get rid of compat_mc_getsockopt()

now we can do MCAST_MSFILTER in compat ->getsockopt() without
playing silly buggers with copying things back and forth.
We can form a native struct group_filter (sans the variable-length
tail) on stack, pass that + pointer to the tail of original request
to the helper doing the bulk of the work, then do the rest of
copyout - same as the native getsockopt() does.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/net/compat.h b/include/net/compat.h
index 69a8cd2..d714076 100644 (file)
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -70,9 +70,6 @@ int cmsghdr_from_user_compat_to_kern(struct msghdr *, struct sock *,
 int compat_mc_setsockopt(struct sock *, int, int, char __user *, unsigned int,
                         int (*)(struct sock *, int, int, char __user *,
                                 unsigned int));
-int compat_mc_getsockopt(struct sock *, int, int, char __user *, int __user *,
-                        int (*)(struct sock *, int, int, char __user *,
-                                int __user *));
 
 struct compat_group_req {
        __u32                            gr_interface;

diff --git a/net/compat.c b/net/compat.c
index 032114d..7bdfda2 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -538,85 +538,6 @@ int compat_mc_setsockopt(struct sock *sock, int level, int optname,
 }
 EXPORT_SYMBOL(compat_mc_setsockopt);
 
-int compat_mc_getsockopt(struct sock *sock, int level, int optname,
-       char __user *optval, int __user *optlen,
-       int (*getsockopt)(struct sock *, int, int, char __user *, int __user *))
-{
-       struct compat_group_filter __user *gf32 = (void __user *)optval;
-       struct group_filter __user *kgf;
-       int __user      *koptlen;
-       u32 interface, fmode, numsrc;
-       int klen, ulen, err;
-
-       if (optname != MCAST_MSFILTER)
-               return getsockopt(sock, level, optname, optval, optlen);
-
-       koptlen = compat_alloc_user_space(sizeof(*koptlen));
-       if (!access_ok(optlen, sizeof(*optlen)) ||
-           __get_user(ulen, optlen))
-               return -EFAULT;
-
-       /* adjust len for pad */
-       klen = ulen + sizeof(*kgf) - sizeof(*gf32);
-
-       if (klen < GROUP_FILTER_SIZE(0))
-               return -EINVAL;
-
-       if (!access_ok(koptlen, sizeof(*koptlen)) ||
-           __put_user(klen, koptlen))
-               return -EFAULT;
-
-       /* have to allow space for previous compat_alloc_user_space, too */
-       kgf = compat_alloc_user_space(klen+sizeof(*optlen));
-
-       if (!access_ok(gf32, __COMPAT_GF0_SIZE) ||
-           __get_user(interface, &gf32->gf_interface) ||
-           __get_user(fmode, &gf32->gf_fmode) ||
-           __get_user(numsrc, &gf32->gf_numsrc) ||
-           __put_user(interface, &kgf->gf_interface) ||
-           __put_user(fmode, &kgf->gf_fmode) ||
-           __put_user(numsrc, &kgf->gf_numsrc) ||
-           copy_in_user(&kgf->gf_group, &gf32->gf_group, sizeof(kgf->gf_group)))
-               return -EFAULT;
-
-       err = getsockopt(sock, level, optname, (char __user *)kgf, koptlen);
-       if (err)
-               return err;
-
-       if (!access_ok(koptlen, sizeof(*koptlen)) ||
-           __get_user(klen, koptlen))
-               return -EFAULT;
-
-       ulen = klen - (sizeof(*kgf)-sizeof(*gf32));
-
-       if (!access_ok(optlen, sizeof(*optlen)) ||
-           __put_user(ulen, optlen))
-               return -EFAULT;
-
-       if (!access_ok(kgf, klen) ||
-           !access_ok(gf32, ulen) ||
-           __get_user(interface, &kgf->gf_interface) ||
-           __get_user(fmode, &kgf->gf_fmode) ||
-           __get_user(numsrc, &kgf->gf_numsrc) ||
-           __put_user(interface, &gf32->gf_interface) ||
-           __put_user(fmode, &gf32->gf_fmode) ||
-           __put_user(numsrc, &gf32->gf_numsrc))
-               return -EFAULT;
-       if (numsrc) {
-               int copylen;
-
-               klen -= GROUP_FILTER_SIZE(0);
-               copylen = numsrc * sizeof(gf32->gf_slist[0]);
-               if (copylen > klen)
-                       copylen = klen;
-               if (copy_in_user(gf32->gf_slist, kgf->gf_slist, copylen))
-                       return -EFAULT;
-       }
-       return err;
-}
-EXPORT_SYMBOL(compat_mc_getsockopt);
-
-
 /* Argument list sizes for compat_sys_socketcall */
 #define AL(x) ((x) * sizeof(u32))
 static unsigned char nas[21] = {

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index e3703a3..65a30e7 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1607,9 +1607,47 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 {
        int err;
 
-       if (optname == MCAST_MSFILTER)
-               return compat_mc_getsockopt(sk, level, optname, optval, optlen,
-                       ip_getsockopt);
+       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;
+       }
 
        err = do_ip_getsockopt(sk, level, optname, optval, optlen,
                MSG_CMSG_COMPAT);

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index e4a62ca..0bbafe7 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1446,9 +1446,44 @@ int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
        if (level != SOL_IPV6)
                return -ENOPROTOOPT;
 
-       if (optname == MCAST_MSFILTER)
-               return compat_mc_getsockopt(sk, level, optname, optval, optlen,
-                       ipv6_getsockopt);
+       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 (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;
+
+               if (gf.gf_group.ss_family != AF_INET6)
+                       return -EADDRNOTAVAIL;
+               lock_sock(sk);
+               err = ip6_mc_msfget(sk, &gf, p->gf_slist);
+               release_sock(sk);
+               if (err)
+                       return err;
+               if (num > gf.gf_numsrc)
+                       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;
+       }
 
        err = do_ipv6_getsockopt(sk, level, optname, optval, optlen,
                                 MSG_CMSG_COMPAT);