From: Geliang Tang <tanggeliang@kylinos.cn>
This patch exports mptcp path manager helpers into BPF, adds these
kfunc names into mptcp common kfunc_set.
bpf_kmemdup_entry() and bpf_kfree_entry() are wrappers of kmemdup() and
kfree(), using to alloc and free an mptcp address entry.
bpf_set_bit() and bpf_bitmap_fill() are wrappers of __set_bit() and
bitmap_fill(), using for mptcp address ID bitmap.
bpf_spin_lock_bh() and bpf_spin_unlock_bh() are wrappers of spin_lock_bh()
and spin_unlock_bh(), using to lock and unlock the mptcp pm lock.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
net/mptcp/bpf.c | 48 +++++++++++++++++++++++++++++++++++++++++++
net/mptcp/pm_kernel.c | 27 ++++++++++++++++++++++++
2 files changed, 75 insertions(+)
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index 596574102b89..e411ae8382f2 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -540,6 +540,38 @@ bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it)
{
}
+__bpf_kfunc static struct mptcp_pm_addr_entry *
+bpf_kmemdup_entry(struct mptcp_pm_addr_entry *entry, int size, gfp_t priority)
+{
+ return kmemdup(entry, size, priority);
+}
+
+__bpf_kfunc static void
+bpf_kfree_entry(struct mptcp_pm_addr_entry *entry)
+{
+ kfree(entry);
+}
+
+__bpf_kfunc static void bpf_set_bit(unsigned long nr, unsigned long *addr__ign)
+{
+ __set_bit(nr, addr__ign);
+}
+
+__bpf_kfunc static void bpf_bitmap_fill(unsigned long *dst__ign, unsigned int nbits)
+{
+ bitmap_fill(dst__ign, nbits);
+}
+
+__bpf_kfunc static void bpf_spin_lock_bh(spinlock_t *lock)
+{
+ spin_lock_bh(lock);
+}
+
+__bpf_kfunc static void bpf_spin_unlock_bh(spinlock_t *lock)
+{
+ spin_unlock_bh(lock);
+}
+
__bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
{
return tcp_rtx_queue_empty(sk);
@@ -564,6 +596,22 @@ BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY)
+BTF_ID_FLAGS(func, bpf_kmemdup_entry)
+BTF_ID_FLAGS(func, bpf_kfree_entry)
+BTF_ID_FLAGS(func, bpf_set_bit)
+BTF_ID_FLAGS(func, bpf_bitmap_fill)
+BTF_ID_FLAGS(func, bpf_spin_lock_bh)
+BTF_ID_FLAGS(func, bpf_spin_unlock_bh)
+BTF_ID_FLAGS(func, mptcp_pm_nl_lookup_addr)
+BTF_ID_FLAGS(func, mptcp_pm_nl_append_new_local_addr_msk)
+BTF_ID_FLAGS(func, mptcp_pm_get_add_addr_signal_max)
+BTF_ID_FLAGS(func, mptcp_pm_get_add_addr_accept_max)
+BTF_ID_FLAGS(func, mptcp_pm_get_subflows_max)
+BTF_ID_FLAGS(func, mptcp_pm_get_local_addr_max)
+BTF_ID_FLAGS(func, mptcp_pm_add_addr_recv)
+BTF_ID_FLAGS(func, mptcp_pm_is_init_remote_addr)
+BTF_ID_FLAGS(func, mptcp_pm_create_subflow_or_signal_addr)
+BTF_ID_FLAGS(func, mptcp_pm_rm_addr_recv)
BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled)
BTF_ID_FLAGS(func, mptcp_subflow_active)
BTF_ID_FLAGS(func, mptcp_set_timeout)
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index 4f7b2e0e998d..3cf81986c70d 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -253,6 +253,9 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info)
return NULL;
}
+__bpf_kfunc_start_defs();
+
+__bpf_kfunc
static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
{
struct sock *sk = (struct sock *)msk;
@@ -367,6 +370,8 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
mptcp_pm_nl_check_work_pending(msk);
}
+__bpf_kfunc_end_defs();
+
static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
{
spin_lock_bh(&msk->pm.lock);
@@ -1493,3 +1498,25 @@ void __init mptcp_pm_kernel_register(void)
mptcp_pm_register(&mptcp_pm_kernel);
}
+
+__bpf_kfunc_start_defs();
+
+__bpf_kfunc static struct mptcp_pm_addr_entry *
+mptcp_pm_nl_lookup_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *info)
+{
+ struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
+
+ return __lookup_addr(pernet, info);
+}
+
+__bpf_kfunc static int
+mptcp_pm_nl_append_new_local_addr_msk(struct mptcp_sock *msk,
+ struct mptcp_pm_addr_entry *entry,
+ bool needs_id, bool replace)
+{
+ struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
+
+ return mptcp_pm_nl_append_new_local_addr(pernet, entry, needs_id, replace);
+}
+
+__bpf_kfunc_end_defs();
--
2.43.0
Hi Geliang, On 21/03/2025 02:49, Geliang Tang wrote: > From: Geliang Tang <tanggeliang@kylinos.cn> > > This patch exports mptcp path manager helpers into BPF, adds these > kfunc names into mptcp common kfunc_set. > > bpf_kmemdup_entry() and bpf_kfree_entry() are wrappers of kmemdup() and > kfree(), using to alloc and free an mptcp address entry. That feels really wrong: a BPF program cannot crash or cause problems (deadlock, memleaks, etc.), it should then not be able to reserve memory except in a map or something that can be automatically freed when the bpf program is removed. > bpf_set_bit() and bpf_bitmap_fill() are wrappers of __set_bit() and > bitmap_fill(), using for mptcp address ID bitmap. Is it really needed? Are there not already some it not store stuff in a BPF map? > bpf_spin_lock_bh() and bpf_spin_unlock_bh() are wrappers of spin_lock_bh() > and spin_unlock_bh(), using to lock and unlock the mptcp pm lock. Same here, a BPF should not be able to lock something and never unlock it. I think there are some stuff in BPF to get a lock automatically. (Polymorphisme?) (...) > @@ -564,6 +596,22 @@ BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, KF_RET_NULL) > BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS) > BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL) > BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY) > +BTF_ID_FLAGS(func, bpf_kmemdup_entry) > +BTF_ID_FLAGS(func, bpf_kfree_entry) > +BTF_ID_FLAGS(func, bpf_set_bit) > +BTF_ID_FLAGS(func, bpf_bitmap_fill) > +BTF_ID_FLAGS(func, bpf_spin_lock_bh) > +BTF_ID_FLAGS(func, bpf_spin_unlock_bh) This should not be needed, a BPF program should not need them. Not sure about the bitmap, but for the rest, something else should be used (maps?) or automatically done (locks). > +BTF_ID_FLAGS(func, mptcp_pm_nl_lookup_addr) > +BTF_ID_FLAGS(func, mptcp_pm_nl_append_new_local_addr_msk) That's specific to the in-kernel PM, that feels wrong. Addresses should be stored in BPF maps or similar instead I guess. > +BTF_ID_FLAGS(func, mptcp_pm_get_add_addr_signal_max) > +BTF_ID_FLAGS(func, mptcp_pm_get_add_addr_accept_max) > +BTF_ID_FLAGS(func, mptcp_pm_get_subflows_max) > +BTF_ID_FLAGS(func, mptcp_pm_get_local_addr_max) That feels wrong, it should not be needed, that's specific to the in-kernel PM as well and set via netlink. > +BTF_ID_FLAGS(func, mptcp_pm_add_addr_recv) Should not be needed, see my comments in part 6. > +BTF_ID_FLAGS(func, mptcp_pm_is_init_remote_addr) Should it not be handled by the core (pm.c) or specific to in-kernel? (I didn't check) > +BTF_ID_FLAGS(func, mptcp_pm_create_subflow_or_signal_addr) Specific to the in-kernel PM, that feels wrong. > +BTF_ID_FLAGS(func, mptcp_pm_rm_addr_recv) Maybe not needed, see my comments in part 6. (...) Cheers, Matt -- Sponsored by the NGI0 Core fund.
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