Re: [PATCH net-next 2/4] netconsole: use the address family instead of the ipv6 flag

Now that we have the address family in inet_addr, use that and remove
nt->ipv6.

We no longer need netcons_local_ip_unset() to check that all bytes are
zeroes, as that is now denoted by (family == AF_UNSPEC).

Signed-off-by: Gustavo Luiz Duarte <redacted>
---
 drivers/net/netconsole.c | 82 ++++++++++++++----------------------------------
 1 file changed, 23 insertions(+), 59 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index d615a9256787..070bae7b4fd7 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c

@@ -181,7 +181,6 @@ enum target_state {
  *		local_mac	(read-only)
  * @local_ip:	Source IP address of the target (read-write).
  * @remote_ip:	Destination IP address of the target (read-write).
- * @ipv6:	Whether the target addresses are IPv6 (read-write).
  * @local_port:	Source UDP port of the target (read-write).
  * @remote_port: Destination UDP port of the target (read-write).
  * @remote_mac:	Destination ethernet address of the target (read-write).

@@ -213,7 +212,6 @@ struct netconsole_target {
 	bool			release;
 	struct netpoll		np;
 	struct inet_addr	local_ip, remote_ip;
-	bool			ipv6;
 	u16			local_port, remote_port;
 	u8			remote_mac[ETH_ALEN];
 	/* protected by target_list_lock; +1 gives scnprintf() room for its

@@ -463,23 +461,6 @@ static int netcons_take_ipv4(struct netconsole_target *nt,
 	return 0;
 }
 
-/*
- * Test whether the caller left nt->local_ip unset, so that
- * netcons_netpoll_setup() should auto-populate it from the egress device.
- *
- * nt->local_ip is a union of __be32 (IPv4) and struct in6_addr (IPv6),
- * so an IPv6 address whose first 4 bytes are zero (e.g. ::1, ::2,
- * IPv4-mapped ::ffff:a.b.c.d) must not be tested via the IPv4 arm —
- * doing so would misclassify a caller-supplied address as unset and
- * silently overwrite it with whatever address the device exposes.
- */
-static bool netcons_local_ip_unset(const struct netconsole_target *nt)
-{
-	if (nt->ipv6)
-		return ipv6_addr_any(&nt->local_ip.in6);
-	return !nt->local_ip.ip;
-}
-
 static int netcons_netpoll_setup(struct netconsole_target *nt)
 {
 	struct net *net = current->nsproxy->net_ns;

@@ -525,16 +506,13 @@ static int netcons_netpoll_setup(struct netconsole_target *nt)
 		rtnl_lock();
 	}
 
-	if (netcons_local_ip_unset(nt)) {
-		if (!nt->ipv6) {
-			err = netcons_take_ipv4(nt, ndev);
-			if (err)
-				goto put;
-		} else {
+	if (nt->local_ip.family == AF_UNSPEC) {
+		if (nt->remote_ip.family == AF_INET6)
 			err = netcons_take_ipv6(nt, ndev);
-			if (err)
-				goto put;
-		}
+		else
+			err = netcons_take_ipv4(nt, ndev);
+		if (err)
+			goto put;

 		ip_overwritten = true;
 	}
 

@@ -716,22 +694,22 @@ static void netconsole_print_banner(struct netconsole_target *nt)
 	struct netpoll *np = &nt->np;
 
 	np_info(np, "local port %d\n", nt->local_port);
-	if (nt->ipv6)
+	if (nt->local_ip.family == AF_INET6)
 		np_info(np, "local IPv6 address %pI6c\n", &nt->local_ip.in6);
 	else
 		np_info(np, "local IPv4 address %pI4\n", &nt->local_ip.ip);

 	np_info(np, "interface name '%s'\n", np->dev_name);
 	np_info(np, "local ethernet address '%pM'\n", np->dev_mac);
 	np_info(np, "remote port %d\n", nt->remote_port);
-	if (nt->ipv6)
+	if (nt->remote_ip.family == AF_INET6)
 		np_info(np, "remote IPv6 address %pI6c\n", &nt->remote_ip.in6);
 	else

@@ -755,7 +733,7 @@ static int netpoll_parse_ip_addr(const char *str, struct inet_addr *addr)
 	    in6_pton(str, len, (void *)&addr->in6, -1, &end) > 0 &&
 	    (!end || *end == 0 || *end == '\n')) {
 		addr->family = AF_INET6;