netpoll: fix netconsole IPv6 setup

Currently, to make netconsole start over IPv6, the source address
needs to be specified. Without a source address, netpoll_parse_options
assumes we're setting up over IPv4 and the destination IPv6 address is
rejected.

Check if the IP version has been forced by a source address before
checking for a version mismatch when parsing the destination address.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c03f3dec4763fc507edc56167cd8e88a209fb197..a664f7829a6d16db4579789ca5b8c40654cc78d7 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -948,6 +948,7 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 {
        char *cur=opt, *delim;
        int ipv6;
+       bool ipversion_set = false;
 
        if (*cur != '@') {
                if ((delim = strchr(cur, '@')) == NULL)
@@ -960,6 +961,7 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
        cur++;
 
        if (*cur != '/') {
+               ipversion_set = true;
                if ((delim = strchr(cur, '/')) == NULL)
                        goto parse_failed;
                *delim = 0;
@@ -1002,7 +1004,7 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
        ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
        if (ipv6 < 0)
                goto parse_failed;
-       else if (np->ipv6 != (bool)ipv6)
+       else if (ipversion_set && np->ipv6 != (bool)ipv6)
                goto parse_failed;
        else
                np->ipv6 = (bool)ipv6;