include/net/netfilter/nf_tables_ipv4.h

Source file repositories/reference/linux-study-clean/include/net/netfilter/nf_tables_ipv4.h

File Facts

System
Linux kernel
Corpus path
include/net/netfilter/nf_tables_ipv4.h
Extension
.h
Size
2253 bytes
Lines
100
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

#ifndef _NF_TABLES_IPV4_H_
#define _NF_TABLES_IPV4_H_

#include <net/netfilter/nf_tables.h>
#include <net/ip.h>

static inline void nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt)
{
	struct iphdr *ip;

	ip = ip_hdr(pkt->skb);
	pkt->flags = NFT_PKTINFO_L4PROTO;
	pkt->tprot = ip->protocol;
	pkt->ethertype = pkt->skb->protocol;
	pkt->nhoff = 0;
	pkt->thoff = ip_hdrlen(pkt->skb);
	pkt->fragoff = ntohs(ip->frag_off) & IP_OFFSET;
}

static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt,
						  int nhoff)
{
	struct iphdr *iph, _iph;
	u32 len, thoff, skb_len;

	iph = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb) + nhoff,
				 sizeof(*iph), &_iph);
	if (!iph)
		return -1;

	if (iph->ihl < 5 || iph->version != 4)
		return -1;

	len = iph_totlen(pkt->skb, iph);
	thoff = iph->ihl * 4;
	skb_len = pkt->skb->len - skb_network_offset(pkt->skb) - nhoff;

	if (skb_len < len)
		return -1;
	else if (len < thoff)
		return -1;
	else if (thoff < sizeof(*iph))
		return -1;

	pkt->flags = NFT_PKTINFO_L4PROTO;
	pkt->tprot = iph->protocol;
	pkt->ethertype = pkt->skb->protocol;
	pkt->nhoff = nhoff;
	pkt->thoff = skb_network_offset(pkt->skb) + nhoff + thoff;
	pkt->fragoff = ntohs(iph->frag_off) & IP_OFFSET;

	return 0;
}

static inline void nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt)
{
	if (__nft_set_pktinfo_ipv4_validate(pkt, 0) < 0)
		nft_set_pktinfo_unspec(pkt);
}

static inline int nft_set_pktinfo_ipv4_ingress(struct nft_pktinfo *pkt)
{
	struct iphdr *iph;
	u32 len, thoff;

	if (!pskb_may_pull(pkt->skb, sizeof(*iph)))
		return -1;

	iph = ip_hdr(pkt->skb);
	if (iph->ihl < 5 || iph->version != 4)
		goto inhdr_error;

	len = iph_totlen(pkt->skb, iph);
	thoff = iph->ihl * 4;
	if (pkt->skb->len < len) {
		__IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INTRUNCATEDPKTS);
		return -1;
	} else if (len < thoff) {
		goto inhdr_error;
	} else if (thoff < sizeof(*iph)) {
		return -1;
	}

	pkt->flags = NFT_PKTINFO_L4PROTO;
	pkt->ethertype = pkt->skb->protocol;
	pkt->nhoff = 0;
	pkt->tprot = iph->protocol;
	pkt->thoff = thoff;
	pkt->fragoff = ntohs(iph->frag_off) & IP_OFFSET;

Annotation

Implementation Notes