[PATCH net-next 12/19] handle the group_source_req options directly

From: Al Viro
Date: Wed May 20 2020 - 20:38:04 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Native ->setsockopt() handling of these options (MCAST_..._SOURCE_GROUP
and MCAST_{,UN}BLOCK_SOURCE) consists of copyin + call of a helper that
does the actual work. The only change needed for ->compat_setsockopt()
is a slightly different copyin - the helpers can be reused as-is.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
net/ipv4/ip_sockglue.c | 23 +++++++++++++++++++++--
net/ipv6/ipv6_sockglue.c | 23 +++++++++++++++++++++--
2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 7f065a68664e..a2469bc57cfe 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1322,8 +1322,27 @@ int compat_ip_setsockopt(struct sock *sk, int level, int optname,
case MCAST_LEAVE_SOURCE_GROUP:
case MCAST_BLOCK_SOURCE:
case MCAST_UNBLOCK_SOURCE:
- return compat_mc_setsockopt(sk, level, optname, optval, optlen,
- ip_setsockopt);
+ {
+ struct compat_group_source_req __user *gsr32 = (void __user *)optval;
+ struct group_source_req greqs;
+
+ if (optlen != sizeof(struct compat_group_source_req))
+ return -EINVAL;
+
+ if (get_user(greqs.gsr_interface, &gsr32->gsr_interface) ||
+ copy_from_user(&greqs.gsr_group, &gsr32->gsr_group,
+ sizeof(greqs.gsr_group)) ||
+ copy_from_user(&greqs.gsr_source, &gsr32->gsr_source,
+ sizeof(greqs.gsr_source)))
+ return -EFAULT;
+
+ rtnl_lock();
+ lock_sock(sk);
+ err = do_mcast_group_source(sk, optname, &greqs);
+ release_sock(sk);
+ rtnl_unlock();
+ return err;
+ }
case MCAST_MSFILTER:
{
const int size0 = offsetof(struct compat_group_filter, gf_slist);
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index bb049feeb787..e10258c2210e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1015,8 +1015,27 @@ int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
case MCAST_LEAVE_SOURCE_GROUP:
case MCAST_BLOCK_SOURCE:
case MCAST_UNBLOCK_SOURCE:
- return compat_mc_setsockopt(sk, level, optname, optval, optlen,
- ipv6_setsockopt);
+ {
+ struct compat_group_source_req __user *gsr32 = (void __user *)optval;
+ struct group_source_req greqs;
+
+ if (optlen < sizeof(struct compat_group_source_req))
+ return -EINVAL;
+
+ if (get_user(greqs.gsr_interface, &gsr32->gsr_interface) ||
+ copy_from_user(&greqs.gsr_group, &gsr32->gsr_group,
+ sizeof(greqs.gsr_group)) ||
+ copy_from_user(&greqs.gsr_source, &gsr32->gsr_source,
+ sizeof(greqs.gsr_source)))
+ return -EFAULT;
+
+ rtnl_lock();
+ lock_sock(sk);
+ err = do_ipv6_mcast_group_source(sk, optname, &greqs);
+ release_sock(sk);
+ rtnl_unlock();
+ return err;
+ }
case MCAST_MSFILTER:
{
const int size0 = offsetof(struct compat_group_filter, gf_slist);
--
2.11.0