udp: Remove UDPLITE_SEND_CSCOV and UDPLITE_RECV_CSCOV.

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>
Link: https://patch.msgid.link/20260311052020.1213705-10-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 1cbf6b4d3aab3bf4bd542b3ec6cd17d7cbd750f0..ce56ebcee5cbcd1075bf4a39083265e9c1c03098 100644 (file)
--- 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 (file)
index 6bfa1d6..0000000
--- 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 edca3e430305a6bffc34e617421f1f3071582e69..877fb02df8fba888f75c4e067ca68ece767a3f9f 100644 (file)
--- 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 9a2c8ff96e837fe2cd2688cbd6443b2c3360c1d3..d47ca721ef0d6bf502c8f3d27dfa929e8bf5047e 100644 (file)
--- 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 8bb68a0cdfd681a7fb51959fa7cbce96a6dc271a..e1a594873675d580a396691a4c7693986cc01b02 100644 (file)
--- 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 511e3f898be507e1c064c9af1ff5425ce39eeae6..c3d8b5ede164ff314fe4da8eb6d227548143e2bb 100644 (file)
--- 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);
 }