include/net/netfilter/nf_tables_ipv4.h

   1 #ifndef _NF_TABLES_IPV4_H_
   2 #define _NF_TABLES_IPV4_H_
   3
   4 #include <net/netfilter/nf_tables.h>
   5 #include <net/ip.h>
   6
   7 static inline void
   8 nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
   9                      struct sk_buff *skb,
  10                      const struct nf_hook_state *state)
  11 {
  12         struct iphdr *ip;
  13
  14         nft_set_pktinfo(pkt, skb, state);
  15
  16         ip = ip_hdr(pkt->skb);
  17         pkt->tprot_set = true;
  18         pkt->tprot = ip->protocol;
  19         pkt->xt.thoff = ip_hdrlen(pkt->skb);
  20         pkt->xt.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
  21 }
  22
  23 static inline int
  24 __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt,
  25                                 struct sk_buff *skb,
  26                                 const struct nf_hook_state *state)
  27 {
  28         struct iphdr *iph, _iph;
  29         u32 len, thoff;
  30
  31         iph = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*iph),
  32                                  &_iph);
  33         if (!iph)
  34                 return -1;
  35
  36         if (iph->ihl < 5 || iph->version != 4)
  37                 return -1;
  38
  39         len = ntohs(iph->tot_len);
  40         thoff = iph->ihl * 4;
  41         if (skb->len < len)
  42                 return -1;
  43         else if (len < thoff)
  44                 return -1;
  45
  46         pkt->tprot_set = true;
  47         pkt->tprot = iph->protocol;
  48         pkt->xt.thoff = thoff;
  49         pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET;
  50
  51         return 0;
  52 }
  53
  54 static inline void
  55 nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt,
  56                               struct sk_buff *skb,
  57                               const struct nf_hook_state *state)
  58 {
  59         nft_set_pktinfo(pkt, skb, state);
  60         if (__nft_set_pktinfo_ipv4_validate(pkt, skb, state) < 0)
  61                 nft_set_pktinfo_proto_unspec(pkt, skb);
  62 }
  63
  64 extern struct nft_af_info nft_af_ipv4;
  65
  66 #endif