summaryrefslogtreecommitdiffstats
path: root/net/ipv6/ip6_checksum.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--net/ipv6/ip6_checksum.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
new file mode 100644
index 000000000..377717045
--- /dev/null
+++ b/net/ipv6/ip6_checksum.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <asm/checksum.h>
+
+#ifndef _HAVE_ARCH_IPV6_CSUM
+__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __u32 len, __u8 proto, __wsum csum)
+{
+
+ int carry;
+ __u32 ulen;
+ __u32 uproto;
+ __u32 sum = (__force u32)csum;
+
+ sum += (__force u32)saddr->s6_addr32[0];
+ carry = (sum < (__force u32)saddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[1];
+ carry = (sum < (__force u32)saddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[2];
+ carry = (sum < (__force u32)saddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (__force u32)saddr->s6_addr32[3];
+ carry = (sum < (__force u32)saddr->s6_addr32[3]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[0];
+ carry = (sum < (__force u32)daddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[1];
+ carry = (sum < (__force u32)daddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[2];
+ carry = (sum < (__force u32)daddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (__force u32)daddr->s6_addr32[3];
+ carry = (sum < (__force u32)daddr->s6_addr32[3]);
+ sum += carry;
+
+ ulen = (__force u32)htonl((__u32) len);
+ sum += ulen;
+ carry = (sum < ulen);
+ sum += carry;
+
+ uproto = (__force u32)htonl(proto);
+ sum += uproto;
+ carry = (sum < uproto);
+ sum += carry;
+
+ return csum_fold((__force __wsum)sum);
+}
+EXPORT_SYMBOL(csum_ipv6_magic);
+#endif
+
+int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
+{
+ int err;
+
+ UDP_SKB_CB(skb)->partial_cov = 0;
+ UDP_SKB_CB(skb)->cscov = skb->len;
+
+ if (proto == IPPROTO_UDPLITE) {
+ err = udplite_checksum_init(skb, uh);
+ if (err)
+ return err;
+
+ if (UDP_SKB_CB(skb)->partial_cov) {
+ skb->csum = ip6_compute_pseudo(skb, proto);
+ return 0;
+ }
+ }
+
+ /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
+ * we accept a checksum of zero here. When we find the socket
+ * for the UDP packet we'll check if that socket allows zero checksum
+ * for IPv6 (set by socket option).
+ *
+ * Note, we are only interested in != 0 or == 0, thus the
+ * force to int.
+ */
+ err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
+ ip6_compute_pseudo);
+ if (err)
+ return err;
+
+ if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
+ /* If SW calculated the value, we know it's bad */
+ if (skb->csum_complete_sw)
+ return 1;
+
+ /* HW says the value is bad. Let's validate that.
+ * skb->csum is no longer the full packet checksum,
+ * so don't treat is as such.
+ */
+ skb_checksum_complete_unset(skb);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(udp6_csum_init);
+
+/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
+ * for the simple case like when setting the checksum for a UDP tunnel.
+ */
+void udp6_set_csum(bool nocheck, struct sk_buff *skb,
+ const struct in6_addr *saddr,
+ const struct in6_addr *daddr, int len)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (nocheck)
+ uh->check = 0;
+ else if (skb_is_gso(skb))
+ uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+ else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ uh->check = 0;
+ uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+ }
+}
+EXPORT_SYMBOL(udp6_set_csum);