[PATCH v4 15/28] dhcpv6: Convert to iov_tail

[Laurent Vivier <lvivier@redhat.com>]

Use packet_data() and extract headers using IOV_REMOVE_HEADER()
and IOV_PEEK_HEADER() rather than packet_get().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 dhcpv6.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/dhcpv6.c b/dhcpv6.c
index 549ddbbea735..a52af1b7a0fe 100644
--- a/dhcpv6.c
+++ b/dhcpv6.c
@@ -534,9 +534,15 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 	const struct msg_hdr *mh;
 	const struct udphdr *uh;
 	struct opt_hdr *bad_ia;
+	struct iov_tail data;
+	struct msg_hdr mhc;
+	struct udphdr uhc;
 	size_t mlen, n;
 
-	uh = packet_get(p, 0, 0, sizeof(*uh), &mlen);
+	if (!packet_data(p, 0, &data))
+		return -1;
+
+	uh = IOV_REMOVE_HEADER(&data, uhc);
 	if (!uh)
 		return -1;
 
@@ -549,6 +555,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 	if (!IN6_IS_ADDR_MULTICAST(daddr))
 		return -1;
 
+	mlen = iov_tail_size(&data);
 	if (mlen + sizeof(*uh) != ntohs(uh->len) || mlen < sizeof(*mh))
 		return -1;
 
@@ -556,7 +563,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 
 	src = &c->ip6.our_tap_ll;
 
-	mh = packet_get(p, 0, sizeof(*uh), sizeof(*mh), NULL);
+	mh = IOV_PEEK_HEADER(&data, mhc);
 	if (!mh)
 		return -1;
 
-- 
@@ -534,9 +534,15 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 	const struct msg_hdr *mh;
 	const struct udphdr *uh;
 	struct opt_hdr *bad_ia;
+	struct iov_tail data;
+	struct msg_hdr mhc;
+	struct udphdr uhc;
 	size_t mlen, n;
 
-	uh = packet_get(p, 0, 0, sizeof(*uh), &mlen);
+	if (!packet_data(p, 0, &data))
+		return -1;
+
+	uh = IOV_REMOVE_HEADER(&data, uhc);
 	if (!uh)
 		return -1;
 
@@ -549,6 +555,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 	if (!IN6_IS_ADDR_MULTICAST(daddr))
 		return -1;
 
+	mlen = iov_tail_size(&data);
 	if (mlen + sizeof(*uh) != ntohs(uh->len) || mlen < sizeof(*mh))
 		return -1;
 
@@ -556,7 +563,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 
 	src = &c->ip6.our_tap_ll;
 
-	mh = packet_get(p, 0, sizeof(*uh), sizeof(*mh), NULL);
+	mh = IOV_PEEK_HEADER(&data, mhc);
 	if (!mh)
 		return -1;
 
-- 
2.49.0