net/bridge/br_netfilter_ipv6.c

Source file repositories/reference/linux-study-clean/net/bridge/br_netfilter_ipv6.c

File Facts

System
Linux kernel
Corpus path
net/bridge/br_netfilter_ipv6.c
Extension
.c
Size
4739 bytes
Lines
189
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

if (skb_dst(skb)->error) {
			kfree_skb(skb);
			return 0;
		}

		if (skb_dst(skb)->dev == dev) {
			skb->dev = br_indev;
			nf_bridge_update_protocol(skb);
			nf_bridge_push_encap_header(skb);
			br_nf_hook_thresh(NF_BR_PRE_ROUTING,
					  net, sk, skb, skb->dev, NULL,
					  br_nf_pre_routing_finish_bridge);
			return 0;
		}
		ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
		skb->pkt_type = PACKET_HOST;
	} else {
		rt = bridge_parent_rtable(br_indev);
		if (!rt) {
			kfree_skb(skb);
			return 0;
		}
		skb_dst_drop(skb);
		skb_dst_set_noref(skb, &rt->dst);
	}

	skb->dev = br_indev;
	nf_bridge_update_protocol(skb);
	nf_bridge_push_encap_header(skb);
	br_nf_hook_thresh(NF_BR_PRE_ROUTING, net, sk, skb,
			  skb->dev, NULL, br_handle_frame_finish);

	return 0;
}

/* Replicate the checks that IPv6 does on packet reception and pass the packet
 * to ip6tables.
 */
unsigned int br_nf_pre_routing_ipv6(void *priv,
				    struct sk_buff *skb,
				    const struct nf_hook_state *state)
{
	struct nf_bridge_info *nf_bridge;

	if (br_validate_ipv6(state->net, skb))
		return NF_DROP_REASON(skb, SKB_DROP_REASON_IP_INHDR, 0);

	nf_bridge = nf_bridge_alloc(skb);
	if (!nf_bridge)
		return NF_DROP_REASON(skb, SKB_DROP_REASON_NOMEM, 0);
	if (!setup_pre_routing(skb, state->net))
		return NF_DROP_REASON(skb, SKB_DROP_REASON_DEV_READY, 0);

	nf_bridge = nf_bridge_info_get(skb);
	nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;

	skb->protocol = htons(ETH_P_IPV6);
	skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);

	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->net, state->sk, skb,
		skb->dev, NULL,
		br_nf_pre_routing_finish_ipv6);

	return NF_STOLEN;
}

Annotation

Implementation Notes