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 /* IMPORTANT: new bridge port options must be added with netlink support only
  21  *            please do not add new sysfs entries
  22  */
  23
  24 struct brport_attribute {
  25         struct attribute        attr;
  26         ssize_t (*show)(struct net_bridge_port *, char *);
  27         int (*store)(struct net_bridge_port *, unsigned long);
  28         int (*store_raw)(struct net_bridge_port *, char *);
  29 };
  30
  31 #define BRPORT_ATTR_RAW(_name, _mode, _show, _store)                    \
  32 const struct brport_attribute brport_attr_##_name = {                   \
  33         .attr           = {.name = __stringify(_name),                  \
  34                            .mode = _mode },                             \
  35         .show           = _show,                                        \
  36         .store_raw      = _store,                                       \
  37 };
  38
  39 #define BRPORT_ATTR(_name, _mode, _show, _store)                \
  40 const struct brport_attribute brport_attr_##_name = {           \
  41         .attr = {.name = __stringify(_name),                    \
  42                  .mode = _mode },                               \
  43         .show   = _show,                                        \
  44         .store  = _store,                                       \
  45 };
  46
  47 #define BRPORT_ATTR_FLAG(_name, _mask)                          \
  48 static ssize_t show_##_name(struct net_bridge_port *p, char *buf) \
  49 {                                                               \
  50         return sprintf(buf, "%d\n", !!(p->flags & _mask));      \
  51 }                                                               \
  52 static int store_##_name(struct net_bridge_port *p, unsigned long v) \
  53 {                                                               \
  54         return store_flag(p, v, _mask);                         \
  55 }                                                               \
  56 static BRPORT_ATTR(_name, 0644,                                 \
  57                    show_##_name, store_##_name)
  58
  59 static int store_flag(struct net_bridge_port *p, unsigned long v,
  60                       unsigned long mask)
  61 {
  62         struct netlink_ext_ack extack = {0};
  63         unsigned long flags = p->flags;
  64         int err;
  65
  66         if (v)
  67                 flags |= mask;
  68         else
  69                 flags &= ~mask;
  70
  71         if (flags != p->flags) {
  72                 err = br_switchdev_set_port_flag(p, flags, mask, &extack);
  73                 if (err) {
  74                         netdev_err(p->dev, "%s\n", extack._msg);
  75                         return err;
  76                 }
  77
  78                 p->flags = flags;
  79                 br_port_flags_change(p, mask);
  80         }
  81         return 0;
  82 }
  83
  84 static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
  85 {
  86         return sprintf(buf, "%d\n", p->path_cost);
  87 }
  88
  89 static BRPORT_ATTR(path_cost, 0644,
  90                    show_path_cost, br_stp_set_path_cost);
  91
  92 static ssize_t show_priority(struct net_bridge_port *p, char *buf)
  93 {
  94         return sprintf(buf, "%d\n", p->priority);
  95 }
  96
  97 static BRPORT_ATTR(priority, 0644,
  98                          show_priority, br_stp_set_port_priority);
  99
 100 static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
 101 {
 102         return br_show_bridge_id(buf, &p->designated_root);
 103 }
 104 static BRPORT_ATTR(designated_root, 0444, show_designated_root, NULL);
 105
 106 static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
 107 {
 108         return br_show_bridge_id(buf, &p->designated_bridge);
 109 }
 110 static BRPORT_ATTR(designated_bridge, 0444, show_designated_bridge, NULL);
 111
 112 static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
 113 {
 114         return sprintf(buf, "%d\n", p->designated_port);
 115 }
 116 static BRPORT_ATTR(designated_port, 0444, show_designated_port, NULL);
 117
 118 static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
 119 {
 120         return sprintf(buf, "%d\n", p->designated_cost);
 121 }
 122 static BRPORT_ATTR(designated_cost, 0444, show_designated_cost, NULL);
 123
 124 static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
 125 {
 126         return sprintf(buf, "0x%x\n", p->port_id);
 127 }
 128 static BRPORT_ATTR(port_id, 0444, show_port_id, NULL);
 129
 130 static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
 131 {
 132         return sprintf(buf, "0x%x\n", p->port_no);
 133 }
 134
 135 static BRPORT_ATTR(port_no, 0444, show_port_no, NULL);
 136
 137 static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
 138 {
 139         return sprintf(buf, "%d\n", p->topology_change_ack);
 140 }
 141 static BRPORT_ATTR(change_ack, 0444, show_change_ack, NULL);
 142
 143 static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
 144 {
 145         return sprintf(buf, "%d\n", p->config_pending);
 146 }
 147 static BRPORT_ATTR(config_pending, 0444, show_config_pending, NULL);
 148
 149 static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
 150 {
 151         return sprintf(buf, "%d\n", p->state);
 152 }
 153 static BRPORT_ATTR(state, 0444, show_port_state, NULL);
 154
 155 static ssize_t show_message_age_timer(struct net_bridge_port *p,
 156                                             char *buf)
 157 {
 158         return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
 159 }
 160 static BRPORT_ATTR(message_age_timer, 0444, show_message_age_timer, NULL);
 161
 162 static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
 163                                             char *buf)
 164 {
 165         return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
 166 }
 167 static BRPORT_ATTR(forward_delay_timer, 0444, show_forward_delay_timer, NULL);
 168
 169 static ssize_t show_hold_timer(struct net_bridge_port *p,
 170                                             char *buf)
 171 {
 172         return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
 173 }
 174 static BRPORT_ATTR(hold_timer, 0444, show_hold_timer, NULL);
 175
 176 static int store_flush(struct net_bridge_port *p, unsigned long v)
 177 {
 178         br_fdb_delete_by_port(p->br, p, 0, 0); // Don't delete local entry
 179         return 0;
 180 }
 181 static BRPORT_ATTR(flush, 0200, NULL, store_flush);
 182
 183 static ssize_t show_group_fwd_mask(struct net_bridge_port *p, char *buf)
 184 {
 185         return sprintf(buf, "%#x\n", p->group_fwd_mask);
 186 }
 187
 188 static int store_group_fwd_mask(struct net_bridge_port *p,
 189                                 unsigned long v)
 190 {
 191         if (v & BR_GROUPFWD_MACPAUSE)
 192                 return -EINVAL;
 193         p->group_fwd_mask = v;
 194
 195         return 0;
 196 }
 197 static BRPORT_ATTR(group_fwd_mask, 0644, show_group_fwd_mask,
 198                    store_group_fwd_mask);
 199
 200 static ssize_t show_backup_port(struct net_bridge_port *p, char *buf)
 201 {
 202         struct net_bridge_port *backup_p;
 203         int ret = 0;
 204
 205         rcu_read_lock();
 206         backup_p = rcu_dereference(p->backup_port);
 207         if (backup_p)
 208                 ret = sprintf(buf, "%s\n", backup_p->dev->name);
 209         rcu_read_unlock();
 210
 211         return ret;
 212 }
 213
 214 static int store_backup_port(struct net_bridge_port *p, char *buf)
 215 {
 216         struct net_device *backup_dev = NULL;
 217         char *nl = strchr(buf, '\n');
 218
 219         if (nl)
 220                 *nl = '\0';
 221
 222         if (strlen(buf) > 0) {
 223                 backup_dev = __dev_get_by_name(dev_net(p->dev), buf);
 224                 if (!backup_dev)
 225                         return -ENOENT;
 226         }
 227
 228         return nbp_backup_change(p, backup_dev);
 229 }
 230 static BRPORT_ATTR_RAW(backup_port, 0644, show_backup_port, store_backup_port);
 231
 232 BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
 233 BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
 234 BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
 235 BRPORT_ATTR_FLAG(learning, BR_LEARNING);
 236 BRPORT_ATTR_FLAG(unicast_flood, BR_FLOOD);
 237 BRPORT_ATTR_FLAG(proxyarp, BR_PROXYARP);
 238 BRPORT_ATTR_FLAG(proxyarp_wifi, BR_PROXYARP_WIFI);
 239 BRPORT_ATTR_FLAG(multicast_flood, BR_MCAST_FLOOD);
 240 BRPORT_ATTR_FLAG(broadcast_flood, BR_BCAST_FLOOD);
 241 BRPORT_ATTR_FLAG(neigh_suppress, BR_NEIGH_SUPPRESS);
 242 BRPORT_ATTR_FLAG(isolated, BR_ISOLATED);
 243
 244 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 245 static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
 246 {
 247         return sprintf(buf, "%d\n", p->multicast_ctx.multicast_router);
 248 }
 249
 250 static int store_multicast_router(struct net_bridge_port *p,
 251                                       unsigned long v)
 252 {
 253         return br_multicast_set_port_router(&p->multicast_ctx, v);
 254 }
 255 static BRPORT_ATTR(multicast_router, 0644, show_multicast_router,
 256                    store_multicast_router);
 257
 258 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
 259 BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
 260 #endif
 261
 262 static const struct brport_attribute *brport_attrs[] = {
 263         &brport_attr_path_cost,
 264         &brport_attr_priority,
 265         &brport_attr_port_id,
 266         &brport_attr_port_no,
 267         &brport_attr_designated_root,
 268         &brport_attr_designated_bridge,
 269         &brport_attr_designated_port,
 270         &brport_attr_designated_cost,
 271         &brport_attr_state,
 272         &brport_attr_change_ack,
 273         &brport_attr_config_pending,
 274         &brport_attr_message_age_timer,
 275         &brport_attr_forward_delay_timer,
 276         &brport_attr_hold_timer,
 277         &brport_attr_flush,
 278         &brport_attr_hairpin_mode,
 279         &brport_attr_bpdu_guard,
 280         &brport_attr_root_block,
 281         &brport_attr_learning,
 282         &brport_attr_unicast_flood,
 283 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 284         &brport_attr_multicast_router,
 285         &brport_attr_multicast_fast_leave,
 286         &brport_attr_multicast_to_unicast,
 287 #endif
 288         &brport_attr_proxyarp,
 289         &brport_attr_proxyarp_wifi,
 290         &brport_attr_multicast_flood,
 291         &brport_attr_broadcast_flood,
 292         &brport_attr_group_fwd_mask,
 293         &brport_attr_neigh_suppress,
 294         &brport_attr_isolated,
 295         &brport_attr_backup_port,
 296         NULL
 297 };
 298
 299 #define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
 300
 301 static ssize_t brport_show(struct kobject *kobj,
 302                            struct attribute *attr, char *buf)
 303 {
 304         struct brport_attribute *brport_attr = to_brport_attr(attr);
 305         struct net_bridge_port *p = kobj_to_brport(kobj);
 306
 307         if (!brport_attr->show)
 308                 return -EINVAL;
 309
 310         return brport_attr->show(p, buf);
 311 }
 312
 313 static ssize_t brport_store(struct kobject *kobj,
 314                             struct attribute *attr,
 315                             const char *buf, size_t count)
 316 {
 317         struct brport_attribute *brport_attr = to_brport_attr(attr);
 318         struct net_bridge_port *p = kobj_to_brport(kobj);
 319         ssize_t ret = -EINVAL;
 320         unsigned long val;
 321         char *endp;
 322
 323         if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
 324                 return -EPERM;
 325
 326         if (!rtnl_trylock())
 327                 return restart_syscall();
 328
 329         if (brport_attr->store_raw) {
 330                 char *buf_copy;
 331
 332                 buf_copy = kstrndup(buf, count, GFP_KERNEL);
 333                 if (!buf_copy) {
 334                         ret = -ENOMEM;
 335                         goto out_unlock;
 336                 }
 337                 spin_lock_bh(&p->br->lock);
 338                 ret = brport_attr->store_raw(p, buf_copy);
 339                 spin_unlock_bh(&p->br->lock);
 340                 kfree(buf_copy);
 341         } else if (brport_attr->store) {
 342                 val = simple_strtoul(buf, &endp, 0);
 343                 if (endp == buf)
 344                         goto out_unlock;
 345                 spin_lock_bh(&p->br->lock);
 346                 ret = brport_attr->store(p, val);
 347                 spin_unlock_bh(&p->br->lock);
 348         }
 349
 350         if (!ret) {
 351                 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 352                 ret = count;
 353         }
 354 out_unlock:
 355         rtnl_unlock();
 356
 357         return ret;
 358 }
 359
 360 const struct sysfs_ops brport_sysfs_ops = {
 361         .show = brport_show,
 362         .store = brport_store,
 363 };
 364
 365 /*
 366  * Add sysfs entries to ethernet device added to a bridge.
 367  * Creates a brport subdirectory with bridge attributes.
 368  * Puts symlink in bridge's brif subdirectory
 369  */
 370 int br_sysfs_addif(struct net_bridge_port *p)
 371 {
 372         struct net_bridge *br = p->br;
 373         const struct brport_attribute **a;
 374         int err;
 375
 376         err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
 377                                 SYSFS_BRIDGE_PORT_LINK);
 378         if (err)
 379                 return err;
 380
 381         for (a = brport_attrs; *a; ++a) {
 382                 err = sysfs_create_file(&p->kobj, &((*a)->attr));
 383                 if (err)
 384                         return err;
 385         }
 386
 387         strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
 388         return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
 389 }
 390
 391 /* Rename bridge's brif symlink */
 392 int br_sysfs_renameif(struct net_bridge_port *p)
 393 {
 394         struct net_bridge *br = p->br;
 395         int err;
 396
 397         /* If a rename fails, the rollback will cause another
 398          * rename call with the existing name.
 399          */
 400         if (!strncmp(p->sysfs_name, p->dev->name, IFNAMSIZ))
 401                 return 0;
 402
 403         err = sysfs_rename_link(br->ifobj, &p->kobj,
 404                                 p->sysfs_name, p->dev->name);
 405         if (err)
 406                 netdev_notice(br->dev, "unable to rename link %s to %s",
 407                               p->sysfs_name, p->dev->name);
 408         else
 409                 strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
 410
 411         return err;
 412 }