[PATCH v5 05/12] arp: Pass queue pair explicitly through ARP send path

[Laurent Vivier <lvivier@redhat.com>]

Add a qpair parameter to arp(), arp_send_init_req(), and
arp_announce(), forwarding it to tap_send_single() instead of
hardcoding QPAIR_DEFAULT.

tap_start_connection() now consumes the qpair parameter it received
in the previous commit.

fwd_neigh_table_update() has no queue pair context and keeps using
QPAIR_DEFAULT.

No functional change.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 arp.c | 15 +++++++++------
 arp.h |  6 +++---
 fwd.c |  2 +-
 tap.c |  6 ++----
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arp.c b/arp.c
index e97c4de86a99..1dc8b87cd993 100644
--- a/arp.c
+++ b/arp.c
@@ -63,11 +63,12 @@ static bool ignore_arp(const struct ctx *c,
 /**
  * arp() - Check if this is a supported ARP message, reply as needed
  * @c:		Execution context
+ * @qpair:	Queue pair on which to send the reply
  * @data:	Single packet with Ethernet buffer
  *
  * Return: 1 if handled, -1 on failure
  */
-int arp(const struct ctx *c, struct iov_tail *data)
+int arp(const struct ctx *c, unsigned int qpair, struct iov_tail *data)
 {
 	union inany_addr tgt;
 	struct {
@@ -112,7 +113,7 @@ int arp(const struct ctx *c, struct iov_tail *data)
 	memcpy(resp.am.tha,		am->sha,	sizeof(resp.am.tha));
 	memcpy(resp.am.tip,		am->sip,	sizeof(resp.am.tip));
 
-	tap_send_single(c, QPAIR_DEFAULT, &resp, sizeof(resp));
+	tap_send_single(c, qpair, &resp, sizeof(resp));
 
 	return 1;
 }
@@ -120,8 +121,9 @@ int arp(const struct ctx *c, struct iov_tail *data)
 /**
  * arp_send_init_req() - Send initial ARP request to retrieve guest MAC address
  * @c:		Execution context
+ * @qpair:	Queue pair on which to send the request
  */
-void arp_send_init_req(const struct ctx *c)
+void arp_send_init_req(const struct ctx *c, unsigned int qpair)
 {
 	struct {
 		struct ethhdr eh;
@@ -148,16 +150,17 @@ void arp_send_init_req(const struct ctx *c)
 	memcpy(req.am.tip,	&c->ip4.addr,		sizeof(req.am.tip));
 
 	debug("Sending initial ARP request for guest MAC address");
-	tap_send_single(c, QPAIR_DEFAULT, &req, sizeof(req));
+	tap_send_single(c, qpair, &req, sizeof(req));
 }
 
 /**
  * arp_announce() - Send an ARP announcement for an IPv4 host
  * @c:		Execution context
+ * @qpair:	Queue pair on which to send the announcement
  * @ip:	IPv4 address we announce as owned by @mac
  * @mac:	MAC address to advertise for @ip
  */
-void arp_announce(const struct ctx *c, struct in_addr *ip,
+void arp_announce(const struct ctx *c, unsigned int qpair, struct in_addr *ip,
 		  const unsigned char *mac)
 {
 	char ip_str[INET_ADDRSTRLEN];
@@ -202,5 +205,5 @@ void arp_announce(const struct ctx *c, struct in_addr *ip,
 	eth_ntop(mac, mac_str, sizeof(mac_str));
 	debug("ARP announcement for %s / %s", ip_str, mac_str);
 
-	tap_send_single(c, QPAIR_DEFAULT, &msg, sizeof(msg));
+	tap_send_single(c, qpair, &msg, sizeof(msg));
 }
diff --git a/arp.h b/arp.h
index 4b1f38bcec9b..501760393a74 100644
--- a/arp.h
+++ b/arp.h
@@ -22,9 +22,9 @@ struct arpmsg {
 	unsigned char tip[4];
 } __attribute__((__packed__));
 
-int arp(const struct ctx *c, struct iov_tail *data);
-void arp_send_init_req(const struct ctx *c);
-void arp_announce(const struct ctx *c, struct in_addr *ip,
+int arp(const struct ctx *c, unsigned int qpair, struct iov_tail *data);
+void arp_send_init_req(const struct ctx *c, unsigned int qpair);
+void arp_announce(const struct ctx *c, unsigned int qpair, struct in_addr *ip,
 		  const unsigned char *mac);
 
 #endif /* ARP_H */
diff --git a/fwd.c b/fwd.c
index c0a6adacd294..0d0e265b7dc0 100644
--- a/fwd.c
+++ b/fwd.c
@@ -145,7 +145,7 @@ void fwd_neigh_table_update(const struct ctx *c, const union inany_addr *addr,
 		return;
 
 	if (inany_v4(addr))
-		arp_announce(c, inany_v4(addr), e->mac);
+		arp_announce(c, QPAIR_DEFAULT, inany_v4(addr), e->mac);
 	else
 		ndp_unsolicited_na(c, &addr->a6);
 }
diff --git a/tap.c b/tap.c
index 521ccd6d47e7..66dcb83665a7 100644
--- a/tap.c
+++ b/tap.c
@@ -741,7 +741,7 @@ resume:
 		if (!eh)
 			continue;
 		if (ntohs(eh->h_proto) == ETH_P_ARP) {
-			arp(c, &data);
+			arp(c, qpair, &data);
 			continue;
 		}
 
@@ -1453,8 +1453,6 @@ static void tap_start_connection(const struct ctx *c, unsigned int qpair)
 {
 	union epoll_ref ref = { 0 };
 
-	(void)qpair;
-
 	ref.fd = c->fd_tap;
 	switch (c->mode) {
 	case MODE_PASST:
@@ -1474,7 +1472,7 @@ static void tap_start_connection(const struct ctx *c, unsigned int qpair)
 		return;
 
 	if (c->ifi4)
-		arp_send_init_req(c);
+		arp_send_init_req(c, qpair);
 	if (c->ifi6 && !c->no_ndp)
 		ndp_send_init_req(c);
 }
-- 
2.54.0