[PATCH v3 net-next 09/15] udp: Remove UDPLITE_SEND_CSCOV and UDPLITE_RECV_CSCOV.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-03-11 05:20:41
Subsystem:
networking [general], networking [ipv4/ipv6], the rest, user datagram protocol (udp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds, Willem de Bruijn
UDP-Lite supports variable-length checksum and has two socket
options, UDPLITE_SEND_CSCOV and UDPLITE_RECV_CSCOV, to control
the checksum coverage.
Let's remove the support.
setsockopt(UDPLITE_SEND_CSCOV / UDPLITE_RECV_CSCOV) was only
available for UDP-Lite and returned -ENOPROTOOPT for UDP.
Now, the options are handled in ip_setsockopt() and
ipv6_setsockopt(), which still return the same error.
getsockopt(UDPLITE_SEND_CSCOV / UDPLITE_RECV_CSCOV) was available
for UDP and always returned 0, meaning full checksum, but now
-ENOPROTOOPT is returned.
Given that getsockopt() is meaningless for UDP and even the options
are not defined under include/uapi/, this should not be a problem.
$ man 7 udplite
...
BUGS
Where glibc support is missing, the following definitions
are needed:
#define IPPROTO_UDPLITE 136
#define UDPLITE_SEND_CSCOV 10
#define UDPLITE_RECV_CSCOV 11
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
---
v2: Add a detailed reason in include/uapi/linux/udp.h
---
include/linux/udp.h | 10 +--------
include/net/udplite.h | 15 -------------
include/uapi/linux/udp.h | 2 ++
net/ipv4/udp.c | 46 ++--------------------------------------
net/ipv6/ip6_checksum.c | 2 +-
net/ipv6/udp.c | 5 ++---
6 files changed, 8 insertions(+), 72 deletions(-)
delete mode 100644 include/net/udplite.h
diff --git a/include/linux/udp.h b/include/linux/udp.h
index 1cbf6b4d3aab..ce56ebcee5cb 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h@@ -40,8 +40,6 @@ enum { UDP_FLAGS_ACCEPT_FRAGLIST, UDP_FLAGS_ACCEPT_L4, UDP_FLAGS_ENCAP_ENABLED, /* This socket enabled encap */ - UDP_FLAGS_UDPLITE_SEND_CC, /* set via udplite setsockopt */ - UDP_FLAGS_UDPLITE_RECV_CC, /* set via udplite setsockopt */ }; /* per NUMA structure for lockless producer usage. */
@@ -74,11 +72,7 @@ struct udp_sock { */ __u16 len; /* total length of pending frames */ __u16 gso_size; - /* - * Fields specific to UDP-Lite. - */ - __u16 pcslen; - __u16 pcrlen; + /* * For encapsulation sockets. */
@@ -236,8 +230,6 @@ static inline void udp_allow_gso(struct sock *sk) hlist_nulls_for_each_entry_rcu(__up, node, list, udp_lrpa_node) #endif -#define IS_UDPLITE(__sk) (unlikely(__sk->sk_protocol == IPPROTO_UDPLITE)) - static inline struct sock *udp_tunnel_sk(const struct net *net, bool is_ipv6) { #if IS_ENABLED(CONFIG_NET_UDP_TUNNEL)
diff --git a/include/net/udplite.h b/include/net/udplite.h
deleted file mode 100644
index 6bfa1d6833d1..000000000000
--- a/include/net/udplite.h
+++ /dev/null@@ -1,15 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Definitions for the UDP-Lite (RFC 3828) code. - */ -#ifndef _UDPLITE_H -#define _UDPLITE_H - -#include <net/ip6_checksum.h> -#include <net/udp.h> - -/* UDP-Lite socket options */ -#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */ -#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */ - -#endif /* _UDPLITE_H */
diff --git a/include/uapi/linux/udp.h b/include/uapi/linux/udp.h
index edca3e430305..877fb02df8fb 100644
--- a/include/uapi/linux/udp.h
+++ b/include/uapi/linux/udp.h@@ -29,6 +29,8 @@ struct udphdr { /* UDP socket options */ #define UDP_CORK 1 /* Never send partially complete segments */ +/* Deprecated, reserved for UDPLITE_SEND_CSCOV 10 */ +/* Deprecated, reserved for UDPLITE_RECV_CSCOV 11 */ #define UDP_ENCAP 100 /* Set the socket to accept encapsulated packets */ #define UDP_NO_CHECK6_TX 101 /* Disable sending checksum for UDP6X */ #define UDP_NO_CHECK6_RX 102 /* Disable accepting checksum for UDP6 */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 9a2c8ff96e83..d47ca721ef0d 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -117,7 +117,6 @@ #include <net/sock_reuseport.h> #include <net/addrconf.h> #include <net/udp_tunnel.h> -#include <net/udplite.h> #include <net/gro.h> #if IS_ENABLED(CONFIG_IPV6) #include <net/ipv6_stubs.h>
@@ -2924,7 +2923,6 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, struct udp_sock *up = udp_sk(sk); int val, valbool; int err = 0; - int is_udplite = IS_UDPLITE(sk); if (level == SOL_SOCKET) { err = sk_setsockopt(sk, level, optname, optval, optlen);
@@ -3011,36 +3009,6 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, sockopt_release_sock(sk); break; - /* - * UDP-Lite's partial checksum coverage (RFC 3828). - */ - /* The sender sets actual checksum coverage length via this option. - * The case coverage > packet length is handled by send module. */ - case UDPLITE_SEND_CSCOV: - if (!is_udplite) /* Disable the option on UDP sockets */ - return -ENOPROTOOPT; - if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ - val = 8; - else if (val > USHRT_MAX) - val = USHRT_MAX; - WRITE_ONCE(up->pcslen, val); - udp_set_bit(UDPLITE_SEND_CC, sk); - break; - - /* The receiver specifies a minimum checksum coverage value. To make - * sense, this should be set to at least 8 (as done below). If zero is - * used, this again means full checksum coverage. */ - case UDPLITE_RECV_CSCOV: - if (!is_udplite) /* Disable the option on UDP sockets */ - return -ENOPROTOOPT; - if (val != 0 && val < 8) /* Avoid silly minimal values. */ - val = 8; - else if (val > USHRT_MAX) - val = USHRT_MAX; - WRITE_ONCE(up->pcrlen, val); - udp_set_bit(UDPLITE_RECV_CC, sk); - break; - default: err = -ENOPROTOOPT; break;
@@ -3053,7 +3021,7 @@ EXPORT_IPV6_MOD(udp_lib_setsockopt); static int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen) { - if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET) + if (level == SOL_UDP || level == SOL_SOCKET) return udp_lib_setsockopt(sk, level, optname, optval, optlen, udp_push_pending_frames);
@@ -3099,16 +3067,6 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, val = udp_test_bit(GRO_ENABLED, sk); break; - /* The following two cannot be changed on UDP sockets, the return is - * always 0 (which corresponds to the full checksum coverage of UDP). */ - case UDPLITE_SEND_CSCOV: - val = READ_ONCE(up->pcslen); - break; - - case UDPLITE_RECV_CSCOV: - val = READ_ONCE(up->pcrlen); - break; - default: return -ENOPROTOOPT; }
@@ -3124,7 +3082,7 @@ EXPORT_IPV6_MOD(udp_lib_getsockopt); static int udp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { - if (level == SOL_UDP || level == SOL_UDPLITE) + if (level == SOL_UDP) return udp_lib_getsockopt(sk, level, optname, optval, optlen); return ip_getsockopt(sk, level, optname, optval, optlen); }
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
index 8bb68a0cdfd6..e1a594873675 100644
--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c@@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <net/ip.h> +#include <net/ip6_checksum.h> #include <net/udp.h> -#include <net/udplite.h> #include <asm/checksum.h> #ifndef _HAVE_ARCH_IPV6_CSUM
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 511e3f898be5..c3d8b5ede164 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c@@ -58,7 +58,6 @@ #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <trace/events/skb.h> -#include <net/udplite.h> static void udpv6_destruct_sock(struct sock *sk) {
@@ -1831,7 +1830,7 @@ static void udpv6_destroy_sock(struct sock *sk) static int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen) { - if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET) + if (level == SOL_UDP || level == SOL_SOCKET) return udp_lib_setsockopt(sk, level, optname, optval, optlen, udp_v6_push_pending_frames);
@@ -1841,7 +1840,7 @@ 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 || level == SOL_UDPLITE) + if (level == SOL_UDP) return udp_lib_getsockopt(sk, level, optname, optval, optlen); return ipv6_getsockopt(sk, level, optname, optval, optlen); }
--
2.53.0.473.g4a7958ca14-goog