net/ipv4: factor out MCAST_MSFILTER getsockopt helpers

Factor out one helper each for getting the native and compat
version of the MCAST_MSFILTER option.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 95f4248c6fc5eda122360bad79bf3465e4b5f843..70d32c9476a2e314b0d1917388ca4d741004ca39 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1468,6 +1468,74 @@ static bool getsockopt_needs_rtnl(int optname)
        return false;
 }
 
+static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
+               int __user *optlen, int len)
+{
+       const int size0 = offsetof(struct group_filter, gf_slist);
+       struct group_filter __user *p = optval;
+       struct group_filter gsf;
+       int num;
+       int err;
+
+       if (len < size0)
+               return -EINVAL;
+       if (copy_from_user(&gsf, p, size0))
+               return -EFAULT;
+
+       num = gsf.gf_numsrc;
+       err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
+       if (err)
+               return err;
+       if (gsf.gf_numsrc < num)
+               num = gsf.gf_numsrc;
+       if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
+           copy_to_user(p, &gsf, size0))
+               return -EFAULT;
+       return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
+               int __user *optlen)
+{
+       const int size0 = offsetof(struct compat_group_filter, gf_slist);
+       struct compat_group_filter __user *p = optval;
+       struct compat_group_filter gf32;
+       struct group_filter gf;
+       int len, err;
+       int num;
+
+       if (get_user(len, optlen))
+               return -EFAULT;
+       if (len < size0)
+               return -EINVAL;
+
+       if (copy_from_user(&gf32, p, size0))
+               return -EFAULT;
+
+       gf.gf_interface = gf32.gf_interface;
+       gf.gf_fmode = gf32.gf_fmode;
+       num = gf.gf_numsrc = gf32.gf_numsrc;
+       gf.gf_group = gf32.gf_group;
+
+       rtnl_lock();
+       lock_sock(sk);
+       err = ip_mc_gsfget(sk, &gf, p->gf_slist);
+       release_sock(sk);
+       rtnl_unlock();
+       if (err)
+               return err;
+       if (gf.gf_numsrc < num)
+               num = gf.gf_numsrc;
+       len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
+       if (put_user(len, optlen) ||
+           put_user(gf.gf_fmode, &p->gf_fmode) ||
+           put_user(gf.gf_numsrc, &p->gf_numsrc))
+               return -EFAULT;
+       return 0;
+}
+#endif
+
 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
                            char __user *optval, int __user *optlen, unsigned int flags)
 {
@@ -1626,31 +1694,8 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
                goto out;
        }
        case MCAST_MSFILTER:
-       {
-               struct group_filter __user *p = (void __user *)optval;
-               struct group_filter gsf;
-               const int size0 = offsetof(struct group_filter, gf_slist);
-               int num;
-
-               if (len < size0) {
-                       err = -EINVAL;
-                       goto out;
-               }
-               if (copy_from_user(&gsf, p, size0)) {
-                       err = -EFAULT;
-                       goto out;
-               }
-               num = gsf.gf_numsrc;
-               err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
-               if (err)
-                       goto out;
-               if (gsf.gf_numsrc < num)
-                       num = gsf.gf_numsrc;
-               if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
-                   copy_to_user(p, &gsf, size0))
-                       err = -EFAULT;
+               err = ip_get_mcast_msfilter(sk, optval, optlen, len);
                goto out;
-       }
        case IP_MULTICAST_ALL:
                val = inet->mc_all;
                break;
@@ -1762,45 +1807,9 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
        int err;
 
        if (optname == MCAST_MSFILTER) {
-               const int size0 = offsetof(struct compat_group_filter, gf_slist);
-               struct compat_group_filter __user *p = (void __user *)optval;
-               struct compat_group_filter gf32;
-               struct group_filter gf;
-               int ulen, err;
-               int num;
-
                if (level != SOL_IP)
                        return -EOPNOTSUPP;
-
-               if (get_user(ulen, optlen))
-                       return -EFAULT;
-
-               if (ulen < size0)
-                       return -EINVAL;
-
-               if (copy_from_user(&gf32, p, size0))
-                       return -EFAULT;
-
-               gf.gf_interface = gf32.gf_interface;
-               gf.gf_fmode = gf32.gf_fmode;
-               num = gf.gf_numsrc = gf32.gf_numsrc;
-               gf.gf_group = gf32.gf_group;
-
-               rtnl_lock();
-               lock_sock(sk);
-               err = ip_mc_gsfget(sk, &gf, p->gf_slist);
-               release_sock(sk);
-               rtnl_unlock();
-               if (err)
-                       return err;
-               if (gf.gf_numsrc < num)
-                       num = gf.gf_numsrc;
-               ulen = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
-               if (put_user(ulen, optlen) ||
-                   put_user(gf.gf_fmode, &p->gf_fmode) ||
-                   put_user(gf.gf_numsrc, &p->gf_numsrc))
-                       return -EFAULT;
-               return 0;
+               return compat_ip_get_mcast_msfilter(sk, optval, optlen);
        }
 
        err = do_ip_getsockopt(sk, level, optname, optval, optlen,