From: Nikolay Aleksandrov
Take rtnl in the beginning unconditionally as most options already need
it (one exception - MRT_DONE, see the comment inside), make the
lock/unlock places central and move out the switch() local variables.
Signed-off-by: Nikolay Aleksandrov
---
net/ipv4/ipmr.c | 191 +++-
1 file changed, 107 insertions(+), 84 deletions(-)
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 50aec313119d..e384f39202cb 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1276,38 +1276,45 @@ static void mrtsock_destruct(struct sock *sk)
* MOSPF/PIM router set up we can clean this up.
*/
-int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
unsigned int optlen)
+int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
+unsigned int optlen)
{
- int ret, parent = 0;
- struct vifctl vif;
- struct mfcctl mfc;
struct net *net = sock_net(sk);
+ int val, ret = 0, parent = 0;
struct mr_table *mrt;
+ struct vifctl vif;
+ struct mfcctl mfc;
+ u32 uval;
+ /* There's one exception to the lock - MRT_DONE which needs to unlock */
+ rtnl_lock();
if (sk->sk_type != SOCK_RAW ||
- inet_sk(sk)->inet_num != IPPROTO_IGMP)
- return -EOPNOTSUPP;
+ inet_sk(sk)->inet_num != IPPROTO_IGMP) {
+ ret = -EOPNOTSUPP;
+ goto out_unlock;
+ }
mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
- if (!mrt)
- return -ENOENT;
-
+ if (!mrt) {
+ ret = -ENOENT;
+ goto out_unlock;
+ }
if (optname != MRT_INIT) {
if (sk != rcu_access_pointer(mrt->mroute_sk) &&
- !ns_capable(net->user_ns, CAP_NET_ADMIN))
- return -EACCES;
+ !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
+ ret = -EACCES;
+ goto out_unlock;
+ }
}
switch (optname) {
case MRT_INIT:
if (optlen != sizeof(int))
- return -EINVAL;
-
- rtnl_lock();
- if (rtnl_dereference(mrt->mroute_sk)) {
- rtnl_unlock();
- return -EADDRINUSE;
- }
+ ret = -EINVAL;
+ if (rtnl_dereference(mrt->mroute_sk))
+ ret = -EADDRINUSE;
+ if (ret)
+ break;
ret = ip_ra_control(sk, 1, mrtsock_destruct);
if (ret == 0) {
@@ -1317,30 +1324,41 @@ int ip_mroute_setsockopt(struct sock *sk, int optname,
char __user *optval, unsi
NETCONFA_IFINDEX_ALL,
net->ipv4.devconf_all);
}
- rtnl_unlock();
- return ret;
+ break;
case MRT_DONE:
- if (sk != rcu_access_pointer(mrt->mroute_sk))
- return -EACCES;
- return ip_ra_control(sk, 0, NULL);
+ if (sk != rcu_access_pointer(mrt->mroute_sk)) {
+ ret = -EACCES;
+ } else {
+ /* We need to unlock here because mrtsock_destruct takes
+* care of rtnl itself and we can't change that due to
+* the IP_ROUTER_ALERT setsockopt which runs without it.
+*/
+ rtnl_unlock();
+ ret = ip_ra_control(sk, 0, NULL);
+ goto out;
+ }
+ break;
case MRT_ADD_VIF:
case MRT_DEL_VIF:
- if (optlen != sizeof(vif))
- return -EINVAL;
- if (copy_from_user(&vif, optval, sizeof(vif)))
- return -EFAULT;
- if (vif.vifc_vifi >= MAXVIFS)
- return -ENFILE;
- rtnl_lock();
+ if (optlen != sizeof(vif)) {
+ ret = -EINVAL;
+ break;
+ }
+ if (copy_from_user(&vif, optval, sizeof(vif))) {
+ ret = -EFAULT;
+ break;
+ }
+ if (vif.vifc_vifi >= MAXVIFS) {
+ ret = -ENFILE;
+ break;
+ }
if (optname == MRT_ADD_VIF) {
ret = vif_add(net, mrt, &vif,
sk == rtnl_dereference(mrt->mroute_sk));
} else {
ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
}
- rtnl_unlock();
- return ret;
-
+ break;
/* Manipula