netns: ipmr: dynamically allocate vif_table

Preliminary work to make IPv6 multicast routing netns-aware.

Dynamically allocate interface table vif_table and move it to
struct netns_ipv4, and update MIF_EXISTS() macro.

At the moment, vif_table is only referenced in init_net.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 70 insertions, 41 deletions

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 4f00722c7478..edbcccbbc318 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -57,6 +57,8 @@ struct netns_ipv4 {
 
 #ifdef CONFIG_IP_MROUTE
         struct sock             *mroute_sk;
+        struct vif_device       *vif_table;
+        int                     maxvif;
 #endif
 };
 #endif
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index ac324b702e8b..75a5f79cc226 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -77,10 +77,7 @@ static DEFINE_RWLOCK(mrt_lock);
  *      Multicast router control variables
  */
 
-static struct vif_device vif_table[MAXVIFS];            /* Devices              */
-static int maxvif;
-
-#define VIF_EXISTS(idx) (vif_table[idx].dev != NULL)
+#define VIF_EXISTS(_net, _idx) ((_net)->ipv4.vif_table[_idx].dev != NULL)
 
 static int mroute_do_assert;                            /* Set in PIM assert    */
 static int mroute_do_pim;
@@ -286,10 +283,10 @@ static int vif_delete(int vifi, int notify)
         struct net_device *dev;
         struct in_device *in_dev;
 
-        if (vifi < 0 || vifi >= maxvif)
+        if (vifi < 0 || vifi >= init_net.ipv4.maxvif)
                 return -EADDRNOTAVAIL;
 
-        v = &vif_table[vifi];
+        v = &init_net.ipv4.vif_table[vifi];
 
         write_lock_bh(&mrt_lock);
         dev = v->dev;
@@ -305,13 +302,13 @@ static int vif_delete(int vifi, int notify)
                 reg_vif_num = -1;
 #endif
 
-        if (vifi+1 == maxvif) {
+        if (vifi+1 == init_net.ipv4.maxvif) {
                 int tmp;
                 for (tmp=vifi-1; tmp>=0; tmp--) {
-                        if (VIF_EXISTS(tmp))
+                        if (VIF_EXISTS(&init_net, tmp))
                                 break;
                 }
-                maxvif = tmp+1;
+                init_net.ipv4.maxvif = tmp+1;
         }
 
         write_unlock_bh(&mrt_lock);
@@ -411,8 +408,9 @@ static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls)
         cache->mfc_un.res.maxvif = 0;
         memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 
-        for (vifi=0; vifi<maxvif; vifi++) {
-                if (VIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) {
+        for (vifi = 0; vifi < init_net.ipv4.maxvif; vifi++) {
+                if (VIF_EXISTS(&init_net, vifi) &&
+                    ttls[vifi] && ttls[vifi] < 255) {
                         cache->mfc_un.res.ttls[vifi] = ttls[vifi];
                         if (cache->mfc_un.res.minvif > vifi)
                                 cache->mfc_un.res.minvif = vifi;
@@ -425,13 +423,13 @@ static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls)
 static int vif_add(struct vifctl *vifc, int mrtsock)
 {
         int vifi = vifc->vifc_vifi;
-        struct vif_device *v = &vif_table[vifi];
+        struct vif_device *v = &init_net.ipv4.vif_table[vifi];
         struct net_device *dev;
         struct in_device *in_dev;
         int err;
 
         /* Is vif busy ? */
-        if (VIF_EXISTS(vifi))
+        if (VIF_EXISTS(&init_net, vifi))
                 return -EADDRINUSE;
 
         switch (vifc->vifc_flags) {
@@ -509,8 +507,8 @@ static int vif_add(struct vifctl *vifc, int mrtsock)
         if (v->flags&VIFF_REGISTER)
                 reg_vif_num = vifi;
 #endif
-        if (vifi+1 > maxvif)
-                maxvif = vifi+1;
+        if (vifi+1 > init_net.ipv4.maxvif)
+                init_net.ipv4.maxvif = vifi+1;
         write_unlock_bh(&mrt_lock);
         return 0;
 }
@@ -849,8 +847,8 @@ static void mroute_clean_tables(struct sock *sk)
         /*
          *      Shut down all active vif entries
          */
-        for (i=0; i<maxvif; i++) {
-                if (!(vif_table[i].flags&VIFF_STATIC))
+        for (i = 0; i < init_net.ipv4.maxvif; i++) {
+                if (!(init_net.ipv4.vif_table[i].flags&VIFF_STATIC))
                         vif_delete(i, 0);
         }
 
@@ -1088,11 +1086,11 @@ int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
         case SIOCGETVIFCNT:
                 if (copy_from_user(&vr, arg, sizeof(vr)))
                         return -EFAULT;
-                if (vr.vifi >= maxvif)
+                if (vr.vifi >= init_net.ipv4.maxvif)
                         return -EINVAL;
                 read_lock(&mrt_lock);
-                vif=&vif_table[vr.vifi];
-                if (VIF_EXISTS(vr.vifi))        {
+                vif = &init_net.ipv4.vif_table[vr.vifi];
+                if (VIF_EXISTS(&init_net, vr.vifi)) {
                         vr.icount = vif->pkt_in;
                         vr.ocount = vif->pkt_out;
                         vr.ibytes = vif->bytes_in;
@@ -1140,8 +1138,8 @@ static int ipmr_device_event(struct notifier_block *this, unsigned long event, v
 
         if (event != NETDEV_UNREGISTER)
                 return NOTIFY_DONE;
-        v=&vif_table[0];
-        for (ct=0; ct<maxvif; ct++,v++) {
+        v = &init_net.ipv4.vif_table[0];
+        for (ct = 0; ct < init_net.ipv4.maxvif; ct++, v++) {
                 if (v->dev == dev)
                         vif_delete(ct, 1);
         }
@@ -1204,7 +1202,7 @@ static inline int ipmr_forward_finish(struct sk_buff *skb)
 static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi)
 {
         const struct iphdr *iph = ip_hdr(skb);
-        struct vif_device *vif = &vif_table[vifi];
+        struct vif_device *vif = &init_net.ipv4.vif_table[vifi];
         struct net_device *dev;
         struct rtable *rt;
         int    encap = 0;
@@ -1305,8 +1303,8 @@ out_free:
 static int ipmr_find_vif(struct net_device *dev)
 {
         int ct;
-        for (ct=maxvif-1; ct>=0; ct--) {
-                if (vif_table[ct].dev == dev)
+        for (ct = init_net.ipv4.maxvif-1; ct >= 0; ct--) {
+                if (init_net.ipv4.vif_table[ct].dev == dev)
                         break;
         }
         return ct;
@@ -1326,7 +1324,7 @@ static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local
         /*
          * Wrong interface: drop packet and (maybe) send PIM assert.
          */
-        if (vif_table[vif].dev != skb->dev) {
+        if (init_net.ipv4.vif_table[vif].dev != skb->dev) {
                 int true_vifi;
 
                 if (skb->rtable->fl.iif == 0) {
@@ -1362,8 +1360,8 @@ static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local
                 goto dont_forward;
         }
 
-        vif_table[vif].pkt_in++;
-        vif_table[vif].bytes_in += skb->len;
+        init_net.ipv4.vif_table[vif].pkt_in++;
+        init_net.ipv4.vif_table[vif].bytes_in += skb->len;
 
         /*
          *      Forward the frame
@@ -1500,7 +1498,7 @@ static int __pim_rcv(struct sk_buff *skb, unsigned int pimlen)
 
         read_lock(&mrt_lock);
         if (reg_vif_num >= 0)
-                reg_dev = vif_table[reg_vif_num].dev;
+                reg_dev = init_net.ipv4.vif_table[reg_vif_num].dev;
         if (reg_dev)
                 dev_hold(reg_dev);
         read_unlock(&mrt_lock);
@@ -1581,7 +1579,7 @@ ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm)
 {
         int ct;
         struct rtnexthop *nhp;
-        struct net_device *dev = vif_table[c->mfc_parent].dev;
+        struct net_device *dev = init_net.ipv4.vif_table[c->mfc_parent].dev;
         u8 *b = skb_tail_pointer(skb);
         struct rtattr *mp_head;
 
@@ -1597,7 +1595,7 @@ ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm)
                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
                         nhp->rtnh_flags = 0;
                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
-                        nhp->rtnh_ifindex = vif_table[ct].dev->ifindex;
+                        nhp->rtnh_ifindex = init_net.ipv4.vif_table[ct].dev->ifindex;
                         nhp->rtnh_len = sizeof(*nhp);
                 }
         }
@@ -1672,11 +1670,11 @@ struct ipmr_vif_iter {
 static struct vif_device *ipmr_vif_seq_idx(struct ipmr_vif_iter *iter,
                                            loff_t pos)
 {
-        for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) {
-                if (!VIF_EXISTS(iter->ct))
+        for (iter->ct = 0; iter->ct < init_net.ipv4.maxvif; ++iter->ct) {
+                if (!VIF_EXISTS(&init_net, iter->ct))
                         continue;
                 if (pos-- == 0)
-                        return &vif_table[iter->ct];
+                        return &init_net.ipv4.vif_table[iter->ct];
         }
         return NULL;
 }
@@ -1697,10 +1695,10 @@ static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
         if (v == SEQ_START_TOKEN)
                 return ipmr_vif_seq_idx(iter, 0);
 
-        while (++iter->ct < maxvif) {
-                if (!VIF_EXISTS(iter->ct))
+        while (++iter->ct < init_net.ipv4.maxvif) {
+                if (!VIF_EXISTS(&init_net, iter->ct))
                         continue;
-                return &vif_table[iter->ct];
+                return &init_net.ipv4.vif_table[iter->ct];
         }
         return NULL;
 }
@@ -1722,7 +1720,7 @@ static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
 
                 seq_printf(seq,
                            "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
-                           vif - vif_table,
+                           vif - init_net.ipv4.vif_table,
                            name, vif->bytes_in, vif->pkt_in,
                            vif->bytes_out, vif->pkt_out,
                            vif->flags, vif->local, vif->remote);
@@ -1864,9 +1862,9 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
                                    mfc->mfc_un.res.wrong_if);
                         for (n = mfc->mfc_un.res.minvif;
                              n < mfc->mfc_un.res.maxvif; n++ ) {
-                                if (VIF_EXISTS(n)
-                                   && mfc->mfc_un.res.ttls[n] < 255)
-                                seq_printf(seq,
+                                if (VIF_EXISTS(&init_net, n) &&
+                                    mfc->mfc_un.res.ttls[n] < 255)
+                                        seq_printf(seq,
                                            " %2d:%-3d",
                                            n, mfc->mfc_un.res.ttls[n]);
                         }
@@ -1913,6 +1911,29 @@ static struct net_protocol pim_protocol = {
 /*
  *      Setup for IP multicast routing
  */
+static int __net_init ipmr_net_init(struct net *net)
+{
+        int err = 0;
+
+        net->ipv4.vif_table = kcalloc(MAXVIFS, sizeof(struct vif_device),
+                                      GFP_KERNEL);
+        if (!net->ipv4.vif_table) {
+                err = -ENOMEM;
+                goto fail;
+        }
+fail:
+        return err;
+}
+
+static void __net_exit ipmr_net_exit(struct net *net)
+{
+        kfree(net->ipv4.vif_table);
+}
+
+static struct pernet_operations ipmr_net_ops = {
+        .init = ipmr_net_init,
+        .exit = ipmr_net_exit,
+};
 
 int __init ip_mr_init(void)
 {
@@ -1925,6 +1946,10 @@ int __init ip_mr_init(void)
         if (!mrt_cachep)
                 return -ENOMEM;
 
+        err = register_pernet_subsys(&ipmr_net_ops);
+        if (err)
+                goto reg_pernet_fail;
+
         setup_timer(&ipmr_expire_timer, ipmr_expire_process, 0);
         err = register_netdevice_notifier(&ip_mr_notifier);
         if (err)
@@ -1945,6 +1970,8 @@ proc_vif_fail:
 #endif
 reg_notif_fail:
         del_timer(&ipmr_expire_timer);
+        unregister_pernet_subsys(&ipmr_net_ops);
+reg_pernet_fail:
         kmem_cache_destroy(mrt_cachep);
         return err;
 }