netns: ipmr: declare counter cache_resolve_queue_len per-namespace

Preliminary work to make IPv4 multicast routing netns-aware.

Declare variable cache_resolve_queue_len per-namespace: move it into
struct netns_ipv4.

This variable counts the number of unresolved cache entries queued in the
list mfc_unres_queue. This list is kept global to all netns as the number
of entries per namespace is limited to 10 (hardcoded in routine
ipmr_cache_unresolved).
Entries belonging to different namespaces in mfc_unres_queue will be
identified by matching the mfc_net member introduced previously in
struct mfc_cache.

Keeping this list global to all netns, also allows us to keep a single
timer (ipmr_expire_timer) to handle their expiration.
In some places cache_resolve_queue_len value was tested for arming
or deleting the timer. These tests were equivalent to testing
mfc_unres_queue value instead and are replaced in this patch.

At the moment, cache_resolve_queue_len is only referenced in init_net.

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

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 0b4285ac29d45d1a799cc5e990d36439169ba99e..90b7cd20aa695fee8fc23b059d50065bc4a92621 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -60,6 +60,7 @@ struct netns_ipv4 {
        struct mfc_cache        **mfc_cache_array;
        struct vif_device       *vif_table;
        int                     maxvif;
+       atomic_t                cache_resolve_queue_len;
 #endif
 };
 #endif

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 35b868dd3bfdd7c78eaa324b05001790f5afc9f4..feafd14eb7b946050b82ec4d2cebf2a26e712170 100644 (file)
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -83,7 +83,6 @@ static int mroute_do_assert;                          /* Set in PIM assert    */
 static int mroute_do_pim;
 
 static struct mfc_cache *mfc_unres_queue;              /* Queue of unresolved entries */
-static atomic_t cache_resolve_queue_len;               /* Size of unresolved   */
 
 /* Special spinlock for queue of unresolved entries */
 static DEFINE_SPINLOCK(mfc_unres_lock);
@@ -340,7 +339,7 @@ static void ipmr_destroy_unres(struct mfc_cache *c)
        struct sk_buff *skb;
        struct nlmsgerr *e;
 
-       atomic_dec(&cache_resolve_queue_len);
+       atomic_dec(&init_net.ipv4.cache_resolve_queue_len);
 
        while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
                if (ip_hdr(skb)->version == 0) {
@@ -374,7 +373,7 @@ static void ipmr_expire_process(unsigned long dummy)
                return;
        }
 
-       if (atomic_read(&cache_resolve_queue_len) == 0)
+       if (mfc_unres_queue == NULL)
                goto out;
 
        now = jiffies;
@@ -395,7 +394,7 @@ static void ipmr_expire_process(unsigned long dummy)
                ipmr_destroy_unres(c);
        }
 
-       if (atomic_read(&cache_resolve_queue_len))
+       if (mfc_unres_queue != NULL)
                mod_timer(&ipmr_expire_timer, jiffies + expires);
 
 out:
@@ -690,7 +689,8 @@ ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
 
        spin_lock_bh(&mfc_unres_lock);
        for (c=mfc_unres_queue; c; c=c->next) {
-               if (c->mfc_mcastgrp == iph->daddr &&
+               if (net_eq(mfc_net(c), &init_net) &&
+                   c->mfc_mcastgrp == iph->daddr &&
                    c->mfc_origin == iph->saddr)
                        break;
        }
@@ -700,7 +700,7 @@ ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
                 *      Create a new entry if allowable
                 */
 
-               if (atomic_read(&cache_resolve_queue_len) >= 10 ||
+               if (atomic_read(&init_net.ipv4.cache_resolve_queue_len) >= 10 ||
                    (c = ipmr_cache_alloc_unres(&init_net)) == NULL) {
                        spin_unlock_bh(&mfc_unres_lock);
 
@@ -729,7 +729,7 @@ ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
                        return err;
                }
 
-               atomic_inc(&cache_resolve_queue_len);
+               atomic_inc(&init_net.ipv4.cache_resolve_queue_len);
                c->next = mfc_unres_queue;
                mfc_unres_queue = c;
 
@@ -827,14 +827,16 @@ static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
        spin_lock_bh(&mfc_unres_lock);
        for (cp = &mfc_unres_queue; (uc=*cp) != NULL;
             cp = &uc->next) {
-               if (uc->mfc_origin == c->mfc_origin &&
+               if (net_eq(mfc_net(uc), &init_net) &&
+                   uc->mfc_origin == c->mfc_origin &&
                    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
                        *cp = uc->next;
-                       if (atomic_dec_and_test(&cache_resolve_queue_len))
-                               del_timer(&ipmr_expire_timer);
+                       atomic_dec(&init_net.ipv4.cache_resolve_queue_len);
                        break;
                }
        }
+       if (mfc_unres_queue == NULL)
+               del_timer(&ipmr_expire_timer);
        spin_unlock_bh(&mfc_unres_lock);
 
        if (uc) {
@@ -880,18 +882,19 @@ static void mroute_clean_tables(struct sock *sk)
                }
        }
 
-       if (atomic_read(&cache_resolve_queue_len) != 0) {
-               struct mfc_cache *c;
+       if (atomic_read(&init_net.ipv4.cache_resolve_queue_len) != 0) {
+               struct mfc_cache *c, **cp;
 
                spin_lock_bh(&mfc_unres_lock);
-               while (mfc_unres_queue != NULL) {
-                       c = mfc_unres_queue;
-                       mfc_unres_queue = c->next;
-                       spin_unlock_bh(&mfc_unres_lock);
+               cp = &mfc_unres_queue;
+               while ((c = *cp) != NULL) {
+                       if (!net_eq(mfc_net(c), &init_net)) {
+                               cp = &c->next;
+                               continue;
+                       }
+                       *cp = c->next;
 
                        ipmr_destroy_unres(c);
-
-                       spin_lock_bh(&mfc_unres_lock);
                }
                spin_unlock_bh(&mfc_unres_lock);
        }