[NETNS][IPV6] flowlabels - make flowlabels per namespace

This patch introduces a new member, fl_net, in struct ip6_flowlabel.
This allows to create labels with the same value in different namespaces.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 57 insertions, 16 deletions

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 1c98e737dbd0..296f61d84709 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -202,6 +202,7 @@ struct ip6_flowlabel
         u32                     owner;
         unsigned long           lastuse;
         unsigned long           expires;
+        struct net              *fl_net;
 };
 
 #define IPV6_FLOWINFO_MASK      __constant_htonl(0x0FFFFFFF)
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 2b7d9ee98832..78d1d913e36c 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -62,23 +62,23 @@ static DEFINE_RWLOCK(ip6_fl_lock);
 static DEFINE_RWLOCK(ip6_sk_fl_lock);
 
 
-static __inline__ struct ip6_flowlabel * __fl_lookup(__be32 label)
+static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
 {
         struct ip6_flowlabel *fl;
 
         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
-                if (fl->label == label)
+                if (fl->label == label && fl->fl_net == net)
                         return fl;
         }
         return NULL;
 }
 
-static struct ip6_flowlabel * fl_lookup(__be32 label)
+static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
 {
         struct ip6_flowlabel *fl;
 
         read_lock_bh(&ip6_fl_lock);
-        fl = __fl_lookup(label);
+        fl = __fl_lookup(net, label);
         if (fl)
                 atomic_inc(&fl->users);
         read_unlock_bh(&ip6_fl_lock);
@@ -88,8 +88,10 @@ static struct ip6_flowlabel * fl_lookup(__be32 label)
 
 static void fl_free(struct ip6_flowlabel *fl)
 {
-        if (fl)
+        if (fl) {
+                release_net(fl->fl_net);
                 kfree(fl->opt);
+        }
         kfree(fl);
 }
 
@@ -112,7 +114,6 @@ static void fl_release(struct ip6_flowlabel *fl)
                     time_after(ip6_fl_gc_timer.expires, ttd))
                         mod_timer(&ip6_fl_gc_timer, ttd);
         }
-
         write_unlock_bh(&ip6_fl_lock);
 }
 
@@ -148,13 +149,34 @@ static void ip6_fl_gc(unsigned long dummy)
         if (!sched && atomic_read(&fl_size))
                 sched = now + FL_MAX_LINGER;
         if (sched) {
-                ip6_fl_gc_timer.expires = sched;
-                add_timer(&ip6_fl_gc_timer);
+                mod_timer(&ip6_fl_gc_timer, sched);
         }
         write_unlock(&ip6_fl_lock);
 }
 
-static struct ip6_flowlabel *fl_intern(struct ip6_flowlabel *fl, __be32 label)
+static void ip6_fl_purge(struct net *net)
+{
+        int i;
+
+        write_lock(&ip6_fl_lock);
+        for (i = 0; i <= FL_HASH_MASK; i++) {
+                struct ip6_flowlabel *fl, **flp;
+                flp = &fl_ht[i];
+                while ((fl = *flp) != NULL) {
+                        if (fl->fl_net == net && atomic_read(&fl->users) == 0) {
+                                *flp = fl->next;
+                                fl_free(fl);
+                                atomic_dec(&fl_size);
+                                continue;
+                        }
+                        flp = &fl->next;
+                }
+        }
+        write_unlock(&ip6_fl_lock);
+}
+
+static struct ip6_flowlabel *fl_intern(struct net *net,
+                                       struct ip6_flowlabel *fl, __be32 label)
 {
         struct ip6_flowlabel *lfl;
 
@@ -165,7 +187,7 @@ static struct ip6_flowlabel *fl_intern(struct ip6_flowlabel *fl, __be32 label)
                 for (;;) {
                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
                         if (fl->label) {
-                                lfl = __fl_lookup(fl->label);
+                                lfl = __fl_lookup(net, fl->label);
                                 if (lfl == NULL)
                                         break;
                         }
@@ -179,7 +201,7 @@ static struct ip6_flowlabel *fl_intern(struct ip6_flowlabel *fl, __be32 label)
                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
                  * with the same label can only appear on another sock
                  */
-                lfl = __fl_lookup(fl->label);
+                lfl = __fl_lookup(net, fl->label);
                 if (lfl != NULL) {
                         atomic_inc(&lfl->users);
                         write_unlock_bh(&ip6_fl_lock);
@@ -298,7 +320,8 @@ static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned lo
 }
 
 static struct ip6_flowlabel *
-fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
+fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
+          int optlen, int *err_p)
 {
         struct ip6_flowlabel *fl;
         int olen;
@@ -343,6 +366,7 @@ fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *
                 }
         }
 
+        fl->fl_net = hold_net(net);
         fl->expires = jiffies;
         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
         if (err)
@@ -441,6 +465,7 @@ static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 {
         int err;
+        struct net *net = sock_net(sk);
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct in6_flowlabel_req freq;
         struct ipv6_fl_socklist *sfl1=NULL;
@@ -483,7 +508,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
                 read_unlock_bh(&ip6_sk_fl_lock);
 
                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
-                        fl = fl_lookup(freq.flr_label);
+                        fl = fl_lookup(net, freq.flr_label);
                         if (fl) {
                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
                                 fl_release(fl);
@@ -496,7 +521,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
                         return -EINVAL;
 
-                fl = fl_create(&freq, optval, optlen, &err);
+                fl = fl_create(net, &freq, optval, optlen, &err);
                 if (fl == NULL)
                         return err;
                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
@@ -518,7 +543,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
                         read_unlock_bh(&ip6_sk_fl_lock);
 
                         if (fl1 == NULL)
-                                fl1 = fl_lookup(freq.flr_label);
+                                fl1 = fl_lookup(net, freq.flr_label);
                         if (fl1) {
 recheck:
                                 err = -EEXIST;
@@ -559,7 +584,7 @@ release:
                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
                         goto done;
 
-                fl1 = fl_intern(fl, freq.flr_label);
+                fl1 = fl_intern(net, fl, freq.flr_label);
                 if (fl1 != NULL)
                         goto recheck;
 
@@ -717,13 +742,28 @@ static inline void ip6_flowlabel_proc_fini(struct net *net)
 }
 #endif
 
+static inline void ip6_flowlabel_net_exit(struct net *net)
+{
+        ip6_fl_purge(net);
+}
+
+static struct pernet_operations ip6_flowlabel_net_ops = {
+        .exit = ip6_flowlabel_net_exit,
+};
+
 int ip6_flowlabel_init(void)
 {
+        int err;
+
+        err = register_pernet_subsys(&ip6_flowlabel_net_ops);
+        if (err)
+                return err;
         return ip6_flowlabel_proc_init(&init_net);
 }
 
 void ip6_flowlabel_cleanup(void)
 {
         del_timer(&ip6_fl_gc_timer);
+        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
         ip6_flowlabel_proc_fini(&init_net);
 }