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crypto: user - make NETLINK_CRYPTO work inside netns

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Currently, NETLINK_CRYPTO works only in the init network namespace. It
doesn't make much sense to cut it out of the other network namespaces,
so do the minor plumbing work necessary to make it work in any network
namespace. Code inspired by net/core/sock_diag.c.

Tested using kcapi-dgst from libkcapi [1]:
Before:
    # unshare -n kcapi-dgst -c sha256 </dev/null | wc -c
    libkcapi - Error: Netlink error: sendmsg failed
    libkcapi - Error: Netlink error: sendmsg failed
    libkcapi - Error: NETLINK_CRYPTO: cannot obtain cipher information for hmac(sha512) (is required crypto_user.c patch missing? see documentation)
    0

After:
    # unshare -n kcapi-dgst -c sha256 </dev/null | wc -c
    32

[1] https://github.com/smuellerDD/libkcapi

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ondrej Mosnacek 2019-07-09 13:11:24 +02:00 committed by Herbert Xu
parent 31fb084c4e
commit 91b05a7e7d
4 changed files with 31 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
crypto/crypto_user_base.c
View File

@ -10,9 +10,10 @@
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <net/netlink.h>
#include <linux/security.h>
#include <net/netlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
@ -25,9 +26,6 @@
static DEFINE_MUTEX(crypto_cfg_mutex);
/* The crypto netlink socket */
struct sock *crypto_nlsk;
struct crypto_dump_info {
struct sk_buff *in_skb;
struct sk_buff *out_skb;
@ -186,6 +184,7 @@ out:
static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct nlattr **attrs)
{
struct net *net = sock_net(in_skb->sk);
struct crypto_user_alg *p = nlmsg_data(in_nlh);
struct crypto_alg *alg;
struct sk_buff *skb;
@ -217,7 +216,7 @@ drop_alg:
if (err)
return err;
return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}
static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
@ -420,6 +419,7 @@ static const struct crypto_link {
static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *attrs[CRYPTOCFGA_MAX+1];
const struct crypto_link *link;
int type, err;
@ -450,7 +450,7 @@ static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
.done = link->done,
.min_dump_alloc = min(dump_alloc, 65535UL),
};
err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
}
return err;
@ -474,22 +474,35 @@ static void crypto_netlink_rcv(struct sk_buff *skb)
mutex_unlock(&crypto_cfg_mutex);
}
static int __init crypto_user_init(void)
static int __net_init crypto_netlink_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
.input = crypto_netlink_rcv,
};
crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
if (!crypto_nlsk)
return -ENOMEM;
net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
return net->crypto_nlsk == NULL ? -ENOMEM : 0;
}
return 0;
static void __net_exit crypto_netlink_exit(struct net *net)
{
netlink_kernel_release(net->crypto_nlsk);
net->crypto_nlsk = NULL;
}
static struct pernet_operations crypto_netlink_net_ops = {
.init = crypto_netlink_init,
.exit = crypto_netlink_exit,
};
static int __init crypto_user_init(void)
{
return register_pernet_subsys(&crypto_netlink_net_ops);
}
static void __exit crypto_user_exit(void)
{
netlink_kernel_release(crypto_nlsk);
unregister_pernet_subsys(&crypto_netlink_net_ops);
}
module_init(crypto_user_init);

4
crypto/crypto_user_stat.c
View File

@ -10,6 +10,7 @@
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <net/netlink.h>
#include <net/sock.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
@ -298,6 +299,7 @@ out:
int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct nlattr **attrs)
{
struct net *net = sock_net(in_skb->sk);
struct crypto_user_alg *p = nlmsg_data(in_nlh);
struct crypto_alg *alg;
struct sk_buff *skb;
@ -329,7 +331,7 @@ drop_alg:
if (err)
return err;
return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}
MODULE_LICENSE("GPL");

2
include/crypto/internal/cryptouser.h
View File

@ -1,8 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <net/netlink.h>
extern struct sock *crypto_nlsk;
struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact);
#ifdef CONFIG_CRYPTO_STATS

3
include/net/net_namespace.h
View File

@ -170,6 +170,9 @@ struct net {
#endif
#ifdef CONFIG_XDP_SOCKETS
struct netns_xdp xdp;
#endif
#if IS_ENABLED(CONFIG_CRYPTO_USER)
struct sock *crypto_nlsk;
#endif
struct sock *diag_nlsk;
atomic_t fnhe_genid;