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>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index edbcccb..0b4285a 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -57,6 +57,7 @@ struct netns_ipv4 {
 
 #ifdef CONFIG_IP_MROUTE
        struct sock             *mroute_sk;
+       struct mfc_cache        **mfc_cache_array;
        struct vif_device       *vif_table;
        int                     maxvif;
 #endif

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 8428a0f..35b868d 100644 (file)
--- 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);
 }