netns: ipmr: dynamically allocate mfc_cache_array

Preliminary work to make IPv4 multicast routing netns-aware.

Dynamically allocate IPv4 multicast forwarding cache, mfc_cache_array,
and move it to struct netns_ipv4.

At the moment, mfc_cache_array is only referenced in init_net.

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

1 files changed, 28 insertions, 13 deletions

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 8428a0fb5c10..35b868dd3bfd 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -82,8 +82,6 @@ static DEFINE_RWLOCK(mrt_lock);
 static int mroute_do_assert;                            /* Set in PIM assert    */
 static int mroute_do_pim;
 
-static struct mfc_cache *mfc_cache_array[MFC_LINES];    /* Forwarding cache     */
-
 static struct mfc_cache *mfc_unres_queue;               /* Queue of unresolved entries */
 static atomic_t cache_resolve_queue_len;                /* Size of unresolved   */
 
@@ -524,7 +522,7 @@ static struct mfc_cache *ipmr_cache_find(__be32 origin, __be32 mcastgrp)
         int line = MFC_HASH(mcastgrp, origin);
         struct mfc_cache *c;
 
-        for (c=mfc_cache_array[line]; c; c = c->next) {
+        for (c = init_net.ipv4.mfc_cache_array[line]; c; c = c->next) {
                 if (c->mfc_origin==origin && c->mfc_mcastgrp==mcastgrp)
                         break;
         }
@@ -764,7 +762,8 @@ static int ipmr_mfc_delete(struct mfcctl *mfc)
 
         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
 
-        for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
+        for (cp = &init_net.ipv4.mfc_cache_array[line];
+             (c = *cp) != NULL; cp = &c->next) {
                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
                         write_lock_bh(&mrt_lock);
@@ -785,7 +784,8 @@ static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
 
         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
 
-        for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
+        for (cp = &init_net.ipv4.mfc_cache_array[line];
+             (c = *cp) != NULL; cp = &c->next) {
                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr)
                         break;
@@ -816,8 +816,8 @@ static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
                 c->mfc_flags |= MFC_STATIC;
 
         write_lock_bh(&mrt_lock);
-        c->next = mfc_cache_array[line];
-        mfc_cache_array[line] = c;
+        c->next = init_net.ipv4.mfc_cache_array[line];
+        init_net.ipv4.mfc_cache_array[line] = c;
         write_unlock_bh(&mrt_lock);
 
         /*
@@ -866,7 +866,7 @@ static void mroute_clean_tables(struct sock *sk)
         for (i=0; i<MFC_LINES; i++) {
                 struct mfc_cache *c, **cp;
 
-                cp = &mfc_cache_array[i];
+                cp = &init_net.ipv4.mfc_cache_array[i];
                 while ((c = *cp) != NULL) {
                         if (c->mfc_flags&MFC_STATIC) {
                                 cp = &c->next;
@@ -1767,10 +1767,11 @@ static struct mfc_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos)
 {
         struct mfc_cache *mfc;
 
-        it->cache = mfc_cache_array;
+        it->cache = init_net.ipv4.mfc_cache_array;
         read_lock(&mrt_lock);
         for (it->ct = 0; it->ct < MFC_LINES; it->ct++)
-                for (mfc = mfc_cache_array[it->ct]; mfc; mfc = mfc->next)
+                for (mfc = init_net.ipv4.mfc_cache_array[it->ct];
+                     mfc; mfc = mfc->next)
                         if (pos-- == 0)
                                 return mfc;
         read_unlock(&mrt_lock);
@@ -1812,10 +1813,10 @@ static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
         if (it->cache == &mfc_unres_queue)
                 goto end_of_list;
 
-        BUG_ON(it->cache != mfc_cache_array);
+        BUG_ON(it->cache != init_net.ipv4.mfc_cache_array);
 
         while (++it->ct < MFC_LINES) {
-                mfc = mfc_cache_array[it->ct];
+                mfc = init_net.ipv4.mfc_cache_array[it->ct];
                 if (mfc)
                         return mfc;
         }
@@ -1843,7 +1844,7 @@ static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
 
         if (it->cache == &mfc_unres_queue)
                 spin_unlock_bh(&mfc_unres_lock);
-        else if (it->cache == mfc_cache_array)
+        else if (it->cache == init_net.ipv4.mfc_cache_array)
                 read_unlock(&mrt_lock);
 }
 
@@ -1929,12 +1930,26 @@ static int __net_init ipmr_net_init(struct net *net)
                 err = -ENOMEM;
                 goto fail;
         }
+
+        /* Forwarding cache */
+        net->ipv4.mfc_cache_array = kcalloc(MFC_LINES,
+                                            sizeof(struct mfc_cache *),
+                                            GFP_KERNEL);
+        if (!net->ipv4.mfc_cache_array) {
+                err = -ENOMEM;
+                goto fail_mfc_cache;
+        }
+        return 0;
+
+fail_mfc_cache:
+        kfree(net->ipv4.vif_table);
 fail:
         return err;
 }
 
 static void __net_exit ipmr_net_exit(struct net *net)
 {
+        kfree(net->ipv4.mfc_cache_array);
         kfree(net->ipv4.vif_table);
 }