From 716a926ef485602d3e5aafd93ed5893d1eca39b6 Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Fri, 6 Jan 2023 11:43:14 +1100
Subject: util: Parameterize ethernet header initializer macro

We have separate IPv4 and IPv6 versions of a macro to construct an
initializer for ethernet headers.  However, now that we have htons_constant
it's easy to simply paramterize this with the ethernet protocol number.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 tcp.c  |  8 ++++----
 udp.c  |  4 ++--
 util.h | 11 ++---------
 3 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/tcp.c b/tcp.c
index ee3c6e5..ccb5895 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1059,7 +1059,7 @@ static void tcp_sock4_iov_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(tcp4_l2_buf); i++) {
 		tcp4_l2_buf[i] = (struct tcp4_l2_buf_t) {
-			.eh = L2_BUF_ETH_IP4_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IP),
 			.iph = L2_BUF_IP4_INIT(IPPROTO_TCP),
 			.th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 }
 		};
@@ -1067,7 +1067,7 @@ static void tcp_sock4_iov_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(tcp4_l2_flags_buf); i++) {
 		tcp4_l2_flags_buf[i] = (struct tcp4_l2_flags_buf_t) {
-			.eh = L2_BUF_ETH_IP4_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IP),
 			.iph = L2_BUF_IP4_INIT(IPPROTO_TCP)
 		};
 	}
@@ -1091,7 +1091,7 @@ static void tcp_sock6_iov_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(tcp6_l2_buf); i++) {
 		tcp6_l2_buf[i] = (struct tcp6_l2_buf_t) {
-			.eh = L2_BUF_ETH_IP6_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IPV6),
 			.ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP),
 			.th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 }
 		};
@@ -1099,7 +1099,7 @@ static void tcp_sock6_iov_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(tcp6_l2_flags_buf); i++) {
 		tcp6_l2_flags_buf[i] = (struct tcp6_l2_flags_buf_t) {
-			.eh = L2_BUF_ETH_IP6_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IPV6),
 			.ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP)
 		};
 	}
diff --git a/udp.c b/udp.c
index fb3f790..4549316 100644
--- a/udp.c
+++ b/udp.c
@@ -329,7 +329,7 @@ static void udp_sock4_iov_init(const struct ctx *c)
 
 	for (i = 0; i < ARRAY_SIZE(udp4_l2_buf); i++) {
 		udp4_l2_buf[i] = (struct udp4_l2_buf_t) {
-			.eh = L2_BUF_ETH_IP4_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IP),
 			.iph = L2_BUF_IP4_INIT(IPPROTO_UDP)
 		};
 	}
@@ -370,7 +370,7 @@ static void udp_sock6_iov_init(const struct ctx *c)
 
 	for (i = 0; i < ARRAY_SIZE(udp6_l2_buf); i++) {
 		udp6_l2_buf[i] = (struct udp6_l2_buf_t) {
-			.eh = L2_BUF_ETH_IP6_INIT,
+			.eh = L2_BUF_ETH_INIT(ETH_P_IPV6),
 			.ip6h = L2_BUF_IP6_INIT(IPPROTO_UDP)
 		};
 	}
diff --git a/util.h b/util.h
index b4c139d..b5be7a6 100644
--- a/util.h
+++ b/util.h
@@ -102,18 +102,11 @@ int do_clone(int (*fn)(void *), char *stack_area, size_t stack_size, int flags,
 			 (void *)(arg));				\
 	} while (0)
 
-#define L2_BUF_ETH_IP4_INIT						\
+#define L2_BUF_ETH_INIT(proto)						\
 	{								\
 		.h_dest		= { 0 },				\
 		.h_source	= { 0 },				\
-		.h_proto	= htons_constant(ETH_P_IP),		\
-	}
-
-#define L2_BUF_ETH_IP6_INIT						\
-	{								\
-		.h_dest		= { 0 },				\
-		.h_source	= { 0 },				\
-		.h_proto	= htons_constant(ETH_P_IPV6),		\
+		.h_proto	= htons_constant(proto),		\
 	}
 
 #define L2_BUF_IP4_INIT(proto)						\
-- 
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