From: Geliang Tang tanggeliang@kylinos.cn
When userspace PM requires to create an ID 0 subflow in "userspace pm create id 0 subflow" test like this:
userspace_pm_add_sf $ns2 10.0.3.2 0
An ID 1 subflow, in fact, is created.
Since in mptcp_pm_nl_append_new_local_addr(), 'id 0' will be treated as no ID is set by userspace, and will allocate a new ID immediately:
if (!e->addr.id) e->addr.id = find_next_zero_bit(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, 1);
To solve this issue, a new parameter needs_id is added for mptcp_userspace_pm_append_new_local_addr() to distinguish between whether userspace PM has set an ID 0 or whether userspace PM has not set any address.
needs_id is true in mptcp_userspace_pm_get_local_id(), but false in mptcp_pm_nl_announce_doit() and mptcp_pm_nl_subflow_create_doit().
Fixes: e5ed101a6028 ("mptcp: userspace pm allow creating id 0 subflow") Cc: stable@vger.kernel.org Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm_userspace.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index 4f3901d5b8ef..e582b3b2d174 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -26,7 +26,8 @@ void mptcp_free_local_addr_list(struct mptcp_sock *msk) }
static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, - struct mptcp_pm_addr_entry *entry) + struct mptcp_pm_addr_entry *entry, + bool needs_id) { DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); struct mptcp_pm_addr_entry *match = NULL; @@ -41,7 +42,7 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, spin_lock_bh(&msk->pm.lock); list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) { addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true); - if (addr_match && entry->addr.id == 0) + if (addr_match && entry->addr.id == 0 && needs_id) entry->addr.id = e->addr.id; id_match = (e->addr.id == entry->addr.id); if (addr_match && id_match) { @@ -64,7 +65,7 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, }
*e = *entry; - if (!e->addr.id) + if (!e->addr.id && needs_id) e->addr.id = find_next_zero_bit(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, 1); @@ -153,7 +154,7 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, if (new_entry.addr.port == msk_sport) new_entry.addr.port = 0;
- return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry); + return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true); }
int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info) @@ -198,7 +199,7 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info) goto announce_err; }
- err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val); + err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false); if (err < 0) { GENL_SET_ERR_MSG(info, "did not match address and id"); goto announce_err; @@ -378,7 +379,7 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info) }
local.addr = addr_l; - err = mptcp_userspace_pm_append_new_local_addr(msk, &local); + err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false); if (err < 0) { GENL_SET_ERR_MSG(info, "did not match address and id"); goto create_err;