icmp: use iov_tail rather than pool

This patch refactors the icmp_tap_handler() function to accept
`struct iov_tail *data` directly as its packet input, replacing the
`const struct pool *p` parameter.

This change simplifies callers, such as tap4_handler(), which now pass
the iov_tail representing the L4 ICMP message directly.
This removes the need for intermediate packet pool handling.

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

3 files changed, 8 insertions, 15 deletions

diff --git a/icmp.c b/icmp.c
index 9d90141..6dffafb 100644
--- a/icmp.c
+++ b/icmp.c
@@ -230,20 +230,19 @@ cancel:
  * @af:		Address family, AF_INET or AF_INET6
  * @saddr:	Source address
  * @daddr:	Destination address
- * @p:		Packet pool, single packet with ICMP/ICMPv6 header
+ * @data:	Single packet with ICMP/ICMPv6 header
  * @now:	Current timestamp
  *
  * Return: count of consumed packets (always 1, even if malformed)
  */
 int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		     const void *saddr, const void *daddr,
-		     const struct pool *p, const struct timespec *now)
+		     struct iov_tail *data, const struct timespec *now)
 {
 	struct iovec iov[MAX_IOV_ICMP];
 	struct icmp_ping_flow *pingf;
 	const struct flowside *tgt;
 	union sockaddr_inany sa;
-	struct iov_tail data;
 	struct msghdr msh;
 	uint16_t id, seq;
 	union flow *flow;
@@ -253,14 +252,11 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 	(void)saddr;
 	ASSERT(pif == PIF_TAP);
 
-	if (!packet_get(p, 0, &data))
-		return -1;
-
 	if (af == AF_INET) {
 		struct icmphdr ih_storage;
 		const struct icmphdr *ih;
 
-		ih = IOV_PEEK_HEADER(&data, ih_storage);
+		ih = IOV_PEEK_HEADER(data, ih_storage);
 		if (!ih)
 			return 1;
 
@@ -274,7 +270,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		struct icmp6hdr ih_storage;
 		const struct icmp6hdr *ih;
 
-		ih = IOV_PEEK_HEADER(&data, ih_storage);
+		ih = IOV_PEEK_HEADER(data, ih_storage);
 		if (!ih)
 			return 1;
 
@@ -288,7 +284,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		ASSERT(0);
 	}
 
-	cnt = iov_tail_clone(&iov[0], MAX_IOV_ICMP, &data);
+	cnt = iov_tail_clone(&iov[0], MAX_IOV_ICMP, data);
 	if (cnt < 0)
 		return 1;
 
diff --git a/icmp.h b/icmp.h
index 5ce22b5..d1cecb2 100644
--- a/icmp.h
+++ b/icmp.h
@@ -14,7 +14,7 @@ struct icmp_ping_flow;
 void icmp_sock_handler(const struct ctx *c, union epoll_ref ref);
 int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		     const void *saddr, const void *daddr,
-		     const struct pool *p, const struct timespec *now);
+		     struct iov_tail *data, const struct timespec *now);
 void icmp_init(void);
 
 /**
diff --git a/tap.c b/tap.c
index a340e43..1a7088a 100644
--- a/tap.c
+++ b/tap.c
@@ -764,17 +764,14 @@ resume:
 			continue;
 
 		if (iph->protocol == IPPROTO_ICMP) {
-			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
-
 			if (c->no_icmp)
 				continue;
 
 			tap_packet_debug(iph, NULL, NULL, 0, NULL, 1);
 
-			packet_add(pkt, &data);
 			icmp_tap_handler(c, PIF_TAP, AF_INET,
 					 &iph->saddr, &iph->daddr,
-					 pkt, now);
+					 &data, now);
 			continue;
 		}
 
@@ -964,7 +961,7 @@ resume:
 			tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1);
 
 			icmp_tap_handler(c, PIF_TAP, AF_INET6,
-					 saddr, daddr, pkt, now);
+					 saddr, daddr, &data, now);
 			continue;
 		}