/* * Forwarding decision * Linux ethernet bridge * * Authors: * Lennert Buytenhek * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include "br_private.h" /* Don't forward packets to originating port or forwarding disabled */ static inline int should_deliver(const struct net_bridge_port *p, const struct sk_buff *skb) { struct net_bridge_vlan_group *vg; vg = nbp_vlan_group_rcu(p); return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING && nbp_switchdev_allowed_egress(p, skb); } int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) { if (!is_skb_forwardable(skb->dev, skb)) goto drop; skb_push(skb, ETH_HLEN); br_drop_fake_rtable(skb); if (skb->ip_summed == CHECKSUM_PARTIAL && (skb->protocol == htons(ETH_P_8021Q) || skb->protocol == htons(ETH_P_8021AD))) { int depth; if (!__vlan_get_protocol(skb, skb->protocol, &depth)) goto drop; skb_set_network_header(skb, depth); } dev_queue_xmit(skb); return 0; drop: kfree_skb(skb); return 0; } EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, net, sk, skb, NULL, skb->dev, br_dev_queue_push_xmit); } EXPORT_SYMBOL_GPL(br_forward_finish); static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb, bool local_orig) { struct net_bridge_vlan_group *vg; struct net_device *indev; struct net *net; int br_hook; vg = nbp_vlan_group_rcu(to); skb = br_handle_vlan(to->br, to, vg, skb); if (!skb) return; indev = skb->dev; skb->dev = to->dev; if (!local_orig) { if (skb_warn_if_lro(skb)) { kfree_skb(skb); return; } br_hook = NF_BR_FORWARD; skb_forward_csum(skb); net = dev_net(indev); } else { if (unlikely(netpoll_tx_running(to->br->dev))) { if (!is_skb_forwardable(skb->dev, skb)) { kfree_skb(skb); } else { skb_push(skb, ETH_HLEN); br_netpoll_send_skb(to, skb); } return; } br_hook = NF_BR_LOCAL_OUT; net = dev_net(skb->dev); indev = NULL; } NF_HOOK(NFPROTO_BRIDGE, br_hook, net, NULL, skb, indev, skb->dev, br_forward_finish); } static int deliver_clone(const struct net_bridge_port *prev, struct sk_buff *skb, bool local_orig) { struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; skb = skb_clone(skb, GFP_ATOMIC); if (!skb) { dev->stats.tx_dropped++; return -ENOMEM; } __br_forward(prev, skb, local_orig); return 0; } /** * br_forward - forward a packet to a specific port * @to: destination port * @skb: packet being forwarded * @local_rcv: packet will be received locally after forwarding * @local_orig: packet is locally originated * * Should be called with rcu_read_lock. */ void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, bool local_rcv, bool local_orig) { if (to && should_deliver(to, skb)) { if (local_rcv) deliver_clone(to, skb, local_orig); else __br_forward(to, skb, local_orig); return; } if (!local_rcv) kfree_skb(skb); } EXPORT_SYMBOL_GPL(br_forward); static struct net_bridge_port *maybe_deliver( struct net_bridge_port *prev, struct net_bridge_port *p, struct sk_buff *skb, bool local_orig) { int err; if (!should_deliver(p, skb)) return prev; if (!prev) goto out; err = deliver_clone(prev, skb, local_orig); if (err) return ERR_PTR(err); out: return p; } /* called under rcu_read_lock */ void br_flood(struct net_bridge *br, struct sk_buff *skb, enum br_pkt_type pkt_type, bool local_rcv, bool local_orig) { u8 igmp_type = br_multicast_igmp_type(skb); struct net_bridge_port *prev = NULL; struct net_bridge_port *p; list_for_each_entry_rcu(p, &br->port_list, list) { /* Do not flood unicast traffic to ports that turn it off */ if (pkt_type == BR_PKT_UNICAST && !(p->flags & BR_FLOOD)) continue; if (pkt_type == BR_PKT_MULTICAST && !(p->flags & BR_MCAST_FLOOD)) continue; /* Do not flood to ports that enable proxy ARP */ if (p->flags & BR_PROXYARP) continue; if ((p->flags & BR_PROXYARP_WIFI) && BR_INPUT_SKB_CB(skb)->proxyarp_replied) continue; prev = maybe_deliver(prev, p, skb, local_orig); if (IS_ERR(prev)) goto out; if (prev == p) br_multicast_count(p->br, p, skb, igmp_type, BR_MCAST_DIR_TX); } if (!prev) goto out; if (local_rcv) deliver_clone(prev, skb, local_orig); else __br_forward(prev, skb, local_orig); return; out: if (!local_rcv) kfree_skb(skb); } #ifdef CONFIG_BRIDGE_IGMP_SNOOPING static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb, const unsigned char *addr, bool local_orig) { struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; const unsigned char *src = eth_hdr(skb)->h_source; if (!should_deliver(p, skb)) return; /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */ if (skb->dev == p->dev && ether_addr_equal(src, addr)) return; skb = skb_copy(skb, GFP_ATOMIC); if (!skb) { dev->stats.tx_dropped++; return; } if (!is_broadcast_ether_addr(addr)) memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN); __br_forward(p, skb, local_orig); } /* called with rcu_read_lock */ void br_multicast_flood(struct net_bridge_mdb_entry *mdst, struct sk_buff *skb, bool local_rcv, bool local_orig) { struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; u8 igmp_type = br_multicast_igmp_type(skb); struct net_bridge *br = netdev_priv(dev); struct net_bridge_port *prev = NULL; struct net_bridge_port_group *p; struct hlist_node *rp; rp = rcu_dereference(hlist_first_rcu(&br->router_list)); p = mdst ? rcu_dereference(mdst->ports) : NULL; while (p || rp) { struct net_bridge_port *port, *lport, *rport; lport = p ? p->port : NULL; rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : NULL; if ((unsigned long)lport > (unsigned long)rport) { port = lport; if (port->flags & BR_MULTICAST_TO_UNICAST) { maybe_deliver_addr(lport, skb, p->eth_addr, local_orig); goto delivered; } } else { port = rport; } prev = maybe_deliver(prev, port, skb, local_orig); delivered: if (IS_ERR(prev)) goto out; if (prev == port) br_multicast_count(port->br, port, skb, igmp_type, BR_MCAST_DIR_TX); if ((unsigned long)lport >= (unsigned long)port) p = rcu_dereference(p->next); if ((unsigned long)rport >= (unsigned long)port) rp = rcu_dereference(hlist_next_rcu(rp)); } if (!prev) goto out; if (local_rcv) deliver_clone(prev, skb, local_orig); else __br_forward(prev, skb, local_orig); return; out: if (!local_rcv) kfree_skb(skb); } #endif 0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/mac80211/sta_info.c')