can: network namespace support for CAN gateway

The CAN gateway was not implemented as per-net in the initial network
namespace support by Mario Kicherer (8e8cda6d737d).
This patch enables the CAN gateway to be used in different namespaces.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/include/net/netns/can.h b/include/net/netns/can.h
index 0f3c31aab8a8decb977961b17511dad07c188aaa..b106e6ae2e5b46dc119a322ebf22437e88158962 100644 (file)
--- a/include/net/netns/can.h
+++ b/include/net/netns/can.h
@@ -32,6 +32,9 @@ struct netns_can {
        struct timer_list can_stattimer;/* timer for statistics update */
        struct s_stats *can_stats;      /* packet statistics */
        struct s_pstats *can_pstats;    /* receive list statistics */
+
+       /* CAN GW per-net gateway jobs */
+       struct hlist_head cgw_list;
 };
 
 #endif /* __NETNS_CAN_H__ */

diff --git a/net/can/gw.c b/net/can/gw.c
index ad5bf5d508d3808bc1e9186902660bf85a418104..29748d844c3fac1bda35d494cdc1474fe81849a9 100644 (file)
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -1,7 +1,7 @@
 /*
  * gw.c - CAN frame Gateway/Router/Bridge with netlink interface
  *
- * Copyright (c) 2011 Volkswagen Group Electronic Research
+ * Copyright (c) 2017 Volkswagen Group Electronic Research
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,7 +59,7 @@
 #include <net/net_namespace.h>
 #include <net/sock.h>
 
-#define CAN_GW_VERSION "20130117"
+#define CAN_GW_VERSION "20170425"
 #define CAN_GW_NAME "can-gw"
 
 MODULE_DESCRIPTION("PF_CAN netlink gateway");
@@ -79,9 +79,7 @@ MODULE_PARM_DESC(max_hops,
                 __stringify(CGW_MAX_HOPS) " hops, "
                 "default: " __stringify(CGW_DEFAULT_HOPS) ")");
 
-static HLIST_HEAD(cgw_list);
 static struct notifier_block notifier;
-
 static struct kmem_cache *cgw_cache __read_mostly;
 
 /* structure that contains the (on-the-fly) CAN frame modifications */
@@ -438,16 +436,16 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
                gwj->handled_frames++;
 }
 
-static inline int cgw_register_filter(struct cgw_job *gwj)
+static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
 {
-       return can_rx_register(&init_net, gwj->src.dev, gwj->ccgw.filter.can_id,
+       return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
                               gwj->ccgw.filter.can_mask, can_can_gw_rcv,
                               gwj, "gw", NULL);
 }
 
-static inline void cgw_unregister_filter(struct cgw_job *gwj)
+static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
 {
-       can_rx_unregister(&init_net, gwj->src.dev, gwj->ccgw.filter.can_id,
+       can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
                          gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
 }
 
@@ -455,9 +453,8 @@ static int cgw_notifier(struct notifier_block *nb,
                        unsigned long msg, void *ptr)
 {
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+       struct net *net = dev_net(dev);
 
-       if (!net_eq(dev_net(dev), &init_net))
-               return NOTIFY_DONE;
        if (dev->type != ARPHRD_CAN)
                return NOTIFY_DONE;
 
@@ -468,11 +465,11 @@ static int cgw_notifier(struct notifier_block *nb,
 
                ASSERT_RTNL();
 
-               hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
+               hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
 
                        if (gwj->src.dev == dev || gwj->dst.dev == dev) {
                                hlist_del(&gwj->list);
-                               cgw_unregister_filter(gwj);
+                               cgw_unregister_filter(net, gwj);
                                kmem_cache_free(cgw_cache, gwj);
                        }
                }
@@ -592,12 +589,13 @@ cancel:
 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
 {
+       struct net *net = sock_net(skb->sk);
        struct cgw_job *gwj = NULL;
        int idx = 0;
        int s_idx = cb->args[0];
 
        rcu_read_lock();
-       hlist_for_each_entry_rcu(gwj, &cgw_list, list) {
+       hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
                if (idx < s_idx)
                        goto cont;
 
@@ -812,6 +810,7 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
 static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
                          struct netlink_ext_ack *extack)
 {
+       struct net *net = sock_net(skb->sk);
        struct rtcanmsg *r;
        struct cgw_job *gwj;
        struct cf_mod mod;
@@ -842,7 +841,7 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
                ASSERT_RTNL();
 
                /* check for updating an existing job with identical uid */
-               hlist_for_each_entry(gwj, &cgw_list, list) {
+               hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
 
                        if (gwj->mod.uid != mod.uid)
                                continue;
@@ -880,7 +879,7 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
 
        err = -ENODEV;
 
-       gwj->src.dev = __dev_get_by_index(&init_net, gwj->ccgw.src_idx);
+       gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
 
        if (!gwj->src.dev)
                goto out;
@@ -888,7 +887,7 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
        if (gwj->src.dev->type != ARPHRD_CAN)
                goto out;
 
-       gwj->dst.dev = __dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
+       gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
 
        if (!gwj->dst.dev)
                goto out;
@@ -898,9 +897,9 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
 
        ASSERT_RTNL();
 
-       err = cgw_register_filter(gwj);
+       err = cgw_register_filter(net, gwj);
        if (!err)
-               hlist_add_head_rcu(&gwj->list, &cgw_list);
+               hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
 out:
        if (err)
                kmem_cache_free(cgw_cache, gwj);
@@ -908,16 +907,16 @@ out:
        return err;
 }
 
-static void cgw_remove_all_jobs(void)
+static void cgw_remove_all_jobs(struct net *net)
 {
        struct cgw_job *gwj = NULL;
        struct hlist_node *nx;
 
        ASSERT_RTNL();
 
-       hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
+       hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
                hlist_del(&gwj->list);
-               cgw_unregister_filter(gwj);
+               cgw_unregister_filter(net, gwj);
                kmem_cache_free(cgw_cache, gwj);
        }
 }
@@ -925,6 +924,7 @@ static void cgw_remove_all_jobs(void)
 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
                          struct netlink_ext_ack *extack)
 {
+       struct net *net = sock_net(skb->sk);
        struct cgw_job *gwj = NULL;
        struct hlist_node *nx;
        struct rtcanmsg *r;
@@ -953,7 +953,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
 
        /* two interface indices both set to 0 => remove all entries */
        if (!ccgw.src_idx && !ccgw.dst_idx) {
-               cgw_remove_all_jobs();
+               cgw_remove_all_jobs(net);
                return 0;
        }
 
@@ -962,7 +962,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
        ASSERT_RTNL();
 
        /* remove only the first matching entry */
-       hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
+       hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
 
                if (gwj->flags != r->flags)
                        continue;
@@ -985,7 +985,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
                        continue;
 
                hlist_del(&gwj->list);
-               cgw_unregister_filter(gwj);
+               cgw_unregister_filter(net, gwj);
                kmem_cache_free(cgw_cache, gwj);
                err = 0;
                break;
@@ -994,6 +994,24 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
        return err;
 }
 
+static int __net_init cangw_pernet_init(struct net *net)
+{
+       INIT_HLIST_HEAD(&net->can.cgw_list);
+       return 0;
+}
+
+static void __net_exit cangw_pernet_exit(struct net *net)
+{
+       rtnl_lock();
+       cgw_remove_all_jobs(net);
+       rtnl_unlock();
+}
+
+static struct pernet_operations cangw_pernet_ops = {
+       .init = cangw_pernet_init,
+       .exit = cangw_pernet_exit,
+};
+
 static __init int cgw_module_init(void)
 {
        /* sanitize given module parameter */
@@ -1002,6 +1020,7 @@ static __init int cgw_module_init(void)
        pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n",
                max_hops);
 
+       register_pernet_subsys(&cangw_pernet_ops);
        cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
                                      0, 0, NULL);
 
@@ -1031,10 +1050,7 @@ static __exit void cgw_module_exit(void)
 
        unregister_netdevice_notifier(&notifier);
 
-       rtnl_lock();
-       cgw_remove_all_jobs();
-       rtnl_unlock();
-
+       unregister_pernet_subsys(&cangw_pernet_ops);
        rcu_barrier(); /* Wait for completion of call_rcu()'s */
 
        kmem_cache_destroy(cgw_cache);