static ssize_t store_group_addr(struct device *d, struct device_attribute *attr, const char *buf, size_t len) { struct net_bridge *br = to_bridge(d); u8 new_addr[6]; int i; if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN)) return -EPERM; if (sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &new_addr[0], &new_addr[1], &new_addr[2], &new_addr[3], &new_addr[4], &new_addr[5]) != 6) return -EINVAL; if (!is_link_local_ether_addr(new_addr)) return -EINVAL; if (new_addr[5] == 1 || /* 802.3x Pause address */ new_addr[5] == 2 || /* 802.3ad Slow protocols */ new_addr[5] == 3) /* 802.1X PAE address */ return -EINVAL; spin_lock_bh(&br->lock); for (i = 0; i < 6; i++) br->group_addr[i] = new_addr[i]; spin_unlock_bh(&br->lock); return len; }
/* * 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 (unlikely(is_link_local_ether_addr(dest))) { /* * 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) goto forward; break; case 0x01: /* IEEE MAC (Pause) */ goto drop; default: /* Allow selective forwarding for most other protocols */ if (p->br->group_fwd_mask & (1u << dest[5])) goto forward; } /* Deliver packet to local host only */ if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, NULL, br_handle_local_finish)) { return RX_HANDLER_CONSUMED; /* consumed by filter */ } else { *pskb = skb; return RX_HANDLER_PASS; /* continue processing */ } } 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, skb, skb->dev, NULL, br_handle_frame_finish); break; default: drop: kfree_skb(skb); } return RX_HANDLER_CONSUMED; }
/* * 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 (unlikely(is_link_local_ether_addr(dest))) { /* Pause frames shouldn't be passed up by driver anyway */ if (skb->protocol == htons(ETH_P_PAUSE)) goto drop; /* If STP is turned off, then forward */ if (p->br->stp_enabled == BR_NO_STP && dest[5] == 0) goto forward; /* Deliver packet to local host only */ if (BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, NULL, br_handle_local_finish)) { return RX_HANDLER_CONSUMED; /* consumed by filter */ } else { *pskb = skb; return RX_HANDLER_PASS; /* continue processing */ } } 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 (!compare_ether_addr(p->br->dev->dev_addr, dest)) skb->pkt_type = PACKET_HOST; BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, br_handle_frame_finish); break; default: drop: kfree_skb(skb); } return RX_HANDLER_CONSUMED; }