211_ops); i++) {
 413                 err = genl_register_ops(&nl80211_fam, &nl80211_ops[i]);
 414                 if (err)
 415                         goto err_out;
 416         }
 417
 418         err = genl_register_mc_group(&nl80211_fam, &nl80211_config_mcgrp);
 419         if (err)
 420                 goto err_out;
 421
 422         return 0;
 423  err_out:
 424         genl_unregister_family(&nl80211_fam);
 425         return err;
 426 }
 427
 428 void nl80211_exit(void)
 429 {
 430         genl_unregister_family(&nl80211_fam);
 431 }