353 lines
9.1 KiB
C
353 lines
9.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Multipath TCP
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*
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* Copyright (c) 2021, Red Hat.
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*/
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#define pr_fmt(fmt) "MPTCP: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <net/sock.h>
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#include <net/protocol.h>
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#include <net/tcp.h>
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#include <net/mptcp.h>
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#include "protocol.h"
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static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk)
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{
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sock_owned_by_me((const struct sock *)msk);
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if (likely(!__mptcp_check_fallback(msk)))
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return NULL;
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return msk->first;
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}
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static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname,
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sockptr_t optval, unsigned int optlen)
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{
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struct sock *sk = (struct sock *)msk;
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struct socket *ssock;
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int ret;
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switch (optname) {
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case SO_REUSEPORT:
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case SO_REUSEADDR:
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lock_sock(sk);
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ssock = __mptcp_nmpc_socket(msk);
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if (!ssock) {
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release_sock(sk);
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return -EINVAL;
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}
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ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen);
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if (ret == 0) {
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if (optname == SO_REUSEPORT)
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sk->sk_reuseport = ssock->sk->sk_reuseport;
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else if (optname == SO_REUSEADDR)
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sk->sk_reuse = ssock->sk->sk_reuse;
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}
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release_sock(sk);
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return ret;
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}
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return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen);
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}
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static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname,
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sockptr_t optval, unsigned int optlen)
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{
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struct sock *sk = (struct sock *)msk;
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int ret = -EOPNOTSUPP;
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struct socket *ssock;
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switch (optname) {
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case IPV6_V6ONLY:
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lock_sock(sk);
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ssock = __mptcp_nmpc_socket(msk);
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if (!ssock) {
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release_sock(sk);
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return -EINVAL;
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}
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ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen);
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if (ret == 0)
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sk->sk_ipv6only = ssock->sk->sk_ipv6only;
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release_sock(sk);
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break;
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}
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return ret;
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}
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static bool mptcp_supported_sockopt(int level, int optname)
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{
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if (level == SOL_SOCKET) {
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switch (optname) {
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case SO_DEBUG:
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case SO_REUSEPORT:
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case SO_REUSEADDR:
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/* the following ones need a better implementation,
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* but are quite common we want to preserve them
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*/
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case SO_BINDTODEVICE:
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case SO_SNDBUF:
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case SO_SNDBUFFORCE:
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case SO_RCVBUF:
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case SO_RCVBUFFORCE:
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case SO_KEEPALIVE:
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case SO_PRIORITY:
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case SO_LINGER:
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case SO_TIMESTAMP_OLD:
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case SO_TIMESTAMP_NEW:
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case SO_TIMESTAMPNS_OLD:
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case SO_TIMESTAMPNS_NEW:
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case SO_TIMESTAMPING_OLD:
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case SO_TIMESTAMPING_NEW:
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case SO_RCVLOWAT:
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case SO_RCVTIMEO_OLD:
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case SO_RCVTIMEO_NEW:
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case SO_SNDTIMEO_OLD:
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case SO_SNDTIMEO_NEW:
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case SO_MARK:
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case SO_INCOMING_CPU:
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case SO_BINDTOIFINDEX:
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case SO_BUSY_POLL:
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case SO_PREFER_BUSY_POLL:
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case SO_BUSY_POLL_BUDGET:
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/* next ones are no-op for plain TCP */
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case SO_NO_CHECK:
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case SO_DONTROUTE:
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case SO_BROADCAST:
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case SO_BSDCOMPAT:
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case SO_PASSCRED:
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case SO_PASSSEC:
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case SO_RXQ_OVFL:
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case SO_WIFI_STATUS:
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case SO_NOFCS:
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case SO_SELECT_ERR_QUEUE:
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return true;
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}
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/* SO_OOBINLINE is not supported, let's avoid the related mess */
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/* SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF,
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* SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER,
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* we must be careful with subflows
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*/
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/* SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks
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* explicitly the sk_protocol field
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*/
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/* SO_PEEK_OFF is unsupported, as it is for plain TCP */
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/* SO_MAX_PACING_RATE is unsupported, we must be careful with subflows */
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/* SO_CNX_ADVICE is currently unsupported, could possibly be relevant,
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* but likely needs careful design
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*/
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/* SO_ZEROCOPY is currently unsupported, TODO in sndmsg */
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/* SO_TXTIME is currently unsupported */
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return false;
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}
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if (level == SOL_IP) {
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switch (optname) {
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/* should work fine */
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case IP_FREEBIND:
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case IP_TRANSPARENT:
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/* the following are control cmsg related */
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case IP_PKTINFO:
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case IP_RECVTTL:
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case IP_RECVTOS:
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case IP_RECVOPTS:
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case IP_RETOPTS:
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case IP_PASSSEC:
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case IP_RECVORIGDSTADDR:
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case IP_CHECKSUM:
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case IP_RECVFRAGSIZE:
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/* common stuff that need some love */
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case IP_TOS:
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case IP_TTL:
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case IP_BIND_ADDRESS_NO_PORT:
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case IP_MTU_DISCOVER:
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case IP_RECVERR:
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/* possibly less common may deserve some love */
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case IP_MINTTL:
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/* the following is apparently a no-op for plain TCP */
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case IP_RECVERR_RFC4884:
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return true;
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}
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/* IP_OPTIONS is not supported, needs subflow care */
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/* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */
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/* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF,
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* IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP,
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* IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE,
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* MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP,
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* MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE,
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* MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal
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* with mcast stuff
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*/
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/* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */
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return false;
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}
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if (level == SOL_IPV6) {
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switch (optname) {
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case IPV6_V6ONLY:
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/* the following are control cmsg related */
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case IPV6_RECVPKTINFO:
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case IPV6_2292PKTINFO:
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case IPV6_RECVHOPLIMIT:
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case IPV6_2292HOPLIMIT:
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case IPV6_RECVRTHDR:
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case IPV6_2292RTHDR:
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case IPV6_RECVHOPOPTS:
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case IPV6_2292HOPOPTS:
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case IPV6_RECVDSTOPTS:
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case IPV6_2292DSTOPTS:
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case IPV6_RECVTCLASS:
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case IPV6_FLOWINFO:
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case IPV6_RECVPATHMTU:
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case IPV6_RECVORIGDSTADDR:
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case IPV6_RECVFRAGSIZE:
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/* the following ones need some love but are quite common */
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case IPV6_TCLASS:
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case IPV6_TRANSPARENT:
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case IPV6_FREEBIND:
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case IPV6_PKTINFO:
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case IPV6_2292PKTOPTIONS:
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case IPV6_UNICAST_HOPS:
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case IPV6_MTU_DISCOVER:
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case IPV6_MTU:
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case IPV6_RECVERR:
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case IPV6_FLOWINFO_SEND:
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case IPV6_FLOWLABEL_MGR:
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case IPV6_MINHOPCOUNT:
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case IPV6_DONTFRAG:
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case IPV6_AUTOFLOWLABEL:
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/* the following one is a no-op for plain TCP */
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case IPV6_RECVERR_RFC4884:
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return true;
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}
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/* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are
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* not supported
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*/
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/* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF,
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* IPV6_MULTICAST_IF, IPV6_ADDRFORM,
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* IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
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* IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP,
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* MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP,
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* MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER
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* are not supported better not deal with mcast
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*/
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/* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */
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/* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */
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/* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */
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return false;
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}
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if (level == SOL_TCP) {
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switch (optname) {
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/* the following are no-op or should work just fine */
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case TCP_THIN_DUPACK:
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case TCP_DEFER_ACCEPT:
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/* the following need some love */
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case TCP_MAXSEG:
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case TCP_NODELAY:
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case TCP_THIN_LINEAR_TIMEOUTS:
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case TCP_CONGESTION:
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case TCP_ULP:
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case TCP_CORK:
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case TCP_KEEPIDLE:
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case TCP_KEEPINTVL:
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case TCP_KEEPCNT:
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case TCP_SYNCNT:
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case TCP_SAVE_SYN:
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case TCP_LINGER2:
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case TCP_WINDOW_CLAMP:
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case TCP_QUICKACK:
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case TCP_USER_TIMEOUT:
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case TCP_TIMESTAMP:
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case TCP_NOTSENT_LOWAT:
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case TCP_TX_DELAY:
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return true;
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}
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/* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */
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/* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS,
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* TCP_REPAIR_WINDOW are not supported, better avoid this mess
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*/
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/* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE,
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* are not supported fastopen is currently unsupported
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*/
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/* TCP_INQ is currently unsupported, needs some recvmsg work */
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}
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return false;
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}
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int mptcp_setsockopt(struct sock *sk, int level, int optname,
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sockptr_t optval, unsigned int optlen)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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struct sock *ssk;
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pr_debug("msk=%p", msk);
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if (!mptcp_supported_sockopt(level, optname))
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return -ENOPROTOOPT;
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if (level == SOL_SOCKET)
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return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen);
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/* @@ the meaning of setsockopt() when the socket is connected and
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* there are multiple subflows is not yet defined. It is up to the
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* MPTCP-level socket to configure the subflows until the subflow
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* is in TCP fallback, when TCP socket options are passed through
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* to the one remaining subflow.
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*/
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lock_sock(sk);
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ssk = __mptcp_tcp_fallback(msk);
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release_sock(sk);
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if (ssk)
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return tcp_setsockopt(ssk, level, optname, optval, optlen);
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if (level == SOL_IPV6)
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return mptcp_setsockopt_v6(msk, optname, optval, optlen);
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return -EOPNOTSUPP;
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}
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int mptcp_getsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int __user *option)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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struct sock *ssk;
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pr_debug("msk=%p", msk);
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/* @@ the meaning of setsockopt() when the socket is connected and
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* there are multiple subflows is not yet defined. It is up to the
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* MPTCP-level socket to configure the subflows until the subflow
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* is in TCP fallback, when socket options are passed through
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* to the one remaining subflow.
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*/
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lock_sock(sk);
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ssk = __mptcp_tcp_fallback(msk);
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release_sock(sk);
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if (ssk)
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return tcp_getsockopt(ssk, level, optname, optval, option);
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return -EOPNOTSUPP;
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}
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