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can: initial support for network namespaces
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This patch adds initial support for network namespaces. The changes only
enable support in the CAN raw, proc and af_can code. GW and BCM still
have their checks that ensure that they are used only from the main
namespace.

The patch boils down to moving the global structures, i.e. the global
filter list and their /proc stats, into a per-namespace structure and passing
around the corresponding "struct net" in a lot of different places.

Changes since v1:
 - rebased on current HEAD (2bfe01e)
 - fixed overlong line

Signed-off-by: Mario Kicherer <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>
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@anyc @marckleinebudde
anyc authored and marckleinebudde committed Apr 4, 2017
1 parent dabf54d commit 8e8cda6
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Showing 9 changed files with 242 additions and 179 deletions.
7 changes: 4 additions & 3 deletions include/linux/can/core.h
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Original file line number Diff line number Diff line change
Expand Up @@ -45,12 +45,13 @@ struct can_proto {
extern int can_proto_register(const struct can_proto *cp);
extern void can_proto_unregister(const struct can_proto *cp);

int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
int can_rx_register(struct net *net, struct net_device *dev,
canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *),
void *data, char *ident, struct sock *sk);

extern void can_rx_unregister(struct net_device *dev, canid_t can_id,
canid_t mask,
extern void can_rx_unregister(struct net *net, struct net_device *dev,
canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *),
void *data);

Expand Down
4 changes: 4 additions & 0 deletions include/net/net_namespace.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@
#include <net/netns/nftables.h>
#include <net/netns/xfrm.h>
#include <net/netns/mpls.h>
#include <net/netns/can.h>
#include <linux/ns_common.h>
#include <linux/idr.h>
#include <linux/skbuff.h>
Expand Down Expand Up @@ -140,6 +141,9 @@ struct net {
#endif
#if IS_ENABLED(CONFIG_MPLS)
struct netns_mpls mpls;
#endif
#if IS_ENABLED(CONFIG_CAN)
struct netns_can can;
#endif
struct sock *diag_nlsk;
atomic_t fnhe_genid;
Expand Down
31 changes: 31 additions & 0 deletions include/net/netns/can.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,31 @@
/*
* can in net namespaces
*/

#ifndef __NETNS_CAN_H__
#define __NETNS_CAN_H__

#include <linux/spinlock.h>

struct dev_rcv_lists;

struct netns_can {
#if IS_ENABLED(CONFIG_PROC_FS)
struct proc_dir_entry *proc_dir;
struct proc_dir_entry *pde_version;
struct proc_dir_entry *pde_stats;
struct proc_dir_entry *pde_reset_stats;
struct proc_dir_entry *pde_rcvlist_all;
struct proc_dir_entry *pde_rcvlist_fil;
struct proc_dir_entry *pde_rcvlist_inv;
struct proc_dir_entry *pde_rcvlist_sff;
struct proc_dir_entry *pde_rcvlist_eff;
struct proc_dir_entry *pde_rcvlist_err;
#endif

/* receive filters subscribed for 'all' CAN devices */
struct dev_rcv_lists *can_rx_alldev_list;
spinlock_t can_rcvlists_lock;
};

#endif /* __NETNS_CAN_H__ */
122 changes: 70 additions & 52 deletions net/can/af_can.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,9 +75,7 @@ static int stats_timer __read_mostly = 1;
module_param(stats_timer, int, S_IRUGO);
MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");

/* receive filters subscribed for 'all' CAN devices */
struct dev_rcv_lists can_rx_alldev_list;
static DEFINE_SPINLOCK(can_rcvlists_lock);
static int can_net_id;

static struct kmem_cache *rcv_cache __read_mostly;

Expand Down Expand Up @@ -145,9 +143,6 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
if (protocol < 0 || protocol >= CAN_NPROTO)
return -EINVAL;

if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;

cp = can_get_proto(protocol);

#ifdef CONFIG_MODULES
Expand Down Expand Up @@ -331,10 +326,11 @@ EXPORT_SYMBOL(can_send);
* af_can rx path
*/

static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
static struct dev_rcv_lists *find_dev_rcv_lists(struct net *net,
struct net_device *dev)
{
if (!dev)
return &can_rx_alldev_list;
return net->can.can_rx_alldev_list;
else
return (struct dev_rcv_lists *)dev->ml_priv;
}
Expand Down Expand Up @@ -467,9 +463,9 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
* -ENOMEM on missing cache mem to create subscription entry
* -ENODEV unknown device
*/
int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *), void *data,
char *ident, struct sock *sk)
int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
canid_t mask, void (*func)(struct sk_buff *, void *),
void *data, char *ident, struct sock *sk)
{
struct receiver *r;
struct hlist_head *rl;
Expand All @@ -481,13 +477,16 @@ int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
if (dev && dev->type != ARPHRD_CAN)
return -ENODEV;

if (dev && !net_eq(net, dev_net(dev)))
return -ENODEV;

r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
if (!r)
return -ENOMEM;

spin_lock(&can_rcvlists_lock);
spin_lock(&net->can.can_rcvlists_lock);

d = find_dev_rcv_lists(dev);
d = find_dev_rcv_lists(net, dev);
if (d) {
rl = find_rcv_list(&can_id, &mask, d);

Expand All @@ -510,7 +509,7 @@ int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
err = -ENODEV;
}

spin_unlock(&can_rcvlists_lock);
spin_unlock(&net->can.can_rcvlists_lock);

return err;
}
Expand Down Expand Up @@ -540,8 +539,9 @@ static void can_rx_delete_receiver(struct rcu_head *rp)
* Description:
* Removes subscription entry depending on given (subscription) values.
*/
void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *), void *data)
void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
canid_t mask, void (*func)(struct sk_buff *, void *),
void *data)
{
struct receiver *r = NULL;
struct hlist_head *rl;
Expand All @@ -550,9 +550,12 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
if (dev && dev->type != ARPHRD_CAN)
return;

spin_lock(&can_rcvlists_lock);
if (dev && !net_eq(net, dev_net(dev)))
return;

d = find_dev_rcv_lists(dev);
spin_lock(&net->can.can_rcvlists_lock);

d = find_dev_rcv_lists(net, dev);
if (!d) {
pr_err("BUG: receive list not found for "
"dev %s, id %03X, mask %03X\n",
Expand Down Expand Up @@ -598,7 +601,7 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
}

out:
spin_unlock(&can_rcvlists_lock);
spin_unlock(&net->can.can_rcvlists_lock);

/* schedule the receiver item for deletion */
if (r) {
Expand Down Expand Up @@ -696,10 +699,10 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
rcu_read_lock();

/* deliver the packet to sockets listening on all devices */
matches = can_rcv_filter(&can_rx_alldev_list, skb);
matches = can_rcv_filter(dev_net(dev)->can.can_rx_alldev_list, skb);

/* find receive list for this device */
d = find_dev_rcv_lists(dev);
d = find_dev_rcv_lists(dev_net(dev), dev);
if (d)
matches += can_rcv_filter(d, skb);

Expand All @@ -719,9 +722,6 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
{
struct canfd_frame *cfd = (struct canfd_frame *)skb->data;

if (unlikely(!net_eq(dev_net(dev), &init_net)))
goto drop;

if (WARN_ONCE(dev->type != ARPHRD_CAN ||
skb->len != CAN_MTU ||
cfd->len > CAN_MAX_DLEN,
Expand All @@ -743,9 +743,6 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
{
struct canfd_frame *cfd = (struct canfd_frame *)skb->data;

if (unlikely(!net_eq(dev_net(dev), &init_net)))
goto drop;

if (WARN_ONCE(dev->type != ARPHRD_CAN ||
skb->len != CANFD_MTU ||
cfd->len > CANFD_MAX_DLEN,
Expand Down Expand Up @@ -835,9 +832,6 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct dev_rcv_lists *d;

if (!net_eq(dev_net(dev), &init_net))
return NOTIFY_DONE;

if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;

Expand All @@ -855,7 +849,7 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
break;

case NETDEV_UNREGISTER:
spin_lock(&can_rcvlists_lock);
spin_lock(&dev_net(dev)->can.can_rcvlists_lock);

d = dev->ml_priv;
if (d) {
Expand All @@ -869,14 +863,48 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
pr_err("can: notifier: receive list not found for dev "
"%s\n", dev->name);

spin_unlock(&can_rcvlists_lock);
spin_unlock(&dev_net(dev)->can.can_rcvlists_lock);

break;
}

return NOTIFY_DONE;
}

static int can_pernet_init(struct net *net)
{
net->can.can_rcvlists_lock =
__SPIN_LOCK_UNLOCKED(net->can.can_rcvlists_lock);
net->can.can_rx_alldev_list =
kzalloc(sizeof(struct dev_rcv_lists), GFP_KERNEL);

if (IS_ENABLED(CONFIG_PROC_FS))
can_init_proc(net);

return 0;
}

static void can_pernet_exit(struct net *net)
{
struct net_device *dev;

if (IS_ENABLED(CONFIG_PROC_FS))
can_remove_proc(net);

/* remove created dev_rcv_lists from still registered CAN devices */
rcu_read_lock();
for_each_netdev_rcu(net, dev) {
if (dev->type == ARPHRD_CAN && dev->ml_priv) {
struct dev_rcv_lists *d = dev->ml_priv;

BUG_ON(d->entries);
kfree(d);
dev->ml_priv = NULL;
}
}
rcu_read_unlock();
}

/*
* af_can module init/exit functions
*/
Expand All @@ -902,6 +930,13 @@ static struct notifier_block can_netdev_notifier __read_mostly = {
.notifier_call = can_notifier,
};

static struct pernet_operations can_pernet_ops __read_mostly = {
.init = can_pernet_init,
.exit = can_pernet_exit,
.id = &can_net_id,
.size = 0,
};

static __init int can_init(void)
{
/* check for correct padding to be able to use the structs similarly */
Expand All @@ -912,8 +947,6 @@ static __init int can_init(void)

pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");

memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));

rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
0, 0, NULL);
if (!rcv_cache)
Expand All @@ -925,9 +958,10 @@ static __init int can_init(void)
setup_timer(&can_stattimer, can_stat_update, 0);
mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
}
can_init_proc();
}

register_pernet_subsys(&can_pernet_ops);

/* protocol register */
sock_register(&can_family_ops);
register_netdevice_notifier(&can_netdev_notifier);
Expand All @@ -939,13 +973,9 @@ static __init int can_init(void)

static __exit void can_exit(void)
{
struct net_device *dev;

if (IS_ENABLED(CONFIG_PROC_FS)) {
if (stats_timer)
del_timer_sync(&can_stattimer);

can_remove_proc();
}

/* protocol unregister */
Expand All @@ -954,19 +984,7 @@ static __exit void can_exit(void)
unregister_netdevice_notifier(&can_netdev_notifier);
sock_unregister(PF_CAN);

/* remove created dev_rcv_lists from still registered CAN devices */
rcu_read_lock();
for_each_netdev_rcu(&init_net, dev) {
if (dev->type == ARPHRD_CAN && dev->ml_priv) {

struct dev_rcv_lists *d = dev->ml_priv;

BUG_ON(d->entries);
kfree(d);
dev->ml_priv = NULL;
}
}
rcu_read_unlock();
unregister_pernet_subsys(&can_pernet_ops);

rcu_barrier(); /* Wait for completion of call_rcu()'s */

Expand Down
4 changes: 2 additions & 2 deletions net/can/af_can.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,8 +114,8 @@ struct s_pstats {
extern struct dev_rcv_lists can_rx_alldev_list;

/* function prototypes for the CAN networklayer procfs (proc.c) */
void can_init_proc(void);
void can_remove_proc(void);
void can_init_proc(struct net *net);
void can_remove_proc(struct net *net);
void can_stat_update(unsigned long data);

/* structures and variables from af_can.c needed in proc.c for reading */
Expand Down
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