In all the MPTCP backup related tests, the backup flag was set on one side, and the expected behaviour is to have both sides respecting this decision. That's also the "natural" way, and what the users seem to expect.
On the scheduler side, only the 'backup' field was checked, which is supposed to be set only if the other peer flagged a subflow as backup. But in various places, this flag was also set when the local host flagged the subflow as backup, certainly to have the expected behaviour mentioned above.
Patch 1 modifies the packet scheduler to check if the backup flag has been set on both directions, not to change its behaviour after having applied the following patches. That's what the default packet scheduler should have done since the beginning in v5.7.
Patch 2 fixes the backup flag being mirrored on the MPJ+SYN+ACK by accident since its introduction in v5.7. Instead, the received and sent backup flags are properly distinguished in requests.
Patch 3 stops setting the received backup flag as well when sending an MP_PRIO, something that was done since the MP_PRIO support in v5.12.
Patch 4 adds related and missing MIB counters to be able to easily check if MP_JOIN are sent with a backup flag. Certainly because these counters were not there, the behaviour that is fixed by patches here was not properly verified.
Patch 5 validates the previous patch by extending the MPTCP Join selftest.
Patch 6 fixes the backup support in signal endpoints: if a signal endpoint had the backup flag, it was not set in the MPJ+SYN+ACK as expected. It was only set for ongoing connections, but not future ones as expected, since the introduction of the backup flag in endpoints in v5.10.
Patch 7 validates the previous patch by extending the MPTCP Join selftest as well.
Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Matthieu Baerts (NGI0) (7): mptcp: sched: check both directions for backup mptcp: distinguish rcv vs sent backup flag in requests mptcp: pm: only set request_bkup flag when sending MP_PRIO mptcp: mib: count MPJ with backup flag selftests: mptcp: join: validate backup in MPJ mptcp: pm: fix backup support in signal endpoints selftests: mptcp: join: check backup support in signal endp
include/trace/events/mptcp.h | 2 +- net/mptcp/mib.c | 2 + net/mptcp/mib.h | 2 + net/mptcp/options.c | 2 +- net/mptcp/pm.c | 12 +++++ net/mptcp/pm_netlink.c | 19 ++++++- net/mptcp/pm_userspace.c | 18 +++++++ net/mptcp/protocol.c | 10 ++-- net/mptcp/protocol.h | 4 ++ net/mptcp/subflow.c | 10 ++++ tools/testing/selftests/net/mptcp/mptcp_join.sh | 72 ++++++++++++++++++++----- 11 files changed, 132 insertions(+), 21 deletions(-) --- base-commit: 301927d2d2eb8e541357ba850bc7a1a74dbbd670 change-id: 20240727-upstream-net-20240727-mptcp-backup-signal-948235f2ad08
Best regards,
The 'mptcp_subflow_context' structure has two items related to the backup flags:
- 'backup': the subflow has been marked as backup by the other peer
- 'request_bkup': the backup flag has been set by the host
Before this patch, the scheduler was only looking at the 'backup' flag. That can make sense in some cases, but it looks like that's not what we wanted for the general use, because either the path-manager was setting both of them when sending an MP_PRIO, or the receiver was duplicating the 'backup' flag in the subflow request.
Note that the use of these two flags in the path-manager are going to be fixed in the next commits, but this change here is needed not to modify the behaviour.
Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- To: Steven Rostedt rostedt@goodmis.org To: Masami Hiramatsu mhiramat@kernel.org To: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: linux-trace-kernel@vger.kernel.org --- include/trace/events/mptcp.h | 2 +- net/mptcp/protocol.c | 10 ++++++---- 2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/include/trace/events/mptcp.h b/include/trace/events/mptcp.h index 09e72215b9f9..085b749cdd97 100644 --- a/include/trace/events/mptcp.h +++ b/include/trace/events/mptcp.h @@ -34,7 +34,7 @@ TRACE_EVENT(mptcp_subflow_get_send, struct sock *ssk;
__entry->active = mptcp_subflow_active(subflow); - __entry->backup = subflow->backup; + __entry->backup = subflow->backup || subflow->request_bkup;
if (subflow->tcp_sock && sk_fullsock(subflow->tcp_sock)) __entry->free = sk_stream_memory_free(subflow->tcp_sock); diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index a26c2c840fd9..a2fc54ed68c0 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1422,13 +1422,15 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) }
mptcp_for_each_subflow(msk, subflow) { + bool backup = subflow->backup || subflow->request_bkup; + trace_mptcp_subflow_get_send(subflow); ssk = mptcp_subflow_tcp_sock(subflow); if (!mptcp_subflow_active(subflow)) continue;
tout = max(tout, mptcp_timeout_from_subflow(subflow)); - nr_active += !subflow->backup; + nr_active += !backup; pace = subflow->avg_pacing_rate; if (unlikely(!pace)) { /* init pacing rate from socket */ @@ -1439,9 +1441,9 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) }
linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace); - if (linger_time < send_info[subflow->backup].linger_time) { - send_info[subflow->backup].ssk = ssk; - send_info[subflow->backup].linger_time = linger_time; + if (linger_time < send_info[backup].linger_time) { + send_info[backup].ssk = ssk; + send_info[backup].linger_time = linger_time; } } __mptcp_set_timeout(sk, tout);
When sending an MP_JOIN + SYN + ACK, it is possible to mark the subflow as 'backup' by setting the flag with the same name. Before this patch, the backup was set if the other peer set it in its MP_JOIN + SYN request.
It is not correct: the backup flag should be set in the MPJ+SYN+ACK only if the host asks for it, and not mirroring what was done by the other peer. It is then required to have a dedicated bit for each direction, similar to what is done in the subflow context.
Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/options.c | 2 +- net/mptcp/protocol.h | 1 + net/mptcp/subflow.c | 1 + 3 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 8e8dcfbc2993..8a68382a4fe9 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -909,7 +909,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, return true; } else if (subflow_req->mp_join) { opts->suboptions = OPTION_MPTCP_MPJ_SYNACK; - opts->backup = subflow_req->backup; + opts->backup = subflow_req->request_bkup; opts->join_id = subflow_req->local_id; opts->thmac = subflow_req->thmac; opts->nonce = subflow_req->local_nonce; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index b11a4e50d52b..b8b25124e7de 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -448,6 +448,7 @@ struct mptcp_subflow_request_sock { u16 mp_capable : 1, mp_join : 1, backup : 1, + request_bkup : 1, csum_reqd : 1, allow_join_id0 : 1; u8 local_id; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 39e2cbdf3801..a3778aee4e77 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -2005,6 +2005,7 @@ static void subflow_ulp_clone(const struct request_sock *req, new_ctx->fully_established = 1; new_ctx->remote_key_valid = 1; new_ctx->backup = subflow_req->backup; + new_ctx->request_bkup = subflow_req->request_bkup; WRITE_ONCE(new_ctx->remote_id, subflow_req->remote_id); new_ctx->token = subflow_req->token; new_ctx->thmac = subflow_req->thmac;
The 'backup' flag from mptcp_subflow_context structure is supposed to be set only when the other peer flagged a subflow as backup, not the opposite.
Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm_netlink.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index ea9e5817b9e9..59527335c68e 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -471,7 +471,6 @@ static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_con slow = lock_sock_fast(ssk); if (prio) { subflow->send_mp_prio = 1; - subflow->backup = backup; subflow->request_bkup = backup; }
Without such counters, it is difficult to easily debug issues with MPJ not having the backup flags on production servers.
This is not strictly a fix, but it eases to validate the following patches without requiring to take packet traces, to query ongoing connections with Netlink with admin permissions, or to guess by looking at the behaviour of the packet scheduler. Also, the modification is self contained, isolated, well controlled, and the increments are done just after others, there from the beginning. It looks then safe, and helpful to backport this.
Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/mib.c | 2 ++ net/mptcp/mib.h | 2 ++ net/mptcp/subflow.c | 6 ++++++ 3 files changed, 10 insertions(+)
diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c index c30405e76833..7884217f33eb 100644 --- a/net/mptcp/mib.c +++ b/net/mptcp/mib.c @@ -19,7 +19,9 @@ static const struct snmp_mib mptcp_snmp_list[] = { SNMP_MIB_ITEM("MPTCPRetrans", MPTCP_MIB_RETRANSSEGS), SNMP_MIB_ITEM("MPJoinNoTokenFound", MPTCP_MIB_JOINNOTOKEN), SNMP_MIB_ITEM("MPJoinSynRx", MPTCP_MIB_JOINSYNRX), + SNMP_MIB_ITEM("MPJoinSynBackupRx", MPTCP_MIB_JOINSYNBACKUPRX), SNMP_MIB_ITEM("MPJoinSynAckRx", MPTCP_MIB_JOINSYNACKRX), + SNMP_MIB_ITEM("MPJoinSynAckBackupRx", MPTCP_MIB_JOINSYNACKBACKUPRX), SNMP_MIB_ITEM("MPJoinSynAckHMacFailure", MPTCP_MIB_JOINSYNACKMAC), SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX), SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC), diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h index 2704afd0dfe4..66aa67f49d03 100644 --- a/net/mptcp/mib.h +++ b/net/mptcp/mib.h @@ -14,7 +14,9 @@ enum linux_mptcp_mib_field { MPTCP_MIB_RETRANSSEGS, /* Segments retransmitted at the MPTCP-level */ MPTCP_MIB_JOINNOTOKEN, /* Received MP_JOIN but the token was not found */ MPTCP_MIB_JOINSYNRX, /* Received a SYN + MP_JOIN */ + MPTCP_MIB_JOINSYNBACKUPRX, /* Received a SYN + MP_JOIN + backup flag */ MPTCP_MIB_JOINSYNACKRX, /* Received a SYN/ACK + MP_JOIN */ + MPTCP_MIB_JOINSYNACKBACKUPRX, /* Received a SYN/ACK + MP_JOIN + backup flag */ MPTCP_MIB_JOINSYNACKMAC, /* HMAC was wrong on SYN/ACK + MP_JOIN */ MPTCP_MIB_JOINACKRX, /* Received an ACK + MP_JOIN */ MPTCP_MIB_JOINACKMAC, /* HMAC was wrong on ACK + MP_JOIN */ diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index a3778aee4e77..be406197b1c4 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -168,6 +168,9 @@ static int subflow_check_req(struct request_sock *req, return 0; } else if (opt_mp_join) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); + + if (mp_opt.backup) + SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNBACKUPRX); }
if (opt_mp_capable && listener->request_mptcp) { @@ -577,6 +580,9 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) subflow->mp_join = 1; MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
+ if (subflow->backup) + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKBACKUPRX); + if (subflow_use_different_dport(msk, sk)) { pr_debug("synack inet_dport=%d %d", ntohs(inet_sk(sk)->inet_dport),
A peer can notify the other one that a subflow has to be treated as "backup" by two different ways: either by sending a dedicated MP_PRIO notification, or by setting the backup flag in the MP_JOIN handshake.
The selftests were previously monitoring the former, but not the latter. This is what is now done here by looking at these new MIB counters when validating the 'backup' cases:
MPTcpExtMPJoinSynBackupRx MPTcpExtMPJoinSynAckBackupRx
The 'Fixes' tag here below is the same as the one from the previous commit: this patch here is not fixing anything wrong in the selftests, but it will help to validate a new fix for an issue introduced by this commit ID.
Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 42 +++++++++++++++++++------ 1 file changed, 32 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 108aeeb84ef1..655715c8c6d9 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -1634,6 +1634,8 @@ chk_prio_nr() { local mp_prio_nr_tx=$1 local mp_prio_nr_rx=$2 + local mpj_syn=$3 + local mpj_syn_ack=$4 local count
print_check "ptx" @@ -1655,6 +1657,26 @@ chk_prio_nr() else print_ok fi + + print_check "syn backup" + count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinSynBackupRx") + if [ -z "$count" ]; then + print_skip + elif [ "$count" != "$mpj_syn" ]; then + fail_test "got $count JOIN[s] syn with Backup expected $mpj_syn" + else + print_ok + fi + + print_check "synack backup" + count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynAckBackupRx") + if [ -z "$count" ]; then + print_skip + elif [ "$count" != "$mpj_syn_ack" ]; then + fail_test "got $count JOIN[s] synack with Backup expected $mpj_syn_ack" + else + print_ok + fi }
chk_subflow_nr() @@ -2612,7 +2634,7 @@ backup_tests() sflags=nobackup speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 1 - chk_prio_nr 0 1 + chk_prio_nr 0 1 1 0 fi
# single address, backup @@ -2625,7 +2647,7 @@ backup_tests() run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 1 chk_add_nr 1 1 - chk_prio_nr 1 1 + chk_prio_nr 1 1 0 0 fi
# single address with port, backup @@ -2638,7 +2660,7 @@ backup_tests() run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 1 chk_add_nr 1 1 - chk_prio_nr 1 1 + chk_prio_nr 1 1 0 0 fi
if reset "mpc backup" && @@ -2647,7 +2669,7 @@ backup_tests() speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 0 0 0 - chk_prio_nr 0 1 + chk_prio_nr 0 1 0 0 fi
if reset "mpc backup both sides" && @@ -2657,7 +2679,7 @@ backup_tests() speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 0 0 0 - chk_prio_nr 1 1 + chk_prio_nr 1 1 0 0 fi
if reset "mpc switch to backup" && @@ -2666,7 +2688,7 @@ backup_tests() sflags=backup speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 0 0 0 - chk_prio_nr 0 1 + chk_prio_nr 0 1 0 0 fi
if reset "mpc switch to backup both sides" && @@ -2676,7 +2698,7 @@ backup_tests() sflags=backup speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 0 0 0 - chk_prio_nr 1 1 + chk_prio_nr 1 1 0 0 fi }
@@ -3053,7 +3075,7 @@ fullmesh_tests() addr_nr_ns2=1 sflags=backup,fullmesh speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 2 2 2 - chk_prio_nr 0 1 + chk_prio_nr 0 1 1 0 chk_rm_nr 0 1 fi
@@ -3066,7 +3088,7 @@ fullmesh_tests() sflags=nobackup,nofullmesh speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 2 2 2 - chk_prio_nr 0 1 + chk_prio_nr 0 1 1 0 chk_rm_nr 0 1 fi } @@ -3318,7 +3340,7 @@ userspace_tests() sflags=backup speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 0 - chk_prio_nr 0 0 + chk_prio_nr 0 0 0 0 fi
# userspace pm type prevents rm_addr
There was a support for signal endpoints, but only when the endpoint's flag was changed during a connection. If an endpoint with the signal and backup was already present, the MP_JOIN reply was not containing the backup flag as expected.
That's confusing to have this inconsistent behaviour. On the other hand, the infrastructure to set the backup flag in the SYN + ACK + MP_JOIN was already there, it was just never set before. Now when requesting the local ID from the path-manager, the backup status is also requested.
Note that when the userspace PM is used, the backup flag can be set if the local address was already used before with a backup flag, e.g. if the address was announced with the 'backup' flag, or a subflow was created with the 'backup' flag.
Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/507 Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm.c | 12 ++++++++++++ net/mptcp/pm_netlink.c | 18 ++++++++++++++++++ net/mptcp/pm_userspace.c | 18 ++++++++++++++++++ net/mptcp/protocol.h | 3 +++ net/mptcp/subflow.c | 3 +++ 5 files changed, 54 insertions(+)
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 55406720c607..23bb89c94e90 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -426,6 +426,18 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) return mptcp_pm_nl_get_local_id(msk, &skc_local); }
+bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc) +{ + struct mptcp_addr_info skc_local; + + mptcp_local_address((struct sock_common *)skc, &skc_local); + + if (mptcp_pm_is_userspace(msk)) + return mptcp_userspace_pm_is_backup(msk, &skc_local); + + return mptcp_pm_nl_is_backup(msk, &skc_local); +} + int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id, u8 *flags, int *ifindex) { diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 59527335c68e..85346db71d0f 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1101,6 +1101,24 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc return ret; }
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc) +{ + struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); + struct mptcp_pm_addr_entry *entry; + bool backup = false; + + rcu_read_lock(); + list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { + if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) { + backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); + break; + } + } + rcu_read_unlock(); + + return backup; +} + #define MPTCP_PM_CMD_GRP_OFFSET 0 #define MPTCP_PM_EV_GRP_OFFSET 1
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index f0a4590506c6..8eaa9fbe3e34 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -165,6 +165,24 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true); }
+bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, + struct mptcp_addr_info *skc) +{ + struct mptcp_pm_addr_entry *entry; + bool backup = false; + + spin_lock_bh(&msk->pm.lock); + list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) { + if (mptcp_addresses_equal(&entry->addr, skc, false)) { + backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); + break; + } + } + spin_unlock_bh(&msk->pm.lock); + + return backup; +} + int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info) { struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN]; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index b8b25124e7de..60c6b073d65f 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -1109,6 +1109,9 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); +bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc); +bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc); +bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc); int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb); int mptcp_pm_nl_dump_addr(struct sk_buff *msg, struct netlink_callback *cb); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index be406197b1c4..0e4b5bfbeaa1 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -100,6 +100,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) return NULL; } subflow_req->local_id = local_id; + subflow_req->request_bkup = mptcp_pm_is_backup(msk, (struct sock_common *)req);
return msk; } @@ -620,6 +621,8 @@ static int subflow_chk_local_id(struct sock *sk) return err;
subflow_set_local_id(subflow, err); + subflow->request_bkup = mptcp_pm_is_backup(msk, (struct sock_common *)sk); + return 0; }
Before the previous commit, 'signal' endpoints with the 'backup' flag were ignored when sending the MP_JOIN.
The MPTCP Join selftest has then been modified to validate this case: the "single address, backup" test, is now validating the MP_JOIN with a backup flag as it is what we expect it to do with such name. The previous version has been kept, but renamed to "single address, switch to backup" to avoid confusions.
The "single address with port, backup" test is also now validating the MPJ with a backup flag, which makes more sense than checking the switch to backup with an MP_PRIO.
The "mpc backup both sides" test is now validating that the backup flag is also set in MP_JOIN from and to the addresses used in the initial subflow, using the special ID 0.
The 'Fixes' tag here below is the same as the one from the previous commit: this patch here is not fixing anything wrong in the selftests, but it validates the previous fix for an issue introduced by this commit ID.
Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 34 ++++++++++++++++++++----- 1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 655715c8c6d9..9c7d0ab106d0 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -2639,6 +2639,19 @@ backup_tests()
# single address, backup if reset "single address, backup" && + continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; then + pm_nl_set_limits $ns1 0 1 + pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup + pm_nl_set_limits $ns2 1 1 + sflags=nobackup speed=slow \ + run_tests $ns1 $ns2 10.0.1.1 + chk_join_nr 1 1 1 + chk_add_nr 1 1 + chk_prio_nr 1 0 0 1 + fi + + # single address, switch to backup + if reset "single address, switch to backup" && continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; then pm_nl_set_limits $ns1 0 1 pm_nl_add_endpoint $ns1 10.0.2.1 flags signal @@ -2654,13 +2667,13 @@ backup_tests() if reset "single address with port, backup" && continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; then pm_nl_set_limits $ns1 0 1 - pm_nl_add_endpoint $ns1 10.0.2.1 flags signal port 10100 + pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup port 10100 pm_nl_set_limits $ns2 1 1 - sflags=backup speed=slow \ + sflags=nobackup speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 1 chk_add_nr 1 1 - chk_prio_nr 1 1 0 0 + chk_prio_nr 1 0 0 1 fi
if reset "mpc backup" && @@ -2674,12 +2687,21 @@ backup_tests()
if reset "mpc backup both sides" && continue_if mptcp_lib_kallsyms_doesnt_have "T mptcp_subflow_send_ack$"; then - pm_nl_add_endpoint $ns1 10.0.1.1 flags subflow,backup + pm_nl_set_limits $ns1 0 2 + pm_nl_set_limits $ns2 1 2 + pm_nl_add_endpoint $ns1 10.0.1.1 flags signal,backup pm_nl_add_endpoint $ns2 10.0.1.2 flags subflow,backup + + # 10.0.2.2 (non-backup) -> 10.0.1.1 (backup) + pm_nl_add_endpoint $ns2 10.0.2.2 flags subflow + # 10.0.1.2 (backup) -> 10.0.2.1 (non-backup) + pm_nl_add_endpoint $ns1 10.0.2.1 flags signal + ip -net "$ns2" route add 10.0.2.1 via 10.0.1.1 dev ns2eth1 # force this path + speed=slow \ run_tests $ns1 $ns2 10.0.1.1 - chk_join_nr 0 0 0 - chk_prio_nr 1 1 0 0 + chk_join_nr 2 2 2 + chk_prio_nr 1 1 1 1 fi
if reset "mpc switch to backup" &&
Hello:
This series was applied to netdev/net.git (main) by Paolo Abeni pabeni@redhat.com:
On Sat, 27 Jul 2024 12:01:22 +0200 you wrote:
In all the MPTCP backup related tests, the backup flag was set on one side, and the expected behaviour is to have both sides respecting this decision. That's also the "natural" way, and what the users seem to expect.
On the scheduler side, only the 'backup' field was checked, which is supposed to be set only if the other peer flagged a subflow as backup. But in various places, this flag was also set when the local host flagged the subflow as backup, certainly to have the expected behaviour mentioned above.
[...]
Here is the summary with links: - [net,1/7] mptcp: sched: check both directions for backup https://git.kernel.org/netdev/net/c/b6a66e521a20 - [net,2/7] mptcp: distinguish rcv vs sent backup flag in requests https://git.kernel.org/netdev/net/c/efd340bf3d77 - [net,3/7] mptcp: pm: only set request_bkup flag when sending MP_PRIO https://git.kernel.org/netdev/net/c/4258b94831bb - [net,4/7] mptcp: mib: count MPJ with backup flag https://git.kernel.org/netdev/net/c/4dde0d72ccec - [net,5/7] selftests: mptcp: join: validate backup in MPJ https://git.kernel.org/netdev/net/c/935ff5bb8a1c - [net,6/7] mptcp: pm: fix backup support in signal endpoints https://git.kernel.org/netdev/net/c/6834097fc38c - [net,7/7] selftests: mptcp: join: check backup support in signal endp https://git.kernel.org/netdev/net/c/f833470c2783
You are awesome, thank you!
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Matthieu Baerts (NGI0) -
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