From: Paolo Abeni pabeni@redhat.com
[ Upstream commit 86e39e04482b0aadf3ee3ed5fcf2d63816559d36 ]
Include into the path manager status a bitmap tracking the list of local endpoints still available - not yet used - for the relevant mptcp socket.
Keep such map updated at endpoint creation/deletion time, so that we can easily skip already used endpoint at local address selection time.
The endpoint used by the initial subflow is lazyly accounted at subflow creation time: the usage bitmap is be up2date before endpoint selection and we avoid such unneeded task in some relevant scenarios - e.g. busy servers accepting incoming subflows but not creating any additional ones nor annuncing additional addresses.
Overall this allows for fair local endpoints usage in case of subflow failure.
As a side effect, this patch also enforces that each endpoint is used at most once for each mptcp connection.
Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/pm.c | 1 + net/mptcp/pm_netlink.c | 125 +++++++++++------- net/mptcp/protocol.c | 3 +- net/mptcp/protocol.h | 12 +- .../testing/selftests/net/mptcp/mptcp_join.sh | 5 +- 5 files changed, 91 insertions(+), 55 deletions(-)
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 6ab386ff32944..332ac6eda3ba4 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -370,6 +370,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk) WRITE_ONCE(msk->pm.accept_subflow, false); WRITE_ONCE(msk->pm.remote_deny_join_id0, false); msk->pm.status = 0; + bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
spin_lock_init(&msk->pm.lock); INIT_LIST_HEAD(&msk->pm.anno_list); diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 27427aeeee0e5..ad3dc9c6c5310 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -38,10 +38,6 @@ struct mptcp_pm_add_entry { u8 retrans_times; };
-/* max value of mptcp_addr_info.id */ -#define MAX_ADDR_ID U8_MAX -#define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG) - struct pm_nl_pernet { /* protects pernet updates */ spinlock_t lock; @@ -53,14 +49,14 @@ struct pm_nl_pernet { unsigned int local_addr_max; unsigned int subflows_max; unsigned int next_id; - unsigned long id_bitmap[BITMAP_SZ]; + DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); };
#define MPTCP_PM_ADDR_MAX 8 #define ADD_ADDR_RETRANS_MAX 3
static bool addresses_equal(const struct mptcp_addr_info *a, - struct mptcp_addr_info *b, bool use_port) + const struct mptcp_addr_info *b, bool use_port) { bool addr_equals = false;
@@ -174,6 +170,9 @@ select_local_address(const struct pm_nl_pernet *pernet, if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) continue;
+ if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) + continue; + if (entry->addr.family != sk->sk_family) { #if IS_ENABLED(CONFIG_MPTCP_IPV6) if ((entry->addr.family == AF_INET && @@ -184,23 +183,17 @@ select_local_address(const struct pm_nl_pernet *pernet, continue; }
- /* avoid any address already in use by subflows and - * pending join - */ - if (!lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) { - ret = entry; - break; - } + ret = entry; + break; } rcu_read_unlock(); return ret; }
static struct mptcp_pm_addr_entry * -select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos) +select_signal_address(struct pm_nl_pernet *pernet, struct mptcp_sock *msk) { struct mptcp_pm_addr_entry *entry, *ret = NULL; - int i = 0;
rcu_read_lock(); /* do not keep any additional per socket state, just signal @@ -209,12 +202,14 @@ select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos) * can lead to additional addresses not being announced. */ list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { + if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) + continue; + if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) continue; - if (i++ == pos) { - ret = entry; - break; - } + + ret = entry; + break; } rcu_read_unlock(); return ret; @@ -258,9 +253,11 @@ EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
static void check_work_pending(struct mptcp_sock *msk) { - if (msk->pm.add_addr_signaled == mptcp_pm_get_add_addr_signal_max(msk) && - (msk->pm.local_addr_used == mptcp_pm_get_local_addr_max(msk) || - msk->pm.subflows == mptcp_pm_get_subflows_max(msk))) + struct pm_nl_pernet *pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id); + + if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) || + (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap, + MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) WRITE_ONCE(msk->pm.work_pending, false); }
@@ -460,6 +457,35 @@ static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullm return i; }
+static struct mptcp_pm_addr_entry * +__lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id) +{ + struct mptcp_pm_addr_entry *entry; + + list_for_each_entry(entry, &pernet->local_addr_list, list) { + if (entry->addr.id == id) + return entry; + } + return NULL; +} + +static int +lookup_id_by_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *addr) +{ + struct mptcp_pm_addr_entry *entry; + int ret = -1; + + rcu_read_lock(); + list_for_each_entry(entry, &pernet->local_addr_list, list) { + if (addresses_equal(&entry->addr, addr, entry->addr.port)) { + ret = entry->addr.id; + break; + } + } + rcu_read_unlock(); + return ret; +} + static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { struct sock *sk = (struct sock *)msk; @@ -475,6 +501,19 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) local_addr_max = mptcp_pm_get_local_addr_max(msk); subflows_max = mptcp_pm_get_subflows_max(msk);
+ /* do lazy endpoint usage accounting for the MPC subflows */ + if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) { + struct mptcp_addr_info local; + int mpc_id; + + local_address((struct sock_common *)msk->first, &local); + mpc_id = lookup_id_by_addr(pernet, &local); + if (mpc_id < 0) + __clear_bit(mpc_id, msk->pm.id_avail_bitmap); + + msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED); + } + pr_debug("local %d:%d signal %d:%d subflows %d:%d\n", msk->pm.local_addr_used, local_addr_max, msk->pm.add_addr_signaled, add_addr_signal_max, @@ -482,21 +521,16 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
/* check first for announce */ if (msk->pm.add_addr_signaled < add_addr_signal_max) { - local = select_signal_address(pernet, - msk->pm.add_addr_signaled); + local = select_signal_address(pernet, msk);
if (local) { if (mptcp_pm_alloc_anno_list(msk, local)) { + __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); msk->pm.add_addr_signaled++; mptcp_pm_announce_addr(msk, &local->addr, false); mptcp_pm_nl_addr_send_ack(msk); } - } else { - /* pick failed, avoid fourther attempts later */ - msk->pm.local_addr_used = add_addr_signal_max; } - - check_work_pending(msk); }
/* check if should create a new subflow */ @@ -510,19 +544,16 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) int i, nr;
msk->pm.local_addr_used++; - check_work_pending(msk); nr = fill_remote_addresses_vec(msk, fullmesh, addrs); + if (nr) + __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); spin_unlock_bh(&msk->pm.lock); for (i = 0; i < nr; i++) __mptcp_subflow_connect(sk, &local->addr, &addrs[i]); spin_lock_bh(&msk->pm.lock); - return; } - - /* lookup failed, avoid fourther attempts later */ - msk->pm.local_addr_used = local_addr_max; - check_work_pending(msk); } + check_work_pending(msk); }
static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk) @@ -736,6 +767,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, msk->pm.subflows--; __MPTCP_INC_STATS(sock_net(sk), rm_type); } + __set_bit(rm_list->ids[1], msk->pm.id_avail_bitmap); if (!removed) continue;
@@ -765,6 +797,9 @@ void mptcp_pm_nl_work(struct mptcp_sock *msk)
msk_owned_by_me(msk);
+ if (!(pm->status & MPTCP_PM_WORK_MASK)) + return; + spin_lock_bh(&msk->pm.lock);
pr_debug("msk=%p status=%x", msk, pm->status); @@ -810,7 +845,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, /* to keep the code simple, don't do IDR-like allocation for address ID, * just bail when we exceed limits */ - if (pernet->next_id == MAX_ADDR_ID) + if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID) pernet->next_id = 1; if (pernet->addrs >= MPTCP_PM_ADDR_MAX) goto out; @@ -830,7 +865,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, if (!entry->addr.id) { find_next: entry->addr.id = find_next_zero_bit(pernet->id_bitmap, - MAX_ADDR_ID + 1, + MPTCP_PM_MAX_ADDR_ID + 1, pernet->next_id); if (!entry->addr.id && pernet->next_id != 1) { pernet->next_id = 1; @@ -1197,18 +1232,6 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) return 0; }
-static struct mptcp_pm_addr_entry * -__lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id) -{ - struct mptcp_pm_addr_entry *entry; - - list_for_each_entry(entry, &pernet->local_addr_list, list) { - if (entry->addr.id == id) - return entry; - } - return NULL; -} - int mptcp_pm_get_flags_and_ifindex_by_id(struct net *net, unsigned int id, u8 *flags, int *ifindex) { @@ -1467,7 +1490,7 @@ static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info) list_splice_init(&pernet->local_addr_list, &free_list); __reset_counters(pernet); pernet->next_id = 1; - bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1); + bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); spin_unlock_bh(&pernet->lock); mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list); synchronize_rcu(); @@ -1577,7 +1600,7 @@ static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg, pernet = net_generic(net, pm_nl_pernet_id);
spin_lock_bh(&pernet->lock); - for (i = id; i < MAX_ADDR_ID + 1; i++) { + for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) { if (test_bit(i, pernet->id_bitmap)) { entry = __lookup_addr_by_id(pernet, i); if (!entry) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 0cd55e4c30fab..70a3cac85f7b8 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2416,8 +2416,7 @@ static void mptcp_worker(struct work_struct *work)
mptcp_check_fastclose(msk);
- if (msk->pm.status) - mptcp_pm_nl_work(msk); + mptcp_pm_nl_work(msk);
if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) mptcp_check_for_eof(msk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index d87cc040352e3..0387ad9fb43f7 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -174,16 +174,25 @@ enum mptcp_pm_status { MPTCP_PM_ADD_ADDR_SEND_ACK, MPTCP_PM_RM_ADDR_RECEIVED, MPTCP_PM_ESTABLISHED, - MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */ MPTCP_PM_SUBFLOW_ESTABLISHED, + MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */ + MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is + * accounted int id_avail_bitmap + */ };
+/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */ +#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1) + enum mptcp_addr_signal_status { MPTCP_ADD_ADDR_SIGNAL, MPTCP_ADD_ADDR_ECHO, MPTCP_RM_ADDR_SIGNAL, };
+/* max value of mptcp_addr_info.id */ +#define MPTCP_PM_MAX_ADDR_ID U8_MAX + struct mptcp_pm_data { struct mptcp_addr_info local; struct mptcp_addr_info remote; @@ -202,6 +211,7 @@ struct mptcp_pm_data { u8 local_addr_used; u8 subflows; u8 status; + DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); struct mptcp_rm_list rm_list_tx; struct mptcp_rm_list rm_list_rx; }; diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 7ef639a9d4a6f..bbafa4cf54538 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -1071,7 +1071,10 @@ signal_address_tests() ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags signal ip netns exec $ns2 ./pm_nl_ctl add 10.0.4.2 flags signal run_tests $ns1 $ns2 10.0.1.1 - chk_add_nr 4 4 + + # the server will not signal the address terminating + # the MPC subflow + chk_add_nr 3 3 }
link_failure_tests()