net: ipmr: rearrange and cleanup setsockopt
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 <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 50aec31..e384f39 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1276,38 +1276,45 @@
* 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 net *net = sock_net(sk);
+ int val, ret = 0, parent = 0;
+ struct mr_table *mrt;
struct vifctl vif;
struct mfcctl mfc;
- struct net *net = sock_net(sk);
- struct mr_table *mrt;
+ 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 @@
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;
/* Manipulate the forwarding caches. These live
* in a sort of kernel/user symbiosis.
*/
@@ -1349,82 +1367,87 @@
parent = -1;
case MRT_ADD_MFC_PROXY:
case MRT_DEL_MFC_PROXY:
- if (optlen != sizeof(mfc))
- return -EINVAL;
- if (copy_from_user(&mfc, optval, sizeof(mfc)))
- return -EFAULT;
+ if (optlen != sizeof(mfc)) {
+ ret = -EINVAL;
+ break;
+ }
+ if (copy_from_user(&mfc, optval, sizeof(mfc))) {
+ ret = -EFAULT;
+ break;
+ }
if (parent == 0)
parent = mfc.mfcc_parent;
- rtnl_lock();
if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
ret = ipmr_mfc_delete(mrt, &mfc, parent);
else
ret = ipmr_mfc_add(net, mrt, &mfc,
sk == rtnl_dereference(mrt->mroute_sk),
parent);
- rtnl_unlock();
- return ret;
+ break;
/* Control PIM assert. */
case MRT_ASSERT:
- {
- int v;
- if (optlen != sizeof(v))
- return -EINVAL;
- if (get_user(v, (int __user *)optval))
- return -EFAULT;
- mrt->mroute_do_assert = v;
- return 0;
- }
- case MRT_PIM:
- {
- int v;
-
- if (!pimsm_enabled())
- return -ENOPROTOOPT;
- if (optlen != sizeof(v))
- return -EINVAL;
- if (get_user(v, (int __user *)optval))
- return -EFAULT;
- v = !!v;
-
- rtnl_lock();
- ret = 0;
- if (v != mrt->mroute_do_pim) {
- mrt->mroute_do_pim = v;
- mrt->mroute_do_assert = v;
+ if (optlen != sizeof(val)) {
+ ret = -EINVAL;
+ break;
}
- rtnl_unlock();
- return ret;
- }
+ if (get_user(val, (int __user *)optval)) {
+ ret = -EFAULT;
+ break;
+ }
+ mrt->mroute_do_assert = val;
+ break;
+ case MRT_PIM:
+ if (!pimsm_enabled()) {
+ ret = -ENOPROTOOPT;
+ break;
+ }
+ if (optlen != sizeof(val)) {
+ ret = -EINVAL;
+ break;
+ }
+ if (get_user(val, (int __user *)optval)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ val = !!val;
+ if (val != mrt->mroute_do_pim) {
+ mrt->mroute_do_pim = val;
+ mrt->mroute_do_assert = val;
+ }
+ break;
case MRT_TABLE:
- {
- u32 v;
+ if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
+ ret = -ENOPROTOOPT;
+ break;
+ }
+ if (optlen != sizeof(uval)) {
+ ret = -EINVAL;
+ break;
+ }
+ if (get_user(uval, (u32 __user *)optval)) {
+ ret = -EFAULT;
+ break;
+ }
- if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES))
- return -ENOPROTOOPT;
- if (optlen != sizeof(u32))
- return -EINVAL;
- if (get_user(v, (u32 __user *)optval))
- return -EFAULT;
-
- rtnl_lock();
- ret = 0;
if (sk == rtnl_dereference(mrt->mroute_sk)) {
ret = -EBUSY;
} else {
- mrt = ipmr_new_table(net, v);
+ mrt = ipmr_new_table(net, uval);
if (IS_ERR(mrt))
ret = PTR_ERR(mrt);
else
- raw_sk(sk)->ipmr_table = v;
+ raw_sk(sk)->ipmr_table = uval;
}
- rtnl_unlock();
- return ret;
- }
+ break;
/* Spurious command, or MRT_VERSION which you cannot set. */
default:
- return -ENOPROTOOPT;
+ ret = -ENOPROTOOPT;
}
+out_unlock:
+ rtnl_unlock();
+out:
+ return ret;
}
/* Getsock opt support for the multicast routing system. */