// SPDX-License-Identifier: GPL-2.0 /* Multipath TCP * * Copyright (c) 2021, Red Hat. */ #define pr_fmt(fmt) "MPTCP: " fmt #include <linux/kernel.h> #include <linux/module.h> #include <net/sock.h> #include <net/protocol.h> #include <net/tcp.h> #include <net/mptcp.h> #include "protocol.h" #define MIN_INFO_OPTLEN_SIZE 16 static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk) { sock_owned_by_me((const struct sock *)msk); if (likely(!__mptcp_check_fallback(msk))) return NULL; return msk->first; } static u32 sockopt_seq_reset(const struct sock *sk) { sock_owned_by_me(sk); /* Highbits contain state. Allows to distinguish sockopt_seq * of listener and established: * s0 = new_listener() * sockopt(s0) - seq is 1 * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0) * sockopt(s0) - seq increments to 2 on s0 * sockopt(s1) // seq increments to 2 on s1 (different option) * new ssk completes join, inherits options from s0 // seq 2 * Needs sync from mptcp join logic, but ssk->seq == msk->seq * * Set High order bits to sk_state so ssk->seq == msk->seq test * will fail. */ return (u32)sk->sk_state << 24u; } static void sockopt_seq_inc(struct mptcp_sock *msk) { u32 seq = (msk->setsockopt_seq + 1) & 0x00ffffff; msk->setsockopt_seq = sockopt_seq_reset((struct sock *)msk) + seq; } static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval, unsigned int optlen, int *val) { if (optlen < sizeof(int)) return -EINVAL; if (copy_from_sockptr(val, optval, sizeof(*val))) return -EFAULT; return 0; } static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, int val) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; lock_sock(sk); sockopt_seq_inc(msk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast(ssk); switch (optname) { case SO_DEBUG: sock_valbool_flag(ssk, SOCK_DBG, !!val); break; case SO_KEEPALIVE: if (ssk->sk_prot->keepalive) ssk->sk_prot->keepalive(ssk, !!val); sock_valbool_flag(ssk, SOCK_KEEPOPEN, !!val); break; case SO_PRIORITY: ssk->sk_priority = val; break; case SO_SNDBUF: case SO_SNDBUFFORCE: ssk->sk_userlocks |= SOCK_SNDBUF_LOCK; WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); break; case SO_RCVBUF: case SO_RCVBUFFORCE: ssk->sk_userlocks |= SOCK_RCVBUF_LOCK; WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); break; case SO_MARK: if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) { ssk->sk_mark = sk->sk_mark; sk_dst_reset(ssk); } break; case SO_INCOMING_CPU: WRITE_ONCE(ssk->sk_incoming_cpu, val); break; } subflow->setsockopt_seq = msk->setsockopt_seq; unlock_sock_fast(ssk, slow); } release_sock(sk); } static int mptcp_sol_socket_intval(struct mptcp_sock *msk, int optname, int val) { sockptr_t optval = KERNEL_SOCKPTR(&val); struct sock *sk = (struct sock *)msk; int ret; ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, sizeof(val)); if (ret) return ret; mptcp_sol_socket_sync_intval(msk, optname, val); return 0; } static void mptcp_so_incoming_cpu(struct mptcp_sock *msk, int val) { struct sock *sk = (struct sock *)msk; WRITE_ONCE(sk->sk_incoming_cpu, val); mptcp_sol_socket_sync_intval(msk, SO_INCOMING_CPU, val); } static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optname, int val) { sockptr_t optval = KERNEL_SOCKPTR(&val); struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; int ret; ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, sizeof(val)); if (ret) return ret; lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast(ssk); sock_set_timestamp(sk, optname, !!val); unlock_sock_fast(ssk, slow); } release_sock(sk); return 0; } static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { int val, ret; ret = mptcp_get_int_option(msk, optval, optlen, &val); if (ret) return ret; switch (optname) { case SO_KEEPALIVE: mptcp_sol_socket_sync_intval(msk, optname, val); return 0; case SO_DEBUG: case SO_MARK: case SO_PRIORITY: case SO_SNDBUF: case SO_SNDBUFFORCE: case SO_RCVBUF: case SO_RCVBUFFORCE: return mptcp_sol_socket_intval(msk, optname, val); case SO_INCOMING_CPU: mptcp_so_incoming_cpu(msk, val); return 0; case SO_TIMESTAMP_OLD: case SO_TIMESTAMP_NEW: case SO_TIMESTAMPNS_OLD: case SO_TIMESTAMPNS_NEW: return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val); } return -ENOPROTOOPT; } static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; struct so_timestamping timestamping; int ret; if (optlen == sizeof(timestamping)) { if (copy_from_sockptr(×tamping, optval, sizeof(timestamping))) return -EFAULT; } else if (optlen == sizeof(int)) { memset(×tamping, 0, sizeof(timestamping)); if (copy_from_sockptr(×tamping.flags, optval, sizeof(int))) return -EFAULT; } else { return -EINVAL; } ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, KERNEL_SOCKPTR(×tamping), sizeof(timestamping)); if (ret) return ret; lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast(ssk); sock_set_timestamping(sk, optname, timestamping); unlock_sock_fast(ssk, slow); } release_sock(sk); return 0; } static int mptcp_setsockopt_sol_socket_linger(struct mptcp_sock *msk, sockptr_t optval, unsigned int optlen) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; struct linger ling; sockptr_t kopt; int ret; if (optlen < sizeof(ling)) return -EINVAL; if (copy_from_sockptr(&ling, optval, sizeof(ling))) return -EFAULT; kopt = KERNEL_SOCKPTR(&ling); ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling)); if (ret) return ret; lock_sock(sk); sockopt_seq_inc(msk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast(ssk); if (!ling.l_onoff) { sock_reset_flag(ssk, SOCK_LINGER); } else { ssk->sk_lingertime = sk->sk_lingertime; sock_set_flag(ssk, SOCK_LINGER); } subflow->setsockopt_seq = msk->setsockopt_seq; unlock_sock_fast(ssk, slow); } release_sock(sk); return 0; } static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { struct sock *sk = (struct sock *)msk; struct socket *ssock; int ret; switch (optname) { case SO_REUSEPORT: case SO_REUSEADDR: case SO_BINDTODEVICE: case SO_BINDTOIFINDEX: lock_sock(sk); ssock = __mptcp_nmpc_socket(msk); if (!ssock) { release_sock(sk); return -EINVAL; } ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen); if (ret == 0) { if (optname == SO_REUSEPORT) sk->sk_reuseport = ssock->sk->sk_reuseport; else if (optname == SO_REUSEADDR) sk->sk_reuse = ssock->sk->sk_reuse; else if (optname == SO_BINDTODEVICE) sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; else if (optname == SO_BINDTOIFINDEX) sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; } release_sock(sk); return ret; case SO_KEEPALIVE: case SO_PRIORITY: case SO_SNDBUF: case SO_SNDBUFFORCE: case SO_RCVBUF: case SO_RCVBUFFORCE: case SO_MARK: case SO_INCOMING_CPU: case SO_DEBUG: case SO_TIMESTAMP_OLD: case SO_TIMESTAMP_NEW: case SO_TIMESTAMPNS_OLD: case SO_TIMESTAMPNS_NEW: return mptcp_setsockopt_sol_socket_int(msk, optname, optval, optlen); case SO_TIMESTAMPING_OLD: case SO_TIMESTAMPING_NEW: return mptcp_setsockopt_sol_socket_timestamping(msk, optname, optval, optlen); case SO_LINGER: return mptcp_setsockopt_sol_socket_linger(msk, optval, optlen); case SO_RCVLOWAT: case SO_RCVTIMEO_OLD: case SO_RCVTIMEO_NEW: case SO_BUSY_POLL: case SO_PREFER_BUSY_POLL: case SO_BUSY_POLL_BUDGET: /* No need to copy: only relevant for msk */ return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen); case SO_NO_CHECK: case SO_DONTROUTE: case SO_BROADCAST: case SO_BSDCOMPAT: case SO_PASSCRED: case SO_PASSSEC: case SO_RXQ_OVFL: case SO_WIFI_STATUS: case SO_NOFCS: case SO_SELECT_ERR_QUEUE: return 0; } /* SO_OOBINLINE is not supported, let's avoid the related mess * SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF, * SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER, * we must be careful with subflows * * SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks * explicitly the sk_protocol field * * SO_PEEK_OFF is unsupported, as it is for plain TCP * SO_MAX_PACING_RATE is unsupported, we must be careful with subflows * SO_CNX_ADVICE is currently unsupported, could possibly be relevant, * but likely needs careful design * * SO_ZEROCOPY is currently unsupported, TODO in sndmsg * SO_TXTIME is currently unsupported */ return -EOPNOTSUPP; } static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { struct sock *sk = (struct sock *)msk; int ret = -EOPNOTSUPP; struct socket *ssock; switch (optname) { case IPV6_V6ONLY: lock_sock(sk); ssock = __mptcp_nmpc_socket(msk); if (!ssock) { release_sock(sk); return -EINVAL; } ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen); if (ret == 0) sk->sk_ipv6only = ssock->sk->sk_ipv6only; release_sock(sk); break; } return ret; } static bool mptcp_supported_sockopt(int level, int optname) { if (level == SOL_IP) { switch (optname) { /* should work fine */ case IP_FREEBIND: case IP_TRANSPARENT: /* the following are control cmsg related */ case IP_PKTINFO: case IP_RECVTTL: case IP_RECVTOS: case IP_RECVOPTS: case IP_RETOPTS: case IP_PASSSEC: case IP_RECVORIGDSTADDR: case IP_CHECKSUM: case IP_RECVFRAGSIZE: /* common stuff that need some love */ case IP_TOS: case IP_TTL: case IP_BIND_ADDRESS_NO_PORT: case IP_MTU_DISCOVER: case IP_RECVERR: /* possibly less common may deserve some love */ case IP_MINTTL: /* the following is apparently a no-op for plain TCP */ case IP_RECVERR_RFC4884: return true; } /* IP_OPTIONS is not supported, needs subflow care */ /* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */ /* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF, * IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP, * IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE, * MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP, * MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, * MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal * with mcast stuff */ /* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */ return false; } if (level == SOL_IPV6) { switch (optname) { case IPV6_V6ONLY: /* the following are control cmsg related */ case IPV6_RECVPKTINFO: case IPV6_2292PKTINFO: case IPV6_RECVHOPLIMIT: case IPV6_2292HOPLIMIT: case IPV6_RECVRTHDR: case IPV6_2292RTHDR: case IPV6_RECVHOPOPTS: case IPV6_2292HOPOPTS: case IPV6_RECVDSTOPTS: case IPV6_2292DSTOPTS: case IPV6_RECVTCLASS: case IPV6_FLOWINFO: case IPV6_RECVPATHMTU: case IPV6_RECVORIGDSTADDR: case IPV6_RECVFRAGSIZE: /* the following ones need some love but are quite common */ case IPV6_TCLASS: case IPV6_TRANSPARENT: case IPV6_FREEBIND: case IPV6_PKTINFO: case IPV6_2292PKTOPTIONS: case IPV6_UNICAST_HOPS: case IPV6_MTU_DISCOVER: case IPV6_MTU: case IPV6_RECVERR: case IPV6_FLOWINFO_SEND: case IPV6_FLOWLABEL_MGR: case IPV6_MINHOPCOUNT: case IPV6_DONTFRAG: case IPV6_AUTOFLOWLABEL: /* the following one is a no-op for plain TCP */ case IPV6_RECVERR_RFC4884: return true; } /* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are * not supported */ /* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF, * IPV6_MULTICAST_IF, IPV6_ADDRFORM, * IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST, * IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP, * MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP, * MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER * are not supported better not deal with mcast */ /* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */ /* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */ /* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */ return false; } if (level == SOL_TCP) { switch (optname) { /* the following are no-op or should work just fine */ case TCP_THIN_DUPACK: case TCP_DEFER_ACCEPT: /* the following need some love */ case TCP_MAXSEG: case TCP_NODELAY: case TCP_THIN_LINEAR_TIMEOUTS: case TCP_CONGESTION: case TCP_ULP: case TCP_CORK: case TCP_KEEPIDLE: case TCP_KEEPINTVL: case TCP_KEEPCNT: case TCP_SYNCNT: case TCP_SAVE_SYN: case TCP_LINGER2: case TCP_WINDOW_CLAMP: case TCP_QUICKACK: case TCP_USER_TIMEOUT: case TCP_TIMESTAMP: case TCP_NOTSENT_LOWAT: case TCP_TX_DELAY: return true; } /* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */ /* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS, * TCP_REPAIR_WINDOW are not supported, better avoid this mess */ /* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE, * are not supported fastopen is currently unsupported */ /* TCP_INQ is currently unsupported, needs some recvmsg work */ } return false; } static int mptcp_setsockopt_sol_tcp_congestion(struct mptcp_sock *msk, sockptr_t optval, unsigned int optlen) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; char name[TCP_CA_NAME_MAX]; bool cap_net_admin; int ret; if (optlen < 1) return -EINVAL; ret = strncpy_from_sockptr(name, optval, min_t(long, TCP_CA_NAME_MAX - 1, optlen)); if (ret < 0) return -EFAULT; name[ret] = 0; cap_net_admin = ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN); ret = 0; lock_sock(sk); sockopt_seq_inc(msk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); int err; lock_sock(ssk); err = tcp_set_congestion_control(ssk, name, true, cap_net_admin); if (err < 0 && ret == 0) ret = err; subflow->setsockopt_seq = msk->setsockopt_seq; release_sock(ssk); } if (ret == 0) strcpy(msk->ca_name, name); release_sock(sk); return ret; } static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { switch (optname) { case TCP_ULP: return -EOPNOTSUPP; case TCP_CONGESTION: return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen); } return -EOPNOTSUPP; } int mptcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen) { struct mptcp_sock *msk = mptcp_sk(sk); struct sock *ssk; pr_debug("msk=%p", msk); if (level == SOL_SOCKET) return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen); if (!mptcp_supported_sockopt(level, optname)) return -ENOPROTOOPT; /* @@ the meaning of setsockopt() when the socket is connected and * there are multiple subflows is not yet defined. It is up to the * MPTCP-level socket to configure the subflows until the subflow * is in TCP fallback, when TCP socket options are passed through * to the one remaining subflow. */ lock_sock(sk); ssk = __mptcp_tcp_fallback(msk); release_sock(sk); if (ssk) return tcp_setsockopt(ssk, level, optname, optval, optlen); if (level == SOL_IPV6) return mptcp_setsockopt_v6(msk, optname, optval, optlen); if (level == SOL_TCP) return mptcp_setsockopt_sol_tcp(msk, optname, optval, optlen); return -EOPNOTSUPP; } static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname, char __user *optval, int __user *optlen) { struct sock *sk = (struct sock *)msk; struct socket *ssock; int ret = -EINVAL; struct sock *ssk; lock_sock(sk); ssk = msk->first; if (ssk) { ret = tcp_getsockopt(ssk, level, optname, optval, optlen); goto out; } ssock = __mptcp_nmpc_socket(msk); if (!ssock) goto out; ret = tcp_getsockopt(ssock->sk, level, optname, optval, optlen); out: release_sock(sk); return ret; } void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) { struct sock *sk = &msk->sk.icsk_inet.sk; u32 flags = 0; bool slow; u8 val; memset(info, 0, sizeof(*info)); slow = lock_sock_fast(sk); info->mptcpi_subflows = READ_ONCE(msk->pm.subflows); info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled); info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used); info->mptcpi_subflows_max = mptcp_pm_get_subflows_max(msk); val = mptcp_pm_get_add_addr_signal_max(msk); info->mptcpi_add_addr_signal_max = val; val = mptcp_pm_get_add_addr_accept_max(msk); info->mptcpi_add_addr_accepted_max = val; info->mptcpi_local_addr_max = mptcp_pm_get_local_addr_max(msk); if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) flags |= MPTCP_INFO_FLAG_FALLBACK; if (READ_ONCE(msk->can_ack)) flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED; info->mptcpi_flags = flags; info->mptcpi_token = READ_ONCE(msk->token); info->mptcpi_write_seq = READ_ONCE(msk->write_seq); info->mptcpi_snd_una = READ_ONCE(msk->snd_una); info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq); info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled); unlock_sock_fast(sk, slow); } EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *optlen) { struct mptcp_info m_info; int len; if (get_user(len, optlen)) return -EFAULT; len = min_t(unsigned int, len, sizeof(struct mptcp_info)); mptcp_diag_fill_info(msk, &m_info); if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, &m_info, len)) return -EFAULT; return 0; } static int mptcp_put_subflow_data(struct mptcp_subflow_data *sfd, char __user *optval, u32 copied, int __user *optlen) { u32 copylen = min_t(u32, sfd->size_subflow_data, sizeof(*sfd)); if (copied) copied += sfd->size_subflow_data; else copied = copylen; if (put_user(copied, optlen)) return -EFAULT; if (copy_to_user(optval, sfd, copylen)) return -EFAULT; return 0; } static int mptcp_get_subflow_data(struct mptcp_subflow_data *sfd, char __user *optval, int __user *optlen) { int len, copylen; if (get_user(len, optlen)) return -EFAULT; /* if mptcp_subflow_data size is changed, need to adjust * this function to deal with programs using old version. */ BUILD_BUG_ON(sizeof(*sfd) != MIN_INFO_OPTLEN_SIZE); if (len < MIN_INFO_OPTLEN_SIZE) return -EINVAL; memset(sfd, 0, sizeof(*sfd)); copylen = min_t(unsigned int, len, sizeof(*sfd)); if (copy_from_user(sfd, optval, copylen)) return -EFAULT; /* size_subflow_data is u32, but len is signed */ if (sfd->size_subflow_data > INT_MAX || sfd->size_user > INT_MAX) return -EINVAL; if (sfd->size_subflow_data < MIN_INFO_OPTLEN_SIZE || sfd->size_subflow_data > len) return -EINVAL; if (sfd->num_subflows || sfd->size_kernel) return -EINVAL; return len - sfd->size_subflow_data; } static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval, int __user *optlen) { struct mptcp_subflow_context *subflow; struct sock *sk = &msk->sk.icsk_inet.sk; unsigned int sfcount = 0, copied = 0; struct mptcp_subflow_data sfd; char __user *infoptr; int len; len = mptcp_get_subflow_data(&sfd, optval, optlen); if (len < 0) return len; sfd.size_kernel = sizeof(struct tcp_info); sfd.size_user = min_t(unsigned int, sfd.size_user, sizeof(struct tcp_info)); infoptr = optval + sfd.size_subflow_data; lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); ++sfcount; if (len && len >= sfd.size_user) { struct tcp_info info; tcp_get_info(ssk, &info); if (copy_to_user(infoptr, &info, sfd.size_user)) { release_sock(sk); return -EFAULT; } infoptr += sfd.size_user; copied += sfd.size_user; len -= sfd.size_user; } } release_sock(sk); sfd.num_subflows = sfcount; if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) return -EFAULT; return 0; } static void mptcp_get_sub_addrs(const struct sock *sk, struct mptcp_subflow_addrs *a) { struct inet_sock *inet = inet_sk(sk); memset(a, 0, sizeof(*a)); if (sk->sk_family == AF_INET) { a->sin_local.sin_family = AF_INET; a->sin_local.sin_port = inet->inet_sport; a->sin_local.sin_addr.s_addr = inet->inet_rcv_saddr; if (!a->sin_local.sin_addr.s_addr) a->sin_local.sin_addr.s_addr = inet->inet_saddr; a->sin_remote.sin_family = AF_INET; a->sin_remote.sin_port = inet->inet_dport; a->sin_remote.sin_addr.s_addr = inet->inet_daddr; #if IS_ENABLED(CONFIG_IPV6) } else if (sk->sk_family == AF_INET6) { const struct ipv6_pinfo *np = inet6_sk(sk); if (WARN_ON_ONCE(!np)) return; a->sin6_local.sin6_family = AF_INET6; a->sin6_local.sin6_port = inet->inet_sport; if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) a->sin6_local.sin6_addr = np->saddr; else a->sin6_local.sin6_addr = sk->sk_v6_rcv_saddr; a->sin6_remote.sin6_family = AF_INET6; a->sin6_remote.sin6_port = inet->inet_dport; a->sin6_remote.sin6_addr = sk->sk_v6_daddr; #endif } } static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *optval, int __user *optlen) { struct sock *sk = &msk->sk.icsk_inet.sk; struct mptcp_subflow_context *subflow; unsigned int sfcount = 0, copied = 0; struct mptcp_subflow_data sfd; char __user *addrptr; int len; len = mptcp_get_subflow_data(&sfd, optval, optlen); if (len < 0) return len; sfd.size_kernel = sizeof(struct mptcp_subflow_addrs); sfd.size_user = min_t(unsigned int, sfd.size_user, sizeof(struct mptcp_subflow_addrs)); addrptr = optval + sfd.size_subflow_data; lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); ++sfcount; if (len && len >= sfd.size_user) { struct mptcp_subflow_addrs a; mptcp_get_sub_addrs(ssk, &a); if (copy_to_user(addrptr, &a, sfd.size_user)) { release_sock(sk); return -EFAULT; } addrptr += sfd.size_user; copied += sfd.size_user; len -= sfd.size_user; } } release_sock(sk); sfd.num_subflows = sfcount; if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) return -EFAULT; return 0; } static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, char __user *optval, int __user *optlen) { switch (optname) { case TCP_ULP: case TCP_CONGESTION: case TCP_INFO: case TCP_CC_INFO: return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname, optval, optlen); } return -EOPNOTSUPP; } static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, char __user *optval, int __user *optlen) { switch (optname) { case MPTCP_INFO: return mptcp_getsockopt_info(msk, optval, optlen); case MPTCP_TCPINFO: return mptcp_getsockopt_tcpinfo(msk, optval, optlen); case MPTCP_SUBFLOW_ADDRS: return mptcp_getsockopt_subflow_addrs(msk, optval, optlen); } return -EOPNOTSUPP; } int mptcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *option) { struct mptcp_sock *msk = mptcp_sk(sk); struct sock *ssk; pr_debug("msk=%p", msk); /* @@ the meaning of setsockopt() when the socket is connected and * there are multiple subflows is not yet defined. It is up to the * MPTCP-level socket to configure the subflows until the subflow * is in TCP fallback, when socket options are passed through * to the one remaining subflow. */ lock_sock(sk); ssk = __mptcp_tcp_fallback(msk); release_sock(sk); if (ssk) return tcp_getsockopt(ssk, level, optname, optval, option); if (level == SOL_TCP) return mptcp_getsockopt_sol_tcp(msk, optname, optval, option); if (level == SOL_MPTCP) return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option); return -EOPNOTSUPP; } static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk) { static const unsigned int tx_rx_locks = SOCK_RCVBUF_LOCK | SOCK_SNDBUF_LOCK; struct sock *sk = (struct sock *)msk; if (ssk->sk_prot->keepalive) { if (sock_flag(sk, SOCK_KEEPOPEN)) ssk->sk_prot->keepalive(ssk, 1); else ssk->sk_prot->keepalive(ssk, 0); } ssk->sk_priority = sk->sk_priority; ssk->sk_bound_dev_if = sk->sk_bound_dev_if; ssk->sk_incoming_cpu = sk->sk_incoming_cpu; if (sk->sk_userlocks & tx_rx_locks) { ssk->sk_userlocks |= sk->sk_userlocks & tx_rx_locks; if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); } if (sock_flag(sk, SOCK_LINGER)) { ssk->sk_lingertime = sk->sk_lingertime; sock_set_flag(ssk, SOCK_LINGER); } else { sock_reset_flag(ssk, SOCK_LINGER); } if (sk->sk_mark != ssk->sk_mark) { ssk->sk_mark = sk->sk_mark; sk_dst_reset(ssk); } sock_valbool_flag(ssk, SOCK_DBG, sock_flag(sk, SOCK_DBG)); if (inet_csk(sk)->icsk_ca_ops != inet_csk(ssk)->icsk_ca_ops) tcp_set_congestion_control(ssk, msk->ca_name, false, true); } static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) { bool slow = lock_sock_fast(ssk); sync_socket_options(msk, ssk); unlock_sock_fast(ssk, slow); } void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); msk_owned_by_me(msk); if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { __mptcp_sockopt_sync(msk, ssk); subflow->setsockopt_seq = msk->setsockopt_seq; } } void mptcp_sockopt_sync_all(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; u32 seq; seq = sockopt_seq_reset(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); u32 sseq = READ_ONCE(subflow->setsockopt_seq); if (sseq != msk->setsockopt_seq) { __mptcp_sockopt_sync(msk, ssk); WRITE_ONCE(subflow->setsockopt_seq, seq); } else if (sseq != seq) { WRITE_ONCE(subflow->setsockopt_seq, seq); } cond_resched(); } msk->setsockopt_seq = seq; }