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->tprot_set = true; 14 pkt->tprot = ip->protocol; 15 pkt->xt.thoff = ip_hdrlen(pkt->skb); 16 pkt->xt.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 39 pkt->tprot_set = true; 40 pkt->tprot = iph->protocol; 41 pkt->xt.thoff = thoff; 42 pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET; 43 44 return 0; 45 } 46 47 static inline void nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt) 48 { 49 if (__nft_set_pktinfo_ipv4_validate(pkt) < 0) 50 nft_set_pktinfo_unspec(pkt); 51 } 52 53 static inline int nft_set_pktinfo_ipv4_ingress(struct nft_pktinfo *pkt) 54 { 55 struct iphdr *iph; 56 u32 len, thoff; 57 58 if (!pskb_may_pull(pkt->skb, sizeof(*iph))) 59 return -1; 60 61 iph = ip_hdr(pkt->skb); 62 if (iph->ihl < 5 || iph->version != 4) 63 goto inhdr_error; 64 65 len = ntohs(iph->tot_len); 66 thoff = iph->ihl * 4; 67 if (pkt->skb->len < len) { 68 __IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INTRUNCATEDPKTS); 69 return -1; 70 } else if (len < thoff) { 71 goto inhdr_error; 72 } 73 74 pkt->tprot_set = true; 75 pkt->tprot = iph->protocol; 76 pkt->xt.thoff = thoff; 77 pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET; 78 79 return 0; 80 81 inhdr_error: 82 __IP_INC_STATS(nft_net(pkt), IPSTATS_MIB_INHDRERRORS); 83 return -1; 84 } 85 #endif 86