keys: Network namespace domain tag

Create key domain tags for network namespaces and make it possible to
automatically tag keys that are used by networked services (e.g. AF_RXRPC,
AFS, DNS) with the default network namespace if not set by the caller.

This allows keys with the same description but in different namespaces to
coexist within a 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
This commit is contained in:
David Howells 2019-06-26 21:02:33 +01:00
parent 218e6424e7
commit 9b24261051
6 changed files with 35 additions and 1 deletions

View File

@ -74,6 +74,9 @@ struct key_type {
*/
size_t def_datalen;
unsigned int flags;
#define KEY_TYPE_NET_DOMAIN 0x00000001 /* Keys of this type have a net namespace domain */
/* vet a description */
int (*vet_description)(const char *description);

View File

@ -71,6 +71,9 @@ struct net {
*/
struct llist_node cleanup_list; /* namespaces on death row */
#ifdef CONFIG_KEYS
struct key_tag *key_domain; /* Key domain of operation tag */
#endif
struct user_namespace *user_ns; /* Owning user namespace */
struct ucounts *ucounts;
spinlock_t nsid_lock;

View File

@ -38,9 +38,16 @@ EXPORT_SYMBOL_GPL(net_namespace_list);
DECLARE_RWSEM(net_rwsem);
EXPORT_SYMBOL_GPL(net_rwsem);
#ifdef CONFIG_KEYS
static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
#endif
struct net init_net = {
.count = REFCOUNT_INIT(1),
.dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
#ifdef CONFIG_KEYS
.key_domain = &init_net_key_domain,
#endif
};
EXPORT_SYMBOL(init_net);
@ -386,10 +393,22 @@ static struct net *net_alloc(void)
if (!net)
goto out_free;
#ifdef CONFIG_KEYS
net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
if (!net->key_domain)
goto out_free_2;
refcount_set(&net->key_domain->usage, 1);
#endif
rcu_assign_pointer(net->gen, ng);
out:
return net;
#ifdef CONFIG_KEYS
out_free_2:
kmem_cache_free(net_cachep, net);
net = NULL;
#endif
out_free:
kfree(ng);
goto out;
@ -566,6 +585,7 @@ static void cleanup_net(struct work_struct *work)
list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
list_del_init(&net->exit_list);
dec_net_namespaces(net->ucounts);
key_remove_domain(net->key_domain);
put_user_ns(net->user_ns);
net_drop_ns(net);
}

View File

@ -314,6 +314,7 @@ static long dns_resolver_read(const struct key *key,
struct key_type key_type_dns_resolver = {
.name = "dns_resolver",
.flags = KEY_TYPE_NET_DOMAIN,
.preparse = dns_resolver_preparse,
.free_preparse = dns_resolver_free_preparse,
.instantiate = generic_key_instantiate,

View File

@ -43,6 +43,7 @@ static long rxrpc_read(const struct key *, char __user *, size_t);
*/
struct key_type key_type_rxrpc = {
.name = "rxrpc",
.flags = KEY_TYPE_NET_DOMAIN,
.preparse = rxrpc_preparse,
.free_preparse = rxrpc_free_preparse,
.instantiate = generic_key_instantiate,
@ -58,6 +59,7 @@ EXPORT_SYMBOL(key_type_rxrpc);
*/
struct key_type key_type_rxrpc_s = {
.name = "rxrpc_s",
.flags = KEY_TYPE_NET_DOMAIN,
.vet_description = rxrpc_vet_description_s,
.preparse = rxrpc_preparse_s,
.free_preparse = rxrpc_free_preparse_s,

View File

@ -17,10 +17,12 @@
#include <linux/seq_file.h>
#include <linux/err.h>
#include <linux/user_namespace.h>
#include <linux/nsproxy.h>
#include <keys/keyring-type.h>
#include <keys/user-type.h>
#include <linux/assoc_array_priv.h>
#include <linux/uaccess.h>
#include <net/net_namespace.h>
#include "internal.h"
/*
@ -220,7 +222,10 @@ void key_set_index_key(struct keyring_index_key *index_key)
memcpy(index_key->desc, index_key->description, n);
index_key->domain_tag = &default_domain_tag;
if (index_key->type->flags & KEY_TYPE_NET_DOMAIN)
index_key->domain_tag = current->nsproxy->net_ns->key_domain;
else
index_key->domain_tag = &default_domain_tag;
hash_key_type_and_desc(index_key);
}