keys: Pass the network namespace into request_key mechanism

Create a request_key_net() function and use it to pass the network
namespace domain tag into DNS revolver keys and rxrpc/AFS keys so that keys
for different domains can coexist in the same keyring.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: netdev@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-afs@lists.infradead.org
diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index 2d26043..cab4e0d 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -40,6 +40,7 @@
 #include <linux/cred.h>
 #include <linux/dns_resolver.h>
 #include <linux/err.h>
+#include <net/net_namespace.h>
 
 #include <keys/dns_resolver-type.h>
 #include <keys/user-type.h>
@@ -48,6 +49,7 @@
 
 /**
  * dns_query - Query the DNS
+ * @net: The network namespace to operate in.
  * @type: Query type (or NULL for straight host->IP lookup)
  * @name: Name to look up
  * @namelen: Length of name
@@ -69,7 +71,8 @@
  *
  * Returns the size of the result on success, -ve error code otherwise.
  */
-int dns_query(const char *type, const char *name, size_t namelen,
+int dns_query(struct net *net,
+	      const char *type, const char *name, size_t namelen,
 	      const char *options, char **_result, time64_t *_expiry,
 	      bool invalidate)
 {
@@ -122,7 +125,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	 * add_key() to preinstall malicious redirections
 	 */
 	saved_cred = override_creds(dns_resolver_cache);
-	rkey = request_key(&key_type_dns_resolver, desc, options);
+	rkey = request_key_net(&key_type_dns_resolver, desc, net, options);
 	revert_creds(saved_cred);
 	kfree(desc);
 	if (IS_ERR(rkey)) {