/* * Return NULL if skb is handled * note: already called with rcu_read_lock */ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) { struct net_bridge_port *p; struct sk_buff *skb = *pskb; const unsigned char *dest = eth_hdr(skb)->h_dest; br_should_route_hook_t *rhook; if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) return RX_HANDLER_PASS; if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) goto drop; skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) return RX_HANDLER_CONSUMED; p = br_port_get_rcu(skb->dev); if (p->flags & BR_VLAN_TUNNEL) { if (br_handle_ingress_vlan_tunnel(skb, p, nbp_vlan_group_rcu(p))) goto drop; } if (unlikely(is_link_local_ether_addr(dest))) { u16 fwd_mask = p->br->group_fwd_mask_required; /* * See IEEE 802.1D Table 7-10 Reserved addresses * * Assignment Value * Bridge Group Address 01-80-C2-00-00-00 * (MAC Control) 802.3 01-80-C2-00-00-01 * (Link Aggregation) 802.3 01-80-C2-00-00-02 * 802.1X PAE address 01-80-C2-00-00-03 * * 802.1AB LLDP 01-80-C2-00-00-0E * * Others reserved for future standardization */ switch (dest[5]) { case 0x00: /* Bridge Group Address */ /* If STP is turned off, then must forward to keep loop detection */ if (p->br->stp_enabled == BR_NO_STP || fwd_mask & (1u << dest[5])) goto forward; *pskb = skb; __br_handle_local_finish(skb); return RX_HANDLER_PASS; case 0x01: /* IEEE MAC (Pause) */ goto drop; case 0x0E: /* 802.1AB LLDP */ fwd_mask |= p->br->group_fwd_mask; if (fwd_mask & (1u << dest[5])) goto forward; *pskb = skb; __br_handle_local_finish(skb); return RX_HANDLER_PASS; default: /* Allow selective forwarding for most other protocols */ fwd_mask |= p->br->group_fwd_mask; if (fwd_mask & (1u << dest[5])) goto forward; } /* Deliver packet to local host only */ NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), NULL, skb, skb->dev, NULL, br_handle_local_finish); return RX_HANDLER_CONSUMED; } forward: switch (p->state) { case BR_STATE_FORWARDING: rhook = rcu_dereference(br_should_route_hook); if (rhook) { if ((*rhook)(skb)) { *pskb = skb; return RX_HANDLER_PASS; } dest = eth_hdr(skb)->h_dest; } /* fall through */ case BR_STATE_LEARNING: if (ether_addr_equal(p->br->dev->dev_addr, dest)) skb->pkt_type = PACKET_HOST; NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, dev_net(skb->dev), NULL, skb, skb->dev, NULL, br_handle_frame_finish); break; default: drop: kfree_skb(skb); } return RX_HANDLER_CONSUMED; }
/* note: already called with rcu_read_lock */ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { const unsigned char *dest = eth_hdr(skb)->h_dest; struct net_bridge_port *p = br_port_get_rcu(skb->dev); struct net_bridge *br; struct net_bridge_fdb_entry *dst; struct net_bridge_mdb_entry *mdst; struct sk_buff *skb2; bool unicast = true; u16 vid = 0; if (!p || p->state == BR_STATE_DISABLED) goto drop; if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) goto out; /* insert into forwarding database after filtering to avoid spoofing */ br = p->br; if (p->flags & BR_LEARNING) br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && br_multicast_rcv(br, p, skb, vid)) goto drop; if (p->state == BR_STATE_LEARNING) goto drop; BR_INPUT_SKB_CB(skb)->brdev = br->dev; /* The packet skb2 goes to the local host (NULL to skip). */ skb2 = NULL; if (br->dev->flags & IFF_PROMISC) skb2 = skb; dst = NULL; if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) br_do_proxy_arp(skb, br, vid, p); if (is_broadcast_ether_addr(dest)) { skb2 = skb; unicast = false; } else if (is_multicast_ether_addr(dest)) { mdst = br_mdb_get(br, skb, vid); if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && br_multicast_querier_exists(br, eth_hdr(skb))) { if ((mdst && mdst->mglist) || br_multicast_is_router(br)) skb2 = skb; br_multicast_forward(mdst, skb, skb2); skb = NULL; if (!skb2) goto out; } else skb2 = skb; unicast = false; br->dev->stats.multicast++; } else if ((dst = __br_fdb_get(br, dest, vid)) && dst->is_local) { skb2 = skb; /* Do not forward the packet since it's local. */ skb = NULL; } if (skb) { if (dst) { dst->used = jiffies; br_forward(dst->dst, skb, skb2); } else br_flood_forward(br, skb, skb2, unicast); } if (skb2) return br_pass_frame_up(skb2); out: return 0; drop: kfree_skb(skb); goto out; }
/* note: already called with rcu_read_lock */ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { struct net_bridge_port *p = br_port_get_rcu(skb->dev); enum br_pkt_type pkt_type = BR_PKT_UNICAST; struct net_bridge_fdb_entry *dst = NULL; struct net_bridge_mdb_entry *mdst; bool local_rcv, mcast_hit = false; const unsigned char *dest; struct net_bridge *br; u16 vid = 0; if (!p || p->state == BR_STATE_DISABLED) goto drop; if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) goto out; nbp_switchdev_frame_mark(p, skb); /* insert into forwarding database after filtering to avoid spoofing */ br = p->br; if (p->flags & BR_LEARNING) br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); local_rcv = !!(br->dev->flags & IFF_PROMISC); dest = eth_hdr(skb)->h_dest; if (is_multicast_ether_addr(dest)) { /* by definition the broadcast is also a multicast address */ if (is_broadcast_ether_addr(dest)) { pkt_type = BR_PKT_BROADCAST; local_rcv = true; } else { pkt_type = BR_PKT_MULTICAST; if (br_multicast_rcv(br, p, skb, vid)) goto drop; } } if (p->state == BR_STATE_LEARNING) goto drop; BR_INPUT_SKB_CB(skb)->brdev = br->dev; if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) br_do_proxy_arp(skb, br, vid, p); switch (pkt_type) { case BR_PKT_MULTICAST: mdst = br_mdb_get(br, skb, vid); if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && br_multicast_querier_exists(br, eth_hdr(skb))) { if ((mdst && mdst->mglist) || br_multicast_is_router(br)) { local_rcv = true; br->dev->stats.multicast++; } mcast_hit = true; } else { local_rcv = true; br->dev->stats.multicast++; } break; case BR_PKT_UNICAST: dst = br_fdb_find_rcu(br, dest, vid); default: break; } if (dst) { unsigned long now = jiffies; if (dst->is_local) return br_pass_frame_up(skb); if (now != dst->used) dst->used = now; br_forward(dst->dst, skb, local_rcv, false); } else { if (!mcast_hit) br_flood(br, skb, pkt_type, local_rcv, false); else br_multicast_flood(mdst, skb, local_rcv, false); } if (local_rcv) return br_pass_frame_up(skb); out: return 0; drop: kfree_skb(skb); goto out; }