[PATCH net-next v2 1/4] net: add sockopt_init_user() for getsockopt conversion
From: Breno Leitao <leitao@debian.org>
Date: 2026-06-30 14:01:51
Also in:
linux-kselftest, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add a helper that initializes a user-backed sockopt_t from the (optval,
optlen) __user pair passed to a getsockopt() callback.
It is used by transitional __user getsockopt wrappers while the
proto-layer getsockopt callbacks are converted to take a sockopt_t, and
is removed once the conversion is complete.
The goal is to help to convert leafs. Example:
sock_common_getsockopt(... char __user *optval, int __user *optlen)
→ udp_getsockopt(sk, level, optname, optval__user, optlen__user)
→ udp_lib_getsockopt(sk, level, optname, &opt) /* needs a sockopt_t */
Signed-off-by: Breno Leitao <leitao@debian.org>
---
include/linux/net.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/include/linux/net.h b/include/linux/net.h
index f268f395ce473..277188a40c72e 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h@@ -47,6 +47,29 @@ typedef struct sockopt { int optlen; } sockopt_t; +/* + * Initialize a user-backed sockopt_t from the (optval, optlen) __user pair of + * a getsockopt() callback. Used by transitional __user getsockopt wrappers + * while the proto-layer callbacks are converted to take a sockopt_t; the + * caller writes opt->optlen back to the user optlen after the callback. + */ +static inline int sockopt_init_user(sockopt_t *opt, char __user *optval, + int __user *optlen) +{ + int len; + + if (get_user(len, optlen)) + return -EFAULT; + if (len < 0) + return -EINVAL; + + iov_iter_ubuf(&opt->iter_out, ITER_DEST, optval, len); + iov_iter_ubuf(&opt->iter_in, ITER_SOURCE, optval, len); + opt->optlen = len; + + return 0; +} + struct poll_table_struct; struct pipe_inode_info; struct inode;
--
2.53.0-Meta