1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/kernel.h> 3 #include <linux/netfilter.h> 4 #include <linux/netfilter_ipv4.h> 5 #include <linux/netfilter_ipv6.h> 6 #include <net/netfilter/nf_queue.h> 7 #include <net/ip6_checksum.h> 8 9 #ifdef CONFIG_INET 10 __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook, 11 unsigned int dataoff, u8 protocol) 12 { 13 const struct iphdr *iph = ip_hdr(skb); 14 __sum16 csum = 0; 15 16 switch (skb->ip_summed) { 17 case CHECKSUM_COMPLETE: 18 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 19 break; 20 if ((protocol != IPPROTO_TCP && protocol != IPPROTO_UDP && 21 !csum_fold(skb->csum)) || 22 !csum_tcpudp_magic(iph->saddr, iph->daddr, 23 skb->len - dataoff, protocol, 24 skb->csum)) { 25 skb->ip_summed = CHECKSUM_UNNECESSARY; 26 break; 27 } 28 fallthrough; 29 case CHECKSUM_NONE: 30 if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP) 31 skb->csum = 0; 32 else 33 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 34 skb->len - dataoff, 35 protocol, 0); 36 csum = __skb_checksum_complete(skb); 37 } 38 return csum; 39 } 40 EXPORT_SYMBOL(nf_ip_checksum); 41 #endif 42 43 static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook, 44 unsigned int dataoff, unsigned int len, 45 u8 protocol) 46 { 47 const struct iphdr *iph = ip_hdr(skb); 48 __sum16 csum = 0; 49 50 switch (skb->ip_summed) { 51 case CHECKSUM_COMPLETE: 52 if (len == skb->len - dataoff) 53 return nf_ip_checksum(skb, hook, dataoff, protocol); 54 fallthrough; 55 case CHECKSUM_NONE: 56 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol, 57 skb->len - dataoff, 0); 58 skb->ip_summed = CHECKSUM_NONE; 59 return __skb_checksum_complete_head(skb, dataoff + len); 60 } 61 return csum; 62 } 63 64 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 65 unsigned int dataoff, u8 protocol) 66 { 67 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 68 __sum16 csum = 0; 69 70 switch (skb->ip_summed) { 71 case CHECKSUM_COMPLETE: 72 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 73 break; 74 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 75 skb->len - dataoff, protocol, 76 csum_sub(skb->csum, 77 skb_checksum(skb, 0, 78 dataoff, 0)))) { 79 skb->ip_summed = CHECKSUM_UNNECESSARY; 80 break; 81 } 82 fallthrough; 83 case CHECKSUM_NONE: 84 skb->csum = ~csum_unfold( 85 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 86 skb->len - dataoff, 87 protocol, 88 csum_sub(0, 89 skb_checksum(skb, 0, 90 dataoff, 0)))); 91 csum = __skb_checksum_complete(skb); 92 } 93 return csum; 94 } 95 EXPORT_SYMBOL(nf_ip6_checksum); 96 97 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 98 unsigned int dataoff, unsigned int len, 99 u8 protocol) 100 { 101 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 102 __wsum hsum; 103 __sum16 csum = 0; 104 105 switch (skb->ip_summed) { 106 case CHECKSUM_COMPLETE: 107 if (len == skb->len - dataoff) 108 return nf_ip6_checksum(skb, hook, dataoff, protocol); 109 fallthrough; 110 case CHECKSUM_NONE: 111 hsum = skb_checksum(skb, 0, dataoff, 0); 112 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 113 &ip6h->daddr, 114 skb->len - dataoff, 115 protocol, 116 csum_sub(0, hsum))); 117 skb->ip_summed = CHECKSUM_NONE; 118 return __skb_checksum_complete_head(skb, dataoff + len); 119 } 120 return csum; 121 }; 122 123 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook, 124 unsigned int dataoff, u8 protocol, 125 unsigned short family) 126 { 127 __sum16 csum = 0; 128 129 switch (family) { 130 case AF_INET: 131 csum = nf_ip_checksum(skb, hook, dataoff, protocol); 132 break; 133 case AF_INET6: 134 csum = nf_ip6_checksum(skb, hook, dataoff, protocol); 135 break; 136 } 137 138 return csum; 139 } 140 EXPORT_SYMBOL_GPL(nf_checksum); 141 142 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, 143 unsigned int dataoff, unsigned int len, 144 u8 protocol, unsigned short family) 145 { 146 __sum16 csum = 0; 147 148 switch (family) { 149 case AF_INET: 150 csum = nf_ip_checksum_partial(skb, hook, dataoff, len, 151 protocol); 152 break; 153 case AF_INET6: 154 csum = nf_ip6_checksum_partial(skb, hook, dataoff, len, 155 protocol); 156 break; 157 } 158 159 return csum; 160 } 161 EXPORT_SYMBOL_GPL(nf_checksum_partial); 162 163 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl, 164 bool strict, unsigned short family) 165 { 166 const struct nf_ipv6_ops *v6ops __maybe_unused; 167 int ret = 0; 168 169 switch (family) { 170 case AF_INET: 171 ret = nf_ip_route(net, dst, fl, strict); 172 break; 173 case AF_INET6: 174 ret = nf_ip6_route(net, dst, fl, strict); 175 break; 176 } 177 178 return ret; 179 } 180 EXPORT_SYMBOL_GPL(nf_route); 181 182 /* Only get and check the lengths, not do any hop-by-hop stuff. */ 183 int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen) 184 { 185 int len, off = sizeof(struct ipv6hdr); 186 unsigned char *nh; 187 188 if (!pskb_may_pull(skb, off + 8)) 189 return -ENOMEM; 190 nh = (unsigned char *)(ipv6_hdr(skb) + 1); 191 len = (nh[1] + 1) << 3; 192 193 if (!pskb_may_pull(skb, off + len)) 194 return -ENOMEM; 195 nh = skb_network_header(skb); 196 197 off += 2; 198 len -= 2; 199 while (len > 0) { 200 int optlen; 201 202 if (nh[off] == IPV6_TLV_PAD1) { 203 off++; 204 len--; 205 continue; 206 } 207 if (len < 2) 208 return -EBADMSG; 209 optlen = nh[off + 1] + 2; 210 if (optlen > len) 211 return -EBADMSG; 212 213 if (nh[off] == IPV6_TLV_JUMBO) { 214 u32 pkt_len; 215 216 if (nh[off + 1] != 4 || (off & 3) != 2) 217 return -EBADMSG; 218 pkt_len = ntohl(*(__be32 *)(nh + off + 2)); 219 if (pkt_len <= IPV6_MAXPLEN || 220 ipv6_hdr(skb)->payload_len) 221 return -EBADMSG; 222 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) 223 return -EBADMSG; 224 *plen = pkt_len; 225 } 226 off += optlen; 227 len -= optlen; 228 } 229 230 return len ? -EBADMSG : 0; 231 } 232 EXPORT_SYMBOL_GPL(nf_ip6_check_hbh_len); 233