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-rw-r--r--net/mptcp/ctrl.c4
-rw-r--r--net/mptcp/mib.c5
-rw-r--r--net/mptcp/mib.h7
-rw-r--r--net/mptcp/options.c6
-rw-r--r--net/mptcp/pm.c8
-rw-r--r--net/mptcp/protocol.c104
-rw-r--r--net/mptcp/protocol.h36
-rw-r--r--net/mptcp/sockopt.c33
-rw-r--r--net/mptcp/subflow.c40
9 files changed, 174 insertions, 69 deletions
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index d9290c5bb6c7..fed40dae5583 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -533,9 +533,9 @@ void mptcp_active_detect_blackhole(struct sock *ssk, bool expired)
to_max = mptcp_get_pernet(net)->syn_retrans_before_tcp_fallback;
if (timeouts == to_max || (timeouts < to_max && expired)) {
- MPTCP_INC_STATS(net, MPTCP_MIB_MPCAPABLEACTIVEDROP);
subflow->mpc_drop = 1;
- mptcp_subflow_early_fallback(mptcp_sk(subflow->conn), subflow);
+ mptcp_early_fallback(mptcp_sk(subflow->conn), subflow,
+ MPTCP_MIB_MPCAPABLEACTIVEDROP);
}
}
diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 0c24545f0e8d..cf879c188ca2 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -80,6 +80,11 @@ static const struct snmp_mib mptcp_snmp_list[] = {
SNMP_MIB_ITEM("RcvWndConflict", MPTCP_MIB_RCVWNDCONFLICT),
SNMP_MIB_ITEM("MPCurrEstab", MPTCP_MIB_CURRESTAB),
SNMP_MIB_ITEM("Blackhole", MPTCP_MIB_BLACKHOLE),
+ SNMP_MIB_ITEM("MPCapableDataFallback", MPTCP_MIB_MPCAPABLEDATAFALLBACK),
+ SNMP_MIB_ITEM("MD5SigFallback", MPTCP_MIB_MD5SIGFALLBACK),
+ SNMP_MIB_ITEM("DssFallback", MPTCP_MIB_DSSFALLBACK),
+ SNMP_MIB_ITEM("SimultConnectFallback", MPTCP_MIB_SIMULTCONNFALLBACK),
+ SNMP_MIB_ITEM("FallbackFailed", MPTCP_MIB_FALLBACKFAILED),
SNMP_MIB_SENTINEL
};
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index 250c6b77977e..309bac6fea32 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -81,6 +81,13 @@ enum linux_mptcp_mib_field {
MPTCP_MIB_RCVWNDCONFLICT, /* Conflict with while updating msk rcv wnd */
MPTCP_MIB_CURRESTAB, /* Current established MPTCP connections */
MPTCP_MIB_BLACKHOLE, /* A blackhole has been detected */
+ MPTCP_MIB_MPCAPABLEDATAFALLBACK, /* Missing DSS/MPC+data on first
+ * established packet
+ */
+ MPTCP_MIB_MD5SIGFALLBACK, /* Conflicting TCP option enabled */
+ MPTCP_MIB_DSSFALLBACK, /* Bad or missing DSS */
+ MPTCP_MIB_SIMULTCONNFALLBACK, /* Simultaneous connect */
+ MPTCP_MIB_FALLBACKFAILED, /* Can't fallback due to msk status */
__MPTCP_MIB_MAX
};
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 421ced031289..70c0ab0ecf90 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -978,8 +978,10 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
if (subflow->mp_join)
goto reset;
subflow->mp_capable = 0;
- pr_fallback(msk);
- mptcp_do_fallback(ssk);
+ if (!mptcp_try_fallback(ssk, MPTCP_MIB_MPCAPABLEDATAFALLBACK)) {
+ MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_FALLBACKFAILED);
+ goto reset;
+ }
return false;
}
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index feb01747d7d8..420d416e2603 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -765,8 +765,14 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
pr_debug("fail_seq=%llu\n", fail_seq);
- if (!READ_ONCE(msk->allow_infinite_fallback))
+ /* After accepting the fail, we can't create any other subflows */
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_infinite_fallback) {
+ spin_unlock_bh(&msk->fallback_lock);
return;
+ }
+ msk->allow_subflows = false;
+ spin_unlock_bh(&msk->fallback_lock);
if (!subflow->fail_tout) {
pr_debug("send MP_FAIL response and infinite map\n");
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index edf14c2c2062..9a287b75c1b3 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -11,6 +11,7 @@
#include <linux/netdevice.h>
#include <linux/sched/signal.h>
#include <linux/atomic.h>
+#include <net/aligned_data.h>
#include <net/sock.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
@@ -67,6 +68,26 @@ static const struct proto_ops *mptcp_fallback_tcp_ops(const struct sock *sk)
return &inet_stream_ops;
}
+bool __mptcp_try_fallback(struct mptcp_sock *msk, int fb_mib)
+{
+ struct net *net = sock_net((struct sock *)msk);
+
+ if (__mptcp_check_fallback(msk))
+ return true;
+
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_infinite_fallback) {
+ spin_unlock_bh(&msk->fallback_lock);
+ return false;
+ }
+
+ msk->allow_subflows = false;
+ set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
+ __MPTCP_INC_STATS(net, fb_mib);
+ spin_unlock_bh(&msk->fallback_lock);
+ return true;
+}
+
static int __mptcp_socket_create(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
@@ -560,11 +581,7 @@ static bool mptcp_check_data_fin(struct sock *sk)
static void mptcp_dss_corruption(struct mptcp_sock *msk, struct sock *ssk)
{
- if (READ_ONCE(msk->allow_infinite_fallback)) {
- MPTCP_INC_STATS(sock_net(ssk),
- MPTCP_MIB_DSSCORRUPTIONFALLBACK);
- mptcp_do_fallback(ssk);
- } else {
+ if (!mptcp_try_fallback(ssk, MPTCP_MIB_DSSCORRUPTIONFALLBACK)) {
MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSCORRUPTIONRESET);
mptcp_subflow_reset(ssk);
}
@@ -792,7 +809,7 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk)
static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
{
mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
- WRITE_ONCE(msk->allow_infinite_fallback, false);
+ msk->allow_infinite_fallback = false;
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
}
@@ -803,6 +820,14 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
if (sk->sk_state != TCP_ESTABLISHED)
return false;
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_subflows) {
+ spin_unlock_bh(&msk->fallback_lock);
+ return false;
+ }
+ mptcp_subflow_joined(msk, ssk);
+ spin_unlock_bh(&msk->fallback_lock);
+
/* attach to msk socket only after we are sure we will deal with it
* at close time
*/
@@ -811,7 +836,6 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
mptcp_subflow_ctx(ssk)->subflow_id = msk->subflow_id++;
mptcp_sockopt_sync_locked(msk, ssk);
- mptcp_subflow_joined(msk, ssk);
mptcp_stop_tout_timer(sk);
__mptcp_propagate_sndbuf(sk, ssk);
return true;
@@ -1136,10 +1160,13 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk,
mpext->infinite_map = 1;
mpext->data_len = 0;
- MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
+ if (!mptcp_try_fallback(ssk, MPTCP_MIB_INFINITEMAPTX)) {
+ MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_FALLBACKFAILED);
+ mptcp_subflow_reset(ssk);
+ return;
+ }
+
mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
- pr_fallback(msk);
- mptcp_do_fallback(ssk);
}
#define MPTCP_MAX_GSO_SIZE (GSO_LEGACY_MAX_SIZE - (MAX_TCP_HEADER + 1))
@@ -1376,7 +1403,7 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
* - estimate the faster flow linger time
* - use the above to estimate the amount of byte transferred
* by the faster flow
- * - check that the amount of queued data is greter than the above,
+ * - check that the amount of queued data is greater than the above,
* otherwise do not use the picked, slower, subflow
* We select the subflow with the shorter estimated time to flush
* the queued mem, which basically ensure the above. We just need
@@ -2543,9 +2570,9 @@ static void mptcp_check_fastclose(struct mptcp_sock *msk)
static void __mptcp_retrans(struct sock *sk)
{
+ struct mptcp_sendmsg_info info = { .data_lock_held = true, };
struct mptcp_sock *msk = mptcp_sk(sk);
struct mptcp_subflow_context *subflow;
- struct mptcp_sendmsg_info info = {};
struct mptcp_data_frag *dfrag;
struct sock *ssk;
int ret, err;
@@ -2590,6 +2617,18 @@ static void __mptcp_retrans(struct sock *sk)
info.sent = 0;
info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len :
dfrag->already_sent;
+
+ /*
+ * make the whole retrans decision, xmit, disallow
+ * fallback atomic
+ */
+ spin_lock_bh(&msk->fallback_lock);
+ if (__mptcp_check_fallback(msk)) {
+ spin_unlock_bh(&msk->fallback_lock);
+ release_sock(ssk);
+ return;
+ }
+
while (info.sent < info.limit) {
ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
if (ret <= 0)
@@ -2603,8 +2642,9 @@ static void __mptcp_retrans(struct sock *sk)
len = max(copied, len);
tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
info.size_goal);
- WRITE_ONCE(msk->allow_infinite_fallback, false);
+ msk->allow_infinite_fallback = false;
}
+ spin_unlock_bh(&msk->fallback_lock);
release_sock(ssk);
}
@@ -2730,7 +2770,8 @@ static void __mptcp_init_sock(struct sock *sk)
WRITE_ONCE(msk->first, NULL);
inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
- WRITE_ONCE(msk->allow_infinite_fallback, true);
+ msk->allow_infinite_fallback = true;
+ msk->allow_subflows = true;
msk->recovery = false;
msk->subflow_id = 1;
msk->last_data_sent = tcp_jiffies32;
@@ -2738,6 +2779,7 @@ static void __mptcp_init_sock(struct sock *sk)
msk->last_ack_recv = tcp_jiffies32;
mptcp_pm_data_init(msk);
+ spin_lock_init(&msk->fallback_lock);
/* re-use the csk retrans timer for MPTCP-level retrans */
timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
@@ -3117,7 +3159,16 @@ static int mptcp_disconnect(struct sock *sk, int flags)
* subflow
*/
mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
+
+ /* The first subflow is already in TCP_CLOSE status, the following
+ * can't overlap with a fallback anymore
+ */
+ spin_lock_bh(&msk->fallback_lock);
+ msk->allow_subflows = true;
+ msk->allow_infinite_fallback = true;
WRITE_ONCE(msk->flags, 0);
+ spin_unlock_bh(&msk->fallback_lock);
+
msk->cb_flags = 0;
msk->recovery = false;
WRITE_ONCE(msk->can_ack, false);
@@ -3503,7 +3554,7 @@ void mptcp_sock_graft(struct sock *sk, struct socket *parent)
write_lock_bh(&sk->sk_callback_lock);
rcu_assign_pointer(sk->sk_wq, &parent->wq);
sk_set_socket(sk, parent);
- sk->sk_uid = SOCK_INODE(parent)->i_uid;
+ WRITE_ONCE(sk->sk_uid, SOCK_INODE(parent)->i_uid);
write_unlock_bh(&sk->sk_callback_lock);
}
@@ -3524,7 +3575,13 @@ bool mptcp_finish_join(struct sock *ssk)
/* active subflow, already present inside the conn_list */
if (!list_empty(&subflow->node)) {
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_subflows) {
+ spin_unlock_bh(&msk->fallback_lock);
+ return false;
+ }
mptcp_subflow_joined(msk, ssk);
+ spin_unlock_bh(&msk->fallback_lock);
mptcp_propagate_sndbuf(parent, ssk);
return true;
}
@@ -3648,16 +3705,15 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
* TCP option space.
*/
if (rcu_access_pointer(tcp_sk(ssk)->md5sig_info))
- mptcp_subflow_early_fallback(msk, subflow);
+ mptcp_early_fallback(msk, subflow, MPTCP_MIB_MD5SIGFALLBACK);
#endif
if (subflow->request_mptcp) {
- if (mptcp_active_should_disable(sk)) {
- MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPCAPABLEACTIVEDISABLED);
- mptcp_subflow_early_fallback(msk, subflow);
- } else if (mptcp_token_new_connect(ssk) < 0) {
- MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_TOKENFALLBACKINIT);
- mptcp_subflow_early_fallback(msk, subflow);
- }
+ if (mptcp_active_should_disable(sk))
+ mptcp_early_fallback(msk, subflow,
+ MPTCP_MIB_MPCAPABLEACTIVEDISABLED);
+ else if (mptcp_token_new_connect(ssk) < 0)
+ mptcp_early_fallback(msk, subflow,
+ MPTCP_MIB_TOKENFALLBACKINIT);
}
WRITE_ONCE(msk->write_seq, subflow->idsn);
@@ -3729,7 +3785,7 @@ static struct proto mptcp_prot = {
.stream_memory_free = mptcp_stream_memory_free,
.sockets_allocated = &mptcp_sockets_allocated,
- .memory_allocated = &tcp_memory_allocated,
+ .memory_allocated = &net_aligned_data.tcp_memory_allocated,
.per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
.memory_pressure = &tcp_memory_pressure,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 3dd11dd3ba16..b15d7fab5c4b 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -326,6 +326,7 @@ struct mptcp_sock {
int keepalive_cnt;
int keepalive_idle;
int keepalive_intvl;
+ int maxseg;
struct work_struct work;
struct sk_buff *ooo_last_skb;
struct rb_root out_of_order_queue;
@@ -346,10 +347,16 @@ struct mptcp_sock {
u64 rtt_us; /* last maximum rtt of subflows */
} rcvq_space;
u8 scaling_ratio;
+ bool allow_subflows;
u32 subflow_id;
u32 setsockopt_seq;
char ca_name[TCP_CA_NAME_MAX];
+
+ spinlock_t fallback_lock; /* protects fallback,
+ * allow_infinite_fallback and
+ * allow_join
+ */
};
#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
@@ -1216,17 +1223,6 @@ static inline bool mptcp_check_fallback(const struct sock *sk)
return __mptcp_check_fallback(msk);
}
-static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
-{
- if (__mptcp_check_fallback(msk)) {
- pr_debug("TCP fallback already done (msk=%p)\n", msk);
- return;
- }
- if (WARN_ON_ONCE(!READ_ONCE(msk->allow_infinite_fallback)))
- return;
- set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
-}
-
static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
{
struct sock *ssk = READ_ONCE(msk->first);
@@ -1236,14 +1232,17 @@ static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
TCPF_SYN_RECV | TCPF_LISTEN));
}
-static inline void mptcp_do_fallback(struct sock *ssk)
+bool __mptcp_try_fallback(struct mptcp_sock *msk, int fb_mib);
+
+static inline bool mptcp_try_fallback(struct sock *ssk, int fb_mib)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
struct sock *sk = subflow->conn;
struct mptcp_sock *msk;
msk = mptcp_sk(sk);
- __mptcp_do_fallback(msk);
+ if (!__mptcp_try_fallback(msk, fb_mib))
+ return false;
if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
gfp_t saved_allocation = ssk->sk_allocation;
@@ -1255,16 +1254,15 @@ static inline void mptcp_do_fallback(struct sock *ssk)
tcp_shutdown(ssk, SEND_SHUTDOWN);
ssk->sk_allocation = saved_allocation;
}
+ return true;
}
-#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)\n", __func__, a)
-
-static inline void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
- struct mptcp_subflow_context *subflow)
+static inline void mptcp_early_fallback(struct mptcp_sock *msk,
+ struct mptcp_subflow_context *subflow,
+ int fb_mib)
{
- pr_fallback(msk);
subflow->request_mptcp = 0;
- __mptcp_do_fallback(msk);
+ WARN_ON_ONCE(!__mptcp_try_fallback(msk, fb_mib));
}
static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 3caa0a9d3b38..2c267aff95be 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -798,6 +798,23 @@ unlock:
return ret;
}
+static int mptcp_setsockopt_all_sf(struct mptcp_sock *msk, int level,
+ int optname, sockptr_t optval,
+ unsigned int optlen)
+{
+ struct mptcp_subflow_context *subflow;
+ int ret = 0;
+
+ mptcp_for_each_subflow(msk, subflow) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+ ret = tcp_setsockopt(ssk, level, optname, optval, optlen);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -859,6 +876,11 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
&msk->keepalive_cnt,
val);
break;
+ case TCP_MAXSEG:
+ msk->maxseg = val;
+ ret = mptcp_setsockopt_all_sf(msk, SOL_TCP, optname, optval,
+ optlen);
+ break;
default:
ret = -ENOPROTOOPT;
}
@@ -914,10 +936,8 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int
lock_sock(sk);
ssk = msk->first;
- if (ssk) {
- ret = tcp_getsockopt(ssk, level, optname, optval, optlen);
- goto out;
- }
+ if (ssk)
+ goto get;
ssk = __mptcp_nmpc_sk(msk);
if (IS_ERR(ssk)) {
@@ -925,6 +945,7 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int
goto out;
}
+get:
ret = tcp_getsockopt(ssk, level, optname, optval, optlen);
out:
@@ -1407,6 +1428,9 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
return mptcp_put_int_option(msk, optval, optlen, msk->notsent_lowat);
case TCP_IS_MPTCP:
return mptcp_put_int_option(msk, optval, optlen, 1);
+ case TCP_MAXSEG:
+ return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname,
+ optval, optlen);
}
return -EOPNOTSUPP;
}
@@ -1553,6 +1577,7 @@ static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk)
tcp_sock_set_keepidle_locked(ssk, msk->keepalive_idle);
tcp_sock_set_keepintvl(ssk, msk->keepalive_intvl);
tcp_sock_set_keepcnt(ssk, msk->keepalive_cnt);
+ tcp_sock_set_maxseg(ssk, msk->maxseg);
inet_assign_bit(TRANSPARENT, ssk, inet_test_bit(TRANSPARENT, sk));
inet_assign_bit(FREEBIND, ssk, inet_test_bit(FREEBIND, sk));
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 15613d691bfe..3f1b62a9fe88 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -544,10 +544,13 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
mptcp_get_options(skb, &mp_opt);
if (subflow->request_mptcp) {
if (!(mp_opt.suboptions & OPTION_MPTCP_MPC_SYNACK)) {
- MPTCP_INC_STATS(sock_net(sk),
- MPTCP_MIB_MPCAPABLEACTIVEFALLBACK);
- mptcp_do_fallback(sk);
- pr_fallback(msk);
+ if (!mptcp_try_fallback(sk,
+ MPTCP_MIB_MPCAPABLEACTIVEFALLBACK)) {
+ MPTCP_INC_STATS(sock_net(sk),
+ MPTCP_MIB_FALLBACKFAILED);
+ goto do_reset;
+ }
+
goto fallback;
}
@@ -1300,20 +1303,29 @@ static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ss
mptcp_schedule_work(sk);
}
-static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
+static bool mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
unsigned long fail_tout;
+ /* we are really failing, prevent any later subflow join */
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_infinite_fallback) {
+ spin_unlock_bh(&msk->fallback_lock);
+ return false;
+ }
+ msk->allow_subflows = false;
+ spin_unlock_bh(&msk->fallback_lock);
+
/* graceful failure can happen only on the MPC subflow */
if (WARN_ON_ONCE(ssk != READ_ONCE(msk->first)))
- return;
+ return false;
/* since the close timeout take precedence on the fail one,
* no need to start the latter when the first is already set
*/
if (sock_flag((struct sock *)msk, SOCK_DEAD))
- return;
+ return true;
/* we don't need extreme accuracy here, use a zero fail_tout as special
* value meaning no fail timeout at all;
@@ -1325,6 +1337,7 @@ static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
tcp_send_ack(ssk);
mptcp_reset_tout_timer(msk, subflow->fail_tout);
+ return true;
}
static bool subflow_check_data_avail(struct sock *ssk)
@@ -1385,17 +1398,16 @@ fallback:
(subflow->mp_join || subflow->valid_csum_seen)) {
subflow->send_mp_fail = 1;
- if (!READ_ONCE(msk->allow_infinite_fallback)) {
+ if (!mptcp_subflow_fail(msk, ssk)) {
subflow->reset_transient = 0;
subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
goto reset;
}
- mptcp_subflow_fail(msk, ssk);
WRITE_ONCE(subflow->data_avail, true);
return true;
}
- if (!READ_ONCE(msk->allow_infinite_fallback)) {
+ if (!mptcp_try_fallback(ssk, MPTCP_MIB_DSSFALLBACK)) {
/* fatal protocol error, close the socket.
* subflow_error_report() will introduce the appropriate barriers
*/
@@ -1413,8 +1425,6 @@ reset:
WRITE_ONCE(subflow->data_avail, false);
return false;
}
-
- mptcp_do_fallback(ssk);
}
skb = skb_peek(&ssk->sk_receive_queue);
@@ -1679,7 +1689,6 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_pm_local *local,
/* discard the subflow socket */
mptcp_sock_graft(ssk, sk->sk_socket);
iput(SOCK_INODE(sf));
- WRITE_ONCE(msk->allow_infinite_fallback, false);
mptcp_stop_tout_timer(sk);
return 0;
@@ -1845,14 +1854,11 @@ static void subflow_state_change(struct sock *sk)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
struct sock *parent = subflow->conn;
- struct mptcp_sock *msk;
__subflow_state_change(sk);
- msk = mptcp_sk(parent);
if (subflow_simultaneous_connect(sk)) {
- mptcp_do_fallback(sk);
- pr_fallback(msk);
+ WARN_ON_ONCE(!mptcp_try_fallback(sk, MPTCP_MIB_SIMULTCONNFALLBACK));
subflow->conn_finished = 1;
mptcp_propagate_state(parent, sk, subflow, NULL);
}
generated by cgit (git 2.34.1) at 2025-07-31 17:47:31 +0000