[PATCH net-next v2 2/4] udp: convert udp_lib_getsockopt to sockopt_t
From: Breno Leitao <leitao@debian.org>
Date: 2026-06-30 14:01:55
Also in:
linux-kselftest, lkml
Subsystem:
networking [general], the rest, user datagram protocol (udp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn
In preparation for converting the proto-layer getsockopt callbacks to the sockopt_t interface, switch udp_lib_getsockopt() to take a sockopt_t. The thin udp_getsockopt()/udpv6_getsockopt() wrappers keep their __user signature for now: they build a user-backed sockopt_t with sockopt_init_user(), call the helper, and write the returned length back to optlen. The helper uses copy_to_iter() instead of copy_to_user(). No functional change. Signed-off-by: Breno Leitao <leitao@debian.org> --- include/net/udp.h | 2 +- net/ipv4/udp.c | 39 +++++++++++++++++++++++++++++---------- net/ipv6/udp.c | 19 ++++++++++++++++--- 3 files changed, 46 insertions(+), 14 deletions(-)
diff --git a/include/net/udp.h b/include/net/udp.h
index 8262e2b215b4e..1fee17274745f 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h@@ -430,7 +430,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, netdev_features_t features, bool is_ipv6); int udp_lib_getsockopt(struct sock *sk, int level, int optname, - char __user *optval, int __user *optlen); + sockopt_t *opt); int udp_lib_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen, int (*push_pending_frames)(struct sock *));
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 70f6cbd4ef73b..59248a59358ca 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -76,6 +76,7 @@ #include <linux/bpf-cgroup.h> #include <linux/uaccess.h> +#include <linux/uio.h> #include <asm/ioctls.h> #include <linux/memblock.h> #include <linux/highmem.h>
@@ -2995,14 +2996,13 @@ static int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t opt } int udp_lib_getsockopt(struct sock *sk, int level, int optname, - char __user *optval, int __user *optlen) + sockopt_t *opt) { struct udp_sock *up = udp_sk(sk); int val, len; - if (get_user(len, optlen)) - return -EFAULT; - + len = opt->optlen; + /* keep the check so direct sockopt_t callers stay covered. */ if (len < 0) return -EINVAL;
@@ -3037,9 +3037,8 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, return -ENOPROTOOPT; } - if (put_user(len, optlen)) - return -EFAULT; - if (copy_to_user(optval, &val, len)) + opt->optlen = len; + if (copy_to_iter(&val, len, &opt->iter_out) != len) return -EFAULT; return 0; }
@@ -3047,9 +3046,29 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, static int udp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { - if (level == SOL_UDP) - return udp_lib_getsockopt(sk, level, optname, optval, optlen); - return ip_getsockopt(sk, level, optname, optval, optlen); + sockopt_t opt; + int err; + + /* + * keep the old __user pointers, until ip_getsockopt() moves + * to sockopt_t + */ + if (level != SOL_UDP) + return ip_getsockopt(sk, level, optname, optval, optlen); + + err = sockopt_init_user(&opt, optval, optlen); + if (err) + return err; + + err = udp_lib_getsockopt(sk, level, optname, &opt); + if (err) + return err; + + /* optval was written by copy_to_iter() in udp_lib_getsockopt() */ + if (put_user(opt.optlen, optlen)) + return -EFAULT; + + return 0; } /**
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 15e032194eccc..392e18b970454 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c@@ -1826,9 +1826,22 @@ static int udpv6_setsockopt(struct sock *sk, int level, int optname, static int udpv6_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { - if (level == SOL_UDP) - return udp_lib_getsockopt(sk, level, optname, optval, optlen); - return ipv6_getsockopt(sk, level, optname, optval, optlen); + sockopt_t opt; + int err; + + if (level != SOL_UDP) + return ipv6_getsockopt(sk, level, optname, optval, optlen); + + err = sockopt_init_user(&opt, optval, optlen); + if (err) + return err; + + err = udp_lib_getsockopt(sk, level, optname, &opt); + if (err) + return err; + if (put_user(opt.optlen, optlen)) + return -EFAULT; + return 0; }
--
2.53.0-Meta