// SPDX-License-Identifier: GPL-2.0-or-later /* * Ioctl handler * Linux ethernet bridge * * Authors: * Lennert Buytenhek <buytenh@gnu.org> */ #include <linux/capability.h> #include <linux/compat.h> #include <linux/kernel.h> #include <linux/if_bridge.h> #include <linux/netdevice.h> #include <linux/slab.h> #include <linux/times.h> #include <net/net_namespace.h> #include <linux/uaccess.h> #include "br_private.h" static int get_bridge_ifindices(struct net *net, int *indices, int num) { struct net_device *dev; int i = 0; rcu_read_lock(); for_each_netdev_rcu(net, dev) { if (i >= num) break; if (netif_is_bridge_master(dev)) indices[i++] = dev->ifindex; } rcu_read_unlock(); return i; } /* called with RTNL */ static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num) { struct net_bridge_port *p; list_for_each_entry(p, &br->port_list, list) { if (p->port_no < num) ifindices[p->port_no] = p->dev->ifindex; } } /* * Format up to a page worth of forwarding table entries * userbuf -- where to copy result * maxnum -- maximum number of entries desired * (limited to a page for sanity) * offset -- number of records to skip */ static int get_fdb_entries(struct net_bridge *br, void __user *userbuf, unsigned long maxnum, unsigned long offset) { int num; void *buf; size_t size; /* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */ if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry)) maxnum = PAGE_SIZE/sizeof(struct __fdb_entry); size = maxnum * sizeof(struct __fdb_entry); buf = kmalloc(size, GFP_USER); if (!buf) return -ENOMEM; num = br_fdb_fillbuf(br, buf, maxnum, offset); if (num > 0) { if (copy_to_user(userbuf, buf, array_size(num, sizeof(struct __fdb_entry)))) num = -EFAULT; } kfree(buf); return num; } /* called with RTNL */ static int add_del_if(struct net_bridge *br, int ifindex, int isadd) { struct net *net = dev_net(br->dev); struct net_device *dev; int ret; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; dev = __dev_get_by_index(net, ifindex); if (dev == NULL) return -EINVAL; if (isadd) ret = br_add_if(br, dev, NULL); else ret = br_del_if(br, dev); return ret; } #define BR_UARGS_MAX 4 static int br_dev_read_uargs(unsigned long *args, size_t nr_args, void __user **argp, void __user *data) { int ret; if (nr_args < 2 || nr_args > BR_UARGS_MAX) return -EINVAL; if (in_compat_syscall()) { unsigned int cargs[BR_UARGS_MAX]; int i; ret = copy_from_user(cargs, data, nr_args * sizeof(*cargs)); if (ret) goto fault; for (i = 0; i < nr_args; ++i) args[i] = cargs[i]; *argp = compat_ptr(args[1]); } else { ret = copy_from_user(args, data, nr_args * sizeof(*args)); if (ret) goto fault; *argp = (void __user *)args[1]; } return 0; fault: return -EFAULT; } /* * Legacy ioctl's through SIOCDEVPRIVATE * This interface is deprecated because it was too difficult * to do the translation for 32/64bit ioctl compatibility. */ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd) { struct net_bridge *br = netdev_priv(dev); struct net_bridge_port *p = NULL; unsigned long args[4]; void __user *argp; int ret; ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data); if (ret) return ret; switch (args[0]) { case BRCTL_ADD_IF: case BRCTL_DEL_IF: return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF); case BRCTL_GET_BRIDGE_INFO: { struct __bridge_info b; memset(&b, 0, sizeof(struct __bridge_info)); rcu_read_lock(); memcpy(&b.designated_root, &br->designated_root, 8); memcpy(&b.bridge_id, &br->bridge_id, 8); b.root_path_cost = br->root_path_cost; b.max_age = jiffies_to_clock_t(br->max_age); b.hello_time = jiffies_to_clock_t(br->hello_time); b.forward_delay = br->forward_delay; b.bridge_max_age = br->bridge_max_age; b.bridge_hello_time = br->bridge_hello_time; b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay); b.topology_change = br->topology_change; b.topology_change_detected = br->topology_change_detected; b.root_port = br->root_port; b.stp_enabled = (br->stp_enabled != BR_NO_STP); b.ageing_time = jiffies_to_clock_t(br->ageing_time); b.hello_timer_value = br_timer_value(&br->hello_timer); b.tcn_timer_value = br_timer_value(&br->tcn_timer); b.topology_change_timer_value = br_timer_value(&br->topology_change_timer); b.gc_timer_value = br_timer_value(&br->gc_work.timer); rcu_read_unlock(); if (copy_to_user((void __user *)args[1], &b, sizeof(b))) return -EFAULT; return 0; } case BRCTL_GET_PORT_LIST: { int num, *indices; num = args[2]; if (num < 0) return -EINVAL; if (num == 0) num = 256; if (num > BR_MAX_PORTS) num = BR_MAX_PORTS; indices = kcalloc(num, sizeof(int), GFP_KERNEL); if (indices == NULL) return -ENOMEM; get_port_ifindices(br, indices, num); if (copy_to_user(argp, indices, array_size(num, sizeof(int)))) num = -EFAULT; kfree(indices); return num; } case BRCTL_SET_BRIDGE_FORWARD_DELAY: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; ret = br_set_forward_delay(br, args[1]); break; case BRCTL_SET_BRIDGE_HELLO_TIME: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; ret = br_set_hello_time(br, args[1]); break; case BRCTL_SET_BRIDGE_MAX_AGE: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; ret = br_set_max_age(br, args[1]); break; case BRCTL_SET_AGEING_TIME: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; ret = br_set_ageing_time(br, args[1]); break; case BRCTL_GET_PORT_INFO: { struct __port_info p; struct net_bridge_port *pt; rcu_read_lock(); if ((pt = br_get_port(br, args[2])) == NULL) { rcu_read_unlock(); return -EINVAL; } memset(&p, 0, sizeof(struct __port_info)); memcpy(&p.designated_root, &pt->designated_root, 8); memcpy(&p.designated_bridge, &pt->designated_bridge, 8); p.port_id = pt->port_id; p.designated_port = pt->designated_port; p.path_cost = pt->path_cost; p.designated_cost = pt->designated_cost; p.state = pt->state; p.top_change_ack = pt->topology_change_ack; p.config_pending = pt->config_pending; p.message_age_timer_value = br_timer_value(&pt->message_age_timer); p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer); p.hold_timer_value = br_timer_value(&pt->hold_timer); rcu_read_unlock(); if (copy_to_user(argp, &p, sizeof(p))) return -EFAULT; return 0; } case BRCTL_SET_BRIDGE_STP_STATE: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; ret = br_stp_set_enabled(br, args[1], NULL); break; case BRCTL_SET_BRIDGE_PRIORITY: if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; br_stp_set_bridge_priority(br, args[1]); ret = 0; break; case BRCTL_SET_PORT_PRIORITY: { if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; spin_lock_bh(&br->lock); if ((p = br_get_port(br, args[1])) == NULL) ret = -EINVAL; else ret = br_stp_set_port_priority(p, args[2]); spin_unlock_bh(&br->lock); break; } case BRCTL_SET_PATH_COST: { if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; spin_lock_bh(&br->lock); if ((p = br_get_port(br, args[1])) == NULL) ret = -EINVAL; else ret = br_stp_set_path_cost(p, args[2]); spin_unlock_bh(&br->lock); break; } case BRCTL_GET_FDB_ENTRIES: return get_fdb_entries(br, argp, args[2], args[3]); default: ret = -EOPNOTSUPP; } if (!ret) { if (p) br_ifinfo_notify(RTM_NEWLINK, NULL, p); else netdev_state_change(br->dev); } return ret; } static int old_deviceless(struct net *net, void __user *data) { unsigned long args[3]; void __user *argp; int ret; ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data); if (ret) return ret; switch (args[0]) { case BRCTL_GET_VERSION: return BRCTL_VERSION; case BRCTL_GET_BRIDGES: { int *indices; int ret = 0; if (args[2] >= 2048) return -ENOMEM; indices = kcalloc(args[2], sizeof(int), GFP_KERNEL); if (indices == NULL) return -ENOMEM; args[2] = get_bridge_ifindices(net, indices, args[2]); ret = copy_to_user(argp, indices, array_size(args[2], sizeof(int))) ? -EFAULT : args[2]; kfree(indices); return ret; } case BRCTL_ADD_BRIDGE: case BRCTL_DEL_BRIDGE: { char buf[IFNAMSIZ]; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; if (copy_from_user(buf, argp, IFNAMSIZ)) return -EFAULT; buf[IFNAMSIZ-1] = 0; if (args[0] == BRCTL_ADD_BRIDGE) return br_add_bridge(net, buf); return br_del_bridge(net, buf); } } return -EOPNOTSUPP; } int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, struct ifreq *ifr, void __user *uarg) { int ret = -EOPNOTSUPP; rtnl_lock(); switch (cmd) { case SIOCGIFBR: case SIOCSIFBR: ret = old_deviceless(net, uarg); break; case SIOCBRADDBR: case SIOCBRDELBR: { char buf[IFNAMSIZ]; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) { ret = -EPERM; break; } if (copy_from_user(buf, uarg, IFNAMSIZ)) { ret = -EFAULT; break; } buf[IFNAMSIZ-1] = 0; if (cmd == SIOCBRADDBR) ret = br_add_bridge(net, buf); else ret = br_del_bridge(net, buf); } break; case SIOCBRADDIF: case SIOCBRDELIF: ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF); break; } rtnl_unlock(); return ret; }