iov, checksum: Replace csum_iov() with csum_iov_tail()

We usually want to checksum only the tail part of a frame, excluding at
least some headers.  csum_iov() does that for a frame represented as an
IO vector, not actually summing the entire IO vector.  We now have struct
iov_tail to explicitly represent this construct, so replace csum_iov()
with csum_iov_tail() taking that representation rather than 3 parameters.

We propagate the same change to csum_udp4() and csum_udp6() which take
similar parameters.  This slightly simplifies the code, and will allow some
further simplifications as struct iov_tail is more widely used.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/checksum.h b/checksum.h
index 31ba322..e243c97 100644
--- a/checksum.h
+++ b/checksum.h
@@ -9,6 +9,7 @@
 struct udphdr;
 struct icmphdr;
 struct icmp6hdr;
+struct iov_tail;
 
 uint32_t sum_16b(const void *buf, size_t len);
 uint16_t csum_fold(uint32_t sum);
@@ -19,20 +20,19 @@ uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
 				struct in_addr saddr, struct in_addr daddr);
 void csum_udp4(struct udphdr *udp4hr,
 	       struct in_addr saddr, struct in_addr daddr,
-	       const struct iovec *iov, int iov_cnt, size_t offset);
+	       struct iov_tail *data);
 void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t dlen);
 uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
 				const struct in6_addr *saddr,
 				const struct in6_addr *daddr);
 void csum_udp6(struct udphdr *udp6hr,
 	       const struct in6_addr *saddr, const struct in6_addr *daddr,
-	       const struct iovec *iov, int iov_cnt, size_t offset);
+	       struct iov_tail *data);
 void csum_icmp6(struct icmp6hdr *icmp6hr,
 		const struct in6_addr *saddr, const struct in6_addr *daddr,
 		const void *payload, size_t dlen);
 uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init);
 uint16_t csum(const void *buf, size_t len, uint32_t init);
-uint16_t csum_iov(const struct iovec *iov, size_t n, size_t offset,
-		  uint32_t init);
+uint16_t csum_iov_tail(struct iov_tail *tail, uint32_t init);
 
 #endif /* CHECKSUM_H */