From 47f60d9689552fe0c36a3e97b63441c43f8e7422 Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Thu, 11 Jul 2024 17:39:01 +0200 Subject: [PATCH] mptcp: pm: fix backup support in signal endpoints 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. The MPTCP Join selftest has been modified to validate this case: the test "single address, backup", is now validating the MPJ with a backup flag. The previous version has been kept, but renamed to "single address, switch to backup" to avoid confusions. The test "single address with port, backup" is also now validating the MPJ with a backup flag, which makes more sense. Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/507 Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/pm.c | 9 ++++++--- net/mptcp/pm_netlink.c | 4 +++- net/mptcp/pm_userspace.c | 6 ++++-- net/mptcp/protocol.h | 9 ++++++--- net/mptcp/subflow.c | 7 +++++-- .../testing/selftests/net/mptcp/mptcp_join.sh | 19 ++++++++++++++++--- 6 files changed, 40 insertions(+), 14 deletions(-) diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 55406720c60711..98b0b31e3b8d59 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -405,7 +405,8 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, return ret; } -int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) +int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc, + bool *backup) { struct mptcp_addr_info skc_local; struct mptcp_addr_info msk_local; @@ -413,6 +414,8 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) if (WARN_ON_ONCE(!msk)) return -1; + *backup = false; + /* The 0 ID mapping is defined by the first subflow, copied into the msk * addr */ @@ -422,8 +425,8 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) return 0; if (mptcp_pm_is_userspace(msk)) - return mptcp_userspace_pm_get_local_id(msk, &skc_local); - return mptcp_pm_nl_get_local_id(msk, &skc_local); + return mptcp_userspace_pm_get_local_id(msk, &skc_local, backup); + return mptcp_pm_nl_get_local_id(msk, &skc_local, backup); } int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id, diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 7635fac9153989..44bfab3516937d 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1064,7 +1064,8 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk, return err; } -int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc) +int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc, + bool *backup) { struct mptcp_pm_addr_entry *entry; struct pm_nl_pernet *pernet; @@ -1076,6 +1077,7 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) { ret = entry->addr.id; + *backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); break; } } diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index f0a4590506c69a..adc015af168ea7 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -137,7 +137,7 @@ int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, } int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, - struct mptcp_addr_info *skc) + struct mptcp_addr_info *skc, bool *backup) { struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry; __be16 msk_sport = ((struct inet_sock *) @@ -151,8 +151,10 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, } } spin_unlock_bh(&msk->pm.lock); - if (entry) + if (entry) { + *backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); return entry->addr.id; + } memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry)); new_entry.addr = *skc; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 6b6b76152db52a..cee0a8098b4160 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -1111,9 +1111,12 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb, bool *drop_other_suboptions); bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, struct mptcp_rm_list *rm_list); -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); +int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc, + bool *backup); +int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc, + bool *backup); +int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc, + bool *backup); 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 a3778aee4e77f8..955fb9aa2ce528 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -87,6 +87,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct mptcp_sock *msk; int local_id; + bool backup; msk = mptcp_token_get_sock(sock_net(req_to_sk(req)), subflow_req->token); if (!msk) { @@ -94,12 +95,13 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) return NULL; } - local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); + local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req, &backup); if (local_id < 0) { sock_put((struct sock *)msk); return NULL; } subflow_req->local_id = local_id; + subflow_req->request_bkup = backup; return msk; } @@ -604,12 +606,13 @@ static int subflow_chk_local_id(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); + bool backup; int err; if (likely(subflow->local_id >= 0)) return 0; - err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); + err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk, &backup); if (err < 0) return err; diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 55d84a1bde15de..167914df05fa8e 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -2617,6 +2617,19 @@ 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 $ns2 10.0.1.1 + chk_join_nr 1 1 1 + chk_add_nr 1 1 + chk_prio_nr 1 0 + fi + + # single address, switch to backup + if reset "single address, switch to backup" && continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; then pm_nl_set_limits $ns1 0 1 pm_nl_add_endpoint $ns1 10.0.2.1 flags signal @@ -2632,13 +2645,13 @@ backup_tests() if reset "single address with port, backup" && continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; 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 + chk_prio_nr 1 0 fi if reset "mpc backup" &&