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>

1 files changed, 44 insertions, 28 deletions

diff --git a/net/can/gw.c b/net/can/gw.c
index ad5bf5d508d3..29748d844c3f 100644
--- 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);