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ip6mr: Make mroute_sk rcu-based

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In ipmr the mr_table socket is handled under RCU. Introduce the same
for ip6mr.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yuval Mintz 2018-02-28 23:29:30 +02:00 committed by David S. Miller
parent 6853f21f76
commit 8571ab479a
3 changed files with 31 additions and 22 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

6
include/linux/mroute6.h
View file

@ -111,12 +111,12 @@ extern int ip6mr_get_route(struct net *net, struct sk_buff *skb,
struct rtmsg *rtm, u32 portid); struct rtmsg *rtm, u32 portid);
#ifdef CONFIG_IPV6_MROUTE #ifdef CONFIG_IPV6_MROUTE
extern struct sock *mroute6_socket(struct net *net, struct sk_buff *skb); bool mroute6_is_socket(struct net *net, struct sk_buff *skb);
extern int ip6mr_sk_done(struct sock *sk); extern int ip6mr_sk_done(struct sock *sk);
#else #else
static inline struct sock *mroute6_socket(struct net *net, struct sk_buff *skb) static inline bool mroute6_is_socket(struct net *net, struct sk_buff *skb)
{ {
return NULL; return false;
} }
static inline int ip6mr_sk_done(struct sock *sk) static inline int ip6mr_sk_done(struct sock *sk)
{ {

2
net/ipv6/ip6_output.c
View file

@ -71,7 +71,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *
struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
((mroute6_socket(net, skb) && ((mroute6_is_socket(net, skb) &&
!(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
&ipv6_hdr(skb)->saddr))) { &ipv6_hdr(skb)->saddr))) {

45
net/ipv6/ip6mr.c
View file

@ -58,7 +58,7 @@ struct mr6_table {
struct list_head list; struct list_head list;
possible_net_t net; possible_net_t net;
u32 id; u32 id;
struct sock *mroute6_sk; struct sock __rcu *mroute6_sk;
struct timer_list ipmr_expire_timer; struct timer_list ipmr_expire_timer;
struct list_head mfc6_unres_queue; struct list_head mfc6_unres_queue;
struct list_head mfc6_cache_array[MFC6_LINES]; struct list_head mfc6_cache_array[MFC6_LINES];
@ -1121,6 +1121,7 @@ static void ip6mr_cache_resolve(struct net *net, struct mr6_table *mrt,
static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt, static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,
mifi_t mifi, int assert) mifi_t mifi, int assert)
{ {
struct sock *mroute6_sk;
struct sk_buff *skb; struct sk_buff *skb;
struct mrt6msg *msg; struct mrt6msg *msg;
int ret; int ret;
@ -1190,17 +1191,19 @@ static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,
skb->ip_summed = CHECKSUM_UNNECESSARY; skb->ip_summed = CHECKSUM_UNNECESSARY;
} }
if (!mrt->mroute6_sk) { rcu_read_lock();
mroute6_sk = rcu_dereference(mrt->mroute6_sk);
if (!mroute6_sk) {
rcu_read_unlock();
kfree_skb(skb); kfree_skb(skb);
return -EINVAL; return -EINVAL;
} }
mrt6msg_netlink_event(mrt, skb); mrt6msg_netlink_event(mrt, skb);
/* /* Deliver to user space multicast routing algorithms */
* Deliver to user space multicast routing algorithms ret = sock_queue_rcv_skb(mroute6_sk, skb);
*/ rcu_read_unlock();
ret = sock_queue_rcv_skb(mrt->mroute6_sk, skb);
if (ret < 0) { if (ret < 0) {
net_warn_ratelimited("mroute6: pending queue full, dropping entries\n"); net_warn_ratelimited("mroute6: pending queue full, dropping entries\n");
kfree_skb(skb); kfree_skb(skb);
@ -1584,11 +1587,11 @@ static int ip6mr_sk_init(struct mr6_table *mrt, struct sock *sk)
rtnl_lock(); rtnl_lock();
write_lock_bh(&mrt_lock); write_lock_bh(&mrt_lock);
if (likely(mrt->mroute6_sk == NULL)) { if (rtnl_dereference(mrt->mroute6_sk)) {
mrt->mroute6_sk = sk;
net->ipv6.devconf_all->mc_forwarding++;
} else {
err = -EADDRINUSE; err = -EADDRINUSE;
} else {
rcu_assign_pointer(mrt->mroute6_sk, sk);
net->ipv6.devconf_all->mc_forwarding++;
} }
write_unlock_bh(&mrt_lock); write_unlock_bh(&mrt_lock);
@ -1614,9 +1617,9 @@ int ip6mr_sk_done(struct sock *sk)
rtnl_lock(); rtnl_lock();
ip6mr_for_each_table(mrt, net) { ip6mr_for_each_table(mrt, net) {
if (sk == mrt->mroute6_sk) { if (sk == rtnl_dereference(mrt->mroute6_sk)) {
write_lock_bh(&mrt_lock); write_lock_bh(&mrt_lock);
mrt->mroute6_sk = NULL; RCU_INIT_POINTER(mrt->mroute6_sk, NULL);
net->ipv6.devconf_all->mc_forwarding--; net->ipv6.devconf_all->mc_forwarding--;
write_unlock_bh(&mrt_lock); write_unlock_bh(&mrt_lock);
inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
@ -1630,11 +1633,12 @@ int ip6mr_sk_done(struct sock *sk)
} }
} }
rtnl_unlock(); rtnl_unlock();
synchronize_rcu();
return err; return err;
} }
struct sock *mroute6_socket(struct net *net, struct sk_buff *skb) bool mroute6_is_socket(struct net *net, struct sk_buff *skb)
{ {
struct mr6_table *mrt; struct mr6_table *mrt;
struct flowi6 fl6 = { struct flowi6 fl6 = {
@ -1646,8 +1650,9 @@ struct sock *mroute6_socket(struct net *net, struct sk_buff *skb)
if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0) if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
return NULL; return NULL;
return mrt->mroute6_sk; return rcu_access_pointer(mrt->mroute6_sk);
} }
EXPORT_SYMBOL(mroute6_is_socket);
/* /*
* Socket options and virtual interface manipulation. The whole * Socket options and virtual interface manipulation. The whole
@ -1674,7 +1679,8 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
return -ENOENT; return -ENOENT;
if (optname != MRT6_INIT) { if (optname != MRT6_INIT) {
if (sk != mrt->mroute6_sk && !ns_capable(net->user_ns, CAP_NET_ADMIN)) if (sk != rcu_access_pointer(mrt->mroute6_sk) &&
!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EACCES; return -EACCES;
} }
@ -1696,7 +1702,8 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
if (vif.mif6c_mifi >= MAXMIFS) if (vif.mif6c_mifi >= MAXMIFS)
return -ENFILE; return -ENFILE;
rtnl_lock(); rtnl_lock();
ret = mif6_add(net, mrt, &vif, sk == mrt->mroute6_sk); ret = mif6_add(net, mrt, &vif,
sk == rtnl_dereference(mrt->mroute6_sk));
rtnl_unlock(); rtnl_unlock();
return ret; return ret;
@ -1731,7 +1738,9 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
ret = ip6mr_mfc_delete(mrt, &mfc, parent); ret = ip6mr_mfc_delete(mrt, &mfc, parent);
else else
ret = ip6mr_mfc_add(net, mrt, &mfc, ret = ip6mr_mfc_add(net, mrt, &mfc,
sk == mrt->mroute6_sk, parent); sk ==
rtnl_dereference(mrt->mroute6_sk),
parent);
rtnl_unlock(); rtnl_unlock();
return ret; return ret;
@ -1783,7 +1792,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
/* "pim6reg%u" should not exceed 16 bytes (IFNAMSIZ) */ /* "pim6reg%u" should not exceed 16 bytes (IFNAMSIZ) */
if (v != RT_TABLE_DEFAULT && v >= 100000000) if (v != RT_TABLE_DEFAULT && v >= 100000000)
return -EINVAL; return -EINVAL;
if (sk == mrt->mroute6_sk) if (sk == rcu_access_pointer(mrt->mroute6_sk))
return -EBUSY; return -EBUSY;
rtnl_lock(); rtnl_lock();