net/bridge/br_sysfs_if.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Sysfs attributes of bridge ports
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Stephen Hemminger               <shemminger@osdl.org>
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/kernel.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/if_bridge.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/sched/signal.h>
  17
  18 #include "br_private.h"
  19
  20 struct brport_attribute {
  21         struct attribute        attr;
  22         ssize_t (*show)(struct net_bridge_port *, char *);
  23         int (*store)(struct net_bridge_port *, unsigned long);
  24         int (*store_raw)(struct net_bridge_port *, char *);
  25 };
  26
  27 #define BRPORT_ATTR_RAW(_name, _mode, _show, _store)                    \
  28 const struct brport_attribute brport_attr_##_name = {                   \
  29         .attr           = {.name = __stringify(_name),                  \
  30                            .mode = _mode },                             \
  31         .show           = _show,                                        \
  32         .store_raw      = _store,                                       \
  33 };
  34
  35 #define BRPORT_ATTR(_name, _mode, _show, _store)                \
  36 const struct brport_attribute brport_attr_##_name = {           \
  37         .attr = {.name = __stringify(_name),                    \
  38                  .mode = _mode },                               \
  39         .show   = _show,                                        \
  40         .store  = _store,                                       \
  41 };
  42
  43 #define BRPORT_ATTR_FLAG(_name, _mask)                          \
  44 static ssize_t show_##_name(struct net_bridge_port *p, char *buf) \
  45 {                                                               \
  46         return sprintf(buf, "%d\n", !!(p->flags & _mask));      \
  47 }                                                               \
  48 static int store_##_name(struct net_bridge_port *p, unsigned long v) \
  49 {                                                               \
  50         return store_flag(p, v, _mask);                         \
  51 }                                                               \
  52 static BRPORT_ATTR(_name, 0644,                                 \
  53                    show_##_name, store_##_name)
  54
  55 static int store_flag(struct net_bridge_port *p, unsigned long v,
  56                       unsigned long mask)
  57 {
  58         unsigned long flags;
  59
  60         flags = p->flags;
  61
  62         if (v)
  63                 flags |= mask;
  64         else
  65                 flags &= ~mask;
  66
  67         if (flags != p->flags) {
  68                 p->flags = flags;
  69                 br_port_flags_change(p, mask);
  70         }
  71         return 0;
  72 }
  73
  74 static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
  75 {
  76         return sprintf(buf, "%d\n", p->path_cost);
  77 }
  78
  79 static BRPORT_ATTR(path_cost, 0644,
  80                    show_path_cost, br_stp_set_path_cost);
  81
  82 static ssize_t show_priority(struct net_bridge_port *p, char *buf)
  83 {
  84         return sprintf(buf, "%d\n", p->priority);
  85 }
  86
  87 static BRPORT_ATTR(priority, 0644,
  88                          show_priority, br_stp_set_port_priority);
  89
  90 static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
  91 {
  92         return br_show_bridge_id(buf, &p->designated_root);
  93 }
  94 static BRPORT_ATTR(designated_root, 0444, show_designated_root, NULL);
  95
  96 static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
  97 {
  98         return br_show_bridge_id(buf, &p->designated_bridge);
  99 }
 100 static BRPORT_ATTR(designated_bridge, 0444, show_designated_bridge, NULL);
 101
 102 static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
 103 {
 104         return sprintf(buf, "%d\n", p->designated_port);
 105 }
 106 static BRPORT_ATTR(designated_port, 0444, show_designated_port, NULL);
 107
 108 static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
 109 {
 110         return sprintf(buf, "%d\n", p->designated_cost);
 111 }
 112 static BRPORT_ATTR(designated_cost, 0444, show_designated_cost, NULL);
 113
 114 static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
 115 {
 116         return sprintf(buf, "0x%x\n", p->port_id);
 117 }
 118 static BRPORT_ATTR(port_id, 0444, show_port_id, NULL);
 119
 120 static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
 121 {
 122         return sprintf(buf, "0x%x\n", p->port_no);
 123 }
 124
 125 static BRPORT_ATTR(port_no, 0444, show_port_no, NULL);
 126
 127 static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
 128 {
 129         return sprintf(buf, "%d\n", p->topology_change_ack);
 130 }
 131 static BRPORT_ATTR(change_ack, 0444, show_change_ack, NULL);
 132
 133 static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
 134 {
 135         return sprintf(buf, "%d\n", p->config_pending);
 136 }
 137 static BRPORT_ATTR(config_pending, 0444, show_config_pending, NULL);
 138
 139 static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
 140 {
 141         return sprintf(buf, "%d\n", p->state);
 142 }
 143 static BRPORT_ATTR(state, 0444, show_port_state, NULL);
 144
 145 static ssize_t show_message_age_timer(struct net_bridge_port *p,
 146                                             char *buf)
 147 {
 148         return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
 149 }
 150 static BRPORT_ATTR(message_age_timer, 0444, show_message_age_timer, NULL);
 151
 152 static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
 153                                             char *buf)
 154 {
 155         return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
 156 }
 157 static BRPORT_ATTR(forward_delay_timer, 0444, show_forward_delay_timer, NULL);
 158
 159 static ssize_t show_hold_timer(struct net_bridge_port *p,
 160                                             char *buf)
 161 {
 162         return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
 163 }
 164 static BRPORT_ATTR(hold_timer, 0444, show_hold_timer, NULL);
 165
 166 static int store_flush(struct net_bridge_port *p, unsigned long v)
 167 {
 168         br_fdb_delete_by_port(p->br, p, 0, 0); // Don't delete local entry
 169         return 0;
 170 }
 171 static BRPORT_ATTR(flush, 0200, NULL, store_flush);
 172
 173 static ssize_t show_group_fwd_mask(struct net_bridge_port *p, char *buf)
 174 {
 175         return sprintf(buf, "%#x\n", p->group_fwd_mask);
 176 }
 177
 178 static int store_group_fwd_mask(struct net_bridge_port *p,
 179                                 unsigned long v)
 180 {
 181         if (v & BR_GROUPFWD_MACPAUSE)
 182                 return -EINVAL;
 183         p->group_fwd_mask = v;
 184
 185         return 0;
 186 }
 187 static BRPORT_ATTR(group_fwd_mask, 0644, show_group_fwd_mask,
 188                    store_group_fwd_mask);
 189
 190 static ssize_t show_backup_port(struct net_bridge_port *p, char *buf)
 191 {
 192         struct net_bridge_port *backup_p;
 193         int ret = 0;
 194
 195         rcu_read_lock();
 196         backup_p = rcu_dereference(p->backup_port);
 197         if (backup_p)
 198                 ret = sprintf(buf, "%s\n", backup_p->dev->name);
 199         rcu_read_unlock();
 200
 201         return ret;
 202 }
 203
 204 static int store_backup_port(struct net_bridge_port *p, char *buf)
 205 {
 206         struct net_device *backup_dev = NULL;
 207         char *nl = strchr(buf, '\n');
 208
 209         if (nl)
 210                 *nl = '\0';
 211
 212         if (strlen(buf) > 0) {
 213                 backup_dev = __dev_get_by_name(dev_net(p->dev), buf);
 214                 if (!backup_dev)
 215                         return -ENOENT;
 216         }
 217
 218         return nbp_backup_change(p, backup_dev);
 219 }
 220 static BRPORT_ATTR_RAW(backup_port, 0644, show_backup_port, store_backup_port);
 221
 222 BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
 223 BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
 224 BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
 225 BRPORT_ATTR_FLAG(learning, BR_LEARNING);
 226 BRPORT_ATTR_FLAG(unicast_flood, BR_FLOOD);
 227 BRPORT_ATTR_FLAG(proxyarp, BR_PROXYARP);
 228 BRPORT_ATTR_FLAG(proxyarp_wifi, BR_PROXYARP_WIFI);
 229 BRPORT_ATTR_FLAG(multicast_flood, BR_MCAST_FLOOD);
 230 BRPORT_ATTR_FLAG(broadcast_flood, BR_BCAST_FLOOD);
 231 BRPORT_ATTR_FLAG(neigh_suppress, BR_NEIGH_SUPPRESS);
 232 BRPORT_ATTR_FLAG(isolated, BR_ISOLATED);
 233
 234 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 235 static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
 236 {
 237         return sprintf(buf, "%d\n", p->multicast_router);
 238 }
 239
 240 static int store_multicast_router(struct net_bridge_port *p,
 241                                       unsigned long v)
 242 {
 243         return br_multicast_set_port_router(p, v);
 244 }
 245 static BRPORT_ATTR(multicast_router, 0644, show_multicast_router,
 246                    store_multicast_router);
 247
 248 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
 249 BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
 250 #endif
 251
 252 static const struct brport_attribute *brport_attrs[] = {
 253         &brport_attr_path_cost,
 254         &brport_attr_priority,
 255         &brport_attr_port_id,
 256         &brport_attr_port_no,
 257         &brport_attr_designated_root,
 258         &brport_attr_designated_bridge,
 259         &brport_attr_designated_port,
 260         &brport_attr_designated_cost,
 261         &brport_attr_state,
 262         &brport_attr_change_ack,
 263         &brport_attr_config_pending,
 264         &brport_attr_message_age_timer,
 265         &brport_attr_forward_delay_timer,
 266         &brport_attr_hold_timer,
 267         &brport_attr_flush,
 268         &brport_attr_hairpin_mode,
 269         &brport_attr_bpdu_guard,
 270         &brport_attr_root_block,
 271         &brport_attr_learning,
 272         &brport_attr_unicast_flood,
 273 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 274         &brport_attr_multicast_router,
 275         &brport_attr_multicast_fast_leave,
 276         &brport_attr_multicast_to_unicast,
 277 #endif
 278         &brport_attr_proxyarp,
 279         &brport_attr_proxyarp_wifi,
 280         &brport_attr_multicast_flood,
 281         &brport_attr_broadcast_flood,
 282         &brport_attr_group_fwd_mask,
 283         &brport_attr_neigh_suppress,
 284         &brport_attr_isolated,
 285         &brport_attr_backup_port,
 286         NULL
 287 };
 288
 289 #define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
 290
 291 static ssize_t brport_show(struct kobject *kobj,
 292                            struct attribute *attr, char *buf)
 293 {
 294         struct brport_attribute *brport_attr = to_brport_attr(attr);
 295         struct net_bridge_port *p = kobj_to_brport(kobj);
 296
 297         if (!brport_attr->show)
 298                 return -EINVAL;
 299
 300         return brport_attr->show(p, buf);
 301 }
 302
 303 static ssize_t brport_store(struct kobject *kobj,
 304                             struct attribute *attr,
 305                             const char *buf, size_t count)
 306 {
 307         struct brport_attribute *brport_attr = to_brport_attr(attr);
 308         struct net_bridge_port *p = kobj_to_brport(kobj);
 309         ssize_t ret = -EINVAL;
 310         unsigned long val;
 311         char *endp;
 312
 313         if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
 314                 return -EPERM;
 315
 316         if (!rtnl_trylock())
 317                 return restart_syscall();
 318
 319         if (brport_attr->store_raw) {
 320                 char *buf_copy;
 321
 322                 buf_copy = kstrndup(buf, count, GFP_KERNEL);
 323                 if (!buf_copy) {
 324                         ret = -ENOMEM;
 325                         goto out_unlock;
 326                 }
 327                 spin_lock_bh(&p->br->lock);
 328                 ret = brport_attr->store_raw(p, buf_copy);
 329                 spin_unlock_bh(&p->br->lock);
 330                 kfree(buf_copy);
 331         } else if (brport_attr->store) {
 332                 val = simple_strtoul(buf, &endp, 0);
 333                 if (endp == buf)
 334                         goto out_unlock;
 335                 spin_lock_bh(&p->br->lock);
 336                 ret = brport_attr->store(p, val);
 337                 spin_unlock_bh(&p->br->lock);
 338         }
 339
 340         if (!ret) {
 341                 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 342                 ret = count;
 343         }
 344 out_unlock:
 345         rtnl_unlock();
 346
 347         return ret;
 348 }
 349
 350 const struct sysfs_ops brport_sysfs_ops = {
 351         .show = brport_show,
 352         .store = brport_store,
 353 };
 354
 355 /*
 356  * Add sysfs entries to ethernet device added to a bridge.
 357  * Creates a brport subdirectory with bridge attributes.
 358  * Puts symlink in bridge's brif subdirectory
 359  */
 360 int br_sysfs_addif(struct net_bridge_port *p)
 361 {
 362         struct net_bridge *br = p->br;
 363         const struct brport_attribute **a;
 364         int err;
 365
 366         err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
 367                                 SYSFS_BRIDGE_PORT_LINK);
 368         if (err)
 369                 return err;
 370
 371         for (a = brport_attrs; *a; ++a) {
 372                 err = sysfs_create_file(&p->kobj, &((*a)->attr));
 373                 if (err)
 374                         return err;
 375         }
 376
 377         strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
 378         return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
 379 }
 380
 381 /* Rename bridge's brif symlink */
 382 int br_sysfs_renameif(struct net_bridge_port *p)
 383 {
 384         struct net_bridge *br = p->br;
 385         int err;
 386
 387         /* If a rename fails, the rollback will cause another
 388          * rename call with the existing name.
 389          */
 390         if (!strncmp(p->sysfs_name, p->dev->name, IFNAMSIZ))
 391                 return 0;
 392
 393         err = sysfs_rename_link(br->ifobj, &p->kobj,
 394                                 p->sysfs_name, p->dev->name);
 395         if (err)
 396                 netdev_notice(br->dev, "unable to rename link %s to %s",
 397                               p->sysfs_name, p->dev->name);
 398         else
 399                 strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
 400
 401         return err;
 402 }