[PATCH v6 26/30] ndp: use iov_tail rather than pool

[Laurent Vivier <lvivier@redhat.com>]

The ndp() function signature is changed to accept `struct iov_tail *data`
directly, replacing the previous `const struct pool *p` and
`const struct icmp6hdr *ih` parameters.

This change simplifies callers, like tap6_handler(), which now provide
the iov_tail representing the L4 ICMPv6 segment directly to ndp().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 ndp.c | 19 +++++++++++--------
 ndp.h |  4 ++--
 tap.c | 10 +++-------
 3 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/ndp.c b/ndp.c
index fb2bf1161b66..09d43546b91e 100644
--- a/ndp.c
+++ b/ndp.c
@@ -337,13 +337,20 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
  * @c:		Execution context
  * @ih:		ICMPv6 header
  * @saddr:	Source IPv6 address
- * @p:		Packet pool
+ * @data:	Single packet with ICMPv6 header
  *
  * Return: 0 if not handled here, 1 if handled, -1 on failure
  */
-int ndp(const struct ctx *c, const struct icmp6hdr *ih,
-	const struct in6_addr *saddr, const struct pool *p)
+int ndp(const struct ctx *c, const struct in6_addr *saddr,
+	struct iov_tail *data)
 {
+	struct icmp6hdr ih_storage;
+	const struct icmp6hdr *ih;
+
+	ih = IOV_PEEK_HEADER(data, ih_storage);
+	if (!ih)
+		return -1;
+
 	if (ih->icmp6_type < RS || ih->icmp6_type > NA)
 		return 0;
 
@@ -353,12 +360,8 @@ int ndp(const struct ctx *c, const struct icmp6hdr *ih,
 	if (ih->icmp6_type == NS) {
 		struct ndp_ns ns_storage;
 		const struct ndp_ns *ns;
-		struct iov_tail data;
-
-		if (!packet_get(p, 0, &data))
-			return -1;
 
-		ns = IOV_REMOVE_HEADER(&data, ns_storage);
+		ns = IOV_REMOVE_HEADER(data, ns_storage);
 		if (!ns)
 			return -1;
 
diff --git a/ndp.h b/ndp.h
index 41c2000356ec..b1dd5e82c085 100644
--- a/ndp.h
+++ b/ndp.h
@@ -8,8 +8,8 @@
 
 struct icmp6hdr;
 
-int ndp(const struct ctx *c, const struct icmp6hdr *ih,
-	const struct in6_addr *saddr, const struct pool *p);
+int ndp(const struct ctx *c, const struct in6_addr *saddr,
+	struct iov_tail *data);
 void ndp_timer(const struct ctx *c, const struct timespec *now);
 
 #endif /* NDP_H */
diff --git a/tap.c b/tap.c
index 683da5b6d431..964e036d8de5 100644
--- a/tap.c
+++ b/tap.c
@@ -940,9 +940,7 @@ resume:
 		}
 
 		if (proto == IPPROTO_ICMPV6) {
-			struct icmp6hdr l4h_storage;
-			const struct icmp6hdr *l4h;
-			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
+			struct iov_tail ndp_data;
 
 			if (c->no_icmp)
 				continue;
@@ -950,10 +948,8 @@ resume:
 			if (l4len < sizeof(struct icmp6hdr))
 				continue;
 
-			packet_add(pkt, &data);
-
-			l4h = IOV_PEEK_HEADER(&data, l4h_storage);
-			if (ndp(c, (struct icmp6hdr *)l4h, saddr, pkt))
+			ndp_data = data;
+			if (ndp(c, saddr, &ndp_data))
 				continue;
 
 			tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1);
-- 
@@ -940,9 +940,7 @@ resume:
 		}
 
 		if (proto == IPPROTO_ICMPV6) {
-			struct icmp6hdr l4h_storage;
-			const struct icmp6hdr *l4h;
-			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
+			struct iov_tail ndp_data;
 
 			if (c->no_icmp)
 				continue;
@@ -950,10 +948,8 @@ resume:
 			if (l4len < sizeof(struct icmp6hdr))
 				continue;
 
-			packet_add(pkt, &data);
-
-			l4h = IOV_PEEK_HEADER(&data, l4h_storage);
-			if (ndp(c, (struct icmp6hdr *)l4h, saddr, pkt))
+			ndp_data = data;
+			if (ndp(c, saddr, &ndp_data))
 				continue;
 
 			tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1);
-- 
2.49.0