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