1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _NF_TABLES_IPV4_H_ 3 #define _NF_TABLES_IPV4_H_ 4 5 #include <net/netfilter/nf_tables.h> 6 #include <net/ip.h> 7 8 static inline void nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt) 9 { 10 struct iphdr *ip; 11 12 ip = ip_hdr(pkt->skb); 13 pkt->flags = NFT_PKTINFO_L4PROTO; 14 pkt->tprot = ip->protocol; 15 pkt->thoff = ip_hdrlen(pkt->skb); 16 pkt->fragoff = ntohs(ip->frag_off) & IP_OFFSET; 17 } 18 19 static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt) 20 { 21 struct iphdr *iph, _iph; 22 u32 len, thoff; 23 24 iph = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb), 25 sizeof(*iph), &_iph); 26 if (!iph) 27 return -1; 28 29 if (iph->ihl < 5 || iph->version != 4) 30 return -1; 31 32 len = ntohs(iph->tot_len); 33 thoff = iph->ihl * 4; 34 if (pkt->skb->len < len) 35 return -1; 36 else if (len < thoff) 37 return -1; 38 else if (thoff < sizeof(*iph)) 39 return -1; 40 41 pkt->flags = NFT_PKTINFO_L4PROTO; 42 pkt->tprot = iph->protocol; 43 pkt->thoff = thoff; 44 pkt->fragoff = ntohs(iph->frag_off) & IP_OFFSET; 45 46 return 0; 47 } 48 49 static inline void nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt) 50 { 51 if (__nft_set_pktinfo_ipv4_validate(pkt) < 0) 52 nft_set_pktinfo_unspec(pkt); 53 } 54 55 static inline int nft_set_pktinfo_ipv4_ingress(struct nft_pktinfo *pkt) 56 { 57 struct iphdr *iph; 58 u32 len, thoff; 59 60 if (!pskb_may_pull(pkt->skb, sizeof(*iph))) 61 return -1; 62 63 iph = ip_hdr(pkt->skb); 64 if (iph->ihl < 5 || iph->version != 4) 65 goto inhdr_error; 66 67 len = ntohs(iph->tot_len); 68 thoff = iph->ihl * 4; 69 if (pkt->skb->len < len) { 70 __IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INTRUNCATEDPKTS); 71 return -1; 72 } else if (len < thoff) { 73 goto inhdr_error; 74 } else if (thoff < sizeof(*iph)) { 75 return -1; 76 } 77 78 pkt->flags = NFT_PKTINFO_L4PROTO; 79 pkt->tprot = iph->protocol; 80 pkt->thoff = thoff; 81 pkt->fragoff = ntohs(iph->frag_off) & IP_OFFSET; 82 83 return 0; 84 85 inhdr_error: 86 __IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INHDRERRORS); 87 return -1; 88 } 89 90 #endif 91