mirror of
https://github.com/torvalds/linux.git
synced 2024-12-11 13:41:55 +00:00
5147dfb508
add ulp-specific diagnostic functions, so that subflow information can be dumped to userspace programs like 'ss'. v2 -> v3: - uapi: use bit macros appropriate for userspace Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1156 lines
30 KiB
C
1156 lines
30 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Multipath TCP
|
|
*
|
|
* Copyright (c) 2017 - 2019, Intel Corporation.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "MPTCP: " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/netdevice.h>
|
|
#include <crypto/algapi.h>
|
|
#include <net/sock.h>
|
|
#include <net/inet_common.h>
|
|
#include <net/inet_hashtables.h>
|
|
#include <net/protocol.h>
|
|
#include <net/tcp.h>
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
#include <net/ip6_route.h>
|
|
#endif
|
|
#include <net/mptcp.h>
|
|
#include "protocol.h"
|
|
|
|
static int subflow_rebuild_header(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
int local_id, err = 0;
|
|
|
|
if (subflow->request_mptcp && !subflow->token) {
|
|
pr_debug("subflow=%p", sk);
|
|
err = mptcp_token_new_connect(sk);
|
|
} else if (subflow->request_join && !subflow->local_nonce) {
|
|
struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn;
|
|
|
|
pr_debug("subflow=%p", sk);
|
|
|
|
do {
|
|
get_random_bytes(&subflow->local_nonce, sizeof(u32));
|
|
} while (!subflow->local_nonce);
|
|
|
|
if (subflow->local_id)
|
|
goto out;
|
|
|
|
local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)sk);
|
|
if (local_id < 0)
|
|
return -EINVAL;
|
|
|
|
subflow->local_id = local_id;
|
|
}
|
|
|
|
out:
|
|
if (err)
|
|
return err;
|
|
|
|
return subflow->icsk_af_ops->rebuild_header(sk);
|
|
}
|
|
|
|
static void subflow_req_destructor(struct request_sock *req)
|
|
{
|
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
|
|
|
|
pr_debug("subflow_req=%p", subflow_req);
|
|
|
|
if (subflow_req->mp_capable)
|
|
mptcp_token_destroy_request(subflow_req->token);
|
|
tcp_request_sock_ops.destructor(req);
|
|
}
|
|
|
|
static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
|
|
void *hmac)
|
|
{
|
|
u8 msg[8];
|
|
|
|
put_unaligned_be32(nonce1, &msg[0]);
|
|
put_unaligned_be32(nonce2, &msg[4]);
|
|
|
|
mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
|
|
}
|
|
|
|
/* validate received token and create truncated hmac and nonce for SYN-ACK */
|
|
static bool subflow_token_join_request(struct request_sock *req,
|
|
const struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
|
|
u8 hmac[MPTCPOPT_HMAC_LEN];
|
|
struct mptcp_sock *msk;
|
|
int local_id;
|
|
|
|
msk = mptcp_token_get_sock(subflow_req->token);
|
|
if (!msk) {
|
|
pr_debug("subflow_req=%p, token=%u - not found\n",
|
|
subflow_req, subflow_req->token);
|
|
return false;
|
|
}
|
|
|
|
local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req);
|
|
if (local_id < 0) {
|
|
sock_put((struct sock *)msk);
|
|
return false;
|
|
}
|
|
subflow_req->local_id = local_id;
|
|
|
|
get_random_bytes(&subflow_req->local_nonce, sizeof(u32));
|
|
|
|
subflow_generate_hmac(msk->local_key, msk->remote_key,
|
|
subflow_req->local_nonce,
|
|
subflow_req->remote_nonce, hmac);
|
|
|
|
subflow_req->thmac = get_unaligned_be64(hmac);
|
|
|
|
sock_put((struct sock *)msk);
|
|
return true;
|
|
}
|
|
|
|
static void subflow_init_req(struct request_sock *req,
|
|
const struct sock *sk_listener,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
|
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
|
|
struct tcp_options_received rx_opt;
|
|
|
|
pr_debug("subflow_req=%p, listener=%p", subflow_req, listener);
|
|
|
|
memset(&rx_opt.mptcp, 0, sizeof(rx_opt.mptcp));
|
|
mptcp_get_options(skb, &rx_opt);
|
|
|
|
subflow_req->mp_capable = 0;
|
|
subflow_req->mp_join = 0;
|
|
subflow_req->remote_key_valid = 0;
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
/* no MPTCP if MD5SIG is enabled on this socket or we may run out of
|
|
* TCP option space.
|
|
*/
|
|
if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info))
|
|
return;
|
|
#endif
|
|
|
|
if (rx_opt.mptcp.mp_capable && rx_opt.mptcp.mp_join)
|
|
return;
|
|
|
|
if (rx_opt.mptcp.mp_capable && listener->request_mptcp) {
|
|
int err;
|
|
|
|
err = mptcp_token_new_request(req);
|
|
if (err == 0)
|
|
subflow_req->mp_capable = 1;
|
|
|
|
subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
|
|
} else if (rx_opt.mptcp.mp_join && listener->request_mptcp) {
|
|
subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
|
|
subflow_req->mp_join = 1;
|
|
subflow_req->backup = rx_opt.mptcp.backup;
|
|
subflow_req->remote_id = rx_opt.mptcp.join_id;
|
|
subflow_req->token = rx_opt.mptcp.token;
|
|
subflow_req->remote_nonce = rx_opt.mptcp.nonce;
|
|
pr_debug("token=%u, remote_nonce=%u", subflow_req->token,
|
|
subflow_req->remote_nonce);
|
|
if (!subflow_token_join_request(req, skb)) {
|
|
subflow_req->mp_join = 0;
|
|
// @@ need to trigger RST
|
|
}
|
|
}
|
|
}
|
|
|
|
static void subflow_v4_init_req(struct request_sock *req,
|
|
const struct sock *sk_listener,
|
|
struct sk_buff *skb)
|
|
{
|
|
tcp_rsk(req)->is_mptcp = 1;
|
|
|
|
tcp_request_sock_ipv4_ops.init_req(req, sk_listener, skb);
|
|
|
|
subflow_init_req(req, sk_listener, skb);
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
static void subflow_v6_init_req(struct request_sock *req,
|
|
const struct sock *sk_listener,
|
|
struct sk_buff *skb)
|
|
{
|
|
tcp_rsk(req)->is_mptcp = 1;
|
|
|
|
tcp_request_sock_ipv6_ops.init_req(req, sk_listener, skb);
|
|
|
|
subflow_init_req(req, sk_listener, skb);
|
|
}
|
|
#endif
|
|
|
|
/* validate received truncated hmac and create hmac for third ACK */
|
|
static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow)
|
|
{
|
|
u8 hmac[MPTCPOPT_HMAC_LEN];
|
|
u64 thmac;
|
|
|
|
subflow_generate_hmac(subflow->remote_key, subflow->local_key,
|
|
subflow->remote_nonce, subflow->local_nonce,
|
|
hmac);
|
|
|
|
thmac = get_unaligned_be64(hmac);
|
|
pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n",
|
|
subflow, subflow->token,
|
|
(unsigned long long)thmac,
|
|
(unsigned long long)subflow->thmac);
|
|
|
|
return thmac == subflow->thmac;
|
|
}
|
|
|
|
static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct sock *parent = subflow->conn;
|
|
|
|
subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);
|
|
|
|
if (inet_sk_state_load(parent) != TCP_ESTABLISHED) {
|
|
inet_sk_state_store(parent, TCP_ESTABLISHED);
|
|
parent->sk_state_change(parent);
|
|
}
|
|
|
|
if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp)
|
|
return;
|
|
|
|
if (subflow->mp_capable) {
|
|
pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
|
|
subflow->remote_key);
|
|
mptcp_finish_connect(sk);
|
|
subflow->conn_finished = 1;
|
|
|
|
if (skb) {
|
|
pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq);
|
|
subflow->ssn_offset = TCP_SKB_CB(skb)->seq;
|
|
}
|
|
} else if (subflow->mp_join) {
|
|
pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u",
|
|
subflow, subflow->thmac,
|
|
subflow->remote_nonce);
|
|
if (!subflow_thmac_valid(subflow)) {
|
|
subflow->mp_join = 0;
|
|
goto do_reset;
|
|
}
|
|
|
|
subflow_generate_hmac(subflow->local_key, subflow->remote_key,
|
|
subflow->local_nonce,
|
|
subflow->remote_nonce,
|
|
subflow->hmac);
|
|
|
|
if (skb)
|
|
subflow->ssn_offset = TCP_SKB_CB(skb)->seq;
|
|
|
|
if (!mptcp_finish_join(sk))
|
|
goto do_reset;
|
|
|
|
subflow->conn_finished = 1;
|
|
} else {
|
|
do_reset:
|
|
tcp_send_active_reset(sk, GFP_ATOMIC);
|
|
tcp_done(sk);
|
|
}
|
|
}
|
|
|
|
static struct request_sock_ops subflow_request_sock_ops;
|
|
static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops;
|
|
|
|
static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
|
|
pr_debug("subflow=%p", subflow);
|
|
|
|
/* Never answer to SYNs sent to broadcast or multicast */
|
|
if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
|
|
goto drop;
|
|
|
|
return tcp_conn_request(&subflow_request_sock_ops,
|
|
&subflow_request_sock_ipv4_ops,
|
|
sk, skb);
|
|
drop:
|
|
tcp_listendrop(sk);
|
|
return 0;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops;
|
|
static struct inet_connection_sock_af_ops subflow_v6_specific;
|
|
static struct inet_connection_sock_af_ops subflow_v6m_specific;
|
|
|
|
static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
|
|
pr_debug("subflow=%p", subflow);
|
|
|
|
if (skb->protocol == htons(ETH_P_IP))
|
|
return subflow_v4_conn_request(sk, skb);
|
|
|
|
if (!ipv6_unicast_destination(skb))
|
|
goto drop;
|
|
|
|
return tcp_conn_request(&subflow_request_sock_ops,
|
|
&subflow_request_sock_ipv6_ops, sk, skb);
|
|
|
|
drop:
|
|
tcp_listendrop(sk);
|
|
return 0; /* don't send reset */
|
|
}
|
|
#endif
|
|
|
|
/* validate hmac received in third ACK */
|
|
static bool subflow_hmac_valid(const struct request_sock *req,
|
|
const struct tcp_options_received *rx_opt)
|
|
{
|
|
const struct mptcp_subflow_request_sock *subflow_req;
|
|
u8 hmac[MPTCPOPT_HMAC_LEN];
|
|
struct mptcp_sock *msk;
|
|
bool ret;
|
|
|
|
subflow_req = mptcp_subflow_rsk(req);
|
|
msk = mptcp_token_get_sock(subflow_req->token);
|
|
if (!msk)
|
|
return false;
|
|
|
|
subflow_generate_hmac(msk->remote_key, msk->local_key,
|
|
subflow_req->remote_nonce,
|
|
subflow_req->local_nonce, hmac);
|
|
|
|
ret = true;
|
|
if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac)))
|
|
ret = false;
|
|
|
|
sock_put((struct sock *)msk);
|
|
return ret;
|
|
}
|
|
|
|
static struct sock *subflow_syn_recv_sock(const struct sock *sk,
|
|
struct sk_buff *skb,
|
|
struct request_sock *req,
|
|
struct dst_entry *dst,
|
|
struct request_sock *req_unhash,
|
|
bool *own_req)
|
|
{
|
|
struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk);
|
|
struct mptcp_subflow_request_sock *subflow_req;
|
|
struct tcp_options_received opt_rx;
|
|
bool fallback_is_fatal = false;
|
|
struct sock *new_msk = NULL;
|
|
struct sock *child;
|
|
|
|
pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn);
|
|
|
|
if (tcp_rsk(req)->is_mptcp == 0)
|
|
goto create_child;
|
|
|
|
/* if the sk is MP_CAPABLE, we try to fetch the client key */
|
|
subflow_req = mptcp_subflow_rsk(req);
|
|
if (subflow_req->mp_capable) {
|
|
if (TCP_SKB_CB(skb)->seq != subflow_req->ssn_offset + 1) {
|
|
/* here we can receive and accept an in-window,
|
|
* out-of-order pkt, which will not carry the MP_CAPABLE
|
|
* opt even on mptcp enabled paths
|
|
*/
|
|
goto create_msk;
|
|
}
|
|
|
|
opt_rx.mptcp.mp_capable = 0;
|
|
mptcp_get_options(skb, &opt_rx);
|
|
if (opt_rx.mptcp.mp_capable) {
|
|
subflow_req->remote_key = opt_rx.mptcp.sndr_key;
|
|
subflow_req->remote_key_valid = 1;
|
|
} else {
|
|
subflow_req->mp_capable = 0;
|
|
goto create_child;
|
|
}
|
|
|
|
create_msk:
|
|
new_msk = mptcp_sk_clone(listener->conn, req);
|
|
if (!new_msk)
|
|
subflow_req->mp_capable = 0;
|
|
} else if (subflow_req->mp_join) {
|
|
fallback_is_fatal = true;
|
|
opt_rx.mptcp.mp_join = 0;
|
|
mptcp_get_options(skb, &opt_rx);
|
|
if (!opt_rx.mptcp.mp_join ||
|
|
!subflow_hmac_valid(req, &opt_rx))
|
|
return NULL;
|
|
}
|
|
|
|
create_child:
|
|
child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst,
|
|
req_unhash, own_req);
|
|
|
|
if (child && *own_req) {
|
|
struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child);
|
|
|
|
/* we have null ctx on TCP fallback, which is fatal on
|
|
* MPJ handshake
|
|
*/
|
|
if (!ctx) {
|
|
if (fallback_is_fatal)
|
|
goto close_child;
|
|
goto out;
|
|
}
|
|
|
|
if (ctx->mp_capable) {
|
|
/* new mpc subflow takes ownership of the newly
|
|
* created mptcp socket
|
|
*/
|
|
inet_sk_state_store(new_msk, TCP_ESTABLISHED);
|
|
mptcp_pm_new_connection(mptcp_sk(new_msk), 1);
|
|
ctx->conn = new_msk;
|
|
new_msk = NULL;
|
|
} else if (ctx->mp_join) {
|
|
struct mptcp_sock *owner;
|
|
|
|
owner = mptcp_token_get_sock(ctx->token);
|
|
if (!owner)
|
|
goto close_child;
|
|
|
|
ctx->conn = (struct sock *)owner;
|
|
if (!mptcp_finish_join(child))
|
|
goto close_child;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/* dispose of the left over mptcp master, if any */
|
|
if (unlikely(new_msk))
|
|
sock_put(new_msk);
|
|
return child;
|
|
|
|
close_child:
|
|
tcp_send_active_reset(child, GFP_ATOMIC);
|
|
inet_csk_prepare_forced_close(child);
|
|
tcp_done(child);
|
|
return NULL;
|
|
}
|
|
|
|
static struct inet_connection_sock_af_ops subflow_specific;
|
|
|
|
enum mapping_status {
|
|
MAPPING_OK,
|
|
MAPPING_INVALID,
|
|
MAPPING_EMPTY,
|
|
MAPPING_DATA_FIN
|
|
};
|
|
|
|
static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq)
|
|
{
|
|
if ((u32)seq == (u32)old_seq)
|
|
return old_seq;
|
|
|
|
/* Assume map covers data not mapped yet. */
|
|
return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32));
|
|
}
|
|
|
|
static void warn_bad_map(struct mptcp_subflow_context *subflow, u32 ssn)
|
|
{
|
|
WARN_ONCE(1, "Bad mapping: ssn=%d map_seq=%d map_data_len=%d",
|
|
ssn, subflow->map_subflow_seq, subflow->map_data_len);
|
|
}
|
|
|
|
static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
|
|
unsigned int skb_consumed;
|
|
|
|
skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq;
|
|
if (WARN_ON_ONCE(skb_consumed >= skb->len))
|
|
return true;
|
|
|
|
return skb->len - skb_consumed <= subflow->map_data_len -
|
|
mptcp_subflow_get_map_offset(subflow);
|
|
}
|
|
|
|
static bool validate_mapping(struct sock *ssk, struct sk_buff *skb)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
|
|
u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset;
|
|
|
|
if (unlikely(before(ssn, subflow->map_subflow_seq))) {
|
|
/* Mapping covers data later in the subflow stream,
|
|
* currently unsupported.
|
|
*/
|
|
warn_bad_map(subflow, ssn);
|
|
return false;
|
|
}
|
|
if (unlikely(!before(ssn, subflow->map_subflow_seq +
|
|
subflow->map_data_len))) {
|
|
/* Mapping does covers past subflow data, invalid */
|
|
warn_bad_map(subflow, ssn + skb->len);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static enum mapping_status get_mapping_status(struct sock *ssk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
|
|
struct mptcp_ext *mpext;
|
|
struct sk_buff *skb;
|
|
u16 data_len;
|
|
u64 map_seq;
|
|
|
|
skb = skb_peek(&ssk->sk_receive_queue);
|
|
if (!skb)
|
|
return MAPPING_EMPTY;
|
|
|
|
mpext = mptcp_get_ext(skb);
|
|
if (!mpext || !mpext->use_map) {
|
|
if (!subflow->map_valid && !skb->len) {
|
|
/* the TCP stack deliver 0 len FIN pkt to the receive
|
|
* queue, that is the only 0len pkts ever expected here,
|
|
* and we can admit no mapping only for 0 len pkts
|
|
*/
|
|
if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
|
|
WARN_ONCE(1, "0len seq %d:%d flags %x",
|
|
TCP_SKB_CB(skb)->seq,
|
|
TCP_SKB_CB(skb)->end_seq,
|
|
TCP_SKB_CB(skb)->tcp_flags);
|
|
sk_eat_skb(ssk, skb);
|
|
return MAPPING_EMPTY;
|
|
}
|
|
|
|
if (!subflow->map_valid)
|
|
return MAPPING_INVALID;
|
|
|
|
goto validate_seq;
|
|
}
|
|
|
|
pr_debug("seq=%llu is64=%d ssn=%u data_len=%u data_fin=%d",
|
|
mpext->data_seq, mpext->dsn64, mpext->subflow_seq,
|
|
mpext->data_len, mpext->data_fin);
|
|
|
|
data_len = mpext->data_len;
|
|
if (data_len == 0) {
|
|
pr_err("Infinite mapping not handled");
|
|
return MAPPING_INVALID;
|
|
}
|
|
|
|
if (mpext->data_fin == 1) {
|
|
if (data_len == 1) {
|
|
pr_debug("DATA_FIN with no payload");
|
|
if (subflow->map_valid) {
|
|
/* A DATA_FIN might arrive in a DSS
|
|
* option before the previous mapping
|
|
* has been fully consumed. Continue
|
|
* handling the existing mapping.
|
|
*/
|
|
skb_ext_del(skb, SKB_EXT_MPTCP);
|
|
return MAPPING_OK;
|
|
} else {
|
|
return MAPPING_DATA_FIN;
|
|
}
|
|
}
|
|
|
|
/* Adjust for DATA_FIN using 1 byte of sequence space */
|
|
data_len--;
|
|
}
|
|
|
|
if (!mpext->dsn64) {
|
|
map_seq = expand_seq(subflow->map_seq, subflow->map_data_len,
|
|
mpext->data_seq);
|
|
pr_debug("expanded seq=%llu", subflow->map_seq);
|
|
} else {
|
|
map_seq = mpext->data_seq;
|
|
}
|
|
|
|
if (subflow->map_valid) {
|
|
/* Allow replacing only with an identical map */
|
|
if (subflow->map_seq == map_seq &&
|
|
subflow->map_subflow_seq == mpext->subflow_seq &&
|
|
subflow->map_data_len == data_len) {
|
|
skb_ext_del(skb, SKB_EXT_MPTCP);
|
|
return MAPPING_OK;
|
|
}
|
|
|
|
/* If this skb data are fully covered by the current mapping,
|
|
* the new map would need caching, which is not supported
|
|
*/
|
|
if (skb_is_fully_mapped(ssk, skb))
|
|
return MAPPING_INVALID;
|
|
|
|
/* will validate the next map after consuming the current one */
|
|
return MAPPING_OK;
|
|
}
|
|
|
|
subflow->map_seq = map_seq;
|
|
subflow->map_subflow_seq = mpext->subflow_seq;
|
|
subflow->map_data_len = data_len;
|
|
subflow->map_valid = 1;
|
|
subflow->mpc_map = mpext->mpc_map;
|
|
pr_debug("new map seq=%llu subflow_seq=%u data_len=%u",
|
|
subflow->map_seq, subflow->map_subflow_seq,
|
|
subflow->map_data_len);
|
|
|
|
validate_seq:
|
|
/* we revalidate valid mapping on new skb, because we must ensure
|
|
* the current skb is completely covered by the available mapping
|
|
*/
|
|
if (!validate_mapping(ssk, skb))
|
|
return MAPPING_INVALID;
|
|
|
|
skb_ext_del(skb, SKB_EXT_MPTCP);
|
|
return MAPPING_OK;
|
|
}
|
|
|
|
static int subflow_read_actor(read_descriptor_t *desc,
|
|
struct sk_buff *skb,
|
|
unsigned int offset, size_t len)
|
|
{
|
|
size_t copy_len = min(desc->count, len);
|
|
|
|
desc->count -= copy_len;
|
|
|
|
pr_debug("flushed %zu bytes, %zu left", copy_len, desc->count);
|
|
return copy_len;
|
|
}
|
|
|
|
static bool subflow_check_data_avail(struct sock *ssk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
|
|
enum mapping_status status;
|
|
struct mptcp_sock *msk;
|
|
struct sk_buff *skb;
|
|
|
|
pr_debug("msk=%p ssk=%p data_avail=%d skb=%p", subflow->conn, ssk,
|
|
subflow->data_avail, skb_peek(&ssk->sk_receive_queue));
|
|
if (subflow->data_avail)
|
|
return true;
|
|
|
|
msk = mptcp_sk(subflow->conn);
|
|
for (;;) {
|
|
u32 map_remaining;
|
|
size_t delta;
|
|
u64 ack_seq;
|
|
u64 old_ack;
|
|
|
|
status = get_mapping_status(ssk);
|
|
pr_debug("msk=%p ssk=%p status=%d", msk, ssk, status);
|
|
if (status == MAPPING_INVALID) {
|
|
ssk->sk_err = EBADMSG;
|
|
goto fatal;
|
|
}
|
|
|
|
if (status != MAPPING_OK)
|
|
return false;
|
|
|
|
skb = skb_peek(&ssk->sk_receive_queue);
|
|
if (WARN_ON_ONCE(!skb))
|
|
return false;
|
|
|
|
/* if msk lacks the remote key, this subflow must provide an
|
|
* MP_CAPABLE-based mapping
|
|
*/
|
|
if (unlikely(!READ_ONCE(msk->can_ack))) {
|
|
if (!subflow->mpc_map) {
|
|
ssk->sk_err = EBADMSG;
|
|
goto fatal;
|
|
}
|
|
WRITE_ONCE(msk->remote_key, subflow->remote_key);
|
|
WRITE_ONCE(msk->ack_seq, subflow->map_seq);
|
|
WRITE_ONCE(msk->can_ack, true);
|
|
}
|
|
|
|
old_ack = READ_ONCE(msk->ack_seq);
|
|
ack_seq = mptcp_subflow_get_mapped_dsn(subflow);
|
|
pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack,
|
|
ack_seq);
|
|
if (ack_seq == old_ack)
|
|
break;
|
|
|
|
/* only accept in-sequence mapping. Old values are spurious
|
|
* retransmission; we can hit "future" values on active backup
|
|
* subflow switch, we relay on retransmissions to get
|
|
* in-sequence data.
|
|
* Cuncurrent subflows support will require subflow data
|
|
* reordering
|
|
*/
|
|
map_remaining = subflow->map_data_len -
|
|
mptcp_subflow_get_map_offset(subflow);
|
|
if (before64(ack_seq, old_ack))
|
|
delta = min_t(size_t, old_ack - ack_seq, map_remaining);
|
|
else
|
|
delta = min_t(size_t, ack_seq - old_ack, map_remaining);
|
|
|
|
/* discard mapped data */
|
|
pr_debug("discarding %zu bytes, current map len=%d", delta,
|
|
map_remaining);
|
|
if (delta) {
|
|
read_descriptor_t desc = {
|
|
.count = delta,
|
|
};
|
|
int ret;
|
|
|
|
ret = tcp_read_sock(ssk, &desc, subflow_read_actor);
|
|
if (ret < 0) {
|
|
ssk->sk_err = -ret;
|
|
goto fatal;
|
|
}
|
|
if (ret < delta)
|
|
return false;
|
|
if (delta == map_remaining)
|
|
subflow->map_valid = 0;
|
|
}
|
|
}
|
|
return true;
|
|
|
|
fatal:
|
|
/* fatal protocol error, close the socket */
|
|
/* This barrier is coupled with smp_rmb() in tcp_poll() */
|
|
smp_wmb();
|
|
ssk->sk_error_report(ssk);
|
|
tcp_set_state(ssk, TCP_CLOSE);
|
|
tcp_send_active_reset(ssk, GFP_ATOMIC);
|
|
return false;
|
|
}
|
|
|
|
bool mptcp_subflow_data_available(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct sk_buff *skb;
|
|
|
|
/* check if current mapping is still valid */
|
|
if (subflow->map_valid &&
|
|
mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) {
|
|
subflow->map_valid = 0;
|
|
subflow->data_avail = 0;
|
|
|
|
pr_debug("Done with mapping: seq=%u data_len=%u",
|
|
subflow->map_subflow_seq,
|
|
subflow->map_data_len);
|
|
}
|
|
|
|
if (!subflow_check_data_avail(sk)) {
|
|
subflow->data_avail = 0;
|
|
return false;
|
|
}
|
|
|
|
skb = skb_peek(&sk->sk_receive_queue);
|
|
subflow->data_avail = skb &&
|
|
before(tcp_sk(sk)->copied_seq, TCP_SKB_CB(skb)->end_seq);
|
|
return subflow->data_avail;
|
|
}
|
|
|
|
static void subflow_data_ready(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct sock *parent = subflow->conn;
|
|
|
|
if (!subflow->mp_capable && !subflow->mp_join) {
|
|
subflow->tcp_data_ready(sk);
|
|
|
|
parent->sk_data_ready(parent);
|
|
return;
|
|
}
|
|
|
|
if (mptcp_subflow_data_available(sk))
|
|
mptcp_data_ready(parent, sk);
|
|
}
|
|
|
|
static void subflow_write_space(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct sock *parent = subflow->conn;
|
|
|
|
sk_stream_write_space(sk);
|
|
if (sk_stream_is_writeable(sk)) {
|
|
set_bit(MPTCP_SEND_SPACE, &mptcp_sk(parent)->flags);
|
|
smp_mb__after_atomic();
|
|
/* set SEND_SPACE before sk_stream_write_space clears NOSPACE */
|
|
sk_stream_write_space(parent);
|
|
}
|
|
}
|
|
|
|
static struct inet_connection_sock_af_ops *
|
|
subflow_default_af_ops(struct sock *sk)
|
|
{
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
if (sk->sk_family == AF_INET6)
|
|
return &subflow_v6_specific;
|
|
#endif
|
|
return &subflow_specific;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
void mptcpv6_handle_mapped(struct sock *sk, bool mapped)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct inet_connection_sock_af_ops *target;
|
|
|
|
target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk);
|
|
|
|
pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d",
|
|
subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped);
|
|
|
|
if (likely(icsk->icsk_af_ops == target))
|
|
return;
|
|
|
|
subflow->icsk_af_ops = icsk->icsk_af_ops;
|
|
icsk->icsk_af_ops = target;
|
|
}
|
|
#endif
|
|
|
|
static void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
|
|
struct sockaddr_storage *addr)
|
|
{
|
|
memset(addr, 0, sizeof(*addr));
|
|
addr->ss_family = info->family;
|
|
if (addr->ss_family == AF_INET) {
|
|
struct sockaddr_in *in_addr = (struct sockaddr_in *)addr;
|
|
|
|
in_addr->sin_addr = info->addr;
|
|
in_addr->sin_port = info->port;
|
|
}
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
else if (addr->ss_family == AF_INET6) {
|
|
struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr;
|
|
|
|
in6_addr->sin6_addr = info->addr6;
|
|
in6_addr->sin6_port = info->port;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
int __mptcp_subflow_connect(struct sock *sk, int ifindex,
|
|
const struct mptcp_addr_info *loc,
|
|
const struct mptcp_addr_info *remote)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct mptcp_subflow_context *subflow;
|
|
struct sockaddr_storage addr;
|
|
struct socket *sf;
|
|
u32 remote_token;
|
|
int addrlen;
|
|
int err;
|
|
|
|
if (sk->sk_state != TCP_ESTABLISHED)
|
|
return -ENOTCONN;
|
|
|
|
err = mptcp_subflow_create_socket(sk, &sf);
|
|
if (err)
|
|
return err;
|
|
|
|
subflow = mptcp_subflow_ctx(sf->sk);
|
|
subflow->remote_key = msk->remote_key;
|
|
subflow->local_key = msk->local_key;
|
|
subflow->token = msk->token;
|
|
mptcp_info2sockaddr(loc, &addr);
|
|
|
|
addrlen = sizeof(struct sockaddr_in);
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
if (loc->family == AF_INET6)
|
|
addrlen = sizeof(struct sockaddr_in6);
|
|
#endif
|
|
sf->sk->sk_bound_dev_if = ifindex;
|
|
err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen);
|
|
if (err)
|
|
goto failed;
|
|
|
|
mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL);
|
|
pr_debug("msk=%p remote_token=%u", msk, remote_token);
|
|
subflow->remote_token = remote_token;
|
|
subflow->local_id = loc->id;
|
|
subflow->request_join = 1;
|
|
subflow->request_bkup = 1;
|
|
mptcp_info2sockaddr(remote, &addr);
|
|
|
|
err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK);
|
|
if (err && err != -EINPROGRESS)
|
|
goto failed;
|
|
|
|
spin_lock_bh(&msk->join_list_lock);
|
|
list_add_tail(&subflow->node, &msk->join_list);
|
|
spin_unlock_bh(&msk->join_list_lock);
|
|
|
|
return err;
|
|
|
|
failed:
|
|
sock_release(sf);
|
|
return err;
|
|
}
|
|
|
|
int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock)
|
|
{
|
|
struct mptcp_subflow_context *subflow;
|
|
struct net *net = sock_net(sk);
|
|
struct socket *sf;
|
|
int err;
|
|
|
|
err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP,
|
|
&sf);
|
|
if (err)
|
|
return err;
|
|
|
|
lock_sock(sf->sk);
|
|
|
|
/* kernel sockets do not by default acquire net ref, but TCP timer
|
|
* needs it.
|
|
*/
|
|
sf->sk->sk_net_refcnt = 1;
|
|
get_net(net);
|
|
#ifdef CONFIG_PROC_FS
|
|
this_cpu_add(*net->core.sock_inuse, 1);
|
|
#endif
|
|
err = tcp_set_ulp(sf->sk, "mptcp");
|
|
release_sock(sf->sk);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
subflow = mptcp_subflow_ctx(sf->sk);
|
|
pr_debug("subflow=%p", subflow);
|
|
|
|
*new_sock = sf;
|
|
sock_hold(sk);
|
|
subflow->conn = sk;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk,
|
|
gfp_t priority)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct mptcp_subflow_context *ctx;
|
|
|
|
ctx = kzalloc(sizeof(*ctx), priority);
|
|
if (!ctx)
|
|
return NULL;
|
|
|
|
rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
|
|
INIT_LIST_HEAD(&ctx->node);
|
|
|
|
pr_debug("subflow=%p", ctx);
|
|
|
|
ctx->tcp_sock = sk;
|
|
|
|
return ctx;
|
|
}
|
|
|
|
static void __subflow_state_change(struct sock *sk)
|
|
{
|
|
struct socket_wq *wq;
|
|
|
|
rcu_read_lock();
|
|
wq = rcu_dereference(sk->sk_wq);
|
|
if (skwq_has_sleeper(wq))
|
|
wake_up_interruptible_all(&wq->wait);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static bool subflow_is_done(const struct sock *sk)
|
|
{
|
|
return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE;
|
|
}
|
|
|
|
static void subflow_state_change(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
|
|
struct sock *parent = subflow->conn;
|
|
|
|
__subflow_state_change(sk);
|
|
|
|
/* as recvmsg() does not acquire the subflow socket for ssk selection
|
|
* a fin packet carrying a DSS can be unnoticed if we don't trigger
|
|
* the data available machinery here.
|
|
*/
|
|
if (subflow->mp_capable && mptcp_subflow_data_available(sk))
|
|
mptcp_data_ready(parent, sk);
|
|
|
|
if (!(parent->sk_shutdown & RCV_SHUTDOWN) &&
|
|
!subflow->rx_eof && subflow_is_done(sk)) {
|
|
subflow->rx_eof = 1;
|
|
parent->sk_shutdown |= RCV_SHUTDOWN;
|
|
__subflow_state_change(parent);
|
|
}
|
|
}
|
|
|
|
static int subflow_ulp_init(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct mptcp_subflow_context *ctx;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int err = 0;
|
|
|
|
/* disallow attaching ULP to a socket unless it has been
|
|
* created with sock_create_kern()
|
|
*/
|
|
if (!sk->sk_kern_sock) {
|
|
err = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
ctx = subflow_create_ctx(sk, GFP_KERNEL);
|
|
if (!ctx) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
pr_debug("subflow=%p, family=%d", ctx, sk->sk_family);
|
|
|
|
tp->is_mptcp = 1;
|
|
ctx->icsk_af_ops = icsk->icsk_af_ops;
|
|
icsk->icsk_af_ops = subflow_default_af_ops(sk);
|
|
ctx->tcp_data_ready = sk->sk_data_ready;
|
|
ctx->tcp_state_change = sk->sk_state_change;
|
|
ctx->tcp_write_space = sk->sk_write_space;
|
|
sk->sk_data_ready = subflow_data_ready;
|
|
sk->sk_write_space = subflow_write_space;
|
|
sk->sk_state_change = subflow_state_change;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static void subflow_ulp_release(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk);
|
|
|
|
if (!ctx)
|
|
return;
|
|
|
|
if (ctx->conn)
|
|
sock_put(ctx->conn);
|
|
|
|
kfree_rcu(ctx, rcu);
|
|
}
|
|
|
|
static void subflow_ulp_fallback(struct sock *sk,
|
|
struct mptcp_subflow_context *old_ctx)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
mptcp_subflow_tcp_fallback(sk, old_ctx);
|
|
icsk->icsk_ulp_ops = NULL;
|
|
rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
|
|
tcp_sk(sk)->is_mptcp = 0;
|
|
}
|
|
|
|
static void subflow_ulp_clone(const struct request_sock *req,
|
|
struct sock *newsk,
|
|
const gfp_t priority)
|
|
{
|
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
|
|
struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk);
|
|
struct mptcp_subflow_context *new_ctx;
|
|
|
|
if (!tcp_rsk(req)->is_mptcp ||
|
|
(!subflow_req->mp_capable && !subflow_req->mp_join)) {
|
|
subflow_ulp_fallback(newsk, old_ctx);
|
|
return;
|
|
}
|
|
|
|
new_ctx = subflow_create_ctx(newsk, priority);
|
|
if (!new_ctx) {
|
|
subflow_ulp_fallback(newsk, old_ctx);
|
|
return;
|
|
}
|
|
|
|
new_ctx->conn_finished = 1;
|
|
new_ctx->icsk_af_ops = old_ctx->icsk_af_ops;
|
|
new_ctx->tcp_data_ready = old_ctx->tcp_data_ready;
|
|
new_ctx->tcp_state_change = old_ctx->tcp_state_change;
|
|
new_ctx->tcp_write_space = old_ctx->tcp_write_space;
|
|
new_ctx->rel_write_seq = 1;
|
|
new_ctx->tcp_sock = newsk;
|
|
|
|
if (subflow_req->mp_capable) {
|
|
/* see comments in subflow_syn_recv_sock(), MPTCP connection
|
|
* is fully established only after we receive the remote key
|
|
*/
|
|
new_ctx->mp_capable = 1;
|
|
new_ctx->fully_established = subflow_req->remote_key_valid;
|
|
new_ctx->can_ack = subflow_req->remote_key_valid;
|
|
new_ctx->remote_key = subflow_req->remote_key;
|
|
new_ctx->local_key = subflow_req->local_key;
|
|
new_ctx->token = subflow_req->token;
|
|
new_ctx->ssn_offset = subflow_req->ssn_offset;
|
|
new_ctx->idsn = subflow_req->idsn;
|
|
} else if (subflow_req->mp_join) {
|
|
new_ctx->ssn_offset = subflow_req->ssn_offset;
|
|
new_ctx->mp_join = 1;
|
|
new_ctx->fully_established = 1;
|
|
new_ctx->backup = subflow_req->backup;
|
|
new_ctx->local_id = subflow_req->local_id;
|
|
new_ctx->token = subflow_req->token;
|
|
new_ctx->thmac = subflow_req->thmac;
|
|
}
|
|
}
|
|
|
|
static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = {
|
|
.name = "mptcp",
|
|
.owner = THIS_MODULE,
|
|
.init = subflow_ulp_init,
|
|
.release = subflow_ulp_release,
|
|
.clone = subflow_ulp_clone,
|
|
};
|
|
|
|
static int subflow_ops_init(struct request_sock_ops *subflow_ops)
|
|
{
|
|
subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock);
|
|
subflow_ops->slab_name = "request_sock_subflow";
|
|
|
|
subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name,
|
|
subflow_ops->obj_size, 0,
|
|
SLAB_ACCOUNT |
|
|
SLAB_TYPESAFE_BY_RCU,
|
|
NULL);
|
|
if (!subflow_ops->slab)
|
|
return -ENOMEM;
|
|
|
|
subflow_ops->destructor = subflow_req_destructor;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void mptcp_subflow_init(void)
|
|
{
|
|
subflow_request_sock_ops = tcp_request_sock_ops;
|
|
if (subflow_ops_init(&subflow_request_sock_ops) != 0)
|
|
panic("MPTCP: failed to init subflow request sock ops\n");
|
|
|
|
subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops;
|
|
subflow_request_sock_ipv4_ops.init_req = subflow_v4_init_req;
|
|
|
|
subflow_specific = ipv4_specific;
|
|
subflow_specific.conn_request = subflow_v4_conn_request;
|
|
subflow_specific.syn_recv_sock = subflow_syn_recv_sock;
|
|
subflow_specific.sk_rx_dst_set = subflow_finish_connect;
|
|
subflow_specific.rebuild_header = subflow_rebuild_header;
|
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops;
|
|
subflow_request_sock_ipv6_ops.init_req = subflow_v6_init_req;
|
|
|
|
subflow_v6_specific = ipv6_specific;
|
|
subflow_v6_specific.conn_request = subflow_v6_conn_request;
|
|
subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock;
|
|
subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect;
|
|
subflow_v6_specific.rebuild_header = subflow_rebuild_header;
|
|
|
|
subflow_v6m_specific = subflow_v6_specific;
|
|
subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit;
|
|
subflow_v6m_specific.send_check = ipv4_specific.send_check;
|
|
subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len;
|
|
subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced;
|
|
subflow_v6m_specific.net_frag_header_len = 0;
|
|
#endif
|
|
|
|
mptcp_diag_subflow_init(&subflow_ulp_ops);
|
|
|
|
if (tcp_register_ulp(&subflow_ulp_ops) != 0)
|
|
panic("MPTCP: failed to register subflows to ULP\n");
|
|
}
|