Line data    Source code

       1             : // SPDX-License-Identifier: GPL-2.0
       2             : #include <net/ip.h>
       3             : #include <net/udp.h>
       4             : #include <net/udplite.h>
       5             : #include <asm/checksum.h>
       6             : 
       7             : #ifndef _HAVE_ARCH_IPV6_CSUM
       8             : __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
       9             :                         const struct in6_addr *daddr,
      10             :                         __u32 len, __u8 proto, __wsum csum)
      11             : {
      12             : 
      13             :         int carry;
      14             :         __u32 ulen;
      15             :         __u32 uproto;
      16             :         __u32 sum = (__force u32)csum;
      17             : 
      18             :         sum += (__force u32)saddr->s6_addr32[0];
      19             :         carry = (sum < (__force u32)saddr->s6_addr32[0]);
      20             :         sum += carry;
      21             : 
      22             :         sum += (__force u32)saddr->s6_addr32[1];
      23             :         carry = (sum < (__force u32)saddr->s6_addr32[1]);
      24             :         sum += carry;
      25             : 
      26             :         sum += (__force u32)saddr->s6_addr32[2];
      27             :         carry = (sum < (__force u32)saddr->s6_addr32[2]);
      28             :         sum += carry;
      29             : 
      30             :         sum += (__force u32)saddr->s6_addr32[3];
      31             :         carry = (sum < (__force u32)saddr->s6_addr32[3]);
      32             :         sum += carry;
      33             : 
      34             :         sum += (__force u32)daddr->s6_addr32[0];
      35             :         carry = (sum < (__force u32)daddr->s6_addr32[0]);
      36             :         sum += carry;
      37             : 
      38             :         sum += (__force u32)daddr->s6_addr32[1];
      39             :         carry = (sum < (__force u32)daddr->s6_addr32[1]);
      40             :         sum += carry;
      41             : 
      42             :         sum += (__force u32)daddr->s6_addr32[2];
      43             :         carry = (sum < (__force u32)daddr->s6_addr32[2]);
      44             :         sum += carry;
      45             : 
      46             :         sum += (__force u32)daddr->s6_addr32[3];
      47             :         carry = (sum < (__force u32)daddr->s6_addr32[3]);
      48             :         sum += carry;
      49             : 
      50             :         ulen = (__force u32)htonl((__u32) len);
      51             :         sum += ulen;
      52             :         carry = (sum < ulen);
      53             :         sum += carry;
      54             : 
      55             :         uproto = (__force u32)htonl(proto);
      56             :         sum += uproto;
      57             :         carry = (sum < uproto);
      58             :         sum += carry;
      59             : 
      60             :         return csum_fold((__force __wsum)sum);
      61             : }
      62             : EXPORT_SYMBOL(csum_ipv6_magic);
      63             : #endif
      64             : 
      65           0 : int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
      66             : {
      67           0 :         int err;
      68             : 
      69           0 :         UDP_SKB_CB(skb)->partial_cov = 0;
      70           0 :         UDP_SKB_CB(skb)->cscov = skb->len;
      71             : 
      72           0 :         if (proto == IPPROTO_UDPLITE) {
      73           0 :                 err = udplite_checksum_init(skb, uh);
      74           0 :                 if (err)
      75             :                         return err;
      76             : 
      77           0 :                 if (UDP_SKB_CB(skb)->partial_cov) {
      78           0 :                         skb->csum = ip6_compute_pseudo(skb, proto);
      79           0 :                         return 0;
      80             :                 }
      81             :         }
      82             : 
      83             :         /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
      84             :          * we accept a checksum of zero here. When we find the socket
      85             :          * for the UDP packet we'll check if that socket allows zero checksum
      86             :          * for IPv6 (set by socket option).
      87             :          *
      88             :          * Note, we are only interested in != 0 or == 0, thus the
      89             :          * force to int.
      90             :          */
      91           0 :         err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
      92             :                                                         ip6_compute_pseudo);
      93           0 :         if (err)
      94             :                 return err;
      95             : 
      96           0 :         if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
      97             :                 /* If SW calculated the value, we know it's bad */
      98           0 :                 if (skb->csum_complete_sw)
      99             :                         return 1;
     100             : 
     101             :                 /* HW says the value is bad. Let's validate that.
     102             :                  * skb->csum is no longer the full packet checksum,
     103             :                  * so don't treat is as such.
     104             :                  */
     105           0 :                 skb_checksum_complete_unset(skb);
     106             :         }
     107             : 
     108             :         return 0;
     109             : }
     110             : EXPORT_SYMBOL(udp6_csum_init);
     111             : 
     112             : /* Function to set UDP checksum for an IPv6 UDP packet. This is intended
     113             :  * for the simple case like when setting the checksum for a UDP tunnel.
     114             :  */
     115           0 : void udp6_set_csum(bool nocheck, struct sk_buff *skb,
     116             :                    const struct in6_addr *saddr,
     117             :                    const struct in6_addr *daddr, int len)
     118             : {
     119           0 :         struct udphdr *uh = udp_hdr(skb);
     120             : 
     121           0 :         if (nocheck)
     122           0 :                 uh->check = 0;
     123           0 :         else if (skb_is_gso(skb))
     124           0 :                 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
     125           0 :         else if (skb->ip_summed == CHECKSUM_PARTIAL) {
     126           0 :                 uh->check = 0;
     127           0 :                 uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
     128           0 :                 if (uh->check == 0)
     129           0 :                         uh->check = CSUM_MANGLED_0;
     130             :         } else {
     131           0 :                 skb->ip_summed = CHECKSUM_PARTIAL;
     132           0 :                 skb->csum_start = skb_transport_header(skb) - skb->head;
     133           0 :                 skb->csum_offset = offsetof(struct udphdr, check);
     134           0 :                 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
     135             :         }
     136           0 : }
     137             : EXPORT_SYMBOL(udp6_set_csum);