Add csum_ip4_header() helper to calculate IPv4 header checksums

We calculate IPv4 header checksums in at least two places, in dhcp() and
in tap_ip_send.  Add a helper to handle this calculation in both places.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/checksum.h b/checksum.h
index 2a5e915..91e9954 100644
--- a/checksum.h
+++ b/checksum.h
@@ -13,6 +13,7 @@ struct icmp6hdr;
 uint32_t sum_16b(const void *buf, size_t len);
 uint16_t csum_fold(uint32_t sum);
 uint16_t csum_unaligned(const void *buf, size_t len, uint32_t init);
+void csum_ip4_header(struct iphdr *ip4h);
 void csum_udp4(struct udphdr *udp4hr, in_addr_t saddr, in_addr_t daddr,
 	       const void *payload, size_t len);
 void csum_icmp4(struct icmphdr *ih, const void *payload, size_t len);